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Sample records for ptat-pmo conjugate targeted

  1. Nanobody-photosensitizer conjugates for targeted photodynamic therapy

    NARCIS (Netherlands)

    Heukers, Raimond; van Bergen en Henegouwen, P; Santos Oliveira, Sabrina

    2014-01-01

    Photodynamic therapy (PDT) induces cell death through light activation of a photosensitizer (PS). Targeted delivery of PS via monoclonal antibodies has improved tumor selectivity. However, these conjugates have long half-lives, leading to relatively long photosensitivity in patients. In an attempt t

  2. RPM peptide conjugated bioreducible polyethylenimine targeting invasive colon cancer.

    Science.gov (United States)

    Lee, Yeong Mi; Lee, Duhwan; Kim, Jihoon; Park, Hansoo; Kim, Won Jong

    2015-05-10

    CPIEDRPMC (RPM) peptide is a peptide that specifically targets invasive colorectal cancer, which is one of the leading causes of cancer-related deaths worldwide. In this study, we exploited RPM peptide as a targeting ligand to produce a novel and efficient gene delivery system that could potentially be used to treat invasive colon cancer. In order to achieve enhanced specificity to colon cancer cells, the RPM peptide was conjugated to a bioreducible gene carrier consisting of a reducible moiety of disulfide-crosslinked low molecular weight polyethylenimine, IR820 dye, and polyethylene glycol. Here, we examined the physiochemical properties, cytotoxicity, in vitro transfection efficiency, and in vivo biodistribution of the RPM-conjugated polyplex. Our results showed that the RPM-conjugated gene carrier formed a compact polyplex with pDNA that had low toxicity. Furthermore, the RPM-conjugated polymer not only had higher cellular uptake in invasive colon cancer than the non-targeted polymer, but also showed enhanced transfection efficiency in invasive colon cancer cells in vitro and in vivo.

  3. Tumor targeting of HPMA copolymer conjugates containing sulfadiazine groups

    Institute of Scientific and Technical Information of China (English)

    Jian Chao Yuan; Xiao Li Xie; Xian Wu Zeng; Hong Yun Guo; Cheng Ping Miao

    2012-01-01

    To develop new tumor targeting macromolecular conjugates,poly(HPMA)-SD-APMA-DTPA (HPMA:N-(2-hydroxypropyl)-methacrylamide; APMA:N-(3-aminopropyl)methacrylamide; DTPA:diethylenetriarninepentaacetic acid; SD:sulfadiazine) was synthesized and characterized.The poly(HPMA)-SD-DTPA conjugates were radiolabeled with the radionuclide 99mTc and tested for uptake by cultured H22 cells in vitro.DTPA-99mTc (radiotracer 1) and poly(HPMA)-DTPA-99mTc (radiotracer 2) were also synthesized and characterized for comparison.The uptake of poly(HPMA)-SD-DTPA-99mTc (radiotracer 3,34.76%) was significantly higher than that of poly(HPMA)-DTPA-99mTc (16.40%),indicating that uptake of the poly(HPMA)-SD-DTPA-99mT was active binding.The uptake of poly(HPMA)-DTPA-99mTc was significantly higher than that of DTPA-99mTc (2.98%),suggesting that uptake of the poly(HPMA)-DTPA-99mT was passive binding.The data suggest thin the poly(HPMA)-SD-APMA-DTPA conjugates might be useful as tumor targeting macromolecular conjugates.

  4. Adenosine conjugated lipidic nanoparticles for enhanced tumor targeting.

    Science.gov (United States)

    Swami, Rajan; Singh, Indu; Jeengar, Manish Kumar; Naidu, V G M; Khan, Wahid; Sistla, Ramakrishna

    2015-01-01

    Delivering chemotherapeutics by nanoparticles into tumor is impeded majorly by two factors: nonspecific targeting and inefficient penetration. Targeted delivery of anti-cancer agents solely to tumor cells introduces a smart strategy because it enhances the therapeutic index compared with untargeted drugs. The present study was performed to investigate the efficiency of adenosine (ADN) to target solid lipid nanoparticles (SLN) to over expressing adenosine receptor cell lines such as human breast cancer and prostate cancer (MCF-7 and DU-145 cells), respectively. SLN were prepared by emulsification and solvent evaporation process using docetaxel (DTX) as drug and were characterized by various techniques like dynamic light scattering, differential scanning calorimeter and transmission electron microscopy. DTX loaded SLNs were surface modified with ADN, an adenosine receptors ligand using carbodiimide coupling. Conjugation was confirmed using infrared spectroscopy and quantified using phenol-sulfuric acid method. Conjugated SLN were shown to have sustained drug release as compared to unconjugated nanoparticles and drug suspension. Compared with free DTX and unconjugated SLN, ADN conjugated SLN showed significantly higher cytotoxicity of loaded DTX, as evidenced by in vitro cell experiments. The IC50 was 0.41 μg/ml for native DTX, 0.30 μg/ml for unconjugated SLN formulation, and 0.09 μg/ml for ADN conjugated SLN formulation in MCF-7 cell lines. Whereas, in DU-145, there was 2 fold change in IC50 of ADN-SLN as compared to DTX. IC50 was found to be 0.44 μg/ml for free DTX, 0.39 μg/ml for unconjugated SLN and 0.22 μg/ml for ADN-SLN. Annexin assay and cell cycle analysis assay further substantiated the cell cytotoxicity. Fluorescent cell uptake and competitive ligand-receptor binding assay corroborated the receptor mediated endocytosis pathway indicated role of adenosine receptors in internalization of conjugated particles. Pharmacokinetic studies of lipidic

  5. Targeting the Eph System with Peptides and Peptide Conjugates.

    Science.gov (United States)

    Riedl, Stefan J; Pasquale, Elena B

    2015-01-01

    Eph receptor tyrosine kinases and ephrin ligands constitute an important cell communication system that controls development, tissue homeostasis and many pathological processes. Various Eph receptors/ephrins are present in essentially all cell types and their expression is often dysregulated by injury and disease. Thus, the 14 Eph receptors are attracting increasing attention as a major class of potential drug targets. In particular, agents that bind to the extracellular ephrin-binding pocket of these receptors show promise for medical applications. This pocket comprises a broad and shallow groove surrounded by several flexible loops, which makes peptides particularly suitable to target it with high affinity and selectivity. Accordingly, a number of peptides that bind to Eph receptors with micromolar affinity have been identified using phage display and other approaches. These peptides are generally antagonists that inhibit ephrin binding and Eph receptor/ ephrin signaling, but some are agonists mimicking ephrin-induced Eph receptor activation. Importantly, some of the peptides are exquisitely selective for single Eph receptors. Most identified peptides are linear, but recently the considerable advantages of cyclic scaffolds have been recognized, particularly in light of potential optimization towards drug leads. To date, peptide improvements have yielded derivatives with low nanomolar Eph receptor binding affinity, high resistance to plasma proteases and/or long in vivo half-life, exemplifying the merits of peptides for Eph receptor targeting. Besides their modulation of Eph receptor/ephrin function, peptides can also serve to deliver conjugated imaging and therapeutic agents or various types of nanoparticles to tumors and other diseased tissues presenting target Eph receptors.

  6. Radiolabeled Cetuximab Conjugates for EGFR Targeted Cancer Diagnostics and Therapy

    Directory of Open Access Journals (Sweden)

    Wiebke Sihver

    2014-03-01

    Full Text Available The epidermal growth factor receptor (EGFR has evolved over years into a main molecular target for the treatment of different cancer entities. In this regard, the anti-EGFR antibody cetuximab has been approved alone or in combination with: (a chemotherapy for treatment of colorectal and head and neck squamous cell carcinoma and (b with external radiotherapy for treatment of head and neck squamous cell carcinoma. The conjugation of radionuclides to cetuximab in combination with the specific targeting properties of this antibody might increase its therapeutic efficiency. This review article gives an overview of the preclinical studies that have been performed with radiolabeled cetuximab for imaging and/or treatment of different tumor models. A particularly promising approach seems to be the treatment with therapeutic radionuclide-labeled cetuximab in combination with external radiotherapy. Present data support an important impact of the tumor micromilieu on treatment response that needs to be further validated in patients. Another important challenge is the reduction of nonspecific uptake of the radioactive substance in metabolic organs like liver and radiosensitive organs like bone marrow and kidneys. Overall, the integration of diagnosis, treatment and monitoring as a theranostic approach appears to be a promising strategy for improvement of individualized cancer treatment.

  7. Targeting cancer cells with folic acid-iminoboronate fluorescent conjugates.

    Science.gov (United States)

    Cal, Pedro M S D; Frade, Raquel F M; Chudasama, Vijay; Cordeiro, Carlos; Caddick, Stephen; Gois, Pedro M P

    2014-05-25

    Herein we present the synthesis of fluorescent 2-acetylbenzeneboronic acids that undergo B-N promoted conjugation with lysozyme and N-(2-aminoethyl) folic acid (EDA-FA), generating conjugates that are selectively recognized and internalized by cancer cells that over-express folic acid receptors.

  8. Conjugation with receptor-targeted histidine-rich peptides enhances the pharmacological effectiveness of antisense oligonucleotides.

    Science.gov (United States)

    Nakagawa, Osamu; Ming, Xin; Carver, Kyle; Juliano, Rudy

    2014-01-15

    Ineffective delivery to intracellular sites of action is one of the key limitations to the use of antisense and siRNA oligonucleotides as therapeutic agents. Here, we describe molecular scale antisense oligonucleotide conjugates that bind selectively to a cell surface receptor, are internalized, and then partially escape from nonproductive endosomal locations to reach their sites of action in the nucleus. Peptides that include bombesin sequences for receptor targeting and a run of histidine residues for endosomal disruption were covalently linked to a splice switching antisense oligonucleotide. The conjugates were tested for their ability to correct splicing and up-regulate expression of a luciferase reporter in prostate cancer cells that express the bombesin receptor. We found that trivalent conjugates that included both the targeting sequence and several histidine residues were substantially more effective than conjugates containing only the bombesin or histidine moieties. This demonstrates the potential of creating molecular scale oligonucleotide conjugates with both targeting and endosome escape capabilities.

  9. Tumor-targeted HPMA copolymer-(RGDfK)-(CHX-A''-DTPA) conjugates show increased kidney accumulation.

    Science.gov (United States)

    Borgman, Mark P; Coleman, Tomika; Kolhatkar, Rohit B; Geyser-Stoops, Sandra; Line, Bruce R; Ghandehari, Hamidreza

    2008-12-18

    N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-RGDfK conjugates targeting the alpha(v)beta(3) integrin have shown increased accumulation in solid tumors and promise for selective delivery of radiotherapeutics to sites of angiogenesis- or tumor-expressed alpha(v)beta(3) integrin. An unresolved issue in targeting radiotherapeutics to solid tumors is toxicity to non-target organs. To reduce toxicity of radiolabeled conjugates, we have synthesized HPMA copolymer-RGDfK conjugates with varying molecular weight and charge content to help identify a polymeric structure that maximizes tumor accumulation while rapidly clearing from non-targeted organs. Endothelial cell binding studies showed that copolymer conjugates of approximately 43, 20 and 10 kD actively bind to the alpha(v)beta(3) integrin. Scintigraphic images showed rapid clearance of indium-111 ((111)In) radiolabeled conjugates from the blood pool and high kidney accumulation within 1 h in tumor bearing mice. Biodistribution data confirms images with high accumulation in kidney (max 210% ID/g for 43 kD conjugate) and lower tumor accumulation (max 1.8% ID/g for 43 kD conjugate). While actively binding to the alpha(v)beta(3) integrin in vitro, HPMA copolymer-RGDfK conjugates with increased negative charge through increased CHX-A''-DTPA chelator content in the side chains causes increased kidney accumulation with a loss of tumor accumulation in vivo.

  10. Tumor-Targeted HPMA Copolymer-(RGDfK)-(CHX-A″-DTPA) Conjugates Show Increased Kidney Accumulation

    Science.gov (United States)

    Borgman, Mark P.; Coleman, Tomika; Kolhatkar, Rohit B.; Geyser-Stoops, Sandra; Line, Bruce R.; Ghandehari, Hamidreza

    2008-01-01

    N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-RGDfK conjugates targeting the αvβ3 integrin have shown increased accumulation in solid tumors and promise for selective delivery of radiotherapeutics to sites of angiogenesis- or tumor-expressed αvβ3 integrin. An unresolved issue in targeting radiotherapeutics to solid tumors is toxicity to non-target organs. To reduce toxicity of radiolabeled conjugates, we have synthesized HPMA copolymer-RGDfK conjugates with varying molecular weight and charge content to help identify a polymeric structure that maximizes tumor accumulation while rapidly clearing from non-targeted organs. Endothelial cell binding studies showed that copolymer conjugates of approximately 43, 20 and 10 kD actively bind to the αvβ3 integrin. Scintigraphic images showed rapid clearance of indium-111 radiolabeled conjugates from the blood pool and high kidney accumulation within 1 h in tumor bearing mice. Biodistribution data confirms images with high accumulation in kidney (max 210% ID/g for 43 kD conjugate) and lower tumor accumulation (max 1.8% ID/g for 43kD conjugate). While actively binding to the αvβ3 integrin in vitro, HPMA copolymer-RGDfK conjugates with increased negative charge through increased CHX-A″-DTPA chelator content in the side chains causes increased kidney accumulation with a loss of tumor binding in vivo. PMID:18687371

  11. Improved drug targeting of cancer cells by utilizing actively targetable folic acid-conjugated albumin nanospheres.

    Science.gov (United States)

    Shen, Zheyu; Li, Yan; Kohama, Kazuhiro; Oneill, Brian; Bi, Jingxiu

    2011-01-01

    Folic acid-conjugated albumin nanospheres (FA-AN) have been developed to provide an actively targetable drug delivery system for improved drug targeting of cancer cells with reduced side effects. The nanospheres were prepared by conjugating folic acid onto the surface of albumin nanospheres using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as a catalyst. To test the efficacy of these nanospheres as a potential delivery platform, doxorubicin-loaded albumin nanospheres (DOX-AN) and doxorubicin-loaded FA-AN (FA-DOX-AN) were prepared by entrapping DOX (an anthracycline, antibiotic drug widely used in cancer chemotherapy that works by intercalating DNA) into AN and FA-AN nanoparticles. Cell uptake of the DOX was then measured. The results show that FA-AN was incorporated into HeLa cells (tumor cells) only after 2.0h incubation, whereas HeLa cells failed to incorporate albumin nanospheres without conjugated folic acid after 4.0h incubation. When HeLa cells were treated with the DOX-AN, FA-DOX-AN nanoparticles or free DOX, cell viability decreased with increasing culture time (i.e. cell death increases with time) over a 70h period. Cell viability was always the lowest for free DOX followed by FA-DOX-AN4 and then DOX-AN. In a second set of experiments, HeLa cells washed to remove excess DOX after an initial incubation for 2h were incubated for 70h. The corresponding cell viability was slightly higher when the cells were treated with FA-DOX-AN or free DOX whilst cells treated with DOX-AN nanoparticles remained viable. The above experiments were repeated for non-cancerous, aortic smooth muscle cells (AoSMC). As expected, cell viability of the HeLa cells (with FA receptor alpha, FRα) and AoSMC cells (without FRα) decreased rapidly with time in the presence of free DOX, but treatment with FA-DOX-AN resulted in selective killing of the tumor cells. These results indicated that FA-AN may be used as a promising actively targetable drug delivery system to improve drug

  12. Targeted gene correction using psoralen, chlorambucil and camptothecin conjugates of triplex forming peptide nucleic acid (PNA)

    DEFF Research Database (Denmark)

    Birkedal, Henrik; Nielsen, Peter E

    2011-01-01

    Gene correction activation effects of a small series of triplex forming peptide nucleic acid (PNA) covalently conjugated to the DNA interacting ligands psoralen, chlorambucil and camptothecin targeted proximal to a stop codon mutation in an EGFP reporter gene were studied. A 15-mer homopyrimidine...... PNA conjugated to the topoisomerase I inhibitor camptothecin was found to increase the frequency of repair domain mediated gene correctional events of the EGFP reporter in an in vitro HeLa cell nuclear extract assay, whereas PNA psoralen or chlorambucil conjugates both of which form covalent and also....... Consistent with the extract experiments, treatment with adduct forming PNA conjugates (psoralen and chlorambucil) resulted in a decrease in background correction frequencies in transiently transfected cells, whereas unmodified PNA or the PNA-camptothecin conjugate had little or no effect. These results...

  13. Smart linkers in polymer-drug conjugates for tumor-targeted delivery.

    Science.gov (United States)

    Chang, Minglu; Zhang, Fang; Wei, Ting; Zuo, Tiantian; Guan, Yuanyuan; Lin, Guimei; Shao, Wei

    2016-01-01

    To achieve effective chemotherapy, many types of drug delivery systems have been developed for the specific environments in tumor tissues. Polymer-drug conjugates are increasingly used in tumor therapy due to several significant advantages over traditional delivery systems. In the fabrication of polymer-drug conjugates, a smart linker is an important component that joins two fragments or molecules together and can be cleared by a specific stimulus, which results in targeted drug delivery and controlled release. By regulating the conjugation between the drug and the nanocarriers, stimulus-sensitive systems based on smart linkers can offer high payloads, certified stability, controlled release and targeted delivery. In this review, we summarize the current state of smart linkers (e.g. disulfide, hydrazone, peptide, azo) used recently in various polymer-drug conjugate-based delivery systems with a primary focus on their sophisticated design principles and drug delivery mechanisms as well as in vivo processes.

  14. Targeted images of KB cells using folate-conjugated gold nanoparticles

    Science.gov (United States)

    Rathinaraj, Pierson; Lee, Kyubae; Park, Soo-Young; Kang, Inn-Kyu

    2015-01-01

    Mercaptosuccinic acid-coated gold (GM) nanoparticles were prepared and characterized by transmission electron microscopy and dynamic light scattering. Folic acid (F) was then conjugated to the GM to preferentially target oral squamous cancer (KB) cells with folate receptors expressed on their membranes and facilitate the transit of the nanoparticles across the cell membrane. Finally, a fluorescence dye (Atto) was conjugated to the nanoparticles to visualize their internalization into KB cells. After culture of the cells in a medium containing GM and folate-conjugated GM (GF), the interaction of surface-modified gold nanoparticles with KB cells was studied.

  15. Integrin Targeting and Toxicological Assessment of Peptide-Conjugated Liposome Delivery Systems to Activated Endothelial Cells

    DEFF Research Database (Denmark)

    Kermanizadeh, Ali; Villadsen, Klaus; Østrem, Ragnhild Garborg

    2017-01-01

    Utilisation of functionalized liposomes as the means of targeted delivery of therapeutics may enhance specific transport of biologically active drugs to target tissues, while avoiding or reducing undesired side effects. In the present investigation, peptide-conjugated cationic liposomes were cons....... Therefore, this study demonstrates the feasibility of constructing a peptide-conjugated cationic liposome, which displays targeting to activated endothelial cells at concentrations that are not cytotoxic or inflammogenic to the cells....... constructed with the aim of targeting integrins (i.e. vitronectin and/or fibronectin receptors) on activated endothelial cells. The peptide-conjugated liposomes induced only cytotoxicity at the highest concentration in non-activated or activated endothelial cells, as well as in co-culture of endothelial cells...

  16. Translational Motion Compensation for Ballistic Targets Based on Delayed Conjugated Multiplication

    Directory of Open Access Journals (Sweden)

    He Si-san

    2014-10-01

    Full Text Available The micro-motion is combined with the high velocity of translation motion for ballistic targets. The translation motion should be compensated for micro-Doppler information extraction. A new method based on delay conjugate multiplication is proposed to compensate the translation motion of ballistic target. By delay conjugate multiplication of the received signal, the micro-Doppler information are canceled out and the translation motion parameters estimation problem is transformed as an multi-polynomial phase signal parameters estimation problem. Thus, the translation parameters can be estimated. Simulation results suggest that the proposed algorithm can achieve high-precision compensation for ballistic targets under low SNR.

  17. Linker-free conjugation and specific cell targeting of antibody functionalized iron-oxide nanoparticles

    Science.gov (United States)

    Xu, Yaolin; Baiu, Dana C.; Sherwood, Jennifer A.; McElreath, Meghan R.; Qin, Ying; Lackey, Kimberly H.; Otto, Mario; Bao, Yuping

    2015-01-01

    Specific targeting is a key step to realize the full potential of iron oxide nanoparticles in biomedical applications, especially tumor-associated diagnosis and therapy. Here, we developed anti-GD2 antibody conjugated iron oxide nanoparticles for highly efficient neuroblastoma cell targeting. The antibody conjugation was achieved through an easy, linker-free method based on catechol reactions. The targeting efficiency and specificity of the antibody-conjugated nanoparticles to GD2-positive neuroblastoma cells were confirmed by flow cytometry, fluorescence microscopy, Prussian blue staining and transmission electron microscopy. These detailed studies indicated that the receptor-recognition capability of the antibody was fully retained after conjugation and the conjugated nanoparticles quickly attached to GD2-positive cells within four hours. Interestingly, longer treatment (12 h) led the cell membrane-bound nanoparticles to be internalized into cytosol, either by directly penetrating the cell membrane or escaping from the endosomes. Last but importantly, the uniquely designed functional surfaces of the nanoparticles allow easy conjugation of other bioactive molecules. PMID:26660881

  18. Peptide-conjugated micelles as a targeting nanocarrier for gene delivery

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wen Jen, E-mail: wjlin@ntu.edu.tw; Chien, Wei Hsuan [National Taiwan University, School of Pharmacy, Graduate Institute of Pharmaceutical Sciences (China)

    2015-09-15

    The aim of this study was to develop peptide-conjugated micelles possessing epidermal growth factor receptor (EGFR) targeting ability for gene delivery. A sequence-modified dodecylpeptide, GE11(2R), with enhancing EGF receptor binding affinity, was applied in this study as a targeting ligand. The active targeting micelles were composed of poly(d,l-lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) copolymer conjugated with GE11(2R)-peptide. The particle sizes of peptide-free and peptide-conjugated micelles were 277.0 ± 5.1 and 308.7 ± 14.5 nm, respectively. The peptide-conjugated micelles demonstrated the cellular uptake significantly higher than peptide-free micelles in EGFR high-expressed MDA-MB-231 and MDA-MB-468 cells due to GE11(2R)-peptide specificity. Furthermore, the peptide-conjugated micelles were able to encapsulate plasmid DNA and expressed cellular transfection higher than peptide-free micelles in EGFR high-expressed cells. The EGFR-targeting delivery micelles enhanced DNA internalized into cells and achieved higher cellular transfection in EGFR high-expressed cells.

  19. DNA-templated antibody conjugation for targeted drug delivery to cancer cells

    DEFF Research Database (Denmark)

    Liu, Tianqiang

    2016-01-01

    -templated organic synthesis due to the wide existence of the 3-histidine cluster in most wild-type proteins. In this thesis, three projects that relate to targeted drug delivery to cancer cells based on the DTPC method is described. The first project was a delivery system which uses transferrin as the targeting...... ligand and saporin (ribosome inactivating protein) as the warhead to achieve enhanced cellular uptake and cytotoxicity of saporin to transferrin receptor overexpressed cancer cell line. The transferrin-saporin conjugate complex are formed by linking the site-selective DNA-transferrin conjugates with mono...... to cancer cells. The DNA duplex in the conjugates could be used for doxorubicin intercalation since it contains CGA repeats. Confocal microscopy and flow cytometry results showed a receptor-mediated targeting manner to EGFR+ cancer cell lines (KB and MDA-MB-231), and resulted in enhanced cell killing...

  20. RGD-peptide conjugated inulin-ibuprofen nanoparticles for targeted delivery of Epirubicin.

    Science.gov (United States)

    Zhang, Luzhong; Li, Guicai; Gao, Ming; Liu, Xin; Ji, Bing; Hua, Ruheng; Zhou, Youlang; Yang, Yumin

    2016-08-01

    Recently, chemotherapy-based polymeric nanoparticles have been extensively investigated for solid tumor treatment. Tumor targeted nanoparticles demonstrated great potential for improved accumulation in the tumor tissue, superior anticancer activity and reduced side effects. Thus, inulin-ibuprofen polymer was synthesized by esterification between inulin and ibuprofen, and RGD targeted epirubicin (EPB) loaded nanoparticles were prepared by the self-assembly of inulin-ibuprofen polymer and in situ encapsulation of EPB. RGD conjugated EPB loaded nanoparticles were characterized by dynamic light scattering (DLS) and transmission electron microscope (TEM). The EPB release from the nanoparticles showed pH-dependent profile and accelerated by the decreased pH value, which would favor the effective drug delivery in vivo. Intracellular uptake analysis suggested that RGD conjugated nanoparticles could be easily internalized by the cancer cells. In vitro cytotoxicity revealed that RGD conjugated EPB loaded nanoparticles exhibited the better antitumor efficacy compared with non-conjugated nanoparticles. More importantly, RGD conjugated EPB loaded nanoparticles showed superior anticancer effects and reduced toxicity than free EPB and non-conjugated nanoparticles by in vivo antitumor activity, EPB biodistribution and histology analysis.

  1. Glycyrrhizin conjugated chitosan nanoparticles for hepatocyte-targeted delivery of lamivudine.

    Science.gov (United States)

    Mishra, Deepak; Jain, Nivrati; Rajoriya, Vaibhav; Jain, Ashish K

    2014-08-01

    The present study was focused to prepare controlled release glycyrrhizin (GL) conjugated low molecular weight chitosan nanoparticles (CS-NPs) for liver targeting. The hydrophilic antiretroviral drug lamivudine was chosen as a model drug and encapsulated within glycyrrhizin conjugated low molecular weight chitosan nanoparticles (GL-CS-NPs) for liver specificity. First, the low molecular weight chitosan (CS) was synthesized through depolymerization method. The low molecular weight chitosan nanoparticles were prepared by inotropic gelation method. Then glycyrrhizin was conjugated with previously prepared low molecular weight chitosan nanoparticles (CS-NPs) and conjugation was confirmed by Fourier transform infrared (FT-IR) spectroscopy. The prepared GL-CS-NPs were characterized using dynamic light scattering, transmission electron microscopy and FT-IR. The encapsulation efficiency and in-vitro drug release behaviour of drug-loaded GL-CS-NPs were studied using ultra violet spectroscopy and high performance liquid chromatographic methods. Release of lamivudine from the nanoparticles exhibited a biphasic pattern, initial burst release and consequently sustained release. In-vivo biodistribution study suggested the target ability of GL-CS-NPs is better and haematological study shows decline of the tissue damage in comparison with plain drug solution. The experimental results show that the glycyrrhizin conjugated LMWC nanoparticles may be used as a potential drug delivery system with hepatocyte-targeting characteristics. © 2014 Royal Pharmaceutical Society.

  2. Albumin-Folate Conjugates for Drug-targeting in Photodynamic Therapy.

    Science.gov (United States)

    Butzbach, Kathrin; Rasse-Suriani, Federico A O; Gonzalez, M Micaela; Cabrerizo, Franco M; Epe, Bernd

    2016-07-01

    Photodynamic therapy (PDT) is based on the cytotoxicity of photosensitizers in the presence of light. Increased selectivity and effectivity of the treatment is expected if a specific uptake of the photosensitizers into the target cells, often tumor cells, can be achieved. An attractive transporter for that purpose is the folic acid receptor α (FRα), which is overexpressed on the surface of many tumor cells and mediates an endocytotic uptake. Here, we describe the synthesis and photobiological characterization of polar β-carboline derivatives as photosensitizers covalently linked to folate-tagged albumin as the carrier system. The particles were taken up by KB (human carcinoma) cells within albumin-β-carbolinium conjugate proved to be phototoxic, while the corresponding albumin-β-carbolinium conjugates without FA were nontoxic, both with and without irradiation. An excess of free folate as competitor for the FRα-mediated uptake completely inhibited the photocytotoxicity. Interestingly, the albumin conjugates are devoid of photodynamic activity under cell-free conditions, as shown for DNA as a target. Thus, phototoxicity requires cellular uptake and lysosomal degradation of the conjugates. In conclusion, albumin-folate conjugates appear to be promising vehicles for a tumor cell targeted PDT.

  3. Folate-conjugated gold nanoparticle as a new nanoplatform for targeted cancer therapy.

    Science.gov (United States)

    Samadian, Hadi; Hosseini-Nami, Samira; Kamrava, Seyed Kamran; Ghaznavi, Habib; Shakeri-Zadeh, Ali

    2016-11-01

    Conventional cancer treatment methods suffer from many limitations such as non-specificity and low efficacy in discrimination between healthy and cancer cells. Recent developments in nanotechnology have introduced novel and smart therapeutic nanomaterials that basically take advantage of various targeting approaches. Targeted nanomaterials selectively bind to the cancer cells and affect them with minor effects on healthy cells. Folic acid (folate) is an essential molecule in DNA synthesis pathway which is highly needed for cancer cell duplication. Some certain cancer cells overexpress folate receptors higher than normal cells, and this fact is the basis of folate targeting strategy. There are many publications reporting various folate conjugated nanomaterials among which folate-conjugated gold nanoparticles hold great promises in targeted cancer therapy. Gold nanoparticles have been identified as promising candidates for new cancer therapy modalities because of biocompatibility, easy synthesis and functionalization, chemo-physical stability, and optical tunable characteristics. In the last decade, there has been a significant explosion in gold nanoparticles research, with a rapid increase in publications related to the area of biomedicine. Although there are many reports published on "gold nanoparticles" and "folate targeting," there are a few reports on "folate-conjugated gold nanoparticles" in biomedical literature. This paper intends to review and illustrate the recent advances in biomedicine which have been designed on the basis of folate-conjugated gold nanoparticles.

  4. Kinetic Optimization of Folic Acid Polymer Conjugates for Drug Targeting

    Directory of Open Access Journals (Sweden)

    Jacob M. Ngoy

    2011-01-01

    Full Text Available Problem statement: Folic Acid (FA is an essential, bioavailable water soluble B-complex vitamin that helps in the replication of normal cells. It is obtained from natural sources and it deficiency can leads to oncogenic cells development. Within this frame work in mind, we designed and synthesized a new bioconjugate carrier that can enhance the effectiveness of FA. Approach: The polymeric carrier: Polysucscinimide (PSI was synthesized via the polycondensation of aspartic acid by attaching 3-(N,N-Dimethylamino Propylamine (DMP and 1,3-P-propylenediamine (PDA for solubility behavior and reactivity for FA site anchoring. Also the use of an ester 2-(1H-benzotrial-1- yl-1,1,3,3-tetramethylurium Hexafluorophosphate (HBTU as coupling agent to FA. The bioreversible binding of the water-soluble and biocompatible macromolecular were attested through kinetic studies. The kinetic reactions were investigated through the nuclear resonance (H1NMR spectra analysis. Results and Conclusion: The H1NMR optimization reaction times were found within the range of 120-130 min (80-85% as optimum coupling. The yield of the FA occurred within the same time range but with maximum incorporation between 90-100%. The growth of FA incorporation in terms of reaction time resulted to an increase inherent viscosity relative to the decrease of water solubility of the conjugate obtained.

  5. Design, synthesis and evaluation of N-acetyl glucosamine (NAG)-PEG-doxorubicin targeted conjugates for anticancer delivery.

    Science.gov (United States)

    Pawar, Smita K; Badhwar, Archana J; Kharas, Firuza; Khandare, Jayant J; Vavia, Pradeep R

    2012-10-15

    Efficacy of anticancer drug is limited by the severe adverse effects induced by drug; therefore the crux is in designing delivery systems targeted only to cancer cells. Toward this objectives, we propose, synthesis of poly(ethylene glycol) (PEG)-doxorubicin (DOX) prodrug conjugates consisting N-acetyl glucosamine (NAG) as a targeting moiety. Multicomponent system proposed here is characterized by (1)H NMR, UV spectroscopy, and HPLC. The multicomponent system is evaluated for in vitro cellular kinetics and anticancer activity using MCF-7 and MDA-MB-231 cells. Molecular modeling study demonstrated sterically stabilized conformations of polymeric conjugates. Interestingly, PEG-DOX conjugate with NAG ligand showed significantly higher cytotoxicity compared to drug conjugate with DOX. In addition, the polymer drug conjugate with NAG and DOX showed enhanced internalization and retention effect in cancer cells, compared to free DOX. Thus, with enhanced internalization and targeting ability of PEG conjugate of NAG-DOX has implication in targeted anticancer therapy.

  6. Transtuzumab-conjugated liposome-coated fluorscent magnetic namoparticles to target breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Mi Jung; Lee, Hak Jong; Hwang, Sung Il; Yun, Bo La; Kim, Sun Mi [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Yoon, Young Il; Kwon, Yong Soo [Nanoimaging and Therapy Research Center, Institute of Nanoconvergence, Advanced Institutes of Convergence Technology, Seoul National University, Suwon (Korea, Republic of); Yoon, Tae Jong [NanoBio Materials Chemistry Lab., Dept. of Applied Bioscience, CHA University, Pocheon (Korea, Republic of)

    2014-08-15

    To synthesize mesoporous silica-core-shell magnetic nanoparticles (MNPs) encapsulated by liposomes (Lipo [MNPm-SiO{sub 2}]) in order to enhance their stability, allow them to be used in any buffer solution, and to produce trastuzumab-conjugated (Lipo[MNPm-SiO{sub 2}]-Her2Ab) nanoparticles to be utilized in vitro for the targeting of breast cancer. The physiochemical characteristics of Lipo[MNPm-SiO{sub 2}] were assessed in terms of size, morphological features, and in vitro safety. The multimodal imaging properties of the organic dye incorporated into Lipo[MNPm-SiO{sub 2}] were assessed with both in vitro fluorescence and MR imaging. The specific targeting ability of trastuzumab (Her2/neu antibody, Herceptin)-conjugated Lipo[MNPm-SiO{sub 2}] for Her2/neu-positive breast cancer cells was also evaluated with fluorescence and MR imaging. We obtained uniformly-sized and evenly distributed Lipo[MNPm-SiO{sub 2}] that demonstrated biological stability, while not disrupting cell viability. Her2/neu-positive breast cancer cell targeting by trastuzumab-conjugated Lipo[MNPm-SiO{sub 2}] was observed by in vitro fluorescence and MR imaging. Trastuzumab-conjugated Lipo[MNPm-SiO{sub 2}] is a potential treatment tool for targeted drug delivery in Her2/neu-positive breast cancer.

  7. Hyaluronic acid-serum albumin conjugate-based nanoparticles for targeted cancer therapy.

    Science.gov (United States)

    Edelman, Ravit; Assaraf, Yehuda G; Levitzky, Inna; Shahar, Tal; Livney, Yoav D

    2017-02-15

    Multiple carcinomas including breast, ovarian, colon, lung and stomach cancer, overexpress the hyaluronic acid (HA) receptor, CD44. Overexpression of CD44 contributes to key cancer processes including tumor invasion, metastasis, recurrence, and chemoresistance. Herein, we devised novel targeted nanoparticles (NPs) for delivery of anticancer chemotherapeutics, comprised of self-assembling Maillard reaction-based conjugates of HA and bovine serum albumin (BSA). HA served as the hydrophilic block, and as the ligand for actively targeting cancer cells overexpressing CD44. We demonstrate that Maillard reaction-based covalent conjugates of BSA-HA self-assemble into NPs, which efficiently entrap hydrophobic cytotoxic drugs including paclitaxel and imidazoacridinones. Furthermore, BSA-HA conjugates stabilized paclitaxel and prevented its aggregation and crystallization. The diameter of the NPs was < 15 nm, thus enabling CD44 receptor-mediated endocytosis. These NPs were selectively internalized by ovarian cancer cells overexpressing CD44, but not by cognate cells lacking this HA receptor. Moreover, free HA abolished the endocytosis of drug-loaded BSA-HA conjugates. Consistently, drug-loaded NPs were markedly more cytotoxic to cancer cells overexpressing CD44 than to cells lacking CD44, due to selective internalization, which could be competitively inhibited by excess free HA. Finally, a CD44-targeted antibody which blocks receptor activity, abolished internalization of drug-loaded NPs. In conclusion, a novel cytotoxic drug-loaded nanomedicine platform has been developed, which is based on natural biocompatible biopolymers, capabale of targeting cancer cells with functional surface expression of CD44.

  8. Conjugate-SELEX: A High-throughput Screening of Thioaptamer-liposomal Nanoparticle Conjugates for Targeted Intracellular Delivery of Anticancer Drugs.

    Science.gov (United States)

    Mu, Qingshan; Annapragada, Akshaya; Srivastava, Mayank; Li, Xin; Wu, Jean; Thiviyanathan, Varatharasa; Wang, Hongyu; Williams, Alexander; Gorenstein, David; Annapragada, Ananth; Vigneswaran, Nadarajah

    2016-11-01

    Patients with advanced head and neck squamous cell carcinoma receiving chemotherapy have a poor prognosis partly due to normal tissue toxicity; therefore, development of a tumor-targeted drug delivery platform to minimize collateral toxicity is a goal of cancer nanomedicine. Aptamers can achieve this purpose. While conventional Systematic Evolution of Ligands by Exponential Enrichment (SELEX) screens aptamer-only libraries and conjugates them to delivery vehicles after selection, we hypothesized that specific delivery requires screening libraries with aptamer-nanoparticle conjugates. We designed a procedure called, "Conjugate-SELEX", where liposomal nanoparticles (LNP) conjugated with aptamers is screened to identify aptamers that carried attached LNPs to the human head and neck squamous cell carcinoma cell cytosol. Aptamer-LNPs were simultaneously selected for a low affinity to human hepatocytes, minimizing hepatoxicity and LNP clearance. Post-SELEX Next Generation sequencing demonstrated convergence to a family of sequences with one base difference. Affinity pulldown and proteomics analysis identified the uptake-mediating surface receptor as the neuroblast differentiation-associated protein AHNAK (Desmoyokin), a ubiquitous intracellular protein expressed in certain epithelial cell types. Uptake studies with the lead aptamer-conjugates showed enhanced uptake and increased cytotoxicity induced by doxorubicin in cells treated with aptamer-conjugated LNPs over LNP controls. Conjugate-SELEX identifies aptamers capable of targeted cytosolic delivery of attached LNPs payload, while minimizing off-target delivery. The technique lends itself to identification of uptake-mediating surface receptors.

  9. Antimicrobial Peptide-PNA Conjugates Selectively Targeting Bacterial Genes

    Science.gov (United States)

    2013-07-22

    change, (Good, 2000). In the case of MRSA, RNA polymerase σ⁷⁷ (encoded by gene rpoD) is a conserved prokaryotic factor essential for transcription...silencing technology to bacteria is the inefficient entry of PNAs into the targeted cell due to restrictions imposed by the bacterial membrane . Peptide...AMP and (RW)3, a linear hexameric peptide, both designed in our lab, interact with wall polymers and cause penetration of the cell membrane at sub

  10. Nanobody conjugated PLGA nanoparticles for active targeting of African Trypanosomiasis.

    Science.gov (United States)

    Arias, José L; Unciti-Broceta, Juan D; Maceira, José; Del Castillo, Teresa; Hernández-Quero, José; Magez, Stefan; Soriano, Miguel; García-Salcedo, José A

    2015-01-10

    Targeted delivery of therapeutics is an alternative approach for the selective treatment of infectious diseases. The surface of African trypanosomes, the causative agents of African trypanosomiasis, is covered by a surface coat consisting of a single variant surface glycoprotein, termed VSG. This coat is recycled by endocytosis at a very high speed, making the trypanosome surface an excellent target for the delivery of trypanocidal drugs. Here, we report the design of a drug nanocarrier based on poly ethylen glycol (PEG) covalently attached (PEGylated) to poly(D,L-lactide-co-glycolide acid) (PLGA) to generate PEGylated PLGA nanoparticles. This nanocarrier was coupled to a single domain heavy chain antibody fragment (nanobody) that specifically recognizes the surface of the protozoan pathogen Trypanosoma brucei. Nanoparticles were loaded with pentamidine, the first-line drug for T. b. gambiense acute infection. An in vitro effectiveness assay showed a 7-fold decrease in the half-inhibitory concentration (IC50) of the formulation relative to free drug. Furthermore, in vivo therapy using a murine model of African trypanosomiasis demonstrated that the formulation cured all infected mice at a 10-fold lower dose than the minimal full curative dose of free pentamidine and 60% of mice at a 100-fold lower dose. This nanocarrier has been designed with components approved for use in humans and loaded with a drug that is currently in use to treat the disease. Moreover, this flexible nanobody-based system can be adapted to load any compound, opening a range of new potential therapies with application to other diseases.

  11. Folate Receptor-Targeted Dendrimer-Methotrexate Conjugate for Inflammatory Arthritis.

    Science.gov (United States)

    Qi, Rong; Majoros, Istvan; Misra, Asish C; Koch, Alisa E; Campbell, Phil; Marotte, Hubert; Bergin, Ingrid L; Cao, Zhengyi; Goonewardena, Sascha; Morry, Jingga; Zhang, Shuai; Beer, Michael; Makidon, Paul; Kotlyar, Alina; Thomas, Thommey P; Baker, James R

    2015-08-01

    Generation 5 (G5) poly(amidoamide) (PAMAM) dendrimers are synthetic polymers that have been broadly applied as drug delivery carriers. Methotrexate (MTX), an anti-folate metabolite, has been successfully used as an anti-inflammatory drug to treat rheumatoid arthritis (RA) in the clinic. In this study, we examine the therapeutic efficacy of G5 PAMAM dendrimer methotrexate conjugates (G5-MTX) that also have folic acid (FA) conjugated to the G5-MTX (G5-FA-MTX) to target inflammation-activated folate receptors overexpressing macrophages. These cells are thought to play an important role in the development of RA. With G5 serving as a control, the in vitro binding affinities of G5-FA-MTX and G5-MTX to activated macrophages were assessed in RAW264.7, NR8383 and primary rat peritoneal macrophages. The results indicated that the binding of either conjugate to macrophages was concentration- and temperature-dependent and could be blocked by the presence of 6.25 mM free FA (p < 0.005). The preventive effects of G5-MTX and G5-FA-MTX conjugates on the development of arthritis were explored on an adjuvant-induced inflammatory arthritis model and had similar preventive effects in inflammatory arthritis at a MTX equivalent dose of 4.95 μmol/kg. These studies indicated that when multiples of MTX are conjugated on dendritic polymers, they specifically bind to folate receptor overexpressing macrophages and have comparable anti-inflammatory effects to folate targeted MTX conjugated polymers.

  12. Indocyanine green as effective antibody conjugate for intracellular molecular targeted photodynamic therapy

    Science.gov (United States)

    Wang, Sijia; Hüttmann, Gereon; Rudnitzki, Florian; Diddens-Tschoeke, Heyke; Zhang, Zhenxi; Rahmanzadeh, Ramtin

    2016-07-01

    The fluorescent dye indocyanine green (ICG) is clinically approved and has been applied for ophthalmic and intraoperative angiography, measurement of cardiac output and liver function, or as contrast agent in cancer surgery. Though ICG is known for its photochemical effects, it has played a minor role so far in photodynamic therapy or techniques for targeted protein-inactivation. Here, we investigated ICG as an antibody-conjugate for the selective inactivation of the protein Ki-67 in the nucleus of cells. Conjugates of the Ki-67 antibody TuBB-9 with different amounts of ICG were synthesized and delivered into HeLa and OVCAR-5 cells through conjugation to the nuclear localization sequence. Endosomal escape of the macromolecular antibodies into the cytoplasm was optically triggered by photochemical internalization with the photosensitizer BPD. The second light irradiation at 690 nm inactivated Ki-67 and subsequently caused cell death. Here, we show that ICG as an antibody-conjugate can be an effective photosensitizing agent. Best effects were achieved with 1.8 ICG molecules per antibody. Conjugated to antibodies, the ICG absorption peaks vary proportionally with concentration. The absorption of ICG above 650 nm within the optical window of tissue opens the possibility of selective Ki-67 inactivation deep inside of tissues.

  13. 2-Deoxyglucose conjugated platinum (II) complexes for targeted therapy: design, synthesis, and antitumor activity.

    Science.gov (United States)

    Mi, Qian; Ma, Yuru; Gao, Xiangqian; Liu, Ran; Liu, Pengxing; Mi, Yi; Fu, Xuegang; Gao, Qingzhi

    2016-11-01

    Malignant neoplasms exhibit an elevated rate of glycolysis over normal cells. To target the Warburg effect, we designed a new series of 2-deoxyglucose (2-DG) conjugated platinum (II) complexes for glucose transporter 1 (GLUT1)-mediated anticancer drug delivery. The potential GLUT1 transportability of the complexes was investigated through a comparative molecular docking analysis utilizing the latest GLUT1 protein crystal structure. The key binding site for 2-DG as GLUT1's substrate was identified with molecular dynamics simulation, and the docking study demonstrated that the 2-DG conjugated platinum (II) complexes can be recognized by the same binding site as potential GLUT1 substrate. The conjugates were synthesized and evaluated for in vitro cytotoxicity study with seven human cancer cell lines. The results of this study revealed that 2-DG conjugated platinum (II) complexes are GLUT1 transportable substrates and exhibit improved cytotoxicities in cancer cell lines that over express GLUT1 when compared to the clinical drug, Oxaliplatin. The correlation between GLUT1 expression and antitumor effects are also confirmed. The study provides fundamental information supporting the potential of the 2-DG conjugated platinum (II) complexes as lead compounds for further pharmaceutical R&D.

  14. Phthalocyanine-Biomolecule Conjugated Photosensitizers for Targeted Photodynamic Therapy and Imaging.

    Science.gov (United States)

    Iqbal, Zafar; Chen, Jincan; Chen, Zhuo; Huang, Mingdong

    2015-01-01

    Photodynamic therapy (PDT) is now in clinical practice in many European and American countries as a minimally invasive therapeutic technique to treat oncologic malignancies and other nononcologic conditions. Phthalocyanines (Pcs) are gathering importance as effective photosensitizers in targeted PDT and imaging of tumors. The possibility of modification around the Pc macrocycle led the researchers to the synthesis of a diversity of photosensitizers with varied cell specificity, cellular internalization and localization, photodynamic cytotoxicity and excretion. Cellular targeting is the primary aspect of an ideal photosensitizer for targeting PDT. Therefore, Pcs have been structurally modified with a variety of biomolecules capable of recognizing the specific lesions. This review emphasizes the photocytotoxicity and the cellular uptakes of phthalocyanine photosensitizers conjugated with biomolecules including carbohydrates, nucleotides and protein constituents such as amino acids and peptides. In addition, the role of the Pc-biomolecule conjugates in imaging and antimicrobial chemotherapy has been discussed.

  15. Targeting of follicle stimulating hormone peptide-conjugated dendrimers to ovarian cancer cells

    Science.gov (United States)

    Modi, Dimple A.; Sunoqrot, Suhair; Bugno, Jason; Lantvit, Daniel D.; Hong, Seungpyo; Burdette, Joanna E.

    2014-02-01

    Ovarian cancer is the most lethal gynecological malignancy. Current treatment modalities include a combination of surgery and chemotherapy, which often lead to loss of fertility in premenopausal women and a myriad of systemic side effects. To address these issues, we have designed poly(amidoamine) (PAMAM) dendrimers to selectively target the follicle stimulating hormone receptor (FSHR), which is overexpressed by tumorigenic ovarian cancer cells but not by immature primordial follicles and other non-tumorigenic cells. Fluorescein-labeled generation 5 (G5) PAMAM dendrimers were conjugated with the binding peptide domain of FSH (FSH33) that has a high affinity to FSHR. The targeted dendrimers exhibited high receptor selectivity to FSHR-expressing OVCAR-3 cells, resulting in significant uptake and downregulation of an anti-apoptotic protein survivin, while showing minimal interactions with SKOV-3 cells that do not express FSHR. The selectivity of the FSH33-targeted dendrimers was further validated in 3D organ cultures of normal mouse ovaries. Immunostaining of the conjugates revealed their selective binding and uptake by ovarian surface epithelium (OSE) cells that express FSHR, while sparing the immature primordial follicles. In addition, an in vivo study monitoring tissue accumulation following a single intraperitoneal (i.p.) injection of the conjugates showed significantly higher accumulation of FSH33-targeted dendrimers in the ovary and oviduct compared to the non-targeted conjugates. These proof-of-concept findings highlight the potential of these FSH33-targeted dendrimers to serve as a delivery platform for anti-ovarian cancer drugs, while reducing their systemic side effects by preventing nonspecific uptake by the primordial follicles.Ovarian cancer is the most lethal gynecological malignancy. Current treatment modalities include a combination of surgery and chemotherapy, which often lead to loss of fertility in premenopausal women and a myriad of systemic side

  16. Targeted Shiga toxin-drug conjugates prepared via Cu-free click chemistry.

    Science.gov (United States)

    Kostova, Vesela; Dransart, Estelle; Azoulay, Michel; Brulle, Laura; Bai, Siau-Kun; Florent, Jean-Claude; Johannes, Ludger; Schmidt, Frédéric

    2015-11-15

    The main drawback of the anticancer chemotherapy consists in the lack of drug selectivity causing severe side effects. The targeted drug delivery appears to be a very promising strategy for controlling the biodistribution of the cytotoxic agent only on malignant tissues by linking it to tumor-targeting moiety. Here we exploit the natural characteristics of Shiga toxin B sub-unit (STxB) as targeting carrier on Gb3-positive cancer cells. Two cytotoxic conjugates STxB-doxorubicin (STxB-Doxo) and STxB-monomethyl auristatin F (STxB-MMAF) were synthesised using copper-free 'click' chemistry. Both conjugates were obtained in very high yield and demonstrated strong tumor inhibition activity in a nanomolar range on Gb3-positive cells.

  17. Cerebral ischemia/stroke and small ubiquitin-like modifier (SUMO) conjugation--a new target for therapeutic intervention?

    Science.gov (United States)

    Yang, Wei; Sheng, Huaxin; Homi, H Mayumi; Warner, David S; Paschen, Wulf

    2008-08-01

    Transient cerebral ischemia/stroke activates various post-translational protein modifications such as phosphorylation and ubiquitin conjugation that are believed to play a major role in the pathological process triggered by an interruption of blood supply and culminating in cell death. A new system of post-translational protein modification has been identified, termed as small ubiquitin-like modifier (SUMO) conjugation. Like ubiquitin, SUMO is conjugated to the lysine residue of target proteins in a complex process. This review summarizes observations from recent experiments focusing on the effect of cerebral ischemia on SUMO conjugation. Transient global and focal cerebral ischemia both induced a rapid, dramatic and long-lasting rise in levels of SUMO2/3 conjugation. After transient focal cerebral ischemia, SUMO conjugation was particularly prominent in neurons located at the border of the ischemic territory where SUMO-conjugated proteins translocated to the nucleus. Many SUMO conjugation target proteins are transcription factors and sumoylation has been shown to have a major impact on the activity, stability, and cellular localization of target proteins. The rise in levels of SUMO-conjugated proteins is therefore likely to have a major effect on the fate of post-ischemic neurons. The sumoylation process could provide an exciting new target for therapeutic intervention.

  18. Use of biotin targeted methotrexate–human serum albumin conjugated nanoparticles to enhance methotrexate antitumor efficacy

    Directory of Open Access Journals (Sweden)

    Taheri A

    2011-09-01

    Full Text Available Azade Taheri1, Rassoul Dinarvand1,2, Faranak Salman Nouri1, Mohammad Reza Khorramizadeh3, Atefeh Taheri Borougeni4, Pooria Mansoori5, Fatemeh Atyabi1,21Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; 2Nanotechnology Research Centre, Faculty of Pharmacy, Tehran University of Medical sciences, Tehran, Iran; 3Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; 4Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran; 5Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IranAbstract: Biotin molecules could be used as suitable targeting moieties in targeted drug delivery systems against tumors. To develop a biotin targeted drug delivery system, we employed human serum albumin (HSA as a carrier. Methotrexate (MTX molecules were conjugated to HSA. MTX-HSA nanoparticles (MTX-HSA NPs were prepared from these conjugates by cross-linking the HSA molecules. Biotin molecules were then conjugated on the surface of MTX-HSA NPs. The anticancer efficacy of biotin targeted MTX-HSA NPs was evaluated in mice bearing 4T1 breast carcinoma. A single dose of biotin targeted MTX-HSA NPs showed stronger in vivo antitumor activity than non-targeted MTX-HSA NPs and free MTX. By 7 days after treatment, average tumor volume in the biotin targeted MTX-HSA NPs-treated group decreased to 17.6% of the initial tumor volume when the number of attached biotin molecules on MTX-HSA-NPs was the highest. Average tumor volume in non-targeted MTX-HSA NPs-treated mice grew rapidly and reached 250.7% of the initial tumor volume. Biotin targeted MTX-HSA NPs increased the survival of tumor-bearing mice to 47.5 ± 0.71 days and increased their life span up to 216.7%. Mice treated with biotin targeted MTX-HSA NPs showed slight body weight loss (8% 21 days after treatment, whereas non-targeted MTX

  19. Self-assembled Nanoparticles based on Folic Acid Modiifed Carboxymethyl Chitosan Conjugated with Targeting Antibody

    Institute of Scientific and Technical Information of China (English)

    HU Zhengyu; ZHENG Hua; LI Dan; XIONG Xiong; TAN Mingyuan; HUANG Dan; GUO Xing; ZHANG Xueqiong; YAN Han

    2016-01-01

    Nanoparticles conjugated with antibody were designed as active drug delivery system to reduce the toxicity and side effects of drugs for acute myeloid leukemia (AML). Moreover, methotrexate (MTX) was chosen as model drug and encapsulate within folic acid modified carboxymethyl chitosan (FA-CMCS) nanoparticles through self-assembling. The chemical structure, morphology, release and targeting of nanoparticles were characterized by routine detection. It is demonstrated that the mean diameter is about 150 nm, the release rate increases with the decreasing of pH, the binding rate of CD33 antibody and FA-CMCS nanoparticles is about 5:2, and nanoparticles can effectively bind onto HL60 cells in vitro. The experimental results indicate that the FA-CMCS nanoparticles conjugated with antibody may be used as a potential pH-sensitive drug delivery system with leukemic targeting properties.

  20. Conjugation of Vitamin E Analog α-TOS to Pt(IV) Complexes for Dual-Targeting Anticancer Therapy

    Science.gov (United States)

    Suntharalingam, Kogularamanan; Song, Ying

    2014-01-01

    We report two platinum(IV) complexes conjugated with a vitamin E analog, α-tocopherol succinate (α-TOS). One of the conjugates displays the activity of both cisplatin and αTOS in cancer cells, causing damage to DNA and mitochondria simultaneously. Accordingly, it serves as promising dual-targeting anticancer agent. PMID:24452361

  1. Effects of mycophenolic acid-glucosamine conjugates on the base of kidney targeted drug delivery.

    Science.gov (United States)

    Wang, Xiaohong; Lin, Yan; Zeng, Yingchun; Sun, Xun; Gong, Tao; Zhang, Zhirong

    2013-11-01

    Mycophenolic acid has played an important role in treating immunosuppression and autoimmune diseases. Nevertheless, the agent needs a high dosage in treatment, following some side effects. To tackle this problem, in this study, mycophenolic acid-glucosamine conjugate (MGC), modified by 2-glucosamine, was synthesized to achieve kidney targeting and improved drug efficacy with a lower dosage. (1)H NMR, (13)C NMR and HRMS spectroscopy were used to verify the conjugate whose stability was good in vitro. The transport of MGC by human proximal renal tubular epithelial HK-2 cells was temperature-, time-, concentration-dependent and saturable, suggesting the involvement of carrier-mediated uptake. In addition, the cellular uptake of MGC dropped substantially with the inhibition of megalin receptor. The specific tissue distribution indicated the commendable renal-targeting capability of MGC. The concentration of MGC was improved in the kidney except for other tissues, about 6.76 times higher than that of MPA. Further, the bioavailability of MGC in plasma decreased as compared with mycophenolic acid. Moreover, therapeutic effect of MGC was enhanced significantly compared with MPA in the acute kidney injury model. All the findings suggested the potential of mycophenolic acid-glucosamine conjugate in kidney targeted drug delivery.

  2. Aptamer conjugated paclitaxel and magnetic fluid loaded fluorescently tagged PLGA nanoparticles for targeted cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Aravind, Athulya; Nair, Remya; Raveendran, Sreejith; Veeranarayanan, Srivani; Nagaoka, Yutaka; Fukuda, Takahiro; Hasumura, Takahashi; Morimoto, Hisao; Yoshida, Yasuhiko; Maekawa, Toru; Sakthi Kumar, D., E-mail: sakthi@toyo.jp

    2013-10-15

    Controlled and targeted drug delivery is an essential criterion in cancer therapy to reduce the side effects caused by non-specific drug release and toxicity. Targeted chemotherapy, sustained drug release and optical imaging have been achieved using a multifunctional nanocarrier constructed from poly (D, L-lactide-co-glycolide) nanoparticles (PLGA NPs), an anticancer drug paclitaxel (PTX), a fluorescent dye Nile red (NR), magnetic fluid (MF) and aptamers (Apt, AS1411, anti-nucleolin aptamer). The magnetic fluid and paclitaxel loaded fluorescently labeled PLGA NPs (MF-PTX-NR-PLGA NPs) were synthesized by a single-emulsion technique/solvent evaporation method using a chemical cross linker bis (sulfosuccinimidyl) suberate (BS3) to enable binding of aptamer on to the surface of the nanoparticles. Targeting aptamers were then introduced to the particles through the reaction with the cross linker to target the nucleolin receptors over expressed on the cancer cell surface. Specific binding and uptake of the aptamer conjugated magnetic fluid loaded fluorescently tagged PLGA NPs (Apt-MF-NR-PLGA NPs) to the target cancer cells induced by aptamers was observed using confocal microscopy. Cytotoxicity assay conducted in two cell lines (L929 and MCF-7) confirmed that targeted MCF-7 cancer cells were killed while control cells were unharmed. In addition, aptamer mediated delivery resulting in enhanced binding and uptake to the target cancer cells exhibited increased therapeutic effect of the drug. Moreover, these aptamer conjugated magnetic polymer vehicles apart from actively transporting drugs into specifically targeted tumor regions can also be used to induce hyperthermia or for facilitating magnetic guiding of particles to the tumor regions. - Highlights: • Aptamer escorted, theranostic biodegradable PLGA carriers were developed. • Can target cancer cells, control drug release, image and magnetically guide. • Highly specific to the targeted cancer cells thus delivering

  3. Development of Viral Capsid DNA Aptamer Conjugates as Cell-Targeted Delivery Vehicles

    Science.gov (United States)

    Tong, Gary Jen-Wei

    The ability to generate semi-synthetic DNA-protein conjugates has become increasingly important in the fields of chemical biology and nanobiotechnology. As applications in these fields become more complex, there is also an increased need for methods of attaching synthetic DNA to protein substrates in a well-defined manner. This work outlines the development of new methods for site-specific DNA-protein bioconjugation, as well as the development of novel viral capsid DNA aptamer conjugates for cell-targeting purposes. In order to generate DNA-protein conjugates in a site-specific manner, chemistries orthogonal to native functional groups present on DNA and proteins were exploited. In one method, the attachment of DNA to proteins was achieved via oxime formation. This strategy involved the in situ deprotection of an allyloxycarbonyl-protected alkoxyamine-bearing DNA in the presence of a protein containing a single ketone group. The utility of this approach was demonstrated in the synthesis of a DNA-GFP conjugate. In addition to the oxime formation route, two oxidative coupling methods were also developed for DNA-protein bioconjugation. The first reaction coupled phenylenediamine-containing DNA to anilines, which had been site-specifically incorporated into proteins, in the presence of NaIO4. These reaction conditions were demonstrated on the proteins bacteriophage MS2 and GFP, and were mild enough for the components to retain both protein structure and DNA base-pairing capabilities. The second oxidative coupling reaction conjugated aniline-containing proteins to DNA bearing an o-aminophenol moiety. This reaction occurred under similarly mild conditions; however, higher coupling yields were achieved on MS2 at shorter reaction times by using this strategy. In all three of these methods, the generation of a singly-modified product was achieved. Using one of our oxidative coupling strategies, MS2-DNA aptamer conjugates were synthesized for the development of multivalent

  4. Superparamagnetic iron oxide nanoparticles conjugated with epidermal growth factor (SPION–EGF for targeting brain tumors

    Directory of Open Access Journals (Sweden)

    Shevtsov MA

    2014-01-01

    Full Text Available Maxim A Shevtsov,1,2 Boris P Nikolaev,3 Ludmila Y Yakovleva,3 Yaroslav Y Marchenko,3 Anatolii V Dobrodumov,4 Anastasiya L Mikhrina,5 Marina G Martynova,1 Olga A Bystrova,1 Igor V Yakovenko,2 Alexander M Ischenko31Institute of Cytology of the Russian Academy of Sciences (RAS, 2AL Polenov Russian Scientific Research Institute of Neurosurgery, 3Research Institute of Highly Pure Biopreparations, 4Institute of Macromolecular Compounds of the Russian Academy of Sciences (RAS, 5IM Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (RAS, St Petersburg, RussiaAbstract: Superparamagnetic iron oxide nanoparticles (SPIONs conjugated with recombinant human epidermal growth factor (SPION–EGF were studied as a potential agent for magnetic resonance imaging contrast enhancement of malignant brain tumors. Synthesized conjugates were characterized by transmission electron microscopy, dynamic light scattering, and nuclear magnetic resonance relaxometry. The interaction of SPION–EGF conjugates with cells was analyzed in a C6 glioma cell culture. The distribution of the nanoparticles and their accumulation in tumors were assessed by magnetic resonance imaging in an orthotopic model of C6 gliomas. SPION–EGF nanosuspensions had the properties of a negative contrast agent with high coefficients of relaxation efficiency. In vitro studies of SPION–EGF nanoparticles showed high intracellular incorporation and the absence of a toxic influence on C6 cell viability and proliferation. Intravenous administration of SPION–EGF conjugates in animals provided receptor-mediated targeted delivery across the blood–brain barrier and tumor retention of the nanoparticles; this was more efficient than with unconjugated SPIONs. The accumulation of conjugates in the glioma was revealed as hypotensive zones on T2-weighted images with a twofold reduction in T2 relaxation time in comparison to unconjugated SPIONs (P<0.001. SPION

  5. Conjugated platinum(IV)-peptide complexes for targeting angiogenic tumor vasculature.

    Science.gov (United States)

    Mukhopadhyay, Sumitra; Barnés, Carmen M; Haskel, Ariel; Short, Sarah M; Barnes, Katie R; Lippard, Stephen J

    2008-01-01

    The integrins alpha vbeta3 and alpha vbeta5 and the membrane-spanning surface protein aminopeptidase N (APN) are highly expressed in tumor-induced angiogenesis, making them attractive targets for therapeutic intervention. Both integrins and APN recognize a broad range of peptides containing RGD (Arg-Gly-Asp) and NGR (Asn-Gly-Arg) motifs, respectively. Here, we describe the design, synthesis, and characterization of a series of mono- and difunctionalized platinum(IV) complexes in which a conjugated peptide motif, containing RGD, (CRGDC)c, (RGDfK)c, or NGR, is appended as a "tumor-homing device" to target tumor endothelial cells selectively over healthy cells. Platinum(IV)-peptide complexes with nonspecific amino acids or peptide moieties were prepared as controls. Concentration-response curves of these compounds were evaluated against primary proliferating endothelial cells and tumor cell lines and compared to those of cisplatin, a well-described platinum-based chemotherapeutic agent. The Pt(IV)-RGD conjugates were highly and specifically cytotoxic to cell lines containing alpha vbeta3 and alpha vbeta5, approaching the activity of cisplatin. The Pt(IV)-NGR complexes were less active than Pt(IV)-RGD-containing compounds but more active than nonspecific Pt-peptide controls. Integrin alpha vbeta3 mediated, at least in part, the anti-proliferative effect of a Pt(IV)-RGD conjugate, as demonstrated by a decreased inhibitory response when endothelial cells were either (1) incubated with an excess of alpha vbeta3/alpha vbeta5-specific RGD pentapeptides or (2) transfected with RNAi for beta 3, but not beta 1, integrins. These results suggest a rational approach to improved chemotherapy with Pt(IV)-peptide conjugates by selective drug delivery to the tumor compartment.

  6. Aptamer conjugated paclitaxel and magnetic fluid loaded fluorescently tagged PLGA nanoparticles for targeted cancer therapy

    Science.gov (United States)

    Aravind, Athulya; Nair, Remya; Raveendran, Sreejith; Veeranarayanan, Srivani; Nagaoka, Yutaka; Fukuda, Takahiro; Hasumura, Takahashi; Morimoto, Hisao; Yoshida, Yasuhiko; Maekawa, Toru; Sakthi Kumar, D.

    2013-10-01

    Controlled and targeted drug delivery is an essential criterion in cancer therapy to reduce the side effects caused by non-specific drug release and toxicity. Targeted chemotherapy, sustained drug release and optical imaging have been achieved using a multifunctional nanocarrier constructed from poly (D, L-lactide-co-glycolide) nanoparticles (PLGA NPs), an anticancer drug paclitaxel (PTX), a fluorescent dye Nile red (NR), magnetic fluid (MF) and aptamers (Apt, AS1411, anti-nucleolin aptamer). The magnetic fluid and paclitaxel loaded fluorescently labeled PLGA NPs (MF-PTX-NR-PLGA NPs) were synthesized by a single-emulsion technique/solvent evaporation method using a chemical cross linker bis (sulfosuccinimidyl) suberate (BS3) to enable binding of aptamer on to the surface of the nanoparticles. Targeting aptamers were then introduced to the particles through the reaction with the cross linker to target the nucleolin receptors over expressed on the cancer cell surface. Specific binding and uptake of the aptamer conjugated magnetic fluid loaded fluorescently tagged PLGA NPs (Apt-MF-NR-PLGA NPs) to the target cancer cells induced by aptamers was observed using confocal microscopy. Cytotoxicity assay conducted in two cell lines (L929 and MCF-7) confirmed that targeted MCF-7 cancer cells were killed while control cells were unharmed. In addition, aptamer mediated delivery resulting in enhanced binding and uptake to the target cancer cells exhibited increased therapeutic effect of the drug. Moreover, these aptamer conjugated magnetic polymer vehicles apart from actively transporting drugs into specifically targeted tumor regions can also be used to induce hyperthermia or for facilitating magnetic guiding of particles to the tumor regions.

  7. Erlotinib-Conjugated Iron Oxide Nanoparticles as a Smart Cancer-Targeted Theranostic Probe for MRI

    Science.gov (United States)

    Ali, Ahmed Atef Ahmed; Hsu, Fei-Ting; Hsieh, Chia-Ling; Shiau, Chia-Yang; Chiang, Chiao-Hsi; Wei, Zung-Hang; Chen, Cheng-Yu; Huang, Hsu-Shan

    2016-11-01

    We designed and synthesized novel theranostic nanoparticles that showed the considerable potential for clinical use in targeted therapy, and non-invasive real-time monitoring of tumors by MRI. Our nanoparticles were ultra-small with superparamagnetic iron oxide cores, conjugated to erlotinib (FeDC-E NPs). Such smart targeted nanoparticles have the preference to release the drug intracellularly rather than into the bloodstream, and specifically recognize and kill cancer cells that overexpress EGFR while being non-toxic to EGFR-negative cells. MRI, transmission electron microscopy and Prussian blue staining results indicated that cellular uptake and intracellular accumulation of FeDC-E NPs in the EGFR overexpressing cells was significantly higher than those of the non-erlotinib-conjugated nanoparticles. FeDC-E NPs inhibited the EGFR-ERK-NF-κB signaling pathways, and subsequently suppressed the migration and invasion capabilities of the highly invasive and migrative CL1-5-F4 cancer cells. In vivo tumor xenograft experiments using BALB/c nude mice showed that FeDC-E NPs could effectively inhibit the growth of tumors. T2-weighted MRI images of the mice showed significant decrease in the normalized signal within the tumor post-treatment with FeDC-E NPs compared to the non-targeted control iron oxide nanoparticles. This is the first study to use erlotinib as a small-molecule targeting agent for nanoparticles.

  8. Targeting Glycoprotein NMB With Antibody-Drug Conjugate, Glembatumumab Vedotin, for the Treatment of Osteosarcoma.

    Science.gov (United States)

    Roth, Michael; Barris, David M; Piperdi, Sajida; Kuo, Vicky; Everts, Stephanie; Geller, David; Houghton, Peter; Kolb, E Anders; Hawthorne, Thomas; Gill, Jonathan; Gorlick, Richard

    2016-01-01

    Cure rates for children and young adults with osteosarcoma have remained stagnant over the past three decades. Targeting glycoprotein non-metastatic b (GPNMB) with the antibody-drug conjugate glembatumumab vedotin has improved outcomes for patients with melanoma and breast cancer. The potential utility of targeting GPNMB in osteosarcoma was explored. GPNMB protein expression was evaluated by immunohistochemistry in human osteosarcoma tumor samples and by enzyme-linked immunosorbent assay (ELISA) in osteosarcoma cell lines. mRNA expression was measured by quantitative PCR in primary osteosarcoma samples and cell lines. Surface GPNMB expression was evaluated by flow cytometry and correlated with in vitro and in vivo cytotoxicity of glembatumumab vedotin. Sixty seven human osteosarcoma samples were evaluated by immunohistochemistry, including 12 samples from initial biopsy, 38 samples from definitive surgery, and 17 from the time of disease recurrence. GPNMB was expressed in 92.5% (62/67) of osteosarcoma samples. All primary osteosarcoma samples expressed high levels of GPNMB mRNA. Glembatumumab induced cytotoxic effects in 74% (14/19) of osteosarcoma cell lines, and GPNMB protein levels correlated with glembatumumab in vitro cytotoxicity (r = -0.46, P = 0.04). All osteosarcoma cell lines demonstrated surface GPNMB expression. GPNMB is expressed in osteosarcoma and targeting GPNMB with the antibody-drug conjugate glembatumumab vedotin demonstrates osteosarcoma cytotoxic activity. Clinical trials are indicated to assess the efficacy of targeting GPNMB in patients with osteosarcoma. © 2015 Wiley Periodicals, Inc.

  9. Targeting protein translation, RNA splicing, and degradation by morpholino-based conjugates in Plasmodium falciparum.

    Science.gov (United States)

    Garg, Aprajita; Wesolowski, Donna; Alonso, Dulce; Deitsch, Kirk W; Ben Mamoun, Choukri; Altman, Sidney

    2015-09-22

    Identification and genetic validation of new targets from available genome sequences are critical steps toward the development of new potent and selective antimalarials. However, no methods are currently available for large-scale functional analysis of the Plasmodium falciparum genome. Here we present evidence for successful use of morpholino oligomers (MO) to mediate degradation of target mRNAs or to inhibit RNA splicing or translation of several genes of P. falciparum involved in chloroquine transport, apicoplast biogenesis, and phospholipid biosynthesis. Consistent with their role in the parasite life cycle, down-regulation of these essential genes resulted in inhibition of parasite development. We show that a MO conjugate that targets the chloroquine-resistant transporter PfCRT is effective against chloroquine-sensitive and -resistant parasites, causes enlarged digestive vacuoles, and renders chloroquine-resistant strains more sensitive to chloroquine. Similarly, we show that a MO conjugate that targets the PfDXR involved in apicoplast biogenesis inhibits parasite growth and that this defect can be rescued by addition of isopentenyl pyrophosphate. MO-based gene regulation is a viable alternative approach to functional analysis of the P. falciparum genome.

  10. Multi-small molecule conjugations as new targeted delivery carriers for tumor therapy

    Directory of Open Access Journals (Sweden)

    Shan L

    2015-09-01

    Full Text Available Lingling Shan,1 Ming Liu,2 Chao Wu,1 Liang Zhao,1 Siwen Li,3 Lisheng Xu,1 Wengen Cao,1 Guizhen Gao,1 Yueqing Gu3 1Institute of Pharmaceutical Biotechnology, School of Biology and Food Engineering, Suzhou University, Suzhou, People’s Republic of China; 2Department of Biology, University of South Dakota, Vermillion, SD, USA; 3Department of Biomedical Engineering, School of Life Science and Technology, China Pharmaceutical University, Nanjing, People’s Republic of China Abstract: In response to the challenges of cancer chemotherapeutics, including poor physicochemical properties, low tumor targeting ability, and harmful side effects, we developed a new tumor-targeted multi-small molecule drug delivery platform. Using paclitaxel (PTX as a model therapeutic, we prepared two prodrugs, ie, folic acid-fluorescein-5(6-isothiocyanate-arginine-paclitaxel (FA-FITC-Arg-PTX and folic acid-5-aminofluorescein-glutamic-paclitaxel (FA-5AF-Glu-PTX, composed of folic acid (FA, target, amino acids (Arg or Glu, linker, and fluorescent dye (fluorescein in vitro or near-infrared fluorescent dye in vivo in order to better understand the mechanism of PTX prodrug targeting. In vitro and acute toxicity studies demonstrated the low toxicity of the prodrug formulations compared with the free drug. In vitro and in vivo studies indicated that folate receptor-mediated uptake of PTX-conjugated multi-small molecule carriers induced high antitumor activity. Notably, compared with free PTX and with PTX-loaded macromolecular carriers from our previous study, this multi-small molecule-conjugated strategy improved the water solubility, loading rate, targeting ability, antitumor activity, and toxicity profile of PTX. These results support the use of multi-small molecules as tumor-targeting drug delivery systems. Keywords: multi-small molecules, paclitaxel, prodrugs, targeting, tumor therapy

  11. Sequence-specific targeting of RNA with an oligonucleotide-neomycin conjugate.

    Science.gov (United States)

    Charles, Irudayasamy; Xi, Hongjuan; Arya, Dev P

    2007-01-01

    The synthesis of neomycin covalently attached at the C5-position of 2'-deoxyuridine is reported. The synthesis outlined allows for incorporation of an aminoglycoside (neomycin) at any given site in an oligonucleotide (ODN) where a thymidine (or uridine) is present. Incorporation of this modified base into an oligonucleotide, which is complementary to a seven-bases-long alpha-sarcin loop RNA sequence, leads to enhanced duplex hybridization. The increase in Tm for this duplex (DeltaTm = 6 degrees C) suggests a favorable interaction of neomycin within the duplex groove. CD spectroscopy shows that the modified duplex adopts an A-type confirmation. ITC measurements indicate the additive effects of ODN and neomycin binding to the RNA target (Ka = 4.5 x 107 M-1). The enhanced stability of the hybrid duplex from this neomycin-ODN conjugate originates primarily from the enthalpic contribution of neomycin {DeltaDeltaHobs = -7.21 kcal/mol (DeltaHneomycin conjugated - DeltaH nonconjugated)} binding to the hybrid duplex. The short linker length allows for selective stabilization of the hybrid duplex over the hybrid triplex. The results described here open up new avenues in the design and synthesis of nucleo-aminoglycoside-conjugates (N-Ag-C) where the inclusion of any number of aminoglycoside (neomycin) molecules per oligonucleotide can be accomplished.

  12. Silica-shell cross-linked micelles encapsulating fluorescent conjugated polymers for targeted cellular imaging.

    Science.gov (United States)

    Tan, Happy; Zhang, Yu; Wang, Miao; Zhang, Zhongxing; Zhang, Xinhai; Yong, Anna Marie; Wong, Siew Yee; Chang, Alex Yuang-chi; Chen, Zhi-Kuan; Li, Xu; Choolani, Mahesh; Wang, John

    2012-01-01

    A bioinspired silification approach was successfully used to encapsulate fluorescent conjugated polymers inside silica-shell cross-linked polymeric micelles (CP-SSCL) in the highly benign synthesis environment of room temperature and near-neutral aqueous environment. Four different conjugated polymers were employed to demonstrate the versatility of the bioinspired silification, resulting in the formation of CP-SSCL with different emission wavelengths across the visible spectrum. The CP-SSCL are characterized by a large absorption coefficient and high quantum yield, indicating that they exhibit the required high fluorescence brightness for cellular imaging application. In addition, the CP-SSCL also exhibit a high colloidal stability and low cytotoxicity. The in vitro studies of using MDA-MB-231 breast cancer cells show that the CP-SSCL are successfully uptaken by the cancer cells and located at the cytoplasm of the cells. Furthermore, by conjugating folic acid on their surfaces, the uptake of CP-SSCL by MDA-MB-231 cells was enhanced significantly, suggesting their great potential for targeted imaging and early detection of cancer cells.

  13. Brain-targeted delivery of trans-activating transcriptor-conjugated magnetic PLGA/lipid nanoparticles.

    Directory of Open Access Journals (Sweden)

    Xiangru Wen

    Full Text Available Magnetic poly (D,L-lactide-co-glycolide (PLGA/lipid nanoparticles (MPLs were fabricated from PLGA, L-α-phosphatidylethanolamine (DOPE, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-amino (polyethylene glycol (DSPE-PEG-NH2, and magnetic nanoparticles (NPs, and then conjugated to trans-activating transcriptor (TAT peptide. The TAT-MPLs were designed to target the brain by magnetic guidance and TAT conjugation. The drugs hesperidin (HES, naringin (NAR, and glutathione (GSH were encapsulated in MPLs with drug loading capacity (>10% and drug encapsulation efficiency (>90%. The therapeutic efficacy of the drug-loaded TAT-MPLs in bEnd.3 cells was compared with that of drug-loaded MPLs. The cells accumulated higher levels of TAT-MPLs than MPLs. In addition, the accumulation of QD-loaded fluorescein isothiocyanate (FITC-labeled TAT-MPLs in bEnd.3 cells was dose and time dependent. Our results show that TAT-conjugated MPLs may function as an effective drug delivery system that crosses the blood brain barrier to the brain.

  14. Folic acid-CdTe quantum dot conjugates and their applications for cancer cell targeting

    Energy Technology Data Exchange (ETDEWEB)

    Suriamoorthy, Preethi; Zhang, Xing; Hao, Guiyang; Joly, Alan G.; Singh, S.; Hossu, Marius; Sun, Xiankai; Chen, Wei

    2010-12-01

    In this study, we report the preparation,luminescence, and targeting properties of folic acid- CdTe quantum dot conjugates. Water-soluble CdTe quantum dots were synthesized and conjugated with folic acid using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-N-hydroxysuccinimide chemistry. The in-fluence of folic acid on the luminescence properties of CdTe quantum dots was investigated, and no energy transfer between them was observed. To investigate the efficiency of folic acid-CdTe nanoconjugates for tumor targeting, pure CdTe quantum dots and folic acid-coated CdTe quantum dots were incubated with human naso- pharyngeal epidermal carcinoma cell line with positive expressing folic acid receptors (KB cells) and lung cancer cells without expression of folic acid receptors (A549 cells). For the cancer cells with positive folate receptors (KB cells), the uptake for CdTe quantum dots is very low, but for folic acid-CdTe nanoconjugates, the uptake is very high. For the lung cancer cells without folate receptors (A549 cells), the uptake for folic acid- CdTe nanoconjugates is also very low. The results indicate that folic acid is an effective targeting molecule for tumor cells with overexpressed folate receptors.

  15. Aptamer-conjugated Magnetic Nanoparticles as Targeted Magnetic Resonance Imaging Contrast Agent for Breast Cancer

    Science.gov (United States)

    Keshtkar, Mohammad; Shahbazi-Gahrouei, Daryoush; Khoshfetrat, Seyyed Mehdi; Mehrgardi, Masoud A.; Aghaei, Mahmoud

    2016-01-01

    Early detection of breast cancer is the most effective way to improve the survival rate in women. Magnetic resonance imaging (MRI) offers high spatial resolution and good anatomic details, and its lower sensitivity can be improved by using targeted molecular imaging. In this study, AS1411 aptamer was conjugated to Fe3O4@Au nanoparticles for specific targeting of mouse mammary carcinoma (4T1) cells that overexpress nucleolin. In vitro cytotoxicity of aptamer-conjugated nanoparticles was assessed on 4T1 and HFFF-PI6 (control) cells. The ability of the synthesized nanoprobe to target specifically the nucleolin overexpressed cells was assessed with the MRI technique. Results show that the synthesized nanoprobe produced strongly darkened T2-weighted magnetic resonance (MR) images with 4T1 cells, whereas the MR images of HFFF-PI6 cells incubated with the nanoprobe are brighter, showing small changes compared to water. The results demonstrate that in a Fe concentration of 45 μg/mL, the nanoprobe reduced by 90% MR image intensity in 4T1 cells compared with the 27% reduction in HFFF-PI6 cells. Analysis of MR signal intensity showed statistically significant signal intensity difference between 4T1 and HFFF-PI6 cells treated with the nanoprobe. MRI experiments demonstrate the high potential of the synthesized nanoprobe as a specific MRI contrast agent for detection of nucleolin-expressing breast cancer cells. PMID:28028501

  16. Recent development of biotin conjugation in biological imaging, sensing, and target delivery.

    Science.gov (United States)

    Ren, Wen Xiu; Han, Jiyou; Uhm, Soojin; Jang, Yu Jin; Kang, Chulhun; Kim, Jong-Hoon; Kim, Jong Seung

    2015-07-04

    Despite encouraging results from preliminary studies of anticancer therapies, the lack of tumor specificity remains an important issue in the modern pharmaceutical industry. New findings indicate that biotin or biotin-conjugates could be favorably assimilated by tumor cells that over-express biotin-selective transporters. Furthermore, biotin can form stable complexes with avidin and its bacterial counterpart streptavidin. The strong bridging between avidin and biotin moieties on other molecules is a proven adaptable tool with broad biological applications. Under these circumstances, a biotin moiety is certainly an attractive choice for live-cell imaging, biosensing, and target delivery.

  17. RGD-conjugated PLA-PLL nanoparticles targeting to Bacp-37 breast cancer xenografts in vivo.

    Science.gov (United States)

    Liu, Peifeng; Qi, Xuelian; Sun, Ying; Wang, Hongzhi; Li, Yaogang; Duan, Yourong

    2011-12-01

    Targeted delivery carriers are receiving considerable attention, the development of a more precise targeted delivery carrier is critical for the advancement of cancer chemotherapy. In this study, we evaluated the effects of RGD-conjugated poly (lactic acid-co-lysine)-(Arginine-Glycine-Aspartic) nanoparticles (PLA-PLL-RGD NPs) on targeted delivery to Bacp-37 breast cancer bearing mice. PLA-PLL-RGD NPs were prepared by using the emulsion-solvent evaporation method. A subsequent MTT assay indicated that the NPs were non-toxic and had good biocompatibility. In vitro, the results of Confocal Laser Scanning Microscope (CLSM) and FAC Scan flow cytometry (FACS) indicated that the PLA-PLL-RGD NPs can bind more significantly to human umbilical vein endothelial cells, compared to PLA-PLL NPs. In vivo, the results of target imaging and biodistribution showed that PLA-PLL-RGD can significantly target to tumor of Bacp-37 breast cancer bearing mice. These results demonstrated that PLA-PLL-RGD NPs can effectively enhance targeted efficiency in vivo, and have the potential to be used as targeted delivery carrier.

  18. Overcoming Instability of Antibody-Nanomaterial Conjugates: Next Generation Targeted Nanomedicines Using Bispecific Antibodies.

    Science.gov (United States)

    Howard, Christopher B; Fletcher, Nicholas; Houston, Zachary H; Fuchs, Adrian V; Boase, Nathan R B; Simpson, Joshua D; Raftery, Lyndon J; Ruder, Tim; Jones, Martina L; de Bakker, Christopher J; Mahler, Stephen M; Thurecht, Kristofer J

    2016-08-01

    Targeted nanomaterials promise improved therapeutic efficacy, however their application in nanomedicine is limited due to complexities associated with protein conjugations to synthetic nanocarriers. A facile method to generate actively targeted nanomaterials is developed and exemplified using polyethylene glycol (PEG)-functional nanostructures coupled to a bispecific antibody (BsAb) with dual specificity for methoxy PEG (mPEG) epitopes and cancer targets such as epidermal growth factor receptor (EGFR). The EGFR-mPEG BsAb binds with high affinity to recombinant EGFR (KD : 1 × 10(-9) m) and hyperbranched polymer (HBP) consisting of mPEG (KD : 10 × 10(-9) m) and demonstrates higher avidity for HBP compared to linear mPEG. The binding of BsAb-HBP bioconjugate to EGFR on MDA-MB-468 cancer cells is investigated in vitro using a fluorescently labeled polymer, and in in vivo xenograft models by small animal optical imaging. The antibody-targeted nanostructures show improved accumulation in tumor cells compared to non-targeted nanomaterials. This demonstrates a facile approach for tuning targeting ligand density on nanomaterials, by modulating surface functionality. Antibody fragments are tethered to the nanomaterial through simple mixing prior to administration to animals, overcoming the extensive procedures encountered for developing targeted nanomedicines.

  19. Anti-Lymphoma Efficacy Comparison of Anti-Cd20 Monoclonal Antibody-Targeted and Non-Targeted Star-Shaped Polymer-Prodrug Conjugates

    Directory of Open Access Journals (Sweden)

    Ondřej Lidický

    2015-11-01

    Full Text Available Here we describe the synthesis and biological properties of two types of star-shaped polymer-doxorubicin conjugates: non-targeted conjugate prepared as long-circulating high-molecular-weight (HMW polymer prodrugs with a dendrimer core and a targeted conjugate with the anti-CD20 monoclonal antibody (mAb rituximab (RTX. The copolymers were linked to the dendrimer core or to the reduced mAb via one-point attachment forming a star-shaped structure with a central antibody or dendrimer surrounded by hydrophilic polymer chains. The anticancer drug doxorubicin (DOX was attached to the N-(2-hydroxypropylmethacrylamide (HPMA-based copolymer chain in star polymer systems via a pH-labile hydrazone linkage. Such polymer-DOX conjugates were fairly stable in aqueous solutions at pH 7.4, and the drug was readily released in mildly acidic environments at pH 5–5.5 by hydrolysis of the hydrazone bonds. The cytotoxicity of the polymer conjugates was tested on several CD20-positive or negative human cell lines. Similar levels of in vitro cytotoxicity were observed for all tested polymer conjugates regardless of type or structure. In vivo experiments using primary cell-based murine xenograft models of human diffuse large B-cell lymphoma confirmed the superior anti-lymphoma efficacy of the polymer-bound DOX conjugate when compared with the original drug. Targeting with RTX did not further enhance the anti-lymphoma efficacy relative to the non-targeted star polymer conjugate. Two mechanisms could play roles in these findings: changes in the binding ability to the CD-20 receptor and a significant loss of the immunological properties of RTX in the polymer conjugates.

  20. Photosensitizer and peptide-conjugated PAMAM dendrimer for targeted in vivo photodynamic therapy

    Directory of Open Access Journals (Sweden)

    Narsireddy A

    2015-11-01

    Full Text Available Amreddy Narsireddy,1 Kurra Vijayashree,2 Mahesh G Adimoolam,1 Sunkara V Manorama,1 Nalam M Rao21CSIR – Indian Institute of Chemical Technology, 2CSIR – Centre for Cellular and Molecular Biology, Hyderabad, IndiaAbstract: Challenges in photodynamic therapy (PDT include development of efficient near infrared-sensitive photosensitizers (5,10,15,20-tetrakis(4-hydroxyphenyl-21H,23H-porphine [PS] and targeted delivery of PS to the tumor tissue. In this study, a dual functional dendrimer was synthesized for targeted PDT. For targeting, a poly(amidoamine dendrimer (G4 was conjugated with a PS and a nitrilotriacetic acid (NTA group. A peptide specific to human epidermal growth factor 2 was expressed in Escherichia coli with a His-tag and was specifically bound to the NTA group on the dendrimer. Reaction conditions were optimized to result in dendrimers with PS and the NTA at a fractional occupancy of 50% and 15%, respectively. The dendrimers were characterized by nuclear magnetic resonance, matrix-assisted laser desorption/ionization, absorbance, and fluorescence spectroscopy. Using PS fluorescence, cell uptake of these particles was confirmed by confocal microscopy and fluorescence-activated cell sorting. PS-dendrimers are more efficient than free PS in PDT-mediated cell death assays in HER2 positive cells, SK-OV-3. Similar effects were absent in HER2 negative cell line, MCF-7. Compared to free PS, the PS-dendrimers have shown significant tumor suppression in a xenograft animal tumor model. Conjugation of a PS with dendrimers and with a targeting agent has enhanced photodynamic therapeutic effects of the PS.Keywords: photodynamic therapy, dendrimers, nanoparticle, targeted delivery, Affibody, xenograft animal model

  1. Pre- and postfunctionalized self-assembled π-conjugated fluorescent organic nanoparticles for dual targeting.

    Science.gov (United States)

    Petkau, Katja; Kaeser, Adrien; Fischer, Irén; Brunsveld, Luc; Schenning, Albertus P H J

    2011-10-26

    There is currently a high demand for novel approaches to engineer fluorescent nanoparticles with precise surface properties suitable for various applications, including imaging and sensing. To this end, we report a facile and highly reproducible one-step method for generating functionalized fluorescent organic nanoparticles via self-assembly of prefunctionalized π-conjugated oligomers. The engineered design of the nonionic amphiphilic oligomers enables the introduction of different ligands at the extremities of inert ethylene glycol side chains without interfering with the self-assembly process. The intrinsic fluorescence of the nanoparticles permits the measurement of their surface properties and binding to dye-labeled target molecules via Förster resonance energy transfer (FRET). Co-assembly of differently functionalized oligomers is also demonstrated, which enables the tuning of ligand composition and density. Furthermore, nanoparticle prefunctionalization has been combined with subsequent postmodification of azide-bearing oligomers via click chemistry. This allows for expanding ligand diversity at two independent stages in the nanoparticle fabrication process. The practicability of the different methods entails greater control over surface functionality. Through labeling with different ligands, selective binding of proteins, bacteria, and functionalized beads to the nanoparticles has been achieved. This, in combination with the absence of unspecific adsorption, clearly demonstrates the broad potential of these nanoparticles for selective targeting and sequestration. Therefore, controlled bifunctionalization of fluorescent π-conjugated oligomer nanoparticles represents a novel approach with high applicability to multitargeted imaging and sensing in biology and medicine.

  2. Folic Acid-Chitosan Conjugated Nanoparticles for Improving Tumor-Targeted Drug Delivery

    Directory of Open Access Journals (Sweden)

    Huijuan Song

    2013-01-01

    Full Text Available Objective. To prepare folic acid-chitosan conjugated nanoparticles (FA-CS NPs and evaluate their targeting specificity on tumor cells. Methods. Chitosan (CS NPs were prepared by ionic cross linking method, and folic acid (FA was conjugated with CS NPs by electrostatic interaction. The properties of NPs were investigated, and doxorubicin hydrochloride (Dox as a model drug was encapsulated for investigating drug release pattern in vitro. The cytotoxicity and cellular uptake of FA-CS NPs were also investigated. Results. The results reveal that the obtained FA-CS NPs were monodisperse nanoparticles with suitable average size and positive surface charge. Dox was easily loaded into FA-CS NPs, and the release pattern showed a long and biphasic drug release. Noticeable phagocytosis effect was observed in the presence of rhodamine B-labeled FA-CSNPs when incubating with the folate receptor-positive SMMC-7221 cells. Conclusion. Compared with the unmodified CS NPs, FA-CS NPs showed much higher cell uptaking ability due to the known folate-receptor mediated endocytosis. FA-CS NPs provide a potential way to enhance the using efficiency of antitumor drug by folate receptor mediated targeting delivery.

  3. Efficient payload delivery by a bispecific antibody-drug conjugate targeting HER2 and CD63

    DEFF Research Database (Denmark)

    de Goeij, Bart E.C.G.; Vink, Tom; Ten Napel, Hendrik

    2016-01-01

    essential. For many cell surface proteins and carbohydrate structures on tumor cells, however, the magnitude of these processes is insufficient to allow for an effective ADC approach. We hypothesized that we could overcome this limitation by enhancing lysosomal ADC delivery via a bispecific antibody (bs......Antibody-drug conjugates (ADC) are designed to be stable in circulation and to release potent cytotoxic drugs intracellularly following antigen-specific binding, uptake, and degradation in tumor cells. Efficient internalization and routing to lysosomes where proteolysis can take place is therefore......Ab) approach, in which one binding domain would provide tumor specificity, whereas the other binding domain would facilitate targeting to the lysosomal compartment. We therefore designed a bsAb in which one binding arm specifically targeted CD63, a protein that is described to shuttle between the plasma...

  4. Lanreotide-conjugated PEG-DSPE micelles: an efficient nanocarrier targeting to somatostatin receptor positive tumors.

    Science.gov (United States)

    Zheng, Nan; Dai, Wenbing; Zhang, Hua; Wang, Xueqing; Wang, Jiancheng; Zhang, Xuan; Wang, Kun; Li, Jian; Zhang, Qiang

    2015-01-01

    Lanreotide is an octapeptide analog of endogenous somatostatin, specifically binding with tumors over-express somatostatin receptor 2 (SSTR2). In this study, we conjugated lanreotide to 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (poly-(ethylene glycol))-2000] (PEG-DSPE), constructed active targeted micelles (lanreotide-PM), characterized their in vitro and in vivo targeting effect, and explored the receptor mediated transportion. The uptake of lanreotide-PM was found to be related to the expression level of SSTR2 in different cell lines and the competitive inhibition phenomenon indicated that the cellular uptake of lanreotide-PM was via a receptor meditated mechanism. In vivo, more lanreotide-PM accumulated in SSTR2 high expression tumor xenografts, endocytosed by the tumor cells, induced more apoptosis of tumor cells, and suppressed tumor growth efficiently. In conclusion, lanreotide-modified micelles containing antitumor drugs provide a promising strategy for the treatment of SSTR-expressing tumors.

  5. Enzymatic prenylation and oxime ligation for the synthesis of stable and homogeneous protein-drug conjugates for targeted therapy.

    Science.gov (United States)

    Lee, Joong-Jae; Choi, Hyo-Jung; Yun, Misun; Kang, YingJin; Jung, Ji-Eun; Ryu, Yiseul; Kim, Tae Yoon; Cha, Young-Je; Cho, Hyun-Soo; Min, Jung-Joon; Chung, Chul-Woong; Kim, Hak-Sung

    2015-10-05

    Targeted therapy based on protein-drug conjugates has attracted significant attention owing to its high efficacy and low side effects. However, efficient and stable drug conjugation to a protein binder remains a challenge. Herein, a chemoenzymatic method to generate highly stable and homogenous drug conjugates with high efficiency is presented. The approach comprises the insertion of the CaaX sequence at the C-terminal end of the protein binder, prenylation using farnesyltransferase, and drug conjugation through an oxime ligation reaction. MMAF and an EGFR-specific repebody are used as the antitumor agent and protein binder, respectively. The method enables the precisely controlled synthesis of repebody-drug conjugates with high yield and homogeneity. The utility of this approach is illustrated by the notable stability of the repebody-drug conjugates in human plasma, negligible off-target effects, and a remarkable antitumor activity in vivo. The present method can be widely used for generating highly homogeneous and stable PDCs for targeted therapy.

  6. Preclinical Efficacy of an Antibody-Drug Conjugate Targeting Mesothelin Correlates with Quantitative Zr-89-ImmunoPET

    NARCIS (Netherlands)

    Terwisscha Van Scheltinga, Anton; Ogasawara, Annie; Pacheco, Glenn; Vanderbilt, Alexander N.; Tinianow, Jeff N.; Gupta, Nidhi; Li, Dongwei; Firestein, Ron; Marik, Jan; Scales, Suzie J.; Williams, Simon-Peter

    2017-01-01

    Antibody-drug conjugates (ADC) use monoclonal antibodies (mAb) as vehicles to deliver potent cytotoxic drugs selectively to tumor cells expressing the target. Molecular imaging with zirconium-89 (Zr-89)-labeled mAbs recapitulates similar targeting biology and might help predict the efficacy of these

  7. Targeting of peptide conjugated magnetic nanoparticles to urokinase plasminogen activator receptor (uPAR) expressing cells

    Science.gov (United States)

    Hansen, Line; Unmack Larsen, Esben Kjær; Nielsen, Erik Holm; Iversen, Frank; Liu, Zhuo; Thomsen, Karen; Pedersen, Michael; Skrydstrup, Troels; Nielsen, Niels Chr.; Ploug, Michael; Kjems, Jørgen

    2013-08-01

    Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles are currently being used as a magnetic resonance imaging (MRI) contrast agent in vivo, mainly by their passive accumulation in tissues of interest. However, a higher specificity can ideally be achieved when the nanoparticles are targeted towards cell specific receptors and this may also facilitate specific drug delivery by an enhanced target-mediated endocytosis. We report efficient peptide-mediated targeting of magnetic nanoparticles to cells expressing the urokinase plasminogen activator receptor (uPAR), a surface biomarker for poor patient prognosis shared by several cancers including breast, colorectal, and gastric cancers. Conjugation of a uPAR specific targeting peptide onto polyethylene glycol (PEG) coated USPIO nanoparticles by click chemistry resulted in a five times higher uptake in vitro in a uPAR positive cell line compared to nanoparticles carrying a non-binding control peptide. In accordance with specific receptor-mediated recognition, a low uptake was observed in the presence of an excess of ATF, a natural ligand for uPAR. The uPAR specific magnetic nanoparticles can potentially provide a useful supplement for tumor patient management when combined with MRI and drug delivery.Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles are currently being used as a magnetic resonance imaging (MRI) contrast agent in vivo, mainly by their passive accumulation in tissues of interest. However, a higher specificity can ideally be achieved when the nanoparticles are targeted towards cell specific receptors and this may also facilitate specific drug delivery by an enhanced target-mediated endocytosis. We report efficient peptide-mediated targeting of magnetic nanoparticles to cells expressing the urokinase plasminogen activator receptor (uPAR), a surface biomarker for poor patient prognosis shared by several cancers including breast, colorectal, and gastric cancers. Conjugation of a uPAR specific

  8. Liposomes for targeting hepatocellular carcinoma: use of conjugated arabinogalactan as targeting ligand.

    Science.gov (United States)

    Shah, Sanket M; Goel, Peeyush N; Jain, Ankitkumar S; Pathak, Pankaj O; Padhye, Sameer G; Govindarajan, Srinath; Ghosh, Sandipto S; Chaudhari, Pradip R; Gude, Rajiv P; Gopal, Vijaya; Nagarsenker, Mangal S

    2014-12-30

    Present study investigates the potential of chemically modified (Shah et al., 2013) palmitoylated arabinogalactan (PAG) in guiding liposomal delivery system and targeting asialoglycoprotein receptors (ASGPR) which are expressed in hepatocellular carcinoma (HCC). PAG was incorporated in liposomes during preparation and doxorubicin hydrochloride was actively loaded in preformed liposomes with and without PAG. The liposomal systems with or without PAG were evaluated for in vitro release, in vitro cytotoxicity, in vitro cell uptake on ASGPR(+) cells, in vivo pharmacokinetic study, in vivo biodistribution study, and in vivo efficacy study in immunocompromised mice. The particle size for all the liposomal systems was below 200 nm with a negative zeta potential. Doxorubicin loaded PAG liposomes released significantly higher amount of doxorubicin at pH 5.5 as compared to pH 7.4, providing advantage for targeted tumor therapy. Doxorubicin in PAG liposomes showed superior cytotoxicity on ASGPR(+) HepG2 cells as compared to ASGPR(-), MCF7, A549, and HT29 cells. Superior uptake of doxorubicin loaded PAG liposomes as compared to doxorubicin loaded conventional liposomes was evident in confocal microscopy studies. Higher AUC in pharmacokinetic study and higher deposition in liver was observed for PAG liposomes compared to conventional liposomes. Significantly higher tumor suppression was noted in immunocompromised mice for mice treated with PAG liposomes as compared to the conventional liposomes. Targeting ability and superior activity of PAG liposomes is established pre-clinically suggesting potential of targeted delivery system for improved treatment of HCC.

  9. Low Molecular Weight Hydroxyethyl Chitosan-Prednisolone Conjugate for Renal Targeting Therapy: Synthesis, Characterization and In Vivo Studies

    Directory of Open Access Journals (Sweden)

    Xia-kai He, Zhi-xiang Yuan, Xiao-juan Wu, Chao-qun Xu, Wan-yu Li

    2012-01-01

    Full Text Available To further evaluate the potential renal targeting profile of low molecular weight hydroxyethyl chitosan (LMWHC we developed before, prednisolone (Pre was conjugated with LMWHC by EDC/NHS chemistry to improve the therapeutic effect of glucocorticoids in vivo. The conjugate was denoted as LMWHC-Pre. The prednisolone content of the conjugate was determined by reversed-phase high-performance liquid chromatography (HPLC with Kromasil C18 column. The results showed that the average coupling degree of prednisolone to LMWHC was 76.7±3.2 μg·mg-1. The stability and physicochemical characterization of LMWHC-Pre under various conditions were also investigated. To study the fate of LMWHC-Pre after intravenous (i.v. administration, fluorescein isothiocyanate (FITC was coupled to the conjugate to explore the renal targeting efficacy. The in vivo results showed that significant amount of the conjugate was accumulated into the kidneys while negligible signal could be detected when the mixture of FITC-LMWHC and prednisolone was co-administered. The preliminary pharmacodynamics study of LMWHC-Pre showed that the conjugate could effectively alleviate the nephrotic syndrome of rats induced by minimal change nephrosis (MCN model. Toxicity study also revealed that there was little glucocorticoid-induced osteoporosis by LMWHC-Pre upon 20 days of treatment. From this study, LMWHC-Pre may be employed as an effective potential drug candidate for the treatment of chronic renal disease.

  10. Photosensitizer-Conjugated Hyaluronic Acid-Shielded Polydopamine Nanoparticles for Targeted Photomediated Tumor Therapy.

    Science.gov (United States)

    Han, Jieun; Park, Wooram; Park, Sin-Jung; Na, Kun

    2016-03-01

    Photodynamic therapy (PDT) is a widely used clinical option for tumor therapy. However, the clinical utilization of conventional small-molecule photosensitizers (PSs) for PDT has been limited by their low selectivity for disease sites, and undesirable photoactivation. To overcome these limitations, we demonstrated a tumor-specific and photoactivity-controllable nanoparticle photomedicine based on a combination of PS-biomacromolecule conjugates and polydopamine nanoparticles (PD-NP) for an effective tumor therapy. This novel photomedicine consisted of a PD-NP core and a PS-conjugated hyaluronic acid (PS-HA) shell. The PD-NP and the PS-HA play roles as a quencher for PSs and a cancer targeting moiety, respectively. The synthesized PS-HA-shielded PD-NPs (PHPD-NPs) had a relatively narrow size distribution (approximately 130 nm) with uniform spherical shapes. In response to cancer-specific intracellular enzymes (e.g., hyaluronidase), the PHPD-NPs exhibited an excellent singlet oxygen generation capacity for PDT. Furthermore, an efficient photothermal conversion ability for photothermal therapy (PTT) was also shown in the PHPD-NPs system. These properties provide superior therapeutic efficacy against cancer cells. In mice tumor model, the photoactive restorative effects of the PHPD-NPs were much higher in cancer microenvironments compared to that in the normal tissue. As a result, the PHPD-NPs showed a significant antitumor activity in in vivo mice tumor model. The nanoparticle photomedicine design is a novel strategy for effective tumor therapy.

  11. Drug resistance to chlorambucil in murine B-cell leukemic cells is overcome by its conjugation to a targeting peptide.

    Science.gov (United States)

    Gellerman, Gary; Baskin, Sophia; Galia, Luboshits; Gilad, Yosef; Firer, Michael A

    2013-02-01

    Targeting drugs through small-molecule carriers with a high affinity to receptors on cancer cells can overcome the lack of target cell specificity of most anticancer drugs. These targeted carrier-drug conjugates are also capable of reversing drug resistance in cancer cells. Although many targeted drug delivery approaches are being tested, the linkage of several and different drugs to a single carrier molecule might further enhance their therapeutic efficacy, particularly if the drugs are engineered for variable time release. This report shows that murine B-cell leukemic cells previously resistant to a chemotherapeutic drug can be made sensitive to that drug as long as it is conjugated to a targeting peptide and, in particular, when the conjugate contains multiple copies of the drug. Using a 13mer peptide (VHFFKNIVTPRTP) derived from the myelin basic protein (p-MBP), dendrimer-based peptide conjugates containing one, two, or four molecules of chlorambucil were synthesized. Although murine hybridomas expressing antibodies to either p-MBP (MBP cells) or a nonrelevant antigen (BCL-1 cells) were both resistant to free chlorambucil, exposure of the cells to the p-MBP-chlorambucil conjugate completely reversed the drug resistance in MBP, but not BCL-1 cells or normal spleen cells. Moreover, at equivalent drug doses, there was significant enhancement in the cytotoxic activity of multidrug versus single-drug copy conjugates. On the basis of these results, the use of multifunctional dendrone linkers bearing several covalently bound cytotoxic agents allows the development of more effective targeted drug systems and enhances the efficacy of currently approved drugs for B-cell leukemia.

  12. Chlorin e6 Conjugated Interleukin-6 Receptor Aptamers Selectively Kill Target Cells Upon Irradiation

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    Sven Kruspe

    2014-01-01

    Full Text Available Photodynamic therapy (PDT uses the therapeutic properties of light in combination with certain chemicals, called photosensitizers, to successfully treat brain, breast, prostate, and skin cancers. To improve PDT, current research focuses on the development of photosensitizers to specifically target cancer cells. In the past few years, aptamers have been developed to directly deliver cargo molecules into target cells. We conjugated the photosensitizer chlorin e6 (ce6 with a human interleukin-6 receptor (IL-6R binding RNA aptamer, AIR-3A yielding AIR-3A-ce6 for application in high efficient PDT. AIR-3A-ce6 was rapidly and specifically internalized by IL-6R presenting (IL-6R+ cells. Upon light irradiation, targeted cells were selectively killed, while free ce6 did not show any toxic effect. Cells lacking the IL-6R were also not affected by AIR-3A-ce6. With this approach, we improved the target specificity of ce6-mediated PDT. In the future, other tumor-specific aptamers might be used to selectively localize photosensitizers into cells of interest and improve the efficacy and specificity of PDT in cancer and other diseases.

  13. Hyaluronic acid-conjugated liposome nanoparticles for targeted delivery to CD44 overexpressing glioblastoma cells

    Science.gov (United States)

    Hayward, Stephen L.; Wilson, Christina L.; Kidambi, Srivatsan

    2016-01-01

    Glioblastoma Multiforme (GBM) is a highly prevalent and deadly brain malignancy characterized by poor prognosis and restricted disease management potential. Despite the success of nanocarrier systems to improve drug/gene therapy for cancer, active targeting specificity remains a major hurdle for GBM. Additionally, since the brain is a multi-cell type organ, there is a critical need to develop an approach to distinguish between GBM cells and healthy brain cells for safe and successful treatment. In this report, we have incorporated hyaluronic acid (HA) as an active targeting ligand for GBM. To do so, we employed HA conjugated liposomes (HALNPs) to study the uptake pathway in key cells in the brain including primary astrocytes, microglia, and human GBM cells. We observed that the HALNPs specifically target GBM cells over other brain cells due to higher expression of CD44 in tumor cells. Furthermore, CD44 driven HALNP uptake into GBM cells resulted in lysosomal evasion and increased efficacy of Doxorubicin, a model anti-neoplastic agent, while the astrocytes and microglia cells exhibited extensive HALNP-lysosome co-localization and decreased antineoplastic potency. In summary, novel CD44 targeted lipid based nanocarriers appear to be proficient in mediating site-specific delivery of drugs via CD44 receptors in GBM cells, with an improved therapeutic margin and safety. PMID:27120809

  14. Direct Cytoplasmic Delivery and Nuclear Targeting Delivery of HPMA-MT Conjugates in a Microtubules Dependent Fashion.

    Science.gov (United States)

    Zhong, Jiaju; Zhu, Xi; Luo, Kui; Li, Lian; Tang, Manlin; Liu, Yanxi; Zhou, Zhou; Huang, Yuan

    2016-09-06

    As the hearts of tumor cells, the nucleus is the ultimate target of many chemotherapeutic agents and genes. However, nuclear drug delivery is always hampered by multiple intracellular obstacles, such as low efficiency of lysosome escape and insufficient nuclear trafficking. Herein, an N-(2-hydroxypropyl) methacrylamide (HPMA) polymer-based drug delivery system was designed, which could achieve direct cytoplasmic delivery by a nonendocytic pathway and transport into the nucleus in a microtubules dependent fashion. A special targeting peptide (MT), derived from an endogenic parathyroid hormone-related protein, was conjugated to the polymer backbone, which could accumulate into the nucleus a by microtubule-mediated pathway. The in vitro studies found that low temperature and NaN3 could not influence the cell internalization of the conjugates. Besides, no obvious overlay of the conjugates with lysosome demonstrated that the polymer conjugates could enter the tumor cell cytoplasm by a nonendocytic pathway, thus avoiding the drug degradation in the lysosome. Furthermore, after suppression of the microtubule dynamics with microtubule stabilizing docetaxel (DTX) and destabilizing nocodazole (Noc), the nuclear accumulation of polymeric conjugates was significantly inhibited. Living cells fluorescence recovery after photobleaching study found that the nuclear import rate of conjugates was 2-fold faster compared with the DTX and Noc treated groups. These results demonstrated that the conjugates transported into the nucleus in a microtubules dependent way. Therefore, in addition to direct cytoplasmic delivery, our peptide conjugated polymeric platform could simultaneously mediate nuclear drug accumulation, which may open a new path for further intracellular genes/peptides delivery.

  15. Plant virus-resembling optical nano-materials conjugated with anti-EGFR for targeted cancer imaging

    Science.gov (United States)

    Gupta, Sharad; Wilder, Hailey; Rao, A. L. N.; Vullev, V. I.; Anvari, Bahman

    2012-03-01

    We recently reported the construction of a new type of optically active nano-particles composed of genome-depleted plant infecting brome mosaic virus (BMV) doped with indocyanine green (ICG), an FDA-approved chromophore . We refer to these constructs as optical viral ghosts (OVGs) since only the capsid protein (CP) subunits of BMV remain to encapsulate ICG. Herein, we covalently conjugated the surface of OVGs with anti-epidermal growth factor receptors (anti-EGFR) to target cancerous human bronchial epithelial cells (C-HBECs) in-vitro. Our preliminary results demonstrate the utility of conjugated OVGs for targeted imaging of cancer cells.

  16. Synthesis of taurine–fluorescein conjugate and evaluation of its retina-targeted efficiency in vitro

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    Meihong Huang

    2014-12-01

    Full Text Available In this work, retinal penetration of fluorescein was achieved in vitro by covalent attachment of taurine to fluorescein, yielding the F–Tau conjugate. Nuclear magnetic resonance (NMR and high resolution mass spectrometry (HRMS were used to confirm the successful synthesis of F–Tau. The cellular uptake of F–Tau in adult retinal pigment epithelial cells (ARPE-19 and human retinal microvascular endothelial cells (hRMECs was visualized via confocal scanning microscopy. The results indicated an improvement of solubility and a reduction of logP of F–Tau compared with fluorescein. As compared with fluorescein, F–Tau showed little toxicity, and was retained longer by cells in uptake experiments. F–Tau also displayed higher transepithelial permeabilities than fluorescein in ARPE-19 and hRMECs monolayer cells (P<0.05. These results showed that taurine may be a useful ligand for targeting small-molecule hydrophobic pharmaceuticals into the retina.

  17. Design and characteristics of cytotoxic fibroblast growth factor 1 conjugate for fibroblast growth factor receptor-targeted cancer therapy

    Directory of Open Access Journals (Sweden)

    Szlachcic A

    2016-08-01

    Full Text Available Anna Szlachcic, Malgorzata Zakrzewska, Michal Lobocki, Piotr Jakimowicz, Jacek Otlewski Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland Abstract: Fibroblast growth factor receptors (FGFRs are attractive candidate cancer therapy targets as they are overexpressed in multiple types of tumors, such as breast, prostate, bladder, and lung cancer. In this study, a natural ligand of FGFR, an engineered variant of fibroblast growth factor 1 (FGF1V, was conjugated to a potent cytotoxic drug, monomethyl auristatin E (MMAE, and used as a targeting agent for cancer cells overexpressing FGFRs, similar to antibodies in antibody–drug conjugates. The FGF1V–valine–citrulline–MMAE conjugate showed a favorable stability profile, bound FGFRs on the cell surface specifically, and efficiently released the drug (MMAE upon cleavage by the lysosomal protease cathepsin B. Importantly, the conjugate showed a prominent cytotoxic effect toward cell lines expressing FGFR. FGF1V–vcMMAE was highly cytotoxic at concentrations even an order of magnitude lower than those found for free MMAE. This effect was FGFR-specific as cells lacking FGFR did not show any increased mortality. Keywords: fibroblast growth factor 1, FGF receptor, targeted cancer therapy, cytotoxic conjugates, FGFR-dependent cancer, MMAE, auristatin

  18. VEGF₁₂₁-conjugated mesoporous silica nanoparticle: a tumor targeted drug delivery system.

    Science.gov (United States)

    Goel, Shreya; Chen, Feng; Hong, Hao; Valdovinos, Hector F; Hernandez, Reinier; Shi, Sixiang; Barnhart, Todd E; Cai, Weibo

    2014-12-10

    The vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) signaling cascade plays a critical role in tumor angiogenesis and metastasis and has been correlated with several poorly prognostic cancers such as malignant gliomas. Although a number of anti-VEGFR therapies have been conceived, inefficient drug administration still limits their therapeutic efficacy and raises concerns of potential side effects. In the present work, we propose the use of uniform mesoporous silica nanoparticles (MSNs) for VEGFR targeted positron emission tomography imaging and delivery of the anti-VEGFR drug (i.e., sunitinib) in human glioblastoma (U87MG) bearing murine models. MSNs were synthesized, characterized and modified with polyethylene glycol, anti-VEGFR ligand VEGF121 and radioisotope (64)Cu, followed by extensive in vitro, in vivo and ex vivo studies. Our results demonstrated that a significantly higher amount of sunitinib could be delivered to the U87MG tumor by targeting VEGFR when compared with the non-targeted counterparts. The as-developed VEGF121-conjugated MSN could become another attractive nanoplatform for the design of future theranostic nanomedicine.

  19. A Drosophila model to identify polyamine-drug conjugates that target the polyamine transporter in an intact epithelium.

    Science.gov (United States)

    Tsen, Chung; Iltis, Mark; Kaur, Navneet; Bayer, Cynthia; Delcros, Jean-Guy; von Kalm, Laurence; Phanstiel, Otto

    2008-01-24

    Polyamine transport is elevated in many tumor types, suggesting that toxic polyamine-drug conjugates could be targeted to cancer cells via the polyamine transporter (PAT). We have previously reported the use of Chinese hamster ovary (CHO) cells and its PAT-deficient mutant cell line, CHO-MG, to screen anthracene-polyamine conjugates for their PAT-selective targeting ability. We report here a novel Drosophila-based model for screening anthracene-polyamine conjugates in a developing and intact epithelium ( Drosophila imaginal discs), wherein cell-cell adhesion properties are maintained. Data from the Drosophila assay are consistent with previous results in CHO cells, indicating that the Drosophila epithelium has a PAT with vertebrate-like characteristics. This assay will be of use to medicinal chemists interested in screening drugs that use PAT for cellular entry, and it offers the possibility of genetic dissection of the polyamine transport process, including identification of a Drosophila PAT.

  20. Conjugate of biotin with silicon(IV) phthalocyanine for tumor-targeting photodynamic therapy.

    Science.gov (United States)

    Li, Ke; Qiu, Ling; Liu, Qingzhu; Lv, Gaochao; Zhao, Xueyu; Wang, Shanshan; Lin, Jianguo

    2017-09-01

    In order to improve the efficacy of photodynamic therapy (PDT), biotin was axially conjugated with silicon(IV) phthalocyanine (SiPc) skeleton to develop a new tumor-targeting photosensitizer SiPc-biotin. The target compound SiPc-biotin showed much higher binding affinity toward BR-positive (biotin receptor overexpressed) HeLa human cervical carcinoma cells than its precursor SiPc-pip. However, when the biotin receptors of HeLa cells were blocked by free biotin, >50% uptake of SiPc-biotin was suppressed, demonstrating that SiPc-biotin could selectively accumulate in BR-positive cancer cells via the BR-mediated internalization. The confocal fluorescence images further confirmed the target binding ability of SiPc-biotin. As a consequence of specificity of SiPc-biotin toward BR-positive HeLa cells, the photodynamic effect was also largely dependent on the BR expression level of HeLa cells. The photodynamic activities of SiPc-biotin against HeLa cells were dramatically reduced when the biotin receptors were blocked by the free biotin (IC50: 0.18μM vs. 0.46μM). It is concluded that SiPc-biotin can selectively damage BR-positive cancer cells under irradiation. Furthermore, the dark toxicity of SiPc-biotin toward human normal liver cell lines LO2 was much lower than that of its precursor SiPc-pip. The targeting photodynamic activity and low dark toxicity suggest that SiPc-biotin is a promising photosensitizer for tumor-targeting photodynamic therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Synthesis and biological evaluation of benzimidazole-oxindole conjugates as microtubule-targeting agents.

    Science.gov (United States)

    Kamal, Ahmed; Nagaseshadri, B; Nayak, V Lakshma; Srinivasulu, Vunnam; Sathish, Manda; Kapure, Jeevak Sopanrao; Suresh Reddy, C

    2015-12-01

    A series of benzimidazole-oxindole conjugates were synthesized and evaluated for their cytotoxic activity. The cytotoxicity assay results suggest that conjugates 5c and 5p exhibit promising cytotoxicity against human breast cancer cell line (MCF-7). The Cell cycle analysis revealed that these conjugates induced cell cycle arrest at G2/M phase in MCF-7 cells. The tubulin polymerization assay results suggested that these conjugates inhibit tubulin polymerization with IC50 values 1.12 and 1.59μM respectively. Immunofluorescence analysis also suggested that these conjugates effectively inhibited the microtubule assembly in MCF-7 cells. Further, molecular docking studies indicated that these conjugates 5c and 5p interact and binds efficiently with the tubulin protein. By and large, the results demonstrated that these benzimidazole-oxindole conjugates possess cytotoxic property by inhibiting the tubulin polymerization.

  2. Folate/NIR 797-conjugated albumin magnetic nanospheres: synthesis, characterisation, and in vitro and in vivo targeting evaluation.

    Directory of Open Access Journals (Sweden)

    Qiusha Tang

    Full Text Available A practical and effective strategy for synthesis of Folate-NIR 797-conjugated Magnetic Albumin Nanospheres (FA-NIR 797-MAN was developed. For this strategy, Magnetic Albumin Nanospheres (MAN, composed of superparamagnetic iron oxide nanoparticles (SPIONs and bovine serum albumin (BSA, were covalently conjugated with folic acid (FA ligands to enhance the targeting capability of the particles to folate receptor (FR over-expressing tumours. Subsequently, a near-infrared (NIR fluorescent dye NIR 797 was conjugated with FA-conjugated MAN for in vivo fluorescence imaging. The FA-NIR 797-MAN exhibited low toxicity to a human nasopharyngeal epidermal carcinoma cell line (KB cells. Additionally, in vitro and in vivo evaluation of the dynamic behaviour and targeting ability of FA-NIR 797-MAN to KB tumours validated the highly selective affinity of FA-NIR 797-MAN for FR-positive tumours. In summary, the FA-NIR 797-MAN prepared here exhibited great potential for tumour imaging, since the near-infrared fluorescence contrast agents target cells via FR-mediated endocytosis. The high fluorescence intensity together with the targeting effect makes FA-NIR 797-MAN a promising candidate for imaging, monitoring, and early diagnosis of cancer at the molecular and cellular levels.

  3. Folate/NIR 797-conjugated albumin magnetic nanospheres: synthesis, characterisation, and in vitro and in vivo targeting evaluation.

    Science.gov (United States)

    Tang, Qiusha; An, Yanli; Liu, Dongfang; Liu, Peidang; Zhang, Dongsheng

    2014-01-01

    A practical and effective strategy for synthesis of Folate-NIR 797-conjugated Magnetic Albumin Nanospheres (FA-NIR 797-MAN) was developed. For this strategy, Magnetic Albumin Nanospheres (MAN), composed of superparamagnetic iron oxide nanoparticles (SPIONs) and bovine serum albumin (BSA), were covalently conjugated with folic acid (FA) ligands to enhance the targeting capability of the particles to folate receptor (FR) over-expressing tumours. Subsequently, a near-infrared (NIR) fluorescent dye NIR 797 was conjugated with FA-conjugated MAN for in vivo fluorescence imaging. The FA-NIR 797-MAN exhibited low toxicity to a human nasopharyngeal epidermal carcinoma cell line (KB cells). Additionally, in vitro and in vivo evaluation of the dynamic behaviour and targeting ability of FA-NIR 797-MAN to KB tumours validated the highly selective affinity of FA-NIR 797-MAN for FR-positive tumours. In summary, the FA-NIR 797-MAN prepared here exhibited great potential for tumour imaging, since the near-infrared fluorescence contrast agents target cells via FR-mediated endocytosis. The high fluorescence intensity together with the targeting effect makes FA-NIR 797-MAN a promising candidate for imaging, monitoring, and early diagnosis of cancer at the molecular and cellular levels.

  4. HAI-178 antibody-conjugated fluorescent magnetic nanoparticles for targeted imaging and simultaneous therapy of gastric cancer

    Science.gov (United States)

    Wang, Can; Bao, Chenchen; Liang, Shujing; Zhang, Lingxia; Fu, Hualin; Wang, Yutian; Wang, Kan; Li, Chao; Deng, Min; Liao, Qiande; Ni, Jian; Cui, Daxiang

    2014-05-01

    The successful development of safe and highly effective nanoprobes for targeted imaging and simultaneous therapy of in vivo gastric cancer is a great challenge. Herein we reported for the first time that anti-α-subunit of ATP synthase antibody, HAI-178 monoclonal antibody-conjugated fluorescent magnetic nanoparticles, was successfully used for targeted imaging and simultaneous therapy of in vivo gastric cancer. A total of 172 specimens of gastric cancer tissues were collected, and the expression of α-subunit of ATP synthase in gastric cancer tissues was investigated by immunohistochemistry method. Fluorescent magnetic nanoparticles were prepared and conjugated with HAI-178 monoclonal antibody, and the resultant HAI-178 antibody-conjugated fluorescent magnetic nanoparticles (HAI-178-FMNPs) were co-incubated with gastric cancer MGC803 cells and gastric mucous GES-1 cells. Gastric cancer-bearing nude mice models were established, were injected with prepared HAI-178-FMNPs via tail vein, and were imaged by magnetic resonance imaging and small animal fluorescent imaging system. The results showed that the α-subunit of ATP synthase exhibited high expression in 94.7% of the gastric cancer tissues. The prepared HAI-178-FMNPs could target actively MGC803 cells, realized fluorescent imaging and magnetic resonance imaging of in vivo gastric cancer, and actively inhibited growth of gastric cancer cells. In conclusion, HAI-178 antibody-conjugated fluorescent magnetic nanoparticles have a great potential in applications such as targeted imaging and simultaneous therapy of in vivo early gastric cancer cells in the near future.

  5. Targeted lipid based drug conjugates: a novel strategy for drug delivery.

    Science.gov (United States)

    Vadlapudi, Aswani Dutt; Vadlapatla, Ramya Krishna; Kwatra, Deep; Earla, Ravinder; Samanta, Swapan K; Pal, Dhananjay; Mitra, Ashim K

    2012-09-15

    A majority of studies involving prodrugs are directed to overcome low bioavailability of the parent drug. The aim of this study is to increase the bioavailability of acyclovir (ACV) by designing a novel prodrug delivery system which is more lipophilic, and at the same time site specific. In this study, a lipid raft has been conjugated to the parent drug molecule to impart lipophilicity. Simultaneously a targeting moiety that can be recognized by a specific transporter/receptor in the cell membrane has also been tethered to the other terminal of lipid raft. Targeted lipid prodrugs i.e., biotin-ricinoleicacid-acyclovir (B-R-ACV) and biotin-12hydroxystearicacid-acyclovir (B-12HS-ACV) were synthesized with ricinoleicacid and 12hydroxystearicacid as the lipophilic rafts and biotin as the targeting moiety. Biotin-ACV (B-ACV), ricinoleicacid-ACV (R-ACV) and 12hydroxystearicacid-ACV (12HS-ACV) were also synthesized to delineate the individual effects of the targeting and the lipid moieties. Cellular accumulation studies were performed in confluent MDCK-MDR1 and Caco-2 cells. The targeted lipid prodrugs B-R-ACV and B-12HS-ACV exhibited much higher cellular accumulation than B-ACV, R-ACV and 12HS-ACV in both cell lines. This result indicates that both the targeting and the lipid moiety act synergistically toward cellular uptake. The biotin conjugated prodrugs caused a decrease in the uptake of [(3)H] biotin suggesting the role of sodium dependent multivitamin transporter (SMVT) in uptake. The affinity of these targeted lipid prodrugs toward SMVT was studied in MDCK-MDR1 cells. Both the targeted lipid prodrugs B-R-ACV (20.25 ± 1.74 μM) and B-12HS-ACV (23.99 ± 3.20 μM) demonstrated higher affinity towards SMVT than B-ACV (30.90 ± 4.19 μM). Further, dose dependent studies revealed a concentration dependent inhibitory effect on [(3)H] biotin uptake in the presence of biotinylated prodrugs. Transepithelial transport studies showed lowering of [(3)H] biotin permeability in

  6. Folic acid-modified methotrexate-conjugated PEGylated poly(ɛ-caprolactone) nanoparticles for targeted delivery

    Science.gov (United States)

    Issarachot, Ousanee; Suksiriworapong, Jiraphong; Takano, Mikihisa; Yumoto, Ryoko; Junyaprasert, Varaporn Buraphacheep

    2014-02-01

    Functionalized nanoparticles of polymer-drug conjugates of PEGylated poly(ɛ-caprolactone) (PEGylated P(CL)) with methotrexate (MTX) and folic acid (FOL) were developed and investigated for their targeting efficiency. FOL- and MTX-conjugated PEGylated P(CL) copolymers were employed to prepare P(MTXCLCL)2-PEG NPs and FOL-P(MTXCLCL)2-PEG NPs. By varying the amount of MTX, the different characteristics of nanoparticles were obtained. The results showed that an increase in particle size and more negative surface charge of P(MTXCLCL)2-PEG NPs were related to an increased amount of MTX along the polymer backbone. After being decorated with FOL, the particle size increased by nearly twofolds while the zeta potential decreased. All nanoparticles were spherical as observed under SEM micrographs. The release profiles showed pH-dependent and sustained release over 20 days. Higher extent of MTX was released in pH 4.5 medium as compared to the drug release in pH 7.4 medium. All nanoparticles showed greater toxicity to MCF-7 cells than A549 cells. In addition, FOL-P(MTXCLCL)2-PEG NPs exhibited the highest toxicity to MCF-7 cells as compared to all P(MTXCLCL)2-PEG NPs and free MTX. Furthermore, FOL-P(MTXCLCL)2-PEG NPs were internalized into MCF-7 cells higher than P(MTXCLCL)2-PEG NPs and FOL-P(MTXCLCL)2-PEG NPs incubated with free FOL. The results indicated that FOL-P(MTXCLCL)2-PEG NPs efficiently entered into MCF-7 cells via folate receptor-mediated endocytosis together with adsorptive endocytosis.

  7. Molecular photoacoustic imaging of breast cancer using an actively targeted conjugated polymer

    Directory of Open Access Journals (Sweden)

    Balasundaram G

    2015-01-01

    Full Text Available Ghayathri Balasundaram,1,* Chris Jun Hui Ho,1,* Kai Li,2 Wouter Driessen,3 US Dinish,1 Chi Lok Wong,1 Vasilis Ntziachristos,3 Bin Liu,2 Malini Olivo1,41Bio-Optical Imaging Group, Singapore Bioimaging Consortium (SBIC, 2Institute of Materials Research and Engineering (IMRE, Agency for Science, Technology and Research (A*STAR, Singapore; 3Institute of Biological and Medical Imaging, Helmholtz Center Munich, Neuherberg, Germany; 4School of Physics, National University of Ireland, Galway, Ireland *These authors contributed equally to this work Abstract: Conjugated polymers (CPs are upcoming optical contrast agents in view of their unique optical properties and versatile synthetic chemistry. Biofunctionalization of these polymer-based nanoparticles enables molecular imaging of biological processes. In this work, we propose the concept of using a biofunctionalized CP for noninvasive photoacoustic (PA molecular imaging of breast cancer. In particular, after verifying the PA activity of a CP nanoparticle (CP dots in phantoms and the targeting efficacy of a folate-functionalized version of the same (folate-CP dots in vitro, we systemically administered the probe into a folate receptor-positive (FR+ve MCF-7 breast cancer xenograft model to demonstrate the possible application of folate-CP dots for imaging FR+ve breast cancers in comparison to CP dots with no folate moieties. We observed a strong PA signal at the tumor site of folate-CP dots-administered mice as early as 1 hour after administration as a result of the active targeting of the folate-CP dots to the FR+ve tumor cells but a weak PA signal at the tumor site of CP-dots-administered mice as a result of the passive accumulation of the probe by enhanced permeability and retention effect. We also observed that folate-CP dots produced ~4-fold enhancement in the PA signal in the tumor, when compared to CP dots. These observations demonstrate the great potential of this active-targeting CP to be used

  8. Folate-conjugated boron nitride nanospheres for targeted delivery of anticancer drug

    Directory of Open Access Journals (Sweden)

    Feng S

    2016-09-01

    Full Text Available Shini Feng,1 Huijie Zhang,1 Ting Yan,1 Dandi Huang,1 Chunyi Zhi,2 Hideki Nakanishi,1 Xiao-Dong Gao1 1Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, People’s Republic of China; 2Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, People’s Republic of China Abstract: With its unique physical and chemical properties and structural similarity to carbon, boron nitride (BN has attracted considerable attention and found many applications. Biomedical applications of BN have recently started to emerge, raising great hopes in drug and gene delivery. Here, we developed a targeted anticancer drug delivery system based on folate-conjugated BN nanospheres (BNNS with receptor-mediated targeting. Folic acid (FA was successfully grafted onto BNNS via esterification reaction. In vitro cytotoxicity assay showed that BNNS-FA complexes were non-toxic to HeLa cells up to a concentration of 100 µg/mL. Then, doxorubicin hydrochloride (DOX, a commonly used anticancer drug, was loaded onto BNNS-FA complexes. BNNS-FA/DOX complexes were stable at pH 7.4 but effectively released DOX at pH 5.0, which exhibited a pH sensitive and sustained release pattern. BNNS-FA/DOX complexes could be recognized and specifically internalized by HeLa cells via FA receptor-mediated endocytosis. BNNS-FA/DOX complexes exhibited greater cytotoxicity to HeLa cells than free DOX and BNNS/DOX complexes due to the increased cellular uptake of DOX mediated by the FA receptor. Therefore, BNNS-FA complexes had strong potential for targeted cancer therapy. Keywords: boron nitride nanospheres, folic acid, doxorubicin, targeted delivery, cancer therapy

  9. Pathogenic bacteria target NEDD8-conjugated cullins to hijack host-cell signaling pathways.

    Directory of Open Access Journals (Sweden)

    Grégory Jubelin

    2010-09-01

    Full Text Available The cycle inhibiting factors (Cif, produced by pathogenic bacteria isolated from vertebrates and invertebrates, belong to a family of molecules called cyclomodulins that interfere with the eukaryotic cell cycle. Cif blocks the cell cycle at both the G₁/S and G₂/M transitions by inducing the stabilization of cyclin-dependent kinase inhibitors p21(waf1 and p27(kip1. Using yeast two-hybrid screens, we identified the ubiquitin-like protein NEDD8 as a target of Cif. Cif co-compartmentalized with NEDD8 in the host cell nucleus and induced accumulation of NEDD8-conjugated cullins. This accumulation occurred early after cell infection and correlated with that of p21 and p27. Co-immunoprecipitation revealed that Cif interacted with cullin-RING ubiquitin ligase complexes (CRLs through binding with the neddylated forms of cullins 1, 2, 3, 4A and 4B subunits of CRL. Using an in vitro ubiquitylation assay, we demonstrate that Cif directly inhibits the neddylated CUL1-associated ubiquitin ligase activity. Consistent with this inhibition and the interaction of Cif with several neddylated cullins, we further observed that Cif modulates the cellular half-lives of various CRL targets, which might contribute to the pathogenic potential of diverse bacteria.

  10. Peptide-Conjugated Quantum Dots Act as the Target Marker for Human Pancreatic Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Shuang-ling Li

    2016-03-01

    Full Text Available Background/Aims: In the present study, we describe a novel and straightforward approach to produce a cyclic- arginine-glycine-aspartic (RGD-peptide-conjugated quantum dot (QD probe as an ideal target tumor biomarker. Due to its specific structure, the probe can be used for targeted imaging of pancreatic carcinoma cells. Methods: Pancreatic carcinoma cells were routinely cultured and marked with QD-RGD probe. The QD-RGD probe on the fluorescence-labeled cancer cell was observed by fluorescence microscopy and laser confocal microscopy. Cancer cell viability was detected by MTT assay after culturing with QD-RGD probe. Results: Fluorescence microscopy and laser confocal microscopy displayed that 10nmol/L QD-RGD probe was able to effectively mark pancreatic carcinoma cells. In comparison with organic dyes and fluorescent proteins, the quantum dot-RGD probe had unique optical and electronic properties. Conclusion: QD-RGD probe has a low cytotoxicity with an excellent optical property and biocompatibility. These findings support further evaluation of QD-RGD probes for the early detection of pancreatic cancer.

  11. Glucose-conjugated chitosan nanoparticles for targeted drug delivery and their specific interaction with tumor cells

    Science.gov (United States)

    Li, Jing; Ma, Fang-Kui; Dang, Qi-Feng; Liang, Xing-Guo; Chen, Xi-Guang

    2014-12-01

    A novel targeted drug delivery system, glucose-conjugated chitosan nanoparticles (GCNPs), was developed for specific recognition and interaction with glucose transporters (Gluts) over-expressed by tumor cells. GC was synthesized by using succinic acid as a linker between glucosamine and chitosan (CS), and successful synthesis was confirmed by NMR and elemental analysis. GCNPs were prepared by ionic crosslinking method, and characterized in terms of morphology, size, and zeta potential. The optimally prepared nanoparticles showed spherical shapes with an average particle size of (187.9 ± 3.8) nm and a zeta potential of (- 15.43 ± 0.31) mV. The GCNPs showed negligible cytotoxicity to mouse embryo fibroblast and 4T1 cells. Doxorubicin (DOX) could be efficiently entrapped into GCNPs, with a loading capacity and encapsulation efficiency of 20.11% and 64.81%, respectively. DOX-loaded nanoparticles exhibited sustained-release behavior in phosphate buffered saline (pH 7.4). In vitro cellular uptake studies showed that the GCNPs had better endocytosis ability than CSNPs, and the antitumor activity of DOX/GCNPs was 4-5 times effectiveness in 4T1 cell killing than that of DOX/CSNPs. All the results demonstrate that nanoparticles decorated with glucose have specific interactions with cancer cells via the recognition between glucose and Gluts. Therefore, Gluts-targeted GCNPs may be promising delivery agents in cancer therapies.

  12. Trihydroxamate siderophore-fluoroquinolone conjugates are selective sideromycin antibiotics that target Staphylococcus aureus.

    Science.gov (United States)

    Wencewicz, Timothy A; Long, Timothy E; Möllmann, Ute; Miller, Marvin J

    2013-03-20

    Siderophores are multidentate iron(III) chelators used by bacteria for iron assimilation. Sideromycins, also called siderophore-antibiotic conjugates, are a unique subset of siderophores that enter bacterial cells via siderophore uptake pathways and deliver the toxic antibiotic in a "Trojan horse" fashion. Sideromycins represent a novel antibiotic delivery technology with untapped potential for developing sophisticated microbe-selective antibacterial agents that limit the emergence of bacterial resistance. The chemical synthesis of a series of mono-, bis-, and trihydroxamate sideromycins are described here along with their biological evaluation in antibacterial susceptibility assays. The linear hydroxamate siderophores used for the sideromycins in this study were derived from the ferrioxamine family and inspired by the naturally occurring salmycin sideromycins. The antibacterial agents used were a β-lactam carbacepholosporin, Lorabid, and a fluoroquinolone, ciprofloxacin, chosen for the different locations of their biological targets, the periplasm (extracellular) and the cytoplasm (intracellular). The linear hydroxamate-based sideromycins were selectively toxic toward Gram-positive bacteria, especially Staphylococcus aureus SG511 (MIC = 1.0 μM for the trihydroxamate-fluoroquinolone sideromycin). Siderophore-sideromycin competition assays demonstrated that only the fluoroquinolone sideromycins required membrane transport to reach their cytoplasmic biological target and that a trihydroxamate siderophore backbone was required for protein-mediated active transport of the sideromycins into S. aureus cells via siderophore uptake pathways. This work represents a comprehensive study of linear hydroxamate sideromycins and teaches how to build effective hydroxamate-based sideromycins as Gram-positive selective antibiotic agents.

  13. Pathogenic bacteria target NEDD8-conjugated cullins to hijack host-cell signaling pathways.

    Science.gov (United States)

    Jubelin, Grégory; Taieb, Frédéric; Duda, David M; Hsu, Yun; Samba-Louaka, Ascel; Nobe, Rika; Penary, Marie; Watrin, Claude; Nougayrède, Jean-Philippe; Schulman, Brenda A; Stebbins, C Erec; Oswald, Eric

    2010-09-30

    The cycle inhibiting factors (Cif), produced by pathogenic bacteria isolated from vertebrates and invertebrates, belong to a family of molecules called cyclomodulins that interfere with the eukaryotic cell cycle. Cif blocks the cell cycle at both the G₁/S and G₂/M transitions by inducing the stabilization of cyclin-dependent kinase inhibitors p21(waf1) and p27(kip1). Using yeast two-hybrid screens, we identified the ubiquitin-like protein NEDD8 as a target of Cif. Cif co-compartmentalized with NEDD8 in the host cell nucleus and induced accumulation of NEDD8-conjugated cullins. This accumulation occurred early after cell infection and correlated with that of p21 and p27. Co-immunoprecipitation revealed that Cif interacted with cullin-RING ubiquitin ligase complexes (CRLs) through binding with the neddylated forms of cullins 1, 2, 3, 4A and 4B subunits of CRL. Using an in vitro ubiquitylation assay, we demonstrate that Cif directly inhibits the neddylated CUL1-associated ubiquitin ligase activity. Consistent with this inhibition and the interaction of Cif with several neddylated cullins, we further observed that Cif modulates the cellular half-lives of various CRL targets, which might contribute to the pathogenic potential of diverse bacteria.

  14. Split-Inteins for Simultaneous, site-specific conjugation of Quantum Dots to multiple protein targets In vivo

    Directory of Open Access Journals (Sweden)

    Christodoulou Neophytos

    2011-09-01

    Full Text Available Abstract Background Proteins labelled with Quantum Dots (QDs can be imaged over long periods of time with ultrahigh spatial and temporal resolution, yielding important information on the spatiotemporal dynamics of proteins within live cells or in vivo. However one of the major problems regarding the use of QDs for biological imaging is the difficulty of targeting QDs onto proteins. We have recently developed a DnaE split intein-based method to conjugate Quantum Dots (QDs to the C-terminus of target proteins in vivo. In this study, we expand this approach to achieve site-specific conjugation of QDs to two or more proteins simultaneously with spectrally distinguishable QDs for multiparameter imaging of cellular functions. Results Using the DnaE split intein we target QDs to the C-terminus of paxillin and show that paxillin-QD conjugates become localized at focal adhesions allowing imaging of the formation and dissolution of these complexes. We go on to utilize a different split intein, namely Ssp DnaB mini-intein, to demonstrate N-terminal protein tagging with QDs. Combination of these two intein systems allowed us to simultaneously target two distinct proteins with spectrally distinguishable QDs, in vivo, without any cross talk between the two intein systems. Conclusions Multiple target labeling is a unique feature of the intein based methodology which sets it apart from existing tagging methodologies in that, given the large number of characterized split inteins, the number of individual targets that can be simultaneously tagged is only limited by the number of QDs that can be spectrally distinguished within the cell. Therefore, the intein-mediated approach for simultaneous, in vivo, site-specific (N- and C-terminus conjugation of Quantum Dots to multiple protein targets opens up new possibilities for bioimaging applications and offers an effective system to target QDs and other nanostructures to intracellular compartments as well as specific

  15. Bispecific antibody complex pre-targeting and targeted delivery of polymer drug conjugates for imaging and therapy in dual human mammary cancer xenografts. Targeted polymer drug conjugates for cancer diagnosis and therapy

    Energy Technology Data Exchange (ETDEWEB)

    Khaw, Ban-An; Gada, Keyur S.; Patil, Vishwesh; Panwar, Rajiv; Mandapati, Savitri [Northeastern University, Department of Pharmaceutical Sciences, Bouve College of Health Sciences, School of Pharmacy, Boston, MA (United States); Hatefi, Arash [Rutgers University, Department of Pharmaceutics, New Brunswick, NJ (United States); Majewski, Stan [West Virginia University, Department of Radiology, Morgantown, WV (United States); Weisenberger, Andrew [Thomas Jefferson National Accelerator Facility, Jefferson Lab, Newport News, VA (United States)

    2014-08-15

    Doxorubicin, a frontline chemotherapeutic agent, limited by its cardiotoxicity and other tissue toxicities, was conjugated to N-terminal DTPA-modified polyglutamic acid (D-Dox-PGA) to produce polymer pro-drug conjugates. D-Dox-PGA or Tc-99 m labeled DTPA-succinyl-polylysine polymers (DSPL) were targeted to HER2-positive human mammary carcinoma (BT-474) in a double xenografted SCID mouse model also hosting HER2-negative human mammary carcinoma (BT-20). After pretargeting with bispecific anti-HER2-affibody-anti-DTPA-Fab complexes (BAAC), anti-DTPA-Fab or only phosphate buffered saline, D-Dox-PGA or Tc-99 m DSPL were administered. Positive therapeutic control mice were injected with Dox alone at maximum tolerated dose (MTD). Only BT-474 lesions were visualized by gamma imaging with Tc-99 m-DSPL; BT-20 lesions were not. Therapeutic efficacy was equivalent in mice pretargeted with BAAC/targeted with D-Dox-PGA to mice treated only with doxorubicin. There was no total body weight (TBW) loss at three times the doxorubicin equivalent MTD with D-Dox-PGA, whereas mice treated with doxorubicin lost 10 % of TBW at 2 weeks and 16 % after the second MTD injection leading to death of all mice. Our cancer imaging and pretargeted therapeutic approaches are highly target specific, delivering very high specific activity reagents that may result in the development of a novel theranostic application. HER/2 neu specific affibody-anti-DTPA-Fab bispecific antibody pretargeting of HER2 positive human mammary xenografts enabled exquisite targeting of polymers loaded with radioisotopes for molecular imaging and doxorubicin for effective therapy without the associating non-tumor normal tissue toxicities. (orig.)

  16. Dual targeting of a thermosensitive nanogel conjugated with transferrin and RGD-containing peptide for effective cell uptake and drug release

    Energy Technology Data Exchange (ETDEWEB)

    Quan Changyun; Chang Cong; Wei Hua; Chen Changsheng; Xu Xiaoding; Cheng Sixue; Zhang Xianzheng; Zhuo Renxi, E-mail: xz-zhang@whu.edu.c [Key Laboratory of Biomedical Polymers of Ministry of Education and Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2009-08-19

    In this paper, both arginine-glycine-aspartic acid (RGD)-containing peptide and transferrin (Tf) were conjugated to the thermosensitive poly(N-isopropylacrylamide-co-propyl acrylic acid) (poly(NIPAAm-co-PAAc)) nanogel to prepare a dual-targeting drug carrier. The obtained nanogel was characterized in terms of fluorescence spectroscopy, UV-vis spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM). In order to track the dual-ligand conjugated nanogel, fluorescein isothiocyanate (FITC) was further conjugated to the nanogel. A cell internalization experiment showed that the dual-ligand conjugated nanogel exhibited obviously enhanced endocytosis by HeLa cells as compared with non-tumorous cells (COS-7 cells). The drug-loaded dual-ligand conjugated nanogel could be transported efficiently into the target tumor cells and the anti-tumor effect was enhanced significantly, suggesting that the dual-ligand conjugated nanogel has great potential as a tumor targeting drug carrier.

  17. Quantum-dot-conjugated graphene as a probe for simultaneous cancer-targeted fluorescent imaging, tracking, and monitoring drug delivery.

    Science.gov (United States)

    Chen, Mei-Ling; He, Ye-Ju; Chen, Xu-Wei; Wang, Jian-Hua

    2013-03-20

    We report a novel quantum-dot-conjugated graphene, i.e., hybrid SiO2-coated quantum dots (HQDs)-conjugated graphene, for targeted cancer fluorescent imaging, tracking, and monitoring drug delivery, as well as cancer therapy. The hybrid SiO2 shells on the surface of QDs not only mitigate its toxicity, but also protect its fluorescence from being quenched by graphene. By functionalizing the surface of HQDs-conjugated graphene (graphene-HQDs) with transferrin (Trf), we developed a targeted imaging system capable of differential uptake and imaging of cancer cells that express the Trf receptor. The widely used fluorescent antineoplastic anthracycline drug, doxorubicin (DOX), is adsorbed on the surface of graphene and results in a large loading capacity of 1.4 mg mg(-1). It is advantageous that the new delivery system exhibits different fluorescence color in between graphene-HQDs and DOX in the aqueous core upon excitation at a same wavelength for the purpose of tracking and monitoring drug delivery. This simple multifunctional nanoparticle system can deliver DOX to the targeted cancer cells and enable us to localize the graphene-HQDs and monitor intracellular DOX release. The specificity and safety of the nanoparticle conjugate for cancer imaging, monitoring, and therapy has been demonstrated in vitro.

  18. Folate-conjugated immunoglobulin targets melanoma tumor cells for NK cell effector functions

    Science.gov (United States)

    Skinner, Cassandra C.; McMichael, Elizabeth L.; Jaime-Ramirez, Alena C.; Abrams, Zachary B.; Lee, Robert J.; Carson, William E.

    2016-01-01

    The folate receptor (FR) is over-expressed on the vascular side of cancerous cells including those of the breast, ovaries, testes, and cervix. We hypothesized that a folate-conjugated immunoglobulin (F-IgG) would bind to the FR that is over-expressed on melanoma tumor cells to target these cells for lysis by natural killer (NK) cells. Folate receptor expression was confirmed in the Mel-39 (human melanoma) cell line by flow cytometry and immunoblot analysis, using KB (human oral epithelial) and F01 (human melanoma) as a positive and negative control, respectively. FR-positive and negative cell lines were treated with F-IgG or control immunoglobulin G (C-IgG) in the presence or absence of cytokines in order to determine NK cell ability to lyse FR-positive cell lines. NK cell activation was significantly upregulated and lysis of Mel 39 tumor cells enhanced following treatment with F-IgG, as compared to C-IgG at all effector:target (E:T) ratios (p<0.01). This trend was further enhanced by NK cell stimulation with the activating cytokine interleukin-12 (IL-12). NK cell production of cytokines such as interferon-gamma (IFN-γ), macrophage inflammatory protein 1 alpha (MIP-1α), and regulated on activation normal T-cell expressed and secreted (RANTES) were also significantly increased in response to co-stimulation with IL-12 stimulation and F-IgG-coated Mel 39 target cells, as compared to controls (p<0.01). In contrast, F-IgG did not bind to the FR-negative cell line F01 and had no significant effect on NK cell lysis or cytokine production. This research indicates the potential use of F-IgG for its ability to induce an immune response from NK cells against FR-positive melanoma tumor cells which can be further enhanced by the addition of cytokines. PMID:27035691

  19. Folate-conjugated polymer micelles for active targeting to cancer cells: preparation, in vitro evaluation of targeting ability and cytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    You Jian [College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Li Xin [College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Cui Fude [College of Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang 110016 (China); Du Yongzhong [College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Yuan Hong [College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Hu Fuqiang [College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China)

    2008-01-30

    To obtain an active-targeting carrier to cancer cells, folate-conjugated stearic acid grafted chitosan oligosaccharide (Fa-CSOSA) was synthesized by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-mediated coupling reaction. The substitution degree is 22.1%. The critical micelle concentrations (CMCs) of Fa-CSOSA were 0.017 and 0.0074 mg ml{sup -1} in distilled water and PBS (pH 7.4), respectively. The average volume size range of Fa-CSOSA micelles was 60-120 nm. The targeting ability of Fa-CSOSA micelles was investigated against two kinds of cell lines (A549 and Hela), which have different amounts of folate receptors in their surface. The results indicated that Fa-CSOSA micelles presented a targeting ability to the cells (Hela) with a higher expression of folate receptor during a short-time incubation (<6 h). As incubation proceeded, the special spatial structure of the micelles gradually plays a main role in cellular internalization of the micelles. Good internalization of the micelles into both Hela and A549 cells was shown. Then, paclitaxel (PTX) was encapsulated into the micelles, and the content of PTX in the micelles was about 4.8% (w/w). The average volume size range of PTX-loaded micelles was 150-340 nm. Furthermore, the anti-tumor efficacy in vitro was investigated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) method. The IC{sub 50} of Taxol (a clinical formulation containing PTX) on A549 and Hela cells was 7.0 and 11.0 {mu}g ml{sup -1}, respectively. The cytotoxicity of PTX-loaded micelles was improved sharply (IC{sub 50} on A549: 0.32 {mu}g ml{sup -1}; IC{sub 50} on Hela: 0.268 {mu}g ml{sup -1}). This is attributed to the increased intracellular delivery of the drug. The Fa-CSOSA micelles that are presented may be a promising active-targeting carrier candidate via folate mediation.

  20. CD33 monoclonal antibody conjugated Au cluster nano-bioprobe for targeted flow-cytometric detection of acute myeloid leukaemia

    Energy Technology Data Exchange (ETDEWEB)

    Retnakumari, Archana; Jayasimhan, Jasusri; Chandran, Parwathy; Menon, Deepthy; Nair, Shantikumar; Mony, Ullas; Koyakutty, Manzoor, E-mail: manzoork@aims.amrita.edu, E-mail: ullasmony@aims.amrita.edu [Amrita Centre for Nanoscience and Molecular Medicine, Amrita Institute of Medical Science, Cochin 682 041 (India)

    2011-07-15

    Protein stabilized gold nanoclusters (Au-NCs) are biocompatible, near-infrared (NIR) emitting nanosystems having a wide range of biomedical applications. Here, we report the development of a Au-NC based targeted fluorescent nano-bioprobe for the flow-cytometric detection of acute myeloid leukaemia (AML) cells. Au-NCs with {approx} 25-28 atoms showing bright red-NIR fluorescence (600-750 nm) and average size of {approx} 0.8 nm were prepared by bovine serum albumin assisted reduction-cum-stabilization in aqueous phase. The protein protected clusters were conjugated with monoclonal antibody against CD33 myeloid antigen, which is overexpressed in {approx} 99.2% of the primitive population of AML cells, as confirmed by immunophenotyping using flow cytometry. Au-NC-CD33 conjugates having average size of {approx} 12 nm retained bright fluorescence over an extended duration of {approx} a year, as the albumin protein protects Au-NCs against degradation. Nanotoxicity studies revealed excellent biocompatibility of Au-NC conjugates, as they showed no adverse effect on the cell viability and inflammatory response. Target specificity of the conjugates for detecting CD33 expressing AML cells (KG1a) in flow cytometry showed specific staining of {approx} 95.4% of leukaemia cells within 1-2 h compared to a non-specific uptake of {approx} 8.2% in human peripheral blood cells (PBMCs) which are CD33{sup low}. The confocal imaging also demonstrated the targeted uptake of CD33 conjugated Au-NCs by leukaemia cells, thus confirming the flow cytometry results. This study demonstrates that novel nano-bioprobes can be developed using protein protected fluorescent nanoclusters of Au for the molecular receptor targeted flow cytometry based detection and imaging of cancer cells.

  1. Development and Evaluation of a Fluorescent Antibody-Drug Conjugate for Molecular Imaging and Targeted Therapy of Pancreatic Cancer.

    Directory of Open Access Journals (Sweden)

    Steve Knutson

    Full Text Available Antibodies are widely available and cost-effective research tools in life science, and antibody conjugates are now extensively used for targeted therapy, immunohistochemical staining, or in vivo diagnostic imaging of cancer. Significant advances in site-specific antibody labeling technologies have enabled the production of highly characterized and homogenous conjugates for biomedical purposes, and some recent studies have utilized site-specific labeling to synthesize bifunctional antibody conjugates with both imaging and drug delivery properties. While these advances are important for the clinical safety and efficacy of such biologics, these techniques can also be difficult, expensive, and time-consuming. Furthermore, antibody-drug conjugates (ADCs used for tumor treatment generally remain distinct from conjugates used for diagnosis. Thus, there exists a need to develop simple dual-labeling methods for efficient therapeutic and diagnostic evaluation of antibody conjugates in pre-clinical model systems. Here, we present a rapid and simple method utilizing commercially available reagents for synthesizing a dual-labeled fluorescent ADC. Further, we demonstrate the fluorescent ADC's utility for simultaneous targeted therapy and molecular imaging of cancer both in vitro and in vivo. Employing non-site-specific, amine-reactive chemistry, our novel biopharmaceutical theranostic is a monoclonal antibody specific for a carcinoembryonic antigen (CEA biomarker conjugated to both paclitaxel and a near-infrared (NIR, polyethylene glycol modified (PEGylated fluorophore (DyLight™ 680-4xPEG. Using in vitro systems, we demonstrate that this fluorescent ADC selectively binds a CEA-positive pancreatic cancer cell line (BxPC-3 in immunofluorescent staining and flow cytometry, exhibits efficient internalization kinetics, and is cytotoxic. Model studies using a xenograft of BxPC-3 cells in athymic mice also show the fluorescent ADC's efficacy in detecting tumors in

  2. Synthesis, biological activity, and DNA-damage profile of platinum-threading intercalator conjugates designed to target adenine.

    Science.gov (United States)

    Guddneppanavar, Rajsekhar; Saluta, Gilda; Kucera, Gregory L; Bierbach, Ulrich

    2006-06-01

    PT-ACRAMTU {[PtCl(en)(ACRAMTU)](NO3)2, 2; ACRAMTU = 1-[2-(acridin-9-ylamino)ethyl]-1,3-dimethylthiourea, 1, en = ethane-1,2-diamine} is the prototype of a series of DNA-targeted adenine-affinic dual intercalating/platinating agents. Several novel 4,9-disubstituted acridines and the corresponding platinum-acridine conjugates were synthesized. The newly introduced 4-carboxamide side chains contain H-bond donor/acceptor functions designed to promote groove- and sequence-specific platinum binding. In HL-60 (leukemia) and H460 (lung) cancer cells, IC50 values in the micromolar to millimolar range were observed. Several of the intercalators show enhanced cytotoxicity compared to prototype 1, but conjugate 2 appears to be the most potent hybrid agent. Enzymatic digestion assays in conjunction with liquid chromatography-electrospray mass spectrometry analysis indicate that the new conjugates produce PT-ACRAMTU-type DNA damage. Platinum-modified 2'-deoxyguanosine, dG, and several dinucleotide fragments, d(NpN)*, were detected. One of the conjugates showed significantly higher levels of binding to A-containing sites than conjugate 2 (35 +/- 3% vs 24 +/- 3%). Possible structure-activity relationships are discussed.

  3. Anti-neuropilin 1 antibody Fab' fragment conjugated liposomal docetaxel for active targeting of tumours.

    Science.gov (United States)

    Manjappa, Arehalli S; Goel, Peeyush N; Gude, Rajiv P; Ramachandra Murthy, Rayasa S

    2014-09-01

    Neuropilin-1, a transmembrane receptor entailed in wide range of human tumour cell lines and diverse neoplasms, mediates the effects of VEGF and Semaphorins during the processes of cellular proliferation, survival and migration. In view of this, we had developed and evaluated in vitro and in vivo efficacy of anti-neuropilin-1 immunoliposomes against neuropilin-1 receptor expressing tumours. The PEGylated liposomes loaded with docetaxel were prepared using thin film hydration method. Functionalised PEGylated liposomes were prepared using post-insertion technique. Anti-neuropilin-1 immunoliposomes were prepared by covalently conjugating Fab' fragments of neuropilin-1 antibody to functionalised PEGylated liposomes via thioether linkage. In vivo evaluation of Taxotere and liposomal formulations was performed using intradermal tumour model to demonstrate anti-angiogenic and tumour regression ability. The modified Fab' fragments and immunoliposomes were found to be immunoreactive against A549 cells. Further, docetaxel loaded PEGylated liposomes and PEGylated immunoliposomes demonstrated higher in vitro cytotoxicity than Taxotere formulation at the same drug concentration and exposure time. The live imaging showed distinctive cellular uptake of functional immunoliposomes. Further, significant decrease in micro-blood vessel density and tumour volumes was observed using bio-engineered liposomes. The results clearly highlight the need to seek neuropilin-1 as one of the prime targets in developing an anti-angiogenic therapy.

  4. Self-assembled nanoparticles comprising aptide-SN38 conjugates for use in targeted cancer therapy

    Science.gov (United States)

    Kim, Hyungjun; Lee, Yonghyun; Kang, Sukmo; Choi, Minsuk; Lee, Soyoung; Kim, Sunghyun; Gujrati, Vipul; Kim, Jinjoo; Jon, Sangyong

    2016-12-01

    Self-assembled nanoparticles (NPs) have been intensively utilized as cancer drug delivery carriers because hydrophobic anticancer drugs may be efficiently loaded into the particle cores. In this study, we synthesized and evaluated the therapeutic index of self-assembled NPs chemically conjugated to a fibronectin extra domain B-specific peptide (APTEDB) and an anticancer agent SN38. The APTEDB-SN38 formed self-assembled structures with a diameter of 58 ± 3 nm in an aqueous solution and displayed excellent drug loading, solubility, and stability properties. A pharmacokinetic study revealed that the blood circulation half-life of SN38 following injection of the APTEDB-SN38 NPs was markedly higher than that of the small molecule CPT-11. The APTEDB-SN38 NPs delivered SN38 to tumor sites by both passive and active targeting. Finally, the APTEDB-SN38 NPs exhibited potent antitumor activities and low toxicities against EDB-expressing tumors (LLC, U87MG) in mice. This system merits further preclinical and clinical investigations for SN38 delivery.

  5. A tumor-targeted activatable phthalocyanine-tetrapeptide-doxorubicin conjugate for synergistic chemo-photodynamic therapy.

    Science.gov (United States)

    Ke, Mei-Rong; Chen, Shao-Fang; Peng, Xiao-Hui; Zheng, Qiao-Feng; Zheng, Bi-Yuan; Yeh, Chih-Kuang; Huang, Jian-Dong

    2017-02-15

    Chemo-photodynamic therapy is a promising strategy for cancer treatments. However, it remains a challenge to develop a chemo-photodynamic therapeutic agent with little side effect, high tumor-targeting, and efficient synergistic effect simultaneously. Herein, we report a zinc(II) phthalocyanine (ZnPc)-doxorubicin (DOX) prodrug linked with a fibroblast activation protein (FAP)-responsive short peptide with the sequence of Thr-Ser-Gly-Pro for chemo-photodynamic therapy. In the conjugate, both photosensitizing activity of ZnPc and cytotoxicity of DOX are inhibited obviously. However, FAP-triggered separation of the photosensitizer and DOX can enhance fluorescence emission, singlet oxygen generation, dark- and photo-cytotoxicity significantly, and lead to a synergistic anticancer efficacy against HepG2 cells. The prodrug can also be specifically and efficiently activated in tumor tissue of mice. Thus, this prodrug shows great potential for clinical application in chemo-photodynamic therapy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  6. Anticancer medicines (Doxorubicin and methotrexate) conjugated with magnetic nanoparticles for targeting drug delivery through iron.

    Science.gov (United States)

    Samra, Zahoor Qadir; Ahmad, Snober; Javeid, Mehwish; Dar, Nadia; Aslam, Muhammad Shahbaz; Gull, Iram; Ahmad, Mubashar Mustaneer

    2013-01-01

    The uptake of iron is increased by cancer cells. Iron magnetic nanoparticles (MNP) can be used as a nanovehicle for immobilization of anticancer medicines and to integrate them at a target site. The anticancer medicines doxorubicin (DOX) and methotrexate (MTX) were immobilized separately and in combination onto MNP by a glutaraldehyde activation method and confirmed by magnetic nanoparticles linked immunosorbent assay (MagLISA) and Fourier-transform infrared (FTIR) spectroscopy. The phenol peaks of DOX and MTX at 2896.6 cm⁻¹ to 2912.5 cm⁻¹ in FTIR spectra of immobilized medicines indicated the conjugation. Affinity-purified anti-DOX and anti-MTX antibodies were used to evaluate the coupling of DOX and MTX onto MNP, and the binding was found 34.6% to 37.2% and 51.8% to 54.3% separately, respectively. The immobilization of DOX and MTX in combination onto MNP was 18% and 27%, respectively. HeLa and B cells were cultured with DOX-MNP, MTX-MNP, and DOX-MNP-MTX separately, and MagLISA indicated that the binding of DOX-MNP/MTX-MNP was 41.5% to 45% with HeLa cells and 20% to 26% with B cells. No significant difference was observed in binding of DOX-MNP-MTX with HeLa and B cells. Results also indicated that the release of medicines at pH 5.0 is more (39% to 44%) than at pH 7.4 (3.7% to 10.2%). Sixteen to 22% more killing effect was observed on HeLa cells than on B cells. In immunohistochemical staining, more deposition of brown color on HeLa cells than on B cells may be due to more expression of iron-binding sites on cancer cells. The dual property of MNP can be used for binding of medicines and for targeting drug delivery.

  7. Targeted pancreatic cancer therapy with the small molecule drug conjugate SW IV-134.

    Science.gov (United States)

    Hashim, Yassar M; Spitzer, Dirk; Vangveravong, Suwanna; Hornick, Mary C; Garg, Gunjal; Hornick, John R; Goedegebuure, Peter; Mach, Robert H; Hawkins, William G

    2014-07-01

    Pancreatic adenocarcinoma is highly resistant to conventional therapeutics and has been shown to evade apoptosis by deregulation of the X-linked and cellular inhibitors of apoptosis proteins (XIAP and cIAP). Second mitochondria-derived activator of caspases (Smac) induces and amplifies cell death by reversing the anti-apoptotic activity of IAPs. Thus, Smac-derived peptide analogues (peptidomimetics) have been developed and shown to represent promising cancer therapeutics. Sigma-2 receptors are overexpressed in many proliferating tumor cells including pancreatic cancer. Selected ligands to this receptor are rapidly internalized by cancer cells. These characteristics have made the sigma-2 receptor an attractive target for drug delivery because selective delivery to cancer cells has the potential to increase therapeutic efficacy while minimizing toxicity to normal tissues. Here, we describe the initial characterization of SW IV-134, a chemically linked drug conjugate between the sigma-2 ligand SW43 and the Smac mimetic SW IV-52 as a novel treatment option for pancreatic adenocarcinoma. The tumor killing characteristics of our dual-domain therapeutic SW IV-134 was far greater than either component in isolation or in an equimolar mix and suggests enhanced cellular delivery when chemically linked to the sigma-2 ligand. One of the key findings was that SW IV-134 retained target selectivity of the Smac cargo with the involvement of the NF-κB/TNFα signaling pathway. Importantly, SW IV-134 slowed tumor growth and improved survival in murine models of pancreatic cancer. Our data support further study of this novel therapeutic and this drug delivery strategy because it may eventually benefit patients with pancreatic cancer.

  8. Styrene-maleic acid-copolymer conjugated zinc protoporphyrin as a candidate drug for tumor-targeted therapy and imaging.

    Science.gov (United States)

    Fang, Jun; Tsukigawa, Kenji; Liao, Long; Yin, Hongzhuan; Eguchi, Kanami; Maeda, Hiroshi

    2016-01-01

    Previous studies indicated the potential of zinc protoporphyrin (ZnPP) as an antitumor agent targeting to the tumor survival factor heme oxygenase-1, and/or for photodynamic therapy (PDT). In this study, to achieve tumor-targeted delivery, styrene-maleic acid-copolymer conjugated ZnPP (SMA-ZnPP) was synthesized via amide bond, which showed good water solubility, having ZnPP loading of 15%. More importantly, it forms micelles in aqueous solution with a mean particle size of 111.6 nm, whereas it has an apparent Mw of 65 kDa. This micelle formation was not detracted by serum albumin, suggesting it is stable in circulation. Further SMA-ZnPP conjugate will behave as an albumin complex in blood with much larger size (235 kDa) by virtue of the albumin binding property of SMA. Consequently, SMA-ZnPP conjugate exhibited prolonged circulating retention and preferential tumor accumulation by taking advantage of enhanced permeability and retention (EPR) effect. Clear tumor imaging was thus achieved by detecting the fluorescence of ZnPP. In addition, the cytotoxicity and PDT effect of SMA-ZnPP conjugate was confirmed in human cervical cancer HeLa cells. Light irradiation remarkably increased the cytotoxicity (IC50, from 33 to 5 μM). These findings may provide new options and knowledge for developing ZnPP based anticancer theranostic drugs.

  9. Doxorubicin-conjugated bacteriophages carrying anti-MHC class I chain-related A for targeted cancer therapy in vitro

    Science.gov (United States)

    Phumyen, Achara; Jantasorn, Siriporn; Jumnainsong, Amonrat; Leelayuwat, Chanvit

    2014-01-01

    Background Cancer therapy by systemic administration of anticancer drugs, besides the effectiveness shown on cancer cells, demonstrated the side effects and cytotoxicity on normal cells. The targeted drug-carrying nanoparticles may decrease the required drug concentration at the site and the distribution of drugs to normal tissues. Overexpression of major histocompatibility complex class I chain–related A (MICA) in cancer is useful as a targeted molecule for the delivery of doxorubicin to MICA-expressing cell lines. Methods The application of 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide (EDC) chemistry was employed to conjugate the major coat protein of bacteriophages carrying anti-MICA and doxorubicin in a mildly acid condition. Doxorubicin (Dox) on phages was determined by double fluorescence of phage particles stained by M13-fluorescein isothiocyanate (FITC) and drug autofluorescence by flow cytometry. The ability of anti-MICA on phages to bind MICA after doxorubicin conjugation was evaluated by indirect enzyme-linked immunosorbent assay. One cervical cancer and four cholangiocarcinoma cell lines expressing MICA were used as models to evaluate targeting activity by cell cytotoxicity test. Results Flow cytometry and indirect enzyme-linked immunosorbent assay demonstrated that most of the phages (82%) could be conjugated with doxorubicin, and the Dox-carrying phage-displaying anti-MICA (Dox-phage) remained the binding activity against MICA. Dox-phage was more efficient than free drugs in killing all the cell lines tested. The half maximal inhibitory concentration (IC50) values of Dox-phage were lower than those of free drugs at approximately 1.6–6 times depending on MICA expressions and the cell lines tested. Conclusion Evidently, the application of 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide chemistry is effective to conjugate doxorubicin and major coat protein of bacteriophages without destroying binding activity of MICA antibodies. Dox

  10. M-cell targeted delivery of recombinant hepatitis B surface antigen using cholera toxin B subunit conjugated bilosomes.

    Science.gov (United States)

    Shukla, Anshuman; Katare, O P; Singh, Bhupinder; Vyas, Suresh P

    2010-01-29

    The present study aims to improve upon our earlier findings with bilosomes as potential delivery vehicle through oral route for recombinant hepatitis B surface antigen (HBsAg). The work entails the conjugation of bilosomal system with cholera toxin B subunit (CTB) to increase transmucosal uptake via M-cell specific delivery approach. The study encompasses the development and characterization of HBsAg-loaded CTB-conjugated system for percent antigen entrapment, size, shape, and stability in SGF (USP, pH 1.2), SIF (USP, pH 7.5) and in bile salt solutions. Biological activity of CTB, subsequent to conjugation, was verified by hemagglutination test. Anti-HBsAg IgG response in serum and anti-HBsAg sIgA in various body secretions were estimated using ELISA, following oral immunization with 10 microg dose-loaded CTB-conjugated bilosomes (CTB2) and 20 microg dose-loaded CTB-conjugated bilosomes (CTB1) in BALB/c mice. The results showed that CTB1 produced anti-HBsAg IgG antibody titre response comparable to that of the intramuscular (i.m.) injection of 10 microg of alum-adsorbed HBsAg. Moreover, all the bilosomal preparations elicited measurable sIgA vis-à-vis negligible response with i.m. administered HBsAg. Thus, HBsAg-loaded CTB-conjugated bilosomes provide a promising potential for targeted oral immunization against hepatitis B. 2009 Elsevier B.V. All rights reserved.

  11. Flow Cytometric Measurement of [Ca2+]i and pHi in Conjugated Natural Killer Cells and K562 Target Cells during the Cytotoxic Process1,2

    NARCIS (Netherlands)

    van Graft, Marja; van Graft, M.; Kraan, Yvonne M.; Segers-Nolten, Gezina M.J.; Radosevic, K.; Radosevic, Katarina; de Grooth, B.G.; Greve, Jan

    1993-01-01

    We describe a flow cytometric assay that enables one to follow conjugate formation between cytotoxic cells and their target cells during the cytotoxic process. In addition, the internal calcium concentration ([Ca2+]i) and internal pH (pHi) of the conjugated cells can be monitored and directly

  12. Herceptin conjugated PLGA-PHis-PEG pH sensitive nanoparticles for targeted and controlled drug delivery.

    Science.gov (United States)

    Zhou, Zilan; Badkas, Apurva; Stevenson, Max; Lee, Joo-Youp; Leung, Yuet-Kin

    2015-06-20

    A dual functional nano-scaled drug carrier, comprising of a targeting ligand and pH sensitivity, has been made in order to increase the specificity and efficacy of the drug delivery system. The nanoparticles are made of a tri-block copolymer, poly(d,l lactide-co-glycolide) (PLGA)-b-poly(l-histidine) (PHis)-b-polyethylene glycol (PEG), via nano-precipitation. To provide the nanoparticle feature of endolysosomal escape and pH sensitivity, poly(l-histidine) was chosen as a proton sponge polymer. Herceptin, which specifically binds to HER2 antigen, was conjugated to the nanoparticles through click chemistry. The nanoparticles were characterized via dynamic light scattering (DLS) and transmission electron microscopy (TEM). Both methods showed the sizes of about 100nm with a uniform size distribution. The pH sensitivity was assessed by drug releases and size changes at different pH conditions. As pH decreased from 7.4 to 5.2, the drug release rate accelerated and the size significantly increased. During in vitro tests against human breast cancer cell lines, MCF-7 and SK-BR-3 showed significantly increased uptake for Herceptin-conjugated nanoparticles, as compared to non-targeted nanoparticles. Herceptin-conjugated pH-sensitive nanoparticles showed the highest therapeutic effect, and thus validated the efficacy of a combined approach of pH sensitivity and active targeting.

  13. Self-assembled ternary complexes stabilized with hyaluronic acid-green tea catechin conjugates for targeted gene delivery.

    Science.gov (United States)

    Liang, Kun; Bae, Ki Hyun; Lee, Fan; Xu, Keming; Chung, Joo Eun; Gao, Shu Jun; Kurisawa, Motoichi

    2016-03-28

    Nanosized polyelectrolyte complexes are attractive delivery vehicles for the transfer of therapeutic genes to diseased cells. Here we report the application of self-assembled ternary complexes constructed with plasmid DNA, branched polyethylenimine and hyaluronic acid-green tea catechin conjugates for targeted gene delivery. These conjugates not only stabilize plasmid DNA/polyethylenimine complexes via the strong DNA-binding affinity of green tea catechin, but also facilitate their transport into CD44-overexpressing cells via receptor-mediated endocytosis. The hydrodynamic size, surface charge and physical stability of the complexes are characterized. We demonstrate that the stabilized ternary complexes display enhanced resistance to nuclease attack and polyanion-induced dissociation. Moreover, the ternary complexes can efficiently transfect the difficult-to-transfect HCT-116 colon cancer cell line even in serum-supplemented media due to their enhanced stability and CD44-targeting ability. Confocal microscopic analysis demonstrates that the stabilized ternary complexes are able to promote the nuclear transport of plasmid DNA more effectively than binary complexes and hyaluronic acid-coated ternary complexes. The present study suggests that the ternary complexes stabilized with hyaluronic acid-green tea catechin conjugates can be widely utilized for CD44-targeted delivery of nucleic acid-based therapeutics.

  14. (68) Ga-labeled Ciprofloxacin Conjugates as Radiotracers for Targeting Bacterial Infection.

    Science.gov (United States)

    Satpati, Drishty; Arjun, Chanda; Krishnamohan, Repaka; Samuel, Grace; Banerjee, Sharmila

    2016-05-01

    With an aim of developing a bacteria-specific molecular imaging agent, ciprofloxacin has been modified with a propylamine spacer and linked to two common bifunctional chelators, p-SCN-Bz-DOTA and p-SCN-Bz-NOTA. The two ciprofloxacin conjugates, CP-PA-SCN-Bz-DOTA (1) and CP-PA-SCN-Bz-NOTA (2), were radiolabeled with (68)Ga in >90% radiochemical yield and were moderately stable in vitro for 4 h. The efficacy of (68)Ga-1 and (68)Ga-2 has been investigated in vitro in Staphylococcus aureus cells where bacterial binding of the radiotracers (0.9-1.0% for (68)Ga-1 and 1.6-2.3% for (68)Ga-2) could not be blocked in the presence of excess amount of unlabeled ciprofloxacin. However, uptake of radiotracers in live bacterial cells was significantly higher (p 68)Ga-1 and (68)Ga-2 was tested in vivo in rats where the infected muscle-to-inflamed muscle ((68)Ga-1: 2 ± 0.2, (68)Ga-2: 3 ± 0.5) and infected muscle-to-normal muscle ratios ((68)Ga-1: 3 ± 0.4, (68)Ga-2: 6.6 ± 0.8) were found to improve at 120 min p.i. Fast blood clearance and renal excretion was observed for both the radiotracers. The two (68)Ga-labeled infection targeting radiotracers could discriminate between bacterial infection and inflammation in vivo and are worthy of further detailed investigation as infection imaging agents at the clinical level.

  15. Overcoming photodynamic resistance and tumor targeting dual-therapy mediated by indocyanine green conjugated gold nanospheres.

    Science.gov (United States)

    Li, Wei; Guo, Xiaomeng; Kong, Fenfen; Zhang, Hanbo; Luo, Lihua; Li, Qingpo; Zhu, Chunqi; Yang, Jie; Du, Yongzhong; You, Jian

    2017-07-28

    Photodynamic therapy (PDT) and photothermal therapy (PTT) have captured much attention due to the great potential to cure malignant tumor. Nevertheless, photodynamic resistance of cancer cells has limited the further efficacy of PDT. Unfortunately, the resistance mechanism and efforts to overcome the resistance still have been rarely reported so far. Here, we report a nanosystem with specific tumor targeting for combined PDT and PTT mediated by near-infrared (NIR) light, which was established by covalently conjugating indocyanine green (ICG) and TNYL peptide onto the surface of hollow gold nanospheres (HAuNS). Our nanosystem (TNYL-ICG-HAuNS) was proved to possess significantly increased light stability, reactive oxygen species (ROS) production and photothermal effect under NIR light irradiation, thus presenting a remarkably enhanced antitumor efficacy. The up-regulation of nuclear factor erythroid 2-related factor 2 (NFE2L2, Nrf2) in cancer cells during PDT induced a significant increase of ABCG2, NQO-1 and HIF-1α expression, causing PDT resistance of the cells. Interestingly, ABCG2 expression could almost keep a normal level in the whole PDT process mediated by TNYL-ICG-HAuNS. After repeated irradiations, TNYL-ICG-HAuNS could still produce almost constant ROS in cells while the Nrf2 expression reduced significantly. Furthermore, PDT resistance induced an obvious decrease of the internalization of free ICG, but didn't influence the cell uptake of TNYL-ICG-HAuNS. Our data explained that TNYL-ICG-HAuNS could overcome the photodynamic resistance of cancer cells, acting as a promising modality for simultaneous photothermal and photodynamic cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Steroid Probes Conjugated with Protein-Protected Gold Nanocluster: Specific and Rapid Fluorescence Imaging of Steroid Receptors in Target Cells.

    Science.gov (United States)

    Tsai, Chi-Yan; Li, Chun-Wei; Li, Jie-Ren; Jang, Bo-Han; Chen, Shu-Hui

    2016-07-01

    Steroid ligands can easily diffuse through the cell membrane and this property makes it feasible to be used for in-situ staining of the nuclear receptors. However, nonspecific binding of the internalized ligand probe with the cellular components has caused serious interferences for the detection of receptor-expressing cells. We report a novel gold nanocluster (AuNC)-conjugated estrogen probe that can eliminate nonspecific internalization and accelerate nuclear localization to achieve selective and rapid detection of estrogen receptors (ERs) in live cells. The AuNC, protected by bovine serum albumin (BSA), BSA-AuNCs, was prepared by the synthesis and confirmed to be 1.9 nm in core size and 18 nm in diameter. Ethinyl estradiol was used as the precursor of 17β-estradial (E2) to conjugate with BSA-protected AuNCs via polyethylene glycol linker (E2-PEG/BSA-AuNCs) or to conjugate with Cy3 dyes (E2-Cy3). The conjugated probe was determined to contain five E2 molecules per BSA-AuNC by mass spectrometry and exhibit an emission maximum of around 640 nm, which was not altered by E2 conjugation indicating that the structural integrity of BSA-AuNCs was conserved. E2-PEG/BSA-AuNCs probes were quickly internalized by MCF-7 (ER+) cells and localized to the nuclei in 2 h. Such internalization was sensitive to competition by free E2 and was rarely detected in the controls using either non-conjugated BSA-AuNCs in MCF-7 (ER+) cells or E2-PEG/BSA-AuNCs in MDA-MB-231 (ER-) cells. In contrast to the high specificity of E2-PEG/BSA-AuNCs probe, the uptake of E2-Cy3 probe could not differentiate between MCF-7(ER+) and MDA-MB-231(ER-) cells during the early phases of the treatment. Moreover, nuclear targeting by E2-Cy3 was three times slower than that by the E2-PEG/BSA-AuNC probe. Such accelerated nuclei targeting was consistent with the enhanced cell viability by conjugating E2 with BSA-AuNC. In conclusion, the E2-PEG/BSA-AuNC probes are promising candidates that can be used for the

  17. Folate-targeted paclitaxel-conjugated polymeric micelles inhibits pulmonary metastatic hepatoma in experimental murine H22 metastasis models

    Directory of Open Access Journals (Sweden)

    Zhang Y

    2014-04-01

    Full Text Available Yan Zhang,1 Hui Zhang,2 Wenbin Wu,2 Fuhong Zhang,3,4 Shi Liu,3 Rui Wang,3 Yingchun Sun,1 Ti Tong,1 Xiabin Jing3 1Department of Thoracic Surgery, The Second Hospital of Jilin University, Changchun, Jilin, People's Republic of China; 2Department of Thoracic Surgery, Xuzhou Central Hospital, Xuzhou, Jiangsu, People's Republic of China; 3State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, People's Republic of China; 4Department of Otolaryngology, The First Hospital of Lanzhou University, Lanzhou, Gansu, People's Republic of China Abstract: Hepatocellular carcinoma shows low response to most conventional chemotherapies; additionally, extrahepatic metastasis from hepatoma is considered refractory to conventional systemic chemotherapy. Target therapy is a promising strategy for advanced hepatoma; however, targeted accumulation and controlled release of therapeutic agents into the metastatic site is still a great challenge. Folic acid (FA and paclitaxel (PTX containing composite micelles (FA-M[PTX] were prepared by coassembling the FA polymer conjugate and PTX polymer conjugate. The main purpose of this study is to investigate the inhibitory efficacy of FA-M(PTX on the pulmonary metastasis of intravenously injected murine hepatoma 22 (H22 on BALB/c mice models. The lung metastatic burden of H22 were measured and tissues were analyzed by immunohistochemistry and histology (hematoxylin and eosin stain, followed by survival analysis. The results indicated that FA-M(PTX prevented pulmonary metastasis of H22, and the efficacy was stronger than pure PTX and simple PTX-conjugated micelles. In particular, the formation of lung metastasis colonies in mice was evidently inhibited, which was paralleled with the downregulated expression of matrix metalloproteinase-2 and matrix metalloproteinase-9. Furthermore, the mice bearing pulmonary metastatic hepatoma in the FA

  18. Intracellular delivery and trafficking dynamics of a lymphoma-targeting antibody-polymer conjugate.

    Science.gov (United States)

    Berguig, Geoffrey Y; Convertine, Anthony J; Shi, Julie; Palanca-Wessels, Maria Corinna; Duvall, Craig L; Pun, Suzie H; Press, Oliver W; Stayton, Patrick S

    2012-12-03

    Ratiometric fluorescence and cellular fractionation studies were employed to characterize the intracellular trafficking dynamics of antibody-poly(propylacrylic acid) (PPAA) conjugates in CD22+ RAMOS-AW cells. The HD39 monoclonal antibody (mAb) directs CD22-dependent, receptor-mediated uptake in human B-cell lymphoma cells, where it is rapidly trafficked to the lysosomal compartment. To characterize the intracellular-release dynamics of the polymer-mAb conjugates, HD39-streptavidin (HD39/SA) was dual-labeled with pH-insensitive Alexa Fluor 488 and pH-sensitive pHrodo fluorophores. The subcellular pH distribution of the HD39/SA-polymer conjugates was quantified as a function of time by live-cell fluorescence microscopy, and the average intracellular pH value experienced by the conjugates was also characterized as a function of time by flow cytometry. PPAA was shown to alter the intracellular trafficking kinetics strongly relative to HD39/SA alone or HD39/SA conjugates with a control polymer, poly(methacryclic acid) (PMAA). Subcellular trafficking studies revealed that after 6 h, only 11% of the HD39/SA-PPAA conjugates had been trafficked to acidic lysosomal compartments with values at or below pH 5.6. In contrast, the average intracellular pH of HD39/SA alone dropped from 6.7 ± 0.2 at 1 h to 5.6 ± 0.5 after 3 h and 4.7 ± 0.6 after 6 h. Conjugation of the control polymer PMAA to HD39/SA showed an average pH drop similar to that of HD39/SA. Subcellular fractionation studies with tritium-labeled HD39/SA demonstrated that after 6 h, 89% of HD39/SA was associated with endosomes (Rab5+) and lysosomes (Lamp2+), while 45% of HD39/SA-PPAA was translocated to the cytosol (lactate dehydrogenase+). These results demonstrate the endosomal-releasing properties of PPAA with antibody-polymer conjugates and detail their intracellular trafficking dynamics and subcellular compartmental distributions over time.

  19. Doxorubicin-conjugated bacteriophages carrying anti-MHC class I chain-related A for targeted cancer therapy in vitro

    Directory of Open Access Journals (Sweden)

    Phumyen A

    2014-11-01

    Full Text Available Achara Phumyen,1–3 Siriporn Jantasorn,1 Amonrat Jumnainsong,1 Chanvit Leelayuwat1–4 1The Centre for Research and Development of Medical Diagnostic Laboratories (CMDL, Faculty of Associated Medical Sciences, 2The Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, 3Research Cluster: Specific Health Problem of Grater Maekong Subregion (SHeP-GMS, 4Department of Clinical Immunology and Transfusion Sciences, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand Background: Cancer therapy by systemic administration of anticancer drugs, besides the effectiveness shown on cancer cells, demonstrated the side effects and cytotoxicity on normal cells. The targeted drug-carrying nanoparticles may decrease the required drug concentration at the site and the distribution of drugs to normal tissues. Overexpression of major histocompatibility complex class I chain–related A (MICA in cancer is useful as a targeted molecule for the delivery of doxorubicin to MICA-expressing cell lines. Methods: The application of 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide (EDC chemistry was employed to conjugate the major coat protein of bacteriophages carrying anti-MICA and doxorubicin in a mildly acid condition. Doxorubicin (Dox on phages was determined by double fluorescence of phage particles stained by M13-fluorescein isothiocyanate (FITC and drug autofluorescence by flow cytometry. The ability of anti-MICA on phages to bind MICA after doxorubicin conjugation was evaluated by indirect enzyme-linked immunosorbent assay. One cervical cancer and four cholangiocarcinoma cell lines expressing MICA were used as models to evaluate targeting activity by cell cytotoxicity test. Results: Flow cytometry and indirect enzyme-linked immunosorbent assay demonstrated that most of the phages (82% could be conjugated with doxorubicin, and the Dox-carrying phage-displaying anti-MICA (Dox-phage remained the binding activity against MICA

  20. Biotin/Folate-decorated Human Serum Albumin Nanoparticles of Docetaxel: Comparison of Chemically Conjugated Nanostructures and Physically Loaded Nanoparticles for Targeting of Breast Cancer.

    Science.gov (United States)

    Nateghian, Navid; Goodarzi, Navid; Amini, Mohsen; Atyabi, Fatemeh; Khorramizadeh, Mohammad Reza; Dinarvand, Rassoul

    2016-01-01

    Docetaxel (DTX) is a widely used chemotherapeutic agent with very low water solubility. Conjugation of DTX to human serum albumin (HSA) is an effective way to increase its water solubility. Attachment of folic acid (FA) or biotin as targeting moieties to DTX-HSA conjugates may lead to active targeting and specific uptake by cancer cells with overexpressed FA or biotin receptors. In this study, FA or biotin molecules were attached to DTX-HSA conjugates by two different methods. In one method, FA or biotin molecules were attached to remaining NH2 residues of HSA in DTX-HSA conjugate by covalent bonds. In the second method, HSA-FA or HSA-biotin conjugates were synthesized separately and then combined by DTX-HSA conjugate in proper ratio to prepare nanoparticles containing DTX-HSA plus HSA-FA or HSA-biotin. Cell viability of different nanoparticle was evaluated on MDA-MB-231 (folate receptor positive), A549 (folate receptor negative), and 4T1 (biotin receptor positive) and showed superior cytotoxicity compared with free docetaxel (Taxotere). In vivo studies of DTX-HSA-FA and DTX-HSA-biotin conjugates in BULB/c mice, tumorized by 4T1 cell line, showed the conjugates prepared in this study were more powerful in the reduction in tumor size and increasing the survival rate when compared to free docetaxel.

  1. Conjugate Heat Transfer and Thermal Mechanical Analysis for Liquid Metal Targets for High Power Electron Beams.

    Energy Technology Data Exchange (ETDEWEB)

    Olivas, Eric Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-26

    A conjugate heat transfer and thermal structural analysis was completed, with the objective of determining the following: Lead bismuth eutectic (LBE) peak temperature, free convective velocity patterns in the LBE, peak beam window temperature, and thermal stress/deformation in the window.

  2. Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity.

    Directory of Open Access Journals (Sweden)

    Martin Kreutz

    Full Text Available Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is paramount. However, co-administration of unlinked adjuvant cannot ensure that all cells targeted by the antibody conjugates are appropriately activated. Furthermore, antigen-presenting cells (APC that do not present the desired antigen are equally strongly activated and could prime undesired responses against self-antigens. We, therefore, were interested in exploring targeted co-delivery of antigen and adjuvant in cis in form of antibody-antigen-adjuvant conjugates for the induction of anti-tumour immunity. In this study, we report on the assembly and characterization of conjugates consisting of DEC205-specific antibody, the model antigen ovalbumin (OVA and CpG oligodeoxynucleotides (ODN. We show that such conjugates are more potent at inducing cytotoxic T lymphocyte (CTL responses than control conjugates mixed with soluble CpG. However, our study also reveals that the nucleic acid moiety of such antibody-antigen-adjuvant conjugates alters their binding and uptake and allows delivery of the antigen and the adjuvant to cells partially independently of DEC205. Nevertheless, antibody-antigen-adjuvant conjugates are superior to antibody-free antigen-adjuvant conjugates in priming CTL responses and efficiently induce anti-tumour immunity in the murine B16 pseudo-metastasis model. A better understanding of the role of the antibody moiety is required to inform future conjugate vaccination strategies for efficient induction of anti-tumour responses.

  3. Retrodirective tracking of a moving target using phase conjugate light generated in a Fabry-Pérot Nd:YAG laser

    Science.gov (United States)

    Kawakami, K.; Komurasaki, K.; Okamura, H.

    2017-03-01

    This report describes the retrodirective tracking of a target moving at a constant speed using a Fabry-Pérot laser resonator-type self-starting phase conjugator. Three-dimensional pointing ability was confirmed with this system: the generated phase conjugate light can focus at a target position. To track the moving targets, target-reflected light is Doppler-shifted, which causes wash-out of the gain grating. To address this problem, numerical analysis and experiments showed that shortening the pulse width is an efficient means of eliminating the gain grating wash-out effect. For the measured target speeds of 0-80 mm/s, the phase conjugate light output is unaffected when the pulse width of 18 ns was used, in contrast to the case of 400 μs pulse width, where the phase conjugate light output rapidly decreased as the target speed approached 10 mm/s. Numerical simulation revealed that phase conjugate light can even be generated for fast-moving targets such as space debris in low-earth-orbit with pulses of several tens of picoseconds. Unlike conventional mechanical gimbal steering methods, this system is applicable for wireless energy transfer to rapidly moving objects.

  4. Design and synthesis of pyrazole-oxindole conjugates targeting tubulin polymerization as new anticancer agents.

    Science.gov (United States)

    Kamal, Ahmed; Shaik, Anver Basha; Jain, Nishant; Kishor, Chandan; Nagabhushana, Ananthamurthy; Supriya, Bhukya; Bharath Kumar, G; Chourasiya, Sumit S; Suresh, Yerramsetty; Mishra, Rakesh K; Addlagatta, Anthony

    2015-03-06

    A series of twenty one compounds with pyrazole and oxindole conjugates were synthesized by Knoevenagel condensation and investigated for their antiproliferative activity on different human cancer cell lines. The conjugates are comprised of a four ring scaffold; the structural isomers 12b and 12c possess chloro-substitution in the D ring. Among the congeners 12b, 12c, and 12d manifested significant cytotoxicity and inhibited tubulin assembly. Treatments with 12b, 12c and 12d resulted in accumulation of cells in G2/M phase, disruption of microtubule network, and increase in cyclin B1 protein. Zebrafish screening revealed that 12b, and 12d caused developmental defects. Docking analysis demonstrated that the congeners occupy the colchicine binding pocket of tubulin.

  5. Synthesis and evaluation of a technetium-99m labeled cytotoxic bombesin peptide conjugate for targeting bombesin receptor-expressing tumors

    Energy Technology Data Exchange (ETDEWEB)

    Okarvi, Subhani M. [Cyclotron and Radiopharmaceuticals Department, King Faisal Specialist Hospital and Research Centre, MBC-03, PO Box 3354, Riyadh 11211 (Saudi Arabia)], E-mail: sokarvi@kfshrc.edu.sa; Al Jammaz, Ibrahim [Cyclotron and Radiopharmaceuticals Department, King Faisal Specialist Hospital and Research Centre, MBC-03, PO Box 3354, Riyadh 11211 (Saudi Arabia)

    2010-04-15

    Conjugation of the cytotoxic drugs to receptor-binding peptides is an attractive approach for the targeted delivery of cytotoxic peptide conjugates to tumor cells. In an attempt to develop an efficient peptide-based radiopharmaceutical for targeting bombesin (BN) receptor-expressing tumors (i.e., breast and prostate), we have prepared by solid-phase peptide synthesis, a novel BN analog derived from the universal sequence of BN and conjugated to a widely characterized antineoplastic agent, methotrexate (MTX). MTX-BN, after radiolabeling with {sup 99m}Tc via stannous-tartrate exchange, showed a good stability against cysteine and histidine transchelation as well as a high in vitro metabolic stability in human plasma. In vitro cell-binding and internalization on MDA-MB-231, MCF-7, T47-D breast cancer and PC-3 prostate cancer cell lines demonstrated high affinity and specificity of {sup 99m}Tc-MTX-BN towards both human breast and prostate cancer cells (binding affinities in nanomolar range). In addition, the radioconjugate displayed a significant internalization (values ranged between 19-35%) into the tumor cells. In vivo biodistribution and clearance kinetics in Balb/c mice are characterized by an efficient clearance from the blood and excretion mainly through the renal-urinary pathway with some elimination via the hepatobiliary system. In vivo tumor uptake in nude mice bearing MDA-MB-231 cells was 2.70{+-}0.44% ID/g at 1 h, whereas in nude mice with human epidermoid KB cells the accumulation in the tumor was found to be 1.48{+-}0.31% ID/g at 1 h post injection. The tumor uptake was always higher than in the blood and muscle, with good tumor retention and good tumor-to-blood and tumor-to-muscle ratios. The accumulation/retention in the major organs (i.e., lungs, stomach, liver, intestines, etc.) was low to moderate (<6% ID/g) in both healthy and tumor-bearing mice. However, the uptake/retention in the kidneys was rather high (up to 11.05{+-}1.80% ID/g), which is of a

  6. Legomedicine—A Versatile Chemo-Enzymatic Approach for the Preparation of Targeted Dual-Labeled Llama Antibody–Nanoparticle Conjugates

    Science.gov (United States)

    2017-01-01

    Conjugation of llama single domain antibody fragments (Variable Heavy chain domains of Heavy chain antibodies, VHHs) to diagnostic or therapeutic nanoparticles, peptides, proteins, or drugs offers many opportunities for optimized targeted cancer treatment. Currently, mostly nonspecific conjugation strategies or genetic fusions are used that may compromise VHH functionality. In this paper we present a versatile modular approach for bioorthogonal VHH modification and conjugation. First, sortase A mediated transPEGylation is used for introduction of a chemical click moiety. The resulting clickable VHHs are then used for conjugation to other groups employing the Cu+-independent strain-promoted alkyne–azide cycloadition (SPAAC) reaction. Using this approach, tail-to-tail bispecific VHHs and VHH-targeted nanoparticles are generated without affecting VHH functionality. Furthermore, this approach allows the bioconjugation of multiple moieties to VHHs for simple and convenient production of VHH-based theranostics. PMID:28045502

  7. Targeting of the prostacyclin specific IP1 receptor in lungs with molecular conjugates comprising prostaglandin I2 analogues.

    Science.gov (United States)

    Geiger, Johannes; Aneja, Manish K; Hasenpusch, Günther; Yüksekdag, Gülnihal; Kummerlöwe, Grit; Luy, Burkhard; Romer, Tina; Rothbauer, Ulrich; Rudolph, Carsten

    2010-04-01

    Molecular conjugates comprising targeting ligands hold great promise for site-specific gene delivery to distant tumors and individual organs including the lung. Here we show that prostaglandin I2 analogues can be used to improve gene transfer efficiency of polyethylenimine (PEI) gene vectors on bronchial and alveolar epithelial cells in vitro and lungs of mice in vivo. Prostacyclin (IP1) receptor expression was confirmed in pulmonary epithelial cell lines by western blot. Iloprost (ILO) and treprostinil (TRP), two prostaglandin I2 analogues, were conjugated to fluorescein-labeled BSA (FLUO-BSA) and compared for IP1 receptor binding/uptake in different lung cell lines. Binding of FLUO-BSA-ILO was 2-4-fold higher than for FLUO-BSA-TRP and could be specifically inhibited by free ILO and IP1 receptor antagonist CAY10449. Internalization of FLUO-BSA-ILO was confirmed by confocal microscopy. Molecular conjugates of PEI and ILO (PEI-g-ILO) were synthesized with increasing coupling degree (F(ILO) (ILO:PEI) = 2, 5, 8, 16) and analyzed for DNA binding, particle formation and transfection efficiency. At optimized conditions (N/P 4, F(ILO) = 5), gene expression using PEI-g-ILO was significantly up to 46-fold higher than for PEI gene vectors and specifically inhibited by CAY10449. Gene expression in the lungs of mice after aerosol delivery was 14-fold higher with PEI-g-ILO F(ILO) = 5 than for PEI. We suggest that targeting of IP1 receptor using ILO represents a promising approach to improve pulmonary gene transfer.

  8. N-Acetylgalactosamine-Targeted Delivery of Dendrimer-Doxorubicin Conjugates Influences Doxorubicin Cytotoxicity and Metabolic Profile in Hepatic Cancer Cells.

    Science.gov (United States)

    Kuruvilla, Sibu P; Tiruchinapally, Gopinath; ElAzzouny, Mahmoud; ElSayed, Mohamed E H

    2017-03-01

    This study describes the development of targeted, doxorubicin (DOX)-loaded generation 5 (G5) polyamidoamine dendrimers able to achieve cell-specific DOX delivery and release into the cytoplasm of hepatic cancer cells. G5 is functionalized with poly(ethylene glycol) (PEG) brushes displaying N-acetylgalactosamine (NAcGal) ligands to target hepatic cancer cells. DOX is attached to G5 through one of two aromatic azo-linkages, L3 or L4, achieving either P1 ((NAcGalβ -PEGc)16.6 -G5-(L3-DOX)11.6 ) or P2 ((NAcGalβ -PEGc)16.6 -G5-(L4-DOX)13.4 ) conjugates. After confirming the conjugates' biocompatibility, flow cytometry studies show P1/P2 achieve 100% uptake into hepatic cancer cells at 30-60 × 10(-9) m particle concentration. This internalization correlates with cytotoxicity against HepG2 cells with 50% inhibitory concentration (IC50 ) values of 24.8, 1414.0, and 237.8 × 10(-9) m for free DOX, P1, and P2, respectively. Differences in cytotoxicity prompted metabolomics analysis to identify the intracellular release behavior of DOX. Results show that P1/P2 release alternative DOX metabolites than free DOX. Stable isotope tracer studies show that the different metabolites induce different effects on metabolic cycles. Namely, free DOX reduces glycolysis and increases fatty acid oxidation, while P1/P2 increase glycolysis, likely as a response to high oxidative stress. Overall, P1/P2 conjugates offer a platform drug delivery technology for improving hepatic cancer therapy.

  9. Preparation of folate-conjugated starch nanoparticles and its application to tumor-targeted drug delivery vector

    Institute of Scientific and Technical Information of China (English)

    XIAO Suyao; TONG Chunyi; LIU Xuanming; YU Danmi; LIU Qiaoling; XUE Changgang; TANG Dongyin; ZHAO Lijian

    2006-01-01

    Anion starch nanoparticles (StNP) were prepared in water-in-oil microemulsion. Folate modified with PEG was conjugated to the surface of StNP to obtain the folate-conjugated starch nanoparticles (FA-PEG/StNP). The average diameter of FA-PEG/StNP determined by AFM and Zeta-Sizer apparatus was about 130 nm. Doxorubicin (DOX)-loaded FA-PEG/StNP was obtained via infiltrating combination.The result of UV spectrophotometer showed that the saturation concentration of DOX-loaded FA-PEG/StNP was 28 μg/mg, which was effective for the controlled release of anticancer drug DOX. The cell experiments showed that the Lc50 of DOX-loaded FA-PEG/StNP and DOX-loaded StNP was higher than that of DOX, which indicates that FA-PEG/StNP and StNP can decrease the toxicity of DOX; while the lethal rate of DOX-loaded FA-PEG/StNP was 3 times that of DOX-loaded StNP with the same quantity of DOX, which indicates that FA in FA-PEG/StNP is effective for improving the targeting function of nanoparticles, thus enhancing the inhibition effect of anticancer drug to cancer cell. This work demonstrates that the FA-PEG/StNP system is a potentially useful system for the targeted delivery of anticancer drug DOX.

  10. IL-6 Antibody and RGD Peptide Conjugated Poly(amidoamine) Dendrimer for Targeted Drug Delivery of HeLa Cells.

    Science.gov (United States)

    Mekuria, Shewaye Lakew; Debele, Tilahun Ayane; Chou, Hsiao-Ying; Tsai, Hsieh-Chih

    2016-01-14

    In this study, PAMAM dendrimer (G4.5) was conjugated with two targeting moieties, IL-6 antibody and RGD peptide (G4.5-IL6 and G4.5-RGD conjugates). Doxorubicin anticancer drug was physically loaded onto G4.5-IL6 and G4.5-RGD with the encapsulation efficiency of 51.3 and 30.1% respectively. The cellular internalization and uptake efficiency of G4.5-IL6/DOX and G4.5-RGD/DOX complexes was observed and compared by confocal microscopy and flow cytometry using HeLa cells, respectively. The lower IC50 value of G4.5-IL6/DOX in comparison to G4.5-RGD/DOX is indication that higher drug loading and faster drug release rate corresponded with greater cytotoxicity. The cytotoxic effect was further verified by increment in late apoptotic/necrotic cells due to delivery of drug through receptor-mediated endocytosis. On the basis of these results, G4.5-IL6 is a better suited carrier for targeted drug delivery of DOX to cervical cancer cells.

  11. Specific targeting delivery to MUC1 overexpressing tumors by albumin-chitosan nanoparticles conjugated to DNA aptamer.

    Science.gov (United States)

    Esfandyari-Manesh, Mehdi; Mohammadi, Ali; Atyabi, Fatemeh; Nabavi, Seyedeh Maryam; Ebrahimi, Seyedeh Masoumeh; Shahmoradi, Elnaz; Varnamkhasti, Behrang Shiri; Ghahremani, Mohammad Hossein; Dinarvand, Rassoul

    2016-12-30

    Chitosan-coated human serum albumin nanoparticles were functionalized by MUC1 aptamer to obtain a selective drug carrier toward cancers overexpressing MUC1. The negative charges of albumin nanoparticles were shifted to positive charges by surface modification with chitosan, and MUC1 was conjugated through an acrylate spacer. The cytotoxicity of targeted nanoparticles was significantly more than non-aptamer nanoparticles, and also the chitosan-coated nanoparticles had more cytotoxic effects than the negatively charged albumin nanoparticles. The IC50 of targeted nanoparticles was 28 and 26% of free paclitaxel in MCF7 and T47D cells at 48h, respectively. Confocal laser scanning electron microscopy showed that aptamer conjugation and positive charge increase the cellular uptake. 66% of paclitaxel was released within 32h, but 100% of drug was released at pH=5.5 (similar cancer cells). The paclitaxel plasma amount was at a good level of 17.6% at 2h for increasing the chance of cellular uptake. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Preparation and functional characterization of tumor-targeted folic acid-chitosan conjugated nanoparticles loaded with mitoxantrone

    Institute of Scientific and Technical Information of China (English)

    王炜; 童春义; 刘星言; 李涛; 刘斌; 熊炜

    2015-01-01

    Folic acid conjugated chitosan was prepared by cross-linking reaction with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC), and then used as a template to prepare folic acid-chitosan (FA-CS) conjugated nanoparticles and load mitoxantrone nanoparticles (FA-CSNP/MTX). Drug dissolution testing, CCK-8 method, and confocal microscopy were used to detect their controlled-release capability in different situations and the specific uptake by HONE1 cells. The experimental results show that the nanoparticles have uniform size distribution of 48−58 nm. The highest encapsulation rate of the particles on mitoxantrone hydrochloride (MTX) is (77.5±1.9)%, and the drug loading efficiency is (18.4±0.4)%. The sustained release effect, cell growth inhibition activity and targeting effect of the FA-CS/MTX nanoparticles are good in artificial gastric fluid and intestinal fluid. It is demonstrated that the FA-CSNP system is a potentially useful system for the targeted delivery of anticancer drug MTX.

  13. Targeting Mast Cells and Basophils with Anti-FcεRIα Fab-Conjugated Celastrol-Loaded Micelles Suppresses Allergic Inflammation.

    Science.gov (United States)

    Peng, Xia; Wang, Juan; Li, Xianyang; Lin, Lihui; Xie, Guogang; Cui, Zelin; Li, Jia; Wang, Yuping; Li, Li

    2015-12-01

    Mast cells and basophils are effector cells in the pathophysiology of allergic diseases. Targeted elimination of these cells may be a promising strategy for the treatment of allergic disorders. Our present study aims at targeted delivery of anti-FcεRIα Fab-conjugated celastrol-loaded micelles toward FcεRIα receptors expressed on mast cells and basophils to have enhanced anti-allergic effect. To achieve this aim, we prepared celastrol-loaded (PEO-block-PPO-block-PEO, Pluronic) polymeric nanomicelles using thin-film hydration method. The anti-FcεRIα Fab Fragment was then conjugated to carboxyl groups on drug-loaded micelles via EDC amidation reaction. The anti-FcεRIα Fab-conjugated celastrol-loaded micelles revealed uniform particle size (93.43 ± 12.93 nm) with high loading percentage (21.2 ± 1.5% w/w). The image of micelles showed oval and rod like. The anti-FcεRIα Fab-conjugated micelles demonstrated enhanced cellular uptake and cytotoxity toward target KU812 cells than non-conjugated micelles in vitro. Furthermore, diffusion of the drug into the cells allowed an efficient induction of cell apoptosis. In mouse model of allergic asthma, treatment with anti-FcεRIα Fab-conjugated micelles increased lung accumulation of micelles, and significantly reduced OVA-sIgE, histamine and Th2 cytokines (IL-4, IL-5, TNF-α) levels, eosinophils infiltration and mucus production. In addition, in mouse model of passive cutaneous anaphylaxis, anti-FcεRIα Fab-conjugated celastrol-loaded micelles treatment significantly decreased extravasated evan's in the ear. These results indicate that anti-FcεRIα Fab-conjugated celastrol-loaded micelles can target and selectively kill mast cells and basophils which express FcεRIα, and may be efficient reagents for the treatment of allergic disorders and mast cell related diseases.

  14. Use of N-terminal modified poly(L-lysine)-antibody conjugate as a carrier for targeted gene delivery in mouse lung endothelial cells.

    Science.gov (United States)

    Trubetskoy, V S; Torchilin, V P; Kennel, S J; Huang, L

    1992-01-01

    A DNA targeted delivery and expression system has been designed based on an N-terminal modified poly(L-lysine) (NPLL)-antibody conjugate, which readily forms a complex with plasmid DNA. Monoclonal antibodies against the cell-surface thrombomodulin conjugated with NPLL were used for targeted delivery of foreign plasmid DNA to an antigen-expressing mouse lung endothelial cell line in vitro and to mouse lungs in vivo. In both cases significant amounts of DNA can be specifically bound to the target cells or tissues. Specific gene expression was observed in the treated mouse lung endothelial cells.

  15. Slowly on, Slowly off: Bisubstrate-Analogue Conjugates of 5-Iodotubercidin and Histone H3 Peptide Targeting Protein Kinase Haspin.

    Science.gov (United States)

    Kestav, Katrin; Viht, Kaido; Konovalov, Anton; Enkvist, Erki; Uri, Asko; Lavogina, Darja

    2017-02-09

    The atypical protein kinase Haspin serves as one of a key players in mitosis by catalysing phosphorylation of Thr3 in histone H3, and thus sustaining the normal functioning of the chromosomal passenger complex. Here, we report the development of bisubstrate-analogue inhibitors targeting Haspin. The compounds were constructed by linking 5-iodotubercidin moiety to the N-terminal sequence of histone H3. The new conjugates possessed high affinity (KD in the subnanomolar range) towards Haspin as well as slow kinetics of association and dissociation (residence time on the scale of several hours), which reflected their unique binding mode and translated into improved selectivity. The latter was confirmed in a biochemical binding/displacement assay with a panel of 10 protein kinases, in thermal shift assay with off-targets of 5-iodotubercidin represented by adenosine kinase and the Cdc2-like kinase family, as well as in assay with spiked lysates of HeLa cells.

  16. Biotin-conjugated tumour-targeting photocytotoxic iron(III) complexes.

    Science.gov (United States)

    Saha, Sounik; Majumdar, Ritankar; Hussain, Akhtar; Dighe, Rajan R; Chakravarty, Akhil R

    2013-07-28

    Iron(III) complexes [FeL(B)] (1-4) of a tetradentate phenolate-based ligand (H3L) and biotin-conjugated dipyridophenazine bases (B), viz. 7-aminodipyrido [3,2-a:2',3'-c]-phenazine (dppza in 1), (N-dipyrido[3,2-a:2',3'-c]-phenazino)amidobiotin (dppzNB in 2), dipyrido [3,2-a:2',3'-c]-phenazine-11-carboxylic acid (dppzc in 3) and 2-((2-biotinamido)ethyl) amido-dipyrido[3,2-a:2',3'-c]-phenazine (dppzCB in 4) are prepared, characterized and their interaction with streptavidin and DNA and their photocytotoxicity and cellular uptake in various cells studied. The high-spin iron(III) complexes display Fe(III)/Fe(II) redox couple near -0.7 V versus saturated calomel electrode in dimethyl sulfoxide-0.1 M tetrabutylammonium perchlorate. The complexes show non-specific interaction with DNA as determined from the binding studies. Complexes with appended biotin moiety show similar binding to streptavidin as that of free biotin, suggesting biotin conjugation to dppz does not cause any loss in its binding affinity to streptavidin. The photocytotoxicity of the complexes is tested in HepG2, HeLa and HEK293 cell lines. Complex 2 shows higher photocytotoxicity in HepG2 cells than in HeLa or HEK293, forming reactive oxygen species. This effect is attributed to the presence of overexpressed sodium-dependent multi-vitamin transporters in HepG2 cells. Microscopic studies in HepG2 cells show internalization of the biotin complexes 2 and 4 essentially occurring by receptor-mediated endocytosis, which is similar to that of native biotin and biotin fluorescein isothiocyanate conjugate.

  17. RGD-conjugated silica-coated gold nanorods on the surface of carbon nanotubes for targeted photoacoustic imaging of gastric cancer

    Science.gov (United States)

    Wang, Can; Bao, Chenchen; Liang, Shujing; Fu, Hualin; Wang, Kan; Deng, Min; Liao, Qiande; Cui, Daxiang

    2014-05-01

    Herein, we reported for the first time that RGD-conjugated silica-coated gold nanorods on the surface of multiwalled carbon nanotubes were successfully used for targeted photoacoustic imaging of in vivo gastric cancer cells. A simple strategy was used to attach covalently silica-coated gold nanorods (sGNRs) onto the surface of multiwalled carbon nanotubes (MWNTs) to fabricate a hybrid nanostructure. The cross-linked reaction occurred through the combination of carboxyl groups on the MWNTs and the amino group on the surface of sGNRs modified with a silane coupling agent. RGD peptides were conjugated with the sGNR/MWNT nanostructure; resultant RGD-conjugated sGNR/MWNT probes were investigated for their influences on viability of MGC803 and GES-1 cells. The nude mice models loaded with gastric cancer cells were prepared, the RGD-conjugated sGNR/MWNT probes were injected into gastric cancer-bearing nude mice models via the tail vein, and the nude mice were observed by an optoacoustic imaging system. Results showed that RGD-conjugated sGNR/MWNT probes showed good water solubility and low cellular toxicity, could target in vivo gastric cancer cells, and obtained strong photoacoustic imaging in the nude model. RGD-conjugated sGNR/MWNT probes will own great potential in applications such as targeted photoacoustic imaging and photothermal therapy in the near future.

  18. Targeted conjugation of breast anticancer drug tamoxifen and its metabolites with synthetic polymers.

    Science.gov (United States)

    Sanyakamdhorn, S; Agudelo, D; Bekale, L; Tajmir-Riahi, H A

    2016-09-01

    Conjugation of antitumor drug tamoxifen and its metabolites, 4-hydroxytamxifen and ednoxifen with synthetic polymers poly(ethylene glycol) (PEG), methoxypoly (ethylene glycol) polyamidoamine (mPEG-PAMAM-G3) and polyamidoamine (PAMAM-G4) dendrimers was studied in aqueous solution at pH 7.4. Multiple spectroscopic methods, transmission electron microscopy (TEM) and molecular modeling were used to characterize the drug binding process to synthetic polymers. Structural analysis showed that drug-polymer binding occurs via both H-bonding and hydrophobic contacts. The order of binding is PAMAM-G4>mPEG-PAMAM-G3>PEG-6000 with 4-hydroxttamoxifen forming more stable conjugate than tamoxifen and endoxifen. Transmission electron microscopy showed significant changes in carrier morphology with major changes in the shape of the polymer aggregate as drug encapsulation occurred. Modeling also showed that drug is located in the surface and in the internal cavities of PAMAM with the free binding energy of -3.79 for tamoxifen, -3.70 for 4-hydroxytamoxifen and -3.69kcal/mol for endoxifen, indicating of spontaneous drug-polymer interaction at room temperature. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Transferrin-PEG-PE modified dexamethasone conjugated cationic lipid carrier mediated gene delivery system for tumor-targeted transfection

    Science.gov (United States)

    Wang, Wei; Zhou, Fang; Ge, Linfu; Liu, Ximin; Kong, Fansheng

    2012-01-01

    Background The main barriers to non-viral gene delivery include cellular and nuclear membranes. As such, the aim of this study was to develop a type of vector that can target cells through receptor-mediated pathways and by using nuclear localization signal (NLS) to increase the nuclear uptake of genetic materials. Methods A dexamethasone (Dexa)-conjugated lipid was synthesized as the material of the solid lipid nanoparticles (SLNs), and transferrin (Tf) was linked onto polyethylene glycol-phosphatidylethanolamine (PEG-PE) to obtain Tf-PEG-PE ligands for the surface modification of the carriers. The in vitro transfection efficiency of the novel modified vectors was evaluated in human hepatoma carcinoma cell lines, and in vivo effects were observed in an animal model. Results Tf-PEG-PE modified SLNs/enhanced green fluorescence protein plasmid (pEGFP) had a particle size of 222 nm and a gene loading quantity of 90%. Tf-PEG-PE-modified SLNs/pEGFP (Tf-SLNs/pEGFP) displayed remarkably higher transfection efficiency than non-modified SLNs/pEGFP and the vectors not containing Dexa, both in vitro and in vivo. Conclusion It can be concluded that Tf and Dexa could function as an excellent active targeting ligand to improve the cell targeting and nuclear targeting ability of the carriers, and the resulting nanomedicine could be a promising active targeting drug/gene delivery system. PMID:22679364

  20. Enhanced Anti-Tumoral Activity of Methotrexate-Human Serum Albumin Conjugated Nanoparticles by Targeting with Luteinizing Hormone-Releasing Hormone (LHRH) Peptide

    Science.gov (United States)

    Taheri, Azade; Dinarvand, Rassoul; Atyabi, Fatemeh; Ahadi, Fatemeh; Nouri, Farank Salman; Ghahremani, Mohammad Hossein; Ostad, Seyed Nasser; Borougeni, Atefeh Taheri; Mansoori, Pooria

    2011-01-01

    Active targeting could increase the efficacy of anticancer drugs. Methotrexate-human serum albumin (MTX-HSA) conjugates, functionalized by luteinizing hormone-releasing hormone (LHRH) as targeting moieties, with the aim of specifically targeting the cancer cells, were prepared. Owing to the high expression of LHRH receptors in many cancer cells as compared to normal cells, LHRH was used as the targeting ligand in this study. LHRH was conjugated to MTX-HSA nanoparticles via a cross-linker. Three types of LHRH targeted nanoparticles with a mean particle size between 120–138 nm were prepared. The cytotoxicity of LHRH targeted and non-targeted nanoparticles were determined on the LHRH positive and negative cell lines. The internalization of the targeted and non-targeted nanoparticles in LHRH receptor positive and negative cells was investigated using flow cytometry analysis and fluorescence microscopy. The cytotoxicity of the LHRH targeted nanoparticles on the LHRH receptor positive cells were significantly more than non-targeted nanoparticles. LHRH targeted nanoparticles were also internalized by LHRH receptor positive cells significantly more than non-targeted nanoparticles. There were no significant differences between the uptake of targeted and non-targeted nanoparticles to the LHRH receptor negative cells. The active targeting procedure using LHRH targeted MTX-HSA nanoparticles could increase the anti-tumoral activity of MTX. PMID:21845098

  1. Enhanced Anti-Tumoral Activity of Methotrexate-Human Serum Albumin Conjugated Nanoparticles by Targeting with Luteinizing Hormone-Releasing Hormone (LHRH Peptide

    Directory of Open Access Journals (Sweden)

    Pooria Mansoori

    2011-07-01

    Full Text Available Active targeting could increase the efficacy of anticancer drugs. Methotrexate-human serum albumin (MTX-HSA conjugates, functionalized by luteinizing hormone-releasing hormone (LHRH as targeting moieties, with the aim of specifically targeting the cancer cells, were prepared. Owing to the high expression of LHRH receptors in many cancer cells as compared to normal cells, LHRH was used as the targeting ligand in this study. LHRH was conjugated to MTX-HSA nanoparticles via a cross-linker. Three types of LHRH targeted nanoparticles with a mean particle size between 120–138 nm were prepared. The cytotoxicity of LHRH targeted and non-targeted nanoparticles were determined on the LHRH positive and negative cell lines. The internalization of the targeted and non-targeted nanoparticles in LHRH receptor positive and negative cells was investigated using flow cytometry analysis and fluorescence microscopy. The cytotoxicity of the LHRH targeted nanoparticles on the LHRH receptor positive cells were significantly more than non-targeted nanoparticles. LHRH targeted nanoparticles were also internalized by LHRH receptor positive cells significantly more than non-targeted nanoparticles. There were no significant differences between the uptake of targeted and non-targeted nanoparticles to the LHRH receptor negative cells. The active targeting procedure using LHRH targeted MTX-HSA nanoparticles could increase the anti-tumoral activity of MTX.

  2. Bone-targeting parathyroid hormone conjugates outperform unmodified PTH in the anabolic treatment of osteoporosis in rats.

    Science.gov (United States)

    Yang, Yang; Aghazadeh-Habashi, Ali; Panahifar, Arash; Wu, Yuchin; Bhandari, Krishna H; Doschak, Michael R

    2017-08-01

    Synthetic parathyroid hormone (PTH) is clinically indicated for the treatment of osteoporosis, through its anabolic effects on parathyroid hormone receptors (PTHRs), located on osteoblast cells. However, the bioavailability of PTH for bone cells is restricted by the short half-life of PTH and the widespread distribution of PTHRs in non-skeletal tissues. To impart affinity for mineralized bone surfaces, bisphosphonate (BP)-mediated PTH analogues were synthesized, characterized, and evaluated in vitro and in vivo. The successful synthesis of PTH-PEG-BP was identified on MALDI-ToF mass spectra; bone-targeting potential was evaluated by hydroxyapatite binding test; and receptor bioactivity was assessed in UMR-106 (rat osteosarcoma) cells that constitutively express PTHRs. Therapeutic efficacy was evaluated using ovariectomized rats that remained untreated for 8 weeks to allow development of osteopenia. Those rats then received daily subcutaneous injections of PTH-PEG-BP, thiol-BP vehicle, or unmodified PTH, and compared to sham-operated healthy rats at 0, 4, 8, 12, and 16 weeks. In vivo micro-CT was conducted on the proximal tibial metaphysis to measure microstructural bone parameters, and new bone formation was detected using dynamic labeling. Bone strength was assessed using three-point bending mechanical testing. Our study determined that PTH-PEG-BP conjugates significantly enhanced PTH targeting to the bone matrix while retaining full PTH bioactivity. Moreover, PTH-PEG-BP conjugates significantly increased trabecular bone quality, anabolic bone formation, and improved bone strength over systemically administered PTH alone. We highlight the promise of a novel class of bone-targeting anabolic compound for the treatment of osteoporosis and related bone disorders.

  3. Design and evaluation of novel pH-sensitive ureido-conjugated chitosan/TPP nanoparticles targeted to Helicobacter pylori.

    Science.gov (United States)

    Jing, Zi-Wei; Jia, Yi-Yang; Wan, Ning; Luo, Min; Huan, Meng-Lei; Kang, Tai-Bin; Zhou, Si-Yuan; Zhang, Bang-Le

    2016-04-01

    The covalently modified ureido-conjugated chitosan/TPP multifunctional nanoparticles have been developed as targeted nanomedicine delivery system for eradication of Helicobacter pylori. H. pylori can specifically express the urea transport protein on its membrane to transport urea into cytoplasm for urease to produce ammonia, which protects the bacterium in the acid milieu of stomach. The clinical applicability of topical antimicrobial agent is needed to eradicate H. pylori in the infected fundal area. In this study, we designed and synthesized two ureido-conjugated chitosan derivatives UCCs-1 and UCCs-2 for preparation of multifunctional nanoparticles. The process was optimized in order to prepare UCCs/TPP nanoparticles for encapsulation of amoxicillin. The results showed that the amoxicillin-UCCs/TPP nanoparticles exhibited favorable pH-sensitive characteristics, which could procrastinate the release of amoxicillin at gastric acids and enable the drug to deliver and target to H. pylori at its survival region effectively. Compared with unmodified amoxicillin-chitosan/TPP nanoparticles, a more specific and effective H. pylori growth inhibition was observed for amoxicillin-UCCs/TPP nanoparticles. Drug uptake analysis tested by flow cytometry and confocal laser scanning microscopy verified that the uptake of FITC-UCCs-2/TPP nanoparticles was associated with urea transport protein on the membrane of H. pylori and reduced with the addition of urea as competitive transport substrate. These findings suggest that the multifunctional amoxicillin-loaded nanoparticles have great potential for effective therapy of H. pylori infection. They may also serve as pharmacologically effective nanocarriers for oral targeted delivery of other therapeutic drugs to treat H. pylori.

  4. Disposition and Pharmacology of a GalNAc3-conjugated ASO Targeting Human Lipoprotein (a) in Mice

    Science.gov (United States)

    Yu, Rosie Z; Graham, Mark J; Post, Noah; Riney, Stan; Zanardi, Thomas; Hall, Shannon; Burkey, Jennifer; Shemesh, Colby S; Prakash, Thazha P; Seth, Punit P; Swayze, Eric E; Geary, Richard S; Wang, Yanfeng; Henry, Scott

    2016-01-01

    Triantennary N-acetyl galactosamine (GalNAc3)-conjugated antisense oligonucleotides (ASOs) have greatly improved potency via receptor-mediated uptake. In the present study, the in vivo pharmacology of a 2′-O-(2-methoxyethyl)-modified ASO conjugated with GalNAc3 (ISIS 681257) together with its unmodified congener (ISIS 494372) targeting human apolipoprotein (a) (apo(a)), were studied in human LPA transgenic mice. Further, the disposition kinetics of ISIS 681257 was studied in CD-1 mice. ISIS 681257 demonstrated over 20-fold improvement in potency over ISIS 494372 as measured by liver apo(a) mRNA and plasma apo(a) protein levels. Following subcutaneous (SC) dosing, ISIS 681257 cleared rapidly from plasma and distributed to tissues. Intact ISIS 681257 was the major full-length oligonucleotide species in plasma. In tissues, however, GalNAc sugar moiety was rapidly metabolized and unconjugated ISIS 681257 accounted > 97% of the total exposure, which was then cleared slowly from tissues with a half-life of 7–8 days, similar to the half-life in plasma. ISIS 681257 is highly bound to plasma proteins (> 94% bound), which limited its urinary excretion. This study confirmed dose-dependent exposure to the parent drug ISIS 681257 in plasma and rapid conversion to unconjugated ASO in tissues. Safety data and the extended half-life support its further development and weekly dosing in phase 1 clinical studies. PMID:27138177

  5. Disposition and Pharmacology of a GalNAc3-conjugated ASO Targeting Human Lipoprotein (a in Mice

    Directory of Open Access Journals (Sweden)

    Rosie Z Yu

    2016-01-01

    Full Text Available Triantennary N-acetyl galactosamine (GalNAc3-conjugated antisense oligonucleotides (ASOs have greatly improved potency via receptor-mediated uptake. In the present study, the in vivo pharmacology of a 2′-O-(2-methoxyethyl-modified ASO conjugated with GalNAc3 (ISIS 681257 together with its unmodified congener (ISIS 494372 targeting human apolipoprotein (a (apo(a, were studied in human LPA transgenic mice. Further, the disposition kinetics of ISIS 681257 was studied in CD-1 mice. ISIS 681257 demonstrated over 20-fold improvement in potency over ISIS 494372 as measured by liver apo(a mRNA and plasma apo(a protein levels. Following subcutaneous (SC dosing, ISIS 681257 cleared rapidly from plasma and distributed to tissues. Intact ISIS 681257 was the major full-length oligonucleotide species in plasma. In tissues, however, GalNAc sugar moiety was rapidly metabolized and unconjugated ISIS 681257 accounted > 97% of the total exposure, which was then cleared slowly from tissues with a half-life of 7–8 days, similar to the half-life in plasma. ISIS 681257 is highly bound to plasma proteins (> 94% bound, which limited its urinary excretion. This study confirmed dose-dependent exposure to the parent drug ISIS 681257 in plasma and rapid conversion to unconjugated ASO in tissues. Safety data and the extended half-life support its further development and weekly dosing in phase 1 clinical studies.

  6. Clinical Safety and Immunogenicity of Tumor-Targeted, Plant-Made Id-KLH Conjugate Vaccines for Follicular Lymphoma

    Directory of Open Access Journals (Sweden)

    Daniel Tusé

    2015-01-01

    Full Text Available We report the first evaluation of plant-made conjugate vaccines for targeted treatment of B-cell follicular lymphoma (FL in a Phase I safety and immunogenicity clinical study. Each recombinant personalized immunogen consisted of a tumor-derived, plant-produced idiotypic antibody (Ab hybrid comprising the hypervariable regions of the tumor-associated light and heavy Ab chains, genetically grafted onto a common human IgG1 scaffold. Each immunogen was produced in Nicotiana benthamiana plants using twin magnICON vectors expressing the light and heavy chains of the idiotypic Ab. Each purified Ab was chemically linked to the carrier protein keyhole limpet hemocyanin (KLH to form a conjugate vaccine. The vaccines were administered to FL patients over a series of ≥6 subcutaneous injections in conjunction with the adjuvant Leukine (GM-CSF. The 27 patients enrolled in the study had previously received non-anti-CD20 cytoreductive therapy followed by ≥4 months of immune recovery prior to first vaccination. Of 11 patients who became evaluable at study conclusion, 82% (9/11 displayed a vaccine-induced, idiotype-specific cellular and/or humoral immune response. No patients showed serious adverse events (SAE related to vaccination. The fully scalable plant-based manufacturing process yields safe and immunogenic personalized FL vaccines that can be produced within weeks of obtaining patient biopsies.

  7. A bifunctional poly(ethylene glycol) silane immobilized on metallic oxide-based nanoparticles for conjugation with cell targeting agents

    Energy Technology Data Exchange (ETDEWEB)

    Kohler, Nathan J.; Fryxell, Glen E.; Zhang, Miqin

    2004-06-16

    A trifluoroethylester-terminal poly (ethylene glycol) (PEG) silane was synthesized and self-assembled on iron oxide nanoparticles. The nanoparticle system thus prepared has the flexibility to conjugate with cell targeting agents having either carboxylic and amine terminal groups for a number of biomedical applications, including magnetic resonance imaging (MRI) and controlled drug delivery. The trifluoroethylester silane was synthesized by modifying a PEG diacid to form the corresponding bistrifluoroethylester (TFEE), followed by a reaction with 3-aminopropyltriethoxysilane (APS). The APS coupled with PEG chains confers the stability of PEG self-assembled monolayers (SAMs) and increases the PEG packing density on nanoparticles by establishing hydrogen bonding between the carbonyl and amine groups present within the monolayer structure. The success of the synthesis of the PEG TEFE silane was confirmed with 1H NMR and Fourier transform infrared spectroscopy (FTIR). The conjugating flexibility of the PEG TEFE was demonstrated with folic acid having carboxylic acid groups and amine terminal groups respectively and confirmed by FTIR. TEM analysis showed the dispersion of nanoparticles before and after they were coated with PEG and folic acid.

  8. Synthesis and biological evaluation of (68) Ga-labeled Pteroyl-Lys conjugates for folate receptor-targeted tumor imaging.

    Science.gov (United States)

    Zhang, Xuran; Yu, Qian; He, Yingfang; Zhang, Chun; Zhu, Hua; Yang, Zhi; Lu, Jie

    2016-07-01

    In order to develop novel (68) Ga-labeled PET tracers for folate receptor imaging, two DOTA-conjugated Pteroyl-Lys derivatives, Pteroyl-Lys-DOTA and Pteroyl-Lys-DAV-DOTA, were designed, synthesized and radiolabeled with (68) Ga. Biological evaluations of the two radiotracers were performed with FR-positive KB cell line and athymic nude mice bearing KB tumors. Both (68) Ga-DOTA-Lys-Pteroyl and (68) Ga-DOTA-DAV-Lys-Pteroyl exhibited receptor specific binding in KB cells in vitro. The tumor uptake values of (68) Ga-DOTA-Lys-Pteroyl and (68) Ga-DOTA-DAV-Lys-Pteroy were 10.06 ± 0.59%ID/g and 11.05 ± 0.60%ID/g at 2 h post-injection, respectively. Flank KB tumor was clearly visualized with (68) Ga-DOTA-DAV-Lys-Pteroyl by Micro-PET imaging at 2 h post-injection, suggesting the feasibility of using (68) Ga-labeled Pteroyl-Lys conjugates as a novel class of FR targeted probes.

  9. Exploring clustering in alpha-conjugate nuclei using the thick target inverse kinematic technique for multiple alpha emission

    Science.gov (United States)

    Barbui, M.; Hagel, K.; Gauthier, J.; Wuenschel, S.; Goldberg, V. Z.; Zheng, H.; Giuliani, G.; Rapisarda, G.; Kim, E.-J.; Liu, X.; Natowitz, J. B.; Desouza, R. T.; Hudan, S.; Fang, D.

    2015-10-01

    Searching for alpha cluster states analogous to the 12C Hoyle state in heavier alpha-conjugate nuclei can provide tests of the existence of alpha condensates in nuclear matter. Such states are predicted for 16O, 20Ne, 24Mg, etc. at excitation energies slightly above the decay threshold. The Thick Target Inverse Kinematics (TTIK) technique can be successfully used to study the breakup of excited self-conjugate nuclei into many alpha particles. The reaction 20Ne + α at 11 and 13 AMeV was studied at Cyclotron Institute at Texas A&M University. Here the TTIK method was used to study both single α-particle emission and multiple α-particle decays. Due to the limited statistics, only events with alpha multiplicity up to three were analyzed. The analysis of the three α-particle emission data allowed the identification of the Hoyle state and other 12C excited states decaying into three alpha particles. The results will be shown and compared with other data available in the literature. Another experiment is planned in August 2015 to study the system 28Si + α at 15 AMeV. Preliminary results will be shown. Supported by the U.S. DOE and the Robert A. Welch Foundation, Grant No. A0330.

  10. Development of a novel microbubble-liposome complex conjugated with peptide ligands targeting IL4R on brain tumor cells.

    Science.gov (United States)

    Park, See-Hyoung; Yoon, Young Ii; Moon, Hyoungwon; Lee, Ga-Hyun; Lee, Byung-Heon; Yoon, Tae-Jong; Lee, Hak Jong

    2016-07-01

    Gas (SF6)-filled microbubbles (MBs) were prepared by emulsion and solvent-evaporation method. The prepared MBs were further conjugated with doxorubicin (Dox)-loaded nano-sized liposome and peptide ligands to interleukin-4 receptor (IL4R) for targeting brain tumor cells. The final MB-liposome (Dox)-IL4R targeting peptide ligand [MB-Lipo (Dox)-IL4RTP] had a spherical structure with the mean size of 1,500 nm. The MB-Lipo (Dox)‑IL4RTP exhibited cellular uptake in U87MG brain tumor cells (a brain tumor cell line expressing strongly IL4R) with frequency ultrasound energy suggesting that MB-Lipo (Dox)‑IL4RTP provided effective targeting ability for brain tumor cells. In addition, WST-1 assay results showed that MB-Lipo (Dox)‑IL4RTP inhibited the proliferation of U87MG cells IL4R‑dependently. This was confirmed by western blotting of γH2AX, phospho (Ser15)-p53, p53 and p21 which are signal transduction proteins involved in DNA damage response and cell cycle arrest. Taken together, these results indicate that MB-Lipo (Dox)-IL4RTP represents a promising ultrasonic contrast agent for tumor-targeting ultrasonic imaging.

  11. Cationic liposomes enhance targeted delivery and expression of exogenous DNA mediated by N-terminal modified poly(L-lysine)-antibody conjugate in mouse lung endothelial cells.

    Science.gov (United States)

    Trubetskoy, V S; Torchilin, V P; Kennel, S; Huang, L

    1992-07-15

    A new and improved system for targeted gene delivery and expression is described. Transfection efficiency of N-terminal modified poly(L-lysine) (NPLL) conjugated with anti-thrombomodulin antibody 34A can be improved by adding to the system a lipophilic component, cationic liposomes. DNA, antibody conjugate and cationic liposomes form a ternary electrostatic complex which preserves the ability to bind specifically to the target cells. At the same time the addition of liposomes enhance the specific transfection efficiency of antibody-polylysine/DNA binary complex by 10 to 20-fold in mouse lung endothelial cells in culture.

  12. Hyaluronic Acid Conjugates as Vectors for the Active Targeting of Drugs, Genes and Nanocomposites in Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Silvia Arpicco

    2014-03-01

    Full Text Available Hyaluronic acid (HA is a naturally-occurring glycosaminoglycan and a major component of the extracellular matrix. Low levels of the hyaluronic acid receptor CD44 are found on the surface of epithelial, hematopoietic, and neuronal cells; it is overexpressed in many cancer cells, and in particular in tumor-initiating cells. HA has recently attracted considerable interest in the field of developing drug delivery systems, having been used, as such or encapsulated in different types of nanoassembly, as ligand to prepare nano-platforms for actively targeting drugs, genes, and diagnostic agents. This review describes recent progress made with the several chemical strategies adopted to synthesize conjugates and prepare novel delivery systems with improved behaviors.

  13. Site-specific antibody-liposome conjugation through copper-free click chemistry: a molecular biology approach for targeted photodynamic therapy (Conference Presentation)

    Science.gov (United States)

    Obaid, Girgis; Wang, Yucheng; Kuriakose, Jerrin; Broekgaarden, Mans; Alkhateeb, Ahmed; Bulin, Anne-Laure; Hui, James; Tsourkas, Andrew; Hasan, Tayyaba

    2016-03-01

    Nanocarriers, such as liposomes, have the ability to potentiate photodynamic therapy (PDT) treatment regimens by the encapsulation of high payloads of photosensitizers and enhance their passive delivery to tumors through the enhanced permeability and retention effect. By conjugating targeting moieties to the surface of the liposomal nanoconstructs, cellular selectivity is imparted on them and PDT-based therapies can be performed with significantly higher dose tolerances, as off-target toxicity is simultaneously reduced.1 However, the maximal benefits of conventional targeted nanocarriers, including liposomes, are hindered by practical limitations including chemical instability, non-selective conjugation chemistry, poor control over ligand orientation, and loss of ligand functionality following conjugation, amongst others.2 We have developed a robust, physically and chemically stable liposomal nanoplatform containing benzoporphyrin derivative photosensitizer molecules within the phospholipid bilayer and an optimized surface density of strained cyclooctyne moieties for `click' conjugation to azido-functionalized antibodies.3 The clinical chimeric anti-EGFR antibody Cetuximab is site-specifically photocrosslinked to a recombinant bioengineered that recognizes the antibody's Fc region, containing a terminal azide.4 The copper-free click conjugation of the bioengineered Cetuximab derivative to the optimized photosensitizing liposome provides exceptional control over the antibody's optimal orientation for cellular antigen binding. Importantly, the reaction occurs rapidly under physiological conditions, bioorthogonally (selectively in the presence of other biomolecules) and without the need for toxic copper catalysis.3 Such state-of-the-art conjugation strategies push the boundaries of targeted photodynamic therapy beyond the limitations of traditional chemical coupling techniques to produce more robust and effective targeted therapeutics with applications beyond

  14. Doxorubicin conjugated functionalizable carbon dots for nucleus targeted delivery and enhanced therapeutic efficacy

    Science.gov (United States)

    Yang, Lei; Wang, Zheran; Wang, Ju; Jiang, Weihua; Jiang, Xuewei; Bai, Zhaoshi; He, Yunpeng; Jiang, Jianqi; Wang, Dongkai; Yang, Li

    2016-03-01

    Carbon dots (CDs) have shown great potential in imaging and drug/gene delivery applications. In this work, CDs functionalized with a nuclear localization signal peptide (NLS-CDs) were employed to transport doxorubicin (DOX) into cancer cells for enhanced antitumor activity. DOX was coupled to NLS-CDs (DOX-CDs) through an acid-labile hydrazone bond, which was cleavable in the weakly acidic intracellular compartments. The cytotoxicity of DOX-CD complexes was evaluated by the MTT assay and the cellular uptake was monitored using flow cytometry and confocal laser scanning microscopy. Cell imaging confirmed that DOX-CDs were mainly located in the nucleus. Furthermore, the complexes could efficiently induce apoptosis in human lung adenocarcinoma A549 cells. The in vivo therapeutic efficacy of DOX-CDs was investigated in an A549 xenograft nude mice model and the complexes exhibited an enhanced ability to inhibit tumor growth compared with free DOX. Thus, the DOX-CD conjugates may be exploited as promising drug delivery vehicles in cancer therapy.Carbon dots (CDs) have shown great potential in imaging and drug/gene delivery applications. In this work, CDs functionalized with a nuclear localization signal peptide (NLS-CDs) were employed to transport doxorubicin (DOX) into cancer cells for enhanced antitumor activity. DOX was coupled to NLS-CDs (DOX-CDs) through an acid-labile hydrazone bond, which was cleavable in the weakly acidic intracellular compartments. The cytotoxicity of DOX-CD complexes was evaluated by the MTT assay and the cellular uptake was monitored using flow cytometry and confocal laser scanning microscopy. Cell imaging confirmed that DOX-CDs were mainly located in the nucleus. Furthermore, the complexes could efficiently induce apoptosis in human lung adenocarcinoma A549 cells. The in vivo therapeutic efficacy of DOX-CDs was investigated in an A549 xenograft nude mice model and the complexes exhibited an enhanced ability to inhibit tumor growth compared

  15. p-Hydroxy benzoic acid-conjugated dendrimer nanotherapeutics as potential carriers for targeted drug delivery to brain: an in vitro and in vivo evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Swami, Rajan; Singh, Indu [National Institute of Pharmaceutical Education & Research (NIPER), Department of Pharmaceutics (India); Kulhari, Hitesh [CSIR-Indian Institute of Chemical Technology, Medicinal Chemistry & Pharmacology Division (India); Jeengar, Manish Kumar [National Institute of Pharmaceutical Education & Research (NIPER), Departmentof Pharmacology (India); Khan, Wahid, E-mail: wahid@niperhyd.ac.in; Sistla, Ramakrishna, E-mail: sistla@iict.res.in, E-mail: rksistla@yahoo.com [National Institute of Pharmaceutical Education & Research (NIPER), Department of Pharmaceutics (India)

    2015-06-15

    Dendrimers which are discrete nanostructures/nanoparticles are emerging as promising candidates for many nanomedicine applications. Ligand-conjugated dendrimer facilitate the delivery of therapeutics in a targeted manner. Small molecules such as p-hydroxyl benzoic acid (pHBA) were found to have high affinity for sigma receptors which are prominent in most parts of central nervous system and tumors. The aim of this study was to synthesize pHBA-dendrimer conjugates as colloidal carrier for site-specific delivery of practically water insoluble drug, docetaxel (DTX) to brain tumors and to determine its targeting efficiency. pHBA, a small molecule ligand was coupled to the surface amine groups of generation 4-PAMAM dendrimer via a carbodiimide reaction and loaded with DTX. The conjugation was confirmed by {sup 1}HNMR and FT-IR spectroscopy. In vitro release of drug from DTX-loaded pHBA-conjugated dendrimer was found to be less as compared to unconjugated dendrimers. The prepared drug delivery system exhibited good physico-chemical stability and decrease in hemolytic toxicity. Cell viability and cell uptake studies were performed against U87MG human glioblastoma cells and formulations exerted considerable anticancer effect than plain drug. Conjugation of dendrimer with pHBA significantly enhanced the brain uptake of DTX which was shown by the recovery of a higher percentage of the dose from the brain following administration of pHBA-conjugated dendrimers compared with unconjugated dendrimer or formulation in clinical use (Taxotere{sup ®}). Therefore, pHBA conjugated dendrimers could be an efficient delivery vehicle for the targeting of anticancer drugs to brain tumors.

  16. BRCAA1 monoclonal antibody conjugated fluorescent magnetic nanoparticles for in vivo targeted magnetofluorescent imaging of gastric cancer

    Directory of Open Access Journals (Sweden)

    Ni Jian

    2011-05-01

    Full Text Available Abstract Background Gastric cancer is 2th most common cancer in China, and is still the second most common cause of cancer-related death in the world. How to recognize early gastric cancer cells is still a great challenge for early diagnosis and therapy of patients with gastric cancer. This study is aimed to develop one kind of multifunctional nanoprobes for in vivo targeted magnetofluorescent imaging of gastric cancer. Methods BRCAA1 monoclonal antibody was prepared, was used as first antibody to stain 50 pairs of specimens of gastric cancer and control normal gastric mucous tissues, and conjugated with fluorescent magnetic nanoparticles with 50 nm in diameter, the resultant BRCAA1-conjugated fluorescent magnetic nanoprobes were characterized by transmission electron microscopy and photoluminescence spectrometry, as-prepared nanoprobes were incubated with gastric cancer MGC803 cells, and were injected into mice model loaded with gastric cancer of 5 mm in diameter via tail vein, and then were imaged by fluorescence optical imaging and magnetic resonance imaging, their biodistribution was investigated. The tissue slices were observed by fluorescent microscopy, and the important organs such as heart, lung, kidney, brain and liver were analyzed by hematoxylin and eosin (HE stain method. Results BRCAA1 monoclonal antibody was successfully prepared, BRCAA1 protein exhibited over-expression in 64% gastric cancer tissues, no expression in control normal gastric mucous tissues, there exists statistical difference between two groups (P in vivo gastric cancer tissues loaded by mice, and could be used to image gastric cancer tissues by fluorescent imaging and magnetic resonance imaging, and mainly distributed in local gastric cancer tissues within 12 h post-injection. HE stain analysis showed that no obvious damages were observed in important organs. Conclusions The high-performance BRCAA1 monoclonal antibody-conjugated fluorescent magnetic nanoparticles

  17. Novel platinum(IV) complexes conjugated with a wogonin derivative as multi-targeted anticancer agents.

    Science.gov (United States)

    Qin, Xiaodong; Xu, Gang; Chen, Feihong; Fang, Lei; Gou, Shaohua

    2017-04-15

    Platinum-based complexes like cisplatin and oxaliplatin are well known the mainstay of chemotherapy regimens on clinic. Wogonin, a natural product that possesses wide biological activities, is now in phase I clinical test as an anticancer agent in China. Herein reported are a series of novel Pt(IV) complexes that conjugated a wogonin derivative (compound 3) to the axial position via a linker group. After being tethered to the platinum(IV) complexes, the wogonin derivative provided multiple anticancer effects, especially in compound 10, a fusion containing wogonin and cisplatin units. Compound 10 not only inherited the genotoxicity from cisplatin, but also obtained the COX inhibitory property from the wogonin derivative. Further mechanistic investigation revealed that compound 10 caused the accumulation of ROS, decreased the mitochondrial membrane potential (ΔΨm) and then activated the p53 pathway. Overall, the research demonstrates that the "integrative" prodrug can be an effective strategy to promote the anticancer potency of Pt-based drugs for cancer treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Targeted inactivation of Snail family EMT regulatory factors by a Co(III)-Ebox conjugate.

    Science.gov (United States)

    Harney, Allison S; Meade, Thomas J; LaBonne, Carole

    2012-01-01

    Snail family proteins are core EMT (epithelial-mesenchymal transition) regulatory factors that play essential roles in both development and disease processes and have been associated with metastasis in carcinomas. Snail factors are required for the formation of neural crest stem cells in most vertebrate embryos, as well as for the migratory invasive behavior of these cells. Snail factors have recently been linked to the formation of cancer stem cells, and expression of Snail proteins may be associated with tumor recurrence and resistance to chemotherapy and radiotherapy. We report that Co(III)-Ebox is a potent inhibitor of Snail-mediated transcriptional repression in breast cancer cells and in the neural crest of Xenopus. We further show that the activity of Co(III)-Ebox can be modulated by temperature, increasing the utility of this conjugate as a Snail inhibitor in model organisms. We exploit this feature to further delineate the requirements for Snail function during neural crest development, showing that in addition to the roles that Snail factors play in neural crest precursor formation and neural crest EMT/migration, inhibition of Snail function after the onset of neural crest migration leads to a loss of neural crest derived melanocytes. Co(III)-Ebox-mediated inhibition therefore provides a powerful tool for analysing the function of these core EMT factors with unparalleled temporal resolution. Moreover, the potency of Co(III)-Ebox as a Snail inhibitor in breast cancer cells suggests its potential as a therapeutic inhibitor of tumor progression and metastasis.

  19. Prostate stem cell antigen antibody-conjugated multiwalled carbon nanotubes for targeted ultrasound imaging and drug delivery.

    Science.gov (United States)

    Wu, Huixia; Shi, Haili; Zhang, Hao; Wang, Xue; Yang, Yan; Yu, Chao; Hao, Caiqin; Du, Jing; Hu, He; Yang, Shiping

    2014-07-01

    Multiwalled carbon nanotubes (MWCNTs) are cut short and grafted with polyethylenimine (PEI) for further covalent conjugation to fluorescein isothiocyanate (FITC) and prostate stem cell antigen (PSCA) monoclonal antibody (mAb). The in vitro and in vivo toxicity data reveal that the as-prepared CNT-PEI(FITC)-mAb has good biocompatibility. Combined flow cytometry and confocal luminescence imaging experiments confirm that the CNT-PEI(FITC)-mAb can specifically target the cancer cells which overexpress PSCA. The results of in vitro and in vivo ultrasound (US) imaging indicate that CNT-PEI(FITC)-mAb has great potential to be used as a targeted US contrast agent. The in vivo anti-cancer efficacy testing using PC-3 tumor-bearing mice as animal models demonstrates that CNT-PEI(FITC)-mAb can targetedly deliver drug to the tumors and suppress tumor growth. Findings from this study suggest that the CNT-PEI(FITC)-mAb could be used as a multifunctional platform for simultaneous US imaging and drug delivery applications.

  20. Targeting DNA with "light-up" pyrimidine triple-helical forming oligonucleotides conjugated to stabilizing fluorophores (LU-TFOs).

    Science.gov (United States)

    Renard, Brice-Loïc; Lartia, Rémy; Asseline, Ulysse

    2008-12-07

    The synthesis of triple-helix-forming oligonucleotides (TFOs) linked to a series of cyanine monomethines has been performed. Eight cyanines including one thiocyanine, four thiazole orange analogues, and three quinocyanines were attached to the 5'-end of 10-mer pyrimidine TFOs. The binding properties of these modified TFOs with their double-stranded DNA target were studied by absorption and steady-state fluorescence spectroscopy. The stability of the triplex structures depended on the cyanine structure and the linker size used to connect both entities. The most efficient cyanines able to stabilize the triplex structures, when attached at the 5'-end of the TFO, have been incorporated at both ends and provided triplex structures with increased stability. Fluorescence studies have shown that for the TFOs involving one cyanine, an important intensity increase (up to 37-fold) in the fluorescent signal was observed upon their hybridization with the double-stranded target, proving hybridization. The conjugates involving thiazole orange attached by the benzothiazole ring provided the most balanced properties in terms of triplex stabilization, fluorescence intensity and fluorescence enhancement upon hybridization with the double-stranded target. In order to test the influence of different parameters such as the TFO sequence and length, thiazole orange was used to label 17-mer TFOs. Hybridizations of these TFOs with different duplexes, designed to study the influence of mismatches at both internal and terminal positions on the triplex structures, confirmed the possibility of triplex formation without loss of specificity together with a strong fluorescence enhancement (up to 13-fold).

  1. CD9 monoclonal antibody-conjugated PEGylated liposomes for targeted delivery of rapamycin in the treatment of cellular senescence

    Science.gov (United States)

    Thuy Nguyen, Hanh; Thapa, Raj Kumar; Shin, Beom Soo; Jeong, Jee-Heon; Kim, Jae-Ryong; Yong, Chul Soon; Kim, Jong Oh

    2017-03-01

    Premature cellular senescence refers to the state of irreversible cell cycle arrest due to DNA damage or other stresses. In this study, CD9 monoclonal antibody (CD9mAb) was successfully conjugated to the surface of PEGylated liposomes for targeted delivery of rapamycin (LR-CD9mAb) to overcome senescence of CD9 receptor-overexpressing cells. LR-CD9mAb has a small particle size (143.3 ± 2.4 nm), narrow size distribution (polydispersity index: 0.220 ± 0.036), and negative zeta potential (‑14.6 ± 1.2 mV). The uptake of CD9-targeted liposomes by premature senescent human dermal fibroblasts (HDFs) was higher than that by young HDFs, as displayed by confocal microscopic images. The senescence might not be reversed by treatment with rapamycin; however, the drug promoted cell proliferation and reduced the number of cells that expressed the senescence-associated-β-galactosidase (SA-β-gal). These effects were further confirmed by cell viability, cell cycle, and Western blotting analyses. Moreover, CD9-targeted liposomes showed better anti-senescence activity, in comparison with free rapamycin or the conventional liposomal formulation, suggesting the potential application of this system in further in vivo studies.

  2. Targeted inactivation of Snail family EMT regulatory factors by a Co(III-Ebox conjugate.

    Directory of Open Access Journals (Sweden)

    Allison S Harney

    Full Text Available Snail family proteins are core EMT (epithelial-mesenchymal transition regulatory factors that play essential roles in both development and disease processes and have been associated with metastasis in carcinomas. Snail factors are required for the formation of neural crest stem cells in most vertebrate embryos, as well as for the migratory invasive behavior of these cells. Snail factors have recently been linked to the formation of cancer stem cells, and expression of Snail proteins may be associated with tumor recurrence and resistance to chemotherapy and radiotherapy. We report that Co(III-Ebox is a potent inhibitor of Snail-mediated transcriptional repression in breast cancer cells and in the neural crest of Xenopus. We further show that the activity of Co(III-Ebox can be modulated by temperature, increasing the utility of this conjugate as a Snail inhibitor in model organisms. We exploit this feature to further delineate the requirements for Snail function during neural crest development, showing that in addition to the roles that Snail factors play in neural crest precursor formation and neural crest EMT/migration, inhibition of Snail function after the onset of neural crest migration leads to a loss of neural crest derived melanocytes. Co(III-Ebox-mediated inhibition therefore provides a powerful tool for analysing the function of these core EMT factors with unparalleled temporal resolution. Moreover, the potency of Co(III-Ebox as a Snail inhibitor in breast cancer cells suggests its potential as a therapeutic inhibitor of tumor progression and metastasis.

  3. Targeting of peptide conjugated magnetic nanoparticles to urokinase plasminogen activator receptor (uPAR) expressing cells

    DEFF Research Database (Denmark)

    Hansen, Line; Unmack Larsen, Esben Kjær; Nielsen, Erik Holm

    2013-01-01

    Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles are currently being used as a magnetic resonance imaging (MRI) contrast agent in vivo, mainly by their passive accumulation in tissues of interest. However, a higher specificity can ideally be achieved when the nanoparticles are targeted...... towards cell specific receptors and this may also facilitate specific drug delivery by an enhanced target-mediated endocytosis. We report efficient peptide-mediated targeting of magnetic nanoparticles to cells expressing the urokinase plasminogen activator receptor (uPAR), a surface biomarker for poor...... to nanoparticles carrying a non-binding control peptide. In accordance with specific receptor-mediated recognition, a low uptake was observed in the presence of an excess of ATF, a natural ligand for uPAR. The uPAR specific magnetic nanoparticles can potentially provide a useful supplement for tumor patient...

  4. Molecular targets of omega 3 and conjugated linoleic fatty acids – micromanaging cellular response

    Directory of Open Access Journals (Sweden)

    Francesco eVisioli

    2012-02-01

    Full Text Available Essential fatty acids cannot be synthesized de novo by mammals and need to be ingested either with the diet or through the use of supplements/functional foods to ameliorate cardiovascular prognosis. This review focus on the molecular targets of omega 3 fatty acids and CLA, as paradigmatic molecules that can be explored both as nutrients and as pharmacological agents, especially as related to cardioprotection. In addition, we indicate novel molecular targets, namely microRNAs that might contribute to the observed biological activities of such essential fatty acids.

  5. Gold nanoparticles generated and stabilized by water soluble curcumin-polymer conjugate: blood compatibility evaluation and targeted drug delivery onto cancer cells.

    Science.gov (United States)

    Manju, S; Sreenivasan, K

    2012-02-15

    Curcumin (Cur) shows low anticancer activity in vivo due to its reduced systemic bioavailability stemmed from its poor aqueous solubility and instability. Suitably functionalized nanocarriers designed to empty the drug specifically at tumor sites can potentially enhance the antitumor activity of Cur. We devised a simple method for the fabrication of water soluble Cur conjugated gold nanoparticles to target various cancer cell lines. Cur was conjugated to hyaluronic acid (HA) to get a water soluble conjugate (HA-Cur). We generated gold nanoparticles (AuNPs) by reducing chloroauric acid using HA-Cur, which played the dual role of a reducing and stabilizing agent and subsequently anchored folate conjugated PEG. These entities were probed using different analytical techniques, assayed the blood compatibility and cytotoxicity. Their interaction with cancer cell lines (HeLa cells, glyoma cells and Caco 2 cells) was followed by flow cytometry and confocal microscopy. Blood-materials interactions studies showed that the nanoparticles are highly hemocompatible. Flow cytometry and confocal microscopy results showed significant cellular uptake and internalization of the particles by cells. HA-Cur@AuNPs exhibited more cytotoxicity comparing to free Cur. The strategy, we adopted here, resulted the formation blood compatible Cur conjugated AuNPs with enhanced targeting and improved efficacy. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity

    NARCIS (Netherlands)

    Kreutz, M.; Giquel, B.; Hu, Q.; Abuknesha, R.; Uematsu, S.; Akira, S.; Nestle, F.O.; Diebold, S.S.

    2012-01-01

    Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC) by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is par

  7. BRCAA1 antibody- and Her2 antibody-conjugated amphiphilic polymer engineered CdSe/ZnS quantum dots for targeted imaging of gastric cancer

    Science.gov (United States)

    Li, Chao; Ji, Yang; Wang, Can; Liang, Shujing; Pan, Fei; Zhang, Chunlei; Chen, Feng; Fu, Hualin; Wang, Kan; Cui, Daxiang

    2014-05-01

    Successful development of safe and highly effective nanoprobes for targeted imaging of in vivo early gastric cancer is a great challenge. Herein, we choose the CdSe/ZnS (core-shell) quantum dots (QDs) as prototypical materials, synthesized one kind of a new amphiphilic polymer including dentate-like alkyl chains and multiple carboxyl groups, and then used the prepared amphiphilic polymer to modify QDs. The resultant amphiphilic polymer engineered QDs (PQDs) were conjugated with BRCAA1 and Her2 monoclonal antibody, and prepared BRCAA1 antibody- and Her2 antibody-conjugated QDs were used for in vitro MGC803 cell labeling and in vivo targeted imaging of gastric cancer cells. Results showed that the PQDs exhibited good water solubility, strong photoluminescence (PL) intensity, and good biocompatibility. BRCAA1 antibody- and Her2 antibody-conjugated QD nanoprobes successfully realized targeted imaging of in vivo gastric cancer MGC803 cells. In conclusion, BRCAA1 antibody- and Her2 antibody-conjugated PQDs have great potential in applications such as single cell labeling and in vivo tracking, and targeted imaging and therapeutic effects' evaluation of in vivo early gastric cancer cells in the near future.

  8. SM5-1-conjugated PLA nanoparticles loaded with 5-fluorouracil for targeted hepatocellular carcinoma imaging and therapy.

    Science.gov (United States)

    Ma, Xibo; Cheng, Zhen; Jin, Yushen; Liang, Xiaolong; Yang, Xin; Dai, Zhifei; Tian, Jie

    2014-03-01

    SM5-1 is a humanized mouse antibody which has a high binding specificity for a membrane protein of about 230 kDa overexpressed in hepatocellular carcinoma (HCC), melanoma and breast cancer. In this study, SM5-1-conjugated poly D, L (lactide-coglycolide) (PLA) PLA containing Cy7 (PLA-Cy7-SM5-1) was prepared to study the targeting specificity of the bioconjugate to HCC-LM3-fLuc cell. Then, SM5-1-conjugated PLA containing 5-fluorouracil (5-FU) (PLA-5FU-SM5-1) and PLA containing 5-FU (PLA-5FU) were prepared for treatment of subcutaneous HCC-LM3-fLuc tumor mice. The results showed that PLA-5FU-SM5-1, PLA-5FU and 5-FU induced a 45.07%, 23.56% and 19.05% tumor growth inhibition rate, respectively, on day 31 post-treatment as determined by bioluminescent intensity. In addition, in order to evaluate the antitumor efficacy of PLA-5FU-SM5-1, HCC-LM3-fLuc cells were injected into the liver to establish the experimental orthotopic liver tumor models. The experiments showed that PLA-5FU-SM5-1, PLA-5FU and 5-FU induced a 53.24%, 31.00%, and 18.11% tumor growth inhibition rate, respectively, on day 31 post-treatment determined by the bioluminescent intensity of the abdomen in tumor-bearing mice. Furthermore, we have calculated the three-dimensional location of the liver cancer in mice using a multilevel adaptive finite element algorithm based on bioluminescent intensity decay calibration. The reconstruction results demonstrated that PLA-5FU-SM5-1 inhibited the tumor rapid progression, which were consistent with the results of subcutaneous tumor mice experiments and in vitro cell experiment results.

  9. Preparation, characterization and targeting of micronized 10-hydroxycamptothecin-loaded folate-conjugated human serum albumin nanoparticles to cancer cells

    Directory of Open Access Journals (Sweden)

    et al

    2011-02-01

    Full Text Available Qingyong Li, Chen Liu, Xiuhua Zhao, Yuangang Zu, Ying Wang, Baoyou Zhang, Dongmei Zhao, Qi Zhao, Lin Su, Yang Gao, Baihe SunKey Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang, People's Republic of ChinaBackground: The purpose of this study was to develop a method for targeted delivery of 10-hydroxycamptothecin (HCPT-loaded nanoparticles (NPs to cancer cells.Methods: We first used a supercritical antisolvent process to prepare micronized HCPT (nHCPT, and then folate-conjugated human serum albumin (HSA nHCPT-loaded NPs (FA-HSA-nHCPT-NPs were prepared using a NP-coated method combined with a desolvation technique. The amount of folate conjugation was 16 µg · mg-1 HSA.Results: The particle size of the spherical nHCPT microparticles obtained was 118.5 ± 6.6 nm. The particle size and zeta potential of the FA-HSA-nHCPT-NPs were 233.9 ± 1.2 nm and -25.23 ± 2.98 mV, respectively. The FA-HSA-nHCPT-NPs exhibited a smooth surface and a distinct spherical shape, and the results of differential scanning calorimetry and X-ray diffraction indicated that the FA-HSA-nHCPT-NPs presented in a nanostructured amorphous state. The FA-HSA-nHCPT-NPs showed sustained-release characteristics for 120 hours in vitro, with a drug-loading content of 7.3% and an encapsulating efficiency of 79.1%.Conclusion: The FA-NPs were effective delivery systems for uptake by SGC7901 cells compared with folate-free NPs. These results suggest that a NP-coated method combined with a desolvation technique is effective for preparing NPs with drugs having poor solubility in water and most organic solvents, using albumin as the wall material. FA-HSA-NPs are a stable delivery system and have the potential for targeted delivery of anticancer drugs.Keywords: nanoparticle-coated, desolvation technique, 10-hydroxycamptothecin, human serum albumin, folate, targeted delivery 

  10. Ligand-conjugated mesoporous silica nanorattles based on enzyme targeted prodrug delivery system for effective lung cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sundarraj, Shenbagamoorthy, E-mail: sundarrajbu09@gmail.com [Proteomics and Molecular Cell Physiology Laboratory, Department of Zoology, Bharathiar University, Coimbatore 641 046, TN (India); Thangam, Ramar [Proteomics and Molecular Cell Physiology Laboratory, Department of Zoology, Bharathiar University, Coimbatore 641 046, TN (India); Department of Virology, King Institute of Preventive Medicine and Research, Guindy, Chennai 600 032, TN (India); Sujitha, Mohanan V.; Vimala, Karuppaiya [Proteomics and Molecular Cell Physiology Laboratory, Department of Zoology, Bharathiar University, Coimbatore 641 046, TN (India); Kannan, Soundarapandian, E-mail: skperiyaruniv@gmail.com [Proteomics and Molecular Cell Physiology Laboratory, Department of Zoology, Bharathiar University, Coimbatore 641 046, TN (India); Department of Zoology, Periyar University, Salem 636 011, TN (India)

    2014-03-15

    Epidermal growth factor receptor antibody (EGFRAb) conjugated silica nanorattles (SNs) were synthesized and used to develop receptor mediated endocytosis for targeted drug delivery strategies for cancer therapy. The present study determined that the rate of internalization of silica nanorattles was found to be high in lung cancer cells when compared with the normal lung cells. EGFRAb can specifically bind to EGFR, a receptor that is highly expressed in lung cancer cells, but is expressed at low levels in other normal cells. Furthermore, in vitro studies clearly substantiated that the cPLA{sub 2}α activity, arachidonic acid release and cell proliferation were considerably reduced by pyrrolidine-2 loaded EGFRAb-SN in H460 cells. The cytotoxicity, cell cycle arrest and apoptosis were significantly induced by the treatment of pyrrolidine-2 loaded EGFRAb-SN when compared with free pyrrolidine-2 and pyrrolidine-2 loaded SNs in human non-small cell lung cancer cells. An in vivo toxicity assessment showed that silica nanorattles and EGFRAb-SN-pyrrolidine-2 exhibited low systemic toxicity in healthy Balb/c mice. The EGFRAb-SN-pyrrolidine-2 showed a much better antitumor activity (38%) with enhanced tumor inhibition rate than the pyrrolidine-2 on the non-small cell lung carcinoma subcutaneous model. Thus, the present findings validated the low toxicity and high therapeutic potentials of EGFRAb-SN-pyrrolidine-2, which may provide a convincing evidence of the silica nanorattles as new potential carriers for targeted drug delivery systems. - Highlights: • EGFRAb-SN developed for receptor-mediated Drug delivery system (DDS). • EGFRAb-SN-pyrrolidine-2 targeted DDS for cPLA2α inhibition in NSLC. • Study indicates EGFRAb-SN-pyrrolidine-2 as an efficient in target dug delivery carrier. • Study explains entire efficiency of EGFRAb-SN-pyrrolidine-2 in vitro and in vivo models.

  11. Development of a potent DOTA-conjugated bombesin antagonist for targeting GRPr-positive tumours

    Energy Technology Data Exchange (ETDEWEB)

    Mansi, Rosalba; Maecke, Helmut R. [University Hospital Basel, Division of Radiological Chemistry, Basel (Switzerland); University of Freiburg, Department of Nuclear Medicine, Freiburg (Germany); Wang, Xuejuan [University Hospital Basel, Division of Radiological Chemistry, Basel (Switzerland); Forrer, Flavio [University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); Erasmus Medical Centre, Nuclear Medicine, Rotterdam (Netherlands); Waser, Beatrice; Cescato, Renzo; Reubi, Jean Claude [University of Berne, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, Berne (Switzerland); Graham, Keith; Borkowski, Sandra [Bayer Schering Pharma AG, Global Drug Discovery, Berlin (Germany)

    2011-01-15

    Radiolabelled somatostatin-based antagonists show a higher uptake in tumour-bearing mouse models than agonists of similar or even distinctly higher receptor affinity. Very similar results were obtained with another family of G protein-coupled receptor ligands, the bombesin family. We describe a new conjugate, RM2, with the chelator DOTA coupled to D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH{sub 2} via the cationic spacer 4-amino-1-carboxymethyl-piperidine for labelling with radiometals such as {sup 111}In and {sup 68}Ga. RM2 was synthesized on a solid support and evaluated in vitro in PC-3 cells. IC{sub 50} and K{sub d} values were determined. The antagonist potency was evaluated by immunofluorescence-based internalization and Ca{sup 2+} mobilization assays. Biodistribution studies were performed in PC-3 and LNCaP tumour-bearing mice with {sup 111}In-RM2 and {sup 68}Ga-RM2, respectively. PET/CT studies were performed on PC-3 and LNCaP tumour-bearing nude mice with {sup 68}Ga-RM2. RM2 and {sup 111}In-RM2 are high-affinity and selective ligands for the GRP receptor (7.7{+-}3.3 nmol/l for RM2; 9.3{+-}3.3 nmol/l for {sup nat}In-RM2). The potent antagonistic properties were confirmed by an immunofluorescence-based internalization and Ca{sup 2+} mobilization assays. {sup 68}Ga- and {sup 111}In-RM2 showed high and specific uptake in both the tumour and the pancreas. Uptake in the tumour remained high (15.2{+-}4.8%IA/g at 1 h; 11.7{+-}2.4%IA/g at 4 h), whereas a relatively fast washout from the pancreas and the other abdominal organs was observed. Uptake in the pancreas decreased rapidly from 22.6{+-}4.7%IA/g at 1 h to 1.5{+-}0.5%IA/g at 4 h. RM2 was shown to be a potent GRPr antagonist. Pharmacokinetics and imaging studies indicate that {sup 111}In-RM2 and {sup 68}Ga-RM2 are ideal candidates for clinical SPECT and PET studies. (orig.)

  12. The targeted transduction of MMP-overexpressing tumor cells by ACPP-HPMA copolymer-coated adenovirus conjugates.

    Directory of Open Access Journals (Sweden)

    Shuhua Li

    Full Text Available We have designed and tested a new way to selectively deliver HPMA polymer-coated adenovirus type 5 (Ad5 particles into matrix metalloproteinase (MMP-overexpressing tumor cells. An activatable cell penetrating peptide (ACPP was designed and attached to the reactive 4-nitrophenoxy groups of HPMA polymers by the C-terminal amino acid (asparagine, N. ACPPs are activatable cell penetrating peptides (CPPs with a linker between polycationic and polyanionic domains, and MMP-mediated cleavage releases the CPP portion and its attached cargo to enable cell entry. Our data indicate that the transport of these HPMA polymer conjugates by a single ACPP molecule to the cytoplasm occurs via a nonendocytotic and concentration-independent process. The uptake was observed to finish within 20 minutes by inverted fluorescence microscopy. In contrast, HPMA polymer-coated Ad5 without ACPPs was internalized solely by endocytosis. The optimal formulation was not affected by the presence of Ad5 neutralizing antibodies during transduction, and ACPP/polymer-coated Ad5 also retained high targeting capability to several MMP-overexpressing tumor cell types. For the first time, ACPP-mediated cytoplasmic delivery of polymer-bound Ad5 to MMP-overexpressing tumor cells was demonstrated. These findings are significant, as they demonstrate the use of a polymer-based system for the targeted delivery into MMP-overexpressing solid tumors and highlight how to overcome major cellular obstacles to achieve intracellular macromolecular delivery.

  13. Photosensitizer-conjugated magnetic nanoparticles for in vivo simultaneous magnetofluorescent imaging and targeting therapy.

    Science.gov (United States)

    Huang, Peng; Li, Zhiming; Lin, Jing; Yang, Dapeng; Gao, Guo; Xu, Cheng; Bao, Le; Zhang, Chunlei; Wang, Kan; Song, Hua; Hu, Hengyao; Cui, Daxiang

    2011-05-01

    A major challenge in nanotechnology and nanomedicine is to integrate tumor targeting, imaging, and selective therapy functions into a small single nanoparticle (gastric cancer imaging and therapy. The second generation photosensitizer chlorin e6 (Ce6) was covalently anchored on the surface of magnetic nanoparticles with silane coupling agent. We found that the covalently incorporated Ce6 molecules retained their spectroscopic and functional properties for near-infrared (NIR) fluorescence imaging and photodynamic therapy (PDT), and the core magnetic nanoparticles offered the functions of magnetically guided drug delivery and magnetic resonance imaging (MRI). The as-prepared single particle platform is suitable for simultaneous targeting PDT and in vivo dual-mode NIR fluorescence imaging and MRI of nude mice loaded with gastric cancer or other tumors.

  14. TNYL peptide functional chitosan-g-stearate conjugate micelles for tumor specific targeting

    Directory of Open Access Journals (Sweden)

    Chen FY

    2014-09-01

    Full Text Available Feng-Ying Chen,1 Jing-Jing Yan,1 Han-Xi Yi,2 Fu-Qiang Hu,2 Yong-Zhong Du,2 Hong Yuan,2 Jian You,2 Meng-Dan Zhao1 1Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, People’s Republic of China; 2College of Pharmaceutical Science, Zhejiang University, Hangzhou, People’s Republic of China Abstract: Nowadays, a real challenge in cancer therapy is to design drug delivery systems that can achieve high concentrations of drugs at the target site for improved therapeutic effect with reduced side effects. In this research, we designed and synthesized a homing peptide-(TNYLFSPNGPIA, TNYL modified chitosan-g-stearate (CS polymer micelle (named T-CS for targeting delivery. The peptide displayed specific binding affinity to EphB4 which is a member of the Eph family of receptor tyrosine protein kinases. The amphiphilic polymer T-CS can gather into micelles by themselves in an aqueous environment with a low critical micelle concentration value (91.2 µg/L and nano-scaled size (82.1±2.8 nm. The drug encapsulation efficiency reached 86.43% after loading the hydrophobic drug doxorubicin (DOX. The cytotoxicity of T-CS/DOX against SKOV3 cells was enhanced by approximately 2.3-fold when compared with CS/DOX. The quantitative and qualitative analysis for cellular uptake indicated that TNYL modification can markedly increase cellular internalization in the EphB4-overexpressing SKOV3 cell line, especially with a short incubation time. It is interesting that relatively higher uptake of the T-CS/DOX micelles by SKOV3 cells (positive-EphB4 than A549 cells (negative-EphB4 was observed when the two cells were co-incubated. Furthermore, in vivo distribution experiment using a bilateral-tumor model showed that there was more fluorescence accumulation in the SKOV3 tumor than in the A549 tumor over the whole experiment. These results suggest that TNYL-modified CS micelles may be promising drug carriers as targeting therapy for the EphB4-overexpressing

  15. Folic acid conjugated guar gum nanoparticles for targeting methotrexate to colon cancer.

    Science.gov (United States)

    Sharma, Monika; Malik, Ritu; Verma, Ashwni; Dwivedi, Pankaj; Banoth, Gabbar Singh; Pandey, Nagendra; Sarkar, Jayant; Mishra, Prabhat Ranjan; Dwivedi, Anil Kumar

    2013-01-01

    It was envisaged to develop surface modified Guar Gum Nanoparticles (GGNP) with Folic acid (FA) charged with methotrexate (MTX) to target the colon specifically. The MTX loaded FA functionalized GGNP (MTX-FA-GGNP) have been prepared by emulsion crosslinking method. These surface modified nanoparticles were compared with unmodified MTX loaded GGNP (MTX-GGNP). The developed formulations were evaluated for size and size distribution, zeta potential, Differential Scanning Calorimetry (DSC), release profile and uptake studies. The nanoparticles have been found to have average size of 325 nm in diameter having polydispersity index (PDI) 0.177 indicating mono-disperse particles. The zeta potential of the particles was found to be -36.9 mV. The percent growth inhibition of Caco 2 cells with MTX-FA-GGNP was found to be better than MTX-GGNP indicating folate receptor mediated uptake. The MTX-GGNP protects the release of MTX in upper gastrointestinal tract while maximum release of MTX occurred in simulated colonic fluids of pH 6.8. The in vivo uptake studies revealed preferential uptake of nanoparticles formulation in the colon. These studies provide evidences that MTX-FA-GGNP holds promise to address colorectal cancer over-expressing folate receptors. This prototype formulation enjoys dual advantage of having propensity to release the drug in the colon and in the conditions of colorectal carcinoma; it could be better localized and targeted with improved therapy due to over-expression of folate receptors.

  16. A renal-targeted triptolide aminoglycoside (TPAG) conjugate for lowering systemic toxicities of triptolide.

    Science.gov (United States)

    Qi, Bowen; Wang, Xinyi; Zhou, Yangyang; Han, Qiao; He, Ling; Gong, Tao; Sun, Xun; Fu, Yao; Zhang, Zhirong

    2015-06-01

    Triptolide (TP), a naturally derived compound, is proven effective in the treatment of nephritis and chronic allograft nephropathy. However, the severe multiorgan toxicity greatly limited it from further clinic use. 2-Glucosamine was demonstrated as a potential targeting ligand that could specifically interact with megalin receptors highly expressed in renal proximal tubules. In this study, 2-glucosamine was employed as a glycosyl donor while triptolide the acceptor to afford a nonhydrolyzable triptolide derivative-triptolide aminoglycoside (TPAG). The kidney-targeting efficiency, pharmacodynamic properties and safety of TPAG were thus evaluated. TPAG displayed 6.94-fold of AUC(0-t, kidney) and 13.96-fold of MRT(0-t, kidney) compared to TP. Additionally, TPAG presented improved protective effect against renal ischemia/reperfusion injury. Compared to TP's multiorgan toxicity, TPAG showed minimum toxicity toward the kidney and genital systems, and greatly lowered toxicity in the liver and immune systems. In sum, our study presented an alternative structure modification of triptolide with improved safety and efficacy profiles.

  17. Antibody-conjugated soybean oil-filled calcium phosphate nanoshells for targetted delivery of hydrophobic molecules.

    Science.gov (United States)

    Schmidt, H T; Kroczynski, M; Maddox, J; Chen, Y; Josephs, R; Ostafin, A E

    2006-11-01

    Hollow calcium phosphate nanoparticles capable of encapsulating poorly water-soluble molecules were produced by self-assembly. Previously reported were solid calcium phosphate nanoparticles and water-filled calcium phosphate nanocapsules suited for encapsulating mostly hydrophilic, but not hydrophobic compounds. Here, calcium phosphate was deposited around 100 nm diameter, 1,2-dioleoyl-sn-glycero-3-phosphate stabilized soybean oil nanoemulsions using either calcium chloride or NaOH titrations to achieve shell thickness between 20-70 nm. The surface was functionalized with carboxylic acid via the addition of carboxyethylphosphonic acid to attach Molecular Probes AB-594C antibody using sulpho-n-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride with an efficiency of approximately 70%, while retaining near complete antibody function. Hydrophobic pyrene was encapsulated with an efficiency of 95%, at concentrations much higher than its water solubility limit, and exhibited spectral features characteristic of a hydrophobic environment. These materials can be used in the targeted delivery of many useful, yet poorly water-soluble pharmaceutical and nutraceutical compounds.

  18. Binding and NMR structural studies on indoloquinoline-oligonucleotide conjugates targeting duplex DNA.

    Science.gov (United States)

    Eick, Andrea; Riechert-Krause, Fanny; Weisz, Klaus

    2012-06-20

    An 11-phenyl-indolo[3,2-b]quinoline (PIQ) was tethered through an aminoalkyl linker to the 5'-end of four pyrimidine oligonucleotides with T/C scrambled sequences at their two 5'-terminal positions. Binding to different double-helical DNA targets formed parallel triple helices with a PIQ-mediated stabilization that strongly depends on pH and the terminal base triad at the 5'-triplex-duplex junction. The most effective stabilization was observed with a TAT triplet at the 5'-junction under low pH conditions, pointing to a protonated ligand with a high triplex binding affinity and unfavorable charge repulsions in the case of a terminal C(+)GC triplet at the junction. The latter preference of the PIQ ligand for TAT over CGC is alleviated yet still preserved at higher pH. Intercalation of PIQ at the 5'-triplex-duplex junction as suggested by the triplex melting experiments was confirmed by homonuclear and heteronuclear NMR structural studies on a specifically isotope-labeled triplex. The NMR analysis revealed two coexisting species that only differ by a 180° rotation of the indoloquinoline within the intercalation pocket. NOE-derived molecular models indicate extensive stacking interactions of the indoloquinoline moiety with the TAT base triplet and CG base pair at the junction and a phenyl substituent that is positioned in the major groove and oriented almost perpendicular to the plane of the indoloquinoline.

  19. Bone-targeted acid-sensitive doxorubicin conjugate micelles as potential osteosarcoma therapeutics.

    Science.gov (United States)

    Low, Stewart A; Yang, Jiyuan; Kopeček, Jindřich

    2014-11-19

    Osteosarcoma is a malignancy of the bone that primarily affects adolescents. Current treatments retain mortality rates, which are higher than average cancer mortality rates for the adolescent age group. We designed a micellar delivery system with the aim to increase drug accumulation in the tumor and potentially reduce side effects associated with chemotherapy. The design features are the use of the hydrophilic D-aspartic acid octapeptide as both the effective targeting agent as well as the hydrophilic micelle corona. Micelle stabilization was accomplished by binding of model drug (doxorubicin) via an acid-sensitive hydrazone bond and incorporating one to four 11-aminoundecanoic acid (AUA) moieties to manipulate the hydrophobic/hydrophilic ratio. Four micelle-forming unimers have been synthesized and their self-assembly into micelles was evaluated. Size of the micelles could be modified by changing the architecture of the unimers from linear to branched. The stability of the micelles increased with increasing content of AUA moieties. Adsorption of all micelles to hydroxyapatite occurred rapidly. Doxorubicin release occurred at pH 5.5, whereas no release was detected at pH 7.4. Cytotoxicity toward human osteosarcoma Saos-2 cells correlated with drug release data.

  20. Cyclodextrin conjugated magnetic colloidal nanoparticles as a nanocarrier for targeted anticancer drug delivery

    Science.gov (United States)

    Banerjee, Shashwat S.; Chen, Dong-Hwang

    2008-07-01

    A novel magnetic nanocarrier (CD-GAMNPs) was fabricated for targeted anticancer drug delivery by grafting cyclodextrin (CD) onto gum arabic modified magnetic nanoparticles (GAMNPs) using hexamethylene diisocyanate (HMDI) as a linker. Analyses by transmission electron microscopy (TEM) and dynamic light scattering (DLS) revealed that the product had a mean diameter of 17.1 nm and a mean hydrodynamic diameter of 44.1 nm. The CD grafting was confirmed by Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA) indicated that the amount of CD grafted on the GAMNPs was 16.8 mg g-1. The study on the loading of anticancer drug all-trans-retinoic acid (retinoic acid) revealed that the newly fabricated magnetic nanocarrier possessed a considerably higher adsorption capability as compared to GAMNPs due to the special hydrophobic cavity structure of CD, which could act as a host-guest complex with retinoic acid. Furthermore, it was found that the complexation of CD-GAMNPs with retinoic acid was exothermic and the presence of a surfactant (sodium dodecyl sulfate) led to the decrease in the inclusion of retinoic acid because the linear structure of sodium dodecyl sulfate made it easier to enter the cavity of CD as compared to less linear retinoic acid. In addition, the in vitro release profile of retinoic acid from CD-GAMNPs was characterized by an initial fast release followed by a delayed release phase.

  1. Cyclodextrin conjugated magnetic colloidal nanoparticles as a nanocarrier for targeted anticancer drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Shashwat S; Chen, D.-H. [Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China)], E-mail: chendh@mail.ncku.edu.tw

    2008-07-02

    A novel magnetic nanocarrier (CD-GAMNPs) was fabricated for targeted anticancer drug delivery by grafting cyclodextrin (CD) onto gum arabic modified magnetic nanoparticles (GAMNPs) using hexamethylene diisocyanate (HMDI) as a linker. Analyses by transmission electron microscopy (TEM) and dynamic light scattering (DLS) revealed that the product had a mean diameter of 17.1 nm and a mean hydrodynamic diameter of 44.1 nm. The CD grafting was confirmed by Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA) indicated that the amount of CD grafted on the GAMNPs was 16.8 mg g{sup -1}. The study on the loading of anticancer drug all-trans-retinoic acid (retinoic acid) revealed that the newly fabricated magnetic nanocarrier possessed a considerably higher adsorption capability as compared to GAMNPs due to the special hydrophobic cavity structure of CD, which could act as a host-guest complex with retinoic acid. Furthermore, it was found that the complexation of CD-GAMNPs with retinoic acid was exothermic and the presence of a surfactant (sodium dodecyl sulfate) led to the decrease in the inclusion of retinoic acid because the linear structure of sodium dodecyl sulfate made it easier to enter the cavity of CD as compared to less linear retinoic acid. In addition, the in vitro release profile of retinoic acid from CD-GAMNPs was characterized by an initial fast release followed by a delayed release phase.

  2. Development of (153) Sm-folate-polyethyleneimine-conjugated chitosan nanoparticles for targeted therapy.

    Science.gov (United States)

    Mollarazi, Esmail; Jalilian, Amir R; Johari-Daha, Fariba; Atyabi, Fatemeh

    2015-06-30

    The aim of this study was to develop biocompatible, water-soluble (153) Sm-labeled chitosan nanoparticles (NPs) containing folate and polyethyleneimine functionalities i.e. chitosan-graft-PEI-folate (CHI-DTPA-g-PEI-FA), suitable for targeted therapy. The physicochemical properties of the obtained NPs were characterized by dynamic light-scattering analysis for their mean size, size distribution, and zeta potential; scanning electron microscopy for surface morphology; and (1) H-NMR, FT-IR analyses for molecular dispersity of folate in the NPs. NPs were spherical with mean diameter below 250 nm, polydispersity of below 0.15, and positive zeta potential values. The NP complex ((153) Sm-CHI-DTPA-g-PEI-FA) was stable at 25 °C (6-8 h, >90% radiochemical purity, instant thin layer chromatography (ITLC)). Binding studies using fluorescent NPs for internalization also demonstrated significant uptake in MCF-7 cells. MCF-7 cell internalization was significantly greater for 4T1. In blocking studies, both MCF-7 and 4T1 cell lines demonstrated specific folate receptor (FR) binding (decreasing 45%). In vivo biodistribution studies indicated major excretion of NPs metabolites and/or free (153) Sm through the kidneys. The preliminary imaging studies in 4T1 tumor-bearing mice showed minor uptake up to 96 h. The present folic acid that functionalized chitosan NP is a candidate material for folate receptor therapy. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Design, Synthesis, and Antimicrobial Evaluation of a Novel Bone-Targeting Bisphosphonate-Ciprofloxacin Conjugate for the Treatment of Osteomyelitis Biofilms.

    Science.gov (United States)

    Sedghizadeh, Parish P; Sun, Shuting; Junka, Adam F; Richard, Eric; Sadrerafi, Keivan; Mahabady, Susan; Bakhshalian, Neema; Tjokro, Natalia; Bartoszewicz, Marzenna; Oleksy, Monika; Szymczyk, Patrycja; Lundy, Mark W; Neighbors, Jeffrey D; Russell, R Graham G; McKenna, Charles E; Ebetino, Frank H

    2017-03-23

    Osteomyelitis is a major problem worldwide and is devastating due to the potential for limb-threatening sequelae and mortality. Osteomyelitis pathogens are bone-attached biofilms, making antibiotic delivery challenging. Here we describe a novel osteoadsorptive bisphosphonate-ciprofloxacin conjugate (BV600022), utilizing a "target and release" chemical strategy, which demonstrated a significantly enhanced therapeutic index versus ciprofloxacin for the treatment of osteomyelitis in vivo. In vitro antimicrobial susceptibility testing of the conjugate against common osteomyelitis pathogens revealed an effective bactericidal profile and sustained release of the parent antibiotic over time. Efficacy and safety were demonstrated in an animal model of periprosthetic osteomyelitis, where a single dose of 10 mg/kg (15.6 μmol/kg) conjugate reduced the bacterial load by 99% and demonstrated nearly an order of magnitude greater activity than the parent antibiotic ciprofloxacin (30 mg/kg, 90.6 μmol/kg) given in multiple doses. Conjugates incorporating a bisphosphonate and an antibiotic for bone-targeted delivery to treat osteomyelitis biofilm pathogens constitute a promising approach to providing high bone-antimicrobial potency while minimizing systemic exposure.

  4. Synthesis and characterization of Her2-NLP peptide conjugates targeting circulating breast cancer cells: cellular uptake and localization by fluorescent microscopic imaging.

    Science.gov (United States)

    Cai, Huawei; Singh, Ajay N; Sun, Xiankai; Peng, Fangyu

    2015-01-01

    To synthesize a fluorescent Her2-NLP peptide conjugate consisting of Her2/neu targeting peptide and nuclear localization sequence peptide (NLP) and assess its cellular uptake and intracellular localization for radionuclide cancer therapy targeting Her2/neu-positive circulating breast cancer cells (CBCC). Fluorescent Cy5.5 Her2-NLP peptide conjugate was synthesized by coupling a bivalent peptide sequence, which consisted of a Her2-binding peptide (NH2-GSGKCCYSL) and an NLP peptide (CGYGPKKKRKVGG) linked by a polyethylene glycol (PEG) chain with 6 repeating units, with an activated Cy5.5 ester. The conjugate was separated and purified by HPLC and then characterized by Maldi-MS. The intracellular localization of fluorescent Cy5.5 Her2-NLP peptide conjugate was assessed by fluorescent microscopic imaging using a confocal microscope after incubation of Cy5.5-Her2-NLP with Her2/neu positive breast cancer cells and Her2/neu negative control breast cancer cells, respectively. Fluorescent signals were detected in cytoplasm of Her2/neu positive breast cancer cells (SKBR-3 and BT474 cell lines), but not or little in cytoplasm of Her2/neu negative breast cancer cells (MDA-MB-231), after incubation of the breast cancer cells with Cy5.5-Her2-NLP conjugates in vitro. No fluorescent signals were detected within the nuclei of Her2/neu positive SKBR-3 and BT474 breast cancer cells, neither Her2/neu negative MDA-MB-231 cells, incubated with the Cy5.5-Her2-NLP peptide conjugates, suggesting poor nuclear localization of the Cy5.5-Her2-NLP conjugates localized within the cytoplasm after their cellular uptake and internalization by the Her2/neu positive breast cancer cells. Her2-binding peptide (KCCYSL) is a promising agent for radionuclide therapy of Her2/neu positive breast cancer using a β(-) or α emitting radionuclide, but poor nuclear localization of the Her2-NLP peptide conjugates may limit its use for eradication of Her2/neu-positive CBCC using I-125 or other Auger electron

  5. Reducing toxicity of 4–1BB costimulation: targeting 4–1BB ligands to the tumor stroma with bi-specific aptamer conjugates

    Science.gov (United States)

    Schrand, B; Berezhnoy, A; Brenneman, R; Williams, A; Levay, A; Gilboa, E

    2015-01-01

    Systemic administration of immune modulatory antibodies to cancer patients is associated with autoimmune pathologies. We have developed a clinically feasible and broadly applicable approach to limit immune stimulation to disseminated tumor lesions using a bi-specific agonistic 4–1BB oligonucleotide aptamer targeted to a broadly expressed stromal product (e.g., VEGF or osteopontin). The stroma-targeted aptamer conjugates engendered potent antitumor immunity against unrelated tumors and exhibited a superior therapeutic index compared to non-targeted agonistic 4–1BB antibody. PMID:25949891

  6. Targeted delivery of mutant tolerant anti-coxsackievirus artificial microRNAs using folate conjugated bacteriophage Phi29 pRNA.

    Directory of Open Access Journals (Sweden)

    Xin Ye

    Full Text Available BACKGROUND: Myocarditis is the major heart disease in infants and young adults. It is very commonly caused by coxsackievirus B3 (CVB3 infection; however, no specific treatment or vaccine is available at present. RNA interference (RNAi-based anti-viral therapy has shown potential to inhibit viral replication, but this strategy faces two major challenges; viral mutational escape from drug suppression and targeted delivery of the reagents to specific cell populations. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we designed artificial microRNAs (AmiRs targeting the 3'untranslated region (3'UTR of CVB3 genome with mismatches to the central region of their targeting sites. Antiviral evaluation showed that AmiR-1 and AmiR-2 reduced CVB3 (Kandolf and CG strains replication approximately 100-fold in both HeLa cells and HL-1 cardiomyocytes. To achieve specific delivery, we linked AmiRs to the folate-conjugated bacterial phage packaging RNA (pRNA and delivered the complexes into HeLa cells, a folate receptor positive cancer cells widely used as an in vitro model for CVB3 infection, via folate-mediated specific internalization. We found that our designed pRNA-AmiRs conjugates were tolerable to target mutations and have great potential to suppress viral mutational escape with little effect on triggering interferon induction. CONCLUSION/SIGNIFICANCE: This study provides important clues for designing AmiRs targeting the 3'UTR of viral genome. It also proves the feasibility of specific deliver of AmiRs using conjugated pRNA vehicles. These small AmiRs combined with pRNA-folate conjugates could form a promising system for antiviral drug development.

  7. A Conjugate Based on Anti-HER2 Diaffibody and Auristatin E Targets HER2-Positive Cancer Cells

    Science.gov (United States)

    Serwotka-Suszczak, Anna M.; Sochaj-Gregorczyk, Alicja M.; Pieczykolan, Jerzy; Krowarsch, Daniel; Jelen, Filip; Otlewski, Jacek

    2017-01-01

    Antibody-drug conjugates (ADCs) have recently emerged as efficient and selective cancer treatment therapeutics. Currently, alternative forms of drug carriers that can replace monoclonal antibodies are under intensive investigation. Here, a cytotoxic conjugate of an anti-HER2 (Human Epidermal Growth Factor Receptor 2) diaffibody with monomethyl-auristatin E (MMAE) is proposed as a potential anticancer therapeutic. The anti-HER2 diaffibody was based on the ZHER2:4 affibody amino acid sequence. The anti-HER2 diaffibody has been expressed as a His-tagged protein in E. coli and purified by Ni-nitrilotriacetyl (Ni-NTA) agarose chromatography. The molecule was properly folded, and the high affinity and specificity of its interaction with HER2 was confirmed by surface plasmon resonance (SPR) and flow cytometry, respectively. The (ZHER2:4)2DCS-MMAE conjugate was obtained by coupling the maleimide group linked with MMAE to cysteines, which were introduced in a drug conjugation sequence (DCS). Cytotoxicity of the conjugate was evaluated using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide MTT assay and the xCELLigence Real-Time Cell Analyzer. Our experiments demonstrated that the conjugate delivered auristatin E specifically to HER2-positive tumor cells, which finally led to their death. These results indicate that the cytotoxic diaffibody conjugate is a highly potent molecule for the treatment of various types of cancer overexpressing HER2 receptors. PMID:28216573

  8. Systemic co-delivery of doxorubicin and siRNA using nanoparticles conjugated with EGFR-specific targeting peptide to enhance chemotherapy in ovarian tumor bearing mice

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C. W.; Lin, W. J., E-mail: wjlin@ntu.edu.tw [National Taiwan University, Graduate Institute of Pharmaceutical Sciences, School of Pharmacy (China)

    2013-10-15

    This aim of this study was to develop peptide-conjugated nanoparticles (NPs) for systemic co-delivery of siRNA and doxorubicin to enhance chemotherapy in epidermal growth factor receptor (EGFR) high-expressed ovarian tumor bearing mice. The active targeting NPs were prepared using heptapeptide-conjugated poly(d,l-lactic-co-glycolic acid)-poly(ethylene glycol). The particle sizes of peptide-free and peptide-conjugated NPs were 159.3 {+-} 32.5 and 184.0 {+-} 52.9 nm, respectively, with zeta potential -21.3 {+-} 3.8 and -15.3 {+-} 2.8 mV. The peptide-conjugated NPs uptake were more efficient in EGFR high-expressed SKOV3 cells than in EGFR low-expressed HepG2 cells due to heptapeptide specificity. The NPs were used to deliver small molecule anticancer drug (e.g., doxorubicin) and large molecule genetic agent (e.g., siRNA). The IC{sub 50} of doxorubicin-loaded peptide-conjugated NPs (0.09 {+-} 0.06 {mu}M) was significantly lower than peptide-free NPs (5.72 {+-} 2.64 {mu}M). The similar result was observed in siRNA-loaded NPs. The peptide-conjugated NPs not only served as a nanocarrier to efficiently deliver doxorubicin and siRNA to EGFR high-expressed ovarian cancer cells but also increased the intracellular accumulation of the therapeutic agents to induce assured anti-tumor growth effect in vivo.

  9. Studies in Multifunctional Drug Development: Preparation and Evaluation of 11beta-Substituted Estradiol-Drug Conjugates, Cell Membrane Targeting Imaging Agents, and Target Multifunctional Nanoparticles

    Science.gov (United States)

    Dao, KinhLuan Lenny D.

    Cancer is the second leading cause of death after cardiovascular disease in the United State. Despite extensive research in development of antitumor drugs, most of these therapeutic entities often possess nonspecific toxicity, thus they can only be used to treat tumors in higher doses or more frequently. Because of the cytotoxicity and severe side effects, the drug therapeutic window normally is limited. Beside the toxicity issue, antitumor drug are also not selectively taken up by tumor cells, thus the necessitating concentrations that would eradicate the tumor can often not be used. In addition, tumor cells tend to develop resistance against the anticancer drugs after prolonged treatment. Therefore, alleviating the systemic cytotoxicity and side effects, improving in tumor selectivity, high potency, and therapeutic efficacy are still major obstacles in the area of anticancer drug development. A more promising approach for developing a selective agent for cancer is to conjugate a potent therapeutic drug, or an imaging agent with a targeting group, such as antibody or a high binding-specificity small molecule, that selectively recognize the overexpressed antigens or proteins on tumor cells. My research combines several approaches to describe this strategy via using different targeting molecules to different diseases, as well as different potent cytotoxic drugs for different therapies. Three studies related to the preparation and biological evaluation of new therapeutic agents, such as estradiol-drug hybrids, cell membrane targeted molecular imaging agents, and multifunctional NPs will be discussed. The preliminary results of these studies indicated that our new reagents achieved their initial objectives and can be further improved for optimized synthesis and in vivo experiments. The first study describes the method in which we employed a modular assembly approach to synthesize a novel 11beta-substituted steroidal anti-estrogen. The key intermediate was synthesized

  10. Fluoridated hydroxyapatite: Eu3+ nanorods-loaded folate-conjugated D-α-tocopheryl polyethylene glycol succinate (vitamin E TPGS) micelles for targeted imaging of cancer cells

    Science.gov (United States)

    Wan, Dong; Liu, Weijiao; Wang, Lei; Wang, Hao; Pan, Jie

    2016-03-01

    In this study, fluoridated hydroxyapatite: Eu3+ nanorod-loaded folate-conjugated TPGS micelles were prepared by thin-film hydration. The findings in this study demonstrate that micelles show improved dispersion, high stability, and excellent fluorescent property in aqueous solutions, suitable for targeted imaging of cancer cells with over-expressing folate receptors on their surface. The micelles designed in this study will be a promising tool for early detection of cancer.

  11. Enhanced cellular uptake and phototoxicity of Verteporfin-conjugated gold nanoparticles as theranostic nanocarriers for targeted photodynamic therapy and imaging of cancers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Linlin [Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science & Engineering, Tianjin University of Technology, Tianjin 300384 (China); Graduate School of Energy Science and Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, Tae-Hyun; Kim, Hae-Won [Department of Nanobiomedical Science, Dankook University Graduate School, Cheonan 330-714 (Korea, Republic of); Institute of Tissue Regeneration Engineering (ITREN) & College of Dentistry, Dankook University, Cheonan 330-714 (Korea, Republic of); Ahn, Jin-Chul [Department of Biomedical Science, College of Medicine, Dankook University, Cheonan, 330-714 (Korea, Republic of); Kim, So Yeon, E-mail: kimsy@cnu.ac.kr [Graduate School of Energy Science and Technology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Department of Chemical Engineering Education, College of Education, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2016-10-01

    Activatable theranostics with the capacity to respond to a given stimulus have recently been intensively explored to develop more specific, individualized therapies for various diseases, and to combine diagnostic and therapeutic capabilities into a single agent. In this work, we designed tumor-targeting ligand-conjugated block copolymer-gold nanoparticle (AuNP) conjugates as multifunctional nanocarriers of the hydrophobic photosensitizer (PS), verteporfin (Verte), for simultaneous photodynamic therapy and imaging of cancers. Folic acid (FA)-conjugated block copolymers composed of polyethylene glycol (PEG) and poly-β-benzyl-L-aspartate (PBLA) were attached to citrate-stabilized AuNPs through a bidentate dihydrolipoic acid (DHLA) linker. The resulting AuNP conjugates (FA-PEG-P(Asp-Hyd)-DHLA-AuNPs) were significantly more stable than unmodified AuNPs, and their optical properties were not affected by pH. The hydrophobic PS, Verte, was covalently incorporated onto the surfaces of the AuNP conjugates through a pH-sensitive linkage, which increased the water solubility of Verte from < 1 μg/ml to > 2000 μg/ml. The size of FA-PEG-P(Asp-Hyd)-DHLA-AuNPs-Verte as determined by light-scattering measurements was about 110.3 nm, and FE-SEM and FE-TEM images showed that these nanoparticles were spherical and showed adequate dispersivity after modification. In particular, an in vitro cell study revealed high intracellular uptake of FA-PEG-P(Asp-Hyd)-DHLA-AuNPs-Verte (about 98.62%) and marked phototoxicity after laser irradiation compared with free Verte. These results suggest that FA-PEG-P(Asp-Hyd)-DHLA-AuNPs-Verte has great potential as an effective nanocarrier for dual imaging and photodynamic therapy. - Highlights: • We designed theranostic nanocarriers for photodynamic therapy and imaging of cancers. • AuNP conjugates had a spherical shape and a narrow size distribution with a mean diameter of 110.3 nm. • Cellular uptake of free Verte was 18.86%, whereas that of Au

  12. Dual Targeting of Intracellular Pathogenic Bacteria with a Cleavable Conjugate of Kanamycin and an Antibacterial Cell-Penetrating Peptide.

    Science.gov (United States)

    Brezden, Anna; Mohamed, Mohamed F; Nepal, Manish; Harwood, John S; Kuriakose, Jerrin; Seleem, Mohamed N; Chmielewski, Jean

    2016-08-31

    Bacterial infection caused by intracellular pathogens, such as Mycobacterium, Salmonella, and Brucella, is a burgeoning global health epidemic that necessitates urgent action. However, the therapeutic value of a number of antibiotics, including aminoglycosides, against intracellular pathogenic bacteria is compromised due to their inability to traverse eukaryotic membranes. For this significant problem to be addressed, a cleavable conjugate of the antibiotic kanamycin and a nonmembrane lytic, broad-spectrum antimicrobial peptide with efficient mammalian cell penetration, P14LRR, was prepared. This approach allows kanamycin to enter mammalian cells as a conjugate linked via a tether that breaks down in the reducing environment within cells. Potent antimicrobial activity of the P14KanS conjugate was demonstrated in vitro, and this reducible conjugate effectively cleared intracellular pathogenic bacteria within macrophages more potently than that of a conjugate lacking the disulfide moiety. Notably, successful clearance of Mycobacterium tuberculosis within macrophages was observed with the dual antibiotic conjugate, and Salmonella levels were significantly reduced in an in vivo Caenorhabditis elegans model.

  13. Sequence-specific DNA alkylation and transcriptional inhibition by long-chain hairpin pyrrole-imidazole polyamide-chlorambucil conjugates targeting CAG/CTG trinucleotide repeats.

    Science.gov (United States)

    Asamitsu, Sefan; Kawamoto, Yusuke; Hashiya, Fumitaka; Hashiya, Kaori; Yamamoto, Makoto; Kizaki, Seiichiro; Bando, Toshikazu; Sugiyama, Hiroshi

    2014-09-01

    Introducing novel building blocks to solid-phase peptide synthesis, we readily synthesized long-chain hairpin pyrrole-imidazole (PI) polyamide-chlorambucil conjugates 3 and 4 via the introduction of an amino group into a GABA (γ-turn) contained in 3, to target CAG/CTG repeat sequences, which are associated with various hereditary disorders. A high-resolution denaturing polyacrylamide sequencing gel revealed sequence-specific alkylation both strands at the N3 of adenines or guanines in CAG/CTG repeats by conjugates 3 and 4, with 11bp recognition. In vitro transcription assays using conjugate 4 revealed that specific alkylation inhibited the progression of RNA polymerase at the alkylating sites. Chiral substitution of the γ-turn with an amino group resulted in higher binding affinity observed in SPR assays. These assays suggest that conjugates 4 with 11bp recognition has the potential to cause specific DNA damage and transcriptional inhibition at the alkylating sites. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Targeting urokinase and the transferrin receptor with novel, anti-mitotic N-alkylisatin cytotoxin conjugates causes selective cancer cell death and reduces tumor growth.

    Science.gov (United States)

    Vine, K L; Indira Chandran, V; Locke, J M; Matesic, L; Lee, J; Skropeta, D; Bremner, J B; Ranson, M

    2012-01-01

    Tumor-specific delivery of ligand-directed prodrugs can increase the therapeutic window of chemotherapeutics by maintaining efficacy whilst decreasing toxic side effects. We have previously described a series of synthetic N-alkylated isatin cytotoxins that destabilize microtubules and induce apoptosis with 10-fold greater potency than conventional anti-mitotics in vitro. Here, we report the characterization, in vitro cytotoxicity and in vivo efficacy of a lead compound, 5,7-dibromo-N-(p-hydroxymethylbenzyl)isatin (N-AI) conjugated via an esterase-labile linker (N-AIE) to two proven targeting ligands, transferrin (Tf) and plasminogen activator inhibitor type 2 (PAI-2/serpinB2). N-AI was released from N-AIE and the targeting ligands Tf/PAI-2 in an esterase-dependent manner at 37 C and both Tf- and PAI-2-N-AIE conjugates were stable at physiological pH. Human cancer cell lines which vary in their expression levels of Tf receptor (TfR/CD71) and PAI-2 target, receptor bound urokinase (uPA) selectively internalized the conjugates. Tf-N-AIE was up to 24 times more active than the free drug and showed clear selectivity patterns based on TfR levels. PAI-2-N-AIE showed equivalent activity compared to the parent drug and strong selectivity patterns for uPA levels. In preliminary in vivo experiments, the PAI-2- and Tf-N-AIE conjugates were efficacious at 1/20(th) and 1/10(th) of the dose of the free N-AI, respectively, in a metastatic, orthotopic human breast tumor xenograft mouse model. Thus, this strategy specifically delivers and concentrates a novel class of isatin-based, tubulin destabilizing agents to tumors in vivo and warrants further detailed preclinical investigation.

  15. Enhanced immunogenicity of a tricomponent mannan tetanus toxoid conjugate vaccine targeted to dendritic cells via Dectin-1 by incorporating β-glucan.

    Science.gov (United States)

    Lipinski, Tomasz; Fitieh, Amira; St Pierre, Joëlle; Ostergaard, Hanne L; Bundle, David R; Touret, Nicolas

    2013-04-15

    In a previous attempt to generate a protective vaccine against Candida albicans, a β-mannan tetanus toxoid conjugate showed poor immunogenicity in mice. To improve the specific activation toward the fungal pathogen, we aimed to target Dectin-1, a pattern-recognition receptor expressed on monocytes, macrophages, and dendritic cells. Laminarin, a β-glucan ligand of Dectin-1, was incorporated into the original β-mannan tetanus toxoid conjugate providing a tricomponent conjugate vaccine. A macrophage cell line expressing Dectin-1 was employed to show binding and activation of Dectin-1 signal transduction pathway by the β-glucan-containing vaccine. Ligand binding to Dectin-1 resulted in the following: 1) activation of Src family kinases and Syk revealed by their recruitment and phosphorylation in the vicinity of bound conjugate and 2) translocation of NF-κB to the nucleus. Treatment of immature bone marrow-derived dendritic cells (BMDCs) with tricomponent or control vaccine confirmed that the β-glucan-containing vaccine exerted its enhanced activity by virtue of dendritic cell targeting and uptake. Immature primary cells stimulated by the tricomponent vaccine, but not the β-mannan tetanus toxoid vaccine, showed activation of BMDCs. Moreover, treated BMDCs secreted increased levels of several cytokines, including TGF-β and IL-6, which are known activators of Th17 cells. Immunization of mice with the novel type of vaccine resulted in improved immune response manifested by high titers of Ab recognizing C. albicans β-mannan Ag. Vaccine containing laminarin also affected distribution of IgG subclasses, showing that vaccine targeting to Dectin-1 receptor can benefit from augmentation and immunomodulation of the immune response.

  16. Targeting 4-1BB costimulation to the tumor stroma with bispecific aptamer conjugates enhances the therapeutic index of tumor immunotherapy.

    Science.gov (United States)

    Schrand, Brett; Berezhnoy, Alexey; Brenneman, Randall; Williams, Anthony; Levay, Agata; Kong, Ling-Yuan; Rao, Ganesh; Zhou, Shouhao; Heimberger, Amy B; Gilboa, Eli

    2014-09-01

    Despite the recent successes of using immune modulatory Abs in patients with cancer, autoimmune pathologies resulting from the activation of self-reactive T cells preclude the dose escalations necessary to fully exploit their therapeutic potential. To reduce the observed and expected toxicities associated with immune modulation, here we describe a clinically feasible and broadly applicable approach to limit immune costimulation to the disseminated tumor lesions of the patient, whereby an agonistic 4-1BB oligonucleotide aptamer is targeted to the tumor stroma by conjugation to an aptamer that binds to a broadly expressed stromal product, VEGF. This approach was predicated on the premise that by targeting the costimulatory ligands to products secreted into the tumor stroma, the T cells will be costimulated before their engagement of the MHC-peptide complex on the tumor cell, thereby obviating the need to target the costimulatory ligands to noninternalizing cell surface products expressed on the tumor cells. Underscoring the potency of stroma-targeted costimulation and the broad spectrum of tumors secreting VEGF, in preclinical murine tumor models, systemic administration of the VEGF-targeted 4-1BB aptamer conjugates engendered potent antitumor immunity against multiple unrelated tumors in subcutaneous, postsurgical lung metastasis, methylcholantrene-induced fibrosarcoma, and oncogene-induced autochthonous glioma models, and exhibited a superior therapeutic index compared with nontargeted administration of an agonistic 4-1BB Ab or 4-1BB aptamer.

  17. Nasal immunization with M cell-targeting ligand-conjugated ApxIIA toxin fragment induces protective immunity against Actinobacillus pleuropneumoniae infection in a murine model.

    Science.gov (United States)

    Park, Jisang; Seo, Ki-Weon; Kim, Sae-Hae; Lee, Ha-Yan; Kim, Bumseok; Lim, Chae Woong; Kim, Jin-Hee; Yoo, Han Sang; Jang, Yong-Suk

    2015-05-15

    Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia and severe economic loss in the swine industry has been caused by the infection. Therefore, the development of an effective vaccine against the bacteria is necessary. ApxII toxin, among several virulence factors expressed by the bacteria, is considered to be a promising vaccine candidate because ApxII toxin not only accompanies cytotoxic and hemolytic activities, but is also expressed in all 15 serotypes of bacteria except serotypes 10 and 14. In this study, we identified the peptide ligand capable of targeting the ligand-conjugated ApxIIA #5 fragment antigen to nasopharynx-associated lymphoid tissue. It was found that nasal immunization with ligand-conjugated ApxIIA #5 induced efficient mucosal and systemic immune responses measured at the levels of antigen-specific antibodies, cytokine-secreting cells after antigen exposure, and antigen-specific lymphocyte proliferation. More importantly, the nasal immunization induced protective immunity against nasal challenge infection of the bacteria, which was confirmed by histopathological studies and bacterial clearance after challenge infection. Collectively, we confirmed that the ligand capable of targeting the ligand-conjugated antigen to nasopharynx-associated lymphoid tissue can be used as an effective nasal vaccine adjuvant to induce protective immunity against A. pleuropneumoniae infection. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. SGN-CD33A: a novel CD33-targeting antibody-drug conjugate using a pyrrolobenzodiazepine dimer is active in models of drug-resistant AML.

    Science.gov (United States)

    Kung Sutherland, May S; Walter, Roland B; Jeffrey, Scott C; Burke, Patrick J; Yu, Changpu; Kostner, Heather; Stone, Ivan; Ryan, Maureen C; Sussman, Django; Lyon, Robert P; Zeng, Weiping; Harrington, Kimberly H; Klussman, Kerry; Westendorf, Lori; Meyer, David; Bernstein, Irwin D; Senter, Peter D; Benjamin, Dennis R; Drachman, Jonathan G; McEarchern, Julie A

    2013-08-22

    Outcomes in acute myeloid leukemia (AML) remain unsatisfactory, and novel treatments are urgently needed. One strategy explores antibodies and their drug conjugates, particularly those targeting CD33. Emerging data with gemtuzumab ozogamicin (GO) demonstrate target validity and activity in some patients with AML, but efficacy is limited by heterogeneous drug conjugation, linker instability, and a high incidence of multidrug resistance. We describe here the development of SGN-CD33A, a humanized anti-CD33 antibody with engineered cysteines conjugated to a highly potent, synthetic DNA cross-linking pyrrolobenzodiazepine dimer via a protease-cleavable linker. The use of engineered cysteine residues at the sites of drug linker attachment results in a drug loading of approximately 2 pyrrolobenzodiazepine dimers per antibody. In preclinical testing, SGN-CD33A is more potent than GO against a panel of AML cell lines and primary AML cells in vitro and in xenotransplantation studies in mice. Unlike GO, antileukemic activity is observed with SGN-CD33A in AML models with the multidrug-resistant phenotype. Mechanistic studies indicate that the cytotoxic effects of SGN-CD33A involve DNA damage with ensuing cell cycle arrest and apoptotic cell death. Together, these data suggest that SGN-CD33A has CD33-directed antitumor activity and support clinical testing of this novel therapeutic in patients with AML.

  19. Methyl 6-Amino-6-deoxy-d-pyranoside-Conjugated Platinum(II) Complexes for Glucose Transporter (GLUT)-Mediated Tumor Targeting: Synthesis, Cytotoxicity, and Cellular Uptake Mechanism.

    Science.gov (United States)

    Li, Taoli; Gao, Xiangqian; Yang, Liu; Shi, Yunli; Gao, Qingzhi

    2016-05-19

    Methyl 6-aminodeoxy-d-pyranoside-derived platinum(II) glycoconjugates were designed and synthesized based on the clinical drug oxaliplatin for glucose transporter (GLUT)-mediated tumor targeting. In addition to a substantial improvement in water solubility, the conjugates exhibited cytotoxicity similar to or higher than that of oxaliplatin in six different human cancer cell lines. GLUT-mediated transport of the complexes was investigated with a cell-based fluorescence competition assay and GLUT-inhibitor-mediated cytotoxicity analysis in a GLUT-overexpressing human colorectal adenocarcinoma (HT29) cell line. The antitumor effect of the aminodeoxypyranoside-conjugated platinum(II) complexes was found to depend significantly on the GLUT inhibitor, and the cellular uptake of the molecules was regulated by GLUT-mediated transport. The results from this study demonstrate the potential advantages of aminodeoxypyranosides as sugar motifs for glycoconjugation for Warburg-effect-targeted drug design. These fundamental results also support the potential of aminodeoxypyranoside-conjugated platinum(II) complexes as lead compounds for further preclinical evaluation.

  20. Modulation of mdm2 pre-mRNA splicing by 9-aminoacridine-PNA (peptide nucleic acid) conjugates targeting intron-exon junctions

    DEFF Research Database (Denmark)

    Shiraishi, Takehiko; Eysturskard, Jonhard; Nielsen, Peter E

    2010-01-01

    ABSTRACT: BACKGROUND: Modulation of pre-mRNA splicing by antisense molecules is a promising mechanism of action for gene therapeutic drugs. In this study, we have examined the potential of peptide nucleic acid (PNA) 9-aminoacridine conjugates to modulate the pre-mRNA splicing of the mdm2 human ca...... method to evaluate the cellular function of MDM2 splice variants as well as a promising approach for discovery of mdm2 targeted anticancer drugs.......ABSTRACT: BACKGROUND: Modulation of pre-mRNA splicing by antisense molecules is a promising mechanism of action for gene therapeutic drugs. In this study, we have examined the potential of peptide nucleic acid (PNA) 9-aminoacridine conjugates to modulate the pre-mRNA splicing of the mdm2 human...

  1. Enhanced drug loading on magnetic nanoparticles by layer-by-layer assembly using drug conjugates: blood compatibility evaluation and targeted drug delivery in cancer cells.

    Science.gov (United States)

    Manju, S; Sreenivasan, K

    2011-12-06

    Drug targeting using magnetic nanoparticles (MNPs) under the action of an external magnetic field constitutes an important mode of drug delivery. Low cargo capacity, particularly in hydrophobic drugs, is one limitation shown by MNPs. This article describes a simple strategy to enhance the drug-loading capacity of MNPs. The approach was to use polymer-drug conjugates to modify MNPs by layer-by-layer assembly (LbL). Curcumin (CUR) has shown remarkably high cytotoxicity toward various cancer cell lines. However, the drug shows low anticancer activity in vivo because of its reduced systemic bioavailability acquired from its poor aqueous solubility and instability. To address this issue, we synthesized cationic and anionic CUR conjugates by anchoring CUR onto poly(vinylpyrroidone) (PVP-Cur) and onto hyaluronic acid (HA-Cur). We used these oppositely charged conjugates to modify MNPs by layer-by-layer (LbL) assembly. Six double layers of curcumin conjugates were constructed on positively charged amino-terminated magnetic nanoparticles, TMSPEDA@MNPs. Finally, HA was coated onto the outer surface to form HA (HA-Cur/PVP-Cur)(6)@MNPs. Cellular viability studies showed the dose-dependent antiproliferative effect of HA (HA-Cur/PVP-Cur)(6)@MNPs in two cancer cell lines (glioma cells and Caco-2 cells). HA (HA-Cur/PVP-Cur)(6)@MNPs exhibited more cytotoxicity than did free curcumin, which was attributed to the enhanced solubility along with better absorption via hyaluronic acid receptor-mediated endocytosis. Flow cytometry showed enhanced intake of the modified MNPs by cells. Confocal microscope images also confirmed the uptake of HA (HA-Cur/PVP-Cur)(6)@MNPs with greater efficacy. Thus, the strategy that we adopted here appears to have substantial potential in carrying enhanced payloads of hydrophobic drugs to specified targets. © 2011 American Chemical Society

  2. Ligand-specific targeting of microspheres to phagocytes by surface modification with poly(L-lysine)-grafted poly(ethylene glycol) conjugate.

    Science.gov (United States)

    Faraasen, Sofia; Vörös, János; Csúcs, Gábor; Textor, Marcus; Merkle, Hans P; Walter, Elke

    2003-02-01

    The purpose of this study was to demonstrate specific receptor-mediated targeting of phagocytes by functional surface coatings of microparticles, shielding from nonspecific phagocytosis and allowing ligand-specific interactions via molecular recognition. Coatings of the comb polymer poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG) were investigated for potential to inhibit 1) nonspecific spreading of human blood-derived macrophages (MOs) and dendritic cells (DCs) on glass and 2) nonspecific phagocytosis of PLL-g-PEG-coated, carboxylated polystyrene (PS) or biodegradable poly(D,L-lactide-co-glycolide) (PLGA) microspheres. Coating was performed by adsorption of positively charged PLL-g-PEG on negatively charged microparticles or plasma-cleaned glass through electrostatic interaction. The feasibility of ligand-specific interactions was tested with a model ligand, RGD, conjugated to PEG chains of PLL-g-PEG to form PLL-g-PEG-RGD and compared with inactive ligand conjugate, PLL-g-PEG-RDG. Coatings with PLL-g-PEG largely impaired the adherence and spreading of MOs and DCs on glass. The repellent character of PLL-g-PEG coatings drastically reduced phagocytosis of coated PS and PLGA microparticles to 10% in presence of serum. With both MOs and DCs, we observed ligand-specific interactions with PLL-g-PEG-RGD coatings on glass and PS and PLGA microspheres. Ligand specificity was abolished when using inactive ligand conjugate PLL-g-PEG-RDG, whereas repellency of coating was maintained. Coatings of PLL-g-PEG-ligand conjugates provide a novel technology for ligand specific targeting of microspheres to MOs and DCs while reducing nonspecific phagocytosis.

  3. Molecular imaging of a cancer-targeting theragnostics probe using a nucleolin aptamer- and microRNA-221 molecular beacon-conjugated nanoparticle.

    Science.gov (United States)

    Kim, Jin Kyeoung; Choi, Kyung-Ju; Lee, Minhyung; Jo, Mi-hee; Kim, Soonhag

    2012-01-01

    MicroRNAs (miRNA, miR) have been reported as cancer biomarkers that regulate tumor suppressor genes. Hence, simultaneous detecting and inhibiting of miRNA function will be useful as a cancer theragnostics probe to minimize side effects and invasiveness. In this study, we developed a cancer-targeting therangostics probe in a single system using an AS1411 aptamer - and miRNA-221 molecular beacon (miR-221 MB)-conjugated magnetic fluorescence (MF) nanoparticle (MFAS miR-221 MB) to simultaneously target to cancer tissue, image intracellularly expressed miRNA-221 and treat miRNA-221-involved carcinogenesis. AS1411 aptamer-conjugated MF (MFAS) nanoparticles displayed a great selectivity and delivery into various cancer cell lines. The miR-221 MB detached from the MFAS miR-221 MB in the cytoplasm of C6 cells clearly imaged miRNA-221 biogenesis and simultaneously resulted in antitumor therapeutic effects by inhibiting miRNA function, indicating a successful astrocytoma-targeting theragnostics. MFAS miRNA MB can be easily applied to other cancers by simply changing a targeted miRNA highly expressed in cancers.

  4. Folic Acid Conjugated Chitosan for Targeted Delivery of siRNA to Activated Macrophages in vitro and in vivo

    DEFF Research Database (Denmark)

    Yang, Chuanxu; Gao, Shan; Kjems, Jørgen

    2014-01-01

    was conjugated to chitosan (FA–CS) and used to formulate siRNA into nanoparticles capable of cell specific delivery. The physiochemical properties of the nanoparticles, including size, zeta-potential and encapsulation efficiency, were characterized and the intracellular uptake and gene silencing efficiency were...

  5. Phototoxic effects of free phthalocyanine and phthalocyanine conjugated to gold nanoparticles for targeted photodynamic therapy of melanoma cancer

    Science.gov (United States)

    Manoto, Sello L.; Oluwole, David O.; Malabi, Rudzani; Maphanga, Charles; Ombinda-Lemboumba, Saturnin; Nyokong, Tebello; Mthunzi-Kufa, Patience

    2017-02-01

    Photodynamic therapy (PDT) has emerged as an effective treatment modality for various malignant neoplasia and diseases. In PDT, the photochemical interaction of photosensitizer (PS), light and molecular oxygen produces singlet oxygen which can lead to tumour cell apoptosis, necrosis or autophagy. The success of PDT is limited by the hydrophobic characteristic of the PS which hinders treatment administration and efficiency. To circumvent this limitation, PS can be incorporated in nanostructured drug delivery systems such as gold nanoparticles (AuNPs). In this study, we investigated the effectiveness of free zinc monocarboxyphenoxy phthalocyanine (ZnMCPPc) and ZnMCPPc conjugated to AuNPs. Commercially purchased melanoma cancer cells cultured as cell monolayers were used in this study. Changes in cellular response were evaluated using cellular morphology, viability, proliferation and cytotoxicity. Untreated cells showed no changes in cellular morphology, proliferation and cytotoxicity. However, photoactivated free ZnMCPPc and ZnMCPPc conjugated to AuNPs showed changes in cellular morphology and a dose dependent decrease in cellular viability and proliferation as well as an increase in cell membrane. ZnMCPPc conjugated to AuNPs showed an improved efficiency in PDT as compared to free ZnMCPPc, which might be as a result of the vehicle effect of AuNPs. Both PSs used in this study were effective in inducing cell death with ZnMCPPc conjugated to AuNPs showing great potential as an effective PS for PDT.

  6. Folic acid conjugated self-assembled layered double hydroxide nanoparticles for high-efficacy-targeted drug delivery.

    Science.gov (United States)

    Yan, Li; Chen, Wei; Zhu, Xiaoyue; Huang, Longbiao; Wang, Zhigang; Zhu, Guangyu; Roy, V A L; Yu, K N; Chen, Xianfeng

    2013-12-04

    Enhanced selectivity and efficacy is important for advanced drug delivery. Herein, a novel type of folic acid conjugated self-assembled layered double hydroxide nanoparticles is reported. These nanoparticles have a drug loading capacity of 27 wt% and are able to enter cell nuclei and dramatically improve the efficacy of MTX.

  7. Polymeric nanoparticles conjugate a novel heptapeptide as an epidermal growth factor receptor-active targeting ligand for doxorubicin

    Directory of Open Access Journals (Sweden)

    Liu CW

    2012-08-01

    Full Text Available Chia Wen Liu,1,2 Wen Jen Lin11Graduate Institute of Pharmaceutical Sciences, College of Medicine, National Taiwan University, Taipei; 2Drug Delivery Department, Biomedical Engineering Research Laboratories, Industrial Technology Research Institute, Hsinchu, TaiwanBackground: This study was performed to develop a functional poly(D,L-lactide-co-glycolide-poly(ethylene glycol (PLGA-PEG-bearing amino-active end group for peptide conjugation.Methods and results: PLGA was preactivated following by copolymerization with PEG diamine. The resulting amphiphilic PLGA-PEG copolymer bearing 97.0% of amino end groups had a critical micelle concentration of 3.0 × 10-8 mol/L, and the half-effective inhibition concentration (IC50 of the prepared PLGA-PEG nanoparticles was >100 mg/mL, which was much higher than that of PLGA nanoparticles (1.02 ± 0.37 mg/mL. The amphiphilic properties of PLGA-PEG spontaneously formed a core-shell conformation in the aqueous environment, and this special feature provided the amino group on the PEG chain scattered on the surface of PLGA-PEG nanoparticles for efficient peptide conjugation. The peptide-conjugated PLGA-PEG nanoparticles showed three-fold higher uptake than peptide-free PLGA-PEG nanoparticles in a SKOV3 cell line with high expression of epidermal growth factor receptor. Both peptide-conjugated and peptide-free PLGA-PEG nanoparticles were used as nanocarriers for delivery of doxorubicin. Although the rate of release of doxorubicin from both nanoparticles was similar, drug release at pH 4.0 (500 U lipase was faster than at pH 7.4. The IC50 of doxorubicin-loaded peptide-conjugated PLGA-PEG nanoparticles in SKOV3 cells (0.05 ± 0.03 µg/mL was much lower (by 62.4-fold than that of peptide-free PLGA-PEG nanoparticles (3.12 ± 1.44 µg/mL.Conclusion: This in vivo biodistribution study in SKOV3 tumor-bearing mice was further promising in that accumulation of doxorubicin in tumor tissue was in the order of peptide-conjugated

  8. Elimination of Tumor Cells Using Folate Receptor Targeting by Antibody-Conjugated, Gold-Coated Magnetite Nanoparticles in a Murine Breast Cancer Model

    Directory of Open Access Journals (Sweden)

    Evan S. Krystofiak

    2012-01-01

    Full Text Available Background. The chemotherapeutic treatment of cancer suffers from poor specificity for targeting the tumor cells and often results in adverse effects such as systemic toxicity, damage to nontarget tissues, and development of drug-resistant tumors in patients. Increasingly, drug nanocarriers have been explored as a way of lessening or overcoming these problems. In this study, antibody-conjugated Au-coated magnetite nanoparticles, in conjunction with inductive heating produced by exposure to an oscillating magnetic field (OMF, were evaluated for their effects on the viability of tumor cells in a murine model of breast cancer. Treatment effects were evaluated by light microscopy and SEM. Results. 4T1 mammary epithelial carcinoma cells overexpressing the folate receptor were targeted with an anti-folate receptor primary antibody, followed by labeling with secondary antibody-conjugated Au-coated magnetite nanoparticles. In the absence of OMF exposure, nanoparticle labeling had no effect on 4T1 cell viability. However, following OMF treatment, many of the labeled 4T1 cells showed extensive membrane damage by SEM analysis, and dramatically reduced viability as assessed using a live/dead staining assay. Conclusions. These results demonstrate that Au-coated magnetite targeted to tumor cells through binding to an overexpressed surface receptor, in the presence of an OMF, can lead to tumor cell death.

  9. Anti-PDGF receptor β antibody-conjugated squarticles loaded with minoxidil for alopecia treatment by targeting hair follicles and dermal papilla cells.

    Science.gov (United States)

    Aljuffali, Ibrahim A; Pan, Tai-Long; Sung, Calvin T; Chang, Shu-Hao; Fang, Jia-You

    2015-08-01

    This study developed lipid nanocarriers, called squarticles, conjugated with anti-platelet-derived growth factor (PDGF)-receptor β antibody to determine whether targeted Minoxidil (MXD) delivery to the follicles and dermal papilla cells (DPCs) could be achieved. Squalene and hexadecyl palmitate (HP) were used as the matrix of the squarticles. The PDGF-squarticles showed a mean diameter and zeta potential of 195 nm and -46 mV, respectively. Nanoparticle encapsulation enhanced MXD porcine skin deposition from 0.11 to 0.23 μg/mg. The antibody-conjugated nanoparticles ameliorated follicular uptake of MXD by 3-fold compared to that of the control solution in the in vivo mouse model. Both vertical and horizontal skin sections exhibited a wide distribution of nanoparticles in the follicles, epidermis, and deeper skin strata. The encapsulated MXD moderately elicited proliferation of DPCs and vascular endothelial growth factor (VEGF) expression. The active targeting of PDGF-squarticles may be advantageous to improving the limited success of alopecia therapy. Topical use of minoxidil is only one of the very few treatment options for alopecia. Nonetheless, the current delivery method is far from ideal. In this article, the authors developed lipid nanocarriers with anti-platelet-derived growth factor receptor ? antibody to target dermal papilla cells, and showed enhanced uptake of minoxidil. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Enhanced and selective delivery of enzyme therapy to 9L-glioma tumor via magnetic targeting of PEG-modified, β-glucosidase-conjugated iron oxide nanoparticles.

    Science.gov (United States)

    Zhou, Jie; Zhang, Jian; Gao, Wenxi

    2014-01-01

    The stability of enzyme-conjugated magnetic iron oxide nanoparticles in plasma is of great importance for in vivo delivery of the conjugated enzyme. In this study, β-glucosidase was conjugated on aminated magnetic iron oxide nanoparticles using the glutaraldehyde method (β-Glu-MNP), and further PEGylated via N-hydroxysuccinimide chemistry. The PEG-modified, β-glucosidase-immobilized magnetic iron oxide nanoparticles (PEG-β-Glu-MNPs) were characterized by hydrodynamic diameter distribution, zeta potential, Fourier transform infrared spectroscopy, transmission electron microscopy, and a superconducting quantum interference device. The results showed that the multidomain structure and magnetization properties of these nanoparticles were conserved well throughout the synthesis steps, with an expected diameter increase and zeta potential shifts. The Michaelis constant was calculated to evaluate the activity of conjugated β-glucosidase on the magnetic iron oxide nanoparticles, indicating 73.0% and 65.4% of enzyme activity remaining for β-Glu-MNP and PEG-β-Glu-MNP, respectively. Both magnetophoretic mobility analysis and pharmacokinetics showed improved in vitro/in vivo stability of PEG-β-Glu-MNP compared with β-Glu-MNP. In vivo magnetic targeting of PEG-β-Glu-MNP was confirmed by magnetic resonance imaging and electron spin resonance analysis in a mouse model of subcutaneous 9L-glioma. Satisfactory accumulation of PEG-β-Glu-MNP in tumor tissue was successfully achieved, with an iron content of 627±45 nmol Fe/g tissue and β-glucosidase activity of 32.2±8.0 mU/g tissue.

  11. Design of Chemical Conjugate for Targeted Therapy of Multiple Sclerosis Based of Constant Fragment of Human Antibody Heavy Chain and Peptoid Analog of Autoantigen MOG35-55.

    Science.gov (United States)

    Lomakin, Y A; Stepanov, A V; Balabashin, D S; Ponomarenko, N A; Smirnov, I V; Belogurov, A A

    2017-04-01

    Elimination of B cells producing autoantibodies to neuroantigens is considered as beneficial in the treatment of multiple sclerosis. Myelin oligodendrocyte glycoprotein (MOG) is a significant autoantigen in multiple sclerosis. It was shown that MOG-like peptoid AMogP3 can bind autoantibodies produced by pathological lymphocytes. We propose a structure of an innovative drug for targeted elimination of the pool of autoreactive B cells responsible for multiple sclerosis pathogenesis; this compound is a complex of peptoid AMogP3 with Fc fragment of human immunoglobulin. The obtained Fc-PEG-AMogP3 conjugate effectively interact with autoreactive antibodies, which attests to their high therapeutic potential.

  12. Anti-HER2 antibody and ScFvEGFR-conjugated antifouling magnetic iron oxide nanoparticles for targeting and magnetic resonance imaging of breast cancer

    Directory of Open Access Journals (Sweden)

    Chen H

    2013-10-01

    Full Text Available Hongwei Chen,1,* Liya Wang,1,2,* Qiqi Yu,1,2 Weiping Qian,3 Diana Tiwari,1 Hong Yi,4 Andrew Y Wang,5 Jing Huang,1,2 Lily Yang,3 Hui Mao1,2 1Department of Radiology and Imaging Sciences, 2Center for Systems Imaging, 3Department of Surgery, Emory University School of Medicine, 4Robert Apkarian Electron Microscopy Core, Emory University, Atlanta, GA, 5Ocean NanoTech LLC, Springdale, AK, USA *These authors contributed equally to this work Abstract: Antifouling magnetic iron oxide nanoparticles (IONPs coated with block copolymer poly(ethylene oxide-block-poly(γ-methacryloxypropyltrimethoxysilane (PEO-b-PγMPS were investigated for improving cell targeting by reducing nonspecific uptake. Conjugation of a HER2 antibody, Herceptin®, or a single chain fragment (ScFv of antibody against epidermal growth factor receptor (ScFvEGFR to PEO-b-PγMPS-coated IONPs resulted in HER2-targeted or EGFR-targeted IONPs (anti-HER2-IONPs or ScFvEGFR-IONPs. The anti-HER2-IONPs bound specifically to SK-BR-3, a HER2-overexpressing breast cancer cell line, but not to MDA-MB-231, a HER2-underexpressing cell line. On the other hand, the ScFvEGFR-IONPs showed strong reactivity with MDA-MB-231, an EGFR-positive human breast cancer cell line, but not with MDA-MB-453, an EGFR-negative human breast cancer cell line. Transmission electron microscopy revealed internalization of the receptor-targeted nanoparticles by the targeted cancer cells. In addition, both antibody-conjugated and non-antibody-conjugated IONPs showed reduced nonspecific uptake by RAW264.7 mouse macrophages in vitro. The developed IONPs showed a long blood circulation time (serum half-life 11.6 hours in mice and low accumulation in both the liver and spleen. At 24 hours after systemic administration of ScFvEGFR-IONPs into mice bearing EGFR-positive breast cancer 4T1 mouse mammary tumors, magnetic resonance imaging revealed signal reduction in the tumor as a result of the accumulation of the targeted IONPs

  13. Intranuclear targeting and nuclear export of the adenovirus E1B-55K protein are regulated by SUMO1 conjugation

    OpenAIRE

    Kindsmüller, Kathrin; Groitl, Peter; Härtl, Barbara; Blanchette, Paola; Hauber, Joachim; Dobner, Thomas

    2007-01-01

    We have investigated the requirements for CRM1-mediated nuclear export and SUMO1 conjugation of the adenovirus E1B-55K protein during productive infection. Our data show that CRM1 is the major export receptor for E1B-55K in infected cells. Functional inactivation of the E1B-55K CRM1-dependent nuclear export signal (NES) or leptomycin B treatment causes an almost complete redistribution of the viral protein from the cytoplasm to the nucleus and its accumulation at the periphery of the viral re...

  14. FH3, a domain found in formins, targets the fission yeast formin Fus1 to the projection tip during conjugation

    DEFF Research Database (Denmark)

    Petersen, J; Nielsen, O; Egel, R;

    1998-01-01

    of the late G2 cells in a vegetatively growing population. Expression of both FH3-GFP fusions also affected cytokinesis. Overexpression of the spindle pole body component Sad1 altered the distribution of both Sad1 and the FH3-GFP domain. Together these data suggest that proteins at multiple sites can interact...... is required for conjugation, and is localized to the projection tip in cells of mating pairs. We replaced genomic fus1+ with green fluorescent protein (GFP)- tagged versions that lacked either the FH1, FH2, or FH3 domain. Deletion of any FH domain essentially abolished mating. FH3, but neither FH1 nor FH2...

  15. Fluorescent CdSe/ZnS nanocrystal-peptide conjugates for long-term, nontoxic imaging and nuclear targeting in living cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fanqing; Gerion, Daniele

    2004-06-14

    One of the biggest challenges in cell biology is the imaging of living cells. For this purpose, the most commonly used visualization tool is fluorescent markers. However, conventional labels, such as organic fluorescent dyes or green fluorescent proteins (GFP), lack the photostability to allow the tracking of cellular events that happen over minutes to days. In addition, they are either toxic to cells (dyes), or difficult to construct and manipulate (GFP). We report here the use of a new class of fluorescent labels, silanized CdSe/ZnS nanocrystal-peptide conjugates, for imaging the nuclei of living cells. CdSe/ZnS nanocrystals, or so called quantum dots (qdots), are extremely photostable, and have been used extensively in cellular imaging of fixed cells. However, most of the studies about living cells so far have been concerned only with particle entry into the cytoplasm or the localization of receptors on the cell membrane. Specific targeting of qdots to the nucleus of living cells ha s not been reported in previous studies, due to the lack of a targeting mechanism and proper particle size. Here we demonstrate for the first time the construction of a CdSe/ZnS nanocrystal-peptide conjugate that carries the SV40 large T antigen nuclear localization signal (NLS), and the transfection of the complex into living cells. By a novel adaptation of commonly used cell transfection techniques for qdots, we were able to introduce and retain the NLS-qdots conjugate in living cells for up to a week without detectable negative cellular effects. Moreover, we can visualize the movement of the CdSe/ZnS nanocrystal-peptide conjugates from cytoplasm to the nucleus, and the accumulation of the complex in the cell nucleus, over a long observation time period. This report opens the door for using qdots to visualize long-term biological events that happen in the cell nucleus, and provides a new nontoxic, long-term imaging platform for cell nuclear processes.

  16. Fluorescent CdSe/ZnS Nanocrystal-Peptide Conjugates for Long-term, Nontoxic Imaging and Nuclear Targeting in Living Cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, F; Gerion, D

    2004-06-08

    One of the biggest challenges in cell biology is the imaging of living cells. For this purpose, the most commonly used visualization tool is fluorescent markers. However, conventional labels, such as organic fluorescent dyes or green fluorescent proteins (GFP), lack the photostability to allow the tracking of cellular events that happen over minutes to days. In addition, they are either toxic to cells (dyes), or difficult to construct and manipulate (GFP). We report here the use of a new class of fluorescent labels, silanized CdSe/ZnS nanocrystal-peptide conjugates, for imaging the nuclei of living cells. CdSe/ZnS nanocrystals, or so called quantum dots (qdots), are extremely photostable, and have been used extensively in cellular imaging of fixed cells. Most of the studies about living cells so far have been concerned only with particle entry into the cytoplasm or the localization of receptors on the cell membrane. Specific targeting of qdots to the nucleus of living cells has not been reported in previous studies, due to the lack of a targeting mechanism and proper particle size. Here we demonstrate for the first time the construction of a CdSe/ZnS nanocrystal-peptide conjugate that carries the SV40 large T antigen nuclear localization signal (NLS), and the transfection of the complex into living cells. By a novel adaptation of a commonly used cell transfection technique for qdots, we were able to introduce and retain the NLS-qdot conjugates in living cells for up to a week without detectable negative cellular effects. Moreover, we can visualize the movement of the CdSe/ZnS qdot-peptide conjugates from cytoplasm to the nucleus, and the accumulation of the complex in the cell nucleus, over a long observation time period. This report opens the door for using qdots to visualize long-term biological events that happen in the cell nucleus, and provides a new nontoxic, long-term imaging platform for nuclear trafficking mechanisms and cell nuclear processes.

  17. Enhanced and selective delivery of enzyme therapy to 9L-glioma tumor via magnetic targeting of PEG-modified, ß-glucosidase- conjugated iron oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Zhou J

    2014-06-01

    Full Text Available Jie Zhou,1,* Jian Zhang,2,* Wenxi Gao11Department of Urology, Hubei Hospital of Traditional Chinese Medicine, Hubei University of Chinese Medicine, Wuhan, People’s Republic of China; 2Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, USA*These authors contributed equally to this workAbstract: The stability of enzyme-conjugated magnetic iron oxide nanoparticles in plasma is of great importance for in vivo delivery of the conjugated enzyme. In this study, ß-glucosidase was conjugated on aminated magnetic iron oxide nanoparticles using the glutaraldehyde method (ß-Glu-MNP, and further PEGylated via N-hydroxysuccinimide chemistry. The PEG-modified, ß-glucosidase-immobilized magnetic iron oxide nanoparticles (PEG-ß-Glu-MNPs were characterized by hydrodynamic diameter distribution, zeta potential, Fourier transform infrared spectroscopy, transmission electron microscopy, and a superconducting quantum interference device. The results showed that the multidomain structure and magnetization properties of these nanoparticles were conserved well throughout the synthesis steps, with an expected diameter increase and zeta potential shifts. The Michaelis constant was calculated to evaluate the activity of conjugated ß-glucosidase on the magnetic iron oxide nanoparticles, indicating 73.0% and 65.4% of enzyme activity remaining for ß-Glu-MNP and PEG-ß-Glu-MNP, respectively. Both magnetophoretic mobility analysis and pharmacokinetics showed improved in vitro/in vivo stability of PEG-ß-Glu-MNP compared with ß-Glu-MNP. In vivo magnetic targeting of PEG-ß-Glu-MNP was confirmed by magnetic resonance imaging and electron spin resonance analysis in a mouse model of subcutaneous 9L-glioma. Satisfactory accumulation of PEG-ß-Glu-MNP in tumor tissue was successfully achieved, with an iron content of 627±45 nmol Fe/g tissue and ß-glucosidase activity of 32.2±8.0 mU/g tissue.Keywords: ß-glucosidase, enzyme

  18. Oral Gavage Delivery of PR8 Antigen with β-Glucan-Conjugated GRGDS Carrier to Enhance M-Cell Targeting Ability and Induce Immunity.

    Science.gov (United States)

    Lee, Dong-Yi; Nurunnabi, Md; Kang, Sung Hun; Nafiujjaman, Md; Huh, Kang Moo; Lee, Yong-Kyu; Kim, Yeu-Chun

    2017-04-10

    Oral gavage is known as one of most convenient routes for therapeutic administration in comparison with other available routes such as intravenous, intra muscular, suppository, etc. An oral vaccine delivery system has additional potential as it may provide a convenient way to prevent infectious diseases by introducing optimum immunization in mucus. Although oral vaccine delivery has attracted tremendous interest in vaccine delivery research, various limitations have prevented its rate of progress up to the level that was initially expected. However, the major problems of oral vaccine delivery are vaccine instability and lack of absorbability, resulting from degradation of the sophisticated antigens in the acidic medium in the stomach. In order to obtain adequate microfold-cell (M-cell) targeting and uptake, the therapeutic material is required to pass through the stomach and reach the small intestine without degradation. In this project, we have introduced a conjugate of β-glucan and Glycine-Arginine-Glycine-Aspartic acid-Serine (GRGDS) that is effective for simultaneous protection of the antigen (PR8) and M-cell targeting. According to the experimental results, the cationic β-glucan-GRGDS conjugate can encapsulate a certain amount of anionic PR8 through electrostatic interaction, which forms nanoparticles with a range of diameter of 200-250 nm. Also, the PR8 incorporated nanoparticles showed high cell viability and stability in diverse environments. Finally, excellent M-cell targeting ability was verified in an in vitro M-cell model. Most importantly, the in vivo test obviously demonstrated the superiority of this system, which significantly increases antibody concentration in serum, intestine, and mucus as measured 21 days after immunization.

  19. Antibody-drug conjugates: targeting melanoma with cisplatin encapsulated in protein-cage nanoparticles based on human ferritin

    Science.gov (United States)

    Falvo, Elisabetta; Tremante, Elisa; Fraioli, Rocco; Leonetti, Carlo; Zamparelli, Carlotta; Boffi, Alberto; Morea, Veronica; Ceci, Pierpaolo; Giacomini, Patrizio

    2013-11-01

    A novel antibody-drug conjugate (ADC) was synthesized incorporating ferritin-based nanoparticles. An average of three molecules of monoclonal antibody (mAb) Ep1 to the human melanoma-specific antigen CSPG4 were conjugated to a single ferritin cage encapsulating about 50 cisplatin molecules (HFt-Pt-Ep1). The HFt-Pt-Ep1 nanoparticle had an estimated molecular size of about 900 kD and 33 nm, and flow cytometry demonstrated specific binding to a CSPG4+ melanoma cell line, but not to a CSPG4- breast carcinoma cell line. As compared to the cisplatin-containing ferritin nanoparticle alone (HFt-Pt), which inhibited thymidine incorporation more efficiently in breast carcinoma than melanoma cells, the mAb-derivatized HFt-Pt-Ep1 nanoparticle had a 25-fold preference for the latter. A similar preference for melanoma was observed upon systemic intravenous administration of HFt-Pt-Ep1 to nude mice xenotransplanted with pre-established, palpable melanoma and breast carcinoma tumors. Thus, we have been able to determine precise combinations and stoichiometric relationships between mAbs and nanoparticle protein cages, whereby the latter lose their tropism for ubiquitously distributed cellular receptors, and acquire instead remarkably lineage-selective binding. HFt-Pt-Ep1 is therefore an interesting model to improve the therapeutic index of antiblastic therapy in a tumor such as melanoma, which at its advanced stages is totally refractory to mono- and combination-chemotherapy.A novel antibody-drug conjugate (ADC) was synthesized incorporating ferritin-based nanoparticles. An average of three molecules of monoclonal antibody (mAb) Ep1 to the human melanoma-specific antigen CSPG4 were conjugated to a single ferritin cage encapsulating about 50 cisplatin molecules (HFt-Pt-Ep1). The HFt-Pt-Ep1 nanoparticle had an estimated molecular size of about 900 kD and 33 nm, and flow cytometry demonstrated specific binding to a CSPG4+ melanoma cell line, but not to a CSPG4- breast carcinoma cell

  20. Characterization of the paclitaxel loaded chitosan graft Pluronic F127 copolymer micelles conjugate with a DNA aptamer targeting HER-2 overexpressing breast cancer cells

    Science.gov (United States)

    Thach Nguyen, Kim; Nguyen, Thu Ha; Do, Dinh Ho; Huan Le, Quang

    2017-03-01

    In this work we report the isolation of DNA aptamer that is specifically bound to a HER-2 overexpressing SK-BR-3 human breast cancer cell line, using SELEX strategy. Paclitaxel (PTX) loaded chitosan graft Pluronic F127 copolymer micelles conjugate with a DNA aptamer was synthesized and its structure was confirmed by TEM image. This binary mixed system consisting of DNA aptamer modified Pluronic F127 and chitosan could enhance PTX loading capacity and increase micelle stability. Morphology images confirmed the existence of PTX micelles, with an average size of approximately 86.22 ± 1.45 nm diameters. Drug release profile showed that the PTX conjugate maintained a sustained PTX release. From in vitro cell experiment it was shown that 89%–93%, 50%–58%, 55%–62%, 24%–28% and 2%–7% of the SK-BR-3, NS-VN-67, LH-VN-48, HT-VN-26 and NV-VN-31, respectively, were dead after 6–48 h. These results demonstrated a novel DNA aptamer-micelle assembly for efficient detection and a system for the delivery of PTX targeting specific HER-2 overexpressing. We have also successfully cultivated cancer tissues of explants from Vietnamese patients on a type I collagen substrate. The NS-VN-67, LH-VN-48, HT-VN-26 and NV-VN-31cell lines were used as cellular model sources for the study of chemotherapy drug in cancer.

  1. RGD Peptides-Conjugated Pluronic Triblock Copolymers Encapsulated with AP-2α Expression Plasmid for Targeting Gastric Cancer Therapy in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2015-07-01

    Full Text Available Gastric cancer, a high-risk malignancy, is a genetic disease developing from a cooperation of multiple gene mutations and a multistep process. Gene therapy is a novel treatment method for treating gastric cancer. Here, we developed a novel Arg-Gly-Asp (RGD peptides conjugated copolymers nanoparticles-based gene delivery system in order to actively targeting inhibit the growth of gastric cancer cells. These transcription factor (AP-2α expression plasmids were also encapsulated into pluronic triblock copolymers nanoparticles which was constituted of poly(ethylene glycol-block-poly(propylene glycol- block-poly(ethylene glycol (PEO-block-PPO-block-PEO, P123. The size, morphology and composition of prepared nanocomposites were further characterized by nuclear magnetic resonance (NMR, transmission electron microscopy (TEM and dynamic light scattering (DLS. In MTT (3-(4,5-dimethyl-2-thiazolyl-2,5-diphenyltetrazolium bromide analysis, these nanocomposites have minor effects on the proliferation of GES-1 cells but significantly decreased the viability of MGC-803, suggesting they own low cytotoxicity but good antitumor activity. The following in vivo evaluation experiments confirmed that these nanocomposites could prevent the growth of gastric cancer cells in the tumor xenograft mice model. In conclusion, these unique RGD peptides conjugated P123 encapsulated AP-2α nanocomposites could selectively and continually kill gastric cancer cells by over-expression of AP-2α in vitro and in vivo; this exhibits huge promising applications in clinical gastric cancer therapy.

  2. A Novel Active Targeting Preparation, Vinorelbine Tartrate (VLBT Encapsulated by Folate-Conjugated Bovine Serum Albumin (BSA Nanoparticles: Preparation, Characterization and in Vitro Release Study

    Directory of Open Access Journals (Sweden)

    Xinyang Yu

    2012-11-01

    Full Text Available Vinorelbine tartrate (VLBT, as a kind of high hydrophilic and temperature-induced degradation drug, was prepared into nanoparticles by a desolvation procedure. Bovine serum albumin (BSA, as a drug carrier, was stabilized by chemical cross-linking with glutaraldehyde. Firstly, the optimization process of preparing VLBT-loaded BSA nanoparticles (VLBT-BSANPs was accomplished using response surface methodology (RSM by desolvation. Then VLBT-BSANPs were conjugated with folate, namely Fa-BSANPs-VLBT. Hence targeting drug carrier delivery system loading VLBT was produced. In this study, the characteristics of the nanoparticles, such as the amount of folate conjugation, surface morphology, surface chemistry, physical status of VLBT in Fa-BSANPs-VLBT, stability of Fa-BSANPs-VLBT with mannitol and in vitro drug release behavior were all investigated. The VLBT-BSANPs were obtained under optimum conditions, with a mean particle size (MPS of 155.4 nm and a zeta potential (ZP of −32.97 mV at a pH value of 5.4. Drug loading efficiency (DLE and drug entrapment efficiency (DEE of this obtained drug were approximately 45.6% and 90.6%, respectively.

  3. Quantum dots conjugated with Fe3O4-filled carbon nanotubes for cancer-targeted imaging and magnetically guided drug delivery.

    Science.gov (United States)

    Chen, Mei-Ling; He, Ye-Ju; Chen, Xu-Wei; Wang, Jian-Hua

    2012-11-27

    A novel and specific nanoplatform for in vitro simultaneous cancer-targeted optical imaging and magnetically guided drug delivery is developed by conjugating CdTe quantum dots with Fe(3)O(4)-filled carbon nanotubes (CNTs) for the first time. Fe(3)O(4) is filled into the interior of the CNTs, which facilitates magnetically guided delivery and improves the synergetic targeting efficiency. In comparison with that immobilized on the external surface of CNTs, the magnetite nanocrystals inside the CNTs protect it from agglomeration, enhance its chemical stability, and improve the drug loading capacity. It also avoids magnetic nanocrystals-induced quenching of fluorescence of the quantum dots. The SiO(2)-coated quantum dots (HQDs) attached on the surface of CNTs exhibit favorable fluorescence as the hybrid SiO(2) shells on the QDs surface prevent its fluorescence quenching caused by the CNTs. In addition, the hybrid SiO(2) shells also mitigate the toxicity of the CdTe QDs. By coating transferrin on the surface of the herein modified CNTs, it provides a dual-targeted drug delivery system to transport the doxorubicin hydrochloride (DOX) into Hela cells by means of an external magnetic field. The nanocarrier based on the multifunctional nanoplatform exhibits an excellent drug loading capability of ca. 110%, in addition to cancer-targeted optical imaging as well as magnetically guided drug delivery.

  4. Synthesis of tumor-targeted folate conjugated fluorescent magnetic albumin nanoparticles for enhanced intracellular dual-modal imaging into human brain tumor cells.

    Science.gov (United States)

    Wang, Xueqin; Tu, Miaomiao; Tian, Baoming; Yi, Yanjie; Wei, ZhenZhen; Wei, Fang

    2016-11-01

    Superparamagnetic iron oxide nanoparticles (SPIO NPs), utilized as carriers are attractive materials widely applied in biomedical fields, but target-specific SPIO NPs with lower toxicity and excellent biocompatibility are still lacking for intracellular visualization in human brain tumor diagnosis and therapy. Herein, bovine serum albumin (BSA) coated superparamagnetic iron oxide, i.e. γ-Fe2O3 nanoparticles (BSA-SPIO NPs), are synthesized. Tumor-specific ligand folic acid (FA) is then conjugated onto BSA-SPIO NPs to fabricate tumor-targeted NPs, FA-BSA-SPIO NPs as a contrast agent for MRI imaging. The FA-BSA-SPIO NPs are also labeled with fluorescein isothiocyanate (FITC) for intracellular visualization after cellular uptake and internalization by glioma U251 cells. The biological effects of the FA-BSA-SPIO NPs are investigated in human brain tumor U251 cells in detail. These results show that the prepared FA-BSA-SPIO NPs display undetectable cytotoxicity, excellent biocompatibility, and potent cellular uptake. Moreover, the study shows that the made FA-BSA-SPIO NPs are effectively internalized for MRI imaging and intracellular visualization after FITC labeling in the targeted U251 cells. Therefore, the present study demonstrates that the fabricated FITC-FA-BSA-SPIO NPs hold promising perspectives by providing a dual-modal imaging as non-toxic and target-specific vehicles in human brain tumor treatment in future.

  5. Co-injection of a targeted, reversibly masked endosomolytic polymer dramatically improves the efficacy of cholesterol-conjugated small interfering RNAs in vivo.

    Science.gov (United States)

    Wong, So C; Klein, Jason J; Hamilton, Holly L; Chu, Qili; Frey, Christina L; Trubetskoy, Vladimir S; Hegge, Julia; Wakefield, Darren; Rozema, David B; Lewis, David L

    2012-12-01

    Effective in vivo delivery of small interfering (siRNA) has been a major obstacle in the development of RNA interference therapeutics. One of the first attempts to overcome this obstacle utilized intravenous injection of cholesterol-conjugated siRNA (chol-siRNA). Although studies in mice revealed target gene knockdown in the liver, delivery was relatively inefficient, requiring 3 daily injections of 50 mg/kg of chol-siRNA to obtain measurable reduction in gene expression. Here we present a new delivery approach that increases the efficacy of the chol-siRNA over 500-fold and allows over 90% reduction in target gene expression in mice and, for the first time, high levels of gene knockdown in non-human primates. This improved efficacy is achieved by the co-injection of a hepatocyte-targeted and reversibly masked endosomolytic polymer. We show that knockdown is absolutely dependent on the presence of hepatocyte-targeting ligand on the polymer, the cognate hepatocyte receptor, and the cholesterol moiety of the siRNA. Importantly, we provide evidence that this increase in efficacy is not dependent on interactions between the chol-siRNA with the polymer prior to injection or in the bloodstream. The simplicity of the formulation and efficacy of this mode of siRNA delivery should prove beneficial in the use of siRNA as a therapeutic.

  6. Green self-assembly of zein-conjugated ZnO/Cd(OH)Cl hierarchical nanocomposites with high cytotoxicity and immune organs targeting

    Science.gov (United States)

    Wang, Hua-Jie; Cao, Ying; Wang, Cai-Feng; Cui, Shi-Zhong; Mi, Li-Wei; Miyazawa, Teruo

    2016-04-01

    Inorganic nanomedicines in the fight against cancer have progressed rapidly during recent years, with the synergistic advantages of multifunctional nanosystems compared to single component. Herein, a drug-combination opinion was introduced into “nanomedicine” based on the understanding of Trojan horse-anti-tumor mechanism of inorganic nano-medicines. Moreover, we reported the green and facile synthesis route of mono-dispersed and rod-like zein-conjugated ZnO/Cd(OH)Cl hierarchical nanocomposites. We found that the nanocomposites exhibited high-efficiency killing ability to tumor cells through lipid peroxidation mediated-membrane disintegration route. The safety studies in BALB/c mice didn’t detect injection anaphylaxis, hemolysis and cytotoxicity. More interestingly, the nano-composites could specially accumulate in liver and kidney, which will be helpful for targeting cure to these regional cancers.

  7. Targeted delivery and pH-triggered release of a saporin toxin conjugated to transferrin via a DNA i-motif

    DEFF Research Database (Denmark)

    Liu, Tianqiang

    2016-01-01

    mechanism was studied by immobilizing the saporin i-motif conjugates on DNA origami, where the release was imaged by atomic force microscopy. In vitro studies demonstrated that the DNA-linked saporin-transferrin conjugates dramatically enhanced cell uptake and cytotoxicity. Furthermore, conjugates that were...

  8. Long-term tumor regression induced by an antibody-drug conjugate that targets 5T4, an oncofetal antigen expressed on tumor-initiating cells.

    Science.gov (United States)

    Sapra, Puja; Damelin, Marc; Dijoseph, John; Marquette, Kimberly; Geles, Kenneth G; Golas, Jonathon; Dougher, Maureen; Narayanan, Bitha; Giannakou, Andreas; Khandke, Kiran; Dushin, Russell; Ernstoff, Elana; Lucas, Judy; Leal, Mauricio; Hu, George; O'Donnell, Christopher J; Tchistiakova, Lioudmila; Abraham, Robert T; Gerber, Hans-Peter

    2013-01-01

    Antibody-drug conjugates (ADC) represent a promising therapeutic modality for the clinical management of cancer. We sought to develop a novel ADC that targets 5T4, an oncofetal antigen expressed on tumor-initiating cells (TIC), which comprise the most aggressive cell population in the tumor. We optimized an anti-5T4 ADC (A1mcMMAF) by sulfydryl-based conjugation of the humanized A1 antibody to the tubulin inhibitor monomethylauristatin F (MMAF) via a maleimidocaproyl linker. A1mcMMAF exhibited potent in vivo antitumor activity in a variety of tumor models and induced long-term regressions for up to 100 days after the last dose. Strikingly, animals showed pathologic complete response in each model with doses as low as 3 mg antibody/kg dosed every 4 days. In a non-small cell lung cancer patient-derived xenograft model, in which 5T4 is preferentially expressed on the less differentiated tumor cells, A1mcMMAF treatment resulted in sustained tumor regressions and reduced TIC frequency. These results highlight the potential of ADCs that target the most aggressive cell populations within tumors, such as TICs. In exploratory safety studies, A1mcMMAF exhibited no overt toxicities when administered to cynomolgus monkeys at doses up to 10 mg antibody/kg/cycle × 2 and displayed a half-life of 5 days. The preclinical efficacy and safety data established a promising therapeutic index that supports clinical testing of A1mcMMAF.

  9. Fabrication and spectroscopic studies of folic acid-conjugated Fe3O4@Au core-shell for targeted drug delivery application

    Science.gov (United States)

    Karamipour, Sh.; Sadjadi, M. S.; Farhadyar, N.

    2015-09-01

    Gold coated magnetite core shell is a kind of nanoparticle that include magnetic iron oxide core with a thin layer nanogold. Fe3O4-gold core-shell nanostructure can be used in biomedical applications such as magnetic bioseparation, bioimaging, targeting drug delivery and cancer treatment. In this study, the synthesis and characterization of gold coated magnetite nanoparticles were discussed. Magnetite nanoparticles with an average size of 6 nm in diameter were synthesized by the chemical co-precipitation method and gold-coated Fe3O4 core-shell nanostructures were produced with an average size of 11.5 nm in diameter by reduction of Au3+ with citrate ion in the presence of Fe3O4. Folate-conjugated gold coated magnetite nanoparticles were synthesized to targeting folate receptor that is overexpressed on the surface of cancerous cells. For this purpose, we used L-cysteine, as a bi-functional linker for attachment to gold surface and it was linked to the gold nanoparticles surface through its thiol group. Then, we conjugated amino-terminated nanoparticles to folic acid with an amide-linkage formation. These gold magnetic nanoparticles were characterized by various techniques such as X-ray powder diffraction (XRD) analysis, Fourier transform infrared spectrometer (FT-IR), UV-visible spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), dispersive analysis of X-ray (EDAX) and vibrating sample magnetometer (VSM) analysis. The magnetic and optical properties of Fe3O4 nanostructure were changed by gold coating and attachment of L-cysteine and folic acid to Fe3O4@Au nanoparticles.

  10. DOTA conjugate with an albumin-binding entity enables the first folic acid-targeted 177Lu-radionuclide tumor therapy in mice.

    Science.gov (United States)

    Müller, Cristina; Struthers, Harriet; Winiger, Christian; Zhernosekov, Konstantin; Schibli, Roger

    2013-01-01

    The folate receptor (FR) has proven a valuable target for nuclear imaging using folic acid radioconjugates. However, using folate-based radiopharmaceuticals for therapy has long been regarded as an unattainable goal because of their considerable renal accumulation. Herein, we present a novel strategy in which a DOTA-folate conjugate with an albumin-binding entity (cm09) was designed with the aim of prolonging circulation in the blood and therewith potentially improving tumor-to-kidney ratios. The folate conjugate cm09 was radiolabeled with (177)LuCl(3), and stability experiments were performed in plasma. Cell uptake studies were performed on FR-positive KB tumor cells, and an ultrafiltration assay was used to determine the plasma protein-binding properties of (177)Lu-cm09. In vivo, (177)Lu-cm09 was tested in KB tumor-bearing mice using SPECT/CT. The therapeutic anticancer effect of (177)Lu-cm09 (20 MBq) applied as a single injection or as fractionated injections was investigated in different groups of mice (n = 5) by monitoring tumor size and the survival time of treated mice, compared with untreated controls. Compound cm09 was radiolabeled at a specific activity of 40 MBq/nmol, a radiochemical yield of more than 98%, and a stability of more than 99% over 5 d in plasma. Ultrafiltration revealed significant binding of (177)Lu-cm09 to serum proteins (∼91%) in plasma, compared with folate radioconjugate without an albumin-binding entity. Cell uptake and internalization of (177)Lu-cm09 was FR-specific and comparable to other folate radioconjugates. In vivo studies resulted in high tumor uptake (17.56 percentage injected dose per gram [%ID/g] at 4 h after injection), which was almost completely retained for at least 72 h. Renal accumulation was significantly reduced (28 %ID/g at 4 h after injection), compared with folate conjugates that lack an albumin-binding entity (∼70 %ID/g at 4 h after injection). These circumstances enabled SPECT imaging of excellent quality

  11. The collagen receptor uPARAP/Endo180 as a novel target for antibody-drug conjugate mediated treatment of mesenchymal and leukemic cancers

    DEFF Research Database (Denmark)

    Nielsen, Christoffer Fagernæs; van Putten, Sander Maarten; Lund, Ida Katrine

    2017-01-01

    A key task in developing the field of personalized cancer therapy is the identification of novel molecular targets that enable treatment of cancers not susceptible to other means of specific therapy. The collagen receptor uPARAP/Endo180 is overexpressed by malignant cells in several non-epithelia......A key task in developing the field of personalized cancer therapy is the identification of novel molecular targets that enable treatment of cancers not susceptible to other means of specific therapy. The collagen receptor uPARAP/Endo180 is overexpressed by malignant cells in several non......-epithelial cancers, notably including sarcomas, glioblastomas and subsets of acute myeloid leukemia. In contrast, in healthy adult individuals, expression is restricted to minor subsets of mesenchymal cells. Functionally, uPARAP/Endo180 is a rapidly recycling endocytic receptor that delivers its cargo directly...... into the endosomal-lysosomal system, thus opening a potential route of entry into receptor-positive cells. This combination of specific expression and endocytic function appears well suited for targeting of uPARAP/Endo180-positive cancers by antibody-drug conjugate (ADC) mediated drug delivery. Therefore, we...

  12. MAPK pathway inhibition enhances the efficacy of an anti-endothelin B receptor drug conjugate by inducing target expression in melanoma.

    Science.gov (United States)

    Asundi, Jyoti; Lacap, Jennifer A; Clark, Suzanna; Nannini, Michelle; Roth, Leslie; Polakis, Paul

    2014-06-01

    Therapies targeting the mitogen-activated protein (MAP) kinase pathway in melanoma have produced significant clinical responses; however, duration of response is limited by acquisition of drug resistance. Rational drug combinations may improve outcomes in this setting. We assessed the therapeutic combination of an antibody-drug conjugate (ADC) targeting the endothelin B receptor (EDNRB) with small-molecule inhibitors of the MAP kinase signaling pathway in melanoma. Cell lines and tumor models containing either mutant BRAF or NRAS, or wild-type for both, were exposed to small-molecule inhibitors of BRAF and MEK. Expression of EDNRB was analyzed and the therapeutic impact of combining the anti-EDNRB ADC with the BRAF and MEK inhibitors was assessed. Increased expression of EDNRB in response to inhibition of BRAF and/or MEK was observed and augmented the antitumor activity of the ADC. Enhanced target expression and ADC antitumor activity were realized irrespective of the response of the tumor model to the BRAF or MEK inhibitors alone and could be achieved in melanoma with mutant NRAS, BRAF, or neither mutation. Cells that acquired resistance to BRAF inhibition through long-term culture retained drug-induced elevated levels of EDNRB expression. Expression of EDNRB was not enhanced in normal human melanocytes by inhibition of BRAF and the combination of the ADC with MAPK inhibitors was well-tolerated in mice. The anti-EDNRB ADC combines well with BRAF and MEK inhibitors and could have therapeutic use in the majority of human melanoma cases.

  13. Synthesis of a novel polyamidoamine dendrimer conjugating with alkali blue as a lymphatic tracer and study on the lymphatic targeting in vivo.

    Science.gov (United States)

    Yang, Rui; Xia, Suxia; Ye, Tiantian; Yao, Jianhua; Zhang, Ruizhi; Wang, Shujun; Wang, Siling

    2016-09-01

    In this study, a novel lymphatic tracer polyamidoamin-alkali blue (PAMAM-AB) was synthesized in order to evaluate the intra-lymphatic targeting ability and lymphatic tropism of PAMAM-AB after subcutaneous administration. UV-Vis, FT-IR, NMR and HPLC characterization were performed to prove the successful synthesis of PAMAM-AB. The calculated AB payload of PAMAM-AB conjugate was seven per dendrimer molecule (27.16% by weight). Hydrolysis stability of PAMAM-AB in vitro was evaluated, which was stable in PBS and human plasma. Lymphatic tracing were studied to determine the blue-stained intensity of PAMAM-AB in right popliteral lymph nodes (PLNs), iliac lymph nodes (ILNs) and para-aortic lymph nodes (PALNs) after subcutaneous administration. The pharmacokinetics and biodistribution of PAMAM-AB in mice were investigated. PLNs, ILNs and PALNs could be obviously blue-stained within 10 min after PAMAM-AB administration, and displayed a more rapid lymphatic absorption, a higher AUC value in lymph nodes and a longer lymph nodes residence time compared with methylene blue solution (MB-S), MB water-in-oil microemulsion (MB-ME), MB multiple microemulsion (MB-MME). Enhanced lymphatic drainage from the injection site and uptake into lymph of PAMAM-AB indicated that PAMAM-AB possesses the double function of lymphatic tracing and lymphatic targeting, and suggested the potential for the development of lymphatic targeting vectors or as a lymphatic tracer in its own right.

  14. Specific targeting of nasopharyngeal carcinoma cell line CNE1 by C225-conjugated ultrasmall superparamagnetic iron oxide particles with magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Dongbo Lin; Chunli Chen; Guangyuaa Hu; Qi Mei; Hong Qiu; Guoxian Long; Guoqing Hu

    2011-01-01

    An accurate definition of clinical target volume (CTV) is essential for the application of radiotherapy in nasopharvngeai carcinoma (NPC) treatment. A novel epidermal growth factor receptor (EGFR)-targeting contrast agent (C225-USPIO) was designed by conjugating ultrasmail superparamagnetic iron oxide (USPIO) nanoparticles with cetuximab (C225), to non-invasively define the CTV of tumor. The immunobinding activity of C225-USPIO to NPC cell line CNEI was confirmed by flow cytometry and immunofluorescence. The time-dependent accumulation of C225-USPIO in CNE1 cells was evaluated using Prussian blue staining. Targeted internalization and subcellular localization of C225-USPIO was confirmed by transmission electron microscope. The results indicated that C225-USPIO specifically bound to EGFR on the surface of CNEI cells and was taken up into the cell. The uptake of C225-USPIO by CNE1 cells increased significantly with time, when compared with human IgG-USPIO. In addition, 4.7 T magnetic resonance imaging (MRI) revealed that C225-USPIO had a capacity to accumulate in the CNE1 cells, with a resultant marked decrease in MRI T2-weighted signal intensity over time. These findings imply that C225-USPIO has the potential as an MRI contrast agent and can be employed to non-invasively detect early-stage NPC with EGFR overexpression. This provides sufficient theoretical basis for commencing in vivo experiments with the compound.

  15. Organometallic B12-DNA conjugate

    DEFF Research Database (Denmark)

    Hunger, Miriam; Mutti, Elena; Rieder, Alexander

    2014-01-01

    Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets in hum...

  16. Poly(lactic-co-glycolic acid nanoparticles conjugated with CD133 aptamers for targeted salinomycin delivery to CD133+ osteosarcoma cancer stem cells

    Directory of Open Access Journals (Sweden)

    Ni MZ

    2015-03-01

    Full Text Available Miaozhong Ni,1,* Min Xiong,1,* Xinchao Zhang,1,* Guoping Cai,1 Huaiwen Chen,2 Qingmin Zeng,1 Zuochong Yu1 1Department of Orthopedics, Jinshan Hospital, Fudan University, 2International Joint Cancer Institute, the Second Military Medical University, Shanghai, People’s Republic of China *These authors contributed equally to this work Background: Cancer stem cells (CSCs possess the characteristics associated with normal stem cells and are responsible for cancer initiation, recurrence, and metastasis. CD133 is regarded as a CSCs marker of osteosarcoma, which is the most common primary bone malignancy in childhood and adolescence. Salinomycin, a polyether ionophore antibiotic, has been shown to kill various CSCs, including osteosarcoma CSCs. However, salinomycin displayed poor aqueous solubility that hinders its clinical application. The objective of this study was to develop salinomycin-loaded nanoparticles to eliminate CD133+ osteosarcoma CSCs.Methods: The salinomycin-loaded PEGylated poly(lactic-co-glycolic acid nanoparticles (SAL-NP conjugated with CD133 aptamers (Ap-SAL-NP were developed by an emulsion/solvent evaporation method, and the targeting and cytotoxicity of Ap-SAL-NP to CD133+ osteosarcoma CSCs were evaluated.Results: The nanoparticles are of desired particle size (~150 nm, drug encapsulation efficiency (~50%, and drug release profile. After 48 hours treatment of the Saos-2 CD133+ osteosarcoma cells with drugs formulated in Ap-SAL-NP, SAL-NP, and salinomycin, the concentrations needed to kill 50% of the incubated cells were found to be 2.18, 10.72, and 5.07 µg/mL, respectively, suggesting that Ap-SAL-NP could be 4.92 or 2.33 fold more effective than SAL-NP or salinomycin, respectively. In contrast, Ap-SAL-NP was as effective as SAL-NP, and less effective than salinomycin in Saos-2 CD133- cells, suggesting that Ap-SAL-NP possess specific cytotoxicity toward Saos-2 CD133+ cells. Ap-SAL-NP showed the best therapeutic effect in Saos-2

  17. Targeted delivery of let-7a microRNA encapsulated ephrin-A1 conjugated liposomal nanoparticles inhibit tumor growth in lung cancer

    Directory of Open Access Journals (Sweden)

    Lee HY

    2013-11-01

    Full Text Available Hung-Yen Lee,1,2 Kamal A Mohammed,1,3 Fredric Kaye,4 Parvesh Sharma,5 Brij M Moudgil,5 William L Clapp,6 Najmunnisa Nasreen1,3 1Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine in the College of Medicine, 2Biomaterials Center, Department of Materials Sciences and Engineering, 3North Florida/South Georgia Veterans Health System, Malcom Randall VA Medical Center, 4Division of Hematology and Oncology, Department of Medicine in the College of Medicine, 5Particle Engineering Research Center and Department of Materials Science and Engineering, 6Renal Pathology, Surgical Pathology, University of Florida, Gainesville, FL, USA Abstract: MicroRNAs (miRs are small noncoding RNA sequences that negatively regulate the expression of target genes by posttranscriptional repression. miRs are dysregulated in various diseases, including cancer. let-7a miR, an antioncogenic miR, is downregulated in lung cancers. Our earlier studies demonstrated that let-7a miR inhibits tumor growth in malignant pleural mesothelioma (MPM and could be a potential therapeutic against lung cancer. EphA2 (ephrin type-A receptor 2 tyrosine kinase is overexpressed in most cancer cells, including MPM and non-small-cell lung cancer (NSCLC cells. Ephrin-A1, a specific ligand of the EphA2 receptor, inhibits cell proliferation and migration. In this study, to enhance the delivery of miR, the miRs were encapsulated in the DOTAP (N-[1-(2.3-dioleoyloxypropyl]-N,N,N-trimethyl ammonium/Cholesterol/DSPE (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[cyanur(polyethylene glycol-2000]-PEG (polyethylene glycol-cyanur liposomal nanoparticles (LNP and ephrin-A1 was conjugated on the surface of LNP to target receptor EphA2 on lung cancer cells. The LNP with an average diameter of 100 nm showed high stability, low cytotoxicity, and high loading efficiency of precursor let-7a miR and ephrin-A1. The ephrin-A1 conjugated LNP (ephrin-A1–LNP and let-7a miR encapsulated LNP

  18. Synthesis and formulation of methotrexate (MTX) conjugated LaF3:Tb(3+)/chitosan nanoparticles for targeted drug delivery applications.

    Science.gov (United States)

    Mangaiyarkarasi, Rajendiran; Chinnathambi, Shanmugavel; Aruna, Prakasarao; Ganesan, Singaravelu

    2015-02-01

    Chitosan functionalized luminescent rare earth doped terbium nanoparticles (LaF3:Tb(3+)/chi NPs) as a drug carrier for methotrexate (MTX) was designed using a simple chemical precipitation method. The synthesized chitosan functionalized nanoparticles were found to be spherical in shape with an average diameter of 10-12nm. They are water soluble and biocompatible, in which the hydroxyl and amino functional groups on its surface are utilized for the bioconjugation of the anticancer drug, the methotrexate. The nature of MTX binding with LaF3:Tb(3+)/chi nanoparticles were examined using X-ray diffraction, zeta potential analyzer and transmission electron microscopy. The other interactions due to complex formation between MTX and LaF3:Tb(3+)/chi NPs were carried out by UV-Visible, steady and excited state fluorescence spectroscopy. The photo-physical characterization revealed that the adsorption and release of MTX from LaF3:Tb(3+)/chi NPs is faster than gold nanoparticles and also confirms that this may be due to weak interaction i.e. the Vander Waals force of attraction between the carboxyl and amino group of drug and nanoparticles. The maximum percentage yield and entrapment efficiency of 85.91±0.71 and 83.82± 0.14 were achieved at a stochiometric ratio of 4:5 of MTX and LaF3:Tb(3+)/chi nanoparticles respectively. In addition, antitumoral activity study reveals that MTX conjugated LaF3:Tb(3+)/chi nanoparticles show higher cytotoxic effect on MCF-7 breast cancer cell lines than that of free MTX.

  19. Targeted delivery of tanshinone IIA-conjugated mPEG-PLGA-PLL-cRGD nanoparticles to hepatocellular carcinoma.

    Science.gov (United States)

    Wang, Yan; Song, Daqian; Costanza, Frankie; Ji, Guang; Fan, Zhongze; Cai, Jianfeng; Li, Qi

    2014-11-01

    Tanshinone IIA (TSIIA) is an active constituent of the traditional Chinese medicinal plant Salvia miltiorrhiza that is known to have anti-tumor properties. In order to increase the selectivity of TSIIA's anti-tumor activity, the current study evaluated the tumor-targeting efficacy of TSIIA incorporated into nanoparticles (NPs). TSIIA was loaded into mPEG-PLGA-PLL-cRGD (methoxy polyethylene glycol, polylactic-co-glycolic acid, poly-L-lysine, cyclic arginine-glycine-aspartic acid) nanoparticles (TNPs) and used to treat hepatocellular carcinoma in vitro and in vivo. Our data demonstrate that TNPs were stable and had an even size distribution as well as an extended TSIIA releasing time, and improved tumor-targeting activity. As a novel drug carrier system, TNPs significantly inhibited the development of liver cancer both in vitro and in vivo, proving to be a novel promising targeted treatment for liver cancer.

  20. Aptamer-conjugated multifunctional nanoflowers as a platform for targeting, capture, and detection in laser desorption ionization mass spectrometry.

    Science.gov (United States)

    Ocsoy, Ismail; Gulbakan, Basri; Shukoor, Mohammed Ibrahim; Xiong, Xiangling; Chen, Tao; Powell, David H; Tan, Weihong

    2013-01-22

    Although many different nanomaterials have been tested as substrates for laser desorption and ionization mass spectrometry (LDI-MS), this emerging field still requires more efficient multifuncional nanomaterials for targeting, enrichment, and detection. Here, we report the use of gold manganese oxide (Au@MnO) hybrid nanoflowers as an efficient matrix for LDI-MS. The nanoflowers were also functionalized with two different aptamers to target cancer cells and capture adenosine triphosphate (ATP). These nanoflowers were successfully used for metabolite extraction from cancer cell lysates. Thus, in one system, our multifunctional nanoflowers can (1) act as an ionization substrate for mass spectrometry, (2) target cancer cells, and (3) detect and analyze metabolites from cancer cells.

  1. Aptamer Conjugated Multifunctional Nanoflowers as a Platform for Targeting, Capture and Detection in Laser Desorption Ionization Mass Spectrometry

    Science.gov (United States)

    Ocsoy, Ismail; Gulbakan, Basri; Shukoor, Mohammed Ibrahim; Xiong, Xiangling; Chen, Tao; Powell, David H.; Tan, Weihong

    2013-01-01

    Although many different nanomaterials have been tested as substrates for laser desorption and ionization mass spectrometry (LDI-MS), this emerging field still requires more efficient multifuncional nanomaterials for targeting, enrichment and detection. Here, we report the use of gold-manganese oxide (Au@MnO) hybrid nanoflowers as an efficient matrix for LDI–MS. The nanoflowers were also functionalized with two different aptamers to target cancer cells and capture adenosine triphosphate (ATP), respectively. These nanoflowers were successfully used for metabolite extraction from cancer cell lysates. Thus, in one system, our multifunctional nanoflowers can 1) act as an ionization substrate for mass spectrometry, 2) target cancer cells, and 3) detect and analyze metabolites from cancer cells. PMID:23211039

  2. Detection of Human Neutrophil Elastase with Fluorescent Peptide Sensors Conjugated to Nanocellulosic Solid Supports Targeting Wound Care Diagnostics

    Science.gov (United States)

    Human neutrophil elastase (HNE) is a biomarker for chronic wounds and a therapeutic target for certain diseases. An unchecked influx of neutrophils, which contain about one pictogram of elastase per neutrophil, is responsible for degrading growth factors and collagen formation, indefinitely delaying...

  3. TARGETING OF ANTIVIRAL DRUGS TO LYMPHOCYTES-T4 - ANTI-HIV ACTIVITY OF NEOGLYCOPROTEIN AZTMP CONJUGATES INVITRO

    NARCIS (Netherlands)

    MOLEMA, G; JANSEN, RW; PAUWELS, R; DECLERCQ, E; MEIJER, DKF

    1990-01-01

    The delivery of the anti-HIV agent 3'-azido-3'-deoxythymidine (AZT), in its 5'-monophosphate form, (in)to human T-lymphocyte MT-4 cells in vitro through covalent coupling to neoglycoproteins was investigated. In vivo application of this drug targeting concept may lead to increased efficacy and/or di

  4. Renal targeting of captopril using captopril-lysozyme conjugate enhances its antiproteinuric effect in adriamycin-induced nephrosis

    NARCIS (Netherlands)

    Windt, Willemijn; Prakash, Jai; Kok, R.J; Moolenaar, Frits; Kluppel, C. A.; de Zeeuw, D; van Dokkum, Richard; Henning, R.H

    2004-01-01

    Introduction High-sodium intake blunts the renoprotective efficacy of angiotensin-converting enzyme (ACE) inhibitors. We investigated whether targeting the drug to the kidneys may attenuate the inferior response to ACE inhibitor (ACE-I) under high-sodium conditions. The ACE-I, captopril, was coupled

  5. Preparation of 10-hydroxycamptothecin-loaded glycyrrhizic acid-conjugated bovine serum albumin nanoparticles for hepatocellular carcinoma-targeted drug delivery

    Directory of Open Access Journals (Sweden)

    Zu Y

    2013-03-01

    Full Text Available Yuangang Zu, Li Meng, Xiuhua Zhao, Yunlong Ge, Xinyang Yu, Yin Zhang, Yiping Deng Key Laboratory of Forest Plant Ecology, Northeast Forestry University, Ministry of Education, Harbin, People’s Republic of China Introduction: The livertaxis of glycyrrhizic acid-conjugated bovine serum albumin (GL-BSA has been reported in the literature. Now, in this paper, we describe a novel type of drug-targeted delivery system containing 10-hydroxycamptothecin (HCPT with liver tumor targeting. Methods: First, GL was coupled to BSA then HCPT was encapsulated in GL-BSA by high-pressure homogenization emulsification. In the experimental design, the influencing variables on particle size and drug loading efficiency were determined to be BSA concentration, volume ratio of water to organic phase, and speed and speed duration of homogenization as well as homogenization pressure and the number of times homogenized at certain pressures. Particle size plays an important role in screening optimal conditions of nanoparticles preparation. Characteristics of 10-hydroxycamptothecin-loaded glycyrrhizic acid-conjugated bovine serum albumin nanoparticles (GL-BSA-HCPT-NPs, such as the drug encapsulation efficiency, drug loading efficiency, and GL-BSA content were studied. In addition, the morphology of the nanoparticles (NPs and weight loss rate were determined and Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, and thermal analysis performed. Results: The average particle size of the sample NPs prepared under optimal conditions was 157.5 nm and the zeta potential was −22.51 ± 0.78 mV; the drug encapsulation efficiency and drug loading efficiency were 93.7% and 10.9%, respectively. The amount of GL coupling to BSA was 98.26 µg/mg. Through physical property study of the samples, we determined that the HCPT had been successfully wrapped in GL-BSA. In vitro drug-release study showed that the nanoparticles could release the drug slowly and continuously

  6. Ionizing radiation improves glioma-specific targeting of superparamagnetic iron oxide nanoparticles conjugated with cmHsp70.1 monoclonal antibodies (SPION-cmHsp70.1)

    Science.gov (United States)

    Shevtsov, Maxim A.; Nikolaev, Boris P.; Ryzhov, Vyacheslav A.; Yakovleva, Ludmila Y.; Marchenko, Yaroslav Y.; Parr, Marina A.; Rolich, Valerij I.; Mikhrina, Anastasiya L.; Dobrodumov, Anatolii V.; Pitkin, Emil; Multhoff, Gabriele

    2015-12-01

    The stress-inducible 72 kDa heat shock protein Hsp70 is known to be expressed on the membrane of highly aggressive tumor cells including high-grade gliomas, but not on the corresponding normal cells. Membrane Hsp70 (mHsp70) is rapidly internalized into tumor cells and thus targeting of mHsp70 might provide a promising strategy for theranostics. Superparamagnetic iron oxide nanoparticles (SPIONs) are contrast negative agents that are used for the detection of tumors with MRI. Herein, we conjugated the Hsp70-specific antibody (cmHsp70.1) which is known to recognize mHsp70 to superparamagnetic iron nanoparticles to assess tumor-specific targeting before and after ionizing irradiation. In vitro experiments demonstrated the selectivity of SPION-cmHsp70.1 conjugates to free and mHsp70 in different tumor cell types (C6 glioblastoma, K562 leukemia, HeLa cervix carcinoma) in a dose-dependent manner. High-resolution MRI (11 T) on T2-weighted images showed the retention of the conjugates in the C6 glioma model. Accumulation of SPION-cmHsp70.1 nanoparticles in the glioma resulted in a nearly 2-fold drop of values in comparison to non-conjugated SPIONs. Biodistribution analysis using NLR-M2 measurements showed a 7-fold increase in the tumor-to-background (normal brain) uptake ratio of SPION-cmHsp70.1 conjugates in glioma-bearing rats in comparison to SPIONs. This accumulation within Hsp70-positive glioma was further enhanced after a single dose (10 Gy) of ionizing radiation. Elevated accumulation of the magnetic conjugates in the tumor due to radiosensitization proves the combination of radiotherapy and application of Hsp70-targeted agents in brain tumors.The stress-inducible 72 kDa heat shock protein Hsp70 is known to be expressed on the membrane of highly aggressive tumor cells including high-grade gliomas, but not on the corresponding normal cells. Membrane Hsp70 (mHsp70) is rapidly internalized into tumor cells and thus targeting of mHsp70 might provide a promising strategy

  7. Investigation of folate-conjugated fluorescent silica nanoparticles for targeting delivery to folate receptor-positive tumors and their internalization mechanism

    Directory of Open Access Journals (Sweden)

    Yang H

    2011-09-01

    Full Text Available Hong Yang1,*, Changchun Lou1,*, Mingming Xu1, Chunhui Wu1, Hirokazu Miyoshi2, Yiyao Liu1,31Department of Biophysics, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, Sichuan, People’s Republic of China; 2Radioisotope Research Center, University of Tokushima, Tokushima, Japan; 3Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing, People’s Republic of China *These authors contributed equally to this work Abstract: Multifunctionalized nanoparticles (NPs are emerging as ideal tools for gene/drug delivery, bioimaging, labeling, or intracellular tracking in biomedical applications, and have attracted considerable attention owing to their unique advantages. In this study, fluorescent silica NPs were synthesized by a modified Stöber method using conjugates of 3- mercaptopropyltrimethoxysilane (MPS and maleimide-fluorescein isothiocyanate (maleimide-FITC. Mean diameters of the NPs were controlled between 212–2111 nm by regulating MPS concentration in the reaction mixture. Maleimide-FITC molecules were doped into NPs or conjugated to the surface of NPs through the chemical reaction of maleimide and thiol groups. The data showed that the former NPs are better than the latter by comparing their fluorescence intensity. Furthermore, folate molecules were linked to the FITC-doped silica NPs by using polyethylene glycol (PEG (NH2-PEG-maleimide as a spacer, thus forming folate receptor targeting fluorescent NPs, referred to as NPs(FITC-PEG-Folate. The quantitative analysis of cellular internalization into different cancer cells showed that the delivery efficiency of KB cells (folate receptor-positive cells is more than six-fold higher than that of A549 cells (folate receptor-negative cells. The delivery efficiency of KB cells decreased significantly after free folate addition to the cell culture medium because the

  8. 2-Amino-2-deoxy-glucose conjugated cobalt ferrite magnetic nanoparticle (2DG-MNP) as a targeting agent for breast cancer cells.

    Science.gov (United States)

    Aşık, Elif; Aslan, Tuğba Nur; Volkan, Mürvet; Güray, N Tülin

    2016-01-01

    In this study, 2-amino-2-deoxy-glucose (2DG) was conjugated to COOH modified cobalt ferrite magnetic nanoparticles (COOH-MNPs), which were designed to target tumor cells as a potential targetable drug/gene delivery agent for cancer treatment. According to our results, it is apparent that, 2DG labeled MNPs were internalized more efficiently than COOH-MNPs under the same conditions in all cell types (MDA-MB-231 and MCF-7 cancer and MCF-10A normal breast cells) (p<0.001). Moreover, the highest amount of uptake was observed in MDA-MB-231, followed by MCF-7 and normal MCF-10A cells for both MNPs. The apoptotic effects of 2DG-MNPs were further evaluated, and it was found that apoptosis was not induced at low concentrations of 2DG-MNPs in all cell types, whereas dramatic cell death was observed at higher concentrations. In addition, the gene expression levels of four drug-metabolizing enzymes, two Phase I (CYP1A1, CYP1B1) and two Phase II (GSTM3, GSTZ1) were also increased with the high concentrations of 2DG-MNPs. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. An in vitro demonstration of overcoming drug resistance in SKOV3 TR and MCF7 ADR with targeted delivery of polymer pro-drug conjugates.

    Science.gov (United States)

    Bhattarai, Prashant; Vance, Dylan; Hatefi, Arash; Khaw, Ban An

    2017-01-05

    Drug resistance is a common phenomenon that occurs in cancer chemotherapy. Delivery of chemotherapeutic agents as polymer pro-drug conjugates (PPDCs) pretargeted with bispecific antibodies could circumvent drug resistance in cancer cells. To demonstrate this approach to overcome drug resistance, Paclitaxel (Ptxl)-resistant SKOV3 TR human ovarian- and doxorubicin (Dox)-resistant MCF7 ADR human mammary-carcinoma cell lines were used. Pre-targeting over-expressed biotin or HER2/neu receptors on cancer cells was conducted by biotinylated anti-DTPA or anti-HER2/neu affibody - anti-DTPA Fab bispecific antibody complexes. The targeting PPDCs are either D-Dox-PGA or D-Ptxl-PGA. Cytotoxicity studies demonstrate that the pretargeted approach increases cytotoxicity of Ptxl or Dox in SKOV3 TR or MCF7 ADR resistant cell lines by 5.4 and 27 times, respectively. Epifluorescent microscopy - used to track internalization of D-Dox-PGA and Dox in MCF7 ADR cells - shows that the pretargeted delivery of D-Dox-PGA resulted in a 2- to 4-fold increase in intracellular Dox concentration relative to treatment with free Dox. The mechanism of internalization of PPDCs is consistent with endocytosis. Enhanced drug delivery and intracellular retention following pretargeted delivery of PPDCs resulted in greater tumor cell toxicity in the current in vitro studies.

  10. Octa-ammonium POSS-conjugated single-walled carbon nanotubes as vehicles for targeted delivery of paclitaxel

    Directory of Open Access Journals (Sweden)

    Naghmeh Naderi

    2015-09-01

    Full Text Available Background: Carbon nanotubes (CNTs have unique physical and chemical properties. Furthermore, novel properties can be developed by attachment or encapsulation of functional groups. These unique properties facilitate the use of CNTs in drug delivery. We developed a new nanomedicine consisting of a nanocarrier, cell-targeting molecule, and chemotherapeutic drug and assessed its efficacy in vitro. Methods: The efficacy of a single-walled carbon nanotubes (SWCNTs-based nanoconjugate system is assessed in the targeted delivery of paclitaxel (PTX to cancer cells. SWCNTs were oxidized and reacted with octa-ammonium polyhedral oligomeric silsesquioxanes (octa-ammonium POSS to render them biocompatible and water dispersable. The functionalized SWCNTs were loaded with PTX, a chemotherapeutic agent toxic to cancer cells, and Tn218 antibodies for cancer cell targeting. The nanohybrid composites were characterized with transmission electron microscopy (TEM, Fourier transform infrared (FTIR, and ultraviolet–visible–near-infrared (UV–Vis–NIR. Additionally, their cytotoxic effects on Colon cancer cell (HT-29 and Breast cancer cell (MCF-7 lines were assessed in vitro. Results: TEM, FTIR, and UV–Vis–NIR studies confirmed side-wall functionalization of SWCNT with COOH-groups, PTX, POSS, and antibodies. Increased cell death was observed with PTX–POSS–SWCNT, PTX–POSS–Ab–SWCNT, and free PTX compared to functionalized-SWCNT (f-SWCNT, POSS–SWCNT, and cell-only controls at 48 and 72 h time intervals in both cell lines. At all time intervals, there was no significant cell death in the POSS–SWCNT samples compared to cell-only controls. Conclusion: The PTX-based nanocomposites were shown to be as cytotoxic as free PTX. This important finding indicates successful release of PTX from the nanocomposites and further reiterates the potential of SWCNTs to deliver drugs directly to targeted cells and tissues.

  11. Synthesis and purification of a toxin-linked conjugate targeting epidermal growth factor receptor in Escherichia coli.

    Science.gov (United States)

    Ma, Chengyuan; Li, Yang; Li, Zhixin; Huang, Haiyan; Xu, Kan; Xu, Haiyang; Bai, Jieying; Li, Xiao; Zhao, Gang

    2012-05-01

    Aberrant epidermal growth factor receptor (EGFR) signaling is a common feature of multiple tumor types, including glioblastoma (GBM). As such, EGFR has emerged as an attractive target for antitumor therapy. In the present study, we sought to develop an immunotoxin capable of specifically targeting EGFR-expressing cells and mediating inhibition of cell growth and cell killing. The Luffin P1 (LP1) ribosome inactivating protein was chosen to generate a fusion protein, antiEGFR/LP1, based upon its potent protein synthesis inhibition and small size (5 kDa). LP1 was fused to the C-terminus of an anti-EGFR single-chain antibody (scFv). The recombinant antiEGFR/LP1 protein was expressed in Escherichia coli, and refolded and purified on an immobilized Ni(2+)-affinity chromatography column. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting analysis revealed that antiEGFR/LP1 was sufficiently expressed. Confocal microscopy and flow cytometry demonstrated that antiEGFR/LP1 bound specifically to EGFR-positive cells (U251), as almost no binding to EGFR-negative (Jurkat cells) was observed under identical time and dosage conditions. Finally, the MTT cell viability assay showed that antiEGFR/LP1 elicited obvious cytotoxicity toward EGFR-positive tumor cells. Collectively, these results suggest that antiEGFR/LP1 is biologically active and specific toward EGFR-positive tumor cells and may represent an effective EGFR-targeted cancer therapy.

  12. Self-assembled targeted nanoparticles based on transferrin-modified eight-arm-polyethylene glycol–dihydroartemisinin conjugate

    Science.gov (United States)

    Liu, Kefeng; Dai, Lin; Li, Chunxiao; Liu, Jing; Wang, Luying; Lei, Jiandu

    2016-07-01

    Poor delivery of insoluble anticancer drugs has so far precluded their clinical application. In this study, an efficient tumor targeted-nanoparticle delivery system, transferrin-eight-arm-polyethylene glycol–dihydroartemisinin nanoparticles (TF-8arm-PEG-DHA NPs) for the vehiculation of dihydroartemisinin (DHA) was first prepared and evaluated for its targeting efficiency and cytotoxicity in vitro and in vivo to Lewis lung carcinoma (LLC) cells, which overexpress transferrin receptors (TFRs). The synthesized TF-8arm-PEG–DHA NPs had high solubility (~102 fold of free DHA), relatively high drug loading (~10 wt% DHA), long circulating half-life and moderate particle size (~147 nm). The in vitro cytotoxicity and in vivo tumor growth inhibition studies in LLC-tumor bearing mice confirmed the enhanced efficacy of TF-modified 8arm-PEG-DHA NPs compared to free DHA and non-modified 8arm-PEG-DHA NPs. All these results together supported that the formulation developed in this work exhibited great potential as an effective tumor targeting delivery system for insoluble anticancer drugs.

  13. Tailored polymer-lipid hybrid nanoparticles for the delivery of drug conjugate: dual strategy for brain targeting.

    Science.gov (United States)

    Agrawal, Udita; Chashoo, Gousia; Sharma, Parduman Raj; Kumar, Ashok; Saxena, Ajit Kumar; Vyas, S P

    2015-02-01

    The object of the present study was to investigate the glioma targeting propensity of folic acid (F) decorated polymer-lipid hybrid nanoparticles (PLNs) encapsulating cyclo-[Arg-Gly-Asp-D-Phe-Lys] (cRGDfK) modified paclitaxel (PtxR-FPLNs). The prepared PLNs were supposed to bypass the blood-brain barrier (BBB) efficiently and subsequently target integrin rich glioma cells. The developed formulations were characterized for size, shape, drug entrapment efficiency, and in vitro release profile. PtxR-FPLNs demonstrated highest in vitro inhibitory effect, cell apoptosis and cell uptake. Pharmacokinetics and biodistribution studies showed efficacy of PtxR-FPLNs in vivo. In vivo anti-tumor studies clearly revealed that the median survival time for Balb/C mice treated with PtxR-FPLNs (42 days) was extended significantly as compared to PtxR-PLNs (35 days), free PtxR (18 days), Ptx-FPLNs (38 days), Ptx-PLNs (30 days), free Ptx (14 days) and control group (12 days). From the results it can be concluded that the developed dual targeted nanoformulation was able to efficiently cross the BBB and significantly deliver higher amounts of drug to brain tumor for better therapeutic outcome.

  14. A new fluorescence/PET probe for targeting intracellular human telomerase reverse transcriptase (hTERT) using Tat peptide-conjugated IgM

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyung oh [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Biomedical Sciences, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Tumor Microenvironment Global Core Research Center, Seoul National University (Korea, Republic of); Youn, Hyewon, E-mail: hwyoun@snu.ac.kr [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Tumor Microenvironment Global Core Research Center, Seoul National University (Korea, Republic of); Cancer Imaging Center, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Seung Hoo [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Kim, Young-Hwa [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Biomedical Sciences, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Kang, Keon Wook [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Chung, June-Key, E-mail: jkchung@snu.ac.kr [Department of Nuclear Medicine, Seoul National University College of Medicine (Korea, Republic of); Biomedical Sciences, Seoul National University College of Medicine (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine (Korea, Republic of); Tumor Microenvironment Global Core Research Center, Seoul National University (Korea, Republic of)

    2016-08-26

    Despite an increasing need for methods to visualize intracellular proteins in vivo, the majority of antibody-based imaging methods available can only detect membrane proteins. The human telomerase reverse transcriptase (hTERT) is an intracellular target of great interest because of its high expression in several types of cancer. In this study, we developed a new probe for hTERT using the Tat peptide. An hTERT antibody (IgG or IgM) was conjugated with the Tat peptide, a fluorescence dye and {sup 64}Cu. HT29 (hTERT+) and U2OS (hTERT−) were used to visualize the intracellular hTERT. The hTERT was detected by RT-PCR and western blot. Fluorescence signals for hTERT were obtained by confocal microscopy, live cell imaging, and analyzed by Tissue-FAXS. In nude mice, tumors were visualized using the fluorescence imaging devices Maestro™ and PETBOX. In RT-PCR and western blot, the expression of hTERT was detected in HT29 cells, but not in U2OS cells. Fluorescence signals were clearly observed in HT29 cells and in U2OS cells after 1 h of treatment, but signals were only detected in HT29 cells after 24 h. Confocal microscopy showed that 9.65% of U2OS and 78.54% of HT29 cells had positive hTERT signals. 3D animation images showed that the probe could target intranuclear hTERT in the nucleus. In mice models, fluorescence and PET imaging showed that hTERT in HT29 tumors could be efficiently visualized. In summary, we developed a new method to visualize intracellular and intranuclear proteins both in vitro and in vivo. - Highlights: • We developed new probes for imaging hTERT using Tat-conjugated IgM antibodies labeled with a fluorescent dye and radioisotope. • This probes could be used to overcome limitation of conventional antibody imaging system in live cell imaging. • This system could be applicable to monitor intracellular and intranuclear proteins in vitro and in vivo.

  15. Folic acid-conjugated GdPO4:Tb3+@SiO2 Nanoprobe for folate receptor-targeted optical and magnetic resonance bi-modal imaging

    Science.gov (United States)

    Xu, Xianzhu; Zhang, Xiaoying; Wu, Yanli

    2016-11-01

    Both fluorescent and magnetic nanoprobes have great potential applications for diagnostics and therapy. In the present work, a folic acid-conjugated and silica-modified GdPO4:Tb3+ (GdPO4:Tb3+@SiO2-FA) dual nanoprobe was strategically designed and synthesized for the targeted dual-modality optical and magnetic resonance (MR) imaging via a facile aqueous method. Their structural, optical, and magnetic properties were determined using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), ultraviolet-visible spectra (UV-Vis), photoluminescence (PL), and superconducting quantum interference device (SQUID). These results indicated that GdPO4:Tb3+@SiO2-FA were uniform monodisperse core-shell structured nanorods (NRs) with an average length of 200 nm and an average width of 25 nm. The paramagnetic property of the synthesized GdPO4:Tb3+@SiO2-FA NRs was confirmed with its linear hysteresis plot (M-H). In addition, the NRs displayed an obvious T1-weighted effect and thus it could potentially serve as a T1-positive contrast agent. The NRs emitted green lights due to the 5D4 → 7F5 transition of the Tb3+. The in vitro assays with NCI-H460 lung cancer cells and human embryonic kidney cell line 293T cells indicated that the GdPO4:Tb3+@SiO2-FA nanoprobe could specifically bind the cells bearing folate receptors (FR). The MTT assay of the NRs revealed that its cytotoxicity was very low. Further in vivo MRI experiments distinctively depict enhanced anatomical features in a xenograft tumor. These results suggest that the GdPO4:Tb3+@SiO2-FA NPs have excellent imaging and cell-targeting abilities for the folate receptor-targeted dual-modality optical and MR imaging and can be potentially used as the nanoprobe for bioimaging.

  16. Folate conjugated Mn{sub 3}O{sub 4}@SiO{sub 2} nanoparticles for targeted magnetic resonance imaging in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xinyi [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Zhou, Zhiguo, E-mail: zgzhou@shnu.edu.cn [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Wang, Li; Tang, Caizhi; Yang, Hong [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Yang, Shiping, E-mail: shipingy@shnu.edu.cn [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); The Education Ministry Key Lab of Pesticide and Chemical Biology, South China Agricultural University, Guangzhou 510641 (China)

    2014-09-15

    Graphical abstract: The Mn{sub 3}O{sub 4}@SiO{sub 2}(PEG)–FA has been used as a T{sub 1}-MRI probe for in vivo. - Highlights: • The PEG and FA modified Mn{sub 3}O{sub 4}@SiO{sub 2} nanoparticles (Mn{sub 3}O{sub 4}@SiO{sub 2}–FA) were prepared. • Mn{sub 3}O{sub 4}@SiO{sub 2}–FA exhibited the good colloidal stability in the simulated biological medium. • Mn{sub 3}O{sub 4}@SiO{sub 2}–FA showed the targeting ability to HeLa cells overexpressed the FA receptor. • The T{sub 1}-weighted magnetic resonance (MR) imaging demonstrated the targeting ability of Mn{sub 3}O{sub 4}@SiO{sub 2}–FA in vivo tumor. - Abstract: The monodisperse silica-coated manganese oxide nanoparticles (Mn{sub 3}O{sub 4}@SiO{sub 2} NPs) were synthesized via the high temperature pyrolysis approach and were aminated through silanization. The amine-functionalized Mn{sub 3}O{sub 4} NPs enabled the covalent conjugation of hydrophilic methoxypoly(ethylene glycol) (PEG) and the targeting ligand of folate (FA) onto their surface. The formed PEG and FA modified Mn{sub 3}O{sub 4} NPs (Mn{sub 3}O{sub 4}@SiO{sub 2}(PEG)–FA) exhibited the good colloidal stability in the simulated biological medium and the targeting ability to HeLa cells overexpressed the FA receptor. The T{sub 1}-weighted magnetic resonance (MR) imaging and inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis of Mn{sub 3}O{sub 4}@SiO{sub 2}(PEG)–FA NPs further demonstrated their targeting ability in tumor.

  17. Monitoring Tumor Targeting and Treatment Effects of IRDye 800CW and GX1-Conjugated Polylactic Acid Nanoparticles Encapsulating Endostar on Glioma by Optical Molecular Imaging.

    Science.gov (United States)

    Li, Yaqian; Du, Yang; Liu, Xia; Zhang, Qian; Jing, Lijia; Liang, Xiaolong; Chi, Chongwei; Dai, Zhifei; Tian, Jie

    2015-01-01

    Molecular imaging used in cancer diagnosis and therapeutic response monitoring is important for glioblastoma (GBM) research. Antiangiogenic therapy currently is one of the emerging approaches for GBM treatment. In this study, a multifunctional nanoparticle was fabricated that can facilitate the fluorescence imaging of tumor and deliver a therapeutic agent to the tumor region in vivo and therefore possesses broad application in cancer diagnosis and treatment. This particle was polylactic acid (PLA) nanoparticles encapsulating Endostar, which was further conjugated with GX1 peptide and the near-infrared (NIR) dye IRDye 800CW (IGPNE). We demonstrated noninvasive angiogenesis targeting and therapy of IGPNE on U87MG xenografts in vivo using dual-modality optical molecular imaging including NIR fluorescence molecular imaging (FMI) and bioluminescence imaging (BLI). The NIR FMI results demonstrated that IGPNE had more accumulation to the tumor site compared to free IRDye 800CW. To further evaluate the antitumor treatment efficacy of IGPNE, BLI and immunohistochemistry analysis were performed on tumor-bearing mice. With the aid of molecular imaging, the results confirmed that IGPNE enhanced antitumor treatment efficacy compared to free Endostar. In conclusion, IGPNE realizes real-time imaging of U87MG tumors and improves the antiangiogenic therapeutic efficacy in vivo.

  18. Gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid conjugate of arabinogalactan as a potential liver-targeting magnetic resonance imaging contrast agent.

    Science.gov (United States)

    Xiao, Yan; Xue, Rong; You, Tianyan; Li, Xiaojing; Pei, Fengkui; Wang, Xuxia; Lei, Hao

    2014-08-18

    A novel biocompatible macromolecule (AG-CM-EDA-DOTA-Gd) was synthesized as a liver magnetic resonance imaging (MRI) contrast agent. AG-CM-EDA-DOTA-Gd consisted of a carboxymethyl-arabinogalactan unit conjugated with gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (Gd-DOTA) via ethylenediamine, and was specifically designed to bind to hepatocyte asialoglycoprotein in vivo, in an effort to develop a potential new tool for the diagnosis of liver diseases. The T1-relaxivity (8.87mmol(-1)Ls(-1)) of AG-CM-EDA-DOTA-Gd was 1.86 times than that of Gd-DOTA (4.76mmol(-1)Ls(-1)) in D2O at 9.4 T and 25°C. MRI experiments showed significant enhancement in rat liver following the intravenous administration of AG-CM-EDA-DOTA-Gd (0.094mmol Gd(3+)/kg body weight), which persisted for longer than Gd-DOTA (0.098mmol Gd(3+)/kg body weight). The mean percentage enhancements in the liver parenchyma were 85.2±6.5% and 19.3±3.3% for AG-CM-EDA-DOTA-Gd and Gd-DOTA, respectively. The results of this study therefore indicate that AG-CM-EDA-DOTA-Gd could be used as a potential liver-targeting contrast agent for MRI.

  19. Conjugation Magnetic PAEEP-PLLA Nanoparticles with Lactoferrin as a Specific Targeting MRI Contrast Agent for Detection of Brain Glioma in Rats

    Science.gov (United States)

    Luo, Binhua; Wang, Siqi; Rao, Rong; Liu, Xuhan; Xu, Haibo; Wu, Yun; Yang, Xiangliang; Liu, Wei

    2016-04-01

    The diagnosis of malignant brain gliomas is largely based on magnetic resonance imaging (MRI) with contrast agents. In recent years, nano-sized contrast agents have been developed for improved MRI diagnosis. In this study, oleylamine-coated Fe3O4 magnetic nanoparticles (OAM-MNPs) were synthesized with thermal decomposition method and encapsulated in novel amphiphilic poly(aminoethyl ethylene phosphate)/poly(L-lactide) (PAEEP-PLLA) copolymer nanoparticles. The OAM-MNP-loaded PAEEP-PLLA nanoparticles (M-PAEEP-PLLA-NPs) were further conjugated with lactoferrin (Lf) for glioma tumor targeting. The Lf-conjugated M-PAEEP-PLLA-NPs (Lf-M-PAEEP-PLLA-NPs) were characterized by photon correlation spectroscopy (PCS), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The average size of OAM-MNPs, M-PAEEP-PLLA-NPs, and Lf-M-PAEEP-PLLA-NPs were 8.6 ± 0.3, 165.7 ± 0.6, and 218.2 ± 0.4 nm, with polydispersity index (PDI) of 0.185 ± 0.023, 0.192 ± 0.021, and 0.224 ± 0.036, respectively. TEM imaging showed that OAM-MNPs were monodisperse and encapsulated in Lf-M-PAEEP-PLLA-NPs. TGA analysis showed that the content of iron oxide nanoparticles was 92.8 % in OAM-MNPs and 45.2 % in Lf-M-PAEEP-PLLA-NPs. VSM results indicated that both OAM-MNPs and Lf-M-PAEEP-PLLA-NPs were superparamagnetic, and the saturated magnetic intensity were 77.1 and 74.8 emu/g Fe. Lf-M-PAEEP-PLLA-NPs exhibited good biocompatibility in cytotoxicity assay. The high cellular uptake of Lf-M-PAEEP-PLLA-NPs in C6 cells indicated that Lf provided effective targeting for the brain tumor cells. The T 2 relaxation rate ( r 2) of M-PAEEP-PLLA-NPs and Lf-M-PAEEP-PLLA-NPs were calculated to be 167.2 and 151.3 mM-1 s-1. In MRI on Wistar rat-bearing glioma tumor, significant contrast enhancement could clearly appear at 4 h after injection and last 48 h. Prussian blue staining of the section clearly

  20. Conjugation Magnetic PAEEP-PLLA Nanoparticles with Lactoferrin as a Specific Targeting MRI Contrast Agent for Detection of Brain Glioma in Rats.

    Science.gov (United States)

    Luo, Binhua; Wang, Siqi; Rao, Rong; Liu, Xuhan; Xu, Haibo; Wu, Yun; Yang, Xiangliang; Liu, Wei

    2016-12-01

    The diagnosis of malignant brain gliomas is largely based on magnetic resonance imaging (MRI) with contrast agents. In recent years, nano-sized contrast agents have been developed for improved MRI diagnosis. In this study, oleylamine-coated Fe3O4 magnetic nanoparticles (OAM-MNPs) were synthesized with thermal decomposition method and encapsulated in novel amphiphilic poly(aminoethyl ethylene phosphate)/poly(L-lactide) (PAEEP-PLLA) copolymer nanoparticles. The OAM-MNP-loaded PAEEP-PLLA nanoparticles (M-PAEEP-PLLA-NPs) were further conjugated with lactoferrin (Lf) for glioma tumor targeting. The Lf-conjugated M-PAEEP-PLLA-NPs (Lf-M-PAEEP-PLLA-NPs) were characterized by photon correlation spectroscopy (PCS), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The average size of OAM-MNPs, M-PAEEP-PLLA-NPs, and Lf-M-PAEEP-PLLA-NPs were 8.6 ± 0.3, 165.7 ± 0.6, and 218.2 ± 0.4 nm, with polydispersity index (PDI) of 0.185 ± 0.023, 0.192 ± 0.021, and 0.224 ± 0.036, respectively. TEM imaging showed that OAM-MNPs were monodisperse and encapsulated in Lf-M-PAEEP-PLLA-NPs. TGA analysis showed that the content of iron oxide nanoparticles was 92.8 % in OAM-MNPs and 45.2 % in Lf-M-PAEEP-PLLA-NPs. VSM results indicated that both OAM-MNPs and Lf-M-PAEEP-PLLA-NPs were superparamagnetic, and the saturated magnetic intensity were 77.1 and 74.8 emu/g Fe. Lf-M-PAEEP-PLLA-NPs exhibited good biocompatibility in cytotoxicity assay. The high cellular uptake of Lf-M-PAEEP-PLLA-NPs in C6 cells indicated that Lf provided effective targeting for the brain tumor cells. The T 2 relaxation rate (r 2) of M-PAEEP-PLLA-NPs and Lf-M-PAEEP-PLLA-NPs were calculated to be 167.2 and 151.3 mM(-1) s(-1). In MRI on Wistar rat-bearing glioma tumor, significant contrast enhancement could clearly appear at 4 h after injection and last 48 h. Prussian

  1. A long-linker conjugate of fluorescein and triphenylphosphonium as mitochondria-targeted uncoupler and fluorescent neuro- and nephroprotector.

    Science.gov (United States)

    Antonenko, Yuri N; Denisov, Stepan S; Silachev, Denis N; Khailova, Ljudmila S; Jankauskas, Stanislovas S; Rokitskaya, Tatyana I; Danilina, Tatyana I; Kotova, Elena A; Korshunova, Galina A; Plotnikov, Egor Y; Zorov, Dmitry B

    2016-11-01

    Limited uncoupling of oxidative phosphorylation is known to be beneficial in various laboratory models of diseases. Linking a triphenyl-phosphonium cation to fluorescein through a decyl (C10) spacer yields a fluorescent uncoupler, coined mitoFluo, that selectively accumulates in energized mitochondria (Denisov et al., Chem.Commun. 2014). Proton-transport activity of mitoFluo was tested in liposomes reconstituted with bacteriorhodopsin. To examine the uncoupling action on mitochondria, we monitored mitochondrial membrane potential in parallel with oxygen consumption. Neuro- and nephroprotecting activity was detected by a limb-placing test and a kidney ischemia/reperfusion protocol, respectively. We compared mitoFluo properties with those of its newly synthesized analog having a short (butyl) spacer (C4-mitoFluo). MitoFluo, but not C4-mitoFluo, caused collapse of mitochondrial membrane potential resulting in stimulation of mitochondrial respiration. The dramatic difference in the uncoupling activity of mitoFluo and C4-mitoFluo was in line with the difference in their protonophoric activity on a lipid membrane. The accumulation of mitoFluo in mitochondria was more pronounced than that of C4-mitoFluo. MitoFluo decreased the rate of ROS production in mitochondria. MitoFluo was effective in preventing consequences of brain trauma in rats: it suppressed trauma-induced brain swelling and reduced a neurological deficit. Besides, mitoFluo attenuated acute kidney injury after ischemia/reperfusion in rats. A long alkyl linker was proved mandatory for mitoFluo to be a mitochondria- targeted uncoupler. MitoFluo showed high protective efficacy in certain models of oxidative stress-related diseases. MitoFluo is a candidate for developing therapeutic and fluorescence imaging agents to treat brain and kidney pathologies. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. A smart tumor targeting peptide-drug conjugate, pHLIP-SS-DOX: synthesis and cellular uptake on MCF-7 and MCF-7/Adr cells.

    Science.gov (United States)

    Song, Qin; Chuan, Xingxing; Chen, Binlong; He, Bing; Zhang, Hua; Dai, Wenbing; Wang, Xueqing; Zhang, Qiang

    2016-06-01

    Doxorubicin (DOX) is a potent anticancer drug for the treatment of tumors, but the poor specificity and multi-drug resistance (MDR) on tumor cells have restricted its application. Here, a pH and reduction-responsive peptide-drug conjugate (PDC), pHLIP-SS-DOX, was synthesized to overcome these drawbacks. pH low insertion peptide (pHLIP) is a cell penetrating peptide (CPP) with pH-dependent transmembrane ability. And because of the unique cell membrane insertion pattern, it might reverse the MDR. The cellular uptake study showed that on both drug-sensitive MCF-7 and drug-resistant MCF-7/Adr cells, pHLIP-SS-DOX obviously facilitated the uptake of DOX at pH 6.0 and the uptake level on MCF-7/Adr cells was similar with that on MCF-7 cells, indicating that pHLIP-SS-DOX had the ability to target acidic tumor cells and reverse MDR. In vitro cytotoxicity study mediated by GSH-OEt demonstrated that the cytotoxic effect of pHLIP-SS-DOX was reduction responsive, with obvious cytotoxicity at pH 6.0; while it had poor cytotoxicity at pH 7.4, no matter with or without GSH-OEt pretreatment. This illustrated that pHLIP could deliver DOX into tumor cells with acidic microenvironment specifically and could not deliver drugs into normal cells with neutral microenvironment. In summary, pHLIP-SS-DOX is a promising strategy to target drugs to tumors and provides a possibility to overcome MDR.

  3. Angiopep-2-conjugated poly(ethylene glycol)-co- poly(ε-caprolactone) polymersomes for dual-targeting drug delivery to glioma in rats

    Science.gov (United States)

    Lu, Fei; Pang, Zhiyong; Zhao, Jingjing; Jin, Kai; Li, Haichun; Pang, Qiang; Zhang, Long; Pang, Zhiqing

    2017-01-01

    The blood–brain barrier is a formidable obstacle for glioma chemotherapy due to its compact structure and drug efflux ability. In this study, a dual-targeting drug delivery system involving Angiopep-2-conjugated biodegradable polymersomes loaded with doxorubicin (Ang-PS-DOX) was developed to exploit transport by the low-density lipoprotein receptor-related protein 1 (LRP1), which is overexpressed in both blood–brain barrier and glioma cells. The polymersomes (PS) were prepared using a thin-film hydration method. The PS were loaded with doxorubicin using the pH gradient method (Ang-PS-DOX). The resulting PS were uniformly spherical, with diameters of ~135 nm and with ~159.9 Angiopep-2 molecules on the surface of each PS. The drug-loading capacity and the encapsulation efficiency for doxorubicin were 7.94%±0.17% and 95.0%±1.6%, respectively. Permeability tests demonstrated that the proton diffusion coefficient across the PS membrane was far slower than that across the liposome membrane, and the common logarithm value was linearly dependent on the dioxane content in the external phase. Compared with PS-DOX, Ang-PS-DOX demonstrated significantly higher cellular uptake and stronger cytotoxicity in C6 cells. In vivo pharmacokinetics and brain distribution experiments revealed that Ang-PS-DOX achieved a more extensive distribution and more abundant accumulation in glioma cells than PS-DOX. Moreover, the survival time of glioma-bearing rats treated with Ang-PS-DOX was significantly prolonged compared with those treated with PS-DOX or a solution of free doxorubicin. These results suggested that Ang-PS-DOX can target glioma cells and enhance chemotherapeutic efficacy. PMID:28356732

  4. Receptor-targeted cytotoxic peptide-drug conjugates%受体靶向多肽载体抗肿瘤药物

    Institute of Scientific and Technical Information of China (English)

    孙立春; Coy DH

    2015-01-01

    常规化疗药物对癌细胞没有选择性,常常会导致严重的副作用。提高这些药物的靶向特异性已成为药物开发的热点方向之一。一些小分子多肽能够靶向作用于特定的受体,因而被用作癌症化疗药物的载体。化疗药物与多肽载体偶联构成新的多肽载体抗肿瘤药物。这些药物具有高特异性、高亲和力和肿瘤渗透力等优点,能够通过细胞表面的特定受体将药物送到靶向癌细胞内,提高抗癌效果、减少副作用和癌细胞的耐药性。多肽载体靶向药物被誉为新一代的靶向特异性的抗肿瘤药物之一。%Conventional cancer chemotherapy has very limited effects due to lacking speciifcity resulting in severe toxic side effects. Certain G protein-coupled receptors (GPCRs) are highly expressed in many tumor cells and tumoral blood veins, with their cognate ligands being peptides. Therefore, these peptides, especially their long-acting analogs, can be applied as drug-delivery vehicles by coupling with cytotoxic agents. These novel cytotoxic peptide-drug conjugates display more potent anti-tumor efifcacy by targeting the cognate receptors while reducing toxic side effects and overcoming multiple drug resistance. This new receptor-targeted approach may provide a promising opportunity for the improvement of cancer treatments.

  5. Novel lactoferrin-conjugated amphiphilic poly(aminoethyl ethylene phosphate/poly(L-lactide copolymer nanobubbles for tumor-targeting ultrasonic imaging

    Directory of Open Access Journals (Sweden)

    Luo BH

    2015-09-01

    Full Text Available Binhua Luo,1,2,* Huageng Liang,3,* Shengwei Zhang,3 Xiaojuan Qin,4 Xuhan Liu,1 Wei Liu,1,5 Fuqing Zeng,3 Yun Wu,6 Xiangliang Yang1,51College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 2College of Pharmacy, Hubei University of Science and Technology, Xianning, 3Department of Urology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 4Department of Medical Ultrasound, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 5National Engineering Research Center for Nanomedicine, Huazhong University of Science and Technology, Wuhan, People’s Republic of China; 6Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, USA*These authors contributed equally to this workAbstract: In the study reported here, a novel amphiphilic poly(aminoethyl ethylene phosphate/poly(L-lactide (PAEEP-PLLA copolymer was synthesized by ring-opening polymerization reaction. The perfluoropentane-filled PAEEP-PLLA nanobubbles (NBs were prepared using the O1/O2/W double-emulsion and solvent-evaporation method, with the copolymer as the shell and liquid perfluoropentane as the core of NBs. The prepared NBs were further conjugated with lactoferrin (Lf for tumor-cell targeting. The resulting Lf-conjugated amphiphilic poly(aminoethyl ethylene phosphate/poly(L-lactide nanobubbles (Lf-PAEEP-PLLA NBs were characterized by photon correlation spectroscopy, polyacrylamide gel electrophoresis, Fourier transform infrared spectroscopy, and transmission electron microscopy. The average size of the Lf-PAEEP-PLLA NBs was 328.4±5.1 nm, with polydispersity index of 0.167±0.020, and zeta potential of -12.6±0.3 mV. Transmission electron microscopy imaging showed that the Lf-PAEEP-PLLA NBs had a near-spherical structure, were quite monodisperse, and there was a clear interface between the copolymer shell and the liquid

  6. Angiopep-2-conjugated poly(ethylene glycol-co-poly(ε-caprolactone polymersomes for dual-targeting drug delivery to glioma in rats

    Directory of Open Access Journals (Sweden)

    Lu F

    2017-03-01

    Full Text Available Fei Lu,1,2 Zhiyong Pang,2,3 Jingjing Zhao,2 Kai Jin,4 Haichun Li,2 Qiang Pang,2 Long Zhang,2 Zhiqing Pang2 1Department of Pharmacy, Xianju People’s Hospital, Xianju, Zhejiang, 2Department of Pharmaceutics, Key Laboratory of Smart Drug Delivery, Ministry of Education and PLA, School of Pharmacy, Fudan University, Shanghai, 3Chongyang Center for Disease Control and Prevention, Xianning, Hubei, 4School of Life Science, Fudan University, Shanghai, People’s Republic of China Abstract: The blood–brain barrier is a formidable obstacle for glioma chemotherapy due to its compact structure and drug efflux ability. In this study, a dual-targeting drug delivery system involving Angiopep-2-conjugated biodegradable polymersomes loaded with doxorubicin (Ang-PS-DOX was developed to exploit transport by the low-density lipoprotein receptor-related protein 1 (LRP1, which is overexpressed in both blood–brain barrier and glioma cells. The polymersomes (PS were prepared using a thin-film hydration method. The PS were loaded with doxorubicin using the pH gradient method (Ang-PS-DOX. The resulting PS were uniformly spherical, with diameters of ~135 nm and with ~159.9 Angiopep-2 molecules on the surface of each PS. The drug-loading capacity and the encapsulation efficiency for doxorubicin were 7.94%±0.17% and 95.0%±1.6%, respectively. Permeability tests demonstrated that the proton diffusion coefficient across the PS membrane was far slower than that across the liposome membrane, and the common logarithm value was linearly dependent on the dioxane content in the external phase. Compared with PS-DOX, Ang-PS-DOX demonstrated significantly higher cellular uptake and stronger cytotoxicity in C6 cells. In vivo pharmacokinetics and brain distribution experiments revealed that Ang-PS-DOX achieved a more extensive distribution and more abundant accumulation in glioma cells than PS-DOX. Moreover, the survival time of glioma-bearing rats treated with Ang-PS-DOX was

  7. Optimization of the preparation process of vinblastine sulfate (VBLS-loaded folate-conjugated bovine serum albumin (BSA nanoparticles for tumor-targeted drug delivery using response surface methodology (RSM

    Directory of Open Access Journals (Sweden)

    Yuangang Zu

    2009-12-01

    Full Text Available Yuangang Zu, Yu Zhang, Xiuhua Zhao, Qi Zhang, Yang Liu, Ru JiangKey Laboratory of Forest Plant Ecology, Northeast Forestry University, Ministry of Education, Harbin, Heilongjiang, ChinaAbstract: Response surface methodology (RSM was used to optimize the process of preparing bovine serum albumin (BSA nanoparticles by desolvation, then the resulting BSA nanoparticles (BSANPs were conjugated with folate to produce a drug carrier system that can specifically target tumors. The anticancer drug, vinblastine sulfate (VBLS, was loaded to this tumor-specific drug carrier system for the purpose of overcoming the nonspecific targeting characteristics and side effects of the drug. A central composite design was applied for modeling the process, which was composed of four independent variables, namely BSA concentration, the rate of adding ethanol (ethanol rate, ethanol amount, and the degree of crosslinking. The mean particle size and residual amino groups of the BSANPs were chosen as response variables. The interactive effects of the four independent variables on the response variables were studied. The characteristics of the nanoparticles; such as amount of folate conjugation, drug entrapment efficiency, drug-loading efficiency, surface morphology and release kinetics in vitro were investigated. Optimum conditions for preparing desired BSANPs, with a mean particle size of 156.6 nm and residual amino groups of 668.973 nM/mg, were obtained. The resulting folate-conjugated BSANPs (FA-BSANPs showed a drug entrapment efficiency of 84.83% and drug-loading efficiency of 42.37%, respectively, and the amount of folate conjugation was 383.996 µM/g BSANPs. The results of this study indicate that using FA-BSANPs as a drug carrier system could be effective in targeting VBLS-sensitive tumors in the future.Keywords: bovine serum albumin, vinblastine sulfate, folate, targeted drug delivery, nanoparticles, response surface methodology

  8. mZD7349 peptide-conjugated PLGA nanoparticles directed against VCAM-1 for targeted delivery of simvastatin to restore dysfunctional HUVECs.

    Science.gov (United States)

    Imanparast, Fatemeh; Faramarzi, Mohammad Ali; Vatannejad, Akram; Paknejad, Maliheh; Deiham, Behnas; Kobarfard, Farzad; Amani, Amir; Doosti, Mahmood

    2017-02-02

    Endothelial dysfunction is initial and critical step of atherosclerosis. Impaired bioavailability of endothelial nitric oxide synthase (eNOS) is one of the main reasons of endothelial dysfunction. Improving bioavailability of eNOS by increasing its expression or activity using statins is an effective therapeutic strategy in restoring endothelial dysfunction. In this study, simvastatin (SIM) as a poorly water-soluble drug was loaded in poly (lactic-co-glycolic acid) (PLGA) nanoparticles (SIM-PLGA-NPs). NPs were then conjugated with mZD7349 peptide (mZD7349-SIM-PLGA-NPs) and directed against vascular cell adhesion molecule 1 (VCAM-1). In vitro evaluation of the NPs for targeted delivery of SIM was performed on activated Human Umbilical Cord Vascular Endothelial Cells (HUVECs) by tumor necrosis factor alpha (TNF-α). Effect of mZD7349-SIM-PLGA-NPs and SIM-PLGA-NPs was compared on eNOS phosphorylation (ser-1177). Results of western blot showed SIM post-treatment increased significantly phosphor-eNOS (Ser1177) expression but no total eNOS expression. The study showed that mZD7349-SIM-PLGA-NPs have particle size, zeta potential value, polydispersity index (PDI) and encapsulation efficacy % of 233±18nm, -9.6±1.1mV, 0.59±0.066 and 69±17.3%, respectively. Also phosphor-eNOS (Ser1177) expression in activated HUVECs treated with mZD7349-SIM-PLGA-NPs was significantly (p<0.05) better than treated cells with SIM-PLGA-NPs. The results suggest that mZD7349-SIM-PLGA-NPs may be usable as an appropriate drug carrier for restoring endothelial dysfunction.

  9. Preparation and characterization of a novel Al(18)F-NOTA-BZA conjugate for melanin-targeted imaging of malignant melanoma.

    Science.gov (United States)

    Chang, Chih-Chao; Chang, Chih-Hsien; Lo, Yi-Hsuan; Lin, Ming-Hsien; Shen, Chih-Chieh; Liu, Ren-Shyan; Wang, Hsin-Ell; Chen, Chuan-Lin

    2016-08-15

    Melanin is an attractive target for the diagnosis and treatment of malignant melanoma. Previous studies have demonstrated the specific binding ability of benzamide moiety to melanin. In this study, we developed a novel (18)F-labeled NOTA-benzamide conjugate, Al(18)F-NOTA-BZA, which can be synthesized in 30min with a radiochemical yield of 20-35% and a radiochemical purity of >95%. Al(18)F-NOTA-BZA is highly hydrophilic (logP=-1.96) and shows good in vitro stability. Intravenous administration of Al(18)F-NOTA-BZA in two melanoma-bearing mouse models revealed highly specific uptake in B16F0 melanotic melanoma (6.67±0.91 and 1.50±0.26%ID/g at 15 and 120min p.i., respectively), but not in A375 amelanotic melanoma (0.87±0.21 and 0.24±0.09%ID/g at 15 and 120min p.i., respectively). The clearance from most normal tissues was fast. A microPET scan of Al(18)F-NOTA-BZA-injected mice also displayed high-contrast tumor images as compared with normal organs. Owing to the favorable in vivo distribution of Al(18)F-NOTA-BZA after intravenous administration, the estimated absorption dose was low in all normal organs and tissues. The melanin-specific binding ability, sustained tumor retention, fast normal tissues clearance and thelow projected human dosimetry supported that Al(18)F-NOTA-BZA is a very promising melanin-specific PET probe for melanin-positive melanoma.

  10. Galactose conjugated platinum(II) complex targeting the Warburg effect for treatment of non-small cell lung cancer and colon cancer.

    Science.gov (United States)

    Wu, Meng; Li, Hong; Liu, Ran; Gao, Xiangqian; Zhang, Menghua; Liu, Pengxing; Fu, Zheng; Yang, Jinna; Zhang-Negrerie, Daisy; Gao, Qingzhi

    2016-03-03

    Malignant neoplasms exhibit a higher rate of glycolysis than normal cells; this is known as the Warburg effect. To target it, a galactose-conjugated (trans-R,R-cyclohexane-1,2-diamine)-2-chloromalonato-platinum(II) complex (Gal-Pt) was designed, synthesized, and evaluated in five human cancer cell lines and against two different xenograft tumour models. Gal-Pt exhibits much higher aqueous solubility (over 25 times) and improved cytotoxicity than oxaliplatin, especially in human colon (HT29) and lung (H460) cancer cell lines. The safety profile of Gal-Pt was investigated in vivo by exploring the maximum tolerated dose (MTD) and animal mortality rate. The ratios of the animal lethal dosage values to the cytotoxicity in HT29 (LD50/IC50) showed that Gal-Pt was associated with an increased therapeutic index by over 30-fold compared to cisplatin and oxaliplatin. We evaluated in vivo antitumor activity by single agent intravenous treatment comparison studies of Gal-Pt (50 mg/kg as 65% MTD) and cisplatin (3 mg/kg, as 80% MTD) in a H460 lung cancer xenograft model, and with oxaliplatin (7 mg/kg, as 90% MTD) in a HT29 colon cancer xenograft model. The results show that Gal-Pt was more efficacious against H460 than cisplatin, and had superior potency in HT29 cells compared to oxaliplatin under nontoxic dosage conditions. The dependency between cytotoxicity of Gal-Pt and glucose transporters (GLUTs) was investigated by using quercetin as an inhibitor of GLUTs in HT29 cells. The cytotoxic potency of Gal-Pt was highly reduced by the inhibitor, suggesting that the uptake of Gal-Pt was regulated by glucose transporters. The GLUT mediated transportability and cellular uptake of Gal-Pt was also demonstrated using a fluorescent glucose bioprobe in HT29 competition assay.

  11. Targeted drug delivery of near IR fluorescent doxorubicin-conjugated poly(ethylene glycol) bisphosphonate nanoparticles for diagnosis and therapy of primary and metastatic bone cancer in a mouse model.

    Science.gov (United States)

    Rudnick-Glick, S; Corem-Salkmon, E; Grinberg, I; Margel, S

    2016-12-05

    Most primary and metastatic bone tumors demonstrate increased osteoclast activity and bone resorption. Current treatment is based on a combination of surgery, radiotherapy and chemotherapy. Severe side effects are associated with chemotherapy due to use of high dosage and nonspecific uptake. Bisphosphonates have a strong affinity to Ca(2+) ions and are widely used in the treatment of bone disorders. We have engineered a unique biodegradable bisphosphonate nanoparticle (NPs) bearing two functional surface groups: (1) primary amine groups for covalent attachment of a dye/drug (e.g. NIR dye Cy 7 or doxorubicin); (2) bisphosphonate groups for targeting and chelation to bone hydroxyapatite. In addition, these engineered NPs contain high polyethyleneglycol (PEG) concentration in order to increase their blood half life time. In vitro experiments on Saos-2 human osteosarcoma cell line, demonstrated that at a tenth of the concentration, doxorubicin-conjugated bisphosphonate NPs achieved a similar uptake to free doxorubicin. In vivo targeting experiments using the NIR fluorescence bisphosphonate NPs on both Soas-2 human osteosarcoma xenograft mouse model and orthotopic bone metastases mCherry-labeled 4T1 breast cancer mouse model confirmed specific targeting. In addition, therapeutic in vivo experiments using doxorubicin-conjugated bisphosphonate NPs demonstrated a 40% greater inhibition of tumor growth in Saos-2 human osteosarcoma xenograft mouse model when compared to free doxorubicin. In this research we have shown the potential use of doxorubicin-conjugated BP NPs for the targeting and treatment of primary and metastatic bone tumors. The targeted delivery of doxorubicin to the tumor significantly increased the efficacy of the anti-cancer drug, thus enabling the effective use of a lower concentration of doxorubicin. Furthermore, the targeting ability of the BP NPs in an orthotopic xenograft mouse model reinforced our findings that these BP NPs have the potential to be

  12. Targeted nano-delivery of novel omega-3 conjugate against hepatocellular carcinoma: Regulating COX-2/bcl-2 expression in an animal model.

    Science.gov (United States)

    Khan, Azmat Ali; Alanazi, Amer M; Jabeen, Mumtaz; Hassan, Iftekhar; Bhat, Mashooq Ahmad

    2016-07-01

    The present approach enumerates the effectiveness of tuftsin tagged nano-liposome for the cytosolic transport of 2,6-di-isopropylphenol-linolenic acid conjugate against liver cancer in mice. Initially, the conjugate in its free form was examined for anticancer potential on HepG2 liver cancer cells. Induction of apoptosis and suppression of migration and adhesion of HepG2 cells confirmed the effectiveness of conjugate as an anticancer agent. After this, role of the conjugate entrapped in a nano-carrier was evaluated in animal model. The nano-formulation comprising of conjugate bearing tuftsin tagged liposome was firsly characterized and then its therapeutic effect was determined. The nano-formulation had 100-130nm size nanoparticles and showed sustained release of the conjugate in the surrounding milieu. The nano-formulation distinctly reduced the expression of COX-2, an important molecule that is vastly expressed in hepatocellular carcinoma. The utilization of in-house engineered nano-formulation was also successful in significantly up-regulating Bax and down-regulating bcl-2 gene expression eventually helping in better survival of treated mice. Histopathological analysis also revealed positive recovery of the general architecture and the violent death of cancer cells by apoptosis at tumor specific site. The site specific delivery of conjugate entrapped in tuftsin tagged liposomes was highly safe as well as efficaceous. Nano-formulation based approach showed a visible chemotherapeutic effect on liver cancer progression in experimental mice thereby making it a potential candidate for treatment of liver cancer in clinical settings.

  13. In vivo tumor targeting and imaging with anti-vascular endothelial growth factor antibody-conjugated dextran-coated iron oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Hsieh WJ

    2012-06-01

    Full Text Available Wan-Ju Hsieh,1 Chan-Jung Liang,1 Jen-Jie Chieh,4 Shu-Huei Wang,1 I-Rue Lai,1 Jyh-Horng Chen,2 Fu-Hsiung Chang,3 Wei-Kung Tseng,4–6 Shieh-Yueh Yang,4 Chau-Chung Wu,7 Yuh-Lien Chen11Institute of Anatomy and Cell Biology, College of Medicine, 2Department of Electrical Engineering, 3Institute of Biochemistry and Molecular Biology, National Taiwan University, Taipei, Taiwan; 4Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, Taiwan; 5Division of Cardiology, Department of Internal Medicine, E-Da Hospital, Taipei, Taiwan; 6Department of Medical Imaging and Radiological Sciences, I-Shou University, Taipei, Taiwan; 7Department of Internal Medicine and Primary Care Medicine, National Taiwan University Hospital, Taipei, TaiwanBackground: Active targeting by specific antibodies combined with nanoparticles is a promising technology for cancer imaging and detection by magnetic resonance imaging (MRI. The aim of the present study is to investigate whether the systemic delivery of antivascular endothelial growth factor antibodies conjugating to the surface of functionalized supermagnetic iron oxide nanoparticles (anti-VEGF-NPs led to target-specific accumulation in the tumor.Methods: The VEGF expression in human colon cancer and in Balb/c mice bearing colon cancers was examined by immunohistochemistry. The distribution of these anti-VEGF-NPs particles or NPs particles were evaluated by MRI at days 1, 2, or 9 after the injection into the jugular vein of Balb/c mice bearing colon cancers. Tumor and normal tissues (liver, spleen, lung, and kidney were collected and were examined by Prussian blue staining to determine the presence and distribution of NPs in the tissue sections.Results: VEGF is highly expressed in human and mouse colon cancer tissues. MRI showed significant changes in the T*2 signal and T2 relaxation in the anti-VEGF-NP- injected-mice, but not in mice injected with NP alone. Examination of paraffin

  14. N-(2-Hydroxypropyl)methacrylamide-based polymer conjugates with pH-controlled activation of doxorubicin for cell-specific or passive tumour targeting. Synthesis by RAFT polymerisation and physicochemical characterisation.

    Science.gov (United States)

    Chytil, Petr; Etrych, Tomáš; Kříž, Jaroslav; Subr, Vladimír; Ulbrich, Karel

    2010-11-20

    Controlled radical reversible addition-fragmentation chain transfer (RAFT) polymerisation was used to prepare water-soluble polymer-drug carriers based on copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA) with a hydrazide group-containing monomer, showing well-defined structure with narrow molecular weight distribution (approx. 1.1-1.2). The anticancer therapeutic doxorubicin was bound to the polymeric carrier by a hydrazone bond, enabling pH-controlled release under mildly acid conditions that mimics the environment in endosomes/lysosomes of tumour cells. RAFT polymerisation facilitated the synthesis of semitelechelic copolymers, which were used in the synthesis of monoclonal anti-CD20 antibody-polymer-drug conjugate designed for cell-specific tumour targeting. They were also used for producing a biodegradable high-molecular-weight graft polymer-drug conjugate that degrade in the presence of glutathione, which is designed for passive targeting to solid tumours. The conjugates exhibited well-defined structures with narrow molecular weight distributions of approx. 1.3 and pH-controlled drug release.

  15. Specific targeting of angiogenesis in lung cancer with RGD-conjugated ultrasmall superparamagnetic iron oxide particles using a 4.7T magnetic resonance scanner

    Institute of Scientific and Technical Information of China (English)

    LIU Can; LIU Dong-bo; LONG Guo-xian; WANG Jun-feng; MEI Qi; HU Guang-yuan; QIU Hong

    2013-01-01

    Background Angiogenesis is an essential step for tumor development and metastasis.The cell adhesion molecule αvβ3 integrin plays an important role in angiogenesis and is a specific marker of tumor angiogenesis.A novel αvβ3 integrintargeted magnetic resonance (MR) imaging contrast agent utilizing Arg-Gly-Asp (RGD) and ultrasmall superparamagnetic iron oxide particles (USPIO) (referred to as RGD-USPIO) was designed and its uptake by endothelial cells was assessed both in vitro and in vivo to evaluate the angiogenic profile of lung cancer.Methods USPIO were coated with-NH3+ and conjugated with RGD peptides.Prussian blue staining was performed to evaluate the specific uptake of RGD-USPIO by human umbilical vein endothelial cells (HUVECs).Targeted uptake and subcellular localization of RGD-USPIO in HUVECs were confirmed by transmission electron microscopy (TEM).The ability of RGD-USPIO to noninvasively assess αvβ3 integrin positive vessels in lung adenocarcinoma A549 tumor xenografts was evaluated with a 4.7T MR scanner.Immunohistochemistry was used to detect αvβ3 integrin expression and vessel distribution in A549 tumor xenografts.Results HUVECs internalized RGD-USPIO significantly more than plain USPIO.The uptake of RGD-USPIO by HUVECs could be competitively inhibited by addition of free RGD.A significant decrease in T2 signal intensity (SI) was observed at the periphery of A549 tumor xenografts at 30 minutes (P <0.05) and 2 hours (P <0.01) after RGD-USPIO was injected via the tail vein.Angiogenic blood vessels were mainly distributed in the periphery of tumor xenografts with positive αvβ3 integrin expression.Conclusions RGD-USPIO could specifically label αvβ3 integrin and be taken up by HUVECs.This molecular MR imaging contrast agent can specifically evaluate the angiogenic profile of lung cancer using a 4.7T MR scanner.

  16. Dual receptor-targeting ⁹⁹mTc-labeled Arg-Gly-Asp-conjugated Alpha-Melanocyte stimulating hormone hybrid peptides for human melanoma imaging.

    Science.gov (United States)

    Xu, Jingli; Yang, Jianquan; Miao, Yubin

    2015-04-01

    The aim of this study was to examine whether the substitution of the Lys linker with the aminooctanoic acid (Aoc) and polyethylene glycol (PEG) linker could substantially decrease the non-specific renal uptake of (99m)Tc-labeled Arg-Gly-Asp-conjugated α-melanocyte stimulating hormone (α-MSH) hybrid peptides. The RGD motif {Arg-Gly-Asp-DTyr-Asp} was coupled to [Cys(3,4,10), D-Phe(7), Arg(11)]α-MSH₃₋₁₃ via the Aoc or PEG₂ linker to generate RGD-Aoc-(Arg(11))CCMSH and RGD-PEG-(Arg(11))CCMSH. The biodistribution results of (99m)Tc-RGD-Aoc-(Arg(11))CCMSH and (99m)Tc-RGD-PEG₂-(Arg(11))CCMSH were examined in M21 human melanoma-xenografted nude mice. The substitution of Lys linker with Aoc and PEG₂ linker significantly reduced the renal uptake of (99m)Tc-RGD-Aoc-(Arg(11))CCMSH and (99m)Tc-RGD-PEG₂-(Arg(11))CCMSH by 58% and 63% at 2h post-injection. The renal uptake of (99m)Tc-RGD-Aoc-(Arg(11))CCMSH and (99m)Tc-RGD-PEG₂-(Arg(11))CCMSH was 27.93 ± 3.98 and 22.01 ± 9.89% ID/g at 2 h post-injection. (99m)Tc-RGD-Aoc-(Arg(11))CCMSH displayed higher tumor uptake than (99m)Tc-RGD-PEG₂-(Arg(11))CCMSH (2.35 ± 0.12 vs. 1.71 ± 0.25% ID/g at 2 h post-injection). The M21 human melanoma lesions could be clearly visualized by SPECT/CT using (99m)Tc-RGD-Aoc-(Arg(11))CCMSH as an imaging probe. The favorable effect of Aoc and PEG₂ linker in reducing the renal uptake provided a new insight into the design of novel dual receptor-targeting radiolabeled peptides. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Nuclear estrogen receptor targeted photodynamic therapy: selective uptake and killing of MCF-7 breast cancer cells by a C17alpha-alkynylestradiol-porphyrin conjugate.

    Science.gov (United States)

    Swamy, Narasimha; Purohit, Ajay; Fernandez-Gacio, Ana; Jones, Graham B; Ray, Rahul

    2006-10-15

    We hypothesized that over-expression of estrogen receptor (ER) in hormone-sensitive breast cancer could be harnessed synergistically with the tumor-migrating effect of porphyrins to selectively deliver estrogen-porphyrin conjugates into breast tumor cells, and preferentially kill the tumor cells upon exposure to red light. In the present work we synthesized four (4) conjugates of C17-alpha-alkynylestradiol and chlorin e6-dimethyl ester with varying tether lengths, and showed that all these conjugates specifically bound to recombinant ER alpha. In a cellular uptake assay with ER-positive MCF-7 and ER-negative MDA-MB 231 human breast cancer cell-lines, we observed that one such conjugate (E17-POR, XIV) was selectively taken up in a dose-dependent and saturable manner by MCF-7 cells, but not by MDA-MB 231 cells. Furthermore, MCF-7 cells, but not MDA-MB 231 cells, were selectively and efficiently killed by exposure to red light after incubation with E17-POR. Therefore, the combination approach, including drug and process modalities has the potential to be applied clinically for hormone-sensitive cancers in organs where ER is significantly expressed. This could potentially be carried out either as monotherapy involving a photo-induced selective destruction of tumor cells and/or adjuvant therapy in post-surgical treatment for the destruction of residual cancer cells in tissues surrounding the tumor.

  18. Direct in vitro and in vivo comparison of {sup 161}Tb and {sup 177}Lu using a tumour-targeting folate conjugate

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Cristina; Reber, Josefine; Haller, Stephanie [Paul Scherrer Institute, Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Villigen (Switzerland); Dorrer, Holger; Tuerler, Andreas [Paul Scherrer Institute, Laboratory of Radiochemistry and Environmental Chemistry, Villigen (Switzerland); University of Bern, Laboratory of Radiochemistry and Environmental Chemistry, Department of Chemistry and Biochemistry, Bern (Switzerland); Bernhardt, Peter [The Sahlgrenska Academy, University of Gothenburg, Department of Radiation Physics, Gothenburg (Sweden); Sahlgrenska University Hospital, Department of Medical Physics and Medical Bioengeneering, Gothenburg (Sweden); Zhernosekov, Konstantin [Paul Scherrer Institute, Laboratory of Radiochemistry and Environmental Chemistry, Villigen (Switzerland); Schibli, Roger [Paul Scherrer Institute, Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Villigen (Switzerland); ETH Zurich, Department of Chemistry and Applied Biosciences, Zurich (Switzerland)

    2014-03-15

    The radiolanthanide {sup 161}Tb (T{sub 1/2} = 6.90 days, Eβ{sup -}{sub av} = 154 keV) was recently proposed as a potential alternative to {sup 177}Lu (T{sub 1/2} = 6.71 days, Eβ{sup -}{sub av} = 134 keV) due to similar physical decay characteristics but additional conversion and Auger electrons that may enhance the therapeutic efficacy. The goal of this study was to compare {sup 161}Tb and {sup 177}Lu in vitro and in vivo using a tumour-targeted DOTA-folate conjugate (cm09). {sup 161}Tb-cm09 and {sup 177}Lu-cm09 were tested in vitro on folate receptor (FR)-positive KB and IGROV-1 cancer cells using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) viability assay. In vivo {sup 161}Tb-cm09 and {sup 177}Lu-cm09 (10 MBq, 0.5 nmol) were investigated in two different tumour mouse models with regard to the biodistribution, the possibility for single photon emission computed tomography (SPECT) imaging and the antitumour efficacy. Potentially undesired side effects were monitored over 6 months by determination of plasma parameters and examination of kidney function with quantitative SPECT using {sup 99m}Tc-dimercaptosuccinic acid (DMSA). To obtain half-maximal inhibition of tumour cell viability a 4.5-fold (KB) and 1.7-fold (IGROV-1) lower radioactivity concentration was required for {sup 161}Tb-cm09 (IC{sub 50} ∝0.014 MBq/ml and ∝2.53 MBq/ml) compared to {sup 177}Lu-cm09 (IC{sub 50} ∝0.063 MBq/ml and ∝4.52 MBq/ml). SPECT imaging visualized tumours of mice with both radioconjugates. However, in therapy studies {sup 161}Tb-cm09 reduced tumour growth more efficiently than {sup 177}Lu-cm09. These findings were in line with the higher absorbed tumour dose for {sup 161}Tb-cm09 (3.3 Gy/MBq) compared to {sup 177}Lu-cm09 (2.4 Gy/MBq). None of the monitored parameters indicated signs of impaired kidney function over the whole time period of investigation after injection of the radiofolates. Compared to {sup 177}Lu-cm09 we demonstrated equal imaging

  19. Synthesis, characterization and in vitro evaluation of methotrexate conjugated fluorescent carbon nanoparticles as drug delivery system for human lung cancer targeting.

    Science.gov (United States)

    Ajmal, Muhammad; Yunus, Uzma; Matin, Abdul; Haq, Noaman Ul

    2015-12-01

    Nanotechnology based cancer therapeutics have rapidly advanced towards the solution of many limitations associated with other drug delivery agents such as nonspecific distribution within the body, low water solubility and non-biocompatibility. Carbon nanoparticles have demonstrated unique properties that are useful to combat with these issues, including their properties dependent on size, high stability in different solvents, compatible size for drug delivery and ease of surface modifications. Fluorescent carbon nanoparticles with good water solubility were obtained from a carbohydrate source by acid assisted ultrasonic treatment at 35kHz for 4h. This simple and economical method can be used for large scale production. Electron microscopic, spectroscopic and thermo gravimetric analysis techniques were used to characterize these carbon nanoparticles. Functionalized CNPs were further conjugated with anticancer drug-methotrexate and used as fluorescent nano-carriers. In this research work, we determined the in vitro bioactivity of CNPs-methotrexate conjugates by lactate dehydrogenase assay, cell adhesion assay and sulforhodamine B assay in human lung carcinoma cell line (H157). The CNPs showed promising biocompatibility and CNPs-MTX conjugates demonstrated potent cytotoxic effects and high anticancer activities in human lung cancer cell line.

  20. Cancer Cell Targeting Using Folic Acid/Anti-HER2 Antibody Conjugated Fluorescent CdSe/CdS/ZnS-MPA and CdTe-MSA Quantum Dots.

    Science.gov (United States)

    Singh, Gurpal; Kumar, Manoj; Soni, Udit; Arora, Vikas; Bansal, Vivek; Gupta, Dikshi; Bhat, Madhusudan; Dinda, Amit K; Sapra, Sameer; Singh, Harpal

    2015-12-01

    CdSe/CdS/ZnS and CdTe quantum dots (QDs) were synthesized by successive ion layer adsorption and reaction (SILAR) technique and direct aqueous synthesis respectively using thiol stabilizers. Synthesized CdSe/CdS/ZnS and CdTe QDs stabilized with 3-mercaptopropionic acid (MPA) and mercaptosuccinic acid (MSA) were used as fluorescent labels after conjugation with folic acid (FA) and anti-HER2 antibodies. Photoluminescence quantum yield of folated CdSe/CdS/ZnS-MPA and CdTe-MSA QDs was 59% and 77% than that of non-folated hydrophilic QDs. The folate receptor-mediated delivery of folic acid-conjugated CdTe-MSA and CdSe/CdS/ZnS-MPA QDs showed higher cellular internalization as observed by confocal laser scanning microscopic studies. Folated and non-folated CdTe-MSA QDs were highly toxic and exhibited only 10% cell viability as compared to > 80% cell viability with CdSe/CdS/ZnS-MPA QDs over the concentration ranging from 3.38 to 50 pmoles. Immunohistochemistry (IHC) results of human breast cancer tissue samples showed positive results with anti-HER2 antibody conjugated CdSe/CdS/ZnS-MPA QDs with better sensitivity and specificity as compared to conventional IHC analysis using diaminobenzedene staining.

  1. Aptamer-Drug Conjugates.

    Science.gov (United States)

    Zhu, Guizhi; Niu, Gang; Chen, Xiaoyuan

    2015-11-18

    Western medicine often aims to specifically treat diseased tissues or organs. However, the majority of current therapeutics failed to do so owing to their limited selectivity and the consequent "off-target" side effects. Targeted therapy aims to enhance the selectivity of therapeutic effects and reduce adverse side effects. One approach toward this goal is to utilize disease-specific ligands to guide the delivery of less-specific therapeutics, such that the therapeutic effects can be guided specifically to diseased tissues or organs. Among these ligands, aptamers, also known as chemical antibodies, have emerged over the past decades as a novel class of targeting ligands that are capable of specific binding to disease biomarkers. Compared with other types of targeting ligands, aptamers have an array of unique advantageous features, which make them promising for developing aptamer-drug conjugates (ApDCs) for targeted therapy. In this Review, we will discuss ApDCs for targeted drug delivery in chemotherapy, gene therapy, immunotherapy, photodynamic therapy, and photothermal therapy, primarily of cancer.

  2. Targeting metastatic breast cancer with ANG1005, a novel peptide-paclitaxel conjugate that crosses the blood-brain-barrier (BBB

    Directory of Open Access Journals (Sweden)

    Fei Li

    2017-03-01

    Full Text Available We devoted this short interview piece with Dr Shou-Ching Tang at Augusta University to feature some promising results from a clinical phase II trial on a novel brain-penetrating peptide-paclitaxel-conjugate, ANG1005, in treating brain metastatic breast cancer. These results were presented by Dr. Tang at the recent annual meeting of the European Society for Medical Oncology (ESMO 2016 Congress. This development heralds an important step forward towards the development of effective chemotherapeutic agents, which can cross the blood-brain-barrier and effectively treat and prevent the brain metastatic cancers.

  3. Chemically optimized antimyosin Fab conjugates with chelating polymers: importance of the nature of the protein-polymer single site covalent bond for biodistribution and infarction localization.

    Science.gov (United States)

    Trubetskoy, V S; Narula, J; Khaw, B A; Torchilin, V P

    1993-01-01

    Murine antimyosin Fab fragment was conjugated with 111In-labeled N-terminal-modified DTPA-polylysine using three bifunctional reagents: N-hydroxysuccinimide esters of 3-(2-pyridyldithio)propionic acid (SPDP conjugate), 4-(maleimidomethyl)cyclohexanecarboxylic acid (SMCC conjugate) and bromoacetic acid (BrAc conjugate) for potential localization of experimental myocardial infarction. Using various antibody preparations and a rabbit acute myocardial infarction model the following parameters were observed: (1) an in vitro antigen binding activity of SPDP conjugate = SMCC conjugate > BrAc conjugate, (2) a blood clearance rate of SPDP conjugate > BrAc conjugate > SMCC conjugate, (3) a liver and splenic accumulation of SPDP conjugate > BrAc conjugate > SMCC conjugate, and (4) the infarcted tissue activity showed an accumulation of SMCC conjugate > SPDP conjugate > BrAc conjugate. This study exemplifies the importance of rational chemical design of antimyosin Fab-chelating polymer conjugate for improved target tissue localization in vivo.

  4. Paclitaxel conjugated Fe3O4@LaF3:Ce3+,Tb3+ nanoparticles as bifunctional targeting carriers for Cancer theranostics application

    Science.gov (United States)

    Mangaiyarkarasi, Rajendiran; Chinnathambi, Shanmugavel; Karthikeyan, Subramani; Aruna, Prakasarao; Ganesan, Singaravelu

    2016-02-01

    The bi-functional Chitosan functionalized magnetite doped luminescent rare earth nanoparticles (Fe3O4@LaF3: Ce3+,Tb3+/chi NPs) as a carrier of paclitaxel (PTX) drug was designed using a co-precipitation and facile direct precipitation method. The synthesized nanoparticles are spherical in shape with a typical diameter of 19-37 nm respectively. They are water soluble, super paramagnetic and biocompatible, in which the amino groups on the nanoparticles surface are used for the conjugation with an anticancer drug, paclitaxel. The nature of PTX binding with Fe3O4@LaF3: Ce3+,Tb3+/chi nanoparticles were studied using X-ray diffraction, vibrating sample magnetometer and scanning electron micrograph. The nature of interactions between PTX and Fe3O4@LaF3: Ce3+,Tb3+/chi NPs due to complex formation were conceded out by various spectroscopic methods viz., UV-visible, steady state and excited state fluorescence spectroscopy. The photo-physical characterization reveals that the adsorption and release of PTX from Fe3O4@LaF3:Tb3+/chi nanoparticles is quicker when compared with other nanoparticles and also confirms that this may be due to the hydrogen bond formation between the hydroxyl group of drug and amino group of nanoparticles respectively. The maximum loading capacity and entrapment efficiency of 83.69% and 80.51% were attained at a ratio of 5:8 of PTX and Fe3O4@LaF3: Ce3+,Tb3+/chi NPs respectively. In addition with that, antitumoral activity study of PTX conjugated Fe3O4@LaF3:Tb3+/chi nanoparticles exhibits increased cytotoxic effects on A549 lung cancer cell lines than that of unconjugated PTX.

  5. Energetic Tuning in Spirocyclic Conjugated Polymers

    Directory of Open Access Journals (Sweden)

    Hugo Bronstein

    2016-01-01

    Full Text Available Precise control of the energy levels in a conjugated polymer is the key to allowing their exploitation in optoelectronic devices. The introduction of spirocycles into conjugated polymers has traditionally been used to enhance their solid state microstructure. Here we present a highly novel method of energetic tuning through the use of electronically active spirocyclic systems. By modifying the size and oxidation state of a heteroatom in an orthogonal spirocycle we demonstrate energetic fine tuning in both the absorption and emission of a conjugated polymer. Furthermore, the synthesis of highly novel triplet-decker spirocyclic conjugated polymers is presented. This new method of energetic manipulation in a conjugated polymer paves the way for future application targeted synthesis of polymers with electronically active spirocycles.

  6. Highly sensitive biosensors based on water-soluble conjugated polymers

    Institute of Scientific and Technical Information of China (English)

    XU Hui; WU Haiping; FAN Chunhai; LI Wenxin; ZHANG Zhizhou; HE Lin

    2004-01-01

    Conjugated, conductive polymers are a kind of important organic macromolecules, which has found applications in a variety of areas. The application of conjugated polymers in developing fluorescent biosensors represents the merge of polymer sciences and biological sciences. Conjugated polymers are very good light harvesters as well as fluorescent polymers, and they are also "molecular wires". Through elaborate designs, these important features, i.e. efficient light harvesting and electron/energy transfer, can be used as signal amplification in fluorescent biosensors. This might significantly improve the sensitivity of conjugated polymer-based biosensors. In this article, we reviewed the application of conjugated polymers, via either electron transfer or energy transfer, to detections of gene targets, antibodies or enzymes. We also reviewed recent efforts in conjugated polymer-based solid-state sensor designs as well as chip-based multiple target detection. Possible directions in this conjugated polymer-based biosensor area are also discussed.

  7. TARGET:?

    National Research Council Canada - National Science Library

    James M Acton

    2014-01-01

      By 2003. as military planners had become worried that the country's long-range conventional weapons, such as cruise missiles, might be too slow to reach hypothetical distant targets that needed to be struck urgently...

  8. Conjugates of folic acids with BSA-coated quantum dots for cancer cell targeting and imaging by single-photon and two-photon excitation.

    Science.gov (United States)

    Meng, He; Chen, Ji-Yao; Mi, Lan; Wang, Pei-Nan; Ge, Mei-Ying; Yue, Yang; Dai, Ning

    2011-01-01

    Bovine serum albumin (BSA)-coated CdTe/ZnS quantum dots (BSA-QDs) were selected to conjugate with folic acid (FA), forming FA-BSA-QDs. This study aims to develop these small FA-BSA-QDs (less than 10 nm) for the diagnosis of cancers in which the FA receptor (FR) is overexpressed. The enhancement of cellular uptake in FR-positive human nasopharyngeal carcinoma cells (KB cells) for FA-BSA-QDs was found by means of confocal fluorescence microscopy under single-photon and two-photon excitation. The uptake enhancement for FA-BSA-QDs was further evaluated by flow-cytometric analysis in 10(4) KB cells, and was about 3 times higher than for BSA-QDs on average. The uptake enhancement was suppressed when KB cells had been pretreated with excess FA, reflecting that the enhancement was mediated by the association of FR at cell membranes with FA-BSA-QDs. When human embryonic kidney cells (293T) (FR-negative cells) and KB cells, respectively, were incubated with FA-BSA-QDs (1 μM) for 40 min, the FA-BSA-QD uptake by 293T cells was much weaker than that by KB cells, demonstrating that FA-BSA-QDs could undergo preferential binding on FR-positive cancer cells. These characteristics suggest that FA-BSA-QDs are potential candidates for cancer diagnosis.

  9. Synthesis of 5α,8α-Ergosterol Peroxide 3-Carbamate Derivatives and a Fluorescent Mitochondria-Targeting Conjugate for Enhanced Anticancer Activities.

    Science.gov (United States)

    Bu, Ming; Cao, Tingting; Li, Hongxia; Guo, Mingzhou; Yang, Burton B; Zeng, Chengchu; Hu, Liming

    2017-03-17

    Inspired by the significant anticancer activity of our previously screened natural ergosterol peroxide (1), we synthesized and characterized a series of novel ergosterol peroxide 3-carbamate derivatives. The antiproliferative activities of the synthesized compounds against human hepatocellular carcinoma cells (HepG2, SK-Hep1) and human breast cancer cells (MCF-7, MDA-MB231) were investigated. 5α,8α-Epidioxyergosta-3-yl-(piperazine-1)carbamate (3 d) and 5α,8α-epidioxyergosta-3-yl-(piperidin-4-methylamine)carbamate (3 f) and their hydrochloride salts exhibited significant in vitro antiproliferative activities against the tested tumor cell lines, with IC50 values ranging from 0.85 to 4.62 μm. Furthermore, fluorescent imaging showed that the designed coumarin-3 d conjugate (5) localized mainly in mitochondria, leading to enhanced anticancer activities over the parent structure 1. As a whole, it appeared that substituent changes at the C3 position could serve as a promising launch point for further design of this type of steroidal anticancer agent. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Differentiation between naproxen, naproxen-protein conjugates, and naproxen-lysine in plasma via micellar electrokinetic capillary chromatography : a new approach in the bioanalysis of drug targeting preparations

    NARCIS (Netherlands)

    Albrecht, C.; Reichen, J; Visser, Jan; Meijer, D.K F; Thormann, W

    1997-01-01

    Pharmacotherapy through the targeting of drugs is a promising new approach that requires adequate analytical methods capable of differentiating between the free drug the drug carrier, and metabolites. Using micellar electrokinetic capillary chromatography (MECC), we report the separation of naproxen

  11. Suppression of B-Raf(V600E) melanoma cell survival by targeting mitochondria using triphenyl-phosphonium-conjugated nitroxide or ubiquinone.

    Science.gov (United States)

    Hong, Seung-Keun; Starenki, Dmytro; Wu, Pui-Kei; Park, Jong-In

    2017-02-01

    Most BRAF-mutated melanomas initially responsive to the FDA-approved inhibitors preferentially targeting B-Raf mutated in Val600 residue eventually relapse, requiring additional therapeutic modalities. Recent studies report the significance of metabolic reprograming in mitochondria for maintenance of BRAF-mutated melanomas and for development of their drug resistance to B-Raf inhibitors, providing a rationale for targeting mitochondria as a potential therapeutic strategy for melanoma. We therefore determined whether mitochondria-targeted metabolism-interfering agents can effectively suppress human B-Raf(V600E) melanoma cell lines and their dabrafenib/PLX4032-resistant progenies using mitochondria-targeted carboxy-proxyl (Mito-CP) and ubiquinone (Mito-Q). These agents exhibited comparable efficacy to PLX4032 in suppressing SK-MEL28, A375, and RPMI-7951 cells in vitro. As determined in SK-MEL28 and A375 cells, Mito-CP induced apoptotic cell death mediated by mitochondrial membrane depolarization and subsequent oxidative stress, which PLX4032 could not induce. Of note, Mito-CP also effectively suppressed PLX4032-resistant progenies of SK-MEL28 and A375. Moreover, when orally administered, Mito-CP suppressed SK-MEL28 xenografts in mice as effectively as PLX4032 without serious adverse effects. These data demonstrate that mitochondria-targeted agents have therapeutic potential to effectively suppress BRAF-mutated melanomas via an effect(s) distinct from those of B-Raf inhibitors.

  12. pH-Sensitive Delivery Vehicle Based on Folic Acid-Conjugated Polydopamine-Modified Mesoporous Silica Nanoparticles for Targeted Cancer Therapy.

    Science.gov (United States)

    Cheng, Wei; Nie, Junpeng; Xu, Lv; Liang, Chaoyu; Peng, Yunmei; Liu, Gan; Wang, Teng; Mei, Lin; Huang, Laiqiang; Zeng, Xiaowei

    2017-06-07

    In this study, we introduced a targeting polymer poly(ethylene glycol)-folic acid (PEG-FA) on the surface of polydopamine (PDA)-modified mesoporous silica nanoparticles (MSNs) to develop the novel nanoparticles (NPs) MSNs@PDA-PEG-FA, which were employed as a drug delivery system loaded with doxorubicin (DOX) as a model drug for cervical cancer therapy. The chemical structure and properties of these NPs were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, N2 adsorption/desorption, dynamic light scattering-autosizer, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The pH-sensitive PDA coating served as a gatekeeper. The in vitro drug release experiments showed pH-dependent and sustained drug release profiles that could enhance the therapeutic anticancer effect and minimize potential damage to normal cells due to the acidic microenvironment of the tumor. These MSNs@PDA-PEG-FA achieved significantly high targeting efficiency, which was demonstrated by the in vitro cellular uptake and cellular targeting assay. Compared with that of free DOX and DOX-loaded NPs without the folic targeting ligand, the FA-targeted NPs exhibited higher antitumor efficacy in vivo, implying that they are a highly promising potential carrier for cancer treatments.

  13. Transferrin conjugated poly (γ-glutamic acid-maleimide-co-L-lactide)-1,2-dipalmitoylsn-glycero-3-phosphoethanolamine copolymer nanoparticles for targeting drug delivery.

    Science.gov (United States)

    Zhao, Caiyan; Liu, Xiaoguang; Liu, Junxing; Yang, Zhiwei; Rong, Xianghui; Li, Mingjun; Liang, Xingjie; Wu, Yan

    2014-11-01

    Targeted drug delivery strategies have shown great potential in solving some problems of chemotherapy, such as non-selectivity and severe side effects, thus enhancing the anti-tumor efficiency of chemotherapeutic agents. In this work, we have prepared a novel nanoparticle consisted of amphiphilic poly(γ-glutamic acid-maleimide-co-L-lactide)-1,2-dipalmitoylsn-glycero-3-phosphoethanolamine (γ-PGA-MAL-PLA-DPPE) copolymer decorated with transferrin (Tf), which can specifically deliver anti-cancer drug paclitaxel (PTX) to the tumor cells for targeting chemotherapy. These nanoparticles (NPs) have preferable particle size, high encapsulation efficiency and a pH-dependent release profile. As expected, The Tf modification mediate specific targeting to nasopharyngeal carcinoma (C666-1) cells and human cervical carcinoma (Hela) cells with the transferrin receptor (TfR) overexpressed and enhance cellular uptake of the NPs, as demonstrated by flow cytometry and confocal microscopy assays. In vitro cytotoxicity studies reveal that the NPs have excellent biocompatibility, and the presence of Tf enhance the activity of PTX to the targeted cells. All these results prove that Tf modified γ-PGA-MAL-PLA-DPPE NPs could facilitate the tumor-specific therapy. Therefore, such a targeting drug delivery system provides significant advances toward cancer therapy. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Revisiting conjugate schedules.

    Science.gov (United States)

    MacAleese, Kenneth R; Ghezzi, Patrick M; Rapp, John T

    2015-07-01

    The effects of conjugate reinforcement on the responding of 13 college students were examined in three experiments. Conjugate reinforcement was provided via key presses that changed the clarity of pictures displayed on a computer monitor in a manner proportional to the rate of responding. Experiment 1, which included seven parameters of clarity change per response, revealed that responding decreased as the percentage clarity per response increased for all five participants. These results indicate that each participant's responding was sensitive to intensity change, which is a parameter of conjugate reinforcement schedules. Experiment 2 showed that responding increased during conjugate reinforcement phases and decreased during extinction phases for all four participants. Experiment 3 also showed that responding increased during conjugate reinforcement and further showed that responding decreased during a conjugate negative punishment condition for another four participants. Directions for future research with conjugate schedules are briefly discussed.

  15. Photoacoustic imaging with an acoustic lens detects prostate cancer cells labeled with PSMA-targeting near-infrared dye-conjugates

    Science.gov (United States)

    Dogra, Vikram; Chinni, Bhargava; Singh, Shalini; Schmitthenner, Hans; Rao, Navalgund; Krolewski, John J.; Nastiuk, Kent L.

    2016-06-01

    There is an urgent need for sensitive and specific tools to accurately image early stage, organ-confined human prostate cancers to facilitate active surveillance and reduce unnecessary treatment. Recently, we developed an acoustic lens that enhances the sensitivity of photoacoustic imaging. Here, we report the use of this device in conjunction with two molecular imaging agents that specifically target the prostate-specific membrane antigen (PSMA) expressed on the tumor cell surface of most prostate cancers. We demonstrate successful imaging of phantoms containing cancer cells labeled with either of two different PSMA-targeting agents, the ribonucleic acid aptamer A10-3.2 and a urea-based peptidomimetic inhibitor, each linked to the near-infrared dye IRDye800CW. By specifically targeting cells with these agents linked to a dye chosen for optimal signal, we are able to discriminate prostate cancer cells that express PSMA.

  16. Inhibiting the growth of methicillin-resistant Staphylococcus aureus in vitro with antisense peptide nucleic acid conjugates targeting the ftsZ gene

    Directory of Open Access Journals (Sweden)

    Shumei Liang

    2015-01-01

    Conclusion: Our results demonstrate that the potent effects of PNAs on bacterial growth and cell viability were mediated by the down-regulation or even knock-out of ftsZ gene expression. This highlights the utility of ftsZ as a promising target for the development of new antisense antibacterial agents to treat MRSA infections.

  17. The collagen receptor uPARAP/Endo180 as a novel target for antibody-drug conjugate mediated treatment of mesenchymal and leukemic cancers

    DEFF Research Database (Denmark)

    Nielsen, Christoffer Fagernæs; van Putten, Sander Maarten; Lund, Ida Katrine

    2017-01-01

    A key task in developing the field of personalized cancer therapy is the identification of novel molecular targets that enable treatment of cancers not susceptible to other means of specific therapy. The collagen receptor uPARAP/Endo180 is overexpressed by malignant cells in several non-epithelia...

  18. Liposome-mediated targeting of enzymes to cancer cells for site-specific activation of prodrugs : Comparison with the corresponding antibody-enzyme conjugate

    NARCIS (Netherlands)

    Fonseca, Maria José; Jagtenberg, Joycelyn C.; Haisma, Hidde J.; Storm, Gert

    2003-01-01

    Purpose. Immunoenzymosomes are tumor-targeted immunoliposomes bearing enzymes on their surface. These enzymes are capable of converting relatively nontoxic prodrugs into active cytostatic agents. The aims of this study were to compare the enzyme delivery capability of immunoenzymosomes with that of

  19. Liposome-mediated targeting of enzymes to cancer cells for site-specific activation of prodrugs : Comparison with the corresponding antibody-enzyme conjugate

    NARCIS (Netherlands)

    Fonseca, Maria José; Jagtenberg, Joycelyn C.; Haisma, Hidde J.; Storm, Gert

    Purpose. Immunoenzymosomes are tumor-targeted immunoliposomes bearing enzymes on their surface. These enzymes are capable of converting relatively nontoxic prodrugs into active cytostatic agents. The aims of this study were to compare the enzyme delivery capability of immunoenzymosomes with that of

  20. Site-Selective Conjugation of Native Proteins with DNA

    DEFF Research Database (Denmark)

    Trads, Julie Brender; Tørring, Thomas; Gothelf, Kurt Vesterager

    2017-01-01

    . In recent years, a number of chemical methods that target conjugation to specific sites at native proteins have become available, and an overview of these methods is provided in this Account. Our laboratory has investigated DNA-templated protein conjugation (DTPC), which offers an alternative approach...... to site-selective conjugation of DNA to proteins. The method is inspired by the concept of DNA-templated synthesis where functional groups conjugated to DNA strands are preorganized by DNA hybridization to dramatically increase the reaction rate. In DPTC, we target metal binding sites in proteins...

  1. Enhancing PET Signal at Target Tissue in Vivo: Dendritic and Multimeric Tris(hydroxypyridinone) Conjugates for Molecular Imaging of αvβ3 Integrin Expression with Gallium-68.

    Science.gov (United States)

    Imberti, Cinzia; Terry, Samantha Y A; Cullinane, Carleen; Clarke, Fiona; Cornish, Georgina H; Ramakrishnan, Nisha K; Roselt, Peter; Cope, Andrew P; Hicks, Rodney J; Blower, Philip J; Ma, Michelle T

    2017-02-15

    Tris(hydroxypyridinone) chelators conjugated to peptides can rapidly complex the positron-emitting isotope gallium-68 ((68)Ga) under mild conditions, and the resulting radiotracers can delineate peptide receptor expression at sites of diseased tissue in vivo. We have synthesized a dendritic bifunctional chelator containing nine 1,6-dimethyl-3-hydroxypyridin-4-one groups (SCN-HP9) that can coordinate up to three Ga(3+) ions. This derivative has been conjugated to a trimeric peptide (RGD3) containing three peptide groups that target the αvβ3 integrin receptor. The resulting dendritic compound, HP9-RGD3, can be radiolabeled in 97% radiochemical yield at a 3-fold higher specific activity than its homologues HP3-RGD and HP3-RGD3 that contain only a single metal binding site. PET scanning and biodistribution studies show that [(68)Ga(HP9-RGD3)] demonstrates higher receptor-mediated tumor uptake in animals bearing U87MG tumors that overexpress αvβ3 integrin than [(68)Ga(HP3-RGD)] and [(68)Ga(HP3-RGD3)]. However, concomitant nontarget organ retention of [(68)Ga(HP9-RGD3)] results in low tumor to nontarget organ contrast in PET images. On the other hand, the trimeric peptide homologue containing a single tris(hydroxypyridinone) chelator, [(68)Ga(HP3-RGD3)], clears nontarget organs and exhibits receptor-mediated uptake in mice bearing tumors and in mice with induced rheumatoid arthritis. PET imaging with [(68)Ga(HP3-RGD3)] enables clear delineation of αvβ3 integrin receptor expression in vivo.

  2. Prospective Preliminary In Vitro Investigation of a Magnetic Iron Oxide Nanoparticle Conjugated with Ligand CD80 and VEGF Antibody As a Targeted Drug Delivery System for the Induction of Cell Death in Rodent Osteosarcoma Cells.

    Science.gov (United States)

    Kovach, AnneMarie Kay; Gambino, Jen M; Nguyen, Vina; Nelson, Zach; Szasz, Taylor; Liao, Jun; Williams, Lakiesha; Bulla, Sandra; Prabhu, Raj

    2016-01-01

    Target drug deliveries using nanotechnology are a novel consideration in the treatment of cancer. We present herein an in vitro mouse model for the preliminary investigation of the efficacy of an iron oxide nanoparticle complex conjugated to vascular endothelial growth factor (VEGF) antibody and ligand cluster of differentiation 80 (CD80) for the purpose of eventual translational applications in the treatment of human osteosarcoma (OSA). The 35 nm diameter iron oxide magnetic nanoparticles are functionalized with an n-hydroxysuccinimide biocompatible coating and are conjugated on the surface to proteins VEGF antibody and ligand CD80. Combined, these proteins have the ability to target OSA cells and induce apoptosis. The proposed system was tested on a cancerous rodent osteoblast cell line (ATCCTM(NPO) CRL-2836) at four different concentrations (0.1, 1.0, 10.0, and 100.0 μg/mL) of ligand CD80 alone, VEGF antibody alone, and a combination thereof (CD80+VEGF). Systems were implemented every 24 h over different sequential treatment timelines: 24, 48, and 72 h, to find the optimal protein concentration required for a reduction in cell proliferation. Results demonstrated that a combination of ligand CD80 and VEGF antibody was consistently most effective at reducing aberrant osteoblastic proliferation for both the 24- and 72-h timelines. At 48 h, however, an increase in cell proliferation was documented for the 0.1 and 1 μg/mL groups. For the 24- and 72-h tests, concentrations of 1.0 μg/mL of CD80+VEGF and 0.1 μg/mL of VEGF antibody were most effective. Concentrations of 10.0 and 100.0 μg/mL of CD80+VEGF reduced cell proliferation, but not as remarkably as the 1.0 μg/mL concentration. In addition, cell proliferation data showed that multiple treatments (72-h test) induced cell death in the osteoblasts better than a single treatment. Future targeted drug delivery system research includes trials in OSA cell lines from greater phylum species having

  3. Prospective Preliminary In Vitro Investigation of a Magnetic Iron Oxide Nanoparticle Conjugated with Ligand CD80 and VEGF Antibody As a Targeted Drug Delivery System for the Induction of Cell Death in Rodent Osteosarcoma Cells

    Directory of Open Access Journals (Sweden)

    Anne Marie Kay Kovach

    2016-10-01

    Full Text Available Target drug deliveries using nanotechnology are a novel consideration in the treatment of cancer. We present herein an in vitro mouse model for the preliminary investigation of the efficacy of an iron oxide nanoparticle complex conjugated to vascular endothelial growth factor (VEGF antibody and ligand cluster of differentiation 80 (CD80 for the purpose of eventual translational applications in the treatment of human osteosarcoma (OSA. The 35 nm diameter iron oxide magnetic nanoparticles are functionalized with an n-hydroxysuccinimide biocompatible coating and are conjugated on the surface to proteins VEGF antibody and ligand CD80. Combined, these proteins have the ability to target OSA cells and induce apoptosis. The proposed system was tested on a cancerous rodent osteoblast cell line (ATCCTMNPO CRL-2836 at four different concentrations (0.1, 1.0, 10.0, and 100.0 μg/mL of ligand CD80 alone, VEGF antibody alone, and a combination thereof (CD80+VEGF. Systems were implemented every 24 h over different sequential treatment timelines: 24, 48, and 72 h, to find the optimal protein concentration required for a reduction in cell proliferation. Results demonstrated that a combination of ligand CD80 and VEGF antibody was consistently most effective at reducing aberrant osteoblastic proliferation for both the 24- and 72-h timelines. At 48 h, however, an increase in cell proliferation was documented for the 0.1 and 1 μg/mL groups. For the 24- and 72-h tests, concentrations of 1.0 μg/mL of CD80+VEGF and 0.1 μg/mL of VEGF antibody were most effective. Concentrations of 10.0 and 100.0 μg/mL of CD80+VEGF reduced cell proliferation, but not as remarkably as the 1.0 μg/mL concentration. In addition, cell proliferation data showed that multiple treatments (72-h test induced cell death in the osteoblasts better than a single treatment. Future targeted drug delivery system research includes trials in OSA cell lines from greater phylum

  4. A phospholipid-PEG2000 conjugate of a vascular endothelial growth factor receptor 2 (VEGFR2)-targeting heterodimer peptide for contrast-enhanced ultrasound imaging of angiogenesis.

    Science.gov (United States)

    Pillai, R; Marinelli, E R; Fan, H; Nanjappan, P; Song, B; von Wronski, M A; Cherkaoui, S; Tardy, I; Pochon, S; Schneider, M; Nunn, A D; Swenson, R E

    2010-03-17

    The transition of a targeted ultrasound contrast agent from animal imaging to testing in clinical studies requires considerable chemical development. The nature of the construct changes from an agent that is chemically attached to microbubbles to one where the targeting group is coupled to a phospholipid, for direct incorporation to the bubble surface. We provide an efficient method to attach a heterodimeric peptide to a pegylated phospholipid and show that the resulting construct retains nanomolar affinity for its target, vascular endothelial growth factor receptor 2 (VEGFR2), for both the human (kinase insert domain-containing receptor - KDR) and the mouse (fetal liver kinase 1 - Flk-1) receptors. The purified phospholipid-PEG-peptide isolated from TFA-based eluents is not stable with respect to hydrolysis of the fatty ester moieties. This leads to the time-dependent formation of the lysophospholipid and the phosphoglycerylamide derived from the degradation of the product. Purification of the product using neutral eluent systems provides a stable product. Methods to prepare the lysophospholipid (hydrolysis product) are also included. Biacore binding data demonstrated the retention of binding of the lipopeptide to the KDR receptor. The phospholipid-PEG2000-peptide is smoothly incorporated into gas-filled microbubbles and provides imaging of angiogenesis in a rat tumor model.

  5. PSMA-Targeted Nano-Conjugates as Dual-Modality (MRI/PET) Imaging Probes for the Non-Invasive Detection of Prostate Cancer

    Science.gov (United States)

    2009-10-01

    mM PBS, 0.1M MES, goat serum, methanol (99.9%), DMSO(99.9%)) at room temperature (Fig. 2). The nanotag solutions were monitored by UV-Vis, DLS, and...in metabolic cages (4 mice per cage) to collect urine and feces at 24 h, 48 h, and 72 h p.i. For the evaluation of pharmacokinetic (PK) parameters...targeted PET/MRI dual modality imaging probes was impeded by the availability of arsenic -74, we were able to take a different route to develop multi

  6. Design and Application of Antimicrobial Peptide Conjugates

    Directory of Open Access Journals (Sweden)

    Andre Reinhardt

    2016-05-01

    Full Text Available Antimicrobial peptides (AMPs are an interesting class of antibiotics characterized by their unique antibiotic activity and lower propensity for developing resistance compared to common antibiotics. They belong to the class of membrane-active peptides and usually act selectively against bacteria, fungi and protozoans. AMPs, but also peptide conjugates containing AMPs, have come more and more into the focus of research during the last few years. Within this article, recent work on AMP conjugates is reviewed. Different aspects will be highlighted as a combination of AMPs with antibiotics or organometallic compounds aiming to increase antibacterial activity or target selectivity, conjugation with photosensitizers for improving photodynamic therapy (PDT or the attachment to particles, to name only a few. Owing to the enormous resonance of antimicrobial conjugates in the literature so far, this research topic seems to be very attractive to different scientific fields, like medicine, biology, biochemistry or chemistry.

  7. A novel delivery vector for targeted delivery of the antiangiogenic drug paclitaxel to angiogenic blood vessels: TLTYTWS-conjugated PEG-PLA nanoparticles

    Science.gov (United States)

    Tan, Fei; Mo, Xiao-hui; Zhao, Jian; Liang, Hui; Chen, Zhong-jian; Wang, Xiu-li

    2017-02-01

    Antiangiogenesis has been widely accepted as an attractive strategy to combat tumor growth, invasion, and metastasis. An actively targeting nanoparticle-based drug delivery system (nano-DDS) would provide an alternative method to achieve antiangiogenic antitumor therapy. In the present study, our group fabricated novel nano-DDS, TLTYTWS (TS) peptide-modified poly(ethylene glycol)-poly(lactic acid) (PEG-PLA) nanoparticles (TS-NPs) encapsulating a drug with antiangiogenic potential, paclitaxel (Ptx) (TS-Ptx-NPs). The nanoparticles were uniformly spherical and had a unimodal particle size distribution and slightly negative zeta potential. TS-NPs accumulated significantly in human umbilical vein endothelial cells (HUVECs) via energy-dependent and caveolae- and lipid raft-mediated endocytosis and improved the antiproliferative, antimigratory, and antitube-forming abilities of paclitaxel in vitro. Following intravenous administration, TS-Ptx-NPs presented favorable pharmacokinetic profiles. Melanoma distribution assays confirmed that TS-NPs achieved higher accumulation and penetration at melanoma sites. These results collectively indicated that TLTYTWS-decorated nanoparticles can be considered to be a promising nano-DDS for chemotherapies targeting tumor angiogenesis and have great potential to improve the efficacy of antiangiogenic therapy in melanoma tumor-bearing nude mice.

  8. Synthesis and characterization of HPMA copolymer-5-FU conjugates

    Institute of Scientific and Technical Information of China (English)

    Fang Yuan; Fu Chen; Qing Yu Xiang; Xuan Qin; Zhi Rong Zhang; Yuan Huang

    2008-01-01

    N-(2-Hydroxypropyl)methacrylamide copolymer-5-fluorouracil (PHPMA-FU)conjugates were synthesized by a novel and simplified synthetic mute,and characterized by UV,FTIR and HPLC analyses.The conjugated content of 5-fluorouracil (5-FU)was 3.41 ± 0.07 wt%.The stabilities of PHPMA-FU conjugates under different conditions were studied.The results showed that HPMA copolymer was a potential carrier for tumor-targeting delivery of 5-FU.

  9. A Tat-conjugated Peptide Nucleic Acid Tat-PNA-DR Inhibits Hepatitis B Virus Replication In Vitro and In Vivo by Targeting LTR Direct Repeats of HBV RNA

    Directory of Open Access Journals (Sweden)

    Zhengyang Zeng

    2016-01-01

    Full Text Available Hepatitis B virus (HBV infection is a major cause of chronic active hepatitis, cirrhosis, and primary hepatocellular carcinoma, all of which are severe threats to human health. However, current clinical therapies for HBV are limited by potential side effects, toxicity, and drug-resistance. In this study, a cell-penetrating peptide-conjugated peptide nucleic acid (PNA, Tat-PNA-DR, was designed to target the direct repeat (DR sequences of HBV. Tat-PNA-DR effectively inhibited HBV replication in HepG2.2.15 cells. Its anti-HBV effect relied on the binding of Tat-PNA-DR to the DR, whereby it suppressed the translation of hepatitis B e antigen (HBeAg, HBsAg, HBV core, hepatitis B virus x protein, and HBV reverse transcriptase (RT and the reverse transcription of the HBV genome. Furthermore, Tat-PNA-DR administered by intravenous injection efficiently cleared HBeAg and HBsAg in an acute hepatitis B mouse model. Importantly, it induced an 80% decline in HBV DNA in mouse serum, which was similar to the effect of the widely used clinical drug Lamivudine (3TC. Additionally, a long-term hydrodynamics HBV mouse model also demonstrated Tat-PNA-DR's antiviral effect. Interestingly, Tat-PNA-DR displayed low cytotoxicity, low mouse acute toxicity, low immunogenicity, and high serum stability. These data indicate that Tat-PNA-DR is a unique PNA and a promising drug candidate against HBV.

  10. cRGD conjugated mPEG-PLGA-PLL nanoparticles for SGC-7901 gastric cancer cells-targeted Delivery of fluorouracil.

    Science.gov (United States)

    Liu, Peifeng; Wang, Hongbin; Wang, Qi; Sun, Ying; Shen, Ming; Zhu, Mingjie; Wan, Zhiyong; Duan, Yourong

    2012-06-01

    The main purpose of this study was to evaluate the targeting effect of cyclic arginine-glycine-aspartic peptide (cRGD)-modified monomethoxy (polyethylene glycol)-poly (D, L-lactide-co-glycolide)-poly (L-lysine) nanoparticles (mPEG-PLGA-PLL-cRGD NPs) for gastric cancer SGC-7901 cells. We prepared the 5-Fulorouracil (5Fu)-loaded mPEG-PLGA-PLL-cRGD (5Fu/mPEG-PLGA-PLL-cRGD) NPs that had an average particle size of 180 nm and a zeta potential 2.77 mV. The results of cytotoxicity demonstrated the mPEG-PLGA-PLL-cRGD NPs showed the ignorable cytotoxicity and the 5Fu/mPEG-PLGA-PLL-cRGD NPs could significantly enhance the cytotoxicity of 5Fu. In vitro drug release experiments showed that the release of drug was effectively prolonged and sustained. The results of confocal laser scanning microscope (CLSM) and flow cytometer analysis demonstrated that the fluorescence intensity of the SGC-7901 gastric cancer cells treated with Rb/mPEG-PLGA-PLL-cRGD NPs was significantly higher than that treated with Rb, this suggested that Rb/mPEG-PLGA-PLL-cRGD NPs could effectively be internalized by SGC-7901 gastric cancer cells. In summary, the above experimental results illustrate that mPEG-PLGA-PLL-cRGD NPs have great potential to be used as an effective delivery carriers.

  11. The Chemistry and Biology of Oligonucleotide Conjugates

    Science.gov (United States)

    Juliano, R.L.; Ming, Xin; Nakagawa, Osamu

    2012-01-01

    CONSPECTUS Short DNA or RNA oligonucleotides have tremendous potential as therapeutic agents. Because of their ability to engage in Watson-Crick base pairing they can interact with messenger mRNA or pre-mRNA targets with high selectivity and thus offer the possibility of precise manipulation of gene expression. This possibility has engendered extensive efforts to develop oligonucleotides as drugs, with many candidates already in clinical trials. However, a major impediment to the maturation of oligonucleotide-based therapeutics is the fact that these relatively large and usually highly charged molecules have great difficulty crossing cellular membranes and thus in penetrating to their sites of action in the cytosol or nucleus. In this Account we first summarize some basic aspects of the biology of antisense and siRNA oligonucleotides and then discuss chemical conjugation as an approach to improving the intracellular delivery and therapeutic potential of these agents. Our emphasis will be on the pharmacological ramifications of oligonucleotide conjugates rather than the details of conjugation chemistry. One important approach has been conjugation with ligands designed to bind to particular receptors and thus provide specificity to the interaction of cells with oligonucleotides. Another approach has been to couple antisense or siRNA with agents such as cell penetrating peptides that are designed to provoke escape of the conjugate from intracellular vesicular compartments. Both of these approaches have enjoyed some success. However, there remains much to be learned before oligonucleotide conjugates can find an important place in human therapeutics. PMID:22353142

  12. Methotrexate and epirubicin conjugates as potential antitumor drugs

    Directory of Open Access Journals (Sweden)

    Szymon Wojciech Kmiecik

    2017-07-01

    Full Text Available Introduction: The use of hybrid molecules has become one of the most significant approaches in new cytotoxic drug design. This study describes synthesis and characterization of conjugates consisting of two well-known and characterized chemotherapeutic agents: methotrexate (MTX and epirubicin (EPR. The synthesized conjugates combine two significant anticancer strategies: combinatory therapy and targeted therapy. These two drugs were chosen because they have different mechanisms of action, which can increase the anticancer effect of the obtained conjugates. MTX, which is a folic acid analog, has high cytotoxic properties and can serve as a targeting moiety that can reach folate receptors (FRs overexpresing tumor cells. Combination of nonselective drugs such as EPR with MTX can increase the selectivity of the obtained conjugates, while maintaining the high cytotoxic properties.Materials and methods: Conjugates were purified by RP-HPLC and the structure was investigated by MS and MS/MS methods. The effect of the conjugates on proliferation of LoVo, LoVo/Dx, MCF-7 and MV-4-11 human cancer cell lines was determined by SRB or MTT assay.Results: The conjugation reaction results in the formation of monosubstituted (α, γ and disubstituted MTX derivatives. In vitro proliferation data demonstrate that the conjugates synthesized in our study show lower cytotoxic properties than both chemotherapeutics used alone.Discussion: Epirubicin cytotoxicity was not observed in obtained conjugates. Effective drugs release after internalization needs further investigation.

  13. Segmented conjugated polymers

    Indian Academy of Sciences (India)

    G Padmanaban; S Ramakrishnan

    2003-08-01

    Segmented conjugated polymers, wherein the conjugation is randomly truncated by varying lengths of non-conjugated segments, form an interesting class of polymers as they not only represent systems of varying stiffness, but also ones where the backbone can be construed as being made up of chromophores of varying excitation energies. The latter feature, especially when the chromophores are fluorescent, like in MEHPPV, makes these systems particularly interesting from the photophysics point of view. Segmented MEHPPV- samples, where x represents the mole fraction of conjugated segments, were prepared by a novel approach that utilizes a suitable precursor wherein selective elimination of one of the two eliminatable groups is affected; the uneliminated units serve as conjugation truncations. Control of the composition x of the precursor therefore permits one to prepare segmented MEHPPV- samples with varying levels of conjugation (elimination). Using fluorescence spectroscopy, we have seen that even in single isolated polymer chains, energy migration from the shorter (higher energy) chromophores to longer (lower energy) ones occurs – the extent of which depends on the level of conjugation. Further, by varying the solvent composition, it is seen that the extent of energy transfer and the formation of poorly emissive inter-chromophore excitons are greatly enhanced with increasing amounts of non-solvent. A typical S-shaped curve represents the variation of emission yields as a function of composition suggestive of a cooperative collapse of the polymer coil, reminiscent of conformational transitions seen in biological macromolecules.

  14. Development and application of nanoparticles synthesized with folic acid-conjugated soy protein

    Science.gov (United States)

    In this study, soy protein isolate (SPI) was conjugated with folic acid (FA) to prepare nanoparticles for target-specific drug delivery. Successful conjugation was evidenced by UV spectrophotometry and primary amino group analysis. An increase in count rate by at least 142% was observed in FA-conjug...

  15. Conjugated Polymers/DNA Hybrid Materials for Protein Inactivation.

    Science.gov (United States)

    Zhao, Likun; Zhang, Jiangyan; Xu, Huiming; Geng, Hao; Cheng, Yongqiang

    2016-09-01

    Chromophore-assisted light inactivation (CALI) is a powerful tool for analyzing protein functions due to the high degree of spatial and temporal resolution. In this work, we demonstrate a CALI approach based on conjugated polymers (CPs)/DNA hybrid material for protein inactivation. The target protein is conjugated with single-stranded DNA in advance. Single-stranded DNA can form CPs/DNA hybrid material with cationic CPs via electrostatic and hydrophobic interactions. Through the formation of CPs/DNA hybrid material, the target protein that is conjugated with DNA is brought into close proximity to CPs. Under irradiation, CPs harvest light and generate reactive oxygen species (ROS), resulting in the inactivation of the adjacent target protein. This approach can efficiently inactivate any target protein which is conjugated with DNA and has good specificity and universality, providing a new strategy for studies of protein function and adjustment of protein activity.

  16. Qualidade conjugal: mapeando conceitos

    Directory of Open Access Journals (Sweden)

    Clarisse Mosmann

    2006-12-01

    Full Text Available Apesar da ampla utilização do conceito de qualidade conjugal, identifica-se falta de clareza conceitual acerca das variáveis que o compõem. Esse artigo apresenta revisão da literatura na área com o objetivo de mapear o conceito de qualidade conjugal. Foram analisadas sete principais teorias sobre o tema: Troca Social, Comportamental, Apego, Teoria da Crise, Interacionismo Simbólico. Pelos postulados propostos nas diferentes teorias, podem-se identificar três grupos de variáveis fundamentais na definição da qualidade conjugal: recursos pessoais dos cônjuges, contexto de inserção do casal e processos adaptativos. Neste sentido, a qualidade conjugal é resultado do processo dinâmico e interativo do casal, razão deste caráter multidimensional.

  17. Polymers for Protein Conjugation

    Directory of Open Access Journals (Sweden)

    Gianfranco Pasut

    2014-01-01

    Full Text Available Polyethylene glycol (PEG at the moment is considered the leading polymer for protein conjugation in view of its unique properties, as well as to its low toxicity in humans, qualities which have been confirmed by its extensive use in clinical practice. Other polymers that are safe, biodegradable and custom-designed have, nevertheless, also been investigated as potential candidates for protein conjugation. This review will focus on natural polymers and synthetic linear polymers that have been used for protein delivery and the results associated with their use. Genetic fusion approaches for the preparation of protein-polypeptide conjugates will be also reviewed and compared with the best known chemical conjugation ones.

  18. CO-releasing molecule (CORM) conjugate systems.

    Science.gov (United States)

    Kautz, Anna Christin; Kunz, Peter C; Janiak, Christoph

    2016-11-15

    The development of CORMs (CO-releasing molecules) as a prodrug for CO administration in living organisms has attracted significant attention. CORMs offer the promising possibility of a safe and controllable release of CO in low amounts triggered by light, ligands, enzymes, etc. For the targeting of specific tissues or diseases and to prevent possible side effects from metals and other residues after CO release, these CORMs are attached to biocompatible systems, like peptides, polymers, nanoparticles, dendrimers, protein cages, non-wovens, tablets, and metal-organic frameworks. We discuss in this review the known CORM carrier conjugates, in short CORM conjugates, with covalently-bound or incorporated CORMs for medicinal and therapeutic applications. Most conjugates are nontoxic, show increasing half-lives of CO release, and make use of the EPR-effect, but still show problems because of a continuous background of CO release and the absence of an on/off-switch for the CO release.

  19. The photochemical thiol–ene reaction as a versatile method for the synthesis of glutathione S-conjugates targeting the bacterial potassium efflux system Kef† †Electronic supplementary information (ESI) available: Further experimental details and NMR spectra. See DOI: 10.1039/c5qo00436e Click here for additional data file.

    Science.gov (United States)

    Rasmussen, Tim; Miller, Samantha; Booth, Ian R.

    2016-01-01

    The thiol–ene coupling reaction is emerging as an important conjugation reaction that is suitable for use in a biological setting. Here, we explore the utility of this reaction for the synthesis of glutathione-S-conjugates (GSX) and present a general, operationally simple, protocol with a wide substrate scope. The GSX afforded are an important class of compounds and provide invaluable molecular tools to study glutathione-binding proteins. In this study we apply the diverse library of GSX synthesised to further our understanding of the structural requirements for binding to the glutathione-binding protein, Kef, a bacterial K+ efflux system, found in many bacterial pathogens. This system is vital to the survival of bacteria upon exposure to electrophiles, and plays an essential role in the maintenance of intracellular pH and K+ homeostasis. Consequently, Kef is an appealing target for the development of novel antibacterial drugs. PMID:27110363

  20. DS-8201a, a new HER2-targeting antibody-drug conjugate incorporating a novel DNA topoisomerase I inhibitor, overcomes HER2-positive gastric cancer T-DM1 resistance.

    Science.gov (United States)

    Takegawa, Naoki; Nonagase, Yoshikane; Yonesaka, Kimio; Sakai, Kazuko; Maenishi, Osamu; Ogitani, Yusuke; Tamura, Takao; Nishio, Kazuto; Nakagawa, Kazuhiko; Tsurutani, Junji

    2017-10-15

    Anti-HER2 therapies are beneficial for patients with HER2-positive breast or gastric cancer. T-DM1 is a HER2-targeting antibody-drug conjugate (ADC) comprising the antibody trastuzumab, a linker, and the tubulin inhibitor DM1. Although effective in treating advanced breast cancer, all patients eventually develop T-DM1 resistance. DS-8201a is a new ADC incorporating an anti-HER2 antibody, a newly developed, enzymatically cleavable peptide linker, and a novel, potent, exatecan-derivative topoisomerase I inhibitor (DXd). DS-8201a has a drug-to-antibody-ratio (DAR) of 8, which is higher than that of T-DM1 (3.5). Owing to these unique characteristics and unlike T-DM1, DS-8201a is effective against cancers with low-HER2 expression. In the present work, T-DM1-resistant cells (N87-TDMR), established using the HER2-positive gastric cancer line NCI-N87 and continuous T-DM1 exposure, were shown to be susceptible to DS-8201a. The ATP-binding cassette (ABC) transporters ABCC2 and ABCG2 were upregulated in N87-TDMR cells, but HER2 overexpression was retained. Furthermore, inhibition of ABCC2 and ABCG2 by MK571 restored T-DM1 sensitivity. Therefore, resistance to T-DM1 is caused by efflux of its payload DM1, due to aberrant expression of ABC transporters. In contrast to DM1, DXd payload of DS-8201a inhibited the growth of N87-TDMR cells in vitro. This suggests that either DXd may be a poor substrate of ABCC2 and ABCG2 in comparison to DM1, or the high DAR of DS-8201a relative to T-DM1 compensates for increased efflux. Notably, N87-TDMR xenograft tumor growth was prevented by DS-8201a. In conclusion, the efficacy of DS-8201a as a treatment for patients with T-DM1-resistant breast or gastric cancer merits investigation. © 2017 UICC.

  1. In vitro biological properties of flavonoid conjugates found in vivo.

    Science.gov (United States)

    Williamson, G; Barron, D; Shimoi, K; Terao, J

    2005-05-01

    For some flavonoids such as quercetin, isoflavones and catechins, the pathways of absorption and metabolism are now reasonably well characterised and understood. By definition, for biological activity of flavonoids to be manifest, the target tissue, which includes the blood and vascular system, must respond to the form(s) of flavonoid that it encounters. Bioavailability studies have shown that the circulating form of most flavonoids is as conjugates, with a few notable exceptions. There have been several recent papers on the in vitro biological properties of conjugates that have been found in vivo. This paper reviews the properties of these conjugates. Most of the information currently available is on quercetin glucuronides, but also on isoflavone and catechin conjugates. In addition to the biological properties of the conjugates, the partition coefficients and methods of synthesis are also presented.

  2. Peptide-LNA oligonucleotide conjugates

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Hansen, Lykke Haastrup; Vester, Birte

    2013-01-01

    properties, peptides were introduced into oligonucleotides via a 2'-alkyne-2'-amino-LNA scaffold. Derivatives of methionine- and leucine-enkephalins were chosen as model peptides of mixed amino acid content, which were singly and doubly incorporated into LNA/DNA strands using highly efficient copper......Although peptide-oligonucleotide conjugates (POCs) are well-known for nucleic acids delivery and therapy, reports on internal attachment of peptides to oligonucleotides are limited in number. To develop a convenient route for preparation of internally labeled POCs with improved biomedical......(i)-catalyzed azide-alkyne cycloaddition (CuAAC) "click" chemistry. DNA/RNA target binding affinity and selectivity of the resulting POCs were improved in comparison to LNA/DNA mixmers and unmodified DNA controls. This clearly demonstrates that internal attachment of peptides to oligonucleotides can significantly...

  3. Phase conjugation of high energy lasers.

    Energy Technology Data Exchange (ETDEWEB)

    Bliss, David E; Valley, Michael T.; Atherton, Briggs W.; Bigman, Verle Howard; Boye, Lydia Ann; Broyles, Robin Scott; Kimmel, Mark W.; Law, Ryan J.; Yoder, James R.

    2013-01-01

    In this report we explore claims that phase conjugation of high energy lasers by stimulated Brillouin scattering (SBS) can compensate optical aberrations associated with severely distorted laser amplifier media and aberrations induced by the atmosphere. The SBS media tested was a gas cell pressurized up to 300 psi with SF6 or Xe or both. The laser was a 10 Hz, 3J, Q-switched Nd:YAG with 25 ns wide pulses. Atmospheric aberrations were created with space heaters, helium jets and phase plates designed with a Kolmogorov turbulence spectrum characterized by a Fried parameter, ro , ranging from 0.6 6.0 mm. Phase conjugate tests in the laboratory were conducted without amplification. For the strongest aberrations, D/ro ~ 20, created by combining the space heaters with the phase plate, the Strehl ratio was degraded by a factor of ~50. Phase conjugation in SF6 restored the peak focusable intensity to about 30% of the original laser. Phase conjugate tests at the outdoor laser range were conducted with laser amplifiers providing gain in combination with the SBS cell. A large 600,000 BTU kerosene space heater was used to create turbulence along the beam path. An atmospheric structure factor of Cn2 = 5x10-13 m2/3 caused the illumination beam to expand to a diameter 250mm and overfill the receiver. The phase conjugate amplified return could successfully be targeted back onto glints 5mm in diameter. Use of a lenslet arrays to lower the peak focusable intensity in the SBS cell failed to produce a useful phase conjugate beam; The Strehl ratio was degraded with multiple random lobes instead of a single focus. I will review literature results which show how multiple beams can be coherently combined by SBS when a confocal reflecting geometry is used to focus the laser in the SBS cell.

  4. Conjugation in "Escherichia coli"

    Science.gov (United States)

    Phornphisutthimas, Somkiat; Thamchaipenet, Arinthip; Panijpan, Bhinyo

    2007-01-01

    Bacterial conjugation is a genetic transfer that involves cell-to-cell between donor and recipient cells. With the current method used to teach students in genetic courses at the undergraduate level, the transconjugants are identified using bacterial physiology and/or antibiotic resistance. Using physiology, however, is difficult for both…

  5. DNA-cell conjugates

    Science.gov (United States)

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2016-05-03

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  6. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  7. Various methods of gold nanoparticles (GNPs conjugation to antibodies

    Directory of Open Access Journals (Sweden)

    Mir Hadi Jazayeri

    2016-07-01

    These applications require an increasingly complex level of surface decoration in order to achieve efficacy, and limit off-target toxicity. This review will discuss the chemical and physical approaches commonly utilized in relation to surface decoration and the powerful system used to indicate success of the conjugation. Finally, we review the range of recent studies about covalent and noncovalent modes for conjugation of antibodies to the particle surface that aim to advance gold nanoparticle treatments and diagnostics toward the clinic.

  8. Cancer Cell Targeting Using Folic Acid/Anti-HER2 Antibody Conjugated Fluorescent CdSe/CdS/ZnS-Mercaptopropionic Acid and CdTe-Mercaptosuccinic Acid Quantum Dots.

    Science.gov (United States)

    Singh, Gurpal; Kumar, Manoj; Soni, Udit; Arora, Vikas; Bansal, Vivek; Gupta, Dikshi; Bhat, Madhusudan; Dinda, Amit K; Sapra, Sameer; Singh, Harpal

    2016-01-01

    CdSe/CdS/ZnS and CdTe quantum dots (QDs) were synthesized by successive ion layer adsorption and reaction (SILAR) technique and direct aqueous synthesis respectively using thiol stabilizers. Synthesized CdSe/CdS/ZnS and CdTe QDs stabilized with 3-mercaptopropionic acid (MPA) and mercaptosuccinic acid (MSA) were used as fluorescent labels after conjugation with folic acid (FA) and anti-HER2 antibodies. Photoluminescence quantum yield of folated CdSe/CdS/ZnS-MPA and CdTe-MSA QDs was 59% and 77% than that of non-folated hydrophilic QDs. The folate receptor-mediated delivery of folic acid-conjugated CdTe-MSA and CdSe/CdS/ZnS-MPA QDs showed higher cellular internalization as observed by confocal laser scanning microscopic studies. Folated and non-folated CdTe-MSA QDs were highly toxic and exhibited only 10% cell viability as compared to > 80% cell viability with CdSe/CdS/ZnS-MPA QDs over the concentration ranging from 3.38 to 50 pmoles. Immunohistochemistry (IHC) results of human breast cancer tissue samples showed positive results with anti-HER2 antibody conjugated CdSe/CdS/ZnS-MPA QDs with better sensitivity and specificity as compared to conventional IHC analysis using diaminobenzedene staining.

  9. Polymer decorated gold nanoparticles in nanomedicine conjugates.

    Science.gov (United States)

    Capek, Ignác

    2017-02-15

    Noble metal, especially gold nanoparticles and their conjugates with biopolymers have immense potential for disease diagnosis and therapy on account of their surface plasmon resonance (SPR) enhanced light scattering and absorption. Conjugation of noble metal nanoparticles to ligands specifically targeted to biomarkers on diseased cells allows molecular-specific imaging and detection of disease. The development of smart gold nanoparticles (AuNPs) that can deliver therapeutics at a sustained rate directly to cancer cells may provide better efficacy and lower toxicity for treating cancer tumors. We highlight some of the promising classes of targeting systems that are under development for the delivery of gold nanoparticles. Nanoparticles designed for biomedical applications are often coated with polymers containing reactive functional groups to conjugate targeting ligands, cell receptors or drugs. Using targeted nanoparticles to deliver chemotherapeutic agents in cancer therapy offers many advantages to improve drug/gene delivery and to overcome many problems associated with conventional radiotherapy and chemotherapy. The targeted nanoparticles were found to be effective in killing cancer cells which were studied using various anticancer assays. Cell morphological analysis shows the changes occurred in cancer cells during the treatment with AuNPs. The results determine the influence of particle size and concentration of AuNPs on their absorption, accumulation, and cytotoxicity in model normal and cancer cells. As the mean particle diameter of the AuNPs decreased, their rate of absorption by the intestinal epithelium cells increased. These results provide important insights into the relationship between the dimensions of AuNPs and their gastrointestinal uptake and potential cytotoxicity. Furthermore gold nanoparticles efficiently convert the absorbed light into localized heat, which can be exploited for the selective laser photothermal therapy of cancer. We also review

  10. SPECIFIC UPTAKE OF MONOCLONAL ANTIBODY-CONJUGATED METHOTREXATE BY HUMAN LYMPHOCYTIC LEUKEMIC B CELLS

    Institute of Scientific and Technical Information of China (English)

    Zhu Zhenping; Yang Chunzheng; Tarunendu Ghose; Jaroslav Kralovec

    1998-01-01

    Objective: To analysis the uptake of free MTX and MTX conjugated to tumor specific monoclonal antibody by target and non-target cells. Methods: The folate antagonist methotrexate (MTX) was conjugated to two monoclonal antibodies (Mab) directed against human chronic lymphocytic leukemia (CLL), Dal B01 and Dal B02, by an active ester method. Both conjugates were more cytotoxic toward the target tumor cell line D10-1than to the non-target cell line MOLT-3, and Dal B02-MTX conjugate was more inhibitory to D10-1 cells than free MTX in a 6 h pulse exposure assay. Results: Drug uptake studies revealed that D10-1 cells took up much more Dal B01 and Dal B02-conjugated MTX than free MTX. The amounts of drug taken up by D10-1 cells incubated with Dal B01 and Dal B02-conjugated MTX were always 3 to 5-fold higher than that taken up by MOLT-3 cells, although the latter took up more drug when incubated with free MTX. Furthermore, tumor cells incubated with Dal B01 or Dal B02-conjugated MTX retained much larger amounts of drug for a prolonged period of time than those incubated with free MTX.Conclusion: The enhanced specific cytotoxicity of Dal B01 and Dal B02-MTX conjugates toward target tumor cells is therefore likely due to (Ⅰ) delivery of larger amounts of MTX to target cells when the drug is conjugated to Mab;(ii) longer retention of Mab-conjugated MTX by target cells; and (iii) slow, prolonged release of MTX from the surface-bound or endocytosed conjugates, rendering them into a sustained release dosage form.

  11. Theory of Digitized Conjugate Surface and Solution to Conjugate Surface

    Institute of Scientific and Technical Information of China (English)

    Xiao Lai-yuan; Liao Dao-xun; Yi Chuan-yun

    2004-01-01

    In order to meet the needs of designing and processing digitized surfaces, the method to spreading digitized surface has been proposed. The key technique is to solve the problem of digitized conjugate surface. In the paper, the digitized conjugate surface was theoretically investigated, and the solution of conjugate surface based on digitized surface was also studied. The digitized conjugate surface theory was then proposed, and applied to build the model of solving conjugate surface based on digitized surface. A corresponding algorithm was developed. This paper applies the software Conjugater-1.0 that is developed by ourselves to compute the digitized conjugate surfaces of the drum-tooth surface. This study provides theoretical and technical bases for analyzing engagement of digitized surface, simulation and numerical processing technique.

  12. IRDye78 Conjugates for Near-Infrared Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Atif Zaheer

    2002-10-01

    Full Text Available The detection of human malignancies by near-infrared (NIR fluorescence will require the conjugation of cancer-specific ligands to NIR fluorophores that have optimal photoproperties and pharmacokinetics. IRDye78, a tetra-sulfonated heptamethine indocyanine NIR fluorophore, meets most of the criteria for an in vivo imaging agent, and is available as an N-hydroxysuccinimide ester for conjugation to low-molecular-weight ligands. However, IRDye78 has a high charge-to-mass ratio, complicating purification of conjugates. It also has a potentially labile linkage between fluorophore and ligand. We have developed an ion-pairing purification strategy for IRDye78 that can be performed with a standard C18 column under neutral conditions, thus preserving the stability of fluorophore, ligand, and conjugate. By employing parallel evaporative light scatter and absorbance detectors, all reactants and products are identified, and conjugate purity is maximized. We describe reversible and irreversible conversions of IRDye78 that can occur during sample purification, and describe methods for preserving conjugate stability. Using seven ligands, spanning several classes of small molecules and peptides (neutral, charged, and/or hydrophobic, we illustrate the robustness of these methods, and confirm that IRDye78 conjugates so purified retain bioactivity and permit NIR fluorescence imaging of specific targets.

  13. Peptide conjugation: before or after nanoparticle formation?

    Science.gov (United States)

    Valetti, Sabrina; Mura, Simona; Noiray, Magali; Arpicco, Silvia; Dosio, Franco; Vergnaud, Juliette; Desmaële, Didier; Stella, Barbara; Couvreur, Patrick

    2014-11-19

    We report herein a detailed study concerning the impact of different bioconjugation and nanoformulation strategies on the in vitro targeting ability of peptide-decorated squalenoyl gemcitabine (SQdFdC) nanoparticles (NPs). NPs have been functionalized with the CKAAKN peptide, previously identified as an efficient homing device within the pancreatic pathological microenvironment. Two approaches have been followed: (i) either the CKAAKN peptide was directly conjugated at the surface of preformed SQdFdC nanoparticles (conjugation after NP formation) or (ii) it was first reacted with a maleimide squalenoyl derivative before the resulting bioconjugate was co-nanoprecipitated with SQdFdC to form the peptide-decorated NPs (conjugation before NP formation). NPs were characterized with respect to mean diameter, zeta potential, and stability over time. Then, their specific interaction with the sFRP-4 protein was evaluated by surface plasmon resonance. Although both synthetic strategies allowed us to formulate NPs able to interact with the corresponding receptor, enhanced target binding and better specific avidity were observed with CKAAKN-NPs functionalized before NP formation. These NPs displayed the highest cell uptake and cytotoxicity in an in vitro model of human MIA Paca-2 pancreatic cancer cells.

  14. Fullerene-biomolecule conjugates and their biomedicinal applications.

    Science.gov (United States)

    Yang, Xinlin; Ebrahimi, Ali; Li, Jie; Cui, Quanjun

    2014-01-01

    Fullerenes are among the strongest antioxidants and are characterized as "radical sponges." The research on biomedicinal applications of fullerenes has achieved significant progress since the landmark publication by Friedman et al in 1993. Fullerene-biomolecule conjugates have become an important area of research during the past 2 decades. By a thorough literature search, we attempt to update the information about the synthesis of different types of fullerene-biomolecule conjugates, including fullerene-containing amino acids and peptides, oligonucleotides, sugars, and esters. Moreover, we also discuss in this review recently reported data on the biological and pharmaceutical utilities of these compounds and some other fullerene derivatives of biomedical importance. While within the fullerene-biomolecule conjugates, in which fullerene may act as both an antioxidant and a carrier, specific targeting biomolecules conjugated to fullerene will undoubtedly strengthen the delivery of functional fullerenes to sites of clinical interest.

  15. Impact of linker and conjugation chemistry on antigen binding, Fc receptor binding and thermal stability of model antibody-drug conjugates.

    Science.gov (United States)

    Acchione, Mauro; Kwon, Hyewon; Jochheim, Claudia M; Atkins, William M

    2012-01-01

    Antibody-drug conjugates (ADCs) with biotin as a model cargo tethered to IgG1 mAbs via different linkers and conjugation methods were prepared and tested for thermostability and ability to bind target antigen and Fc receptor. Most conjugates demonstrated decreased thermostability relative to unconjugated antibody, based on DSC, with carbohydrate and amine coupled ADCs showing the least effect compared with thiol coupled conjugates. A strong correlation between biotin-load and loss of stability is observed with thiol conjugation to one IgG scaffold, but the stability of a second IgG scaffold is relatively insensitive to biotin load. The same correlation for amine coupling was less significant. Binding of antibody to antigen and Fc receptor was investigated using surface plasmon resonance. None of the conjugates exhibited altered antigen affinity. Fc receptor FcγIIb (CD32b) interactions were investigated using captured antibody conjugate. Protein G and Protein A, known inhibitors of Fc receptor (FcR) binding to IgG, were also used to extend the analysis of the impact of conjugation on Fc receptor binding. H10NPEG4 was the only conjugate to show significant negative impact to FcR binding, which is likely due to higher biotin-load compared with the other ADCs. The ADC aHISNLC and aHISTPEG8 demonstrated some loss in affinity for FcR, but to much lower extent. The general insensitivity of target binding and effector function of the IgG1 platform to conjugation highlight their utility. The observed changes in thermostability require consideration for the choice of conjugation chemistry, depending on the system being pursued and particular application of the conjugate.

  16. Sequence-selective DNA binding with cell-permeable oligoguanidinium-peptide conjugates.

    Science.gov (United States)

    Mosquera, Jesús; Sánchez, Mateo I; Valero, Julián; de Mendoza, Javier; Vázquez, M Eugenio; Mascareñas, José L

    2015-03-21

    Conjugation of a short peptide fragment from a bZIP protein to an oligoguanidinium tail results in a DNA-binding miniprotein that selectively interacts with composite sequences containing the peptide-binding site next to an A/T-rich tract. In addition to stabilizing the complex with the target DNA, the oligoguanidinium unit also endows the conjugate with cell internalization properties.

  17. Nano-assembly of nanodiamonds by conjugation to actin filaments.

    Science.gov (United States)

    Bradac, Carlo; Say, Jana M; Rastogi, Ishan D; Cordina, Nicole M; Volz, Thomas; Brown, Louise J

    2016-03-01

    Fluorescent nanodiamonds (NDs) are remarkable objects. They possess unique mechanical and optical properties combined with high surface areas and controllable surface reactivity. They are non-toxic and hence suited for use in biological environments. NDs are also readily available and commercially inexpensive. Here, the exceptional capability of controlling and tailoring their surface chemistry is demonstrated. Small, bright diamond nanocrystals (size ˜30 nm) are conjugated to protein filaments of actin (length ˜3-7 µm). The conjugation to actin filaments is extremely selective and highly target-specific. These unique features, together with the relative simplicity of the conjugation-targeting method, make functionalised nanodiamonds a powerful and versatile platform in biomedicine and quantum nanotechnologies. Applications ranging from using NDs as superior biological markers to, potentially, developing novel bottom-up approaches for the fabrication of hybrid quantum devices that would bridge across the bio/solid-state interface are presented and discussed.

  18. Hierarchically deflated conjugate residual

    CERN Document Server

    Yamaguchi, Azusa

    2016-01-01

    We present a progress report on a new class of multigrid solver algorithm suitable for the solution of 5d chiral fermions such as Domain Wall fermions and the Continued Fraction overlap. Unlike HDCG \\cite{Boyle:2014rwa}, the algorithm works directly on a nearest neighbour fine operator. The fine operator used is Hermitian indefinite, for example $\\Gamma_5 D_{dwf}$, and convergence is achieved with an indefinite matrix solver such as outer iteration based on conjugate residual. As a result coarse space representations of the operator remain nearest neighbour, giving an 8 point stencil rather than the 81 point stencil used in HDCG. It is hoped this may make it viable to recalculate the matrix elements of the little Dirac operator in an HMC evolution.

  19. Dihydroazulene-buckminsterfullerene conjugates

    DEFF Research Database (Denmark)

    Santella, Marco; Mazzanti, Virginia; Jevric, Martyn;

    2012-01-01

    The dihydroazulene (DHA)/vinylheptafulvene (VHF) photo/thermoswitch has recently attracted interest as a molecular switch for molecular electronics. In this field, Buckminsterfullerene, C(60), has been shown to be a useful anchoring group for adhering a molecular wire to an electrode. Here we have...... combined the two units with the overall aim to elucidate how C(60) influences the DHA-VHF switching events. Efficient synthetic protocols for making covalently linked DHA-C(60) conjugates were developed, using Prato, Sonogashira, Hay, and Cadiot-Chodkiewicz reactions. These syntheses provide as well...... of DHA to its corresponding VHF. Thus, C(60) was found to significantly quench this conversion when situated closely to the DHA unit....

  20. Generalized conjugate gradient squared

    Energy Technology Data Exchange (ETDEWEB)

    Fokkema, D.R.; Sleijpen, G.L.G. [Utrecht Univ. (Netherlands)

    1994-12-31

    In order to solve non-symmetric linear systems of equations, the Conjugate Gradient Squared (CGS) is a well-known and widely used iterative method. In practice the method converges fast, often twice as fast as the Bi-Conjugate Gradient method. This is what you may expect, since CGS uses the square of the BiCG polynomial. However, CGS may suffer from its erratic convergence behavior. The method may diverge or the approximate solution may be inaccurate. BiCGSTAB uses the BiCG polynomial and a product of linear factors in an attempt to smoothen the convergence. In many cases, this has proven to be very effective. Unfortunately, the convergence of BiCGSTAB may stall when a linear factor (nearly) degenerates. BiCGstab({ell}) is designed to overcome this degeneration of linear factors. It generalizes BiCGSTAB and uses both the BiCG polynomial and a product of higher order factors. Still, CGS may converge faster than BiCGSTAB or BiCGstab({ell}). So instead of using a product of linear or higher order factors, it may be worthwhile to look for other polynomials. Since the BiCG polynomial is based on a three term recursion, a natural choice would be a polynomial based on another three term recursion. Possibly, a suitable choice of recursion coefficients would result in method that converges faster or as fast as CGS, but less erratic. It turns out that an algorithm for such a method can easily be formulated. One particular choice for the recursion coefficients leads to CGS. Therefore one could call this algorithm generalized CGS. Another choice for the recursion coefficients leads to BiCGSTAB. It is therefore possible to mix linear factors and some polynomial based on a three term recursion. This way one may get the best of both worlds. The authors will report on their findings.

  1. Recombinogenic engineering of conjugative plasmids with fluorescent marker cassettes

    DEFF Research Database (Denmark)

    Reisner, A.; Molin, Søren; Zechner, E.L.

    2002-01-01

    An efficient approach for the insertion of fluorescent marker genes with sequence specificity into conjugative plasmids in Escherichia coli is described. For this purpose, homologous recombination of linear double-stranded targeting DNA was mediated by the bacteriophage lambda recombination funct...

  2. Amifostine-conjugated pH-sensitive calcium phosphate-covered magnetic-amphiphilic gelatin nanoparticles for controlled intracellular dual drug release for dual-targeting in HER-2-overexpressing breast cancer.

    Science.gov (United States)

    Li, Wei-Ming; Chiang, Chih-Sheng; Huang, Wei-Chen; Su, Chia-Wei; Chiang, Min-Yu; Chen, Jian-Yi; Chen, San-Yuan

    2015-12-28

    We developed a surfactant-free method utilizing amifostine to stably link a targeting ligand (Herceptin) to amphiphilic gelatin (AG)-iron oxide@calcium phosphate (CaP) nanoparticles with hydrophobic curcumin (CUR) and hydrophilic doxorubicin (DOX) encapsulated in the AG core and CaP shell (AGIO@CaP-CD), respectively. This multi-functional nanoparticle system has a pH-sensitive CaP shell and degradable amphiphilic gelatin (AG) core, which enables controllable sequential release of the two drugs. The dual-targeting system of AGIO@CaP-CD (HER-AGIO@CaP-CD) with a bioligand and magnetic targeting resulted in significantly elevated cellular uptake in HER2-overexpressing SKBr3 cells and more efficacious therapy than delivery of targeting ligand alone due to the synergistic cell multi-drug resistance/apoptosis-inducing effect of the CUR and DOX combination. This nanoparticle combined with Herceptin and iron oxide nanoparticles not only provided a dual-targeting functionality, but also encapsulated CUR and DOX as a dual-drug delivery system for the combination therapy. This study further demonstrated that the therapeutic efficacy of this dual-targeting co-delivery system can be improved by modifying the application duration of magnetic targeting, which makes this combination therapy system a powerful new tool for in vitro/in vivo cancer therapy, especially for HER2-positive cancers.

  3. SYNTHESYS OF A FUNCTIONALIZED TETRAHYDROFURAN FRAGMENT THROUGH BROMINATION-CYCLIZATION OF A CONJUGATED DIENE

    Directory of Open Access Journals (Sweden)

    Veaceslav Kulciţki

    2010-06-01

    Full Text Available Conjugate 1,4-addition of N-bromosuccinimide (NBS to a diene system, possessing a suitable oxygen functionality, leads to functionalized tetrahydrofuran derivatives, which can be further derivatized into different synthetic targets.

  4. Development of antibacterial conjugates using sulfamethoxazole with monocyclic terpenes: A systematic medicinal chemistry based computational approach.

    Science.gov (United States)

    Swain, Shasank S; Paidesetty, Sudhir K; Padhy, Rabindra N

    2017-03-01

    To develop 6 conjugate agents of the moribund antibiotic sulfamethoxazole (SMZ) joined to 6 individual monoterpenes, followed by protocols of medicinal chemistry as potent antibacterials, against multidrug resistant (MDR) human gruesome pathogenic bacteria. Antibacterial activities of the proposed conjugates were ascertained by the 'prediction of activity spectra of substances' (PASS) program. Drug-likeness parameters and toxicity profiles of conjugates were standardized with the Lipinski rule of five, using cheminformatic tools, Molsoft, molinspiration, OSIRIS and ProTox. Antibacterial activities of individual chemicals and conjugates were examined by targeting the bacterial folic acid biosynthesis enzyme, dihydropteroate synthases (DHPSs) of bacteria, Bacillus anthracis, Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae and Mycobacterium tuberculosis, with 3D structures of DHPSs from protein data bank. According to the PASS program, biological spectral values of conjugate-2, conjugate-5 and conjugate-6 were ascertained effective with 'probably active' or 'Pa' value > 0.5, for anti-infective and antituberculosic activities. Using molecular docking against 5 cited bacterial DHPSs, effective docking scores of 6 monoterpenes in the specified decreasing order (kcal/mol): -9.72 (eugenol against B. anthracis), -9.61 (eugenol against S. pneumoniae), -9. 42 (safrol, against B. anthracis), -9.39 (thymol, against M. tuberculosis), -9.34 (myristicin, against S. pneumoniae) and -9.29 (thymol, against B. anthracis); whereas the lowest docking score of SMZ was -8.46kcal/mol against S. aureus DHPS. Similarly, effective docking scores of conjugates were as specified (kcal/mol.): -10.80 (conjugate-4 consisting SMZ+safrol, against M. tuberculosis), -10.78 (conjugate-5 consisting SMZ+thymol, against M. tuberculosis), -10.60 (conjugate-5 against B. anthracis), -10.26 (conjugate-2 consisting SMZ+ eugenol, against M. tuberculosis), -10.25 (conjugate-5, against S

  5. Sequential measurements of conjugate observables

    Energy Technology Data Exchange (ETDEWEB)

    Carmeli, Claudio [Dipartimento di Fisica, Universita di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Heinosaari, Teiko [Department of Physics and Astronomy, Turku Centre for Quantum Physics, University of Turku, 20014 Turku (Finland); Toigo, Alessandro, E-mail: claudio.carmeli@gmail.com, E-mail: teiko.heinosaari@utu.fi, E-mail: alessandro.toigo@polimi.it [Dipartimento di Matematica ' Francesco Brioschi' , Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2011-07-15

    We present a unified treatment of sequential measurements of two conjugate observables. Our approach is to derive a mathematical structure theorem for all the relevant covariant instruments. As a consequence of this result, we show that every Weyl-Heisenberg covariant observable can be implemented as a sequential measurement of two conjugate observables. This method is applicable both in finite- and infinite-dimensional Hilbert spaces, therefore covering sequential spin component measurements as well as position-momentum sequential measurements.

  6. Hacking into the granuloma: could antibody antibiotic conjugates be developed for TB?

    Science.gov (United States)

    Ekins, Sean

    2014-12-01

    Alternatives to small molecule or vaccine approaches to treating tuberculosis are rarely discussed. Attacking Mycobacterium tuberculosis in the granuloma represents a challenge. It is proposed that the conjugation of small molecules onto a monoclonal antibody that recognizes macrophage or lymphocytes cell surface receptors, might be a way to target the bacteria in the granuloma. This antibody drug conjugate approach is currently being used in 2 FDA approved targeted cancer therapies. The pros and cons of this proposal for further research are discussed.

  7. Production of carrier-peptide conjugates using chemically reactive unnatural amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Young, Travis; Schultz, Peter G.

    2015-08-18

    Provided are methods of making carrier polypeptide that include incorporating a first unnatural amino acid into a carrier polypeptide variant, incorporating a second unnatural amino acid into a target polypeptide variant, and reacting the first and second unnatural amino acids to produce the conjugate. Conjugates produced using the provided methods are also provided. In addition, orthogonal translation systems in methylotrophic yeast and methods of using these systems to produce carrier and target polypeptide variants comprising unnatural amino acids are provided.

  8. Production of carrier-peptide conjugates using chemically reactive unnatural amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Young, Travis; Schultz, Peter G

    2014-01-28

    Provided are methods of making carrier polypeptide that include incorporating a first unnatural amino acid into a carrier polypeptide variant, incorporating a second unnatural amino acid into a target polypeptide variant, and reacting the first and second unnatural amino acids to produce the conjugate. Conjugates produced using the provided methods are also provided. In addition, orthogonal translation systems in methylotrophic yeast and methods of using these systems to produce carrier and target polypeptide variants comprising unnatural amino acids are provided.

  9. Production of carrier-peptide conjugates using chemically reactive unnatural amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Young, Travis; Schultz, Peter G

    2013-12-17

    Provided are methods of making carrier polypeptide that include incorporating a first unnatural amino acid into a carrier polypeptide variant, incorporating a second unnatural amino acid into a target polypeptide variant, and reacting the first and second unnatural amino acids to produce the conjugate. Conjugates produced using the provided methods are also provided. In addition, orthogonal translation systems in methylotrophic yeast and methods of using these systems to produce carrier and target polypeptide variants comprising unnatural amino acids are provided.

  10. Field Guide to Challenges and Opportunities in Antibody-Drug Conjugates for Chemists.

    Science.gov (United States)

    Gordon, Mallory R; Canakci, Mine; Li, Longyu; Zhuang, Jiaming; Osborne, Barbara; Thayumanavan, S

    2015-11-18

    Antibody-drug conjugates have attracted a great amount of attention as a therapeutic strategy for diseases where targeting specific tissues and cells are critical components, such as in cancer therapy. Although promising, the number of approved ADC drugs is relatively limited. This emanates from the challenges associated with generating the conjugates and the complexities associated with the stability requirements for these conjugates during circulation and after reaching the target. Here, we provide a comprehensive overview of the design challenges facing the ADC field. These challenges also provide several unique research and development opportunities, which are also highlighted throughout the review.

  11. Paclitaxel conjugated Fe{sub 3}O{sub 4}@LaF{sub 3}:Ce{sup 3+},Tb{sup 3+} nanoparticles as bifunctional targeting carriers for Cancer theranostics application

    Energy Technology Data Exchange (ETDEWEB)

    Mangaiyarkarasi, Rajendiran; Chinnathambi, Shanmugavel; Karthikeyan, Subramani; Aruna, Prakasarao; Ganesan, Singaravelu, E-mail: sganesan@annauniv.edu

    2016-02-01

    The bi-functional Chitosan functionalized magnetite doped luminescent rare earth nanoparticles (Fe{sub 3}O{sub 4}@LaF{sub 3}: Ce{sup 3+},Tb{sup 3+}/chi NPs) as a carrier of paclitaxel (PTX) drug was designed using a co-precipitation and facile direct precipitation method. The synthesized nanoparticles are spherical in shape with a typical diameter of 19–37 nm respectively. They are water soluble, super paramagnetic and biocompatible, in which the amino groups on the nanoparticles surface are used for the conjugation with an anticancer drug, paclitaxel. The nature of PTX binding with Fe{sub 3}O{sub 4}@LaF{sub 3}: Ce{sup 3+},Tb{sup 3+}/chi nanoparticles were studied using X-ray diffraction, vibrating sample magnetometer and scanning electron micrograph. The nature of interactions between PTX and Fe{sub 3}O{sub 4}@LaF{sub 3}: Ce{sup 3+},Tb{sup 3+}/chi NPs due to complex formation were conceded out by various spectroscopic methods viz., UV–visible, steady state and excited state fluorescence spectroscopy. The photo-physical characterization reveals that the adsorption and release of PTX from Fe{sub 3}O{sub 4}@LaF{sub 3}:Tb{sup 3+}/chi nanoparticles is quicker when compared with other nanoparticles and also confirms that this may be due to the hydrogen bond formation between the hydroxyl group of drug and amino group of nanoparticles respectively. The maximum loading capacity and entrapment efficiency of 83.69% and 80.51% were attained at a ratio of 5:8 of PTX and Fe{sub 3}O{sub 4}@LaF{sub 3}: Ce{sup 3+},Tb{sup 3+}/chi NPs respectively. In addition with that, antitumoral activity study of PTX conjugated Fe{sub 3}O{sub 4}@LaF{sub 3}:Tb{sup 3+}/chi nanoparticles exhibits increased cytotoxic effects on A549 lung cancer cell lines than that of unconjugated PTX. - Highlights: • Fe{sub 3}O{sub 4}@LaF{sub 3}: Ce{sup 3+},Tb{sup 3+}/chi nanoparticles as a carrier of paclitaxel. • These particles are water soluble, super paramagnetic and biocompatible. • The maximum

  12. Growth Inhibition of Re-Challenge B16 Melanoma Transplant by Conjugates of Melanogenesis Substrate and Magnetite Nanoparticles as the Basis for Developing Melanoma-Targeted Chemo-Thermo-Immunotherapy

    Directory of Open Access Journals (Sweden)

    Tomoaki Takada

    2009-01-01

    Full Text Available Melanogenesis substrate, N-propionyl-cysteaminylphenol (NPrCAP, is selectively incorporated into melanoma cells and inhibits their growth by producing cytotoxic free radicals. Magnetite nanoparticles also disintegrate cancer cells and generate heat shock protein (HSP upon exposure to an alternating magnetic field (AMF. This study tested if a chemo-thermo-immunotherapy (CTI therapy strategy can be developed for better management of melanoma by conjugating NPrCAP on the surface of magnetite nanoparticles (NPrCAP/M. We examined the feasibility of this approach in B16 mouse melanoma and evaluated the impact of exposure temperature, frequency, and interval on the inhibition of re-challenged melanoma growth. The therapeutic protocol against the primary transplanted tumor with or without AMF exposure once a day every other day for a total of three treatments not only inhibited the growth of the primary transplant but also prevented the growth of the secondary, re-challenge transplant. The heat-generated therapeutic effect was more significant at a temperature of 43∘C than either 41∘C or 46∘C. NPrCAP/M with AMF exposure, instead of control magnetite alone or without AMF exposure, resulted in the most significant growth inhibition of the re-challenge tumor and increased the life span of the mice. HSP70 production was greatest at 43∘C compared to that with 41∘C or 46∘C. CD+T cells were infiltrated at the site of the re-challenge melanoma transplant.

  13. Targeting π-conjugated multiple donor-acceptor motifs exemplified by tetrathiafulvalene-linked quinoxalines and tetrabenz[bc,ef,hi,uv]ovalenes: synthesis, spectroscopic, electrochemical, and theoretical characterization.

    Science.gov (United States)

    Jia, Hong-Peng; Ding, Jie; Ran, Ying-Fen; Liu, Shi-Xia; Blum, Carmen; Petkova, Irina; Hauser, Andreas; Decurtins, Silvio

    2011-12-02

    An efficient synthetic approach to a symmetrically functionalized tetrathiafulvalene (TTF) derivative with two diamine moieties, 2-[5,6-diamino-4,7-bis(4-pentylphenoxy)-1,3-benzodithiol-2-ylidene]-4,7-bis(4-pentylphenoxy)-1,3-benzodithiole-5,6-diamine (2), is reported. The subsequent Schiff-base reactions of 2 afford large π-conjugated multiple donor-acceptor (D-A) arrays, for example, the triad 2-[4,9-bis(4-pentylphenoxy)-1,3-dithiolo[4,5-g]quinoxalin-2-ylidene]-4,9-bis(4-pentylphenoxy)-1,3-dithiolo[4,5-g]quinoxaline (8) and the corresponding tetrabenz[bc,ef,hi,uv]ovalene-fused pentad 1, in good yields and high purity. The novel redox-active nanographene 1 is so far the largest known TTF-functionalized polycyclic aromatic hydrocarbon (PAH) with a well-resolved (1)H NMR spectrum. The electrochemically highly amphoteric pentad 1 and triad 8 exhibit various electronically excited charge-transfer states in different oxidation states, thus leading to intense optical intramolecular charge-transfer (ICT) absorbances over a wide spectral range. The chemical and electrochemical oxidations of 1 result in an unprecedented TTF(⋅+) radical cation dimerization, thereby leading to the formation of [1(⋅+)](2) at room temperature in solution due to the stabilizing effect, which arises from strong π-π interactions. Moreover, ICT fluorescence is observed with large solvent-dependent Stokes shifts and quantum efficiencies of 0.05 for 1 and 0.035 for 8 in dichloromethane. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Position for Site-Specific Attachment of a DOTA Chelator to Synthetic Affibody Molecules Has a Different Influence on the Targeting Properties of 68Ga-Compared to 111In-Labeled Conjugates

    Directory of Open Access Journals (Sweden)

    Hadis Honarvar

    2014-12-01

    Full Text Available Affibody molecules, small (7 kDa scaffold proteins, are a promising class of probes for radionuclide molecular imaging. Radiolabeling of Affibody molecules with the positron-emitting nuclide 68Ga would permit the use of positron emission tomography (PET, providing better resolution, sensitivity, and quantification accuracy than single-photon emission computed tomography (SPECT. The synthetic anti-HER2 ZHER2:S1 Affibody molecule was conjugated with DOTA at the N-terminus, in the middle of helix 3, or at the C-terminus. The biodistribution of 68Ga- and 111In-labeled Affibody molecules was directly compared in NMRI nu/nu mice bearing SKOV3 xenografts. The position of the chelator strongly influenced the biodistribution of the tracers, and the influence was more pronounced for 68Ga-labeled Affibody molecules than for the 111In-labeled counterparts. The best 68Ga-labeled variant was 68Ga-[DOTA-A1]-ZHER2:S1 which provided a tumor uptake of 13 ± 1 %ID/g and a tumor to blood ratio of 39 ± 12 at 2 hours after injection. 111In-[DOTA-A1]-ZHER2:S1 and 111In-[DOTA-K58]-ZHER2:S1 were equally good at this time point, providing a tumor uptake of 15 to 16 %ID/g and a tumor to blood ratio in the range of 60 to 80. In conclusion, the selection of the best position for a chelator in Affibody molecules can be used for optimization of their imaging properties. This may be important for the development of Affibody-based and other protein-based imaging probes.

  15. Synthesis and Spectral Studies of CdTe–Dendrimer Conjugates

    Directory of Open Access Journals (Sweden)

    Ghosh Srabanti

    2009-01-01

    Full Text Available Abstract In order to couple high cellular uptake and target specificity of dendrimer molecule with excellent optical properties of semiconductor nanoparticles, the interaction of cysteine-capped CdTe quantum dots with dendrimer was investigated through spectroscopic techniques. NH2-terminated dendrimer molecule quenched the photoluminescence of CdTe quantum dots. The binding constants and binding capacity were calculated, and the nature of binding was found to be noncovalent. Significant decrease in luminescence intensity of CdTe quantum dots owing to noncovalent binding with dendrimer limits further utilization of these nanoassemblies. Hence, an attempt is made, for the first time, to synthesize stable, highly luminescent, covalently linked CdTe–Dendrimer conjugate in aqueous medium using glutaric dialdehyde (G linker. Conjugate has been characterized through Fourier transform infrared spectroscopy and transmission electron microscopy. In this strategy, photoluminescence quantum efficiency of CdTe quantum dots with narrow emission bandwidths remained unaffected after formation of the conjugate.

  16. Synthesis and Spectral Studies of CdTe-Dendrimer Conjugates

    Science.gov (United States)

    Ghosh, Srabanti; Saha, Abhijit

    2009-08-01

    In order to couple high cellular uptake and target specificity of dendrimer molecule with excellent optical properties of semiconductor nanoparticles, the interaction of cysteine-capped CdTe quantum dots with dendrimer was investigated through spectroscopic techniques. NH2-terminated dendrimer molecule quenched the photoluminescence of CdTe quantum dots. The binding constants and binding capacity were calculated, and the nature of binding was found to be noncovalent. Significant decrease in luminescence intensity of CdTe quantum dots owing to noncovalent binding with dendrimer limits further utilization of these nanoassemblies. Hence, an attempt is made, for the first time, to synthesize stable, highly luminescent, covalently linked CdTe-Dendrimer conjugate in aqueous medium using glutaric dialdehyde (G) linker. Conjugate has been characterized through Fourier transform infrared spectroscopy and transmission electron microscopy. In this strategy, photoluminescence quantum efficiency of CdTe quantum dots with narrow emission bandwidths remained unaffected after formation of the conjugate.

  17. Recent advances in the construction of antibody-drug conjugates

    Science.gov (United States)

    Chudasama, Vijay; Maruani, Antoine; Caddick, Stephen

    2016-02-01

    Antibody-drug conjugates (ADCs) comprise antibodies covalently attached to highly potent drugs using a variety of conjugation technologies. As therapeutics, they combine the exquisite specificity of antibodies, enabling discrimination between healthy and diseased tissue, with the cell-killing ability of cytotoxic drugs. This powerful and exciting class of targeted therapy has shown considerable promise in the treatment of various cancers with two US Food and Drug Administration approved ADCs currently on the market (Adcetris and Kadcyla) and approximately 40 currently undergoing clinical evaluation. However, most of these ADCs exist as heterogeneous mixtures, which can result in a narrow therapeutic window and have major pharmacokinetic implications. In order for ADCs to deliver their full potential, sophisticated site-specific conjugation technologies to connect the drug to the antibody are vital. This Perspective discusses the strategies currently used for the site-specific construction of ADCs and appraises their merits and disadvantages.

  18. Tocilizumab - Alendronate Conjugate for Treatment of Rheumatoid Arthritis.

    Science.gov (United States)

    Lee, Hwiwon; Bhang, Suk Ho; Lee, Jeong Ho; Kim, Hyemin; Hahn, Sei Kwang

    2017-01-20

    An autoimmune disease of rheumatoid arthritis (RA) causes severe inflammation on the synovial membrane, which results in the destruction of articular cartilage and bone. Here, Tocilizumab (TCZ) - Alendronate (ALD) conjugate is synthesized for the early intervention of RA. A humanized monoclonal antibody of TCZ shows an immunosuppressive effect, targeting interleukin-6 (IL-6) receptor in the RA pathogenesis. ALD is an anti-inflammatory bisphosphonate drug which can bind to the exposed bone surface. ALD is conjugated selectively to N-glycan on Fc region of TCZ using a chemical linker of 3-(2-pyridyldithio) propionyl hydrazide (PDPH) - poly(ethylene glycol) - N-hydroxysuccinimide (PDPH-PEG-NHS). The successful synthesis of TCZ-ALD conjugate is corroborated by 1H NMR, the purpald assay, mass spectrometry (MS), and high performance liquid chromatography (HPLC). In vitro binding affinity and cell viability tests confirmed the biological activity of TCZ-ALD conjugate. Furthermore, in vivo efficacy of TCZ-ALD conjugate is confirmed by micro computed tomography (CT), histological, and western blot analyses for the treatment of RA.

  19. Preparation of Conjugates of Cytotoxic Lupane Triterpenes with Biotin.

    Science.gov (United States)

    Soural, Miroslav; Hodon, Jiri; Dickinson, Niall J; Sidova, Veronika; Gurska, Sona; Dzubak, Petr; Hajduch, Marian; Sarek, Jan; Urban, Milan

    2015-12-16

    To better understand the mechanism of action of antitumor triterpenes, we are developing methods to identify their molecular targets. A promising method is based on combination of quantitative proteomics with SILAC and uses active compounds anchored to magnetic beads via biotin-streptavidin interaction. We developed a simple and fast solid-phase synthetic technique to connect terpenes to biotin through a linker. Betulinic acid was biotinylated from three different conjugation sites for use as a standard validation tool since many molecular targets of this triterpene are already known. Then, a set of four other cytotoxic triterpenoids was biotinylated. Biotinylated terpenes were similarly cytotoxic to their nonbiotinylated parents, which suggests that the target identification should not be influenced by linker or biotin. The developed solid-phase synthetic approach is the first attempt to use solid-phase synthesis to connect active triterpenes to biotin and is applicable as a general procedure for routine conjugation of triterpenes with other molecules of choice.

  20. Research study of conjugate materials; Conjugate material no chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper reported an introductory research on possibilities of new glass `conjugate materials.` The report took up the structure and synthetic process of conjugate materials to be researched/developed, classified them according to structural elements on molecular, nanometer and cluster levels, and introduced the structures and functions. Further, as glasses with new functions to be proposed, the paper introduced transparent and high-strength glass used for houses and vehicles, light modulation glass which realizes energy saving and optical data processing, and environmentally functional glass which realizes environmental cleaning or high performance biosensor. An initial survey was also conducted on rights of intellectual property to be taken notice of in Japan and abroad in the present situation. Reports were summed up and introduced of Osaka National Research Institute, Electrotechnical Laboratory, and National Industrial Research Institute of Nagoya which are all carrying out leading studies of conjugate materials. 235 refs., 135 figs., 6 tabs.

  1. Solution Structure and Constrained Molecular Dynamics Study of Vitamin B12 Conjugates of the Anorectic Peptide PYY(3-36).

    Science.gov (United States)

    Henry, Kelly E; Kerwood, Deborah J; Allis, Damian G; Workinger, Jayme L; Bonaccorso, Ron L; Holz, George G; Roth, Christian L; Zubieta, Jon; Doyle, Robert P

    2016-05-06

    Vitamin B12 -peptide conjugates have considerable therapeutic potential through improved pharmacokinetic and/or pharmacodynamic properties imparted on the peptide upon covalent attachment to vitamin B12 (B12 ). There remains a lack of structural studies investigating the effects of B12 conjugation on peptide secondary structure. Determining the solution structure of a B12 -peptide conjugate or conjugates and measuring functions of the conjugate(s) at the target peptide receptor may offer considerable insight concerning the future design of fully optimized conjugates. This methodology is especially useful in tandem with constrained molecular dynamics (MD) studies, such that predictions may be made about conjugates not yet synthesized. Focusing on two B12 conjugates of the anorectic peptide PYY(3-36), one of which was previously demonstrated to have improved food intake reduction compared with PYY(3-36), we performed NMR structural analyses and used the information to conduct MD simulations. The study provides rare structural insight into vitamin B12 conjugates and validates the fact that B12 can be conjugated to a peptide without markedly affecting peptide secondary structure.

  2. Conjugated polymer nanoparticles, methods of using, and methods of making

    KAUST Repository

    Habuchi, Satoshi

    2017-03-16

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  3. Cysteine-containing peptide tag for site-specific conjugation of proteins

    Science.gov (United States)

    Backer, Marina V.; Backer, Joseph M.

    2008-04-08

    The present invention is directed to a biological conjugate, comprising: (a) a targeting moiety comprising a polypeptide having an amino acid sequence comprising the polypeptide sequence of SEQ ID NO:2 and the polypeptide sequence of a selected targeting protein; and (b) a binding moiety bound to the targeting moiety; the biological conjugate having a covalent bond between the thiol group of SEQ ID NO:2 and a functional group in the binding moiety. The present invention is directed to a biological conjugate, comprising: (a) a targeting moiety comprising a polypeptide having an amino acid sequence comprising the polypeptide sequence of SEQ ID NO:2 and the polypeptide sequence of a selected targeting protein; and (b) a binding moiety that comprises an adapter protein, the adapter protein having a thiol group; the biological conjugate having a disulfide bond between the thiol group of SEQ ID NO:2 and the thiol group of the adapter protein. The present invention is also directed to biological sequences employed in the above biological conjugates, as well as pharmaceutical preparations and methods using the above biological conjugates.

  4. Conjugate Gradient with Subspace Optimization

    CERN Document Server

    Karimi, Sahar

    2012-01-01

    In this paper we present a variant of the conjugate gradient (CG) algorithm in which we invoke a subspace minimization subproblem on each iteration. We call this algorithm CGSO for "conjugate gradient with subspace optimization". It is related to earlier work by Nemirovsky and Yudin. We apply the algorithm to solve unconstrained strictly convex problems. As with other CG algorithms, the update step on each iteration is a linear combination of the last gradient and last update. Unlike some other conjugate gradient methods, our algorithm attains a theoretical complexity bound of $O(\\sqrt{L/l} \\log(1/\\epsilon))$, where the ratio $L/l$ characterizes the strong convexity of the objective function. In practice, CGSO competes with other CG-type algorithms by incorporating some second order information in each iteration.

  5. Persistence Mechanisms of Conjugative Plasmids

    DEFF Research Database (Denmark)

    Bahl, Martin Iain; Hansen, Lars H.; Sørensen, Søren Johannes

    2009-01-01

    Are plasmids selfish parasitic DNA molecules or an integrated part of the bacterial genome? This chapter reviews the current understanding of the persistence mechanisms of conjugative plasmids harbored by bacterial cells and populations. The diversity and intricacy of mechanisms affecting...... the successful propagation and long-term continued existence of these extra-chromosomal elements is extensive. Apart from the accessory genetic elements that may provide plasmid-harboring cells a selective advantage, special focus is placed on the mechanisms conjugative plasmids employ to ensure their stable...... maintenance in the host cell. These importantly include the ability to self-mobilize in a process termed conjugative transfer, which may occur across species barriers. Other plasmid stabilizing mechanisms include the multimer resolution system, active partitioning, and post-segregational-killing of plasmid...

  6. Conjugated linoleic acid isomers and their precursor fatty acids regulate peroxisome proliferator-activated receptor subtypes and major peroxisome proliferator responsive element-bearing target genes in HepG2 cell model

    Institute of Scientific and Technical Information of China (English)

    Sailas BENJAMIN; Silke FLOTHO; Torsten B(O)RCHERS; Friedrich SPENER

    2013-01-01

    The purpose of this study was to examine the induction profiles(as judged by quantitative reverse transcription polymerase chain reaction(qRT-PCR))of peroxisome proliferator-activated receptor(PPAR)α,β,Y subtypes and major PPAR-target genes bearing a functional peroxisome proliferator responsive element(PPRE)in HepG2 cell model upon feeding with cis-9,trans-11-octadecadienoic acid(9-CLA)or trans-10,cis-12-octadecadienoic acid (10-CLA)or their precursor fatty acids(FAs).HepG2 cells were treated with 100 μmol/L 9-CLA or 10-CLA or their precursor FAs,viz.,oleic,linoleic,and trans-11-vaccenic acids against bezafibrate control to evaluate the induction/expression profiles of PPAR α,β,Y subtypes and major PPAR-target genes bearing a functional PPRE,i.e.,fatty acid transporter(FAT),glucose transporter-2(GLUT-2),liver-type FA binding protein(L-FABP),acyl CoA oxidase-1 (ACOX-1),and peroxisomal bifunctional enzyme(PBE)with reference to β-actin as house keeping gene.Of the three housekeeping genes(glyceraldehyde 3-phosphate dehydrogenase(GAPDH),β-actin,and ubiquitin),β-actin was found to be stable.Dimethyl sulfoxide(DMSO),the common solubilizer of agonists,showed a significantly higher induction of genes analyzed.qRT-PCR profiles of CLAs and their precursor FAs clearly showed upregulation of FAT,GLUT-2,and L-FABP(~0.5-2.0-fold).Compared to 10-CLA,9-CLA decreased the induction of the FA metabolizing gene ACOX-1 less than did PBE,while 10-CLA decreased the induction of PBE less than did ACOX-1.Both CLAs and precursor FAs upregulated PPRE-bearing genes,but with comparatively less or marginal activation of PPAR subtypes.This indicates that the binding of CLAs and their precursor FAs to PPAR subtypes results in PPAR activation,thereby induction of the target transporter genes coupled with downstream lipid metabolising genes such as ACOX-1 and PBE.To sum up,the expression profiles of these candidate genes showed that CLAs and their precursor FAs are involved in lipid

  7. Gold Nanorod Bioconjugates for Active Tumor Targeting and Photothermal Therapy

    OpenAIRE

    Green, Hadiyah N; Martyshkin, Dmitry V; Rodenburg, Cynthia M.; Rosenthal, Eben L.; Mirov, Sergey B.

    2011-01-01

    The mastery of active tumor targeting is a great challenge in near infrared photothermal therapy (NIRPTT). To improve efficiency for targeted treatment of malignant tumors, we modify the technique of conjugating gold nanoparticles to tumor-specific antibodies. Polyethylene glycol-coated (PEGylated) gold nanorods (GNRs) were fabricated and conjugated to an anti-EGFR antibody. We characterized the conjugation efficiency of the GNRs by comparing the efficiency of antibody binding and the phototh...

  8. Hypercube Solutions for Conjugate Directions

    Science.gov (United States)

    1991-12-01

    alternative term that emphasizes the role of A in this definition. We also say that x and y are A-orthogonal. [Ref. 18: p. 410] The method of conjugate...conjugate (A-orthogonal). begin CG u0 =zeros(n) (arbitrary initial guess) Po = r0 = b- Auo for i = 0 : n = pTAp , (denominator used below) ai = (pTri...application, it could characterize water or chemical penetration in soil. We shall continue to use the term "heat equation", though, for the sake of

  9. Aptamer conjugated magnetic nanoparticles as nanosurgeons

    Science.gov (United States)

    Nair, Baiju G.; Nagaoka, Yutaka; Morimoto, Hisao; Yoshida, Yasuhiko; Maekawa, Toru; Sakthi Kumar, D.

    2010-11-01

    Magnetic nanoparticles have shown promise in the fields of targeted drug delivery, hyperthermia and magnetic resonance imaging (MRI) in cancer therapy. The ability of magnetic nanoparticles to undergo surface modification and the effect of external magnetic field in the dynamics of their movement make them an excellent nanoplatform for cancer destruction. Surgical removal of cancerous or unwanted cells selectively from the interior of an organ or tissue without any collateral damage is a serious problem due to the highly infiltrative nature of cancer. To address this problem in surgery, we have developed a nanosurgeon for the selective removal of target cells using aptamer conjugated magnetic nanoparticles controlled by an externally applied three-dimensional rotational magnetic field. With the help of the nanosurgeon, we were able to perform surgical actions on target cells in in vitro studies. LDH and intracellular calcium release assay confirmed the death of cancer cells due to the action of the nanosurgeon which in turn nullifies the possibility of proliferation by the removed cells. The nanosurgeon will be a useful tool in the medical field for selective surgery and cell manipulation studies. Additionally, this system could be upgraded for the selective removal of complex cancers from diverse tissues by incorporating various target specific ligands on magnetic nanoparticles.

  10. High-conjugation-efficiency aqueous CdSe quantum dots.

    Science.gov (United States)

    Au, Giang H T; Shih, Wan Y; Shih, Wei-Heng

    2013-11-12

    Quantum dots (QDs) are photoluminescent nanoparticles that can be directly or indirectly coupled with a receptor such as an antibody to specifically image a target biomolecule such as an antigen. Recent studies have shown that QDs can be directly made at room temperature and in an aqueous environment (AQDs) with 3-mercaptopropionic acid (MPA) as the capping ligand without solvent and ligand exchange typically required by QDs made by the organic solvent routes (OQDs). In this study, we have synthesized CdSe AQDs and compared their conjugation efficiency and imaging efficacy with commercial carboxylated OQDs in HT29 colon cancer cells using a primary antibody-biotinylated secondary antibody-streptavidin (SA) sandwich. We showed that the best imaging condition for AQDs occurred when one AQD was bound with 3 ± 0.3 SA with a nominal SA/AQD ratio of 4 corresponding to an SA conjugation efficiency of 75 ± 7.5%. In comparison, for commercial CdSe-ZnS OQDs to achieve 2.7 ± 0.4 bound SAs per OQD for comparable imaging efficacy a nominal SA/OQD ratio of 80 was needed corresponding to an SA conjugation efficiency of 3.4 ± 0.5% for CdSe-ZnS OQDs. The more than 10 times better SA conjugation efficiency of the CdSe AQDs as compared to that of the CdSe-ZnS OQDs was attributed to more capping molecules on the AQD surface as a result of the direct aqueous synthesis. More capping molecules on the AQD surface also allowed the SA-AQD conjugate to be stable in cell culture medium for more than three days without losing their staining capability in a flowing cell culture medium. In contrast, SA-OQD conjugates aggregated in cell culture medium and in phosphate buffer saline solution over time.

  11. On contravariant product conjugate connections

    Directory of Open Access Journals (Sweden)

    A. M. Blaga

    2012-02-01

    Full Text Available Invariance properties for the covariant and contravariant connections on a Riemannian manifold with respect to an almost product structure are stated. Restricting to a distribution of the contravariant connections is also discussed. The particular case of the conjugate connection is investigated and properties of the extended structural and virtual tensors for the contravariant connections are given.

  12. Actinomycete integrative and conjugative elements

    NARCIS (Netherlands)

    Poele, Evelien M. te; Bolhuis, Henk; Dijkhuizen, Lubbert

    2008-01-01

    This paper reviews current knowledge on actinomycete integrative and conjugative elements (AICEs). The best characterised AICEs, pSAM2 of Streptomyces ambofaciens (10.9 kb), SLP1 (17.3 kb) of Streptomyces coelicolor and pMEA300 of Amycolatopsis methanolica (13.3 kb), are present as integrative eleme

  13. Bio-degradable highly fluorescent conjugated polymer nanoparticles for bio-medical imaging applications.

    Science.gov (United States)

    Repenko, Tatjana; Rix, Anne; Ludwanowski, Simon; Go, Dennis; Kiessling, Fabian; Lederle, Wiltrud; Kuehne, Alexander J C

    2017-09-07

    Conjugated polymer nanoparticles exhibit strong fluorescence and have been applied for biological fluorescence imaging in cell culture and in small animals. However, conjugated polymer particles are hydrophobic and often chemically inert materials with diameters ranging from below 50 nm to several microns. As such, conjugated polymer nanoparticles cannot be excreted through the renal system. This drawback has prevented their application for clinical bio-medical imaging. Here, we present fully conjugated polymer nanoparticles based on imidazole units. These nanoparticles can be bio-degraded by activated macrophages. Reactive oxygen species induce scission of the conjugated polymer backbone at the imidazole unit, leading to complete decomposition of the particles into soluble low molecular weight fragments. Furthermore, the nanoparticles can be surface functionalized for directed targeting. The approach opens a wide range of opportunities for conjugated polymer particles in the fields of medical imaging, drug-delivery, and theranostics.Conjugated polymer nanoparticles have been applied for biological fluorescence imaging in cell culture and in small animals, but cannot readily be excreted through the renal system. Here the authors show fully conjugated polymer nanoparticles based on imidazole units that can be bio-degraded by activated macrophages.

  14. Glutathione conjugation as a bioactivation reaction

    NARCIS (Netherlands)

    Bladeren, P.J. van

    2000-01-01

    In general, glutathione conjugation is regarded as a detoxication reaction. However, depending on the properties of the substrate, bioactivation is also possible. Four types of activation reaction have been recognized: direct-acting compounds, conjugates that are activated through cysteine conjugate

  15. Glutathione conjugation as a bioactivation reaction

    NARCIS (Netherlands)

    Bladeren, P.J. van

    2000-01-01

    In general, glutathione conjugation is regarded as a detoxication reaction. However, depending on the properties of the substrate, bioactivation is also possible. Four types of activation reaction have been recognized: direct-acting compounds, conjugates that are activated through cysteine conjugate

  16. Bacteriophytochromes control conjugation in Agrobacterium fabrum.

    Science.gov (United States)

    Bai, Yingnan; Rottwinkel, Gregor; Feng, Juan; Liu, Yiyao; Lamparter, Tilman

    2016-08-01

    Bacterial conjugation, the transfer of single stranded plasmid DNA from donor to recipient cell, is mediated through the type IV secretion system. We performed conjugation assays using a transmissible artificial plasmid as reporter. With this assay, conjugation in Agrobacterium fabrum was modulated by the phytochromes Agp1 and Agp2, photoreceptors that are most sensitive in the red region of visible light. In conjugation studies with wild-type donor cells carrying a pBIN-GUSINT plasmid as reporter that lacked the Ti (tumor inducing) plasmid, no conjugation was observed. When either agp1(-) or agp2(-) knockout donor strains were used, plasmid DNA was delivered to the recipient, indicating that both phytochromes suppress conjugation in the wild type donor. In the recipient strains, the loss of Agp1 or Agp2 led to diminished conjugation. When wild type cells with Ti plasmid and pBIN-GUS reporter plasmid were used as donor, a high rate of conjugation was observed. The DNA transfer was down regulated by red or far-red light by a factor of 3.5. With agp1(-) or agp2(-) knockout donor cells, conjugation in the dark was about 10 times lower than with the wild type donor, and with the double knockout donor no conjugation was observed. These results imply that the phytochrome system has evolved to inhibit conjugation in the light. The decrease of conjugation under different temperature correlated with the decrease of phytochrome autophosphorylation.

  17. Thermal Stability of siRNA Modulates Aptamer- conjugated siRNA Inhibition

    Directory of Open Access Journals (Sweden)

    Alexey Berezhnoy

    2012-01-01

    Full Text Available Oligonucleotide aptamer-mediated in vivo cell targeting of small interfering RNAs (siRNAs is emerging as a useful approach to enhance the efficacy and reduce the adverse effects resulting from siRNA-mediated genetic interference. A current main impediment in aptamer-mediated siRNA targeting is that the activity of the siRNA is often compromised when conjugated to an aptamer, often requiring labor intensive and time consuming design and testing of multiple configurations to identify a conjugate in which the siRNA activity has not been significantly reduced. Here, we show that the thermal stability of the siRNA is an important parameter of siRNA activity in its conjugated form, and that siRNAs with lower melting temperature (Tm are not or are minimally affected when conjugated to the 3′ end of 2′F-pyrimidine-modified aptamers. In addition, the configuration of the aptamer-siRNA conjugate retains activity comparable with the free siRNA duplex when the passenger strand is co-transcribed with the aptamer and 3′ overhangs on the passenger strand are removed. The approach described in this paper significantly reduces the time and effort necessary to screening siRNA sequences that retain biological activity upon aptamer conjugation, facilitating the process of identifying candidate aptamer-siRNA conjugates suitable for in vivo testing.

  18. Polymer-Drug Conjugates: Recent Development in Clinical Oncology

    OpenAIRE

    Li, Chun; Wallace, Sidney

    2008-01-01

    Targeted drug delivery aims to increase the therapeutic index by making more drug molecules available at the diseased sites while reducing systemic drug exposure. In this update, we provide an overview of polymer-drug conjugates that have advanced into the clinical trials. These systems use synthetic water-soluble polymers as the drug carriers. The preclinical pharmacology and recent data in clinical trials with poly(L-glutamic acid)-paclitaxel (PG-TXL) are discussed first. This is followed b...

  19. Linkers Having a Crucial Role in Antibody–Drug Conjugates

    OpenAIRE

    Jun Lu; Feng Jiang; Aiping Lu; Ge Zhang

    2016-01-01

    Antibody–drug conjugates (ADCs) comprised of a desirable monoclonal antibody, an active cytotoxic drug and an appropriate linker are considered to be an innovative therapeutic approach for targeted treatment of various types of tumors and cancers, enhancing the therapeutic parameter of the cytotoxic drug and reducing the possibility of systemic cytotoxicity. An appropriate linker between the antibody and the cytotoxic drug provides a specific bridge, and thus helps the antibody to selectively...

  20. Double phase conjugation in tungsten bronze crystals.

    Science.gov (United States)

    Sharp, E J; Clark Iii, W W; Miller, M J; Wood, G L; Monson, B; Salamo, G J; Neurgaonkar, R R

    1990-02-20

    In this paper we report a new method for double phase conjugation particularly suited to the tungsten bronze crystal strontium barium niobate. It has also been observed to produce conjugate waves in BaTiO(3) and BSKNN. This new arrangement is called the bridge conjugator because the two beams enter opposing [100] crystal faces and fan together to form a bridge without reflection off a crystal face. Our measurements indicate that the bridge conjugator is competitive with previously reported double phase conjugate mirrors in reflectivity, response time, ease of alignment, and fidelity.

  1. Conjugative plasmids of Neisseria gonorrhoeae.

    Directory of Open Access Journals (Sweden)

    Emilia Pachulec

    Full Text Available Many clinical isolates of the human pathogen Neisseria gonorrhoeae contain conjugative plasmids. The host range of these plasmids is limited to Neisseria species, but presence of a tetracycline (tetM determinant inserted in several of these plasmids is an important cause of the rapid spread of tetracycline resistance. Previously plasmids with different backbones (Dutch and American type backbones and with and without different tetM determinants (Dutch and American type tetM determinants have been identified. Within the isolates tested, all plasmids with American or Dutch type tetM determinants contained a Dutch type plasmid backbone. This demonstrated that tetM determinants should not be used to differentiate between conjugal plasmid backbones. The nucleotide sequences of conjugative plasmids with Dutch type plasmid backbones either not containing the tetM determinant (pEP5233 or containing Dutch (pEP5289 or American (pEP5050 type tetM determinants were determined. Analysis of the backbone sequences showed that they belong to a novel IncP1 subfamily divergent from the IncP1alpha, beta, gamma, delta and epsilon subfamilies. The tetM determinants were inserted in a genetic load region found in all these plasmids. Insertion was accompanied by the insertion of a gene with an unknown function, and rearrangement of a toxin/antitoxin gene cluster. The genetic load region contains two toxin/antitoxins of the Zeta/Epsilon toxin/antitoxin family previously only found in Gram positive organisms and the virulence associated protein D of the VapD/VapX toxin/antitoxin family. Remarkably, presence of VapX of pJD1, a small cryptic neisserial plasmid, in the acceptor strain strongly increased the conjugation efficiency, suggesting that it functions as an antitoxin for the conjugative plasmid. The presence of the toxin and antitoxin on different plasmids might explain why the host range of this IncP1 plasmid is limited to Neisseria species. The isolated plasmids

  2. Fullerene–biomolecule conjugates and their biomedicinal applications

    Directory of Open Access Journals (Sweden)

    Yang X

    2013-12-01

    Full Text Available Xinlin Yang,1 Ali Ebrahimi,1 Jie Li,1,2 Quanjun Cui11Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, VA, USA; 2School of Materials Science, Beijing Institute of Technology, Beijing, People's Republic of ChinaAbstract: Fullerenes are among the strongest antioxidants and are characterized as "radical sponges." The research on biomedicinal applications of fullerenes has achieved significant progress since the landmark publication by Friedman et al in 1993. Fullerene–biomolecule conjugates have become an important area of research during the past 2 decades. By a thorough literature search, we attempt to update the information about the synthesis of different types of fullerene–biomolecule conjugates, including fullerene-containing amino acids and peptides, oligonucleotides, sugars, and esters. Moreover, we also discuss in this review recently reported data on the biological and pharmaceutical utilities of these compounds and some other fullerene derivatives of biomedical importance. While within the fullerene–biomolecule conjugates, in which fullerene may act as both an antioxidant and a carrier, specific targeting biomolecules conjugated to fullerene will undoubtedly strengthen the delivery of functional fullerenes to sites of clinical interest.Keywords: fullerene, amino acid, peptide, oligonucleotide, sugar, ester

  3. Intein-mediated site-specific conjugation of Quantum Dots to proteins in vivo

    Directory of Open Access Journals (Sweden)

    Skourides Paris A

    2009-12-01

    Full Text Available Abstract We describe an intein based method to site-specifically conjugate Quantum Dots (QDs to target proteins in vivo. This approach allows the covalent conjugation of any nanostructure and/or nanodevice to any protein and thus the targeting of such material to any intracellular compartment or signalling complex within the cells of the developing embryo. We genetically fused a pleckstrin-homology (PH domain with the N-terminus half of a split intein (IN. The C-terminus half (IC of the intein was conjugated to QDs in vitro. IC-QD's and RNA encoding PH-IN were microinjected into Xenopus embryos. In vivo intein-splicing resulted in fully functional QD-PH conjugates that could be monitored in real time within live embryos. Use of Near Infra Red (NIR-emitting QDs allowed monitoring of QD-conjugates within the embryo at depths where EGFP is undetectable demonstrating the advantages of QD's for this type of experiment. In conclusion, we have developed a novel in vivo methodology for the site-specific conjugation of QD's and other artificial structures to target proteins in different intracellular compartments and signaling complexes.

  4. Biological characterization of cetuximab-conjugated gold nanoparticles in a tumor animal model.

    Science.gov (United States)

    Kao, Hao-Wen; Lin, Yi-Yu; Chen, Chao-Cheng; Chi, Kwan-Hwa; Tien, Der-Chi; Hsia, Chien-Chung; Lin, Wuu-Jyh; Chen, Fu-Du; Lin, Ming-Hsien; Wang, Hsin-Ell

    2014-07-25

    Gold nanoparticles (AuNPs) are widely applied to the diagnosis and treatment of cancer and can be modified to contain target-specific ligands via gold-thiolate bonding. This study investigated the pharmacokinetics and microdistribution of antibody-mediated active targeting gold nanoparticles in mice with subcutaneous lung carcinoma. We conjugated AuNPs with cetuximab (C225), an antibody-targeting epidermal growth factor receptor (EGFR), and then labeled with In-111, which created EGFR-targeted AuNPs. In vitro studies showed that after a 2 h incubation, the uptake of C225-conjugated AuNPs in high EGFR-expression A549 cells was 14.9-fold higher than that of PEGylated AuNPs; furthermore, uptake was also higher at 3.8-fold when MCF7 cells with lower EGFR-expression were used. MicroSPECT/CT imaging and a biodistribution study conducted by using a A549 tumor xenograft mouse model provided evidence of elevated uptake of the C225-conjugated AuNPs into the tumor cells as a result of active targeting. Moreover, the microdistribution of PEGylated AuNPs revealed that a large portion of AuNPs remained in the tumor interstitium, whereas the C225-conjugated AuNPs displayed enhanced internalization via antibody-mediated endocytosis. Our findings suggest that the anti-EGFR antibody-conjugated AuNPs are likely to be a plausible nano-sized vehicle for drug delivery to EGFR-expressing tumors.

  5. Fiber bundle phase conjugate mirror

    Science.gov (United States)

    Ward, Benjamin G.

    2012-05-01

    An improved method and apparatus for passively conjugating the phases of a distorted wavefronts resulting from optical phase mismatch between elements of a fiber laser array are disclosed. A method for passively conjugating a distorted wavefront comprises the steps of: multiplexing a plurality of probe fibers and a bundle pump fiber in a fiber bundle array; passing the multiplexed output from the fiber bundle array through a collimating lens and into one portion of a non-linear medium; passing the output from a pump collection fiber through a focusing lens and into another portion of the non-linear medium so that the output from the pump collection fiber mixes with the multiplexed output from the fiber bundle; adjusting one or more degrees of freedom of one or more of the fiber bundle array, the collimating lens, the focusing lens, the non-linear medium, or the pump collection fiber to produce a standing wave in the non-linear medium.

  6. Conjugated Polymers for Energy Production

    DEFF Research Database (Denmark)

    Livi, Francesco

    arylation (DAr) and direct arylation polymerization (DArP) have been applied to the preparation of PPDTBT, making this polymer readily available in only 4 synthetic steps and thus easily transferable to a large scale-production setup. DArP avoids organometallic species and therefore is an appealing......This dissertation is aimed at developing materials for flexible, large area, ITO-free polymer solar cells (PSCs) fully printed under ambient conditions. A large screening of conjugated polymers, both novel and well-known materials, has been carried out in order to find suitable candidates...... for scalable PSCs fully printed under ambient conditions [Adv. Energy Mater. 2015, 5, 1402186]. PPDTBT resulted to be the conjugated polymer with the best photovoltaic performance within the 104 synthesized macromolecules. Therefore, further studies have been done on such material. The impact of side chain...

  7. Conjugated polyelectrolytes fundamentals and applications

    CERN Document Server

    Liu, Bin

    2013-01-01

    This is the first monograph to specifically focus on fundamentals and applications of polyelectrolytes, a class of molecules that gained substantial interest due to their unique combination of properties. Combining both features of organic semiconductors and polyelectrolytes, they offer a broad field for fundamental research as well as applications to analytical chemistry, optical imaging, and opto-electronic devices. The initial chapters introduce readers to the synthesis, optical and electrical properties of various conjugated polyelectrolytes. This is followed by chapters on the applica

  8. Targeted tumor radiotherapy

    Directory of Open Access Journals (Sweden)

    Unak Perihan

    2002-01-01

    Full Text Available Targeted tumor radiotherapy is selectively delivery of curative doses of radiation to malignant sites. The aim of the targeted tumor radiotherapy is to use the radionuclides which have high LET particle emissions conjugated to appropriate carrier molecules. The radionuclides are selectively collected by tumor cells, depositing lethal doses to tumor cells while no admission occur to normal cells. In theory, targeted radiotherapy has several advantages over conventional radiotherapy since it allows a high radiation dose to be administered without causing normal tissue toxicity, although there are some limitations in the availability of appropriate targeting agents and in the calculations of administered doses. Therefore, for routine clinical applications more progress is still needed. In this article, the potential use of targeted tumor radiotherapy is briefly reviewed. More general aspects and considerations, such as potential radionuclides, mechanisms of tumor targeting was also outlined.

  9. Cytotoxicity analysis of gold nanorods conjugated with dual-target inhibitors on humant-riple negative breast cancer cell%偶联双基因靶点的多功能金纳米颗粒对三阴性乳腺癌细胞的毒性分析

    Institute of Scientific and Technical Information of China (English)

    李冰馨; 赵宁; 傅深

    2015-01-01

    目的::设计并构建偶联双基因靶点的多功能金纳米棒颗粒(TKI-258-pGNRs@mSiO2-RGD),并探讨该多功能金纳米棒颗粒对人三阴性乳腺癌MDA-MB-231细胞的细胞毒性,初步明确该新型多功能金纳米棒颗粒在体外实验中所需的剂量范围。方法:运用种子介导生长法制备金纳米棒,以改良的奥伯法对其表面进行介孔二氧化硅包裹,通过表面修饰偶联整合素αvβ3和表皮生长因子受体( VEGFR )的特异性抑制剂RGD和TKI-258,采用紫外分光光度计和透射电镜对其特征进行检测。以不同浓度(0、12.5、25、50、100、200μg/ml)多功能金纳米棒颗粒孵育人三阴性乳腺癌MDA-MB-231细胞株,采用CCK-8法检测细胞增殖率,并进行细胞毒性评级。结果:多功能金纳米棒颗粒物理状态稳定,吸收峰位于515、860 nm处。偶联的双基因靶点抑制剂TKI-258、RGD分别在360、204 nm 处有特征性吸收峰,药物包封率分别为58.18%±7.13%,57.95%±5.22%,载药率分别为4.26%±0.42%,4.35%±0.79%。不同浓度多功能金纳米棒处理后,细胞增殖率在50%-100%之间,细胞毒性评级为I-II级,0-100μg/ml浓度范围内无细胞毒性。结论:偶联双基因靶点的多功能金纳米棒颗粒( TKI-258-pGNRs@mSiO2-RGD)具有热疗/放疗增敏的特殊光学性质,偶联双基因靶点抑制剂TKI-258、RGD的载药量稳定,生物相容性良好,可作为三阴性乳腺癌细胞特异性靶向的热疗/放疗载药增敏材料。%Objective:Background and objective:The combination of nanotechnology and phototherapy/radiothera-py is a new focus in tumor therapy. Our study design and synthesized multifunctional gold nanoparticles conjugated with dual-target inhibitors( TKI-258-pGNRs@mSiO2-RGD) andanalysis cytotoxicity on human triple negative breast cancer MDA-MB-231 cell lineto preliminary identify the effective dose of multifunctional gold nanoparticles in vitro. Methods:Gold nanorods were synthesized byseed

  10. Uptake of Single-Walled Carbon Nanotubes Conjugated with DNA by Microvascular Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Joseph Harvey

    2012-01-01

    Full Text Available Single-walled carbon nanotubes (SWCNTs have been proposed to have great therapeutic potential. SWCNTs conjugated with drugs or genes travel in the systemic circulation to reach target cells or tissues following extravasation from microvessels although the interaction between SWCNT conjugates and the microvascular endothelial cells (ECs remains unknown. We hypothesized that SWCNT-DNA conjugates would be taken up by microvascular ECs and that this process would be facilitated by SWCNTs compared to facilitation by DNA alone. ECs were treated with various concentrations of SWCNT-DNA-FITC conjugates, and the uptake and intracellular distribution of these conjugates were determined by a confocal microscope imaging system followed by quantitative analysis of fluorescence intensity. The uptake of SWCNT-DNA-FITC conjugates (2 μg/mL by microvascular ECs was significantly greater than that of DNA-FITC (2 μg/mL, observed at 6 hrs after treatment. For the intracellular distribution, SWCNT-DNA-FITC conjugates were detected in the nucleus of ECs, while DNA-FITC was restricted to the cytoplasm. The fluorescence intensity and distribution of SWCNTs were concentration and time independent. The findings demonstrate that SWCNTs facilitate DNA delivery into microvascular ECs, thus suggesting that SWCNTs serving as drug and gene vehicles have therapeutic potential.

  11. Con-A conjugated mucoadhesive microspheres for the colonic delivery of diloxanide furoate.

    Science.gov (United States)

    Anande, Nalini M; Jain, Sunil K; Jain, Narendra K

    2008-07-01

    The aim of the research work was to develop cyst-targeted novel concanavalin-A (Con-A) conjugated mucoadhesive microspheres of diloxanide furoate (DF) for the effective treatment of amoebiasis. Eudragit microspheres of DF were prepared using emulsification-solvent evaporation method. Formulations were characterized for particle size and size distribution, % drug entrapment, surface morphology and in vitro drug release in simulated gastrointestinal (GI) fluids. Eudragit microspheres of DF were conjugated with Con-A. IR spectroscopy and DSC were used to confirm successful conjugation of Con-A to Eudragit microspheres while Con-A conjugated microspheres were further characterized using the parameters of zeta potential, mucoadhesiveness to colonic mucosa and Con-A conjugation efficiency with microspheres. IR studies confirmed the attachment of Con-A with Eudragit microspheres. All the microsphere formulations showed good % drug entrapment (78+/-5%). Zeta potential of Eudragit microspheres and Con-A conjugated Eudragit microspheres were found to be 3.12+/-0.7mV and 16.12+/-0.5mV, respectively. Attachment of lectin to the Eudragit microspheres significantly increases the mucoadhesiveness and also controls the release of DF in simulated GI fluids. Gamma scintigraphy study suggested that Eudragit S100 coated gelatin capsule retarded the release of Con-A conjugated microspheres at low pH and released microspheres slowly at pH 7.4 in the colon.

  12. A novel injectable water-soluble amphotericin B-arabinogalactan conjugate.

    Science.gov (United States)

    Falk, R; Domb, A J; Polacheck, I

    1999-08-01

    New, stable, highly water-soluble, nontoxic polysaccharide conjugates of amphotericin B (AmB) are described. AmB was conjugated by a Schiff-base reaction with oxidized arabinogalactan (AG). AG is a highly branched natural polysaccharide with unusual water solubility (70% in water). A high yield of active AmB was obtained with the conjugates which were similarly highly water soluble and which could be appropriately formulated for injection. They showed comparable MICs for Candida albicans and Cryptococcus neoformans (MICs, 0.1 to 0.2 microg/ml). The reduced AmB conjugate, which was synthesized at pH 11 for 48 h at 37 degrees C, was nonhemolytic and was much safer than conventional micellar AmB-deoxycholate. It was the least toxic AmB-AG conjugate among those tested with mice (maximal tolerated dose, 50 mg/kg of body weight), and histopathology indicated no damage to the liver or kidneys. This conjugate, similarly to the liposomal formulation (AmBisome), was more effective than AmB-deoxycholate in prolonging survival. It was more effective than both the liposomal and the deoxycholate formulations in eradicating yeast cells from target organs. The overall results suggest that after further development of the AmB-AG conjugate, it may be a potent agent in the treatment of fungal infections.

  13. Anti-CD163-dexamethasone conjugate inhibits the acute phase response to lipopolysaccharide in rats

    DEFF Research Database (Denmark)

    Thomsen, Karen Louise; Møller, Holger Jon; Graversen, Jonas Heilskov

    2016-01-01

    AIM: To study the effect of a new anti-CD163-dexamethasone conjugate targeting activated macrophages on the hepatic acute phase response in rats. METHODS: Wistar rats were injected intravenous with either the CD163 targeted dexamethasone-conjugate (0.02 mg/kg) or free dexamethasone (0.02 or 1 mg/...... the hepatic acute phase response to LPS. This indicates an anti-inflammatory potential of the conjugate in vivo.......AIM: To study the effect of a new anti-CD163-dexamethasone conjugate targeting activated macrophages on the hepatic acute phase response in rats. METHODS: Wistar rats were injected intravenous with either the CD163 targeted dexamethasone-conjugate (0.02 mg/kg) or free dexamethasone (0.02 or 1 mg....../kg) 24 h prior to lipopolysaccharide (LPS) (2.5 mg/kg intraperitoneal). We measured plasma concentrations of tumour necrosis factor-α (TNF-α) and interleukin 6 (IL-6) 2 h post-LPS and liver mRNAs and serum concentrations of the rat acute phase protein α-2-macroglobulin (α-2-M) 24 h after LPS. Also...

  14. Characterization and evaluation of amphotericin B loaded MDP conjugated poly(propylene imine) dendrimers.

    Science.gov (United States)

    Jain, Keerti; Verma, Ashwni Kumar; Mishra, Prabhat Ranjan; Jain, Narendra Kumar

    2015-04-01

    This paper describes a novel strategy for targeted delivery of amphotericin B (AmB) to macrophages with muramyl dipeptide (MDP) conjugated multimeric poly(propyleneimine) (PPI) dendrimers. Synergistic antiparasitic activity due to immunostimulation by multimeric presentation of MDP on dendrimers was anticipated. MDP conjugated 5.0G PPI (MdPPI) dendrimers were synthesized and characterized. Therapeutic activity and toxicity of dendrimeric formulation of AmB (MdPPIA) were compared with marketed formulations of AmB. Highly significant (PMDP conjugated dendrimeric formulation of AmB as a promising immunostimulant targeted drug delivery system and a safer alternative to marketed formulations. From the clinical editor: Parasitic infections remain a significant issue in the clinical setting. The authors in this article studied the use of ligand anchored dendrimeric formulation of Amphotericin B to target infected macrophages and showed reduced toxicity, high anti-leishmanial activity. This may add another treatment option to available formulations in the future.

  15. Hypothesis: conjugate vaccines may predispose children to autism spectrum disorders.

    Science.gov (United States)

    Richmand, Brian J

    2011-12-01

    The first conjugate vaccine was approved for use in the US in 1988 to protect infants and young children against the capsular bacteria Haemophilus influenzae type b (Hib). Since its introduction in the US, this vaccine has been approved in most developed countries, including Denmark and Israel where the vaccine was added to their national vaccine programs in 1993 and 1994, respectively. There have been marked increases in the reported prevalence of autism spectrum disorders (ASDs) among children in the US beginning with birth cohorts in the late 1980s and in Denmark and Israel starting approximately 4-5 years later. Although these increases may partly reflect ascertainment biases, an exogenous trigger could explain a significant portion of the reported increases in ASDs. It is hypothesized here that the introduction of the Hib conjugate vaccine in the US in 1988 and its subsequent introduction in Denmark and Israel could explain a substantial portion of the initial increases in ASDs in those countries. The continuation of the trend toward increased rates of ASDs could be further explained by increased usage of the vaccine, a change in 1990 in the recommended age of vaccination in the US from 15 to 2 months, increased immunogenicity of the vaccine through changes in its carrier protein, and the subsequent introduction of the conjugate vaccine for Streptococcus pneumoniae. Although conjugate vaccines have been highly effective in protecting infants and young children from the significant morbidity and mortality caused by Hib and S. pneumoniae, the potential effects of conjugate vaccines on neural development merit close examination. Conjugate vaccines fundamentally change the manner in which the immune systems of infants and young children function by deviating their immune responses to the targeted carbohydrate antigens from a state of hypo-responsiveness to a robust B2 B cell mediated response. This period of hypo-responsiveness to carbohydrate antigens coincides

  16. Chlorambucil conjugates of dinuclear p-cymene ruthenium trithiolato complexes: synthesis, characterization and cytotoxicity study in vitro and in vivo.

    Science.gov (United States)

    Stíbal, David; Therrien, Bruno; Süss-Fink, Georg; Nowak-Sliwinska, Patrycja; Dyson, Paul J; Čermáková, Eva; Řezáčová, Martina; Tomšík, Pavel

    2016-07-01

    Four diruthenium trithiolato chlorambucil conjugates have been prepared via Steglich esterification from chlorambucil and the corresponding trithiolato precursors. All conjugates are highly cytotoxic towards human ovarian A2780 and A2780cisR cancer cell lines with IC50 values in the nanomolar range. The conjugates exhibit selectivity towards A2780 cells as compared to non-cancerous HEK293 cells, while being only slightly selective for RF24 and A2780cisR cells. In vivo, the conjugate [10]BF4 suppressed the growth of a solid Ehrlich tumor in immunocompetent NMRI mice but did not prolong their overall survival. The reactivity of the chlorambucil conjugates with glutathione, a potential target of the dinuclear ruthenium motive, and with the 2-deoxyguanosine 5'-monophosphate (dGMP-a model target of chlorambucil) was studied by mass spectrometry and NMR spectroscopy. The conjugates did not show catalytic activity for the oxidation of glutathione nor binding to nucleotides, indicating that glutathione oxidation and DNA alkylation are not key mechanisms of action. Four highly cytotoxic diruthenium trithiolato chlorambucil conjugates have been prepared. All conjugates exhibit selectivity towards A2780 cells as compared to HEK293 cells, while being only slightly active in RF24 and A2780cisR cells. In vivo, the best candidate suppressed the growth of a solid Ehrlich tumor in immunocompetent NMRI mice but did not prolong their overall survival.

  17. Modelling conjugation with stochastic differential equations.

    Science.gov (United States)

    Philipsen, K R; Christiansen, L E; Hasman, H; Madsen, H

    2010-03-07

    Conjugation is an important mechanism involved in the transfer of resistance between bacteria. In this article a stochastic differential equation based model consisting of a continuous time state equation and a discrete time measurement equation is introduced to model growth and conjugation of two Enterococcus faecium strains in a rich exhaustible media. The model contains a new expression for a substrate dependent conjugation rate. A maximum likelihood based method is used to estimate the model parameters. Different models including different noise structure for the system and observations are compared using a likelihood-ratio test and Akaike's information criterion. Experiments indicating conjugation on the agar plates selecting for transconjugants motivates the introduction of an extended model, for which conjugation on the agar plate is described in the measurement equation. This model is compared to the model without plate conjugation. The modelling approach described in this article can be applied generally when modelling dynamical systems.

  18. In vitro and in vivo evaluation of cysteine and site specific conjugated herceptin antibody-drug conjugates.

    Directory of Open Access Journals (Sweden)

    Dowdy Jackson

    Full Text Available Antibody drug conjugates (ADCs are monoclonal antibodies designed to deliver a cytotoxic drug selectively to antigen expressing cells. Several components of an ADC including the selection of the antibody, the linker, the cytotoxic drug payload and the site of attachment used to attach the drug to the antibody are critical to the activity and development of the ADC. The cytotoxic drugs or payloads used to make ADCs are typically conjugated to the antibody through cysteine or lysine residues. This results in ADCs that have a heterogeneous number of drugs per antibody. The number of drugs per antibody commonly referred to as the drug to antibody ratio (DAR, can vary between 0 and 8 drugs for a IgG1 antibody. Antibodies with 0 drugs are ineffective and compete with the ADC for binding to the antigen expressing cells. Antibodies with 8 drugs per antibody have reduced in vivo stability, which may contribute to non target related toxicities. In these studies we incorporated a non-natural amino acid, para acetyl phenylalanine, at two unique sites within an antibody against Her2/neu. We covalently attached a cytotoxic drug to these sites to form an ADC which contains two drugs per antibody. We report the results from the first direct preclinical comparison of a site specific non-natural amino acid anti-Her2 ADC and a cysteine conjugated anti-Her2 ADC. We report that the site specific non-natural amino acid anti-Her2 ADCs have superior in vitro serum stability and preclinical toxicology profile in rats as compared to the cysteine conjugated anti-Her2 ADCs. We also demonstrate that the site specific non-natural amino acid anti-Her2 ADCs maintain their in vitro potency and in vivo efficacy against Her2 expressing human tumor cell lines. Our data suggests that site specific non-natural amino acid ADCs may have a superior therapeutic window than cysteine conjugated ADCs.

  19. Novel liver-specific cholic acid-cytarabine conjugates with potent antitumor activities: Synthesis and biological characterization

    Institute of Scientific and Technical Information of China (English)

    Dan-qi CHEN; Xin WANG; Lin CHEN; Jin-xue HE; Ze-hong MIAO; Jing-kang SHEN

    2011-01-01

    Aim: Cytarabine is an efficient anticancer agent for acute myelogenous leukemia, but with short plasma half-life and rapid deamination to its inactive metabolite. The aim of this study was to design and synthesize novel cholic acid-cytarabine conjugates to improve its pharmacokinetic parameters.Methods: The in vitro stability of novel cholic acid-cytarabine conjugates was investigated in simulated gastric and intestinal fluid, mouse blood and liver homogenate using HPLC. The portacaval samples of the conjugates were examined in male Sprague-Dawley rats using LC/MS, and in vivo distribution was examined in male Kunming mice using LC/MS. Antitumor activities were tested in HL60 cells using MTT assay.Results: Cholic acid-cytarabine compounds with four different linkers were designed and synthesized. All the four cholic acid-cytarabine conjugates could release cytarabine when incubated with the simulated gastric and intestinal fluid, mouse blood and liver homoge-nate. The conjugates 6,/2, and 16 were present in the portacaval samples, whereas the conjugate 7 was not detected. The conju-gates 6 and 16 showed high specificity in targeting the liver (liver target index 34.9 and 16.3, respectively) and good absorption in vivo, as compared with cytarabine. In cytarabine-sensitive HL60 cells, the conjugates 6, 12, and 16 retained potent antitumor activities.Conclusion: Three novel cholic acid-cytarabine conjugates with good liver-targeting properties and absorption were obtained. Further optimization of the conjugates is needed in the future.

  20. Efficient Synthesis and Biological Evaluation of 5'-GalNAc Conjugated Antisense Oligonucleotides.

    Science.gov (United States)

    Østergaard, Michael E; Yu, Jinghua; Kinberger, Garth A; Wan, W Brad; Migawa, Michael T; Vasquez, Guillermo; Schmidt, Karsten; Gaus, Hans J; Murray, Heather M; Low, Audrey; Swayze, Eric E; Prakash, Thazha P; Seth, Punit P

    2015-08-19

    Conjugation of triantennary N-acetyl galactosamine (GalNAc) to oligonucleotide therapeutics results in marked improvement in potency for reducing gene targets expressed in hepatocytes. In this report we describe a robust and efficient solution-phase conjugation strategy to attach triantennary GalNAc clusters (mol. wt. ∼2000) activated as PFP (pentafluorophenyl) esters onto 5'-hexylamino modified antisense oligonucleotides (5'-HA ASOs, mol. wt. ∼8000 Da). The conjugation reaction is efficient and was used to prepare GalNAc conjugated ASOs from milligram to multigram scale. The solution phase method avoids loading of GalNAc clusters onto solid-support for automated synthesis and will facilitate evaluation of GalNAc clusters for structure activity relationship (SAR) studies. Furthermore, we show that transfer of the GalNAc cluster from the 3'-end of an ASO to the 5'-end results in improved potency in cells and animals.

  1. Cysteine S-conjugate β-lyases

    OpenAIRE

    Arthur J. L. Cooper; Krasnikov, Boris F.; Pinto, John T.; Bruschi, Sam A.

    2010-01-01

    Cysteine S-conjugate β-lyases are pyridoxal 5′-phosphate (PLP)-containing enzymes that catalyze the conversion of cysteine S-conjugates [RSCH2CH(NH3+)CO2−] and selenium Se-conjugates [RSeCH2CH(NH3+)CO2−] that contain a leaving group in the β position to pyruvate, ammonium and a sulfur-containing fragment (RSH) or selenium-containing fragment (RSeH), respectively. At least ten PLP enzymes catalyze β-elimination reactions with such cysteine S-conjugates. All are enzymes involved in amino acid m...

  2. The Tcp conjugation system of Clostridium perfringens.

    Science.gov (United States)

    Wisniewski, Jessica A; Rood, Julian I

    2017-03-07

    The Gram-positive pathogen Clostridium perfringens possesses a family of large conjugative plasmids that is typified by the tetracycline resistance plasmid pCW3. Since these plasmids may carry antibiotic resistance genes or genes encoding extracellular or sporulation-associated toxins, the conjugative transfer of these plasmids appears to be important for the epidemiology of C. perfringens-mediated diseases. Sequence analysis of members of this plasmid family identified a highly conserved 35kb region that encodes proteins with various functions, including plasmid replication and partitioning. The tcp conjugation locus also was identified in this region, initially based on low-level amino acid sequence identity to conjugation proteins from the integrative conjugative element Tn916. Genetic studies confirmed that the tcp locus is required for conjugative transfer and combined with biochemical and structural analyses have led to the development of a functional model of the Tcp conjugation apparatus. This review summarises our current understanding of the Tcp conjugation system, which is now one of the best-characterized conjugation systems in Gram-positive bacteria.

  3. Modelling conjugation with stochastic differential equations

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Hasman, Henrik

    2010-01-01

    Conjugation is an important mechanism involved in the transfer of resistance between bacteria. In this article a stochastic differential equation based model consisting of a continuous time state equation and a discrete time measurement equation is introduced to model growth and conjugation of two...... using a likelihood-ratio test and Akaike's information criterion. Experiments indicating conjugation on the agar plates selecting for transconjugants motivates the introduction of an extended model, for which conjugation on the agar plate is described in the measurement equation. This model is compared...

  4. Test of charge conjugation invariance.

    Science.gov (United States)

    Nefkens, B M K; Prakhov, S; Gårdestig, A; Allgower, C E; Bekrenev, V; Briscoe, W J; Clajus, M; Comfort, J R; Craig, K; Grosnick, D; Isenhower, D; Knecht, N; Koetke, D; Koulbardis, A; Kozlenko, N; Kruglov, S; Lolos, G; Lopatin, I; Manley, D M; Manweiler, R; Marusić, A; McDonald, S; Olmsted, J; Papandreou, Z; Peaslee, D; Phaisangittisakul, N; Price, J W; Ramirez, A F; Sadler, M; Shafi, A; Spinka, H; Stanislaus, T D S; Starostin, A; Staudenmaier, H M; Supek, I; Tippens, W B

    2005-02-04

    We report on the first determination of upper limits on the branching ratio (BR) of eta decay to pi0pi0gamma and to pi0pi0pi0gamma. Both decay modes are strictly forbidden by charge conjugation (C) invariance. Using the Crystal Ball multiphoton detector, we obtained BR(eta-->pi0pi0gamma)pi0pi0pi0gamma)<6 x 10(-5) at the 90% confidence level, in support of C invariance of isovector electromagnetic interactions.

  5. Waveguide mutually pumped phase conjugators

    OpenAIRE

    James, S. W.; Youden, K.E.; Jeffrey, P. M.; EASON, R. W.; Chandler, P.J.; Zhang, L.; Townsend, P.D.

    1993-01-01

    The operation of the Bridge Mutually Pumped Phase Conjugator is reported in a planar waveguide structure in photorefractive BaTiO3. The waveguide was fabricated by the technique of ion implantation. using 1.5 MeV H+ at a dose of 10^16 ions/cm^2. An order of magnitude decrease in response time is observed in the waveguide as compared to typical values obtained in bulk crystals, probably resulting from a combination of the optical confinement within the waveguide, and possibly modification of t...

  6. Short Conjugators in Solvable Groups

    CERN Document Server

    Sale, Andrew W

    2011-01-01

    We give an upper bound on the size of short conjugators in certain solvable groups. Diestel-Leader graphs, which are a horocyclic product of trees, are discussed briefly and used to study the lamplighter groups. The other solvable groups we look at can be recognised in a similar vein, as groups which act on a horocyclic product of well known spaces. These include the Baumslag-Solitar groups BS(1,q) and semidirect products of Z^n with Z^k. Results can also be applied to the conjugacy of parabolic elements in Hilbert modular groups and to elements in 3-manifold groups.

  7. Photoluminescence of Conjugated Star Polymers

    Science.gov (United States)

    Ferguson, J. B.; Prigodin, N. V.; Epstein, A. J.; Wang, F.

    2000-10-01

    Higher dimensionality "star" polymers provide new properties beyond those found in their linear analogs. They have been used to improving electronic properties for nonlinear optics through exciton transfer and molecular antenna structures for example (M. Kawa, J. M. J. Frechet, Chem. Mater. 10, 286 (1998).). We report on photoluminescence properties of star polymers with a hyperbranched core (both hyperbranched phenlyene and hyperbranched triphenylamine) and polyhexylthiophene arms. The arm is a conjugated oligomer of polythiophene that has been investigated extensively for metallic like conductivity when doped as well as utilized in field effect transistors in its undoped form (A. Tsumara, H. Koezuka, T. Ando, Appl. Phys. Lett. 49, 1210 (1986).). The cores are respectively, a nonconjugated polymer in the case of hyperbranched phenlyene and a conjugated polymer in the case of hyperbranched triphenylamine. The photoluminesce spectrum (λ_max at 575 nm) is identical for both star polymers with the two electronically different hyperbranched cores and for linear polythiophene alone. We conclude the wave functions of the core and arms do not strongly interact to form states different from their individual states and excitons formed on the hyperbranched cores migrate to the lower bandgap polythiophene before recombining.

  8. Subgap Absorption in Conjugated Polymers

    Science.gov (United States)

    Sinclair, M.; Seager, C. H.; McBranch, D.; Heeger, A. J; Baker, G. L.

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination.

  9. Multiplexed detection of various breast cancer cells by perfluorocarbon/quantum dot nanoemulsions conjugated with antibodies

    Science.gov (United States)

    Bae, Pan Kee; Chung, Bong Hyun

    2014-07-01

    The effective targeting of cancer cell surface antigens is an attractive approach in cancer diagnosis and therapy. Multifunctional nanoprobes with cell-targeting specificity are likely to find important applications in bioanalysis, biomedicine, and clinical diagnosis. In this study, we have fabricated biocompatible perfluorocan/quantum dot nanoemulsions as bimodal imaging nanoprobes for the targeting of breast cancer cells. Perfluorocarbon/quantum dot nanoemulsions conjugated with monoclonal antibodies, as a type of bimodal imaging nanoprobe based on 19 F-MR and optical imaging, have been synthesized and applied for targeted imaging of three different breast cancer cells (SKBR3, MCF-7, MDA-MB 468), respectively. We have shown that the cancer-detection capabilities of antibody-conjugated PFC/QDs nanoemulsions could be successfully applied to target of various breast cancer cells. These modified PFC/QDs nanoemulsions were shown to target the cancer cell surface receptors specially. Conjugation of ligands to nanoemulsions targeting over-expressed cell surface receptors is a promising approach for targeted imaging to tumor cells. We further propose that the PFC/QDs nanoemulsions could be used in targeted imaging of breast cancer cells.

  10. Conjugates of Phthalocyanines With Oligonucleotides as Reagents for Sensitized or Catalytic DNA Modification

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Several conjugates of metallophthalocyanines with deoxyribooligonucleotides were synthesized to investigate sequence-specific modification of DNA by them. Oligonucleotide parts of these conjugates were responsible for the recognition of selected complementary sequences on the DNA target. Metallophthalocyanines were able to induce the DNA modification: phthalocyanines of Zn(II and Al(III were active as photosensitizers in the generation of singlet oxygen 1 O 2 , while phthalocyanine of Co(II promoted DNA oxidation by molecular oxygen through the catalysis of formation of reactive oxygen species ( ⋅ O 2 − , O 2 H 2 , OH. Irradiation of the reaction mixture containing either Zn(II- or Al(III-tetracarboxyphthalocyanine conjugates of oligonucleotide pd(TCTTCCCA with light of > 340 nm wavelength (Hg lamp or He/Ne laser resulted in the modification of the 22-nucleotide target d(TGAATGGGAAGAGGGTCAGGTT. A conjugate of Co(II-tetracarboxyphthalocyanine with the oligonucleotide was found to modify the DNA target in the presence of O 2 and 2-mercaptoethanol or in the presence of O 2 H 2 . Under both sensitized and catalyzed conditions, the nucleotides G 13 – G 15 were mainly modified, providing evidence that the reaction proceeded in the double-stranded oligonucleotide. These results suggest the possible use of phthalocyanine-oligonucleotide conjugates as novel artificial regulators of gene expression and therapeutic agents for treatment of cancer.

  11. Trends in therapeutic drug conjugates for bacterial diseases: a patent review.

    Science.gov (United States)

    Cal, Pedro M S D; Matos, Maria J; Bernardes, Gonçalo J L

    2017-02-01

    Drug conjugates are trend topics in Chemical Biology. These entities are an emerging class of highly potent biopharmaceutical drugs, best known in the field of oncology, that have been also designed as a targeted therapy/diagnosis for the treatment/prevention of several bacterial diseases. Antibiotic resistance is now a major threat to public health, and targeted strategies can reduce resistance. The following review aims at giving an overview of the patented therapeutic innovations covering these areas. Particular attention has been given to antibacterial drug conjugates in the last 30 years. Areas covered: The authors provide an overview of the scientific reports describing the research and development of new drug conjugates for bacterial diseases. The review emphasizes the rationale behind synthesis, biological activities and improvement of the new drug conjugates. New technologies applied for the research in this field have also been discussed. The article is based on the most relevant literature related to the development of new therapeutic solutions. The patents presented in this review have been collected from multiple electronic databases including SciFinder, Pubmed, Espacenet and Mendeley. Expert opinion: The new drug conjugates described in the current review proved to display improved delivery, efficacy, targeting abilities and fewer side effects. Versatile approaches were invented to achieve these goals.

  12. Synthesis and anti-angiogenic effect of conjugates between serum albumin and non-steroidal anti-inflammatory drugs

    DEFF Research Database (Denmark)

    Kjaer, B; Struve, C; Friis, T

    2010-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit tumor growth and angiogenesis. Covalent linkage of naproxen to human serum albumin (HSA) has been shown to target it efficiently to the liver and this may potentially be exploited for liver-selective inhibition of angiogenesis. With the aim...... of investigating the anti-angiogenic efficiency of NSAID-HSA conjugates in vitro, three NSAIDs, aspirin, ibuprofen, and naproxen were conjugated to HSA using different concentrations of their N-hydroxysuccinimide esters. Conjugation ratios from 10 to 50 were achieved and the conjugates retained a growth inhibitory...... effect on endothelial cells at or above the level of the non-conjugated NSAIDs in an in vitro angiogenesis assay....

  13. Synthesis and evaluation of the biostability and cell compatibility of novel conjugates of nucleobase, peptidic epitope, and saccharide

    Directory of Open Access Journals (Sweden)

    Dan Yuan

    2015-08-01

    Full Text Available This article reports the synthesis of a new class of conjugates containing a nucleobase, a peptidic epitope, and a saccharide and the evalution of their gelation, biostability, and cell compatibility. We demonstrate a facile synthetic process, based on solid-phase peptide synthesis of nucleopeptides, to connect a saccharide with the nucleopeptides for producing the target conjugates. All the conjugates themselves (1–8 display excellent solubility in water without forming hydrogels. However, a mixture of 5 and 8 self-assembles to form nanofibers and results in a supramolecular hydrogel. The proteolytic stabilities of the conjugates depend on the functional peptidic epitopes. We found that TTPV is proteolytic resistant and LGFNI is susceptible to proteolysis. In addition, all the conjugates are compatible to the mammalian cells tested.

  14. The Conjugate Acid-Base Chart.

    Science.gov (United States)

    Treptow, Richard S.

    1986-01-01

    Discusses the difficulties that beginning chemistry students have in understanding acid-base chemistry. Describes the use of conjugate acid-base charts in helping students visualize the conjugate relationship. Addresses chart construction, metal ions, buffers and pH titrations, and the organic functional groups and nonaqueous solvents. (TW)

  15. DENDRIMER CONJUGATES FOR SELECTIVE OF PROTEIN AGGREGATES

    DEFF Research Database (Denmark)

    2004-01-01

    Dendrimer conjugates are presented, which are formed between a dendrimer and a protein solubilising substance. Such dendrimer conjugates are effective in the treatment of protein aggregate-related diseases (e.g. prion-related diseases). The protein solubilising substance and the dendrimer together...

  16. CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

    NARCIS (Netherlands)

    Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

    1995-01-01

    In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

  17. Bio-Conjugates for Nanoscale Applications

    DEFF Research Database (Denmark)

    Villadsen, Klaus

    Bio-conjugates for Nanoscale Applications is the title of this thesis, which covers three different projects in chemical bio-conjugation research, namely synthesis and applications of: Lipidated fluorescent peptides, carbohydrate oxime-azide linkers and N-aryl O-R2 oxyamine derivatives. Lipidated...

  18. CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

    NARCIS (Netherlands)

    Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

    1995-01-01

    In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

  19. CONJUGATE-SYMPLECTICITY OF LINEAR MULTISTEP METHODS

    Institute of Scientific and Technical Information of China (English)

    Ernst Hairer

    2008-01-01

    For the numerical treatment of Hamiltonian differential equations, symplectic integra-tors are the most suitable choice, and methods that are conjugate to a symplectic integrator share the same good long-time behavior. This note characterizes linear multistep methods whose underlying one-step method is conjugate to a symplectic integrator. The bounded-hess of parasitic solution components is not addressed.

  20. Kinetic models of conjugated metabolic cycles

    Science.gov (United States)

    Ershov, Yu. A.

    2016-01-01

    A general method is developed for the quantitative kinetic analysis of conjugated metabolic cycles in the human organism. This method is used as a basis for constructing a kinetic graph and model of the conjugated citric acid and ureapoiesis cycles. The results from a kinetic analysis of the model for these cycles are given.

  1. Bio-Conjugates for Nanoscale Applications

    DEFF Research Database (Denmark)

    Villadsen, Klaus

    Bio-conjugates for Nanoscale Applications is the title of this thesis, which covers three different projects in chemical bio-conjugation research, namely synthesis and applications of: Lipidated fluorescent peptides, carbohydrate oxime-azide linkers and N-aryl O-R2 oxyamine derivatives. Lipidated...

  2. LEDs based on conjugated PPV block copolymers

    NARCIS (Netherlands)

    Brouwer, H.J.; Hilberer, A.; Krasnikov, V.V.; Werts, M.; Wildeman, J.; Hadziioannou, G.

    1997-01-01

    A way to control the bandgap in semi-conducting polymers is by preparing polymers with a partially conjugated backbone. In our laboratory, three conjugated copolymers containing PPV trimers as light emitting chromophores have been synthesized, which emit in the blue, green and orange wavelength regi

  3. A new family of conjugate gradient methods

    Science.gov (United States)

    Shi, Zhen-Jun; Guo, Jinhua

    2009-02-01

    In this paper we develop a new class of conjugate gradient methods for unconstrained optimization problems. A new nonmonotone line search technique is proposed to guarantee the global convergence of these conjugate gradient methods under some mild conditions. In particular, Polak-Ribiére-Polyak and Liu-Storey conjugate gradient methods are special cases of the new class of conjugate gradient methods. By estimating the local Lipschitz constant of the derivative of objective functions, we can find an adequate step size and substantially decrease the function evaluations at each iteration. Numerical results show that these new conjugate gradient methods are effective in minimizing large-scale non-convex non-quadratic functions.

  4. ANALYSIS OF A CONJUGATE BETWEEN ANTICARCINOEMBRYONIC ANTIGEN MONOCLONAL-ANTIBODY AND ALKALINE-PHOSPHATASE FOR SPECIFIC ACTIVATION OF THE PRODRUG ETOPOSIDE PHOSPHATE

    NARCIS (Netherlands)

    Haisma, Hidde; BOVEN, E; VANMUIJEN, M; DEVRIES, R; PINEDO, HM

    1992-01-01

    The selective targeting of tumours by enzymes conjugated to monoclonal antibodies (mAb) may be an ideal approach to convert relatively nontoxic prodrugs into active agents at the tumour site. We used the anti-carcinoembryonic antigen mAb BW431/26 conjugated to alkaline phosphatase (AP) and phosphory

  5. Collagen-Gold Nanoparticle Conjugates for Versatile Biosensing

    Directory of Open Access Journals (Sweden)

    Sarah Unser

    2017-02-01

    Full Text Available Integration of noble metal nanoparticles with proteins offers promising potential to create a wide variety of biosensors that possess both improved selectivity and versatility. The multitude of functionalities that proteins offer coupled with the unique optical properties of noble metal nanoparticles can allow for the realization of simple, colorimetric sensors for a significantly larger range of targets. Herein, we integrate the structural protein collagen with 10 nm gold nanoparticles to develop a protein-nanoparticle conjugate which possess the functionality of the protein with the desired colorimetric properties of the nanoparticles. Applying the many interactions that collagen undergoes in the extracellular matrix, we are able to selectively detect both glucose and heparin with the same collagen-nanoparticle conjugate. Glucose is directly detected through the cross-linking of the collagen fibrils, which brings the attached nanoparticles into closer proximity, leading to a red-shift in the LSPR frequency. Conversely, heparin is detected through a competition assay in which heparin-gold nanoparticles are added to solution and compete with heparin in the solution for the binding sites on the collagen fibrils. The collagen-nanoparticle conjugates are shown to detect both glucose and heparin in the physiological range. Lastly, glucose is selectively detected in 50% mouse serum with the collagen-nanoparticle devices possessing a linear range of 3–25 mM, which is also within the physiologically relevant range.

  6. GPCR ligand-dendrimer (GLiDe) conjugates: future smart drugs?

    Science.gov (United States)

    Jacobson, Kenneth A

    2010-12-01

    Unlike nanocarriers that are intended to release their drug cargo at the site of action, biocompatibile polyamidoamine (PAMAM) conjugates are designed to act at cell surface G protein-coupled receptors (GPCRs) without drug release. These multivalent GPCR ligand-dendrimer (GLiDe) conjugates display qualitatively different pharmacological properties in comparison with monomeric drugs. They might be useful as novel tools to study GPCR homodimers and heterodimers as well as higher aggregates. The structure of the conjugate determines the profile of biological activity, receptor selectivity, and physical properties such as water solubility. Prosthetic groups for characterization and imaging of receptors can be introduced without loss of affinity. The feasibility of targeting multiple adenosine and P2Y receptors for synergistic effects has been shown. Testing in vivo will be needed to explore the effects on pharmacokinetics and tissue targeting.

  7. Photoconductive properties of conjugated polymers

    CERN Document Server

    Halls, J J M

    1997-01-01

    The research described in my dissertation has involved the fabrication and characterisation of photovoltaic cells based on conjugated polymers, including the widely studied polymer poly(p-phenylenevinylene). These materials have semiconducting properties which arise from the delocalisation of electrons along the pi-electron systems of the polymer chains. Research into these materials is motivated both by their novel electronic properties, and also their potential for use in a wide range of applications including light-emitting diodes (LEDs), thin-film transistors, and photovoltaic cells (solar cells and light detectors). Light absorbed in a photovoltaic cell generates opposite charges which are collected at two different electrodes, giving rise to an electric current

  8. Test of Charge Conjugation Invariance

    Science.gov (United States)

    Nefkens, B. M.; Prakhov, S.; Gårdestig, A.; Allgower, C. E.; Bekrenev, V.; Briscoe, W. J.; Clajus, M.; Comfort, J. R.; Craig, K.; Grosnick, D.; Isenhower, D.; Knecht, N.; Koetke, D.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.; Lolos, G.; Lopatin, I.; Manley, D. M.; Manweiler, R.; Marušić, A.; McDonald, S.; Olmsted, J.; Papandreou, Z.; Peaslee, D.; Phaisangittisakul, N.; Price, J. W.; Ramirez, A. F.; Sadler, M.; Shafi, A.; Spinka, H.; Stanislaus, T. D.; Starostin, A.; Staudenmaier, H. M.; Supek, I.; Tippens, W. B.

    2005-02-01

    We report on the first determination of upper limits on the branching ratio (BR) of η decay to π0π0γ and to π0π0π0γ. Both decay modes are strictly forbidden by charge conjugation (C) invariance. Using the Crystal Ball multiphoton detector, we obtained BR(η→π0π0γ)<5×10-4 at the 90% confidence level, in support of C invariance of isoscalar electromagnetic interactions of the light quarks. We have also measured BR(η→π0π0π0γ)<6×10-5 at the 90% confidence level, in support of C invariance of isovector electromagnetic interactions.

  9. Lectin-conjugated microspheres for eradication of Helicobacter pylori infection and interaction with mucus.

    Science.gov (United States)

    Adebisi, Adeola O; Conway, Barbara R

    2014-08-15

    Using second generation mucoadhesives may enhance targeting antibiotics for eradication of Helicobacter pylori from the stomach for the treatment of peptic ulcer. The aim of this research was to prepare and characterise ethylcellulose/chitosan microspheres containing clarithromycin with their surfaces functionalised with concanavalin A to produce a floating-mucoadhesive formulation. The microspheres were prepared using an emulsification-solvent evaporation method. Particle size, surface morphology, in vitro buoyancy profile, zeta potential, drug entrapment efficiency, in vitro drug release and release kinetics of the particles were determined. Lectin was conjugated to the microsphere surface using two-stage carbodiimide activation and confirmed using FTIR, fluorescence studies and zeta potential measurements. Conjugation ranged from 11 to 15 μg Con A/mg microspheres which represents over 56% efficiency although there was some drug loss during the conjugation process. Conjugation did not have a significant effect on the buoyancy and release of drug from the microspheres using a mucus diffusion model with 53% and 40% of drug released from unconjugated and conjugated microspheres within 12h. Conjugation improved mucoadhesion and interaction with porcine gastric mucin compared to unconjugated microspheres. The buoyancy and improved mucoadhesion of the microspheres provides potential for delivery of clarithromycin and other drugs to the stomach.

  10. Fragment-based solid-phase assembly of oligonucleotide conjugates with peptide and polyethylene glycol ligands.

    Science.gov (United States)

    Dirin, Mehrdad; Urban, Ernst; Noe, Christian R; Winkler, Johannes

    2016-10-04

    Ligand conjugation to oligonucleotides is an attractive strategy for enhancing the therapeutic potential of antisense and siRNA agents by inferring properties such as improved cellular uptake or better pharmacokinetic properties. Disulfide linkages enable dissociation of ligands and oligonucleotides in reducing environments found in endosomal compartments after cellular uptake. Solution-phase fragment coupling procedures for producing oligonucleotide conjugates are often tedious, produce moderate yields and reaction byproducts are frequently difficult to remove. We have developed an improved method for solid-phase coupling of ligands to oligonucleotides via disulfides directly after solid-phase synthesis. A 2'-thiol introduced using a modified nucleotide building block was orthogonally deprotected on the controlled pore glass solid support with N-butylphosphine. Oligolysine peptides and a short monodisperse ethylene glycol chain were successfully coupled to the deprotected thiol. Cleavage from the resin and full removal of oligonucleotide protection groups were achieved using methanolic ammonia. After standard desalting, and without further purification, homogenous conjugates were obtained as demonstrated by HPLC, gel electrophoresis, and mass spectrometry. The attachment of both amphiphilic and cationic ligands proves the versatility of the conjugation procedure. An antisense oligonucleotide conjugate with hexalysine showed pronounced gene silencing in a cell culture tumor model in the absence of a transfection reagent and the corresponding ethylene glycol conjugate resulted in down regulation of the target gene to nearly 50% after naked application. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. Easy and Efficient 111Indium Labeling of Long-Term Stored DTPA Conjugated Protein

    DEFF Research Database (Denmark)

    Nalla, Amarnadh; Buch, Inge; Hesse, Birger

    2011-01-01

    The labelling efficiency of long-term stored DTPA-conjugates has not been reported previously even though DTPA has been in extensive use as metal chelator in the development of radiopharmaceuticals and contrast agents. DTPA is often used as a bifunctional chelating agent conjugated to tumor...... targeting vehicles such as monoclonal antibodies and receptor directed peptides. The purpose of this study was to monitor the labelling efficiency of a DTPA-conjugate on long-term storage using 111In-chloride at two different temperatures and incubation times for the In-labelling. Method: Cyclic......-diethylene-triamine-pentaacetic acid (cDTAP) was conjugated to a polyclonal immunoglobulin-G (IgG) in borate buffer, pH 8.2 at +4?C for 4 hours. Then the DTPA-conjugate was dialyzed against 50 mmol/l sodium citrate buffer saline, pH 6.0 and stored at -80° C in aliquots of 1 mg/0.5 ml. The DTPA-conjugate was labeled with 111In...

  12. High Relaxivity Gadolinium Hydroxypyridonate-Viral Capsid Conjugates: Nano-sized MRI Contrast Agents

    Energy Technology Data Exchange (ETDEWEB)

    Meux, Susan C.; Datta, Ankona; Hooker, Jacob M.; Botta, Mauro; Francis, Matthew B.; Aime, Silvio; Raymond, Kenneth N.

    2007-08-29

    High relaxivity macromolecular contrast agents based on the conjugation of gadolinium chelates to the interior and exterior surfaces of MS2 viral capsids are assessed. The proton nuclear magnetic relaxation dispersion (NMRD) profiles of the conjugates show up to a five-fold increase in relaxivity, leading to a peak relaxivity (per Gd{sup 3+} ion) of 41.6 mM{sup -1}s{sup -1} at 30 MHz for the internally modified capsids. Modification of the exterior was achieved through conjugation to flexible lysines, while internal modification was accomplished by conjugation to relatively rigid tyrosines. Higher relaxivities were obtained for the internally modified capsids, showing that (1) there is facile diffusion of water to the interior of capsids and (2) the rigidity of the linker attaching the complex to the macromolecule is important for obtaining high relaxivity enhancements. The viral capsid conjugated gadolinium hydroxypyridonate complexes appear to possess two inner-sphere water molecules (q = 2) and the NMRD fittings highlight the differences in the local motion for the internal ({tau}{sub RI} = 440 ps) and external ({tau}{sub RI} = 310 ps) conjugates. These results indicate that there are significant advantages of using the internal surface of the capsids for contrast agent attachment, leaving the exterior surface available for the installation of tissue targeting groups.

  13. Unsteady conjugate heat transfer analysis for impinging jet cooling

    Science.gov (United States)

    Tejero, F.; Flaszyński, P.; Szwaba, R.; Telega, J.

    2016-10-01

    The paper presents the numerical investigations of the heat transfer on a flat plate cooled by a single impinging jet. The thermal conductivity of the plate was modified from a high thermal case (steel -λ= 35 W/m/K) to a low one (steel alloy Inconel -λ= 9.8 W/m/K). The numerical simulations results are compared with the experimental data from the Institute of Fluid-Flow Machinery Polish Academy of Sciences, Gdansk (Poland). The numerical simulations are carried out by means of Ansys/Fluent and k-ω SST turbulence model and the temperature evolution on the target plate is investigated by conjugated heat transfer computations.

  14. Protopanaxadiol aglycone ginsenoside-polyethylene glycol conjugates: synthesis, physicochemical characterizations, and in vitro studies.

    Science.gov (United States)

    Mathiyalagan, Ramya; Kim, Yeon Ju; Wang, Chao; Jin, Yan; Subramaniyam, Sathiyamoorthy; Singh, Priyanka; Wang, Dandan; Yang, Deok Chun

    2016-12-01

    Ginsenosides are triterpenoid saponins, which is an active compound responsible for most of the pharmacological effects of ginseng (Panax ginseng Meyer). It is known to have numerous structural and pharmacological properties. However, aqueous solubility and delivery of ginsenosides in targeted region by avoiding undesirable toxicity to normal cell is also of prime importance. The aim of this study was to obtain amphiphilic ginsenoside derivatives in which hydrophilic polymers were conjugated to ginsenosides to enhance the water solubility and targeted delivery. To this end, the hydrophobic protopanaxadiol ginsenoside aglycone (aPPD) was covalently conjugated to the backbone of hydrophilic polyethylene glycol (PEG) through a pH sensitive ester linkage, which was confirmed by (1)H NMR and FTIR. The resultant PPD is covalently conjugated to hydrophilic PEG through esterification (PEG-PPD) forming self-assembled spherical nanoparticles, whose average particle diameter was 189 nm as observed by FE-TEM and particle size analyzer respectively. In vitro release experiments revealed that the release rate of PPD was rapidly increased from the self-assembled nanoparticles under acidic conditions (pH 5.0) than in a physiological buffer (pH 7.4) condition. Furthermore, in vitro cytotoxicity assays revealed that PEG-PPD conjugates exhibited lower cytotoxicity in HT-29 cancer cells compared with PPD alone. Since the slow release of PPD from conjugates is triggered only by acidic environmental conditions, such as those found in extracellular solid tumor tissues, intracellular endosomes, and intracellular lysosomes, the conjugation of PPD may aid its selective delivery to these targets. Overall, results suggest that pH-dependent release of PPD, which expected in reduced cytotoxicity to non-targeted regions, may enhance the overall efficacy of PPD.

  15. Reduction-sensitive liposomes from a multifunctional lipid conjugate and natural phospholipids: reduction and release kinetics and cellular uptake.

    Science.gov (United States)

    Goldenbogen, Björn; Brodersen, Nicolai; Gramatica, Andrea; Loew, Martin; Liebscher, Jürgen; Herrmann, Andreas; Egger, Holger; Budde, Bastian; Arbuzova, Anna

    2011-09-06

    The development of targeted and triggerable delivery systems is of high relevance for anticancer therapies. We report here on reduction-sensitive liposomes composed of a novel multifunctional lipidlike conjugate, containing a disulfide bond and a biotin moiety, and natural phospholipids. The incorporation of the disulfide conjugate into vesicles and the kinetics of their reduction were studied using dansyl-labeled conjugate 1 in using the dansyl fluorescence environmental sensitivity and the Förster resonance energy transfer from dansyl to rhodamine-labeled phospholipids. Cleavage of the disulfide bridge (e.g., by tris(2-carboxyethyl)phosphine (TCEP), dithiothreitol (DTT), l-cysteine, or glutathione (GSH)) removed the hydrophilic headgroup of the conjugate and thus changed the membrane organization leading to the release of entrapped molecules. Upon nonspecific uptake of vesicles by macrophages, calcein release from reduction-sensitive liposomes consisting of the disulfide conjugate and phospholipids was more efficient than from reduction-insensitive liposomes composed only of phospholipids. The binding of streptavidin to the conjugates did not interfere with either the subsequent reduction of the disulfide bond of the conjugate or the release of entrapped molecules. Breast cancer cell line BT-474, overexpressing the HER2 receptor, showed a high uptake of the reduction-sensitive doxorubicin-loaded liposomes functionalized with the biotin-tagged anti-HER2 antibody. The release of the entrapped cargo inside the cells was observed, implying the potential of using our system for active targeting and delivery. © 2011 American Chemical Society

  16. Role of SbmA in the Uptake of Peptide Nucleic Acid (PNA)-Peptide Conjugates in E. coli

    DEFF Research Database (Denmark)

    Ghosal, Anubrata; Vitali, Ally; Stach, James E M

    2013-01-01

    Antisense PNA oligomers targeting essential genes (acpP or ftsZ) and conjugated to the delivery peptide L((KFF)(3)K) show complete growth inhibition of wild type E. coli strain (MG1655) with submicromolar MIC. In this study we show that resistant mutants generated against such PNA......-peptide conjugates had disruptions in the region of sbmA, a gene encoding an inner membrane peptide transporter. The wild type sensitivity to the PNA conjugates was re-established in the resistance mutants by complementation with sbmA. Furthermore, deletion of sbmA in E. coli AS19, a strain that is sensitive...

  17. Specific Conjugation of the Hinge Region for Homogeneous Preparation of Antibody Fragment-Drug Conjugate: A Case Study for Doxorubicin-PEG-anti-CD20 Fab' Synthesis.

    Science.gov (United States)

    Zhou, Zhan; Zhang, Jing; Zhang, Yan; Ma, Guanghui; Su, Zhiguo

    2016-01-20

    Conventional preparation strategies for antibody-drug conjugates (ADCs) result in heterogeneous products with various molecular sizes and species. In this study, we developed a homogeneous preparation strategy by site-specific conjugation of the anticancer drug with an antibody fragment. The model drug doxorubicin (DOX) was coupled to the Fab' fragment of anti-CD20 IgG at its permissive sites through a heterotelechelic PEG linker, generating an antibody fragment-drug conjugate (AFDC). Anti-CD20 IgG was digested and reduced specifically with β-mercaptoethylamine to generate the Fab' fragment with two free mercapto groups in its hinge region. Meanwhile, DOX was conjugated with α-succinimidylsuccinate ω-maleimide polyethylene glycol (NHS-PEG-MAL) to form MAL-PEG-DOX, which was subsequently linked to the free mercapto containing Fab' fragment to form a Fab'-PEG-DOX conjugate. The dual site-specific bioconjugation was achieved through the combination of highly selective reduction of IgG and introduction of heterotelechelic PEG linker. The resulting AFDC provides an utterly homogeneous product, with a definite ratio of one fragment to two drugs. Laser confocal microscopy and cell ELISA revealed that the AFDC could accumulate in the antigen-positive Daudi tumor cell. In addition, the Fab'-PEG-DOX retained appreciable targeting ability and improved antitumor activity, demonstrating an excellent therapeutic effect on the lymphoma mice model for better cure rate and significantly reduced side effects.

  18. Site-specific conjugation of an antibody-binding protein catalyzed by horseradish peroxidase creates a multivalent protein conjugate with high affinity to IgG.

    Science.gov (United States)

    Minamihata, Kosuke; Goto, Masahiro; Kamiya, Noriho

    2015-01-01

    Cross-linking proteins offers an approach to enhance the distinct function of proteins due to the multivalent effect. In this study, we demonstrated the preparation of a multivalent antibody-binding protein possessing high affinity to IgG by conjugating a number of antibody-binding proteins using the horseradish peroxidase (HRP)-mediated protein conjugation method. By introducing a peptide tag containing a tyrosine (Y-tag) to the C-terminus of the model protein, a chimera protein of protein G and protein A (pG2 pA), the Tyr residue in the Y-tag was efficiently recognized by HRP and cross-linked with each other to yield a pG2 pA conjugate, composed of mainly two to three units of pG2 pA. The cross-linking occurred site specifically at the Tyr residue in the Y-tag and introduction of the Y-tag showed no effect on the function of pG2 pA. The affinity of the Y-tagged pG2 pA conjugate against IgG clearly increased because of the multivalent effect, demonstrating the benefit of this protein cross-linking reaction, which yields functional protein oligomers. Such multivalent protein conjugates created by this reaction should have potential to be used in ELISA and Western blotting applications in which highly sensitive detection of target molecules is desired.

  19. Nanodiamond-DGEA peptide conjugates for enhanced delivery of doxorubicin to prostate cancer

    Directory of Open Access Journals (Sweden)

    Amanee D Salaam

    2014-07-01

    Full Text Available The field of nanomedicine has emerged as an approach to enhance the specificity and efficacy of cancer treatments as stand-alone therapies and in combination with standard chemotherapeutic treatment regimens. The current standard of care for metastatic cancer, doxorubicin (DOX, is presented with challenges, namely toxicity due to a lack of specificity and targeted delivery. Nano-enabled targeted drug delivery systems can provide an avenue to overcome these issues. Nanodiamonds (ND, in particular, have been researched over the past five years for use in various drug delivery systems but minimal work has been done that incorporates targeting capability. In this study, a novel targeted drug delivery system for bone metastatic prostate cancer was developed, characterized, and evaluated in vitro. NDs were conjugated with the Asp–Gly–Glu–Ala (DGEA peptide to target α2β1 integrins over-expressed in prostate cancers during metastasis. To facilitate drug delivery, DOX was adsorbed to the surface of the ND-DGEA conjugates. Successful preparation of the ND-DGEA conjugates and the ND-DGEA+DOX system was confirmed with transmission electron microscopy, hydrodynamic size, and zeta potential measurements. Since traditional DOX treatment regimens lack specificity and increased toxicity to normal tissues, the ND-DGEA conjugates were designed to distinguish between cells that overexpress α2β1 integrin, bone metastatic prostate cancers cells (PC3, and cells that do not, human mesenchymal stem cells (hMSC. Utilizing the ND-DGEA+DOX system, the efficacy of 1 µg/mL and 2 µg/mL DOX doses increased from 2.5% to 12% cell death and 11% to 34% cell death, respectively. These studies confirmed that the delivery and efficacy of DOX were enhanced by ND-DGEA conjugates. Thus, the targeted ND-DGEA+DOX system provides a novel approach for decreasing toxicity and drug doses.

  20. KrF laser amplifier with phase-conjugate Brillouin retroreflectors.

    Science.gov (United States)

    Gower, M C

    1982-09-01

    We have demonstrated the use of phase-conjugate stimulated Brillouin scattering mirrors to produce high-quality, short-pulse KrF laser beams from angular multiplexed and regenerative amplifiers. The mirror was also shown to isolate systems optically from amplifier spontaneous emission. Automatic alignment of targets using this mirror as a retroreflector was also demonstrated.

  1. Folate targeted polymeric 'green' nanotherapy for cancer

    Science.gov (United States)

    Narayanan, Sreeja; Binulal, N. S.; Mony, Ullas; Manzoor, Koyakutty; Nair, Shantikumar; Menon, Deepthy

    2010-07-01

    The concept of 'green' chemotherapy by employing targeted nanoparticle mediated delivery to enhance the efficacy of phytomedicines is reported. Poly (lactide-co-glycolide) (PLGA) nanoparticles encapsulating a well known nutraceutical namely, grape seed extract (GSE)—'NanoGSE'—was prepared by a nanoprecipitation technique. The drug-loaded nanoparticles of size ~ 100 nm exhibited high colloidal stability at physiological pH. Molecular receptor targeting of this nanophytomedicine against folate receptor over-expressing cancers was demonstrated in vitro by conjugation with a potential cancer targeting ligand, folic acid (FA). Fluorescence microscopy and flow cytometry data showed highly specific cellular uptake of FA conjugated NanoGSE on folate receptor positive cancer cells. Studies were also conducted to investigate the efficiency of targeted (FA conjugated) versus non-targeted (non-FA conjugated) nanoformulations in causing cancer cell death. The IC50 values were lowered by a factor of ~ 3 for FA-NanoGSE compared to the free drug, indicating substantially enhanced bioavailability to the tumor cells, sparing the normal ones. Receptor targeting of FA-NanoGSE resulted in a significant increase in apoptotic index, which was also quantified by flow cytometry and fluorescence microscopy. This in vitro study provides a basis for the use of nanoparticle mediated delivery of anticancer nutraceuticals to enhance bioavailability and effectively target cancer by a 'green' approach.

  2. Preparation of folic acid-conjugated CDDP nanomedicine for targeted therapy on nasopharyngeal carcinoma cells%叶酸-顺铂纳米药物的制备及其对人鼻咽癌细胞的靶向治疗作用

    Institute of Scientific and Technical Information of China (English)

    张宏征; 谢民强; 张涛; 陈帅君

    2011-01-01

    Objective To preparation folic acid-conjugated cis-platin nanomedicine that can transport cisplatin by folate receptor-mediated endocytosis,and to investigate the therapy effect of this medicine for nasopharyngeal carcinoma ( NPC) cells. Methods Cis-platin loaded nanomedicine was prepared by co-precipitation method using sodium alginate as modification material. Folic acid linked nanoparticles (FA-MNP-CDDP) was synthesized through PEG (NH2)2. Capacity of FA-MNP-CDDP for targeted drug delivery and inhibitory effects on human NPC cells was evaluated hy Prussian Staining and MTT assay. Results CDDP content in CDDP-MNP-FA suspension was ( 1.6 ± 0.1 )mg/mL. An average core size of ( 10.1 ± 1.5)nm was found by transmission electronic microscopy (TEM). By comparing with CNE-2 cells, HNE-1 cells had a higher uptake for FA-MNP-CDDP. This nanomedicine had strong inhibitory effects on HNE-1 cells . the IC5o of it [ ( 1.300 ± 0.10) μg/mL] was 40% lower than CDDP [ (2.161± .085) μg/mL]. Conclusion FA-MNP-CDDP nanomedicine show promise for targeted drug delivery and therapy effect in folate receptor over-expressing NPC cells.%目的:制备连接叶酸分子的顺铂纳米药物,并研究该药物对人鼻咽癌细胞的体外靶向治疗作用.方法:采用化学共沉淀法制备顺铂纳米药物并通过聚乙二醇二胺连接叶酸分子合成叶酸-顺铂纳米药物(FA-MNP-CDDP)并对其进行表征.将人鼻咽癌细胞HNE-1和CNE-2与FA-MNP-CDDP体外共培养,采用普鲁士蓝染色法测定细胞摄取纳米药物的情况,采用MTT法测定纳米药物的细胞毒性.结果:合成FA-MNPCDDP纳米药物顺铂含量为(1.6 ±0.1)mg/mL,药物粒子平均直径为(10.1 ±1.5)nm.表达叶酸受体的HNE-1细胞对该纳米药物摄取能力显著强于不表达叶酸受体的CNE-2细胞.FA-MNP-CDDP对HNE-1细胞的体外抑制效果明显,IC50[(1.300±0.10)μg/mL]较单纯顺铂[(2.161±0.85)μg/mL]降低约40%.结论:叶酸-顺铂纳米药物具有针对鼻咽

  3. Comparison of anti-EGFR-Fab’ conjugated immunoliposomes modified with two different conjugation linkers for siRNA delivery in SMMC-7721 cells

    Directory of Open Access Journals (Sweden)

    Deng L

    2013-08-01

    Full Text Available Li Deng,1,* Yingying Zhang,1,* Lulu Ma,1,5,* Xiaolong Jing,1,3 Xingfa Ke,1,3 Jianhao Lian,1,3 Qiang Zhao,1,3 Bo Yan,1,3 Jinfeng Zhang,4 Jianzhong Yao,2 Jianming Chen1 1Department of Pharmaceutical Science, 2Department of Medicinal Chemistry, School of Pharmacy, Second Military Medical University, Shanghai, People’s Republic of China; 3Department of Pharmacy, Fujian University of Traditional Chinese Medicine, Fujian, People’s Republic of China; 4Shanghai TCM Integrated Hospital, Shanghai, People’s Republic of China; 5Department of Pharmacy, First Affiliated Hospital of Bengbu Medical College, Bengbu, People’s Republic of China *These authors contributed equally to this paper Background: Targeted liposome-polycation-DNA complex (LPD, mainly conjugated with antibodies using functionalized PEG derivatives, is an effective nanovector for systemic delivery of small interference RNA (siRNA. However, there are few studies reporting the effect of different conjugation linkers on LPD for gene silencing. To clarify the influence of antibody conjugation linkers on LPD, we prepared two different immunoliposomes to deliver siRNA in which DSPE-PEG-COOH and DSPE-PEG-MAL, the commonly used PEG derivative linkers, were used to conjugate anti-EGFR Fab’ with the liposome. Methods: First, 600 µg of anti-EGFR Fab’ was conjugated with 28.35 µL of a micelle solution containing DSPE-PEG-MAL or DSPE-PEG-COOH, and then post inserted into the prepared LPD. Various liposome parameters, including particle size, zeta potential, stability, and encapsulation efficiency were evaluated, and the targeting ability and gene silencing activity of TLPD-FPC (DSPE-PEG-COOH conjugated with Fab’ was compared with that of TLPD-FPM (DSPE-PEG-MAL conjugated with Fab’ in SMMC-7721 hepatocellular carcinoma cells. Results: There was no significant difference in particle size between the two TLPDs, but the zeta potential was significantly different. Further, although there was

  4. Research on multi-component gas optical detection system based on conjugated interferometer

    Science.gov (United States)

    Gui, Xin; Tong, Yuheng; Wang, Honghai; Yu, Haihu; Li, Zhengying

    2017-09-01

    An optical multi-component gas detection system based on the conjugated interferometer (CI) is proposed and experimentally demonstrated. It can realize the concentration detection of mixture gas in the environment. The CI can transform the absorption spectrum of the target gases to a conjugated emission spectrum, when combining the CI with the broadband light source, the spectrum of output light matches well with the absorption spectrum of target gases. The CI design for different target gases can be achieved by replacing the kind of target absorbing gas in the CI filter. Traditional fiber gas sensor system requires multiple light sources for detection when there are several kinds of gases, and this problem has been solved by using the CI filter combined with the broadband light source. The experimental results show that the system can detect the concentration of multi-component gases, which are mixed with C2H2 and NH3. Experimental results also show a good concentration sensing linearity.

  5. Evaluation of iodovinyl antibody conjugates: Comparison with a p-iodobenzoyl conjugate and direct radioiodination

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, S.W.; Wilbur, D.S. (NeoRx Corporation, Seattle, WA (USA))

    1990-03-01

    The preparations and conjugations of 2,3,5,6-tetrafluorophenyl 5-(125I/131I)iodo-4-pentenoate (7a) and 2,3,5,6-tetrafluorophenyl 3,3-dimethyl-5-(125I/131I)iodo-4-pentenoate (7b) to monoclonal antibodies are reported. Reagents 7a and 7b were prepared in high radiochemical yield by iododestannylation of their corresponding 5-tri-n-butylstannyl precursors. Radioiodinated antibody conjugates were prepared by reaction of 7a or 7b with the protein at basic pH. Evaluation of these conjugates by several in vitro procedures demonstrated that the radiolabel was attached to the antibody in a stable manner and that the conjugates maintained immunoreactivity. Comparative dual-isotope biodistribution studies of a monoclonal antibody Fab fragment conjugate of 7a and 7b with the same Fab fragment labeled with N-succinimidyl p-(131I)iodobenzoate (PIB, p-iodobenzoate, 2) or directly radioiodinated have been carried out in tumor-bearing nude mice. Coinjection of the Fab conjugate of 7a with the Fab conjugate of 2 demonstrated that the biodistributions were similar in most organs, except the neck tissue (thyroid-containing) and the stomach, which contained substantially increased levels of the 7a label. Coinjection of the Fab conjugate of 7a with the Fab fragment radioiodinated by using the chloramine-T method demonstrated that the biodistributions were remarkably similar, suggesting roughly equivalent in vivo deiodination of these labeled antibody fragments. Coinjection of the Fab conjugate of 7a with the Fab conjugate of 7b indicated that there was {approximately} a 2-fold reduction in the amount of in vivo deiodination of the 7b conjugate as compared to the 7a conjugate.

  6. Context Dependent Effects of Chimeric Peptide Morpholino Conjugates Contribute to Dystrophin Exon-skipping Efficiency

    Directory of Open Access Journals (Sweden)

    HaiFang Yin

    2013-01-01

    Full Text Available We have recently reported that cell-penetrating peptides (CPPs and novel chimeric peptides containing CPP (referred as B peptide and muscle-targeting peptide (referred as MSP motifs significantly improve the systemic exon-skipping activity of morpholino phosphorodiamidate oligomers (PMOs in dystrophin-deficient mdx mice. In the present study, the general mechanistic significance of the chimeric peptide configuration on the activity and tissue uptake of peptide conjugated PMOs in vivo was investigated. Four additional chimeric peptide-PMO conjugates including newly identified peptide 9 (B-9-PMO and 9-B-PMO and control peptide 3 (B-3-PMO and 3-B-PMO were tested in mdx mice. Immunohistochemical staining, RT-PCR and western blot results indicated that B-9-PMO induced significantly higher level of exon skipping and dystrophin restoration than its counterpart (9-B-PMO, further corroborating the notion that the activity of chimeric peptide-PMO conjugates is dependent on relative position of the tissue-targeting peptide motif within the chimeric peptide with respect to PMOs. Subsequent mechanistic studies showed that enhanced cellular uptake of B-MSP-PMO into muscle cells leads to increased exon-skipping activity in comparison with MSP-B-PMO. Surprisingly, further evidence showed that the uptake of chimeric peptide-PMO conjugates of both orientations (B-MSP-PMO and MSP-B-PMO was ATP- and temperature-dependent and also partially mediated by heparan sulfate proteoglycans (HSPG, indicating that endocytosis is likely the main uptake pathway for both chimeric peptide-PMO conjugates. Collectively, our data demonstrate that peptide orientation in chimeric peptides is an important parameter that determines cellular uptake and activity when conjugated directly to oligonucleotides. These observations provide insight into the design of improved cell targeting compounds for future therapeutics studies.

  7. Context Dependent Effects of Chimeric Peptide Morpholino Conjugates Contribute to Dystrophin Exon-skipping Efficiency.

    Science.gov (United States)

    Yin, Haifang; Boisguerin, Prisca; Moulton, Hong M; Betts, Corinne; Seow, Yiqi; Boutilier, Jordan; Wang, Qingsong; Walsh, Anthony; Lebleu, Bernard; Wood, Matthew Ja

    2013-09-24

    We have recently reported that cell-penetrating peptides (CPPs) and novel chimeric peptides containing CPP (referred as B peptide) and muscle-targeting peptide (referred as MSP) motifs significantly improve the systemic exon-skipping activity of morpholino phosphorodiamidate oligomers (PMOs) in dystrophin-deficient mdx mice. In the present study, the general mechanistic significance of the chimeric peptide configuration on the activity and tissue uptake of peptide conjugated PMOs in vivo was investigated. Four additional chimeric peptide-PMO conjugates including newly identified peptide 9 (B-9-PMO and 9-B-PMO) and control peptide 3 (B-3-PMO and 3-B-PMO) were tested in mdx mice. Immunohistochemical staining, RT-PCR and western blot results indicated that B-9-PMO induced significantly higher level of exon skipping and dystrophin restoration than its counterpart (9-B-PMO), further corroborating the notion that the activity of chimeric peptide-PMO conjugates is dependent on relative position of the tissue-targeting peptide motif within the chimeric peptide with respect to PMOs. Subsequent mechanistic studies showed that enhanced cellular uptake of B-MSP-PMO into muscle cells leads to increased exon-skipping activity in comparison with MSP-B-PMO. Surprisingly, further evidence showed that the uptake of chimeric peptide-PMO conjugates of both orientations (B-MSP-PMO and MSP-B-PMO) was ATP- and temperature-dependent and also partially mediated by heparan sulfate proteoglycans (HSPG), indicating that endocytosis is likely the main uptake pathway for both chimeric peptide-PMO conjugates. Collectively, our data demonstrate that peptide orientation in chimeric peptides is an important parameter that determines cellular uptake and activity when conjugated directly to oligonucleotides. These observations provide insight into the design of improved cell targeting compounds for future therapeutics studies.Molecular Therapy-Nucleic Acids (2013) 2, e124; doi:10.1038/mtna.2013

  8. Deciphering conjugative plasmid permissiveness in wastewater microbiomes

    DEFF Research Database (Denmark)

    Jacquiod, Samuel Jehan Auguste; Brejnrod, Asker Daniel; Milani, Stefan Morberg

    2017-01-01

    Wastewater treatment plants (WWTPs) are designed to robustly treat polluted water. They are characterized by ceaseless flows of organic, chemical and microbial matter, followed by treatment steps before environmental release. WWTPs are hotspots of horizontal gene transfer between bacteria via...... still remains largely uncharted. Furthermore, current in vitro methods used to assess conjugation in complex microbiomes do not include in situ behaviours of recipient cells, resulting in partial understanding of transfers. We investigated the in vitro conjugation capacities of WWTP microbiomes from...... diversity of recipient bacterial phyla for the plasmid was observed, especially in WWTP outlets. We also identified permissive bacteria potentially able to cross WWTPs and engage in conjugation before and after water treatment. Bacterial activity and lifestyle seem to influence conjugation extent...

  9. Conjugated amplifying polymers for optical sensing applications.

    Science.gov (United States)

    Rochat, Sébastien; Swager, Timothy M

    2013-06-12

    Thanks to their unique optical and electrochemical properties, conjugated polymers have attracted considerable attention over the last two decades and resulted in numerous technological innovations. In particular, their implementation in sensing schemes and devices was widely investigated and produced a multitude of sensory systems and transduction mechanisms. Conjugated polymers possess numerous attractive features that make them particularly suitable for a broad variety of sensing tasks. They display sensory signal amplification (compared to their small-molecule counterparts) and their structures can easily be tailored to adjust solubility, absorption/emission wavelengths, energy offsets for excited state electron transfer, and/or for use in solution or in the solid state. This versatility has made conjugated polymers a fluorescence sensory platform of choice in the recent years. In this review, we highlight a variety of conjugated polymer-based sensory mechanisms together with selected examples from the recent literature.

  10. Direct oligonucleotide-photosensitizer conjugates for photochemical delivery of antisense oligonucleotides.

    Science.gov (United States)

    Yuan, Ahu; Laing, Brian; Hu, Yiqiao; Ming, Xin

    2015-04-18

    Activation of photosensitizers in endosomes enables release of therapeutic macromolecules into the cytosol of the target cells for pharmacological actions. In this study, we demonstrate that direct conjugation of photosensitizers to oligonucleotides (ONs) allows spatial and temporal co-localization of the two modalities in the target cells, and thus leads to superior functional delivery of ONs. Further, light-activated delivery of an anticancer ON caused cancer cell killing via modulation of an oncogene and photodynamic therapy.

  11. Enhanced toxicity and cellular uptake of methotrexate-conjugated nanoparticles in folate receptor-positive cancer cells by decorating with folic acid-conjugated d-α-tocopheryl polyethylene glycol 1000 succinate.

    Science.gov (United States)

    Junyaprasert, Varaporn Buraphacheep; Dhanahiranpruk, Sirithip; Suksiriworapong, Jiraphong; Sripha, Kittisak; Moongkarndi, Primchanien

    2015-12-01

    Folic acid-conjugated d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS-FOL) decorated methotrexate (MTX)-conjugated nanoparticles were developed for targeted delivery of MTX to folate receptor-expressed tumor cells. The synthesis of TPGS-FOL followed 3-step process. Firstly, the terminal hydroxyl group of TPGS was converted to sulfonyl chloride using mesyl chloride in comparison with nosyl and tosyl chlorides. The highest conversion efficiency and yield were obtained by mesyl chloride due to the formation of higher reactive intermediate in a presence of triethylamine. Secondly, the substitution of sulfonyl group by sodium azide produced considerably high yield with conversion efficiency of over 90%. Lastly, the coupling reaction of azido-substituted TPGS and propargyl folamide by click reaction resulted in 96% conjugation efficiency without polymer degradation. To fabricate the folate receptor-targeted nanoparticles, 10 and 20%mol MTX-conjugated PEGylated poly(ϵ-caprolactone) nanoparticles were decorated with TPGS-FOL. The size and size distribution of MTX-conjugated nanoparticles relatively increased with %MTX. The MTX release from the nanoparticles was accelerated in acidic medium with an increase of %MTX but retarded in physiological pH medium. The decoration of TPGS-FOL onto the nanoparticles slightly enlarged the size and size distribution of the nanoparticles; however, it did not affect the surface charge. The cytotoxicity and cellular uptake of MCF-7 cells demonstrated that 10% MTX-conjugated nanoparticles and FOL-decorated nanoparticles possessed higher toxicity and uptake efficiency than 20% MTX-conjugated nanoparticles and undecorated nanoparticles, respectively. The results indicated that FOL-10% MTX-conjugated nanoparticles exhibited potential targeted delivery of MTX to folate receptor-expressed cancer cells.

  12. A Targeting Microbubble for Ultrasound Molecular Imaging.

    Directory of Open Access Journals (Sweden)

    James Shue-Min Yeh

    Full Text Available Microbubbles conjugated with targeting ligands are used as contrast agents for ultrasound molecular imaging. However, they often contain immunogenic (streptavidin, which impedes application in humans. Although targeting bubbles not employing the biotin-(streptavidin conjugation chemistry have been explored, only a few reached the stage of ultrasound imaging in vivo, none were reported/evaluated to show all three of the following properties desired for clinical applications: (i low degree of non-specific bubble retention in more than one non-reticuloendothelial tissue; (ii effective for real-time imaging; and (iii effective for acoustic quantification of molecular targets to a high degree of quantification. Furthermore, disclosures of the compositions and methodologies enabling reproduction of the bubbles are often withheld.To develop and evaluate a targeting microbubble based on maleimide-thiol conjugation chemistry for ultrasound molecular imaging.Microbubbles with a previously unreported generic (non-targeting components composition were grafted with anti-E-selectin F(ab'2 using maleimide-thiol conjugation, to produce E-selectin targeting microbubbles. The resulting targeting bubbles showed high specificity to E-selectin in vitro and in vivo. Non-specific bubble retention was minimal in at least three non-reticuloendothelial tissues with inflammation (mouse heart, kidneys, cremaster. The bubbles were effective for real-time ultrasound imaging of E-selectin expression in the inflamed mouse heart and kidneys, using a clinical ultrasound scanner. The acoustic signal intensity of the targeted bubbles retained in the heart correlated strongly with the level of E-selectin expression (|r|≥0.8, demonstrating a high degree of non-invasive molecular quantification.Targeting microbubbles for ultrasound molecular imaging, based on maleimide-thiol conjugation chemistry and the generic composition described, may possess properties (i-(iii desired for

  13. Hybrid electronics and electrochemistry with conjugated polymers.

    Science.gov (United States)

    Inganäs, Olle

    2010-07-01

    In this critical review, we discuss the history and development of polymer devices wherein manipulation of the electronic conductivity by electrochemical redox processes in a conjugated polymer is used to form new functions. The devices employed are an electrochemical transistor, an electrolyte-gated field-effect transistor and light-emitting electrochemical cells, all of which combine doping/undoping of a conjugated polymer with modification of electronic transport (130 references).

  14. Rapid modification of retroviruses using lipid conjugates

    Science.gov (United States)

    Mukherjee, Nimisha G.; Lyon, L. Andrew; LeDoux, Joseph M.

    2009-02-01

    Methods are needed to manipulate natural nanoparticles. Viruses are particularly interesting because they can act as therapeutic cellular delivery agents. Here we examine a new method for rapidly modifying retroviruses that uses lipid conjugates composed of a lipid anchor (1,2-distearoyl-sn-glycero-3-phosphoethanolamine), a polyethylene glycol chain, and biotin. The conjugates rapidly and stably modified retroviruses and enabled them to bind streptavidin. The implication of this work for modifying viruses for gene therapy and vaccination protocols is discussed.

  15. Energetic tuning in spirocyclic conjugated polymers

    OpenAIRE

    Hugo Bronstein; Frank D. King

    2016-01-01

    Precise control of the energy levels in a conjugated polymer is the key to allowing their exploitation in optoelectronic devices. The introduction of spirocycles into conjugated polymers has traditionally been used to enhance their solid state microstructure. Here we present a highly novel method of energetic tuning through the use of electronically active spirocyclic systems. By modifying the size and oxidation state of a heteroatom in an orthogonal spirocycle we demonstrate energetic fine t...

  16. Metal-leachate-induced conjugate protein instability.

    Science.gov (United States)

    Li, Ning; Osborne, Brandi; Singh, Satish K; Wang, Wei

    2012-08-01

    During the scale-up of an ultrafiltration/diafiltration (UF/DF) step for a protein-based conjugate vaccine, significant precipitation was observed at room temperature. It was found that a specific type of metal hosebarb fitting used in the UF/DF system, when placed in the conjugate solution, caused the precipitation. Inductively Coupled Plasma Mass Spectrometry analysis showed significant amounts of Ni(II), Zn(II), and Cu(II) present in the conjugate solution. A kinetic study showed that the concentration of these metal ions gradually increased with increasing incubation time with a corresponding decrease in conjugate concentration. Direct spiking of trace amounts of NiCl₂, ZnCl₂, and CuCl₂ into the conjugate solution also caused precipitation, and spiking studies showed that the metal ions caused precipitation of the conjugate but not of the carrier protein, antigen, or carrier protein + linker. The precipitation was found to be significantly dependent on buffer species but not solution pH and led to an irreversible loss of tertiary structure even after dissolution in and removal of guanidine hydrochloride. The precipitation is likely the result of formation of transition-metal complexes with histidine residues on the antigen peptide, which may involve both intraconjugate and interconjugate antigens. Such complexation may lead to formation of multimers that may exceed the solubility limit.

  17. Conjugated microporous polymers: design, synthesis and application.

    Science.gov (United States)

    Xu, Yanhong; Jin, Shangbin; Xu, Hong; Nagai, Atsushi; Jiang, Donglin

    2013-10-21

    Conjugated microporous polymers (CMPs) are a class of organic porous polymers that combine π-conjugated skeletons with permanent nanopores, in sharp contrast to other porous materials that are not π-conjugated and with conventional conjugated polymers that are nonporous. As an emerging material platform, CMPs offer a high flexibility for the molecular design of conjugated skeletons and nanopores. Various chemical reactions, building blocks and synthetic methods have been developed and a broad variety of CMPs with different structures and specific properties have been synthesized, driving the rapid growth of the field. CMPs are unique in that they allow the complementary utilization of π-conjugated skeletons and nanopores for functional exploration; they have shown great potential for challenging energy and environmental issues, as exemplified by their excellent performance in gas adsorption, heterogeneous catalysis, light emitting, light harvesting and electrical energy storage. This review describes the molecular design principles of CMPs, advancements in synthetic and structural studies and the frontiers of functional exploration and potential applications.

  18. Dosing Schedules for Pneumococcal Conjugate Vaccine

    Science.gov (United States)

    2014-01-01

    Since second generation pneumococcal conjugate vaccines (PCVs) targeting 10 and 13 serotypes became available in 2010, the number of national policy makers considering these vaccines has steadily increased. An important consideration for a national immunization program is the timing and number of doses—the schedule—that will best prevent disease in the population. Data on disease epidemiology and the efficacy or effectiveness of PCV schedules are typically considered when choosing a schedule. Practical concerns, such as the existing vaccine schedule, and vaccine program performance are also important. In low-income countries, pneumococcal disease and deaths typically peak well before the end of the first year of life, making a schedule that provides PCV doses early in life (eg, a 6-, 10- and 14-week schedule) potentially the best option. In other settings, a schedule including a booster dose may address disease that peaks in the second year of life or may be seen to enhance a schedule already in place. A large and growing body of evidence from immunogenicity studies, as well as clinical trials and observational studies of carriage, pneumonia and invasive disease, has been systematically reviewed; these data indicate that schedules of 3 or 4 doses all work well, and that the differences between these regimens are subtle, especially in a mature program in which coverage is high and indirect (herd) effects help enhance protection provided directly by a vaccine schedule. The recent World Health Organization policy statement on PCVs endorsed a schedule of 3 primary doses without a booster or, as a new alternative, 2 primary doses with a booster dose. While 1 schedule may be preferred in a particular setting based on local epidemiology or practical considerations, achieving high coverage with 3 doses is likely more important than the specific timing of doses. PMID:24336059

  19. Essential role of Ufm1 conjugation in the hematopoietic system.

    Science.gov (United States)

    Cai, Yafei; Singh, Nagendra; Li, Honglin

    2016-06-01

    Protein modification by ubiquitin (Ub) and ubiquitin-like (Ubl) proteins plays a pivotal role in a wide range of cellular functions and signaling pathways. The Ufm1 conjugation system is a novel ubiquitin-like system that consists of Ufm1, Uba5 (E1), Ufc1 (E2), and less defined E3 ligase(s) and targets. Despite its discovery more than a decade ago, its biological functions and working mechanism remains poorly understood. Recent genetic studies using knockout mouse models provide unambiguous evidence for the indispensable role of the Ufm1 system in animal development and hematopoiesis, especially erythroid development. In this short review, we summarize the recent progress on this important protein modification system and highlight potential challenges ahead. Further elucidation of the function and working mechanism of the ufmylation pathway would provide insight into disease pathogenesis and novel therapeutic targets for blood-related diseases such as anemia.

  20. A small-molecule drug conjugate for the treatment of carbonic anhydrase IX expressing tumors.

    Science.gov (United States)

    Krall, Nikolaus; Pretto, Francesca; Decurtins, Willy; Bernardes, Gonçalo J L; Supuran, Claudiu T; Neri, Dario

    2014-04-14

    Antibody-drug conjugates are a very promising class of new anticancer agents, but the use of small-molecule ligands for the targeted delivery of cytotoxic drugs into solid tumors is less well established. Here, we describe the first small-molecule drug conjugates for the treatment of carbonic anhydrase IX expressing solid tumors. Using ligand-dye conjugates we demonstrate that such molecules can preferentially accumulate inside antigen-positive lesions, have fast targeting kinetics and good tumor-penetrating properties, and are easily accessible by total synthesis. A disulfide-linked drug conjugate with the maytansinoid DM1 as the cytotoxic payload and a derivative of acetazolamide as the targeting ligand exhibited a potent antitumor effect in SKRC52 renal cell carcinoma in vivo. It was furthermore superior to sunitinib and sorafenib, both small-molecule standard-of-care drugs for the treatment of kidney cancer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Comparative Analysis of Nanoparticle-Antibody Conjugations: Carbodiimide Versus Click Chemistry

    Directory of Open Access Journals (Sweden)

    Daniel L.J. Thorek

    2009-07-01

    Full Text Available The ability to modify the physical, chemical, and biologic properties of nanoparticles has led to their use as multifunctional platforms for drug delivery and diagnostic imaging applications. Typically, these applications involve functionalizing the nanoparticles with targeting agents. Antibodies remain an attractive choice as targeting agents because of their large epitope space and high affinity; however, implementation of antibody-nanoparticle conjugates is plagued by low coupling efficiencies and the high cost of reagents. Click chemistry may provide a solution to this problem, with reported coupling efficiencies nearing 100%. Although click chemistries have been used to functionalize nanoparticles with small molecules, they have not previously been used to functionalize nanoparticles with antibodies. Concerns associated with extending this procedure to antibodies are that reaction catalysts or the ligands required for cross-linking may result in loss of functionality. We evaluated the efficiency of conjugations between antibodies and superparamagnetic iron oxide nanoparticles using click chemistry as well as the functionality of the product. The results were compared with conjugates formed through carbodiimide cross-linking. The click reaction allowed for a higher extent and efficiency of labeling compared with carbodiimide, thus requiring less antibody. Further, conjugates prepared via the click reaction exhibited improved binding to target receptors.

  2. Use of quantum dot-conjugated antibodies to study intracellular cancer biomarkers in living and fixed cells

    Science.gov (United States)

    Ling, Jian

    2008-02-01

    Quantum dots have unique properties for long-term immunofluorescence imaging of molecular activities inside living cells. The key is how to deliver the quantum dot-conjugated antibodies into cells and further allow the antibodies freely move inside cells to bind target molecules. This study investigated the feasibility of using Pep-1, a cell penetration protein, to facilitate the internalization of quantum dot-conjugated antibodies for the labeling of two intracellular cervical cancer biomarkers: p16 and Mcm5. Quantum dots were directly conjugated with the antibodies to p16 and Mcm5 and, they were able to stain fixed cells and to differentiate biomarker positive and negative cells. The non-covalent binding between the conjugates and Pep-1 peptides allows the quick internalization of the quantum dot-conjugated antibodies into living cells. The internalized conjugates were concentrated in the perinuclear regions of the biomarker-positive HeLa cells. In the biomarker negative Um-Uc-3 cells, however, the conjugates concentrated in juxtaneclear region. Cells bearing with quantum dots still go through the mitosis process. Although the study indicates many questions need to be answered and many problems need to be solved, the use of cell penetration peptide is a promising method for the intracellular labeling of living cell molecules using quantum dots.

  3. Transposase-Mediated Excision, Conjugative Transfer, and Diversity of ICE6013 Elements in Staphylococcus aureus.

    Science.gov (United States)

    Sansevere, Emily A; Luo, Xiao; Park, Joo Youn; Yoon, Sunghyun; Seo, Keun Seok; Robinson, D Ashley

    2017-04-15

    ICE6013 represents one of two families of integrative conjugative elements (ICEs) identified in the pan-genome of the human and animal pathogen Staphylococcus aureus Here we investigated the excision and conjugation functions of ICE6013 and further characterized the diversity of this element. ICE6013 excision was not significantly affected by growth, temperature, pH, or UV exposure and did not depend on recA The IS30-like DDE transposase (Tpase; encoded by orf1 and orf2) of ICE6013 must be uninterrupted for excision to occur, whereas disrupting three of the other open reading frames (ORFs) on the element significantly affects the level of excision. We demonstrate that ICE6013 conjugatively transfers to different S. aureus backgrounds at frequencies approaching that of the conjugative plasmid pGO1. We found that excision is required for conjugation, that not all S. aureus backgrounds are successful recipients, and that transconjugants acquire the ability to transfer ICE6013 Sequencing of chromosomal integration sites in serially passaged transconjugants revealed a significant integration site preference for a 15-bp AT-rich palindromic consensus sequence, which surrounds the 3-bp target site that is duplicated upon integration. A sequence analysis of ICE6013 from different host strains of S. aureus and from eight other species of staphylococci identified seven divergent subfamilies of ICE6013 that include sequences previously classified as a transposon, a plasmid, and various ICEs. In summary, these results indicate that the IS30-like Tpase functions as the ICE6013 recombinase and that ICE6013 represents a diverse family of mobile genetic elements that mediate conjugation in staphylococci.IMPORTANCE Integrative conjugative elements (ICEs) encode the abilities to integrate into and excise from bacterial chromosomes and plasmids and mediate conjugation between bacteria. As agents of horizontal gene transfer, ICEs may affect bacterial evolution. ICE6013 represents one

  4. Construction of humanized carcinoembryonic antigen specific single chain variable fragment and mitomycin conjugate

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To construct a new target-oriented conjugate of humanized carcinoembryonic antigen (CEA) specific single chain variable fragment (scFv) and mitomycin (MMC) against colorectal cancer, and to investigate its influence on the growth and apoptosis of colorectal cancer cells.METHODS: The primer was designed according to the gene sequence described in reference 16, which respectively contains restriction enzyme cleavage sites BamH Ⅰ and EcoR Ⅰ in its upstream and downstream.PCR was performed with the plasmid as template containing genes of humanized anti-CEA scFv. The product was digested by BamH Ⅰ and EcoR Ⅰ, and connected to an expression vector which also has the restriction enzyme cleavage sites BamH Ⅰ and EcoR.Expression of the reaction was induced by isopropy-β-D-thiogalactoside (IPTG). Then the expression product was covalently coupled with MMC by dextran T-40. The immunoreactivity of the conjugate against colorectal cancer cells as well as CEA was measured by enzyme linked immunosorbent assay (ELISA). The inhibiting ratio of conjugate on the growth of colorectal cancer cells was also measured by ELISA. The effect of conjugate on the apoptosis of colorectal cancer cells was determined by flow cytometry (FCM).RESULTS: Restriction endonuclease cleavage and gene sequencing confirmed that the expression vector was successfully constructed. Sodium dodecyl sulfate polyacrylamide gel electropheresis (SDS-VAGE) confirmed that this vector correctly expressed the fusion protein.ELISA confirmed that the conjugate had quite a strong immunoreactivity against colorectal cancer cells and CEA. The conjugate had inhibitory effects on colorectal cancer cells in a concentration-dependent manner and could induce apoptosis of colorectal cancer cells in a concentration-dependent manner.CONCLUSION: The CEA-scFv-MMC conjugate can be successfully constructed and is able to inhibit the growth and induce apoptosis of colorectal cancer cells.

  5. Methyllithium-Doped Naphthyl-Containing Conjugated Microporous Polymer with Enhanced Hydrogen Storage Performance.

    Science.gov (United States)

    Xu, Dan; Sun, Lei; Li, Gang; Shang, Jin; Yang, Rui-Xia; Deng, Wei-Qiao

    2016-06-01

    Hydrogen storage is a primary challenge for using hydrogen as a fuel. With ideal hydrogen storage kinetics, the weak binding strength of hydrogen to sorbents is the key barrier to obtain decent hydrogen storage performance. Here, we reported the rational synthesis of a methyllithium-doped naphthyl-containing conjugated microporous polymer with exceptional binding strength of hydrogen to the polymer guided by theoretical simulations. Meanwhile, the experimental results showed that isosteric heat can reach up to 8.4 kJ mol(-1) and the methyllithium-doped naphthyl-containing conjugated microporous polymer exhibited an enhanced hydrogen storage performance with 150 % enhancement compared with its counterpart naphthyl-containing conjugated microporous polymer. These results indicate that this strategy provides a direction for design and synthesis of new materials that meet the US Department of Energy (DOE) hydrogen storage target.

  6. Access to site-specific Fc-cRGD peptide conjugates through streamlined expressed protein ligation.

    Science.gov (United States)

    Frutos, S; Jordan, J B; Bio, M M; Muir, T W; Thiel, O R; Vila-Perelló, M

    2016-10-12

    An ideal drug should be highly effective, non-toxic and be delivered by a convenient and painless single dose. We are still far from such optimal treatment but peptides, with their high target selectivity and low toxicity profiles, provide a very attractive platform from which to strive towards it. One of the major limitations of peptide drugs is their high clearance rates, which limit dosage regimen options. Conjugation to antibody Fc domains is a viable strategy to improve peptide stability by increasing their hydrodynamic radius and hijacking the Fc recycling pathway. We report the use of a split-intein based semi-synthetic approach to site-specifically conjugate a synthetic integrin binding peptide to an Fc domain. The strategy described here allows conjugating synthetic peptides to Fc domains, which is not possible via genetic methods, fully maintaining the ability of both the Fc domain and the bioactive peptide to interact with their binding partners.

  7. Implications of Partial Conjugation of Whey Protein Isolate to Durian Seed Gum through Maillard Reactions: Foaming Properties, Water Holding Capacity and Interfacial Activity

    Directory of Open Access Journals (Sweden)

    Bahareh Tabatabaee Amid

    2013-12-01

    Full Text Available This paper deals with the conjugation of durian seed gum (DSG with whey protein isolate (WPI through Maillard reactions. Subsequently, the functional properties of durian seed gum in the non-conjugated (control sample and conjugated forms were compared with several commercial gums (i.e., Arabic gum, sodium alginate, kappa carrageenan, guar gum, and pectin. The current study revealed that the conjugation of durian seed gum with whey protein isolate significantly (p < 0.05 improved its foaming properties. In this study, the conjugated durian seed gum produced the most stable foam among all samples. On the other hand, the emulsion stabilized with the conjugated durian seed gum also showed more uniform particles with a larger specific surface area than the emulsion containing the non-conjugated durian seed gum. The conjugated durian seed gum showed significant different foaming properties, specific surface area, particle uniformity and water holding capacity (WHC as compared to the target polysaccharide gums. The conjugated durian seed gum showed more similar functional properties to Arabic gum rather than other studied gums.

  8. Implications of partial conjugation of whey protein isolate to durian seed gum through Maillard reactions: foaming properties, water holding capacity and interfacial activity.

    Science.gov (United States)

    Amid, Bahareh Tabatabaee; Mirhosseini, Hamed; Poorazarang, Hashem; Mortazavi, Seyed Ali

    2013-12-06

    This paper deals with the conjugation of durian seed gum (DSG) with whey protein isolate (WPI) through Maillard reactions. Subsequently, the functional properties of durian seed gum in the non-conjugated (control sample) and conjugated forms were compared with several commercial gums (i