Internal radiotherapy and dosimetric study for {sup 111}In/{sup 177}Lu-pegylated liposomes conjugates in tumor-bearing mice

Energy Technology Data Exchange (ETDEWEB)

Wang, H.-E. [Institute of Radiological Sciences, National Yang Ming University, Taipei, Taiwan (China); Yu, H.-M. [Institute of Radiological Sciences, National Yang Ming University, Taipei, Taiwan (China); Lu, Y.-C. [Institute of Radiological Sciences, National Yang Ming University, Taipei, Taiwan (China); Heish, N.-N. [National Health Research Institute, Taipei, Taiwan (China); Tseng, Yun-Long [Taiwan Liposome Co. Ltd., Taipei, Taiwan (China); Huang, K.-L. [Institute of Nuclear Energy Research, Taoyuan, Taiwan (China); Chuang, K.-T. [Institute of Nuclear Energy Research, Taoyuan, Taiwan (China); Chen, Chin-Hsiung [Institute of Radiological Sciences, National Yang Ming University, Taipei, Taiwan (China); Hwang, J.-J. [Institute of Radiological Sciences, National Yang Ming University, Taipei, Taiwan (China); Lin, W.-J. [Institute of Nuclear Energy Research, Taoyuan, Taiwan (China); Wang, Shyh-Jen [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan (China); Ting, G. [National Health Research Institute, Taipei, Taiwan (China); Whang-Peng, Jacqueline [National Health Research Institute, Taipei, Taiwan (China); Deng, W.-P. [Graduate Institute of Biomedical Materials, Taipei Medical University, Taipei, Taiwan (China)]. E-mail: wpdeng@tmu.edu.tw

2006-12-20

In vivo characterization and dosimetric analysis has been performed to evaluate the potential of pegylated liposomes as carriers of radionuclides in tumor internal radiotherapy. Methods: The DTPA/PEG-liposomes were synthesized with a medium size of 110 nm, conjugated with {sup 111}In/{sup 177}Lu-(oxine){sub 3} to afford {sup 111}In/{sup 177}Lu-liposome. The stability of {sup 111}In/{sup 177}Lu-liposome in serum was investigated. The biodistribution, scintigraphic imaging and pharmacokinetics of {sup 111}In/{sup 177}Lu-liposomes after intravenous(i.v.) injection into C-26 tumor-bearing BALB/cByJ mice were studied. Radiation dose was estimated by MIRD-III program. Results: The incorporation efficiency of {sup 111}In/{sup 177}Lu into liposomes was 95%. After incubation at 37 {sup o}C for 72 h in serum, more than 83% of radioactivity was still retained in the intact {sup 111}In/{sup 177}Lu-liposomes. The biodistribution of {sup 111}In-liposomes showed that the radioactivity in the blood decreased from 23.14{+-}8.16%ID/g at 1 h to 0.02{+-}0.00%ID/g at 72 h post-injection (p.i.), while reaching its maximum accumulation in tumors at 48 h p.i., with half-life in blood of 10.2 h. The results were supported by that of {sup 177}Lu-liposomes. Scintigraphic imaging with {sup 111}In-liposomes showed unambiguous tumor images at 48 h p.i. Dose estimation showed that the absorbed dose in tumor from {sup 177}Lu-liposomes was 5.74x10{sup -5} Gy/MBq. Conclusions: This study provides an in vivo characterization and dosimetric evaluation for the use of liposome systems as carriers in targeted radionuclide therapy. The results suggest that adequate tumor targeting as well as dose delivered to tumors could be achieved by the use of radionuclide targeted liposomes.

Determination of liposomal boron biodistribution in tumor bearing mice by using neutron capture autoradiography

International Nuclear Information System (INIS)

Yanagie, H.; Yasuhara, H.; Ogura, K.; Maruyama, K.; Matsumoto, T.; Skvarc, J.; Ilic, R.; Kuhne, G.; Eriguchi, M.; Kobayashi, H.

2001-01-01

It is necessary to accumulate the 10 B atoms selectively to the tumor cells for effective boron neutron capture therapy (BNCT). In order to achieve accurate measurements of 10 B concentrations in biological samples, we employ a technique of neutron capture autoradiography (NCAR) of the sliced whole body samples of tumor bearing mice using CR- 39 plastic track detectors. The CR-39 detectors attached with samples were exposed to thermal neutrons in the thermal column of the TRIGA II reactor at the Institute for Atomic Energy, Rikkyo University. We obtained NCAR images for mice injected intraveneously by 10 B-polyethylene-glycol (PEG) binding liposome or 10 B-bare liposome. The 10 B concentrations in the tumor tissue of mice were estimated by means of alpha and lithium track density measurements. In this study, we increased the accumulation of 10 B atoms in the tumor tissues by binding PEG chains to the surface of liposome, which increase the retension in the blood flow and escape the phagocytosis by reticulo-endotherial systems. Therefore, 10 B-PEG liposome is a candidate for an effective 10 B carrier in BNCT.(author)

Computed Tomography Imaging of Solid Tumors Using a Liposomal-Iodine Contrast Agent in Companion Dogs with Naturally Occurring Cancer.

Science.gov (United States)

Ghaghada, Ketan B; Sato, Amy F; Starosolski, Zbigniew A; Berg, John; Vail, David M

2016-01-01

Companion dogs with naturally occurring cancer serve as an important large animal model in translational research because they share strong similarities with human cancers. In this study, we investigated a long circulating liposomal-iodine contrast agent (Liposomal-I) for computed tomography (CT) imaging of solid tumors in companion dogs with naturally occurring cancer. The institutional animal ethics committees approved the study and written informed consent was obtained from all owners. Thirteen dogs (mean age 10.1 years) with a variety of masses including primary and metastatic liver tumors, sarcomas, mammary carcinoma and lung tumors, were enrolled in the study. CT imaging was performed pre-contrast and at 15 minutes and 24 hours after intravenous administration of Liposomal-I (275 mg/kg iodine dose). Conventional contrast-enhanced CT imaging was performed in a subset of dogs, 90 minutes prior to administration of Liposomal-I. Histologic or cytologic diagnosis was obtained for each dog prior to admission into the study. Liposomal-I resulted in significant (p contrast agent was demonstrated. Liposomal-I enabled visualization of primary and metastatic liver tumors. Sub-cm sized liver lesions grossly appeared as hypo-enhanced compared to the surrounding normal parenchyma with improved lesion conspicuity in the post-24 hour scan. Large liver tumors (> 1 cm) demonstrated a heterogeneous pattern of intra-tumoral signal with visibly higher signal enhancement at the post-24 hour time point. Extra-hepatic, extra-splenic tumors, including histiocytic sarcoma, anaplastic sarcoma, mammary carcinoma and lung tumors, were visualized with a heterogeneous enhancement pattern in the post-24 hour scan. The long circulating liposomal-iodine contrast agent enabled prolonged visualization of small and large tumors in companion dogs with naturally occurring cancer. The study warrants future work to assess the sensitivity and specificity of the Liposomal-I agent in various types of

Protease-Sensitive Liposomes in Chemotherapy & Chemoradiotherapy: From Material Development to In Vivo Application in Tumor-Bearing Mice

DEFF Research Database (Denmark)

Brogaard, Rikke Yding; Melander, Fredrik

to enhance therapeutic efficacies. In this thesis, the development, characterization, and evaluation of an advanced liposomal DDS and its potential in chemoradiotherapy is presented from material development to in vivo application in tumor*bearing mice. In the first part of the thesis, we report the design...... concept of the liposomal DDS, which leads to rapid cellular uptake. Various lipid compositions are tested in uptake and cytotoxicity experiments in vitro, followed by in vivo experiments where the ability of the liposomal DDS to accumulate in tumors together with its anti*cancer activity is explored...... in tumor*bearing mice. The in vivo data demonstrates superior anti*cancer activity relative to the free drug and to conventional, long circulating liposomes. This indicates that the MMP*sensitive liposomal DDS holds potential in therapeutic applications. In the second part of the thesis, the potential...

Peptide-Mediated Liposomal Drug Delivery System Targeting Tumor Blood Vessels in Anticancer Therapy

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Han-Chung Wu

2010-01-01

Full Text Available Solid tumors are known to recruit new blood vessels to support their growth. Therefore, unique molecules expressed on tumor endothelial cells can function as targets for the antiangiogenic therapy of cancer. Current efforts are focusing on developing therapeutic agents capable of specifically targeting cancer cells and tumor-associated microenvironments including tumor blood vessels. These therapies hold the promise of high efficacy and low toxicity. One recognized strategy for improving the therapeutic effectiveness of conventional chemotherapeutics is to encapsulate anticancer drugs into targeting liposomes that bind to the cell surface receptors expressed on tumor-associated endothelial cells. These anti-angiogenic drug delivery systems could be used to target both tumor blood vessels as well as the tumor cells, themselves. This article reviews the mechanisms and advantages of various present and potential methods using peptide-conjugated liposomes to specifically destroy tumor blood vessels in anticancer therapy.

Influence of vascular normalization on interstitial flow and delivery of liposomes in tumors

International Nuclear Information System (INIS)

Ozturk, Deniz; Yonucu, Sirin; Yilmaz, Defne; Unlu, Mehmet Burcin

2015-01-01

Elevated interstitial fluid pressure is one of the barriers of drug delivery in solid tumors. Recent studies have shown that normalization of tumor vasculature by anti-angiogenic factors may improve the delivery of conventional cytotoxic drugs, possibly by increasing blood flow, decreasing interstitial fluid pressure, and enhancing the convective transvascular transport of drug molecules. Delivery of large therapeutic agents such as nanoparticles and liposomes might also benefit from normalization therapy since their transport depends primarily on convection. In this study, a mathematical model is presented to provide supporting evidence that normalization therapy may improve the delivery of 100 nm liposomes into solid tumors, by both increasing the total drug extravasation and providing a more homogeneous drug distribution within the tumor. However these beneficial effects largely depend on tumor size and are stronger for tumors within a certain size range. It is shown that this size effect may persist under different microenvironmental conditions and for tumors with irregular margins or heterogeneous blood supply. (paper)

In vitro study of novel gadolinium-loaded liposomes guided by GBI-10 aptamer for promising tumor targeting and tumor diagnosis by magnetic resonance imaging

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Gu MJ

2015-08-01

Full Text Available Meng-Jie Gu,1,* Kun-Feng Li,1,* Lan-Xin Zhang,1 Huan Wang,1 Li-Si Liu,2 Zhuo-Zhao Zheng,2 Nan-Yin Han,1 Zhen-Jun Yang,1 Tian-Yuan Fan1 1State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 2Department of Radiology, Peking University Third Hospital, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: Novel gadolinium-loaded liposomes guided by GBI-10 aptamer were developed and evaluated in vitro to enhance magnetic resonance imaging (MRI diagnosis of tumor. Nontargeted gadolinium-loaded liposomes were achieved by incorporating amphipathic material, Gd (III [N,N-bis-stearylamidomethyl-N'-amidomethyl] diethylenetriamine tetraacetic acid, into the liposome membrane using lipid film hydration method. GBI-10, as the targeting ligand, was then conjugated onto the liposome surface to get GBI-10-targeted gadolinium-loaded liposomes (GTLs. Both nontargeted gadolinium-loaded liposomes and GTLs displayed good dispersion stability, optimal size, and zeta potential for tumor targeting, as well as favorable imaging properties with enhanced relaxivity compared with a commercial MRI contrast agent (CA, gadopentetate dimeglumine. The use of GBI-10 aptamer in this liposomal system was intended to result in increased accumulation of gadolinium at the periphery of C6 glioma cells, where the targeting extracellular matrix protein tenascin-C is overexpressed. Increased cellular binding of GTLs to C6 cells was confirmed by confocal microscopy, flow cytometry, and MRI, demonstrating the promise of this novel delivery system as a carrier of MRI contrast agent for the diagnosis of tumor. These studies provide a new strategy furthering the development of nanomedicine for both diagnosis and therapy of tumor. Keywords: magnetic resonance imaging, gadolinium, liposomes, tenascin-C, GBI-10 aptamer, tumor targeting

The Treatment of Breast Cancer Using Liposome Technology

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Sarah Brown

2012-01-01

Full Text Available Liposome-based chemotherapeutics used in the treatment of breast cancer can in principle enhance the therapeutic index of otherwise unencapsulated anticancer drugs. This is partially attributed to the fact that encapsulation of cytotoxic agents within liposomes allows for increased concentrations of the drug to be delivered to the tumor site. In addition, the presence of the phospholipid bilayer prevents the encapsulated active form of the drug from being broken down in the body prior to reaching tumor tissue and also serves to minimize exposure of the drug to healthy sensitive tissue. While clinically approved liposome-based chemotherapeutics such as Doxil have proven to be quite effective in the treatment of breast cancer, significant challenges remain involving poor drug transfer between the liposome and cancerous cells. In this review, we discuss the recent advancements made in the development of liposome-based chemotherapeutics with respect to improved drug transfer for use in breast cancer therapy.

Smart thermosensitive liposomes for effective solid tumor therapy and in vivo imaging.

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Kevin Affram

Full Text Available In numerous studies, liposomes have been used to deliver anticancer drugs such as doxorubicin to local heat-triggered tumor. Here, we investigate: (i the ability of thermosensitive liposomal nanoparticle (TSLnp as a delivery system to deliver poorly membrane-permeable anticancer drug, gemcitabine (Gem to solid pancreatic tumor with the aid of local mild hyperthermia and, (ii the possibility of using gadolinium (Magnevist® loaded-TSLnps (Gd-TSLnps to increase magnetic resonance imaging (MRI contrast in solid tumor. In this study, we developed and tested gemcitabine-loaded thermosensitive liposomal nanoparticles (Gem-TSLnps and gadolinium-loaded thermosensitive liposomal nanoparticles (Gd-TSLnps both in in-vitro and in-vivo. The TSLnps exhibited temperature-dependent release of Gem, at 40-42°C, 65% of Gem was released within 10 min, whereas < 23% Gem leakage occurred at 37°C after a period of 2 h. The pharmacokinetic parameters and tissue distribution of both Gem-TSLnps and Gd-TSLnps were significantly greater compared with free Gem and Gd, while Gem-TSLnps plasma clearance was reduced by 17-fold and that of Gd-TSLpns was decreased by 2-fold. Area under the plasma concentration time curve (AUC of Gem-TSLnps (35.17± 0.04 μghr/mL was significantly higher than that of free Gem (2.09 ± 0.01 μghr/mL whereas, AUC of Gd-TSLnps was higher than free Gd by 3.9 fold high. TSLnps showed significant Gem accumulation in heated tumor relative to free Gem. Similar trend of increased Gd-TSLnps accumulation was observed in non-heated tumor compared to that of free Gd; however, no significant difference in MRI contrast enhancement between free Gd and Gd-TSLnps ex-vivo tumor images was observed. Despite Gem-TSLnps dose being half of free Gem dose, antitumor efficacy of Gem-TSLnps was comparable to that of free Gem(Gem-TSLnps 10 mg Gem/kg compared with free Gem 20 mg/kg. Overall, the findings suggest that TSLnps may be used to improve Gem delivery and enhance

Photo activation of HPPH encapsulated in "Pocket" liposomes triggers multiple drug release and tumor cell killing in mouse breast cancer xenografts.

Science.gov (United States)

Sine, Jessica; Urban, Cordula; Thayer, Derek; Charron, Heather; Valim, Niksa; Tata, Darrell B; Schiff, Rachel; Blumenthal, Robert; Joshi, Amit; Puri, Anu

2015-01-01

We recently reported laser-triggered release of photosensitive compounds from liposomes containing dipalmitoylphosphatidylcholine (DPPC) and 1,2 bis(tricosa-10,12-diynoyl)-sn-glycero-3-phosphocholine (DC(8,9)PC). We hypothesized that the permeation of photoactivated compounds occurs through domains of enhanced fluidity in the liposome membrane and have thus called them "Pocket" liposomes. In this study we have encapsulated the red light activatable anticancer photodynamic therapy drug 2-(1-Hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH) (Ex/Em410/670 nm) together with calcein (Ex/Em490/517 nm) as a marker for drug release in Pocket liposomes. A mole ratio of 7.6:1 lipid:HPPH was found to be optimal, with >80% of HPPH being included in the liposomes. Exposure of liposomes with a cw-diode 660 nm laser (90 mW, 0-5 minutes) resulted in calcein release only when HPPH was included in the liposomes. Further analysis of the quenching ratios of liposome-entrapped calcein in the laser treated samples indicated that the laser-triggered release occurred via the graded mechanism. In vitro studies with MDA-MB-231-LM2 breast cancer cell line showed significant cell killing upon treatment of cell-liposome suspensions with the laser. To assess in vivo efficacy, we implanted MDA-MB-231-LM2 cells containing the luciferase gene along the mammary fat pads on the ribcage of mice. For biodistribution experiments, trace amounts of a near infrared lipid probe DiR (Ex/Em745/840 nm) were included in the liposomes. Liposomes were injected intravenously and laser treatments (90 mW, 0.9 cm diameter, for an exposure duration ranging from 5-8 minutes) were done 4 hours postinjection (only one tumor per mouse was treated, keeping the second flank tumor as control). Calcein release occurred as indicated by an increase in calcein fluorescence from laser treated tumors only. The animals were observed for up to 15 days postinjection and tumor volume and luciferase expression was measured. A

Therapeutic efficacy and microSPECT/CT imaging of {sup 188}Re-DXR-liposome in a C26 murine colon carcinoma solid tumor model

Energy Technology Data Exchange (ETDEWEB)

Chang, Y.-J.; Chang, C.-H.; Yu, C.-Y.; Chang, T.-J.; Chen, L.-C. [Institute of Nuclear Energy Research, Taoyuan, Taiwan (China); Chen, M.-H. [National Health Research Institutes, Miaoli, Taiwan (China); Lee, T.-W. [Institute of Nuclear Energy Research, Taoyuan, Taiwan (China); Ting Gann [National Health Research Institutes, Miaoli, Taiwan (China)], E-mail: gann.ting@msa.hinet.net

2010-01-15

Nanocarriers can selectively target cancer sites and carry payloads, thereby improving diagnostic and therapeutic effectiveness and reducing toxicity. The objective of this study was to investigate the therapeutic efficacy of a new co-delivery radiochemotherapeutics of {sup 188}Re-N,N-bis (2-mercaptoethyl)-N',N'-diethylethylenediamine (BMEDA)-labeled pegylated liposomal doxorubicin (DXR) ({sup 188}Re-DXR-liposome) in a C26 murine colon carcinoma solid tumor model. To evaluate the targeting and localization of {sup 188}Re-DXR-liposome in C26 murine tumor-bearing mice, biodistribution, microSPECT/CT imaging and pharmacokinetic studies were performed. The antitumor effect of {sup 188}Re-DXR-liposome was assessed by tumor growth inhibition, survival ratio and histopathological hematoxylin-eosin staining. The tumor target and localization of the nanoliposome delivery radiochemotherapeutics of {sup 188}Re-DXR-liposome were demonstrated in the biodistribution, pharmacokinetics and in vivo nuclear imaging studies. In the study on therapeutic efficacy, the tumor-bearing mice treated with bimodality radiochemotherapeutics of {sup 188}Re-DXR-liposome showed better mean tumor growth inhibition rate (MGI) and longer median survival time (MGI=0.048; 74 days) than those treated with radiotherapeutics of {sup 188}Re-liposome (MGI=0.134; 60 days) and chemotherapeutics of Lipo-Dox (MGI=0.413; 38 days). The synergistic tumor regression effect was observed with the combination index (CI) exceeding 1 (CI=1.145) for co-delivery radiochemotherapeutics of {sup 188}Re-DXR-liposome. Two (25%) of the mice treated with radiochemotherapeutics were completely cured after 120 days. The therapeutic efficacy of radiotherapeutics of {sup 188}Re-liposome and the synergistic effect of the combination radiochemotherapeutics of {sup 188}Re-DXR-liposome have been demonstrated in a C26 murine solid tumor animal model, which pointed to the potential benefit and promise of the co-delivery of

Photo activation of HPPH encapsulated in “Pocket” liposomes triggers multiple drug release and tumor cell killing in mouse breast cancer xenografts

Science.gov (United States)

Sine, Jessica; Urban, Cordula; Thayer, Derek; Charron, Heather; Valim, Niksa; Tata, Darrell B; Schiff, Rachel; Blumenthal, Robert; Joshi, Amit; Puri, Anu

2015-01-01

We recently reported laser-triggered release of photosensitive compounds from liposomes containing dipalmitoylphosphatidylcholine (DPPC) and 1,2 bis(tricosa-10,12-diynoyl)-sn-glycero-3-phosphocholine (DC8,9PC). We hypothesized that the permeation of photoactivated compounds occurs through domains of enhanced fluidity in the liposome membrane and have thus called them “Pocket” liposomes. In this study we have encapsulated the red light activatable anticancer photodynamic therapy drug 2-(1-Hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH) (Ex/Em410/670 nm) together with calcein (Ex/Em490/517 nm) as a marker for drug release in Pocket liposomes. A mole ratio of 7.6:1 lipid:HPPH was found to be optimal, with >80% of HPPH being included in the liposomes. Exposure of liposomes with a cw-diode 660 nm laser (90 mW, 0–5 minutes) resulted in calcein release only when HPPH was included in the liposomes. Further analysis of the quenching ratios of liposome-entrapped calcein in the laser treated samples indicated that the laser-triggered release occurred via the graded mechanism. In vitro studies with MDA-MB-231-LM2 breast cancer cell line showed significant cell killing upon treatment of cell-liposome suspensions with the laser. To assess in vivo efficacy, we implanted MDA-MB-231-LM2 cells containing the luciferase gene along the mammary fat pads on the ribcage of mice. For biodistribution experiments, trace amounts of a near infrared lipid probe DiR (Ex/Em745/840 nm) were included in the liposomes. Liposomes were injected intravenously and laser treatments (90 mW, 0.9 cm diameter, for an exposure duration ranging from 5–8 minutes) were done 4 hours postinjection (only one tumor per mouse was treated, keeping the second flank tumor as control). Calcein release occurred as indicated by an increase in calcein fluorescence from laser treated tumors only. The animals were observed for up to 15 days postinjection and tumor volume and luciferase expression was measured. A

Clearance and Biodistribution of Liposomally Encapsulated Nitroxides: A Model for Targeted Delivery of Electron Paramagnetic Resonance Imaging Probes to Tumors

Science.gov (United States)

Burks, Scott R.; Legenzov, Eric A.; Rosen, Gerald M.

2011-01-01

Electron paramagnetic resonance (EPR) imaging using nitroxides as molecular probes is potentially a powerful tool for the detection and physiological characterization of micrometastatic lesions. Encapsulating nitroxides in anti-HER2 immunoliposomes at high concentrations to take advantage of the “self-quenching” phenomenon of nitroxides allows generation of robust EPR signals in HER2-overexpressing breast tumor cells with minimal background from indifferent tissues or circulating liposomes. We investigated the in vivo pharmacological properties of nitroxides encapsulated in sterically stabilized liposomes designed for long circulation times. We show that circulation times of nitroxides can be extended from hours to days; this increases the proportion of liposomes in circulation to enhance tumor targeting. Furthermore, nitroxides encapsulated in sterically stabilized anti-HER2 immunoliposomes can be delivered to HER2-overexpressing tumors at micromolar concentrations, which should be imageable by EPR. Lastly, after in vivo administration, liposomally encapsulated nitroxide signal also appears in the liver, spleen, and kidneys. Although these organs are spatially distinct and would not hinder tumor imaging in our model, understanding nitroxide signal retention in these organs is essential for further improvements in EPR imaging contrast between tumors and other tissues. These results lay the foundation to use liposomally delivered nitroxides and EPR imaging to visualize tumor cells in vivo. PMID:21737567

Liposomes containing alkylated methotrexate analogues for phospholipase A(2) mediated tumor targeted drug delivery

DEFF Research Database (Denmark)

Kaasgaard, Thomas; Andresen, Thomas Lars; Jensen, Simon Skøde

2009-01-01

of alkylated compounds in liposomes, it was demonstrated that the MTX-analogue partitioned into the water phase and thereby became available for cell uptake. It was concluded that liposomes containing alkylated MTX-analogues show promise as a drug delivery system, although the MTX-analogue needs to be more......Two lipophilic methotrexate analogues have been synthesized and evaluated for cytotoxicity against KATO III and HT-29 human colon cancer cells. Both analogues contained a C-16-alkyl chain attached to the gamma-carboxylic acid and one of the analogues had an additional benzyl group attached...... cytotoxicity was incorporated into liposomes that were designed to be particularly Susceptible to a liposome degrading enzyme, secretory phospholipase A(2) (sPLA(2)), which is found in high concentrations in tumors of several different cancer types. Liposome incorporation was investigated by differential...

The preparation of Tc-99m labeled liposomes by a cationic SP/DOPE formulation for tumor imaging

International Nuclear Information System (INIS)

Yu, M.D.; Hsieh, D.S.; Huang, W.S.

2002-01-01

Aim: Liposomes can provide a gene delivery system to be used in the cancer gene therapy. Radiolabeled liposomes can be used in tumor imaging and tumor therapy. A new cationic liposome formulation of sphingosin e (SP) and dioleoylphosphatidylethanolamine (DOPE) was developed and showed very efficient transfection in a wide variety of mammalian cancer cells, including SKOV-3 (human ovarian carcinoma cells), NPC076 (human nasopharyngeal carcinoma cells), and A431 (human epidermoid carcinoma cells) (Kao et al., Oncol Reports. 5:625-629, 1998). The present study is designed and evaluated the labeling and stability of Tc-99m liposomes by SP/DOPE formulation. Material and Methods: A mixture of 8 mg of SP (Sigma Chemical) and 8 mg of DOPE (Sigma Chemical) dissolved in 4 ml absolute ethanol and used as a lipid stock solution (4 mg/ml). In the direct labeling method, taking 0.25 ml (1 mg) stock solution dried under nitrogen gas and then added 1 ml 20 mM HEPES buffer for hydration 8 hours. The remaining stock solution was dried, hydrated 8 hours, and sonicated 10 min to form liposomes for after-loading labeling method (preformed liposomes). The labeling studies included Tc-99m direct labeling (1), Tc-99m HMPAO direct labeling (2), Tc-99m stannous chloride after-loading labeling (3), Tc-99m HMPAO after-loading labeling (4), and Tc-99m pCMVβ DNA inclusion labeling (5). The labeling efficiency (LE) was determined by thin layer chromatography. The labeled liposomes were incubated with fetal bovine serum (FBS) 30 min to evaluate their stability. Results: It is shown that LE (48%) of Tc-99m direct labeling was the highest in the five methods; however, the LE was reduced to 9% (corrected to original LE) after incubating with serum. Tc-99m may be loosely conjugated to the outer surface of the liposomes. The LE (32%) of Tc-99m HMPAO direct labeling was the second; however, LE was most stable when incubating with serum. The LE of the after-loading labeling was not better than that of

Boron-Containing Compounds for Liposome-Mediated Tumor Localization and Application to Neutron Capture Therapy

International Nuclear Information System (INIS)

Hawthorne, M. Frederick

2005-01-01

Medical application of boron neutron capture therapy (BNCT) has been significantly hindered by the slow development of boron drug-targeting methodologies for the selective delivery of high boron concentration sto malignant cells. We have successfully sought to fill this need by creating liposomes suitable as in vivo boron delivery vehicles for BNCT. Delivery of therapeutic quantities of boron to tumors in murine models has been achieved with small unilamellar boron-rich liposomes. Subsequently, attempts have been made to improve delivery efficiency of liposomes encapsulating boron-containing water-soluble species into their hollow core by incorporating lipophilic boron compounds as addenda to the liposome bilayer, incorporating boron compounds as structural components of the bilayer (which however, poses the risk of sacrificing some stability), and combinations thereof. Regardless of the method, approximately 90% of the total liposome mass remains therapeutically inactive and comprised of the vehicle's construction materials, while less than 5% is boron for neutron targeting. Following this laboratory's intensive study, the observed tumor specificity of certain liposomes has been attributed to their diminutive size of these liposomes (30-150 nm), which enables these small vesicles to pass through the porous, immature vasculature of rapidly growing tumor tissue. We surmised that any amphiphilic nanoparticle of suitable size could possess some tumor selectivity. Consequently, the discovery of a very boron-rich nanoparticle delivery agent with biodistribution performance similar to unilamellar liposomes became one of our goals. Closomers, a new class of polyhedral borane derivatives, attracted us as an alternative BNCT drug-delivery system. We specifically envisioned dodeca (nido-carboranyl)-substituted closomers as possibly having a great potential role in BNCT drug delivery. They could function as extraordinarily boron-rich BNCT drugs since they are amphiphilic

Increased tumor localization and reduced immune response to adenoviral vector formulated with the liposome DDAB/DOPE.

Science.gov (United States)

Steel, Jason C; Cavanagh, Heather M A; Burton, Mark A; Abu-Asab, Mones S; Tsokos, Maria; Morris, John C; Kalle, Wouter H J

2007-04-01

We aimed to increase the efficiency of adenoviral vectors by limiting adenoviral spread from the target site and reducing unwanted host immune responses to the vector. We complexed adenoviral vectors with DDAB-DOPE liposomes to form adenovirus-liposomal (AL) complexes. AL complexes were delivered by intratumoral injection in an immunocompetent subcutaneous rat tumor model and the immunogenicity of the AL complexes and the expression efficiency in the tumor and other organs was examined. Animals treated with the AL complexes had significantly lower levels of beta-galactosidase expression in systemic tissues compared to animals treated with the naked adenovirus (NA) (P<0.05). The tumor to non-tumor ratio of beta-galactosidase marker expression was significantly higher for the AL complex treated animals. NA induced significantly higher titers of adenoviral-specific antibodies compared to the AL complexes (P<0.05). The AL complexes provided protection (immunoshielding) to the adenovirus from neutralizing antibody. Forty-seven percent more beta-galactosidase expression was detected following intratumoral injection with AL complexes compared to the NA in animals pre-immunized with adenovirus. Complexing of adenovirus with liposomes provides a simple method to enhance tumor localization of the vector, decrease the immunogenicity of adenovirus, and provide protection of the virus from pre-existing neutralizing antibodies.

High-efficiency liposomal encapsulation of a tyrosine kinase inhibitor leads to improved in vivo toxicity and tumor response profile

Directory of Open Access Journals (Sweden)

Mukthavaram R

2013-10-01

Full Text Available Rajesh Mukthavaram,1 Pengfei Jiang,1 Rohit Saklecha,1 Dmitri Simberg,3,4 Ila Sri Bharati,1 Natsuko Nomura,1 Ying Chao,1 Sandra Pastorino,1 Sandeep C Pingle,1 Valentina Fogal,1 Wolf Wrasidlo,1,2 Milan Makale,1,2 Santosh Kesari1,21Translational Neuro-Oncology Laboratories, 2Department of Neurosciences, 3Solid Tumor Therapeutics Program, Moores Cancer Center, UC San Diego, La Jolla, CA, 4Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Denver, CO, USAAbstract: Staurosporine (STS is a potent pan-kinase inhibitor with marked activity against several chemotherapy-resistant tumor types in vitro. The translational progress of this compound has been hindered by poor pharmacokinetics and toxicity. We sought to determine whether liposomal encapsulation of STS would enhance antitumor efficacy and reduce toxicity, thereby supporting the feasibility of further preclinical development. We developed a novel reverse pH gradient liposomal loading method for STS, with an optimal buffer type and drug-to-lipid ratio. Our approach produced 70% loading efficiency with good retention, and we provide, for the first time, an assessment of the in vivo antitumor activity of STS. A low intravenous dose (0.8 mg/kg inhibited U87 tumors in a murine flank model. Biodistribution showed preferential tumor accumulation, and body weight data, a sensitive index of STS toxicity, was unaffected by liposomal STS, but did decline with the free compound. In vitro experiments revealed that liposomal STS blocked Akt phosphorylation, induced poly(ADP-ribose polymerase cleavage, and produced cell death via apoptosis. This study provides a basis to explore further the feasibility of liposomally encapsulated STS, and potentially related compounds for the management of resistant solid tumors.Keywords: liposomes, staurosporine, glioblastoma, biodistribution, efficacy

Thermo-sensitive liposomes loaded with doxorubicin and lysine modified single-walled carbon nanotubes as tumor-targeting drug delivery system.

Science.gov (United States)

Zhu, Xiali; Xie, Yingxia; Zhang, Yingjie; Huang, Heqing; Huang, Shengnan; Hou, Lin; Zhang, Huijuan; Li, Zhi; Shi, Jinjin; Zhang, Zhenzhong

2014-11-01

This report focuses on the thermo-sensitive liposomes loaded with doxorubicin and lysine-modified single-walled carbon nanotube drug delivery system, which was designed to enhance the anti-tumor effect and reduce the side effects of doxorubicin. Doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes was prepared by reverse-phase evaporation method, the mean particle size was 232.0 ± 5.6 nm, and drug entrapment efficiency was 86.5 ± 3.7%. The drug release test showed that doxorubicin released more quickly at 42℃ than at 37℃. Compared with free doxorubicin, doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes could efficiently cross the cell membranes and afford higher anti-tumor efficacy on the human hepatic carcinoma cell line (SMMC-7721) cells in vitro. For in vivo experiments, the relative tumor volumes of the sarcomaia 180-bearing mice in thermo-sensitive liposomes group and doxorubicin group were significantly smaller than those of N.S. group. Meanwhile, the combination of near-infrared laser irradiation at 808 nm significantly enhanced the tumor growth inhibition both on SMMC-7721 cells and the sarcomaia 180-bearing mice. The quality of life such as body weight, mental state, food and water intake of sarcomaia 180 tumor-bearing mice treated with doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes were much higher than those treated with doxorubicin. In conclusion, doxorubicin-lysine/single-walled carbon nanotube-thermo-sensitive liposomes combined with near-infrared laser irradiation at 808 nm may potentially provide viable clinical strategies for targeting delivery of anti-cancer drugs. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Investigation of particle accumulation, chemosensitivity and thermosensitivity for effective solid tumor therapy using thermosensitive liposomes and hyperthermia

NARCIS (Netherlands)

W.J.M. Lokerse (Wouter); M. Bolkestein (Michiel); T.L.M. ten Hagen (Timo); M. de Jong (Marcel); A.M.M. Eggermont (Alexander); Grüll, H. (Holger); G.A. Koning (Gerben)

2016-01-01

textabstractDoxorubicin (Dox) loaded thermosensitive liposomes (TSLs) have shown promising results for hyperthermia-induced local drug delivery to solid tumors. Typically, the tumor is heated to hyperthermic temperatures (41-42 °C), which induced intravascular drug release from TSLs within the tumor

Photo activation of HPPH encapsulated in “Pocket” liposomes triggers multiple drug release and tumor cell killing in mouse breast cancer xenografts

Directory of Open Access Journals (Sweden)

Sine J

2014-12-01

on the ribcage of mice. For biodistribution experiments, trace amounts of a near infrared lipid probe DiR (Ex/Em745/840 nm were included in the liposomes. Liposomes were injected intravenously and laser treatments (90 mW, 0.9 cm diameter, for an exposure duration ranging from 5–8 minutes were done 4 hours postinjection (only one tumor per mouse was treated, keeping the second flank tumor as control. Calcein release occurred as indicated by an increase in calcein fluorescence from laser treated tumors only. The animals were observed for up to 15 days postinjection and tumor volume and luciferase expression was measured. A significant decrease in luciferase expression and reduction in tumor volume was observed only in laser treated animal groups injected with liposomes containing HPPH. Histopathological examination of tumor tissues indicated tumor necrosis resulting from laser treatment of the HPPH-encapsulated liposomes that were taken up into the tumor area. Keywords: laser-triggered payload release, photo-agents, photopolymerizable phospholipids, tumor regression, phototriggering

Liposome based radiosensitizer cancer therapy

DEFF Research Database (Denmark)

Pourhassan, Houman

Liposome-encapsulated chemotherapeutics have been used in the treatment of a variety of cancers and are feasible for use as mono-therapeutics as well as for combination therapy in conjunction with other modalities. Despite widespread use of liposomal drugs in cancer patient care, insufficient drug...... biomolecules. By modulating the liposomal membrane, liposomes can become sensitive towards enzymatically-driven destabilization and/or functionalization, thereby allowing control of the release of encapsulated therapeutics within the diseased tissue upon intrinsic stimulation from tumor-associated enzymes...... in tumor-bearing mice.The safety and efficacy of sPLA2-sensitive liposomal L-OHP was assessed in sPLA2-deficient FaDu hypopharyngeal squamous cell carcinoma and sPLA2-expressing Colo205 colorectal adenocarcinoma. Also, the feasibility of multimodal cancer therapy employing L-OHP encapsulated in MMP...

Pros and cons of the liposome platform in cancer drug targeting.

Science.gov (United States)

Gabizon, Alberto A; Shmeeda, Hilary; Zalipsky, Samuel

2006-01-01

Coating of liposomes with polyethylene-glycol (PEG) by incorporation in the liposome bilayer of PEG-derivatized lipids results in inhibition of liposome uptake by the reticulo-endothelial system and significant prolongation of liposome residence time in the blood stream. Parallel developments in drug loading technology have improved the efficiency and stability of drug entrapment in liposomes, particularly with regard to cationic amphiphiles such as anthracyclines. An example of this new generation of liposomes is a formulation of pegylated liposomal doxorubicin known as Doxil or Caelyx, whose clinical pharmacokinetic profile is characterized by slow plasma clearance and small volume of distribution. A hallmark of these long-circulating liposomal drug carriers is their enhanced accumulation in tumors. The mechanism underlying this passive targeting effect is the phenomenon known as enhanced permeability and retention (EPR) which has been described in a broad variety of experimental tumor types. Further to the passive targeting effect, the liposome drug delivery platform offers the possibility of grafting tumor-specific ligands on the liposome membrane for active targeting to tumor cells, and potentially intracellular drug delivery. The pros and cons of the liposome platform in cancer targeting are discussed vis-à-vis nontargeted drugs, using as an example a liposome drug delivery system targeted to the folate receptor.

Comparison of conventional chemotherapy, stealth liposomes and temperature-sensitive liposomes in a mathematical model.

Directory of Open Access Journals (Sweden)

Astrid Gasselhuber

Full Text Available Various liposomal drug carriers have been developed to overcome short plasma half-life and toxicity related side effects of chemotherapeutic agents. We developed a mathematical model to compare different liposome formulations of doxorubicin (DOX: conventional chemotherapy (Free-DOX, Stealth liposomes (Stealth-DOX, temperature sensitive liposomes (TSL with intra-vascular triggered release (TSL-i, and TSL with extra-vascular triggered release (TSL-e. All formulations were administered as bolus at a dose of 9 mg/kg. For TSL, we assumed locally triggered release due to hyperthermia for 30 min. Drug concentrations were determined in systemic plasma, aggregate body tissue, cardiac tissue, tumor plasma, tumor interstitial space, and tumor cells. All compartments were assumed perfectly mixed, and represented by ordinary differential equations. Contribution of liposomal extravasation was negligible in the case of TSL-i, but was the major delivery mechanism for Stealth-DOX and for TSL-e. The dominant delivery mechanism for TSL-i was release within the tumor plasma compartment with subsequent tissue- and cell uptake of released DOX. Maximum intracellular tumor drug concentrations for Free-DOX, Stealth-DOX, TSL-i, and TSL-e were 3.4, 0.4, 100.6, and 15.9 µg/g, respectively. TSL-i and TSL-e allowed for high local tumor drug concentrations with reduced systemic exposure compared to Free-DOX. While Stealth-DOX resulted in high tumor tissue concentrations compared to Free-DOX, only a small fraction was bioavailable, resulting in little cellular uptake. Consistent with clinical data, Stealth-DOX resulted in similar tumor intracellular concentrations as Free-DOX, but with reduced systemic exposure. Optimal release time constants for maximum cellular uptake for Stealth-DOX, TSL-e, and TSL-i were 45 min, 11 min, and <3 s, respectively. Optimal release time constants were shorter for MDR cells, with ∼4 min for Stealth-DOX and for TSL-e. Tissue concentrations

Inhibitory effect of Lentinan entrapped in liposomes on hepatic metastasis in rats

International Nuclear Information System (INIS)

Yamashita, I.; Masuyama, K.; Yoshida, M.; Suzuki, Y.; Kasagi, T.; Tazawa, K.; Fujimaki, M.; Kawagoshi, T.; Maeda, M.; Honda, T.; Ochiai, H.

1988-01-01

Using the technique of Drug Delivery System, we experimentally attempted to examine whether the preventive i.v. administration of BRM entrapped in liposomes is useful or not for the cancer metastasis to the liver. As a BRM, we used Lentinan. The liposome used as a carrier in our study showed high stability both in vivo and in vitro with the mol ratio of phosphatidylcholine: cholesterol of 1. Also, high accumulation to reticuloendothelial system was evidenced. NK cell activity in the spleen and the liver on the day of the administration of AH60C hepatoma cells (2x10 6 cells) was higher by 1.3-2.3 times than those of the other groups. The survival ratio of tumor cells in the liver 8 h of tumor cells administration was significantly lower (P<0.01) than in the other groups. Rats with cancer metastasis to the liver on 30th day after the tumor cells administration were significantly decreased (P<0.01). These results suggested the usefulness of the i.v. administration of Lentinan entrapped in liposomes. (orig.)

Nanodrug-enhanced radiofrequency tumor ablation: effect of micellar or liposomal carrier on drug delivery and treatment efficacy.

Directory of Open Access Journals (Sweden)

Marwan Moussa

Full Text Available To determine the effect of different drug-loaded nanocarriers (micelles and liposomes on delivery and treatment efficacy for radiofrequency ablation (RFA combined with nanodrugs.Fischer 344 rats were used (n = 196. First, single subcutaneous R3230 tumors or normal liver underwent RFA followed by immediate administration of i.v. fluorescent beads (20, 100, and 500 nm, with fluorescent intensity measured at 4-24 hr. Next, to study carrier type on drug efficiency, RFA was combined with micellar (20 nm or liposomal (100 nm preparations of doxorubicin (Dox; targeting HIF-1α or quercetin (Qu; targeting HSP70. Animals received RFA alone, RFA with Lipo-Dox or Mic-Dox (1 mg i.v., 15 min post-RFA, and RFA with Lipo-Qu or Mic-Qu given 24 hr pre- or 15 min post-RFA (0.3 mg i.v.. Tumor coagulation and HIF-1α or HSP70 expression were assessed 24 hr post-RFA. Third, the effect of RFA combined with i.v. Lipo-Dox, Mic-Dox, Lipo-Qu, or Mic-Qu (15 min post-RFA compared to RFA alone on tumor growth and animal endpoint survival was evaluated. Finally, drug uptake was compared between RFA/Lipo-Dox and RFA/Mic-Dox at 4-72 hr.Smaller 20 nm beads had greater deposition and deeper tissue penetration in both tumor (100 nm/500 nm and liver (100 nm (p<0.05. Mic-Dox and Mic-Qu suppressed periablational HIF-1α or HSP70 rim thickness more than liposomal preparations (p<0.05. RFA/Mic-Dox had greater early (4 hr intratumoral doxorubicin, but RFA/Lipo-Dox had progressively higher intratumoral doxorubicin at 24-72 hr post-RFA (p<0.04. No difference in tumor growth and survival was seen between RFA/Lipo-Qu and RFA/Mic-Qu. Yet, RFA/Lipo-Dox led to greater animal endpoint survival compared to RFA/Mic-Dox (p<0.03.With RF ablation, smaller particle micelles have superior penetration and more effective local molecular modulation. However, larger long-circulating liposomal carriers can result in greater intratumoral drug accumulation over time and reduced tumor growth. Accordingly

Enhanced anticancer efficacy of paclitaxel through multistage tumor-targeting liposomes modified with RGD and KLA peptides

Directory of Open Access Journals (Sweden)

Sun J

2017-02-01

Full Text Available Jiawei Sun,1 Lei Jiang,2 Yi Lin,3 Ethan Michael Gerhard,4 Xuehua Jiang,1 Li Li,3 Jian Yang,4 Zhongwei Gu3 1West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, 2Department of Pharmaceutics, China Pharmaceutical University, Nanjing, Jiangsu, 3National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 4Department of Biomedical Engineering Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, PA, USA Abstract: Mitochondria serve as both “energy factories” and “suicide weapon stores” of cells. Targeted delivery of cytotoxic drugs to the mitochondria of tumor cells and tumor vascular cells is a promising strategy to improve the efficacy of chemotherapy. Here, multistage tumor-targeting liposomes containing two targeted peptide-modified lipids, cRGD-PEG2000-DSPE and KLA-PEG2000-DSPE, were developed for encapsulation of the anticancer drug paclitaxel (PTX, RGD-KLA/PTX-Lips. Compared with Taxol (free PTX, RGD/PTX-Lips and KLA/PTX-Lips, the half-maximal inhibitory concentration (IC50 value of RGD-KLA/PTX-Lips in vitro was 1.9-, 36.7- and 22.7-fold lower with 4T1 cells, respectively, because of higher levels of cellular uptake. Similar results were also observed with human umbilical vascular endothelial cells (HUVECs. An apoptosis assay showed that the total apoptotic ratio of RGD-KLA/PTX-Lips was the highest because of the mitochondria-targeted drug delivery and the activation of mitochondrial apoptosis pathways, as evidenced by visible mitochondrial localization, decreased mitochondrial membrane potential, release of cytochrome c and increased activities of caspase-9 and caspase-3. The strongest tumor growth inhibition (TGI; 80.6% and antiangiogenesis effects without systemic toxicity were also observed in RGD-KLA/PTX-Lip-treated 4T1 tumor xenograft BALB/c mice. In conclusion, these multistage

Boronated liposome development and evaluation

International Nuclear Information System (INIS)

Hawthorne, M.F.

1995-01-01

The boronated liposome development and evaluation effort consists of two separate tasks. The first is the development of new boron compounds and the synthesis of known boron species with BNCT potential. These compounds are then encapsulated within liposomes for the second task, biodistribution testing in tumor-bearing mice, which examines the potential for the liposomes and their contents to concentrate boron in cancerous tissues

Evaluation of a combination tumor treatment using thermo-triggered liposomal drug delivery and carbon ion irradiation.

Science.gov (United States)

Kokuryo, Daisuke; Aoki, Ichio; Yuba, Eiji; Kono, Kenji; Aoshima, Sadahito; Kershaw, Jeff; Saga, Tsuneo

2017-07-01

The combination of radiotherapy with chemotherapy is one of the most promising strategies for cancer treatment. Here, a novel combination strategy utilizing carbon ion irradiation as a high-linear energy transfer (LET) radiotherapy and a thermo-triggered nanodevice is proposed, and drug accumulation in the tumor and treatment effects are evaluated using magnetic resonance imaging relaxometry and immunohistology (Ki-67, n = 15). The thermo-triggered liposomal anticancer nanodevice was administered into colon-26 tumor-grafted mice, and drug accumulation and efficacy was compared for 6 groups (n = 32) that received or did not receive the radiotherapy and thermo trigger. In vivo quantitative R 1 maps visually demonstrated that the multimodal thermosensitive polymer-modified liposomes (MTPLs) can accumulate in the tumor tissue regardless of whether the region was irradiated by carbon ions or not. The tumor volume after combination treatment with carbon ion irradiation and MTPLs with thermo-triggering was significantly smaller than all the control groups at 8 days after treatment. The proposed strategy of combining high-LET irradiation and the nanodevice provides an effective approach for minimally invasive cancer treatment. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Liposome-based drug delivery in breast cancer treatment

International Nuclear Information System (INIS)

Park, John W

2002-01-01

Drug delivery systems can in principle provide enhanced efficacy and/or reduced toxicity for anticancer agents. Long circulating macromolecular carriers such as liposomes can exploit the 'enhanced permeability and retention' effect for preferential extravasation from tumor vessels. Liposomal anthracyclines have achieved highly efficient drug encapsulation, resulting in significant anticancer activity with reduced cardiotoxicity, and include versions with greatly prolonged circulation such as liposomal daunorubicin and pegylated liposomal doxorubicin. Pegylated liposomal doxorubucin has shown substantial efficacy in breast cancer treatment both as monotherapy and in combination with other chemotherapeutics. Additional liposome constructs are being developed for the delivery of other drugs. The next generation of delivery systems will include true molecular targeting; immunoliposomes and other ligand-directed constructs represent an integration of biological components capable of tumor recognition with delivery technologies

Stimuli-responsive Smart Liposomes in Cancer Targeting.

Science.gov (United States)

Jain, Ankit; Jain, Sanjay K

2018-02-08

Liposomes are vesicular carriers which possess aqueous core entrapped within the lipid bilayer. These are carriers of choice because of biocompatible and biodegradable features in addition to flexibility of surface modifications at surface and lipid compositions of lipid bilayers. Liposomes have been reported well for cancer treatment using both passive and active targeting approaches however tumor microenvironment is still the biggest hurdle for safe and effective delivery of anticancer agents. To overcome this problem, stimuli-responsive smart liposomes have emerged as promising cargoes pioneered to anomalous tumor milieu in response to pH, temperature, and enzymes etc. as internal triggers, and magnetic field, ultrasound, and redox potential as external guides for enhancement of drug delivery to tumors. This review focuses on all such stimuli-responsive approaches using fabrication potentiality of liposomes in combination to various ligands, linkers, and PEGylation etc. Scientists engaged in cancer targeting approaches can get benefited greatly with this knowledgeable assemblage of advances in liposomal nanovectors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Enhancement in blood-tumor barrier permeability and delivery of liposomal doxorubicin using focused ultrasound and microbubbles: evaluation during tumor progression in a rat glioma model

Science.gov (United States)

Aryal, Muna; Park, Juyoung; Vykhodtseva, Natalia; Zhang, Yong-Zhi; McDannold, Nathan

2015-03-01

Effective drug delivery to brain tumors is often challenging because of the heterogeneous permeability of the ‘blood tumor barrier’ (BTB) along with other factors such as increased interstitial pressure and drug efflux pumps. Focused ultrasound (FUS) combined with microbubbles can enhance the permeability of the BTB in brain tumors, as well as the blood-brain barrier in the surrounding tissue. In this study, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was used to characterize the FUS-induced permeability changes of the BTB in a rat glioma model at different times after implantation. 9L gliosarcoma cells were implanted in both hemispheres in male rats. At day 9, 14, or 17 days after implantation, FUS-induced BTB disruption using 690 kHz ultrasound and definity microbubbles was performed in one tumor in each animal. Before FUS, liposomal doxorubicin was administered at a dose of 5.67 mg kg-1. This chemotherapy agent was previously shown to improve survival in animal glioma models. The transfer coefficient Ktrans describing extravasation of the MRI contrast agent Gd-DTPA was measured via DCE-MRI before and after sonication. We found that tumor doxorubicin concentrations increased monotonically (823  ±  600, 1817  ±  732 and 2432  ±  448 ng g-1) in the control tumors at 9, 14 and 17 d. With FUS-induced BTB disruption, the doxorubicin concentrations were enhanced significantly (P benefit from FUS-induced drug enhancement. Corresponding enhancements in Ktrans were found to be variable in large/late-stage tumors and not significantly different than controls, perhaps reflecting the size mismatch between the liposomal drug (~100 nm) and Gd-DTPA (molecular weight: 938 Da; hydrodynamic diameter: ≃2 nm). It may be necessary to use a larger MRI contrast agent to effectively evaluate the sonication-induced enhanced permeabilization in large/late-stage tumors when a large drug carrier such as a liposome is used.

Optimum modality for photodynamic therapy of tumors: gels containing liposomes with hydrophobic photosensitizers

Czech Academy of Sciences Publication Activity Database

Nekvasil, Miloš; Zadinová, M.; Tahotná, Ludmila; Žáčková, Markéta; Poučková, P.; Ježek, Petr

2007-01-01

Roč. 68, č. 5 (2007), s. 235-252 ISSN 0272-4391 R&D Projects: GA MŠk 1P04OE152; GA MPO 2A-1TP1/026; GA MZd NC6564 Institutional research plan: CEZ:AV0Z50110509 Keywords : photodynamic therapy of tumors * liposomal photosensitizer gel * hydroxyl-aluminium phtalocyanine * microfluidizacion Subject RIV: FD - Oncology ; Hematology Impact factor: 0.976, year: 2007

Highly penetrative liposome nanomedicine generated by a biomimetic strategy for enhanced cancer chemotherapy.

Science.gov (United States)

Jia, Yali; Sheng, Zonghai; Hu, Dehong; Yan, Fei; Zhu, Mingting; Gao, Guanhui; Wang, Pan; Liu, Xin; Wang, Xiaobing; Zheng, Hairong

2018-04-25

Liposome nanomedicine has been successfully applied for cancer chemotherapy in patients. However, in general, the therapeutic efficacy is confined by its limited accumulation and penetration in solid tumors. Here, we established a biomimetic strategy for the preparation of highly penetrative liposome nanomedicine for enhanced chemotherapeutic efficacy. By applying this unique type of nanomedicine, membrane proteins on the cancer cells are used as highly penetrative targeting ligands. Biomimetic liposomes are highly stable, exhibiting a superior in vitro homologous targeting ability, and a 2.25-fold deeper penetration in 3D tumor spheroids when compared to conventional liposome nanomedicine. The fluorescence/photoacoustic dual-modal imaging approach demonstrated enhanced tumor accumulation and improved tumor penetration of the biomimetic liposome in C6 glioma tumor-bearing nude mice. Following the intravenous administration of biomimetic liposome nanomedicine, the tumor inhibition rate reached up to 93.3%, which was significantly higher when compared to that of conventional liposome nanomedicine (69.3%). Moreover, histopathological analyses demonstrated that biomimetic liposome nanomedicine has limited side effects. Therefore, these results suggested that a cancer cell membrane-based biomimetic strategy may provide a breakthrough approach for enhancing drug penetration and improving treatment efficacy, holding a great promise for further clinical studies.

Liposomes equipped with cell penetrating peptide BR2 enhances chemotherapeutic effects of cantharidin against hepatocellular carcinoma.

Science.gov (United States)

Zhang, Xue; Lin, Congcong; Lu, Aiping; Lin, Ge; Chen, Huoji; Liu, Qiang; Yang, Zhijun; Zhang, Hongqi

2017-11-01

A main hurdle for the success of tumor-specific liposomes is their inability to penetrate tumors efficiently. In this study, we incorporated a cell-penetrating peptide BR2 onto the surface of a liposome loaded with the anticancer drug cantharidin (CTD) to create a system targeting hepatocellular carcinoma (HCC) cells more efficiently and effectively. The in vitro cytotoxicity assay comparing the loaded liposomes' effects on hepatocellular cancer HepG2 and the control Miha cells showed that CTD-loaded liposomes had a stronger anticancer effect after BR2 modification. The cellular uptake results of HepG2 and Miha cells further confirmed the superior ability of BR2-modified liposomes to penetrate cancer cells. The colocalization study revealed that BR2-modified liposomes could enter tumor cells and subsequently release drugs. A higher efficiency of delivery by BR2 liposomes as compared to unmodified liposomes was evident by evaluation of the HepG2 tumor spheroids penetration and inhibition. The biodistribution studies and anticancer efficacy results in vivo showed the significant accumulation of BR2-modified liposomes into tumor sites and an enhanced tumor inhibition. In conclusion, BR2-modified liposomes improve the anticancer potency of drugs for HCC.

Targeted drug delivery using temperature-sensitive liposomes

International Nuclear Information System (INIS)

Magin, R.L.; Niesman, M.R.

1984-01-01

Liposomes are receiving considerable attention as vehicles for selective drug delivery. One method of targeting liposomal contents involves the combination of local hyperthermia with temperature-sensitive liposomes. Such liposomes have been used to increase the uptake of methotrexate and cis-platinum into locally heated mouse tumors. However, additional information is needed on the mechanism of liposome drug release and the physiologic deposition of liposomes in vivo before clinical trails are begun. Current research is directed at studying the encapsulation and release of water soluble drugs from temperature-sensitive liposomes. The influence of liposome size, structure, and composition on the rapid release in plasma of cytosine arabinoside, cis-platinum, and the radiation sensitizer SR-2508 are described. These results demonstrate potential applications for temperature-sensitive liposomes in selective drug delivery

Liposomal delivery of radionuclides for cancer diagnostics and radiotherapy

DEFF Research Database (Denmark)

Petersen, Anncatrine Luisa

, an in vivo study is presented, where passive tumor accumulation of 64Cu loaded liposomes (64Cu-liposomes) in tumor-bearing mice was quantified directly by PET and computed tomography (CT) imaging. Furthermore, Article I present an evaluation and quantitative measurement of the biodistribution of 64Cu...

Inhibition of hexokinase-2 with targeted liposomal 3-bromopyruvate in an ovarian tumor spheroid model of aerobic glycolysis.

Science.gov (United States)

Gandham, Srujan Kumar; Talekar, Meghna; Singh, Amit; Amiji, Mansoor M

2015-01-01

The objective of this study was to evaluate the expression levels of glycolytic markers, especially hexokinase-2 (HK2), using a three-dimensional multicellular spheroid model of human ovarian adenocarcinoma (SKOV-3) cells and to develop an epidermal growth factor receptor-targeted liposomal formulation for improving inhibition of HK2 and the cytotoxicity of 3-bromopyruvate (3-BPA). Multicellular SKOV-3 tumor spheroids were developed using the hanging drop method and expression levels of glycolytic markers were examined. Non-targeted and epidermal growth factor receptor-targeted liposomal formulations of 3-BPA were formulated and characterized. Permeability and cellular uptake of the liposomal formulations in three-dimensional SKOV-3 spheroids was evaluated using confocal microscopy. The cytotoxicity and HK2 inhibition potential of solution form of 3-BPA was compared to the corresponding liposomal formulation by using cell proliferation and HK2 enzymatic assays. SKOV-3 spheroids were reproducibly developed using the 96-well hanging drop method, with an average size of 900 µm by day 5. HK2 enzyme activity levels under hypoxic conditions were found to be higher than under normoxic conditions (P<0.0001, Student's t-test, unpaired and two-tailed). Liposomal formulations (both non-targeted and targeted) of 3-BPA showed a more potent inhibitory effect (P<0.001, Student's t-test, unpaired and two-tailed) at a dose of 50 µM than the aqueous solution form at 3, 6, and 24 hours post administration. Similarly, the cytotoxic activity 3-BPA at various concentrations (10 µM-100 µM) showed that the liposomal formulations had an enhanced cytotoxic effect of 2-5-fold (P<0.0001, Student's t-test, unpaired and two-tailed) when compared to the aqueous solution form for both 10 µM and 25 µM concentrations. SKOV-3 spheroids developed by the hanging drop method can be used as a tumor aerobic glycolysis model for evaluation of therapies targeting the glycolytic pathway in cancer

Inhibition of hexokinase-2 with targeted liposomal 3-bromopyruvate in an ovarian tumor spheroid model of aerobic glycolysis

Directory of Open Access Journals (Sweden)

Gandham SK

2015-07-01

Full Text Available Srujan Kumar Gandham, Meghna Talekar, Amit Singh, Mansoor M Amiji Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, MA, USA Background: The objective of this study was to evaluate the expression levels of glycolytic markers, especially hexokinase-2 (HK2, using a three-dimensional multicellular spheroid model of human ovarian adenocarcinoma (SKOV-3 cells and to develop an epidermal growth factor receptor-targeted liposomal formulation for improving inhibition of HK2 and the cytotoxicity of 3-bromopyruvate (3-BPA. Methods: Multicellular SKOV-3 tumor spheroids were developed using the hanging drop method and expression levels of glycolytic markers were examined. Non-targeted and epidermal growth factor receptor-targeted liposomal formulations of 3-BPA were formulated and characterized. Permeability and cellular uptake of the liposomal formulations in three-dimensional SKOV-3 spheroids was evaluated using confocal microscopy. The cytotoxicity and HK2 inhibition potential of solution form of 3-BPA was compared to the corresponding liposomal formulation by using cell proliferation and HK2 enzymatic assays. Results: SKOV-3 spheroids were reproducibly developed using the 96-well hanging drop method, with an average size of 900 µm by day 5. HK2 enzyme activity levels under hypoxic conditions were found to be higher than under normoxic conditions (P<0.0001, Student’s t-test, unpaired and two-tailed. Liposomal formulations (both non-targeted and targeted of 3-BPA showed a more potent inhibitory effect (P<0.001, Student’s t-test, unpaired and two-tailed at a dose of 50 µM than the aqueous solution form at 3, 6, and 24 hours post administration. Similarly, the cytotoxic activity 3-BPA at various concentrations (10 µM–100 µM showed that the liposomal formulations had an enhanced cytotoxic effect of 2–5-fold (P<0.0001, Student’s t-test, unpaired and two-tailed when compared to the aqueous solution form

Assessment of the tumor load as well as toxic and side effects after herceptin combined with doxorubicin liposome treatment of HER-2 positive breast cance

Directory of Open Access Journals (Sweden)

Guo-Quan Wen

2016-12-01

Full Text Available Objective: To study the effect of herceptin combined with doxorubicin liposome treatment on tumor load as well as toxic and side effects of HER-2 positive breast cancer. Methods: A total of 138 patients with HER-2 positive breast cancer who received chemotherapy in our hospital between July 2014 and December 2015 were selected as the research subjects and randomly divided into two groups, liposome group received herceptin combined with doxorubicin liposome treatment and control group received herceptin combined with doxorubicin treatment. After 8 weeks of treatment, the content of tumor markers, active molecules and myocardial injury markers in serum as well as the expression levels of immune marker molecules in peripheral blood mononuclear cells were detected. Results: After 8 weeks of treatment, CEA, CA199, CA153, CA125, VEGF, nectin-4, TK-1, PF-4, TSGF, CK, CK-MB, cTnI and cTnT content in serum of liposome group were significantly lower than those of control group, and the fluorescence intensity of CD3, CD4, CD8, CD16, CD19 and CD25 on peripheral blood mononuclear cell surface were significantly higher than those of control group. Conclusions: Herceptin combined with doxorubicin liposome treatment of HER-2 positive breast cancer can more effectively reduce the tumor load and cause less toxic and side effects on the heart and the immune system.

In vivo evaluation of PEGylated 64Cu-liposomes with theranostic and radiotherapeutic potential using micro PET/CT

International Nuclear Information System (INIS)

Petersen, Anncatrine Luisa; Andresen, Thomas Lars; Henriksen, Jonas Rosager; Binderup, Tina; Hag, Anne Mette; Kjaer, Andreas; Elema, Dennis Ringkjoebing; Rasmussen, Palle Hedengran

2016-01-01

The objective of this study was to evaluate the potential of PEGylated 64 Cu-liposomes in clinical diagnostic positron emission tomography (PET) imaging and PEGylated 177 Lu-liposomes in internal tumor radiotherapy through in vivo characterization and dosimetric analysis in a human xenograft mouse model. Liposomes with 5 and 10 mol% PEG were characterized with respect to size, charge, and 64 Cu- and 177 Lu-loading efficiency. The tumor imaging potential of 64 Cu-loaded liposomes was evaluated in terms of in vivo biodistribution, tumor accumulation and tumor-to-muscle (T/M) ratios, using PET imaging. The potential of PEGylated liposomes for diagnostic and therapeutic applications was further evaluated through dosimetry analysis using OLINDA/EXM software. The 64 Cu-liposomes were used as biological surrogates to estimate the organ and tumor kinetics of 177 Lu-liposomes. High remote loading efficiency (>95 %) was obtained for both 64 Cu and 177 Lu radionuclides with PEGylated liposomes, and essentially no leakage of the encapsulated radionuclide was observed upon storage and after serum incubation for 24 h at 37 C. The 10 mol% PEG liposomes showed higher tumor accumulation (6.2 ± 0.2 %ID/g) than the 5 mol% PEG liposomes, as evaluated by PET imaging. The dosimetry analysis of the 64 Cu-liposomes estimated an acceptable total effective dose of 3.3.10 -2 mSv/MBq for diagnostic imaging in patients. A high absorbed tumor dose (114 mGy/MBq) was estimated for the potential radiotherapeutic 177 Lu-liposomes. The overall preclinical profile of PEGylated 64 Cu-liposomes showed high potential as a new PET theranostic tracer for imaging in humans. Dosimetry results predicted that initial administered activity of 200 MBq of 64 Cu-liposomes should be acceptable in patients. Work is in progress to validate the utility of PEGylated 64 Cu-liposomes in a clinical research programme. The high absorbed tumor dose (114 mGy/MBq) estimated for 177 Lu-liposomes and the preliminary

Etoposide Incorporated into Camel Milk Phospholipids Liposomes Shows Increased Activity against Fibrosarcoma in a Mouse Model

Directory of Open Access Journals (Sweden)

Hamzah M. Maswadeh

2015-01-01

Full Text Available Phospholipids were isolated from camel milk and identified by using high performance liquid chromatography and gas chromatography-mass spectrometry (GC/MS. Anticancer drug etoposide (ETP was entrapped in liposomes, prepared from camel milk phospholipids, to determine its activity against fibrosarcoma in a murine model. Fibrosarcoma was induced in mice by injecting benzopyrene (BAP and tumor-bearing mice were treated with various formulations of etoposide, including etoposide entrapped camel milk phospholipids liposomes (ETP-Cam-liposomes and etoposide-loaded DPPC-liposomes (ETP-DPPC-liposomes. The tumor-bearing mice treated with ETP-Cam-liposomes showed slow progression of tumors and increased survival compared to free ETP or ETP-DPPC-liposomes. These results suggest that ETP-Cam-liposomes may prove to be a better drug delivery system for anticancer drugs.

Bleomycin-Loaded pH-Sensitive Polymer–Lipid-Incorporated Liposomes for Cancer Chemotherapy

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Eiji Yuba

2018-01-01

Full Text Available Cancer chemotherapeutic systems with high antitumor effects and less adverse effects are eagerly desired. Here, a pH-sensitive delivery system for bleomycin (BLM was developed using egg yolk phosphatidylcholine liposomes modified with poly(ethylene glycol-lipid (PEG-PE for long circulation in the bloodstream and 2-carboxycyclohexane-1-carboxylated polyglycidol-having distearoyl phosphatidylethanolamine (CHexPG-PE for pH sensitization. The PEG-PE/CHexPG-PE-introduced liposomes showed content release responding to pH decrease and were taken up by tumor cells at a rate 2.5 times higher than that of liposomes without CHexPG-PE. BLM-loaded PEG-PE/CHexPG-PE-introduced liposomes exhibited comparable cytotoxicity with that of the free drug. Intravenous administration of these liposomes suppressed tumor growth more effectively in tumor-bearing mice than did the free drug and liposomes without CHexPG-PE. However, at a high dosage of BLM, these liposomes showed severe toxicity to the spleen, liver, and lungs, indicating the trapping of liposomes by mononuclear phagocyte systems, probably because of recognition of the carboxylates on the liposomes. An increase in PEG molecular weight on the liposome surface significantly decreased toxicity to the liver and spleen, although toxicity to the lungs remained. Further improvements such as the optimization of PEG density and lipid composition and the introduction of targeting ligands to the liposomes are required to increase therapeutic effects and to reduce adverse effects.

Liposomalization of oxaliplatin induces skin accumulation of it, but negligible skin toxicity.

Science.gov (United States)

Nishida, Kentaro; Kashiwagi, Misaki; Shiba, Shunsuke; Muroki, Kiwamu; Ohishi, Akihiro; Doi, Yusuke; Ando, Hidenori; Ishida, Tatsuhiro; Nagasawa, Kazuki

2017-12-15

Liposomalization causes alteration of the pharmacokinetics of encapsulated drugs, and allows delivery to tumor tissues through passive targeting via an enhanced permeation and retention (EPR) effect. PEGylated liposomal doxorubicin (Doxil ® , Lipo-DXR), a representative liposomal drug, is well-known to reduce cardiotoxicity and increase the anti-tumor activity of DXR, but to induce the hand-foot syndrome (HFS) as a result of skin DXR accumulation, which is one of its severe adverse effects. We have developed a new liposomal preparation of oxaliplatin (l-OHP), an important anti-tumor drug for treatment of colorectal cancer, using PEGylated liposomes (Lipo-l-OHP), and showed that Lipo-l-OHP exhibits increased anti-tumor activity in tumor-bearing mice compared to the original preparation of l-OHP. However, whether Lipo-l-OHP causes HFS-like skin toxicity similar to Lipo-DXR remains to be determined. Administration of Lipo-l-OHP promoted accumulation of platinum in rat hind paws, however, it caused negligible morphological and histological alterations on the plantar surface of the paws. Administration of DiI-labeled empty PEGylated liposomes gave almost the same distribution profile of dyes into the dermis of hind paws with DXR as in the case of Lipo-DXR. Treatment with Lipo-l-OHP, Lipo-DXR, DiI-labeled empty PEGylated liposomes or empty PEGylated liposomes caused migration of CD68 + macrophages into the dermis of hind paws. These findings suggest that the skin toxicity on administration of liposomalized drugs is reflected in the proinflammatory characteristics of encapsulated drugs, and indicate that Lipo-l-OHP with a higher anti-cancer effect and no HFS may be an outstanding l-OHP preparation leading to an improved quality of life of cancer patients. Copyright © 2017 Elsevier Inc. All rights reserved.

In vivo evaluation of PEGylated {sup 64}Cu-liposomes with theranostic and radiotherapeutic potential using micro PET/CT

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Petersen, Anncatrine Luisa; Andresen, Thomas Lars [Technical University of Denmark, Department of Micro- and Nanotechnology, Lyngby (Denmark); Technical University of Denmark, Center for Nanomedicine and Theranostics, Lyngby (Denmark); Henriksen, Jonas Rosager [Technical University of Denmark, Center for Nanomedicine and Theranostics, Lyngby (Denmark); Technical University of Denmark, Department of Chemistry, Lyngby (Denmark); Binderup, Tina; Hag, Anne Mette; Kjaer, Andreas [University of Copenhagen, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet and Cluster for Molecular Imaging, Faculty of Health Sciences, Copenhagen (Denmark); Elema, Dennis Ringkjoebing [Technical University of Denmark, Center for Nanomedicine and Theranostics, Lyngby (Denmark); Technical University of Denmark, Center for Nuclear Technologies, Hevesy Laboratory, Roskilde (Denmark); Rasmussen, Palle Hedengran [Technical University of Denmark, Center for Nuclear Technologies, Hevesy Laboratory, Roskilde (Denmark)

2016-05-15

The objective of this study was to evaluate the potential of PEGylated {sup 64}Cu-liposomes in clinical diagnostic positron emission tomography (PET) imaging and PEGylated {sup 177}Lu-liposomes in internal tumor radiotherapy through in vivo characterization and dosimetric analysis in a human xenograft mouse model. Liposomes with 5 and 10 mol% PEG were characterized with respect to size, charge, and {sup 64}Cu- and {sup 177}Lu-loading efficiency. The tumor imaging potential of {sup 64}Cu-loaded liposomes was evaluated in terms of in vivo biodistribution, tumor accumulation and tumor-to-muscle (T/M) ratios, using PET imaging. The potential of PEGylated liposomes for diagnostic and therapeutic applications was further evaluated through dosimetry analysis using OLINDA/EXM software. The {sup 64}Cu-liposomes were used as biological surrogates to estimate the organ and tumor kinetics of {sup 177}Lu-liposomes. High remote loading efficiency (>95 %) was obtained for both {sup 64}Cu and {sup 177}Lu radionuclides with PEGylated liposomes, and essentially no leakage of the encapsulated radionuclide was observed upon storage and after serum incubation for 24 h at 37 C. The 10 mol% PEG liposomes showed higher tumor accumulation (6.2 ± 0.2 %ID/g) than the 5 mol% PEG liposomes, as evaluated by PET imaging. The dosimetry analysis of the {sup 64}Cu-liposomes estimated an acceptable total effective dose of 3.3.10{sup -2} mSv/MBq for diagnostic imaging in patients. A high absorbed tumor dose (114 mGy/MBq) was estimated for the potential radiotherapeutic {sup 177}Lu-liposomes. The overall preclinical profile of PEGylated {sup 64}Cu-liposomes showed high potential as a new PET theranostic tracer for imaging in humans. Dosimetry results predicted that initial administered activity of 200 MBq of {sup 64}Cu-liposomes should be acceptable in patients. Work is in progress to validate the utility of PEGylated {sup 64}Cu-liposomes in a clinical research programme. The high absorbed tumor dose

An efficient PEGylated liposomal nanocarrier containing cell-penetrating peptide and pH-sensitive hydrazone bond for enhancing tumor-targeted drug delivery

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Ding Y

2015-10-01

Full Text Available Yuan Ding,1,* Dan Sun,1,* Gui-Ling Wang,1 Hong-Ge Yang,1 Hai-Feng Xu,1 Jian-Hua Chen,2 Ying Xie,1,3 Zhi-Qiang Wang4 1Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing, 2School of Medicine, Jianghan University, Wuhan, 3State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, People’s Republic of China; 4Department of Chemistry and Biochemistry, Kent State University Geauga, Burton, OH, USA *These authors contributed equally to this work Abstract: Cell-penetrating peptides (CPPs as small molecular transporters with abilities of cell penetrating, internalization, and endosomal escape have potential prospect in drug delivery systems. However, a bottleneck hampering their application is the poor specificity for cells. By utilizing the function of hydration shell of polyethylene glycol (PEG and acid sensitivity of hydrazone bond, we constructed a kind of CPP-modified pH-sensitive PEGylated liposomes (CPPL to improve the selectivity of these peptides for tumor targeting. In CPPL, CPP was directly attached to liposome surfaces via coupling with stearate (STR to avoid the hindrance of PEG as a linker on the penetrating efficiency of CPP. A PEG derivative by conjugating PEG with STR via acid-degradable hydrazone bond (PEG2000-Hz-STR, PHS was synthesized. High-performance liquid chromatography and flow cytometry demonstrated that PHS was stable at normal neutral conditions and PEG could be completely cleaved from liposome surface to expose CPP under acidic environments in tumor. An optimal CPP density on liposomes was screened to guaranty a maximum targeting efficiency on tumor cells as well as not being captured by normal cells that consequently lead to a long circulation in blood. In vitro and in vivo studies indicated, in 4 mol% CPP of lipid modified system, that CPP exerted higher efficiency on internalizing the liposomes into

Tumor-targeted Nanobullets: Anti-EGFR nanobody-liposomes loaded with anti-IGF-1R kinase inhibitor for cancer treatment.

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van der Meel, Roy; Oliveira, Sabrina; Altintas, Isil; Haselberg, Rob; van der Veeken, Joris; Roovers, Rob C; van Bergen en Henegouwen, Paul M P; Storm, Gert; Hennink, Wim E; Schiffelers, Raymond M; Kok, Robbert J

2012-04-30

The epidermal growth factor receptor (EGFR) is a validated target for anti-cancer therapy and several EGFR inhibitors are used in the clinic. Over the years, an increasing number of studies have reported on the crosstalk between EGFR and other receptors that can contribute to accelerated cancer development or even acquisition of resistance to anti-EGFR therapies. Combined targeting of EGFR and insulin-like growth factor 1 receptor (IGF-1R) is a rational strategy to potentiate anti-cancer treatment and possibly retard resistance development. In the present study, we have pursued this by encapsulating the kinase inhibitor AG538 in anti-EGFR nanobody-liposomes. The thus developed dual-active nanobody-liposomes associated with EGFR-(over)expressing cells in an EGFR-specific manner and blocked both EGFR and IGF-1R activation, due to the presence of the EGFR-blocking nanobody EGa1 and the anti-IGF-1R kinase inhibitor AG538 respectively. AG538-loaded nanobody-liposomes induced a strong inhibition of tumor cell proliferation even upon short-term exposure followed by a drug-free wash-out period. Therefore, AG538-loaded nanobody-liposomes are a promising anti-cancer formulation due to efficient intracellular delivery of AG538 in combination with antagonistic and downregulating properties of the EGa1 nanobody-liposomes. Copyright © 2011 Elsevier B.V. All rights reserved.

Gemcitabine-loaded liposomes: rationale, potentialities and future perspectives

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Federico C

2012-11-01

Full Text Available Cinzia Federico, Valeria M Morittu, Domenico Britti, Elena Trapasso, Donato CoscoDepartment of Health Sciences, Building of BioSciences, University “Magna Græcia” of Catanzaro, Campus Universitario “S Venuta”, Germaneto, ItalyAbstract: This review describes the strategies used in recent years to improve the biopharmaceutical properties of gemcitabine, a nucleoside analog deoxycytidine antimetabolite characterized by activity against many kinds of tumors, by means of liposomal devices. The main limitation of using this active compound is the rapid inactivation of deoxycytidine deaminase following administration in vivo. Consequently, different strategies based on its encapsulation/complexation in innovative vesicular colloidal carriers have been investigated, with interesting results in terms of increased pharmacological activity, plasma half-life, and tumor localization, in addition to decreased side effects. This review focuses on the specific approaches used, based on the encapsulation of gemcitabine in liposomes, with particular attention to the results obtained during the last 5 years. These approaches represent a valid starting point in the attempt to obtain a novel, commercializable drug formulation as already achieved for liposomal doxorubicin (Doxil®, Caelyx®.Keywords: gemcitabine, liposomes, multidrug, poly(ethylene glycol, tumors

From conventional to stealth liposomes: a new frontier in cancer chemotherapy.

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Cattel, Luigi; Ceruti, Maurizio; Dosio, Franco

2003-01-01

Many attempts have been made to achieve good selectivity to targeted tumor cells by preparing specialized carrier agents that are therapeutically profitable for anticancer therapy. Among these, liposomes are the most studied colloidal particles thus far applied in medicine and in particular in antitumor therapy. Although they were first described in the 1960s, only at the beginning of 1990s did the first therapeutic liposomes appear on the market. The first-generation liposomes (conventional liposomes) comprised a liposome-containing amphotericin B, Ambisome (Nexstar, Boulder, CO, USA), used as an antifungal drug, and Myocet (Elan Pharma Int, Princeton, NJ, USA), a doxorubicin-containing liposome, used in clinical trials to treat metastatic breast cancer. The second-generation liposomes ("pure lipid approach") were long-circulating liposomes, such as Daunoxome, a daunorubicin-containing liposome approved in the US and Europe to treat AIDS-related Kaposi's sarcoma. The third-generation liposomes were surface-modified liposomes with gangliosides or sialic acid, which can evade the immune system responsible for removing liposomes from circulation. The fourth-generation liposomes, pegylated liposomal doxorubicin, were called "stealth liposomes" because of their ability to evade interception by the immune system, in the same way as the stealth bomber was able to evade radar. Actually, the only stealth liposome on the market is Caelyx/Doxil (Schering-Plough, Madison NJ, USA), used to cure AIDS-related Kaposi's sarcoma, resistant ovarian cancer and metastatic breast cancer. Pegylated liposomal doxorubicin is characterized by a very long-circulation half-life, favorable pharmacokinetic behavior and specific accumulation in tumor tissues. These features account for the much lower toxicity shown by Caelyx in comparison to free doxorubicin, in terms of cardiotoxicity, vesicant effects, nausea, vomiting and alopecia. Pegylated liposomal doxorubicin also appeared to be less

A systemic administration of liposomal curcumin inhibits radiation pneumonitis and sensitizes lung carcinoma to radiation

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Shi HS

2012-05-01

Full Text Available Hua-shan Shi1,* Xiang Gao,1,3,* Dan Li,1,* Qiong-wen Zhang,1 Yong-sheng Wang,2 Yu Zheng,1 Lu-Lu Cai,1 Ren-ming Zhong,2 Ao Rui,1 Zhi-yong Li,1 Hao Zheng,1 Xian-cheng Chen,1 Li-juan Chen,11State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medicine School, Sichuan University, Chengdu, Sichuan, People's Republic of China; 2State Key Laboratory of Biotherapy and Department of Thoracic Oncology, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, People's Republic of China; 3Deparment of Pathophysiology, College of Preclinical and Forensic Medical Sciences, Sichuan University, Chengdu, People's Republic of China*These authors contributed equally to this workAbstract: Radiation pneumonitis (RP is an important dose-limiting toxicity during thoracic radiotherapy. Previous investigations have shown that curcumin is used for the treatment of inflammatory conditions and cancer, suggesting that curcumin may prevent RP and sensitize cancer cells to irradiation. However, the clinical advancement of curcumin is limited by its poor water solubility and low bioavailability after oral administration. Here, a water-soluble liposomal curcumin system was developed to investigate its prevention and sensitizing effects by an intravenous administration manner in mice models. The results showed that liposomal curcumin inhibited nuclear factor-κB pathway and downregulated inflammatory factors including tumor necrosis factor-α, interleukin (IL-6, IL-8, and transforming growth factor-β induced by thoracic irradiation. Furthermore, the combined treatment with liposomal curcumin and radiotherapy increased intratumoral apoptosis and microvessel responses to irradiation in vivo. The significantly enhanced inhibition of tumor growth also was observed in a murine lung carcinoma (LL/2 model. There were no obvious toxicities observed in mice. The current results indicate that liposomal curcumin can effectively

Multimodal targeted high relaxivity thermosensitive liposome for in vivo imaging

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Kuijten, Maayke M. P.; Hannah Degeling, M.; Chen, John W.; Wojtkiewicz, Gregory; Waterman, Peter; Weissleder, Ralph; Azzi, Jamil; Nicolay, Klaas; Tannous, Bakhos A.

2015-11-01

Liposomes are spherical, self-closed structures formed by lipid bilayers that can encapsulate drugs and/or imaging agents in their hydrophilic core or within their membrane moiety, making them suitable delivery vehicles. We have synthesized a new liposome containing gadolinium-DOTA lipid bilayer, as a targeting multimodal molecular imaging agent for magnetic resonance and optical imaging. We showed that this liposome has a much higher molar relaxivities r1 and r2 compared to a more conventional liposome containing gadolinium-DTPA-BSA lipid. By incorporating both gadolinium and rhodamine in the lipid bilayer as well as biotin on its surface, we used this agent for multimodal imaging and targeting of tumors through the strong biotin-streptavidin interaction. Since this new liposome is thermosensitive, it can be used for ultrasound-mediated drug delivery at specific sites, such as tumors, and can be guided by magnetic resonance imaging.

Preparation and evaluation of unilamellar liposomes incorporating boron-containing derivatives of cholesterol

International Nuclear Information System (INIS)

Feakes, D.A.; Tate, C.C.; Stefanutti, S.J.

2000-01-01

The application of boron neutron capture therapy is dependent on the identification and preparation of boron-containing compounds that can be delivered and retained by the tumor cells. Unilamellar liposomes have been investigated as potential tumor-specific delivery vehicles for boron-containing compounds that have no inherent tumor specificity. A series of carborane-containing derivatives of cholesterol have been prepared and incorporated into the bilayer of unilamellar liposomes. The cholesterol derivatives vary in the linker moiety (ester and ether), the chain length between the cholesterol and the carborane substituent, and the identity of the carborane group itself (closo- and nido-). The ability of the boron-containing derivatives of cholesterol to be incorporated into the bilayer of the unilamellar liposomes and the stability of the resulting liposome formulations will be presented. (author)

Liposomes as carriers of imaging agents

International Nuclear Information System (INIS)

Caride, V.J.

1985-01-01

This review discusses the utilization of liposomes as imaging agents or as vehicles for contrast materials. The initial approach was the use of radiolabeled liposomes for scintigraphy. To this end liposomes were either labeled in the lipid membrane or aqueous radiotracers were incorporated inside the lipid vesicles. The lipid labeling provides a more stable association of the radioactive tracer and the lipid vesicles, while the use of water-soluble radiotracers provides a wider selection of compounds. Early attempts at selective tumor imaging using radiolabeled liposomes were unsuccessful. The use of monoclonal antibodies attached to liposomes offers new hopes. Several strategies have been proposed in this respect and several others can be envisioned. The use of liposomes permits the use of several administration routes for imaging agents. Of particular interest is the subcutaneous administration for lymph node visualization. Liposomes offer clear advantages over most radiocontrast agents for prolonged hepatosplenic contrast enhancement. This is particularly relevant in the diagnostic evaluation of the abdomen with computed tomography. Important research efforts are being conducted in this area. Two different approaches have been advanced: the incorporation of contrast agents into liposomes and the preparation of radiopaque liposomes from radiodense lipids. Nuclear magnetic resonance imaging can also benefit from contrast agents. Several centers are investigating this exciting field using liposomes loaded with paramagnetic elements.152 references

Application of 10B entrapped PEG-liposome to boron neutron-capture therapy for pancreatic cancer model in vivo

International Nuclear Information System (INIS)

Yanagie, H.; Eriguchi, M.; Maruyama, K.; Takizawa, T.; Ishida, O.; Ogura, K.; Matsumoto, T.; Sakurai, Y.; Kobayashi, T.; Ono, K.; Rant, J.; Skvarc, J.; Ilic, R.; Shinohara, A.; Chiba, M.; Kobayashi, H.

1999-01-01

The cytotoxic effects for tumor were evaluated with intravenous injection 10 B PEG-liposome (Stealth liposome) on human pancreatic carcinoma wenografts in nude mice with thermal neutron irradiation. After thermal neutron irradiation of mice injected with 10 B bare-liposome or 10 B PEG liposome, AsPC-1 tumour growth was suppressed relative to controls. Injection of 10 B PEG-liposome caused the greatest tumour suppression with thermal neutron irradiation in vivo. These results suggest that intravenous injection of 10 B PEG-liposome can increase the retention of 10 B atoms by tumor cells, causing tumor growth suppression in vivo upon thermal neutron irradiation.(author)

Novel liposomal technology applied in esophageal cancer treatment

Science.gov (United States)

Yeh, Chia-Hsien; Hsieh, Yei-San; Yang, Pei-wen; Huang, Leaf; Hsu, Yih-Chih

2018-02-01

Cisplatin (CDDP) has been commonly used as a chemotherapeutic drug, mainly used for the treatment of malignant epithelial cell tumors. We have developed a new method based on innovative lipid calcium phosphate, which encapsulated hydrophobic drugs to form liposomal nanoparticles. Esophageal cancer xenograft model was used to investigate the efficacy of liposomal nanoparticles. and it showed good therapeutic efficacy with lower side effects. Liposomal nanoparticles exhibited a better therapeutic effect than that of conventional CDDP.

Copper-64 labeled liposomes for imaging bone marrow

International Nuclear Information System (INIS)

Lee, Sang-gyu; Gangangari, Kishore; Kalidindi, Teja Muralidhar; Punzalan, Blesida; Larson, Steven M.; Pillarsetty, Naga Vara Kishore

2016-01-01

Introduction: Bone marrow is the soft tissue compartment inside the bones made up of hematopoietic cells, adipocytes, stromal cells, phagocytic cells, stem cells, and sinusoids. While [ 18 F]-FLT has been utilized to image proliferative marrow, to date, there are no reports of particle based positron emission tomography (PET) imaging agents for imaging bone marrow. We have developed copper-64 labeled liposomal formulation that selectively targets bone marrow and therefore serves as an efficient PET probe for imaging bone marrow. Methods: Optimized liposomal formulations were prepared with succinyl PE, DSPC, cholesterol, and mPEG-DSPE (69:39:1:10:0.1) with diameters of 90 and 140 nm, and were doped with DOTA-Bn-DSPE for stable 64 Cu incorporation into liposomes. Results: PET imaging and biodistribution studies with 64 Cu-labeled liposomes indicate that accumulation in bone marrow was as high as 15.18 ± 3.69%ID/g for 90 nm liposomes and 7.01 ± 0.92%ID/g for 140 nm liposomes at 24 h post-administration. In vivo biodistribution studies in tumor-bearing mice indicate that the uptake of 90 nm particles is approximately 0.89 ± 0.48%ID/g in tumor and 14.22 ± 8.07%ID/g in bone marrow, but respective values for Doxil® like liposomes are 0.83 ± 0.49%ID/g and 2.23 ± 1.00%ID/g. Conclusion: Our results indicate that our novel PET labeled liposomes target bone marrow with very high efficiency and therefore can function as efficient bone marrow imaging agents.

Intracellular targeting of mercaptoundecahydrododecaborate (BSH) to malignant glioma by transferrin-PEG liposomes for boron neutron capture therapy (BNCT)

International Nuclear Information System (INIS)

Doi, Atsushi; Miyatake, Shin-ichi; Iida, Kyouko

2006-01-01

Malignant glioma is one of the most difficult tumor to control with usual therapies. In our institute, we select boron neutron capture therapy (BNCT) as an adjuvant radiation therapy after surgical resection. This therapy requires the selective delivery of high concentration of 10 B to malignant tumor tissue. In this study, we focused on a tumor-targeting 10 B delivery system (BDS) for BNCT that uses transferrin-conjugated polyethylene-glycol liposome encapsulating BSH (TF-PEG liposome-BSH) and compared 10 B uptake of the tumor among BSH, PEG liposome-BSH and TF-PEG liposome-BSH. In vitro, we analyzed 10 B concentration of the cultured human U87Δ glioma cells incubated in medium containing 20 μg 10 B/ml derived from each BDS by inductively coupled plasma atomic emission spectrometry (ICP-AES). In vivo, human U87Δ glioma-bearing nude mice were administered with each BDS (35mg 10 B/kg) intravenously. We analyzed 10 B concentration of tumor, normal brain and blood by ICP-AES. The TF-PEG liposome-BSH showed higher absolute concentration more than the other BDS. Moreover, TF-PEG liposome-BSH decreased 10 B concentration in blood and normal tissue while it maintained high 10 B concentration in tumor tissue for a couple of days. This showed the TF-PEG liposome-BSH caused the selective delivery of high concentration of 10 B to malignant tumor tissue. The TF-PEG liposome-BSH is more potent BDS for BNCT to obtain absolute high 10 B concentration and good contrast between tumor and normal tissue than BSH and PEG liposome-BSH. (author)

Reversal of the multidrug resistance by drug combination using multifunctional liposomes

Science.gov (United States)

Patel, Niravkumar R.

One of the major obstacles to the success of cancer chemotherapy is the multi-drug resistance (MDR) that results due mainly to the over-expression of drug efflux transporter pumps such as P-glycoprotein (P-gp). Highly efficacious third generation P-gp inhibitors, like tariquidar, have shown promising results against MDR. However, P-gp is also expressed in normal tissues like the blood-brain barrier, gastrointestinal tract, liver and kidney. It is therefore important to limit the exposure of P-gp inhibitors to normal tissues and increase their co-localization with anticancer agents in tumor tissues to maximize the efficacy of a P-gp inhibitor. To minimize non-specific binding and increase its delivery to tumor tissues, liposomes, self-assembling phospholipid vesicles, were chosen as a drug delivery vehicle. The liposome has been identified as a system capable of carrying molecules with diverse physicochemical properties. It can also alter the pharmacokinetic profile of loaded molecules which is a concern with both tariquidar and paclitaxel. Liposomes can easily be surface-modified rendering them cell-specific as well as organelle-specific. The main objective of present study was to develop an efficient liposomal delivery system which would deliver therapeutic molecules of interest to tumor tissues and avoid interaction with normal tissues. In this study, the co-delivery of tariquidar and paclitaxel into tumor cells to reverse the MDR using long-circulating cationic liposomes was investigated. SKOV-3TR, the resistant variant of SKOV-3 and MCF-7/ADR, the resistant variant of MCF-7 were used as model cell lines. Uniform liposomal formulations were generated with high incorporation efficiency and no apparent decrease in tariquidar potency towards P-gp. Tariquidar- and paclitaxel- co-loaded long-circulating liposomes showed significant re-sensitization of SKOV-3TR and MCF-7/ADR for paclitaxel in vitro. Further modification of these liposomes with antitumor 2C5 resulted

Development of liposomes entrapped in alginate beads for the treatment of colorectal cancer.

Science.gov (United States)

Bansal, Divya; Gulbake, Arvind; Tiwari, Jyoti; Jain, Sanjay K

2016-01-01

Folic Acid conjugated liposomes encapsulating Oxaliplatin (L-OHP) were entrapped in alginate beads and further coated with Eudragit-S-100 for effective delivery to colon tumors. Liposomes were prepared by cast film method and folic acid was coupled on the surface of liposomes. They were further entrapped in alginate beads which were Eudragit coated for degradation in the colonic region. The prepared beads were characterized for shape and surface morphology, percentage entrapment efficiency and drug release studies. The in vitro drug release was investigated using a USP dissolution paddle type apparatus in different simulated gastrointestinal fluids. In vivo studies of the beads containing free drug, folic acid coupled and uncoupled liposomes bearing L-OHP was administered orally at the dose of 10mg L-OHP/kg body weight to tumor bearing NUDE/SCID mice. γ-Scintigraphic study showed that Eudragit coated alginate beads entered into the colon of Balb/c mice between 4.20 and 4.50h after oral administration. In vivo data showed that folic acid coupled liposomes entrapped in alginate beads delivered 2.82 ± 0.58 and 21.52 ± 2.76 μg L-OHP/g tissues in the colon and tumor after 12h, reflecting its targeting potential to colon and tumor. The results clearly demonstrate that Eudragit coated calcium alginate beads bearing folic acid coupled liposome can be used as a prospective carrier for drug delivery to colon specific tumor. Copyright © 2015 Elsevier B.V. All rights reserved.

A novel combination of TRAIL and doxorubicin enhances antitumor effect based on passive tumor-targeting of liposomes

International Nuclear Information System (INIS)

Guo Liangran; Fan Li; Ren Jinfeng; Pang Zhiqing; Ren Yulong; Li Jingwei; Jiang Xinguo; Wen Ziyi

2011-01-01

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a novel anticancer agent for non-small cell lung cancer (NSCLC). However, approximately half of NSCLC cell lines are highly resistant to TRAIL. Doxorubicin (DOX) can sensitize NSCLC cells to TRAIL-induced apoptosis, indicating the possibility of combination therapy. Unfortunately, the therapeutic effect of a DOX and TRAIL combination is limited by multiple factors including the short serum half-life of TRAIL, poor compliance and application difficulty in the clinic, chronic DOX-induced cardiac toxicity, and the multidrug resistance (MDR) property of NSCLC cells. To solve such problems, we developed the combination of TRAIL liposomes (TRAIL-LP) and DOX liposomes (DOX-LP). An in vitro cytotoxicity study indicated that DOX-LP sensitized the NSCLC cell line A-549 to TRAIL-LP-induced apoptosis. Furthermore, this combination therapy of TRAIL-LP and DOX-LP displayed a stronger antitumor effect on NSCLC in xenografted mice when compared with free drugs or liposomal drugs alone. Therefore, the TRAIL-LP and DOX-LP combination therapy has excellent potential to become a new therapeutic approach for patients with advanced NSCLC.

Gemcitabine treatment of rat soft tissue sarcoma with phosphatidyldiglycerol-based thermosensitive liposomes.

Science.gov (United States)

Limmer, Simone; Hahn, Jasmin; Schmidt, Rebecca; Wachholz, Kirsten; Zengerle, Anja; Lechner, Katharina; Eibl, Hansjörg; Issels, Rolf D; Hossann, Martin; Lindner, Lars H

2014-09-01

The pyrimidine analogue gemcitabine (dFdC) is frequently used in the treatment of patients with solid tumors. However, after i.v. application dFdC is rapidly inactivated by metabolization. Here, the potential of thermosensitive liposomes based on 1,2-dipalmitoyl-sn-glycero-3-phosphodiglycerol (DPPG2-TSL) were investigated as carrier and targeting system for delivery of dFdC in combination with local hyperthermia (HT). DPPG2-TSL were prepared by the lipid film hydration and extrusion method and characterized by dynamic light scattering, thin layer chromatography, phosphate assay and HPLC. In vivo experiments were performed in Brown Norway rats with a syngeneic soft tissue sarcoma. Local HT treatment was performed by light exposure. DPPG2-TSL were stable at 37°C in serum and showed a temperature dependent dFdC release >40°C. Plasma half-life of dFdC was strongly increased from 0.07 h (non-liposomal) to 0.53 h (liposomal, vesicle size 105 nm) or 2.59 h (liposomal, 129 nm). Therapy of BN175 tumors with dFdC encapsulated in DPPG2-TSL + HT showed significant improvement in tumor growth delay compared to non-liposomal dFdC without HT (p < 0.05), non-liposomal dFdC with HT (p < 0.01), and liposomal dFdC without HT (p < 0.05), respectively. Gemcitabine encapsulated in DPPG2-TSL in combination with local HT is a promising tool for the treatment of solid tumors. Therefore, these encouraging results ask for further investigation and evaluation.

Application of multifunctional targeting epirubicin liposomes in the treatment of non-small-cell lung cancer

Directory of Open Access Journals (Sweden)

Song X

2017-10-01

Full Text Available Xiao-li Song,1 Rui-jun Ju,2 Yao Xiao,1 Xin Wang,1 Shuang Liu,1 Min Fu,1 Jing-jing Liu,1 Li-yan Gu,1 Xue-tao Li,1 Lan Cheng1 1School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian, 2Department of Pharmaceutical Engineering, Beijing Institute of Petrochemical Technology, Beijing, China Abstract: Chemotherapy for aggressive non-small-cell lung cancer (NSCLC usually results in a poor prognosis due to tumor metastasis, vasculogenic mimicry (VM channels, limited killing of tumor cells, and severe systemic toxicity. Herein, we developed a kind of multifunctional targeting epirubicin liposomes to enhance antitumor efficacy for NSCLC. In the liposomes, octreotide was modified on liposomal surface for obtaining a receptor-mediated targeting effect, and honokiol was incorporated into the lipid bilayer for inhibiting tumor metastasis and eliminating VM channels. In vitro cellular assays showed that multifunctional targeting epirubicin liposomes not only exhibited the strongest cytotoxic effect on Lewis lung tumor cells but also showed the most efficient inhibition on VM channels. Action mechanism studies showed that multifunctional targeting epirubicin liposomes could downregulate PI3K, MMP-2, MMP-9, VE-Cadherin, and FAK and activate apoptotic enzyme caspase 3. In vivo results exhibited that multifunctional targeting epirubicin liposomes could accumulate selectively in tumor site and display an obvious antitumor efficacy. In addition, no significant toxicity of blood system and major organs was observed at a test dose. Therefore, multifunctional targeting epirubicin liposomes may provide a safe and efficient therapy strategy for NSCLC. Keywords: octreotide, honokiol, chemotherapy, vasculogenic mimicry, tumor metastasis, targeting drug delivery

Fluorescent cell-traceable dexamethasone-loaded liposomes for the treatment of inflammatory liver diseases

NARCIS (Netherlands)

Bartneck, M.; Scheyda, K.M.; Warzecha, K.T.; Rizzo, L.Y.; Hittatiya, K.; Luedde, T.; Storm, Gerrit; Trautwein, C.; Lammers, Twan Gerardus Gertudis Maria; Tacke, F.

2015-01-01

Liposomes are routinely used carrier materials for delivering drug molecules to pathological sites. Besides in tumors and inflammatory sites, liposomes also strongly accumulate in liver and spleen. The potential of using liposomes to treat acute and chronic liver disorders, however, has not yet been

Fluorescent cell-traceable dexamethasone-loaded liposomes for the treatment of inflammatory liver diseases

NARCIS (Netherlands)

Bartneck, Matthias; Scheyda, Katharina M; Warzecha, Klaudia T; Rizzo, Larissa Y; Hittatiya, Kanishka; Luedde, Tom; Storm, G; Trautwein, Christian; Lammers, Twan; Tacke, Frank

Liposomes are routinely used carrier materials for delivering drug molecules to pathological sites. Besides in tumors and inflammatory sites, liposomes also strongly accumulate in liver and spleen. The potential of using liposomes to treat acute and chronic liver disorders, however, has not yet been

Validation and Comparison of the Therapeutic Efficacy of Boron Neutron Capture Therapy Mediated By Boron-Rich Liposomes in Multiple Murine Tumor Models

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Charles A Maitz

2017-08-01

Full Text Available Boron neutron capture therapy (BNCT was performed at the University of Missouri Research Reactor in mice bearing CT26 colon carcinoma flank tumors and the results were compared with previously performed studies with mice bearing EMT6 breast cancer flank tumors. Mice were implanted with CT26 tumors subcutaneously in the caudal flank and were given two separate tail vein injections of unilamellar liposomes composed of cholesterol, 1,2-distearoyl-sn-glycer-3-phosphocholine, and K[nido-7-CH3(CH215–7,8-C2B9H11] in the lipid bilayer and encapsulated Na3[1-(2`-B10H9-2-NH3B10H8] within the liposomal core. Mice were irradiated 30 hours after the second injection in a thermal neutron beam for various lengths of time. The tumor size was monitored daily for 72 days. Despite relatively lower tumor boron concentrations, as compared to EMT6 tumors, a 45 minute neutron irradiation BNCT resulted in complete resolution of the tumors in 50% of treated mice, 50% of which never recurred. Median time to tumor volume tripling was 38 days in BNCT treated mice, 17 days in neutron-irradiated mice given no boron compounds, and 4 days in untreated controls. Tumor response in mice with CT26 colon carcinoma was markedly more pronounced than in previous reports of mice with EMT6 tumors, a difference which increased with dose. The slope of the dose response curve of CT26 colon carcinoma tumors is 1.05 times tumor growth delay per Gy compared to 0.09 times tumor growth delay per Gy for EMT6 tumors, indicating that inherent radiosensitivity of tumors plays a role in boron neutron capture therapy and should be considered in the development of clinical applications of BNCT in animals and man.

Detection of peritoneal dissemination with near-infrared fluorescence laparoscopic imaging using a liposomal formulation of a synthesized indocyanine green liposomal derivative.

Science.gov (United States)

Hoshino, Isamu; Maruyama, Tetsuro; Fujito, Hiromichi; Tamura, Yutaka; Suganami, Akiko; Hayashi, Hideki; Toyota, Taro; Akutsu, Yasunori; Murakami, Kentaro; Isozaki, Yuka; Akanuma, Naoki; Takeshita, Nobuyoshi; Toyozumi, Takeshi; Komatsu, Aki; Matsubara, Hisahiro

2015-03-01

Although conventional staging laparoscopy (SL) has improved the diagnostic accuracy of peritoneal dissemination, novel technology is needed to increase the sensitivity of SL. We herein describe a new imaging method employing near-infrared (NIR) fluorescence imaging using a liposomal synthesized indocyanine green (ICG) liposomal derivative, LP-ICG-C18. LP-ICG-C18 is a NIR-photoactivating probe in which an ICG fluorophore is covalently conjugated with a phospholipid moiety. Nude mice were intraperitoneally injected with gastric cancer cells. Twelve days later, the mice were given intravenous injections of LP-ICG-C18 at a dose of 0.15 mg/kg. A NIR imaging system was used to identify the disseminated tumors. The disseminated nodules in mice were detected without any difficulties. Disseminated tumor nodules were collected from mice with or without injections of liposomal formulation and were transferred into the swine peritoneal cavity. The nodules in the swine peritoneal cavity were clearly and promptly defined by the NIR imaging system. NIR-fluorescing liposomal probes can effectively target peritoneal disseminated tumors and can be easily detected by a NIR imaging system. These results warrant future clinical trials of our imaging system and may contribute to a more precise diagnosis and therapeutic approach for gastric cancer patients. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

In vivo study of doxorubicin-loaded cell-penetrating peptide-modified pH-sensitive liposomes: biocompatibility, bio-distribution, and pharmacodynamics in BALB/c nude mice bearing human breast tumors

Directory of Open Access Journals (Sweden)

Ding Y

2017-10-01

Full Text Available Yuan Ding,1,* Wei Cui,2,* Dan Sun,1 Gui-Ling Wang,1 Yu Hei,1 Shuai Meng,1 Jian-Hua Chen,3 Ying Xie,1 Zhi-Qiang Wang4 1Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, 2School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, 3School of Medicine, Jianghan University, Wuhan, People’s Republic of China; 4Department of Chemistry and Biochemistry, Kent State University Geauga, Burton, OH, USA *These authors contributed equally to this work Abstract: In vivo evaluation of drug delivery vectors is essential for clinical translation. In BALB/c nude mice bearing human breast cancer tumors, we investigated the biocompatibility, pharmacokinetics, and pharmacodynamics of doxorubicin (DOX-loaded novel cell-penetrating peptide (CPP-modified pH-sensitive liposomes (CPPL (referred to as CPPL(DOX with an optimal CPP density of 4%. In CPPL, a polyethylene glycol (PEG derivative formed by conjugating PEG with stearate via acid-degradable hydrazone bond (PEG2000-Hz-stearate was inserted into the surface of liposomes, and CPP was directly attached to liposome surfaces via coupling with stearate to simultaneously achieve long circulation time in blood and improve the selectivity and efficacy of CPP for tumor targeting. Compared to PEGylated liposomes, CPPL enhanced DOX accumulation in tumors up to 1.9-fold (p<0.01 and resulted in more cell apoptosis as a result of DNA disruption as well as a relatively lower tumor growth ratio (T/C%. Histological examination did not show any signs of necrosis or inflammation in normal tissues, but large cell dissolving areas were found in tumors following the treatment of animals with CPPL(DOX. Our findings provide important and detailed information regarding the distribution of CPPL(DOX in vivo and reveal their abilities of tumor penetration and potential for the treatment of

Ultrasound, liposomes, and drug delivery: principles for using ultrasound to control the release of drugs from liposomes.

Science.gov (United States)

Schroeder, Avi; Kost, Joseph; Barenholz, Yechezkel

2009-11-01

Ultrasound is used in many medical applications, such as imaging, blood flow analysis, dentistry, liposuction, tumor and fibroid ablation, and kidney stone disruption. In the past, low frequency ultrasound (LFUS) was the main method to downsize multilamellar (micron range) vesicles into small (nano scale) unilamellar vesicles. Recently, the ability of ultrasound to induce localized and controlled drug release from liposomes, utilizing thermal and/or mechanical effects, has been shown. This review, deals with the interaction of ultrasound with liposomes, focusing mainly on the mechanical mechanism of drug release from liposomes using LFUS. The effects of liposome lipid composition and physicochemical properties, on one hand, and of LFUS parameters, on the other, on liposomal drug release, are addressed. Acoustic cavitation, in which gas bubbles oscillate and collapse in the medium, thereby introducing intense mechanical strains, increases release substantially. We suggest that the mechanism of release may involve formation and collapse of small gas nuclei in the hydrophobic region of the lipid bilayer during exposure to LFUS, thereby inducing the formation of transient pores through which drugs are released. Introducing PEG-lipopolymers to the liposome bilayer enhances responsivity to LFUS, most likely due to absorption of ultrasonic energy by the highly hydrated PEG headgroups. The presence of amphiphiles, such as phospholipids with unsaturated acyl chains, which destabilize the lipid bilayer, also increases liposome susceptibility to LFUS. Application of these principles to design highly LFUS-responsive liposomes is discussed.

Zoledronic acid enhances antitumor efficacy of liposomal doxorubicin.

Science.gov (United States)

Hattori, Yoshiyuki; Shibuya, Kazuhiko; Kojima, Kaori; Miatmoko, Andang; Kawano, Kumi; Ozaki, Kei-Ichi; Yonemochi, Etsuo

2015-07-01

Previously, we found that the injection of zoledronic acid (ZOL) into mice bearing tumor induced changes of the vascular structure in the tumor. In this study, we examined whether ZOL treatment could decrease interstitial fluid pressure (IFP) via change of tumor vasculature, and enhance the antitumor efficacy of liposomal doxorubicin (Doxil®). When ZOL solution was injected at 40 µg/mouse per day for three consecutive days into mice bearing murine Lewis lung carcinoma LLC tumor, depletion of macrophages in tumor tissue and decreased density of tumor vasculature were observed. Furthermore, ZOL treatments induced inflammatory cytokines such as interleukin (IL)-10 and -12, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor (TNF)-α in serum of LLC tumor-bearing mice, but not in normal mice, indicating that ZOL treatments might induce an inflammatory response in tumor tissue. Furthermore, ZOL treatments increased antitumor activity by Doxil in mice bearing a subcutaneous LLC tumor, although they did not significantly increase the tumor accumulation of doxorubicin (DXR). These results suggest that ZOL treatments might increase the therapeutic efficacy of Doxil via improvement of DXR distribution in a tumor by changing the tumor vasculature. ZOL treatment can be an alternative approach to increase the antitumor effect of liposomal drugs.

Dual drug delivery using "smart" liposomes for triggered release of anticancer agents

Science.gov (United States)

Jain, Ankit; Gulbake, Arvind; Jain, Ashish; Shilpi, Satish; Hurkat, Pooja; Jain, Sanjay K.

2013-07-01

Ovarian cancer is one of the most fatal gynecologic cancers. In this debut study, dual approach using synergistically active combination of paclitaxel-topotecan (Pac-Top; 20:1, w/w) is investigated with utilization of characteristic features of tumor micro-environment and additionally overexpressed folate receptors (FR-α) to achieve targeting to tumor site. Various liposomes namely liposomes, PEGylated liposomes, and FR-targeted PEGylated liposomes with lipid compositions viz. DPPC:DMPG (85.5:9.5), DPPC:DMPG:mPEG2000-DSPE (85.5:9.5:5), and DPPC:DMPG:mPEG2000-DSPE:DSPE-PEG-folate (85.5:9.5:4.5:0.5), respectively, were developed using thin film casting method. These were nanometric in size around 200 nm. In vitro drug release study showed initial burst release followed by sustained release for more than 72 h at physiological milieu (37 ± 0.5 °C, pH 7.4) while burst release (i.e., more than 90 %) within 5 min at simulated tumor milieu (41 ± 1 °C, pH 4). SRB cytotoxicity assay in OVCAR-3 cell line revealed Pac-Top free (20:1, w/w) to be more toxic (GI50 = 6.5 μg/ml) than positive control (Adriamycin, GI50 = 9.1 μg/ml) and FR-targeted PEGylated liposomes GI50 (14.7 μg/ml). Moreover, florescence microscopy showed the highest cell uptake of FR-targeted PEGylated liposomes so called "smart liposomes" which has not only mediated effective targeting to FR-α but also triggered release of drugs upon hyperthermia.

64Cu loaded liposomes as positron emission tomography imaging agents

DEFF Research Database (Denmark)

Petersen, Anncatrine Luisa; Binderup, Tina; Rasmussen, Palle

2011-01-01

applicable as PET imaging agents. We show the utility of the 64Cu-liposomes for quantitative in vivo imaging of healthy and tumor-bearing mice using PET. This remote loading method is a powerful tool for characterizing the in vivo performance of liposome based nanomedicine, and has great potential...

Liposome imaging agents in personalized medicine

DEFF Research Database (Denmark)

Petersen, Anncatrine Luisa; Hansen, Anders Elias; Gabizon, Alberto

2012-01-01

In recent years the importance of molecular and diagnostic imaging has increased dramatically in the treatment planning of many diseases and in particular in cancer therapy. Within nanomedicine there are particularly interesting possibilities for combining imaging and therapy. Engineered liposomes...... that selectively localize in tumor tissue can transport both drugs and imaging agents, which allows for a theranostic approach with great potential in personalized medicine. Radiolabeling of liposomes have for many years been used in preclinical studies for evaluating liposome in vivo performance and has been...... start to consider how to use imaging for patient selection and treatment monitoring in connection to nanocarrier based medicines. Nanocarrier imaging agents could furthermore have interesting properties for disease diagnostics and staging. Here, we review the major advances in the development...

Antibody-Hapten Recognition at the Surface of Functionalized Liposomes Studied by SPR: Steric Hindrance of Pegylated Phospholipids in Stealth Liposomes Prepared for Targeted Radionuclide Delivery

Directory of Open Access Journals (Sweden)

Eliot. P. Botosoa

2011-01-01

Full Text Available Targeted PEGylated liposomes could increase the amount of drugs or radionuclides delivered to tumor cells. They show favorable stability and pharmacokinetics, but steric hindrance of the PEG chains can block the binding of the targeting moiety. Here, specific interactions between an antihapten antibody (clone 734, specific for the DTPA-indium complex and DTPA-indium-tagged liposomes were characterized by surface plasmon resonance (SPR. Non-PEGylated liposomes fused on CM5 chips whereas PEGylated liposomes did not. By contrast, both PEGylated and non-PEGylated liposomes attached to L1 chips without fusion. SPR binding kinetics showed that, in the absence of PEG, the antibody binds the hapten at the surface of lipid bilayers with the affinity of the soluble hapten. The incorporation of PEGylated lipids hinders antibody binding to extents depending on PEGylated lipid fraction and PEG molecular weight. SPR on immobilized liposomes thus appears as a useful technique to optimize formulations of liposomes for targeted therapy.

Near-infrared light activation of quenched liposomal Ce6 for synergistic cancer phototherapy with effective skin protection.

Science.gov (United States)

Feng, Liangzhu; Tao, Danlei; Dong, Ziliang; Chen, Qian; Chao, Yu; Liu, Zhuang; Chen, Meiwan

2017-05-01

Current photodynamic therapy (PDT) is suffering from limited efficacy towards hypoxia tumors and severe post-treatment photo-toxicity such as light-induced skin damages. To make PDT more effective in cancer treatment while being patient-comfortable, herein, a hexylamine conjugated chlorin e6 (hCe6) as the photosensitizer together with a lipophilic near-infrared (NIR) dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DiR) are co-encapsulated into polyethylene glycol (PEG) shelled liposomes. In the obtained DiR-hCe6-liposome, the photosensitizing effect of hCe6 is quenched by DiR via fluorescence resonance energy transfer (FRET). Interestingly, upon irradiation with a 785-nm NIR laser to photobleach DiR, both fluorescence and photodynamic effect of hCe6 in DiR-hCe6-liposome would be activated. Meanwhile, such NIR irradiation applied on tumors of mice with intravenous injection of DiR-hCe6-liposome could result in mild photothermal heating, which in turn would promote intra-tumor blood flow and relieve tumor hypoxia, contributing to the enhanced photodynamic tumor treatment. Importantly, compared to hCe6-loaded liposomes, DiR-hCe6-liposome without being activated by the 785-nm laser shows much lower skin photo-toxicity, demonstrating its great skin protection effect. This work demonstrates a promising yet simple strategy to prepare NIR-light-activatable photodynamic theranostics for synergistic cancer phototherapy, which is featured high specificity/efficacy in tumor treatment with minimal photo-toxicity towards the skin. Copyright © 2016. Published by Elsevier Ltd.

Heparin octasaccharide decoy liposomes inhibit replication of multiple viruses

Science.gov (United States)

Hendricks, Gabriel L.; Velazquez, Lourdes; Pham, Serena; Qaisar, Natasha; Delaney, James C.; Viswanathan, Karthik; Albers, Leila; Comolli, James C.; Shriver, Zachary; Knipe, David M.; Kurt-Jones, Evelyn A.; Fygenson, Deborah K.; Trevejo, Jose M.

2016-01-01

Heparan sulfate (HS) is a ubiquitous glycosaminoglycan that serves as a cellular attachment site for a number of significant human pathogens, including respiratory syncytial virus (RSV), human parainfluenza virus 3 (hPIV3), and herpes simplex virus (HSV). Decoy receptors can target pathogens by binding to the receptor pocket on viral attachment proteins, acting as ‘molecular sinks’ and preventing the pathogen from binding to susceptible host cells. Decoy receptors functionalized with HS could bind to pathogens and prevent infection, so we generated decoy liposomes displaying HS-octasaccharide (HS-octa). These decoy liposomes significantly inhibited RSV, hPIV3, and HSV infectivity in vitro to a greater degree than the original HS-octa building block. The degree of inhibition correlated with the density of HS-octa displayed on the liposome surface. Decoy liposomes with HS-octa inhibited infection of viruses to a greater extent than either full-length heparin or HS-octa alone. Decoy liposomes were effective when added prior to infection or following the initial infection of cells in vitro. By targeting the well-conserved receptor-binding sites of HS-binding viruses, decoy liposomes functionalized with HS-octa are a promising therapeutic antiviral agent and illustrate the utility of the liposome delivery platform. PMID:25637710

Clinical developments of chemotherapeutic nanomedicines: Polymers and liposomes for delivery of camptothecins and platinum (II) drugs

KAUST Repository

Kieler-Ferguson, Heidi M.

2013-01-17

For the past 40 years, liposomal and polymeric delivery vehicles have been studied as systems capable of modulating the cytotoxicity of small molecule chemotherapeutics, increasing tumor bearing animal survival times, and improving drug targeting. Although a number of macromolecular-drug conjugates have progressed to clinical trials, tuning drug release to maintain efficacy in conjunction with controlling drug toxicity has prevented the clinical adoption of many vehicles. In this article, we review the motivations for and approaches to polymer and liposomal delivery with regard to camptothecin and cisplatin delivery. WIREs Nanomed Nanobiotechnol 2013, 5:130-138. doi: 10.1002/wnan.1209 For further resources related to this article, please visit the WIREs website. Conflict of interest: Drs Kieler-Ferguson and Fréchet declare no conflicts of interest. Dr Szoka is the founder of a liposome drug delivery company that is not working on any of the compounds mentioned in this article. © 2013 Wiley Periodicals, Inc.

Prospects of liposomes using for creating of new forms of the medicinal and preventive preparations

Directory of Open Access Journals (Sweden)

M. A. Kisjakova

2010-07-01

Full Text Available Information on the structure, physical and chemical characteristics of the phospholipid vesicles (liposomes – the effective natural drug delivery system is presented. Types of liposomes, procedures of its productions, penetration mechanisms into cells and functional features of liposomal drugs are described. Data on production of liposomes with lactobacilli acellular homogenates and the methods of the liposomes structure control asre demonstrated.

Method of hyperthermia and tumor size influence effectiveness of doxorubicin release from thermosensitive liposomes in experimental tumors.

Science.gov (United States)

Willerding, Linus; Limmer, Simone; Hossann, Martin; Zengerle, Anja; Wachholz, Kirsten; Ten Hagen, Timo L M; Koning, Gerben A; Sroka, Ronald; Lindner, Lars H; Peller, Michael

2016-01-28

Systemic chemotherapy of solid tumors could be enhanced by local hyperthermia (HT) in combination with thermosensitive liposomes (TSL) as drug carriers. In such an approach, effective HT of the tumor is considered essential for successful triggering local drug release and targeting of the drug to the tumor. To investigate the effect of HT method on the effectiveness of drug delivery, a novel laser-based HT device designed for the use in magnetic resonance imaging (MRI) was compared systematically with the frequently used cold light lamp and water bath HT. Long circulating phosphatidyldiglycerol-based TSL (DPPG2-TSL) with encapsulated doxorubicin (DOX) were used as drug carrier enabling intravascular drug release. Experiments were performed in male Brown Norway rats with a syngeneic soft tissue sarcoma (BN 175) located on both hind legs. One tumor was heated while the second tumor remained unheated as a reference. Six animals were investigated per HT method. DPPG2-TSL were injected i.v. at a stable tumor temperature above 40°C. Thereafter, temperature was maintained for 60min. Total DOX concentration in plasma, tumor tissue and muscle was determined post therapy by HPLC. Finally, the new laser-based device was tested in a MRI environment at 3T using DPPG2-TSL with encapsulated Gd-based contrast agent. All methods showed effective DOX delivery by TSL with 4.5-23.1ng/mg found in the heated tumors. In contrast, DOX concentration in the non-heated tumors was 0.5±0.1ng/mg. Independent of used HT methods, higher DOX levels were found in the smaller tumors. In comparison water bath induced lowest DOX delivery but still showing fourfold higher DOX concentrations compared to the non-heated tumors. With the laser-based applicator, a 13 fold higher DOX deposition was possible for large tumors and a 15 fold higher for the small tumors, respectively. Temperature gradients in the tumor tissue were higher with the laser and cold light lamp (-0.3°C/mm to -0.5°C/mm) compared to

PLGA nanoparticles introduction into mitoxantrone-loaded ultrasound-responsive liposomes: In vitro and in vivo investigations.

Science.gov (United States)

Xin, Yuxuan; Qi, Qi; Mao, Zhenmin; Zhan, Xiaoping

2017-08-07

A novel ultrasound-responsive liposomal system for tumor targeting was prepared in order to increase the antitumor efficacy and decrease serious side effects. In this paper, PLGA nanoparticles were used ultrasound-responsive agents instead of conventional microbubbles. The PLGA-nanoparticles were prepared by an emulsion solvent evaporation method. The liposomes were prepared by a lipid film hydration method. Particle size, zeta potential, encapsulation efficiency and drug loading capacity of the liposomes were studied by light scattering analysis and dialysis. Transmission electron microscopy (TEM) and atomic force microscope (AFM) were used to investigate the morphology of liposomes. The release in vitro was carried out in the pH 7.4 phosphate buffer solutions, as a result, liposome L3 encapsulating PLGA-nanoparticles displayed good stability under simulative physiological conditions and quickly responsive release under the ultrasound. The release in vivo was carried out on the rats, as a result, liposome L3 showed higher bioavailability than traditional intravenous injectable administration, and liposome L3 showed higher elimination ratio after stimulation by ultrasound than L3 without stimulation. Thus, the novel ultrasound-responsive liposome encapsulating PLGA-nanoparticles has a potential to be developed as a new drug delivery system for anti-tumor drug. Copyright © 2017 Elsevier B.V. All rights reserved.

Dual drug delivery using “smart” liposomes for triggered release of anticancer agents

International Nuclear Information System (INIS)

Jain, Ankit; Gulbake, Arvind; Jain, Ashish; Shilpi, Satish; Hurkat, Pooja; Jain, Sanjay K.

2013-01-01

Ovarian cancer is one of the most fatal gynecologic cancers. In this debut study, dual approach using synergistically active combination of paclitaxel–topotecan (Pac–Top; 20:1, w/w) is investigated with utilization of characteristic features of tumor micro-environment and additionally overexpressed folate receptors (FR-α) to achieve targeting to tumor site. Various liposomes namely liposomes, PEGylated liposomes, and FR-targeted PEGylated liposomes with lipid compositions viz. DPPC:DMPG (85.5:9.5), DPPC:DMPG:mPEG 2000 –DSPE (85.5:9.5:5), and DPPC:DMPG:mPEG 2000 –DSPE:DSPE–PEG–folate (85.5:9.5:4.5:0.5), respectively, were developed using thin film casting method. These were nanometric in size around 200 nm. In vitro drug release study showed initial burst release followed by sustained release for more than 72 h at physiological milieu (37 ± 0.5 °C, pH 7.4) while burst release (i.e., more than 90 %) within 5 min at simulated tumor milieu (41 ± 1 °C, pH 4). SRB cytotoxicity assay in OVCAR-3 cell line revealed Pac–Top free (20:1, w/w) to be more toxic (GI 50 = 6.5 μg/ml) than positive control (Adriamycin, GI 50 = 9.1 μg/ml) and FR-targeted PEGylated liposomes GI 50 (14.7 μg/ml). Moreover, florescence microscopy showed the highest cell uptake of FR-targeted PEGylated liposomes so called “smart liposomes” which has not only mediated effective targeting to FR-α but also triggered release of drugs upon hyperthermia

Modification of liposomal concentration in liposome/adenoviral complexes allows significant protection of adenoviral vectors from neutralising antibody, in vitro.

Science.gov (United States)

Steel, Jason C; Cavanagh, Heather M A; Burton, Mark A; Dingwall, Daniel J; Kalle, Wouter H J

2005-06-01

Adenoviral vectors have been commonly used in gene therapy protocols, however the success of their use is often limited by the induction of host immunity to the vector. Following exposure to the adenoviral vector, adenoviral-specific neutralising antibodies are produced which limits further administration. This study examines the efficacy of complexing liposomes to adenovirus for the protection of the adenovirus from neutralising antibodies in an in vitro setting. Dimethyldioctadecylammonium bromide (DDAB)-dioleoyl-l-phosphatidylethanolamine (DOPE) liposomes were bound at varying concentrations to adenovirus to form AL complexes and tested these complexes' ability to prevent adenoviral neutralisation. It is shown that by increasing the concentration of liposomes in the adenoviral-liposome (AL) complexes we can increase the level of immuno-shielding afforded the adenovirus. It is also shown that the increase in liposomal concentration may lead to drawbacks such as increased cytotoxicity and reductions in expression levels.

Thermosensitive liposomal drug delivery systems: state of the art review

Directory of Open Access Journals (Sweden)

Kneidl B

2014-09-01

Full Text Available Barbara Kneidl,1,2 Michael Peller,3 Gerhard Winter,2 Lars H Lindner,1 Martin Hossann11Department of Internal Medicine III, University Hospital Munich, 2Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, 3Institute for Clinical Radiology, University Hospital Munich, Ludwig-Maximilians University, Munich, GermanyAbstract: Thermosensitive liposomes are a promising tool for external targeting of drugs to solid tumors when used in combination with local hyperthermia or high intensity focused ultrasound. In vivo results have demonstrated strong evidence that external targeting is superior over passive targeting achieved by highly stable long-circulating drug formulations like PEGylated liposomal doxorubicin. Up to March 2014, the Web of Science listed 371 original papers in this field, with 45 in 2013 alone. Several formulations have been developed since 1978, with lysolipid-containing, low temperature-sensitive liposomes currently under clinical investigation. This review summarizes the historical development and effects of particular phospholipids and surfactants on the biophysical properties and in vivo efficacy of thermosensitive liposome formulations. Further, treatment strategies for solid tumors are discussed. Here we focus on temperature-triggered intravascular and interstitial drug release. Drug delivery guided by magnetic resonance imaging further adds the possibility of performing online monitoring of a heating focus to calculate locally released drug concentrations and to externally control drug release by steering the heating volume and power. The combination of external targeting with thermosensitive liposomes and magnetic resonance-guided drug delivery will be the unique characteristic of this nanotechnology approach in medicine.Keywords: thermosensitive liposomes, phosphatidyloligoglycerol, hyperthermia, high intensity focused ultrasound, drug delivery, drug targeting

Dual drug delivery using 'smart' liposomes for triggered release of anticancer agents

Energy Technology Data Exchange (ETDEWEB)

Jain, Ankit; Gulbake, Arvind; Jain, Ashish; Shilpi, Satish; Hurkat, Pooja; Jain, Sanjay K., E-mail: drskjainin@yahoo.com [Dr. Hari Singh Gour Vishwavidyalaya, Pharmaceutics Research Projects Laboratory, Department of Pharmaceutical Sciences (India)

2013-07-15

Ovarian cancer is one of the most fatal gynecologic cancers. In this debut study, dual approach using synergistically active combination of paclitaxel-topotecan (Pac-Top; 20:1, w/w) is investigated with utilization of characteristic features of tumor micro-environment and additionally overexpressed folate receptors (FR-{alpha}) to achieve targeting to tumor site. Various liposomes namely liposomes, PEGylated liposomes, and FR-targeted PEGylated liposomes with lipid compositions viz. DPPC:DMPG (85.5:9.5), DPPC:DMPG:mPEG{sub 2000}-DSPE (85.5:9.5:5), and DPPC:DMPG:mPEG{sub 2000}-DSPE:DSPE-PEG-folate (85.5:9.5:4.5:0.5), respectively, were developed using thin film casting method. These were nanometric in size around 200 nm. In vitro drug release study showed initial burst release followed by sustained release for more than 72 h at physiological milieu (37 {+-} 0.5 Degree-Sign C, pH 7.4) while burst release (i.e., more than 90 %) within 5 min at simulated tumor milieu (41 {+-} 1 Degree-Sign C, pH 4). SRB cytotoxicity assay in OVCAR-3 cell line revealed Pac-Top free (20:1, w/w) to be more toxic (GI{sub 50} = 6.5 {mu}g/ml) than positive control (Adriamycin, GI{sub 50} = 9.1 {mu}g/ml) and FR-targeted PEGylated liposomes GI{sub 50} (14.7 {mu}g/ml). Moreover, florescence microscopy showed the highest cell uptake of FR-targeted PEGylated liposomes so called 'smart liposomes' which has not only mediated effective targeting to FR-{alpha} but also triggered release of drugs upon hyperthermia.

Influence of polymer size, liposomal composition, surface charge, and temperature on the permeability of pH-sensitive liposomes containing lipid-anchored poly(2-ethylacrylic acid

Directory of Open Access Journals (Sweden)

Lu T

2012-09-01

Full Text Available Tingli Lu,1 Zhao Wang,2 Yufan Ma,1 Yang Zhang,2 Tao Chen1,21Key Laboratory for Space Bioscience and Biotechnology, School of Life Science, Northwestern Polytechnical University, 2Liposome Research Centre, Xi'an, ChinaBackground: Liposomes containing pH-sensitive polymers are promising candidates for the treatment of tumors and localized infection. This study aimed to identify parameters influencing the extent of contents release from poly(ethylacrylic acid (PEAA vesicles, focusing on the effects of polymer size, lipid composition, vesicle surface charge, and temperature.Methods: Anchored lipid pH-sensitive PEAA was synthesized using PEAA with a molecular weight of 8.4 kDa. PEAA vesicles were prepared by insertion of the lipid-anchored PEAA into preformed large unilamellar vesicles. The preformed liposomes were manipulated by varying the phosphocholine and cholesterol content, and by adding negative or positive charges to the liposomes. A calcein release assay was used to evaluate the effects of polymer size, liposome composition, surface charge, and temperature on liposomal permeability.Results: The release efficiency of the calcein-entrapped vesicles was found to be dependent on the PEAA polymer size. PEAA vesicles containing a phosphatidylcholine to cholesterol ratio of 60:40 (mol/mol released more than 80% of their calcein content when the molecular weight of PEAA was larger than 8.4 kDa. Therefore, the same-sized polymer of 8.4 kDa was used for the rest of study. The calcein release potential was found to decrease as the percentage of cholesterol increased and with an increase in the phosphocholine acyl chain length (DMPC . DPPC . DSPC. Negatively charged and neutral vesicles released similar amounts of calcein, whereas positively charged liposomes released a significant amount of their contents. pH-sensitive release was dependent on temperature. Dramatic content release was observed at higher temperatures.Conclusion: The observed

In Vitro and In Vivo Effective Gene Delivery with Novel Liposomal Bubbles

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Nishiie, Norihito; Suzuki, Ryo; Oda, Yusuke; Hirata, Keiichi; Taira, Yuichiro; Utoguchi, Naoki; Negishi, Yoichi; Maruyama, Kazuo

2010-03-01

Microbubbles, which were ultrasound contrast agents, could improve the transfection efficiency by cavitation with ultrasound exposure. However, conventional microbubbles had some problems regarding size and targeting ability. To solve these problems, we paid attention to liposomes that had many advantages as drug, antigen and gene delivery carriers. Because they can easily be controlled their size and added a targeting function. And we succeeded to prepare novel liposomal bubbles (Bubble liposomes) entrapping perfluoropropane which was utilized for contrast enhancement in ultrasonography. In this study, we assessed the feasibility of Bubble liposomes as gene delivery tools utilized cavitation by ultrasound exposure. In vitro gene delivery, Bubble liposomes could deliver plasmid DNA to many cell types such as tumor cells, T cell line and endothelial cells without cytotoxicity. In vivo gene delivery, Bubble liposomes could effectively deliver plasmid DNA into mouse femoral artery. This method was more effectively than conventional lipofection. We conclude that Bubble liposomes are unique and efficient gene delivery tools in vitro and in vivo.

Radiolabeling of liposomes and polymeric micelles with PET-isotopes

Energy Technology Data Exchange (ETDEWEB)

Ingemann Jensen, A.T.

2013-06-01

This thesis is divided into three separate chapters that can be read independently. Chapter 1 is a general introduction, touching upon liposomes and polymeric micelles and radiolabeling with 18F and 64Cu. Chapter 2 and 3 address two separate research projects, each described below. A complete reference list is compiled in the end, immediately after the three chapters. This is followed by the supplementary information, divided into appropriate sections. Finally, the two first-authored manuscripts are attached as appendices. Chapter 1. The field of nanoparticulate drug delivery has been hailed as a revolution in modern therapeutics, especially in chemotherapy. A major reason is the ability of nanoparticles to accumulate in tumor tissue. Liposomes are the classic nanoparticle, consisting of a lipid membrane with an aqueous core. Polymeric micelles are made from amphiphilic detergent-like copolymers, that self-assemble in water. Therapy with nanoparticles is hampered by often poor tumor accumulation, combined with massive uptake by macrophages in the liver and spleen. For this reason, visualizing nanoparticle pharmacokinetics in-vivo is a valuable tool in the on-going research. Such visualization can be done by labeling with radio isotopes. Isotopes that emit positrons (PET-isotopes) can be detected by PET (positron emission tomography) technology, an accurate technique that has gained popularity in recent years. PET-isotopes of interest include 18F and 64Cu. In addition to being a research tool, radiolabeled nanoparticles hold promise as a radiopharmaceutical in themselves, as a means of imaging tumor tissue, aiding in diagnosis and surgery. Chapter 2. A method for labeling liposomes with 18F (97% positron decay, T = 110 min) was investigated. 18F is widely available, but is hampered by a short half-life only allowing up to 8 hours scans. 18F must be covalently attached to components of the liposome. By binding to a lipid, it can be stably lodged in the membrane. A

Radiolabeling of liposomes and polymeric micelles with PET-isotopes

International Nuclear Information System (INIS)

Ingemann Jensen, A.T.

2013-01-01

This thesis is divided into three separate chapters that can be read independently. Chapter 1 is a general introduction, touching upon liposomes and polymeric micelles and radiolabeling with 18F and 64Cu. Chapter 2 and 3 address two separate research projects, each described below. A complete reference list is compiled in the end, immediately after the three chapters. This is followed by the supplementary information, divided into appropriate sections. Finally, the two first-authored manuscripts are attached as appendices. Chapter 1. The field of nanoparticulate drug delivery has been hailed as a revolution in modern therapeutics, especially in chemotherapy. A major reason is the ability of nanoparticles to accumulate in tumor tissue. Liposomes are the classic nanoparticle, consisting of a lipid membrane with an aqueous core. Polymeric micelles are made from amphiphilic detergent-like copolymers, that self-assemble in water. Therapy with nanoparticles is hampered by often poor tumor accumulation, combined with massive uptake by macrophages in the liver and spleen. For this reason, visualizing nanoparticle pharmacokinetics in-vivo is a valuable tool in the on-going research. Such visualization can be done by labeling with radio isotopes. Isotopes that emit positrons (PET-isotopes) can be detected by PET (positron emission tomography) technology, an accurate technique that has gained popularity in recent years. PET-isotopes of interest include 18F and 64Cu. In addition to being a research tool, radiolabeled nanoparticles hold promise as a radiopharmaceutical in themselves, as a means of imaging tumor tissue, aiding in diagnosis and surgery. Chapter 2. A method for labeling liposomes with 18F (97% positron decay, T = 110 min) was investigated. 18F is widely available, but is hampered by a short half-life only allowing up to 8 hours scans. 18F must be covalently attached to components of the liposome. By binding to a lipid, it can be stably lodged in the membrane. A

Positron emission tomography evaluation of somatostatin receptor targeted (64)Cu-TATE-liposomes in a human neuroendocrine carcinoma mouse model

DEFF Research Database (Denmark)

Petersen, Anncatrine Luisa; Binderup, Tina; Jølck, Rasmus Irming

2012-01-01

-liposomes without TATE. PEGylated liposomes with or without TATE accumulated at significantly higher quantities in NETs (5.1±0.3 and 5.8±0.2 %ID/g, respectively) than the free peptide (64)Cu-DOTA-TATE (1.4±0.3 %ID/g) 24h post-injection. Importantly, (64)Cu-loaded PEGylated liposomes with TATE showed significantly...... higher tumor-to-muscle (T/M) ratio (12.7±1.0) than the control-liposomes without TATE (8.9±0.9) and the (64)Cu-DOTA-TATE free peptide (7.2±0.3). The higher T/M ratio of the PEGylated liposomes with TATE suggests some advantage of active targeting of NETs, although no absolute benefit in tumor...... to image NETs was evaluated using PET. Additionally, the liposome accumulation and imaging capability was compared with free radiolabelled TATE peptide administered as (64)Cu-DOTA-TATE. The presence of TATE on the liposomes resulted in a significantly faster initial blood clearance in comparison to control...

Immune mechanisms regulating pharmacokinetics and pharmacodynamics of PEGylated liposomal anticancer agents

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Song, Gina

Nanotechnology has made significant advances in drug delivery system for the treatment of cancer. Among various nanoparticle (NP) platforms, liposomes have been most widely used as a NP drug carrier for cancer therapy. High variation in pharmacokinetics (PK) and pharmacodynamics (PD) of liposome-based therapeutics has been reported. However, the interaction of liposome-based therapeutics with the immune system, specifically the mononuclear phagocyte system (MPS), and underlying molecular mechanisms for variable responses to liposomal drugs remain poorly understood. The objective of this dissertation was to elucidate immune mechanisms for the variable responses to PEGylated liposomal doxorubicin (PLD; DoxilRTM), a clinically relevant NP, in animal models and in patients. In vitro, in vivo and clinical systems were investigated to evaluate the effects of chemokines (CCL2 and CCL5), heterogeneity of the tumor microenvironment, and genetic variations on PK and PD of PLD. Results showed that there was a significantly positive linear relationship between PLD exposure (AUC) and total amount of CCL2 and CCL5, most prevalent chemokines in plasma, in patients with recurrent ovarian cancer. Consistent with these findings, preclinical studies using mice bearing SKOV3 orthotopic ovarian cancer xenografts demonstrated that PLD induced the production and secretion of chemokines into plasma. In addition, in vitro studies using human monocytic THP-1 cells demonstrated that PLD altered monocyte migration towards CCL2 and CCL5. The PK and efficacy studies of PLD in murine models of breast cancer showed that heterogeneous tumor microenvironment was associated with significantly different tumor delivery and efficacy of PLD, but not small molecule doxorubicin between two breast tumor models. A candidate genetic locus that was associated with clearance of PLD in 23 inbred mouse strains contains a gene that encodes for engulfment adapter PTB domain containing 1 (Gulp1). By using

Custom-designed Laser-based Heating Apparatus for Triggered Release of Cisplatin from Thermosensitive Liposomes with Magnetic Resonance Image Guidance.

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Dou, Yannan N; Weersink, Robert A; Foltz, Warren D; Zheng, Jinzi; Chaudary, Naz; Jaffray, David A; Allen, Christine

2015-12-13

Liposomes have been employed as drug delivery systems to target solid tumors through exploitation of the enhanced permeability and retention (EPR) effect resulting in significant reductions in systemic toxicity. Nonetheless, insufficient release of encapsulated drug from liposomes has limited their clinical efficacy. Temperature-sensitive liposomes have been engineered to provide site-specific release of drug in order to overcome the problem of limited tumor drug bioavailability. Our lab has designed and developed a heat-activated thermosensitive liposome formulation of cisplatin (CDDP), known as HTLC, to provide triggered release of CDDP at solid tumors. Heat-activated delivery in vivo was achieved in murine models using a custom-built laser-based heating apparatus that provides a conformal heating pattern at the tumor site as confirmed by MR thermometry (MRT). A fiber optic temperature monitoring device was used to measure the temperature in real-time during the entire heating period with online adjustment of heat delivery by alternating the laser power. Drug delivery was optimized under magnetic resonance (MR) image guidance by co-encapsulation of an MR contrast agent (i.e., gadoteridol) along with CDDP into the thermosensitive liposomes as a means to validate the heating protocol and to assess tumor accumulation. The heating protocol consisted of a preheating period of 5 min prior to administration of HTLC and 20 min heating post-injection. This heating protocol resulted in effective release of the encapsulated agents with the highest MR signal change observed in the heated tumor in comparison to the unheated tumor and muscle. This study demonstrated the successful application of the laser-based heating apparatus for preclinical thermosensitive liposome development and the importance of MR-guided validation of the heating protocol for optimization of drug delivery.

Visualization of liposomes by magnetic resonance imaging: an opportunity to improve antitumoral liposome therapies

International Nuclear Information System (INIS)

Martinez Bedoya, Darel

2012-01-01

Controlled release of drugs at the tumor site and the development of non-invasive monitoring techniques are two of the main challenges currently facing antitumoral therapies. The paper analyzes some of the potential uses of liposomes as vehicles for the transport of drugs to the tumors, particularly directionalized variants to tumor antigens through antibody coupling (immunoliposomes). These vesicles may also be used in combination with magnetic resonance, one of the most widely used imaging techniques, and one exhibiting great visualization potential at molecular level. Joint use of these two techniques makes it possible to control the amount of drug administered, as well as predict the efficacy of the treatment and monitor its progress

Surrogate MRI markers for hyperthermia-induced release of doxorubicin from thermosensitive liposomes in tumors.

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Peller, Michael; Willerding, Linus; Limmer, Simone; Hossann, Martin; Dietrich, Olaf; Ingrisch, Michael; Sroka, Ronald; Lindner, Lars H

2016-09-10

The efficacy of systemically applied, classical anti-cancer drugs is limited by insufficient selectivity to the tumor and the applicable dose is limited by side effects. Efficacy could be further improved by targeting of the drug to the tumor. Using thermosensitive liposomes (TSL) as a drug carrier, targeting is achieved by control of temperature in the target volume. In such an approach, effective local hyperthermia (40-43°C) (HT) of the tumor is considered essential but technically challenging. Thus, visualization of local heating and drug release using TSL is considered an important tool for further improvement. Visualization and feasibility of chemodosimetry by magnetic resonance imaging (MRI) has previously been demonstrated using TSL encapsulating both, contrast agent (CA) and doxorubicin (DOX) simultaneously in the same TSL. Dosimetry has been facilitated using T1-relaxation time change as a surrogate marker for DOX deposition in the tumor. To allow higher loading of the TSL and to simplify clinical development of new TSL formulations a new approach using a mixture of TSL either loaded with DOX or MRI-CA is suggested. This was successfully tested using phosphatidyldiglycerol-based TSL (DPPG2-TSL) in Brown Norway rats with syngeneic soft tissue sarcomas (BN175) implanted at both hind legs. After intravenous application of DOX-TSL and CA-TSL, heating of one tumor above 40°C for 1h using laser light resulted in highly selective DOX uptake. The DOX-concentration in the heated tumor tissue compared to the non-heated tumor showed an almost 10-fold increase. T1 and additional MRI surrogate parameters such as signal phase change were correlated to intratumoral DOX concentration. Visualization of DOX delivery in the sense of a chemodosimetry was demonstrated. Although phase-based MR-thermometry was affected by CA-TSL, phase information was found suitable for DOX concentration assessment. Local differences of DOX concentration in the tumors indicated the need for

Liposome-based delivery systems for ginsenoside Rh2: in vitro and in vivo comparisons

Energy Technology Data Exchange (ETDEWEB)

Xu, Linqiang [China Pharmaceutical University, Department of Pharmaceutics, State Key Laboratory of Natural Medicines (China); Yu, Hua [University of Macao, Institute of Chinese Medical Sciences (China); Yin, Shaoping; Zhang, Ruixia; Zhou, Yudan; Li, Juan, E-mail: lijuancpu@163.com [China Pharmaceutical University, Department of Pharmaceutics, State Key Laboratory of Natural Medicines (China)

2015-10-15

The Ginsenoside Rh2 (Rh2) has been shown to possess anti-cancer properties both in vitro and in vivo. However, the poor bioavailability and fast plasma elimination limit the further clinical applications of Rh2 for cancer treatments. In the present study, three types of Rh2-loaded liposomes including Rh2-loaded normal liposome (Rh2-LP), Rh2-loaded cationic liposome (Rh2-CLP), and Rh2-loaded Methoxy poly(ethylene glycol)-poly(lactide) (mPEG-PLA) liposome (Rh2-PLP) have been optimized and prepared with mean particle size of 80–125 nm. Compared to Rh2-LP, surface modifications with mPEG or octadecylamine significantly improve the physicochemical and biological properties both in vitro and in vivo. Moreover, PLP presented better tumor accumulation of the fluorescent cyanine dye, 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindotricarbocyanine iodide (DiR) in HepG2-xenografted nude mice than CLP (1.3-fold) or LP (1.6-fold) and prolong the resident time of DiR in tumor and organs (more than 24 h). The in vivo anti-cancer efficacy assessments indicate that Rh2-PLP presents the most activity on suppressing tumor growth in HepG2-xenografted mice than Rh2-LP and Rh2-CLP and without any significant toxicity. Our results indicate that mPEG-PLA modified liposome should be a potential and promising strategy to enhance the therapeutic index for anti-cancer agents.

Tumor targeted delivery of doxorubicin in malignant peripheral nerve sheath tumors.

Directory of Open Access Journals (Sweden)

A B Madhankumar

Full Text Available Peripheral nerve sheath tumors are benign tumors that have the potential to transform into malignant peripheral nerve sheath tumors (MPNSTs. Interleukin-13 receptor alpha 2 (IL13Rα2 is a cancer associated receptor expressed in glioblastoma and other invasive cancers. We analyzed IL13Rα2 expression in several MPNST cell lines including the STS26T cell line, as well as in several peripheral nerve sheath tumors to utilize the IL13Rα2 receptor as a target for therapy. In our studies, we demonstrated the selective expression of IL13Rα2 in several peripheral nerve sheath tumors by immunohistochemistry (IHC and immunoblots. We established a sciatic nerve MPNST mouse model in NIH III nude mice using a luciferase transfected STS26T MPNST cell line. Similarly, analysis of the mouse sciatic nerves after tumor induction revealed significant expression of IL13Rα2 by IHC when compared to a normal sciatic nerve. IL13 conjugated liposomal doxorubicin was formulated and shown to bind and internalized in the MPNST cell culture model demonstrating cytotoxic effect. Our subsequent in vivo investigation in the STS26T MPNST sciatic nerve tumor model indicated that IL13 conjugated liposomal doxorubicin (IL13LIPDXR was more effective in inhibiting tumor progression compared to unconjugated liposomal doxorubicin (LIPDXR. This further supports that IL13 receptor targeted nanoliposomes is a potential approach for treating MPNSTs.

Effects of Polyethylene Glycol Spacer Length and Ligand Density on Folate Receptor Targeting of Liposomal Doxorubicin In Vitro

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Kumi Kawano

2011-01-01

Full Text Available The folate receptor is an attractive target for selective tumor delivery of liposomal doxorubicin (DXR because it is abundantly expressed in a large percentage of tumors. This study examined the effect of polyethylene glycol (PEG spacer length and folate ligand density on the targeting ability of folate-modified liposomes. Liposomes were modified with folate-derivatized PEG-distearoylphosphatidylethanolamine with PEG molecular weights of 2000, 3400, or 5000. The association of DXR-loaded liposomes with KB cells, which overexpress the folate receptor, was evaluated by flow cytometry at various ratios of folate modification. A low ratio of folate modification with a sufficiently long PEG chain showed the highest folate receptor-mediated association with the cells, but did not show the highest in vitro cytotoxicity. DXR release from folate-modified liposomes in endosomes might be different. These findings will be useful for designing folate receptor-targeting carriers.

In vitro and in vivo studies of gadolinium-159 liposomes in cancer treatment

International Nuclear Information System (INIS)

Soares, Daniel Cristian Ferreira

2011-01-01

In Brazil, estimates of new cancer cases, valid for the years 2010 and 2011 show that the disease will be responsible for the deaths of about 500,000 people. As an alternative therapy the radiotherapy technique, widely used in treating various types of tumors, act indiscriminate tumoral and healthy cells. Seeking to minimize these effects, nano structured carriers containing radioisotopes, such as liposomes, have been studied with the aim of improving the specificity of action of ionizing radiation, delivering and retaining adequate amounts of radioactive material in tumor cells, leading them to death. In this context, the present study, we prepared liposomes stealth pH-sensitive metal complex containing the radioactive 159 Gd-DTPA-BMA ( 159 Gd-SpHL) aiming to study in vitro and in vivo its effects in cancer treatment. The vesicles showed encapsulation rate of about 20%, average diameter of 100 nm and low release kinetics of radioactivity in biological media. The formulation was characterized through physic-chemical and morphological studies and the results revealed a low polydispersity index and negative Zeta potential. We studied in vitro and in vivo its action against the cells of Ehrlich tumor models and RT2 (rat glioma). The results of in vitro studies showed that the complex has significant radioactive cytotoxicity against the cells of two of the three models studied and that, being encapsulated in liposomes, the cytotoxicity was greatly enhanced. Additionally, we investigated the involvement of caspase-3 protein in Ehrlich and RT2 cell death. The results suggest that the main mechanism involved in the cytotoxic action of radioactive complex is related to apoptosis. The results of in vivo studies showed that liposomes containing 159 Gd-DTPA-BMA accumulated significantly in Ehrlich solid tumor in mice. Aiming to improve this uptake, we prepared pH-sensitive liposomes coated with folate containing the same radioactive complex ( 159 Gd-FTSpHL). The results

Liposomal photosensitizers: potential platforms for anticancer photodynamic therapy

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L.A. Muehlmann

2011-08-01

Full Text Available Photodynamic therapy is a well-established and clinically approved treatment for several types of cancer. Antineoplastic photodynamic therapy is based on photosensitizers, i.e., drugs that absorb photons translating light energy into a chemical potential that damages tumor tissues. Despite the encouraging clinical results with the approved photosensitizers available today, the prolonged skin phototoxicity, poor selectivity for diseased tissues, hydrophobic nature, and extended retention in the host organism shown by these drugs have stimulated researchers to develop new formulations for photodynamic therapy. In this context, due to their amphiphilic characteristic (compatibility with both hydrophobic and hydrophilic substances, liposomes have proven to be suitable carriers for photosensitizers, improving the photophysical properties of the photosensitizers. Moreover, as nanostructured drug delivery systems, liposomes improve the efficiency and safety of antineoplastic photodynamic therapy, mainly by the classical phenomenon of extended permeation and retention. Therefore, the association of photosensitizers with liposomes has been extensively studied. In this review, both current knowledge and future perspectives on liposomal carriers for antineoplastic photodynamic therapy are critically discussed.

Encapsulation of Adenovirus Serotype 5 in Anionic Lecithin Liposomes using a Bead-Based Immunoprecipitation Technique Enhances Transfection Efficiency

Science.gov (United States)

Mendez, N.; Herrera, V.; Zhang, L.; Hedjran, F.; Feuer, R.; Blair, S.; Trogler, W.; Reid, T.

2014-01-01

Oncolytic viruses (OVs) constitute a promising class of cancer therapeutics which exploit validated genetic pathways known to be deregulated in many cancers. To overcome an immune response and to enhance its potential use to treat primary and metastatic tumors, a method for liposomal encapsulation of adenovirus has been developed. The encapsulation of adenovirus in non-toxic anionic lecithin-cholesterol-PEG liposomes ranging from 140–180nm in diameter have been prepared by self-assembly around the viral capsid. The encapsulated viruses retain their ability to infect cancer cells. Furthermore, an immunoprecipitation (IP) technique has shown to be a fast and effective method to extract non-encapsulated viruses and homogenize the liposomes remaining in solution. 78% of adenovirus plaque forming units were encapsulated and retained infectivity after IP processing. Additionally, encapsulated viruses have shown enhanced transfection efficiency up to 4× higher compared to non-encapsulated Ads. Extracting non-encapsulated viruses from solution may prevent an adverse in vivo immune response and may enhance treatment for multiple administrations. PMID:25154663

Encapsulation of adenovirus serotype 5 in anionic lecithin liposomes using a bead-based immunoprecipitation technique enhances transfection efficiency.

Science.gov (United States)

Mendez, Natalie; Herrera, Vanessa; Zhang, Lingzhi; Hedjran, Farah; Feuer, Ralph; Blair, Sarah L; Trogler, William C; Reid, Tony R; Kummel, Andrew C

2014-11-01

Oncolytic viruses (OVs) constitute a promising class of cancer therapeutics which exploit validated genetic pathways known to be deregulated in many cancers. To overcome an immune response and to enhance its potential use to treat primary and metastatic tumors, a method for liposomal encapsulation of adenovirus has been developed. The encapsulation of adenovirus in non-toxic anionic lecithin-cholesterol-PEG liposomes ranging from 140 to 180 nm in diameter have been prepared by self-assembly around the viral capsid. The encapsulated viruses retain their ability to infect cancer cells. Furthermore, an immunoprecipitation (IP) technique has shown to be a fast and effective method to extract non-encapsulated viruses and homogenize the liposomes remaining in solution. 78% of adenovirus plaque forming units were encapsulated and retained infectivity after IP processing. Additionally, encapsulated viruses have shown enhanced transfection efficiency up to 4 × higher compared to non-encapsulated Ads. Extracting non-encapsulated viruses from solution may prevent an adverse in vivo immune response and may enhance treatment for multiple administrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

PET imaging of liposomes labeled with an [¹⁸F]-fluorocholesteryl ether probe prepared by automated radiosynthesis

DEFF Research Database (Denmark)

Jensen, Andreas Tue Ingemann; Binderup, Tina; Andresen, Thomas Lars

2012-01-01

, was observed, corresponding to expected liposomal pharmacokinetics. The tumor accumulation 8 hours postinjection accounted for 2.25 +/- 0.23 (mean +/- standard error of the mean) percent of injected dose per gram (%ID/g), and the tumor-to-muscle ratio reached 2.20 +/- 0.24 after 8 hours, which...... is satisfactorily high for visualization of pathological lesions. Moreover, the blood concentration was still at a high level (13.9 +/- 1.5 %ID/g) at the end of the 8-hour time frame. The present work demonstrates the methodology for automated preparation of radiolabeled liposomes, and shows that [F-18]-labeled...... extrusion through 100-nm filters. The [F-18]-labeled liposomes were injected into nude, tumor-bearing mice, and positron emission tomography (PET) scans were performed several times over 8 hours to investigate the in vivo biodistribution. Clear tumor accumulation, as well as hepatic and splenic uptake...

Liposomes derivatized with multimeric copies of KCCYSL peptide as targeting agents for HER-2-overexpressing tumor cells

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Ringhieri P

2017-01-01

Full Text Available Paola Ringhieri,1 Silvia Mannucci,2 Giamaica Conti,2 Elena Nicolato,2 Giulio Fracasso,3 Pasquina Marzola,4 Giancarlo Morelli,1 Antonella Accardo1 1Department of Pharmacy and Interuniversity Research Centre on Bioactive Peptides (CIRPeB, University of Naples “Federico II”, Napoli, 2Department of Neurological Biomedical and Movement Sciences, 3Section of Immunology, Department of Medicine, 4Department of Informatics, University of Verona, Verona, Italy Abstract: Mixed liposomes, obtained by coaggregation of 1,2-dioleoyl-sn-glycero-3-phosphocholine and of the synthetic monomer containing a gadolinium complex ([C18]2DTPA[Gd] have been prepared. Liposomes externally decorated with KCCYSL (P6.1 peptide sequence in its monomeric, dimeric, and tetrameric forms are studied as target-selective delivery systems toward cancer cells overexpressing human epidermal growth factor receptor-2 (HER-2 receptors. Derivatization of liposomal surface with targeting peptides is achieved using the postmodification method: the alkyne-peptide derivative Pra-KCCYSL reacts, through click chemistry procedures, with a synthetic surfactant modified with 1, 2, or 4 azido moieties previously inserted in liposome formulation. Preliminary in vitro data on MDA-MB-231 and BT-474 cells indicated that liposomes functionalized with P6.1 peptide in its tetrameric form had better binding to and uptake into BT-474 cells compared to liposomes decorated with monomeric or dimeric versions of the P6.1 peptide. BT-474 cells treated with liposomes functionalized with the tetrameric form of P6.1 showed high degree of liposome uptake, which was comparable with the uptake of anti-HER-2 antibodies such as Herceptin. Moreover, magnetic MRI experiments have demonstrated the potential of liposomes to act as MRI contrast agents. Keywords: anti-HER2 liposomes, target peptide, KCCYSL peptide, breast cancer, click chemistry, branched peptides 

Stable archaeal tetraether lipid liposomes for photodynamic application: transfer of carboxyfluorescein to cultured T84 tumor cells

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Anton Oertl

2017-01-01

Full Text Available Background: Archaeal membranes have phytanyl ether lipids instead of common fatty acid-glycerol esters in bacterial and eukaryotic cells. Sulfolobus and Thermoplasma species have unique membrane-spanning tetraether lipids (TEL, which form stable liposomes. Recently, we cultured Thermoplasma species from the Indonesian volcano Tangkuban Perahu and isolated TEL. The purpose of this in vitro study is to investigate the transfer of fluorescent dye from stable TEL liposomes to cultured colon carcinoma cells.Methods: TEL was extracted from cultured cells with chloroform-methanol (1:1, then it was fractionated and purified via diethylaminoethyl-cellulose-acetate columns and activated charcoal for the formation of stable liposomes. For the fluorescence exchange assay, TEL liposomes were loaded with water-soluble carboxyfluorescein (CF. Staining experiments were conducted with various cell cultures, and T84 colon carcinoma cells were chosen for the main experiments. Liposome stability was tested by light scattering and electron microscopic size determinations as well as by unspecific CF release at low pH (6.0–7.4 and increased temperature  (4–50°C/70°C.Results: TEL liposomes exhibit high stability and extremely low proton permeability at low pH. CF staining of cultured T84 colon carcinoma cells appeares more intensive from TEL liposomes than from dipalmitoylphosphatidylcholine liposomes.Conclusion: The results of this in vitro study demonstrate CF staining of colon carcinoma cells and high stability of TEL liposomes at low pH, matching the condition in the gastro-intestinal (GI route and in the urogentital (UG tract. For this reason, in vivo studies on liposomal fluorescent photosensitizers for topical application of photodynamic cancer therapy in the GI and UG tracts should be carried out.

Multimodality Molecular Imaging of [18F]-Fluorinated Carboplatin Derivative Encapsulated in [111In]-Labeled Liposomes

Science.gov (United States)

Lamichhane, Narottam

Platinum based chemotherapy is amongst the mainstream DNA-damaging agents used in clinical cancer therapy today. Agents such as cisplatin, carboplatin are clinically prescribed for the treatment of solid tumors either as single agents, in combination, or as part of multi-modality treatment strategy. Despite the potent anti-tumor activity of these drugs, overall effectiveness is still hampered by inadequate delivery and retention of drug in tumor and unwanted normal tissue toxicity, induced by non-selective accumulation of drug in normal cells and tissues. Utilizing molecular imaging and nanoparticle technologies, this thesis aims to contribute to better understanding of how to improve the profile of platinum based therapy. By developing a novel fluorinated derivative of carboplatin, incorporating a Flourine-18 (18F) moiety as an inherent part of the molecule, quantitative measures of drug concentration in tumors and normal tissues can be directly determined in vivo and within the intact individual environment. A potential impact of this knowledge will be helpful in predicting the overall response of individual patients to the treatment. Specifically, the aim of this project, therefore, is the development of a fluorinated carboplatin drug derivative with an inherent positron emission tomography (PET) imaging capability, so that the accumulation of the drug in the tumor and normal organs can be studied during the course of therapy . A secondary objective of this research is to develop a proof of concept for simultaneous imaging of a PET radiolabeled drug with a SPECT radiolabeled liposomal formulation, enabling thereby bi-modal imaging of drug and delivery vehicle in vivo. The approach is challenging because it involves development in PET radiochemistry, PET and SPECT imaging, drug liposomal encapsulation, and a dual-modal imaging of radiolabeled drug and radiolabeled vehicle. The principal development is the synthesis of fluorinated carboplatin 19F-FCP using 2

Combination therapy with gefitinib and doxorubicin inhibits tumor growth in transgenic mice with adrenal neuroblastoma

International Nuclear Information System (INIS)

Kawano, Kumi; Hattori, Yoshiyuki; Iwakura, Hiroshi; Akamizu, Takashi; Maitani, Yoshie

2013-01-01

Highly relevant mouse models of human neuroblastoma (NB) are needed to evaluate new therapeutic strategies against NB. In this study, we characterized transgenic mice with bilateral adrenal tumors. On the basis of information from the tumoral gene expression profiles, we examined the antitumor effects of unencapsulated and liposomal doxorubicin (DXR), alone and in combination with gefitinib, on adrenal NB. We showed that intravenous injection of unencapsulated or liposomal DXR alone inhibited tumor growth in a dose-dependent manner, as assessed by magnetic resonance imaging (MRI). However, liposomal DXR did not exhibit greater antitumor effect than unencapsulated DXR. Immunohistochemical analysis revealed that the adrenal tumor vasculature with abundant pericyte coverage was a less leaky structure for liposomes. Combination therapy with unencapsulated or liposomal DXR plus gefitinib strongly suppressed tumor growth and delayed tumor regrowth than treatment with unencapsulated or liposomal DXR alone, even at a lower dose of DXR. Dynamic contrast-enhanced MRI analysis revealed that gefitinib treatment increased blood flow in the tumor, indicating that gefitinib treatment changes the tumor vascular environment in a manner that may increase the antitumor effect of DXR. In conclusion, the combination of gefitinib and DXR induces growth inhibition of adrenal NBs in transgenic mice. These findings will provide helpful insights into new treatments for NB

In vivo Evaluation of PEGylated 64Cu-liposomes with Theranostic and Radiotherapeutic Potential using Micro PET/CT

DEFF Research Database (Denmark)

Petersen, Anncatrine Luisa; Henriksen, Jonas Rosager; Binderup, Tina

2016-01-01

The objective of this study was to evaluate the potentialof PEGylated 64Cu-liposomes in clinical diagnosticpositron emission tomography (PET) imaging andPEGylated 177Lu-liposomes in internal tumor radiotherapythrough in vivo characterization and dosimetric analysis in ahuman xenograft mouse model...

Chitosan/lecithin liposomal nanovesicles as an oral insulin delivery system.

Science.gov (United States)

Al-Remawi, Mayyas; Elsayed, Amani; Maghrabi, Ibrahim; Hamaidi, Mohammad; Jaber, Nisrein

2017-05-01

In the present work, insulin-chitosan polyelectrolyte complexes associated to lecithin liposomes were investigated as a new carrier for oral delivery of insulin. The preparation was characterized in terms of particle size, zeta potential and encapsulation efficiency. Surface tension measurements revealed that insulin-chitosan polyelectrolyte complexes have some degree of hydrophobicity and should be added to lecithin liposomal dispersion and not the vice versa to prevent their adsorption on the surface. Stability of insulin was enhanced when it was associated to liposomes. Significant reduction of blood glucose levels was noticed after oral administration of liposomal preparation to streptozotocin diabetic rats compared to control. The hypoglycemic activity was more prolonged compared to subcutaneously administered insulin.

Nanostructured Surfaces to Target and Kill Circulating Tumor Cells While Repelling Leukocytes

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Michael J. Mitchell

2012-01-01

Full Text Available Hematogenous metastasis, the process of cancer cell migration from a primary to distal location via the bloodstream, typically leads to a poor patient prognosis. Selectin proteins hold promise in delivering drug-containing nanocarriers to circulating tumor cells (CTCs in the bloodstream, due to their rapid, force-dependent binding kinetics. However, it is challenging to deliver such nanocarriers while avoiding toxic effects on healthy blood cells, as many possess ligands that adhesively interact with selectins. Herein, we describe a nanostructured surface to capture flowing cancer cells, while preventing human neutrophil adhesion. Microtube surfaces with immobilized halloysite nanotubes (HNTs and E-selectin functionalized liposomal doxorubicin (ES-PEG L-DXR significantly increased the number of breast adenocarcinoma MCF7 cells captured from flow, yet also significantly reduced the number of captured neutrophils. Neutrophils firmly adhered and projected pseudopods on surfaces coated only with liposomes, while neutrophils adherent to HNT-liposome surfaces maintained a round morphology. Perfusion of both MCF7 cells and neutrophils resulted in primarily cancer cell adhesion to the HNT-liposome surface, and induced significant cancer cell death. This work demonstrates that nanostructured surfaces consisting of HNTs and ES-PEG L-DXR can increase CTC recruitment for chemotherapeutic delivery, while also preventing healthy cell adhesion and uptake of therapeutic intended for CTCs.

Liposomes and lipid disks traverse the BBB and BBTB as intact forms as revealed by two-step Förster resonance energy transfer imaging

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Tongcheng Dai

2018-03-01

Full Text Available The blood–brain barrier (BBB and the blood–brain tumor barrier (BBTB prevent drug and nano-drug delivery systems from entering the brain. However, ligand-mediated nano-drug delivery systems have significantly enhanced the therapeutic treatment of glioma. In this study we investigated the mechanism especially the integrity of liposomes and lipid disks while traversing the BBB and BBTB both in vitro and in vivo. Fluorophores (DiO, DiI and DiD were loaded into liposomes and lipid disks to form Förster resonance energy transfer (FRET nano-drug delivery systems. Using brain capillary endothelial cells as a BBB model, we show that liposomes and disks are present in the cytoplasm as their intact forms and traverse the BBB with a ratio of 0.68‰ and 1.67‰, respectively. Using human umbilical vein endothelial cells as BBTB model, liposomes and disks remained intact and traversed the BBTB with a ratio of 2.31‰ and 8.32‰ at 3 h. Ex vivo imaging and immunohistochemical results revealed that liposomes and disks could traverse the BBB and BBTB in vivo as intact forms. In conclusion, these observations explain in part the mechanism by which nano-drug delivery systems increase the therapeutic treatment of glioma. KEY WORDS: Liposomes, Disks, Intact form, BBB, BBTB, FRET

Multifunctional liposomes delay phenotype progression and prevent memory impairment in a presymptomatic stage mouse model of Alzheimer disease.

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Mancini, Simona; Balducci, Claudia; Micotti, Edoardo; Tolomeo, Daniele; Forloni, Gianluigi; Masserini, Massimo; Re, Francesca

2017-07-28

The failure of clinical trials largely focused on mild to moderate stages of Alzheimer disease has suggested to the scientific community that the effectiveness of Amyloid-β (Aβ)-centered treatments should be evaluated starting as early as possible, well before irreversible brain damage has occurred. Accordingly, also the preclinical development of new therapies should be carried out taking into account this suggestion. In the present investigation we evaluated the efficacy of a treatment with liposomes multifunctionalized for crossing the blood-brain barrier and targeting Aβ, carried out on young APP/PS1 Tg mice, taken as a model of pre-symptomatic disease stage. Liposomes were administered once a week to Tg mice for 7months, starting at the age of 5months and up to the age of 12 when they display AD-like cognitive and brain biochemical/anatomical features. The treatment prevented the onset of the long-term memory impairment and slowed down the deposition of brain Aβ; at anatomical level, prevented both ventricle enlargement and entorhinal cortex thickness reduction, otherwise occurring in untreated mice. Strikingly, these effects were maintained 3months after treatment discontinuation. An increase of Aβ levels in the liver was detected at the end of the treatment, then followed also by reduction of brain Amyloid Precursor Protein and increase of Aβ-degrading enzymes. These results suggest that the treatment promotes brain Aβ clearance by a peripheral 'sink' effect and ultimately affects Aβ turnover in the brain. Worth of note, the treatment was apparently not toxic for all the organs analyzed, in particular for brain, as suggested by the lower brain TNF-α and MDA levels, and by higher level of SOD activity in treated mice. Together, these findings promote a very early treatment with multi-functional liposomes as a well-tolerated nanomedicine-based approach, potentially suitable for a disease-modifying therapy of AD, able to delay or prevent relevant

RGD-modified liposomes enhance efficiency of aclacinomycin A delivery: evaluation of their effect in lung cancer

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Feng C

2015-08-01

Full Text Available Chan Feng,1,* Xiaoyan Li,2,* Chunyan Dong,1 Xuemei Zhang,1 Xie Zhang,1 Yong Gao11Department of Oncology, Shanghai East Hospital, Tongji University, Shanghai, 2Shanghai Tenth People’s Hospital, Tongji University, Shanghai, People’s Republic of China*These authors contributed equally to this workAbstract: In this study, long-circulating Arg-Gly-Asp (RGD-modified aclacinomycin A (ACM liposomes were prepared by thin film hydration method. Their morphology, particle size, encapsulation efficiency, and in vitro release were investigated. The RGD-ACM liposomes was about 160 nm in size and had the visual appearance of a yellowish suspension. The zeta potential was -22.2 mV and the encapsulation efficiency was more than 93%. The drug-release behavior of the RGD-ACM liposomes showed a biphasic pattern, with an initial burst release and followed by sustained release at a constant rate. After being dissolved in phosphate-buffered saline (pH 7.4 and kept at 4°C for one month, the liposomes did not aggregate and still had the appearance of a milky white colloidal solution. In a pharmacokinetic study, rats treated with RGD-ACM liposomes showed slightly higher plasma concentrations than those treated with ACM liposomes. Maximum plasma concentrations of RGD-ACM liposomes and ACM liposomes were 4,532 and 3,425 ng/mL, respectively. RGD-ACM liposomes had a higher AUC0–∞ (1.54-fold, mean residence time (2.09-fold, and elimination half-life (1.2-fold when compared with ACM liposomes. In an in vivo study in mice, both types of liposomes inhibited growth of human lung adenocarcinoma (A549 cells and markedly decreased tumor size when compared with the control group. There were no obvious pathological tissue changes in any of the treatment groups. Our results indicate that RGD-modified ACM liposomes have a better antitumor effect in vivo than their unmodified counterparts.Keywords: RGD, aclacinomycin A, long-circulating liposomes, pharmacokinetic, tumor

Pharmacokinetic analysis of 111 in-labeled liposomal Doxorubicin in murine glioblastoma after blood-brain barrier disruption by focused ultrasound.

Directory of Open Access Journals (Sweden)

Feng-Yi Yang

Full Text Available The goal of this study was to evaluate the pharmacokinetics of targeted and untargeted (111In-doxorubicin liposomes after these have been intravenously administrated to tumor-bearing mice in the presence of blood-brain barrier disruption (BBB-D induced by focused ultrasound (FUS. An intracranial brain tumor model in NOD-scid mice using human brain glioblastoma multiforme (GBM 8401 cells was developed in this study. (111In-labeled human atherosclerotic plaque-specific peptide-1 (AP-1-conjugated liposomes containing doxorubicin (Lipo-Dox; AP-1 Lipo-Dox were used as a microSPECT probe for radioactivity measurements in the GBM-bearing mice. Compared to the control tumors treated with an injection of (111In-AP-1 Lipo-Dox or (111In-Lipo-Dox, the animals receiving the drugs followed by FUS exhibited enhanced accumulation of the drug in the brain tumors (p<0.05. Combining sonication with drugs significantly increased the tumor-to-normal brain doxorubicin ratio of the target tumors compared to the control tumors. The tumor-to-normal brain ratio was highest after the injection of (111In-AP-1 Lipo-Dox with sonication. The (111In-liposomes micro-SPECT/CT should be able to provide important information about the optimum therapeutic window for the chemotherapy of brain tumors using sonication.

Diagnostic capabilities of the contrast medium verografin in liposomes (animal experiments)

International Nuclear Information System (INIS)

Rozenberg, O.A.; Khason, K.P.; Aliyakparov, M.T.; Davidenkova, E.F.; Zherbin, E.A.; Akademiya Meditsinskikh Nauk SSSR, Leningrad. Inst. Ehksperimental'noj Meditsiny)

1985-01-01

Some examples for the diagnosis of various diseases of liver and spleen after intravenous (cats, dogs) or intraportal (rodents) injection of lecithin-cholesterol liposomes containing the water soluble contrast medium verografin are described. Tumors of 1 mm were found in the spleen of mice with lymphogranulomatosis, hepatomas of 3-5 mm in rats and lesions of 10 mm in cats with turpentine abscesses. The application of liposomes containing radiographic contrast media offers good possibilities for the diagnosis of liver and spleen. (author)

Photosensitization of liposomes by porphyrins

Energy Technology Data Exchange (ETDEWEB)

Grossweiner, L I; Goyal, G C

1984-01-01

Lipid peroxidation was photosensitized in egg phosphatidylcholine (EPC) liposomes by hematoporphyrin (HP), hematoporphyrin derivative (HpD) and uroporphyrin I (Uro-I). Photosensitization by HP was type II via singlet oxygen (/sup 1/O/sub 2/) for the monomeric and dimeric states and type I for aggregated HP. Uro-I was an efficient type II /sup 1/O/sub 2/ photosensitizer. The HpD fraction enriched in the active biological component (HpD-A) was a type II /sup 1/O/sub 2/ photosensitizer at high and low concentrations. The spectral differences between HpD-A in buffer and solubilized in small EPC liposomes are attributed to a conformation change of a key dimer constituent from a folded to a planar geometry. The implications of the results for the action mechanism in photoradiation therapy of tumors with these porphyrins are discussed. 73 references, 1 figure, 5 tables.

Modification of radiation-induced oxidative damage in liposomal and microsomal membrane by eugenol

Energy Technology Data Exchange (ETDEWEB)

Pandey, B.N. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Lathika, K.M. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, K.P. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)]. E-mail: kpm@magnum.barc.ernet.in

2006-03-15

Radiation-induced membrane oxidative damage, and their modification by eugenol, a natural antioxidant, was investigated in liposomes and microsomes. Liposomes prepared with DPH showed decrease in fluorescence after {gamma}-irradiation, which was prevented significantly by eugenol and correlated with magnitude of oxidation of phospholipids. Presence of eugenol resulted in substantial inhibition in MDA formation in irradiated liposomes/microsomes, which was less effective when added after irradiation. Similarly, the increase in phospholipase C activity observed after irradiation in microsomes was inhibited in samples pre-treated with eugenol. Results suggest association of radio- oxidative membrane damage with alterations in signaling molecules, and eugenol significantly prevented these membrane damaging events.

MRI contrast agent for targeting glioma: interleukin-13 labeled liposome encapsulating gadolinium-DTPA.

Science.gov (United States)

Liu, Xiaoli; Madhankumar, Achuthamangalam B; Miller, Patti A; Duck, Kari A; Hafenstein, Susan; Rizk, Elias; Slagle-Webb, Becky; Sheehan, Jonas M; Connor, James R; Yang, Qing X

2016-05-01

Detection of glioma with MRI contrast agent is limited to cases in which the blood-brain barrier (BBB) is compromised as contrast agents cannot cross the BBB. Thus, an early-stage infiltrating tumor is not detectable. Interleukin-13 receptor alpha 2 (IL-13Rα2), which has been shown to be overexpressed in glioma, can be used as a target moiety. We hypothesized that liposomes conjugated with IL-13 and encapsulating MRI contrast agent are capable of passing through an intact BBB and producing MRI contrast with greater sensitivity. The targeted MRI contrast agent was created by encapsulating Magnevist (Gd-DTPA) into liposomes conjugated with IL-13 and characterized by particle size distribution, cytotoxicity, and MRI relaxivity. MR image intensity was evaluated in the brain in normal mice post injection of Gd-DTPA and IL-13-liposome-Gd-DTPA one day apart. The specificity for glioma detection by IL-13-liposome-Gd-DTPA was demonstrated in an intracranial glioma mouse model and validated histologically. The average size of IL-13-liposome-Gd-DTPA was 137 ± 43 nm with relaxivity of 4.0 ± 0.4 L/mmole-s at 7 Tesla. No significant cytotoxicity was observed with MTS assay and serum chemistry in mice. The MRI signal intensity was enhanced up to 15% post injection of IL-13-liposome-Gd-DTPA in normal brain tissue following a similar time course as that for the pituitary gland outside of the BBB. MRI enhanced by IL-13-liposome-Gd-DTPA detected small tumor masses in addition to those seen with Magnevist-enhanced MRI. IL-13-liposome-Gd-DTPA is able to pass through the uncompromised BBB and detect an early stage glioma that cannot be seen with conventional contrast-enhanced MRI. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A novel melittin nano-liposome exerted excellent anti-hepatocellular carcinoma efficacy with better biological safety

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Jie Mao

2017-03-01

Full Text Available Abstract Melittin is the main effective component of bee venom and has extensive biological functions; however, serious side effects have restricted its clinical application. Preclinical and clinical studies showed that the main adverse events were allergic reaction and pain at the administration site. To decrease the toxicity, we prepared melittin nano-liposomes by encapsulating melittin with poloxamer 188 and explored the inhibitory activities on liver cancer together with biological safety. Here, we showed that melittin nano-liposomes significantly inhibited the survival of hepatocellular carcinoma (HCC cells in vitro and prominently suppressed the growth of subcutaneous and orthotopic HCC transplantation tumors in vivo. It was important that it induced less inflammation and allergy in mice compared with melittin. Overall, melittin nano-liposomes would have a better application in HCC therapy due to its significant anti-tumor activity and better biological safety.

A novel melittin nano-liposome exerted excellent anti-hepatocellular carcinoma efficacy with better biological safety.

Science.gov (United States)

Mao, Jie; Liu, Shujun; Ai, Min; Wang, Zhuo; Wang, Duowei; Li, Xianjing; Hu, Kaiyong; Gao, Xinghua; Yang, Yong

2017-03-20

Melittin is the main effective component of bee venom and has extensive biological functions; however, serious side effects have restricted its clinical application. Preclinical and clinical studies showed that the main adverse events were allergic reaction and pain at the administration site. To decrease the toxicity, we prepared melittin nano-liposomes by encapsulating melittin with poloxamer 188 and explored the inhibitory activities on liver cancer together with biological safety. Here, we showed that melittin nano-liposomes significantly inhibited the survival of hepatocellular carcinoma (HCC) cells in vitro and prominently suppressed the growth of subcutaneous and orthotopic HCC transplantation tumors in vivo. It was important that it induced less inflammation and allergy in mice compared with melittin. Overall, melittin nano-liposomes would have a better application in HCC therapy due to its significant anti-tumor activity and better biological safety.

Bioreactor droplets from liposome-stabilized all-aqueous emulsions

Science.gov (United States)

Dewey, Daniel C.; Strulson, Christopher A.; Cacace, David N.; Bevilacqua, Philip C.; Keating, Christine D.

2014-08-01

Artificial bioreactors are desirable for in vitro biochemical studies and as protocells. A key challenge is maintaining a favourable internal environment while allowing substrate entry and product departure. We show that semipermeable, size-controlled bioreactors with aqueous, macromolecularly crowded interiors can be assembled by liposome stabilization of an all-aqueous emulsion. Dextran-rich aqueous droplets are dispersed in a continuous polyethylene glycol (PEG)-rich aqueous phase, with coalescence inhibited by adsorbed ~130-nm diameter liposomes. Fluorescence recovery after photobleaching and dynamic light scattering data indicate that the liposomes, which are PEGylated and negatively charged, remain intact at the interface for extended time. Inter-droplet repulsion provides electrostatic stabilization of the emulsion, with droplet coalescence prevented even for submonolayer interfacial coatings. RNA and DNA can enter and exit aqueous droplets by diffusion, with final concentrations dictated by partitioning. The capacity to serve as microscale bioreactors is established by demonstrating a ribozyme cleavage reaction within the liposome-coated droplets.

Exploiting the Metal-Chelating Properties of the Drug Cargo for In Vivo Positron Emission Tomography Imaging of Liposomal Nanomedicines

DEFF Research Database (Denmark)

Edmonds, Scott; Volpe, Alessia; Shmeeda, Hilary

2016-01-01

of a radiolabeled stealth liposomal nanomedicine containing alendronate that shows high uptake in primary tumors and metastatic organs. The versatility, efficiency, simplicity, and GMP compatibility of this method may enable submicrodosing imaging studies of liposomal nanomedicines containing chelating drugs...

Ursolic acid liposomes with chitosan modification: Promising antitumor drug delivery and efficacy

Energy Technology Data Exchange (ETDEWEB)

Wang, Meili; Zhao, Tingting; Liu, Yanping; Wang, Qianqian; Xing, Shanshan; Li, Lei; Wang, Longgang [Applying Chemistry Key Lab of Hebei Province, Yanshan University, No.438 Hebei Street, Qinhuangdao 066004 (China); Liu, Lanxiang [The First Hospital of Qinhuangdao, No. 258 Cultural Road, Qinhuangdao 066000 (China); Gao, Dawei, E-mail: dwgao@ysu.edu.cn [Applying Chemistry Key Lab of Hebei Province, Yanshan University, No.438 Hebei Street, Qinhuangdao 066004 (China)

2017-02-01

There are tremendous challenges on antitumor and its therapeutic drugs, and preparation of highly efficient nano-vehicles represents one of the novel topics in antitumor pharmaceutical field. Herein, the novel chitosan-coated ursolic acid (UA) liposome (CS-UA-L) was efficiently prepared with highly tumor targeting, drug controlled release and low side-effect. The CS-UA-L was uniformly spherical particles with diameter of ~ 130 nm, and the size was more easily trapped into the tumor tissues. Chitosan modification can make liposomes carrying positive charges, which were inclined to combine with the negative charges on the surface of tumor cells, and then the CS-UA-L could release UA rapidly at pH 5.0 comparing with pH 7.4. Meanwhile, the CS-UA-L exhibited obvious anti-proliferative effect (76.46%) on HeLa cells and significantly antitumor activity (61.26%) in mice bearing U14 cervical cancer. The tumor tissues of CS-UA-L treated mice had enhanced cell apoptosis, extensive necrosis and low cell proliferation activity. These results demonstrated that the multifunctional CS-UA-L allowed a precision treatment for localized tumor, and reducing the total drug dose and side-effect, which hold a great promise in new safe and effective tumor therapy. - Graphical abstract: Schematic diagram representing the principle of synthesis of CS-UA-L and pH-triggered sequential UA release after treatment on tumor bearing mouse. - Highlights: • The novel chitosan-coated ursolic acid liposomes (CS-UA-L) were successfully prepared. • CS-UA-L possessed sensitive pH-response, which could release UA rapidly at pH 5.0 comparing with pH 7.4. • CS-UA-L exhibited obvious anti-proliferative effect (76.46%) on HeLa cells than UA and UA-L. • CS-UA-L suppressed tumor growth more efficiently than those with UA and UA-L in mice bearing U14 cervical cancer. • The CS-UA-L allow for precision treatment of the tumor and potential to reduce the total drug dose and side-effect.

Radiolabeling of liposomes and polymeric micelles with PET-isotopes

DEFF Research Database (Denmark)

Jensen, Andreas Tue Ingemann

as a revolution in modern therapeutics, especially in chemotherapy. A major reason is the ability of nanoparticles to accumulate in tumor tissue. Liposomes are the classic nanoparticle, consisting of a lipid membrane with an aqueous core. Polymeric micelles are made from amphiphilic detergent‐like copolymers......This thesis is divided into three separate chapters that can be read independently. Chapter 1 is a general introduction, touching upon liposomes and polymeric micelles and radiolabeling with 18F and 64Cu. Chapter 2 and 3 address two separate research projects, each described below. A complete......‐life only allowing up to 8 hours scans. 18F must be covalently attached to components of the liposome. By binding to a lipid, it can be stably lodged in the membrane. A glycerolipid and a cholesteryl ether were synthesized with free primary alcohols and a series of their sulphonates (Ms, Ts, Tf) were...

Smart IR780 Theranostic Nanocarrier for Tumor-Specific Therapy: Hyperthermia-Mediated Bubble-Generating and Folate-Targeted Liposomes.

Science.gov (United States)

Guo, Fang; Yu, Meng; Wang, Jinping; Tan, Fengping; Li, Nan

2015-09-23

The therapeutic effectiveness of chemotherapy was hampered by dose-limiting toxicity and was optimal only when tumor cells were subjected to a maximum drug exposure. The purpose of this work was to design a dual-functional thermosensitive bubble-generating liposome (BTSL) combined with conjugated targeted ligand (folate, FA) and photothermal agent (IR780), to realize enhanced therapeutic and diagnostic functions. This drug carrier was proposed to target tumor cells owing to FA-specific binding, followed by triggering drug release due to the decomposition of encapsulated ammonium bicarbonate (NH4HCO3) (generated CO2 bubbles) by being subjected to near-infrared (near-IR) laser irradiation, creating permeable defects in the lipid bilayer that rapidly release drug. In vitro temperature-triggered release study indicated the BTSL system was sensitive to heat triggering, resulting in rapid drug release under hyperthermia. For in vitro cellular uptake experiments, different results were observed on human epidermoid carcinoma cells (KB cells) and human lung cancer cells (A549 cells) due to their different (positive or negative) response to FA receptor. Furthermore, in vivo biodistribution analysis and antitumor study indicated IR780-BTSL-FA could specifically target KB tumor cells, exhibiting longer circulation time than free drug. In the pharmacodynamics experiments, IR780-BTSL-FA efficiently inhibited tumor growth in nude mice with no evident side effect to normal tissues and organs. Results of this study demonstrated that the constructed smart theranostic nanocarrier IR780-BTSL-FA might contribute to establishment of tumor-selective and effective chemotherapy.

Pharmacokinetics, Tissue Distribution and Therapeutic Effect of Cationic Thermosensitive Liposomal Doxorubicin Upon Mild Hyperthermia

OpenAIRE

Dicheva, Bilyana M.; Seynhaeve, Ann L. B.; Soulie, Thomas; Eggermont, Alexander M. M.; ten Hagen, Timo L. M.; Koning, Gerben A.

2015-01-01

textabstractPurpose: To evaluate pharmacokinetic profile, biodistribution and therapeutic effect of cationic thermosensitive liposomes (CTSL) encapsulating doxorubicin (Dox) upon mild hyperthermia (HT). Methods: Non-targeted thermosensitive liposomes (TSL) and CTSL were developed, loaded with Dox and characterized. Blood kinetics and biodistribution of Dox-TSL and Dox-CTSL were followed in B16BL6 tumor bearing mice upon normothermia (NT) or initial hyperthermia conditions. Efficacy study in B...

Cationic liposome-mediated gene transfer to tumor cells in vitro and in vivo.

Science.gov (United States)

Son, K; Sorgi, F; Gao, X; Huang, L

1997-01-01

Development of safe and effective technology for delivering functional DNA into cells in an intact organism is crucial to broad applications of gene therapy to human disease. Both viral and nonviral vectors have been developed. Of the technologies currently being studied, liposomal delivery system is particularly attractive. Cationic liposome-mediated gene transfection (lipofection), a relatively new technique pioneered by Felgner and coworkers (1), was highly efficient for transfecting cells in culture. The liposomes were composed of an equimolar mixture of a synthetic cationic lipid N-[1-(2,3,-dioleyloxy)propyl]-N,N,N,-trimethylammonium chloride (DOTMA) and a helper lipid dioleoyl-phosphatidylethanolamine (DOPE) Fig. 1). The DOTMA/DOPE mixture (Lipofectin) forms complexes with DNA by charge interaction upon mixing at room temperature. Other catronic lipids are DOTAP, LipofectAMINE, Lipofectam, and DC-chol. The DOTAP is a diester analog of DOTMA and commercially available. LipofectAMINE and Lipofectam are polycationic lipids with a spermine head group that show increased frequency and activity of eukaryotic cell transfection (2,3). 3β-[N-(N',N'-dimethyaminoaminoethane) carbamoyl] cholesterol (DC-chol) (Fig. 1), a cationic cholesterol derivative, was introduced by Gao and Huang (4) and is routinely used in our laboratory. The DC-chol is now commercially available but can be easily synthesized with a single-step reaction from N,N-dimethylethylenediamine and cholesterol chloroformate (4), and improves the efficiency of transfection with minimal toxicity.Liposomes prepared with DC-chol and DOPE (3∶2 molar ratio) are stable at 4°C for at least 1 yr (unpublished data).

Safety and efficacy of pegylated liposomal doxorubicin in HIV-associated Kaposi’s sarcoma

Directory of Open Access Journals (Sweden)

Francesca Cainelli

2009-08-01

Full Text Available Francesca Cainelli1, Alfredo Vallone21Department of Internal Medicine, School of Medicine, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana; 2Infectious Diseases Unit, Annunziata Hospital, Cosenza, ItalyAbstract: Kaposi’s sarcoma is a vascular tumor linked to the presence of Kaposi’s sarcoma-associated herpesvirus (human herpesvirus-8 and the incidence of which has increased considerably the world over after the onset of the human immunodeficiency virus (HIV pandemic. Antiretroviral therapy combined with cytotoxic agents has been established as the treatment of choice in the past 10 years. Among chemotherapeutic agents, pegylated liposomal doxorubicin has become the preferred one for patients with HIV-associated Kaposi’s sarcoma in Western countries. The drug in this formulation localizes better to the tumor and has higher efficacy. Skin toxicity, mucositis, and leukopenia/neutropenia are the main side effects. Hepatotoxicity and mild cardiotoxicity are observed less frequently. Pegylated liposomal doxorubicin impacts favorably on quality of life. Although cost effective in Western countries, the drug is less so in developing countries.Keywords: pegylated liposomal doxorubicin, Kaposi’s sarcoma, HIV infection

Factors influencing the drug sensitization of human tumor cells for in situ lipofection.

Science.gov (United States)

Son, K; Huang, L

1996-07-01

The cisplatin induced enhancement of in situ lipofection was optimized by considering the factors that can increase the degree of sensitization. Two other anticancer drugs, mechlorethamine (nitrogen mustard) and taxol, enhanced CAT gene expression but the degree of sensitization was not as great as cisplatin. Besides human 2008 ovarian cancer cells we also found that human lung (A549) and head and neck cancer cells (SCC 25) were transiently sensitized by cisplatin. The transfectability of the two commercially available cationic liposomes, Lipofectin and LipofectAmine, was either weak or not consistent among tumors tested. In vivo transfection efficiency of 2008 cells was the highest at 1 microgram DNA per nmol or microgram liposome with all three cationic liposomes. In vitro transfection efficiency of 2008 cells at 1:1 (microgram of DNA:nmole of DC-chol/DOPE liposome) increased in a dose-dependent manner while at 1:10, an optimal ratio for in vitro lipofection, rapidly decreased with an increase in dose. This result indicated that there was a correlation between in vivo and in vitro lipofection at 1:1 ratio for delivering liposomal DNA. Most of the DNA injected into the tumor was concentrated in the tumor and in the skin above the tumor whether cisplatin was preinjected or liposomes were used as carriers.

Entrapment of ovalbumin into liposomes--factors affecting entrapment efficiency, liposome size, and zeta potential.

Science.gov (United States)

Brgles, Marija; Jurasin, Darija; Sikirić, Maja Dutour; Frkanec, Ruza; Tomasić, Jelka

2008-01-01

Various amounts of Ovalbumin (OVA) were encapsulated into positively and negatively charged multilamellar liposomes, with the aim to investigate the entrapment efficiency in different buffers and to study their effects on the liposome size and zeta potential. Results showed that the entrapment efficiency of OVA in anionic liposomes was the same in 10 mM Phosphate Buffer (PB) as in Phosphate-Buffered Saline (PBS; PB + 0.15 M NaCl). Also, liposome size was approximately 1200 nm for all anionic liposomes incorporating OVA. The entrapment efficiency of OVA in cationic liposomes was highly dependent on ionic strength. The size of cationic liposomes was approximately 1200 nm in PBS, regardless of protein content, but increased with the amount of the incorporated protein in PB. Aggregation of cationic liposomes in PB was observed when the mass of the protein was 2.5 mg or greater. The zeta potential of anionic liposomes was negative and of cationic liposomes positive in the whole range of protein mass tested. These results show how different compositions of lipid and aqueous phases can be used to vary the entrapment efficiency, liposome size, and zeta potential--the factors that are of great importance for the use of liposomes as drug carriers.

Liposome-encapsulated chemotherapy

DEFF Research Database (Denmark)

Børresen, B.; Hansen, A. E.; Kjær, A.

2018-01-01

Cytotoxic drugs encapsulated into liposomes were originally designed to increase the anticancer response, while minimizing off-target adverse effects. The first liposomal chemotherapeutic drug was approved for use in humans more than 20years ago, and the first publication regarding its use...... to inherent issues with the enhanced permeability and retention effect, the tumour phenomenon which liposomal drugs exploit. This effect seems very heterogeneously distributed in the tumour. Also, it is potentially not as ubiquitously occurring as once thought, and it may prove important to select patients...... not resolve the other challenges that liposomal chemotherapy faces, and more work still needs to be done to determine which veterinary patients may benefit the most from liposomal chemotherapy....

Intracellular ROS protection efficiency and free radical-scavenging activity of quercetin and quercetin-encapsulated liposomes.

Science.gov (United States)

Rezaei-Sadabady, Rogaie; Eidi, Akram; Zarghami, Nosratollah; Barzegar, Abolfazl

2016-01-01

Quercetin (3,5,7,3',4'-pentahydroxyflavone) is a natural bio-flavonoid originating from fruits, vegetables, seeds, berries, and tea. The antioxidant activity of quercetin and its protective effects against cardiovascular disorders, anti-cancer, anti-inflammatory, and anti-viral activities have been extensively documented; however, the clinical request of quercetin in cancer treatment is significantly limited due to its very poor delivery features. In order to increase the hydrophilicity and drug delivery capability, we encapsulated quercetin into liposomes. Our data indicated that liposomal quercetin can significantly improve the solubility and bioavailability of quercetin and can be used as an effective antioxidant for ROS protection within the polar cytoplasm, and the nano-sized quercetin encapsulated by liposomes enhanced the cellular uptake (cancer cell human MCF_7). Quercetin has many pharmaceutical applications, many of which arise from its potent antioxidant properties. The present research examined the antioxidant activities of quercetin in polar solvents by a comparative study using reduction of ferric iron in aqueous medium, intracellular ROS/toxicity assays, and reducing DPPH assays. Cell viability and ROS assays demonstrated that quercetin was able to penetrate into the polar medium inside the cells and to protect them against the highly toxic and deadly belongings of cumene hydroperoxide. The purpose of this study was to determine whether a liposomal formulation of quercetin can suggestively improve its solubility and bioavailability and can be a possible request in the treatment of tumor. The authors encapsulated quercetin in a liposomal delivery system. They studied the in vitro effects of this compound on proliferation using human MCF-7 carcinoma cells. The activity of liposomal quercetin was equal to or better than that of free quercetin at equimolar concentrations. Our data indicated that liposomal quercetin can significantly improve the

Targeted delivery of chemically modified anti-miR-221 to hepatocellular carcinoma with negatively charged liposomes

Directory of Open Access Journals (Sweden)

Zhang W

2015-07-01

Full Text Available Wendian Zhang,1 Fangqi Peng,1 Taotao Zhou,1 Yifei Huang,2 Li Zhang,3 Peng Ye,4 Miao Lu,1 Guang Yang,5 Yongkang Gai,1 Tan Yang,1 Xiang Ma,1 Guangya Xiang1 1School of Pharmacy, Tongji Medical College, 2Department of Pharmacy, 3Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 4Department of Pharmacy, Wuhan University, Renmin Hospital, 5School of Medicine, Jianghan University, Wuhan, People’s Republic of China Abstract: Hepatocellular carcinoma (HCC is one of the leading causes of cancer-related death. Gene therapy was established as a new strategy for treating HCC. To explore the potential delivery system to support the gene therapy of HCC, negatively charged liposomal delivery system was used to deliver miR-221 antisense oligonucleotide (anti-miR-221 to the transferrin (Tf receptor over expressed HepG2 cells. The liposome exhibited a mean particle size of 122.5 nm, zeta potential of -15.74 mV, anti-miR-221 encapsulation efficiency of 70%, and excellent colloidal stability at 4°C. Anti-miR-221-encapsulated Tf-targeted liposome demonstrated a 15-fold higher delivery efficiency compared to nontargeted liposome in HepG2 cells in vitro. Anti-miR-221 Tf-targeted liposome effectively delivered anti-miR-221 to HepG2 cells, upregulated miR-221 target genes PTEN, P27kip1, and TIMP3, and exhibited greater silencing efficiency over nontargeted anti-miR-221 liposome. After intravenous injection into HepG2 tumor-bearing xenografted mice with Cy3-labeled anti-miR-221 Tf-targeted liposome, Cy3-anti-miR-221 was successfully delivered to the tumor site and increased the expressions of PTEN, P27kip1, and TIMP3. Our results demonstrate that the Tf-targeted negatively charged liposome could be a potential therapeutic modality in the gene therapy of human HCC. Keywords: transferrin, gene, HCC, target delivery system, anionic liposome 

Evaluation the influence of Polyethylene glycol in circulation and biodistribution of pH-sensitive liposomes, radiolabeled with Technetium 99m in experimental models

International Nuclear Information System (INIS)

Nunes, Shirleide Santos

2016-01-01

Liposomes are lipid vesicles widely studied throughout the world as nanocarriers for different substances. The hydrophilic polymer polyethylene glycol (PEG) might be added onto the surface of liposomes to prolong the circulation time by reducing the opsonization of the vesicles, leading to a reduced uptake by the mononuclear phagocyte system (MPS). Several studies claim that the molecular weight of the PEG, as well as combination of different types of PEG with different molecular weights may alter the pharmacokinetics of the liposome. Therefore, the purpose of this study was to evaluate the influence of molecular weight and PEG combinations with different chain sizes in the pharmacokinetics and biodistribution of pH-sensitive liposomes containing 99m Tc-HYNIC-βAla-Bombesin complex (7-14 ) in tumor models (4T1 and Ehrlich). Eight liposomal formulations were prepared, the results showed that the liposomes exhibited adequate chemical and physical-chemical properties, such as mean diameter less than 300nm, monodisperse populations, neutral zeta potential, and encapsulation content of 26.4 to 38.7%. The images obtained by transmission electron cryomicroscopy (cryo-TEM) allowed visualization of unilamellar vesicles with an average diameter of 90 nm. There was no difference in blood half-life (T1/2), thereby for the composition of liposomes used in this study, PEG did not increase blood circulation time. Biodistribution studies and scintigraphic images showed high uptake by organs of the SMF, liver and spleen. The PEG2000 formulation showed higher concentration in blood. Liposomes with DSPE, PEG2000 or PEG1000 / 5000 showed higher uptake in the tumor compared to the contralateral muscle, but there was no statistical difference between the formulations when tumor-to-muscle ratio, obtained in the biodistribution studies or scintigraphic images, was analyzed. The results suggest that for this specific formulation, the addition of PEG was not efficient for increasing the

Development of liposomal pemetrexed for enhanced therapy against multidrug resistance mediated by ABCC5 in breast cancer

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Bai F

2018-03-01

was 2.6-fold more effective than pemetrexed. The in vivo biodistribution study showed that the liposomes significantly accumulated in tumors 24 h after injection. The antitumor assay in mice bearing MDR breast cancer xenograft tumors confirmed the superior antitumor activity of liposomal pemetrexed over pemetrexed. It was also found that the improved therapeutic effect of liposomal pemetrexed may be attributed to apoptosis through both extrinsic and intrinsic pathways. Conclusion: Liposomal pemetrexed represents a potential therapeutic approach for overcoming breast cancer MDR. Keywords: cancer nanotechnology, breast cancer, multidrug resistance, pemetrexed, liposomes

Trehalose Liposomes Suppress the Growth of Tumors on Human Lung Carcinoma-bearing Mice by Induction of Apoptosis In Vivo.

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Ichihara, Hideaki; Kuwabara, Keiji; Matsumoto, Yoko

2017-11-01

Previous evidence demonstrates that trehalose liposomes (DMTreC14) composed of L-α-dimyristoylphosphatidylcholine (DMPC) and α-D-glycopyranosyl-α-D-glucopyranoside monomyristate (TreC14) inhibit proliferation and invasion on lung carcinoma (A549 cells) in vitro. Here, we aimed to investigate suppressive effects of DMTreC14 on the growth of tumor on human lung carcinoma bearing mice. DMTreC14 composed of 30 mol% DMPC and 70 mol% TreC14 were prepared by the sonication method. Anti-tumor activities of DMTreC14 using the subcutaneous and orthotopic graft-bearing mice of A549 cells were investigated in vivo. The remarkable reduction of volume and weight in subcutaneous tumors on subcutaneous lung carcinoma-bearing mice topically administrated with DMTreC14 were obtained. Apoptotic-positive cells in the subcutaneous tumor slice of subcutaneous lung carcinoma-bearing mice topically administrated with DMTreC14 were observed using TUNEL staining. Lung weights on the orthotopic graft-bearing mice of lung carcinoma intravenously administrated with DMTreC14 were markedly decreased compared to those of the control group. Remarkable decrease in dimensions of tumor area of lung on the orthotopic graft-bearing mice of lung carcinoma intravenously administrated with DMTreC14 was obtained in histological analysis using the hematoxylin and eosin staining. Remarkably high anti-tumor activities of DMTreC14 for the subcutaneous and orthotopic graft-bearing mice of lung carcinoma accompanied with apoptosis were revealed for the first time in vivo. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

High intratumoral accumulation of stealth liposomal doxorubicin in sarcomas--rationale for combination with radiotherapy

International Nuclear Information System (INIS)

Koukourakis, M.I.; Koukouraki, S.; Giatromanolaki, A.; Kakolyris, S.; Georgoulias, V.; Velidaki, A.; Archimandritis, S.; Karkavitsas, N.N.

2000-01-01

Sarcomas are radioresistant tumors, the only curative therapy being radical surgical resection. Stealth liposomal doxorubicin (Caelyx) is a novel drug formulation that allows prolonged circulation and high intratumoral concentration. This study investigates the concurrent use of radiotherapy with Caelyx in a cohort of 7 patients with locally advanced or recurrent sarcoma. Radiotherapy was given as a standard fractionation regimen to a total dose of 70 Gy. Caelyx was given as a 30-min infusion at a dose of 25 mg/m 2 every 2 weeks. Scintigraphic imaging with Caelyx- 99m Tc-DTPA showed an increased (2.8 +/- 0.9 times higher) intratumoral drug accumulation compared to the surrounding healthy tissue. The regimen was well tolerated without any severe hematological or systemic toxicity. 'In field' radiation toxicity was not increased. Complete response was observed in 4/7 cases. It is concluded that combined chemo-radiotherapy with stealth liposomal doxorubicin for locally advanced sarcomas is feasible and promising, the benefit expected from the unique ability of the stealth liposomes to accumulate selectively in the tumoral tissue

Cytoprotective and enhanced anti-inflammatory activities of liposomal piroxicam formulation in lipopolysaccharide-stimulated RAW 264.7 macrophages.

Science.gov (United States)

Chiong, Hoe Siong; Yong, Yoke Keong; Ahmad, Zuraini; Sulaiman, Mohd Roslan; Zakaria, Zainul Amiruddin; Yuen, Kah Hay; Hakim, Muhammad Nazrul

2013-01-01

Liposomal drug delivery systems, a promising lipid-based nanoparticle technology, have been known to play significant roles in improving the safety and efficacy of an encapsulated drug. Liposomes, prepared using an optimized proliposome method, were used in the present work to encapsulate piroxicam, a widely prescribed nonsteroidal anti-inflammatory drug. The cytotoxic effects as well as the in vitro efficacy in regulation of inflammatory responses by free-form piroxicam and liposome-encapsulated piroxicam were evaluated using a lipopolysaccharide-sensitive macrophage cell line, RAW 264.7. Cells treated with liposome-encapsulated piroxicam demonstrated higher cell viabilities than those treated with free-form piroxicam. In addition, the liposomal piroxicam formulation resulted in statistically stronger inhibition of pro-inflammatory mediators (ie, nitric oxide, tumor necrosis factor-α, interleukin-1β, and prostaglandin E2) than piroxicam at an equivalent dose. The liposome-encapsulated piroxicam also caused statistically significant production of interleukin-10, an anti-inflammatory cytokine. This study affirms the potential of a liposomal piroxicam formulation in reducing cytotoxicity and enhancing anti-inflammatory responses in vitro.

Electrochemical analysis in a liposome suspension using lapachol as a hydrophobic electro active species.

Science.gov (United States)

Okumura, Noriko; Wakamatsu, Shiori; Uno, Bunji

2014-01-01

This study demonstrated that the electro-chemical analysis of hydrophobic quinones can be performed in liposome suspension systems. We prepared and analyzed liposome suspensions containing lapachol, which is a quinone-based anti-tumor activity compound. In this suspension system, a simple one redox couple of lapachol is observed. These results are quite different from those obtained in organic solvents. In addition, the pH dependence of redox behaviors of lapachol could be observed in multilamellar vesicle (MLV) suspension system. This MLV suspension system method may approximate the electrochemical behavior of hydrophobic compounds in aqueous conditions. A benefit of this liposome suspension system for electrochemical analysis is that it enables to observe water-insoluble compounds without using organic solvents.

Encapsulation of Liposomes within pH Responsive Microspheres for Oral Colonic Drug Delivery

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M. J. Barea

2012-01-01

Full Text Available A novel liposome-in-microsphere (LIM formulation has been created comprising drug-loaded liposomes within pH responsive Eudragit S100 microspheres. The liposomes contained the model drug 5-ASA and were coated with chitosan in order to protect them during encapsulation within the microspheres and to improve site-specific release characteristics. In vitro drug release studies showed that LIMs prevented drug release within simulated stomach and small intestine conditions with subsequent drug release occurring in large intestine conditions. The formulation therefore has potential for oral colonic drug delivery.

Mechanisms of reduction of antitumor drug toxicity by liposome encapsulation

Energy Technology Data Exchange (ETDEWEB)

Rahman, Y. E.; Hanson, W. R.; Bharucha, J.; Ainsworth, E. J.; Jaroslow, B.

1977-01-01

The antitumor drug Actinomycin D is effective against the growth of some human solid tumors but its use is limited by its extreme toxicity. The development of a method of administering Act. D to reduce its systemic toxicity by incorporating the drug within liposomes reduced its toxicity but its tumoricidal activity was retained.

siRNA-loaded cationic liposomes for cancer therapy: Development, characterization and efficacy evaluation

Science.gov (United States)

Ying, Bo

Cancer is a major health problem in the United States and many other parts of the world. However, cancer treatment is severely limited by the lack of highly effective cytotoxic agents and selective delivery methods which can serve as the "magic bullet" (first raised by Dr. Paul Ehrlich, the goal of targeting a specific location without causing harm to surrounding tissues or to more distant regions in the body). The revolutionary finding that tumors cannot grow beyond a microscopic size without dedicated blood supply provided a highly effective alternative for the treatment of cancer. Currently, anti-angiogenic therapy and the discovery of RNA interference makes it possible to treat some conditions by silencing disorder-causing genes of targeting cells which are otherwise difficult to eradicate with more conventional therapies. However, before siRNA technology could be widely used as a therapeutic approach, the construct must be efficiently and safely delivered to target cells. Strategies used for siRNA delivery should minimize uptake by phagocytes, enzymatic degradation by nucleases and should be taken up preferentially, if not specifically, by the intended cell population. Kinesin spindle proteins (KSP) are the motor proteins which play critical roles during mitosis. Different from tubulins which are also present in post-mitotic cells, such as axons, KSP is exclusively expressed in mitotic cells, which makes them the ideal target for anti-mitotics. In the present study, we intend to develop, characterize and evaluate a liposome-based delivery system which can deliver KSP siRNA selectively to the tumor vasculature (thus inhibiting angiogenesis, destroying tumor vasculature and eventually, eradicating tumor growth). We first developed ten different liposome preparation types with different compositions of lipids. Next, the capacity for loading siRNA and efficiency of targeting the tumor vascular supply was evaluated using relevant cellular and tumor models

Multiseed liposomal drug delivery system using micelle gradient as driving force to improve amphiphilic drug retention and its anti-tumor efficacy.

Science.gov (United States)

Zhang, Wenli; Li, Caibin; Jin, Ya; Liu, Xinyue; Wang, Zhiyu; Shaw, John P; Baguley, Bruce C; Wu, Zimei; Liu, Jianping

2018-11-01

To improve drug retention in carriers for amphiphilic asulacrine (ASL), a novel active loading method using micelle gradient was developed to fabricate the ASL-loaded multiseed liposomes (ASL-ML). The empty ML were prepared by hydrating a thin film with empty micelles. Then the micelles in liposomal compartment acting as 'micelle pool' drove the drug to be loaded after the outer micelles were removed. Some reasoning studies including critical micelle concentration (CMC) determination, influencing factors tests on entrapment efficiency (EE), structure visualization, and drug release were carried out to explore the mechanism of active loading, ASL location, and the structure of ASL-ML. Comparisons were made between pre-loading and active loading method. Finally, the extended drug retention capacity of ML was evaluated through pharmacokinetic, drug tissue irritancy, and in vivo anti-tumor activity studies. Comprehensive results from fluorescent and transmission electron microscope (TEM) observation, encapsulation efficiency (EE) comparison, and release studies demonstrated the formation of ML-shell structure for ASL-ML without inter-carrier fusion. The location of drug mainly in inner micelles as well as the superiority of post-loading to the pre-loading method , in which drug in micelles shifted onto the bilayer membrane was an additional positive of this delivery system. It was observed that the drug amphiphilicity and interaction of micelles with drug were the two prerequisites for this active loading method. The extended retention capacity of ML has been verified through the prolonged half-life, reduced paw-lick responses in rats, and enhanced tumor inhibition in model mice. In conclusion, ASL-ML prepared by active loading method can effectively load drug into micelles with expected structure and improve drug retention.

Combination of TRAIL and actinomycin D liposomes enhances antitumor effect in non-small cell lung cancer

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Guo LG

2012-03-01

Full Text Available Liangran Guo1,2,4, Li Fan1,2, Jinfeng Ren1,2, Zhiqing Pang1,2, Yulong Ren1,2, Jingwei Li1,2, Ziyi Wen1,3, Yong Qian1,2, Lin Zhang1,2, Hang Ma4, Xinguo Jiang1,2 1School of Pharmacy, Fudan University, Zhangheng Road, Shanghai, 2Key Laboratory of Smart Drug Delivery, Ministry of Education and PLA, Shanghai, 3School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, People's Republic of China; 4College of Pharmacy, University of Rhode Island, RI, USAAbstract: The intractability of non-small cell lung cancer (NSCLC to multimodality treatments plays a large part in its extremely poor prognosis. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL is a promising cytokine for selective induction of apoptosis in cancer cells; however, many NSCLC cell lines are resistant to TRAIL-induced apoptosis. The therapeutic effect can be restored by treatments combining TRAIL with chemotherapeutic agents. Actinomycin D (ActD can sensitize NSCLC cells to TRAIL-induced apoptosis by upregulation of death receptor 4 (DR4 or 5 (DR5. However, the use of ActD has significant drawbacks due to the side effects that result from its nonspecific biodistribution in vivo. In addition, the short half-life of TRAIL in serum also limits the antitumor effect of treatments combining TRAIL and ActD. In this study, we designed a combination treatment of long-circulating TRAIL liposomes and ActD liposomes with the aim of resolving these problems. The combination of TRAIL liposomes and ActD liposomes had a synergistic cytotoxic effect against A-549 cells. The mechanism behind this combination treatment includes both increased expression of DR5 and caspase activation. Moreover, systemic administration of the combination of TRAIL liposomes and ActD liposomes suppressed both tumor formation and growth of established subcutaneous NSCLC xenografts in nude mice, inducing apoptosis without causing significant general toxicity. These results provide preclinical proof

MRI monitoring of nanocarrier accumulation and release using Gadolinium-SPIO co-labelled thermosensitive liposomes

NARCIS (Netherlands)

Lorenzato, Cyril; Oerlemans, Chris; van Elk, Merel; Geerts, Willie J C; Denis de Senneville, Baudouin; Moonen, Chrit; Bos, Clemens

2016-01-01

Encapsulation of anticancer drugs in triggerable nanocarriers can beneficially modify pharmacokinetics and biodistribution of chemotherapeutic drugs, and consequently increase tumor drug concentration and efficacy, while reducing side effects. Thermosensitive liposomes release their contents

Absorption and fluorescence studies of curcumin bound to liposomes and lymphocytes: effect of γ- irradiation

International Nuclear Information System (INIS)

Kunwar, Amit; Barik, A.; Indira Priyadarsini, K.; Pandey, R.

2006-01-01

Absorption and fluorescence spectral changes in curcumin were employed to follow its binding to liposomes and lymphocytes. The association constants indicated high affinity of curcumin to liposomes. Tumor lymphocytes show mere intense fluorescence of curcumin over the normal lymphocytes. The loss of curcumin in cells after γ-irradiation could be followed by reduction in curcumin fluorescence. The studies indicate that such fluorescence changes can be used as markers to understand the preferential loading of curcumin to cells. (author)

Absorption and fluorescence studies of curcumin bound to liposomes and lymphocytes: effect of {gamma}- irradiation

Energy Technology Data Exchange (ETDEWEB)

Kunwar, Amit; Barik, A; Indira Priyadarsini, K [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai (India); Pandey, R [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai (India)

2006-01-15

Absorption and fluorescence spectral changes in curcumin were employed to follow its binding to liposomes and lymphocytes. The association constants indicated high affinity of curcumin to liposomes. Tumor lymphocytes show mere intense fluorescence of curcumin over the normal lymphocytes. The loss of curcumin in cells after {gamma}-irradiation could be followed by reduction in curcumin fluorescence. The studies indicate that such fluorescence changes can be used as markers to understand the preferential loading of curcumin to cells. (author)

Liposome fusion and lipid exchange on ultraviolet irradiation of liposomes containing a photochromic phospholipid

International Nuclear Information System (INIS)

Morgan, C.G.; Sandhu, S.S.; Mitchell, A.C.

1995-01-01

A photochromic phospholipid, 1,2-bis[4-n-butylphenylazo)phenylbutyroyl]phosphatidylcholine (Bis-Azo PC) has been incorporated inot liposomes of gel- and liquid-crystalline-phase phospholipids. Liposomes of gel-phase phospholipid are stable in the presence of the trans photostationary state Bis-Az0 PC and can encapsulate fluorescent marker dye. On photoisomerization to the cis photostationary state, trapped marker is rapidly released. Liposomes containing Bis-Azo PC can rapidly fuse together after UV isomerization, this process continuing in the dark. Exposure to white light causes reversion of Bis-Azo PC to the trans form and halts dye leakage and vesicle fusion. Both unilamellar and multilamellar liposomes are able to fuse together on UV exposure. On UV photolysis, liposomes containing Bis-Azo PC do not fuse with a large excess of unlabeled liposomes, but transfer of Bis-Azo PC can be demonstrated spectrophotometrically. Vesicles of pure gel-phase lipid containing trapped marker dye but initially no Bis-Azo PC become leaky as a result of this lipid transfer. Liposomes composed of liquid-crystalline-phase phosphatidylcholine-containing Bis-Azo PC neither leak trapped marker nor fuse together on photolysis, nor do liquid-crystalline-phase liposomes, fuse with gel-phase liposomes under these conditions. (Author)

Fiber-optic triggered release of liposome in vivo: implication of personalized chemotherapy.

Science.gov (United States)

Huang, Huei-Ling; Lu, Pei-Hsuan; Yang, Hung-Chih; Lee, Gi-Da; Li, Han-Ru; Liao, Kuo-Chih

2015-01-01

The aim of this research is to provide proof of principle by applying the fiber-optic triggered release of photo-thermally responsive liposomes embedded with gold nanoparticles (AuNPs) using a 200 μm fiber with 65 mW and 532 nm excitation for topical release in vivo. The tunable delivery function can be paired with an apoptosis biosensor based on the same fiber-optic configuration for providing real-time evaluation of chemotherapy efficacy in vivo to perform as a personalized chemotherapy system. The pattern of topical release triggered by laser excitation conveyed through optical fibers was monitored by the increase in fluorescence resulting from the dilution of self-quenching (75 mM) fluorescein encapsulated in liposomes. In in vitro studies (in 37°C phosphate buffer saline), the AuNP-embedded liposomes showed a more efficient triggered release (74.53%±1.63% in 40 minutes) than traditional temperature-responsive liposomes without AuNPs (14.53%±3.17%) or AuNP-liposomes without excitation (21.92%±2.08%) by spectroscopic measurements. Using the mouse xenograft studies, we first demonstrated that the encapsulation of fluorescein in liposomes resulted in a more substantial content retention (81%) in the tumor than for free fluorophores (14%) at 120 minutes after administration from in vivo fluorescence imaging. Furthermore, the preliminary results also suggested the tunable release capability of the system by demonstrating consecutive triggered releases with fiber-optic guided laser excitation.

Targeted Therapy for Acute Autoimmune Myocarditis with Nano-Sized Liposomal FK506 in Rats.

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Keiji Okuda

Full Text Available Immunosuppressive agents are used for the treatment of immune-mediated myocarditis; however, the need to develop a more effective therapeutic approach remains. Nano-sized liposomes may accumulate in and selectively deliver drugs to an inflammatory lesion with enhanced vascular permeability. The aims of this study were to investigate the distribution of liposomal FK506, an immunosuppressive drug encapsulated within liposomes, and the drug's effects on cardiac function in a rat experimental autoimmune myocarditis (EAM model. We prepared polyethylene glycol-modified liposomal FK506 (mean diameter: 109.5 ± 4.4 nm. We induced EAM by immunization with porcine myosin and assessed the tissue distribution of the nano-sized beads and liposomal FK506 in this model. After liposomal or free FK506 was administered on days 14 and 17 after immunization, the cytokine expression in the rat hearts along with the histological findings and hemodynamic parameters were determined on day 21. Ex vivo fluorescent imaging revealed that intravenously administered fluorescent-labeled nano-sized beads had accumulated in myocarditic but not normal hearts on day 14 after immunization and thereafter. Compared to the administration of free FK506, FK506 levels were increased in both the plasma and hearts of EAM rats when liposomal FK506 was administered. The administration of liposomal FK506 markedly suppressed the expression of cytokines, such as interferon-γ and tumor necrosis factor-α, and reduced inflammation and fibrosis in the myocardium on day 21 compared to free FK506. The administration of liposomal FK506 also markedly ameliorated cardiac dysfunction on day 21 compared to free FK506. Nano-sized liposomes may be a promising drug delivery system for targeting myocarditic hearts with cardioprotective agents.

Targeted Therapy for Acute Autoimmune Myocarditis with Nano-Sized Liposomal FK506 in Rats.

Science.gov (United States)

Okuda, Keiji; Fu, Hai Ying; Matsuzaki, Takashi; Araki, Ryo; Tsuchida, Shota; Thanikachalam, Punniyakoti V; Fukuta, Tatsuya; Asai, Tomohiro; Yamato, Masaki; Sanada, Shoji; Asanuma, Hiroshi; Asano, Yoshihiro; Asakura, Masanori; Hanawa, Haruo; Hao, Hiroyuki; Oku, Naoto; Takashima, Seiji; Kitakaze, Masafumi; Sakata, Yasushi; Minamino, Tetsuo

2016-01-01

Immunosuppressive agents are used for the treatment of immune-mediated myocarditis; however, the need to develop a more effective therapeutic approach remains. Nano-sized liposomes may accumulate in and selectively deliver drugs to an inflammatory lesion with enhanced vascular permeability. The aims of this study were to investigate the distribution of liposomal FK506, an immunosuppressive drug encapsulated within liposomes, and the drug's effects on cardiac function in a rat experimental autoimmune myocarditis (EAM) model. We prepared polyethylene glycol-modified liposomal FK506 (mean diameter: 109.5 ± 4.4 nm). We induced EAM by immunization with porcine myosin and assessed the tissue distribution of the nano-sized beads and liposomal FK506 in this model. After liposomal or free FK506 was administered on days 14 and 17 after immunization, the cytokine expression in the rat hearts along with the histological findings and hemodynamic parameters were determined on day 21. Ex vivo fluorescent imaging revealed that intravenously administered fluorescent-labeled nano-sized beads had accumulated in myocarditic but not normal hearts on day 14 after immunization and thereafter. Compared to the administration of free FK506, FK506 levels were increased in both the plasma and hearts of EAM rats when liposomal FK506 was administered. The administration of liposomal FK506 markedly suppressed the expression of cytokines, such as interferon-γ and tumor necrosis factor-α, and reduced inflammation and fibrosis in the myocardium on day 21 compared to free FK506. The administration of liposomal FK506 also markedly ameliorated cardiac dysfunction on day 21 compared to free FK506. Nano-sized liposomes may be a promising drug delivery system for targeting myocarditic hearts with cardioprotective agents.

H2O2-responsive liposomal nanoprobe for photoacoustic inflammation imaging and tumor theranostics via in vivo chromogenic assay.

Science.gov (United States)

Chen, Qian; Liang, Chao; Sun, Xiaoqi; Chen, Jiawen; Yang, Zhijuan; Zhao, He; Feng, Liangzhu; Liu, Zhuang

2017-05-23

Abnormal H 2 O 2 levels are closely related to many diseases, including inflammation and cancers. Herein, we simultaneously load HRP and its substrate, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), into liposomal nanoparticles, obtaining a Lipo@HRP&ABTS optical nanoprobe for in vivo H 2 O 2 -responsive chromogenic assay with great specificity and sensitivity. In the presence of H 2 O 2 , colorless ABTS would be converted by HRP into the oxidized form with strong near-infrared (NIR) absorbance, enabling photoacoustic detection of H 2 O 2 down to submicromolar concentrations. Using Lipo@HRP&ABTS as an H 2 O 2 -responsive nanoprobe, we could accurately detect the inflammation processes induced by LPS or bacterial infection in which H 2 O 2 is generated. Meanwhile, upon systemic administration of this nanoprobe we realize in vivo photoacoustic imaging of small s.c. tumors (∼2 mm in size) as well as orthotopic brain gliomas, by detecting H 2 O 2 produced by tumor cells. Interestingly, local injection of Lipo@HRP&ABTS further enables differentiation of metastatic lymph nodes from those nonmetastatic ones, based on their difference in H 2 O 2 contents. Moreover, using the H 2 O 2 -dependent strong NIR absorbance of Lipo@HRP&ABTS, tumor-specific photothermal therapy is also achieved. This work thus develops a sensitive H 2 O 2 -responsive optical nanoprobe useful not only for in vivo detection of inflammation but also for tumor-specific theranostic applications.

A Tumor-Targeted Nanodelivery System to Improve Early MRI Detection of Cancer

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Kathleen F. Pirollo

2006-01-01

Full Text Available The development of improvements in magnetic resonance imaging (MRI that would enhance sensitivity, leading to earlier detection of cancer and visualization of metastatic disease, is an area of intense exploration. We have devised a tumor-targeting, liposomal nanodelivery platform for use in gene medicine. This systemically administered nanocomplex has been shown to specifically and efficiently deliver both genes and oligonucleotides to primary and metastatic tumor cells, resulting in significant tumor growth inhibition and even tumor regression. Here we examine the effect on MRI of incorporating conventional MRI contrast agent Magnevist® into our anti-transferrin receptor single-chain antibody (TfRscFv liposomal complex. Both in vitro and in an in vivo orthotopic mouse model of pancreatic cancer, we show increased resolution and image intensity with the complexed Magnevist®. Using advanced microscopy techniques (scanning electron microscopy and scanning probe microscopy, we also established that the Magnevist® is in fact encapsulated by the liposome in the complex and that the complex still retains its nanodimensional size. These results demonstrate that this TfRscFv-liposome-Magnevist® nanocomplex has the potential to become a useful tool in early cancer detection.

NIR responsive liposomal system for rapid release of drugs in cancer therapy

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Chen MM

2017-06-01

Full Text Available Ming-Mao Chen,1 Yuan-Yuan Liu,1 Guang-Hao Su,2 Fei-Fei Song,1 Yan Liu,3 Qi-Qing Zhang1,4 1Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou, 2Institute of Pediatric Research, Children’s Hospital of Soochow University, Suzhou, 3State Key Lab of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 4Key Laboratory of Biomedical Material of Tianjin, Institute of Biomedical Engineering, Chinese Academy of Medical Science & Peking Union Medical College, Tianjin, People’s Republic of China Abstract: To design a rapid release liposomal system for cancer therapy, a NIR responsive bubble-generating thermosensitive liposome (BTSL system combined with photothermal agent (Cypate, doxorubicin (DOX, and NH4HCO3 was developed. Cypate/DOX-BTSL exhibited a good aqueous stability, photostability, and photothermal effect. In vitro release suggested that the amounts of DOX released from BTSL were obviously higher than that of (NH42SO4 liposomes at 42°C. After NIR irradiation, the hyperthermic temperature induced by Cypate led to the decomposition of NH4HCO3 and the generation of a large number of CO2 bubbles, triggering a rapid release of drugs. Confocal laser scanning microscope and acridine orange staining indicated that Cypate/DOX-BTSL upon irradiation could facilitate to disrupt the lysosomal membranes and realize endolysosomal escape into cytosol, improving the intracellular uptake of DOX clearly. MTT and trypan blue staining implied that the cell damage of Cypate/DOX-BTSL with NIR irradiation was more severe than that in the groups without irradiation. In vivo results indicated that Cypate/DOX-BTSL with irradiation could dramatically increase the accumulation of DOX in tumor, inhibit tumor growth, and reduce systemic side effects of DOX. These data demonstrated that Cypate/DOX-BTSL has the potential to be used as a NIR responsive liposomal system for a rapid

Remote-loading of liposomes with manganese-52 and in vivo evaluation of the stabilities of 52Mn-DOTA and 64Cu-DOTA using radiolabelled liposomes and PET imaging.

Science.gov (United States)

Jensen, Andreas I; Severin, Gregory W; Hansen, Anders E; Fliedner, Frederikke P; Eliasen, Rasmus; Parhamifar, Ladan; Kjær, Andreas; Andresen, Thomas L; Henriksen, Jonas R

2018-01-10

Liposomes are nanoparticles used in drug delivery that distribute over several days in humans and larger animals. Radiolabeling with long-lived positron emission tomography (PET) radionuclides, such as manganese-52 ( 52 Mn, T½=5.6days), allow the imaging of this biodistribution. We report optimized protocols for radiolabeling liposomes with 52 Mn, through both remote-loading and surface labeling. For comparison, liposomes were also remote-loaded and surface labeled with copper-64 ( 64 Cu, T½=12.7h) through conventional means. The chelator DOTA was used in all cases. The in vivo stability of radiometal chelates is widely debated but studies that mimic a realistic in vivo setting are lacking. Therefore, we employed these four radiolabeled liposome types as platforms to demonstrate a new concept for such in vivo evaluation, here of the chelates 52 Mn-DOTA and 64 Cu-DOTA. This was done by comparing "shielded" remote-loaded with "exposed" surface labeled variants in a CT26 tumor-bearing mouse model. Remote loading (90min at 55°C) and surface labeling (55°C for 2h) of 52 Mn gave excellent radiolabeling efficiencies of 97-100% and 98-100% respectively, and the liposome biodistribution was imaged by PET for up to 8days. Liposomes with surface-conjugated 52 Mn-DOTA exhibited a significantly shorter plasma half-life (T ½ =14.4h) when compared to the remote-loaded counterpart (T ½ =21.3h), whereas surface-conjugated 64 Cu-DOTA cleared only slightly faster and non-significantly, when compared to remote-loaded (17.2±2.9h versus 20.3±1.2h). From our data, we conclude the successful remote-loading of liposomes with 52 Mn, and furthermore that 52 Mn-DOTA may be unstable in vivo whereas 64 Cu-DOTA appears suitable for quantitative imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of the Encapsulation Efficiency and Size of Liposome on the Oral Bioavailability of Griseofulvin-Loaded Liposomes

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Sandy Gim Ming Ong

2016-08-01

Full Text Available The objective of the present study was to investigate the influence of the encapsulation efficiency and size of liposome on the oral bioavailability of griseofulvin-loaded liposomes. Griseofulvin-loaded liposomes with desired characteristics were prepared from pro-liposome using various techniques. To study the effect of encapsulation efficiency, three preparations of griseofulvin, namely, griseofulvin aqueous suspension and two griseofulvin-loaded liposomes with different amounts of griseofulvin encapsulated [i.e., F1 (32% and F2(98%], were administered to rats. On the other hand, to study the effect of liposome size, the rats were given three different griseofulvin-loaded liposomes of various sizes, generated via different mechanical dispersion techniques [i.e., FTS (142 nm, MS (357 nm and NS (813 nm], but with essentially similar encapsulation efficiencies (about 93%. Results indicated that the extent of bioavailability of griseofulvin was improved 1.7–2.0 times when given in the form of liposomes (F1 compared to griseofulvin suspension. Besides that, there was an approximately two-fold enhancement of the extent of bioavailability following administration of griseofulvin-loaded liposomes with higher encapsulation efficiency (F2, compared to those of F1. Also, the results showed that the extent of bioavailability of liposomal formulations with smaller sizes were higher by approximately three times compared to liposomal formulation of a larger size. Nevertheless, a further size reduction of griseofulvin-loaded liposome (≤400 nm did not promote the uptake or bioavailability of griseofulvin. In conclusion, high drug encapsulation efficiency and small liposome size could enhance the oral bioavailability of griseofulvin-loaded liposomes and therefore these two parameters deserve careful consideration during formulation.

Positron Emission Tomography Based Elucidation of the Enhanced Permeability and Retention Effect in Dogs with Cancer Using Copper-64 Liposomes

DEFF Research Database (Denmark)

Hansen, Anders Elias; Petersen, Anncatrine Luisa; Henriksen, Jonas Rosager

2015-01-01

Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years...... was considered to be a ubiquitous phenomenon. However, the understanding of differences in the EPR-effect between tumor types, heterogeneities within each patient group, and dependency on tumor development stage in humans is sparse. It is therefore important to enhance our understanding of the EPR......-effect in large animals and humans with spontaneously developed cancer. In the present paper, we describe a novel loading method of copper-64 into PEGylated liposomes and use these liposomes to evaluate the EPR-effect in 11 canine cancer patients with spontaneous solid tumors by PET/CT imaging. We thereby provide...

The antitumor activity of a doxorubicin loaded, iRGD-modified sterically-stabilized liposome on B16-F10 melanoma cells: in vitro and in vivo evaluation

Directory of Open Access Journals (Sweden)

Yu KF

2013-07-01

Full Text Available Ke-Fu Yu,1 Wei-Qiang Zhang,1 Li-Min Luo,1 Ping Song,1 Dan Li,1 Ruo Du,1 Wei Ren,1 Dan Huang,1 Wan-Liang Lu,1,2 Xuan Zhang,1 Qiang Zhang1,2 1Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China; 2State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China Abstract: Considering the fact that iRGD (tumor-homing peptide demonstrates tumor-targeting and tumor-penetrating activity, and that B16-F10 (murine melanoma cells overexpress both αv integrin receptor and neuropilin-1 (NRP-1, the purpose of this study was to prepare a novel doxorubicin (DOX-loaded, iRGD-modified, sterically-stabilized liposome (SSL (iRGD-SSL-DOX in order to evaluate its antitumor activity on B16-F10 melanoma cells in vitro and in vivo. The iRGD-SSL-DOX was prepared using a thin-film hydration method. The characteristics of iRGD-SSL-DOX were evaluated. The in vitro leakage of DOX from iRGD-SSL-DOX was tested. The in vitro tumor-targeting and tumor-penetrating characteristics of iRGD-modified liposomes on B16-F10 cells were investigated. The in vivo tumor-targeting and tumor-penetrating activities of iRGD-modified liposomes were performed in B16-F10 tumor-bearing nude mice. The antitumor effect of iRGD-SSL-DOX was evaluated in B16-F10 tumor-bearing C57BL/6 mice in vivo. The average particle size of the iRGD-SSL-DOX was found to be 91 nm with a polydispersity index (PDI of 0.16. The entrapment efficiency of iRGD-SSL-DOX was 98.36%. The leakage of DOX from iRGD-SSL-DOX at the 24-hour time point was only 7.5%. The results obtained from the in vitro flow cytometry and confocal microscopy, as well as in vivo biodistribution and confocal immunofluorescence microscopy experiments, indicate that the tumor-targeting and tumor-penetrating activity of the iRGD-modified SSL was higher than that of unmodified SSL. In vivo antitumor activity

Preparation, characterization, and efficient transfection of cationic liposomes and nanomagnetic cationic liposomes

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Samadikhah HR

2011-10-01

Full Text Available Hamid Reza Samadikhah1,*, Asia Majidi2,*, Maryam Nikkhah2, Saman Hosseinkhani11Department of Biochemistry, 2Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran *These authors contributed equally to this work Purpose: Cationic liposomes (CLs are composed of phospholipid bilayers. One of the most important applications of these particles is in drug and gene delivery. However, using CLs to deliver therapeutic nucleic acids and drugs to target organs has some problems, including low transfection efficiency in vivo. The aim of this study was to develop novel CLs containing magnetite to overcome the deficiencies. Patients and methods: CLs and magnetic cationic liposomes (MCLs were prepared using the freeze-dried empty liposome method. Luciferase-harboring vectors (pGL3 were transferred into liposomes and the transfection efficiencies were determined by luciferase assay. Firefly luciferase is one of most popular reporter genes often used to measure the efficiency of gene transfer in vivo and in vitro. Different formulations of liposomes have been used for delivery of different kinds of gene reporters. Lipoplex (liposome–plasmid DNA complexes formation was monitored by gel retardation assay. Size and charge of lipoplexes were determined using particle size analysis. Chinese hamster ovary cells were transfected by lipoplexes (liposome-pGL3; transfection efficiency and gene expression level was evaluated by luciferase assay. Results: High transfection efficiency of plasmid by CLs and novel nanomagnetic CLs was achieved. Moreover, lipoplexes showed less cytotoxicity than polyethyleneimine and Lipofectamine™. Conclusion: Novel liposome compositions (1,2-dipalmitoyl-sn-glycero-3-phosphocholine [DPPC]/dioctadecyldimethylammonium bromide [DOAB] and DPPC/cholesterol/DOAB with high transfection efficiency can be useful in gene delivery in vitro. MCLs can also be used for targeted gene delivery, due to

Experimental research on treating hepatic carcinoma by arterial injection of liposome mediated p53 genes

Energy Technology Data Exchange (ETDEWEB)

Guangyu, Zhu; Qin, Lu; Gaojun, Teng; Jinhe, Guo; Hui, Yu; Gang, Deng; Shicheng, He; Wen, Fang; Guozhao, Li; Xiaoying, Wei [Zhongda Hospital, Southeast Univ., Nanjing (China)

2007-02-15

Objective: To investigate the transfection and expression of p53 genes mediated by liposome and its feasibility in treatment of liver cancer by transcatheter arterial injection on rabbit VX2 hepatocarcinoma model. Methods: pCMV-myc-p53 plasmids, LipofectAMINE and p53-LipofectAMINE complex were infused into tumor's feeding artery of rabbit VX2 hepatocarcinoma model, respectively, and then protein of cancer tissue was extracted, followed by measuring gene transfection and expression by western blot and immunohistochemistry, p53-LipofectAMlNE complex in different doses were infused into tumor's feeding artery of rabbit VX2 hepatocarcinoma model with the gene transfection and expression detected by the same way. Results: Liposome-mediated p53 gene injected through catheter could be successfully transfected and expressed in the cancer tissue of rabbit VX2 hepatocarcinoma model, with transfection efficiency higher than the gene delivery alone. The efficiency and the gene dose has dose-effect relationship. Conclusions: Treatment of liver cancer by transcatheter arterial injection of p53 genes mediated by liposome is a feasible and effective method, with wide prospect of application. (authors)

Experimental research on treating hepatic carcinoma by arterial injection of liposome mediated p53 genes

International Nuclear Information System (INIS)

Zhu Guangyu; Lu Qin; Teng Gaojun; Guo Jinhe; Yu Hui; Deng Gang; He Shicheng; Fang Wen; Li Guozhao; Wei Xiaoying

2007-01-01

Objective: To investigate the transfection and expression of p53 genes mediated by liposome and its feasibility in treatment of liver cancer by transcatheter arterial injection on rabbit VX2 hepatocarcinoma model. Methods: pCMV-myc-p53 plasmids, LipofectAMINE and p53-LipofectAMINE complex were infused into tumor's feeding artery of rabbit VX2 hepatocarcinoma model, respectively, and then protein of cancer tissue was extracted, followed by measuring gene transfection and expression by western blot and immunohistochemistry, p53-LipofectAMlNE complex in different doses were infused into tumor's feeding artery of rabbit VX2 hepatocarcinoma model with the gene transfection and expression detected by the same way. Results: Liposome-mediated p53 gene injected through catheter could be successfully transfected and expressed in the cancer tissue of rabbit VX2 hepatocarcinoma model, with transfection efficiency higher than the gene delivery alone. The efficiency and the gene dose has dose-effect relationship. Conclusions: Treatment of liver cancer by transcatheter arterial injection of p53 genes mediated by liposome is a feasible and effective method, with wide prospect of application. (authors)

Fiber-optic triggered release of liposome in vivo: implication of personalized chemotherapy

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Huang HL

2015-08-01

Full Text Available Huei-Ling Huang,1 Pei-Hsuan Lu,1 Hung-Chih Yang,1 Gi-Da Lee,1,2 Han-Ru Li,1 Kuo-Chih Liao1 1Graduate Institute of Biomedical Engineering, National Chung Hsing University, 2Department of Radiology, Taichung Veterans General Hospital, Taichung, Taiwan Abstract: The aim of this research is to provide proof of principle by applying the fiber-optic triggered release of photo-thermally responsive liposomes embedded with gold nanoparticles (AuNPs using a 200 µm fiber with 65 mW and 532 nm excitation for topical release in vivo. The tunable delivery function can be paired with an apoptosis biosensor based on the same fiber-optic configuration for providing real-time evaluation of chemotherapy efficacy in vivo to perform as a personalized chemotherapy system. The pattern of topical release triggered by laser excitation conveyed through optical fibers was monitored by the increase in fluorescence resulting from the dilution of self-quenching (75 mM fluorescein encapsulated in liposomes. In in vitro studies (in 37°C phosphate buffer saline, the AuNP-embedded liposomes showed a more efficient triggered release (74.53%±1.63% in 40 minutes than traditional temperature-responsive liposomes without AuNPs (14.53%±3.17% or AuNP-liposomes without excitation (21.92%±2.08% by spectroscopic measurements. Using the mouse xenograft studies, we first demonstrated that the encapsulation of fluorescein in liposomes resulted in a more substantial content retention (81% in the tumor than for free fluorophores (14% at 120 minutes after administration from in vivo fluorescence imaging. Furthermore, the preliminary results also suggested the tunable release capability of the system by demonstrating consecutive triggered releases with fiber-optic guided laser excitation. Keywords: fiber-optic guided excitation, light excitation triggered release, photo-thermal responsive liposome, gold nanoparticles, tunable release in vivo

[Development of a Novel Liposomal DDS by Manipulating Pharmacokinetics and Intracellular Trafficking for Drug Therapy and Nucleic Acid Medicine].

Science.gov (United States)

Hatakeyama, Hiroto

2018-01-01

　Nucleic acid therapy is expected to be a next generation medicine. We recently developed a multifunctional envelope-type nano device (MEND) for use as a novel delivery system. The modification of polyethylene glycol (PEG), i.e., PEGylation, is useful for achieving the delivery of MENDs to tumors via an enhanced permeability and retention (EPR) effect. However, PEGylation strongly inhibits the cellular uptake and endosomal escape of MEND, which results in significant loss of action, and therefore lost effectiveness, of the cargo therapeutic. For successful nucleic acid delivery in cancer treatment, the crucial problem associated with the use of PEG, known as the "PEG dilemma", must be solved. In this review, we describe the development and application of MEND in overcoming the PEG dilemma based on manipulating both the pharmacokinetics and intracellular trafficking of cellular uptake and endosomal release using a cleavable PEG lipid, a pH-sensitive fusogenic peptide, and a pH-sensitive cationic lipid. We also developed dual-ligand liposomes with a controlled diameter of around 300 nm, then modified these with a specific ligand and a cell penetrating peptide designed to target the neovasculature of tumors. Dual-ligand liposomes could induce an anti-tumor effect in drug resistant tumors by delivering drugs to tumor blood vessels, rather than to the cancer cells themselves. Here, we review our recent efforts to develop a novel liposomal drug delivery system (DDS) by manipulating pharmacokinetics and intracellular trafficking for drug therapy and nucleic acid medicine.

Two-step polymer- and liposome-enzyme prodrug therapies for cancer: PDEPT and PELT concepts and future perspectives.

Science.gov (United States)

Scomparin, Anna; Florindo, Helena F; Tiram, Galia; Ferguson, Elaine L; Satchi-Fainaro, Ronit

2017-09-01

Polymer-directed enzyme prodrug therapy (PDEPT) and polymer enzyme liposome therapy (PELT) are two-step therapies developed to provide anticancer drugs site-selective intratumoral accumulation and release. Nanomedicines, such as polymer-drug conjugates and liposomal drugs, accumulate in the tumor site due to extravasation-dependent mechanism (enhanced permeability and retention - EPR - effect), and further need to cross the cellular membrane and release their payload in the intracellular compartment. The subsequent administration of a polymer-enzyme conjugate able to accumulate in the tumor tissue and to trigger the extracellular release of the active drug showed promising preclinical results. The development of polymer-enzyme, polymer-drug conjugates and liposomal drugs had undergone a vast advancement over the past decades. Several examples of enzyme mimics for in vivo therapy can be found in the literature. Moreover, polymer therapeutics often present an enzyme-sensitive mechanism of drug release. These nanomedicines can thus be optimal substrates for PDEPT and this review aims to provide new insights and stimuli toward the future perspectives of this promising combination. Copyright © 2017 Elsevier B.V. All rights reserved.

Baicalin loaded in folate-PEG modified liposomes for enhanced stability and tumor targeting

Czech Academy of Sciences Publication Activity Database

Chen, Y.; Minh, L. V.; Liu, J.; Angelov, Borislav; Drechsler, M.; Garamus, V. M.; Willumeit-Römer, R.; Zou, A.

2016-01-01

Roč. 140, 1 April (2016), s. 74-82 ISSN 0927-7765 R&D Projects: GA ČR(CZ) GC15-10527J Institutional support: RVO:61389013 Keywords : baicalin * liposomes * folate receptor Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.887, year: 2016

Factors affecting the pharmacokinetics and pharmacodynamics of PEGylated liposomal irinotecan (IHL-305 in patients with advanced solid tumors

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Wu H

2015-02-01

Full Text Available Huali Wu,1 Jeffrey R Infante,2 Vicki L Keedy,3 Suzanne F Jones,2 Emily Chan,3 Johanna C Bendell,2 Wooin Lee,4 Whitney P Kirschbrown,1 Beth A Zamboni,5 Satoshi Ikeda,6 Hiroshi Kodaira,6 Mace L Rothenberg,3 Howard A Burris III,2 William C Zamboni1,7–9 1UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 2Sarah Cannon Research Institute/Tennessee Oncology, PLLC, 3Vanderbilt University, Nashville, TN, 4Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 5Department of Mathematics, Carlow University, Pittsburgh, PA, USA; 6Yakult Honsha Co., Ltd., Medical Development Department, Tokyo, Japan; 7UNC Lineberger Comprehensive Cancer Center, 8UNC Institute for Pharmacogenomics and Individualized Therapy, 9Carolina Center for Cancer Nanotechology Excellence, University of North Carolina, Chapel Hill, NC, USA Abstract: IHL-305 is a PEGylated liposomal formulation of irinotecan (CPT-11. The objective of this study was to evaluate the factors associated with interpatient variability in the pharmacokinetics and pharmacodynamics of IHL-305 in patients with advanced solid tumors. IHL-305 was administered intravenously once every 4 weeks as part of a Phase I study. Pharmacokinetic studies of the liposomal sum total CPT-11, released CPT-11, SN-38, SN-38G, 7-ethyl-10-[4-N-(5-aminopentanoic acid-1-piperidino]-carbonyloxycamptothecin, and 7-ethyl-10-[4-amino-1-piperidino]-carbonyloxycamptothecin in plasma were performed. Noncompartmental and compartmental pharmacokinetic analyses were conducted using pharmacokinetic data for sum total CPT-11. The pharmacokinetic variability of IHL-305 is associated with linear and nonlinear clearance. Patients whose age and body composition (ratio of total body weight to ideal body weight [TBW/IBW] were greater than the median age and TBW/IBW of the study had a 1.7-fold to 2.6-fold higher ratio of released CPT-11 area under the concentration versus time

Preparation and characterization of different liposomal formulations containing P5 HER2/neu-derived peptide and evaluation of their immunological responses and antitumor effects

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Sheida Shariat

2015-05-01

Full Text Available Objective(s:Tumor-associated antigen (TAA subunit-based vaccines constitute promising tools for anticancer immunotherapy. However, a major limitation in the development of such vaccines is the poor immunogenicity of peptides when used alone.The aim of this study was to develop an efficient vaccine delivery system and adjuvant to enhance anti-tumor activity of a synthetic HER2/neu derived peptide (P5. Materials and Methods: P5 peptide was encapsulated with different liposomal formulations composed of DMPC:DMPG:Chol:DOPE and loaded with monophosphoryl lipid A (MPL. All formulations were characterized for their physicochemical properties. To evaluate vaccine efficacy, BALB/c mice were first immunized with free peptide or liposomal formulations, then, inoculated with a subcutaneous injection of TUBO tumor cells. Enzyme-linked immunospot, cytotoxicity and intracellular cytokine assays, as well as tumor size and animal survival analysis, were performed to evaluate the immune responses. Results: The results demonstrated that P5 encapsulated into liposomal formulations was not able to induce CD8 and CD4 T cells to produce IFN-γ. That is why, a potent CTL response and antitumor immunity was not induced. Conclusion: The Lip-DOPE-P5-MPL formulation in spite of using pH-sensitive lipid to direct intracellular trafficking of peptide to MHC I presentation pathway and MPL to enhance peptide adjuvanticity was interesting. The failure in inducing anti-tumor immunity may be attributed to low uptake of anionic conventional liposomes by dendritic cells (DCs that have negative surface charge.

Clinical developments of chemotherapeutic nanomedicines: Polymers and liposomes for delivery of camptothecins and platinum (II) drugs

KAUST Repository

Kieler-Ferguson, Heidi M.; Frechet, Jean; Szoka, Francis C.

2013-01-01

For the past 40 years, liposomal and polymeric delivery vehicles have been studied as systems capable of modulating the cytotoxicity of small molecule chemotherapeutics, increasing tumor bearing animal survival times, and improving drug targeting

In vivo and in vitro evaluation of octyl methoxycinnamate liposomes

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de Carvalho Varjão Mota A

2013-12-01

Full Text Available Aline de Carvalho Varjão Mota,1 Zaida Maria Faria de Freitas,1 Eduardo Ricci Júnior,1 Gisela Maria Dellamora-Ortiz,1 Ralph Santos-Oliveira,2 Rafael Antonio Ozzetti,3 André Luiz Vergnanini,3 Vanessa Lira Ribeiro,4 Ronald Santos Silva,4 Elisabete Pereira dos Santos11Faculty of Pharmacy, Federal University of Rio de Janeiro, 2Nuclear Engineering Institute, National Nuclear Energy Commission, 3Allergisa Dermatocosmetic Research, University of Campinas, São Paulo, 4Pharmacology and Toxicology Department, National Insitute of Quality Control in Health, Oswaldo Cruz Foundation, Rio de Janeiro, BrazilAbstract: Solar radiation causes damage to human skin, and photoprotection is the main way to prevent these harmful effects. The development of sunscreen formulations containing nanosystems is of great interest in the pharmaceutical and cosmetic industries because of the many potential benefits. This study aimed to develop and evaluate an octyl methoxycinnamate (OMC liposomal nanosystem (liposome/OMC to obtain a sunscreen formulation with improved safety and efficacy by retaining OMC for longer on the stratum corneum.Methods: The liposome/OMC nanostructure obtained was tested for enzymatic hydrolysis with lipase from Rhizomucor miehei and biodistribution with liposomes labeled with technetium-99m. The liposome/OMC formulation was then incorporated in a gel formulation and tested for ocular irritation using the hen’s egg test-chorio-allantoic membrane (HET-CAM assay, in vitro and in vivo sun protection factor, in vitro release profile, skin biometrics, and in vivo tape stripping.Results: The liposome/OMC nanosystem was not hydrolyzed from R. miehei by lipase. In the biodistribution assay, the liposome/OMC formulation labeled with technetium-99m had mainly deposited in the skin, while for OMC the main organ was the liver, showing that the liposome had higher affinity for the skin than OMC. The liposome/OMC formulation was classified as nonirritating in

Propulsion of liposomes using bacterial motors

International Nuclear Information System (INIS)

Zhang Zhenhai; Li Kejie; Li Zhifei; Yu Wei; Xie Zhihong; Shi Zhiguo

2013-01-01

Here we describe the utilization of flagellated bacteria as actuators to propel spherical liposomes by attaching bacteria to the liposome surface. Bacteria were stably attached to liposomes using a cross-linking antibody. The effect of the number of attached bacteria on propulsion speed was experimentally determined. The effects of bacterial propulsion on the bacteria–antibody–liposome complex were stochastic. We demonstrated that liposomal mobility increased when bacteria were attached, and the propulsion speed correlated with the number of bacteria. (paper)

Neurologic complications of intrathecal liposomal cytarabine administered prophylactically to patients with non-Hodgkin lymphoma.

Science.gov (United States)

Gállego Pérez-Larraya, Jaime; Palma, José Alberto; Carmona-Iragui, María; Fernández-Torrón, Roberto; Irimia, Pablo; Rodríguez-Otero, Paula; Panizo, Carlos; Martínez-Vila, Eduardo

2011-07-01

Central nervous system (CNS) prophylaxis is required during initial treatment of non-Hodgkin lymphoma (NHL) subtypes that carry a high risk of CNS involvement. Intrathecal (IT) liposomal cytarabine, a formulation with prolonged half-life, has been shown to be safe and effective in the treatment of meningeal disease in patients with high-grade lymphoma. We retrospectively reviewed all adult patients with high-grade NHL that received prophylactic therapy with IT liposomal cytarabine and developed neurologic complications in our institution between April 2007 and May 2009. We recorded information on hospital admission, chemotherapy regimens, clinical features, neuroimaging, cerebrospinal fluid, neurophysiology data, and outcome. Neurotoxicity was graded according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC). Four of fourteen patients (28%) developed moderate or severe neurotoxicity (grades 2 and 3 of the NCI-CTC), manifested as conus medullaris/cauda equine syndrome or pseudotumour cerebri-like syndrome, after a median of 3.5 IT courses of liposomal cytarabine. All patients had received corticosteroids to prevent arachnoiditis. Liposomal cytarabine given via the IT route, even with concomitant corticosteroid administration, can result in significant neurotoxicity in some patients. We discuss the potential pathogenesis of these effects and suggest hypothetical therapeutic measures to prevent these complications. Specialists should be aware of these possible complications when administering prophylactic IT liposomal cytarabine in high-grade NHL patients, and additional prospective studies should be conducted to more clearly delineate the frequency and characteristics of these complications.

Pharmacokinetics and efficacy of PEGylated liposomal doxorubicin in an intracranial model of breast cancer.

Directory of Open Access Journals (Sweden)

Carey K Anders

Full Text Available Breast cancer brain metastases (BCBM are a challenging consequence of advanced BC. Nanoparticle agents, including liposomes, have shown enhanced delivery to solid tumors and brain. We compared pharmacokinetics (PK and efficacy of PEGylated liposomal doxorubicin (PLD with non-liposomal doxorubicin (NonL-doxo in an intracranial model of BC.Athymic mice were inoculated intracerebrally with MDA-MB-231-BR-luciferase-expressing cells. Tumor-bearing mice were administered PLD or NonL-doxo at 6 mg/kg IV × 1 and were euthanized prior to and 0.083, 1, 3, 6, 24, 72 and 96 h post-treatment. Samples were processed to measure sum total doxorubicin via HPLC. PLD and NonL-doxo were administered IV weekly as single agents (6 mg/kg or in combination (4.5 mg/kg with the PARP inhibitor, ABT-888, PO 25 mg/kg/day. Efficacy was assessed by survival and bioluminescence.Treatment with PLD resulted in approximately 1,500-fold higher plasma and 20-fold higher intracranial tumor sum total doxorubicin AUC compared with NonL-doxo. PLD was detected at 96 h; NonL-doxo was undetectable after 24 h in plasma and tumor. Median survival of PLD-treated animals was 32 days (d, [CI] 31-38, which was significantly longer than controls (26d [CI 25-28]; p = 0.0012 or NonL-doxo treatment (23.5d [CI 18-28], p = 0.0002. Combination treatment with PLD/ABT-888 yielded improved survival compared to NonL-doxo/ABT-888 (35d [CI 31-38] versus 29.5d [CI 25-34]; p = 0.006.PLD provides both PK and efficacy advantage over NonL-doxo in the treatment of an in vivo model of BCBM. The results provide preclinical rationale to translate findings into early phase trials of PLD, with or without ABT-888, for patients with BCBM.

Delivering minocycline into brain endothelial cells with liposome-based technology

OpenAIRE

Xing, Changhong; Levchenko, Tatyana; Guo, Shuzhen; Stins, Monique; Torchilin, Vladimir P; Lo, Eng H

2012-01-01

Minocycline has been proposed as a way to blunt neurovascular injury from matrix metalloproteinases (MMPs) during stroke. However, recent clinical trials suggest that high levels of minocycline may have deleterious side-effects. Here, we showed that very high minocycline concentrations damage endothelial cells via calpain/caspase pathways. To alleviate this potential cytotoxicity, we encapsulated minocycline in liposomes. Low concentrations of minocycline could not reduce tumor necrosis facto...

DIAGNOSIS AND PREVENTION OF CARDIOTOXICITY IN PATIENTS WITH BREAST CANCER FROM THE STANDPOINT OF AN ONCOLOGIST AND A CARDIOLOGIST

Directory of Open Access Journals (Sweden)

T. Yu. Semiglazova

2017-01-01

Full Text Available Knowledge of anthracycline antibiotics’ (AAs pathogenesis and main risk factors allowed to develop various methods of prevention and early detection of cardiotoxicity as well as to create several guidelines on decreasing the risk of its development. Traditional AAs are a crucial option in treatment of metastatic breast cancer including their repeated prescription. However, their application is significantly limited by various manifestations of toxicity, especially cumulative cardiotoxicity. The most promising is use of pegylated liposomal pharmaceutical formulations of AAs. Among these formulations, pegylated liposomal doxorubicin almost fully lacks anthracycline cardiotoxicity because due to its unique formulation it accumulates almost exclusively in tumor tissue.

Liposomes and nanotechnology in drug development: focus on oncotargets

Directory of Open Access Journals (Sweden)

Kozako T

2012-09-01

Full Text Available Tomohiro Kozako,1 Naomichi Arima,2 Makoto Yoshimitsu,3 Shin-Ichro Honda,1 Shinji Soeda11Department of Biochemistry, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan; 2Division of Hematology and Immunology, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan; 3Department of Hematology and Immunology, Kagoshima University Hospital, Kagoshima, JapanAbstract: Nanotechnology is the development of an engineered device at the atomic, molecular, and macromolecular level in the nanometer range. Advances in nanotechnology have proven beneficial in therapeutic fields such as drug-delivery and gene/protein delivery. Antigen delivery systems are important for inducing and modifying immune responses. In cellular immunity, cytotoxic T lymphocytes (CTLs are important in the host defense against tumors. Key to the development of CTL-inducible vaccines is the ability to deliver antigens to antigen-presenting cells efficiently and to induce the subsequent activation of T cell-mediated immunity without adjuvants, as they can induce excessive inflammation leading to systemic febrile disease. Since expression and cloning methods for tumor-associated antigens have been reported, cancer vaccines that induce effective cell immunity may be promising therapeutic candidates, but Th2 cells are undesirable for use in cancer immunotherapy. Peptide vaccines have immunological and economic advantages as cancer vaccines because CTL epitope peptides from tumor-associated antigens have high antigen-specificity. However, cancer vaccines have had limited effectiveness in clinical responses due to the ability of cancer cells to “escape” from cancer immunity and a low efficiency of antigen-specific CTL induction due to immunogenic-free synthetic peptides. In contrast, carbohydrate-decorated particles such as carbohydrate-coated liposomes with encapsulated antigens might be more suitable as

Phase-Separated Liposomes Enhance the Efficiency of Macromolecular Delivery to the Cellular Cytoplasm.

Science.gov (United States)

Imam, Zachary I; Kenyon, Laura E; Ashby, Grant; Nagib, Fatema; Mendicino, Morgan; Zhao, Chi; Gadok, Avinash K; Stachowiak, Jeanne C

2017-10-01

From viruses to organelles, fusion of biological membranes is used by diverse biological systems to deliver macromolecules across membrane barriers. Membrane fusion is also a potentially efficient mechanism for the delivery of macromolecular therapeutics to the cellular cytoplasm. However, a key shortcoming of existing fusogenic liposomal systems is that they are inefficient, requiring a high concentration of fusion-promoting lipids in order to cross cellular membrane barriers. Toward addressing this limitation, our experiments explore the extent to which membrane fusion can be amplified by using the process of lipid membrane phase separation to concentrate fusion-promoting lipids within distinct regions of the membrane surface. We used confocal fluorescence microscopy to investigate the integration of fusion-promoting lipids into a ternary lipid membrane system that separated into liquid-ordered and liquid-disordered membrane phases. Additionally, we quantified the impact of membrane phase separation on the efficiency with which liposomes transferred lipids and encapsulated macromolecules to cells, using a combination of confocal fluorescence imaging and flow cytometry. Here we report that concentrating fusion-promoting lipids within phase-separated lipid domains on the surfaces of liposomes significantly increases the efficiency of liposome fusion with model membranes and cells. In particular, membrane phase separation enhanced the delivery of lipids and model macromolecules to the cytoplasm of tumor cells by at least 4-fold in comparison to homogenous liposomes. Our findings demonstrate that phase separation can enhance membrane fusion by locally concentrating fusion-promoting lipids on the surface of liposomes. This work represents the first application of lipid membrane phase separation in the design of biomaterials-based delivery systems. Additionally, these results lay the ground work for developing fusogenic liposomes that are triggered by physical and

Nanoparticle Stabilized Liposomes for Acne Therapy

Science.gov (United States)

Fu, Victoria

Acne vulgaris is a common skin disease that affects over 40 million people in the United States alone. The main cause of acne vulgaris is Propionibacterium acnes (P. acnes), resides deep in the pores and follicles of the skin in order to feed on oil produced by the sebaceous glands. The liposome is a lipid based nanoparticle with numerous advantages over free drug molecules as an acne treatment alternative. Bare liposomes loaded with lauric acid (LipoLA) were found to show strong antimicrobial activity against P. acnes while generating minimal toxicity. However, the platform is limited by the spontaneous tendency of liposomes to fuse with each other. Attaching nanoparticles to the surface of liposomes can overcome this challenge by providing steric repulsion and reduce surface tension. Thus, carboxyl-functionalized gold nanoparticles (AuC) were attached to the surface of liposomes (AuC-liposomes) loaded with doxycycline, a general tetracycline antibiotic. These particles were found to have a diameter of 120 nm and a zeta potential of 20.0 mV. Both fluorescent and antimicrobial studies demonstrated that based on electrostatic interaction, negatively charged AuC attached to the liposome's positively charged surface and stabilized liposomes in a neutral pH environment (pH = 7.4). Upon entering the skin's acidic environment (pH = 4), AuC detached from the liposome's surface and liposomes could fuse with P. acnes residing in the pores. Furthermore, toxicity studies showed that AuC-liposomes did not induce any significant toxicity, while two of the leading over-the-counter therapies, benzoyl peroxide and salicylic acid, generated substantial skin irritation.

Biological activity of liposomal vanillin.

Science.gov (United States)

Castan, Leniher; Del Toro, Grisel; Fernández, Adolfo A; González, Manuel; Ortíz, Emilia; Lobo, Daliana

2013-06-01

This article presents a study of vanillin encapsulation inside multilamellar liposomes, with emphasis on the evaluation of antioxidant activity, the hemolytic effect, and the antisickling properties of these products. Egg phosphatidylcholine-cholesterol and egg phosphatidylcholine-cholesterol-1-O-decylglycerol liposomes were prepared by mechanical dispersion, all with vanillin included. Vesicles were characterized by determination of encapsulation efficiency and vanillin retention capacity. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The hemolytic effect of liposomes was also evaluated by spectrophotometry, as well as the antisickling activity by the Huck test using optical microscopy. Results showed that the lipid composition of liposomes did not significantly affect the encapsulation efficiency. Stable vesicles were obtained with a high retention percentage of vanillin. Liposomes exhibited a high capture of the DPPH radical compared to free vanillin and 1-O-decylglycerol (C10) in solution. Vesicles caused no significant hemolisys in normal erythrocytes, nor in those coming from patients with sickle cell anemia. Vanillin encapsulated in liposomes retained its antisickling activity, with a greater effect for C10-containing vesicles. Our results show that vanillin encapsulation in liposomes is a way to enhance the pharmacologic properties of this molecule using a suitable vehicle.

Near-infrared-fluorescence imaging of lymph nodes by using liposomally formulated indocyanine green derivatives.

Science.gov (United States)

Toyota, Taro; Fujito, Hiromichi; Suganami, Akiko; Ouchi, Tomoki; Ooishi, Aki; Aoki, Akira; Onoue, Kazutaka; Muraki, Yutaka; Madono, Tomoyuki; Fujinami, Masanori; Tamura, Yutaka; Hayashi, Hideki

2014-01-15

Liposomally formulated indocyanine green (LP-ICG) has drawn much attention as a highly sensitive near-infrared (NIR)-fluorescence probe for tumors or lymph nodes in vivo. We synthesized ICG derivatives tagged with alkyl chains (ICG-Cn), and we examined NIR-fluorescence imaging for lymph nodes in the lower extremities of mice by using liposomally formulated ICG-Cn (LP-ICG-Cn) as well as conventional liposomally formulated ICG (LP-ICG) and ICG. Analysis with a noninvasive preclinical NIR-fluorescence imaging system revealed that LP-ICG-Cn accumulates in only the popliteal lymph node 1h after injection into the footpad, whereas LP-ICG and ICG accumulate in the popliteal lymph node and other organs like the liver. This result indicates that LP-ICG-Cn is a useful NIR-fluorescence probe for noninvasive in vivo bioimaging, especially for the sentinel lymph node. Copyright © 2013 Elsevier Ltd. All rights reserved.

The pattern recognition molecule deleted in malignant brain tumors 1 (DMBT1) and synthetic mimics inhibit liposomal nucleic acid delivery

DEFF Research Database (Denmark)

Lund Hansen, Pernille; Blaich, Stephanie; End, Caroline

2011-01-01

Liposomal nucleic acid delivery is a preferred option for therapeutic settings. The cellular pattern recognition molecule DMBT1, secreted at high levels in various diseases, and synthetic mimics efficiently inhibit liposomal nucleic acid delivery to human cells. These findings may have relevance...

Liposome kinetics in infarcted canine myocardium

International Nuclear Information System (INIS)

Caride, V.J.; Twickler, J.; Zaret, B.L.

1984-01-01

To study the mechanisms and kinetics of liposome deposition in the region of the experimental myocardial infarction, the myocardial distribution of positive and negative liposomes was determined as a function of regional myocardial blood flow and time after administration. The study was performed in dogs at 1 and 24 h following experimental myocardial infarction. Twenty-four hours after coronary artery occlusion, the initial myocardial distribution of positive and negative liposomes (2 min) is directly proportional to regional myocardial blood flow. With time, there is reduction of the radiotracer associated with negative liposomes from all myocardial regions (p less than 0.01). In contrast, in areas of moderate and severe blood flow reduction, there is progressive accumulation of tracers entrapped or incorporated in positive liposomes. This increment becomes significant in 120 min (p less than 0.005). Similar findings are observed in studies performed 1 h after coronary artery occlusion. Dual-label liposomes [( 3 H]cholesterol and [99mTc]diethylenetriamine pentaacetic acid) were used to study the integrity of liposomes in normal and ischemic myocardium. Significant dissociation of the aqueous and lipid labels of positive liposomes is observed 1 h following coronary artery occlusion. In the 24-h myocardial infarction model, dissociation of the aqueous and lipid labels in ischemic myocardium is also observed. This phenomenon is more pronounced with positive than with negative liposomes (p less than 0.02)

Combination immunotherapy with radiation and CpG-based tumor vaccination for the eradication of radio- and immuno-resistant lung carcinoma cells

International Nuclear Information System (INIS)

Chamoto, Kenji; Wakita, Daiko; Takeshima, Tsuguhide

2009-01-01

Unmethylated cytosine-phosphorothioate-guanine containing oligodeoxynucleotides (CpG-ODN) is known as a ligand of toll-like receptor 9 (TLR9), which selectively activates type-1 immunity. We have already reported that the vaccination of tumor-bearing mice with liposome-CpG coencapsulated with model-tumor antigen, ovalbumin (OVA) (CpG+OVA-liposome) caused complete cure of the mice bearing OVA-expressing EG-7 lymphoma cells. However, the same therapy was not effective to eradicate Lewis lung carcinoma (LLC)-OVA-carcinoma. To overcome the refractoriness of LLC-OVA, we tried the combination therapy of radiation with CpG-based tumor vaccination. When LLC-OVA-carcinoma intradermally (i.d.) injected into C57BL/6 became palpable (7-8 mm), the mice were irradiated twice with a dose of 14 Gy at intervals of 24 h. After the second radiation, CpG+OVA-liposome was i.d. administered near the draining lymph node (DLN) of the tumor mass. The tumor growth of mice treated with radiation plus CpG+OVA-liposome was greatly inhibited and approximately 60% of mice treated were completely cured. Moreover, the combined therapy with radiation and CpG+OVA-liposome allowed the augmented induction of OVA-tetramer + LLC-OVA-specific cytotoxic T lymphocyte (CTL) in DLN of tumor-bearing mice. These results indicate that the combined therapy of radiation with CpG-based tumor vaccine is a useful strategy to eradicate intractable carcinoma. (author)

Liposomal membrane disruption by means of miniaturized dielectric-barrier discharge in air: liposome characterization

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Svarnas, P.; Asimakoulas, L.; Katsafadou, M.; Pachis, K.; Kostazos, N.; Antimisiaris, S. G.

2017-08-01

The increasing interest of the plasma community in the application of atmospheric-pressure cold plasmas to bio-specimen treatment has led to the creation of the emerging field of plasma biomedicine. Accordingly, plasma setups based on dielectric-barrier discharges have already been widely tested for the inactivation of various cells. Most of these systems refer to the plasma jet concept where noble gases penetrate atmospheric air and are subjected to the influence of high electric fields, thus forming guided streamers. Following the original works of our group where liposomal membranes were proposed as models for studying the interaction between plasma jets and cells, we present herein a study on liposomal membrane disruption by means of miniaturized dielectric-barrier discharge running in atmospheric air. Liposomal membranes of various lipid compositions, lamellarities, and sizes are treated at different times. It is shown that the dielectric-barrier discharge of low mean power leads to efficient liposomal membrane disruption. The latter is achieved in a controllable manner and depends on liposome properties. Additionally, it is clearly demonstrated that liposomal membrane disruption takes place even after plasma extinction, i.e. during post-treatment, resembling thus an ‘apoptosis’ effect, which is well known today mainly for cell membranes. Thus, the adoption of the present concept would be beneficial for tailoring studies on plasma-treated cell-mimics. Finally, the liposome treatment is discussed with respect to possible physicochemical mechanisms and potential discharge modification due to the various compositions of the liquid electrode.

Preparation and Evaluation of Oxaliplatin Thermosensitive Liposomes with Rapid Release and High Stability.

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Chunying Zeng

Full Text Available Oxaliplatin (OXP was reported to show low anti-tumor activity when used alone and to display side effects; this low activity was attributed to high partitioning to erythrocytes and low accumulation in tumors. Thermosensitive liposomes (TSL were considered able to specifically deliver drugs to heated tumors and to resolve the OXP distribution problem. Regretfully, TSL encapsulating doxorubicin did not demonstrate significant improvement in progression-free survival. Drug release below 41°C and significant leakage were considered major reasons for the failure. The purpose of this study was to acquire OXP TSL with rapid release at the triggered temperature and high stability at body temperature and at storage temperatures. A small quantity of poloxamer 188 was introduced into the TSL formulation to stabilize the encapsulated drug. It was shown that the addition of poloxamer 188 had no influence on the TSL characteristics. More than 90% of OXP was released within 10 min at 42°C, and less than 15% was released within 60 min at temperatures below 39°C. TSL were stable at 37°C for 96 h and at 4°C for 6 months. The anti-tumor activity of TSL at the dose of 2.5 mg/kg was certified to be equal to those of OXP injection and non-thermosensitive liposomes (NTSL at the dose of 5 mg/kg, and significant improvement of tumor inhibition was observed in TSL compared with injection and NTSL at the same dose. It was also shown from the histological transmutation of tumors that TSL had stronger anti-tumor activity. Therefore, it could be concluded that TSL composed of a proper amount of poloxamer had rapid release and high stability, and OXP TSL would be anticipated to exert prominent anti-tumor activity in the clinic.

Cytoprotective and enhanced anti-inflammatory activities of liposomal piroxicam formulation in lipopolysaccharide-stimulated RAW 264.7 macrophages

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Chiong HS

2013-03-01

Full Text Available Hoe Siong Chiong,1 Yoke Keong Yong,1 Zuraini Ahmad,1 Mohd Roslan Sulaiman,1 Zainul Amiruddin Zakaria,1 Kah Hay Yuen,2 Muhammad Nazrul Hakim1,31Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia; 2School of Pharmaceutical Sciences, Universiti Sains Malaysia, Gelugor, Malaysia; 3Sports Academy, Universiti Putra Malaysia, Serdang, MalaysiaBackground: Liposomal drug delivery systems, a promising lipid-based nanoparticle technology, have been known to play significant roles in improving the safety and efficacy of an encapsulated drug.Methods: Liposomes, prepared using an optimized proliposome method, were used in the present work to encapsulate piroxicam, a widely prescribed nonsteroidal anti-inflammatory drug. The cytotoxic effects as well as the in vitro efficacy in regulation of inflammatory responses by free-form piroxicam and liposome-encapsulated piroxicam were evaluated using a lipopolysaccharide-sensitive macrophage cell line, RAW 264.7.Results: Cells treated with liposome-encapsulated piroxicam demonstrated higher cell viabilities than those treated with free-form piroxicam. In addition, the liposomal piroxicam formulation resulted in statistically stronger inhibition of pro-inflammatory mediators (ie, nitric oxide, tumor necrosis factor-α, interleukin-1β, and prostaglandin E2 than piroxicam at an equivalent dose. The liposome-encapsulated piroxicam also caused statistically significant production of interleukin-10, an anti-inflammatory cytokine.Conclusion: This study affirms the potential of a liposomal piroxicam formulation in reducing cytotoxicity and enhancing anti-inflammatory responses in vitro.Keywords: liposomes, nitric oxide, cytokines, prostaglandin E2, interleukin-1β, piroxicam

Hybrid liposomes showing enhanced accumulation in tumors as theranostic agents in the orthotopic graft model mouse of colorectal cancer.

Science.gov (United States)

Okumura, Masaki; Ichihara, Hideaki; Matsumoto, Yoko

2018-11-01

Hybrid liposomes (HLs) can be prepared by simply sonicating a mixture of vesicular and micellar molecules in a buffer solution. This study aimed to elucidate the therapeutic effects and ability of HLs to detect (diagnosis) cancer in an orthotopic graft mouse model of colorectal cancer with HCT116 cells for the use of HLs as theranostic agents. In the absence of a chemotherapeutic drug, HLs exhibited therapeutic effects by inhibiting the growth of HCT116 colorectal cancer cells in vitro, possibly through an increase in apoptosis. Intravenously administered HLs also caused a remarkable reduction in the relative cecum weight in an orthotopic graft mouse model of colorectal cancer. A decrease in tumor size in the cecal sections was confirmed by histological analysis using HE staining. TUNEL staining indicated an induction of apoptosis in HCT116 cells in the orthotopic graft mouse model of colorectal cancer. For the detection (diagnosis) of colorectal cancer by HLs, the accumulation of HLs encapsulating a fluorescent probe (ICG) was observed in HCT116 cells in the in vivo colorectal cancer model following intravenous administration. These data indicate that HLs can accumulate in tumor cells in the cecum of the orthotopic graft mouse model of colorectal cancer for a prolonged period of time, and inhibit the growth of HCT116 cells.

Gd(III)-DOTA-modified sonosensitive liposomes for ultrasound-triggered release and MR imaging

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Jung, Suk Hyun; Na, Kyunga; Lee, Seul A.; Cho, Sun Hang; Seong, Hasoo; Shin, Byung Cheol

2012-08-01

Ultrasound-sensitive (sonosensitive) liposomes for tumor targeting have been studied in order to increase the antitumor efficacy of drugs and decrease the associated severe side effects. Liposomal contrast agents having Gd(III) are known as a nano-contrast agent system for the efficient and selective delivery of contrast agents into pathological sites. The objective of this study was to prepare Gd(III)-DOTA-modified sonosensitive liposomes (GdSL), which could deliver a model drug, doxorubicin (DOX), to a specific site and, at the same time, be capable of magnetic resonance (MR) imaging. The GdSL was prepared using synthesized Gd(III)-DOTA-1,2-distearoyl- sn-glycero-3-phosphoethanolamine lipid. Sonosensitivity of GdSL to 20-kHz ultrasound induced 33% to 40% of DOX release. The relaxivities ( r 1) of GdSL were 6.6 to 7.8 mM-1 s-1, which were higher than that of MR-bester®. Intracellular uptake properties of GdSL were evaluated according to the intensity of ultrasound. Intracellular uptake of DOX for ultrasound-triggered GdSL was higher than that for non-ultrasound-triggered GdSL. The results of our study suggest that the paramagnetic and sonosensitive liposomes, GdSL, may provide a versatile platform for molecular imaging and targeted drug delivery.

Octanol-assisted liposome assembly on chip

NARCIS (Netherlands)

Deshpande, S.R.; Caspi, Y.; Meijering, A.E.C.; Dekker, C.

2016-01-01

Liposomes are versatile supramolecular assemblies widely used in basic and applied sciences. Here we present a novel microfluidics-based method, octanol-assisted liposome assembly (OLA), to form monodisperse, cell-sized (5–20 μm), unilamellar liposomes with excellent encapsulation efficiency. Akin

Systemic study of solvent-assisted active loading of gambogic acid into liposomes and its formulation optimization for improved delivery.

Science.gov (United States)

Tang, Wei-Lun; Tang, Wei-Hsin; Szeitz, Andras; Kulkarni, Jayesh; Cullis, Pieter; Li, Shyh-Dar

2018-06-01

The solvent-assisted active loading technology (SALT) was developed for encapsulating a water insoluble weak base into the liposomal core in the presence of 5% DMSO. In this study, we further examined the effect of various water miscible solvents in promoting active loading of other types of drugs into liposomes. To achieve complete drug loading, the amount of solvent required must result in complete drug solubilization and membrane permeability enhancement, but must be below the threshold that induces liposomal aggregation or causes bilayer disruption. We then used the SALT to load gambogic acid (GA, an insoluble model drug that shows promising anticancer effect) into liposomes, and optimized the loading gradient and lipid composition to prepare a stable formulation (Lipo-GA) that displayed >95% drug retention after incubation with serum for 3 days. Lipo-GA contained a high drug-to-lipid ratio of 1/5 (w/w) with a mean particle size of ∼75 nm. It also displayed a prolonged circulation half-life (1.5 h vs. 18.6 h) and enhanced antitumor activity in two syngeneic mice models compared to free GA. Particularly, complete tumor regression was observed in the EMT6 tumor model for 14 d with significant inhibition of multiple oncogenes including HIF-1α, VEGF-A, STAT3, BCL-2, and NF-κB. Copyright © 2018 Elsevier Ltd. All rights reserved.

Correlation between radioactivity and chemotherapeutics of the 111In-VNB-liposome in pharmacokinetics and biodistribution in rats

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Tsai TH

2012-02-01

Full Text Available Wen-Chuan Lee1,*, Chih-Hsien Chang2,3,*, Chih-Min Huang1, Yu-Tse Wu1, Liang-Cheng Chen2, Chung-Li Ho2, Tsui-Jung Chang2, Te-Wei Lee2, Tung-Hu Tsai1,41Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, 2Division of Isotope Application, Institute of Nuclear Energy Research, Taoyuan, 3Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, 4Department of Education and Research, Taipei City Hospital, Taipei, Taiwan*These authors contributed equally to this workBackground: The combination of a radioisotope with a chemotherapeutic agent in a liposomal carrier (ie, Indium-111-labeled polyethylene glycol pegylated liposomal vinorelbine, [111In-VNB-liposome] has been reported to show better therapeutic efficiency in tumor growth suppression. Nevertheless, the challenge remains as to whether this therapeutic effect is attributable to the combination of a radioisotope with chemotherapeutics. The goal of this study was to investigate the pharmacokinetics, biodistribution, and correlation of Indium-111 radioactivity and vinorelbine concentration in the 111In-VNB-liposome.Methods: The VNB-liposome and 111In-VNB-liposome were administered to rats. Blood, liver, and spleen tissue were collected to determine the distribution profile of the 111In-VNB-liposome. A liquid chromatography tandem mass spectrometry system and gamma counter were used to analyze the concentration of vinorelbine and radioactivity of Indium-111.Results: High uptake of the 111In-VNB-liposome in the liver and spleen demonstrated the properties of a nanosized drug delivery system. Linear regression showed a good correlation (r = 0.97 between Indium-111 radioactivity and vinorelbine concentration in the plasma of rats administered the 111In-VNB-liposome.Conclusion: A significant positive correlation between the pharmacokinetics and biodistribution of 111Indium radioactivity and vinorelbine in blood, spleen

Comparison of the adverse event profiles of conventional and liposomal formulations of doxorubicin using the FDA adverse event reporting system.

Science.gov (United States)

Fukuda, Akiho; Tahara, Kohei; Hane, Yuuki; Matsui, Toshinobu; Sasaoka, Sayaka; Hatahira, Haruna; Motooka, Yumi; Hasegawa, Shiori; Naganuma, Misa; Abe, Junko; Nakao, Satoshi; Takeuchi, Hirofumi; Nakamura, Mitsuhiro

2017-01-01

Doxorubicin (DOX) is an anthracycline widely used for the treatment of solid and hematological tumors. The aim of this study was to assess the adverse event profiles of conventional DOX and liposomal DOX. This is the first study to evaluate the effect of a liposomal formulation of DOX using spontaneous reporting system (SRS) databases. The SRS used was the US Food and Drug Administration Adverse Event Reporting System (FAERS). This study relied on definitions of preferred terms provided by the Medical Dictionary for Regulatory Activities (MedDRA) and the standardized MedDRA Queries (SMQ) database. We also calculated the reporting odds ratios (RORs) of suspected drugs (conventional DOX; PEGylated-liposome DOX; non-PEGylated-liposome DOX). The FAERS database contained 7,561,254 reports from January 2004 to December 2015. The number of reported AE cases for conventional DOX, PEGylated-liposome DOX, and non-PEGylated-liposome DOX was 5039, 3780, and 349, respectively. Conventional DOX and liposomal DOX have potential risks of causing myelosuppression, cardiotoxicity, alopecia, nausea, and vomiting, among other effects. The RORs (95% CI) from SMQ for haematopoietic leucopenia associated with conventional DOX, PEGylated-liposome DOX, and non-PEGylated-liposome DOX were 12.75 (11.89-13.68), 6.43 (5.81-7.13), and 14.73 (11.42-18.99), respectively. Liposomal DOX formulations were associated with lower RORs with regard to myelosuppression, cardiotoxicity, and alopecia than the conventional DOX was. The RORs (95% CI) for palmar-plantar erythrodysesthesia (PPE) associated with conventional DOX, PEGylated-liposome DOX, and non-PEGylated-liposome DOX were 6.56 (4.74-9.07), 64.77 (56.84-73.80), and 28.76 (15.77-52.45), respectively. This study is the first to evaluate the relationship between DOX liposomal formulations and their adverse event profiles. The results indicate that careful observation for PPE is recommended with the use of liposomal DOX, especially PEGylated-liposome

Comparison of the adverse event profiles of conventional and liposomal formulations of doxorubicin using the FDA adverse event reporting system.

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Akiho Fukuda

Full Text Available Doxorubicin (DOX is an anthracycline widely used for the treatment of solid and hematological tumors. The aim of this study was to assess the adverse event profiles of conventional DOX and liposomal DOX. This is the first study to evaluate the effect of a liposomal formulation of DOX using spontaneous reporting system (SRS databases. The SRS used was the US Food and Drug Administration Adverse Event Reporting System (FAERS. This study relied on definitions of preferred terms provided by the Medical Dictionary for Regulatory Activities (MedDRA and the standardized MedDRA Queries (SMQ database. We also calculated the reporting odds ratios (RORs of suspected drugs (conventional DOX; PEGylated-liposome DOX; non-PEGylated-liposome DOX. The FAERS database contained 7,561,254 reports from January 2004 to December 2015. The number of reported AE cases for conventional DOX, PEGylated-liposome DOX, and non-PEGylated-liposome DOX was 5039, 3780, and 349, respectively. Conventional DOX and liposomal DOX have potential risks of causing myelosuppression, cardiotoxicity, alopecia, nausea, and vomiting, among other effects. The RORs (95% CI from SMQ for haematopoietic leucopenia associated with conventional DOX, PEGylated-liposome DOX, and non-PEGylated-liposome DOX were 12.75 (11.89-13.68, 6.43 (5.81-7.13, and 14.73 (11.42-18.99, respectively. Liposomal DOX formulations were associated with lower RORs with regard to myelosuppression, cardiotoxicity, and alopecia than the conventional DOX was. The RORs (95% CI for palmar-plantar erythrodysesthesia (PPE associated with conventional DOX, PEGylated-liposome DOX, and non-PEGylated-liposome DOX were 6.56 (4.74-9.07, 64.77 (56.84-73.80, and 28.76 (15.77-52.45, respectively. This study is the first to evaluate the relationship between DOX liposomal formulations and their adverse event profiles. The results indicate that careful observation for PPE is recommended with the use of liposomal DOX, especially PEGylated-liposome

Preparation and investigation of Ulex europaeus agglutinin I-conjugated liposomes as potential oral vaccine carriers.

Science.gov (United States)

Li, KeXin; Chen, DaWei; Zhao, XiuLi; Hu, HaiYang; Yang, ChunRong; Pang, DaHai

2011-11-01

We prepared and optimized Ulex europaeus agglutinin I (UEAI)-modified Bovine serum albumin (BSA)-encapsulating liposomes (UEAI-LIP) as oral vaccine carriers and examined the feasibility of inducing systemic and mucosal immune responses by oral administration of UEAILIP. The prepared systems were characterized in vitro for their average size, zeta potential, encapsulation efficiency (EE%) and conjugation efficiency (CE%). In vitro release studies indicated that the presence of UEAI around the optimized liposomes was able to prevent a burst release of loaded BSA and provide sustained release of the encapsulated protein. In vivo immune-stimulating results in KM mice showed that BSA given intramuscularly generated systemic response only but both systemic and mucosal immune responses could be induced simultaneously in the groups in which BSA-loaded liposomes (LIP) and UEAI-LIP were administered intragastrically. Furthermore, the modification of UEAI on the surface of liposomes could further enhance the IgA and IgG levels obviously. In conclusion, this study demonstrated the high potential of lectin-modified liposomes containing the antigen as carriers for oral vaccine.

A targeted liposome delivery system for combretastatin A4: formulation optimization through drug loading and in vitro release studies.

Science.gov (United States)

Nallamothu, Ramakrishna; Wood, George C; Kiani, Mohammad F; Moore, Bob M; Horton, Frank P; Thoma, Laura A

2006-01-01

Efficient liposomal therapeutics require high drug loading and low leakage. The objective of this study is to develop a targeted liposome delivery system for combretastatin A4 (CA4), a novel antivascular agent, with high loading and stable drug encapsulation. Liposomes composed of hydrogenated soybean phosphatidylcholine (HSPC), cholesterol, and distearoyl phosphoethanolamine-PEG-2000 conjugate (DSPE-PEG) were prepared by the lipid film hydration and extrusion process. Cyclic arginine-glycine-aspartic acid (RGD) peptides with affinity for alphav beta3-integrins overexpressed on tumor vascular endothelial cells were coupled to the distal end of polyethylene glycol (PEG) on the liposomes sterically stabilized with PEG (non-targeted liposomes; LCLs). Effect of lipid concentration, drug-to-lipid ratio, cholesterol, and DSPE-PEG content in the formulation on CA4 loading and its release from the liposomes was studied. Total liposomal CA4 levels obtained increased with increasing lipid concentration in the formulation. As the drug-to-lipid ratio increased from 10:100 to 20:100, total drug in the liposome formulation increased from 1.05+/-0.11 mg/mL to 1.55+/-0.13 mg/mL, respectively. When the drug-to-lipid ratio was further raised to 40:100, the total drug in liposome formulation did not increase, but the amount of free drug increased significantly, thereby decreasing the percent of entrapped drug. Increasing cholesterol content in the formulation decreased drug loading. In vitro drug leakage from the liposomes increased with increase in drug-to-lipid ratio or DSPE-PEG content in the formulation; whereas increasing cholesterol content of the formulation up to 30 mol-percent, decreased CA4 leakage from the liposomes. Ligand coupling to the liposome surface increased drug leakage as a function of ligand density. Optimized liposome formulation with 100 mM lipid concentration, 20:100 drug-to-lipid ratio, 30 mol-percent cholesterol, 4 mol-percent DSPE-PEG, and 1 mol

Evaluation of Extrusion Technique for Nanosizing Liposomes

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Sandy Gim Ming Ong

2016-12-01

Full Text Available The aim of the present study was to study the efficiency of different techniques used for nanosizing liposomes. Further, the aim was also to evaluate the effect of process parameters of extrusion techniques used for nanosizing liposomes on the size and size distribution of the resultant liposomes. To compare the efficiency of different nanosizing techniques, the following techniques were used to nanosize the liposomes: extrusion, ultrasonication, freeze-thaw sonication (FTS, sonication and homogenization. The extrusion technique was found to be the most efficient, followed by FTS, ultrasonication, sonication and homogenization. The extruder used in the present study was fabricated using readily available and relatively inexpensive apparatus. Process parameters were varied in extrusion technique to study their effect on the size and size distribution of extruded liposomes. The results obtained indicated that increase in the flow rate of the extrusion process decreased the size of extruded liposomes however the size homogeneity was negatively impacted. Furthermore, the liposome size and distribution was found to decline with decreasing membrane pore size. It was found that by extruding through a filter with a pore size of 0.2 µm and above, the liposomes produced were smaller than the pore size, whereas, when they were extruded through a filter with a pore size of less than 0.2 µm the resultant liposomes were slightly bigger than the nominal pore size. Besides that, increment of extrusion temperature above transition temperature of the pro-liposome had no effect on the size and size distribution of the extruded liposomes. In conclusion, the extrusion technique was reproducible and effective among all the methods evaluated. Furthermore, processing parameters used in extrusion technique would affect the size and size distribution of liposomes. Therefore, the process parameters need to be optimized to obtain a desirable size range and homogeneity

Use of autoantigen-loaded phosphatidylserine-liposomes to arrest autoimmunity in type 1 diabetes.

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Irma Pujol-Autonell

Full Text Available The development of new therapies to induce self-tolerance has been an important medical health challenge in type 1 diabetes. An ideal immunotherapy should inhibit the autoimmune attack, avoid systemic side effects and allow β-cell regeneration. Based on the immunomodulatory effects of apoptosis, we hypothesized that apoptotic mimicry can help to restore tolerance lost in autoimmune diabetes.To generate a synthetic antigen-specific immunotherapy based on apoptosis features to specifically reestablish tolerance to β-cells in type 1 diabetes.A central event on the surface of apoptotic cells is the exposure of phosphatidylserine, which provides the main signal for efferocytosis. Therefore, phosphatidylserine-liposomes loaded with insulin peptides were generated to simulate apoptotic cells recognition by antigen presenting cells. The effect of antigen-specific phosphatidylserine-liposomes in the reestablishment of peripheral tolerance was assessed in NOD mice, the spontaneous model of autoimmune diabetes. MHC class II-peptide tetramers were used to analyze the T cell specific response after treatment with phosphatidylserine-liposomes loaded with peptides.We have shown that phosphatidylserine-liposomes loaded with insulin peptides induce tolerogenic dendritic cells and impair autoreactive T cell proliferation. When administered to NOD mice, liposome signal was detected in the pancreas and draining lymph nodes. This immunotherapy arrests the autoimmune aggression, reduces the severity of insulitis and prevents type 1 diabetes by apoptotic mimicry. MHC class II tetramer analysis showed that peptide-loaded phosphatidylserine-liposomes expand antigen-specific CD4+ T cells in vivo. The administration of phosphatidylserine-free liposomes emphasizes the importance of phosphatidylserine in the modulation of antigen-specific CD4+ T cell expansion.We conclude that this innovative immunotherapy based on the use of liposomes constitutes a promising strategy for

Liposomal Formulation of Retinoids Designed for Enzyme Triggered Release

DEFF Research Database (Denmark)

Pedersen, Palle Jacob; Adolph, Sidsel Kramshøj; Subramanian, Arun Kumar

2010-01-01

The design of retinoid phospholipid prodrugs is described based on molecular dynamics simulations and cytotoxicity studies of synthetic retinoid esters. The prodrugs are degradable by secretory phospholipase A(2) IIA and have potential in liposomal drug delivery targeting tumors. We have synthesi...... displayed IC50 values in the range of 3-19 mu M toward HT-29 and Colo205 colon cancer cells in the presence of phospholipase A(2), while no significant cell death was observed in the absence of the enzyme....

Octanol-assisted liposome assembly on chip

Science.gov (United States)

Deshpande, Siddharth; Caspi, Yaron; Meijering, Anna E. C.; Dekker, Cees

2016-01-01

Liposomes are versatile supramolecular assemblies widely used in basic and applied sciences. Here we present a novel microfluidics-based method, octanol-assisted liposome assembly (OLA), to form monodisperse, cell-sized (5-20 μm), unilamellar liposomes with excellent encapsulation efficiency. Akin to bubble blowing, an inner aqueous phase and a surrounding lipid-carrying 1-octanol phase is pinched off by outer fluid streams. Such hydrodynamic flow focusing results in double-emulsion droplets that spontaneously develop a side-connected 1-octanol pocket. Owing to interfacial energy minimization, the pocket splits off to yield fully assembled solvent-free liposomes within minutes. This solves the long-standing fundamental problem of prolonged presence of residual oil in the liposome bilayer. We demonstrate the unilamellarity of liposomes with functional α-haemolysin protein pores in the membrane and validate the biocompatibility by inner leaflet localization of bacterial divisome proteins (FtsZ and ZipA). OLA offers a versatile platform for future analytical tools, delivery systems, nanoreactors and synthetic cells.

Therapeutic efficacy of boron neutron capture therapy mediated by boron-rich liposomes for oral cancer in the hamster cheek pouch model

Energy Technology Data Exchange (ETDEWEB)

Heber, Elisa M. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Hawthorne, M. Frederick [Univ. of Missouri, Columbia, MO (United States). International Inst. of Nano and Molecular Medicine; Kueffer, Peter J. [Univ. of Missouri, Columbia, MO (United States). International Inst. of Nano and Molecular Medicine; Garabalino, Marcela A. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Thorp, Silvia I. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Pozzi, Emiliano C. C. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Hughes, Andrea Monti [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Maitz, Charles A. [Univ. of Missouri, Columbia, MO (United States). International Inst. of Nano and Molecular Medicine; Jalisatgi, Satish S. [Univ. of Missouri, Columbia, MO (United States). International Inst. of Nano and Molecular Medicine; Nigg, David W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Curotto, Paula [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Trivillin, Verónica A. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Schwint, Amanda E. [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina)

2014-11-11

Unilamellar liposomes formulated with an equimolar mixture of cholesterol and 1,2-distearoyl-sn-glycero-3-phosphocholine, incorporating K[nido-7-CH₃(CH₂)15-7,8-C₂B₉H₁₁] in the lipid bilayer, and encapsulating Na₃[1-(2’-B₁₀-H₉)-2-NH₃B₁₀H₈] were prepared by probe sonication and investigated in vivo. Microwave assisted digestion followed by inductively coupled plasma-optical emission spectroscopy was utilized to determine the biodistribution of boron in various tissues following either a single tail vein injection or two identical injections (separated by 24 hours) of the liposomal suspension in BALB/c mice bearing EMT6 mammary adenocarcinomas in their right flank. Double-injection protocols resulted in a boron content in the tumor exceeding 50 µg of boron per gram of tissue for 48 to 72 hours subsequent to the initial injection while tumor:blood boron ratios were more ideal from 54 hours (1.9:1) to 96 hours (5.7:1) subsequent to the initial injection. Tumor bearing mice were given a double-injection of liposomes containing the ¹⁰B-enriched analogs of the aforementioned agents and subjected to a 30 minute irradiation by thermal neutrons with a flux of 8.8 x 10⁸ (±7%) neutrons/cm² s integrated over the energy range of 0.0 – 0.414 eV. Significant tumor response for a single BNCT treatment was demonstrated by growth curves versus a control group. Vastly diminished tumor growth was witnessed at 14 days (186% increase versus 1551% in controls) in mice that were given a second injection/radiation treatment 7 days after the first. Mice given a one hour neutron irradiation following the double-injection of liposomes had a similar response (169% increase at 14 days) suggesting that neutron fluence is the limiting factor towards BNCT efficacy in this study.

Lymphatic uptake and biodistribution of liposomes after subcutaneous injection - IV. Fate of liposomes in regional lymph nodes

NARCIS (Netherlands)

Oussoren, C; Scherphof, G; van der Want, JJ; van Rooijen, N; Storm, G

1998-01-01

The ability of clodronate-containing liposomes to deplete lymph nodes of macrophages was used as a tool to investigate the fate of liposomes in regional lymph nodes after subcutaneous (s.c.) administration. Reduced lymph node localization of liposomes in macrophage-depleted lymph nodes confirmed

Liposome-mediated transfer of IL-1 receptor antagonist gene to dispersed islet cells does not prevent recurrence of disease in syngeneically transplanted NOD mice

DEFF Research Database (Denmark)

Saldeen, J; Sandler, S; Bendtzen, K

2000-01-01

transplanted non-obese diabetic (NOD) mice. NOD mouse islet cells were transfected using liposome-mediated gene transfer with a human IL-1ra cDNA construct and transplanted two days later to prediabetic NOD mice. Graft infiltration and destruction were monitored three, five and eight days posttransplantation...... by histology and determination of insulin and cytokine content. IL-1ra gene transfer resulted in transient expression of IL-1ra protein in islet cells in vitro as assessed by ELISA and of IL-1ra mRNA in transplanted islets as revealed by RT-PCR. However, both control and IL-1ra transfected NOD grafts exhibited......IL-1beta is cytotoxic to pancreatic beta-cells in vitro but its role in the vicinity of beta-cells in vivo is unknown. We explored whether liposome-mediated transfer of the interleukin 1 receptor antagonist (IL-1ra) gene to islet cells might prevent recurrence of disease in syngeneically...

Stimuli-Responsive Liposomes for Controlled Drug Delivery

KAUST Repository

Li, Wengang

2014-09-01

Liposomes are promising drug delivery vesicles due to their biodegradibility, large volume and biocompatibility towards both hydrophilic and hydrophobic drugs. They suffer, however, from poor stability which limits their use in controlled delivery applications. Herein, a novel method was devised for modification of liposomes with small molecules, polymers or nanoparticles to afford stimuli responsive systems that release on demand and stay relatively stable in the absence of the trigger.. This dissertation discusses thermosensitive, pH sensitive, light sensitive and magnetically triggered liposomes that have been prepared for controlled drug delivery application. RAFT polymerization was utilized for the preparation of thermosensitive liposomes (Cholesterol-PNIPAm) and acid-labile liposomes (DOPE-PAA). With low Mw Cholesterol-PNIPAm, the thermosensitive liposomes proved to be effective for controlled release and decreased the cytotoxicity of PNIPAm by eliciting the polymer doses. By crosslinking the DOPE-PAA on liposome surface with acid-labile diamine linkers, DOPE-PAA liposomes were verified to be sensitive at low pH. The effects of polymer structures (linear or hyperbranched) have also been studied for the stability and release properties of liposomes. Finally, a dual-responsive Au@SPIO embedded liposome hybrid (ALHs) was prepared with light-induced “on-and-off” function by photo-thermal process (visible light) and instant release properties triggered by alternating magnetic field, respectively. The ALH system would be further applied into the cellular imaging field as MRI contrast agent.

Applications of lipid nanocarriers for solid tumors therapy: literature review; Aplicacoes das nanoparticulas lipidicas no tratamento de tumores solidos: revisao de literatura

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Lidiane Correia de; Souza, Leonardo Gomes; Marreto, Ricardo Neves; Lima, Eliana Martins; Taveira, Stephania Fleury [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Farmacia; Taveira, Eliseu Jose Fleury, E-mail: stephaniafleury@gmail.com [Hospital Erasto Gaertner, Curitiba, PR (Brazil). Oncologia Clinica

2012-07-01

Introduction: Lipid nanocarriers are systems used to target drugs to its site of action and have attracted attention of the scientific community because they are biocompatible and biodegradable. These systems can target drugs to solid tumors, providing sustained drug release in the site of action, thus increasing the utility of the antineoplastic chemotherapy. Objective: To review the available literature on in vivo experiments with lipid nanocarriers containing cytotoxic drugs for solid tumors treatment. Method: A search study was carried out in Pubmed{sup R} database from 2007 to 2011, with subject descriptors: liposomes, lipid nanoparticles, cancer and in vivo, with the boolean operator 'and' among them, in English. Results: 1,595 papers related to the use of liposomes and 77 related to lipid nanoparticles were found. Few studies reported in vivo experiments with lipid nanoparticles (28 papers) compared to liposomes (472 papers), since liposomes were developed two decades before lipid nanoparticles. Four liposomal medicines have already been approved and are used in the clinic while only one medicine containing lipid nanoparticles is in phase I of clinical studies. Conclusion: The number of papers related to the use of nanotechnology for cancer treatment is increasing rapidly, making important to know the different kinds of nanocarriers and, especially, those which are already used in the clinic. There are only few clinical studies on lipid nanocarriers; however, these systems present an enormous potential to improve the clinical practice in oncology. (author)

Sea cucumber saponin liposomes ameliorate obesity-induced inflammation and insulin resistance in high-fat-diet-fed mice.

Science.gov (United States)

Chen, Cheng; Han, Xiuqing; Dong, Ping; Li, Zhaojie; Yanagita, Teruyoshi; Xue, Changhu; Zhang, Tiantian; Wang, Yuming

2018-02-21

Obesity has become a worldwide concern in recent years, which may cause many diseases. Much attention has been paid to food components that are considered to be beneficial in preventing chronic metabolic diseases. The present study was conducted to investigate the effects of sea cucumber saponin liposomes on certain metabolic markers associated with obesity. C57/BL6 mice fed with high-fat diet were treated with different forms of sea cucumber saponins for eight weeks. The results showed that liposomes exhibited better effects on anti-obesity and anti-hyperlipidemia activities than the common form of sea cucumber saponins. Sea cucumber saponin liposomes could also effectively alleviate adipose tissue inflammation by reducing pro-inflammatory cytokine releases and macrophage infiltration. Moreover, sea cucumber saponin liposomes improved insulin resistance by altering the uptake and utilization of glucose. Taken together, our results indicated that the intake of sea cucumber saponin liposomes might be able to ameliorate obesity-induced inflammation and insulin resistance.

磷脂组成对马钱子碱隐形脂质体药剂学性质与抗肿瘤作用的影响%Effect of phospholipid composition on pharmaceutical properties and anti-tumor activity of stealth liposomes containing brucine

Institute of Scientific and Technical Information of China (English)

陈明磊; 陈军; 侯婷; 方芸; 孙巍巍; 胡蓉蓉; 蔡宝昌

2011-01-01

Objective: To compare the pharmaceutical properties and the anti-tumor activities of three kinds of stealth liposomes prepared with different phospholipid composition containing brucine.Method: Stealth liposomes with different phospholipids composition, such as soybean phosphatidycholine (SPC) ,hydrogenated soybean phosphatidylcholine (HSPC) and the complex of SPC and HSPC, were prepared by ammonium sulfate transmembrane gradient method.Pharmaceutical properties such as shape, encapsulation efficiency and size of three stealth liposomes were compared intensively.Anti-tumor activity of SPC, HSPC and novel stealth liposomes composed of both SPC and HSPC were compared by established mouse liver cancer H22 model.Meanwhile, the mice body weight and immune organ weight were also compared.Result: The encapsulation efficiency of novel, SPC and HSPC stealth liposomes were 77.7％ ,64.8％and 74.8％ ,respectively.The mean diameters of them were less than 100 nm.The tumor inhibition rate of novel,HSPC and SPC stealth liposomes were 57.88％ ,49.15％, 23.37％ ,respectively.The mice body weight,thymns gland index of three stealth liposomes group and spleen index of novel stealth liposomes group had no significant difference with the negative group while SPC and HSPC stealth liposomes group increased the spleen index.Conclusion: Phospholipids composition is the key factor which determines the antitumor activity of brucine-loaded stealth liposomes.%目的:比较3种不同磷脂组成的马钱子碱隐形脂质体的药剂学性质以及抗肿瘤作用.方法:采用硫酸铵梯度法和隐形脂质体技术制备马钱子碱氢化大豆磷脂(hydrogenated soybean phoaphatidylcholine,HSPC)、大豆磷脂(soybean phosphati-dylcholine,SPC)、复合磷脂(SPC-HSPC 3:1)隐形脂质体,考察其形态学、粒径、包封率等药剂学性质.建立小鼠移植性肝癌H22模型,测定3�

Liposomal TriCurin, A Synergistic Combination of Curcumin, Epicatechin Gallate and Resveratrol, Repolarizes Tumor-Associated Microglia/Macrophages, and Eliminates Glioblastoma (GBM) and GBM Stem Cells.

Science.gov (United States)

Mukherjee, Sumit; Baidoo, Juliet N E; Sampat, Samay; Mancuso, Andrew; David, Lovena; Cohen, Leah S; Zhou, Shuiqin; Banerjee, Probal

2018-01-18

Glioblastoma (GBM) is a deadly brain tumor with a current mean survival of 12-15 months. Despite being a potent anti-cancer agent, the turmeric ingredient curcumin (C) has limited anti-tumor efficacy in vivo due to its low bioavailability. We have reported earlier a strategy involving the use two other polyphenols, epicatechin gallate (E) from green tea and resveratrol (R) from red grapes at a unique, synergistic molar ratio with C (C:E:R: 4:1:12.5, termed TriCurin) to achieve superior potency against HPV+ tumors than C alone at C:E:R (μM): 32:8:100 (termed 32 μM+ TriCurin). We have now prepared liposomal TriCurin (TrLp) and demonstrated that TrLp boosts activated p53 in cultured GL261 mouse GBM cells to trigger apoptosis of GBM and GBM stem cells in vitro. TrLp administration into mice yielded a stable plasma concentration of 210 nM C for 60 min, which, though sub-lethal for cultured GL261 cells, was able to cause repolarization of M2-like tumor (GBM)-associated microglia/macrophages to the tumoricidal M1-like phenotype and intra-GBM recruitment of activated natural killer cells. The intratumor presence of such tumoricidal immune cells was associated with concomitant suppression of tumor-load, and apoptosis of GBM and GBM stem cells. Thus, TrLp is a potential onco-immunotherapeutic agent against GBM tumors.

Liposomal TriCurin, A Synergistic Combination of Curcumin, Epicatechin Gallate and Resveratrol, Repolarizes Tumor-Associated Microglia/Macrophages, and Eliminates Glioblastoma (GBM and GBM Stem Cells

Directory of Open Access Journals (Sweden)

Sumit Mukherjee

2018-01-01

Full Text Available Glioblastoma (GBM is a deadly brain tumor with a current mean survival of 12–15 months. Despite being a potent anti-cancer agent, the turmeric ingredient curcumin (C has limited anti-tumor efficacy in vivo due to its low bioavailability. We have reported earlier a strategy involving the use two other polyphenols, epicatechin gallate (E from green tea and resveratrol (R from red grapes at a unique, synergistic molar ratio with C (C:E:R: 4:1:12.5, termed TriCurin to achieve superior potency against HPV+ tumors than C alone at C:E:R (μM: 32:8:100 (termed 32 μM+ TriCurin. We have now prepared liposomal TriCurin (TrLp and demonstrated that TrLp boosts activated p53 in cultured GL261 mouse GBM cells to trigger apoptosis of GBM and GBM stem cells in vitro. TrLp administration into mice yielded a stable plasma concentration of 210 nM C for 60 min, which, though sub-lethal for cultured GL261 cells, was able to cause repolarization of M2-like tumor (GBM-associated microglia/macrophages to the tumoricidal M1-like phenotype and intra-GBM recruitment of activated natural killer cells. The intratumor presence of such tumoricidal immune cells was associated with concomitant suppression of tumor-load, and apoptosis of GBM and GBM stem cells. Thus, TrLp is a potential onco-immunotherapeutic agent against GBM tumors.

EXPERIMENTAL LIPOSOMAL VIRAL VACCINE SAFETY

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Romanova OA

2016-12-01

Full Text Available Introduction. With the transport links development there is rather important issue respiratory viral infections spread, especially influenza. The only method controlling influenza is vaccination. Search and development effective and safe vaccines is important. Material and methods. In base SO "Mechnikov Institute Microbiology and Immunology National Ukrainian Academy Medical Sciences" in the scientific theme "Developing new approaches to creating viral vaccines and study specific activity depending of type and degree component`s modification" was created several experimental influenza vaccine with subsequent component`s modification for selecting the most optimal pattern of safety and immunogenicity. In assessing the influenza vaccine safety is using a few criteria, including, reactivity, as measured by the frequency of local and systemic adverse (negative effects, which due to its introduction, and for lipid content drugs, ability to influence oxidation processes. At present study phase was determined: a systemic reaction and local reaction of delayed-type hypersensitivity (foot pad swelling assay;b lipids and proteins peroxidation processes after administration officinal and experimental vaccines (content protein’s carbonyl groups, lipid’s hydroperoxides, activity of glutathione-peroxidase.Study objects were trivalent seasonal influenza vaccine, "Vaxigrip" (Sanofi Pasteur, S.A., France, "Inflexal V" (Biotech Ltd. Berne, Switzerland and experimental vaccine samples. Highest immunogenicity vaccines had undergone improvements and modifications using adjuvant systems and acylation influenza proteins. Liposomes 2 – the experimental influenza vaccine with a liposome negative charge and antigenic composition like split vaccines "Vaksihryp". Liposomes 2.1 - the adjuvantexperimental influenza vaccine with modifications liposomal components (etoniy and chlorophyllipt molecules embedded in liposomal membrane. Liposomes 2.2 - the adjuvant

Preparation and ocular pharmacokinetics of ganciclovir liposomes.

Science.gov (United States)

Shen, Yan; Tu, Jiasheng

2007-12-07

Ophthalmic liposomes of ganciclovir (GCV) were prepared by the reverse phase evaporation method, and their ocular pharmacokinetics in albino rabbits were compared with those obtained after dosing with GCV solution. The in vitro transcorneal permeability of GCV liposomes was found to be 3.9-fold higher than that of the solution. After in vivo instillation in albino rabbits, no difference was found in the precorneal elimination rate of GCV from liposome vs solution dosing. The aqueous humor concentration-time profiles of both liposomes and solution were well described by 2-compartmental pharmacokinetics with first-order absorption. The area under the curve of the aqueous humor concentration-time profiles of GCV liposomes was found to be 1.7-fold higher than that of GCV solution. Ocular tissue distribution of GCV from liposomes was 2 to 10 times higher in the sclera, cornea, iris, lens, and vitreous humor when compared with those observed after solution dosing. These results suggested that liposomes may hold some promise in ocular GCV delivery.

Enhanced antitumor efficacy of folate-linked liposomal doxorubicin with TGF-β type I receptor inhibitor

International Nuclear Information System (INIS)

Taniguchi, Yukimi; Kawano, Kumi; Minowa, Takuya; Shimojo, Yuki; Maitani, Yoshie; Sugino, Takashi

2010-01-01

Tumor cell targeting of drug carriers is a promising strategy and uses the attachment of various ligands to enhance the therapeutic potential of chemotherapy agents. Folic acid is a high-affinity ligand for folate receptor, which is a functional tumor-specific receptor. The transforming growth factor (TGF)-β type I receptor (TβR-I) inhibitor A-83-01 was expected to enhance the accumulation of nanocarriers in tumors by changing the microvascular environment. To enhance the therapeutic effect of folate-linked liposomal doxorubicin (F-SL), we co-administrated F-SL with A-83-01. Intraperitoneally injected A-83-01-induced alterations in the cancer-associated neovasculature were examined by magnetic resonance imaging (MRI) and histological analysis. The targeting efficacy of single intravenous injections of F-SL combined with A-83-01 was evaluated by measurement of the biodistribution and the antitumor effect in mice bearing murine lung carcinoma M109. A-83-01 temporarily changed the tumor vasculature around 3 h post injection. A-83-01 induced 1.7-fold higher drug accumulation of F-SL in the tumor than liposome alone at 24 h post injection. Moreover F-SL co-administrated with A-83-01 showed significantly greater antitumor activity than F-SL alone. This study shows that co-administration of TβR-I inhibitor will open a new strategy for the use of folate receptor (FR)-targeting nanocarriers for cancer treatment. (author)

Kinetic Targeting of pegylated liposomal Doxorubicin: a new Approach to Reduce Toxicity during Chemotherapy (CARL-trial

Directory of Open Access Journals (Sweden)

Jansen Martin

2011-08-01

Full Text Available Abstract Background The therapeutic success of chemotherapeutic agents is often limited by severe adverse effects. To reduce toxicity of these drugs, nanoscale particle-based drug delivery systems (DDS are used. DDS accumulate to some extent in tumor tissues, but only a very small portion of a given dose reaches this target. Accumulation of DDS in tumor tissues is supposed to be much faster than in certain other tissues in which side effects occur ("Kinetic Targeting". Once saturation in tumor tissue is achieved, most of the administered DDS still circulate in the plasma. The extracorporeal elimination of these circulating nanoparticles would probably reduce toxicity. Methods For the CARL-trial (Controlled Application and Removal of Liposomal chemotherapeutics, pegylated liposomal doxorubicin (PLD was used as chemotherapeutic agent and double filtration plasmapheresis (DFPP was performed for extracorporeal elimination of liposomes. PLD was given as 40 mg/m2 every 3 weeks in combination with vinorelbine 2 × 25 mg/m2 (neoadjuvant treatment of breast cancer, 12 patients, or as 40 mg/m2 every 4 weeks (recurrent ovarian cancer, 3 patients. Primary endpoints were the efficiency and safety profile of DFPP, and secondary endpoints were side effects and tumor response. Results DFPP eliminated ~62% of circulating PLD, corresponding to ~45% of the total dose (n = 57 cycles. AUC of doxorubicin was reduced by 50%. No leakage of doxorubicin was detected during elimination, and no relevant DFPP-related side effects occurred. Reduction in tumor size > 30% occurred in 10/12 (neoadjuvant and in 1/3 patients (recurrent. Only five grade 2 events and one grade 3 event (mucositis, neutropenia or leucopenia and a single palmar-plantar erythrodysesthesia grade 2 were reported. Conclusion Extracorporeal elimination of PLD by DFPP is safe and efficient. CARL can diminish the main dose-limiting side effects of PLD, and probably many different DDS alike. Trial

Coadministration of doxorubicin and etoposide loaded in camel milk phospholipids liposomes showed increased antitumor activity in a murine model

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Maswadeh HM

2015-04-01

Full Text Available Hamzah M Maswadeh,1 Ahmed N Aljarbou,1 Mohammed S Alorainy,2 Arshad H Rahmani,3 Masood A Khan3 1Department of Pharmaceutics, College of Pharmacy, 2Department of Pharmacology and Therapeutics, College of Medicine, 3College of Applied Medical Sciences, Qassim University, Buraydah, Kingdom of Saudi Arabia Abstract: Small unilamellar vesicles from camel milk phospholipids (CML mixture or from 1,2 dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC were prepared, and anticancer drugs doxorubicin (Dox or etoposide (ETP were loaded. Liposomal formulations were used against fibrosarcoma in a murine model. Results showed a very high percentage of Dox encapsulation (~98% in liposomes (Lip prepared from CML-Lip or DPPC-Lip, whereas the percentage of encapsulations of ETP was on the lower side, 22% of CML-Lip and 18% for DPPC-Lip. Differential scanning calorimetry curves show that Dox enhances the lamellar formation in CML-Lip, whereas ETP enhances the nonlamellar formation. Differential scanning calorimetry curves also showed that the presence of Dox and ETP together into DPPC-Lip produced the interdigitation effect. The in vivo anticancer activity of liposomal formulations of Dox or ETP or a combination of both was assessed against benzopyrene (BAP-induced fibrosarcoma in a murine model. Tumor-bearing mice treated with a combination of Dox and ETP loaded into CML-Lip showed increased survival and reduced tumor growth compared to other groups, including the combination of Dox and ETP in DPPC-Lip. Fibrosarcoma-bearing mice treated with a combination of free (Dox + ETP showed much higher tumor growth compared to those groups treated with CML-Lip-(Dox + ETP or DPPC-Lip-(Dox + ETP. Immunohistochemical study was also performed to show the expression of tumor-suppressor PTEN, and it was found that the tumor tissues from the group of mice treated with a combination of free (Dox + ETP showed greater loss of cytoplasmic PTEN than tumor tissues obtained from the

Design of multifunctional magnetic iron oxide nanoparticles/mitoxantrone-loaded liposomes for both magnetic resonance imaging and targeted cancer therapy.

Science.gov (United States)

He, Yingna; Zhang, Linhua; Zhu, Dunwan; Song, Cunxian

2014-01-01

Tumor-targeting multifunctional liposomes simultaneously loaded with magnetic iron oxide nanoparticles (MIONs) as a magnetic resonance imaging (MRI) contrast agent and anticancer drug, mitoxantrone (Mit), were developed for targeted cancer therapy and ultrasensitive MRI. The gonadorelin-functionalized MION/Mit-loaded liposome (Mit-GML) showed significantly increased uptake in luteinizing hormone-releasing hormone (LHRH) receptor overexpressing MCF-7 (Michigan Cancer Foundation-7) breast cancer cells over a gonadorelin-free MION/Mit-loaded liposome (Mit-ML) control, as well as in an LHRH receptor low-expressing Sloan-Kettering HER2 3+ Ovarian Cancer (SK-OV-3) cell control, thereby leading to high cytotoxicity against the MCF-7 human breast tumor cell line. The Mit-GML formulation was more effective and less toxic than equimolar doses of free Mit or Mit-ML in the treatment of LHRH receptors overexpressing MCF-7 breast cancer xenografts in mice. Furthermore, the Mit-GML demonstrated much higher T2 enhancement than did Mit-ML controls in vivo. Collectively, the study indicates that the integrated diagnostic and therapeutic design of Mit-GML nanomedicine potentially allows for the image-guided, target-specific treatment of cancer.

Enhancing siRNA-based cancer therapy using a new pH-responsive activatable cell-penetrating peptide-modified liposomal system

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Xiang B

2017-03-01

Full Text Available Bai Xiang,1,* Xue-Li Jia,1,* Jin-Long Qi,2 Li-Ping Yang,1 Wei-Hong Sun,1 Xiao Yan,1 Shao-Kun Yang,1 De-Ying Cao,1 Qing Du,1 Xian-Rong Qi3 1Department of Pharmaceutics, School of Pharmaceutical Sciences, 2Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei, 3School of Pharmaceutical Sciences, Peking University, Beijing, China *These authors contributed equally to this work Abstract: As a potent therapeutic agent, small interfering RNA (siRNA has been exploited to silence critical genes involved in tumor initiation and progression. However, development of a desirable delivery system is required to overcome the unfavorable properties of siRNA such as its high degradability, molecular size, and negative charge to help increase its accumulation in tumor tissues and promote efficient cellular uptake and endosomal/lysosomal escape of the nucleic acids. In this study, we developed a new activatable cell-penetrating peptide (ACPP that is responsive to an acidic tumor microenvironment, which was then used to modify the surfaces of siRNA-loaded liposomes. The ACPP is composed of a cell-penetrating peptide (CPP, an acid-labile linker (hydrazone, and a polyanionic domain, including glutamic acid and histidine. In the systemic circulation (pH 7.4, the surface polycationic moieties of the CPP (polyarginine are “shielded” by the intramolecular electrostatic interaction of the inhibitory domain. When exposed to a lower pH, a common property of solid tumors, the ACPP undergoes acid-catalyzed breakage at the hydrazone site, and the consequent protonation of histidine residues promotes detachment of the inhibitory peptide. Subsequently, the unshielded CPP would facilitate the cellular membrane penetration and efficient endosomal/lysosomal evasion of liposomal siRNA. A series of investigations demonstrated that once exposed to an acidic pH, the ACPP-modified liposomes showed elevated cellular uptake, downregulated expression of polo

Partially polymerized liposomes: stable against leakage yet capable of instantaneous release for remote controlled drug delivery

Energy Technology Data Exchange (ETDEWEB)

Qin Guoting; Li Zheng; Xia Rongmin; Li Feng; O' Neill, Brian E; Li, King C [Department of Radiology, The Methodist Hospital Research Institute, Houston, TX 77030 (United States); Goodwin, Jessica T; Khant, Htet A; Chiu, Wah, E-mail: zli@tmhs.org, E-mail: kli@tmhs.org [National Center for Macromolecular Imaging, Baylor College of Medicine, Houston, TX 77030 (United States)

2011-04-15

A critical issue for current liposomal carriers in clinical applications is their leakage of the encapsulated drugs that are cytotoxic to non-target tissues. We have developed partially polymerized liposomes composed of polydiacetylene lipids and saturated lipids. Cross-linking of the diacetylene lipids prevents the drug leakage even at 40 deg. C for days. These inactivated drug carriers are non-cytotoxic. Significantly, more than 70% of the encapsulated drug can be instantaneously released by a laser that matches the plasmon resonance of the tethered gold nanoparticles on the liposomes, and the therapeutic effect was observed in cancer cells. The remote activation feature of this novel drug delivery system allows for precise temporal and spatial control of drug release.

Effects of a phospholipase A2 inhibitor on uptake and toxicity of liposomes containing plant phosphatidylinositol

International Nuclear Information System (INIS)

Jett, M.; Alving, C.R.

1986-01-01

Plant phosphatidylinositol (PI) has been shown by us to have a direct cytotoxic effect on cultured tumor cells but not on normal cells. Synthetic PI containing 14 C-linoleic acid in the sn-2 position, also showed the same pattern of selective cytotoxicity. When the metabolic fate of synthetic PI was examined with tumor cells, the radioactivity which no longer occurred as PI, was found as either products of phospholipase A 2 (93%, free fatty acids and phosphatidylcholine) or phospholipase C (7%, diglycerides). Uptake of liposomal PI was directly correlated with cytotoxicity. They tested a variety of inhibitors to see the effect on uptake and/or cytotoxicity of plant PI. General metabolic inhibitors such as metrizamide or sodium azide did not alter cellular uptake of the plant PI liposomes. Inhibitors of lipoxygenase formation, such as indomethacin, also did not alter the uptake or cytotoxicity induced by plant PI. Quinacrine, an inhibitor of phospholipase A 2 , decreased the uptake of the PI containing liposomes to 50% of that seen in the presence or absence of any other inhibitor. Although quinacrine is itself toxic to cells, at low concentrations of quinacrine, plant PI did not show the same degree of cytotoxicity as in the absence of quinacrine. These data are compatible with the hypothesis that plant PI exerts cytotoxicity by serving as a substrate for phospholipase A 2

Antibacterial activity of contact lenses bearing surface-immobilized layers of intact liposomes loaded with levofloxacin.

Science.gov (United States)

Danion, Anne; Arsenault, Isabelle; Vermette, Patrick

2007-09-01

In vitro methods to evaluate antibacterial activity were used with contact lenses bearing levofloxacin-loaded liposomes developed for the prevention and treatment of bacterial ocular infections such as keratitis. Levofloxacin was incorporated into liposomes before these intact liposomes were immobilized onto the surfaces of soft contact lenses using a multilayer immobilization strategy. The release of levofloxacin from contact lenses bearing 2, 5, and 10 layers of liposomes into a saline buffer at 37 degrees C was monitored by fluorescence. The levofloxacin release, as a function of time, was described by a mechanism taking into account two independent first-order kinetic models. The total release of levofloxacin from the contact lenses was completed within 6 days. The release of levofloxacin from contact lenses bearing 10 layers of liposomes and subsequently soaked overnight in a levofloxacin solution was also studied and compare to that of dried contact lenses without any chemical modification rehydrated in a levofloxacin solution. The antibacterial activity of the liposome-coated contact lenses against Staphylococcus aureus was evaluated by measuring (i) the diameters of the inhibition zone on an agar plate and (ii) the optical density using a broth assay. The liposome-coated lenses showed an antibacterial activity both on agar and in broth following 24 h. When initial bacteria inocula were equal or below 10(6) CFU/mL, all the bacteria were inhibited within 2 h. When using initial bacteria inocula of 10(8) CFU/mL, an initial burst release provided by soaking the liposomal lenses was required for the first hours to inhibit bacteria growth. (c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.

Plasmonic Nanobubbles Rapidly Detect and Destroy Drug-Resistant Tumors

Science.gov (United States)

Lukianova-Hleb, Ekaterina Y.; Ren, Xiaoyang; Townley, Debra; Wu, Xiangwei; Kupferman, Michael E.; Lapotko, Dmitri O.

2012-01-01

The resistance of residual cancer cells after oncological resection to adjuvant chemoradiotherapies results in both high recurrence rates and high non-specific tissue toxicity, thus preventing the successful treatment of such cancers as head and neck squamous cell carcinoma (HNSCC). The patients' survival rate and quality of life therefore depend upon the efficacy, selectivity and low non-specific toxicity of the adjuvant treatment. We report a novel, theranostic in vivo technology that unites both the acoustic diagnostics and guided intracellular delivery of anti-tumor drug (liposome-encapsulated doxorubicin, Doxil) in one rapid process, namely a pulsed laser-activated plasmonic nanobubble (PNB). HNSCC-bearing mice were treated with gold nanoparticle conjugates, Doxil, and single near-infrared laser pulses of low energy. Tumor-specific clusters of gold nanoparticles (solid gold spheres) converted the optical pulses into localized PNBs. The acoustic signals of the PNB detected the tumor with high specificity and sensitivity. The mechanical impact of the PNB, co-localized with Doxil liposomes, selectively ejected the drug into the cytoplasm of cancer cells. Cancer cell-specific generation of PNBs and their intracellular co-localization with Doxil improved the in vivo therapeutic efficacy from 5-7% for administration of only Doxil or PNBs alone to 90% thus demonstrating the synergistic therapeutic effect of the PNB-based intracellular drug release. This mechanism also reduced the non-specific toxicity of Doxil below a detectable level and the treatment time to less than one minute. Thus PNBs combine highly sensitive diagnosis, overcome drug resistance and minimize non-specific toxicity in a single rapid theranostic procedure for intra-operative treatment. PMID:23139725

The co-delivery of a low-dose P-glycoprotein inhibitor with doxorubicin sterically stabilized liposomes against breast cancer with low P-glycoprotein expression

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Gao W

2014-07-01

Full Text Available Wei Gao,1 Zhiqiang Lin,1 Meiwan Chen,2 Xiucong Yang,1 Zheng Cui,1 Xiaofei Zhang,1 Lan Yuan,3 Qiang Zhang11State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 2State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, 3Medical and Healthy Analytical Center, Peking University, Beijing, People's Republic of China Introduction: P-glycoprotein (P-gp inhibitors are usually used to treat tumors that overexpress P-gps. However, most common types of breast cancers, such as Luminal A, are low-P-gp expressing, at least during the initial phases of treatment. Therefore, it would be interesting to know if P-gp inhibitors are still useful in treating low-P-gp-expressing tumors. Methods: In the study reported here, the human breast-cancer cell line MCF-7, chosen as a model of Luminal A, was found to be low-P-gp expressing. We designed a novel doxorubicin (DOX sterically stabilized liposome system co-loaded with the low-dose P-gp inhibitor cyclosporine A (CsA (DOX/CsA/SSL. Results: The co-delivery system showed good size uniformity, high encapsulation efficiency, and a desirable release profile. The cell-uptake and cytotoxicity studies demonstrated that CsA could significantly enhance the intracellular accumulation and toxicity of free DOX and the liposomal DOX in MCF-7 cells. The confocal microscopy and in vivo imaging study confirmed the intracellular and in vivo targeting effect of DOX/CsA/SSL, respectively. Finally, the in vivo study proved that DOX/CsA/SSL could achieve significantly better antitumor effect against MCF-7 tumor than controls, without inducing obvious systemic toxicity. Conclusion: This study demonstrated that the co-delivery of a low-dose P-gp inhibitor and liposomal DOX could improve the therapy of low-P-gp-expressing cancer, which is of significance in clinical tumor therapy. Keywords: liposomes, low

Phospholipid liposomes functionalized by protein

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Glukhova, O. E.; Savostyanov, G. V.; Grishina, O. A.

2015-03-01

Finding new ways to deliver neurotrophic drugs to the brain in newborns is one of the contemporary problems of medicine and pharmaceutical industry. Modern researches in this field indicate the promising prospects of supramolecular transport systems for targeted drug delivery to the brain which can overcome the blood-brain barrier (BBB). Thus, the solution of this problem is actual not only for medicine, but also for society as a whole because it determines the health of future generations. Phospholipid liposomes due to combination of lipo- and hydrophilic properties are considered as the main future objects in medicine for drug delivery through the BBB as well as increasing their bioavailability and toxicity. Liposomes functionalized by various proteins were used as transport systems for ease of liposomes use. Designing of modification oligosaccharide of liposomes surface is promising in the last decade because it enables the delivery of liposomes to specific receptor of human cells by selecting ligand and it is widely used in pharmacology for the treatment of several diseases. The purpose of this work is creation of a coarse-grained model of bilayer of phospholipid liposomes, functionalized by specific to the structural elements of the BBB proteins, as well as prediction of the most favorable orientation and position of the molecules in the generated complex by methods of molecular docking for the formation of the structure. Investigation of activity of the ligand molecule to protein receptor of human cells by the methods of molecular dynamics was carried out.

The role of cavitation in liposome formation.

Science.gov (United States)

Richardson, Eric S; Pitt, William G; Woodbury, Dixon J

2007-12-15

Liposome size is a vital parameter of many quantitative biophysical studies. Sonication, or exposure to ultrasound, is used widely to manufacture artificial liposomes, yet little is known about the mechanism by which liposomes are affected by ultrasound. Cavitation, or the oscillation of small gas bubbles in a pressure-varying field, has been shown to be responsible for many biophysical effects of ultrasound on cells. In this study, we correlate the presence and type of cavitation with a decrease in liposome size. Aqueous lipid suspensions surrounding a hydrophone were exposed to various intensities of ultrasound and hydrostatic pressures before measuring their size distribution with dynamic light scattering. As expected, increasing ultrasound intensity at atmospheric pressure decreased the average liposome diameter. The presence of collapse cavitation was manifested in the acoustic spectrum at high ultrasonic intensities. Increasing hydrostatic pressure was shown to inhibit the presence of collapse cavitation. Collapse cavitation, however, did not correlate with decreases in liposome size, as changes in size still occurred when collapse cavitation was inhibited either by lowering ultrasound intensity or by increasing static pressure. We propose a mechanism whereby stable cavitation, another type of cavitation present in sound fields, causes fluid shearing of liposomes and reduction of liposome size. A mathematical model was developed based on the Rayleigh-Plesset equation of bubble dynamics and principles of acoustic microstreaming to estimate the shear field magnitude around an oscillating bubble. This model predicts the ultrasound intensities and pressures needed to create shear fields sufficient to cause liposome size change, and correlates well with our experimental data.

Applications of lipid nanocarriers for solid tumors therapy: literature review

International Nuclear Information System (INIS)

Oliveira, Lidiane Correia de; Souza, Leonardo Gomes; Marreto, Ricardo Neves; Lima, Eliana Martins; Taveira, Stephania Fleury; Taveira, Eliseu Jose Fleury

2012-01-01

Introduction: Lipid nanocarriers are systems used to target drugs to its site of action and have attracted attention of the scientific community because they are biocompatible and biodegradable. These systems can target drugs to solid tumors, providing sustained drug release in the site of action, thus increasing the utility of the antineoplastic chemotherapy. Objective: To review the available literature on in vivo experiments with lipid nanocarriers containing cytotoxic drugs for solid tumors treatment. Method: A search study was carried out in Pubmed R database from 2007 to 2011, with subject descriptors: liposomes, lipid nanoparticles, cancer and in vivo, with the boolean operator 'and' among them, in English. Results: 1,595 papers related to the use of liposomes and 77 related to lipid nanoparticles were found. Few studies reported in vivo experiments with lipid nanoparticles (28 papers) compared to liposomes (472 papers), since liposomes were developed two decades before lipid nanoparticles. Four liposomal medicines have already been approved and are used in the clinic while only one medicine containing lipid nanoparticles is in phase I of clinical studies. Conclusion: The number of papers related to the use of nanotechnology for cancer treatment is increasing rapidly, making important to know the different kinds of nanocarriers and, especially, those which are already used in the clinic. There are only few clinical studies on lipid nanocarriers; however, these systems present an enormous potential to improve the clinical practice in oncology. (author)

Liposomal preparation by supercritical fluids technology | Zhong ...

African Journals Online (AJOL)

African Journal of Biotechnology ... technology (SCF) has been utilized in liposomal preparation because of its friendliness, nontoxicity to the environment and its possibility to achieve solvent-free liposomes and industrial-scale of liposome production under the conditions of current good manufacturing practice (cGMP).

Liposomal clodronate selectively eliminates microglia from primary astrocyte cultures

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Kumamaru Hiromi

2012-05-01

Full Text Available Abstract Background There is increasing interest in astrocyte biology because astrocytes have been demonstrated to play prominent roles in physiological and pathological conditions of the central nervous system, including neuroinflammation. To understand astrocyte biology, primary astrocyte cultures are most commonly used because of the direct accessibility of astrocytes in this system. However, this advantage can be hindered by microglial contamination. Although several authors have warned regarding microglial contamination in this system, complete microglial elimination has never been achieved. Methods The number and proliferative potential of contaminating microglia in primary astrocyte cultures were quantitatively assessed by immunocytologic and flow cytometric analyses. To examine the utility of clodronate for microglial elimination, primary astrocyte cultures or MG-5 cells were exposed to liposomal or free clodronate, and then immunocytologic, flow cytometric, and gene expression analyses were performed. The gene expression profiles of microglia-eliminated and microglia-contaminated cultures were compared after interleukin-6 (IL-6 stimulation. Results The percentage of contaminating microglia exceeded 15% and continued to increase because of their high proliferative activity in conventional primary astrocyte cultures. These contaminating microglia were selectively eliminated low concentration of liposomal clodronate. Although primary microglia and MG-5 cells were killed by both liposomal and free clodronate, free clodronate significantly affected the viability of astrocytes. In contrast, liposomal clodronate selectively eliminated microglia without affecting the viability, proliferation or activation of astrocytes. The efficacy of liposomal clodronate was much higher than that of previously reported methods used for decreasing microglial contamination. Furthermore, we observed rapid tumor necrosis factor-α and IL-1b gene induction in

Liposomal Bupivacaine Injection Technique in Total Knee Arthroplasty.

Science.gov (United States)

Meneghini, R Michael; Bagsby, Deren; Ireland, Philip H; Ziemba-Davis, Mary; Lovro, Luke R

2017-01-01

Liposomal bupivacaine has gained popularity for pain control after total knee arthroplasty (TKA), yet its true efficacy remains unproven. We compared the efficacy of two different periarticular injection (PAI) techniques for liposomal bupivacaine with a conventional PAI control group. This retrospective cohort study compared consecutive patients undergoing TKA with a manufacturer-recommended, optimized injection technique for liposomal bupivacaine, a traditional injection technique for liposomal bupivacaine, and a conventional PAI of ropivacaine, morphine, and epinephrine. The optimized technique utilized a smaller gauge needle and more injection sites. Self-reported pain scores, rescue opioids, and side effects were compared. There were 41 patients in the liposomal bupivacaine optimized injection group, 60 in the liposomal bupivacaine traditional injection group, and 184 in the conventional PAI control group. PAI liposomal bupivacaine delivered via manufacturer-recommended technique offered no benefit over PAI ropivacaine, morphine, and epinephrine. Mean pain scores and the proportions reporting no or mild pain, time to first opioid, and amount of opioids consumed were not better with PAI liposomal bupivacaine compared with PAI ropivacaine, morphine, and epinephrine. The use of the manufacturer-recommended technique for PAI of liposomal bupivacaine does not offer benefit over a conventional, less expensive PAI during TKA. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Photophysical studies of zinc phthalocyanine and chloroaluminum phthalocyanine incorporated into liposomes in the presence of additives

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S.M.T. Nunes

2004-02-01

Full Text Available The photophysical properties of zinc phthalocyanine (ZnPC and chloroaluminum phthalocyanine (AlPHCl incorporated into liposomes of dimyristoyl phosphatidylcholine in the presence and absence of additives such as cholesterol or cardiolipin were studied by time-resolved fluorescence, laser flash photolysis and steady-state techniques. The absorbance of the drugs changed linearly with drug concentration, at least up to 5.0 µM in homogeneous and heterogeneous media, indicating that aggregation did not occur in these media within this concentration range. The incorporation of the drugs into liposomes increases the dimerization constant by one order of magnitude (for ZnPC, 3.6 x 10(4 to 1.0 x 10(5 M-1 and for AlPHCl, 3.7 x 10(4 to 1.5 x 10(5 M-1, but this feature dose does not rule out the use of this carrier, since the incorporation of these hydrophobic drugs into liposomes permits their systemic administration. Probe location in biological membranes and predominant positions of the phthalocyanines in liposomes were inferred on the basis of their fluorescence and triplet state properties. Both phthalocyanines are preferentially distributed in the internal regions of the liposome bilayer. The additives affect the distribution of these drugs within the liposomes, a fact that controls their delivery when both are used in a biological medium, retarding their release. The addition of the additives to the liposomes increases the internalization of phthalocyanines. The interaction of the drugs with a plasma protein, bovine serum albumin, was examined quantitatively by the fluorescence technique. The results show that when the drugs were incorporated into small unilamellar liposomes, the association with albumin was enhanced when compared with organic media, a fact that should increase the selectivity of tumor targeting by these phthalocyanines (for ZnPC, 0.71 x 10(6 to 1.30 x 10(7 M-1 and for AlPHCl, 4.86 x 10(7 to 3.10 x 10(8 M-1.

Structural properties of liposomes from digital holographic microscopy

Science.gov (United States)

Di Maio, Isabelle L.; Carl, Daniel; Langehanenberg, Patrik; Valenzuela, Stella M.; Battle, Andrew R.; Al Khazaaly, Sabah; Killingsworth, Murray; Kemper, Bjorn; von Bally, Gert; Martin, Donald K.

2006-01-01

We have constructed liposomes from L alpha Phosphatidylcholine (PC) lipids, which are biomimetic lipids similar to those present in the membranes of mammalian cells. We propose an advance in the use of liposomes, such as for drug delivery, to incorporate into the liposomal membranes transport proteins that have been extracted from the lipid membranes of mammalian cells. In this paper, we describe the usage of a novel optical microscope to characterize the nanomechanical properties of these liposomes. We have applied the technique of digital holographic microscopy, using an instrument recently developed at the University of Münster, Germany. This system enabled us to measure quantitatively the structural changes in liposomes. We have investigated the deformations of these biomimetic lipids comprising these liposomes by applying osmotic stresses, in order to gain insight into the membrane environment prior to incorporation of cloned membrane transport proteins. This control of the nanomechanical properties is important in the stresses transmitted to mechanosensitive ion channels that we have incorporated into the liposomal membranes. These liposomes provide transporting vesicles that respond to mechanical stresses, such as those that occur during implantation.

Modulating the Tumor Microenvironment to Enhance Tumor Nanomedicine Delivery

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Bo Zhang

2017-12-01

Full Text Available Nanomedicines including liposomes, micelles, and nanoparticles based on the enhanced permeability and retention (EPR effect have become the mainstream for tumor treatment owing to their superiority over conventional anticancer agents. Advanced design of nanomedicine including active targeting nanomedicine, tumor-responsive nanomedicine, and optimization of physicochemical properties to enable highly effective delivery of nanomedicine to tumors has further improved their therapeutic benefits. However, these strategies still could not conquer the delivery barriers of a tumor microenvironment such as heterogeneous blood flow, dense extracellular matrix, abundant stroma cells, and high interstitial fluid pressure, which severely impaired vascular transport of nanomedicines, hindered their effective extravasation, and impeded their interstitial transport to realize uniform distribution inside tumors. Therefore, modulation of tumor microenvironment has now emerged as an important strategy to improve nanomedicine delivery to tumors. Here, we review the existing strategies and approaches for tumor microenvironment modulation to improve tumor perfusion for helping more nanomedicines to reach the tumor site, to facilitate nanomedicine extravasation for enhancing transvascular transport, and to improve interstitial transport for optimizing the distribution of nanomedicines. These strategies may provide an avenue for the development of new combination chemotherapeutic regimens and reassessment of previously suboptimal agents.

Modulating the Tumor Microenvironment to Enhance Tumor Nanomedicine Delivery

Science.gov (United States)

Zhang, Bo; Hu, Yu; Pang, Zhiqing

2017-01-01

Nanomedicines including liposomes, micelles, and nanoparticles based on the enhanced permeability and retention (EPR) effect have become the mainstream for tumor treatment owing to their superiority over conventional anticancer agents. Advanced design of nanomedicine including active targeting nanomedicine, tumor-responsive nanomedicine, and optimization of physicochemical properties to enable highly effective delivery of nanomedicine to tumors has further improved their therapeutic benefits. However, these strategies still could not conquer the delivery barriers of a tumor microenvironment such as heterogeneous blood flow, dense extracellular matrix, abundant stroma cells, and high interstitial fluid pressure, which severely impaired vascular transport of nanomedicines, hindered their effective extravasation, and impeded their interstitial transport to realize uniform distribution inside tumors. Therefore, modulation of tumor microenvironment has now emerged as an important strategy to improve nanomedicine delivery to tumors. Here, we review the existing strategies and approaches for tumor microenvironment modulation to improve tumor perfusion for helping more nanomedicines to reach the tumor site, to facilitate nanomedicine extravasation for enhancing transvascular transport, and to improve interstitial transport for optimizing the distribution of nanomedicines. These strategies may provide an avenue for the development of new combination chemotherapeutic regimens and reassessment of previously suboptimal agents. PMID:29311946

Liposomal Cytarabine Induces Less Neurocognitive Dysfunction Than Intrathecal Methotrexate in an Animal Model

DEFF Research Database (Denmark)

Thomsen, Anna M; Gulinello, Maria E; Wen, Jing

2018-01-01

Liposomal cytarabine is currently being tested clinically as an alternative to intrathecal (IT) methotrexate (MTX) for preventing relapse within the central nervous system among patients with acute lymphoblastic leukemia. To compare the toxicity and cognitive deficits caused by IT MTX versus lipo...

Binding of Diphtheria Toxin to Phospholipids in Liposomes

Science.gov (United States)

Alving, Carl R.; Iglewski, Barbara H.; Urban, Katharine A.; Moss, Joel; Richards, Roberta L.; Sadoff, Jerald C.

1980-04-01

Diphtheria toxin bound to the phosphate portion of some, but not all, phospholipids in liposomes. Liposomes consisting of dimyristoyl phosphatidylcholine and cholesterol did not bind toxin. Addition of 20 mol% (compared to dimyristoyl phosphatidylcholine) of dipalmitoyl phosphatidic acid, dicetyl phosphate, phosphatidylinositol phosphate, cardiolipin, or phosphatidylserine in the liposomes resulted in substantial binding of toxin. Inclusion of phosphatidylinositol in dimyristol phosphatidylcholine / cholesterol liposomes did not result in toxin binding. The calcium salt of dipalmitoyl phosphatidic acid was more effective than the sodium salt, and the highest level of binding occurred with liposomes consisting only of dipalmitoyl phosphatidic acid (calcium salt) and cholesterol. Binding of toxin to liposomes was dependent on pH, and the pattern of pH dependence varied with liposomes having different compositions. Incubation of diphtheria toxin with liposomes containing dicetyl phosphate resulted in maximal binding at pH 3.6, whereas binding to liposomes containing phosphatidylinositol phosphate was maximal above pH 7. Toxin did not bind to liposomes containing 20 mol% of a free fatty acid (palmitic acid) or a sulfated lipid (3-sulfogalactosylceramide). Toxin binding to dicetyl phosphate or phosphatidylinositol phosphate was inhibited by UTP, ATP, phosphocholine, or p-nitrophenyl phosphate, but not by uracil. We conclude that (a) diphtheria toxin binds specifically to the phosphate portion of certain phospholipids, (b) binding to phospholipids in liposomes is dependent on pH, but is not due only to electrostatic interaction, and (c) binding may be strongly influenced by the composition of adjacent phospholipids that do not bind toxin. We propose that a minor membrane phospholipid (such as phosphatidylinositol phosphate or phosphatidic acid), or that some other phosphorylated membrane molecule (such as a phosphoprotein) may be important in the initial binding of

Design of multifunctional magnetic iron oxide nanoparticles/mitoxantrone-loaded liposomes for both magnetic resonance imaging and targeted cancer therapy

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He Y

2014-08-01

Full Text Available Yingna He,1 Linhua Zhang,2 Dunwan Zhu,2 Cunxian Song2 1Laboratory of Chinese Medicine Pharmacology, College of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, People’s Republic of China; 2Key Laboratory of Biomedical Material of Tianjin, Institute of Biomedical Engineering, Peking Union Medical College and Chinese Academy of Medical Sciences, Tianjin, People’s Republic of China Abstract: Tumor-targeting multifunctional liposomes simultaneously loaded with magnetic iron oxide nanoparticles (MIONs as a magnetic resonance imaging (MRI contrast agent and anticancer drug, mitoxantrone (Mit, were developed for targeted cancer therapy and ultrasensitive MRI. The gonadorelin-functionalized MION/Mit-loaded liposome (Mit-GML showed significantly increased uptake in luteinizing hormone–releasing hormone (LHRH receptor overexpressing MCF-7 (Michigan Cancer Foundation-7 breast cancer cells over a gonadorelin-free MION/Mit-loaded liposome (Mit-ML control, as well as in an LHRH receptor low-expressing Sloan-Kettering HER2 3+ Ovarian Cancer (SK-OV-3 cell control, thereby leading to high cytotoxicity against the MCF-7 human breast tumor cell line. The Mit-GML formulation was more effective and less toxic than equimolar doses of free Mit or Mit-ML in the treatment of LHRH receptors overexpressing MCF-7 breast cancer xenografts in mice. Furthermore, the Mit-GML demonstrated much higher T2 enhancement than did Mit-ML controls in vivo. Collectively, the study indicates that the integrated diagnostic and therapeutic design of Mit-GML nanomedicine potentially allows for the image-guided, target-specific treatment of cancer. Keywords: multifunctional liposome, magnetic resonance imaging, theranostic nanomedicine, mitoxantrone, gonadorelin

Influence of the state of phase of lipid bilayer on the exposure of glucose residues on the surface of liposomes.

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Villalva, Denise Gradella; Giansanti, Luisa; Mauceri, Alessandro; Ceccacci, Francesca; Mancini, Giovanna

2017-11-01

The presence of carbohydrate-binding proteins (i.e. lectins) on the surface of various bacterial strains and their overexpression in some tumor tissues makes the use of glycosylated liposomes a promising approach for the specific drug delivery in antibacterial and anti-cancer therapies. However, the functionalization of liposome surface with sugar moieties by glycosylated amphiphiles does not ensure the binding of sugar-coated vesicles with lectins. In fact, the composition and properties of lipid bilayer play a pivotal role in the exposure of sugar residues and in the interaction with lectins. The influence of the length of the hydrophilic spacer that links the sugar to liposome surface and of the presence of saturated or unsaturated phospholipids in the lipid bilayer on the ability of glucosylated liposomes to interact with a model lectin, Concanavalin A, was investigated. Our results demonstrate that both the chain length and the prensece of unsaturation, parameters that strongly affect the fluidity of the lipid bilayer, affect agglutination. In particular, agglutination is favored when liposomes are in the gel phase within a defined range of temperature. Moreover, the obtained results confirm that the length of the PEG spacer, that influences both lipid organization and the exposure of sugar moieties to the bulk, plays a crucial role in liposome/lectin interaction. Copyright © 2017 Elsevier B.V. All rights reserved.

Amperometric Adhesion Signals of Liposomes, Cells and Droplets

OpenAIRE

Ivošević DeNardis, N.; Žutić, V.; Svetličić, V.; Frkanec, R.

2009-01-01

Individual soft microparticles (liposomes, living cells and organic droplets) in aqueous media are characterized by their adhesion signals using amperometry at the dropping mercury electrode. We confirmed that the general mechanism established for adhesion of hydrocarbon droplets and cells is valid as well for liposome adhesion within a wide range of surface charge densities. Incidents and shape of adhesion signals in liposome suspensions reflect liposome polydispersity, surface charge den...

Aerosolized liposomes with dipalmitoyl phosphatidylcholine enhance pulmonary insulin delivery.

Science.gov (United States)

Chono, Sumio; Fukuchi, Rie; Seki, Toshinobu; Morimoto, Kazuhiro

2009-07-20

The pulmonary insulin delivery characteristics of liposomes were examined. Aerosolized liposomes containing insulin were administered into rat lungs and the enhancing effect on insulin delivery was evaluated by changes of plasma glucose levels. Liposomes with dipalmitoyl phosphatidylcholine (DPPC) enhanced pulmonary insulin delivery in rats, however, liposomes with dilauroyl, dimyristoyl, distearoyl or dioleoyl phosphatidylcholine did not. Liposomes with DPPC also enhanced the in vitro permeation of FITC dextran (Mw 4400, FD-4) through the calu-3 cell monolayer by reducing the transepithelial electrical resistance and did not harm lung tissues in rats. These findings suggest that liposomes with DPPC enhance pulmonary insulin delivery by opening the epithelial cell space in the pulmonary mucosa not mucosal cell damage. Liposomes with DPPC could be useful as a pulmonary delivery system for peptide and protein drugs.

BODIPY-based fluorescent liposomes with sesquiterpene lactone trilobolide

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Ludmila Škorpilová

2017-07-01

Full Text Available Like thapsigargin, which is undergoing clinical trials, trilobolide is a natural product with promising anticancer and anti-inflammatory properties. Similar to thapsigargin, it has limited aqueous solubility that strongly reduces its potential medicinal applications. The targeted delivery of hydrophobic drugs can be achieved using liposome-based carriers. Therefore, we designed a traceable liposomal drug delivery system for trilobolide. The fluorescent green-emitting dye BODIPY, cholesterol and trilobolide were used to create construct 6. The liposomes were composed of dipalmitoyl-3-trimethylammoniumpropane and phosphatidylethanolamine. The whole system was characterized by atomic force microscopy, the average size of the liposomes was 150 nm in width and 30 nm in height. We evaluated the biological activity of construct 6 and its liposomal formulation, both of which showed immunomodulatory properties in primary rat macrophages. The uptake and intracellular distribution of construct 6 and its liposomal formulation was monitored by means of live-cell fluorescence microscopy in two cancer cell lines. The encapsulation of construct 6 into the liposomes improved the drug distribution in cancer cells and was followed by cell death. This new liposomal trilobolide derivative not only retains the biological properties of pure trilobolide, but also enhances the bioavailability, and thus has potential for the use in theranostic applications.

Renal-targeted delivery of triptolide by entrapment in pegylated TRX-20-modified liposomes.

Science.gov (United States)

Yuan, Zhi-Xiang; Jia, Lu; Lim, Lee Yong; Lin, Ju-Chun; Shu, Gang; Zhao, Ling; Ye, Gang; Liang, Xiao-Xia; Ji, Hongming; Fu, Hua-Lin

2017-01-01

Previously, 3,5-dipentadecyloxybenzamidine hydrochloride (TRX-20)-modified liposomes were reported to specifically target mesangial cells (MCs) in glomeruli. To further gain a better understanding of the characteristics and potential application for glomerular diseases of TRX-20-modified liposomes, we synthesized TRX-20 and prepared TRX-20-modified liposomes (TRX-LPs) with different molar ratios - 6% (6%-TRX-LP), 11% (11%-TRX-LP), and 14% (14%-TRX-LP) - of TRX-20 to total lipid in the present study. All TRX-LPs exhibited concentration-dependent toxicity against the MCs at a lipid concentration ranging from 0.01 to 1.0 mg/mL with IC 50 values of 3.45, 1.13, and 0.55 mg/mL, respectively. Comparison of the cell viability of TRX-LPs indicated that high levels of TRX-20 caused severe cell mortality, with 11%-TRX-LP showing the higher cytoplasmic accumulation in the MCs. Triptolide (TP) as a model drug was first loaded into 11%-TRX-LP and the liposomes were further modified with PEG 5000 (PEG-TRX-TP-LP) in an attempt to prolong their circulation in blood and enhance TP-mediated immune suppression. Due to specific binding to MCs, PEG-TRX-TP-LP undoubtedly showed better anti-inflammatory action in vitro, evidenced by the inhibition of release of nitric oxide (NO) and tumor necrosis factor-α from lipopolysaccharide-stimulated MCs, compared with free TP at the same dose. In vivo, the PEG-TRX-TP-LP effectively attenuated the symptoms of membranous nephropathic (MN) rats and improved biochemical markers including proteinuria, serum cholesterol, and albumin. Therefore, it can be concluded that the TRX-modified liposome is an effective platform to target the delivery of TP to glomeruli for the treatment of MN.

Calcipotriol delivery into the skin with PEGylated liposomes

DEFF Research Database (Denmark)

Knudsen, Nina Østergaard; Rønholt, Stine; Salte, Ragnhild Djønne

2012-01-01

The d-vitamin analogue calcipotriol is commonly used for topical treatment of psoriasis, but skin penetration is required for calcipotriol to reach its pharmacological target: the keratinocytes in the lower epidermis. Liposomes can enhance the delivery of drugs into the skin, but a major challenge...... of the liposomes and the ability to deliver membrane-intercalated calcipotriol into the skin. Inclusion of 0.5, l and 5mol% PEG-DSPE in the membrane enhanced the colloidal stability of the liposomes without compromising the delivery of calcipotriol from the vehicle into excised pig skin. Calcipotriol...... to large multilamellar vesicles, indicating that the liposomes to some extent migrate as intact vesicles into the stratum corneum. However, calcipotriol penetrated the skin better than the lipid component of the liposomes, suggesting that at least a fraction of the drug is released from the liposomes...

Liposome Technology for Industrial Purposes

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Andreas Wagner

2011-01-01

Full Text Available Liposomes, spherical vesicles consisting of one or more phospholipid bilayers, were first described in the mid 60s by Bangham and coworkers. Since then, liposomes have made their way to the market. Today, numerous lab scale but only a few large-scale techniques are available. However, a lot of these methods have serious limitations in terms of entrapment of sensitive molecules due to their exposure to mechanical and/or chemical stress. This paper summarizes exclusively scalable techniques and focuses on strengths, respectively, limitations in respect to industrial applicability. An additional point of view was taken to regulatory requirements concerning liposomal drug formulations based on FDA and EMEA documents.

Boron delivery with liposomes for boron neutron capture therapy (BNCT): biodistribution studies in an experimental model of oral cancer demonstrating therapeutic potential

International Nuclear Information System (INIS)

Nigg, David W.

2012-01-01

Boron neutron capture therapy (BNCT) combines selective accumulation of 10B carriers in tumor tissue with subsequent neutron irradiation. We previously demonstrated the therapeutic efficacy of BNCT in the hamster cheek pouch oral cancer model. Optimization of BNCT depends largely on improving boron targeting to tumor cells. Seeking to maximize the potential of BNCT for the treatment for head and neck cancer, the aim of the present study was to perform boron biodistribution studies in the oral cancer model employing two different liposome formulations that were previously tested for a different pathology, i.e., in experimental mammary carcinoma in BALB/c mice: (1) MAC: liposomes incorporating K(nido-7-CH3(CH2)15-7,8-C2B9H11) in the bilayer membrane and encapsulating a hypertonic buffer, administered intravenously at 6 mg B per kg body weight, and (2) MAC-TAC: liposomes incorporating K(nido-7-CH3(CH2)15-7,8-C2B9H11) in the bilayer membrane and encapsulating a concentrated aqueous solution of the hydrophilic species Na3 (ae-B20H17NH3), administered intravenously at 18 mg B per kg body weight. Samples of tumor, precancerous and normal pouch tissue, spleen, liver, kidney, and blood were taken at different times post-administration and processed to measure boron content by inductively coupled plasma mass spectrometry. No ostensible clinical toxic effects were observed with the selected formulations. Both MAC and MAC-TAC delivered boron selectively to tumor tissue. Absolute tumor values for MAC-TAC peaked to 66.6 ± 16.1 ppm at 48 h and to 43.9 ± 17.6 ppm at 54 h with very favorable ratios of tumor boron relative to precancerous and normal tissue, making these protocols particularly worthy of radiobiological assessment. Boron concentration values obtained would result in therapeutic BNCT doses in tumor without exceeding radiotolerance in precancerous/normal tissue at the thermal neutron facility at RA-3.

Boron delivery with liposomes for boron neutron capture therapy (BNCT): biodistribution studies in an experimental model of oral cancer demonstrating therapeutic potential

Energy Technology Data Exchange (ETDEWEB)

David W. Nigg

2012-05-01

Boron neutron capture therapy (BNCT) combines selective accumulation of 10B carriers in tumor tissue with subsequent neutron irradiation. We previously demonstrated the therapeutic efficacy of BNCT in the hamster cheek pouch oral cancer model. Optimization of BNCT depends largely on improving boron targeting to tumor cells. Seeking to maximize the potential of BNCT for the treatment for head and neck cancer, the aim of the present study was to perform boron biodistribution studies in the oral cancer model employing two different liposome formulations that were previously tested for a different pathology, i.e., in experimental mammary carcinoma in BALB/c mice: (1) MAC: liposomes incorporating K[nido-7-CH3(CH2)15-7,8-C2B9H11] in the bilayer membrane and encapsulating a hypertonic buffer, administered intravenously at 6 mg B per kg body weight, and (2) MAC-TAC: liposomes incorporating K[nido-7-CH3(CH2)15-7,8-C2B9H11] in the bilayer membrane and encapsulating a concentrated aqueous solution of the hydrophilic species Na3 [ae-B20H17NH3], administered intravenously at 18 mg B per kg body weight. Samples of tumor, precancerous and normal pouch tissue, spleen, liver, kidney, and blood were taken at different times post-administration and processed to measure boron content by inductively coupled plasma mass spectrometry. No ostensible clinical toxic effects were observed with the selected formulations. Both MAC and MAC-TAC delivered boron selectively to tumor tissue. Absolute tumor values for MAC-TAC peaked to 66.6 {+-} 16.1 ppm at 48 h and to 43.9 {+-} 17.6 ppm at 54 h with very favorable ratios of tumor boron relative to precancerous and normal tissue, making these protocols particularly worthy of radiobiological assessment. Boron concentration values obtained would result in therapeutic BNCT doses in tumor without exceeding radiotolerance in precancerous/normal tissue at the thermal neutron facility at RA-3.

Liposome encapsulation of fluorescent nanoparticles: Quantum dots and silica nanoparticles

International Nuclear Information System (INIS)

Chen, C.-S.; Yao Jie; Durst, Richard A.

2006-01-01

Quantum dots (QDs) and silica nanoparticles (SNs) are relatively new classes of fluorescent probes that overcome the limitations encountered by organic fluorophores in bioassay and biological imaging applications. We encapsulated QDs and SNs in liposomes and separated nanoparticle-loaded liposomes from unencapsulated nanoparticles by size exclusion chromatography. Fluorescence correlation spectroscopy was used to measure the average number of nanoparticles inside each liposome. Results indicated that nanoparticle-loaded liposomes were formed and separated from unencapsulated nanoparticles by using a Sepharose gel. As expected, fluorescence self-quenching of nanoparticles inside liposomes was not observed. Each liposome encapsulated an average of three QDs. These studies demonstrated that nanoparticles could be successfully encapsulated into liposomes and provided a methodology to quantify the number of nanoparticles inside each liposome by fluorescence correlation spectroscopy

Thermo-responsive magnetic liposomes for hyperthermia-triggered local drug delivery.

Science.gov (United States)

Dai, Min; Wu, Cong; Fang, Hong-Ming; Li, Li; Yan, Jia-Bao; Zeng, Dan-Lin; Zou, Tao

2017-06-01

We prepared and characterised thermo-responsive magnetic liposomes, which were designed to combine features of magnetic targeting and thermo-responsive control release for hyperthermia-triggered local drug delivery. The particle size and zeta-potential of the thermo-responsive magnetic ammonium bicarbonate (MagABC) liposomes were about 210 nm and -14 mV, respectively. The MagABC liposomes showed encapsulation efficiencies of about 15% and 82% for magnetic nanoparticles (mean crystallite size 12 nm) and doxorubicin (DOX), respectively. The morphology of the MagABC liposomes was visualised using transmission electron microscope (TEM). The MagABC liposomes showed desired thermo-responsive release. The MagABC liposomes, when physically targeted to tumour cells in culture by a permanent magnetic field yielded a substantial increase in intracellular accumulation of DOX as compared to non-magnetic ammonium bicarbonate (ABC) liposomes. This resulted in a parallel increase in cytotoxicity for DOX loaded MagABC liposomes over DOX loaded ABC liposomes in tumour cells.

Phosphatidylserine-Liposomes Promote Tolerogenic Features on Dendritic Cells in Human Type 1 Diabetes by Apoptotic Mimicry

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Silvia Rodriguez-Fernandez

2018-02-01

Full Text Available Type 1 diabetes (T1D is a metabolic disease caused by the autoimmune destruction of insulin-producing β-cells. With its incidence increasing worldwide, to find a safe approach to permanently cease autoimmunity and allow β-cell recovery has become vital. Relying on the inherent ability of apoptotic cells to induce immunological tolerance, we demonstrated that liposomes mimicking apoptotic β-cells arrested autoimmunity to β-cells and prevented experimental T1D through tolerogenic dendritic cell (DC generation. These liposomes contained phosphatidylserine (PS—the main signal of the apoptotic cell membrane—and β-cell autoantigens. To move toward a clinical application, PS-liposomes with optimum size and composition for phagocytosis were loaded with human insulin peptides and tested on DCs from patients with T1D and control age-related subjects. PS accelerated phagocytosis of liposomes with a dynamic typical of apoptotic cell clearance, preserving DCs viability. After PS-liposomes phagocytosis, the expression pattern of molecules involved in efferocytosis, antigen presentation, immunoregulation, and activation in DCs concurred with a tolerogenic functionality, both in patients and control subjects. Furthermore, DCs exposed to PS-liposomes displayed decreased ability to stimulate autologous T cell proliferation. Moreover, transcriptional changes in DCs from patients with T1D after PS-liposomes phagocytosis pointed to an immunoregulatory prolife. Bioinformatics analysis showed 233 differentially expressed genes. Genes involved in antigen presentation were downregulated, whereas genes pertaining to tolerogenic/anti-inflammatory pathways were mostly upregulated. In conclusion, PS-liposomes phagocytosis mimics efferocytosis and leads to phenotypic and functional changes in human DCs, which are accountable for tolerance induction. The herein reported results reinforce the potential of this novel immunotherapy to re-establish immunological

Engineering liposomal nanoparticles for targeted gene therapy.

Science.gov (United States)

Zylberberg, C; Gaskill, K; Pasley, S; Matosevic, S

2017-08-01

Recent mechanistic studies have attempted to deepen our understanding of the process by which liposome-mediated delivery of genetic material occurs. Understanding the interactions between lipid nanoparticles and cells is still largely elusive. Liposome-mediated delivery of genetic material faces systemic obstacles alongside entry into the cell, endosomal escape, lysosomal degradation and nuclear uptake. Rational design approaches for targeted delivery have been developed to reduce off-target effects and enhance transfection. These strategies, which have included the modification of lipid nanoparticles with target-specific ligands to enhance intracellular uptake, have shown significant promise at the proof-of-concept stage. Control of physical and chemical specifications of liposome composition, which includes lipid-to-DNA charge, size, presence of ester bonds, chain length and nature of ligand complexation, is integral to the performance of targeted liposomes as genetic delivery agents. Clinical advances are expected to rely on such systems in the therapeutic application of liposome nanoparticle-based gene therapy. Here, we discuss the latest breakthroughs in the development of targeted liposome-based agents for the delivery of genetic material, paying particular attention to new ligand and cationic lipid design as well as recent in vivo advances.

Liposome as nanocarrier: Site targeted delivery in lung cancer

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Najeeb Ullah

2017-08-01

Full Text Available Lung cancer is fatal and spreading rapidly worldwide. Different clinical strategies are applied to stop this cancer. As the lung is a delicate organ, special clinical applications must be used and nanodrugs delivery systems are the most important applications of all. This review discusses the lung problems such as lung cancer, lung inflammation and bronchi constrictions followed by repetitive intake of some drugs. The objective of this review is to study how nanodrug delivery systems were synthesized and used in lung disorder treatment especially in lung cancer. The authors studied some articles from 1989 to 2015. Liposome encapsulation was done in various ways for the delivery of different drugs such as metaproterenol into liposomes caused bronchodilation, immunoliposomes bearing antibodies for doxorubicin reduced 50% inhibitory effects, radioliposomes with high penetrating ability to peripheral airways, aerosol delivery systems with deep pulmonary deposition, polymeric drug delivery having potential to improve beneficial index of drug, solid lipid liposomes, liposomal gentamicin with altered different clinical susceptibilities of resistance, transferrin conjugated liposomes to deliver cytostatic drugs to site of lungs, anti-inflammatory drugs with mannosylated liposomes, liposomal suspensions with single stranded RNAs and peptide encapsulation of liposomes. This review indicates that many animals perished with intravenous administration of drugs but survived in liposomal targeting groups.

Physicochemical aspects of the liposome-wool interaction in wool dyeing.

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Martí, Meritxell; Barsukov, Leonid I; Fonollosa, Jordi; Parra, José Luis; Sukhanov, Stanislav V; Coderch, Luisa

2004-04-13

Despite the promising application of liposomes in wool dyeing, little is known about the mechanism of liposome interactions with the wool fiber and dyestuffs. The kinetics of wool dyeing by two dyes, Acid Green 27 (hydrophobic) and Acid Green 25 (hydrophilic), were compared in three experimental protocols: (1) without liposomes, (2) in the presence of phosphatidylcholine (PC) liposomes, and (3) with wool previously treated with PC liposomes. Physicochemical interactions of liposomes with wool fibers were studied under experimental dyeing conditions with particular interest in the liposome affinity to the fiber surface and changes in the lipid composition of the wool fibers. The results obtained indicate that the presence of liposomes favors the retention of these two dyes in the dyeing bath, this effect being more pronounced in case of the hydrophobic dye. Furthermore, the liposome treatment is accompanied by substantial absorption of PC by wool fibers with simultaneous partial solubilization of their polar lipids (more evident at higher temperatures). This may result in structural modification of the cell membrane complex of wool fibers, which could account for a high level of the dye exhaustion observed at the end of the liposome dyeing process.

Effect of chitosan coating on the characteristics of DPPC liposomes

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Mohsen M. Mady

2010-07-01

Full Text Available Because it is both biocompatible and biodegradable, chitosan has been used to provide a protective capsule in new drug formulations. The present work reports on investigations into some of the physicochemical properties of chitosan-coated liposomes, including drug release rate, transmission electron microscopy (TEM, zeta potential and turbidity measurement. It was found that chitosan increases liposome stability during drug release. The coating of DPPC liposomes with a chitosan layer was confirmed by electron microscopy and the zeta potential of liposomes. The coating of liposomes by chitosan resulted in a marginal increase in the size of the liposomes, adding a layer of (92 ± 27.1 nm. The liposomal zeta potential was found to be increasingly positive as chitosan concentration increased from 0.1% to 0.3% (w/v, before stabilising at a relatively constant value. Turbidity studies revealed that the coating of DPPC liposomes with chitosan did not significantly modify the main phase transition temperature of DPPC at examined chitosan concentrations. The appropriate combination of liposomal and chitosan characteristics may produce liposomes with specific, prolonged and controlled release.

Stabilization of liophilized liposomal products

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2001-08-01

Full Text Available Liposomes as a drug carrier have numerous dominancy. Liophilization is the most propr form of these products for long-term maintenance, but this procedure is affected by unstabilizing agent that results in destruction of membrane, release of content and change in size and microbial contamination; hence for prevention of the adverse effects, the protective role of sugars such as: Maltose, Fructose, Glucose, Galactose, Saccharose and Lactose were studied. For this purpose, after preparation of liposomal suspention, categorized in for duplicate groups and concentrations of 25, 50, 100 percent of these sugars were added to those. On the basis of color and consistency of products, the best method of freezing is as application of absolute alcohol and then chilling in-70 oc for 16 h. In survey of protective substances concentrations 0.7, 1.4, 2.8, and 5.6 percent of the mentioned sugars were used for calculating of leakage percent (Upon on the ratio of optical density of treated samples to untreated. In this study, released maltose had highest effect. Level of fusion and aggregation had any significant difference between pre and post lyophilized samples in centrifugation with 10000 rpm. Microbial state of recent samples were studied by culturing in SCD and SCDA media that indicated microbial growth in both samples.     

Advances and Challenges of Liposome Assisted Drug Delivery

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Lisa eSercombe

2015-12-01

Full Text Available The application of liposomes to assist drug delivery has already had a major impact on many biomedical areas. They have been shown to be beneficial for stabilizing therapeutic compounds, overcoming obstacles to cellular and tissue uptake, and improving biodistribution of compounds to target sites in vivo. This enables effective delivery of encapsulated compounds to target sites while minimizing systemic toxicity. Liposomes present as an attractive delivery system due to their flexible physicochemical and biophysical properties, which allow easy manipulation to address different delivery considerations. Despite considerable research in the last 50 years and the plethora of positive results in preclinical studies, the clinical translation of liposome assisted drug delivery platforms has progressed incrementally. In this review, we will discuss the advances in liposome assisted drug delivery, biological challenges that still remain, and current clinical and experimental use of liposomes for biomedical applications. The translational obstacles of liposomal technology will also be presented.

Selenium prevents tumor development in a rat model for chemical carcinogenesis

DEFF Research Database (Denmark)

Bjorkhem-Bergman, L.; Torndal, U. B.; Eken, S.

2005-01-01

Previous studies in animals and humans have shown that selenium compounds can prevent cancer development. In this work we studied the tumor preventive effect of selenium supplementation, administrated as selenite, in the initiation, promotion and progression phases in a synchronized rat model for...

Characterization of Diclofenac Liposomes Formulated with Palm Oil ...

African Journals Online (AJOL)

Purpose: To characterize diclofenac sodium (DS) liposomes prepared using palm oil fractions. Methods: Reverse-phase evaporation method was used to prepare liposomes containing 10, 20, 30 , 40 or 50% palm oil fractions. The effect of palm oil content on liposome formation, surface morphology, shape, size and zeta ...

Liposomes to target peripheral neurons and Schwann cells.

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Sooyeon Lee

Full Text Available While a wealth of literature for tissue-specific liposomes is emerging, optimal formulations to target the cells of the peripheral nervous system (PNS are lacking. In this study, we asked whether a novel formulation of phospholipid-based liposomes could be optimized for preferential uptake by microvascular endothelia, peripheral neurons and Schwann cells. Here, we report a unique formulation consisting of a phospholipid, a polymer surfactant and cholesterol that result in enhanced uptake by targeted cells. Using fluorescently labeled liposomes, we followed particle internalization and trafficking through a distinct route from dextran and escape from degradative compartments, such as lysosomes. In cultures of non-myelinating Schwann cells, liposomes associate with the lipid raft marker Cholera toxin, and their internalization is inhibited by disruption of lipid rafts or actin polymerization. In contrast, pharmacological inhibition of clathrin-mediated endocytosis does not significantly impact liposome entry. To evaluate the efficacy of liposome targeting in tissues, we utilized myelinating explant cultures of dorsal root ganglia and isolated diaphragm preparations, both of which contain peripheral neurons and myelinating Schwann cells. In these models, we detected preferential liposome uptake into neurons and glial cells in comparison to surrounding muscle tissue. Furthermore, in vivo liposome administration by intramuscular or intravenous injection confirmed that the particles were delivered to myelinated peripheral nerves. Within the CNS, we detected the liposomes in choroid epithelium, but not in myelinated white matter regions or in brain parenchyma. The described nanoparticles represent a novel neurophilic delivery vehicle for targeting small therapeutic compounds, biological molecules, or imaging reagents into peripheral neurons and Schwann cells, and provide a major advancement toward developing effective therapies for peripheral

Filter-extruded liposomes revisited

DEFF Research Database (Denmark)

Hinna, Askell; Steiniger, Frank; Hupfeld, Stefan

2016-01-01

(pore-size, number of filter passages, and flow-rate), flow field-flow fractionation in conjunction with multi-angle laser light scattering (AF4-MALLS, Wyatt Technology Corp., Santa Barbara, CA) was employed. Liposome size-distributions determined by AF4-MALLS were compared with those of dynamic light...... is suggested to prepare large (300 nm) liposomes with rather narrow size distribution, based on the filter extrusion at defined flow-rates in combination with freeze-/ thaw-cycling and bench-top centrifugation....

Optimization and characterization of liposome formulation by mixture design.

Science.gov (United States)

Maherani, Behnoush; Arab-tehrany, Elmira; Kheirolomoom, Azadeh; Reshetov, Vadzim; Stebe, Marie José; Linder, Michel

2012-02-07

This study presents the application of the mixture design technique to develop an optimal liposome formulation by using the different lipids in type and percentage (DOPC, POPC and DPPC) in liposome composition. Ten lipid mixtures were generated by the simplex-centroid design technique and liposomes were prepared by the extrusion method. Liposomes were characterized with respect to size, phase transition temperature, ζ-potential, lamellarity, fluidity and efficiency in loading calcein. The results were then applied to estimate the coefficients of mixture design model and to find the optimal lipid composition with improved entrapment efficiency, size, transition temperature, fluidity and ζ-potential of liposomes. The response optimization of experiments was the liposome formulation with DOPC: 46%, POPC: 12% and DPPC: 42%. The optimal liposome formulation had an average diameter of 127.5 nm, a phase-transition temperature of 11.43 °C, a ζ-potential of -7.24 mV, fluidity (1/P)(TMA-DPH)((¬)) value of 2.87 and an encapsulation efficiency of 20.24%. The experimental results of characterization of optimal liposome formulation were in good agreement with those predicted by the mixture design technique.

Screening Effect of PEG on Avidin Binding to Liposome Surface Receptors

DEFF Research Database (Denmark)

Kaasgaard, Thomas; Mouritsen, Ole G.; Jørgensen, Kent

2000-01-01

This study investigates the screening effect of poly(ethylene glycol)-phospholipids (PE-PEG) on the interaction of avidin with PEGylated liposomes containing surface-bound biotin ligands. The influence of grafting density and lipopolymer chain length is examined. A simple fluorescence assay....... Furthermore. it is found that none of the lipopolymers completely prevents avidin from reaching the surface-bound biotin ligands....

Development of Liposomal Bubbles with Perfluoropropane Gas as Gene Delivery Carriers

Science.gov (United States)

Maruyama, Kazuo; Suzuki, Ryo; Sawamura, Kaori; Takizawa, Tomoko; Utoguchi, Naoki; Negishi, Yoichi

2007-05-01

Liposomes have some advantages as drug, antigen and gene delivery carriers. Their size can be easily controlled and they can be modified to add a targeting function. Based on liposome technology, we developed novel liposomal bubbles (Bubble liposomes) containing the ultrasound imaging gas, perfluoropropane. We assessed the feasibility of Bubble liposomes as carriers for gene delivery after cavitation induced by ultrasound. At first, we investigated their ability to deliver genes with Bubble liposomes and ultrasound to various types of cells such as mouse sarcoma cells, mouse melanoma cells, human T cell line and human umbilical vein endothelial cells. The results showed that the Bubble liposomes could deliver plasmid DNA to many cell types without cytotoxicity. In addition, we found that Bubble liposomes could effectively deliver plasmid DNA into mouse femoral artery in vivo. The gene transduction with Bubble liposomes was more effectively than conventional lipofection. We conclude that Bubble liposomes are unique and efficient gene delivery carriers in vitro and in vivo.

Liposomal curcumin and its application in cancer.

Science.gov (United States)

Feng, Ting; Wei, Yumeng; Lee, Robert J; Zhao, Ling

2017-01-01

Curcumin (CUR) is a yellow polyphenolic compound derived from the plant turmeric. It is widely used to treat many types of diseases, including cancers such as those of lung, cervices, prostate, breast, bone and liver. However, its effectiveness has been limited due to poor aqueous solubility, low bioavailability and rapid metabolism and systemic elimination. To solve these problems, researchers have tried to explore novel drug delivery systems such as liposomes, solid dispersion, microemulsion, micelles, nanogels and dendrimers. Among these, liposomes have been the most extensively studied. Liposomal CUR formulation has greater growth inhibitory and pro-apoptotic effects on cancer cells. This review mainly focuses on the preparation of liposomes containing CUR and its use in cancer therapy.

[Preparation of diclofenac sodium liposomes and its ocular pharmacokinetics].

Science.gov (United States)

Sun, Kao-xiang; Wang, Ai-ping; Huang, Li-jun; Liang, Rong-cai; Liu, Ke

2006-11-01

To prepare diclofenac sodium liposomes and observe its ocular pharmacokinetics in rabbits. The diclofenac sodium cationic liposomes were prepared by reverse-phase evaporation methods and the formula of liposome was optimized with uniform design. HPLC method was established and validated for the determination of diclofenac sodium in precornea, cornea and aqueous humor of rabbit eye. Liposome and eyedrop solution 50 microL with total 50 microg diclofenac sodium were instilled to eyes of rabbits, separately. Samples of tear, cornea and aqueous humor were collected at different time intervals after rabbits were sacrificed. The ocular pharmacokinetics was investigated by the concentration-time data of tear, cornea and aqueous humor. The mean particle size of the diclofenac sodium liposomes was 226.5 nm with zeta potential of + 18. 1 mV. The entrapment efficiency reached 63%. Compared with solution, liposome was characterized by slower clearance in precornea. The concentration of diclotenac in cornea and aqueous humor instilled with liposome were higher than that with eye-drop solution. Cmax of diclofenac sodium in aqueous humor instilled with liposome and eye-drop solution were (0.69 +/- 0.25) and (0.48 +/- 0.19) microg x mL(-1) and (36.68 +/- 11.7) and (21.82 +/- 8.6) microg x g(-1) in cornea, respectively. But no significant difference were found to Tmax in aqueous humor and cornea between liposome and eyedrop, T(1/2) of diclofenac in aqueous humor and cornea with liposoine were longer than that with eye-drop solution. The ocular bioavailability of liposome in aqueous humor was 211% compared with that of eyedrop. Diclofenac sodium cationic liposomes can increase the corneal contact time, enhance the corneal permeability of diclofenac sodium and improve its ocular bioavailability.

Biodistribution of immunoliposome labeled with Tc-99m in tumor xenografted mice

International Nuclear Information System (INIS)

Kitamura, Naoto; Shigematsu, Naoyuki; Nakahara, Tadaki; Kanoh, Momoe; Hashimoto, Jun; Kunieda, Etsuo; Kubo, Atsushi

2009-01-01

Immunoliposome (PEG, GAH, liposome; PGL), consisting of F(ab') 2 fragment of monoclonal antibody, GAH and polyethyleneglycol-coated (PEGylated) liposome was provided. Immunoliposome, PGL was labeled with technetium-99m (Tc-99m) by two methods: labeling F(ab') 2 fragment with Tc-99m; Tc-99m-PGL, and entrapping Tc-99m into liposome; PGL[Tc-99m]. The objective of this study was to compare the biodistribution of Tc-99m-PGL and PGL[Tc-99m] in human gastric cancer xenografted mice. Tc-99m-PGL, PGL[Tc-99m], and Tc-99m-entrapped liposome; Lipo[Tc-99m] were prepared. They were injected into human gastric cancer, MKN45, xenografted mice via the tail vein, and their biodistribution was studied. No marked accumulation of either PGL[Tc-99m] or Lipo[Tc-99m] was observed in the stomach. The uptake of Tc-99m-PGL by the liver, spleen, and lung was higher than that by the tumor. On the other hand, the uptake of PGL[Tc-99m] by the lung and spleen was markedly lower as compared with that of Tc-99m-PGL; the accumulation of PGL[Tc-99m] was lower in the lung and higher in the spleen as compared with that of the tumor. Although the liver uptake of PGL[Tc-99m] was markedly decreased as compared with that of Tc-99m-PGL, it was higher than the uptake of the tumor. The Tc-99m-PGL was strongly taken up by the tumor, with a high level of incorporation also seen in the stomach. These findings suggest the need for further study of the labeling stability. PGL[Tc-99m] appears to show promise for high tumor uptake and retention. This is an important implication for the potential application of immunoliposomes entrapped with Re-186, instead of Tc-99m, in internal radiotherapy. (author)

Bladder uptake of liposomes after intravesical administration occurs by endocytosis.

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Bharathi Raja Rajaganapathy

Full Text Available Liposomes have been used therapeutically and as a local drug delivery system in the bladder. However, the exact mechanism for the uptake of liposomes by bladder cells is unclear. In the present study, we investigated the role of endocytosis in the uptake of liposomes by cultured human UROtsa cells of urothelium and rat bladder. UROtsa cells were incubated in serum-free media with liposomes containing colloidal gold particles for 2 h either at 37°C or at 4°C. Transmission Electron Microscopy (TEM images of cells incubated at 37°C found endocytic vesicles containing gold inside the cells. In contrast, only extracellular binding was noticed in cells incubated with liposomes at 4°C. Absence of liposome internalization at 4°C indicates the need of energy dependent endocytosis as the primary mechanism of entry of liposomes into the urothelium. Flow cytometry analysis revealed that the uptake of liposomes at 37°C occurs via clathrin mediated endocytosis. Based on these observations, we propose that clathrin mediated endocytosis is the main route of entry for liposomes into the urothelial layer of the bladder and the findings here support the usefulness of liposomes in intravesical drug delivery.

Recent Trends of Polymer Mediated Liposomal Gene Delivery System

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Shyamal Kumar Kundu

2014-01-01

Full Text Available Advancement in the gene delivery system have resulted in clinical successes in gene therapy for patients with several genetic diseases, such as immunodeficiency diseases, X-linked adrenoleukodystrophy (X-ALD blindness, thalassemia, and many more. Among various delivery systems, liposomal mediated gene delivery route is offering great promises for gene therapy. This review is an attempt to depict a portrait about the polymer based liposomal gene delivery systems and their future applications. Herein, we have discussed in detail the characteristics of liposome, importance of polymer for liposome formulation, gene delivery, and future direction of liposome based gene delivery as a whole.

Liposomes - experiment of magnetic resonance imaging application

International Nuclear Information System (INIS)

Mathieu, S.

1987-01-01

Most pharmaceutical research effort with liposomes has been involved with the investigation of their use as drug carriers to particular target organs. Recently there has been a growing interest in liposomes not only as carrier of drugs but as a tool for the introduction of various substances into the human body. In this study, liposome delivery of nitroxyl radicals as NMR contrast agent for improved tissue imaging is experimented in rats [fr

Interaction of dipalmitoyl phosphatidylcholine (DPPC) liposomes and insulin

Science.gov (United States)

Mady, Mohsen M.; Elshemey, Wael M.

2011-06-01

Insulin, a peptide that has been used for decades in the treatment of diabetes, has well-defined properties and delivery requirements. Liposomes, which are lipid bilayer vesicles, have gained increasing attention as drug carriers which reduce the toxicity and increase the pharmacological activity of various drugs. The molecular interaction between (uncharged lipid) dipalmitoyl phosphatidylcholine (DPPC) liposomes and insulin has been characterized by using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction. The characteristic protein absorption band peaks, Amide I (at about 1660 cm-1) and Amide II band (at about 1546 cm-1) are potentially reduced in the liposome insulin complex. Wide-angle x-ray scattering measurements showed that the association of insulin with DPPC lipid of liposomes still maintains the characteristic DPPC diffraction peaks with almost no change in relative intensities or change in peak positions. The absence of any shift in protein peak positions after insulin being associated with DPPC liposomes indicates that insulin is successfully forming complex with DPPC liposomes with possibly no pronounced alterations in the structure of insulin molecule.

Calcium-Responsive Liposomes via a Synthetic Lipid Switch.

Science.gov (United States)

Lou, Jinchao; Carr, Adam J; Watson, Alexa J; Mattern-Schain, Samuel I; Best, Michael D

2018-03-07

Liposomal drug delivery would benefit from enhanced control over content release. Here, we report a novel avenue for triggering release driven by chemical composition using liposomes sensitized to calcium-a target chosen due to its key roles in biology and disease. To demonstrate this principle, we synthesized calcium-responsive lipid switch 1, designed to undergo conformational changes upon calcium binding. The conformational change perturbs membrane integrity, thereby promoting cargo release. This was shown through fluorescence-based release assays via dose-dependent response depending on the percentage of 1 in liposomes, with minimal background leakage in controls. DLS experiments indicated dramatic changes in particle size upon treatment of liposomes containing 1 with calcium. In a comparison of ten naturally occurring metal cations, calcium provided the greatest release. Finally, STEM images showed significant changes in liposome morphology upon treatment of liposomes containing 1 with calcium. These results showcase lipid switches driven by molecular recognition principles as an exciting avenue for controlling membrane properties. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Release of Liposomal Contents by Cell-Secreted Matrix Metalloproteinase-9

Science.gov (United States)

Banerjee, Jayati; Hanson, Andrea J.; Gadam, Bhushan; Elegbede, Adekunle I.; Tobwala, Shakila; Ganguly, Bratati; Wagh, Anil; Muhonen, Wallace W.; Law, Benedict; Shabb, John B.; Srivastava, D. K.; Mallik, Sanku

2011-01-01

Liposomes have been widely used as a drug delivery vehicle and currently, more than 10 liposomal formulations are approved by the Food and Drug Administration for clinical use. However, upon targeting, the release of the liposome-encapsulated contents is usually slow. We have recently demonstrated that contents from appropriately-formulated liposomes can be rapidly released by the cancer-associated enzyme matrix metalloproteinase-9 (MMP-9). Herein, we report our detailed studies to optimize the liposomal formulations. By properly selecting the lipopeptide, the major lipid component and their relative amounts, we demonstrate that the contents are rapidly released in the presence of cancer-associated levels of recombinant human MMP-9. We observed that the degree of lipid mismatch between the lipopepides and the major lipid component profoundly affects the release profiles from the liposomes. By utilizing the optimized liposomal formulations, we also demonstrate that cancer cells (HT-29) which secrete low levels of MMP-9 failed to release significant amount of the liposomal contents. Metastatic cancer cells (MCF7) secreting high levels of the enzyme rapidly release the encapsulated contents from the liposomes. PMID:19601658

Nanoparticle-stabilized liposomes for pH-responsive gastric drug delivery.

Science.gov (United States)

Thamphiwatana, Soracha; Fu, Victoria; Zhu, Jingying; Lu, Diannan; Gao, Weiwei; Zhang, Liangfang

2013-10-01

We report a novel pH-responsive gold nanoparticle-stabilized liposome system for gastric antimicrobial delivery. By adsorbing small chitosan-modified gold nanoparticles (diameter ~10 nm) onto the outer surface of negatively charged phospholipid liposomes (diameter ~75 nm), we show that at gastric pH the liposomes have excellent stability with limited fusion ability and negligible cargo releases. However, when the stabilized liposomes are present in an environment with neutral pH, the gold stabilizers detach from the liposomes, resulting in free liposomes that can actively fuse with bacterial membranes. Using Helicobacter pylori as a model bacterium and doxycycline as a model antibiotic, we demonstrate such pH-responsive fusion activity and drug release profile of the nanoparticle-stabilized liposomes. Particularly, at neutral pH the gold nanoparticles detach, and thus the doxycycline-loaded liposomes rapidly fuse with bacteria and cause superior bactericidal efficacy as compared to the free doxycycline counterpart. Our results suggest that the reported liposome system holds a substantial potential for gastric drug delivery; it remains inactive (stable) in the stomach lumen but actively interacts with bacteria once it reaches the mucus layer of the stomach where the bacteria may reside.

Improved Antitumor Efficacy and Pharmacokinetics of Bufalin via PEGylated Liposomes

Science.gov (United States)

Yuan, Jiani; Zhou, Xuanxuan; Cao, Wei; Bi, Linlin; Zhang, Yifang; Yang, Qian; Wang, Siwang

2017-11-01

Bufalin was reported to show strong pharmacological effects including cardiotonic, antiviral, immune-regulation, and especially antitumor effects. The objective of this study was to determine the characterization, antitumor efficacy, and pharmacokinetics of bufalin-loaded PEGylated liposomes compared with bufalin entity, which were prepared by FDA-approved pharmaceutical excipients. Bufalin-loaded PEGylated liposomes and bufalin-loaded liposomes were prepared reproducibly with homogeneous particle size by the combination of thin film evaporation method and high-pressure homogenization method. Their mean particle sizes were 127.6 and 155.0 nm, mean zeta potentials were 2.24 and - 18.5 mV, and entrapment efficiencies were 76.31 and 78.40%, respectively. In vitro release profile revealed that the release of bufalin in bufalin-loaded PEGylated liposomes was slower than that in bufalin-loaded liposomes. The cytotoxicity of blank liposomes has been found within acceptable range, whereas bufalin-loaded PEGylated liposomes showed enhanced cytotoxicity to U251 cells compared with bufalin entity. In vivo pharmacokinetics indicated that bufalin-loaded PEGylated liposomes could extend or eliminate the half-life time of bufalin in plasma in rats. The results suggested that bufalin-loaded PEGylated liposomes improved the solubility and increased the drug concentration in plasma.

pH-triggered echogenicity and contents release from liposomes.

Science.gov (United States)

Nahire, Rahul; Hossain, Rayat; Patel, Rupa; Paul, Shirshendu; Meghnani, Varsha; Ambre, Avinash H; Gange, Kara N; Katti, Kalpana S; Leclerc, Estelle; Srivastava, D K; Sarkar, Kausik; Mallik, Sanku

2014-11-03

Liposomes are representative lipid nanoparticles widely used for delivering anticancer drugs, DNA fragments, or siRNA to cancer cells. Upon targeting, various internal and external triggers have been used to increase the rate for contents release from the liposomes. Among the internal triggers, decreased pH within the cellular lysosomes has been successfully used to enhance the rate for releasing contents. However, imparting pH sensitivity to liposomes requires the synthesis of specialized lipids with structures that are substantially modified at a reduced pH. Herein, we report an alternative strategy to render liposomes pH sensitive by encapsulating a precursor which generates gas bubbles in situ in response to acidic pH. The disturbance created by the escaping gas bubbles leads to the rapid release of the encapsulated contents from the liposomes. Atomic force microscopic studies indicate that the liposomal structure is destroyed at a reduced pH. The gas bubbles also render the liposomes echogenic, allowing ultrasound imaging. To demonstrate the applicability of this strategy, we have successfully targeted doxorubicin-encapsulated liposomes to the pancreatic ductal carcinoma cells that overexpress the folate receptor on the surface. In response to the decreased pH in the lysosomes, the encapsulated anticancer drug is efficiently released. Contents released from these liposomes are further enhanced by the application of continuous wave ultrasound (1 MHz), resulting in substantially reduced viability for the pancreatic cancer cells (14%).

Radioprotective effectiveness of Adeturone incapsulated in liposomes

International Nuclear Information System (INIS)

Pantev, T.

1989-01-01

The radioprotective properties of the radioprotector Adeturone incapsulated in mono- and tricomponent liposomes were studied. Intraperitoneal administration of the radioprotector by means of monocomponent liposomes from egg lecithin, as well as its applicaton alone immediately (15-30 min) before irradiation of mice with 7,5 Gy gamma-quanta (LD 100/30 ) guaranteed high survival -80% and 75% accordingly. Orally introduced Adeturone, incapsulated in tricomponent liposomes (dipalmitoil lecithin, cholesterol, stearinamine - 7:2:1), protected for 0,5 to 4,5 hours lethally X-irradiated mice (7,8 Gy; LD 90/30 ). Under these conditions, Adeturone applied alone 4,5 hours before irradiation was ineffective. These results show the presence of prolonged radioprotective effect of Adeturone, when orally applied in the form of liposomal suspension. 2 tabs., 17 refs

Preparation and ocular pharmacokinetics of ganciclovir liposomes

OpenAIRE

Shen, Yan; Tu, Jiasheng

2007-01-01

Ophthalmic liposomes of ganciclovir (GCV) were prepared by the reverse phase evaporation method, and their ocular pharmacokinetics in albino rabbits were compared with those obtained after dosing with GCV solution. The in vitro transcorneal permeability of GCV liposomes was found to be 3.9-fold higher than that of the solution. After in vivo instillation in albino rabbits, no difference was found in the precorneal elimination rate of GCV from liposome vs solution dosing. The aqueous humor con...

The Role of Cavitation in Liposome Formation

OpenAIRE

Richardson, Eric S.; Pitt, William G.; Woodbury, Dixon J.

2007-01-01

Liposome size is a vital parameter of many quantitative biophysical studies. Sonication, or exposure to ultrasound, is used widely to manufacture artificial liposomes, yet little is known about the mechanism by which liposomes are affected by ultrasound. Cavitation, or the oscillation of small gas bubbles in a pressure-varying field, has been shown to be responsible for many biophysical effects of ultrasound on cells. In this study, we correlate the presence and type of cavitation with a decr...

Inhibition of HIV Virus by Neutralizing Vhh Attached to Dual Functional Liposomes Encapsulating Dapivirine.

Science.gov (United States)

Wang, Scarlet Xiaoyan; Michiels, Johan; Ariën, Kevin K; New, Roger; Vanham, Guido; Roitt, Ivan

2016-12-01

Although highly active antiretroviral therapy (HAART) has greatly improved the life expectancy of HIV/AIDS patients, the treatment is not curative. It is a global challenge which fosters an urgent need to develop an effective drug or neutralizing antibody delivery approach for the prevention and treatment of this disease. Due to the low density of envelope spikes with restricted mobility present on the surface of HIV virus, which limit the antibody potency and allow virus mutation and escape from the immune system, it is important for a neutralizing antibody to form bivalent or multivalent bonds with the virus. Liposome constructs could fulfil this need due to the flexible mobility of the membrane with its attached antibodies and the capacity for drug encapsulation. In this study, we evaluated the neutralization activity of a range of liposome formulations in different sizes coated with anti-gp120 llama antibody fragments (Vhhs) conjugated via either non-covalent metal chelation or a covalent linkage. The non-covalent construct demonstrated identical binding affinity to HIV-1 envelope glycoprotein gp120 and neutralizing ability for HIV virus as free Vhh. Although covalently linked Vhh showed significant binding affinity to gp120, it unexpectedly had a lower neutralization potency. This may be due to the comparability in size of the viral and liposome particles restricting the number which can be bound to the liposome surface so involving only a fraction of the antibodies, whereas non-covalently attached antibodies dissociate from the surface after acting with gp120 and free the remainder to bind further viruses. Covalently conjugated Vhh might also trigger the cellular uptake of a liposome-virion complex. To explore the possible ability of the antibody-coated liposomes to have a further function, we encapsulated the hydrophobic antiviral drug dapivirine into both of the non-covalently and covalently conjugated liposome formulations, both of which revealed high

Inhibition of HIV Virus by Neutralizing Vhh Attached to Dual Functional Liposomes Encapsulating Dapivirine

Science.gov (United States)

Wang, Scarlet Xiaoyan; Michiels, Johan; Ariën, Kevin K.; New, Roger; Vanham, Guido; Roitt, Ivan

2016-07-01

Although highly active antiretroviral therapy (HAART) has greatly improved the life expectancy of HIV/AIDS patients, the treatment is not curative. It is a global challenge which fosters an urgent need to develop an effective drug or neutralizing antibody delivery approach for the prevention and treatment of this disease. Due to the low density of envelope spikes with restricted mobility present on the surface of HIV virus, which limit the antibody potency and allow virus mutation and escape from the immune system, it is important for a neutralizing antibody to form bivalent or multivalent bonds with the virus. Liposome constructs could fulfil this need due to the flexible mobility of the membrane with its attached antibodies and the capacity for drug encapsulation. In this study, we evaluated the neutralization activity of a range of liposome formulations in different sizes coated with anti-gp120 llama antibody fragments (Vhhs) conjugated via either non-covalent metal chelation or a covalent linkage. The non-covalent construct demonstrated identical binding affinity to HIV-1 envelope glycoprotein gp120 and neutralizing ability for HIV virus as free Vhh. Although covalently linked Vhh showed significant binding affinity to gp120, it unexpectedly had a lower neutralization potency. This may be due to the comparability in size of the viral and liposome particles restricting the number which can be bound to the liposome surface so involving only a fraction of the antibodies, whereas non-covalently attached antibodies dissociate from the surface after acting with gp120 and free the remainder to bind further viruses. Covalently conjugated Vhh might also trigger the cellular uptake of a liposome-virion complex. To explore the possible ability of the antibody-coated liposomes to have a further function, we encapsulated the hydrophobic antiviral drug dapivirine into both of the non-covalently and covalently conjugated liposome formulations, both of which revealed high

Clearance and localization of intravitreal liposomes in the aphakic vitrectomized eye

International Nuclear Information System (INIS)

Stern, W.H.; Heath, T.D.; Lewis, G.P.; Guerin, C.J.; Erickson, P.A.; Lopez, N.G.; Hong, K.L.

1987-01-01

The authors have examined the fate of intravitreally injected liposomes in the aphakic, vitrectomized eye of the rabbit. Liposomes labelled with 125 [I]-p-hydroxybenzimidylphosphatidylethanolamine were eliminated rapidly from the intraocular fluid. Nonetheless, a significant fraction of these liposomes were found to bind to various ocular tissues including the retina, iris, sclera, and cornea. Ultrastructural studies with gold colloid-loaded liposomes revealed that retinal bound liposomes were attached to the inner limiting lamina but did not penetrate to the internal cells of the retina. Epiretinal cells bound and internalized gold colloid-loaded liposomes suggesting that these cells may be very sensitive to liposome mediated drug delivery

Liposomal curcumin and its application in cancer

Directory of Open Access Journals (Sweden)

Feng T

2017-08-01

Full Text Available Ting Feng,1,* Yumeng Wei,1,* Robert J Lee,2 Ling Zhao1 1Department of Pharmaceutics, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, People’s Republic of China; 2Division of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, OH, USA *These authors contributed equally to this work Abstract: Curcumin (CUR is a yellow polyphenolic compound derived from the plant turmeric. It is widely used to treat many types of diseases, including cancers such as those of lung, cervices, prostate, breast, bone and liver. However, its effectiveness has been limited due to poor aqueous solubility, low bioavailability and rapid metabolism and systemic elimination. To solve these problems, researchers have tried to explore novel drug delivery systems such as liposomes, solid dispersion, microemulsion, micelles, nanogels and dendrimers. Among these, liposomes have been the most extensively studied. Liposomal CUR formulation has greater growth inhibitory and pro-apoptotic effects on cancer cells. This review mainly focuses on the preparation of liposomes containing CUR and its use in cancer therapy. Keywords: curcumin, liposomes, drug delivery, bioavailability, cancer 

Ultrasound-mediated drug delivery using liposomes modified with a thermosensitive polymer.

Science.gov (United States)

Ninomiya, Kazuaki; Kawabata, Shinya; Tashita, Hiroyuki; Shimizu, Nobuaki

2014-01-01

Ultrasound-mediated drug delivery was established using liposomes that were modified with the thermosensitive polymer (TSP) poly(NIPMAM-co-NIPAM), which sensitized the liposomes to high temperatures. TSP-modified liposomes (TSP liposomes) released encapsulated calcein under 1 MHz ultrasound irradiation at 0.5 W/cm(2) for 120 s as well as the case under incubation at 42 °C for 15 min. In addition, uptake of the drug released from TSP liposomes by cancer cells was enhanced by ultrasound irradiation. In a cell injury assay using doxorubicin (DOX)-loaded TSP liposomes and ultrasound irradiation, cell viability of HepG2 cells at 6 h after ultrasound irradiation (1 MHz, 0.5 W/cm(2) for 30 s) with DOX-loaded TSP liposomes (TSP/lipid ratio=1) was 60%, which was significantly lower than that of the control conditions such as DOX-loaded TSP liposomes alone and DOX-loaded intact liposomes under ultrasound irradiation. Copyright © 2013 Elsevier B.V. All rights reserved.

Recent advances in liposomal nanohybrid cerasomes as promising drug nanocarriers.

Science.gov (United States)

Yue, Xiuli; Dai, Zhifei

2014-05-01

Liposomes have been extensively investigated as possible carriers for diagnostic or therapeutic agents due to their unique properties. However, liposomes still have not attained their full potential as drug and gene delivery vehicles because of their insufficient morphological stability. Recently, a super-stable and freestanding hybrid liposomal cerasome (partially ceramic- or silica-coated liposome) has drawn much attention as a novel drug delivery system because its atomic layer of polyorganosiloxane surface imparts higher morphological stability than conventional liposomes and its liposomal bilayer structure reduces the overall rigidity and density greatly compared to silica nanoparticles. Cerasomes are more biocompatible than silica nanoparticles due to the incorporation of the liposomal architecture into cerasomes. Cerasomes combine the advantages of both liposomes and silica nanoparticles but overcome their disadvantages so cerasomes are ideal drug delivery systems. The present review will first highlights some of the key advances of the past decade in the technology of cerasome production and then review current biomedical applications of cerasomes, with a view to stimulating further research in this area of study. Copyright © 2013 Elsevier B.V. All rights reserved.

Methods for using redox liposome biosensors

Science.gov (United States)

Cheng, Quan; Stevens, Raymond C.

2002-01-01

The present invention provides methods and compositions for detecting the presence of biologically-important analytes by using redox liposome biosensors. In particular, the present invention provides liposome/sol-gel electrodes suitable for the detection of a wide variety of organic molecules, including but not limited to bacterial toxins.

ANTISTAPHYLOCOCCAL ACTIVITY OF LIPOSOMAL FORMS OF LINCOMYCIN

Directory of Open Access Journals (Sweden)

Derkach SA

2015-04-01

Full Text Available Nowadays the vital problem of modern medicine is a tendency to emerging of both nosocomial and community-acquired strains before antibiotic resistance forming. The complexity of antibiotic therapy of diseases caused by methicillin resistant staphylococci having high poly resistance almost to every classes of antibacterial agents is of prime importance. One of the ways to improve antibacterial preparations still remains the development of their liposomal forms. This work studies antistaphylococcal activity (according to MIC of the liposomal form of lincomycin developed in the Institute of Dermatology and Venereology of Ukraine by Ivanova N. N., the Candidate of Сhemical Sciences.The purpose of this research work was to study liposomal inhibiting concentration of the liposomalny form of lincomycin and a commercial preparation lincomycin (produced by CJSC “Pharmaceutical firm "Darnitsa". Determination of the minimum inhibiting concentration was carried out by a tablet micromethod by consecutive cultivations of the samples under study.It is shown that MIC of liposomal lincomycin is eight times as low as usual lincomycin (0,23mkg/ml to 1,87 mkg/ml. Antibacterial activity of the liposomal form of lincomycin is studied concerning the patients selected from the different biotopes with pyo inflammatory diseases of staphylococcus strains (15 strains – methicillin sensitive, 12 strains - methicillin resistant.It is shown authentically the higher sensitivity of S. aureus strains to the liposomal form of lincomycin in comparison with usual lincomycin . Also 50.0% of MRSA strains were sensitive to the liposomalny form of lincomycin that shows the perspective for the development of the liposomal forms of antibiotics to cure staphylococcal infections.

Advanced strategies in liposomal cancer therapy

DEFF Research Database (Denmark)

Andresen, Thomas Lars; Jensen, Simon Skøde; Jørgensen, Kent

2005-01-01

is therefore of great importance. In the first part of this review, we present current strategies in the drug delivery field, focusing on site-specific triggered drug release from liposomes in cancerous tissue. Currently marketed drug delivery systems lack the ability to actively release the carried drug......, none of them have yet led to marketed drugs and are still far from achieving this goal. The most advanced and prospective technologies are probably the prodrug strategies where nontoxic drugs are carried and activated specifically in the malignant tissue by overexpressed enzymes. In the second part......Tumor specific drug delivery has become increasingly interesting in cancer therapy, as the use of chemotherapeutics is often limited due to severe side effects. Conventional drug delivery systems have shown low efficiency and a continuous search for more advanced drug delivery principles...

Presence of electrostatically adsorbed polysaccharides improves spray drying of liposomes.

Science.gov (United States)

Karadag, Ayse; Özçelik, Beraat; Sramek, Martin; Gibis, Monika; Kohlus, Reinhard; Weiss, Jochen

2013-02-01

Spray drying of liposomes with conventional wall materials such as maltodextrins often yields nonfunctional powders, that is, liposomes break down during drying and rehydration. Electrostatically coating the surface of liposomes with a charged polymer prior to spray drying may help solve this problem. Anionic lecithin liposomes (approximately 400 nm) were coated with lower (approximately 500 kDa, LMW-C) or higher (approximately 900 kDa, HMW-C) molecular weight cationic chitosan using the layer-by-layer depositing method. Low (DE20, LMW-MD) or high molecular weight (DE2, HMW-MD) maltodextrin was added as wall material to facilitate spray drying. If surfaces of liposomes (1%) were completely covered with chitosan (0.4%), no bridging or depletion flocculation would occur, and mean particle diameters would be approximately 500 nm. If maltodextrins (20%) were added to uncoated liposomes, extensive liposomal breakdown would occur making the system unsuitable for spray drying. No such aggregation or breakdown was observed when maltodextrin was added to chitosan-coated liposomes. Size changed little or even decreased slightly depending on the molecular weight of maltodextrin added. Scanning electron microscopy images of powders containing chitosan-coated liposomes revealed that their morphologies depended on the type of maltodextrin added. Powders prepared with LMW-MD contained mostly spherical particles while HMW-MD powders contained particles with concavities and dents. Upon redispersion, coated liposomes yielded back dispersions with particle size distributions similar to the original ones, except for LMW-C coated samples that had been spray dried with HMW-MD which yielded aggregates (approximately 30 μm). Results show that coating of liposomes with an absorbing polymer allows them to be spray dried with conventional maltodextrin wall materials. Liposomes have attracted considerable attention in the food and agricultural, biomedical industries for the delivery of

Liposomal Drug Product Development and Quality: Current US Experience and Perspective.

Science.gov (United States)

Kapoor, Mamta; Lee, Sau L; Tyner, Katherine M

2017-05-01

Research in the area of liposomes has grown substantially in the past few decades. Liposomes are lipid bilayer structures that can incorporate drug substances to modify the drug's pharmacokinetic profile thereby improving drug delivery. The agency has received over 400 liposomal drug product submissions (excluding combination therapies), and there are currently eight approved liposomal drug products on the US market. In order to identify the pain points in development and manufacturing of liposomal drug products, a retrospective analysis was performed from a quality perspective on submissions for new and generic liposomal drug products. General analysis on liposomal drug product submissions was also performed. Results indicated that 96% of the submissions were Investigational New Drug (IND) applications, 3% were New Drug Applications (NDAs), and the remaining 1% was Abbreviated New Drug Applications (ANDAs). Doxorubicin hydrochloride was the most commonly used drug substance incorporated into the liposomes (31%). The majority of the liposomal products were administered via intravenous route (84%) with cancer (various types) being the most common indication (63%). From a quality perspective, major challenges during the development of liposomal drug products included identification and (appropriate) characterization of critical quality attributes of liposomal drug products and suitable control strategies during product development. By focusing on these areas, a faster and more efficient development of liposomal drug products may be achieved. Additionally, in this way, the drug review process for such products can be streamlined.

The functional curcumin liposomes induce apoptosis in C6 glioblastoma cells and C6 glioblastoma stem cells in vitro and in animals.

Science.gov (United States)

Wang, Yahua; Ying, Xue; Xu, Haolun; Yan, Helu; Li, Xia; Tang, Hui

2017-01-01

Glioblastoma is a kind of malignant gliomas that is almost impossible to cure due to the poor drug transportation across the blood-brain barrier and the existence of glioma stem cells. We prepared a new kind of targeted liposomes in order to improve the drug delivery system onto the glioma cells and induce the apoptosis of glioma stem cells afterward. In this experiment, curcumin was chosen to kill gliomas, while quinacrine was used to induce apoptosis of the glioma stem cells. Also, p -aminophenyl-α-D-mannopyranoside could facilitate the transport of liposomes across the blood-brain barrier and finally target the brain glioma cells. The cell experiments in vitro indicated that the targeted liposomes could significantly improve the anti-tumor effects of the drugs, while enhancing the uptake effects, apoptosis effects, and endocytic effects of C6 glioma cells and C6 glioma stem cells. Given the animal experiments in vivo, we discovered that the targeted liposomes could obviously increase the survival period of brain glioma-bearing mice and inhibit the growth of gliomas. In summary, curcumin and quinacrine liposomes modified with p -aminophenyl-α-D-mannopyranoside is a potential preparation to treat brain glioma cells and brain glioma stem cells.

Efficient intradermal delivery of superoxide dismutase using a combination of liposomes and iontophoresis for protection against UV-induced skin damage.

Science.gov (United States)

Kigasawa, Kaoru; Miyashita, Moeko; Kajimoto, Kazuaki; Kanamura, Kiyoshi; Harashima, Hideyoshi; Kogure, Kentaro

2012-01-01

Superoxide dismutase (SOD) is a potent antioxidant agent that protects against UV-induced skin damage. However, its high molecular weight is a significant obstacle for efficient delivery into the skin through the stratum corneum and development of antioxidant activity. Recently, we developed a non-invasive transfollicular delivery system for macromolecules using a combination of liposomes and iontophoresis, that represents promising technology for enhancing transdermal administration of charged drugs (IJP, 403, 2011, Kajimoto et al.). In this study, in rats we attempted to apply this system to intradermal delivery of SOD for preventing UV-induced skin injury. SOD encapsulating in cationic liposomes was subjected to anodal iontophoresis. After iontophoretic treatment, the liposomes were diffused widely in the viable skin layer around hair follicles. In contrast, passive diffusion failed to transport liposomes efficiently into the skin. Iontophoretic delivery of liposomes encapsulating SOD caused a marked decrease in the production of oxidative products, such as malondialdehyde, hexanoyl lysine, and 8-hydroxi-2-deoxyguanosine, in UV-irradiated skin. These findings suggested that functional SOD can be delivered into the skin using a combination of iontophoresis and a liposomal system. In conclusion, we succeeded in developing an efficient intradermal SOD delivery system, that would be useful for delivery of other macromolecules.

Liposomal Conjugates for Drug Delivery to the Central Nervous System

Directory of Open Access Journals (Sweden)

Frieder Helm

2015-04-01

Full Text Available Treatments of central nervous system (CNS diseases often fail due to the blood–brain barrier. Circumvention of this obstacle is crucial for any systemic treatment of such diseases to be effective. One approach to transfer drugs into the brain is the use of colloidal carrier systems—amongst others, liposomes. A prerequisite for successful drug delivery by colloidal carriers to the brain is the modification of their surface, making them invisible to the reticuloendothelial system (RES and to target them to specific surface epitopes at the blood–brain barrier. This study characterizes liposomes conjugated with cationized bovine serum albumin (cBSA as transport vectors in vitro in porcine brain capillary endothelial cells (PBCEC and in vivo in rats using fluorescently labelled liposomes. Experiments with PBCEC showed that sterically stabilized (PEGylated liposomes without protein as well as liposomes conjugated to native bovine serum albumin (BSA were not taken up. In contrast, cBSA-liposomes were taken up and appeared to be concentrated in intracellular vesicles. Uptake occurred in a concentration and time dependent manner. Free BSA and free cBSA inhibited uptake. After intravenous application of cBSA-liposomes, confocal fluorescence microscopy of brain cryosections from male Wistar rats showed fluorescence associated with liposomes in brain capillary surrounding tissue after 3, 6 and 24 h, for liposomes with a diameter between 120 and 150 nm, suggesting successful brain delivery of cationized-albumin coupled liposomes.

Multifunctional liposomes for MRI and image-guided drug delivery

NARCIS (Netherlands)

Langereis, Sander; Hijnen, Nicole; Strijkers, Gustav; Nicolay, Klaas; Grüll, Holger

2014-01-01

Liposomes are a class of nanovesicles that have been explored extensively in the biomedical arena for early diagnosis and treatment of disease. In recent years, several liposomal drug formulations have been clinically approved in oncology. In a modular approach, the properties of liposomes can be

Astragaloside IV liposomes ameliorates adriamycin-induced ...

African Journals Online (AJOL)

Methods: The rats were given a single tail intravenous injection of adriamycin (6 mg/kg) within 1 week, and then divided into four groups including normal, model, benazepril and astragaloside IV liposomes group. They were all orally administered dosage of benazepril and astragaloside IV liposomes once daily for 8 weeks.

Liposomal Formulations in Clinical Use: An Updated Review

Directory of Open Access Journals (Sweden)

Upendra Bulbake

2017-03-01

Full Text Available Liposomes are the first nano drug delivery systems that have been successfully translated into real-time clinical applications. These closed bilayer phospholipid vesicles have witnessed many technical advances in recent years since their first development in 1965. Delivery of therapeutics by liposomes alters their biodistribution profile, which further enhances the therapeutic index of various drugs. Extensive research is being carried out using these nano drug delivery systems in diverse areas including the delivery of anti-cancer, anti-fungal, anti-inflammatory drugs and therapeutic genes. The significant contribution of liposomes as drug delivery systems in the healthcare sector is known by many clinical products, e.g., Doxil®, Ambisome®, DepoDur™, etc. This review provides a detailed update on liposomal technologies e.g., DepoFoam™ Technology, Stealth technology, etc., the formulation aspects of clinically used products and ongoing clinical trials on liposomes.

Atmospheric-pressure guided streamers for liposomal membrane disruption

International Nuclear Information System (INIS)

Svarnas, P.; Aleiferis, Sp.; Matrali, S. H.; Gazeli, K.; Clément, F.; Antimisiaris, S. G.

2012-01-01

The potential to use liposomes (LIPs) as a cellular model in order to study interactions of cold atmospheric-pressure plasma with cells is herein investigated. Cold atmospheric-pressure plasma is formed by a dielectric-barrier discharge reactor. Large multilamellar vesicle liposomes, consisted of phosphatidylcholine and cholesterol, are prepared by the thin film hydration technique, to encapsulate a small hydrophilic dye, i.e., calcein. The plasma-induced release of calcein from liposomes is then used as a measure of liposome membrane integrity and, consequently, interaction between the cold atmospheric plasma and lipid bilayers. Physical mechanisms leading to membrane disruption are suggested, based on the plasma characterization including gas temperature calculation.

Construction of a Liposome Dialyzer for preparation of high-value, small-volume liposome formulations

OpenAIRE

Adamala, Katarzyna; Engelhart, Aaron E.; Kamat, Neha P.; Jin, Lin; Szostak, Jack W.

2015-01-01

The liposome dialyzer is a small-volume equilibrium dialysis device, built from commercially available materials, that is designed for rapid exchange of small volumes of an extraliposomal reagent pool against a liposome preparation. The dialyzer is prepared by modification of commercially available dialysis cartridges and consists of a reactor with two 300 µL chambers and a 1.56 cm2 dialysis surface area. The dialyzer is prepared in three stages: 1) disassembly of dialysis cartridges to obtai...

Interactions of a Photochromic Spiropyran with Liposome Model Membranes

KAUST Repository

Jonsson, Fabian

2013-02-19

The interactions between anionic or zwitterionic liposomes and a water-soluble, DNA-binding photochromic spiropyran are studied using UV/vis absorption and linear dichroism (LD) spectroscopy. The spectral characteristics as well as the kinetics of the thermal isomerization process in the absence and presence of the two different liposome types provide information about the environment and whether or not the spiropyran resides in the liposome membrane. By measuring LD on liposomes deformed and aligned by shear flow, further insight is obtained about interaction and binding geometry of the spiropyran at the lipid membranes. We show that the membrane interactions differ between the two types of liposomes used as well as the isomeric forms of the spiropyran photoswitch. © 2013 American Chemical Society.

Plasmon resonant liposomes for controlled drug delivery

Science.gov (United States)

Knights-Mitchell, Shellie S.; Romanowski, Marek

2015-03-01

Nanotechnology use in drug delivery promotes a reduction in systemic toxicity, improved pharmacokinetics, and better drug bioavailability. Liposomes continue to be extensively researched as drug delivery systems (DDS) with formulations such as Doxil® and Ambisome® approved by FDA and successfully marketed in the United States. However, the limited ability to precisely control release of active ingredients from these vesicles continues to challenge the broad implementation of this technology. Moreover, the full potential of the carrier to sequester drugs until it can reach its intended target has yet to be realized. Here, we describe a liposomal DDS that releases therapeutic doses of an anticancer drug in response to external stimulus. Earlier, we introduced degradable plasmon resonant liposomes. These constructs, obtained by reducing gold on the liposome surface, facilitate spatial and temporal release of drugs upon laser light illumination that ultimately induces an increase in temperature. In this work, plasmon resonant liposomes have been developed to stably encapsulate and retain doxorubicin at physiological conditions represented by isotonic saline at 37o C and pH 7.4. Subsequently, they are stimulated to release contents either by a 5o C increase in temperature or by laser illumination (760 nm and 88 mW/cm2 power density). Successful development of degradable plasmon resonant liposomes responsive to near-infrared light or moderate hyperthermia can provide a new delivery method for multiple lipophilic and hydrophilic drugs with pharmacokinetic profiles that limit clinical utility.

Curcumin liposomes prepared with milk fat globule membrane phospholipids and soybean lecithin.

Science.gov (United States)

Jin, Hong-Hao; Lu, Qun; Jiang, Jian-Guo

2016-03-01

Using thin film ultrasonic dispersion method, the curcumin liposomes were prepared with milk fat globule membrane (MFGM) phospholipids and soybean lecithins, respectively, to compare the characteristics and stability of the 2 curcumin liposomes. The processing parameters of curcumin liposomes were investigated to evaluate their effects on the encapsulation efficiency. Curcumin liposomes were characterized in terms of size distribution, ζ-potential, and in vitro release behavior, and then their storage stability under various conditions was evaluated. The curcumin liposomes prepared with MFGM phospholipids had an encapsulation efficiency of about 74%, an average particle size of 212.3 nm, and a ζ-potential of -48.60 mV. The MFGM liposomes showed higher encapsulation efficiency, smaller particle size, higher absolute value of ζ-potential, and slower in vitro release than soybean liposomes. The retention rate of liposomal curcumin was significantly higher than that of free curcumin. The stability of the 2 liposomes under different pH was almost the same, but MFGM liposomes displayed a slightly higher stability than soybean liposomes under the conditions of Fe(3+), light, temperature, oxygen, and relative humidity. In conclusion, MFGM phospholipids have potential advantages in the manufacture of curcumin liposomes used in food systems. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Investigations of a new, highly negative liposome with improved biodistribution for imaging

International Nuclear Information System (INIS)

Hnatowich, D.J.; Clancy, B.

1980-01-01

An attractive feature of liposomes is the wide range of lipid composition that can lead to liposome formation, coupled with the observation that liposome biodistribution may be altered by varying lipid composition. For instance, adding charged lipids to neutral lecithin will alter the biodistribution of the resulting charged liposomes. We have prepared highly negative liposomes by replacing lecithin with negatively charged cardiolipin. The liposomes have been labeled in the lipid phase with Ga-67 and Tc-99m oxine and their properties evaluated. The expected high negative charge of the resulting liposomes was confirmed by an ion-exchange chromatographic technique. Using paper chromatography, the stability of the label was determined during incubation in saline and serum. Finally, biodistributions were determined at 2 h in mice, and the results compared with those for negative lecithin liposomes. Accumulated activities in liver and spleen were reduced by factors of five and 20, respectively, over lecithin liposomes. Since preferential accumulation of activity in these organs constitutes the biggest limitation to the use of lecithin liposomes, cardiolipin liposomes may prove to be more useful carriers of radioactivity in imaging applications. More importantly, however, these results illustrate the value of studying novel liposome types as potential radiopharmaceuticals

Progress involving new techniques for liposome preparation

Directory of Open Access Journals (Sweden)

Zhenjun Huang

2014-08-01

Full Text Available The article presents a review of new techniques being used for the preparation of liposomes. A total of 28 publications were examined. In addition to the theories, characteristics and problems associated with traditional methods, the advantages and drawbacks of the latest techniques were reviewed. In the light of developments in many relevant areas, a variety of new techniques are being used for liposome preparation and each of these new technique has particular advantages over conventional preparation methods. However, there are still some problems associated with these new techniques that could hinder their applications and further improvements are needed. Generally speaking, due to the introduction of these latest techniques, liposome preparation is now an improved procedure. These applications promote not only advances in liposome research but also the methods for their production on an industrial scale.

Enzymatic degradation of polymer covered SOPC-liposomes in relation to drug delivery

DEFF Research Database (Denmark)

Davidsen, Jesper; Vermehren, C.; Frøkjær, S.

2001-01-01

Polyethylenoxide (PEG) covered liposomes are used as lipid-based drug-delivery systems. In comparison to conventional liposomes the polymer-covered liposomes display a long circulation half-life in the blood stream. We investigate the influence of polyethyleneoxide-distearoylphosphatidylethanolam......Polyethylenoxide (PEG) covered liposomes are used as lipid-based drug-delivery systems. In comparison to conventional liposomes the polymer-covered liposomes display a long circulation half-life in the blood stream. We investigate the influence of polyethyleneoxide...

Giant liposomes as delivery system for ecophysiological studies in copepods.

Science.gov (United States)

Buttino, Isabella; De Rosa, Giuseppe; Carotenuto, Ylenia; Ianora, Adrianna; Fontana, Angelo; Quaglia, Fabiana; La Rotonda, Maria Immacolata; Miralto, Antonio

2006-03-01

Giant liposomes are proposed as a potential delivery system in marine copepods, the dominant constituent of the zooplankton. Liposomes were prepared in the same size range as the food ingested by copepods (mean diameter of about 7 microm). The encapsulation of a hydrophilic and high molecular mass fluorescent compound, fluorescein isothiocyanate-dextran (FitcDx), within the liposomes provided a means of verifying copepod ingestion when viewed with the confocal laser-scanning microscope. Females of the calanoid copepod Temora stylifera were fed with FitcDx-encapsulated liposomes alone or mixed with the dinoflagellate alga Prorocentrum minimum. Control copepods were incubated with the P. minimum diet alone. Egg production rates, percentage egg-hatching success and number of faecal pellets produced were evaluated after 24 h and 48 h of feeding. Epifluorescence of copepod gut and faecal pellets indicated that the liposomes were actively ingested by T. stylifera in both experimental food conditions, with or without the dinoflagellate diet. Ingestion rates calculated using 3H-labelled liposomes indicated that females ingested more liposomes when P. minimum was added to the solution (16% vs 7.6% of uptake). When liposomes were supplied together with the algal diet, egg production rate, egg-hatching success and faecal pellet production were as high as those observed for the control diet. By contrary, egg production and hatching success were very low with a diet of liposomes alone and faecal pellet production was similar to that recorded in starved females. This results suggest that liposomes alone did not add any nutritive value to the diet, making them a good candidate as inert carriers to study the nutrient requirements or biological activity of different compounds. In particular, such liposomes are proposed as carriers for diatom-derived polyunsaturated aldehydes, which are known to impair copepod embryo viability. Other potential applications of liposomes as a delivery

Ultrasound triggered drug delivery with liposomal nested microbubbles.

Science.gov (United States)

Wallace, N; Wrenn, S P

2015-12-01

When ultrasound contrast agent microbubbles are nested within a liposome, damage to the liposome membrane caused by both stable and inertial cavitation of the microbubble allows for release of the aqueous core of the liposome. Triggered release was not accomplished unless microbubbles were present within the liposome. Leakage was tested using fluorescence assays developed specifically for this drug delivery vehicle and qualitative measurements using an optical microscope. These studies were done using a 1 MHz focused ultrasound transducer while varying parameters including peak negative ultrasound pressure, average liposome diameter, and microbubble concentration. Two regimes exist for membrane disruption caused by cavitating microbubbles. A faster release rate, as well as permanent membrane damage are seen for samples exposed to high pressure (2.1-3.7 MPa). A slower release rate and dilation/temporary poration are characteristic of stable cavitation for low pressure studies (0.54-1.7 MPa). Copyright © 2015 Elsevier B.V. All rights reserved.

P5 HER2/neu-derived peptide conjugated to liposomes containing MPL adjuvant as an effective prophylactic vaccine formulation for breast cancer.

Science.gov (United States)

Shariat, Sheida; Badiee, Ali; Jalali, Seyed Amir; Mansourian, Mercedeh; Yazdani, Mona; Mortazavi, Seyed Alireza; Jaafari, Mahmoud Reza

2014-12-01

Vaccines containing synthetic peptides derived from tumor-associated antigens (TAA) can elicit potent cytotoxic T lymphocyte (CTL) response if they are formulated in an optimal vaccine delivery system. The aim of this study was to develop a simple and effective lipid-based vaccine delivery system using P5 HER2/neu-derived peptide conjugated to Maleimide-PEG2000-DSPE. The conjugated lipid was then incorporated into liposomes composed of DMPC:DMPG:Chol:DOPE containing Monophosphoryl lipid A (MPL) (Lip-DOPE-P5-MPL). Different liposome formulations were prepared and characterized for their physicochemical properties. To evaluate anti-tumoral efficacy, BALB/c mice were immunized subcutaneously 3 times in two-week intervals and the generated immune response was studied. The results demonstrated that Lip-DOPE-P5-MPL induced a significantly higher IFN-γ production by CD8+ T cells intracellularly which represents higher CTL response in comparison with other control formulations. CTL response induced by this formulation caused the lowest tumor size and the longest survival time in a mice model of TUBO tumor. The encouraging results achieved by Lip-DOPE-P5-MPL formulation could make it a promising candidate in developing effective vaccines against Her2 positive breast cancers. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Evaluation of iron transport from ferrous glycinate liposomes using ...

African Journals Online (AJOL)

Background: Iron fortification of foods is currently a strategy employed to fight iron deficiency in countries. Liposomes were assumed to be a potential carrier of iron supplements. Objective: The objective of this study was to investigate the iron transport from ferrous glycinate liposomes, and to estimate the effects of liposomal ...

Body distributioin of RGD-mediated liposome in brain-targeting drug delivery.

Science.gov (United States)

Qin, Jing; Chen, DaWei; Hu, Haiyang; Qiao, MingXi; Zhao, XiuLi; Chen, Baoyu

2007-09-01

RGD conjugation liposomes (RGD-liposomes) were evaluated for brain-targeting drug delivery. The flow cytometric in vitro study demonstrated that RGD-liposomes could bind to monocytes and neutrophils effectively. Ferulic acid (4-hydroxy-3-methoxycinnamic, FA) was loaded into liposomes. Rats were subjected to intrastriatal microinjections of 100 units of human recombinant IL-1beta to produce brain inflammation and caudal vein injection of three formulations (FA solution, FA liposome and RGD-coated FA liposome). Animals were sacrificed 15, 30, 60 and 120 min after administration to study the body distribution of the FA in the three formulations. HPLC was used to determine the concentration of FA in vivo with salicylic acid as internal standard. The results of body distribution indicated that RGD-coated liposomes could be mediated into the brain with a 6-fold FA concentration compared to FA solution and 3-fold in comparison to uncoated liposome. Brain targeted delivery was achieved and a reduction in dosage might be allowed.

Methylation of the phosphate oxygen moiety of phospholipid-methoxy(polyethylene glycol) conjugate prevents PEGylated liposome-mediated complement activation and anaphylatoxin production

DEFF Research Database (Denmark)

Moghimi, S.M.; Hamad, I.; Andresen, Thomas Lars

2006-01-01

Methoxy(polyethylene glycol), mPEG, -grafted liposomes are known to exhibit prolonged circulation time in the blood, but their infusion into a substantial percentage of human subjects triggers immediate non-IgE-mediated hypersensitivity reactions. These reactions are strongly believed to arise from...... to PEGylated liposome-mediated complement activation. Our findings provide a rational conceptual basis for development of safer vesicles for site-specific drug delivery and controlled release at pathological sites....

Bubble-generating nano-lipid carriers for ultrasound/CT imaging-guided efficient tumor therapy.

Science.gov (United States)

Zhang, Nan; Li, Jia; Hou, Ruirui; Zhang, Jiangnan; Wang, Pei; Liu, Xinyang; Zhang, Zhenzhong

2017-12-20

Ideal therapeutic effectiveness of chemotherapy is obtained only when tumor cells are exposed to a maximal drug concentration, which is often hindered by dose-limiting toxicity. We designed a bubble-generating liposomal delivery system by introducing ammonium bicarbonate and gold nanorods into folic acid-conjugated liposomes to allow both multimodal imaging and the local release of drug (doxorubicin) with hyperthermia. The key component, ammonium bicarbonate, allows a controlled, rapid release of doxorubicin to provide an effective drug concentration in the tumor microenvironment. An in vitro temperature-triggered drug release study showed that cumulative release improved more than two-fold. In addition, in vitro and in vivo studies indicated that local heat treatment or ultrasonic cavitation enhanced the therapeutic efficiency greatly. The delivery system could also serve as an excellent contrast agent to allow ultrasonic imaging and computerized tomography imaging simultaneously to further achieve the aim of accurate diagnostics. Results of this study showed that this versatile bubble-generating liposome is a promising system to provide optimal therapeutic effects that are guided by multimodal imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Transcutaneous drug delivery by liposomes using fractional laser technology.

Science.gov (United States)

Fujimoto, Takahiro; Wang, Jian; Baba, Kazuki; Oki, Yuka; Hiruta, Yuki; Ito, Masayuki; Ito, Shinobu; Kanazawa, Hideko

2017-07-01

Transdermal delivery of hydrophilic peptides remains a challenge due to their poor cellular uptake and transdermal penetration. We hypothesize that combination of a CO 2 fractional laser to enhance percutaneous absorption and liposomes as transdermal carriers would improve skin penetration of hydrophilic drugs. NA. Liposomes were prepared using membrane fusion lipid dioleoylphosphatidylethanolamine, and used to deliver 5-carboxyfluorescein (CF) and fluorescein isothiocyanate-conjugated ovalbumin (OVA-FITC) as model hydrophilic peptide drugs. Liposome size was estimated by dynamic light scattering. Liposome uptake into murine macrophage cells and penetration or permeation into Yucatan micropig skin after irradiation by CO 2 fractional laser at varying energy levels (laser power and exposure duration) were investigated using Franz cell and fluorescence microscopy. Oxidative damage to the irradiated mouse skin was assessed by electron spin resonance. Size of CF and OVA-FITC encapsulated liposomes was 324 ± 75 nm. Cellular uptake of OVA-FITC delivered by liposomes was 10-fold higher (1,370 relative fluorescence units, RFU) than delivered in solution form (130 RFU). Fractional laser irradiation increased skin permeation rate of CF liposomes (0-10%) and OVA-FITC liposomes (4-40%) in a dose-dependent manner. Although peeling off the stratum corneum facilitated CF liposome penetration at low energy levels (2.69-3.29 J/cm 2 ; 10-20 W for 500 μs), drug permeation was similar (7-8%) in peeled or untreated skin at higher laser energy levels (6.06 J/cm 2 ; 20 W for 1,500 μs). FITC penetrated deeper in the skin after laser irradiation. However, OH, O2-, and VC reactive oxygen species were generated upon irradiation of the skin with a fractional CO 2 laser. Increasing laser power and irradiation, time increased liposome uptake by cells and penetration of peptide drugs across the skin in a dose-dependent manner. High-energy CO 2 fractional laser overcomes the

Liposomal encapsulated Zn-DTPA for removing intracellular 169Yb

International Nuclear Information System (INIS)

Blank, M.L.; Cress, E.A.; Byrd, B.L.; Washburn, L.C.; Snyder, F.

1980-01-01

Multilamellar liposomes possessing neutral positive or negative charges were tested for their capacity to encapsulate sodium ethylenediaminetetraacetate (EDTA) and for their selectivity in depositing in specific tissues after being injected into rats. Negative-charged liposomes had the greatest trapping efficiency over a wide range of lipid-to-aqueous phase ratios. In contrast, except for lung, liposomal charge had no significant effect on the tissue distribution of encapsulated EDTA; liver and spleen exhibited the highest uptake with all preparations. The proportion of encapsulated EDTA taken up by the liver decreased as the amount of injected liposomes was increased. Free zinc diethylenetriaminepentaacetate (Zn-DTPA) and multilamellar liposomes containing entrapped Zn-DTPA were administered to rats that had been injected with 169 Yb-citrate 24 hr earlier. At doses of 14 mg Zn-DTPA per kg body weight, both free Zn-DPTA and the liposomal-bound Zn-DTPA caused increased removal of 169 Yb from the animals. However, treatment with the liposomal Zn-DTPA caused significantly more of the 169 Yb to be removed than did the free Zn-DTPA treatment by itself. Our data indicate that lipophilic forms of chelators can effectively increase the removal rates of heavy metal contamination in tissues. (author)

Tumor-targeting magnetic lipoplex delivery of short hairpin RNA suppresses IGF-1R overexpression of lung adenocarcinoma A549 cells in vitro and in vivo

Energy Technology Data Exchange (ETDEWEB)

Wang, Chunmao; Ding, Chao; Kong, Minjian [Department of Cardiothoracic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China); Dong, Aiqiang, E-mail: dr_dongaiqiang@sina.com [Department of Cardiothoracic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China); Qian, Jianfang; Jiang, Daming; Shen, Zhonghua [Department of Cardiothoracic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China)

2011-07-08

Highlights: {yields} We compared lipofection with magnetofection about difference of transfection efficiency on delivery a therapeutic gene in vitro and in vivo. {yields} We investigated the difference of shRNA induced by magnetofection and lipofection into A549 cell and subcutaneous tumor to knockdown IGF-1R overexpressed in A549 cell and A549 tumor. {yields} We investigated in vivo shRNA silenced IGF-1R overexpression 24, 48, and 72 h after shRNA intravenous injection into tumor-bearing mice by way of magnetofection and lipofection. {yields} Our results showed that magnetofection could achieve therapeutic gene targeted delivery into special site, which contributed to targeted gene therapy of lung cancers. -- Abstract: Liposomal magnetofection potentiates gene transfection by applying a magnetic field to concentrate magnetic lipoplexes onto target cells. Magnetic lipoplexes are self-assembling ternary complexes of cationic lipids with plasmid DNA associated with superparamagnetic iron oxide nanoparticles (SPIONs). Type1insulin-like growth factor receptor (IGF-1R), an important oncogene, is frequently overexpressed in lung cancer and mediates cancer cell proliferation and tumor growth. In this study, we evaluated the transfection efficiency (percentage of transfected cells) and therapeutic potential (potency of IGF-1R knockdown) of liposomal magnetofection of plasmids expressing GFP and shRNAs targeting IGF-1R (pGFPshIGF-1Rs) in A549 cells and in tumor-bearing mice as compared to lipofection using Lipofectamine 2000. Liposomal magnetofection provided a threefold improvement in transgene expression over lipofection and transfected up to 64.1% of A549 cells in vitro. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1 {+-} 6% and by liposomal magnetofection by 85.1 {+-} 3%. In vivo delivery efficiency of the pGFPshIGF-1R plasmid into the tumor was significantly higher in the liposomal magnetofection group than in the

Tumor-targeting magnetic lipoplex delivery of short hairpin RNA suppresses IGF-1R overexpression of lung adenocarcinoma A549 cells in vitro and in vivo

International Nuclear Information System (INIS)

Wang, Chunmao; Ding, Chao; Kong, Minjian; Dong, Aiqiang; Qian, Jianfang; Jiang, Daming; Shen, Zhonghua

2011-01-01

Highlights: → We compared lipofection with magnetofection about difference of transfection efficiency on delivery a therapeutic gene in vitro and in vivo. → We investigated the difference of shRNA induced by magnetofection and lipofection into A549 cell and subcutaneous tumor to knockdown IGF-1R overexpressed in A549 cell and A549 tumor. → We investigated in vivo shRNA silenced IGF-1R overexpression 24, 48, and 72 h after shRNA intravenous injection into tumor-bearing mice by way of magnetofection and lipofection. → Our results showed that magnetofection could achieve therapeutic gene targeted delivery into special site, which contributed to targeted gene therapy of lung cancers. -- Abstract: Liposomal magnetofection potentiates gene transfection by applying a magnetic field to concentrate magnetic lipoplexes onto target cells. Magnetic lipoplexes are self-assembling ternary complexes of cationic lipids with plasmid DNA associated with superparamagnetic iron oxide nanoparticles (SPIONs). Type1insulin-like growth factor receptor (IGF-1R), an important oncogene, is frequently overexpressed in lung cancer and mediates cancer cell proliferation and tumor growth. In this study, we evaluated the transfection efficiency (percentage of transfected cells) and therapeutic potential (potency of IGF-1R knockdown) of liposomal magnetofection of plasmids expressing GFP and shRNAs targeting IGF-1R (pGFPshIGF-1Rs) in A549 cells and in tumor-bearing mice as compared to lipofection using Lipofectamine 2000. Liposomal magnetofection provided a threefold improvement in transgene expression over lipofection and transfected up to 64.1% of A549 cells in vitro. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1 ± 6% and by liposomal magnetofection by 85.1 ± 3%. In vivo delivery efficiency of the pGFPshIGF-1R plasmid into the tumor was significantly higher in the liposomal magnetofection group than in the lipofection group. In vivo IGF-1R

Drug targeting to tumors: principles, pitfalls and (pre-) clinical progress

NARCIS (Netherlands)

Lammers, Twan Gerardus Gertudis Maria; Kiessling, F.; Hennink, W.E.; Storm, Gerrit

2012-01-01

Abstract Many different systems and strategies have been evaluated for drug targeting to tumors over the years. Routinely used systems include liposomes, polymers, micelles, nanoparticles and antibodies, and examples of strategies are passive drug targeting, active drug targeting to cancer cells,

Liposomes as potential carrier system for targeted delivery of polyene antibiotics.

Science.gov (United States)

Naik, Suresh R; Desai, Sandhya K; Shah, Priyank D; Wala, Santosh M

2013-09-01

The development of new therapeutic modalities involves the use of drug carrier, such as liposomes, which can modify pharmacokinetic and bio-distribution of drug profile. Polyene antibiotics incorporation into liposomes improves its availability at the site, bio-distribution and therapeutic index mainly through the engulfment of liposomes by circulating monocytes/macrophages and transportation to the site of infection. Polyene antibiotics (AmB, SJA-95, HA-1-92) and other antibiotics (streptomycin, tobramycin, quinolones, anti-tubercular and anti-cancer drugs), liposomal preparations are described with possible advantages from therapeutic efficacy and toxicity point of view. The polyene macrolide antibiotics liposomal preparations proved to be more effective in the treatment of systemic mycosis. The AmB-cyclodextrin derivatives inclusion complex is a major breakthrough in liposomal preparation which can be converted into aqueous phase of liposome. Liposomal drug incorporated preparation has been one of the important areas of research for developing the existing polyene antibiotics into useful chemotherapeutic agents in clinical medicine. In recent past other antibiotics have also been incorporated into liposomes using wide variety of materials, phosphatidylethanolamine derivatives (pegylated liposomes, enzyme sensitive conjugates, fluidosomes of anti-cancer drugs and poly lactic/glycolic acid microspheres for anti-tuberculosis drugs). In addition, attempts were also made to extend the receptor mediated drug targeting and to review some relevant patents.

Development of a DNA-liposome complex for gene delivery applications

Energy Technology Data Exchange (ETDEWEB)

Rasoulianboroujeni, M. [Marquette University School of Dentistry, Milwaukee, WI 53233 (United States); Kupgan, G. [Department of Chemical Engineering, Oklahoma State University, 423 Engineering North, Stillwater, OK 74078 (United States); Moghadam, F. [School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ (United States); Tahriri, M. [Marquette University School of Dentistry, Milwaukee, WI 53233 (United States); Boughdachi, A. [Polymer Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Khoshkenar, P. [Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605 (United States); Ambrose, J.J. [Biomedical Engineering Department, Louisiana Tech University, Ruston, LA 71272 (United States); Kiaie, N. [Tissue Engineering Department, Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Vashaee, D. [Electrical and Computer Engineering Department, North Carolina State University, Raleigh, NC 27606 (United States); Ramsey, J.D. [Department of Chemical Engineering, Oklahoma State University, 423 Engineering North, Stillwater, OK 74078 (United States); Tayebi, L., E-mail: lobat.tayebi@marquette.edu [Marquette University School of Dentistry, Milwaukee, WI 53233 (United States)

2017-06-01

The association structures formed by cationic liposomes and DNA (Deoxyribonucleic acid)-liposome have been effectively utilized as gene carriers in transfection assays. In this research study, cationic liposomes were prepared using a modified lipid film hydration method consisting of a lyophilization step for gene delivery applications. The obtained results demonstrated that the mean particle size had no significant change while the polydispersity (PDI) increased after lyophilization. The mean particle size slightly reduced after lyophilization (520 ± 12 nm to 464 ± 25 nm) while the PDI increased after lyophilization (0.094 ± 0.017 to 0.220 ± 0.004). In addition. The mean particle size of vesicles increases when DNA is incorporated to the liposomes (673 ± 27 nm). According to the Scanning Electron Microscopy (SEM) and transmission electron microscopy (TEM) images, the spherical shape of liposomes confirmed their successful preservation and reconstitution from the powder. It was found that liposomal formulation has enhanced transfection considerably compared to the naked DNA as negative control. Finally, liposomal formulation in this research had a better function than Lipofectamine® 2000 as a commercialized product because the cellular activity (cellular protein) was higher in the prepared lipoplex than Lipofectamine® 2000. - Highlights: • Liposomal formulation in this research had a better function than Lipofectamine® 2000. • The average particle size had no significant change while the PDI increased after lyophilization. • LacZ expression of the developed cationic liposomes is approximately equal to the Lipofectamine® 2000.

The Role of Liposomal Bupivacaine in Value-Based Care.

Science.gov (United States)

Iorio, Richard

Multimodal pain control strategies are crucial in reducing opioid use and delivering effective pain management to facilitate improved surgical outcomes. The utility of liposomal bupivacaine in enabling effective pain control in multimodal strategies has been demonstrated in several studies, but others have found the value of liposomal bupivacaine in such approaches to be insignificant. At New York University Langone Medical Center, liposomal bupivacaine injection and femoral nerve block were compared in their delivery of efficacious and cost-effective multimodal analgesia among patients undergoing total joint arthroplasty (TJA). Retrospective analysis revealed that including liposomal bupivacaine in a multimodal pain control protocol for TJA resulted in improved quality and efficiency metrics, decreased narcotic use, and faster mobilization, all relative to femoral nerve block, and without a significant increase in admission costs. In addition, liposomal bupivacaine use was associated with elimination of the need for patient-controlled analgesia in TJA. Thus, at Langone Medical Center, the introduction of liposomal bupivacaine to TJA has been instrumental in achieving adequate pain control, delivering high-level quality of care, and controlling costs.

A Ketogenic Formula Prevents Tumor Progression and Cancer Cachexia by Attenuating Systemic Inflammation in Colon 26 Tumor-Bearing Mice

Directory of Open Access Journals (Sweden)

Kentaro Nakamura

2018-02-01

Full Text Available Low-carbohydrate, high-fat diets (ketogenic diets might prevent tumor progression and could be used as supportive therapy; however, few studies have addressed the effect of such diets on colorectal cancer. An infant formula with a ketogenic composition (ketogenic formula; KF is used to treat patients with refractory epilepsy. We investigated the effect of KF on cancer and cancer cachexia in colon tumor-bearing mice. Mice were randomized into normal (NR, tumor-bearing (TB, and ketogenic formula (KF groups. Colon 26 cells were inoculated subcutaneously into TB and KF mice. The NR and TB groups received a standard diet, and the KF mice received KF ad libitum. KF mice preserved their body, muscle, and carcass weights. Tumor weight and plasma IL-6 levels were significantly lower in KF mice than in TB mice. In the KF group, energy intake was significantly higher than that in the other two groups. Blood ketone body concentrations in KF mice were significantly elevated, and there was a significant negative correlation between blood ketone body concentration and tumor weight. Therefore, KF may suppress the progression of cancer and the accompanying systemic inflammation without adverse effects on weight gain, or muscle mass, which might help to prevent cancer cachexia.

PEG minocycline-liposomes ameliorate CNS autoimmune disease.

Directory of Open Access Journals (Sweden)

Wei Hu

Full Text Available Minocycline is an oral tetracycline derivative with good bioavailability in the central nervous system (CNS. Minocycline, a potent inhibitor of matrix metalloproteinase (MMP-9, attenuates disease activity in experimental autoimmune encephalomyelitis (EAE, an animal model of multiple sclerosis (MS. Potential adverse effects associated with long-term daily minocycline therapy in human patients are concerning. Here, we investigated whether less frequent treatment with long-circulating polyethylene glycol (PEG minocycline liposomes are effective in treating EAE.Performing in vitro time kinetic studies of PEG minocycline-liposomes in human peripheral blood mononuclear cells (PBMCs, we determined that PEG minocycline-liposome preparations stabilized with CaCl(2 are effective in diminishing MMP-9 activity. Intravenous injections of PEG minocycline-liposomes every five days were as effective in ameliorating clinical EAE as daily intraperitoneal injections of minocycline. Treatment of animals with PEG minocycline-liposomes significantly reduced the number of CNS-infiltrating leukocytes, and the overall expression of MMP-9 in the CNS. There was also a significant suppression of MMP-9 expression and proteolytic activity in splenocytes of treated animals, but not in CNS-infiltrating leukocytes. Thus, leukocytes gaining access to the brain and spinal cord require the same absolute amount of MMP-9 in all treatment groups, but minocycline decreases the absolute cell number.Our data indicate that less frequent injections of PEG minocycline-liposomes are an effective alternative pharmacotherapy to daily minocycline injections for the treatment of CNS autoimmune diseases. Also, inhibition of MMP-9 remains a promising treatment target in EAE and patients with MS.

Experimental photodynamic therapy with MESO-tetrakisphenylporphyrin (TPP) in liposomes leads to disintegration of human amelanotic melanoma implanted to nude mice

Czech Academy of Sciences Publication Activity Database

Ježek, Petr; Nekvasil, Miloš; Škobisová, Eva; Urbánková, Eva; Jirsa, M.; Zadinová, M.; Poučková, P.; Klepáček, I.

2003-01-01

Roč. 103, č. 5 (2003), s. 693-702 ISSN 0020-7136 R&D Projects: GA MZd NC4810; GA MZd NC6564 Institutional research plan: CEZ:AV0Z5011922 Keywords : photodynamic therapy of tumors * meso-tetrakis-phenylporphyrin * liposomal drug delivery Subject RIV: FD - Oncology ; Hematology Impact factor: 4.375, year: 2003

Novel local drug delivery system using thermoreversible gel in combination with polymeric microspheres or liposomes.

Science.gov (United States)

Arai, Takao; Benny, Ofra; Joki, Tatsuhiro; Menon, Lata G; Machluf, Marcelle; Abe, Toshiaki; Carroll, Rona S; Black, Peter M

2010-04-01

The purpose of our study was to evaluate the application of thermoreversible gelation polymer (TGP) as a local drug delivery system for malignant glioma. Polymeric microspheres or liposomes loaded with doxorubicin (sphere-dox or lipo-dox) were combined with TGP to provide continuous drug delivery of doxorubicin (dox) for kinetic release studies and cell viability assays on glioma cell lines in vitro. For in vivo studies, TGP loaded with dox alone (TGP-dox) was combined with sphere-dox or lipo-dox. Their antitumor effects on subcutaneous human glioma xenografts were evaluated in nude mice. In vitro, TGP combined with sphere-dox or lipo-dox released dox for up to 30 days. In vivo, TGP-dox combined with sphere-dox or lipo-dox inhibited subcutaneous glioma tumor growth until day 32 and day 38, respectively. TGP in combination with microspheres or liposomes successfully prolonged the release of dox and its antitumor effects.

Chemical meningitis related to intra-CSF liposomal cytarabine.

Science.gov (United States)

Durand, Bénédicte; Zairi, Fahed; Boulanger, Thomas; Bonneterre, Jacques; Mortier, Laurent; Le Rhun, Emilie

2017-10-01

Therapeutic options of leptomeningeal metastases include intra-cerebrospinal fluid (CSF) chemotherapy. Among intra-CSF agents, liposomal cytarabine has advantages but can induce specific toxicities. A BRAF-V600E-mutated melanoma leptomeningeal metastases patient, treated by dabrafenib and liposomal cytarabine, presented after the first injection of liposomal cytarabine with hyperthermia and headaches. Despite sterile CSF/blood analyses, extended intravenous antibiotics were given and the second injection was delayed. The diagnosis of chemical meningitis was finally made. Dose reduction and appropriate symptomatic treatment permitted the administration of 15 injections of liposomal cytarabine combined with dabrafenib. A confirmation of the diagnosis of chemical meningitis is essential in order (1) not to delay intra-CSF or systemic chemotherapy or (2) to limit the administration of unnecessary but potentially toxic antibiotics.

Treatment of Digital Ischemia with Liposomal Bupivacaine

Directory of Open Access Journals (Sweden)

José Raul Soberón

2014-01-01

Full Text Available Objective. This report describes a case in which the off-label use of liposomal bupivacaine (Exparel in a peripheral nerve block resulted in marked improvement of a patient’s vasoocclusive symptoms. The vasodilating and analgesic properties of liposomal bupivacaine in patients with ischemic symptoms are unknown, but our clinical experience suggests a role in the management of patients suffering from vasoocclusive disease. Case Report. A 45-year-old African American female was admitted to the hospital with severe digital ischemic pain. She was not a candidate for any vascular surgical or procedural interventions. Two continuous supraclavicular nerve blocks were placed with modest clinical improvement. These effects were also short-lived, with the benefits resolving after the discontinuation of the peripheral nerve blocks. She continued to report severe pain and was on multiple anticoagulant medications, so a decision was made to perform an axillary nerve block using liposomal bupivacaine (Exparel given the compressibility of the site as well as the superficial nature of the target structures. Conclusions. This case report describes the successful off-label usage of liposomal bupivacaine (Exparel in a patient with digital ischemia. Liposomal bupivacaine (Exparel is currently FDA approved only for wound infiltration use at this time.

Biophysical aspects of using liposomes as delivery vehicles.

Science.gov (United States)

Ulrich, Anne S

2002-04-01

Liposomes are used as biocompatible carriers of drugs, peptides, proteins, plasmic DNA, antisense oligonucleotides or ribozymes, for pharmaceutical, cosmetic, and biochemical purposes. The enormous versatility in particle size and in the physical parameters of the lipids affords an attractive potential for constructing tailor-made vehicles for a wide range of applications. Some of the recent literature will be reviewed here and presented from a biophysical point of view, thus providing a background for the more specialized articles in this special issue on liposome technology. Different properties (size, colloidal behavior, phase transitions, and polymorphism) of diverse lipid formulations (liposomes, lipoplexes, cubic phases, emulsions, and solid lipid nanoparticles) for distinct applications (parenteral, transdermal, pulmonary, and oral administration) will be rationalized in terms of common structural, thermodynamic and kinetic parameters of the lipids. This general biophysical basis helps to understand pharmaceutically relevant aspects such as liposome stability during storage and towards serum, the biodistribution and specific targeting of cargo, and how to trigger drug release and membrane fusion. Methods for the preparation and characterization of liposomal formulations in vitro will be outlined, too.

Liposomal nanoparticles encapsulating iloprost exhibit enhanced vasodilation in pulmonary arteries

Directory of Open Access Journals (Sweden)

Jain PP

2014-07-01

Full Text Available Pritesh P Jain,1 Regina Leber,1,2 Chandran Nagaraj,1 Gerd Leitinger,3 Bernhard Lehofer,4 Horst Olschewski,1,5 Andrea Olschewski,1,6 Ruth Prassl,1,4 Leigh M Marsh11Ludwig Boltzmann Institute for Lung Vascular Research, 2Biophysics Division, Institute of Molecular Biosciences, University of Graz, 3Research Unit Electron Microscopic Techniques, Institute of Cell Biology, Histology, and Embryology, 4Institute of Biophysics, 5Division of Pulmonology, Department of Internal Medicine, 6Department of Anesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, AustriaAbstract: Prostacyclin analogues are standard therapeutic options for vasoconstrictive diseases, including pulmonary hypertension and Raynaud’s phenomenon. Although effective, these treatment strategies are expensive and have several side effects. To improve drug efficiency, we tested liposomal nanoparticles as carrier systems. In this study, we synthesized liposomal nanoparticles tailored for the prostacyclin analogue iloprost and evaluated their pharmacologic efficacy on mouse intrapulmonary arteries, using a wire myograph. The use of cationic lipids, stearylamine, or 1,2-di-(9Z-octadecenoyl-3-trimethylammonium-propane (DOTAP in liposomes promoted iloprost encapsulation to at least 50%. The addition of cholesterol modestly reduced iloprost encapsulation. The liposomal nanoparticle formulations were tested for toxicity and pharmacologic efficacy in vivo and ex vivo, respectively. The liposomes did not affect the viability of human pulmonary artery smooth muscle cells. Compared with an equivalent concentration of free iloprost, four out of the six polymer-coated liposomal formulations exhibited significantly enhanced vasodilation of mouse pulmonary arteries. Iloprost that was encapsulated in liposomes containing the polymer polyethylene glycol exhibited concentration-dependent relaxation of arteries. Strikingly, half the concentration of iloprost in liposomes elicited

Potential effect of cationic liposomes on interactions with oral bacterial cells and biofilms.

Science.gov (United States)

Sugano, Marika; Morisaki, Hirobumi; Negishi, Yoichi; Endo-Takahashi, Yoko; Kuwata, Hirotaka; Miyazaki, Takashi; Yamamoto, Matsuo

2016-01-01

Although oral infectious diseases have been attributed to bacteria, drug treatments remain ineffective because bacteria and their products exist as biofilms. Cationic liposomes have been suggested to electrostatically interact with the negative charge on the bacterial surface, thereby improving the effects of conventional drug therapies. However, the electrostatic interaction between oral bacteria and cationic liposomes has not yet been examined in detail. The aim of the present study was to examine the behavior of cationic liposomes and Streptococcus mutans in planktonic cells and biofilms. Liposomes with or without cationic lipid were prepared using a reverse-phase evaporation method. The zeta potentials of conventional liposomes (without cationic lipid) and cationic liposomes were -13 and 8 mV, respectively, and both had a mean particle size of approximately 180 nm. We first assessed the interaction between liposomes and planktonic bacterial cells with a flow cytometer. We then used a surface plasmon resonance method to examine the binding of liposomes to biofilms. We confirmed the binding behavior of liposomes with biofilms using confocal laser scanning microscopy. The interactions between cationic liposomes and S. mutans cells and biofilms were stronger than those of conventional liposomes. Microscopic observations revealed that many cationic liposomes interacted with the bacterial mass and penetrated the deep layers of biofilms. In this study, we demonstrated that cationic liposomes had higher affinity not only to oral bacterial cells, but also biofilms than conventional liposomes. This electrostatic interaction may be useful as a potential drug delivery system to biofilms.

The efficacy and safety of the targeted drug combined with adriamycin liposome solution for HER-2-positive breast cancer

Directory of Open Access Journals (Sweden)

Zi-Ping Zhou

2017-05-01

Full Text Available Objective: To study the efficacy and safety of the targeted drug trastuzumab combined with adriamycin liposome solution for HER-2-positive breast cancer. Methods: A total of 112 patients with breast cancer who received chemotherapy in Department of Cardiothoracic Breast Surgery, Guangdong TongJiang Hospital between May 2014 and April 2016 were selected as the research subjects and divided into two groups by random number table, liposome group received trastuzumab + adriamycin liposome chemotherapy, and the control group received trastuzumab + adriamycin chemotherapy. Before chemotherapy as well as 4 weeks and 8 weeks after chemotherapy, serum levels of tumor markers, cytokines and myocardial injury indexes were detected, the electrocardiography was conducted and the degree of myocardial injury was determined. Results: 4 weeks and 8 weeks after chemotherapy, serum CEA, CA15-3, TPS, CTGF, TGF-β, TSGF, VEGF and MK levels of both groups were significantly lower than those before chemotherapy, serum CK-MB and cTnI levels were significantly higher than those before chemotherapy, limb leads QRS amplitudes and chest leads QRS amplitudes were significantly lower than those before chemotherapy, serum CEA, CA15-3, TPS, CTGF, TGF-β, TSGF, VEGF, MK, CK-MB and cTnI levels of liposome group were significantly lower than those of control group, and the limb leads QRS amplitudes and chest lead QRS amplitudes were significantly higher than those of control group. Conclusion: Targeted drug combined with adriamycin liposome therapy for HER-2-positive breast cancer can improve the curative effect and reduce the cardiotoxicity.

Photodynamic therapy-generated vaccines prevent tumor recurrence after radiotherapy

International Nuclear Information System (INIS)

Korbelik, M.; Sun, J.

2003-01-01

Photodynamic therapy (PDT), an established clinical modality for a variety of malignant and non-malignant diseases, inflicts photoreactive drug-mediated oxidative stress that prompts the engagement of host inflammatory and immune responses which contribute to the therapy outcome. Recently, it has become evident that in vitro PDT-treated tumor cells or their lysates can be utilized as an effective vaccine against established tumors of the same origin. The mechanism underlying the vaccine action appears to be based on eliciting immune recognition of the tumor and developing an efficient immune response even against poorly immunogenic tumors. This study examined whether PDT-generated vaccines can be effectively combined with radiotherapy. Subcutaneous SCCVII tumors (squamous cell carcinomas) growing in syngeneic C3H/HeN mice were treated by radiotherapy (60 Gy x-ray dose). PDT-vaccine treatment, done by peritumoral injection of in vitro PDT-treated SCCVII cells (20 million/mouse), was performed either immediately after radiotherapy or ten days later. The mice were then observed for tumor regression/recurrence. The tumors treated with radiotherapy alone shrunk and became impalpable for a brief period after which they all recurred. In contrast, vaccination performed at 10 days post radiotherapy delayed tumor recurrence and prevented it in one of six mice. Even better results were obtained with mice vaccinated immediately after radiotherapy, with mice showing not only a delayed tumor recurrence but also no sign of tumor in 50% of mice. The PDT-vaccine treatment without radiotherapy produced in this trial a significant tumor growth retardation but no complete regressions. These results indicate that PDT-generated vaccines can ensure immune rejection of cancer once the lesion size is reduced by radiotherapy. Even without obtaining a systemic immunity for the elimination of disseminated malignant deposits, these findings suggest that PDT-vaccines can improve local control

Prevention of palmar-plantar erythrodysesthesia with an antiperspirant in breast cancer patients treated with pegylated liposomal doxorubicin (SAKK 92/08).

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Templeton, Arnoud J; Ribi, Karin; Surber, Christian; Sun, Hong; Hsu Schmitz, Shu-Fang; Beyeler, Michael; Dietrich, Daniel; Borner, Markus; Winkler, Annette; Müller, Andreas; von Rohr, Lukas; Winterhalder, Ralph C; Rochlitz, Christoph; von Moos, Roger; Zaman, Khalil; Thürlimann, Beat J K; Ruhstaller, Thomas

2014-06-01

Elevated concentrations of doxorubicin are found in eccrine sweat glands of the palms and soles. We therefore evaluated an antiperspirant as preventive treatment for palmar-plantar erythrodysesthesia (hand-foot syndrome) in patients with metastatic breast cancer treated with pegylated liposomal doxorubicin. An antiperspirant containing aluminum chlorohydrate or placebo cream was applied to the left or right hand and foot in a double-blinded manner (intra-patient randomization). The primary endpoint was the rate of grade 2 or 3 palmar-plantar erythrodysesthesia. A secondary endpoint was the patient-reported symptom burden (tingling, numbness, pain, or skin problems). Using McNemar's matched pairs design, 53 patients were needed to detect a 20% difference between the treatment and placebo sides with a significance level of 5% and power of 90%. Grade 2 or 3 PPE occurred in 30 (58%) of 52 evaluable patients; in six patients adverse effects occurred on the placebo side but not on the treatment side, whereas one patient developed palmar-plantar erythrodysesthesia on the treatment side only (P = 0.07). Four patients developed grade 2 or 3 palmar-plantar erythrodysesthesia on their foot on the placebo side but not on the treatment side (P = 0.05). In the cohort with grade 2 or 3 palmar-plantar erythrodysesthesia there was a trend towards fewer dermatologic symptomatologies with the active treatment (P = 0.05), and no difference for other adverse events. Using topical aluminum chlorohydrate as an antiperspirant appears to reduce the incidence of grade 2 or 3 palmar-plantar erythrodysesthesia following pegylated liposomal doxorubicin chemotherapy for metastatic breast cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pharmacokinetics of a 5-fluorouracil liposomal delivery system.

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Simmons, S T; Sherwood, M B; Nichols, D A; Penne, R B; Sery, T; Spaeth, G L

1988-01-01

A liposomal delivery system was developed in an attempt to prolong ocular levels of 5-fluorouracil for glaucoma filtering surgery. The pharmacokinetics of the 5-fluorouracil liposomal delivery system were studied in normal pigmented rabbits with 5-fluorouracil labelled with carbon-14 (C-14). 14C 5-fluorouracil was incorporated into the liposomes at a concentration of 10 g/l and injected subconjunctivally in doses of 5 and 10 mg. Concentrations of 5-fluorouracil were assayed at 10 time interva...

Biophysical characterization of V3-lipopeptide liposomes influencing HIV-1 infectivity

International Nuclear Information System (INIS)

Rizos, Apostolos K.; Baritaki, Stavroula; Tsikalas, Ioannis; Doetschman, David C.; Spandidos, Demetrios A.; Krambovitis, Elias

2007-01-01

The V3-loop of the HIV-1 gp120 alters host cell immune function and modulates infectivity. We investigated biophysical parameters of liposome constructs with embedded lipopeptides from the principle neutralizing domain of the V3-loop and their influence on viral infectivity. Dynamic light scattering measurements showed liposome supramolecular structures with hydrodynamic radius of the order of 900 and 1300 nm for plain and V3-lipopeptide liposomes. Electron paramagnetic resonance measurements showed almost identical local microenvironment. The difference in liposome hydrodynamic radius was attributed to the fluctuating ionic environment of the V3-lipopeptide liposomes. In vitro HIV-1 infectivity assays showed that plain liposomes reduced virus production in all cell cultures, probably due to the hydrophobic nature of the aggregates. Liposomes carrying V3-lipopeptides with different cationic potentials restored and even enhanced infectivity (p < 0.05). These results highlight the need for elucidation of the involvement of lipid bilayers as dynamic components in supramolecular structures and in HIV-1 fusion mechanisms

Syntheses and characterization of liposome-incorporated adamantyl aminoguanidines.

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Šekutor, Marina; Štimac, Adela; Mlinarić-Majerski, Kata; Frkanec, Ruža

2014-08-21

A series of mono and bis-aminoguanidinium adamantane derivatives has been synthesized and incorporated into liposomes. They combine two biomedically significant molecules, the adamantane moiety and the guanidinium group. The adamantane moiety possesses the membrane compatible features while the cationic guanidinium subunit was recognized as a favourable structural feature for binding to complementary molecules comprising phosphate groups. The liposome formulations of adamantyl aminoguanidines were characterized and it was shown that the entrapment efficiency of the examined compounds is significant. In addition, it was demonstrated that liposomes with incorporated adamantyl aminoguanidines effectively recognized the complementary liposomes via the phosphate group. These results indicate that adamantane derivatives bearing guanidinium groups might be versatile tools for biomedical application, from studies of molecular recognition processes to usage in drug formulation and cell targeting.

Tumor-targeting magnetic lipoplex delivery of short hairpin RNA suppresses IGF-1R overexpression of lung adenocarcinoma A549 cells in vitro and in vivo.

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Wang, Chunmao; Ding, Chao; Kong, Minjian; Dong, Aiqiang; Qian, Jianfang; Jiang, Daming; Shen, Zhonghua

2011-07-08

Liposomal magnetofection potentiates gene transfection by applying a magnetic field to concentrate magnetic lipoplexes onto target cells. Magnetic lipoplexes are self-assembling ternary complexes of cationic lipids with plasmid DNA associated with superparamagnetic iron oxide nanoparticles (SPIONs). Type1 insulin-like growth factor receptor (IGF-1R), an important oncogene, is frequently overexpressed in lung cancer and mediates cancer cell proliferation and tumor growth. In this study, we evaluated the transfection efficiency (percentage of transfected cells) and therapeutic potential (potency of IGF-1R knockdown) of liposomal magnetofection of plasmids expressing GFP and shRNAs targeting IGF-1R (pGFPshIGF-1Rs) in A549 cells and in tumor-bearing mice as compared to lipofection using Lipofectamine 2000. Liposomal magnetofection provided a threefold improvement in transgene expression over lipofection and transfected up to 64.1% of A549 cells in vitro. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1±6% and by liposomal magnetofection by 85.1±3%. In vivo delivery efficiency of the pGFPshIGF-1R plasmid into the tumor was significantly higher in the liposomal magnetofection group than in the lipofection group. In vivo IGF-1R specific-shRNA by lipofection inhibited IGF-1R protein by an average of 43.8±5.3%; that by liposomal magnetofection inhibited IGF-1R protein by 43.4±5.7%, 56.3±9.6%, and 72.2±6.8%, at 24, 48, and 72 h, respectively, after pGFPshIGF-1R injection. Our findings indicate that liposomal magnetofection may be a promising method that allows the targeting of gene therapy to lung cancer. Copyright © 2011 Elsevier Inc. All rights reserved.

Macrophages inhibit human osteosarcoma cell growth after activation with the bacterial cell wall derivative liposomal muramyl tripeptide in combination with interferon-γ.

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Pahl, Jens H W; Kwappenberg, Kitty M C; Varypataki, Eleni M; Santos, Susy J; Kuijjer, Marieke L; Mohamed, Susan; Wijnen, Juul T; van Tol, Maarten J D; Cleton-Jansen, Anne-Marie; Egeler, R Maarten; Jiskoot, Wim; Lankester, Arjan C; Schilham, Marco W

2014-03-10

In osteosarcoma, the presence of tumor-infiltrating macrophages positively correlates with patient survival in contrast to the negative effect of tumor-associated macrophages in patients with other tumors. Liposome-encapsulated muramyl tripeptide (L-MTP-PE) has been introduced in the treatment of osteosarcoma patients, which may enhance the potential anti-tumor activity of macrophages. Direct anti-tumor activity of human macrophages against human osteosarcoma cells has not been described so far. Hence, we assessed osteosarcoma cell growth after co-culture with human macrophages. Monocyte-derived M1-like and M2-like macrophages were polarized with LPS + IFN-γ, L-MTP-PE +/- IFN-γ or IL-10 and incubated with osteosarcoma cells. Two days later, viable tumor cell numbers were analyzed. Antibody-dependent effects were investigated using the therapeutic anti-EGFR antibody cetuximab. M1-like macrophages inhibited osteosarcoma cell growth when activated with LPS + IFN-γ. Likewise, stimulation of M1-like macrophages with liposomal muramyl tripeptide (L-MTP-PE) inhibited tumor growth, but only when combined with IFN-γ. Addition of the tumor-reactive anti-EGFR antibody cetuximab did not further improve the anti-tumor activity of activated M1-like macrophages. The inhibition was mediated by supernatants of activated M1-like macrophages, containing TNF-α and IL-1β. However, specific blockage of these cytokines, nitric oxide or reactive oxygen species did not inhibit the anti-tumor effect, suggesting the involvement of other soluble factors released upon macrophage activation. While LPS + IFN-γ-activated M2-like macrophages had low anti-tumor activity, IL-10-polarized M2-like macrophages were able to reduce osteosarcoma cell growth in the presence of the anti-EGFR cetuximab involving antibody-dependent tumor cell phagocytosis. This study demonstrates that human macrophages can be induced to exert direct anti-tumor activity against osteosarcoma cells. Our

Cross-linkable liposomes stabilize a magnetic resonance contrast-enhancing polymeric fastener.

Science.gov (United States)

Smith, Cartney E; Kong, Hyunjoon

2014-04-08

Liposomes are commonly used to deliver drugs and contrast agents to their target site in a controlled manner. One of the greatest obstacles in the performance of such delivery vehicles is their stability in the presence of serum. Here, we demonstrate a method to stabilize a class of liposomes that load gadolinium, a magnetic resonance (MR) contrast agent, as a model cargo on their surfaces. We hypothesized that the sequential adsorption of a gadolinium-binding chitosan fastener on the liposome surface followed by covalent cross-linking of the lipid bilayer would provide enhanced stability and improved MR signal in the presence of human serum. To investigate this hypothesis, liposomes composed of diyne-containing lipids were assembled and functionalized via chitosan conjugated with a hydrophobic anchor and diethylenetriaminepentaacetic acid (DTPA). This postadsorption cross-linking strategy served to stabilize the thermodynamically favorable association between liposome and polymeric fastener. Furthermore, the chitosan-coated, cross-linked liposomes proved more effective as delivery vehicles of gadolinium than uncross-linked liposomes due to the reduced liposome degradation and chitosan desorption. Overall, this study demonstrates a useful method to stabilize a broad class of particles used for systemic delivery of various molecular payloads.

Liposomes coated with thiolated chitosan enhance oral peptide delivery to rats☆

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Gradauer, K.; Barthelmes, J.; Vonach, C.; Almer, G.; Mangge, H.; Teubl, B.; Roblegg, E.; Dünnhaupt, S.; Fröhlich, E.; Bernkop-Schnürch, A.; Prassl, R.

2013-01-01

The aim of the present study was the in vivo evaluation of thiomer-coated liposomes for an oral application of peptides. For this purpose, salmon calcitonin was chosen as a model drug and encapsulated within liposomes. Subsequently, the drug loaded liposomes were coated with either chitosan–thioglycolic acid (CS–TGA) or an S-protected version of the same polymer (CS–TGA–MNA), leading to an increase in the particle size of about 500 nm and an increase in the zeta potential from approximately − 40 mV to a maximum value of about + 44 mV, depending on the polymer. Coated liposomes were demonstrated to effectively penetrate the intestinal mucus layer where they came in close contact with the underlying epithelium. To investigate the permeation enhancing properties of the coated liposomes ex vivo, we monitored the transport of fluoresceinisothiocyanate-labeled salmon calcitonin (FITC-sCT) through rat small intestine. Liposomes coated with CS–TGA–MNA showed the highest effect, leading to a 3.8-fold increase in the uptake of FITC-sCT versus the buffer control. In vivo evaluation of the different formulations was carried out by the oral application of 40 μg of sCT per rat, either encapsulated within uncoated liposomes, CS–TGA-coated liposomes or CS–TGA–MNA-coated liposomes, or given as a solution serving as negative control. The blood calcium level was monitored over a time period of 24 h. The highest reduction in the blood calcium level, to a minimum of 65% of the initial value after 6 h, was achieved for CS–TGA–MNA-coated liposomes. Comparing the areas above curves (AAC) of the blood calcium levels, CS–TGA–MNA-coated liposomes led to an 8.2-fold increase compared to the free sCT solution if applied orally in the same concentration. According to these results, liposomes coated with S-protected thiomers have demonstrated to be highly valuable carriers for enhancing the oral bioavailability of salmon calcitonin. PMID:24140721

Liposomes coated with thiolated chitosan enhance oral peptide delivery to rats.

Science.gov (United States)

Gradauer, K; Barthelmes, J; Vonach, C; Almer, G; Mangge, H; Teubl, B; Roblegg, E; Dünnhaupt, S; Fröhlich, E; Bernkop-Schnürch, A; Prassl, R

2013-12-28

The aim of the present study was the in vivo evaluation of thiomer-coated liposomes for an oral application of peptides. For this purpose, salmon calcitonin was chosen as a model drug and encapsulated within liposomes. Subsequently, the drug loaded liposomes were coated with either chitosan-thioglycolic acid (CS-TGA) or an S-protected version of the same polymer (CS-TGA-MNA), leading to an increase in the particle size of about 500 nm and an increase in the zeta potential from approximately -40 mV to a maximum value of about +44 mV, depending on the polymer. Coated liposomes were demonstrated to effectively penetrate the intestinal mucus layer where they came in close contact with the underlying epithelium. To investigate the permeation enhancing properties of the coated liposomes ex vivo, we monitored the transport of fluoresceinisothiocyanate-labeled salmon calcitonin (FITC-sCT) through rat small intestine. Liposomes coated with CS-TGA-MNA showed the highest effect, leading to a 3.8-fold increase in the uptake of FITC-sCT versus the buffer control. In vivo evaluation of the different formulations was carried out by the oral application of 40 μg of sCT per rat, either encapsulated within uncoated liposomes, CS-TGA-coated liposomes or CS-TGA-MNA-coated liposomes, or given as a solution serving as negative control. The blood calcium level was monitored over a time period of 24h. The highest reduction in the blood calcium level, to a minimum of 65% of the initial value after 6h, was achieved for CS-TGA-MNA-coated liposomes. Comparing the areas above curves (AAC) of the blood calcium levels, CS-TGA-MNA-coated liposomes led to an 8.2-fold increase compared to the free sCT solution if applied orally in the same concentration. According to these results, liposomes coated with S-protected thiomers have demonstrated to be highly valuable carriers for enhancing the oral bioavailability of salmon calcitonin. © 2013. Published by Elsevier B.V. All rights reserved.

Improved Hepatoprotective Effect of Liposome-Encapsulated Astaxanthin in Lipopolysaccharide-Induced Acute Hepatotoxicity

Directory of Open Access Journals (Sweden)

Chun-Hung Chiu

2016-07-01

Full Text Available Lipopolysaccharide (LPS-induced acute hepatotoxicity is significantly associated with oxidative stress. Astaxanthin (AST, a xanthophyll carotenoid, is well known for its potent antioxidant capacity. However, its drawbacks of poor aqueous solubility and low bioavailability have limited its utility. Liposome encapsulation is considered as an effective alternative use for the improvement of bioavailability of the hydrophobic compound. We hypothesized that AST encapsulated within liposomes (LA apparently shows improved stability and transportability compared to that of free AST. To investigate whether LA administration can efficiently prevent the LPS-induced acute hepatotoxicity, male Sprague-Dawley rats (n = six per group were orally administered liposome-encapsulated AST at 2, 5 or 10 mg/kg-day (LA-2, LA-5, and LA-10 for seven days and then were LPS-challenged (i.p., 5 mg/kg. The LA-10 administered group, but not the other groups, exhibited a significant amelioration of serum glutamic pyruvic transaminase (GPT, glutamic oxaloacetic transaminase (GOT, blood urea nitrogen (BUN, creatinine (CRE, hepatic malondialdehyde (MDA and glutathione peroxidase (GSH-Px, IL-6, and hepatic nuclear NF-κB and inducible nitric oxide synthase (iNOS, suggesting that LA at a 10 mg/kg-day dosage renders hepatoprotective effects. Moreover, the protective effects were even superior to that of positive control N-acetylcysteine (NAC, 200 mg/kg-day. Histopathologically, NAC, free AST, LA-2 and LA-5 partially, but LA-10 completely, alleviated the acute inflammatory status. These results indicate that hydrophobic AST after being properly encapsulated by liposomes improves bioavailability and can also function as potential drug delivery system in treating hepatotoxicity.

Preparation, characterization, and in vitro release study of albendazole-encapsulated nanosize liposomes

Science.gov (United States)

Panwar, Preety; Pandey, Bhumika; Lakhera, P C; Singh, K P

2010-01-01

The purpose of the present study was to formulate effective and controlled release albendazole liposomal formulations. Albendazole, a hydrophobic drug used for the treatment of hydatid cysts, was encapsulated in nanosize liposomes. Rapid evaporation method was used for the preparation of albendazole-encapsulated conventional and PEGylated liposomes consisting of egg phosphatidylcholine (PC) and cholesterol (CH) in the molar ratios of (6:4) and PC:CH: polyethylene glycol (PEG) (5:4:1), respectively. In this study, PEGylated and conventional liposomes containing albendazole were prepared and their characteristics, such as particle size, encapsulation efficiency, and in vitro drug release were investigated. The drug encapsulation efficiency of PEGylated and conventional liposomes was 81% and 72%, respectively. The biophysical characterization of both conventional and PEG-coated liposomes were done by transmission electron microscopy and UV-vis spectrophotometry. Efforts were made to study in vitro release of albendazole. The drug release rate showed decrease in albendazole release in descending order: free albendazole, albendazole-loaded conventional liposomes, and least with albendazole-loaded PEG-liposomes. Biologically relevant vesicles were prepared and in vitro release of liposome-entrapped albendazole was determined. PMID:20309396

Preparation of liposomes containing zedoary turmeric oil using freeze-drying of liposomes via TBA/water cosolvent systems and evaluation of the bioavailability of the oil.

Science.gov (United States)

Yang, Zhiwen; Yu, Songlin; Fu, Dahua

2010-02-01

The purpose of this study was to enhance the absorption of zedoary turmeric oil (ZTO) in vivo and develop new formulations of a water-insoluble oily drug. This study described a method for preparing ZTO liposomes, which involved freeze-drying (FD) of liposomes with TBA/water cosolvent systems. The TBA/water cosolvent systems were used to investigate a feasible method of liposomes manufacture; the two factors, sugar/lipid mass ratio and TBA content (concentration), of the preparation process were evaluated in this study. The results showed that the addition of TBA content could significantly enhance the sublimation of ice resulting in short FD cycles time, and reduce the entrapment efficiency of liposomes. In addition, the residual TBA solvents levels were determined to be less than 0.37% under all optimum formulations and processing conditions. Several physical properties of liposomes were examined by H-600 transmission electron microscope (TEM) and zetamaster analyser system. The results revealed that the liposomes were smooth and spherical with an average particle size of 457 +/- 7.8 nm and the zeta potential was more than 3.65 Mv. The bioavailability of the liposomes was evaluated in rabbits, compared with the conventional self-emulsifying formulation for oral administration. Compared with the conventional self-emulsifying formulation, the plasma concentration-time profiles with improved sustained-release characteristics were achieved after oral administration of the liposomes with a bioavailability of 257.7% (a good strategy for improving the bioavailability of an oily drug). In conclusion, the present experimental findings clearly demonstrated the usefulness of ZTO liposome vesicles in improving therapeutic efficacy by enhancing oral bioavailability. Our study offered an alternative method for designing sustained-release preparations of oily drugs.

Preparation and characterization of clove essential oil-loaded liposomes.

Science.gov (United States)

Sebaaly, Carine; Jraij, Alia; Fessi, Hatem; Charcosset, Catherine; Greige-Gerges, Hélène

2015-07-01

In this study, suitable formulations of natural soybean phospholipid vesicles were developed to improve the stability of clove essential oil and its main component, eugenol. Using an ethanol injection method, saturated (Phospholipon 80H, Phospholipon 90H) and unsaturated soybean (Lipoid S100) phospholipids, in combination with cholesterol, were used to prepare liposomes at various eugenol and clove essential oil concentrations. Liposomal batches were characterized and compared for their size, polydispersity index, Zeta potential, loading rate, encapsulation efficiency and morphology. The liposomes were tested for their stability after storing them for 2 months at 4°C by monitoring changes in their mean size, polydispersity index and encapsulation efficiency (EE) values. It was found that liposomes exhibited nanometric oligolamellar and spherical shaped vesicles and protected eugenol from degradation induced by UV exposure; they also maintained the DPPH-scavenging activity of free eugenol. Liposomes constitute a suitable system for encapsulation of volatile unstable essential oil constituents. Copyright © 2015 Elsevier Ltd. All rights reserved.

Treatment of deep mycoses with liposomal amphotericin B.

Science.gov (United States)

Berenguer, J; Muñoz, P; Parras, F; Fernández-Baca, V; Hernández-Sampelayo, T; Bouza, E

1994-06-01

Amphotericin B is the mainstay of therapy of many deep mycoses, but its use is seriously hampered by dose-limiting nephrotoxicity. In this study a liposomal formulation of amphotericin B was administered to ten patients with proven deep mycoses: invasive aspergillosis (n = 4), deep candidiasis (n = 4) and zygomycosis (n = 2). The mean daily dosage of liposomal amphotericin B was 3.0 mg/kg (range 2.5 to 4 mg/kg), the mean total dosage of liposomal amphotericin B 2,781 mg (range 87 to 5,220 mg) and the mean duration of treatment 17 days (range 3 to 33 days). Treatment with liposomal amphotericin B was associated with little nephrotoxicity and an overall survival rate of 50%. The median increase of serum creatinine from baseline levels was 0.38 mg/dl (-1.2 to 2.6 mg/dl).

Herbal liposome for the topical delivery of ketoconazole for the effective treatment of seborrheic dermatitis

Science.gov (United States)

Dave, Vivek; Sharma, Swati; Yadav, Renu Bala; Agarwal, Udita

2017-11-01

The aim of the present study was to develop liposomal gel containing ketoconazole and neem extract for the treatment of seborrheic dermatitis in an effectual means. Azoles derivatives that are commonly used to prevent superficial fungal infections include triazole category like itraconazole. These drugs are available in the form of oral dosage that required a long period of time for treatment. Ketoconazole is available in the form of gel but is not used with any herbal extract. Neem ( Azadirachta indica) leaves show a good anti-bacterial and anti-fungal activity and have great potential as a bioactive compound. The thin film hydration method was used to design an herbal liposomal preparation. The formulation was further subjected to their characterization as particle size, zeta potential, entrapment efficiency, % cumulative drug release, and anti-fungal activity and it was also characterized by the mean of their physicochemical properties such as FTIR, SEM, DSC, TGA, and AFM. The results show that the formulation of liposomes with neem extract F12 were found to be optimum on the basis of entrapment efficiency in the range 88.9 ± 0.7%, with a desired mean particle size distribution of 141.6 nm and zeta potential - 45 mV. The anti-fungal activity of liposomal formulation F12 was carried out against Aspergillus niger and Candida tropicalis by measuring the inhibition zone 8.9 and 10.2 mm, respectively. Stability of optimized formulation was best seen at refrigerated condition. Overall, these results indicated that developed liposomal gel of ketoconazole with neem extract could have great potential for seborrheic dermatitis and showed synergetic effect for the treatment.

Multimodality imaging demonstrates trafficking of liposomes preferentially to ischemic myocardium

International Nuclear Information System (INIS)

Lipinski, Michael J.; Albelda, M. Teresa; Frias, Juan C.; Anderson, Stasia A.; Luger, Dror; Westman, Peter C.; Escarcega, Ricardo O.; Hellinga, David G.; Waksman, Ron; Arai, Andrew E.; Epstein, Stephen E.

2016-01-01

Introduction: Nanoparticles may serve as a promising means to deliver novel therapeutics to the myocardium following myocardial infarction. We sought to determine whether lipid-based liposomal nanoparticles can be shown through different imaging modalities to specifically target injured myocardium following intravenous injection in an ischemia–reperfusion murine myocardial infarction model. Methods: Mice underwent ischemia–reperfusion surgery and then either received tail-vein injection with gadolinium- and fluorescent-labeled liposomes or no injection (control). The hearts were harvested 24 h later and underwent T1 and T2-weighted ex vivo imaging using a 7 Tesla Bruker magnet. The hearts were then sectioned for immunohistochemistry and optical fluorescent imaging. Results: The mean size of the liposomes was 100 nm. T1-weighted signal intensity was significantly increased in the ischemic vs. the non-ischemic myocardium for mice that received liposomes compared with control. Optical imaging demonstrated significant fluorescence within the infarct area for the liposome group compared with control (163 ± 31% vs. 13 ± 14%, p = 0.001) and fluorescent microscopy confirmed the presence of liposomes within the ischemic myocardium. Conclusions: Liposomes traffic to the heart and preferentially home to regions of myocardial injury, enabling improved diagnosis of myocardial injury and could serve as a vehicle for drug delivery.

Multimodality imaging demonstrates trafficking of liposomes preferentially to ischemic myocardium

Energy Technology Data Exchange (ETDEWEB)

Lipinski, Michael J., E-mail: mjlipinski12@gmail.com [MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC (United States); Albelda, M. Teresa [GIBI2" 3" 0, Grupo de Investigación Biomédica en Imagen, IIS La Fe, Valencia (Spain); Frias, Juan C. [Departamento de Ciencias Biomédicas, Universidad CEU Cardenal Herrera, Valencia (Spain); Anderson, Stasia A. [Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (United States); Luger, Dror; Westman, Peter C.; Escarcega, Ricardo O.; Hellinga, David G.; Waksman, Ron [MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC (United States); Arai, Andrew E. [Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (United States); Epstein, Stephen E. [MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC (United States)

2016-03-15

Introduction: Nanoparticles may serve as a promising means to deliver novel therapeutics to the myocardium following myocardial infarction. We sought to determine whether lipid-based liposomal nanoparticles can be shown through different imaging modalities to specifically target injured myocardium following intravenous injection in an ischemia–reperfusion murine myocardial infarction model. Methods: Mice underwent ischemia–reperfusion surgery and then either received tail-vein injection with gadolinium- and fluorescent-labeled liposomes or no injection (control). The hearts were harvested 24 h later and underwent T1 and T2-weighted ex vivo imaging using a 7 Tesla Bruker magnet. The hearts were then sectioned for immunohistochemistry and optical fluorescent imaging. Results: The mean size of the liposomes was 100 nm. T1-weighted signal intensity was significantly increased in the ischemic vs. the non-ischemic myocardium for mice that received liposomes compared with control. Optical imaging demonstrated significant fluorescence within the infarct area for the liposome group compared with control (163 ± 31% vs. 13 ± 14%, p = 0.001) and fluorescent microscopy confirmed the presence of liposomes within the ischemic myocardium. Conclusions: Liposomes traffic to the heart and preferentially home to regions of myocardial injury, enabling improved diagnosis of myocardial injury and could serve as a vehicle for drug delivery.

Fluorescence Resonance Energy Transfer in Polydiacetylene Liposomes

Science.gov (United States)

Li, Xuelian; Matthews, Shelton; Kohli, Punit

2009-01-01

Conjugated polydiacetylene (PDA) possessing stimuli-responsive properties has been intensively investigated for developing efficient sensors. We report here fluorescence resonance energy transfer (FRET) in liposomes synthesized using different molar ratios of dansyl-tagged diacetylene and diacetylene–carboxylic acid monomers. Photopolymerization of diacetylene resulted in cross-linked PDA liposomes. We used steady-state electronic absorption, emission, and fluorescence anisotropy (FA) analysis to characterize the thermal-induced FRET between dansyl fluorophores (donor) and PDA (acceptor). We found that the monomer ratio of acceptor to donor (Rad) and length of linkers (functional part that connects dansyl fluorophores to the diacetylene group in the monomer) strongly affected FRET. For Rad = 10 000, the acceptor emission intensity was amplified by more than 18 times when the liposome solution was heated from 298 to 338 K. A decrease in Rad resulted in diminished acceptor emission amplification. This was primarily attributed to lower FRET efficiency between donors and acceptors and a higher background signal. We also found that the FRET amplification of PDA emissions after heating the solution was much higher when dansyl was linked to diacetylene through longer and flexible linkers than through shorter linkers. We attributed this to insertion of dansyl in the bilayer of the liposomes, which led to an increased dansyl quantum yield and a higher interaction of multiple acceptors with limited available donors. This was not the case for shorter and more rigid linkers where PDA amplification was much smaller. The present studies aim at enhancing our understanding of FRET between fluorophores and PDA-based conjugated liposomes. Furthermore, receptor tagged onto PDA liposomes can interact with ligands present on proteins, enzymes, and cells, which will produce emission sensing signal. Therefore, using the present approach, there exist opportunities for designing FRET

Carrier-inside-carrier: polyelectrolyte microcapsules as reservoir for drug-loaded liposomes.

Science.gov (United States)

Maniti, Ofelia; Rebaud, Samuel; Sarkis, Joe; Jia, Yi; Zhao, Jie; Marcillat, Olivier; Granjon, Thierry; Blum, Loïc; Li, Junbai; Girard-Egrot, Agnès

2015-01-01

Conventional liposomes have a short life-time in blood, unless they are protected by a polymer envelope, most often polyethylene glycol. However, these stabilizing polymers frequently interfere with cellular uptake, impede liposome-membrane fusion and inhibit escape of liposome content from endosomes. To overcome such drawbacks, polymer-based systems as carriers for liposomes are currently developed. Conforming to this approach, we propose a new and convenient method for embedding small size liposomes, 30-100 nm, inside porous calcium carbonate microparticles. These microparticles served as templates for deposition of various polyelectrolytes to form a protective shell. The carbonate particles were then dissolved to yield hollow polyelectrolyte microcapsules. The main advantage of using this method for liposome encapsulation is that carbonate particles can serve as a sacrificial template for deposition of virtually any polyelectrolyte. By carefully choosing the shell composition, bioavailability of the liposomes and of the encapsulated drug can be modulated to respond to biological requirements and to improve drug delivery to the cytoplasm and avoid endosomal escape.

Liposomal preparations of muramyl glycopeptides as immunomodulators and adjuvants.

Science.gov (United States)

Turánek, Jaroslav; Ledvina, Miroslav; Kasná, Andrea; Vacek, Antonín; Hríbalova, Vera; Krejcí, Josef; Miller, Andrew D

2006-04-12

The need for safe and structurally defined immunomodulators and adjuvants is increasing in connection with the recently observed marked increase in the prevalence of pathological conditions characterized by immunodeficiency. Important groups of such compounds are muramyl glycopeptides, analogs of muramyl dipeptide (MDP), glucosaminyl-muramyl dipeptide (GMDP), and desmuramylpeptides. We have designed and synthesized new types of analogs with changes in both the sugar and the peptide parts of the molecule that show a high immunostimulating and adjuvant activity and suppressed adverse side effects. The introduction of lipophilic residues has also improved their incorporation into liposomes, which represent a suitable drug carrier. The proliposome-liposome method is based on the conversion of the initial proliposome preparation into liposome dispersion by dilution with the aqueous phase. The description of a home-made stirred thermostated cell and its link-up with a liquid delivery system for a rapid and automated preparation of multilamellar liposomes at strictly controlled conditions (sterility, temperature, dilution rate and schedule) is presented. The cell has been designed for laboratory-scale preparation of liposomes (300-1000 mg of phospholipid per run) in a procedure taking less than 90 min. The method can be readily scaled up. Examples of adjuvant and immunostimulatory effect of liposomal preparation in mice model will be presented.

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

Liposomal Antioxidants for Protection against Oxidant-Induced Damage

Directory of Open Access Journals (Sweden)

Zacharias E. Suntres

2011-01-01

Full Text Available Reactive oxygen species (ROS, including superoxide anion, hydrogen peroxide, and hydroxyl radical, can be formed as normal products of aerobic metabolism and can be produced at elevated rates under pathophysiological conditions. Overproduction and/or insufficient removal of ROS result in significant damage to cell structure and functions. In vitro studies showed that antioxidants, when applied directly and at relatively high concentrations to cellular systems, are effective in conferring protection against the damaging actions of ROS, but results from animal and human studies showed that several antioxidants provide only modest benefit and even possible harm. Antioxidants have yet to be rendered into reliable and safe therapies because of their poor solubility, inability to cross membrane barriers, extensive first-pass metabolism, and rapid clearance from cells. There is considerable interest towards the development of drug-delivery systems that would result in the selective delivery of antioxidants to tissues in sufficient concentrations to ameliorate oxidant-induced tissue injuries. Liposomes are biocompatible, biodegradable, and nontoxic artificial phospholipid vesicles that offer the possibility of carrying hydrophilic, hydrophobic, and amphiphilic molecules. This paper focus on the use of liposomes for the delivery of antioxidants in the prevention or treatment of pathological conditions related to oxidative stress.

Effect of Depleting Tumor-Associated Macrophages on Breast Cancer Growth and Response to Chemotherapy

National Research Council Canada - National Science Library

Tsan, Min-Fu

2004-01-01

...-encapsulated clodronate had no effect on the growth of subcutaneous breast cancer (4T1) model in mice. Whether liposome-encapsulated cloronate depletes tumor-assocaited macrophages in this model is currently under investigation.

Exploring the fate of liposomes in the intestine by dynamic in vitro lipolysis

DEFF Research Database (Denmark)

Parmentier, Johannes; Thomas, Nicky; Müllertz, Anette

2012-01-01

precipitation was detected during the lipolysis assay, despite pronounced lipolytic degradation and change in vesicle size. In conclusion, the tested dynamic in vitro lipolysis model is suitable for the assessment of liposome stability in the intestine. Furthermore, liposomes might be a useful alternative......Liposomes are generally well tolerated drug delivery systems with a potential use for the oral route. However, little is known about the fate of liposomes during exposure to the conditions in the gastro-intestinal tract (GIT). To gain a better understanding of liposome stability in the intestine......, a dynamic in vitro lipolysis model, which so far has only been used for the in vitro characterisation of other lipid-based drug delivery systems, was applied to different liposomal formulations. Liposome size and phospholipid (PL) digestion were determined as two markers for liposome stability. In addition...

Tissue distribution of radiolabeled phosphatidylserine-containing liposome in mice

International Nuclear Information System (INIS)

Borborema, Samanta E.T.; Nascimento, Nanci do; Osso Junior, Joao A.

2009-01-01

Liposomes are used as drug delivery systems to modify pharmacokinetic of drugs and also to improve their action in target cells. Liposomes containing phosphatidylserine are efficiently eliminated from the blood by cells of the mononuclear phagocytic system (MPS), predominantly Kupffer cells in the liver. In this way, this is a valuable approach to treat infectious diseases involving MPS, especially leishmaniasis. Leishmaniasis is a severe parasitic disease, caused by intramacrophage protozoa Leishmania sp., and is fatal if left untreated. Leishmania resides mainly in the liver and the spleen. Antileishmanial agents containing-liposomes showed more effective therapies with reduction of toxicity and adverse side effects. The purpose of this study was to investigate the tissue distribution of radioactive meglumine antimoniate encapsulated in phosphatidylserine-containing liposome. Meglumine antimoniate was neutron irradiated inside the IEA-R1 nuclear reactor to produce antimony radiotracers, 122 Sb and 124 Sb, and encapsulated in liposome. Healthy mice received a single intraperitoneal dose of the radiolabeled drug. Analysis of the mean radioactive tissue concentration-time data curves showed that liver and spleen had the highest levels of radioactivity. In addition these levels of drug remained for more than 48 hours. The dominant route of elimination was via biliary excretion with slow rate. Small fraction of the drug was found in the kidneys with very fast elimination. In conclusion, the phosphatidylserine-containing liposome showed to be a very useful tool to target antileishmanial agents to MPS and to sustain the drug levels for longer times. Besides, radiolabeled liposome is the easiest approach to perform biodistribution evaluation. (author)

Tissue distribution of radiolabeled phosphatidylserine-containing liposome in mice

Energy Technology Data Exchange (ETDEWEB)

Borborema, Samanta E.T.; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia], e-mail: samanta@usp.br, e-mail: nnascime@ipen.br; Andrade Junior, Heitor F. de [Instituto de Medicina Tropical de Sao Paulo (IMTSP), Sao Paulo, SP (Brazil)], e-mail: hfandrad@usp.br; Osso Junior, Joao A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Radiofarmacia], e-mail: jaosso@ipen.br

2009-07-01

Liposomes are used as drug delivery systems to modify pharmacokinetic of drugs and also to improve their action in target cells. Liposomes containing phosphatidylserine are efficiently eliminated from the blood by cells of the mononuclear phagocytic system (MPS), predominantly Kupffer cells in the liver. In this way, this is a valuable approach to treat infectious diseases involving MPS, especially leishmaniasis. Leishmaniasis is a severe parasitic disease, caused by intramacrophage protozoa Leishmania sp., and is fatal if left untreated. Leishmania resides mainly in the liver and the spleen. Antileishmanial agents containing-liposomes showed more effective therapies with reduction of toxicity and adverse side effects. The purpose of this study was to investigate the tissue distribution of radioactive meglumine antimoniate encapsulated in phosphatidylserine-containing liposome. Meglumine antimoniate was neutron irradiated inside the IEA-R1 nuclear reactor to produce antimony radiotracers, {sup 122}Sb and {sup 124}Sb, and encapsulated in liposome. Healthy mice received a single intraperitoneal dose of the radiolabeled drug. Analysis of the mean radioactive tissue concentration-time data curves showed that liver and spleen had the highest levels of radioactivity. In addition these levels of drug remained for more than 48 hours. The dominant route of elimination was via biliary excretion with slow rate. Small fraction of the drug was found in the kidneys with very fast elimination. In conclusion, the phosphatidylserine-containing liposome showed to be a very useful tool to target antileishmanial agents to MPS and to sustain the drug levels for longer times. Besides, radiolabeled liposome is the easiest approach to perform biodistribution evaluation. (author)

Recent Advances and Perspectives in Liposomes for Cutaneous Drug Delivery.

Science.gov (United States)

Carita, Amanda C; Eloy, Josimar O; Chorilli, Marlus; Lee, Robert J; Leonardi, Gislaine Ricci

2018-02-13

The cutaneous route is attractive for the delivery of drugs in the treatment of a wide variety of diseases. However the stratum corneum (SC) is an effective barrier that hampers skin penetration. Within this context, liposomes emerge as a potential carrier for improving topical delivery of therapeutic agents. In this review, we aimed to discuss key aspects for the topical delivery by drug-loaded liposomes. Phospholipid type and phase transition temperature have been shown to affect liposomal topical delivery. The effect of surface charge is subject to considerable variation depending on drug and composition. In addition, modified vesicles with the presence of components for permeation enhancement, such as surfactants and solvents, have been shown to have a considerable effect. These liposomes include: Transfersomes, Niosomes, Ethosomes, Transethosomes, Invasomes, coated liposomes, penetration enhancer containing vesicles (PEVs), fatty acids vesicles, Archaeosomes and Marinosomes. Furthermore, adding polymeric coating onto liposome surface could influence cutaneous delivery. Mechanisms of delivery include intact vesicular skin penetration, free drug diffusion, permeation enhancement, vesicle adsorption to and/or fusion with the SC, trans-appendageal penetration, among others. Finally, several skin conditions, including acne, melasma, skin aging, fungal infections and skin cancer, have benefited from liposomal topical delivery of drugs, with promising in vitro and in vivo results. However, despite the existence of some clinical trials, more studies are needed to be conducted in order to explore the potential of liposomes in the dermatological field. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Chemical coupling of thiolated chitosan to preformed liposomes improves mucoadhesive properties

Directory of Open Access Journals (Sweden)

Gradauer K

2012-05-01

Full Text Available Kerstin Gradauer,1 Caroline Vonach,1 Gerd Leitinger,2,3 Dagmar Kolb,2,3 Eleonore Fröhlich,3 Eva Roblegg,4 Andreas Bernkop-Schnürch,5 Ruth Prassl1,61Institute of Biophysics and Nanosystems Research, Austrian Academy of Sciences, Graz, Austria; 2Institute of Cell Biology, Histology, and Embryology, Medical University of Graz, Graz, Austria; 3Center for Medical Research, Medical University of Graz, Graz, Austria; 4Institute of Pharmaceutical Sciences/Pharmaceutical Technology, Karl-Franzens University, Graz, Austria; 5Department of Pharmaceutical Technology, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria; 6Ludwig Boltzmann Institute for Lung Vascular Research, Graz, AustriaAim: To develop mucoadhesive liposomes by anchoring the polymer chitosan-thioglycolic acid (chitosan-TGA to the liposomal surface to target intestinal mucosal membranes.Methods: Liposomes consisting of phosphatidylcholine (POPC and a maleimide-functionalized lipid were incubated with chitosan-TGA, leading to the formation of a thioether bond between free SH-groups of the polymer and maleimide groups of the liposome. Uncoated and newly generated thiomer-coated liposomes were characterized according to their size, zeta potential, and morphology using photon correlation spectroscopy and transmission electron microscopy. The release behavior of calcitonin and the fluorophore/quencher-couple ANTS/DPX (8-aminonaphthalene-1,3,6-trisulfonic acid/p-xylene-bis- pyridinium bromide from coated and uncoated liposomes, was investigated over 24 hours in simulated gastric and intestinal fluids. To test the mucoadhesive properties of thiomer-coated and uncoated liposomes in-vitro, we used freshly excised porcine small intestine.Results: Liposomes showed a concentration-dependent increase in size – from approximately 167 nm for uncoated liposomes to 439 nm for the highest thiomer concentration used in this study. Likewise, their zeta potentials gradually increased from

Dual-coating of liposomes as encapsulating matrix of antimicrobial peptides: Development and characterization

Science.gov (United States)

Gomaa, Ahmed I.; Martinent, Cynthia; Hammami, Riadh; Fliss, Ismail; Subirade, Muriel

2017-11-01

Abstract Antimicrobial peptides have been proposed as a potential biopreservatives in pharmaceutical research and agribusiness. However, many limitations hinder their utilization, such as their vulnerability to proteolytic digestion and their potential interaction with other food ingredients in complex food systems. One approach to overcome such problems is developing formulations entrapping and thereby protecting the antimicrobial peptides. Liposome encapsulation is a strategy that could be implemented to combine protection of the antimicrobial activity of the peptides from proteolytic enzymes and the controlled release of the encapsulated active ingredients. The objective of this study was to develop dual-coated food grade liposome formulations for oral administration of bacteriocins. The formulations were developed from anionic and cationic phospholipids as models of negatively and positively charged liposomes, respectively. Liposomes were prepared by the hydration of lipid films. Subsequently, the liposomes were coated with two layers comprising a biopolymer network (pectin) and whey proteins (WPI) in order to further improve their stability and enable the gradual release of the developed liposomes. Liposomes were characterized for their size, charge, molecular structure, morphology, encapsulation efficiency and release. The results of FTIR, zeta potential, size distribution and transmission electron microscopy confirmed that the liposomes were efficiently coated. Ionic interactions were involved in the stabilization of the positively charged liposome formulations. Negatively charge liposome formulations were stabilized through weak interactions. The release study proved the efficiency of dual coating on the protection of liposomes against gastrointestinal digestion. This work is the first to study the encapsulation of antimicrobial peptides in dual-coated liposomes. Furthermore, the work successfully encapsulated MccJ25 in both negative and positive liposome

Placing and shaping liposomes with reconfigurable DNA nanocages

Science.gov (United States)

Zhang, Zhao; Yang, Yang; Pincet, Frederic; C. Llaguno, Marc; Lin, Chenxiang

2017-07-01

The diverse structure and regulated deformation of lipid bilayer membranes are among a cell's most fascinating features. Artificial membrane-bound vesicles, known as liposomes, are versatile tools for modelling biological membranes and delivering foreign objects to cells. To fully mimic the complexity of cell membranes and optimize the efficiency of delivery vesicles, controlling liposome shape (both statically and dynamically) is of utmost importance. Here we report the assembly, arrangement and remodelling of liposomes with designer geometry: all of which are exquisitely controlled by a set of modular, reconfigurable DNA nanocages. Tubular and toroid shapes, among others, are transcribed from DNA cages to liposomes with high fidelity, giving rise to membrane curvatures present in cells yet previously difficult to construct in vitro. Moreover, the conformational changes of DNA cages drive membrane fusion and bending with predictable outcomes, opening up opportunities for the systematic study of membrane mechanics.

Pharmacokinetics of a 5-fluorouracil liposomal delivery system.

Science.gov (United States)

Simmons, S T; Sherwood, M B; Nichols, D A; Penne, R B; Sery, T; Spaeth, G L

1988-01-01

A liposomal delivery system was developed in an attempt to prolong ocular levels of 5-fluorouracil for glaucoma filtering surgery. The pharmacokinetics of the 5-fluorouracil liposomal delivery system were studied in normal pigmented rabbits with 5-fluorouracil labelled with carbon-14 (C-14). 14C 5-fluorouracil was incorporated into the liposomes at a concentration of 10 g/l and injected subconjunctivally in doses of 5 and 10 mg. Concentrations of 5-fluorouracil were assayed at 10 time intervals from 0.5 to 96 hours in cornea, sclera, and conjunctiva and at six time intervals from 0.5 to 12 hours in aqueous. Two peak concentrations were noted at approximately one and eight hours, with measurable levels present at 96 hours. This study demonstrates the ability of this liposomal delivery system to prolong levels of 5-fluorouracial in normal pigmented rabbits. PMID:3179257

Liposomes self-assembled from electrosprayed composite microparticles

International Nuclear Information System (INIS)

Yu Dengguang; Yang Junhe; Wang Xia; Tian Feng

2012-01-01

Composite microparticles, consisting of polyvinylpyrrolidone (PVP), naproxen (NAP) and lecithin (PC), have been successfully prepared using an electrospraying process and exploited as templates to manipulate molecular self-assembly for the synthesis of liposomes in situ. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) observations demonstrate that the microparticles have an average diameter of 960 ± 140 nm and a homogeneous structure. X-ray diffraction (XRD) patterns, differential scanning calorimetry (DSC) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) results verify that the building blocks NAP and PC are scattered in the polymer matrix in a molecular way owing to the very fast drying of the electrospraying process and the favorable secondary interactions among the components. FESEM, scanning probe microscope (SPM) and TEM observations demonstrate that the liposomes can be achieved through molecular self-assembly in situ when the microparticles contact water thanks to ‘like prefers like’ and by means of the confinement effect of the microparticles. The liposomes have an encapsulation rate of 91.3%, and 80.7% of the drug in the liposomes can be freed into the dissolution medium in a sustained way and by a diffusion mechanism over a period of 24 h. The developed strategy not only provides a new, facile, and effective method to assemble and organize molecules of multiple components into liposomes with electrosprayed microparticles as templates, but also opens a new avenue for nanofabrication in a step-by-step and controllable way. (paper)

Oral administration of insulin by means of liposomes in animal experiments

International Nuclear Information System (INIS)

Tragl, K.H.; Pohl, A.; Kinast, H.

1979-01-01

Liposomes are an effective vehicle for the oral administration of insulin. They are prepared from lipid emulsions by sonication and particles of homogeneous size are generated by elution through sepharose columns. Liposomes are taken up into the gastric mucosa by endocytosis and then transported to the liver via the portal circulation. Oral administration of 10 U insulin/kg body weight to rats is followed by a reduction in blood glucose to 67% of the initial value. When liposome-trapped insulin was injected intravenously a decrease in blood glucose to 40% of the initial value was obtained by the administration of 5 IU insulin/kg body weight. While the effect of orally-administered liposome-trapped insulin is obvious, the problems of standardization of the insulin content of the liposomes and the great variability of liposome uptake into the gastric mucosa by endocytosis remain unsolved. (author)

Exchangeable pulmonary water space evaluation using giant liposomes

International Nuclear Information System (INIS)

Santos, A.C.; Ribeiro, M.J.; Ferreira, N.; De Lima, J.J.P.

1998-01-01

The present work aims to study the potential use of liposomes for the evaluation of pulmonary exchangeable water space, important parameter in some pulmonary oedema situations. This study is based upon the delivery of a diffusible water radiotracer into pulmonary capillary network, which equilibrates with interstitial water space of the lung and returns to the blood circulation. The time constant of this phenomena depends on the magnitude of the water space under study. The release of the diffusible radiotracer in lung capillaries is performed using liposomes with specific formulation. The giant liposomes (15-30μm diameter) used in this study are instable at 37 deg. C. They are biocompatible, biodegradable, with low toxicity and showed no immunogenicity. A water tracer labelled with 99m Tc, encapsulated in the aqueous phase of giant liposomes, has been used. Liposomes were prepared in sterile conditions and with apyrogenic materials. The lipid films composition is L-α-diestearoylphosphatidylcholine (DSPC), L-α-phosphatidyl-DL-glycerol (EPG) and cholesterol (CHOL) (60%/10%/30% mass ratio). After iv injection at +-20 deg. C in the femoral vein of Wistar rats (300g-600g) or albine rabbits (4.5-5Kg), the thermolabile liposomes will be entrapped in lung capillaries and release the radiotracer locally. When the radiodrug is diffusible we will evaluate the volume of the exchangeable pulmonary water analyzing the activity/time curves. These curves are slower for greater water spaces. When the radiotracer is non-diffusible, the disappearance curves are not influenced by the extravascular water space. (author)

Formulation and Evaluation of Rifampicin Liposomes for Buccal Drug Delivery.

Science.gov (United States)

Lankalapalli, Srinivas; Tenneti, V S Vinai Kumar

2016-01-01

Drug delivery through liposomes offers several advantages, but still challenging to the researchers for the use of liposomes as carriers in drug delivery due to their poor physical stability, unpredictable drug encapsulation and systemic availability of the loaded drug. The present investigation was planned with an objective to prepare Rifampicin loaded liposomes by using response surface methodology of statistical 32 factorial design and further to formulate them into pastilles for deliver through buccal route thereby to enhance systemic absorption. Rifampicin liposomes were prepared by using different ratios of soya lecithin and cholesterol by solvent Injection method. These liposomes were characterized by using optical microscopy, Scanning Electron Microscopy (SEM) and evaluated for particle size, entrapment efficiency (EE), in vitro and ex vivo drug release. Main effects and interaction terms of the formulation variables were evaluated quantitatively using a mathematical statistical model approach showing that both independent variables have significant (P value value: 0.0273), percentage entrapment efficiency (P value: 0.0096), percentage drug release through dialysis membrane (P value: 0.0047) and percentage drug release through porcine buccal membrane (P value: 0.0019). The statistical factorial design of liposomal formulations fulfilled all the requirements of the target set and exhibited suitable values for the selected test parameters. Pastilles were prepared for liposomes using glycerol gelatin base and were found to be soft, smooth with uniform drug content and drug release.

Effect of Lipid Composition on In Vitro Release and Skin Deposition of Curcumin Encapsulated Liposomes

Directory of Open Access Journals (Sweden)

Geethi Pamunuwa

2016-01-01

Full Text Available Liposomal encapsulation improves numerous physiochemical and biological properties of curcumin. The aim of this work was to impart slow release and skin delivery of curcumin via liposomal encapsulation. Liposomes were made using egg yolk phosphatidylcholine as the staple lipid while incorporating polysorbate 80 and stearylamine to prepare hybrid liposomes and positively charged liposomes, respectively. Negatively charged liposomes exhibited the highest encapsulation efficiencies (87.8±4.3% and loading capacities (3.4±0.2%. The sizes of all formulations were about 250 nm, while stearylamine increased the polydispersity index. Positively charged liposomes showed lower degradation temperatures than negatively charged liposomes by 10–15°C, attributable to the presence of stearylamine. The melting temperatures of positively charged liposomes (40–50°C were much higher than those of negatively charged liposomes (14-15°C, which may have affected release and skin deposition behavior of liposomes. The positively charged liposomes exhibited the slowest release of curcumin in phosphate buffered saline (pH 6.8 and the release profiles of all liposomal formulations conformed to the Gompertz model. The negatively charged liposomes facilitated the highest skin deposition of curcumin as revealed by studies conducted using excised pig ear skin. Concisely, positively and negatively charged liposomes were optimal for slow release and skin deposition of curcumin, respectively.

Atomic Force Microscopy Study on the Stiffness of Nanosized Liposomes Containing Charged Lipids.

Science.gov (United States)

Takechi-Haraya, Yuki; Goda, Yukihiro; Sakai-Kato, Kumiko

2018-06-18

It has recently been recognized that the mechanical properties of lipid nanoparticles play an important role during in vitro and in vivo behaviors such as cellular uptake, blood circulation, and biodistribution. However, there have been no quantitative investigations of the effect of commonly used charged lipids on the stiffness of nanosized liposomes. In this study, by means of atomic force microscopy (AFM), we quantified the stiffness of nanosized liposomes composed of neutrally charged lipids combined with positively or negatively charged lipids while simultaneously imaging the liposomes in aqueous medium. Our results showed that charged lipids, whether negatively or positively charged, have the effect of reducing the stiffness of nanosized liposomes, independently of the saturation degree of the lipid acyl chains; the measured stiffness values of liposomes containing charged lipids are 30-60% lower than those of their neutral counterpart liposomes. In addition, we demonstrated that the Laurdan generalized polarization values, which are related to the hydration degree of the liposomal membrane interface and often used as a qualitative indicator of liposomal membrane stiffness, do not directly correlate with the physical stiffness values of the liposomes prepared in this study. However, our results indicate that direct quantitative AFM measurement is a valuable method to gain molecular-scale information about how the hydration degree of liposomal interfaces reflects (or does not reflect) liposome stiffness as a macroscopic property. Our AFM method will contribute to the quantitative characterization of the nano-bio interaction of nanoparticles and to the optimization of the lipid composition of liposomes for clinical use.

Poly(amino acid)s: next-generation coatings for long-circulating liposomes

NARCIS (Netherlands)

Romberg, B.

2007-01-01

Incorporation of a lipid conjugate of a water-soluble polymer into liposomes can reduce the adhesion of plasma proteins that would otherwise cause rapid recognition and removal of the liposomes by phagocytes. Such polymer-coated liposomes show prolonged circulation property and passive targeting to

Liposome Delivery Systems for Inhalation: A Critical Review Highlighting Formulation Issues and Anticancer Applications.

Science.gov (United States)

Rudokas, Mindaugas; Najlah, Mohammad; Alhnan, Mohamed Albed; Elhissi, Abdelbary

2016-01-01

This is a critical review on research conducted in the field of pulmonary delivery of liposomes. Issues relating to the mechanism of nebulisation and liposome composition were appraised and correlated with literature reports of liposome formulations used in clinical trials to understand the role of liposome size and composition on therapeutic outcome. A major highlight was liposome inhalation for the treatment of lung cancers. Many in vivo studies that explored the potential of liposomes as anticancer carrier systems were evaluated, including animal studies and clinical trials. Liposomes can entrap anticancer drugs and localise their action in the lung following pulmonary delivery. The safety of inhaled liposomes incorporating anticancer drugs depends on the anticancer agent used and the amount of drug delivered to the target cancer in the lung. The difficulty of efficient targeting of liposomal anticancer aerosols to the cancerous tissues within the lung may result in low doses reaching the target site. Overall, following the success of liposomes as inhalable carriers in the treatment of lung infections, it is expected that more focus from research and development will be given to designing inhalable liposome carriers for the treatment of other lung diseases, including pulmonary cancers. The successful development of anticancer liposomes for inhalation may depend on the future development of effective aerosolisation devices and better targeted liposomes to maximise the benefit of therapy and reduce the potential for local and systemic adverse effects. © 2016 S. Karger AG, Basel.

Binding and internalization of NGR-peptide-targeted liposomal doxorubicin (TVT-DOX) in CD13-expressing cells and its antitumor effects.

Science.gov (United States)

Garde, Seema V; Forté, André J; Ge, Michael; Lepekhin, Eugene A; Panchal, Chandra J; Rabbani, Shafaat A; Wu, Jinzi J

2007-11-01

In an effort to develop new agents and molecular targets for the treatment of cancer, aspargine-glycine-arginine (NGR)-targeted liposomal doxorubicin (TVT-DOX) is being studied. The NGR peptide on the surface of liposomal doxorubicin (DOX) targets an aminopeptidase N (CD13) isoform, specific to the tumor neovasculature, making it a promising strategy. To further understand the molecular mechanisms of action, we investigated cell binding, kinetics of internalization as well as cytotoxicity of TVT-DOX in vitro. We demonstrate the specific binding of TVT-DOX to CD13-expressing endothelial [human umbilical vein endothelial cells (HUVEC) and Kaposi sarcoma-derived endothelial cells (SLK)] and tumor (fibrosarcoma, HT-1080) cells in vitro. Following binding, the drug was shown to internalize through the endosomal pathway, eventually leading to the localization of doxorubicin in cell nuclei. TVT-DOX showed selective toxicity toward CD13-expressing HUVEC, sparing the CD13-negative colon-cancer cells, HT-29. Additionally, the nontargeted counterpart of TVT-DOX, Caelyx, was less cytotoxic to the CD13-positive HUVECs demonstrating the advantages of NGR targeting in vitro. The antitumor activity of TVT-DOX was tested in nude mice bearing human prostate-cancer xenografts (PC3). A significant growth inhibition (up to 60%) of PC3 tumors in vivo was observed. Reduction of tumor vasculature following treatment with TVT-DOX was also apparent. We further compared the efficacies of TVT-DOX and free doxorubicin in the DOX-resistant colon-cancer model, HCT-116, and observed the more pronounced antitumor effects of the TVT-DOX formulation over free DOX. The potential utility of TVT-DOX in a variety of vascularized solid tumors is promising.

An in vitro model to test relative antioxidant potential: Ultraviolet-induced lipid peroxidation in liposomes

International Nuclear Information System (INIS)

Pelle, E.; Maes, D.; Padulo, G.A.; Kim, E.K.; Smith, W.P.

1990-01-01

Since antioxidants have been shown to play a major role in preventing some of the effects of aging and photoaging in skin, it is important to study this phenomenon in a controlled manner. This was accomplished by developing a simple and reliable in vitro technique to assay antioxidant efficacy. Inhibition of peroxidation by antioxidants was used as a measure of relative antioxidant potential. Liposomes, high in polyunsaturated fatty acids (PUFA), were dispersed in buffer and irradiated with ultraviolet (UV) light. Irradiated liposomes exhibited a significantly higher amount of hydroperoxides than liposomes containing antioxidants in a dose- and concentration-dependent manner. Lipid peroxidation was determined spectrophotometrically by an increase in thiobarbituric acid reacting substances. To further substantiate the production of lipid peroxides, gas chromatography was used to measure a decrease in PUFA substrate. In order of decreasing antioxidant effectiveness, the following results were found among lipophilic antioxidants: BHA greater than catechin greater than BHT greater than alpha-tocopherol greater than chlorogenic acid. Among hydrophilic antioxidants, ascorbic acid and dithiothreitol were effective while glutathione was ineffective. In addition, ascorbic acid was observed to act synergistically with alpha-tocopherol, which is in agreement with other published reports on the interaction of these two antioxidants. Although peroxyl radical scavengers seem to be at a selective advantage in this liposomal/UV system, these results demonstrate the validity of this technique as an assay for measuring an antioxidant's potential to inhibit UV-induced peroxidation

Barriers to Liposomal Gene Delivery: from Application Site to the Target.

Science.gov (United States)

Saffari, Mostafa; Moghimi, Hamid Reza; Dass, Crispin R

2016-01-01

Gene therapy is a therapeutic approach to deliver genetic material into cells to alter their function in entire organism. One promising form of gene delivery system (DDS) is liposomes. The success of liposome-mediated gene delivery is a multifactorial issue and well-designed liposomal systems might lead to optimized gene transfection particularly in vivo. Liposomal gene delivery systems face different barriers from their site of application to their target, which is inside the cells. These barriers include presystemic obstacles (epithelial barriers), systemic barriers in blood circulation and cellular barriers. Epithelial barriers differ depending on the route of administration. Systemic barriers include enzymatic degradation, binding and opsonisation. Both of these barriers can act as limiting hurdles that genetic material and their vector should overcome before reaching the cells. Finally liposomes should overcome cellular barriers that include cell entrance, endosomal escape and nuclear uptake. These barriers and their impact on liposomal gene delivery will be discussed in this review.

Liposome distribution after intravenous and selective intraarterial infusion in dogs

International Nuclear Information System (INIS)

Wright, K.C.; Kasi, L.P.; Jahns, M.S.; Hashimoto, S.; Wallace, S.

1990-01-01

In an effort to improve hepatic uptake of liposomes for drug delivery, empty vesicles were administered by means of selective arterial infusion. Negatively charged, multilamellar liposomes were labeled with technetium-99m and infused into healthy adult dogs. Each dog received 100 mg/m2 of lipid over 10 minutes at 2 mL/min. Liposomes were administered via the common hepatic artery after proximal occlusion of the gastroduodenal artery, via the cranial mesenteric artery, and via the cephalic vein. Distribution (liver, spleen, and lungs) was determined by computer-assisted external imaging techniques. On the average, after arterial infusion, 69.2% of the total activity was located in the liver, 3.6% in the spleen, 3.2% in the lungs, and 3.5% in the general circulation. Following venous injection, 50.7% of the radioactivity was found in the liver, 9.1% in the spleen, 8.6% in the lungs, and 6.7% in the peripheral blood. Once the liposomes entered the systemic circulation, they were cleared at the same rate (half-life beta = 21.5 hours) independent of their route of administration. Increased hepatic liposome uptake should translate into higher local and lower systemic liposomal drug levels

Interactions of liposome carriers with infectious fungal hyphae reveals the role of β-glucans.

Science.gov (United States)

Chavan, Neelam L; Young, Joseph K; Drezek, Rebekah A; Lewis, Russell; Bikram, Malavosklish

2012-09-04

Relatively little is known about how liposomal formulations modulate drug delivery to fungal pathogens. We compared patterns of hyphal cell wall binding for empty rhodmine-labeled liposomes and the clinically available amphotericin B-containing liposomal formulation (AmBisome) in Aspergillus fumigatus and Candida albicans. Following 0.5 h of coincubation with A. fumigatus , empty liposomes concentrated primarily in fungal septae along at the surface of the cell wall, suggesting that liposome uptake is concentrated in areas of the cell wall where linear glucan is exposed on the cell surface, which was confirmed by aniline blue staining. Consistent with this hypothesis, pretreatment of liposomes with soluble linear glucan (laminarin) decreased liposome binding in both Aspergillus and Candida fungal hyphae, while growth of Aspergillus hyphae in the presence of an agent that increases fungal cell wall surface exposure of linear β-glucans without cell death (caspofungin) increased liposome uptake throughout the Aspergillus fungal cell wall. Increasing the polyethylene glycol (PEG) concentration in liposomes from 0 to 30% significantly increased fungal uptake of liposomes that was only modestly attenuated when fungal cells were incubated in serum concentrations ranging from 10 to 100%. The presence of β-glucans on the fungal hyphae cell walls of Aspergillus fumigatus is one of the factors responsible for mediating the binding of liposome carriers to the hyphae and could explain possible synergy reported between liposomal amphotericin B and echinocanins.

6-mercaptopurine and daunorubicin double drug liposomes-preparation, drug-drug interaction and characterization.

Science.gov (United States)

Agrawal, Vineet; Paul, Manash K; Mukhopadhyay, Anup K

2005-01-01

This article addresses and investigates the dual incorporation of daunorubicin (DR) and 6-mercaptopurine (6-MP) in liposomes for better chemotherapy. These drugs are potential candidates for interaction due to the quinone (H acceptor) and hydroxyl (H donor) groups on DR and 6-MP, respectively. Interactions between the two drugs in solution were monitored by UV/Vis and fluorescence spectroscopy. Interaction between the two drugs inside the liposomes was evaluated by HPLC (for 6-MP) and by fluorescence spectroscopy (for daunorubicin) after phospholipase-mediated liposome lysis. Our results provide evidence for the lack of interaction between the two drugs in solution and in liposomes. The entrapment efficiencies of 6-MP in the neutral Phosphatidyl choline (PC):Cholesterol (Chol):: 2:1 and anionic PC:Chol:Cardiolipin (CL) :: 4:5:1 single and double drug liposomes were found to be 0.4% and 1.5% (on average), respectively. The entrapment efficiencies of DR in the neutral and anionic double drug liposomes were found to be 55% and 31%, respectively. The corresponding entrapment of daunorubicin in the single drug liposomes was found to be 62% on average. Our thin layer chromatography (TLC) and transmission electron microscopy (TEM) results suggest stability of lipid and liposomes, thus pointing plausible existence of double drug liposomes. Cytotoxicity experiments were performed by using both single drug and double drug liposomes. By comparing the results of phase contrast and fluorescence microscopy, it was observed that the double drug liposomes were internalized in the jurkat and Hut78 (highly resistant cell line) leukemia cells as viewed by the fluorescence of daunorubicin. The cytotoxicity was dose dependent and had shown a synergistic effect when double drug liposome was used.

Liposomal bupivacaine peripheral nerve block for the management of postoperative pain.

Science.gov (United States)

Hamilton, Thomas W; Athanassoglou, Vassilis; Trivella, Marialena; Strickland, Louise H; Mellon, Stephen; Murray, David; Pandit, Hemant G

2016-08-25

due to their small sample size (fewer than 50 participants per arm) leading to uncertainty around effect estimates. Additionally, inconsistency of results and sparseness of data resulted in further downgrading of the quality of the data. A lack of evidence has prevented an assessment of the efficacy of liposomal bupivacaine administered as a peripheral nerve block. At present there is a lack of data to support or refute the use of liposomal bupivacaine administered as a peripheral nerve block for the management of postoperative pain. Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.

Comparison of the cellular transport mechanism of cationic, star-shaped polymers and liposomes in HaCat cells

Directory of Open Access Journals (Sweden)

Luo H

2017-02-01

Full Text Available Heng-Cong Luo,1,2,* Na Li,1,* Li Yan,1 Kai-jin Mai,3 Kan Sun,1 Wei Wang,1 Guo-Juan Lao,1 Chuan Yang,1 Li-Ming Zhang,3 Meng Ren1 1Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen University, Guangzhou, People’s Republic of China; 2Department of Endocrinology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People’s Republic of China; 3School of Materials Science and Engineering, School of Chemistry, Sun Yat-Sen University, Guangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Several biological barriers must be overcome to achieve efficient nonviral gene delivery. These barriers include target cell uptake, lysosomal degradation, and dissociation from the carrier. In this study, we compared the differences in the uptake mechanism of cationic, star-shaped polymer/MMP-9siRNA complexes (β-CD-(D37/MMP-9siRNA complexes: polyplexes and commercial liposome/MMP-9siRNA complexes (Lipofectamine® 2000/MMP-9siRNA complexes: liposomes. The uptake pathway and transfection efficiency of the polyplexes and liposomes were determined by fluorescence microscopy, flow cytometry, and reverse transcriptase-polymerase chain reaction. The occurrence of intracellular processing was assessed by confocal laser scanning microscopy. Endosomal acidification inhibitors were used to explore the endosomal escape mechanisms of the polyplexes and lysosomes. We concluded that the polyplexes were internalized by non-caveolae- and non-clathrin-mediated pathways, with no lysosomal trafficking, thereby inducing successful transfection, while the majority of liposomes were internalized by clathrin-dependent endocytosis (CDE, caveolae-mediated endocytosis, and macropinocytosis, and only CDE induced successful transfection. Liposomes might escape more quickly than polyplexes, and

Liposomes: structure, properties and methods of curative administration in organism

Directory of Open Access Journals (Sweden)

M. A. Kisyakova

2010-07-01

Full Text Available A review of data from scientific sources, devoted to problems of liposomes’ structure, properties and processes of formation was made. Advantages of liposomes used for medical purposes are shown. Methods of liposomes administration in an organism are characterised. Data on mechanisms of interaction between liposomes and cells, peculiarities of liposomes’ lipids composition and dependence of its tropism to definite organs and tissues are generalised.

Alerting the immune system via stromal cells is central to the prevention of tumor growth

DEFF Research Database (Denmark)

Navikas, Shohreh

2013-01-01

Anticancer immunotherapies are highly desired. Conversely, unwanted inflammatory or immune responses contribute to oncogenesis, tumor progression, and cancer-related death. For non-immunogenic therapies to inhibit tumor growth, they must promote, not prevent, the activation of anticancer immune...

Development of a bone-targeted pH-sensitive liposomal formulation containing doxorubicin: physicochemical characterization, cytotoxicity, and biodistribution evaluation in a mouse model of bone metastasis

Directory of Open Access Journals (Sweden)

Ferreira DS

2016-08-01

Full Text Available Diêgo dos Santos Ferreira,1,2 Samilla Dornelas Faria,1 Sávia Caldeira de Araújo Lopes,1 Cláudia Salviano Teixeira,1 Angelo Malachias,3 Rogério Magalhães-Paniago,3 José Dias de Souza Filho,4 Bruno Luis de Jesus Pinto Oliveira,2 Alexander Ramos Guimarães,2 Peter Caravan,2 Lucas Antônio Miranda Ferreira,1 Ricardo José Alves,1 Mônica Cristina Oliveira1 1Department of Pharmaceutical Products, Faculty of Pharmacy,Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; 2Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; 3Department of Physics, 4Department of Chemistry, Institute of Exact Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil Background: Despite recent advances in cancer therapy, the treatment of bone tumors remains a major challenge. A possible underlying hypothesis, limitation, and unmet need may be the inability of therapeutics to penetrate into dense bone mineral, which can lead to poor efficacy and high toxicity, due to drug uptake in healthy organs. The development of nanostructured formulations with high affinity for bone could be an interesting approach to overcome these challenges.Purpose: To develop a liposomal formulation with high affinity for hydroxyapatite and the ability to release doxorubicin (DOX in an acidic environment for future application as a tool for treatment of bone metastases.Materials and methods: Liposomes were prepared by thin-film lipid hydration, followed by extrusion and the sulfate gradient-encapsulation method. Liposomes were characterized by average diameter, ζ-potential, encapsulation percentage, X-ray diffraction, and differential scanning calorimetry. Release studies in buffer (pH 7.4 or 5, plasma, and serum, as well as hydroxyapatite-affinity in vitro analysis were performed. Cytotoxicity was evaluated by MTT assay against the MDA-MB-231 cell line, and biodistribution was

Ultraviolet radiation-induced lipid peroxidation in liposomal membrane: modification by capsaicin

International Nuclear Information System (INIS)

De, A.K.; Ghosh, J.J.; Mandal, T.K.

1993-01-01

Ultraviolet-radiation has been reported to cause lipid peroxidation in the liposomal membrane. In the present study, treatment with capsaicin, (8-methyl-n-vanillyl-6-nonenamide), the pungent principle of red hot pepper, was shown to modify UV-induced lipid peroxidation in the liposomal membrane. Treatment with low doses of capsaicin (less than 0.1 μg/mL of phosphatidyl choline liposome) produced a significant increase in UV-induced lipid peroxidation, while high doses (0.1-0.5 μg/mL of PC liposome) caused a significant decrease of UV-induced peroxidation

Ultraviolet radiation-induced lipid peroxidation in liposomal membrane: modification by capsaicin

Energy Technology Data Exchange (ETDEWEB)

De, A. K.; Ghosh, J. J.; Mandal, T. K. [University College of Science, Department of Biochemistry, 35 Ballygunge Circular Road, Calcutta 700-019 (India)

1993-07-01

Ultraviolet-radiation has been reported to cause lipid peroxidation in the liposomal membrane. In the present study, treatment with capsaicin, (8-methyl-n-vanillyl-6-nonenamide), the pungent principle of red hot pepper, was shown to modify UV-induced lipid peroxidation in the liposomal membrane. Treatment with low doses of capsaicin (less than 0.1 μg/mL of phosphatidyl choline liposome) produced a significant increase in UV-induced lipid peroxidation, while high doses (0.1-0.5 μg/mL of PC liposome) caused a significant decrease of UV-induced peroxidation.

Recent advances on liposomal nanoparticles: synthesis, characterization and biomedical applications.

Science.gov (United States)

Panahi, Yunes; Farshbaf, Masoud; Mohammadhosseini, Majid; Mirahadi, Mozhdeh; Khalilov, Rovshan; Saghfi, Siamak; Akbarzadeh, Abolfazl

2017-06-01

Liposome is a new nanostructure for the encapsulation and delivery of bioactive agents. There are a lot of bioactive materials that could be incorporated into liposomes including cosmetics, food ingredients, and pharmaceuticals. Liposomes possess particular properties such as biocompatibility, biodegradability; accompanied by their nanosize they have potential applications in nanomedicine, cosmetics, and food industry. Nanoliposome technology offers thrilling chances for food technologists in fields including encapsulation and controlled release of food ingredients, also improved bioavailability and stability of sensitive materials. Amid numerous brilliant new drug and gene delivery systems, liposomes provide an advanced technology to carry active molecules to the specific site of action, and now days, various formulations are in clinical use. In this paper, we provide review of the main physicochemical properties of liposomes, current methods of the manufacturing and introduce some of their usage in food nanotechnology as carrier vehicles of nutrients, enzymes, and food antimicrobials and their applications as drug carriers and gene delivery agents in biomedicine.

Evaluation of liposomes coated with a pH responsive polymer

OpenAIRE

Barea, M.J.; Jenkins, M.J.; Gaber, M.H.; Bridson, R.H.

2010-01-01

Liposomes have been coated with the pH responsive polymer, Eudragit S100, and the formulation's potential for lower gastrointestinal (GI) targeting following oral administration assessed. Cationic liposomes were coated with the anionic polymer through simple mixing. The evolution of a polymer coat was studied using zeta potential measurements and laser diffraction size analysis. Further evidence of an association between polymer and liposome was obtained using light and cryo scanning electron...

Preparation and properties of functional mixed-lipid liposomes by γ-ray irradiation

International Nuclear Information System (INIS)

Hosoi, Fumio; Omichi, Hideki; Akama, Kazuhiro; Awai, Kouji; Yano, Yoshihiro; Nakano, Yoshio

1998-01-01

The feature of mixed-lipid liposomes such as polymerization and polymerized liposomes stability were investigated to find means for producing red cells containing hemoglobin inside the liposomes. The surface pressure-area isotherm values of the mixed-lipid monolayer indicated 1-stearoyl-2-(2,4-octadecadienoyl)-glycero-3-phosphocholine (SOPC) to be immiscible in cholesterol (Chol) and stearic acid (SA), and each component to contain separate domains in the bilayer membrane of liposomes. Radiation induced polymerization of mixed-SOPC liposomes was carried out using γ-rays from 60 Co at 4degC to stabilize lipid bilayers. The polymer yield increased significantly by adding Chol and SA to SOPC. The rate of polymerization of SOPC liposomes increased linearly with increasing of dose rate. The molecular weight of the polymer decreased with an increase in irradiation time. Irradiated SOPC/Chol/SA liposome vesicle size was affected by freeze-thawing. The vesicle size did not change when SOPC/Chol/SA was present in the system due to the addition of immiscible saturated 1,2-dipalmitoyl-glycero-3-phosphocholine (DPPC). (author)

Radioprotective effectiveness of Adeturone, incapsulated in liposomes

International Nuclear Information System (INIS)

Pantev, T.

1990-01-01

The radioprotective properties of Adeturone (S,2-aminoethyl isothiuronic adenosine-5-triphosphate), incapsulated in mono- and tricomponent lisosomes was studied. Intraperitoneal adminisration of the radioprotector by means of monocomponent liposomes from egg lecithins, as well as of the radioprotector alone shortly before (15-30 min) gamma irradiation of mice with 7.5 Gy (LD 100/30 ) provided high survival rate - accordingly 80% and 75%. Orally administered Adeturone incapsulated in tricomponent liposomes (dipalmitoil-DL-3-lecithin:cholesterine:stearilamine - 7:2:1) protected mice exposed to lethal X-irradiation (7.8 Gy, LD 90/30 ) for 0.5 to 4.5 hours. Adeturone, applied alone under these conditions 4.5 hours before irradiation, was ineffective. The results clearly demonstrated a prolonged radioprotective effect of Adeturone, administered per os as liposome suspension. 2 tabs., 17 refs

Benchmarking of Sterilizing grade filters with liposome Filtration.

Science.gov (United States)

Loewe, Thomas; Mundlamuri, Ramesh; Loewe, Thomas; Mundrigi, Ashok; Handt, Sebastian; Singh, Bhuwan

2017-12-14

Cytotoxic drugs can be encapsulated in liposomes vesicles, which act as drug delivery vehicles and reduce the risk of exposure of drug to healthy cells(1). The sterility of such liposome solutions is typically ensured using 0.2μm rated sterilizing grade membranes, but due to the high viscosity and low surface tension of these formulations, they can cause pre-mature blocking and increased risk of bacterial penetration through a 0.2μm sterilizing grade membrane(2). The low surface tension of liposome solutions affects the contact angle with membrane and reduces bubble point leading to bacterial penetration through the membrane. This poses a great challenge to select an appropriate sterilizing grade membrane for a given process and for filter manufacturers to develop a sterilizing grade membrane that specifically addresses these needs. In this study, the influence of different variables that could affect the total throughput and bacterial retention performance of different membranes types on processing of liposome solutions have been evaluated. Based on the results, we conclude that the membrane properties e.g., surface porosity, surface tension, pore size, symmetry/asymmetry, hydrophilicity and liposome properties e.g., composition, lipid size and concentration affect bacterial retention and total throughput capacity. Process parameters such as temperature, pressure and flow should also be optimized to improve process efficiency. Copyright © 2017, Parenteral Drug Association.

PRIMARY PREVENTION OF MALIGNANT SKIN TUMORS – PHOTOPROTECTION

Directory of Open Access Journals (Sweden)

Ana Benedičič - Pilih

2001-12-01

Full Text Available Background. The incidence of skin cancer is increasing in the world as well as in our country. Decades of research have increased the understanding of the ethiopathogenetic influences and risk factors for development of malignant skin tumors and stimulated efforts to promote their prevention. There are successes of prevention programs in some places in the world expressing with the reduction of mortality because of the cutaneous malignant melanoma. A primary prevention of a skin cancer attempts to change population knowledge, attitudes and beliefs about sunlight, leading to reduce of sunlight exposure.Conclusions. In this article we are discussing guidelines for photoprevention. The best approach to it is a reduction in the overall exposure to sunlight. The natural protection with the use of shade, clothing and hats is promoted as the best protection. Sunscreens are assumed as an important component of adjuvant photoprotection based on their convenience of use and also on their widespread promotion. While it has been argued that all tanning is a manifestation of skin injury, avoiding of artificial tanning devices is proposed also.

Enzyme sensitive liposomes in chemotherapy and potentiation of immunotherapy

DEFF Research Database (Denmark)

Østrem, Ragnhild Garborg

efficacy and induction of severe adverse effects. Interestingly, the pharmacokinetics and biodistribution of drugs can be substantially altered by encapsulation in liposomal drug delivery vehicles. The first chapter of this thesis gives a brief introduction to cancer followed by a discussion...... of the applicability of liposomes as drug delivery vehicles in cancer therapy. The second chapter describes the development of a liposome system with an inbuilt release mechanism triggered by secretory phospholipase A2 (sPLA2). This enzyme is expressed at elevated levels in many human cancers, and as such represents...... with an introduction to the cancer-immunity cycle and to how treatment approaches can aid this interplay. Subsequently it demonstrates that the presence of a functional immune system is important in the efficacy of liposomal oxaliplatin, and that this efficacy can be substantially enhanced by combination with...

Modeling the Release Kinetics of Poorly Water-Soluble Drug Molecules from Liposomal Nanocarriers

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Stephan Loew

2011-01-01

Full Text Available Liposomes are frequently used as pharmaceutical nanocarriers to deliver poorly water-soluble drugs such as temoporfin, cyclosporine A, amphotericin B, and paclitaxel to their target site. Optimal drug delivery depends on understanding the release kinetics of the drug molecules from the host liposomes during the journey to the target site and at the target site. Transfer of drugs in model systems consisting of donor liposomes and acceptor liposomes is known from experimental work to typically exhibit a first-order kinetics with a simple exponential behavior. In some cases, a fast component in the initial transfer is present, in other cases the transfer is sigmoidal. We present and analyze a theoretical model for the transfer that accounts for two physical mechanisms, collisions between liposomes and diffusion of the drug molecules through the aqueous phase. Starting with the detailed distribution of drug molecules among the individual liposomes, we specify the conditions that lead to an apparent first-order kinetic behavior. We also discuss possible implications on the transfer kinetics of (1 high drug loading of donor liposomes, (2 attractive interactions between drug molecules within the liposomes, and (3 slow transfer of drugs between the inner and outer leaflets of the liposomes.