Nanoparticle-Supported Molecular Polymerization Catalysts

OpenAIRE

Amgoune, Abderramane; Krumova, Marina; Mecking, Stefan

2008-01-01

Homogeneous molecular catalysts are immobilzed in a well-defined fashion on individual silica nanoparticles with a narrow particle size distribution by covalent attachment. This synthetic methodology is demonstrated with modified salicylaldiminato-substituted titanium(IV) complexes incorporating a trimethoxysilane-terminated linker: dichloro-bis[κ2-N,O-6-(3-(trimethoxysilyl)propoxyphenylimino)-2-tert-butyl-phenolato]titanium(IV) (3) and dichlorobis[κ2-N,O-6-(4-(trimethoxysilyl)propoxy-2,3,5,6...

The effect of doping titanium dioxide nanoparticles on phase transformation, photocatalytic activity and anti-bacterial properties

Science.gov (United States)

Buzby, Scott Edward

Nanosized titanium dioxide has a variety of important applications in everyday life including a photocatalyst for pollution remediation, photovoltaic devices, sunscreen, etc. This study focuses on the various properties of titanium dioxide nanoparticles doped with various cation and anion species. Samples were produced by various methods including metalorganic chemical vapor deposition (MOCVD), plasma assisted metalorganic chemical vapor deposition (PA-MOCVD) and sol-gel. Numerous techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron microscopy both scanning (SEM) and transmission (TEM) were used for physical characterization. Photocatalytic properties were determined by the oxidation of methylene blue dye and 2-chlorophenol in water as well as gaseous formic acid with results analyzed by high performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR) and ultra violet - visible spectroscopy (UV-VIS). For the purpose of enhancement of the photocatalytic activity of titanium dioxide nanoparticles, the effect of anion doping and the anatase-rutile phase ratio were studied. Although anatase, rutile and mixed crystallite phases all show some degree of activity in photocatalytic reactions, these results show that anatase is better suited for the degradation of organic compounds in an aqueous medium any advantage in photocatalytic activity gained through the enhancement in optical response from the smaller band gap by addition of rutile was overcome by the negatives associated with the rutile phase. Furthermore substitutional nitrogen doping showed significant improvement in UV photocatalysis as well as allowing for visible light activation of the catalyst. Further studies on the phase transitions in titanium dioxide nanoparticles were carried out by synthesizing various cation doped samples by sol-gel. Analysis of the phases by XRD showed an inverse relationship between dopant size and rutile percentage

Molecular and physiological responses to titanium dioxide and cerium oxide nanoparticles in Arabidopsis

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- Changes in tissue transcriptomes and productivity of Arabidopsis thaliana were investigated during exposure of plants to two widely-used engineered metal oxide nanoparticles, titanium dioxide (nano-titanium) and cerium dioxide (nano-cerium). Microarray analyses confirmed that e...

Cisplatin Loaded Hyaluronic Acid Modified TiO2 Nanoparticles for Neoadjuvant Chemotherapy of Ovarian Cancer

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Enling Liu

2015-01-01

Full Text Available Novel tumor-targeting titanium dioxide (TiO2 nanoparticles modified with hyaluronic acid (HA were developed to explore the feasibility of exploiting the pH-responsive drug release property of TiO2 and the tumor-targeting ability of HA to construct a tumor-targeting cisplatin (CDDP delivery system (HA-TiO2 for potential neoadjuvant chemotherapy of ovarian cancer. The experimental results indicated that CDDP release from the HA-TiO2 nanoparticles was significantly accelerated by decreasing pH from 7.4 to 5.0, which is of particular benefit to cancer therapy. CDDP-loaded HA-TiO2 nanoparticles increased the accumulation of CDDP in A2780 ovarian cancer cells via HA-mediated endocytosis and exhibited superior anticancer activity in vitro. In vivo real-time imaging assay revealed that HA-TiO2 nanoparticles possessed preferable tumor-targeting ability which might potentially minimize the toxic side effects of CDDP in clinical application.

Synthesis and characterization of ester and amide derivatives of titanium(IV) carboxymethylphosphonate

International Nuclear Information System (INIS)

Melánová, Klára; Beneš, Ludvík; Trchová, Miroslava; Svoboda, Jan; Zima, Vítězslav

2013-01-01

A set of layered ester and amide derivatives of titanium(IV) carboxymethylphosphonate was prepared by solvothermal treatment of amorphous titanium(IV) carboxymethylphosphonate with corresponding 1-alkanols, 1,ω-alkanediols, 1-aminoalkanes, 1,ω-diaminoalkanes and 1,ω-amino alcohols and characterized by powder X-ray diffraction, IR spectroscopy and thermogravimetric analysis. Whereas alkyl chains with one functional group form bilayers tilted to the layers, 1,ω-diaminoalkanes and most of 1,ω-alkanediols form bridges connecting the adjacent layers. In the case of amino alcohols, the alkyl chains form bilayer and either hydroxyl or amino group is used for bonding. This simple method for the synthesis of ester and amide derivatives does not require preparation of acid chloride derivative as a precursor or pre-intercalation with alkylamines and can be used also for the preparation of ester and amide derivatives of titanium carboxyethylphosphonate and zirconium carboxymethylphosphonate. - Graphical abstract: Ester and amide derivatives of layered titanium carboxymethylphosphonate were prepared by solvothermal treatment of amorphous solid with alkanol or alkylamine. - Highlights: • Ester and amide derivatives of titanium carboxymethylphosphonate. • Solvothermal treatment of amorphous solid with alkanol or alkylamine. • Ester and amide formation confirmed by IR spectroscopy

Hydroxycamptothecin-loaded nanoparticles enhance target drug delivery and anticancer effect

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Li Su

2008-05-01

Full Text Available Abstract Background Hydroxycamptothecin (HCPT has been shown to have activity against a broad spectrum of cancers. In order to enhance its tissue-specific delivery and anticancer activity, we prepared HCPT-loaded nanoparticles made from poly(ethylene glycol-poly(γ-benzyl-L-glutamate (PEG-PBLG, and then studied their release characteristics, pharmacokinetic characteristics, and anticancer effects. PEG-PBLG nanoparticles incorporating HCPT were prepared by a dialysis method. Scanning electron microscopy (SEM was used to observe the shape and diameter of the nanoparticles. The HCPT release characteristics in vitro were evaluated by ultraviolet spectrophotometry. A high-performance liquid chromatography (HPLC detection method for determining HCPT in rabbit plasma was established. The pharmacokinetic parameters of HCPT/PEG-PBLG nanoparticles were compared with those of HCPT. Results The HCPT-loaded nanoparticles had a core-shell spherical structure, with a core diameter of 200 nm and a shell thickness of 30 nm. Drug-loading capacity and drug encapsulation were 7.5 and 56.8%, respectively. The HCPT release profile was biphasic, with an initial abrupt release, followed by sustained release. The terminal elimination half-lives (t 1/2 β of HCPT and HCPT-loaded nanoparticles were 4.5 and 10.1 h, respectively. Peak concentrations (Cmax of HCPT and HCPT-loaded nanoparticles were 2627.8 and 1513.5 μg/L, respectively. The apparent volumes of distribution of the HCPT and HCPT-loaded nanoparticles were 7.3 and 20.0 L, respectively. Compared with a blank control group, Lovo cell xenografts or Tca8113 cell xenografts in HCPT or HCPT-loaded nanoparticle treated groups grew more slowly and the tumor doubling times were increased. The tumor inhibition effect in the HCPT-loaded nanosphere-treated group was significantly higher than that of the HCPT-treated group (p 0.05. Conclusion Compared to the HCPT- and control-treated groups, the HCPT-loaded nanoparticle

Carbon materials-functionalized tin dioxide nanoparticles toward robust, high-performance nitrogen dioxide gas sensor.

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Zhang, Rui; Liu, Xiupeng; Zhou, Tingting; Wang, Lili; Zhang, Tong

2018-08-15

Carbon (C) materials, which process excellent electrical conductivity and high carrier mobility, are promising sensing materials as active units for gas sensors. However, structural agglomeration caused by chemical processes results in a small resistance change and low sensing response. To address the above issues, structure-derived carbon-coated tin dioxide (SnO 2 ) nanoparticles having distinct core-shell morphology with a 3D net-like structure and highly uniform size are prepared by careful synthesis and fine structural design. The optimum carbon-coated SnO 2 nanoparticles (SnO 2 /C)-based gas sensor exhibits a low working temperature, excellent selectivity and fast response-recovery properties. In addition, the SnO 2 /C-based gas sensor can maintain a sensitivity to nitrogen dioxide (NO 2 ) of 3 after being cycled 4 times at 140 °C for, suggesting its good long-term stability. The structural integrity, good synergistic properties, and high gas-sensing performance of SnO 2 /C render it a promising sensing material for advanced gas sensors. Copyright © 2018 Elsevier Inc. All rights reserved.

Nafcillin-loaded PLGA nanoparticles for treatment of osteomyelitis

International Nuclear Information System (INIS)

Pillai, Rajeev Raghavan; Rabinovich, Monica; Gonsalves, Kenneth E; Somayaji, Shankari N; Hudson, Michael C

2008-01-01

The goal of this investigation is to develop poly(dl-lactide-co-glycolide) (PLGA) nanoparticles for the delivery of antibiotics such as nafcillin to osteoblasts. This is important in order to treat Staphylococcus aureus-mediated osteomyelitis. The latter is often chronic and highly resistant to antibiotics. Nafcillin (a penicillinase-resistant penicillin)-loaded nanoparticles were prepared by a single emulsion/solvent evaporation method. In vitro drug release studies were conducted in an incubator shaker at 37 deg. C in phosphate buffer saline. Drug loading and release were determined by UV-Vis spectroscopy. A viability study was conducted in S. aureus-infected mouse osteoblasts. In vitro release study showed an initial burst release and a second phase of slow release. Following 24 and 48 h of incubation, all formulations of nanoparticles loaded with nafcillin either killed or significantly reduced all of the intracellular bacteria. Our data demonstrate that effective killing of intracellular S. aureus is possible by treating the infected osteoblasts with nanoparticles loaded with nafcillin

Nafcillin-loaded PLGA nanoparticles for treatment of osteomyelitis

Energy Technology Data Exchange (ETDEWEB)

Pillai, Rajeev Raghavan; Rabinovich, Monica; Gonsalves, Kenneth E [Polymer Nanotechnology Laboratory at Center for Optoelectronics and Department of Chemistry, University of North Carolina, Charlotte, NC 28223 (United States); Somayaji, Shankari N; Hudson, Michael C [Department of Biology, University of North Carolina, Charlotte, NC 28223 (United States)], E-mail: kegonsal@uncc.edu

2008-09-01

The goal of this investigation is to develop poly(dl-lactide-co-glycolide) (PLGA) nanoparticles for the delivery of antibiotics such as nafcillin to osteoblasts. This is important in order to treat Staphylococcus aureus-mediated osteomyelitis. The latter is often chronic and highly resistant to antibiotics. Nafcillin (a penicillinase-resistant penicillin)-loaded nanoparticles were prepared by a single emulsion/solvent evaporation method. In vitro drug release studies were conducted in an incubator shaker at 37 deg. C in phosphate buffer saline. Drug loading and release were determined by UV-Vis spectroscopy. A viability study was conducted in S. aureus-infected mouse osteoblasts. In vitro release study showed an initial burst release and a second phase of slow release. Following 24 and 48 h of incubation, all formulations of nanoparticles loaded with nafcillin either killed or significantly reduced all of the intracellular bacteria. Our data demonstrate that effective killing of intracellular S. aureus is possible by treating the infected osteoblasts with nanoparticles loaded with nafcillin.

Encapsulation of fish oil into hollow solid lipid micro- and nanoparticles using carbon dioxide.

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Yang, Junsi; Ciftci, Ozan Nazim

2017-09-15

Fish oil was encapsulated in hollow solid lipid micro- and nanoparticles formed from fully hydrogenated soybean oil (FHSO) using a novel green method based on atomization of supercritical carbon dioxide (SC-CO 2 )-expanded lipid. The highest fish oil loading efficiency (97.5%, w/w) was achieved at 50%, w/w, initial fish oil concentration. All particles were spherical and in the dry free-flowing form; however, less smooth surface with wrinkles was observed when the initial fish oil concentration was increased up to 50%. With increasing initial fish oil concentration, melting point of the fish oil-loaded particles shifted to lower onset melting temperatures, and major polymorphic form transformed from α to β and/or β'. Oxidative stability of the loaded fish oil was significantly increased compared to the free fish oil (p<0.05). This innovative method forms free-flowing powder products that are easy-to-use solid fish oil formulation, which makes the handling and storage feasible and convenient. Copyright © 2017 Elsevier Ltd. All rights reserved.

Titanium(IV), zirconium, hafnium and thorium

International Nuclear Information System (INIS)

Brown, Paul L.; Ekberg, Christian

2016-01-01

Titanium can exist in solution in a number of oxidation states. The titanium(IV) exists in acidic solutions as the oxo-cation, TiO 2+ , rather than Ti 4+ . Zirconium is used in the ceramics industry and in nuclear industry as a cladding material in reactors where its reactivity towards hydrolysis reactions and precipitation of oxides may result in degradation of the cladding. In nature, hafnium is found together with zirconium and as a consequence of the contraction in ionic radii that occurs due to the 4f -electron shell, the ionic radius of hafnium is almost identical to that of zirconium. All isotopes of thorium are radioactive and, as a consequence of it being fertile, thorium is important in the nuclear fuel cycle. The polymeric hydrolysis species that have been reported for thorium are somewhat different to those identified for zirconium and hafnium, although thorium does form the Th 4 (OH) 8 8+ species.

Antimicrobial activity of zinc and titanium dioxide nanoparticles against biofilm-producing methicillin-resistant Staphylococcus aureus

Science.gov (United States)

Jesline, A.; John, Neetu P.; Narayanan, P. M.; Vani, C.; Murugan, Sevanan

2015-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major nosocomial pathogens responsible for a wide spectrum of infections and the emergence of bacterial resistance to antibiotics has lead to treatment drawbacks towards large number of drugs. Formation of biofilms is the main contributing factor to antibiotic resistance. The development of reliable processes for the synthesis of zinc oxide nanoparticles is an important aspect of nanotechnology today. Zinc oxide and titanium dioxide nanoparticles comprise well-known inhibitory and bactericidal effects. Emergence of antimicrobial resistance by pathogenic bacteria is a major health problem in recent years. This study was designed to determine the efficacy of zinc and titanium dioxide nanoparticles against biofilm producing methicillin-resistant S. aureus. Biofilm production was detected by tissue culture plate method. Out of 30 MRSA isolates, 22 isolates showed strong biofilm production and 2 showed weak and moderate biofilm formation. Two strong and weak biofilm-producing methicillin-resistant S. aureus isolates were subjected to antimicrobial activity using commercially available zinc and titanium dioxide nanoparticles. Thus, the nanoparticles showed considerably good activity against the isolates, and it can be concluded that they may act as promising, antibacterial agents in the coming years.

Facile Synthesis of Curcumin-Loaded Starch-Maleate Nanoparticles

OpenAIRE

Suh Cem Pang; Soon Hiang Tay; Suk Fun Chin

2014-01-01

We have demonstrated the loading of curcumin onto starch maleate (SM) under mild conditions by mixing dissolved curcumin and SM nanoparticles separately in absolute ethanol and ethanol/aqueous (40 : 60 v/v), respectively. Curcumin-loaded starch-maleate (CurSM) nanoparticles were subsequently precipitated from a homogeneous mixture of these solutions in absolute ethanol based on the solvent exchange method. TEM analysis indicated that the diameters of CurSM nanoparticles were ranged between 30...

Photocatalytic degradation of furfural in aqueous solution by N-doped titanium dioxide nanoparticles.

Science.gov (United States)

Veisi, Farzaneh; Zazouli, Mohammad Ali; Ebrahimzadeh, Mohammad Ali; Charati, Jamshid Yazdani; Dezfoli, Amin Shiralizadeh

2016-11-01

The photocatalytic degradation of furfural in aqueous solution was investigated using N-doped titanium dioxide nanoparticles under sunlight and ultraviolet radiation (N-TiO 2 /Sun and N-TiO 2 /UV) in a lab-scale batch photoreactor. The N-TiO 2 nanoparticles prepared using a sol-gel method were characterized using XRD, X-ray photoelectron spectroscopy (XPS), and SEM analyses. Using HPLC to monitor the furfural concentration, the effect of catalyst dosage, contact time, initial solution pH, initial furfural concentration, and sunlight or ultraviolet radiation on the degradation efficiency was studied. The efficiency of furfural removal was found to increase with increased reaction time, nanoparticle loading, and pH for both processes, whereas the efficiency decreased with increased furfural concentration. The maximum removal efficiencies for the N-TiO 2 /UV and N-TiO 2 /Sun processes were 97 and 78 %, respectively, whereas the mean removal efficiencies were 80.71 ± 2.08 % and 62.85 ± 2.41 %, respectively. In general, the degradation and elimination rate of furfural using the N-TiO 2 /UV process was higher than that using the N-TiO 2 /Sun process.

Size-mediated cytotoxicity of nanocrystalline titanium dioxide, pure and zinc-doped hydroxyapatite nanoparticles in human hepatoma cells

International Nuclear Information System (INIS)

Devanand Venkatasubbu, G.; Ramasamy, S.; Avadhani, G. S.; Palanikumar, L.; Kumar, J.

2012-01-01

Nanoparticles are highly used in biological applications including nanomedicine. In this present study, the interaction of HepG2 hepatocellular carcinoma cells (HCC) with hydroxyapatite (HAp), zinc-doped hydroxyapatite, and titanium dioxide (TiO 2 ) nanoparticles were investigated. Hydroxyapatite, zinc-doped hydroxyapatite and titanium dioxide nanoparticles were prepared by wet precipitation method. They were subjected to isochronal annealing at different temperatures. Particle morphology and size distribution were characterized by X-ray diffraction and transmission electron microscope. The nanoparticles were co-cultured with HepG2 cells. MTT assay was employed to evaluate the proliferation of tumor cells. The DNA damaging effect of HAp, Zn-doped HAp, and TiO 2 nanoparticles in human hepatoma cells (HepG2) were evaluated using DNA fragmentation studies. The results showed that in HepG2 cells, the anti-tumor activity strongly depend on the size of nanoparticles in HCC cells. Cell cycle arrest analysis for HAp, zinc-doped HAp, and TiO 2 nanoparticles revealed the influence of HAp, zinc-doped HAp, and titanium dioxide nanoparticles on the apoptosis of HepG2 cells. The results imply that the novel nano nature effect plays an important role in the biomedicinal application of nanoparticles.

Phase study of titanium dioxide nanoparticle prepared via sol-gel process

Science.gov (United States)

Oladeji Araoyinbo, Alaba; Bakri Abdullah, Mohd Mustafa Al; Salleh, Mohd Arif Anuar Mohd; Aziz, Nurul Nadia Abdul; Iskandar Azmi, Azwan

2018-03-01

In this study, titanium dioxide nanoparticles have been prepared via sol-gel process using titanium tetraisopropoxide as a precursor with hydrochloric acid as a catalyst, and ethanol with deionized water as solvents. The value of pH used is set to 3, 7 and 8. The sols obtained were dried at 100 °C for 1 hr and calcined at 350, 550, and 750 °C for 3 hrs to observe the phase transformation of titanium dioxide nanoparticle. The samples were characterized by x-ray diffraction and field emission scanning electron microscope. The morphology analysis is obtained from field emission scanning electron microscope. The phase transformation was investigated by x-ray diffraction. It was found that the pH of the solution affect the agglomeration of titanium dioxide particle. The x-ray diffraction pattern of titanium dioxide shows the anatase phase most abundant at temperature of 350 °C. At temperature of 550 °C the anatase and rutile phase were present. At temperature of 750 °C the rutile phase was the most abundant for pH 3, 7 and 8. It was confirmed that at higher temperature the rutile phase which is the stable phase are mostly present.

The Cytotoxicity, Characteristics, and Optimization of Insulin-loaded Nanoparticles

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Yasemin Budama-Kilinc

2017-04-01

Full Text Available Controlled release systems for insulin are frequent subjects of research, because it is rapidly degraded by proteolytic enzymes in the gastrointestinal tract and minimally absorbed after oral administration. Controlled release systems also provide significant contribution to its stability.  Different techniques are used for the preparation of drug-loaded nanoparticles, and many novel techniques are being developed. The size and morphology of insulin-loaded nanoparticles may vary according to performed techniques, even if the same polymer is used. The aim of this study was to demonstrate the cytotoxicity of insulin loaded nanoparticles and the effect of various synthesis parameters on the particle size, polydispersity index (PdI, loading efficiency, and particle morphology. In the experiments, poly(lactic-co-glycolic acid (PLGA and insulin-loaded PLGA nanoparticles were prepared using the double emulsion (w/o/w method. The characterization of the nanoparticles were performed with a UV spectrometer, the Zeta-sizer system, FTIR spectroscopy, and a scanning probe microscope. Cell toxicity of different concentrations was assayed with MTT methods on L929 fibroblast cells. The optimum size of the insulin-loaded PLGA nanoparticle was obtained with a 96.5% encapsulation efficiency, a 224.5 nm average particle size, and a 0.063 polydispersity index. This study obtained and characterized spherical morphology, determined that the nanoparticles have very low toxicity, and showed the effect of different parameters on particle size and polydispersity. DOI: http://dx.doi.org/10.17807/orbital.v9i1.934 

Targeting thyroid cancer with acid-triggered release of doxorubicin from silicon dioxide nanoparticles

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Li SJ

2017-08-01

Full Text Available Shijie Li,1 Daqi Zhang,1 Shihou Sheng,2 Hui Sun1 1Department of Thyroid Surgery, 2Department of Gastrointestinal Colorectal and Anal Surgery, China–Japan Union Hospital of Jilin University, Chang Chun, People’s Republic of China Abstract: Currently, therapy for thyroid cancer mainly involves surgery and radioiodine therapy. However, chemotherapy can be used in advanced and aggressive thyroid cancer that cannot be treated by other options. Nevertheless, a major obstacle to the successful treatment of thyroid cancer is the delivery of drugs to the thyroid gland. Here, we present an example of the construction of silicon dioxide nanoparticles with thyroid–stimulating-hormone receptor-targeting ligand that can specifically target the thyroid cancer. Doxorubicin nanoparticles can be triggered by acid to release the drug payload for cancer therapy. These nanoparticles shrink the tumor size in vivo with less toxic side effects. This research paves the way toward effective chemotherapy for thyroid cancer. Keywords: thyroid cancer, silicon dioxide nanoparticle, doxorubicin, acid-triggered release

Activated carbon-supported CuO nanoparticles: a hybrid material for carbon dioxide adsorption

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Boruban, Cansu; Esenturk, Emren Nalbant

2018-03-01

Activated carbon-supported copper(II) oxide (CuO) nanoparticles were synthesized by simple impregnation method to improve carbon dioxide (CO2) adsorption capacity of the support. The structural and chemical properties of the hybrid material were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (https://www.google.com.tr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CCsQFjAC&url=http%3A%2F%2Fwww.intertek.com%2Fanalytical-laboratories%2Fxrd%2F&ei=-5WZVYSCHISz7Aatqq-IAw&usg=AFQjCNFBlk-9wqy49foh8tskmbD-GGbG9g&sig2=eKrhYjO75rl_Id2sLGpq4w&bvm=bv.96952980,d.bGg) (XRD), X-ray photoelectron spectroscopy (XPS), atomic absorption spectroscopy (AAS), and Brunauer-Emmett-Teller (BET) analyses. The analyses showed that CuO nanoparticles are well-distributed on the activated carbon surface. The CO2 adsorption behavior of the activated carbon-supported CuO nanoparticles was observed by thermogravimetric analysis (TGA), temperature programmed desorption (TPD), Fourier transform infrared (FTIR), and BET analyses. The results showed that CuO nanoparticle loading on activated carbon led to about 70% increase in CO2 adsorption capacity of activated carbon under standard conditions (1 atm and 298 K). The main contributor to the observed increase is an improvement in chemical adsorption of CO2 due to the presence of CuO nanoparticles on activated carbon.

Transfection Agent Induced Nanoparticle Cell Loading

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Karin Montet-Abou

2005-07-01

Full Text Available Loading cells with magnetic nanoparticles, and tracking their fate in vivo by high resolution MRI, is an attractive approach for enhancing the efficacy of cell-based therapies including those utilizing hematopoietic stem cells, neuroprogenitor cells, and T cells. The transfection agent (internalization agent assisted loading with the Feridex IV® nanoparticle is an attractive method of loading because of the low cost of materials, and possible low regulatory barriers for eventual clinical use. We therefore explored the interaction between Feridex IV® and three internalization agents protamine (PRO, polylysine (PLL, and lipofectamine (LFA. Feridex reacted with internalization agents to form aggregates, except when either the internalization agent or Feridex was present in large excess. When Jurkat T cells were incubated with Feridex/LFA or Feridex/PRO mixtures, and washed by centrifugation, nanoparticle aggregates co-purified with cells. With C17.2 cells large iron oxide particles adhered to the cell surface. At 30 μg/mL Feridex and 3 μg/mL LFA, internalization was largely mediated by LFA and was largely cytoplasmic. However, we found that the conditions used to label cells with Feridex and transfection agents need to be carefully selected to avoid the problems of surface adsorption and nanoparticle precipitation.

Modified surface of titanium dioxide nanoparticles-based biosensor for DNA detection

Science.gov (United States)

Nadzirah, Sh.; Hashim, U.; Rusop, M.

2018-05-01

A new technique was used to develop a simple and selective picoammeter DNA biosensor for identification of E. coli O157:H7. This biosensor was fabricated from titanium dioxide nanoparticles that was synthesized by sol-gel method and spin-coated on silicon dioxide substrate via spinner. 3-Aminopropyl triethoxy silane (APTES) was used to modify the surface of TiO2. Simple surface modification approach has been applied; which is single dropping of APTES onto the TiO2 nanoparticles surface. Carboxyl modified probe DNA has been bind onto the surface of APTES/TiO2 without any amplifier element. Electrical signal has been used as the indicator to differentiate each step (surface modification of TiO2 and probe DNA immobilization). The I-V measurements indicate extremely low current (pico-ampere) flow through the device which is 2.8138E-10 A for pure TiO2 nanoparticles, 2.8124E-10 A after APTES modification and 3.5949E-10 A after probe DNA immobilization.

Human in vivo and in vitro studies on gastrointestinal absorption of titanium dioxide nanoparticles.

Science.gov (United States)

Jones, Kate; Morton, Jackie; Smith, Ian; Jurkschat, Kerstin; Harding, Anne-Helen; Evans, Gareth

2015-03-04

The study was designed to conduct human in vivo and in vitro studies on the gastrointestinal absorption of nanoparticles, using titanium dioxide as a model compound, and to compare nanoparticle behaviour with that of larger particles. A supplier's characterisation data may not fully describe a particle formulation. Most particles tested agreed with their supplied characterisation when assessed by particle number but significant proportions of 'nanoparticle formulations' were particles >100nm when assessed by particle weight. Oral doses are measured by weight and it is therefore important that the weight characterisation is taken into consideration. The human volunteer studies demonstrated that very little titanium dioxide is absorbed gastrointestinally after an oral challenge. There was no demonstrable difference in absorption for any of the three particle sizes tested. All tested formulations were shown to agglomerate in simulated gastric fluid, particularly in the smaller particle formulations. Further agglomeration was observed when dispersing formulations in polymeric or elemental foods. Virtually no translocation of titanium dioxide particles across the cell layer was demonstrated. This study found no evidence that nanoparticulate titanium dioxide is more likely to be absorbed in the gut than micron-sized particles. Crown Copyright © 2015. Published by Elsevier Ireland Ltd. All rights reserved.

Gyrospun antimicrobial nanoparticle loaded fibrous polymeric filters

Energy Technology Data Exchange (ETDEWEB)

Eranka Illangakoon, U.; Mahalingam, S.; Wang, K. [Department of Mechanical Engineering, University College London, London WC1E 7JE (United Kingdom); Cheong, Y.-K. [School of Engineering and Technology, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Canales, E. [Department of Civil, Environmental and Geomatic Engineering, University College London, London WC1E 7JE (United Kingdom); Ren, G.G. [School of Engineering and Technology, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Cloutman-Green, E. [Department of Microbiology, Virology, and Infection Prevention Control, Great Ormond Street Hospital NHS Foundation Trust, London WCIN 3JH (United Kingdom); Edirisinghe, M., E-mail: m.edirisinghe@ucl.ac.uk [Department of Mechanical Engineering, University College London, London WC1E 7JE (United Kingdom); Ciric, L. [Department of Civil, Environmental and Geomatic Engineering, University College London, London WC1E 7JE (United Kingdom)

2017-05-01

A one step approach to prepare hybrid nanoparticle embedded polymer fibres using pressurised gyration is presented. Two types of novel antimicrobial nanoparticles and poly(methylmethacrylate) polymer were used in this work. X-ray diffraction analysis of the nanoparticles revealed Ag, Cu and W are the main elements present in them. The concentration of the polymer solution and the nanoparticle concentration had a significant influence on the fibre diameter, pore size and morphology. Fibres with a diameter in the range of 6–20 μm were spun using 20 wt% polymer solutions containing 0.1, 0.25 and 0.5 wt% nanoparticles under 0.3 MPa working pressure and a rotational speed of 36,000 rpm. Continuous, bead-free fibre morphologies were obtained for each case. The pore size in the fibres varied between 36 and 300 nm. Successful incorporation of the nanoparticles in polymer fibres was confirmed by energy dispersive x-ray analysis. The fibres were also gyrospun on to metallic discs to prepare filters which were tested for their antibacterial activity on a suspension of Pseudomonas aeruginosa. Nanoparticle loaded fibres showed higher antibacterial efficacy than pure poly(methylmethacrylate) fibres. - Highlights: • Nanoparticles containing Ag, Cu and W were studied for antimicrobial activity. • Hybrid nanoparticle-polymeric fibres were prepared using pressurised gyration. • Fibre characteristics were tailored using material and forming process variables. • Nanoparticle loaded fibre mats show higher antibacterial efficacy.

Polymorph-dependent titanium dioxide nanoparticle dissolution in acidic and alkali digestions

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Multiple polymorphs (anatase, brookite and rutile) of titanium dioxide nanoparticles (TiO2-NPs) with variable structures were quantified in environmental matrices via microwave-based hydrofluoric (HF) and nitric (HNO3) mixed acid digestion and muffle furnace (MF)-based potassium ...

Titanium dioxide nanoparticles increase sensitivity in the next generation of the water flea Daphnia magna.

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Mirco Bundschuh

Full Text Available The nanoparticle industry is expected to become a trillion dollar business in the near future. Therefore, the unintentional introduction of nanoparticles into the environment is increasingly likely. However, currently applied risk-assessment practices require further adaptation to accommodate the intrinsic nature of engineered nanoparticles. Combining a chronic flow-through exposure system with subsequent acute toxicity tests for the standard test organism Daphnia magna, we found that juvenile offspring of adults that were previously exposed to titanium dioxide nanoparticles exhibit a significantly increased sensitivity to titanium dioxide nanoparticles compared with the offspring of unexposed adults, as displayed by lower 96 h-EC(50 values. This observation is particularly remarkable because adults exhibited no differences among treatments in terms of typically assessed endpoints, such as sensitivity, number of offspring, or energy reserves. Hence, the present study suggests that ecotoxicological research requires further development to include the assessment of the environmental risks of nanoparticles for the next and hence not directly exposed generation, which is currently not included in standard test protocols.

Comparative proteomic analysis of the molecular responses of mouse macrophages to titanium dioxide and copper oxide nanoparticles unravels some toxic mechanisms for copper oxide nanoparticles in macrophages.

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Sarah Triboulet

Full Text Available Titanium dioxide and copper oxide nanoparticles are more and more widely used because of their catalytic properties, of their light absorbing properties (titanium dioxide or of their biocidal properties (copper oxide, increasing the risk of adverse health effects. In this frame, the responses of mouse macrophages were studied. Both proteomic and targeted analyses were performed to investigate several parameters, such as phagocytic capacity, cytokine release, copper release, and response at sub toxic doses. Besides titanium dioxide and copper oxide nanoparticles, copper ions were used as controls. We also showed that the overall copper release in the cell does not explain per se the toxicity observed with copper oxide nanoparticles. In addition, both copper ion and copper oxide nanoparticles, but not titanium oxide, induced DNA strands breaks in macrophages. As to functional responses, the phagocytic capacity was not hampered by any of the treatments at non-toxic doses, while copper ion decreased the lipopolysaccharide-induced cytokine and nitric oxide productions. The proteomic analyses highlighted very few changes induced by titanium dioxide nanoparticles, but an induction of heme oxygenase, an increase of glutathione synthesis and a decrease of tetrahydrobiopterin in response to copper oxide nanoparticles. Subsequent targeted analyses demonstrated that the increase in glutathione biosynthesis and the induction of heme oxygenase (e.g. by lovastatin/monacolin K are critical for macrophages to survive a copper challenge, and that the intermediates of the catecholamine pathway induce a strong cross toxicity with copper oxide nanoparticles and copper ions.

Comparative proteomic analysis of the molecular responses of mouse macrophages to titanium dioxide and copper oxide nanoparticles unravels some toxic mechanisms for copper oxide nanoparticles in macrophages.

Science.gov (United States)

Triboulet, Sarah; Aude-Garcia, Catherine; Armand, Lucie; Collin-Faure, Véronique; Chevallet, Mireille; Diemer, Hélène; Gerdil, Adèle; Proamer, Fabienne; Strub, Jean-Marc; Habert, Aurélie; Herlin, Nathalie; Van Dorsselaer, Alain; Carrière, Marie; Rabilloud, Thierry

2015-01-01

Titanium dioxide and copper oxide nanoparticles are more and more widely used because of their catalytic properties, of their light absorbing properties (titanium dioxide) or of their biocidal properties (copper oxide), increasing the risk of adverse health effects. In this frame, the responses of mouse macrophages were studied. Both proteomic and targeted analyses were performed to investigate several parameters, such as phagocytic capacity, cytokine release, copper release, and response at sub toxic doses. Besides titanium dioxide and copper oxide nanoparticles, copper ions were used as controls. We also showed that the overall copper release in the cell does not explain per se the toxicity observed with copper oxide nanoparticles. In addition, both copper ion and copper oxide nanoparticles, but not titanium oxide, induced DNA strands breaks in macrophages. As to functional responses, the phagocytic capacity was not hampered by any of the treatments at non-toxic doses, while copper ion decreased the lipopolysaccharide-induced cytokine and nitric oxide productions. The proteomic analyses highlighted very few changes induced by titanium dioxide nanoparticles, but an induction of heme oxygenase, an increase of glutathione synthesis and a decrease of tetrahydrobiopterin in response to copper oxide nanoparticles. Subsequent targeted analyses demonstrated that the increase in glutathione biosynthesis and the induction of heme oxygenase (e.g. by lovastatin/monacolin K) are critical for macrophages to survive a copper challenge, and that the intermediates of the catecholamine pathway induce a strong cross toxicity with copper oxide nanoparticles and copper ions.

Characterization of biodegradable polycaprolactone containing titanium dioxide micro and nanoparticles

Czech Academy of Sciences Publication Activity Database

Govorčin Bajsić, E.; Ocelić Bulatović, V.; Šlouf, Miroslav; Šitum, Ana

2014-01-01

Roč. 8, č. 7 (2014), s. 536-540 ISSN 2010-376X R&D Projects: GA TA ČR TE01020118 Institutional support: RVO:61389013 Keywords : morphology * polycaprolactone * thermal properties Subject RIV: EA - Cell Biology http://waset.org/Publication/characterization-of-biodegradable-polycaprolactone-containing-titanium-dioxide-micro-and-nanoparticles/9998694

Endostar-loaded PEG-PLGA nanoparticles: in vitro and in vivo evaluation

Directory of Open Access Journals (Sweden)

Sanyuan Hu

2010-11-01

Full Text Available Sanyuan Hu1, Yangde Zhang21Xiangya School of Medicine and 2National Hepatobiliary and Enteric Surgery Research Center, Ministry of Health, Central South University, Changsha, Hunan Province, People’s Republic of ChinaAbstract: Endostar, a novel recombinant human endostatin, which was approved by the Chinese State Food and Drug Administration in 2005, has a broad spectrum of activity against solid tumors. In this study, we aimed to determine whether the anticancer effect of Endostar is increased by using a nanocarrier system. It is expected that the prolonged circulation of endostar will improve its anticancer activity. Endostar-loaded nanoparticles were prepared to improve controlled release of the drug in mice and rabbits, as well as its anticancer effects in mice with colon cancer. A protein release system could be exploited to act as a drug carrier. Nanoparticles were formulated from poly (ethylene glycol modified poly (DL-lactide-co-glycolide (PEG-PLGA by a double emulsion technique. Physical and release characteristics of endostar-loaded nanoparticles in vitro were evaluated by transmission electron microscopy (TEM, photon correlation spectroscopy (PCS, and micro bicinchoninic acid protein assay. The pharmacokinetic parameters of endostar nanoparticles in rabbit and mice plasma were measured by enzyme-linked immunosorbent assay. Western blot was used to detect endostatin in different tissues. To study the effects of endostar-loaded nanoparticles in vivo, nude mice in which tumor cells HT-29 were implanted, were subsequently treated with endostar or endostar-loaded PEG-PLGA nanoparticles. Using TEM and PCS, endostar-loaded PEG-PLGA nanoparticles were found to have a spherical core-shell structure with a diameter of 169.56 ± 35.03 nm. Drug-loading capacity was 8.22% ± 2.35% and drug encapsulation was 80.17% ± 7.83%. Compared with endostar, endostar-loaded PEG-PLGA nanoparticles had a longer elimination half-life and lower peak

Reduced graphene oxide supported gold nanoparticles for electrocatalytic reduction of carbon dioxide

Science.gov (United States)

Saquib, Mohammad; Halder, Aditi

2018-02-01

Electrochemical reduction of carbon dioxide is one of the methods which have the capability to recycle CO2 into valuable products for energy and industrial applications. This research article describes about a new electrocatalyst "reduced graphene oxide supported gold nanoparticles" for selective electrochemical conversion of carbon dioxide to carbon monoxide. The main aim for conversion of CO2 to CO lies in the fact that the latter is an important component of syn gas (a mixture of hydrogen and carbon monoxide), which is then converted into liquid fuel via well-known industrial process called Fischer-Tropsch process. In this work, we have synthesized different composites of the gold nanoparticles supported on defective reduced graphene oxide to evaluate the catalytic activity of reduced graphene oxide (RGO)-supported gold nanoparticles and the role of defective RGO support towards the electrochemical reduction of CO2. Electrochemical and impedance measurements demonstrate that higher concentration of gold nanoparticles on the graphene support led to remarkable decrease in the onset potential of 240 mV and increase in the current density for CO2 reduction. Lower impedance and Tafel slope values also clearly support our findings for the better performance of RGOAu than bare Au for CO2 reduction.

Cytotoxicity of titanium dioxide nanoparticles in mouse fibroblast cells.

Science.gov (United States)

Jin, Cheng-Yu; Zhu, Bang-Shang; Wang, Xue-Feng; Lu, Qing-Hua

2008-09-01

Nanotitanium dioxide (TiO2) is an important industrial material that is widely used as an additive in cosmetics, pharmaceuticals, and food colorants. Although the small size of the TiO2 nanoparticle is useful in various applications, the biosafety of this material needs to be evaluated. In this study, mouse fibroblast (L929) cells were used to evaluate the cytotoxicity of different concentrations (3-600 microg/mL) of homogeneous and weakly aggregated TiO2 nanoparticles in aqueous solution. The L929 cells became round and even shrank as the concentration of TiO2 nanoparticles increased. Moreover, TiO2 nanoparticle-treated cells had condensed fragmented chromatin or were directly necrosed, as observed by acridine orange (AO) staining. The transmission electron microscopy (TEM) analysis showed that in cells cultured in a medium containing 300 microg/mL TiO2, the number of lysosomes increased, and some cytoplasmic organelles were damaged. In addition, there was a significant increase in oxidative stress at higher TiO2 nanoparticle concentrations (>60 microg/mL). As the concentration of TiO2 nanoparticles increased in the culture medium, the levels of reactive oxygen species (ROS) and lactate dehydrogenase (LDH) increased, while those of methyl tetrazolium cytotoxicity (MTT), glutathione (GSH), and superoxide dismutase (SOD) decreased. A possible mechanism for the cytotoxicity of TiO2 nanoparticles is also discussed.

Preparation and characterization of Tribulus terrestris-loaded nanoparticles

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M. Khanavi*

2017-11-01

Full Text Available Background and objectives: Tribulus terrestris is a flowering herb (Zygophyllaceae with several properties in folk medicine such as diuretic, tonic, aphrodisiac, analgesic, astringent, and stomachic-lithotripter activities. Although, some extracts and phytochemicals represent excellent bio-activity in vitro, less or no in vivo activity is observed due to their improper molecular size. The intend of this research was investigation of the feasibility of encapsulating T. terrestris into [poly (lactic-co-glycolic acid] PLGA nanoparticles. Methods: Aerial parts of the plant were extracted with aqueous ethanol 85% by percolation apparatus. The nanoparticles of T. terrestris-loaded were prepared using a modified simultaneous double-emulsion solvent evaporation/diffusion method. Elucidations were made on the basis of scanning electron microscopy (SEM and differential scanning calorimetry (DSC. The content of nanoparticles was analyzed by HPLC with indirect method. Results: The results stated that increasing the portion of plant extract could cause bigger size with no considerable increase in polydispersity index (PDI. The encapsulation efficiency of T. terrestris-loaded nanoparticles was 40.3 to 78.5 and the drug loadings were 0.806 to 6.104, with different ratios of extract. The overall pattern of the release in SDS 1% in dialysis bag in all formulations showed similar and biphasic release kinetic, an initial burst release in the first day followed by constant release over 10 days. Conclusion: An effective approach for the preparation of T. terrestris-loaded PLGA nanoparticles was performed. The controlled release profile showed that these biodegradable PLGA nanoparticles had great potential and should be given particular consideration in further biological researches.

Fate of cerium dioxide nanoparticles in endothelial cells: exocytosis

Energy Technology Data Exchange (ETDEWEB)

Strobel, Claudia, E-mail: Claudia.Strobel@med.uni-jena.de [Jena University Hospital – Friedrich Schiller University Jena, Department of Experimental Radiology, Institute of Diagnostic and Interventional Radiology (Germany); Oehring, Hartmut [Jena University Hospital – Friedrich Schiller University Jena, Institute of Anatomy II (Germany); Herrmann, Rudolf [University of Augsburg, Department of Physics (Germany); Förster, Martin [Jena University Hospital – Friedrich Schiller University Jena, Department of Internal Medicine I, Division of Pulmonary Medicine and Allergy/Immunology (Germany); Reller, Armin [University of Augsburg, Department of Physics (Germany); Hilger, Ingrid, E-mail: ingrid.hilger@med.uni-jena.de [Jena University Hospital – Friedrich Schiller University Jena, Department of Experimental Radiology, Institute of Diagnostic and Interventional Radiology (Germany)

2015-05-15

Although cytotoxicity and endocytosis of nanoparticles have been the subject of numerous studies, investigations regarding exocytosis as an important mechanism to reduce intracellular nanoparticle accumulation are rather rare and there is a distinct lack of knowledge. The current study investigated the behavior of human microvascular endothelial cells to exocytose cerium dioxide (CeO{sub 2}) nanoparticles (18.8 nm) by utilization of specific inhibitors [brefeldin A; nocodazole; methyl-β-cyclodextrin (MβcD)] and different analytical methods (flow cytometry, transmission electron microscopy, inductively coupled plasma mass spectrometry). Overall, it was found that endothelial cells were able to release CeO{sub 2} nanoparticles via exocytosis after the migration of nanoparticle containing endosomes toward the plasma membrane. The exocytosis process occurred mainly by fusion of vesicular membranes with plasma membrane resulting in the discharge of vesicular content to extracellular environment. Nevertheless, it seems to be likely that nanoparticles present in the cytosol could leave the cells in a direct manner. MβcD treatment led to the strongest inhibition of the nanoparticle exocytosis indicating a significant role of the plasma membrane cholesterol content in the exocytosis process. Brefeldin A (inhibitor of Golgi-to-cell-surface-transport) caused a higher inhibitory effect on exocytosis than nocodazole (inhibitor of microtubules). Thus, the transfer from distal Golgi compartments to the cell surface influenced the exocytosis process of the CeO{sub 2} nanoparticles more than the microtubule-associated transport. In conclusion, endothelial cells, which came in contact with nanoparticles, e.g., after intravenously applied nano-based drugs, can regulate their intracellular nanoparticle amount, which is necessary to avoid adverse nanoparticle effects on cells.

Eugenol-loaded chitosan nanoparticles: II. Application in bio-based plastics for active packaging.

Science.gov (United States)

Woranuch, Sarekha; Yoksan, Rangrong

2013-07-25

The aim of the present research was to study the possibility of using eugenol-loaded chitosan nanoparticles as antioxidants for active bio-based packaging material. Eugenol-loaded chitosan nanoparticles were incorporated into thermoplastic flour (TPF) - a model bio-based plastic - through an extrusion process at temperatures above 150°C. The influences of eugenol-loaded chitosan nanoparticles on crystallinity, morphology, thermal properties, radical scavenging activity, reducing power, tensile properties and barrier properties of TPF were investigated. Although the incorporation of 3% (w/w) of eugenol-loaded chitosan nanoparticles significantly reduced the extensibility and the oxygen barrier property of TPF, it provided antioxidant activity and improved the water vapor barrier property. In addition, TPF containing eugenol-loaded chitosan nanoparticles exhibited superior radical scavenging activity and stronger reducing power compared with TPF containing naked eugenol. The results suggest the applicability of TPF containing eugenol-loaded chitosan nanoparticles as an antioxidant active packaging material. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthesis of Titanium Dioxide nanoparticles via sucrose ester micelle-mediated hydrothermal processing route

International Nuclear Information System (INIS)

Anwar, N.S.; Kassim, A.; Lim, H.N.; Zakarya, S.A.; Huang, N.M.

2010-01-01

Titanium dioxide nanoparticles were synthesized via low-temperature sucrose ester micelle-mediated hydrothermal processing route using titanium isopropoxide as the precursor. X-ray diffractometer revealed that the samples possessed a mixed crystalline phases consisting of anatase and brookite in which anatase was the main phase. Upon increasing the hydrothermal reaction temperature, the degree of crystallinity of the nanoparticles improved and their morphology transformed from bundles of needles to rods and to spheres. Photo catalytic behaviour of the as-synthesized nanoparticles was investigated by photodegradation of methylene blue solution in an ultraviolet A irradiating photo reactor. The as-synthesized nanoparticles exhibited higher photo catalytic performance as compared to the commercial counterpart. (author)

The stress caused by nitrite with titanium dioxide nanoparticles under UVA irradiation in human keratinocyte cell

International Nuclear Information System (INIS)

Tu, Min; Huang, Yi; Li, Hai-Ling; Gao, Zhong-Hong

2012-01-01

Highlights: ► Nitrite increased photo-toxicity of nano-TiO 2 on human keratinocyte cells in a dose-dependant manner. ► Morphological study suggested the cell death may be mediated by apoptosis inducing factor. ► Protein nitration was generated in the cells, and the most abundant nitrated protein was identified as cystatin-A. ► Tyr35 was the most likely site to be nitrated in cystatin-A. -- Abstract: Our previous work found that in the presence of nitrite, titanium dioxide nanoparticles can cause protein tyrosine nitration under UVA irradiation in vivo. In this paper, the human keratinocyte cells was used as a skin cell model to further study the photo-toxicity of titanium dioxide nanoparticles when nitrite was present. The results showed that nitrite increased the photo-toxicity of titanium dioxide in a dose-dependant manner, and generated protein tyrosine nitration in keratinocyte cells. Morphological study of keratinocyte cells suggested a specific apoptosis mediated by apoptosis inducing factor. It was also found the main target nitrated in cells was cystatin-A, which expressed abundantly in cytoplasm and functioned as a cysteine protease inhibitor. The stress induced by titanium dioxide with nitrite under UVA irradiation in human keratinocyte cells appeared to trigger the apoptosis inducing factor mediated cell death and lose the inhibition of active caspase by cystatin-A. We conclude that nitrite can bring new damage and stress to human keratinocyte cells with titanium dioxide nanoparticles under UVA irradiation.

Production of Curcumin-Loaded Silk Fibroin Nanoparticles for Cancer Therapy

Science.gov (United States)

Coburn, Jeannine M.; Cenis, José L.; Víllora, Gloria; Kaplan, David L.

2018-01-01

Curcumin, extracted from the rhizome of Curcuma longa, has been widely used in medicine for centuries due to its anti-inflammatory, anti-cancer, anti-oxidant and anti-microbial effects. However, its bioavailability during treatments is poor because of its low solubility in water, slow dissolution rate and rapid intestinal metabolism. For these reasons, improving the therapeutic efficiency of curcumin using nanocarriers (e.g., biopolymer nanoparticles) has been a research focus, to foster delivery of the curcumin inside cells due to their small size and large surface area. Silk fibroin from the Bombyx mori silkworm is a biopolymer characterized by its biocompatibility, biodegradability, amphiphilic chemistry, and excellent mechanical properties in various material formats. These features make silk fibroin nanoparticles useful vehicles for delivering therapeutic drugs, such as curcumin. Curcumin-loaded silk fibroin nanoparticles were synthesized using two procedures (physical adsorption and coprecipitation) more scalable than methods previously described using ionic liquids. The results showed that nanoparticle formulations were 155 to 170 nm in diameter with a zeta potential of approximately −45 mV. The curcumin-loaded silk fibroin nanoparticles obtained by both processing methods were cytotoxic to carcinogenic cells, while not decreasing viability of healthy cells. In the case of tumor cells, curcumin-loaded silk fibroin nanoparticles presented higher efficacy in cytotoxicity against neuroblastoma cells than hepatocarcinoma cells. In conclusion, curcumin-loaded silk fibroin nanoparticles constitute a biodegradable and biocompatible delivery system with the potential to treat tumors by local, long-term sustained drug delivery. PMID:29495296

Preparation and Optimization OF Palm-Based Lipid Nanoparticles Loaded with Griseofulvin.

Science.gov (United States)

Huei Lim, Wen; Jean Tan, Yann; Sin Lee, Choy; Meng Er, Hui; Fung Wong, Shew

2017-01-01

Palm-based lipid nanoparticle formulation loaded with griseofulvin was prepared by solvent-free hot homogenization method. The griseofulvin loaded lipid nanoparticles were prepared via stages of optimisation, by altering the high pressure homogenisation (HPH) parameters, screening on palm-based lipids and Tween series surfactants and selection of lipid to surfactant ratios. A HPLC method has been validated for the drug loading capacity study. The optimum HPH parameter was determined to be 1500 bar with 5 cycles and among the palm-based lipid materials; Lipid C (triglycerides) was selected for the preparation of lipid nanoparticles. Tween 80 was chosen from the Tween series surfactants for its highest saturated solubility of griseofulvin at 53.1 ± 2.16 µg/mL. The optimum formulation of the griseofulvin loaded lipid nanoparticles demonstrated nano-range of particle size (179.8 nm) with intermediate distribution index (PDI) of 0.306, zeta potential of -27.9 mV and drug loading of 0.77%. The formulation was stable upon storage for 1 month at room temperature (25 ° C) and 45 ° C with consistent drug loading capacity.

Magnetic lipid nanoparticles loading doxorubicin for intracellular delivery: Preparation and characteristics

International Nuclear Information System (INIS)

Ying Xiaoying; Du Yongzhong; Hong Linghong; Yuan Hong; Hu Fuqiang

2011-01-01

Tumor intracellular delivery is an effective route for targeting chemotherapy to enhance the curative effect and minimize the side effect of a drug. In this study, the magnetic lipid nanoparticles with an uptake ability by tumor cells were prepared dispersing ferroso-ferric oxide nanoparticles in aqueous phase using oleic acid (OA) as a dispersant, and following the solvent dispersion of lipid organic solution. The obtained nanoparticles with 200 nm volume average diameter and -30 mV surface zeta potential could be completely removed by external magnetic field from aqueous solution. Using doxorubicin (DOX) as a model drug, the drug-loaded magnetic lipid nanoparticles were investigated in detail, such as the effects of OA, drug and lipid content on volume average diameter, zeta potential, drug encapsulation efficiency, drug loading, and in vitro drug release. The drug loading capacity and encapsulation efficiency were enhanced with increasing drug or lipid content, reduced with increasing OA content. The in vitro drug release could be controlled by changing drug or lipid content. Cellular uptake by MCF-7 cells experiment presented the excellent internalization ability of the prepared magnetic lipid nanoparticles. These results evidenced that the present magnetic lipid nanoparticles have potential for targeting therapy of antitumor drugs. - Research highlights: → A simple solvent diffusion method was developed to prepare magnetic lipid nanoparticles. → The doxorubicin-loaded magnetic lipid nanoparticles could be controlled by preparation recipe. → Magnetic lipid nanoparticles had internalization ability into tumor cells.

Photo-conversion of CO2 using titanium dioxide: enhancements by plasmonic and co-catalytic nanoparticles

International Nuclear Information System (INIS)

Mankidy, Bijith D; Joseph, Babu; Gupta, Vinay K

2013-01-01

Converting carbon dioxide (CO 2 ) to hydrocarbons that can be used as fuels is beneficial from both environmental and economic points of view. In this study, nanoparticles are designed to enhance the photoreduction of CO 2 on a titanium dioxide (TiO 2 ) catalyst. An increase in catalytic activity is reported when silver (Ag), platinum (Pt) or bimetallic Ag–Pt and core–shell Ag@silica (SiO 2 ) nanoparticles are used with the TiO 2 semiconductor catalyst. Nanoparticles with different elemental composition or geometrical structure facilitate successive photo-excitation steps—generation, transport, storage and interfacial transfer of electrons and holes. Results show that while the addition of either type of nanoparticles augments product formation rates, bimetallic co-catalysts improve product selectivity. When both bimetallic co-catalysts and Ag@SiO 2 nanoparticles are used in combination, product yields are enhanced more than seven fold in comparison to native TiO 2 and high selectivity for methane (CH 4 ) is observed. When the bimetallic Ag–Pt co-catalysts are tuned, a selectivity of CH 4 of approximately 80%, as compared to 20% with only TiO 2 , can be achieved. (paper)

Effects of titanium dioxide nanoparticles on soil microbial communities and wheat biomass

NARCIS (Netherlands)

Moll, Janine; Klingenfuss, Florian; Widmer, Franco; Gogos, Alexander; Bucheli, Thomas D.; Hartmann, Martin; van der Heijden, Marcel G.A.

2017-01-01

Titanium dioxide nanoparticles (TiO2 NPs) are the most produced NPs worldwide and have great potential to be utilized in agriculture as additives for plant protection products. However, concerns have been raised that some NPs may negatively affect crops and soil microbial communities, including

Development of flurbiprofen-loaded nanoparticles with a narrow size distribution using sucrose.

Science.gov (United States)

Oh, Dong Hoon; Yan, Yi-Dong; Kim, Dong Wuk; Kim, Jong Oh; Yong, Chul Soon; Choi, Han-Gon

2014-02-01

A novel flurbiprofen-loaded nanoemulsion which gave uniform emulsion droplets with a narrow size distribution was previously reported to be prepared using membrane emulsification method. The purpose of this study is to develop a novel flurbiprofen-loaded nanoparticle with a narrow size distribution and improved bioavailability. The nanoparticle was prepared by solidifying nanoemulsion using sucrose as a carrier via spray drying method. Its physicochemical properties were investigated using SEM, DSC and PXRD. Furthermore, dissolution and bioavailability in rats were evaluated compared to a flurbiprofen-loaded commercial product. The flurbiprofen-loaded nanoparticles with flurbiprofen/sucrose/surfactant mixture (1/20/2, weight ratio) gave good solidification and no stickiness. They associated with about 70,000-fold improved drug solubility and had a mean size of about 300 nm with a narrow size distribution. Flurbiprofen was present in a changed amorphous state in these nanoparticles. Moreover, the nanoparticles gave significantly shorter Tmax, and higher AUC and Cmax of the drug compared to the commercial product (p flurbiprofen-loaded nanoparticles prepared with sucrose by the membrane emulsification and spray drying method would be a potential candidate for orally delivering poorly water-soluble flurbiprofen with enhanced bioavailability.

Titanium dioxide encapsulation of supported Ag nanoparticles on the porous silica bead for increased photocatalytic activity

Science.gov (United States)

Liu, Hui; Deng, Lu; Sun, Chaochao; Li, Junqi; Zhu, Zhenfeng

2015-01-01

A new synthetic strategy has been developed to encapsulate Ag nanoparticles in heterogeneous catalysts to prevent their dropping and sintering. Ag nanoparticles with diameters about 5-10 nm were first supported on the porous silica bead. These were then covered with a fresh layer of titanium dioxide with the thickness about 5 nm. SEM and TEM images were used to confirm the success of each synthesis step, and the photocatalytic activity of the as-synthesized samples was evaluated by photocatalytic decolorization of Rhodamine B (Rh B) aqueous solution at ambient temperature under both UV and visible light irradiation. The resulting titanium dioxide encapsulated Ag nanoparticles exhibited an enhanced photocatalytic activity under both UV and visible light irradiation, this can be attributed to effective charge separation and light harvesting of the plasmonic silver nanoparticles decoration, even the reducing of the exciton recombination rate caused by the small grain size of anatase TiO2 nanocrystals.

HIGH-QUALITY ORNAMENTAL FINE CONCRETES MODIFIED BY NANOPARTICLES OF TITANIUM DIOXIDE

Directory of Open Access Journals (Sweden)

Bazhenov Yuriy Mikhaylovich

2012-10-01

Full Text Available Ultrasonic method of generation of a stable suspension of nano-particles of titanium dioxide and the strengthening properties of the ornamental fine concrete that contains cement binders with a nano-dispersed additive constitute the subject of the research covered by the authors. Nanoparticles react with the basic chemical elements that compose the concrete and act as crystallization centres. Therefore, the concrete porosity is reduced, while physical and technology-related properties of the ornamental fine concrete are improved. The authors have proven that the application of the nano-dispersed additive that contains titanium dioxide influences the processes of the structure formation in respect of fine ornamental concretes and improves the strength, as well as the water and cold resistance of fine concretes. The improvement is attributed to the dense concrete structure and strong adhesion between cement grains and between the cement and the aggregate. This conclusion is based on the data obtained through the employment of an electronic microscope used to identify the porosity of fine concretes.

Production of Curcumin-Loaded Silk Fibroin Nanoparticles for Cancer Therapy

Directory of Open Access Journals (Sweden)

Mercedes G. Montalbán

2018-02-01

Full Text Available Curcumin, extracted from the rhizome of Curcuma longa, has been widely used in medicine for centuries due to its anti-inflammatory, anti-cancer, anti-oxidant and anti-microbial effects. However, its bioavailability during treatments is poor because of its low solubility in water, slow dissolution rate and rapid intestinal metabolism. For these reasons, improving the therapeutic efficiency of curcumin using nanocarriers (e.g., biopolymer nanoparticles has been a research focus, to foster delivery of the curcumin inside cells due to their small size and large surface area. Silk fibroin from the Bombyx mori silkworm is a biopolymer characterized by its biocompatibility, biodegradability, amphiphilic chemistry, and excellent mechanical properties in various material formats. These features make silk fibroin nanoparticles useful vehicles for delivering therapeutic drugs, such as curcumin. Curcumin-loaded silk fibroin nanoparticles were synthesized using two procedures (physical adsorption and coprecipitation more scalable than methods previously described using ionic liquids. The results showed that nanoparticle formulations were 155 to 170 nm in diameter with a zeta potential of approximately −45 mV. The curcumin-loaded silk fibroin nanoparticles obtained by both processing methods were cytotoxic to carcinogenic cells, while not decreasing viability of healthy cells. In the case of tumor cells, curcumin-loaded silk fibroin nanoparticles presented higher efficacy in cytotoxicity against neuroblastoma cells than hepatocarcinoma cells. In conclusion, curcumin-loaded silk fibroin nanoparticles constitute a biodegradable and biocompatible delivery system with the potential to treat tumors by local, long-term sustained drug delivery.

Fluoride loaded polymeric nanoparticles for dental delivery.

Science.gov (United States)

Nguyen, Sanko; Escudero, Carlos; Sediqi, Nadia; Smistad, Gro; Hiorth, Marianne

2017-06-15

The overall aim of the present paper was to develop fluoride loaded nanoparticles based on the biopolymers chitosan, pectin, and alginate, for use in dental delivery. First, the preparation of nanoparticles in the presence of sodium fluoride (NaF) as the active ingredient by ionic gelation was investigated followed by an evaluation of their drug entrapment and release properties. Chitosan formed stable, spherical, and monodisperse nanoparticles in the presence of NaF and tripolyphoshate as the crosslinker, whereas alginate and pectin were not able to form any definite nanostructures in similar conditions. The fluoride loading capacity was found to be 33-113ppm, and the entrapment efficiency 3.6-6.2% for chitosan nanoparticles prepared in 0.2-0.4% (w/w) NaF, respectively. A steady increase in the fluoride release was observed for chitosan nanoparticles prepared in 0.2% NaF both in pH5 and 7 until it reached a maximum at time point 4h and maintained at this level for at least 24h. Similar profiles were observed for formulations prepared in 0.4% NaF; however the fluoride was released at a higher level at pH5. The low concentration, but continuous delivery of fluoride from the chitosan nanoparticles, with possible expedited release in acidic environment, makes these formulations highly promising as dental delivery systems in the protection against caries development. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization and Antiproliferative Activity of Nobiletin-Loaded Chitosan Nanoparticles

Directory of Open Access Journals (Sweden)

Ana G. Luque-Alcaraz

2012-01-01

Full Text Available Nobiletin is a polymethoxyflavonoid with a remarkable antiproliferative effect. In order to overcome its low aqueous solubility and chemical instability, the use of nanoparticles as carriers has been proposed. This study explores the possibility of binding nobiletin to chitosan nanoparticles, as well as to evaluate their antiproliferative activity. The association and loading efficiencies are 69.1% and 7.0%, respectively. The formation of an imine bond between chitosan amine groups and the carbonyl group of nobiletin, via Schiff-base, is proposed. Nobiletin-loaded chitosan nanoparticles exhibit considerable inhibition (IC50=8 μg/mL of cancerous cells, revealing their great potential for applications in cancer chemotherapy.

Anti-pepsin activity of silicon dioxide nanoparticles

Directory of Open Access Journals (Sweden)

Hussein Kadhem Al-Hakeim

2016-09-01

Full Text Available SiO2NPs as an inhibitor of pepsin enzyme for treatment of gastro-esophageal reflux disease (GERD was used. Silicon dioxide nanoparticles (pepsin coated SiO2NPs are among the safest nanoparticles that can be used inside the human body. The activity of pepsin before and after the addition of certain amounts of the NPs to the reaction mixture was measured spectrophotometrically. Furthermore, these experiments were repeated at different temperatures, different weights of NPs, and different ionic strengths. The kinetic aparameters (Km & Vmax of the pepsin catalyzed reactions were calculated from the Lineweaver-Burke plots. The results showed that there is a significant reduction of pepsin activity by SiO2NPs (Vmax of free pepsin = 4.82 U and Vmax of the immobilizedpepsin = 2.90 U. The results also indicated that the presence of ionic strength causes remarkable reduction of pepsin activity. It can be concluded the best condition for inhibition of pepsin activity is by using a combination of SiO2NPs and high concentration NaCl at 37 °C.

In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles

OpenAIRE

Farzin Heravi; Mohammad Ramezani; Maryam Poosti; Mohsen Hosseini; Arezoo Shajiei; Farzaneh Ahrari

2013-01-01

Background and aims. Incorporation of nano-particles to orthodontic bonding systems has been considered to prevent enamel demineralization around appliances. This study investigated cytotoxicity of Transbond XT adhesive containing 1 wt% titanium dioxide (TiO2) nano-particles. Materials and methods. Ten composite disks were prepared from each of the conventional and TiO2-containg composites and aged for 1, 3, 5, 7 and 14 days in Dulbecco’s Modified Eagle’s Medium (DMEM). The extrac...

Effects of titanium dioxide nanoparticles on red clover and its rhizobial symbiont

NARCIS (Netherlands)

Moll, Janine; Okupnik, Annette; Gogos, Alexander; Knauer, Katja; Bucheli, Thomas D.; Van Der Heijden, Marcel G A; Widmer, Franco

2016-01-01

Titanium dioxide nanoparticles (TiO2 NPs) are in consideration to be used in plant protection products. Before these products can be placed on the market, ecotoxicological tests have to be performed. In this study, the nitrogen fixing bacterium Rhizobium trifolii and red clover were exposed to two

Immunological evaluation of chitosan nanoparticles loaded with tetanus toxoid.

Science.gov (United States)

Ghalavand, M; Saadati, M; Ahmadi, A; Abbasi, E; Salimian, J

2018-01-01

The present study was aimed at comparing tetanus toxoid (TT)‑loaded-chitosan nanoparticles with aluminum hydroxide as a common vaccine adjuvant. Tetanus remains to be a major public health problem. Nanoparticles have been extensively used as immune adjuvants. Tetanus toxoid (TT) encapsulated in chitosan nanoparticles is considered to be a promising tetanus vaccine candidate. TT‑loaded chitosan nanoparticles were prepared by the ionic gelation method. The nanoparticles were studied by SEM for their size and morphology. In vivo study was conducted to evaluate the immunity response using mice divided into 4 groups and injected with encapsulated toxoid. The immune responses were then measured using indirect ELISA. The purity and integrity of antigen were confirmed by SDS-PAGE electrophoresis. The size of nanoparticles was estimated at 100 nm. As a result, the IgG antibody levels were 1.9, 1.76, and 0.87 in chitosan nanoparticles, aluminum hydroxide, and TT alone groups, respectively. Also, the immune responses were significantly higher in immunized groups compared to control groups vaccinated with free adjuvant vaccines (p chitosan nanoparticles were reasonable. It enhanced the immune responses as much as aluminum hydroxide adjuvant does and thus may be a good alternative candidate (Tab. 1, Fig. 3, Ref. 16).

Electrospun polyacrylonitrile nanofibers loaded with silver nanoparticles by silver mirror reaction

International Nuclear Information System (INIS)

Shi, Yongzheng; Li, Yajing; Zhang, Jianfeng; Yu, Zhongzhen; Yang, Dongzhi

2015-01-01

The silver mirror reaction (SMR) method was selected in this paper to modify electrospun polyacrylonitrile (PAN) nanofibers, and these nanofibers loaded with silver nanoparticles showed excellent antibacterial properties. PAN nanofibers were first pretreated in AgNO 3 aqueous solution before the SMR process so that the silver nanoparticles were distributed evenly on the outer surface of the nanofibers. The final PAN nanofibers were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), TEM-selected area electron diffraction (SAED), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). SEM, TEM micrographs and SAED patterns confirmed homogeneous dispersion of the silver nanoparticles which were composed of monocrystals with diameters 20–30 nm. EDS and XRD results showed that these monocrystals tended to form face-centered cubic single silver. TGA test indicated that the nanoparticles loaded on the nanofibers reached above 50 wt.%. This material was also evaluated by the viable cell-counting method. The results indicated that PAN nanofibers loaded with silver nanoparticles exhibited excellent antimicrobial activities against gram-negative Escherichia coli (E. coli), gram-positive Staphylococcus aureus (S. aureus) and the fungus Monilia albicans. Thus, this material had many potential applications in biomedical fields. - Highlights: • Silver mirror reaction was used to prepare nanofibers loaded with silver nanoparticles. • The SAED patterns demonstrated the monocrystallinity of silver nanocrystals. • The XRD results showed nanoparticles tended to be face-centered cubic single silver. • The material showed excellent antimicrobial activities against bacteria and fungi

Far-ultraviolet spectral changes of titanium dioxide with gold nanoparticles by ultraviolet and visible light

Science.gov (United States)

Tanabe, Ichiro; Kurawaki, Yuji

2018-05-01

Attenuated total reflectance spectra including the far-ultraviolet (FUV, ≤ 200 nm) region of titanium dioxide (TiO2) with and without gold (Au) nanoparticles were measured. A newly developed external light-irradiation system enabled to observe spectral changes of TiO2 with Au nanoparticles upon light irradiations. Absorption in the FUV region decreased and increased by the irradiation with ultraviolet and visible light, respectively. These spectral changes may reflect photo-induced electron transfer from TiO2 to Au nanoparticles under ultraviolet light and from Au nanoparticles to TiO2 under visible light, respectively.

Biosynthesis of titanium dioxide nanoparticles using Bacillus amyloliquefaciens culture and enhancement of its photocatalytic activity for the degradation of a sulfonated textile dye Reactive Red 31.

Science.gov (United States)

Khan, Razia; Fulekar, M H

2016-08-01

The present study aims at exploiting Bacillus amyloliquefaciens for the biosynthesis of titanium dioxide nanoparticles and also investigates role of bacterial enzymes in the biosynthesis of titanium dioxide nanoparticles. Bacterial synthesized as well as metal doped titanium dioxide nanoparticles were characterized by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDAX). Amylase activity (43.37IU) in culture supernatant evinced a potential involvement of extracellular enzyme in TiO2 nanoparticle biosynthesis. Crystallite size of bio-synthesized nanoparticles was found to be in the range of 15.23-87.6nm. FTIR spectroscopy and native-PAGE (Polyacrylamide Gel Electrophoresis) clearly indicated involvement of alpha amylase in biosynthesis of TiO2 nanoparticles and in their stabilization. TEM micrographs of the synthesized titanium dioxide nanoparticles revealed the formation of spherical nanoparticles with a size range of 22.11-97.28nm. Photocatalytic degradation of Reactive Red 31 (RR31) dye was carried out using bio-synthesized TiO2 nanoparticles under UV radiation. Photocatalytic activity of synthesized nanoparticles was enhanced by Ag, La, Zn and Pt doping. Platinum doped TiO2 showed highest potential (90.98%) in RR31 degradation as compared to undoped (75.83%). Copyright © 2016 Elsevier Inc. All rights reserved.

Dual drug-loaded paclitaxel–thymoquinone nanoparticles for effective breast cancer therapy

Energy Technology Data Exchange (ETDEWEB)

Soni, Parth; Kaur, Jasmine; Tikoo, Kulbhushan, E-mail: tikoo.k@gmail.com [National Institute of Pharmaceutical Education and Research (NIPER), Laboratory of Epigenetics and Diseases, Department of Pharmacology and Toxicology (India)

2015-01-15

The present study highlights the beneficial synergistic blend of anticancer drug paclitaxel (PTX) and thymoquinone (TQ) in MCF-7 breast cancer cells. We aimed to augment the therapeutic index of PTX using a polymeric nanoparticle system loaded with PTX and TQ. PLGA nanoparticles encapsulating the two drugs, individually or in combination, were prepared by single emulsion solvent evaporation method. The formulated nanoparticles were homogenous with an overall negative charge and their size ranging between 200 and 300 nm. Entrapment efficiency of PTX and TQ in the dual drug-loaded nanoparticles was found to be 82.4 ± 2.18 and 65.8 ± 0.45 %, respectively. The release kinetics of PTX and TQ from the nanoparticles exhibited a biphasic pattern characterised by an initial burst, followed by a gradual and continuous release. The anticancer activity of nanoparticles encapsulating both the drugs was higher as compared to the free drugs in MCF-7 breast cancer cells. The combination index for the dual drug-loaded NPs was found to be 0.688 which is indicative of synergistic interaction. Thus, here, we propose the synthesis and use of dual drug-loaded TQ and PTX NPs which exhibits enhanced anticancer activity and can additionally help to alleviate the toxic effects of PTX by lowering its effective dose.

Dual drug-loaded paclitaxel–thymoquinone nanoparticles for effective breast cancer therapy

International Nuclear Information System (INIS)

Soni, Parth; Kaur, Jasmine; Tikoo, Kulbhushan

2015-01-01

The present study highlights the beneficial synergistic blend of anticancer drug paclitaxel (PTX) and thymoquinone (TQ) in MCF-7 breast cancer cells. We aimed to augment the therapeutic index of PTX using a polymeric nanoparticle system loaded with PTX and TQ. PLGA nanoparticles encapsulating the two drugs, individually or in combination, were prepared by single emulsion solvent evaporation method. The formulated nanoparticles were homogenous with an overall negative charge and their size ranging between 200 and 300 nm. Entrapment efficiency of PTX and TQ in the dual drug-loaded nanoparticles was found to be 82.4 ± 2.18 and 65.8 ± 0.45 %, respectively. The release kinetics of PTX and TQ from the nanoparticles exhibited a biphasic pattern characterised by an initial burst, followed by a gradual and continuous release. The anticancer activity of nanoparticles encapsulating both the drugs was higher as compared to the free drugs in MCF-7 breast cancer cells. The combination index for the dual drug-loaded NPs was found to be 0.688 which is indicative of synergistic interaction. Thus, here, we propose the synthesis and use of dual drug-loaded TQ and PTX NPs which exhibits enhanced anticancer activity and can additionally help to alleviate the toxic effects of PTX by lowering its effective dose

Preparation and evaluation of quercetin-loaded lecithin-chitosan nanoparticles for topical delivery

Science.gov (United States)

Tan, Qi; Liu, Weidong; Guo, Chenyu; Zhai, Guangxi

2011-01-01

Background The purpose of this study was to investigate lecithin-chitosan nanoparticles as a topical delivery system for quercetin. Methods Tocopheryl propylene glycol succinate was chosen to be the surfactant for the nanosystem. The mean particle size of the nanoparticles was 95.3 nm, and the entrapment efficiency and drug loading for quercetin were 48.5% and 2.45%, respectively. Topical delivery in vitro and in vivo of the quercetin-loaded nanoparticles was evaluated using quercetin propylene glycol solution as the control. Results Compared with quercetin solution, the quercetin-loaded nanoparticles showed higher permeation ability, and significantly increased accumulation of quercetin in the skin, especially in the epidermis. Microstructure observation of the skin surface after administration indicated that the interaction between ingredients of the nanoparticles and the skin surface markedly changed the morphology of the stratum corneum and disrupted the corneocyte layers, thus facilitating the permeation and accumulation of quercetin in skin. Conclusion Lecithin-chitosan nanoparticles are a promising carrier for topical delivery of quercetin. PMID:21904452

A new bimetallic plasmonic photocatalyst consisting of gold(core)-copper(shell) nanoparticle and titanium(IV) oxide support

Energy Technology Data Exchange (ETDEWEB)

Sato, Yuichi [Department of Applied Chemistry, School of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan); Naya, Shin-ichi [Environmental Research Laboratory, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan); Tada, Hiroaki, E-mail: h-tada@apch.kindai.ac.jp [Department of Applied Chemistry, School of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan); Environmental Research Laboratory, Kinki University, 3-4-1, Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan)

2015-10-01

Ultrathin Cu layers (∼2 atomic layers) have been selectively formed on the Au surfaces of Au nanoparticle-loaded rutile TiO{sub 2} (Au@Cu/TiO{sub 2}) by a deposition precipitation-photodeposition technique. Cyclic voltammetry and photochronopotentiometry measurements indicate that the reaction proceeds via the underpotential deposition. The ultrathin Cu shell drastically increases the activity of Au/TiO{sub 2} for the selective oxidation of amines to the corresponding aldehydes under visible-light irradiation (λ > 430 nm). Photochronoamperometry measurements strongly suggest that the striking Cu shell effect stems from the enhancement of the charge separation in the localized surface plasmon resonance-excited Au/TiO{sub 2}.

A new bimetallic plasmonic photocatalyst consisting of gold(core-copper(shell nanoparticle and titanium(IV oxide support

Directory of Open Access Journals (Sweden)

Yuichi Sato

2015-10-01

Full Text Available Ultrathin Cu layers (∼2 atomic layers have been selectively formed on the Au surfaces of Au nanoparticle-loaded rutile TiO2 (Au@Cu/TiO2 by a deposition precipitation-photodeposition technique. Cyclic voltammetry and photochronopotentiometry measurements indicate that the reaction proceeds via the underpotential deposition. The ultrathin Cu shell drastically increases the activity of Au/TiO2 for the selective oxidation of amines to the corresponding aldehydes under visible-light irradiation (λ > 430 nm. Photochronoamperometry measurements strongly suggest that the striking Cu shell effect stems from the enhancement of the charge separation in the localized surface plasmon resonance-excited Au/TiO2.

Synthesis of Pyrimethanil-Loaded Mesoporous Silica Nanoparticles and Its Distribution and Dissipation in Cucumber Plants.

Science.gov (United States)

Zhao, Pengyue; Cao, Lidong; Ma, Dukang; Zhou, Zhaolu; Huang, Qiliang; Pan, Canping

2017-05-16

Mesoporous silica nanoparticles are used as pesticide carries in plants, which has been considered as a novel method to reduce the indiscriminate use of conventional pesticides. In the present work, mesoporous silica nanoparticles with particle diameters of 200-300 nm were synthesized in order to obtain pyrimethanil-loaded nanoparticles. The microstructure of the nanoparticles was observed by scanning electron microscopy. The loading content of pyrimethanil-loaded nanoparticles was investigated. After treatment on cucumber leaves, the concentrations of pyrimethanil were determined in different parts of cucumber over a period of 48 days using high performance liquid chromatography tandem mass spectrometry. It was shown that the pyrimethanil-loaded mesoporous silica nanoparticles might be more conducive to acropetal, rather than basipetal, uptake, and the dosage had almost no effect on the distribution and dissipation rate in cucumber plants. The application of the pesticide-loaded nanoparticles in leaves had a low risk of pyrimethanil accumulating in the edible part of the plant.

Electrospun polyacrylonitrile nanofibers loaded with silver nanoparticles by silver mirror reaction

Energy Technology Data Exchange (ETDEWEB)

Shi, Yongzheng; Li, Yajing; Zhang, Jianfeng; Yu, Zhongzhen; Yang, Dongzhi, E-mail: yangdz@mail.buct.edu.cn

2015-06-01

The silver mirror reaction (SMR) method was selected in this paper to modify electrospun polyacrylonitrile (PAN) nanofibers, and these nanofibers loaded with silver nanoparticles showed excellent antibacterial properties. PAN nanofibers were first pretreated in AgNO{sub 3} aqueous solution before the SMR process so that the silver nanoparticles were distributed evenly on the outer surface of the nanofibers. The final PAN nanofibers were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), TEM-selected area electron diffraction (SAED), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). SEM, TEM micrographs and SAED patterns confirmed homogeneous dispersion of the silver nanoparticles which were composed of monocrystals with diameters 20–30 nm. EDS and XRD results showed that these monocrystals tended to form face-centered cubic single silver. TGA test indicated that the nanoparticles loaded on the nanofibers reached above 50 wt.%. This material was also evaluated by the viable cell-counting method. The results indicated that PAN nanofibers loaded with silver nanoparticles exhibited excellent antimicrobial activities against gram-negative Escherichia coli (E. coli), gram-positive Staphylococcus aureus (S. aureus) and the fungus Monilia albicans. Thus, this material had many potential applications in biomedical fields. - Highlights: • Silver mirror reaction was used to prepare nanofibers loaded with silver nanoparticles. • The SAED patterns demonstrated the monocrystallinity of silver nanocrystals. • The XRD results showed nanoparticles tended to be face-centered cubic single silver. • The material showed excellent antimicrobial activities against bacteria and fungi.

Encapsulation of antigen-loaded silica nanoparticles into microparticles for intradermal powder injection.

Science.gov (United States)

Deng, Yibin; Mathaes, Roman; Winter, Gerhard; Engert, Julia

2014-10-15

Epidermal powder immunisation (EPI) is being investigated as a promising needle-free delivery methods for vaccination. The objective of this work was to prepare a nanoparticles-in-microparticles (nano-in-micro) system, integrating the advantages of nanoparticles and microparticles into one vaccine delivery system for epidermal powder immunisation. Cationic mesoporous silica nanoparticles (MSNP-NH2) were prepared and loaded with ovalbumin as a model antigen. Loading was driven by electrostatic interactions. Ovalbumin-loaded silica nanoparticles were subsequently formulated into sugar-based microparticles by spray-freeze-drying. The obtained microparticles meet the size requirement for EPI. Confocal microscopy was used to demonstrate that the nanoparticles are homogeneously distributed in the microparticles. Furthermore, the silica nanoparticles in the dry microparticles can be re-dispersed in aqueous solution showing no aggregation. The recovered ovalbumin shows integrity compared to native ovalbumin. The present nano-in-micro system allows (1) nanoparticles to be immobilized and finely distributed in microparticles, (2) microparticle formation and (3) re-dispersion of nanoparticles without subsequent aggregation. The nanoparticles inside microparticles can (1) adsorb proteins to cationic shell/surface voids in spray-dried products without detriment to ovalbumin stability, (2) deliver antigens in nano-sized modes to allow recognition by the immune system. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis of protein-coated biocompatible methotrexate-loaded PLA-PEG-PLA nanoparticles for breast cancer treatment

Directory of Open Access Journals (Sweden)

Salam Massadeh

2016-06-01

Full Text Available Background: PLA-PEG-PLA triblock polymer nanoparticles are promising tools for targeted dug delivery. The main aim in designing polymeric nanoparticles for drug delivery is achieving a controlled and targeted release of a specific drug at the therapeutically optimal rate and choosing a suitable preparation method to encapsulate the drug efficiently, which depends mainly on the nature of the drug (hydrophilic or hydrophobic. In this study, methotrexate (MTX-loaded nanoparticles were prepared by the double emulsion method. Method: Biodegradable polymer polyethylene glycol-polylactide acid tri-block was used with poly(vinyl alcohol as emulsifier. The resulting methotrexate polymer nanoparticles were coated with bovine serum albumin in order to improve their biocompatibility. This study focused on particle size distribution, zeta potential, encapsulation efficiency, loading capacity, and in vitro drug release at various concentrations of PVA (0.5%, 1%, 2%, and 3%. Results: Reduced particle size of methotrexate-loaded nanoparticles was obtained using lower PVA concentrations. Enhanced encapsulation efficiency and loading capacity was obtained using 1% PVA. FT-IR characterization was conducted for the void polymer nanoparticles and for drug-loaded nanoparticles with methotrexate, and the protein-coated nanoparticles in solid state showed the structure of the plain PEG-PLA and the drug-loaded nanoparticles with methotrexate. The methotrexate-loaded PLA-PEG-PLA nanoparticles have been studied in vitro; the drug release, drug loading, and yield are reported. Conclusion: The drug release profile was monitored over a period of 168 hours, and was free of burst effect before the protein coating. The results obtained from this work are promising; this work can be taken further to develop MTX based therapies.

Synthesis of protein-coated biocompatible methotrexate-loaded PLA-PEG-PLA nanoparticles for breast cancer treatment

Science.gov (United States)

Massadeh, Salam; Alaamery, Manal; Al-Qatanani, Shatha; Alarifi, Saqer; Bawazeer, Shahad; Alyafee, Yusra

2016-01-01

Background PLA-PEG-PLA triblock polymer nanoparticles are promising tools for targeted dug delivery. The main aim in designing polymeric nanoparticles for drug delivery is achieving a controlled and targeted release of a specific drug at the therapeutically optimal rate and choosing a suitable preparation method to encapsulate the drug efficiently, which depends mainly on the nature of the drug (hydrophilic or hydrophobic). In this study, methotrexate (MTX)-loaded nanoparticles were prepared by the double emulsion method. Method Biodegradable polymer polyethylene glycol-polylactide acid tri-block was used with poly(vinyl alcohol) as emulsifier. The resulting methotrexate polymer nanoparticles were coated with bovine serum albumin in order to improve their biocompatibility. This study focused on particle size distribution, zeta potential, encapsulation efficiency, loading capacity, and in vitro drug release at various concentrations of PVA (0.5%, 1%, 2%, and 3%). Results Reduced particle size of methotrexate-loaded nanoparticles was obtained using lower PVA concentrations. Enhanced encapsulation efficiency and loading capacity was obtained using 1% PVA. FT-IR characterization was conducted for the void polymer nanoparticles and for drug-loaded nanoparticles with methotrexate, and the protein-coated nanoparticles in solid state showed the structure of the plain PEG-PLA and the drug-loaded nanoparticles with methotrexate. The methotrexate-loaded PLA-PEG-PLA nanoparticles have been studied in vitro; the drug release, drug loading, and yield are reported. Conclusion The drug release profile was monitored over a period of 168 hours, and was free of burst effect before the protein coating. The results obtained from this work are promising; this work can be taken further to develop MTX based therapies.

Essential oil-loaded lipid nanoparticles for wound healing.

Science.gov (United States)

Saporito, Francesca; Sandri, Giuseppina; Bonferoni, Maria Cristina; Rossi, Silvia; Boselli, Cinzia; Icaro Cornaglia, Antonia; Mannucci, Barbara; Grisoli, Pietro; Vigani, Barbara; Ferrari, Franca

2018-01-01

Chronic wounds and severe burns are diseases responsible for severe morbidity and even death. Wound repair is a crucial process and tissue regeneration enhancement and infection prevention are key factors to minimize pain, discomfort, and scar formation. The aim of this work was the development of lipid nanoparticles (solid lipid nanoparticles and nanostructured lipid carriers [NLC]), to be loaded with eucalyptus or rosemary essential oils and to be used, as medical devices, to enhance healing of skin wounds. Lipid nanoparticles were based on natural lipids: cocoa butter, as solid lipid, and olive oil or sesame oil, as liquid lipids. Lecithin was chosen as surfactant to stabilize nanoparticles and to prevent their aggregation. The systems were prepared by high shear homogenization followed by ultrasound application. Nanoparticles were characterized for physical-chemical properties, bioadhesion, cytocompatibility, in vitro proliferation enhancement, and wound healing properties toward normal human dermal fibroblasts. Antimicrobial activity of nanoparticles was evaluated against two reference microbial strains, one of Staphylococcus aureus , the other of Streptococcus pyogenes . Finally, the capability of nanoparticles to promote wound healing in vivo was evaluated on a rat burn model. NLC based on olive oil and loaded with eucalyptus oil showed appropriate physical-chemical properties, good bioadhesion, cytocompatibility, in vitro proliferation enhancement, and wound healing properties toward fibroblasts, associated to antimicrobial properties. Moreover, the in vivo results evidenced the capability of these NLC to enhance the healing process. Olive oil, which is characterized by a high content of oleic acid, proved to exert a synergic effect with eucalyptus oil with respect to antimicrobial activity and wound repair promotion.

Pulmonary toxicity of well-dispersed titanium dioxide nanoparticles following intratracheal instillation

International Nuclear Information System (INIS)

Yoshiura, Yukiko; Izumi, Hiroto; Oyabu, Takako; Hashiba, Masayoshi; Kambara, Tatsunori; Mizuguchi, Yohei; Lee, Byeong Woo; Okada, Takami; Tomonaga, Taisuke; Myojo, Toshihiko; Yamamoto, Kazuhiro; Kitajima, Shinichi; Horie, Masanori; Kuroda, Etsushi; Morimoto, Yasuo

2015-01-01

In order to investigate the pulmonary toxicity of titanium dioxide (TiO 2 ) nanoparticles, we performed an intratracheal instillation study with rats of well-dispersed TiO 2 nanoparticles and examined the pulmonary inflammation and histopathological changes in the lung. Wistar Hannover rats were intratracheally administered 0.2 mg (0.66 mg/kg) and 1.0 mg (3.3 mg/kg) of well-dispersed TiO 2 nanoparticles (P90; diameter of agglomerates: 25 nm), then the pulmonary inflammation responses were examined from 3 days to 6 months after the instillation, and the pathological features were examined up to 24 months. Transient inflammation and the upregulation of chemokines in the broncho-alveolar lavage fluid were observed for 1 month. No respiratory tumors or severe fibrosis were observed during the recovery time. These data suggest that transient inflammation induced by TiO 2 may not lead to chronic, irreversible legions in the lung, and that TiO 2 nanoparticles may not have a high potential for lung disorder

Pulmonary toxicity of well-dispersed titanium dioxide nanoparticles following intratracheal instillation

Energy Technology Data Exchange (ETDEWEB)

Yoshiura, Yukiko, E-mail: y-yoshiura@med.uoeh-u.ac.jp; Izumi, Hiroto [University of Occupational and Environmental Health, Department of Occupational Pneumology, Institute of Industrial Ecological Science (Japan); Oyabu, Takako [University of Occupational and Environmental Health, Department of Environmental Health Engineering, Institute of Industrial Ecological Sciences (Japan); Hashiba, Masayoshi; Kambara, Tatsunori [University of Occupational and Environmental Health, Department of Occupational Pneumology, Institute of Industrial Ecological Science (Japan); Mizuguchi, Yohei; Lee, Byeong Woo; Okada, Takami [University of Occupational and Environmental Health, Department of Environmental Health Engineering, Institute of Industrial Ecological Sciences (Japan); Tomonaga, Taisuke [University of Occupational and Environmental Health, Department of Occupational Pneumology, Institute of Industrial Ecological Science (Japan); Myojo, Toshihiko [University of Occupational and Environmental Health, Department of Environmental Health Engineering, Institute of Industrial Ecological Sciences (Japan); Yamamoto, Kazuhiro [National Institute of Advanced Industrial Science and Technology (AIST) (Japan); Kitajima, Shinichi [National Sanatorium Hoshizuka Keiaien (Japan); Horie, Masanori [National Institute of Advanced Industrial Science and Technology (AIST), Health Research Institute (HRI) (Japan); Kuroda, Etsushi [Osaka University, Laboratory of Vaccine Science, WPI Immunology Frontier Research Center (Japan); Morimoto, Yasuo [University of Occupational and Environmental Health, Department of Occupational Pneumology, Institute of Industrial Ecological Science (Japan)

2015-06-15

In order to investigate the pulmonary toxicity of titanium dioxide (TiO{sub 2}) nanoparticles, we performed an intratracheal instillation study with rats of well-dispersed TiO{sub 2} nanoparticles and examined the pulmonary inflammation and histopathological changes in the lung. Wistar Hannover rats were intratracheally administered 0.2 mg (0.66 mg/kg) and 1.0 mg (3.3 mg/kg) of well-dispersed TiO{sub 2} nanoparticles (P90; diameter of agglomerates: 25 nm), then the pulmonary inflammation responses were examined from 3 days to 6 months after the instillation, and the pathological features were examined up to 24 months. Transient inflammation and the upregulation of chemokines in the broncho-alveolar lavage fluid were observed for 1 month. No respiratory tumors or severe fibrosis were observed during the recovery time. These data suggest that transient inflammation induced by TiO{sub 2} may not lead to chronic, irreversible legions in the lung, and that TiO{sub 2} nanoparticles may not have a high potential for lung disorder.

Acute Toxicity of Intravenously Administered Titanium Dioxide Nanoparticles in Mice

OpenAIRE

Xu, Jiaying; Shi, Hongbo; Ruth, Magaye; Yu, Hongsheng; Lazar, Lissy; Zou, Baobo; Yang, Cui; Wu, Aiguo; Zhao, Jinshun

2013-01-01

BACKGROUND: With a wide range of applications, titanium dioxide (TiO₂) nanoparticles (NPs) are manufactured worldwide in large quantities. Recently, in the field of nanomedicine, intravenous injection of TiO₂ nanoparticulate carriers directly into the bloodstream has raised public concerns on their toxicity to humans. METHODS: In this study, mice were injected intravenously with a single dose of TiO₂ NPs at varying dose levels (0, 140, 300, 645, or 1387 mg/kg). Animal mortality, blood biochem...

Cerium dioxide nanoparticles do not modulate the lipopolysaccharide-induced inflammatory response in human monocytes

Directory of Open Access Journals (Sweden)

Hussain S

2012-03-01

Full Text Available Salik Hussain1,*, Faris Al-Nsour1,*, Annette B Rice1, Jamie Marshburn1, Zhaoxia Ji2, Jeffery I Zink2, Brenda Yingling1, Nigel J Walker3, Stavros Garantziotis11Clinical Research Unit, National Institute of Environmental Health Sciences/National Institute of Health, Research Triangle Park, NC, 2UC Center for Environmental Implications of Nanotechnology University of California, Los Angeles, CA, 3Division of National Toxicology Program, National Institute of Environmental Health Sciences/National Institute of Health, Research Triangle Park, NC, USA*Both are principal authorsBackground: Cerium dioxide (CeO2 nanoparticles have potential therapeutic applications and are widely used for industrial purposes. However, the effects of these nanoparticles on primary human cells are largely unknown. The ability of nanoparticles to exacerbate pre-existing inflammatory disorders is not well documented for engineered nanoparticles, and is certainly lacking for CeO2 nanoparticles. We investigated the inflammation-modulating effects of CeO2 nanoparticles at noncytotoxic concentrations in human peripheral blood monocytes.Methods: CD14+ cells were isolated from peripheral blood samples of human volunteers. Cells were exposed to either 0.5 or 1 µg/mL of CeO2 nanoparticles over a period of 24 or 48 hours with or without lipopolysaccharide (10 ng/mL prestimulation. Modulation of the inflammatory response was studied by measuring secreted tumor necrosis factor-alpha, interleukin-1beta, macrophage chemotactic protein-1, interferon-gamma, and interferon gamma-induced protein 10.Results: CeO2 nanoparticle suspensions were thoroughly characterized using dynamic light scattering analysis (194 nm hydrodynamic diameter, zeta potential analysis (-14 mV, and transmission electron microscopy (irregular-shaped particles. Transmission electron microscopy of CD14+ cells exposed to CeO2 nanoparticles revealed that these nanoparticles were efficiently internalized by monocytes and

Potassium iodate assisted synthesis of titanium dioxide nanoparticles with superior water-dispersibility.

Science.gov (United States)

Wang, Yawen; Duo, Fangfang; Peng, Shiqi; Jia, Falong; Fan, Caimei

2014-09-15

In this paper, we report a novel polyol process to synthesize highly water-dispersible anatase titanium dioxide (TiO2) nanoparticles (∼5 nm) by the introduction of inorganic oxidizing agent--KIO3. The obtained TiO2 nanoparticles are well dispersible in water at pH≥5.0 and the resulting aqueous dispersion remains stable over months. The superior water-dispersibility of as-formed TiO2 is ascribed to the electrostatic repulsion from carboxylic acid group modified on TiO2 nanoparticles, which is the oxidation product of solvent diethylene glycol (DEG) by KIO3. Based on the characterization results, the formation processes of water-dispersibility TiO2 nanoparticles are proposed. Meanwhile, the synthesized TiO2 nanoparticles are found to be doped by iodine and exhibit excellent photocatalytic activity on degradation of rhodamine-B (RhB) under visible-light irradiation. The further tests demonstrate that the O(2-) is the main active species during photodegradation of RhB. Copyright © 2014 Elsevier Inc. All rights reserved.

The effect of electrolytes on the aggregation kinetics of titanium dioxide nanoparticle aggregates

International Nuclear Information System (INIS)

Shih Yanghsin; Zhuang Chengming; Tso Chihping; Lin Chenghan

2012-01-01

Metal oxide nanoparticles (NPs) are receiving increasing attention due to their increased industrial production and potential hazardous effect. The process of aggregation plays a key role in the fate of NPs in the environment and the resultant health risk. The aggregation of commercial titanium dioxide NP powder (25 nm) was investigated with various environmentally relevant solution chemistries containing different concentrations of monovalent (Na + , K + ) and divalent (Ca 2+ ) electrolytes. Titanium dioxide particle size increased with the increase in ion concentration. The stability of titanium dioxide also depended on the ionic composition. Titanium dioxide aggregated to a higher degree in the presence of divalent cations than monovalent ones. The attachment efficiency of NPs was constructed through aggregation kinetics data, from which the critical coagulation concentrations for the various electrolytes are determined (80, 19, and 1 meq/L for Na + , K + , and Ca 2+ , respectively). Our results suggest that titanium dioxide NP powders are relatively unstable in water and could easily be removed by adding multivalent cations so hazardous potentials decrease in aquatic environment.

Cellular uptake and radiosensitization of SR-2508 loaded PLGA nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Jin Cheng [Fourth Military Medical University, Department of Radiation Medicine (China); Bai Ling [Xi' an Gaoxin Hospital, Department of Clinical Laboratories (China); Wu Hong [Fourth Military Medical University, Department of Pharmacy (China); Teng Zenghui [Fourth Military Medical University, Department of Pharmacology (China); Guo Guozhen, E-mail: guozhengg@tom.co [Fourth Military Medical University, Department of Radiation Medicine (China); Chen Jingyuan, E-mail: jy_chen@fmmu.edu.c [Fourth Military Medical University, Department of Occupational and Environmental Health (China)

2008-08-15

SR-2508 (etanidazole), a hypoxic radiosensitizer, has potential applications in radiotherapy. The poly(d,l-lactide-co-glycolide)(PLGA) nanoparticles containing SR-2508 were prepared by w/o/w emulsification-solvent evaporation method. The physicochemical characteristics of the nanoparticles (i.e. encapsulation efficiency, particle size distribution, morphology, in vitro release) were studied. The cellular uptake of the nanoparticles for the two human tumor cell lines: human breast carcinoma cells (MCF-7) and human carcinoma cervices cells (HeLa), was evaluated by fluorescence microscopy and transmission electronic microscopy. Cell viability was measured by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical in shape with size between 90 nm and 190 nm. The encapsulation efficiency was 20.06%. The drug release pattern exhibited an initial burst followed by a plateau for over 24 h. The cellular uptake of nanoparticles was observed. Co-culture of MCF-7 and HeLa cells with SR-2508 loaded nanoparticles showed that released SR-2508 retained its bioactivity and effectively sensitized two hypoxic tumor cell lines to radiation. The radiosensitization of SR-2508 loaded nanoparticles was more significant than that of free drug.

Cellular uptake and radiosensitization of SR-2508 loaded PLGA nanoparticles

International Nuclear Information System (INIS)

Jin Cheng; Bai Ling; Wu Hong; Teng Zenghui; Guo Guozhen; Chen Jingyuan

2008-01-01

SR-2508 (etanidazole), a hypoxic radiosensitizer, has potential applications in radiotherapy. The poly(d,l-lactide-co-glycolide)(PLGA) nanoparticles containing SR-2508 were prepared by w/o/w emulsification-solvent evaporation method. The physicochemical characteristics of the nanoparticles (i.e. encapsulation efficiency, particle size distribution, morphology, in vitro release) were studied. The cellular uptake of the nanoparticles for the two human tumor cell lines: human breast carcinoma cells (MCF-7) and human carcinoma cervices cells (HeLa), was evaluated by fluorescence microscopy and transmission electronic microscopy. Cell viability was measured by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical in shape with size between 90 nm and 190 nm. The encapsulation efficiency was 20.06%. The drug release pattern exhibited an initial burst followed by a plateau for over 24 h. The cellular uptake of nanoparticles was observed. Co-culture of MCF-7 and HeLa cells with SR-2508 loaded nanoparticles showed that released SR-2508 retained its bioactivity and effectively sensitized two hypoxic tumor cell lines to radiation. The radiosensitization of SR-2508 loaded nanoparticles was more significant than that of free drug.

Evaluation of self-assembled HCPT-loaded PEG-b-PLA nanoparticles by comparing with HCPT-loaded PLA nanoparticles.

Science.gov (United States)

Yang, Xiangrui; Wu, Shichao; Wang, Yange; Li, Yang; Chang, Di; Luo, Yin; Ye, Shefang; Hou, Zhenqing

2014-12-01

We present a dialysis technique to prepare the 10-hydroxycamptothecin (HCPT)-loaded nanoparticles (NPs) using methoxypolyethylene glycol-poly(D,L-lactide) (PEG-b-PLA) and PLA, respectively. Both HCPT-loaded PEG-b-PLA NPs and HCPT-loaded PLA NPs were characterized by differential scanning calorimetry (DSC), dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The results showed that the HCPT-loaded PEG-b-PLA NPs and HCPT-loaded PLA NPs presented a hydrodynamic particle size of 120.1 and 226.8 nm, with a polydispersity index of 0.057 and 0.207, a zeta potential of -31.2 and -45.7 mV, drug encapsulation efficiency of 44.52% and 44.94%, and drug-loaded content of 7.42% and 7.49%, respectively. The HCPT-loaded PEG-b-PLA NPs presented faster drug release rate compared to the HCPT-loaded PLA NPs. The HCPT-loaded PEG-b-PLA NPs presented higher cytotoxicity than the HCPT-loaded PLA NPs. These results suggested that the HCPT-loaded PEG-b-PLA NPs presented better characteristics for drug delivery compared to HCPT-loaded PLA NPs.

Pharmacokinetic characteristics and anticancer effects of 5-Fluorouracil loaded nanoparticles

Directory of Open Access Journals (Sweden)

Jiang Wenqi

2008-04-01

Full Text Available Abstract Background It is expected that prolonged circulation of anticancer drugs will increase their anticancer activity while decreasing their toxic side effects. The purpose of this study was to prepare 5-fluorouracil (5-FU loaded block copolymers, with poly(γ-benzyl-L-glutamate (PBLG as the hydrophobic block and poly(ethylene glycol (PEG as the hydrophilic block, and then examine the 5-FU release characteristics, pharmacokinetics, and anticancer effects of this novel compound. Methods 5-FU loaded PEG-PBLG (5-FU/PEG-PBLG nanoparticles were prepared by dialysis and then scanning electron microscopy (SEM and transmission electron microscopy (TEM were used to observe the shape and size of the nanoparticles, and ultraviolet spectrophotometry was used to evaluate the 5-FU in vitro release characteristics. The pharmacokinetic parameters of 5-FU/PEG-PBLG nanoparticles in rabbit plasma were determined by measuring the 5-FUby high-performance liquid chromatography (HPLC. To study in vivo effects, LoVo cells (human colon cancer cell line or Tca8113 cells (human oral squamous cell carcinoma cell line were implanted in BALB/c nude mice that were subsequently treated with 5-FU or 5-FU/PEG-PBLG nanospheres. Results 5-FU/PEG-PBLG nanoparticles had a core-shell spherical structure with a diameter of 200 nm and a shell thickness of 30 nm. The drug loading capacity was 27.1% and the drug encapsulation was 61.5%. Compared with 5-FU, 5-FU/PEG-PBLG nanoparticles had a longer elimination half-life (t1/2, 33.3 h vs. 5 min, lower peak concentration (C, 4563.5 μg/L vs. 17047.3 μg/L, and greater distribution volume (VD, 0.114 L vs. 0.069 L. Compared with a blank control, LoVo cell xenografts and Tca8113 cell xenografts treated with 5-FU or 5-FU/PEG-PBLG nanoparticles grew slower and had prolonged tumor doubling times. 5-FU/PEG-PBLG nanoparticles showed greater inhibition of tumor growth than 5-FU (p 0.05. Conclusion In our model system, 5-FU/PEG-PBLG nanoparticles

Impact of natural organic matter on particle behavior and phototoxicity of titanium dioxide nanoparticles

Science.gov (United States)

Due to their inherent phototoxicity and inevitable environmental release, titanium dioxide nanoparticles (nano-TiO2) are increasingly studied in the field of aquatic toxicology. One of the particular interests is the interactions between nano-TiO2 and natural organic matter (NOM)...

Near-infrared fluorescent aza-BODIPY dye-loaded biodegradable polymeric nanoparticles for optical cancer imaging

International Nuclear Information System (INIS)

Hamon, Casey L.; Dorsey, Christopher L.; Özel, Tuğba; Barnes, Eugenia M.; Hudnall, Todd W.; Betancourt, Tania

2016-01-01

Nanoparticles are being readily investigated as carriers for the delivery of imaging and therapeutic agents for the detection, monitoring, and treatment of cancer and other diseases. In the present work, the preparation of biodegradable polymeric nanoparticles loaded with a near-infrared fluorescent aza-boron dipyrromethene (NIR-BODIPY) derivative, and their use as contrast agents for optical imaging in cancer are described. Nanoparticles were prepared by nanoprecipitation of amphiphilic block copolymers of poly(lactic acid) and poly(ethylene glycol). The size, morphology, dye loading, spectral properties, quantum yield, cytocompatibility, and in vitro NIR imaging potential of the nanoparticles in breast and ovarian cancer cells were evaluated. Spherical nanoparticles of 30–70 nm in diameter were loaded with 0.73 w/w% BODIPY derivative. At this loading, the dye presented a fluorescence quantum yield in the same order of magnitude as in solution. Nanoparticle suspensions at concentrations up to 580 μg/mL were cytocompatible to breast (MDA-MB-231) and ovarian (SKOV-3 and Caov-3) cancer cells after a four-hour incubation period. Fluorescence microscopy images demonstrated the ability of the nanoparticles to act as imaging agents in all three cell lines in as little as 1 hour. The results shown indicate the potential of these NIR-BODIPY-loaded nanoparticles as contrast agents for near-infrared optical imaging in cancer.Graphical abstract

Near-infrared fluorescent aza-BODIPY dye-loaded biodegradable polymeric nanoparticles for optical cancer imaging

Energy Technology Data Exchange (ETDEWEB)

Hamon, Casey L.; Dorsey, Christopher L. [Texas State University, Department of Chemistry and Biochemistry (United States); Özel, Tuğba [Texas State University, Materials Science, Engineering, and Commercialization Program (United States); Barnes, Eugenia M.; Hudnall, Todd W.; Betancourt, Tania, E-mail: tb26@txstate.edu [Texas State University, Department of Chemistry and Biochemistry (United States)

2016-07-15

Nanoparticles are being readily investigated as carriers for the delivery of imaging and therapeutic agents for the detection, monitoring, and treatment of cancer and other diseases. In the present work, the preparation of biodegradable polymeric nanoparticles loaded with a near-infrared fluorescent aza-boron dipyrromethene (NIR-BODIPY) derivative, and their use as contrast agents for optical imaging in cancer are described. Nanoparticles were prepared by nanoprecipitation of amphiphilic block copolymers of poly(lactic acid) and poly(ethylene glycol). The size, morphology, dye loading, spectral properties, quantum yield, cytocompatibility, and in vitro NIR imaging potential of the nanoparticles in breast and ovarian cancer cells were evaluated. Spherical nanoparticles of 30–70 nm in diameter were loaded with 0.73 w/w% BODIPY derivative. At this loading, the dye presented a fluorescence quantum yield in the same order of magnitude as in solution. Nanoparticle suspensions at concentrations up to 580 μg/mL were cytocompatible to breast (MDA-MB-231) and ovarian (SKOV-3 and Caov-3) cancer cells after a four-hour incubation period. Fluorescence microscopy images demonstrated the ability of the nanoparticles to act as imaging agents in all three cell lines in as little as 1 hour. The results shown indicate the potential of these NIR-BODIPY-loaded nanoparticles as contrast agents for near-infrared optical imaging in cancer.Graphical abstract.

Ultrasonic assisted dispersive solid-phase microextraction of Eriochrome Cyanine R from water sample on ultrasonically synthesized lead (II) dioxide nanoparticles loaded on activated carbon: Experimental design methodology.

Science.gov (United States)

Bahrani, Sonia; Ghaedi, Mehrorang; Mansoorkhani, Mohammad Javad Khoshnood; Asfaram, Arash; Bazrafshan, Ali Akbar; Purkait, Mihir Kumar

2017-01-01

The present research focus on designing an appropriate dispersive solid-phase microextraction (UA-DSPME) for preconcentration and determination of Eriochrome Cyanine R (ECR) in aqueous solutions with aid of sonication using lead (II) dioxide nanoparticles loaded on activated carbon (PbO-NPs-AC). This material was fully identified with XRD and SEM. Influence of pH, amounts of sorbent, type and volume of eluent, and sonication time on response properties were investigated and optimized by central composite design (CCD) combined with surface response methodology using STATISTICA. Among different solvents, dimethyl sulfoxide (DMSO) was selected as an efficient eluent, which its combination by present nanoparticles and application of ultrasound waves led to enhancement in mass transfer. The predicted maximum extraction (100%) under the optimum conditions of the process variables viz. pH 4.5, eluent 200μL, adsorbent dosage 2.5mg and 5min sonication was close to the experimental value (99.50%). at optimum conditions some experimental features like wide 5-2000ngmL -1 ECR, low detection limit (0.43ngmL -1 , S/N=3:1) and good repeatability and reproducibility (relative standard deviation, <5.5%, n=12) indicate versatility in successful applicability of present method for real sample analysis. Investigation of accuracy by spiking known concentration of ECR over 200-600ngmL -1 gave mean recoveries from 94.850% to 101.42% under optimal conditions. The procedure was also applied for the pre-concentration and subsequent determination of ECR in tap and waste waters. Copyright © 2016 Elsevier B.V. All rights reserved.

Pharmacokinetic characteristics and anticancer effects of 5-Fluorouracil loaded nanoparticles

International Nuclear Information System (INIS)

Li, Su; Wang, Anxun; Jiang, Wenqi; Guan, Zhongzhen

2008-01-01

It is expected that prolonged circulation of anticancer drugs will increase their anticancer activity while decreasing their toxic side effects. The purpose of this study was to prepare 5-fluorouracil (5-FU) loaded block copolymers, with poly(γ-benzyl-L-glutamate) (PBLG) as the hydrophobic block and poly(ethylene glycol) (PEG) as the hydrophilic block, and then examine the 5-FU release characteristics, pharmacokinetics, and anticancer effects of this novel compound. 5-FU loaded PEG-PBLG (5-FU/PEG-PBLG) nanoparticles were prepared by dialysis and then scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe the shape and size of the nanoparticles, and ultraviolet spectrophotometry was used to evaluate the 5-FU in vitro release characteristics. The pharmacokinetic parameters of 5-FU/PEG-PBLG nanoparticles in rabbit plasma were determined by measuring the 5-FUby high-performance liquid chromatography (HPLC). To study in vivo effects, LoVo cells (human colon cancer cell line) or Tca8113 cells (human oral squamous cell carcinoma cell line) were implanted in BALB/c nude mice that were subsequently treated with 5-FU or 5-FU/PEG-PBLG nanospheres. 5-FU/PEG-PBLG nanoparticles had a core-shell spherical structure with a diameter of 200 nm and a shell thickness of 30 nm. The drug loading capacity was 27.1% and the drug encapsulation was 61.5%. Compared with 5-FU, 5-FU/PEG-PBLG nanoparticles had a longer elimination half-life (t 1/2 , 33.3 h vs. 5 min), lower peak concentration (C, 4563.5 μg/L vs. 17047.3 μg/L), and greater distribution volume (V D , 0.114 L vs. 0.069 L). Compared with a blank control, LoVo cell xenografts and Tca8113 cell xenografts treated with 5-FU or 5-FU/PEG-PBLG nanoparticles grew slower and had prolonged tumor doubling times. 5-FU/PEG-PBLG nanoparticles showed greater inhibition of tumor growth than 5-FU (p < 0.01). In the PEG-PBLG nanoparticle control group, there was no tumor inhibition (p > 0.05). In our

Insulin-loaded poly(epsilon-caprolactone) nanoparticles: efficient, sustained and safe insulin delivery system.

Science.gov (United States)

de Araújo, Thiago M; Teixeira, Zaine; Barbosa-Sampaio, Helena C; Rezende, Luiz F; Boschero, Antonio C; Durán, Nelson; Höehr, Nelci F

2013-06-01

The aim of this work was to develop an efficient, biodegradable, biocompatible and safe controlled release system using insulin-loaded poly(epsilon-caprolactone) (PCL) nanoparticles. The insulin-loaded PCL nanoparticles were prepared by double emulsion method (water-in-oil-in-water) using Pluronic F68 as emulsifier. Using the double emulsion method a high insulin encapsulation efficiency (90.6 +/-1.6%) with a zeta potential of -29 +/-2.7 mV and average particle size of 796 +/-10.5 nm was obtained. Insulin-loaded PCL nanoparticles showed no toxicity to MIN6 cells. Insulin nanoparticles administered subcutaneously and intraperitoneally in rats reduced glycaemia of basal levels after 15 minutes, and presented a sustainable hypoglycemic effect on insulin-dependent type 1 diabetic rats, showing to be more efficient than unencapsulated insulin. Furthermore, these nanoparticles were not hepatotoxic, as evaluated by the effect over liver cell-death and oxidative stress scavenger system in rats. These results suggest that insulin-loaded PCL nanoparticles prepared by water-in-oil-in-water emulsion method are biocompatible, efficient and safe insulin-delivering system with controlled insulin release, which indicates that it may be a powerful tool for insulin-dependent patients care.

Ciprofloxacin-loaded PLGA nanoparticles against Cystic Fibrosis P. aeruginosa Lung Infections.

OpenAIRE

Günday Türeli, Nazende; Torge, Afra; Juntke, Jenny; Schwarz, Bianca C; Schneider-Daum, Nicole; Türeli, Akif Emre; Lehr, Claus-Michael; Schneider, Marc

2017-01-01

Current pulmonary treatments against Pseudomonasaeruginosa infections in cystic fibrosis (CF) lung suffer from deactivation of the drug and immobilization in thick and viscous biofilm/mucus blend, along with the general antibiotic resistance. Administration of nanoparticles (NPs) with high antibiotic load capable of penetrating the tight mesh of biofilm/mucus can be an advent to overcome the treatment bottlenecks. Biodegradable and biocompatible polymer nanoparticles efficiently loaded with c...

Phenotypic and genomic responses to titanium dioxide and cerium oxide nanoparticles in Arabidopsis germinants

Science.gov (United States)

The effects of exposure to two nanoparticles (NPs) -titanium dioxide (nano-titania) and cerium oxide (nano-ceria) at 500 mg NPs L-1 on gene expression and growth in Arabidopsis thaliana germinants were studied using microarrays and phenotype studies. After 12 days post treatment,...

Effect of Treatment Media on the Agglomeration of Titanium Dioxide Nanoparticles: Impact on Genotoxicity, Cellular Interaction, and Cell Cycle

Science.gov (United States)

ABSTRACT The widespread use of titanium dioxide (TiO2) nanoparticles in consumer products increases the probability of exposure to humans and the environment. Although TiO2 nanoparticles have been shown to induce DNA damage (comet assay) and chromosome damage (micronucleus ass...

Cyclodextrin-PEG conjugate-wrapped magnetic ferrite nanoparticles for enhanced drug loading and release

Science.gov (United States)

Enoch, Israel V. M. V.; Ramasamy, Sivaraj; Mohiyuddin, Shanid; Gopinath, Packirisamy; Manoharan, R.

2018-05-01

Magnetic nanoparticles are envisaged to overcome the impediments in the methods of targeted drug delivery and hence cure cancer effectively. We report herein, manganese ferrite nanoparticles, coated with β-cyclodextrin-modified polyethylene glycol as a carrier for the drug, camptothecin. The particles are of the size of 100 nm and they show superparamagnetic behaviour. The saturation magnetization does not get diminished on polymer coverage of the nanoparticles. The β-cyclodextrin-polyethylene glycol conjugates are characterized using NMR and mass spectrometric techniques. By coating the magnetic nanoparticles with the cyclodextrin-tethered polymer, the drug-loading capacity is enhanced and the observed release of the drug is slow and sustained. The cell viability of HEK293 and HCT15 cells is evaluated and the cytotoxicity is enhanced when the drug is loaded in the polymer-coated magnetic nanoparticles. The noncovalent-binding based and enhanced drug loading on the nanoparticles and the sustained release make the nanocarrier a promising agent for carrying the payload to the target.

Drug loading and release on tumor cells using silk fibroin–albumin nanoparticles as carriers

International Nuclear Information System (INIS)

Subia, B; Kundu, S C

2013-01-01

Polymeric and biodegradable nanoparticles are frequently used in drug delivery systems. In this study silk fibroin–albumin blended nanoparticles were prepared using the desolvation method without any surfactant. These nanoparticles are easily internalized by the cells, reside within perinuclear spaces and act as carriers for delivery of the model drug methotrexate. Methotrexate loaded nanoparticles have better encapsulation efficiency, drug loading ability and less toxicity. The in vitro release behavior of methotrexate from the nanoparticles suggests that about 85% of the drug gets released after 12 days. The encapsulation and loading of a drug would depend on factors such as size, charge and hydrophobicity, which affect drug release. MTT assay and conjugation of particles with FITC demonstrate that the silk fibroin–albumin nanoparticles do not affect the viability and biocompatibility of cells. This blended nanoparticle, therefore, could be a promising nanocarrier for the delivery of drugs and other bioactive molecules. (paper)

Resveratrol-loaded Nanoparticles Induce Antioxidant Activity against Oxidative Stress

Directory of Open Access Journals (Sweden)

Jae-Hwan Kim

2016-02-01

Full Text Available Resveratrol acts as a free radical scavenger and a potent antioxidant in the inhibition of numerous reactive oxygen species (ROS. The function of resveratrol and resveratrol-loaded nanoparticles in protecting human lung cancer cells (A549 against hydrogen peroxide was investigated in this study. The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS assay was performed to evaluate the antioxidant properties. Resveratrol had substantially high antioxidant capacity (trolox equivalent antioxidant capacity value compared to trolox and vitamin E since the concentration of resveratrol was more than 50 μM. Nanoparticles prepared from β-lactoglobulin (β-lg were successfully developed. The β-lg nanoparticle showed 60 to 146 nm diameter in size with negatively charged surface. Non-cytotoxicity was observed in Caco-2 cells treated with β-lg nanoparticles. Fluorescein isothiocynate-conjugated β-lg nanoparticles were identified into the cell membrane of Caco-2 cells, indicating that nanoparticles can be used as a delivery system. Hydrogen peroxide caused accumulation of ROS in a dose- and time-dependent manner. Resveratrol-loaded nanoparticles restored H2O2-induced ROS levels by induction of cellular uptake of resveratrol in A549 cells. Furthermore, resveratrol activated nuclear factor erythroid 2-related factor 2-Kelch ECH associating protein 1 (Nrf2-Keap1 signaling in A549 cells, thereby accumulation of Nrf2 abundance, as demonstrated by western blotting approach. Overall, these results may have implications for improvement of oxidative stress in treatment with nanoparticles as a biodegradable and non-toxic delivery carrier of bioactive compounds.

Exposure to titanium dioxide and other metallic oxide nanoparticles induces cytotoxicity on human neural cells and fibroblasts

Directory of Open Access Journals (Sweden)

James C K Lai

2008-12-01

Full Text Available James C K Lai1, Maria B Lai1, Sirisha Jandhyam1, Vikas V Dukhande1, Alok Bhushan1, Christopher K Daniels1, Solomon W Leung21Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, and Biomedical Research Institute; 2Department of Civil and Environmental Engineering, College of Engineering and Biomedical Research Institute, Idaho State University, Pocatello, ID, USAAbstract: The use of titanium dioxide (TiO2 in various industrial applications (eg, production of paper, plastics, cosmetics, and paints has been expanding thereby increasing the occupational and other environmental exposure of these nanoparticles to humans and other species. However, the health effects of exposure to TiO2 nanoparticles have not been systematically assessed even though recent studies suggest that such exposure induces inflammatory responses in lung tissue and cells. Because the effects of such nanoparticles on human neural cells are unknown, we have determined the putative cytotoxic effects of these nanoparticles on human astrocytes-like astrocytoma U87 cells and compared their effects on normal human fibroblasts. We found that TiO2 micro- and nanoparticles induced cell death on both human cell types in a concentration-related manner. We further noted that zinc oxide (ZnO nanoparticles were the most effective, TiO2 nanoparticles the second most effective, and magnesium oxide (MgO nanoparticles the least effective in inducing cell death in U87 cells. The cell death mechanisms underlying the effects of TiO2 micro- and nanoparticles on U87 cells include apoptosis, necrosis, and possibly apoptosis-like and necrosis-like cell death types. Thus, our findings may have toxicological and other pathophysiological implications on exposure of humans and other mammalian species to metallic oxide nanoparticles.Keywords: cytotoxicity of titanium dioxide micro- and nanoparticles, cytotoxicity of zinc oxide and magnesium oxide nanoparticles, human neural cells

Interaction of titanium dioxide nanoparticles with glucose on young rats after oral administration.

Science.gov (United States)

Chen, Zhangjian; Wang, Yun; Zhuo, Lin; Chen, Shi; Zhao, Lin; Chen, Tian; Li, Yang; Zhang, Wenxiao; Gao, Xin; Li, Ping; Wang, Haifang; Jia, Guang

2015-10-01

Titanium dioxide nanoparticles (TiO2 NPs) have a broad application prospect in replace with TiO2 used as a food additive, especially used in sweets. Understanding the interaction of TiO2 NPs with sugar is meaningful for health promotion. We used a young animal model to study the toxicological effect of orally administrated TiO2 NPs at doses of 0, 2, 10 and 50 mg/kg per day with or without daily consumption of 1.8 g/kg glucose for 30 days and 90 days. The results showed that oral exposure to TiO2 NPs and TiO2 NPs+glucose both induced liver, kidney, and heart injuries as well as changes in the count of white and red blood cells in a dose, time and gender-dependent manner. The toxicological interactions between orally-administrated TiO2 NPs and glucose were evident, but differed among target organs. These results suggest that it is necessary to limit dietary co-exposure to TiO2 NPs and sugar. Nanotechnology has gained entrance in the food industry, with the presence of nanoparticles now in many food items. Despite this increasing trend, the potential toxic effects of these nanoparticles to human remain unknown. In this article, the authors studied titanium dioxide nanoparticles (TiO2 NPs), which are commonly used as food additive, together with glucose. The findings of possible adverse effects on liver, kidney, and heart might point to a rethink of using glucose and TiO2 NPs combination. Copyright © 2015 Elsevier Inc. All rights reserved.

Nanoembedded Microparticles for Stabilization and Delivery of Drug-Loaded Nanoparticles

DEFF Research Database (Denmark)

Bohr, Adam; Water, Jorrit; Beck-Broichsitter, Moritz

2015-01-01

Nanoparticle-based pharmaceutical products are currently finding their way onto the market as a popular strategy to improve the therapeutic efficacy of numerous drugs, hereunder medications for a targeted treatment of severe diseases (e.g., cancer). Drug-loaded polymer and lipid nanoparticles...

Synthesis, fractionation, and thin film processing of nanoparticles using the tunable solvent properties of carbon dioxide gas expanded liquids

Science.gov (United States)

Anand, Madhu

nanoparticle populations. This study details the influence of various factors on the size separation process, such as the types of nanoparticles, ligand type and solvent type as well as the use of recursive fractionation and the time allowed for settling during each fractionation step. This size selective precipitation technique was also applied to fractionate and separate polydisperse dispersions of CdSe/ZnS semiconductor nanocrystals into very distinct size and color fractions based solely on the pressure tunable solvent properties of CO2 expanded liquids. This size selective precipitation of nanoparticles is achieved by finely tuning the solvent strength of the CO2/organic solvent medium by simply adjusting the applied CO2 pressure. These subtle changes affect the balance between osmotic repulsive and van der Waals attractive forces thereby allowing fractionation of the nanocrystals into multiple narrow size populations. Thermodynamic analysis of nanoparticle size selective fractionation was performed to develop a theoretical model based on the thermodynamic properties of gas expanded liquids. We have used the general phenomenon of nanoparticle precipitation with CO2 expanded liquids to create dodecanethiol stabilized gold nanoparticle thin films. This method utilizes CO2 as an anti-solvent for low defect, wide area gold nanoparticle film formation employing monodisperse gold nanoparticles. Dodecanethiol stabilized gold particles are precipitated from hexane by controllably expanding the solution with carbon dioxide. Subsequent addition of carbon dioxide as a dense supercritical fluid then provides for removal of the organic solvent while avoiding the dewetting effects common to evaporating solvents. Unfortunately, the use of carbon dioxide as a neat solvent in nanoparticles synthesis and processing is limited by the very poor solvent strength of dense phase CO2. As a result, most current techniques employed to synthesize and disperse nanoparticles in neat carbon dioxide

Biocompatibility and antibacterial activity of nitrogen-doped titanium dioxide nanoparticles for use in dental resin formulations.

Science.gov (United States)

Zane, Andrew; Zuo, Ranfang; Villamena, Frederick A; Rockenbauer, Antal; Digeorge Foushee, Ann Marie; Flores, Kristin; Dutta, Prabir K; Nagy, Amber

The addition of antibacterial functionality to dental resins presents an opportunity to extend their useful lifetime by reducing secondary caries caused by bacterial recolonization. In this study, the potential efficacy of nitrogen-doped titanium dioxide nanoparticles for this purpose was determined. Nitrogen doping was carried out to extend the ultraviolet absorbance into longer wavelength blue light for increased biocompatibility. Titanium dioxide nanoparticles (approximately 20-30 nm) were synthesized with and without nitrogen doping using a sol-gel method. Ultraviolet-Visible spectroscopy indicated a band of trap states, with increasing blue light absorbance as the concentration of the nitrogen dopant increased. Electron paramagnetic resonance measurements indicated the formation of superoxide and hydroxyl radicals upon particle exposure to visible light and oxygen. The particles were significantly toxic to Escherichia coli in a dose-dependent manner after a 1-hour exposure to a blue light source (480 nm). Intracellular reactive oxygen species assay demonstrated that the particles caused a stress response in human gingival epithelial cells when exposed to 1 hour of blue light, though this did not result in detectable release of cytokines. No decrease in cell viability was observed by water-soluble tetrazolium dye assay. The results show that nitrogen-doped titanium dioxide nanoparticles have antibacterial activity when exposed to blue light, and are biocompatible at these concentrations.

Endothelial cell-derived microparticles loaded with iron oxide nanoparticles: feasibility of MR imaging monitoring in mice.

Science.gov (United States)

Al Faraj, Achraf; Gazeau, Florence; Wilhelm, Claire; Devue, Cécile; Guérin, Coralie L; Péchoux, Christine; Paradis, Valérie; Clément, Olivier; Boulanger, Chantal M; Rautou, Pierre-Emmanuel

2012-04-01

To assess the feasibility of loading iron oxide nanoparticles in endothelial microparticles (EMPs), thereby enabling their noninvasive monitoring with magnetic resonance (MR) imaging in mice. Experiments were approved by the French Ministry of Agriculture. Endothelial cells, first labeled with anionic superparamagnetic nanoparticles, were stimulated to generate EMPs, carrying the nanoparticles in their inner compartment. C57BL/6 mice received an intravenous injection of nanoparticle-loaded EMPs, free nanoparticles, or the supernatant of nanoparticle-loaded EMPs. A 1-week follow-up was performed with a 4.7-T MR imaging device by using a gradient-echo sequence for imaging spleen, liver, and kidney and a radial very-short-echo time sequence for lung imaging. Comparisons were performed by using the Student t test. The signal intensity loss induced by nanoparticle-loaded EMPs or free nanoparticles was readily detected within 5 minutes after injection in the liver and spleen, with a more pronounced effect in the spleen for the magnetic EMPs. The kinetics of signal intensity attenuation differed for nanoparticle-loaded EMPs and free nanoparticles. No signal intensity changes were observed in mice injected with the supernatant of nanoparticle-loaded EMPs, confirming that cells had not released free nanoparticles, but only in association with EMPs. The results were confirmed by using Perls staining and immunofluorescence analysis. The strategy to generate EMPs with magnetic properties allowed noninvasive MR imaging assessment and follow-up of EMPs and opens perspectives for imaging the implications of these cellular vectors in diseases. © RSNA, 2012.

PVDF nanofibers with silver nanoparticles and silver/titanium dioxide for antimicrobial applications;Eletrofiacao de nanofibras de PVDF com nanoparticulas de prata e de prata/dioxido de titanio para aplicacoes antimicrobiais

Energy Technology Data Exchange (ETDEWEB)

Costa, Ligia M.M.; Olyveira, Gabriel M. de, E-mail: gmolyveira@yahoo.com.b, E-mail: ligialmmc@hotmail.co [Universidade Federal de Sao Carlos (PPGCEM/UFScar), SP (Brazil). Programa de Pos Graduacao em Ciencia e Engenharia de Materiais; Gregorio Filho, Rinaldo; Pessan, Luiz A., E-mail: pessan@ufscar.b, E-mail: gregorio@ufscar.b [Universidade Federal de Sao Carlos (UFScar), SP (Brazil)

2009-07-01

PVDF nanofibers with and without nanoparticles were produced by the method of electro spinning using dimethylformamide (DMF). Silver nitrate nanoparticles (0,5 and 2 wt %) and silver/titanium dioxide nanoparticles obtained by the reduction method (2 wt %) were synthesized and added to the PVDF solution to prepared nanofibers. The processes of electrospinning and film preparation using PVDF with the nanoparticles were compared. Silver/titanium dioxide nanoparticles were characterized with X-ray diffraction (XRD), Scanning electron microscopy (SEM) with EDX and x-ray photoelectron spectroscopy (XPS) to show silver/titanium dioxide nanoparticles. Nanofibers mats were characterized with SEM to study the effects of the addition of the nanoparticles on the morphology behavior and spectroscopy by Fourier transform infrared (FTIR) to analyze the crystalline phase of PVDF films. (author)

Amikacin loaded PLGA nanoparticles against Pseudomonas aeruginosa.

Science.gov (United States)

Sabaeifard, Parastoo; Abdi-Ali, Ahya; Soudi, Mohammad Reza; Gamazo, Carlos; Irache, Juan Manuel

2016-10-10

Amikacin is a very effective aminoglycoside antibiotic but according to its high toxicity, the use of this antibiotic has been limited. The aim of this study was to formulate and characterize amikacin loaded PLGA nanoparticles. Nanoparticles were synthetized using a solid-in-oil-in-water emulsion technique with different ratio of PLGA 50:50 (Resomer 502H) to drug (100:3.5, 80:3.5 and 60:3.5), two different concentrations of stabilizer (pluronic F68) (0.5% or 1%) and varied g forces to recover the final products. The most efficient formulation based on drug loading (26.0±1.3μg/mg nanoparticle) and encapsulation efficiency (76.8±3.8%) was the one obtained with 100:3.5 PLGA:drug and 0.5% luronic F68, recovered by 20,000×g for 20min. Drug release kinetic study indicated that about 50% of the encapsulated drug was released during the first hour of incubation in phospahte buffer, pH7.4, 37°C, 120rpm. Using different cell viability/cytotoxicity assays, the optimized formulation showed no toxicity against RAW macrophages after 2 and 24h of exposure. Furthermore, released drug was active and maintained its bactericidal activity against Pseudomonas aeruginosa in vitro. These results support the effective utilization of the PLGA nanoparticle formulation for amikacin in further in vivo studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Photodynamic effects of methylene blue-loaded polymeric nanoparticles on dental plaque bacteria.

Science.gov (United States)

Klepac-Ceraj, Vanja; Patel, Niraj; Song, Xiaoqing; Holewa, Colleen; Patel, Chitrang; Kent, Ralph; Amiji, Mansoor M; Soukos, Nikolaos S

2011-09-01

Photodynamic therapy (PDT) is increasingly being explored for treatment of oral infections. Here, we investigate the effect of PDT on human dental plaque bacteria in vitro using methylene blue (MB)-loaded poly(lactic-co-glycolic) (PLGA) nanoparticles with a positive or negative charge and red light at 665 nm. Dental plaque samples were obtained from 14 patients with chronic periodontitis. Suspensions of plaque microorganisms from seven patients were sensitized with anionic, cationic PLGA nanoparticles (50 µg/ml equivalent to MB) or free MB (50 µg/ml) for 20 min followed by exposure to red light for 5 min with a power density of 100 mW/cm2 . Polymicrobial oral biofilms, which were developed on blood agar in 96-well plates from dental plaque inocula obtained from seven patients, were also exposed to PDT as above. Following the treatment, survival fractions were calculated by counting the number of colony-forming units. The cationic MB-loaded nanoparticles exhibited greater bacterial phototoxicity in both planktonic and biofilm phase compared to anionic MB-loaded nanoparticles and free MB, but results were not significantly different (P > 0.05). Cationic MB-loaded PLGA nanoparticles have the potential to be used as carriers of MB for PDT systems. Copyright © 2011 Wiley-Liss, Inc.

Dual drug-loaded nanoparticles on self-integrated scaffold for controlled delivery

Directory of Open Access Journals (Sweden)

Bennet D

2012-07-01

Full Text Available Devasier Bennet,1 Mohana Marimuthu,1 Sanghyo Kim,1 Jeongho An21Department of Bionanotechnology, Gachon University, Gyeonggi, Republic of Korea; 2Department of Polymer Science and Engineering, SunKyunKwan University, Gyeonggi, Republic of KoreaAbstract: Antioxidant (quercetin and hypoglycemic (voglibose drug-loaded poly-D,L-lactide-co-glycolide nanoparticles were successfully synthesized using the solvent evaporation method. The dual drug-loaded nanoparticles were incorporated into a scaffold film using a solvent casting method, creating a controlled transdermal drug-delivery system. Key features of the film formulation were achieved utilizing several ratios of excipients, including polyvinyl alcohol, polyethylene glycol, hyaluronic acid, xylitol, and alginate. The scaffold film showed superior encapsulation capability and swelling properties, with various potential applications, eg, the treatment of diabetes-associated complications. Structural and light scattering characterization confirmed a spherical shape and a mean particle size distribution of 41.3 nm for nanoparticles in the scaffold film. Spectroscopy revealed a stable polymer structure before and after encapsulation. The thermoresponsive swelling properties of the film were evaluated according to temperature and pH. Scaffold films incorporating dual drug-loaded nanoparticles showed remarkably high thermoresponsivity, cell compatibility, and ex vivo drug-release behavior. In addition, the hybrid film formulation showed enhanced cell adhesion and proliferation. These dual drug-loaded nanoparticles incorporated into a scaffold film may be promising for development into a transdermal drug-delivery system.Keywords: quercetin, voglibose, biocompatible materials, encapsulation, transdermal

Photocatalytic Degradation Effect of μ-Dielectric Barrier Discharge Plasma Treated Titanium Dioxide Nanoparticles on Environmental Contaminant.

Science.gov (United States)

Seo, Hyeon Jin; Hwang, Ki-Hwan; Na, Young Hoon; Boo, Jin-Hyo

2018-09-01

This study focused on the photocatalytic degradation effect of the μ-dielectric barrier discharge (μ-DBD) plasma treated titanium dioxide (TiO2) nanoparticles on environmental contaminant such as formaldehyde. TiO2 nanoparticles were treated by a μ-DBD plasma source with nitrogen gas. We analyzed the degradation of formaldehyde with the plasma treated TiO2 nanoparticles by UV-visible spectrophotometer (UV-VIS), and demonstrated that the photocatalytic activity of the μ-DBD plasma-treated TiO2 nanoparticles showed significantly high catalytic efficiency rather than without plasma treated TiO2 nanoparticles. Field emission scanning electron microscopes (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and water contact angle analyzer were used to measure the effects of photocatalytic degradation for the plasma treated TiO2 nanoparticles.

Farnesylthiosalicylic acid-loaded lipid-polyethylene glycol-polymer hybrid nanoparticles for treatment of glioblastoma.

Science.gov (United States)

Kaffashi, Abbas; Lüle, Sevda; Bozdağ Pehlivan, Sibel; Sarısözen, Can; Vural, İmran; Koşucu, Hüsnü; Demir, Taner; Buğdaycı, Kadir Emre; Söylemezoğlu, Figen; Karlı Oğuz, Kader; Mut, Melike

2017-08-01

We aimed to develop lipid-polyethylene glycol (PEG)-polymer hybrid nanoparticles, which have high affinity to tumour tissue with active ingredient, a new generation antineoplastic drug, farnesylthiosalicylic acid (FTA) for treatment of glioblastoma. Farnesylthiosalicylic acid-loaded poly(lactic-co-glycolic acid)-1,2 distearoyl-glycerol-3-phospho-ethanolamine-N [methoxy (PEG)-2000] ammonium salt (PLGA-DSPE-PEG) with or without 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) hybrid nanoparticles has been prepared and evaluated for in-vitro characterization. Cytotoxicity of FTA-loaded nanoparticles along with its efficacy on rat glioma-2 (RG2) cells was also evaluated both in vitro (in comparison with non-malignant cell line, L929) and in vivo. Scanning electron microscopy studies showed that all formulations prepared had smooth surface and spherical in shape. FTA and FTA-loaded nanoparticles have cytotoxic activity against RG2 glioma cell lines in cell culture studies, which further increases with addition of DOTAP. Magnetic resonance imaging and histopathologic evaluation on RG2 tumour cells in rat glioma model (49 female Wistar rats, 250-300 g) comparing intravenous and intratumoral injections of the drug have been performed and FTA-loaded nanoparticles reduced tumour size significantly in in-vivo studies, with higher efficiency of intratumoral administration than intravenous route. Farnesylthiosalicylic acid-loaded PLGA-DSPE-PEG-DOTAP hybrid nanoparticles are proven to be effective against glioblastoma in both in-vitro and in-vivo experiments. © 2017 Royal Pharmaceutical Society.

Modification of Titanium Dioxide Nanoparticles With Copper Oxide Co-Catalyst for Photo catalytic Degradation of 2,4-Dichlorophenoxyacetic Acid

International Nuclear Information System (INIS)

Leny Yuliati; Siah, W.R.; Nur Azmina Roslan; Mustaffa Shamsuddin

2016-01-01

2,4-dichlorophenoxyacetic acid (2,4-D) is a common herbicide that has been used widely. Due to its excessive usage, the 2,4-D herbicides can cause contamination over agricultural land and water bodies. In the present work, a simple impregnation method was used to modify the commercial titanium dioxide (P25 TiO_2) nanoparticles with the copper oxide. The prepared samples were characterized by X-ray Diffraction (XRD), reflectance UV-visible and fluorescence spectroscopies. It was observed that the incorporation of copper oxide did not significantly affect the crystal structure of P25 TiO_2. On the other hand, the presence of copper oxide was confirmed by reflectance UV-visible and fluorescence spectroscopies. The activity of the prepared sample was evaluated for photo catalytic removal of the 2,4-D. The photo catalytic activity of the TiO_2 increased with the increase of copper oxide loading up to 0.5 mol %. Unfortunately, the higher loading amount of copper oxide resulted in the lower photo catalytic activity. This study suggested that the higher photo catalytic activities obtained on the low loading samples were due to the lower electron-hole recombination. (author)

Mucus and microbiota as emerging players in gut nanotoxicology: The example of dietary silver and titanium dioxide nanoparticles.

Science.gov (United States)

Mercier-Bonin, Muriel; Despax, Bernard; Raynaud, Patrice; Houdeau, Eric; Thomas, Muriel

2018-04-13

Given the growing use of nanotechnology in many common consumer products, including foods, evaluation of the consequences of chronic exposure to nanoparticles in humans has become a major public health issue. The oral route of exposure has been poorly explored, despite the presence of a fraction of nanosized particles in certain food additives/supplements and the incorporation of such particles into packaging in contact with foods. After their ingestion, these nanoparticles pass through the digestive tract, where they may undergo physicochemical transformations, with consequences for the luminal environment, before crossing the epithelial barrier to reach the systemic compartment. In this review, we consider two examples, nanosilver and nanotitanium dioxide. Despite the specific features of these particles and the differences between them, both display a close relationship between physicochemical reactivity and bioavailability/biopersistence in the gastrointestinal tract. Few studies have focused on the interactions of nanoparticles of silver or titanium dioxide with the microbiota and mucus. However, the microbiota and mucus play key roles in intestinal homeostasis and host health and are undoubtedly involved in controlling the distribution of nanoparticles in the systemic compartment.

Titanium dioxide (TiO2) nanoparticles filled poly(d,l lactid acid) (PDLLA) matrix composites for bone tissue engineering

NARCIS (Netherlands)

Gerhardt, L.C.; Jell, G.M.R.; Boccaccini, A.R.

2007-01-01

Titanium dioxide (TiO2) nanoparticles were investigated for bone tissue engineering applications with regard to bioactivity and particle cytotoxicity. Composite films on the basis of poly(d,l lactid acid) (PDLLA) filled with 0, 5 and 30 wt% TiO2 nanoparticles were processed by solvent casting.

Magnetic poly(D,L-lactide) nanoparticles loaded with aliskiren: A promising tool for hypertension treatment

International Nuclear Information System (INIS)

Antal, Iryna; Kubovcikova, Martina; Zavisova, Vlasta; Koneracka, Martina; Pechanova, Olga; Barta, Andrej; Cebova, Martina; Antal, Vitaliy; Diko, Pavel; Zduriencikova, Martina; Pudlak, Michal; Kopcansky, Peter

2015-01-01

In this study anti-hypertensive drug called aliskiren was encapsulated in magnetic poly(D,L-lactide) nanoparticles by the modified nanoprecipitation method. The effect of magnetite and drug concentrations on the size distribution and zeta potential of polymer nanoparticles was investigated. The optimized loadings were as follows: theoretical magnetite loading was 20 mg/100 mg polymer nanoparticles and aliskiren was encapsulated in magnetic poly(D,L-lactide) nanoparticles at theoretical loading 0.6 mg aliskiren/100 mg magnetic polymer nanoparticles. The physicochemical characteristics of nanoparticles were studied, with spherical shape of nanoparticles sized between 58 and 227 nm being one of the observed results. Differential scanning calorimetry and infrared spectroscopy confirmed that aliskiren was successfully identified in the magnetic poly(D,L-lactide) nanoparticles. The in vivo experiments indicated that encapsulated aliskiren decreased blood pressure of the studied male spontaneously hypertensive rat even more significantly than common administered drug. - Highlights: • Anti-hypertensive drug called aliskiren was encapsulated in magnetic poly(D,L-lactide) nanoparticles by modified nanoprecipitation method. • The optimisation of magnetite and drug loading with regard to the size distribution and zeta potential was investigated. • The physicochemical characteristics of nanoparticles were studied by different techniques. • The in vivo experiments indicated that encapsulated aliskiren decreased blood pressure of the studied male spontaneously hypertensive rat even more significantly than common administered drug

Magnetic poly(D,L-lactide) nanoparticles loaded with aliskiren: A promising tool for hypertension treatment

Energy Technology Data Exchange (ETDEWEB)

Antal, Iryna, E-mail: iryna.antal@saske.sk [Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice (Slovakia); Kubovcikova, Martina; Zavisova, Vlasta; Koneracka, Martina [Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice (Slovakia); Pechanova, Olga; Barta, Andrej; Cebova, Martina [Institute of Normal and Pathological Physiology, SAS, Bratislava (Slovakia); Antal, Vitaliy; Diko, Pavel [Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice (Slovakia); Zduriencikova, Martina [Cancer Research Institute, SAS, Bratislava (Slovakia); Pudlak, Michal; Kopcansky, Peter [Institute of Experimental Physics, SAS, Watsonova 47, 040 01 Kosice (Slovakia)

2015-04-15

In this study anti-hypertensive drug called aliskiren was encapsulated in magnetic poly(D,L-lactide) nanoparticles by the modified nanoprecipitation method. The effect of magnetite and drug concentrations on the size distribution and zeta potential of polymer nanoparticles was investigated. The optimized loadings were as follows: theoretical magnetite loading was 20 mg/100 mg polymer nanoparticles and aliskiren was encapsulated in magnetic poly(D,L-lactide) nanoparticles at theoretical loading 0.6 mg aliskiren/100 mg magnetic polymer nanoparticles. The physicochemical characteristics of nanoparticles were studied, with spherical shape of nanoparticles sized between 58 and 227 nm being one of the observed results. Differential scanning calorimetry and infrared spectroscopy confirmed that aliskiren was successfully identified in the magnetic poly(D,L-lactide) nanoparticles. The in vivo experiments indicated that encapsulated aliskiren decreased blood pressure of the studied male spontaneously hypertensive rat even more significantly than common administered drug. - Highlights: • Anti-hypertensive drug called aliskiren was encapsulated in magnetic poly(D,L-lactide) nanoparticles by modified nanoprecipitation method. • The optimisation of magnetite and drug loading with regard to the size distribution and zeta potential was investigated. • The physicochemical characteristics of nanoparticles were studied by different techniques. • The in vivo experiments indicated that encapsulated aliskiren decreased blood pressure of the studied male spontaneously hypertensive rat even more significantly than common administered drug.

Wettability alteration properties of fluorinated silica nanoparticles in liquid-loaded pores: An atomistic simulation

Energy Technology Data Exchange (ETDEWEB)

Sepehrinia, Kazem; Mohammadi, Aliasghar, E-mail: amohammadi@sharif.edu

2016-05-15

Highlights: • Properties of fluorinated silica nanoparticles were investigated in water or decane-loaded pores of mineral silica using molecular dynamics simulation. • The water or decane-loaded pores represent liquid bridging. • Addition of nanoparticles to liquid-loaded pores results in weakening of the liquid bridge. • The hydrophobicity of the pore wall increases in the presence of adsorbed fluorinated silica nanoparticles. - Abstract: Control over the wettability of reservoir rocks is of crucial importance for enhancing oil and gas recovery. In order to develop chemicals for controlling the wettability of reservoir rocks, we present a study of functionalized silica nanoparticles as candidates for wettability alteration and improved gas recovery applications. In this paper, properties of fluorinated silica nanoparticles were investigated in water or decane-loaded pores of mineral silica using molecular dynamics simulation. Trifluoromethyl groups as water and oil repellents were placed on the nanoparticles. Simulating a pore in the presence of trapped water or decane molecules leads to liquid bridging for both of the liquids. Adsorption of nanoparticles on the pore wall reduces the density of liquid molecules adjacent to the wall. The density of liquid molecules around the nanoparticles decreases significantly with increasing the number of trifluoromethyl groups on the nanoparticles’ surfaces. An increased hydrophobicity of the pore wall was observed in the presence of adsorbed fluorinated silica nanoparticles. Also, it is observed that increasing the number of the trifluoromethyl groups results in weakening of liquid bridges. Moreover, the free energy of adsorption on mineral surface was evaluated to be more favorable than that of aggregation of nanoparticles, which suggests nanoparticles adsorb preferably on mineral surface.

Wettability alteration properties of fluorinated silica nanoparticles in liquid-loaded pores: An atomistic simulation

International Nuclear Information System (INIS)

Sepehrinia, Kazem; Mohammadi, Aliasghar

2016-01-01

Highlights: • Properties of fluorinated silica nanoparticles were investigated in water or decane-loaded pores of mineral silica using molecular dynamics simulation. • The water or decane-loaded pores represent liquid bridging. • Addition of nanoparticles to liquid-loaded pores results in weakening of the liquid bridge. • The hydrophobicity of the pore wall increases in the presence of adsorbed fluorinated silica nanoparticles. - Abstract: Control over the wettability of reservoir rocks is of crucial importance for enhancing oil and gas recovery. In order to develop chemicals for controlling the wettability of reservoir rocks, we present a study of functionalized silica nanoparticles as candidates for wettability alteration and improved gas recovery applications. In this paper, properties of fluorinated silica nanoparticles were investigated in water or decane-loaded pores of mineral silica using molecular dynamics simulation. Trifluoromethyl groups as water and oil repellents were placed on the nanoparticles. Simulating a pore in the presence of trapped water or decane molecules leads to liquid bridging for both of the liquids. Adsorption of nanoparticles on the pore wall reduces the density of liquid molecules adjacent to the wall. The density of liquid molecules around the nanoparticles decreases significantly with increasing the number of trifluoromethyl groups on the nanoparticles’ surfaces. An increased hydrophobicity of the pore wall was observed in the presence of adsorbed fluorinated silica nanoparticles. Also, it is observed that increasing the number of the trifluoromethyl groups results in weakening of liquid bridges. Moreover, the free energy of adsorption on mineral surface was evaluated to be more favorable than that of aggregation of nanoparticles, which suggests nanoparticles adsorb preferably on mineral surface.

Effects of curcumin-loaded PLGA nanoparticles on the RG2 rat glioma model.

Science.gov (United States)

Orunoğlu, Merdan; Kaffashi, Abbas; Pehlivan, Sibel Bozdağ; Şahin, Selma; Söylemezoğlu, Figen; Oğuz, Kader Karli; Mut, Melike

2017-09-01

Curcumin, the active ingredient of turmeric, has a remarkable antitumor activity against various cancers, including glioblastoma. However, it has poor absorption and low bioavailability; thus, to cross the blood-brain barrier and reach tumor tissue, it needs to be transferred to tumor site by special drug delivery systems, such as nanoparticles. We aimed to evaluate the antitumor activity of curcumin on glioblastoma tissue in the rat glioma-2 (RG2) tumor model when it is loaded on poly(lactic-co-glycolic acid)-1,2-distearoyl-glycerol-3-phospho-ethanolamine-N-[methoxy (polyethylene glycol)-2000] ammonium salt (PLGA-DSPE-PEG) hybrid nanoparticles. Glioblastoma was induced in 42 adult female Wistar rats (250-300g) by RG2 tumor model. The curcumin-loaded nanoparticles were injected by intravenous (n=6) or intratumoral route (n=6). There were five control groups, each containing six rats. First control group was not applied any treatment. The remaining four control groups were given empty nanoparticles or curcumin alone by intravenous or intratumoral route, respectively. The change in tumor volume was assessed by magnetic resonance imaging and histopathology before and 5days after drug injections. Tumor size decreased significantly after 5days of intratumoral injection of curcumin-loaded nanoparticle (from 66.6±44.6 to 34.9±21.7mm 3 , p=0.028), whereas it significantly increased in nontreated control group (from 33.9±21.3 to 123.7±41.1mm 3 , p=0.036) and did not significantly change in other groups (p>0.05 for all). In this in vivo experimental model, intratumoral administration of curcumin-loaded PLGA-DSPE-PEG hybrid nanoparticles was effective against glioblastoma. Curcumine-loaded nanoparticles may have potential application in chemotherapy of glioblastoma. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of Dielectric Properties and Morphology of Epoxy Resin with Silicon Dioxide Microparticles and Nanoparticles

Czech Academy of Sciences Publication Activity Database

Hudec, Jiří; Neděla, Vilém

2016-01-01

Roč. 22, S3 (2016), s. 1896-1897 ISSN 1431-9276 R&D Projects: GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : epoxy resin ESEM * Nanoparticles * silicon dioxide * ESEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.891, year: 2016

Folate receptor targeted 17-allylamino-17-demethoxygeldanamycin (17-AAG) loaded polymeric nanoparticles for breast cancer.

Science.gov (United States)

Saxena, Vipin; Naguib, Youssef; Hussain, M Delwar

2012-06-01

Low water solubility and hepatotoxicity limited the clinical use of 17-allylamino-17-demethoxy geldanamycin (17-AAG), an inhibitor of heat shock protein 90 (HSP90). Folate targeted polylactide-co-glycolide-polyethylene glycol-folic acid (PLGA-PEG-FA) nanoparticles containing 17-AAG were prepared and characterized. Cellular uptake and in vitro cytotoxicity of the prepared nanoparticles were determined in MCF-7 human breast cancer cells. The particle size of 17-AAG loaded folate targeted nanoparticles was 238.67±3.52 nm, drug loading was 8.25±2.49% and about 80% of drug was released from the nanoparticles over 10 days. Cellular uptake studies showed much higher intracellular uptake of folate targeted nanoparticle as compared to nontargeted nanoparticles. Cytotoxicity study showed 2 fold increase (PAAG loaded PLGA-PEG-FA nanoparticles might be developed as a targeted delivery system for breast and other cancer treatment. Copyright © 2012 Elsevier B.V. All rights reserved.

Plasmid DNA loaded chitosan nanoparticles for nasal mucosal immunization against hepatitis B.

Science.gov (United States)

Khatri, Kapil; Goyal, Amit K; Gupta, Prem N; Mishra, Neeraj; Vyas, Suresh P

2008-04-16

This work investigates the preparation and in vivo efficacy of plasmid DNA loaded chitosan nanoparticles for nasal mucosal immunization against hepatitis B. Chitosan pDNA nanoparticles were prepared using a complex coacervation process. Prepared nanoparticles were characterized for size, shape, surface charge, plasmid loading and ability of nanoparticles to protect DNA against nuclease digestion and for their transfection efficacy. Nasal administration of nanoparticles resulted in serum anti-HBsAg titre that was less compared to that elicited by naked DNA and alum adsorbed HBsAg, but the mice were seroprotective within 2 weeks and the immunoglobulin level was above the clinically protective level. However, intramuscular administration of naked DNA and alum adsorbed HBsAg did not elicit sIgA titre in mucosal secretions that was induced by nasal immunization with chitosan nanoparticles. Similarly, cellular responses (cytokine levels) were poor in case of alum adsorbed HBsAg. Chitosan nanoparticles thus produced humoral (both systemic and mucosal) and cellular immune responses upon nasal administration. The study signifies the potential of chitosan nanoparticles as DNA vaccine carrier and adjuvant for effective immunization through non-invasive nasal route.

Curved wall-jet burner for synthesizing titania and silica nanoparticles

KAUST Repository

Ismail, Mohamed

2015-01-01

A novel curved wall-jet (CWJ) burner was designed for flame synthesis, by injecting precursors through a center tube and by supplying fuel/air mixtures as an annular-inward jet for rapid mixing of the precursors in the reaction zone. Titanium dioxide (TiO2) and silicon dioxide (SiO2) nanoparticles were produced in ethylene (C2H4)/air premixed flames using titanium tetraisopropoxide (TTIP) and hexamethyldisiloxane (HMDSO) as the precursors, respectively. Particle image velocimetry measurements confirmed that the precursors can be injected into the flames without appreciably affecting flow structure. The nanoparticles were characterized using X-ray diffraction, Raman spectroscopy, the Brunauer-Emmett-Teller (BET) method, and high-resolution transmission electron microscopy. In the case of TiO2, the phase of nanoparticles could be controlled by adjusting the equivalence ratio, while the particle size was dependent on the precursor loading rate and the flame temperature. The synthesized TiO2 nanoparticles exhibited high crystallinity and the anatase phase was dominant at high equivalence ratios (φ > 1.3). In the case of SiO2, the particle size could be controlled from 11 to 18 nm by adjusting the precursor loading rate. © 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Multiple-diffusion flame synthesis of pure anatase and carbon-coated titanium dioxide nanoparticles

KAUST Repository

Memon, Nasir

2013-09-01

A multi-element diffusion flame burner (MEDB) is useful in the study of flame synthesis of nanomaterials. Here, the growth of pure anatase and carbon-coated titanium dioxide (TiO2) using an MEDB is demonstrated. Hydrogen (H2), oxygen (O2), and argon (Ar) are utilized to establish the flame, whereas titanium tetraisopropoxide is used as the precursor for TiO2. The nanoparticles are characterized using high-resolution transmission electron microscopy, with elemental mapping (of C, O, and Ti), X-ray diffraction, Raman spectroscopy, and thermogravimetric analysis. The growth of pure anatase TiO2 nanoparticles occurs when Ar and H2 are used as the precursor carrier gas, while the growth of carbon-coated nanoparticles ensues when Ar and ethylene (C2H4) are used as the precursor carrier gas. A uniform coating of 3-5nm of carbon is observed around TiO2 particles. The growth of highly crystalline TiO2 nanoparticles is dependent on the gas flow rate of the precursor carrier and amorphous particles are observed at high flow rates. Carbon coating occurs only on crystalline nanoparticles, suggesting a possible growth mechanism of carbon-coated TiO2 nanoparticles. © 2013 The Combustion Institute.

Improved insulin loading in poly(lactic-co-glycolic) acid (PLGA) nanoparticles upon self-assembly with lipids.

Science.gov (United States)

García-Díaz, María; Foged, Camilla; Nielsen, Hanne Mørck

2015-03-30

Polymeric nanoparticles are widely investigated as drug delivery systems for oral administration. However, the hydrophobic nature of many polymers hampers effective loading of the particles with hydrophilic macromolecules such as insulin. Thus, the aim of this work was to improve the loading of insulin into poly(lactic-co-glycolic) acid (PLGA) nanoparticles by pre-assembly with amphiphilic lipids. Insulin was complexed with soybean phosphatidylcholine or sodium caprate by self-assembly and subsequently loaded into PLGA nanoparticles by using the double emulsion-solvent evaporation technique. The nanoparticles were characterized in terms of size, zeta potential, insulin encapsulation efficiency and loading capacity. Upon pre-assembly with lipids, there was an increased distribution of insulin into the organic phase of the emulsion, eventually resulting in significantly enhanced encapsulation efficiencies (90% as compared to 24% in the absence of lipids). Importantly, the insulin loading capacity was increased up to 20% by using the lipid-insulin complexes. The results further showed that a main fraction of the lipid was incorporated into the nanoparticles and remained associated to the polymer during release studies in buffers, whereas insulin was released in a non-complexed form as a burst of approximately 80% of the loaded insulin. In conclusion, the protein load in PLGA nanoparticles can be significantly increased by employing self-assembled protein-lipid complexes. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of Acyclovir-Loaded Albumin Nanoparticles and Improvement of Acyclovir Permeation Across Human Corneal Epithelial T Cells.

Science.gov (United States)

Suwannoi, Panita; Chomnawang, Mullika; Sarisuta, Narong; Reichl, Stephan; Müller-Goymann, Christel C

2017-12-01

The aim of the present study was to develop acyclovir (ACV) ocular drug delivery systems of bovine serum albumin (BSA) nanoparticles as well as to assess their in vitro transcorneal permeation across human corneal epithelial (HCE-T) cell multilayers. The ACV-loaded BSA nanoparticles were prepared by desolvation method along with physicochemical characterization, cytotoxicity, as well as in vitro transcorneal permeation studies across HCE-T cell multilayers. The nanoparticles appeared to be spherical in shape and nearly uniform in size of about 200 nm. The size of nanoparticles became smaller with decreasing BSA concentration, while the ratios of water to ethanol seemed not to affect the size. Increasing the amount of ethanol in desolvation process led to significant reduction of drug entrapment of nanoparticles with smaller size and more uniformity. The ACV-loaded BSA nanoparticles prepared were shown to have no cytotoxic effect on HCE-T cells used in permeation studies. The in vitro transcorneal permeation results revealed that ACV could permeate through the HCE-T cell multilayers significantly higher from BSA nanoparticles than from aqueous ACV solutions. The ACV-loaded BSA nanoparticles could be prepared by desolvation method without glutaraldehyde in the formulation. ACV could increasingly permeate through the multilayers of HCE-T cells from the ACV-loaded BSA nanoparticles. Therefore, the ACV-loaded BSA nanoparticles could be a highly potential ocular drug delivery system.

Novel free paclitaxel-loaded poly(L-γ-glutamylglutamine–paclitaxel nanoparticles

Directory of Open Access Journals (Sweden)

Danbo Yang

2011-01-01

Full Text Available Danbo Yang1, Sang Van2, Xinguo Jiang3, Lei Yu1,21Biomedical Engineering and Technology Institute, Institutes for Advanced Interdisciplinary Research, East China Normal University, Shanghai, People's Republic of China; 2Biomedical Group, Nitto Denko Technical Corporation, Oceanside, CA, USA; 3School of Pharmacy, Fudan University, Shanghai, People's Republic of ChinaAbstract: The purpose of this study was to develop a novel formulation of paclitaxel (PTX that would improve its therapeutic index. Here, we combined a concept of polymer–PTX drug conjugate with a concept of polymeric micelle drug delivery to form novel free PTX-loaded poly(L-γ-glutamylglutamine (PGG–PTX conjugate nanoparticles. The significance of this drug formulation emphasizes the simplicity, novelty, and flexibility of the method of forming nanoparticles that contain free PTX and conjugated PTX in the same drug delivery system. The results of effectively inhibiting tumor growth in mouse models demonstrated the feasibility of the nanoparticle formulation. The versatility and potential of this dual PTX drug delivery system can be explored with different drugs for different indications. Novel and simple formulations of PTX-loaded PGG–PTX nanoparticles could have important implications in translational medicines.Keywords: paclitaxel, polymeric micelle, poly(L-γ-glutamylglutamine–paclitaxel, nanoconjugate, nanoparticles

In situ gelling dorzolamide loaded chitosan nanoparticles for the treatment of glaucoma.

Science.gov (United States)

Katiyar, Shefali; Pandit, Jayamanti; Mondal, Rabi S; Mishra, Anil K; Chuttani, Krishna; Aqil, Mohd; Ali, Asgar; Sultana, Yasmin

2014-02-15

The most important risk associated with glaucoma is the onset and progression of intraocular pressure. The objective of this study was to formulate in situ gel of chitosan nanoparticles to enhance the bioavailability and efficacy of dorzolamide in the glaucoma treatment. Optimized nanoparticles were spherical in shape (particle size: 164 nm) with a loading efficiency of 98.1%. The ex vivo release of the optimized in situ gel nanoparticle formulation showed a sustained drug release as compared to marketed formulation. The gamma scintigraphic study of prepared in situ nanoparticle gel showed good corneal retention compared to marketed formulation. HET-CAM assay of the prepared formulation scored 0.33 in 5 min which indicates the non-irritant property of the formulation. Thus in situ gel of dorzolamide hydrochloride loaded nanoparticles offers a more intensive treatment of glaucoma and a better patient compliance as it requires fewer applications per day compared to conventional eye drops. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cytotoxicity and apoptotic effects of tea polyphenol-loaded chitosan nanoparticles on human hepatoma HepG2 cells.

Science.gov (United States)

Liang, Jin; Li, Feng; Fang, Yong; Yang, Wenjian; An, Xinxin; Zhao, Liyan; Xin, Zhihong; Cao, Lin; Hu, Qiuhui

2014-03-01

Tea polyphenols have strong antioxidant and antitumor activities. However, these health benefits are limited due to their poor in vivo stability and low bioavailability. Chitosan nanoparticles as delivery systems may provide an alternative approach for enhancing bioavailability of poorly absorbed drugs. In this study, tea polyphenol-loaded chitosan nanoparticles have been prepared using two different chitosan biomaterials, and their antitumor effects were evaluated in HepG2 cells, including cell cytotoxicity comparison, cell morphology analysis, cell apoptosis and cell cycle detection. The results indicated that the tea polyphenol-loaded chitosan nanoparticles showed a branch shape and heterogeneous distribution in prepared suspension. MTT assay suggested that tea polyphenol-loaded chitosan nanoparticles could inhibit the proliferation of HepG2 cells, and the cytotoxicity rates were increased gradually and appeared an obvious dose-dependent relationship. Transmission electron microscope images showed that the HepG2 cells treated with tea polyphenol-loaded chitosan nanoparticles exhibited some typical apoptotic features, such as microvilli disappearance, margination of nuclear chromatin, intracytoplasmic vacuoles and the mitochondrial swelling. In addition, the tea polyphenol-loaded chitosan nanoparticles had relatively weak inhibitory effects on HepG2 cancer cells compared with tea polyphenols. Tea polyphenols not only induced cancer cell apoptosis, but also promoted their necrosis. However, tea polyphenol-loaded chitosan nanoparticles exhibited their antitumor effects mainly through inducing cell apoptosis. Our results revealed that the inhibition effects of tea polyphenol-loaded chitosan nanoparticles on tumor cells probably depended on their controlled drug release and effective cell delivery. The chitosan nanoparticles themselves as the delivery carrier showed limited antitumor effects compared with their encapsulated drugs. Copyright © 2013. Published by

Ciprofloxacin-loaded PLGA nanoparticles against cystic fibrosis P. aeruginosa lung infections.

Science.gov (United States)

Günday Türeli, Nazende; Torge, Afra; Juntke, Jenny; Schwarz, Bianca C; Schneider-Daum, Nicole; Türeli, Akif Emre; Lehr, Claus-Michael; Schneider, Marc

2017-08-01

Current pulmonary treatments against Pseudomonas aeruginosa infections in cystic fibrosis (CF) lung suffer from deactivation of the drug and immobilization in thick and viscous biofilm/mucus blend, along with the general antibiotic resistance. Administration of nanoparticles (NPs) with high antibiotic load capable of penetrating the tight mesh of biofilm/mucus can be an advent to overcome the treatment bottlenecks. Biodegradable and biocompatible polymer nanoparticles efficiently loaded with ciprofloxacin complex offer a solution for emerging treatment strategies. NPs were prepared under controlled conditions by utilizing MicroJet Reactor (MJR) to yield a particle size of 190.4±28.6nm with 0.089 PDI. Encapsulation efficiency of the drug was 79% resulting in a loading of 14%. Release was determined to be controlled and medium-independent in PBS, PBS+0.2% Tween 80 and simulated lung fluid. Cytotoxicity assays with Calu-3 cells and CF bronchial epithelial cells (CFBE41o - ) indicated that complex-loaded PLGA NPs were non-toxic at concentrations ≫ MIC cipro against lab strains of the bacteria. Antibacterial activity tests revealed enhanced activity when applied as nanoparticles. NPs' colloidal stability in mucus was proven. Notably, a decrease in mucus turbidity was observed upon incubation with NPs. Herewith, ciprofloxacin complex-loaded PLGA NPs are introduced as promising pulmonary nano drug delivery systems against P.aeruginosa infections in CF lung. Copyright © 2017 Elsevier B.V. All rights reserved.

Photocatalytic ROS production and phototoxicity of titanium dioxide nanoparticles is dependent on solar UV radiation spectrum

Science.gov (United States)

Generation of reactive oxygen species (ROS) by titanium dioxide nanoparticles (nano-TiO2) and its consequent phototoxicity to Daphnia magna were measured under different solar UV radiation spectrum by applying a series of optical filters in a solar simulator. Removing UVB (280-32...

Dynamic mechanical behaviour of nanoparticle loaded biodegradable PVA films for vaginal drug delivery.

Science.gov (United States)

Traore, Yannick L; Fumakia, Miral; Gu, Jijin; Ho, Emmanuel A

2018-03-01

In this study, we investigated the viscoelastic and mechanical behaviour of polyvinyl alcohol films formulated along with carrageenan, plasticizing agents (polyethylene glycol and glycerol), and when loaded with nanoparticles as a model for potential applications as microbicides. The storage modulus, loss modulus and glass transition temperature were determined using a dynamic mechanical analyzer. Films fabricated from 2% to 5% polyvinyl alcohol containing 3 mg or 5 mg of fluorescently labeled nanoparticles were evaluated. The storage modulus and loss modulus values of blank films were shown to be higher than the nanoparticle-loaded films. Glass transition temperature determined using the storage modulus, and loss modulus was between 40-50℃ and 35-40℃, respectively. The tensile properties evaluated showed that 2% polyvinyl alcohol films were more elastic but less resistant to breaking compared to 5% polyvinyl alcohol films (2% films break around 1 N load and 5% films break around 7 N load). To our knowledge, this is the first study to evaluate the influence of nanoparticle and film composition on the physico-mechanical properties of polymeric films for vaginal drug delivery.

Artesunate-loaded chitosan/lecithin nanoparticles: preparation, characterization, and in vivo studies.

Science.gov (United States)

Chadha, Renu; Gupta, Sushma; Pathak, Natasha

2012-12-01

Artesunate (AST), the most widely used artemisnin derivative, has poor aqueous solubility and suffers from low oral bioavailability (~40%). Under these conditions, nanoparticles with controlled and sustained released properties can be a suitable solution for improving its biopharmaceuticals properties. This work reports the preparation and characterization of auto-assembled chitosan/lecithin nanoparticles loaded with AST and AST complexed with β-cyclodextrin (β-CD) to boost its antimalarial activity. The nanoparticles prepared by direct injection of lecithin alcoholic solution into chitosan/water solution have shown the particle size distribution below 300 nm. Drug entrapment efficiency was found to be maximum (90%) for nanoparticles containing 100 mg of AST. Transmission electron microscopy images show spherical shape with contrasted corona (chitosan) surrounded by a lipidic core (lecithin + isopropyl myristate). Differential scanning calorimeter thermograms demonstrated the presence of drug in drug-loaded nanoparticles along with the disappearance of decomposition exotherm suggesting the increased physical stability of drug in prepared formulations. Negligible changes in the characteristic peaks of drug in Fourier-transform infrared spectra indicated the absence of any interaction among the various components entrapped in the nanoparticle formulation. In vitro drug release behavior was found to be influenced by pH value. Increased in vivo antimalarial activity in terms of less mean percent parasitemia was observed in infected Plasmodium berghei mice after the oral administration of all the prepared nanoparticle formulations.

Novel targeted siRNA-loaded hybrid nanoparticles: preparation, characterization and in vitro evaluation.

Science.gov (United States)

Dim, Nneka; Perepelyuk, Maryna; Gomes, Olukayode; Thangavel, Chellappagounder; Liu, Yi; Den, Robert; Lakshmikuttyamma, Ashakumary; Shoyele, Sunday A

2015-09-26

siRNAs have a high potential for silencing critical molecular pathways that are pathogenic. Nevertheless, their clinical application has been limited by a lack of effective and safe nanotechnology-based delivery system that allows a controlled and safe transfection to cytosol of targeted cells without the associated adverse effects. Our group recently reported a very effective and safe hybrid nanoparticle delivery system composing human IgG and poloxamer-188 for siRNA delivery to cancer cells. However, these nanoparticles need to be optimized in terms of particle size, loading capacity and encapsulation efficiency. In the present study, we explored the effects of certain production parameters on particle size, loading capacity and encapsulation efficiency. Further, to make these nanoparticles more specific in their delivery of siRNA, we conjugated anti-NTSR1-mAb to the surface of these nanoparticles to target NTSR1-overexpressing cancer cells. The mechanism of siRNA release from these antiNTSR1-mAb functionalized nanoparticles was also elucidated. It was demonstrated that the concentration of human IgG in the starting nanoprecipitation medium and the rotation speed of the magnetic stirrer influenced the encapsulation efficiency, loading capacity and the size of the nanoparticles produced. We also successfully transformed these nanoparticles into actively targeted nanoparticles by functionalizing with anti-NTSR1-mAb to specifically target NTSR1-overexpressing cancer cells, hence able to avoid undesired accumulation in normal cells. The mechanism of siRNA release from these nanoparticles was elucidated to be by Fickian diffusion. Using flow cytometry and fluorescence microscopy, we were able to confirm the active involvement of NTSR1 in the uptake of these anti-NTSR1-mAb functionalized hybrid nanoparticles by lung adenocarcinoma cells. This hybrid nanoparticle delivery system can be used as a platform technology for intracellular delivery of siRNAs to NTSR1

Cytotoxicity and apoptotic effects of tea polyphenol-loaded chitosan nanoparticles on human hepatoma HepG2 cells

International Nuclear Information System (INIS)

Liang, Jin; Li, Feng; Fang, Yong; Yang, Wenjian; An, Xinxin; Zhao, Liyan; Xin, Zhihong; Cao, Lin; Hu, Qiuhui

2014-01-01

Tea polyphenols have strong antioxidant and antitumor activities. However, these health benefits are limited due to their poor in vivo stability and low bioavailability. Chitosan nanoparticles as delivery systems may provide an alternative approach for enhancing bioavailability of poorly absorbed drugs. In this study, tea polyphenol-loaded chitosan nanoparticles have been prepared using two different chitosan biomaterials, and their antitumor effects were evaluated in HepG2 cells, including cell cytotoxicity comparison, cell morphology analysis, cell apoptosis and cell cycle detection. The results indicated that the tea polyphenol-loaded chitosan nanoparticles showed a branch shape and heterogeneous distribution in prepared suspension. MTT assay suggested that tea polyphenol-loaded chitosan nanoparticles could inhibit the proliferation of HepG2 cells, and the cytotoxicity rates were increased gradually and appeared an obvious dose-dependent relationship. Transmission electron microscope images showed that the HepG2 cells treated with tea polyphenol-loaded chitosan nanoparticles exhibited some typical apoptotic features, such as microvilli disappearance, margination of nuclear chromatin, intracytoplasmic vacuoles and the mitochondrial swelling. In addition, the tea polyphenol-loaded chitosan nanoparticles had relatively weak inhibitory effects on HepG2 cancer cells compared with tea polyphenols. Tea polyphenols not only induced cancer cell apoptosis, but also promoted their necrosis. However, tea polyphenol-loaded chitosan nanoparticles exhibited their antitumor effects mainly through inducing cell apoptosis. Our results revealed that the inhibition effects of tea polyphenol-loaded chitosan nanoparticles on tumor cells probably depended on their controlled drug release and effective cell delivery. The chitosan nanoparticles themselves as the delivery carrier showed limited antitumor effects compared with their encapsulated drugs. - Highlights: • Tea polyphenol-loaded

Cytotoxicity and apoptotic effects of tea polyphenol-loaded chitosan nanoparticles on human hepatoma HepG2 cells

Energy Technology Data Exchange (ETDEWEB)

Liang, Jin [Key Laboratory of Tea Biochemistry and Biotechnology of Ministry of Education and Ministry of Agriculture, Anhui Agricultural University, Hefei 230036 (China); College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); Li, Feng [College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); Fang, Yong; Yang, Wenjian [College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023 (China); An, Xinxin; Zhao, Liyan; Xin, Zhihong; Cao, Lin [College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); Hu, Qiuhui, E-mail: qiuhuihu@njau.edu.cn [College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023 (China)

2014-03-01

Tea polyphenols have strong antioxidant and antitumor activities. However, these health benefits are limited due to their poor in vivo stability and low bioavailability. Chitosan nanoparticles as delivery systems may provide an alternative approach for enhancing bioavailability of poorly absorbed drugs. In this study, tea polyphenol-loaded chitosan nanoparticles have been prepared using two different chitosan biomaterials, and their antitumor effects were evaluated in HepG2 cells, including cell cytotoxicity comparison, cell morphology analysis, cell apoptosis and cell cycle detection. The results indicated that the tea polyphenol-loaded chitosan nanoparticles showed a branch shape and heterogeneous distribution in prepared suspension. MTT assay suggested that tea polyphenol-loaded chitosan nanoparticles could inhibit the proliferation of HepG2 cells, and the cytotoxicity rates were increased gradually and appeared an obvious dose-dependent relationship. Transmission electron microscope images showed that the HepG2 cells treated with tea polyphenol-loaded chitosan nanoparticles exhibited some typical apoptotic features, such as microvilli disappearance, margination of nuclear chromatin, intracytoplasmic vacuoles and the mitochondrial swelling. In addition, the tea polyphenol-loaded chitosan nanoparticles had relatively weak inhibitory effects on HepG2 cancer cells compared with tea polyphenols. Tea polyphenols not only induced cancer cell apoptosis, but also promoted their necrosis. However, tea polyphenol-loaded chitosan nanoparticles exhibited their antitumor effects mainly through inducing cell apoptosis. Our results revealed that the inhibition effects of tea polyphenol-loaded chitosan nanoparticles on tumor cells probably depended on their controlled drug release and effective cell delivery. The chitosan nanoparticles themselves as the delivery carrier showed limited antitumor effects compared with their encapsulated drugs. - Highlights: • Tea polyphenol-loaded

Insulin-loaded polymeric mucoadhesive nanoparticles: development, characterization and cytotoxicity evaluation

Directory of Open Access Journals (Sweden)

Tiago Henrique Honorato Gatti

2018-06-01

Full Text Available Abstract Mucoadhesive nanoparticles are particularly interesting for delivery through nasal or pulmonary routes, as an approach to overcome the mucociliary clearance. Moreover, these nanoparticles are attractive for peptide and protein delivery, particularly for insulin to treat diabetes, as an alternative to conventional parenteral administration. Thus, chitosan, a cationic mucoadhesive polysaccharide found in shells of crustaceans, and the negatively-charged dextran sulfate are able to form nanoparticles through ionic condensation, representing a potential insulin carrier. Herein, chitosan/dextran sulfate nanoparticles at various ratios were prepared for insulin loading. Formulations were characterized for particle size, zeta potential, encapsulation efficiency, scanning electron microscopy, differential scanning calorimetry, and in vitro drug release. Moreover, the interaction with mucin and the cytotoxicity against a lung cell line were studied, which altogether have not been addressed before. Results evidenced that a proper selection of polyelectrolytes is necessary for smaller particle size formation and also the composition and zeta potential impact encapsulation efficiency, which is benefited by the positive charge of chitosan. Insulin remained stable after encapsulation as evidenced by calorimetric assays, and was released in a sustained manner in the first 10 h. Positively-charged nanoparticles based on chitosan/dextran-sulfate at the ratio of 6:4 successfully interacted with mucin, which is a prerequisite for delivery to mucus-containing tissues. Finally, insulin-loaded nanoparticles displayed no cytotoxicity effect against lung cells at tested concentrations, suggesting the potential for further in vivo studies.

Preparation, characterisation and antioxidant activities of rutin-loaded zein-sodium caseinate nanoparticles.

Science.gov (United States)

Zhang, Shuangling; Han, Yue

2018-01-01

Novel rutin-loaded zein-sodium caseinate nanoparticles (ZP) with antioxidant activity in aqueous medium were investigated. The results showed that the sodium caseinate concentrations, dosages of rutin and ethanol volume fractions significantly affected the zein nanoparticles' characteristics. Concerning the antioxidant properties, the highest values of rutin loaded ZP obtained using 2, 2-diphenyl-1-picrylhydrazyl scavenging and 2 and 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) decolourisation assays were 52.7% and 71.2%, respectively, and the total antioxidant capacity was 0.40 nmol g-1. The results suggest that zein-sodium caseinate nanoparticles can be used as a new nano carrier system for rutin or other water insoluble active ingredients.

Visible Light Photocatalytic Properties of Modified Titanium Dioxide Nanoparticles via Aluminium Treatment

Directory of Open Access Journals (Sweden)

Dessy Ariyanti

2016-03-01

Full Text Available Titanium dioxide (TiO2 has gained much attentions for the last few decades due to its remarkable performance in photocatalysis and some other related properties. However, its wide bandgap (~3.2 eV can only absorb UV energy which is only ~5% of solar light spectrum. The objective of this research was to improve the photocatalytic activity of TiO2 by improving the optical absorption to the visible light range. Here, colored TiO2 nanoparticles range from light to dark grey were prepared via aluminium treatment at the temperatures ranging from 400 to 600 oC. The modified TiO2 is able to absorb up to 50% of visible light (400-700 nm and shows a relatively good photocatalytic activity in organic dye (Rhodamine B degradation under visible light irradiation compared with the commercial TiO2. Copyright © 2016 BCREC GROUP. All rights reserved Received: 10th November 2015; Revised: 7th January 2016; Accepted: 7th January 20 How to Cite: Ariyanti, D., Dong, J.Z., Dong, J.Y., Gao, W. (2016. Visible Light Photocatalytic Properties of Modified Titanium Dioxide Nanoparticles via Aluminium Treatment. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (1: 40-47. (doi:10.9767/bcrec.11.1.414.40-47 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.414.40-47

Improved insulin loading in poly (lactic-co-glycolic) acid (PLGA) nanoparticles upon self-assembly with lipids

DEFF Research Database (Denmark)

Garcia Diaz, Maria; Foged, Camilla; Nielsen, Hanne Mørck

2015-01-01

Polymeric nanoparticles are widely investigated as drug delivery systems for oral administration. However, the hydrophobic nature of many polymers hampers effective loading of the particles with hydrophilic macromolecules such as insulin. Thus, the aim of this work was to improve the loading...... of insulin into poly(lactic-co-glycolic) acid (PLGA) nanoparticles by pre-assembly with amphiphilic lipids. Insulin was complexed with soybean phosphatidylcholine or sodium caprate by self-assembly and subsequently loaded into PLGA nanoparticles by using the double emulsion-solvent evaporation technique...... efficiencies (90% as compared to 24% in the absence of lipids). Importantly, the insulin loading capacity was increased up to 20% by using the lipid–insulin complexes. The results further showed that a main fraction of the lipid was incorporated into the nanoparticles and remained associated to the polymer...

Study of interaction between tin dioxide nanoparticle and 1,4-dihydroxy 2,3-dimethyl 9,10-anthraquinone sensitizer

International Nuclear Information System (INIS)

Suvetha Rani, J.; Sasirekha, V.; Ramakrishnan, V.

2013-01-01

The interaction between 1,4-dihydroxy 2,3-dimethyl 9,10-anthraquinone (DHDMAQ) and tin dioxide nanoparticle (SnO 2 NPs) has been investigated using optical absorption and emission techniques. Tin dioxide nanoparticles have been synthesized by chemical precipitation method. The experimental results reveal that the fluorescence intensity of 1,4-dihydroxy 2,3-dimethyl 9,10-anthraquinone has been quenched as the concentration of the SnO 2 NPs increased. The Stern–Volmer plot indicates that SnO 2 NPs have dynamic quenching efficiency on the fluorescence nature of DHDMAQ. The obtained value of the association constant infers that there is an association between DHDMAQ and the SnO 2 nanoparticles. -- Highlights: • The interaction between DHDMAQ and SnO 2 NPs has been investigated using optical absorption and emission techniques. • The fluorescence intensity of the fluorophore has been quenched as the concentration of the SnO 2 NPs increased. • The Stern–Volmer plot indicates that SnO 2 NPs have dynamic quenching efficiency on the fluorescence nature of DHDMAQ

Preparation, characterization and immunological evaluation: canine parvovirus synthetic peptide loaded PLGA nanoparticles.

Science.gov (United States)

Derman, Serap; Mustafaeva, Zeynep Akdeste; Abamor, Emrah Sefik; Bagirova, Melahat; Allahverdiyev, Adil

2015-10-20

Canine parvovirus 2 (CPV-2) remains a significant worldwide canine pathogen and the most common cause of viral enteritis in dogs. The 1 L15 and 7 L15 peptides overlap each other with QPDGGQPAV residues (7-15 of VP2 capsid protein of CPV) is shown to produce high immune response. PLGA nanoparticles were demonstrated to have special properties such as; controlled antigen release, protection from degradation, elimination of booster-dose and enhancing the cellular uptake by antigen presenting cells. Nevertheless, there is no study available in literature, about developing vaccine based on PLGA nanoparticles with adjuvant properties against CPV. Thus, the aim of the present study was to synthesize and characterize high immunogenic W-1 L19 peptide (from the VP2 capsid protein of CPV) loaded PLGA nanoparticle and to evaluate their in vitro immunogenic activity. PLGA nanoparticles were produced with 5.26 ± 0.05 % loading capacity and high encapsulation efficiency with 81.2 ± 3.1 %. Additionally, it was evaluated that free NPs and W-1 L19 peptide encapsulated PLGA nanoparticles have Z-ave of 183.9 ± 12.1 nm, 221.7 ± 15.8 nm and polydispersity index of 0.107 ± 0.08, 0.135 ± 0.12 respectively. It was determined that peptide loaded PLGA nanoparticles were successfully phagocytized by macrophage cells and increased NO production at 2-folds (*P vaccine candidate against Canine Parvovirus. Studies targeting PLGA nanoparticles based delivery system must be maintained in near future in order to develop new and more effective nano-vaccine formulations.

Oxygen Sensing with Perfluorocarbon-Loaded Ultraporous Mesostructured Silica Nanoparticles.

Science.gov (United States)

Lee, Amani L; Gee, Clifford T; Weegman, Bradley P; Einstein, Samuel A; Juelfs, Adam R; Ring, Hattie L; Hurley, Katie R; Egger, Sam M; Swindlehurst, Garrett; Garwood, Michael; Pomerantz, William C K; Haynes, Christy L

2017-06-27

Oxygen homeostasis is important in the regulation of biological function. Disease progression can be monitored by measuring oxygen levels, thus producing information for the design of therapeutic treatments. Noninvasive measurements of tissue oxygenation require the development of tools with minimal adverse effects and facile detection of features of interest. Fluorine magnetic resonance imaging ( 19 F MRI) exploits the intrinsic properties of perfluorocarbon (PFC) liquids for anatomical imaging, cell tracking, and oxygen sensing. However, the highly hydrophobic and lipophobic properties of perfluorocarbons require the formation of emulsions for biological studies, though stabilizing these emulsions has been challenging. To enhance the stability and biological loading of perfluorocarbons, one option is to incorporate perfluorocarbon liquids into the internal space of biocompatible mesoporous silica nanoparticles. Here, we developed perfluorocarbon-loaded ultraporous mesostructured silica nanoparticles (PERFUMNs) as 19 F MRI detectable oxygen-sensing probes. Ultraporous mesostructured silica nanoparticles (UMNs) have large internal cavities (average = 1.8 cm 3 g -1 ), facilitating an average 17% loading efficiency of PFCs, meeting the threshold fluorine concentrations needed for imaging studies. Perfluoro-15-crown-5-ether PERFUMNs have the highest equivalent nuclei per PFC molecule and a spin-lattice (T 1 ) relaxation-based oxygen sensitivity of 0.0032 mmHg -1 s -1 at 16.4 T. The option of loading PFCs after synthesizing UMNs, rather than traditional in situ core-shell syntheses, allows for use of a broad range of PFC liquids from a single material. The biocompatible and tunable chemistry of UMNs combined with the intrinsic properties of PFCs makes PERFUMNs a MRI sensor with potential for anatomical imaging, cell tracking, and metabolic spectroscopy with improved stability.

In vitro digestion of curcuminoid-loaded lipid nanoparticles

International Nuclear Information System (INIS)

Noack, Andreas; Oidtmann, Johannes; Kutza, Johannes; Mäder, Karsten

2012-01-01

Curcuminoid-loaded lipid nanoparticles were produced by melt homogenization. The used lipid matrices were medium chain triglycerides, trimyristin (TM), and tristearin. The mean particle size of the preparations was between 130 and 180 nm. The incorporated curcuminoids revealed a good stability over a period of 12 months. The curcuminoid-loaded lipid nanoparticles were intended for the oral delivery of curcuminoids. Therefore, the fate of the triglyceride matrix in simulated gastric and simulated intestinal media under the influence of pepsin and pancreatin, respectively, was assessed. The degradation of the triglycerides was monitored by the pH–stat method and with high performance thin layer chromatography in connection with spectrodensitometry to quantify the different lipid fractions. The TM nanoparticles were not degraded in simulated gastric fluid (SGF), but the decomposition of the triglyceride matrix was rapid in the intestinal media. The digestion process was faster in the simulated fed state medium compared to the simulated fasted state medium. Additionally, the stability of the incorporated drug was tested in the respective physiological media. The curcuminoids showed an overall good stability in the different test media. The release of the curcuminoids from the lipid nanoparticles was determined by fluorescence imaging techniques. A slow release of the drug was found in phosphate buffer. In contrast, a more distinct release of the curcuminoids was verifiable in SGF and in simulated intestinal fluids. Overall, it was considered that the transfer of the drug into the outer media was mainly triggered by the lipid degradation and not by drug release.

Fabrication of interconnected microporous biomaterials with high hydroxyapatite nanoparticle loading

International Nuclear Information System (INIS)

Zhang Wei; Yao Donggang; Zhang Qingwei; Lelkes, Peter I; Zhou, Jack G

2010-01-01

Hydroxyapatite (HA) is known to promote osteogenicity and enhance the mechanical properties of biopolymers. However, incorporating a large amount of HA into a porous biopolymer still remains a challenge. In the present work, a new method was developed to produce interconnected microporous poly(glycolic-co-lactic acid) (PLGA) with high HA nanoparticle loading. First, a ternary blend comprising PLGA/PS (polystyrene)/HA (40/40/20 wt%) was prepared by melt blending under conditions for formation of a co-continuous phase structure. Next, a dynamic annealing stage under small-strain oscillation was applied to the blend to facilitate nanoparticle redistribution. Finally, the PS phase was sacrificially extracted, leaving a porous matrix. The results from different characterizations suggested that the applied small-strain oscillation substantially accelerated the migration of HA nanoparticles during annealing from the PS phase to the PLGA phase; nearly all HA particles were uniformly presented in the PLGA phase after a short period of annealing. After dissolution of the PS phase, a PLGA material with interconnected microporous structure was successfully produced, with a high HA loading above 30 wt%. The mechanisms beneath the experimental observations, particularly on the enhanced particle migration process, were discussed, and strategies for producing highly particle loaded biopolymers with interconnected microporous structures were proposed.

Formation of TiO/Al2O3/C Composite in Thermal Co-decomposition of Aluminium(III) Acetylacetonate and Titanium(IV) Oxyacetylacetonate.

Czech Academy of Sciences Publication Activity Database

Kovářík, T.; Pokorná, Dana; Urbanová, Markéta; Bezdička, Petr; Bastl, Zdeněk; Kupčík, Jaroslav; Křenek, T.; Pola, M.; Kullová, L.; Pola, Josef

2016-01-01

Roč. 117, JAN 2016 (2016), s. 182-190 ISSN 0165-2370 R&D Projects: GA TA ČR TA04020860 Institutional support: RVO:67985858 ; RVO:61388980 ; RVO:61388955 Keywords : thermal co-decomposition * aluminium(III) acetylacetonate * titanium(IV) oxyacetylacetonate * titanium monoxide * alumina * Carbona Subject RIV: CF - Physical ; Theoretical Chemistry; CA - Inorganic Chemistry (UACH-T) Impact factor: 3.471, year: 2016

Ocular pharmacoscintigraphic and aqueous humoral drug availability of ganciclovir-loaded mucoadhesive nanoparticles in rabbits

NARCIS (Netherlands)

Akhter, Sohail; Ramazani, Farshad; Ahmad, Mohammad Zaki; Ahmad, Farjam Jalees; Rahman, Ziyaur; Bhatnagar, Aseem; Storm, Gerrit

2013-01-01

The present report describes the improved ocular retention and aqueous humoral drug availability of ganciclovir (GCV) when administered via topical instillation of different kind of nanoparticles onto the rabbit eye. GCV was loaded into PLGA nanoparticles, chitosan-coated nanoparticles and

Acute and subchronic toxicity analysis of surface modified paclitaxel attached hydroxyapatite and titanium dioxide nanoparticles

Science.gov (United States)

Venkatasubbu, Gopinath Devanand; Ramasamy, S; Gaddam, Pramod Reddy; Kumar, J

2015-01-01

Nanoparticles are widely used for targeted drug delivery applications. Surface modification with appropriate polymer and ligands is carried out to target the drug to the affected area. Toxicity analysis is carried out to evaluate the safety of the surface modified nanoparticles. In this study, paclitaxel attached, folic acid functionalized, polyethylene glycol modified hydroxyapatite and titanium dioxide nanoparticles were used for targeted drug delivery system. The toxicological behavior of the system was studied in vivo in rats and mice. Acute and subchronic studies were carried out. Biochemical, hematological, and histopathological analysis was also done. There were no significant alterations in the biochemical parameters at a low dosage. There was a small change in alkaline phosphatase (ALP) level at a high dosage. The results indicate a safe toxicological profile. PMID:26491315

Titanium dioxide nanoparticles: some aspects of toxicity/focus on the development.

Science.gov (United States)

Rollerova, E; Tulinska, J; Liskova, A; Kuricova, M; Kovriznych, J; Mlynarcikova, A; Kiss, A; Scsukova, S

2015-04-01

Nanosized titanium dioxide (TiO2) particles belong to the most widely manufactured nanoparticles (NPs) on a global scale because of their photocatalytic properties and the related surface effects. TiO2 NPs are in the top five NPs used in consumer products. Ultrafine TiO2 is widely used in the number of applications, including white pigment in paint, ceramics, food additive, food packaging material, sunscreens, cosmetic creams, and, component of surgical implants. Data evidencing rapid distribution, slow or ineffective elimination, and potential long-time tissue accumulation are especially important for the human risk assessment of ultrafine TiO2 and represent new challenges to more responsibly investigate potential adverse effects by the action of TiO2 NPs considering their ubiquitous exposure in various doses. Transport of ultrafine TiO2 particles in systemic circulation and further transition through barriers, especially the placental and blood-brain ones, are well documented. Therefore, from the developmental point of view, there is a raising concern in the exposure to TiO2 NPs during critical windows, in the pregnancy or the lactation period, and the fact that human mothers, women and men in fertile age and last but not least children may be exposed to high cumulative doses. In this review, toxicokinetics and particularly toxicity of TiO2 NPs in relation to the developing processes, oriented mainly on the development of the central nervous system, are discussed Keywords: nanoparticles, nanotoxicity, nanomaterials, titanium dioxide, reproductive toxicity, developmental toxicity, blood brain barrier, placental barrier.

Influence Of Carboxymethyl Cellulose For The Transport Of Titanium Dioxide Nanoparticles In Clean Silica And Mineral-Coated Sands

Science.gov (United States)

The transport properties of titanium dioxide (anatase polymorph) nanoparticles encapsulated by carboxymethyl cellulose (CMC) were evaluated as a function of changes in the solute chemical properties in clean quartz, amorphous aluminum and iron hydroxide-coated sands. While prist...

Mitochondrial dysfunction and loss of glutamate uptake in primary astrocytes exposed to titanium dioxide nanoparticles

Science.gov (United States)

Wilson, Christina L.; Natarajan, Vaishaali; Hayward, Stephen L.; Khalimonchuk, Oleh; Kidambi, Srivatsan

2015-11-01

Titanium dioxide (TiO2) nanoparticles are currently the second most produced engineered nanomaterial in the world with vast usage in consumer products leading to recurrent human exposure. Animal studies indicate significant nanoparticle accumulation in the brain while cellular toxicity studies demonstrate negative effects on neuronal cell viability and function. However, the toxicological effects of nanoparticles on astrocytes, the most abundant cells in the brain, have not been extensively investigated. Therefore, we determined the sub-toxic effect of three different TiO2 nanoparticles (rutile, anatase and commercially available P25 TiO2 nanoparticles) on primary rat cortical astrocytes. We evaluated some events related to astrocyte functions and mitochondrial dysregulation: (1) glutamate uptake; (2) redox signaling mechanisms by measuring ROS production; (3) the expression patterns of dynamin-related proteins (DRPs) and mitofusins 1 and 2, whose expression is central to mitochondrial dynamics; and (4) mitochondrial morphology by MitoTracker® Red CMXRos staining. Anatase, rutile and P25 were found to have LC50 values of 88.22 +/- 10.56 ppm, 136.0 +/- 31.73 ppm and 62.37 +/- 9.06 ppm respectively indicating nanoparticle specific toxicity. All three TiO2 nanoparticles induced a significant loss in glutamate uptake indicative of a loss in vital astrocyte function. TiO2 nanoparticles also induced an increase in reactive oxygen species generation, and a decrease in mitochondrial membrane potential, suggesting mitochondrial damage. TiO2 nanoparticle exposure altered expression patterns of DRPs at low concentrations (25 ppm) and apoptotic fission at high concentrations (100 ppm). TiO2 nanoparticle exposure also resulted in changes to mitochondrial morphology confirmed by mitochondrial staining. Collectively, our data provide compelling evidence that TiO2 nanoparticle exposure has potential implications in astrocyte-mediated neurological dysfunction.Titanium dioxide (Ti

Silver nanoparticle-loaded chitosan-starch based films: Fabrication and evaluation of tensile, barrier and antimicrobial properties

International Nuclear Information System (INIS)

Yoksan, Rangrong; Chirachanchai, Suwabun

2010-01-01

The fabrication of silver nanoparticles was accomplished by γ-ray irradiation reduction of silver nitrate in a chitosan solution. The obtained nanoparticles were stable in the solution for more than six months, and showed the characteristic surface plasmon band at 411 nm as well as a positively charged surface with 40.4 ± 2.0 mV. The silver nanoparticles presented a spherical shape with an average size of 20-25 nm, as observed by TEM. Minimum inhibitory concentration (MIC) against E. coli, S. aureus and B. cereus of the silver nanoparticles dispersed in the γ-ray irradiated chitosan solution was 5.64 μg/mL. The silver nanoparticle-loaded chitosan-starch based films were prepared by a solution casting method. The incorporation of silver nanoparticles led to a slight improvement of the tensile and oxygen gas barrier properties of the polysaccharide-based films, with diminished water vapor/moisture barrier properties. In addition, silver nanoparticle-loaded films exhibited enhanced antimicrobial activity against E. coli, S. aureus and B. cereus. The results suggest that silver nanoparticle-loaded chitosan-starch based films can be feasibly used as antimicrobial materials for food packaging and/or biomedical applications.

Aerosolized antimicrobial agents based on degradable dextran nanoparticles loaded with silver carbene complexes.

Science.gov (United States)

Ornelas-Megiatto, Cátia; Shah, Parth N; Wich, Peter R; Cohen, Jessica L; Tagaev, Jasur A; Smolen, Justin A; Wright, Brian D; Panzner, Matthew J; Youngs, Wiley J; Fréchet, Jean M J; Cannon, Carolyn L

2012-11-05

Degradable acetalated dextran (Ac-DEX) nanoparticles were prepared and loaded with a hydrophobic silver carbene complex (SCC) by a single-emulsion process. The resulting particles were characterized for morphology and size distribution using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The average particle size and particle size distribution were found to be a function of the ratio of the organic phase to the surfactant containing aqueous phase with a 1:5 volume ratio of Ac-DEX CH(2)Cl(2) (organic):PBS (aqueous) being optimal for the formulation of nanoparticles with an average size of 100 ± 40 nm and a low polydispersity. The SCC loading was found to increase with an increase in the SCC quantity in the initial feed used during particle formulation up to 30% (w/w); however, the encapsulation efficiency was observed to be the best at a feed ratio of 20% (w/w). In vitro efficacy testing of the SCC loaded Ac-DEX nanoparticles demonstrated their activity against both Gram-negative and Gram-positive bacteria; the nanoparticles inhibited the growth of every bacterial species tested. As expected, a higher concentration of drug was required to inhibit bacterial growth when the drug was encapsulated within the nanoparticle formulations compared with the free drug illustrating the desired depot release. Compared with free drug, the Ac-DEX nanoparticles were much more readily suspended in an aqueous phase and subsequently aerosolized, thus providing an effective method of pulmonary drug delivery.

Estradiol-loaded PLGA nanoparticles for improving low bone mineral density of cancellous bone caused by osteoporosis: Application of enhanced charged nanoparticles with iontophoresis.

Science.gov (United States)

Takeuchi, Issei; Kobayashi, Shiori; Hida, Yukari; Makino, Kimiko

2017-07-01

Postmenopausal osteoporosis among older women, which occurs by an ovarian hormone deficiency, is one of the major public health problems. 17 β-estradiol (E2) is used to prevent and treat this disease as a drug of hormone replacement therapy. In oral administration, E2 is significantly affected by first-pass hepatic metabolism, and high dose administration must be needed to obtain drug efficacy. Therefore, alternative administration route is needed, and we have focused on the transdermal drug delivery system. In this study, we have prepared E2-loaded poly(DL-lactide-co-glycolide) (PLGA) nanoparticles for osteoporosis by using a combination of an antisolvent diffusion method with preferential solvation. The average particle diameter of the nanoparticles was 110.0±41.0nm and the surface charge number density was 82 times higher than that of conventional E2-loaded PLGA nanoparticles. Therapeutic evaluation of E2-loaded PLGA nanoparticles was carried out using ovariectomized female rats. Therapeutic efficacy was evaluated to measure bone mineral density of cancellous bone using an X-ray CT system. When the E2-loaded PLGA nanoparticles were administrated once a week, bone mineral density was significantly higher than that of the non-treated group at 60days after the start of treatment. Also, in the group administered this nanoparticle twice a week, the bone mineral density increased significantly at 45days after the start of treatment. From these results, it was revealed that E2-loaded PLGA nanoparticles with iontophoresis were useful to recover bone mineral density of cancellous bone, and it was also suggested that they extend the dosing interval of E2. Copyright © 2017 Elsevier B.V. All rights reserved.

Electrospray deposition of titanium dioxide (TiO{sub 2}) nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Halimi, Siti Umairah, E-mail: fitrah@salam.uitm.edu.my; Bakar, Noor Fitrah Abu, E-mail: fitrah@salam.uitm.edu.my; Ismail, Siti Norazian, E-mail: fitrah@salam.uitm.edu.my; Hashib, Syafiza Abd, E-mail: fitrah@salam.uitm.edu.my [Faculty of Chemical Engineering, UniversitiTeknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Naim, M. Nazli [Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor (Malaysia)

2014-02-24

Deposition of titanium dioxide (TiO{sub 2}) nanoparticles was conducted by using eletrospray method. 0.05wt% of titanium dioxide suspension was prepared and characterized by using Malvern Zetasizer prior to the experiment. From Zetasizer results, stable suspension condition was obtained which is at pH 2 with zeta potential value of ±29.0 mV. In this electrospraying, the suspension was pumped at flowrate of 5 ml/hr by using syringe pump. The input voltage of 2.1 kV was applied at the nozzle tip and counter electrode. Electrosprayed particles were collected on the grounded aluminium plate substrate which was placed at 10–20 cm from counter electrode. Particles were then characterized using FESEM and average size of electrosprayed particles obtained. Initial droplet size was calculated by scaling law and compared with FE-SEM results in order to prove droplet fission occur during electrospray. Due to the results obtained, as the working distance increase from 10–20 cm the deposited TiO{sub 2} droplet size decrease from 247–116 nm to show droplet fission occur during the experiment.

Preparation and characterization of ketoprofen loaded eudragit RS polymeric nanoparticles for controlled release

International Nuclear Information System (INIS)

Tuan Anh, Nguyen; Tuyen Dao, T P; Nhan Le, N T; Mau Chien, Dang; To Hoai, Nguyen; T Chi, Nguyen; Tran, T Khai

2012-01-01

Nanospheres containing ketoprofen (Keto) and polymer eudragit RS were prepared using an emulsion solvent evaporation method. The ultrasonic probe (VCX500, vibracell) was used as a tool to disperse oil phase into aqueous phase leading to water/oil emulsion. Nanoparticles were successfully prepared and their morphologies and diameters were confirmed by transmission electron microscope (TEM) and dynamic light scattering (DLS), respectively. The result showed that particles were spherical with submicron size. The particle size was dependent on the RS concentration, emulsification tools and the types of organic solvents. For the encapsulation ability, Keto-loaded RS nanoparticle showed 9.8% of Keto in nanoparticle, which was evaluated by high-performance liquid chromatography (HPLC). Moreover, the drug release behavior of Keto-loaded eudragit RS nanoparticle was also investigated in vitro at pH 7.4 and compared to referential profenid. (paper)

Oleyl-hyaluronan micelles loaded with upconverting nanoparticles for bio-imaging

Energy Technology Data Exchange (ETDEWEB)

Pospisilova, Martina, E-mail: martina.pospisilova@contipro.com; Mrazek, Jiri; Matuska, Vit; Kettou, Sofiane; Dusikova, Monika; Svozil, Vit; Nesporova, Kristina; Huerta-Angeles, Gloria; Vagnerova, Hana; Velebny, Vladimir [Contipro Biotech (Czech Republic)

2015-09-15

Hyaluronan (HA) represents an interesting polymer for nanoparticle coating due to its biocompatibility and enhanced cell interaction via CD44 receptor. Here, we describe incorporation of oleate-capped β–NaYF{sub 4}:Yb{sup 3+}, Er{sup 3+} nanoparticles (UCNP-OA) into amphiphilic HA by microemulsion method. Resulting structures have a spherical, micelle-like appearance with a hydrodynamic diameter of 180 nm. UCNP-OA-loaded HA micelles show a good stability in PBS buffer and cell culture media. The intensity of green emission of UCNP-OA-loaded HA micelles in water is about five times higher than that of ligand-free UCNP, indicating that amphiphilic HA effectively protects UCNP luminescence from quenching by water molecules. We found that UCNP-OA-loaded HA micelles in concentrations up to 50 μg mL{sup −1} increase cell viability of normal human dermal fibroblasts (NHDF), while viability of human breast adenocarcinoma cells MDA–MB–231 is reduced at these concentrations. The utility of UCNP-OA-loaded HA micelles as a bio-imaging probe was demonstrated in vitro by successful labelling of NHDF and MDA–MB–231 cells overexpressing the CD44 receptor.

Synthesis, characterization, release kinetics and toxicity profile of drug-loaded starch nanoparticles.

Science.gov (United States)

El-Naggar, Mehrez E; El-Rafie, M H; El-sheikh, M A; El-Feky, Gina S; Hebeish, A

2015-11-01

The current research work focuses on the medical application of the cost-effective cross-linked starch nanoparticles, for the transdermal delivery using Diclofenac sodium (DS) as a model drug. The prepared DS-cross-linked starch nanoparticles were synthesized using nanoprecipitation technique at different concentrations of sodium tripolyphosphate (STPP) in the presence of Tween 80 as a surfactant. The resultant cross-linked starch nanoparticles loaded with DS were characterized using world-class facilities such as TEM, DLS, FT-IR, XRD, and DSc. The efficiency of DS loading was also evaluated via entrapment efficiency as well as in vitro release and histopathological study on rat skin. The optimum nanoparticles formulation selected by the JMP(®) software was the formula that composed of 5% maize starch, 57.7mg DS and 0.5% STPP and 0.4% Tween 80, with particle diameter of about 21.04nm, polydispersity index of 0.2 and zeta potential of -35.3mV. It is also worth noting that this selected formula shows an average entrapment efficiency of 95.01 and sustained DS release up to 6h. The histophathological studies using the best formula on rat skin advocate the use of designed transdermal DS loaded cross-linked starch nanoparticles as it is safe and non-irritant to rat skin. The overall results indicate that, the starch nanoparticles could be considered as a good carrier for DS drug regarding the enhancement in its controlled release and successful permeation, thus, offering a promising nanoparticulate system for the transdermal delivery non-steroidal anti-inflammatory drug (NSAID). Copyright © 2015 Elsevier B.V. All rights reserved.

PLGA nanoparticles from nano-emulsion templating as imaging agents: Versatile technology to obtain nanoparticles loaded with fluorescent dyes.

Science.gov (United States)

Fornaguera, C; Feiner-Gracia, N; Calderó, G; García-Celma, M J; Solans, C

2016-11-01

The interest in polymeric nanoparticles as imaging systems for biomedical applications has increased notably in the last decades. In this work, PLGA nanoparticles, prepared from nano-emulsion templating, have been used to prepare novel fluorescent imaging agents. Two model fluorescent dyes were chosen and dissolved in the oil phase of the nano-emulsions together with PLGA. Nano-emulsions were prepared by the phase inversion composition (PIC) low-energy method. Fluorescent dye-loaded nanoparticles were obtained by solvent evaporation of nano-emulsion templates. PLGA nanoparticles loaded with the fluorescent dyes showed hydrodynamic radii lower than 40nm; markedly lower than those reported in previous studies. The small nanoparticle size was attributed to the nano-emulsification strategy used. PLGA nanoparticles showed negative surface charge and enough stability to be used for biomedical imaging purposes. Encapsulation efficiencies were higher than 99%, which was also attributed to the nano-emulsification approach as well as to the low solubility of the dyes in the aqueous component. Release kinetics of both fluorescent dyes from the nanoparticle dispersions was pH-independent and sustained. These results indicate that the dyes could remain encapsulated enough time to reach any organ and that the decrease of the pH produced during cell internalization by the endocytic route would not affect their release. Therefore, it can be assumed that these nanoparticles are appropriate as systemic imaging agents. In addition, in vitro toxicity tests showed that nanoparticles are non-cytotoxic. Consequently, it can be concluded that the preparation of PLGA nanoparticles from nano-emulsion templating represents a very versatile technology that enables obtaining biocompatible, biodegradable and safe imaging agents suitable for biomedical purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

Antitumor activity of docetaxel-loaded polymeric nanoparticles fabricated by Shirasu porous glass membrane-emulsification technique

Directory of Open Access Journals (Sweden)

Yu YN

2013-07-01

Full Text Available Yunni Yu,1,* Songwei Tan,1,2,* Shuang Zhao,1 Xiangting Zhuang,1 Qingle Song,1 Yuliang Wang,1 Qin Zhou,2,3 Zhiping Zhang1,2 1Tongji School of Pharmacy, 2National Engineering Research Center for Nanomedicine, 3College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People’s Republic of China *These authors contributed equally to this work Abstract: Docetaxel (DTX has excellent efficiency against a wide spectrum of cancers. However, the current clinical formulation has limited its usage, as it causes some severe side effects. Various polymeric nanoparticles have thus been developed as alternative formulations of DTX, but they have been mostly fabricated on a laboratory scale. Previously, we synthesized a novel copolymer, poly(lactide-D-α-tocopheryl polyethylene glycol 1000 succinate (PLA-TPGS, and found that it exhibited great potential in drug delivery with improved properties. In this study, we applied the Shirasu porous glass (SPG membrane-emulsification technique to prepare the DTX-loaded PLA-TPGS nanoparticles on a pilot scale. The effect of several formulation variables on the DTX-loaded nanoparticle properties, including particle size, zeta potential, and drug-encapsulation efficiency, were investigated based on surfactant type and concentration in the aqueous phase, organic/aqueous phase volumetric ratio, membrane-pore size, transmembrane cycles, and operation pressure. The DTX-loaded nanoparticles were obtained with sizes of 306.8 ± 5.5 nm and 334.1 ± 2.7 nm (mean value ± standard deviation, and drug-encapsulation efficiency of 81.8% ± 4.5% and 64.5% ± 2.7% for PLA-TPGS and poly(lactic-co-glycolic acid (PLGA nanoparticles, respectively. In vivo pharmacokinetic study exhibited a significant advantage of PLA-TPGS nanoparticles over PLGA nanoparticles and Taxotere. Drug-loaded PLA-TPGS nanoparticles exhibited 1.78-, 6.34- and 3.35-fold higher values for area under the curve, half-life, and mean

Paclitaxel-loaded redox-sensitive nanoparticles based on hyaluronic acid-vitamin E succinate conjugates for improved lung cancer treatment.

Science.gov (United States)

Song, Yu; Cai, Han; Yin, Tingjie; Huo, Meirong; Ma, Ping; Zhou, Jianping; Lai, Wenfang

2018-01-01

Lung cancer is the primary cause of cancer-related death worldwide. A redox-sensitive nanocarrier system was developed for tumor-targeted drug delivery and sufficient drug release of the chemotherapeutic agent paclitaxel (PTX) for improved lung cancer treatment. The redox-sensitive nanocarrier system constructed from a hyaluronic acid-disulfide-vitamin E succinate (HA-SS-VES, HSV) conjugate was synthesized and PTX was loaded in the delivery system. The physicochemical properties of the HSV nanoparticles were characterized. The redox-sensitivity, tumor-targeting and intracellular drug release capability of the HSV nanoparticles were evaluated. Furthermore, in vitro and in vivo antitumor activity of the PTX-loaded HSV nanoparticles was investigated in a CD44 over-expressed A549 tumor model. This HSV conjugate was successfully synthesized and self-assembled to form nanoparticles in aqueous condition with a low critical micelle concentration of 36.3 μg mL -1 . Free PTX was successfully entrapped into the HSV nanoparticles with a high drug loading of 33.5% (w/w) and an entrapment efficiency of 90.6%. Moreover, the redox-sensitivity of the HSV nanoparticles was confirmed by particle size change of the nanoparticles along with in vitro release profiles in different reducing environment. In addition, the HA-receptor mediated endocytosis and the potency of redox-sensitivity for intracellular drug delivery were further verified by flow cytometry and confocal laser scanning microscopic analysis. The antitumor activity results showed that compared to redox-insensitive nanoparticles and Taxol ® , PTX-loaded redox-sensitive nanoparticles exhibited much greater in vitro cytotoxicity and apoptosis-inducing ability against CD44 over-expressed A549 tumor cells. In vivo, the PTX-loaded HSV nanoparticles possessed much higher antitumor efficacy in an A549 mouse xenograft model and demonstrated improved safety profile. In summary, our PTX-loaded redox-sensitive HSV nanoparticles

Dual stimuli-sensitive dendrimers: Photothermogenic gold nanoparticle-loaded thermo-responsive elastin-mimetic dendrimers.

Science.gov (United States)

Fukushima, Daichi; Sk, Ugir Hossain; Sakamoto, Yasuhiro; Nakase, Ikuhiko; Kojima, Chie

2015-08-01

Dendrimers are synthetic macromolecules with unique structures that can work as nanoplatforms for both photothermogenic gold nanoparticles (AuNPs) and thermosensitive elastin-like peptides (ELPs) with valine-proline-glycine-valine-glycine (VPGVG) repeats. In this study, photothermogenic AuNPs were loaded into thermo-responsive elastin-mimetic dendrimers (dendrimers conjugating ELPs at their periphery) to produce dual stimuli-sensitive nanoparticles. Polyamidoamine G4 dendrimers were modified with acetylated VPGVG and (VPGVG)2, and the resulting materials were named ELP1-den and ELP2-den, respectively. The AuNPs were prepared by the reduction of Au ions using a dendrimer-nanotemplated method. The AuNP-loaded elastin-mimetic dendrimers exhibited photothermal properties. ELP1-den and ELP2-den showed similar temperature-dependent changes in their conformations. Phase transitions were observed at around 55°C and 35°C for the AuNP-loaded ELP1-den and AuNP-loaded ELP2-den, respectively, but not for the corresponding PEGylated dendrimer. In contrast to the AuNP-loaded PEGylated dendrimer, AuNP-loaded ELP2-den readily associated with cells and induced efficient photocytotoxicity at 37°C. The cell association and the photocytotoxicity properties of AuNP-loaded ELP2-den could be controlled by temperature. These results therefore suggest that dual stimuli-sensitive dendrimer nanoparticles of this type could be used for photothermal therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

Silver impregnated nanoparticles of titanium dioxide as carriers for {sup 211}At

Energy Technology Data Exchange (ETDEWEB)

Cedrowska, Edyta; Lyczko, Monika; Piotrowska, Agata; Bilewicz, Aleksander [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Stolarz, Anna; Trcinska, Agnieszka [Warsaw Univ. (Poland). Heavy Ion Lab.; Szkliniarz, Katarzyna [Silesia Univ. Katowice (Poland). Inst. of Physics; Was, Bogdan [Polish Academy of Science, Cracow (Poland). Inst. of Nuclear Physics

2016-08-01

The {sup 211}At radioisotope exhibits very attractive nuclear properties for application in radionuclide therapy. Unfortunately use of {sup 211}At is limited, because astatine as the heaviest halogen forms weak bond with carbon atoms in the biomolecules which makes {sup 211}At bioconjugates unstable in physiological conditions. In our work we propose a new solution for binding of {sup 211}At which consists of using nanoparticles of titanium dioxide modified with silver atoms as carriers for {sup 211}At. Ag{sup +} cations have been absorbed on the nanometer-sized TiO{sub 2} particles (15 and 32 nm) through ion exchange process and were reduced in Tollens' reaction. The obtained TiO{sub 2}-Ag nanoparticles were labeled with {sup 211}At. It was found that labeling yields were almost quantitative under reducing conditions, while under oxidizing conditions they dropped to about 80%. The labeled nanoparticles exhibited very high stability in physiological salt, PBS buffer, solutions of peptides (0.001 M cysteine, 0.001 M glutathione) and in human blood serum. To make TiO{sub 2}/Ag nanoparticles well dispersed in water and biocompatible their surface was modified with a silane coupling agent containing poly(ethyleneglycol) molecules. The developed functionalization approach will allow us to attach biomolecules to the TiO{sub 2}/Ag surface.

Improved photodynamic action of nanoparticles loaded with indium (III) phthalocyanine on MCF-7 breast cancer cells

International Nuclear Information System (INIS)

Souto, Carlos Augusto Zanoni; Madeira, Klésia Pirola; Rettori, Daniel; Baratti, Mariana Ozello; Rangel, Letícia Batista Azevedo; Razzo, Daniel; Silva, André Romero da

2013-01-01

Indium (III) phthalocyanine (InPc) was encapsulated into nanoparticles of PEGylated poly(d,l-lactide-co-glycolide) (PLGA-PEG) to improve the photobiological activity of the photosensitizer. The efficacy of nanoparticles loaded with InPc and their cellular uptake was investigated with MCF-7 breast tumor cells, and compared with the free InPc. The influence of photosensitizer (PS) concentration (1.8–7.5 μmol/L), incubation time (1–2 h), and laser power (10–100 mW) were studied on the photodynamic effect caused by the encapsulated and the free InPc. Nanoparticles with a size distribution ranging from 61 to 243 nm and with InPc entrapment efficiency of 72 ± 6 % were used in the experiments. Only the photodynamic effect of encapsulated InPc was dependent on PS concentration and laser power. The InPc-loaded nanoparticles were more efficient in reducing MCF-7 cell viability than the free PS. For a light dose of 7.5 J/cm 2 and laser power of 100 mW, the effectiveness of encapsulated InPc to reduce the viability was 34 ± 3 % while for free InPc was 60 ± 7 %. Confocal microscopy showed that InPc-loaded nanoparticles, as well as free InPc, were found throughout the cytosol. However, the nanoparticle aggregates and the aggregates of free PS were found in the cell periphery and outside of the cell. The nanoparticles aggregates were generated due to the particles concentration used in the experiment because of the small loading of the InPc while the low solubility of InPc caused the formation of aggregates of free PS in the culture medium. The participation of singlet oxygen in the photocytotoxic effect of InPc-loaded nanoparticles was corroborated by electron paramagnetic resonance experiments, and the encapsulation of photosensitizers reduced the photobleaching of InPc

Improved photodynamic action of nanoparticles loaded with indium (III) phthalocyanine on MCF-7 breast cancer cells

Energy Technology Data Exchange (ETDEWEB)

Souto, Carlos Augusto Zanoni [Federal Institute of Espirito Santo (Brazil); Madeira, Klesia Pirola [Federal University of Espirito Santo, Biotechnology Program/RENORBIO, Health Sciences Center (Brazil); Rettori, Daniel [Federal University of Sao Paulo, Department of Exact Sciences and Earth (Brazil); Baratti, Mariana Ozello [University of Campinas, Department of Cellular Biology (Brazil); Rangel, Leticia Batista Azevedo [Federal University of Espirito Santo, Department of Pharmaceutical Sciences (Brazil); Razzo, Daniel [University of Campinas, Department of Physical Chemistry, Institute of Chemistry (Brazil); Silva, Andre Romero da, E-mail: aromero@ifes.edu.br [Federal Institute of Espirito Santo (Brazil)

2013-09-15

Indium (III) phthalocyanine (InPc) was encapsulated into nanoparticles of PEGylated poly(d,l-lactide-co-glycolide) (PLGA-PEG) to improve the photobiological activity of the photosensitizer. The efficacy of nanoparticles loaded with InPc and their cellular uptake was investigated with MCF-7 breast tumor cells, and compared with the free InPc. The influence of photosensitizer (PS) concentration (1.8-7.5 {mu}mol/L), incubation time (1-2 h), and laser power (10-100 mW) were studied on the photodynamic effect caused by the encapsulated and the free InPc. Nanoparticles with a size distribution ranging from 61 to 243 nm and with InPc entrapment efficiency of 72 {+-} 6 % were used in the experiments. Only the photodynamic effect of encapsulated InPc was dependent on PS concentration and laser power. The InPc-loaded nanoparticles were more efficient in reducing MCF-7 cell viability than the free PS. For a light dose of 7.5 J/cm{sup 2} and laser power of 100 mW, the effectiveness of encapsulated InPc to reduce the viability was 34 {+-} 3 % while for free InPc was 60 {+-} 7 %. Confocal microscopy showed that InPc-loaded nanoparticles, as well as free InPc, were found throughout the cytosol. However, the nanoparticle aggregates and the aggregates of free PS were found in the cell periphery and outside of the cell. The nanoparticles aggregates were generated due to the particles concentration used in the experiment because of the small loading of the InPc while the low solubility of InPc caused the formation of aggregates of free PS in the culture medium. The participation of singlet oxygen in the photocytotoxic effect of InPc-loaded nanoparticles was corroborated by electron paramagnetic resonance experiments, and the encapsulation of photosensitizers reduced the photobleaching of InPc.

Doxorubicin loaded PVA coated iron oxide nanoparticles for targeted drug delivery

International Nuclear Information System (INIS)

Kayal, S.; Ramanujan, R.V.

2010-01-01

Magnetic drug targeting is a drug delivery system that can be used in locoregional cancer treatment. Coated magnetic particles, called carriers, are very useful for delivering chemotherapeutic drugs. Magnetic carriers were synthesized by coprecipitation of iron oxide followed by coating with polyvinyl alcohol (PVA). Characterization was carried out using X-ray diffraction, TEM, TGA, FTIR and VSM techniques. The magnetic core of the carriers was magnetite (Fe 3 O 4 ), with average size of 10 nm. The room temperature VSM measurements showed that magnetic particles were superparamagnetic. The amount of PVA bound to the iron oxide nanoparticles were estimated by thermogravimetric analysis (TGA) and the attachment of PVA to the iron oxide nanoparticles was confirmed by FTIR analysis. Doxorubicin (DOX) drug loading and release profiles of PVA coated iron oxide nanoparticles showed that up to 45% of adsorbed drug was released in 80 h, the drug release followed the Fickian diffusion-controlled process. The binding of DOX to the PVA was confirmed by FTIR analysis. The present findings show that DOX loaded PVA coated iron oxide nanoparticles are promising for magnetically targeted drug delivery.

Efficacy of piroxicam plus cisplatin-loaded PLGA nanoparticles in inducing apoptosis in mesothelioma cells.

Science.gov (United States)

Menale, Ciro; Piccolo, Maria Teresa; Favicchia, Ilaria; Aruta, Maria Grazia; Baldi, Alfonso; Nicolucci, Carla; Barba, Vincenzo; Mita, Damiano Gustavo; Crispi, Stefania; Diano, Nadia

2015-02-01

Combined treatment based on cisplatin-loaded Poly(D,L-lactic-co-glicolic)acid (PLGA) nanoparticles (NP-C) plus the NSAID piroxicam was used as novel treatment for mesothelioma to reduce side effects related to cisplatin toxicity. PLGA nanoparticles were prepared by double emulsion solvent evaporation method. Particle size, drug release profile and in vitro cellular uptake were characterized by TEM, DLS, LC/MS and fluorescence microscopy. MSTO-211H cell line was used to analyse NP-C biological efficacy by FACS and protein analysis. Cisplatin was encapsulated in 197 nm PLGA nanoparticles with 8.2% drug loading efficiency and 47% encapsulation efficiency. Cisplatin delivery from nanoparticles reaches 80% of total encapsulated drug in 14 days following a triphasic trend. PLGA nanoparticles in MSTO-211H cells were localized in the perinuclear space NP-C in combination with piroxicam induced apoptosis using a final cisplatin concentration 1.75 fold less than free drug. Delivered cisplatin cooperated with piroxicam in modulating cell cycle regulators as caspase-3, p53 and p21. Cisplatin loaded PLGA nanoparticles plus piroxicam showed a good efficacy in exerting cytotoxic activity and inducing the same molecular apoptotic effects of the free drugs. Sustained cisplatin release allowed to use less amount of drug, decreasing toxic side effects. This novel approach could represent a new strategy for mesothelioma treatment.

Controlled functionalization of nanoparticles & practical applications

Science.gov (United States)

Rashwan, Khaled

With the increasing use of nanoparticles in both science and industry, their chemical modification became a significant part of nanotechnology. Unfortunately, most commonly used procedures provide just randomly functionalized materials. The long-term objective of our work is site- and stoichiometrically-controlled functionalization of nanoparticles with the utilization of solid supports and other nanostructures. On the examples of silica nanoparticles and titanium dioxide nanorods, we have obtained results on the solid-phase chemistry, method development, and modeling, which advanced us toward this goal. At the same time, we explored several applications of nanoparticles that will benefit from the controlled functionalization: imaging of titanium-dioxide-based photocatalysts, bioimaging by fluorescent nanoparticles, drug delivery, assembling of bone implants, and dental compositions. Titanium dioxide-based catalysts are known for their catalytic activity and their application in solar energy utilization such as photosplitting of water. Functionalization of titanium dioxide is essential for enhancing bone-titanium dioxide nanotube adhesion, and, therefore, for its application as an interface between titanium implants and bones. Controlled functionalization of nanoparticles should enhance sensitivity and selectivity of nanoassemblies for imaging and drug delivery applications. Along those lines, we studied the relationship between morphology and surface chemistry of nanoparticles, and their affinity to organic molecules (salicylic and caffeic acid) using Langmuir adsorption isotherms, and toward material surfaces using SEM- and TEM-imaging. We focused on commercial samples of titanium dioxide, titanium dioxide nanorods with and without oleic acid ligands, and differently functionalized silica nanoparticles. My work included synthesis, functionalization, and characterization of several types of nanoparticles, exploring their application in imaging, dentistry, and bone

In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles.

Science.gov (United States)

Heravi, Farzin; Ramezani, Mohammad; Poosti, Maryam; Hosseini, Mohsen; Shajiei, Arezoo; Ahrari, Farzaneh

2013-01-01

Background and aims. Incorporation of nano-particles to orthodontic bonding systems has been considered to prevent enamel demineralization around appliances. This study investigated cytotoxicity of Transbond XT adhesive containing 1 wt% titanium dioxide (TiO2) nano-particles. Materials and methods. Ten composite disks were prepared from each of the conventional and TiO2-containg composites and aged for 1, 3, 5, 7 and 14 days in Dulbecco's Modified Eagle's Medium (DMEM). The extracts were obtained and exposed to culture media of human gingival fibroblasts (HGF) and mouse L929 fibroblasts. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results. Both adhesives were moderately toxic for HGF cells on the first day of the experiment, but the TiO2-containing adhesive produced significantly lower toxicity than the pure adhesive (P0.05). There was a significant reduction in cell toxicity with increasing pre-incubation time (Porthodontic adhesive containing TiO2 nano-particles indicated comparable or even lower toxicity than its nano-particle-free counterpart, indicating that incorporation of 1 wt% TiO2 nano-particles to the composite structure does not result in additional health hazards compared to that occurring with the pure adhesive.

Aerosolized antimicrobial agents based on degradable dextran nanoparticles loaded with silver carbene complexes

KAUST Repository

Ornelas-Megiatto, Cá tia; Shah, Parth N.; Wich, Peter R.; Cohen, Jessica L.; Tagaev, Jasur A.; Smolen, Justin A.; Wright, Brian D.; Panzner, Matthew J.; Youngs, Wiley J.; Frechet, Jean; Cannon, Carolyn L.

2012-01-01

Degradable acetalated dextran (Ac-DEX) nanoparticles were prepared and loaded with a hydrophobic silver carbene complex (SCC) by a single-emulsion process. The resulting particles were characterized for morphology and size distribution using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The average particle size and particle size distribution were found to be a function of the ratio of the organic phase to the surfactant containing aqueous phase with a 1:5 volume ratio of Ac-DEX CH2Cl2 (organic):PBS (aqueous) being optimal for the formulation of nanoparticles with an average size of 100 ± 40 nm and a low polydispersity. The SCC loading was found to increase with an increase in the SCC quantity in the initial feed used during particle formulation up to 30% (w/w); however, the encapsulation efficiency was observed to be the best at a feed ratio of 20% (w/w). In vitro efficacy testing of the SCC loaded Ac-DEX nanoparticles demonstrated their activity against both Gram-negative and Gram-positive bacteria; the nanoparticles inhibited the growth of every bacterial species tested. As expected, a higher concentration of drug was required to inhibit bacterial growth when the drug was encapsulated within the nanoparticle formulations compared with the free drug illustrating the desired depot release. Compared with free drug, the Ac-DEX nanoparticles were much more readily suspended in an aqueous phase and subsequently aerosolized, thus providing an effective method of pulmonary drug delivery. © 2012 American Chemical Society.

Aerosolized antimicrobial agents based on degradable dextran nanoparticles loaded with silver carbene complexes

KAUST Repository

Ornelas-Megiatto, Cátia

2012-11-05

Degradable acetalated dextran (Ac-DEX) nanoparticles were prepared and loaded with a hydrophobic silver carbene complex (SCC) by a single-emulsion process. The resulting particles were characterized for morphology and size distribution using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The average particle size and particle size distribution were found to be a function of the ratio of the organic phase to the surfactant containing aqueous phase with a 1:5 volume ratio of Ac-DEX CH2Cl2 (organic):PBS (aqueous) being optimal for the formulation of nanoparticles with an average size of 100 ± 40 nm and a low polydispersity. The SCC loading was found to increase with an increase in the SCC quantity in the initial feed used during particle formulation up to 30% (w/w); however, the encapsulation efficiency was observed to be the best at a feed ratio of 20% (w/w). In vitro efficacy testing of the SCC loaded Ac-DEX nanoparticles demonstrated their activity against both Gram-negative and Gram-positive bacteria; the nanoparticles inhibited the growth of every bacterial species tested. As expected, a higher concentration of drug was required to inhibit bacterial growth when the drug was encapsulated within the nanoparticle formulations compared with the free drug illustrating the desired depot release. Compared with free drug, the Ac-DEX nanoparticles were much more readily suspended in an aqueous phase and subsequently aerosolized, thus providing an effective method of pulmonary drug delivery. © 2012 American Chemical Society.

Dual drug loaded chitosan nanoparticles-sugar--coated arsenal against pancreatic cancer.

Science.gov (United States)

David, Karolyn Infanta; Jaidev, Leela Raghav; Sethuraman, Swaminathan; Krishnan, Uma Maheswari

2015-11-01

Pancreatic cancer is an aggressive form of cancer with poor survival rates. The increased mortality due to pancreatic cancer arises due to many factors such as development of multidrug resistance, presence of cancer stem cells, development of a stromal barrier and a hypoxic environment due to hypo-perfusion. The present study aims to develop a nanocarrier for a combination of drugs that can address these multiple issues. Quercetin and 5-fluorouracil were loaded in chitosan nanoparticles, individually as well as in combination. The nanoparticles were characterized for morphology, size, zeta potential, percentage encapsulation of drugs as well as their release profiles in different media. The dual drug-loaded carrier exhibited good entrapment efficiency (quercetin 95% and 5-fluorouracil 75%) with chitosan: quercetin: 5-fluorouracil in the ratio 3:1:2. The release profiles suggest that 5-fluorouracil preferentially localized in the periphery while quercetin was located towards the core of chitosan nanoparticles. Both drugs exhibited considerable association with the chitosan matrix. The dual drug-loaded carrier system exhibited significant toxicity towards pancreatic cancer cells both in the 2D as well as in the 3D cultures. We believe that the results from these studies can open up interesting options in the treatment of pancreatic cancer. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and their enhanced photoelectrochemical performance of ZnO nanoparticle-loaded CuO dandelion heterostructures under solar light

Energy Technology Data Exchange (ETDEWEB)

Dong, Guanying; Du, Bin; Liu, Lei; Zhang, Weiwei; Liang, Yujie; Shi, Honglong; Wang, Wenzhong, E-mail: wzhwangmuc@163.com

2017-03-31

Highlights: • ZnO/CuO nanoparticle/dandelion heterostructures were fabricated for the first time. • ZnO/CuO nanoparticle/dandelion heterostructures show enhanced PEC activity. • ZnO nanoparticle loading contents have significant effect on PEC water splitting. • Interaction, charge transfer and enhanced mechanism of photocatalyst were proposed. • p-n junction drives the photoexcited charges efficient separation. - Abstract: Here we report an easy and large-scale synthesis of three-dimensional (3D) ZnO nanoparticle-loaded CuO dandelion (denoted as n-ZnO/p-CuO nanoparticle/dandelion) heterostructures and their photoelectrochemical (PEC) water splitting under simulated solar light illumination. CuO dandelions were fabricated by a facile and cost-effective chemical strategy, in which the ribbon-like CuO nanoplates were first formed and then assembled into dandelion-like architectures. ZnO nanoparticle-loaded CuO dandelion heterostructures were fabricated by calcining Zn(Ac){sub 2}-loaded CuO dandelions. High resolution transmission electron microscope (HRTEM) studies demonstrate that intimate p-n junction is built between p-CuO and n-ZnO interface. The n-ZnO/p-CuO nanoparticle/dandelion photoelectrodes exhibit significant improvement in PEC water splitting to CuO dandelion photoelectrodes. The correlation between photocurrents and different loading contents of ZnO nanoparticles (NPs) is studied in which the n-ZnO/p-CuO nanoparticle/dandelion heterostructures with loading 4.6 wt% ZnO NPs show higher photocathodic current. The efficient separation of the photogenerated electrons and holes driven by the intimate p-n junction between p-type CuO and n-type ZnO interface is mainly contributed to the enhanced photoanode current. The achieved results in the present study offer a very useful strategy for designing p-n junction photoelectrodes for efficiency and low-cost PEC cells for clean solar hydrogen production.

Formulation, characterization and pharmacokinetics of praziquantel-loaded hydrogenated castor oil solid lipid nanoparticles.

Science.gov (United States)

Xie, Shuyu; Pan, Baoliang; Wang, Ming; Zhu, Luyan; Wang, Fenghua; Dong, Zhao; Wang, Xiaofang; Zhou, WenZhong

2010-07-01

The purpose of this study was to formulate praziquantel (PZQ)-loaded hydrogenated castor oil (HCO) solid lipid nanoparticles (SLN) to enhance the bioavailability and prolong the systemic circulation of the drug. PZQ was encapsulated into HCO nanoparticles by a hot homogenization and ultrasonication method. The physicochemical characteristics of SLN were investigated by optical microscope, scanning electron microscopy and photon correlation spectroscopy. Pharmacokinetics were studied after oral, subcutaneous and intramuscular administration in mice. The diameter, polydispersivity index, zeta potential, encapsulation efficiency and loading capacity of the nanoparticles were 344.0 +/- 15.1 nm, 0.31 +/- 0.08, -16.7 +/- 0.5 mV, 62.17 +/- 6.53% and 12.43 +/- 1.31%, respectively. In vitro release of PZQ-loaded HCO-SLN exhibited an initial burst release followed by a sustained release. SLN increased the bioavailability of PZQ by 14.9-, 16.1- and 2.6-fold, and extended the mean residence time of the drug from 7.6, 6.6 and 8.2 to 95.9, 151.6 and 48.2 h after oral, subcutaneous and intramuscular administration, respectively. The PZQ-loaded HCO-SLN could be a promising formulation to enhance the pharmacological activity of PZQ.

Turkevich method for silver/titanium dioxide nanoparticles with antimicrobial application in polymers systems;Obtencao de nanoparticulas de prata/dioxido de titanio pelo metodo Turkevich para aplicacoes antimicrobiais em matrizes polimericas

Energy Technology Data Exchange (ETDEWEB)

Olyveira, Gabriel Molina de; Pessan, Luiz Antonio, E-mail: gmolyveira@yahoo.com.b, E-mail: acarvalho@ufscar.b [Universidade Federal de Sao Carlos (PPG-CEM/UFSCar), SP (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Carvalho, Antonio Jose Felix de [Universidade Federal de Sao Carlos (UFSCar), Sorocaba, SP (Brazil)

2009-07-01

Titanium dioxide nanoparticles were covered with silver nanoparticles using Turkevich Method or citrate reduction method. Silver and titanium dioxide has proved antimicrobial properties then the nanocomposite can be successful incorporated in polymer systems. Silver nitrate was reduced by sodium citrate in the presence of poly(vinyl pyrrolidone)(PVP) resulting in nano-Ag/TiO{sub 2} stabilized suspension. It was tested ammonia hydroxide in the synthesis to avoid the nanoparticles growth. The Ag/TiO{sub 2} nanoparticles were characterized with X-ray diffraction (XRD), Scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS). The best system of coloidal nanoparticles was that one with Poly(vinyl pyrrolidone) and ammonia in the synthesis. (author)

Fabrication and characterization of novel antimicrobial films derived from thymol-loaded zein-sodium caseinate (SC) nanoparticles.

Science.gov (United States)

Li, Kang-Kang; Yin, Shou-Wei; Yang, Xiao-Quan; Tang, Chuan-He; Wei, Zi-Hao

2012-11-21

The objective of this research was to fabricate novel antimicrobial films based on zein colloidal nanoparticles coated with sodium caseinate (SC), an emulsifier/stabilizer. Thymol-loaded zein-SC nanoparticles were prepared using an antisolvent technique, with the average particle size and zeta potential about 200 ± 20 nm and -40 mV, respectively. Zein-SC nanoparticle-based films exhibited higher mechanical resistance and water barrier capacity than the SC films and concomitant good extensibility as compared with zein films. Thymol loadings endowed zein-SC nanoparticle-based films with antimicrobial activity against Escherichia coli and Salmonella as well as DPPH radical scavenging activity. Water vapor permeability, microstructure, mechanical, and controlled release properties of the films were evaluated. The possible relationship between some selected physical properties and microstructure were also discussed. Atomic force microscopy (AFM) analysis indicated that thymol loadings resulted in the emergence phenomena of the nanoparticles to form large particles or packed structure, consisting of clusters of nanoparticles, within the film matrix, in a thymol loading dependent manner. The appearance of large particles or an agglomerate of particles may weaken the compactness of protein network of films and thus impair the water barrier capacity, mechanical resistance, and extensibility of the films. The release kinetics of thymol from nanoparticle-based films can be described as a two-step biphasic process, that is, an initial burst effect followed by subsequent slower release, and zein-SC nanoparticles within the films matrices gave them the ability to sustain the release of thymol. In addition, a schematic illustration of the formation pathway of zein-SC nanoparticle-based films with or without thymol was proposed to illuminate the possible relationship between some selected physical properties and the microstructure of the films.

Biosynthesis of titanium dioxide nanoparticles using a probiotic from coal fly ash effluent

International Nuclear Information System (INIS)

Babitha, S; Korrapati, Purna Sai

2013-01-01

Graphical abstract: - Highlights: • Metal resistant probiotic species was isolated from coal fly ash effluent site. • Uniform sized anatase form of TiO 2 nanoparticles were synthesized using Propionibacterium jensenii. • Diffraction patterns confirmed the anatase – TiO 2 NPs with average size 2 nanoparticle incorporated wound dressing exhibits better wound healing. - Abstract: The synthesis of titanium dioxide nanoparticle (TiO 2 NP) has gained importance in the recent years owing to its wide range of potential biological applications. The present study demonstrates the synthesis of TiO 2 NPs by a metal resistant bacterium isolated from the coal fly ash effluent. This bacterial strain was identified on the basis of morphology and 16s rDNA gene sequence [KC545833]. The physico-chemical characterization of the synthesized nanoparticles is completely elucidated by energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR) and transmission and scanning electron microscopy (TEM, SEM). The crystalline nature of the nanoparticles was confirmed by X-RD pattern. Further, cell viability and haemolytic assays confirmed the biocompatible and non toxic nature of the NPs. The TiO 2 NPs was found to enhance the collagen stabilization and thereby enabling the preparation of collagen based biological wound dressing. The paper essentially provides scope for an easy bioprocess for the synthesis of TiO 2 NPs from the metal oxide enriched effluent sample for future biological applications

Biosynthesis of titanium dioxide nanoparticles using a probiotic from coal fly ash effluent

Energy Technology Data Exchange (ETDEWEB)

Babitha, S; Korrapati, Purna Sai, E-mail: purnasaik.clri@gmail.com

2013-11-15

Graphical abstract: - Highlights: • Metal resistant probiotic species was isolated from coal fly ash effluent site. • Uniform sized anatase form of TiO{sub 2} nanoparticles were synthesized using Propionibacterium jensenii. • Diffraction patterns confirmed the anatase – TiO{sub 2} NPs with average size <80 nm. • TiO{sub 2} nanoparticle incorporated wound dressing exhibits better wound healing. - Abstract: The synthesis of titanium dioxide nanoparticle (TiO{sub 2} NP) has gained importance in the recent years owing to its wide range of potential biological applications. The present study demonstrates the synthesis of TiO{sub 2} NPs by a metal resistant bacterium isolated from the coal fly ash effluent. This bacterial strain was identified on the basis of morphology and 16s rDNA gene sequence [KC545833]. The physico-chemical characterization of the synthesized nanoparticles is completely elucidated by energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR) and transmission and scanning electron microscopy (TEM, SEM). The crystalline nature of the nanoparticles was confirmed by X-RD pattern. Further, cell viability and haemolytic assays confirmed the biocompatible and non toxic nature of the NPs. The TiO{sub 2} NPs was found to enhance the collagen stabilization and thereby enabling the preparation of collagen based biological wound dressing. The paper essentially provides scope for an easy bioprocess for the synthesis of TiO{sub 2} NPs from the metal oxide enriched effluent sample for future biological applications.

Improved drug loading and antibacterial activity of minocycline-loaded PLGA nanoparticles prepared by solid/oil/water ion pairing method

Science.gov (United States)

Kashi, Tahereh Sadat Jafarzadeh; Eskandarion, Solmaz; Esfandyari-Manesh, Mehdi; Marashi, Seyyed Mahmoud Amin; Samadi, Nasrin; Fatemi, Seyyed Mostafa; Atyabi, Fatemeh; Eshraghi, Saeed; Dinarvand, Rassoul

2012-01-01

Background Low drug entrapment efficiency of hydrophilic drugs into poly(lactic-co-glycolic acid) (PLGA) nanoparticles is a major drawback. The objective of this work was to investigate different methods of producing PLGA nanoparticles containing minocycline, a drug suitable for periodontal infections. Methods Different methods, such as single and double solvent evaporation emulsion, ion pairing, and nanoprecipitation were used to prepare both PLGA and PEGylated PLGA nanoparticles. The resulting nanoparticles were analyzed for their morphology, particle size and size distribution, drug loading and entrapment efficiency, thermal properties, and antibacterial activity. Results The nanoparticles prepared in this study were spherical, with an average particle size of 85–424 nm. The entrapment efficiency of the nanoparticles prepared using different methods was as follows: solid/oil/water ion pairing (29.9%) > oil/oil (5.5%) > water/oil/water (4.7%) > modified oil/water (4.1%) > nano precipitation (0.8%). Addition of dextran sulfate as an ion pairing agent, acting as an ionic spacer between PEGylated PLGA and minocycline, decreased the water solubility of minocycline, hence increasing the drug entrapment efficiency. Entrapment efficiency was also increased when low molecular weight PLGA and high molecular weight dextran sulfate was used. Drug release studies performed in phosphate buffer at pH 7.4 indicated slow release of minocycline from 3 days to several weeks. On antibacterial analysis, the minimum inhibitory concentration and minimum bactericidal concentration of nanoparticles was at least two times lower than that of the free drug. Conclusion Novel minocycline-PEGylated PLGA nanoparticles prepared by the ion pairing method had the best drug loading and entrapment efficiency compared with other prepared nanoparticles. They also showed higher in vitro antibacterial activity than the free drug. PMID:22275837

Potential impact of inorganic nanoparticles on macronutrient digestion: titanium dioxide nanoparticles slightly reduce lipid digestion under simulated gastrointestinal conditions.

Science.gov (United States)

Li, Qian; Li, Ti; Liu, Chengmei; DeLoid, Glen; Pyrgiotakis, Georgios; Demokritou, Philip; Zhang, Ruojie; Xiao, Hang; McClements, David Julian

Titanium dioxide (TiO 2 ) particles are used in some food products to alter their optical properties, such as whiteness or brightness. These additives typically contain a population of TiO 2 nanoparticles (d digestion through two physicochemical mechanisms: (i) a fraction of the lipase adsorbs to TiO 2 particle surfaces, thereby reducing the amount available to hydrolyze lipid droplets; (ii) some TiO 2 particles adsorb to the surfaces of lipid droplets, thereby reducing the lipid surface area exposed to lipase. The importance of these mechanisms was tested by passing protein-coated lipid droplets (2%, w/w) through the simulated GIT in the absence and presence of TiO 2 (0.5%, w/w) nanoparticles (18 nm) and fine particles (167 nm). Changes in particle characteristics (size, organization, and charge) and lipid digestion were then measured. Both TiO 2 nanoparticles and fine particles had little impact on the aggregation state and charge of the lipid droplets in the different GIT regions, as well as on the rate and extent of lipid digestion. This suggests that the theoretically predicted impact of particle size on lipid digestion was not seen in practice.

The role of chitosan on oral delivery of peptide-loaded nanoparticle formulation.

Science.gov (United States)

Wong, Chun Y; Al-Salami, Hani; Dass, Crispin R

2017-12-01

Therapeutic peptides are conventionally administered via subcutaneous injection. Chitosan-based nanoparticles are gaining increased attention for their ability to serve as a carrier for oral delivery of peptides and vaccination. They offered superior biocompatibiltiy, controlled drug release profile and facilitated gastrointestinal (GI) absorption. The encapsulated peptides can withstand enzymatic degradation and various pH. Chitosan-based nanoparticles can also be modified by ligand conjugation to the surface of nanoparticle for transcellular absorption and specific-targeted delivery of macromolecules to the tissue of interest. Current research suggests that chitosan-based nanoparticles can deliver therapeutic peptide for the treatment of several medical conditions such as diabetes, bacterial infection and cancer. This review summarises the role of chitosan in oral nanoparticle delivery and identifies the clinical application of peptide-loaded chitosan-based nanoparticles.

Cutaneous biocompatible rutin-loaded gelatin-based nanoparticles increase the SPF of the association of UVA and UVB filters.

Science.gov (United States)

Oliveira, Camila Areias de; Peres, Daniela D'Almeida; Graziola, Fabiana; Chacra, Nádia Araci Bou; Araújo, Gabriel Lima Barros de; Flórido, Ana Catarina; Mota, Joana; Rosado, Catarina; Velasco, Maria Valéria Robles; Rodrigues, Luís Monteiro; Fernandes, Ana Sofia; Baby, André Rolim

2016-01-01

The encapsulation of natural ingredients, such as rutin, can offer improvements in sun protection effectiveness. This strategy can provide enhanced flavonoid content and produces an improved bioactive compound with new physical and functional characteristics. As an alternative to common synthetic-based sunscreens, rutin-entrapped gelatin nanoparticles (GNPs) were designed and associated with ethylhexyl dimethyl PABA (EHDP), ethylhexyl methoxycinnamate (EHMC) and methoxydibenzoylmethane (BMDBM) in sunscreen formulations. The purpose of this study was to develop rutin-loaded gelatin nanoparticles and characterize their physicochemical, thermal, functional and safety properties. Rutin-loaded gelatin nanoparticles increased antioxidant activity by 74% relative to free-rutin (FR) solution. Also, this new ingredient upgraded the Sun Protection Factor (SPF) by 48%, indicating its potential as a raw material for bioactive sunscreens. The safety profile indicated that GNPs and glutaraldehyde (GTA) decreased HaCaT cell viability in a concentration/time-dependent manner. However, both blank nanoparticles (B-NC) and rutin-loaded nanoparticles (R-NC) had good performance on skin compatibility tests. These results functionally characterized rutin-loaded nanoparticles as a safe SPF enhancer in sunscreens, especially in association with UV filters. Copyright © 2015 Elsevier B.V. All rights reserved.

A novel label-free voltammetric immunosensor for the detection of {alpha}-fetoprotein using functional titanium dioxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Liang Wenbin [Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Yuan Ruo [Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)], E-mail: yuanruo@swu.edu.cn; Chai Yaqin; Li Yan; Zhuo Ying [Chongqing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

2008-01-01

A highly sensitive label-free voltammetric immunosensor was developed based on the functional titanium dioxide nanoparticles (PV-NTiP), which was prepared by capping 1,1'-bis-(2-phosphonoethyl)-4,4'-bipyridinium dibromide (PV) on the surface of the titanium dioxide nanoparticles (NTiP) with covalent attachment. The PV-NTiP has prominent biocompatibility, good electron transfer ability, primarily excellent adsorption, large specific surface area and positively charged environment. As a result, the negatively charged gold nanoparticles (NGP) could be adsorbed on the PV-NTiP modified electrode surface by electrostatic adsorption, and then to immobilize {alpha}-1-fetoprotein antibody (anti-AFP) for the assay of {alpha}-1-fetoprotein (AFP). The fabricated procedures and electrochemical behaviors of the immunosensor were characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and cyclic voltammetry (CV). The anti-AFP/NGP/PV-NTiP modified electrode was sensitive to AFP in linear relation between 1.25 and 200 ng/mL with the correlation coefficient of 0.9982, and the detection limit (S/N = 3) is 0.6 ng/mL under the optimal conditions. In addition, the proposed immunosensor exhibits good sensitivity, selectivity, stability and long-term maintenance of bioactivity and it may be used to immobilize other biomoleculars to develop biosensor for the detection of other antigens or biocompounds.

A Novel Docetaxel-Loaded Poly (ɛ-Caprolactone)/Pluronic F68 Nanoparticle Overcoming Multidrug Resistance for Breast Cancer Treatment

Science.gov (United States)

Mei, Lin; Zhang, Yangqing; Zheng, Yi; Tian, Ge; Song, Cunxian; Yang, Dongye; Chen, Hongli; Sun, Hongfan; Tian, Yan; Liu, Kexin; Li, Zhen; Huang, Laiqiang

2009-12-01

Multidrug resistance (MDR) in tumor cells is a significant obstacle to the success of chemotherapy in many cancers. The purpose of this research is to test the possibility of docetaxel-loaded poly (ɛ-caprolactone)/Pluronic F68 (PCL/Pluronic F68) nanoparticles to overcome MDR in docetaxel-resistance human breast cancer cell line. Docetaxel-loaded nanoparticles were prepared by modified solvent displacement method using commercial PCL and self-synthesized PCL/Pluronic F68, respectively. PCL/Pluronic F68 nanoparticles were found to be of spherical shape with a rough and porous surface. The nanoparticles had an average size of around 200 nm with a narrow size distribution. The in vitro drug release profile of both nanoparticle formulations showed a biphasic release pattern. There was an increased level of uptake of PCL/Pluronic F68 nanoparticles in docetaxel-resistance human breast cancer cell line, MCF-7 TAX30, when compared with PCL nanoparticles. The cytotoxicity of PCL nanoparticles was higher than commercial Taxotere® in the MCF-7 TAX30 cell culture, but the differences were not significant ( p > 0.05). However, the PCL/Pluronic F68 nanoparticles achieved significantly higher level of cytotoxicity than both of PCL nanoparticles and Taxotere® ( p < 0.05), indicating docetaxel-loaded PCL/Pluronic F68 nanoparticles could overcome multidrug resistance in human breast cancer cells and therefore have considerable potential for treatment of breast cancer.

Еvaluation of biocompatibility and antioxidant efficiency of chitosan-alginate nanoparticles loaded with quercetin.

Science.gov (United States)

Aluani, Denitsa; Tzankova, Virginia; Kondeva-Burdina, Magdalena; Yordanov, Yordan; Nikolova, Elena; Odzhakov, Feodor; Apostolov, Alexandar; Markova, Tzvetanka; Yoncheva, Krassimira

2017-10-01

The present study deals with development and evaluation of the safety profile of chitosan/alginate nanoparticles as a platform for delivery of a natural antioxidant quercetin. The nanoparticles were prepared by varying the ratios between both biopolymers giving different size and charge of the formulations. The biocompatibility was explored in vitro in cells from different origin: cultivated HepG2 cells, isolated primary rat hepatocytes, isolated murine spleen lymphocytes and macrophages. In vivo toxicological evaluation was performed after repeated 14-day oral administration to rats. The study revealed that chitosan/alginate nanoparticles did not change body weight, the relative weight of rat livers, liver histology, hematology and biochemical parameters. The protective effects of quercetin-loaded nanoparticles were investigated in the models of iron/ascorbic acid (Fe 2+ /AA) induced lipid peroxidation in microsomes and tert-butyl hydroperoxide oxidative stress in isolated rat hepatocytes. Interesting finding was that the empty chitosan/alginate nanoparticles possessed protective activity themselves. The antioxidant effects of quercetin loaded into the nanoparticles formulated with higher concentration of chitosan were superior compared to quercetin encapsulated in nanoparticles with higher amount of sodium alginate. In conclusion, chitosan/alginate nanoparticles can be considered appropriate carrier for quercetin, combining safety profile and improved protective activity of the encapsulated antioxidant. Copyright © 2017 Elsevier B.V. All rights reserved.

Bovine serum albumin nanoparticles loaded with Photosens photosensitizer for effective photodynamic therapy

Science.gov (United States)

Khanadeev, Vitaly; Khlebtsov, Boris; Packirisamy, Gopinath; Khlebtsov, Nikolai

2017-03-01

Polymeric nanoparticles (NPs) are widely used for drug delivery applications due to high biodegradability, low toxicity and high loading capacity. The focus of this study is the development of photosensitizer Photosens (PS) loaded albumin NPs for efficient photodynamic therapy (PDT). To fabricate PS-loaded bovine serum albumin nanoparticles (BSA-PS NPs), we used a coacervation method with glutaraldehyde followed by passive loading of PS. Successful loading of PS was confirmed by appearance of characteristic peak in absorption spectrum which allows to determine the PS loading in BSA NPs. The synthesized BSA-PS NPs demonstrated low toxicity to HeLa cells at therapeutic concentrations of loaded PS. Compared to free PS solution, the synthesized BSA-PS NPs generated the singlet oxygen more effectively under laser irradiation at 660 nm. In addition, due to presence of various chemical groups on the surface of BSA-PS NPs, they are capable to adsorb on cell surface and accumulate in cells due to cellular uptake mechanisms. Owing to combination of PD and cell uptake advantages, BSA-PS NPs demonstrated higher efficacy of photodynamic damage to cancer cells as compared to free PS at equivalent concentrations. These results suggest that non-targeted BSA-PS NPs with high PD activity and low-fabrication costs of are promising candidates for transfer to PD clinic treatments.

Development of Drug Loaded Nanoparticles Binding to Hydroxyapatite Based on a Bisphosphonate Modified Nonionic Surfactant

Directory of Open Access Journals (Sweden)

Jiabin Zhang

2015-01-01

Full Text Available This study aimed at development of drug loaded nanoparticles which could bind to hydroxyapatite (HA to construct drug or growth factor releasing bone graft substitutes. To this end, the terminal hydroxyl group of a nonionic surfactant Brij 78 (polyoxyethylene (20 stearyl ether was first modified with pamidronate (Pa. Using Pa-Brij 78 as both a surfactant and an affinity ligand to HA, three different Pa surface functionalized nanoparticles were prepared, named as solid lipid nanoparticles (Pa-SNPs, nanoemulsions (Pa-NEMs, and PLGA nanoparticles (Pa-PNPs. A model drug curcumin was successfully encapsulated in the three nanoparticles. The sizes of Pa-NEM and Pa-PNP were around 150 nm and the size of Pa-SNP was around 90 nm with polydispersity indexes (PDIs less than 0.20. Drug encapsulation efficiencies of the three nanoparticles were all greater than 85%. Furthermore, the order of binding affinity of the nanoparticles to HA was Pa-PNP>Pa-NEM=Pa-SNP. After lyophilization, the sizes of the three nanoparticles were increased about 0.5–2.0-fold but their binding affinities to HA were almost the same as the fresh prepared nanoparticles. In conclusion, a Pa-modified Brij 78 was synthesized and used for fabrication of a series of drug loaded nanoparticles to construct drug-eluting HA-based bone graft substitutes.

Effects of Material Properties on Sedimentation and Aggregation of Titanium Dioxide Nanoparticles of Anatase and Rutile in the Aqueous Phase

Science.gov (United States)

This study investigated the sedimentation and aggregation kinetics of titanium dioxide (TiO2) nanoparticles with varying material properties (i.e., crystallinity, morphology, and chemical compositions). Used in the study were various types of commercially available TiO2 nanoparti...

Nanoparticulate cerium dioxide and cerium dioxide-titanium dioxide composite thin films on glass by aerosol assisted chemical vapour deposition

International Nuclear Information System (INIS)

Qureshi, Uzma; Dunnill, Charles W.; Parkin, Ivan P.

2009-01-01

Two series of composite thin films were deposited on glass by aerosol assisted chemical vapour deposition (AACVD)-nanoparticulate cerium dioxide and nanoparticulate cerium dioxide embedded in a titanium dioxide matrix. The films were analysed by a range of techniques including UV-visible absorption spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive analysis by X-rays. The AACVD prepared films showed the functional properties of photocatalysis and super-hydrophilicity. The CeO 2 nanoparticle thin films displaying photocatalysis and photo-induced hydrophilicity almost comparable to that of anatase titania.

Room temperature NO2 gas sensing of Au-loaded tungsten oxide nanowires/porous silicon hybrid structure

International Nuclear Information System (INIS)

Wang Deng-Feng; Liang Ji-Ran; Li Chang-Qing; Yan Wen-Jun; Hu Ming

2016-01-01

In this work, we report an enhanced nitrogen dioxide (NO 2 ) gas sensor based on tungsten oxide (WO 3 ) nanowires/porous silicon (PS) decorated with gold (Au) nanoparticles. Au-loaded WO 3 nanowires with diameters of 10 nm–25 nm and lengths of 300 nm–500 nm are fabricated by the sputtering method on a porous silicon substrate. The high-resolution transmission electron microscopy (HRTEM) micrographs show that Au nanoparticles are uniformly distributed on the surfaces of WO 3 nanowires. The effect of the Au nanoparticles on the NO 2 -sensing performance of WO 3 nanowires/porous silicon is investigated over a low concentration range of 0.2 ppm–5 ppm of NO 2 at room temperature (25 °C). It is found that the 10-Å Au-loaded WO 3 nanowires/porous silicon-based sensor possesses the highest gas response characteristic. The underlying mechanism of the enhanced sensing properties of the Au-loaded WO 3 nanowires/porous silicon is also discussed. (paper)

Multimodal doxorubicin loaded magnetic nanoparticles for VEGF targeted theranostics of breast cancer.

Science.gov (United States)

Semkina, Alevtina S; Abakumov, Maxim A; Skorikov, Alexander S; Abakumova, Tatiana O; Melnikov, Pavel A; Grinenko, Nadejda F; Cherepanov, Sergey A; Vishnevskiy, Daniil A; Naumenko, Victor A; Ionova, Klavdiya P; Majouga, Alexander G; Chekhonin, Vladimir P

2018-05-03

In presented paper we have developed new system for cancer theranostics based on vascular endothelial growth factor (VEGF) targeted magnetic nanoparticles. Conjugation of anti-VEGF antibodies with bovine serum albumin coated PEGylated magnetic nanoparticles allows for improved binding with murine breast adenocarcinoma 4T1 cell line and facilitates doxorubicin delivery to tumor cells. It was shown that intravenous injection of doxorubicin loaded VEGF targeted nanoparticles increases median survival rate of mice bearing 4T1 tumors up to 50%. On the other hand magnetic resonance imaging (MRI) of 4T1 tumors 24 h after intravenous injection showed accumulation of nanoparticles in tumors, thus allowing simultaneous cancer therapy and diagnostics. Copyright © 2018. Published by Elsevier Inc.

Controlled-release levodopa methyl ester/benserazide-loaded nanoparticles ameliorate levodopa-induced dyskinesia in rats

Directory of Open Access Journals (Sweden)

Yang X

2012-04-01

Full Text Available Xinxin Yang1*, Ruiyuan Zheng2*, Yunpeng Cai2, Meiling Liao2, Weien Yuan1,2, Zhenguo Liu11Department of Neurology, Xinhua Hospital (affiliated to Shanghai Jiaotong University School of Medicine, 2School of Pharmacy, Shanghai Jiaotong University, Shanghai, People's Republic of China*Xinxin Yang and Ruiyuan Zheng contributed equally to this workBackground: Levodopa remains the most effective drug in the treatment of Parkinson's disease. However, long-term administration of levodopa induces motor complications, such as levodopa-induced dyskinesia. The mechanisms underlying levodopa-induced dyskinesia are not fully understood.Methods: In this study, we prepared levodopa methyl ester (LDME/benserazide-loaded nanoparticles, which can release LDME and benserazide in a sustained manner. Dyskinesia was induced in rats by repeated administration of levodopa then treated with LDME plus benserazide or the same dose of LDME/benserazide-loaded nanoparticles. Apomorphine-induced rotations and abnormal involuntary movements (AIMs were measured on treatment days 1, 5, 10, 15, and 20. In addition, the levels of phosphorylated dopamine- and cyclic adenosine monophosphate-regulated phosphoprotein of 32 kDa, extracellular signal-regulated kinases 1/2, and ΔfosB were determined by Western blot. Tau levels were determined by Western blot and immunohistochemistry. Dynorphin levels in the striatum and cortex of rats were measured using enzyme-linked immunosorbent assay.Results: Over the course of levodopa treatment, the rats developed abnormal AIMs, classified as locomotive, axial, orolingual, and forelimb dyskinesia. The degree of reduction of apomorphine-induced rotations was comparable in dyskinetic rats treated with LDME plus benserazide or LDME/benserazide-loaded nanoparticles. The axial, limb, and orolingual (ALO AIMs of dyskinetic rats treated with LDME/benserazide-loaded nanoparticles were 14 ± 2.5, 9 ± 2.0, and 10 ± 2.1 on treatment days 10, 15, and 20

The influence of adding modified zirconium oxide-titanium dioxide nano-particles on mechanical properties of orthodontic adhesive: an in vitro study

OpenAIRE

Felemban, Nayef H.; Ebrahim, Mohamed I.

2017-01-01

Background The purpose of this in-vitro study was to examine the effect of incorporating different concentrations of Zirconium oxide-Titanium dioxide (ZrO2-TiO2) nanoparticles, which can have antibacterial properties, on the mechanical properties of an orthodontic adhesive. Methods ZrO2-TiO2 (Zirconium oxide, HWNANO, Hongwu International Group Ltd, China) -Titanium dioxide, Nanoshell, USA) nanopowder were incorporated into orthodontic adhesive (Transbond XT, 3?M Unitek, Monrovia, USA) with di...

One-step Synthesis of Pt Nanoparticles Highly Loaded on Graphene Aerogel as Durable Oxygen Reduction Electrocatalyst

International Nuclear Information System (INIS)

Huang, Qinghong; Tao, Feifei; Zou, Liangliang; Yuan, Ting; Zou, Zhiqing; Zhang, Haifeng; Zhang, Xiaogang; Yang, Hui

2015-01-01

Synthesis of highly active and durable Pt based catalysts with a high metal loading for fuel cells’ applications still remains a big challenge. The three-dimensional (3D) graphene aerogel (GA) not only possess the intrinsic property of graphene, but also have abundant pore architecture for anchoring metal nanoparticles, thus would be suitable as metal catalysts’ support. This work reports a simple and mild one-step co-reduction synthesis of Pt nanoparticles highly loaded on 3D GA and the use as durable oxygen reduction catalyst. Both X-ray diffraction and TEM measurements confirm that Pt nanoparticles (ca. 60 wt.% Pt loading) with an average diameter of ca. 3.2 nm are uniformly decorated on the homogeneously interconnected pores of 3D GA even after a heat treatment at 300 °C. Such a Pt/GA catalyst exhibits significantly enhanced electrocatalytic activity and improved durability for the oxygen reduction reaction. The enhancement in both catalytic activity and durability may result from the unique 3-D architecture structure of GA, the uniform dispersion of Pt nanoparticles, and the interaction between the Pt nanoparticles and GA. The GA-supported Pt can serve as a highly active catalyst for fuel cell applications

In vitro evaluation of paclitaxel loaded amorphous chitin nanoparticles for colon cancer drug delivery.

Science.gov (United States)

Smitha, K T; Anitha, A; Furuike, T; Tamura, H; Nair, Shantikumar V; Jayakumar, R

2013-04-01

Chitin and its derivatives have been widely used in drug delivery applications due to its biocompatible, biodegradable and non-toxic nature. In this study, we have developed amorphous chitin nanoparticles (150±50 nm) and evaluated its potential as a drug delivery system. Paclitaxel (PTX), a major chemotherapeutic agent was loaded into amorphous chitin nanoparticles (AC NPs) through ionic cross-linking reaction using TPP. The prepared PTX loaded AC NPs had an average diameter of 200±50 nm. Physico-chemical characterization of the prepared nanoparticles was carried out. These nanoparticles were proven to be hemocompatible and in vitro drug release studies showed a sustained release of PTX. Cellular internalization of the NPs was confirmed by fluorescent microscopy as well as by flow cytometry. Anticancer activity studies proved the toxicity of PTX-AC NPs toward colon cancer cells. These preliminary results indicate the potential of PTX-AC NPs in colon cancer drug delivery. Copyright © 2012 Elsevier B.V. All rights reserved.

Loading of atorvastatin and linezolid in β-cyclodextrin–conjugated cadmium selenide/silica nanoparticles: A spectroscopic study

Energy Technology Data Exchange (ETDEWEB)

Antony, Eva Janet; Shibu, Abhishek [Department of Nanosciences & Technology, Karunya University, Coimbatore 641114, Tamil Nadu (India); Ramasamy, Sivaraj; Paulraj, Mosae Selvakumar [Department of Chemistry, Karunya University, Coimbatore 641114, Tamil Nadu (India); Enoch, Israel V.M.V., E-mail: drisraelenoch@gmail.com [Department of Nanosciences & Technology, Karunya University, Coimbatore 641114, Tamil Nadu (India); Department of Chemistry, Karunya University, Coimbatore 641114, Tamil Nadu (India)

2016-08-01

The preparation of β–cyclodextrin–conjugated cadmium selenide–silica nanoparticles, the loading of two drugs viz., Atorvastatin and linezolid in the cyclodextrin cavity, and the fluorescence energy transfer between CdSe/SiO{sub 2} nanoparticles and the drugs encapsulated in the cyclodextrin cavity are reported in this paper. IR spectroscopy, X-ray diffractometry, transmission electron microscopy, and particle size analysis by light–scattering experiment were used as the tools of characterizing the size and the crystal system of the nanoparticles. The nanoparticles fall under hexagonal system. The silica–shell containing CdSe nanoparticles were functionalized by reaction with aminoethylamino–β–cyclodextrin. Fluorescence spectra of the nanoparticles in their free and drug–encapsulated forms were studied. The FÖrster distances between the encapsulated drugs and the CdSe nanoparticles are below 3 nm. The change in the FÖrster resonance energy parameters under physiological conditions may aid in tracking the release of drugs from the cavity of the cyclodextrin. - Highlights: • CdSe/SiO{sub 2} nanoparticles of crystallite size 15 nm are prepared. • β-Cyclodextrin is attached to the surface of the nanoparticles. • Atorvastatin and linezolid get encapsulated in the cyclodextrin cavity. • FRET efficiency between the nanoparticles and the loaded drugs are determined.

Loading of atorvastatin and linezolid in β-cyclodextrin–conjugated cadmium selenide/silica nanoparticles: A spectroscopic study

International Nuclear Information System (INIS)

Antony, Eva Janet; Shibu, Abhishek; Ramasamy, Sivaraj; Paulraj, Mosae Selvakumar; Enoch, Israel V.M.V.

2016-01-01

The preparation of β–cyclodextrin–conjugated cadmium selenide–silica nanoparticles, the loading of two drugs viz., Atorvastatin and linezolid in the cyclodextrin cavity, and the fluorescence energy transfer between CdSe/SiO_2 nanoparticles and the drugs encapsulated in the cyclodextrin cavity are reported in this paper. IR spectroscopy, X-ray diffractometry, transmission electron microscopy, and particle size analysis by light–scattering experiment were used as the tools of characterizing the size and the crystal system of the nanoparticles. The nanoparticles fall under hexagonal system. The silica–shell containing CdSe nanoparticles were functionalized by reaction with aminoethylamino–β–cyclodextrin. Fluorescence spectra of the nanoparticles in their free and drug–encapsulated forms were studied. The FÖrster distances between the encapsulated drugs and the CdSe nanoparticles are below 3 nm. The change in the FÖrster resonance energy parameters under physiological conditions may aid in tracking the release of drugs from the cavity of the cyclodextrin. - Highlights: • CdSe/SiO_2 nanoparticles of crystallite size 15 nm are prepared. • β-Cyclodextrin is attached to the surface of the nanoparticles. • Atorvastatin and linezolid get encapsulated in the cyclodextrin cavity. • FRET efficiency between the nanoparticles and the loaded drugs are determined.

Probing the impact of loading rate on the mechanical properties of viral nanoparticles

NARCIS (Netherlands)

Snijder, J.; Ivanovska, I.L.; Baclayon, M.; Roos, W.H.; Wuite, G.J.L.

2012-01-01

The effects of changes in the loading rate during the forced dissociation of single bonds have been studied for a wide variety of interactions. Less is known on the loading rate dependent behaviour of more complex systems that consist of multiple bonds. Here we focus on viral nanoparticles, in

XANES studies of titanium dioxide nanoparticles synthesized by using Peltophorum pterocarpum plant extract

Energy Technology Data Exchange (ETDEWEB)

Saravanan, S. [Centre for Photonics and Nanotechnology, Sona College of Technology, Salem 636005, Tamilnadu (India); Balamurugan, M., E-mail: chem.muruga@gmail.com [Centre for Photonics and Nanotechnology, Sona College of Technology, Salem 636005, Tamilnadu (India); Lippitz, A. [Bundesanstalt für Materialforschung und -prüfung, 6.8 Oberflächenanalytik und Grenzflächenchemie Unter den Eichen 44 – 46, 12203, Berlin (Germany); Fonda, E.; Swaraj, S. [Synchrotron SOLEIL, L’ormes des merisiers, Saint Aubin BP-48, 91192, Gif-Sur-Yvette Cedex (France)

2016-12-15

The preparation and characterization of a Titanium dioxide (TiO{sub 2}) by a simple, cost effective, facile and eco-friendly green synthesis method using Peltophorum pterocarpum plant extract is presented. The green synthesized nanoparticles were characterized using X-ray diffraction (XRD), Raman spectroscopy, High-resolution transmission electron microscopy (HR-TEM) and X-ray absorption near edge spectroscopy (XANES). XRD results show that the prepared TiO{sub 2} NPs were significantly crystalline with various percentages of anatase and rutile phases. The nanoparticles were found to have different diameters ranging from 20 to 80 nm. No evidence of any intermediate or different TiO{sub 2} phases were found in XANES measurements performed at the Ti K- and L-edge. It is shown that the TiO{sub 2} NPs with high uniformity, high surface area and minimum aggregation can be prepared with relative ease and the desired anatase: rutile phase ratio can be obtained by controlling the experimental conditions.

A novel solvothermal route for obtaining strontium titanate nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Marquez-Herrera, A., E-mail: alfredo.marquez@uaslp.mx [Universidad Autonoma de San Luis Potosi, Departamento de Ingenieria Mecanica Administrativa, Coordinacion Academica Region Altiplano (COARA) (Mexico); Ovando-Medina, Victor M.; Corona-Rivera, Miguel A. [Universidad Autonoma de San Luis Potosi, Departamento de Ingenieria Quimica, Coordinacion Academica Region Altiplano (COARA) (Mexico); Hernandez-Rodriguez, E.; Zapata-Torres, M. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria IPN (Mexico); Campos-Gonzalez, E.; Guillen-Cervantes, A.; Zelaya-Angel, O.; Melendez-Lira, M. [CINVESTAV-IPN, Departamento de Fisica (Mexico)

2013-04-15

Strontium titanate (SrTiO{sub 3}) has attracted a lot of attention because of its possible applications in new microelectronic devices. It is a material with a high dielectric constant, low leakage current, and some of its properties can be changed by adding or modifying the concentration of a dopant, which can be used for a wide range of functional purposes, from simple capacitors to complicated microwave devices. Therefore, in this work, we report the development of a new route to synthesize SrTiO{sub 3} nanoparticles based on the solvothermal method by employing two precursor solutions: strontium chloride and titanium(IV) butoxide. Our route allows the production of cubic SrTiO{sub 3} nanoparticles with a narrow size distribution. The particle sizes range between 8 and 24 nm, forming agglomerates of SrTiO{sub 3} in the range of 128-229 nm. It was demonstrated that the Ti/Sr molar ratio employed into the precursor solution has an important effect onto the chemical composition of the resulting SrTiO{sub 3} nanoparticles: when using Ti/Sr < 1, the formation and incorporation of the SrCO{sub 3} compound into the nanoparticles was observed while with Ti/Sr {>=} 1 nanoparticles are free of contaminants. The as-prepared nanoparticles were characterized by energy-dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy, high-resolution TEM, selected area electron diffraction, scanning electron microscopy, and dynamic light scattering.

Efficient chemotherapy of rat glioblastoma using doxorubicin-loaded PLGA nanoparticles with different stabilizers.

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Stefanie Wohlfart

Full Text Available BACKGROUND: Chemotherapy of glioblastoma is largely ineffective as the blood-brain barrier (BBB prevents entry of most anticancer agents into the brain. For an efficient treatment of glioblastomas it is necessary to deliver anti-cancer drugs across the intact BBB. Poly(lactic-co-glycolic acid (PLGA nanoparticles coated with poloxamer 188 hold great promise as drug carriers for brain delivery after their intravenous injection. In the present study the anti-tumour efficacy of the surfactant-coated doxorubicin-loaded PLGA nanoparticles against rat glioblastoma 101/8 was investigated using histological and immunohistochemical methods. METHODOLOGY: The particles were prepared by a high-pressure solvent evaporation technique using 1% polyvinylalcohol (PLGA/PVA or human serum albumin (PLGA/HSA as stabilizers. Additionally, lecithin-containing PLGA/HSA particles (Dox-Lecithin-PLGA/HSA were prepared. For evaluation of the antitumour efficacy the glioblastoma-bearing rats were treated intravenously with the doxorubicin-loaded nanoparticles coated with poloxamer 188 using the following treatment regimen: 3 × 2.5 mg/kg on day 2, 5 and 8 after tumour implantation; doxorubicin and poloxamer 188 solutions were used as controls. On day 18, the rats were sacrificed and the antitumour effect was determined by measurement of tumour size, necrotic areas, proliferation index, and expression of GFAP and VEGF as well as Isolectin B4, a marker for the vessel density. CONCLUSION: The results reveal a considerable anti-tumour effect of the doxorubicin-loaded nanoparticles. The overall best results were observed for Dox-Lecithin-PLGA/HSA. These data demonstrate that the poloxamer 188-coated PLGA nanoparticles enable delivery of doxorubicin across the blood-brain barrier in the therapeutically effective concentrations.

In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles

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Farzin Heravi

2013-12-01

Full Text Available Background and aims. Incorporation of nano-particles to orthodontic bonding systems has been considered to prevent enamel demineralization around appliances. This study investigated cytotoxicity of Transbond XT adhesive containing 1 wt% titanium dioxide (TiO2 nano-particles. Materials and methods. Ten composite disks were prepared from each of the conventional and TiO2-containg composites and aged for 1, 3, 5, 7 and 14 days in Dulbecco’s Modified Eagle’s Medium (DMEM. The extracts were obtained and exposed to culture media of human gingival fibroblasts (HGF and mouse L929 fibroblasts. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Results. Both adhesives were moderately toxic for HGF cells on the first day of the experiment, but the TiO2-containing adhesive produced significantly lower toxicity than the pure adhesive (P0.05. There was a significant reduction in cell toxicity with increasing pre-incubation time (P<0.001. L929 cells showed similar toxicity trends, but lower sensitivity to detect cytotoxicity of dental composites. Conclusion. The orthodontic adhesive containing TiO2 nano-particles indicated comparable or even lower toxicity than its nano-particle-free counterpart, indicating that incorporation of 1 wt% TiO2 nano-particles to the composite structure does not result in additional health hazards compared to that occurring with the pure adhesive.

Simultaneous diagnosis and drug delivery by silymarin-loaded magnetic nanoparticles

Directory of Open Access Journals (Sweden)

Maryam Khalkhali

2015-07-01

Full Text Available Objective(s: The aim of this work was to prepare and characterize magnetic nanoparticles (MNPs as theranostic system to act simultaneously as drug carrier and MRI contrast agent. Chitosan-coated MNPs (CMNPs were prepared and loaded with silymarin. Silymarin-loaded CMNPs were characterized with various techniques and their potential as MRI contrast agent was also evaluated. Materials and Methods:The chitosan-coated MNPs were prepared by coprecipitation method and were loaded with silymarin. The synthesized nanoparticles were characterized by various techniques including SEM, TEM, X‐ray diffraction (XRD, FTIR and vibrating sample magnetometer (VSM. In vitro drug release of silymarin was evaluated at 37 ˚C at pH 5.3 and 7.4. Then, their proton relaxivity was evaluated to study the potential of CMNPs as MRI contrast agent in terms of r1 and r2.Results:Silymarin-loaded CMNPs were successfully prepared and characterized by FTIR and XRD techniques. VSM analysis revealed superparamagnetic properties of CMNPs. The release study showed that the maximum drug release accessible for CMNPs in pH=5.3 was higher than pH=7.4. Finally, the r2/r1 value of CMNPs was found to be close to 20 indicating that CMNPs has a strong efficiency as T2 contrast agents for MRI imaging.  Conclusion:The findings demonstrated the potential of CMNPs as efficient MRI contrast agent as well as silymarin drug delivery.

Impact of silica dioxide nanoparticles on the morphology of internal organs in rats by oral supplementation

Directory of Open Access Journals (Sweden)

N.V. Zaitseva

2016-12-01

Full Text Available The object of the study was amorphous silica dioxide (SiO 2 , which is widely used as a food additive (E551, a subsidiary component in pharmaceutical preparations, perfumery and cosmetic products etc. In the specification of JECFA silica dioxide does not have information about the size of its particles, which allows the use of fine amorphous SiO 2 , obtained by gas phase hydrolysis of tetrachlorosilane as a food additive. This material, known as the "Aerosil", is characterized by the size of the specific surface area of 300–380 m 2 /g and the size of its relatively weakly agglomerated particles of 6–30 nm, i.e., it is a nanomaterial. In the biological model the morphological changes in organs and tissue systems on oral supplementation of nanoscale particles of silica dioxide were studied. Wistar male rats were given nanosized silica dioxide with specific surface area of 300 m 2 /g and primary nanoparticle size on the basis of data of electrical, atomic-powered microscopy, and dynamic light scattering in the range of 20–60 nm during 92 days. Light microscopic morphological examination of organs of rats showed a relatively mild inflammation in the structure of parenchymal organs (liver, kidney, not showing a certain dose-dependent nanoparticles. The most pronounced changes were in ileum morphology, consisting of a massive lymph macrophage and eosinophil infiltration of villi, without any apparent violation of their epithelial layer structure, which indirectly indicates the absence of violations of the barrier function of the intestinal epithelium. At the maximum dose of 100 mg/kg bw, the increased immune response was the most significant in the wall of the ileum. The results indicate the potential risks to human health when using SiO 2 having a specific surface area of 300 m 2 /g or higher in the composition of food products as a food additive.

Fabrication, characterization and antimicrobial activities of thymol-loaded zein nanoparticles stabilized by sodium caseinate-chitosan hydrochloride double layers.

Science.gov (United States)

Zhang, Yaqiong; Niu, Yuge; Luo, Yangchao; Ge, Mei; Yang, Tian; Yu, Liangli Lucy; Wang, Qin

2014-01-01

Thymol-loaded zein nanoparticles stabilized with sodium caseinate (SC) and chitosan hydrochloride (CHC) were prepared and characterized. The SC stabilized nanoparticles had well-defined size range and negatively charged surface. Due to the presence of SC, the stabilized zein nanoparticles showed a shift of isoelectric point from 6.18 to 5.05, and had a desirable redispersibility in water at neutral pH after lyophilization. Coating with CHC onto the SC stabilized zein nanoparticles resulted in increased particle size, reversal of zeta potential value from negative to positive, and improved encapsulation efficiency. Both thymol-loaded zein nanoparticles and SC stabilized zein nanoparticles had a spherical shape and smooth surface, while the surfaces of CHC-SC stabilized zein nanoparticles seemed rough and had some clumps. Encapsulated thymol was more effective in suppressing gram-positive bacterium than un-encapsulated thymol for a longer time period. Copyright © 2013 Elsevier Ltd. All rights reserved.

Solid lipid nanoparticles by coacervation loaded with a methotrexate prodrug: preliminary study for glioma treatment.

Science.gov (United States)

Battaglia, Luigi; Muntoni, Elisabetta; Chirio, Daniela; Peira, Elena; Annovazzi, Laura; Schiffer, Davide; Mellai, Marta; Riganti, Chiara; Salaroglio, Iris Chiara; Lanotte, Michele; Panciani, Pierpaolo; Capucchio, Maria Teresa; Valazza, Alberto; Biasibetti, Elena; Gallarate, Marina

2017-03-01

Methotrexate-loaded biocompatible nanoparticles were tested for preliminary efficacy in glioma treatment. Behenic acid nanoparticles, prepared by the coacervation method, were loaded with the ester prodrug didodecylmethotrexate, which was previously tested in vitro against glioblastoma human primary cultures. Nanoparticle conjugation with an ApoE mimicking chimera peptide was performed to obtain active targeting to the brain. Biodistribution studies in healthy rats assessed the superiority of ApoE-conjugated formulation, which was tested on an F98/Fischer glioma model. Differences were observed in tumor growth rate (measured by MRI) between control and treated rats. In vitro tests on F98 cultured cells assessed their susceptibility to treatment, with consequent apoptosis, and allowed us to explain the apoptosis observed in glioma models.

Efficient solar light-driven degradation of Congo red with novel Cu-loaded Fe3O4@TiO2 nanoparticles.

Science.gov (United States)

Arora, Priya; Fermah, Alisha; Rajput, Jaspreet Kaur; Singh, Harminder; Badhan, Jigyasa

2017-08-01

In this work, Cu-loaded Fe 3 O 4 @TiO 2 core shell nanoparticles were prepared in a single pot by coating of TiO 2 on Fe 3 O 4 nanoparticles followed by Cu loading. X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), thermogravimetric analysis (TGA), Brunauer-Emmett- Teller (BET), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS), and valence band X-ray photoelectron spectroscopy (VB XPS) techniques were used for characterization of as prepared nanoparticles. Synergism between copper and titania was evaluated by studying the solar light-driven photodegradation of Congo red dye solution in the presence of Fe 3 O 4 @TiO 2 nanoparticles on one side and Cu-loaded Fe 3 O 4 @TiO 2 nanoparticles on the other side. The latter performed better than the former catalyst, indicating the enhanced activity of copper-loaded catalyst. Further photodegradation was studied by three means, i.e., under ultraviolet (UV), refluxing, and solar radiations. Cu-loaded Fe 3 O 4 @TiO 2 enhanced the degradation efficiency of Congo red dye. Thus, Cu act possibly by reducing the band gap of TiO 2 and widening the optical response of semiconductor, as a result of which solar light could be used to carry out photocatalysis. Graphical abstract Photodegradation of congo red over Cu-loaded Fe 3 O 4 @TiO 2 nanoparticles.

Study of Copolymer Composition on Drug Loading Efficiency of Enalapril in Polymersomes and Cytotoxicity of Drug Loaded Nanoparticles.

Science.gov (United States)

Danafar, H; Manjili, H K; Najafi, M

2016-09-01

Enalapril was used for hypertension and congestive heart failure. Di-block mPEG-PCL copolymers were synthesized and used to prepare of polymersomes for controlled release of enalapril as a hydrophilic drug. The various methods such as HNMR, FTIR, GPC, DSC, PCS and AFM performed for characterization of the polymersomes. The results of AFM showed that the polymersomes had spherical structure and the size of nanoparticles was 97 nm. Drug-loading efficiency of nanoparticles from copolymers with compositions of mPEG1-PCL1, mPEG2-PCL2, and mPEG3-PCL3 were 14.43%, 19.8%, and 12.33% respectively. The release profile of enalapril for drug loaded nanoparticles prepared from mPEG3-PCL3 was very fast and release profile for the nanoparticles prepared from mPEG1-PCL1 and mPEG2-PCL2 was sustained. The IC 50 value of enalapril was determined to be 8 μM while EPM/m-PEG-PCL nanoparticles did not show significant toxicity at equal concentrations in comparison with enalapril drug. Therapeutic preparations of mPEG-PCL micelle are calibrated by the mouse LD 50 assay. A dose-finding scheme of the polymeric micelle showed a safe dose of mPEG-PCL micelles was approximately 330 mg/kg in mice. The relationship between the numbers of animals, number of doses, duration of the assay used to estimate the LD 50 and the precision of the assay were investigated. Overall, the results was showed that m-PEG-PCL polymersomes can be considered as a promising carrier for hydrophilic drugs. © Georg Thieme Verlag KG Stuttgart · New York.

Repetitive heterocoagulation of oppositely charged particles for enhancement of magnetic nanoparticle loading into monodisperse silica particles.

Science.gov (United States)

Matsumoto, Hideki; Nagao, Daisuke; Konno, Mikio

2010-03-16

Oppositely charged particles were repetitively heterocoagulated to fabricate highly monodisperse magnetic silica particles with high loading of magnetic nanoparticles. Positively charged magnetic nanoparticles prepared by surface modification with N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (TSA) were used to heterocoagulate with silica particles under basic conditions to give rise to negative silica surface charge and prevent the oxidation of the magnetic nanoparticles. The resultant particles of silica core homogeneously coated with the magnetic nanoparticles were further coated with thin silica layer with sodium silicate in order to enhance colloidal stability and avoid desorption of the magnetic nanoparticles from the silica cores. Five repetitions of the heterocoagulation and the silica coating could increase saturation magnetization of the magnetic silica particles to 27.7 emu/g, keeping the coefficient of variation of particle sizes (C(V)) less than 6.5%. Highly homogeneous loading of the magnetic component was confirmed by measuring Fe-to-Si atomic ratios of individual particles with energy dispersive X-ray spectroscopy.

Luminescent Study of the Binding Interaction on 1,4-Dihydroxy-2,3-Dimethyl-9,10-Anthraquinone with Titanium Dioxide Nanoparticles

Science.gov (United States)

Pushpam, S.; Yamini, D.; Ramakrishnan, V.

2014-07-01

The photophysical properties of 1,4-dihydroxy-2,3-dimethyl-9,10-anthroquinone (DHDMAQ) in the absence and presence of titanium dioxide (TiO2) nanoparticles have been studied using UV-visible absorption spectroscopy and steady-state fluorescence spectroscopy. The fluorescence intensity of the DHDMAQ decreases as the concentration of TiO2 nanoparticles increases. The quenching is characterized by a Stern-Volmer plot, which displays a positive deviation from linearity. This could be explained by static quenching models. The Stern-Volmer quenching constant, association constant, and binding constant have been calculated. The distance between DHDMAQ and TiO2 nanoparticles has also been evaluated using Forster's theory of non-radiative energy transfer.

Differential permeation of piroxicam-loaded PLGA micro/nanoparticles and their in vitro enhancement

International Nuclear Information System (INIS)

Shankarayan, Raju; Kumar, Sumit; Mishra, Prashant

2013-01-01

Piroxicam is a non-steroidal anti-inflammatory drug used for the treatment of musculoskeletal pain. The main problem encountered when piroxicam is administered orally is its gastric side-effect (ulcer, bleeding and holes in the stomach). Transmucosal delivery and encapsulation of piroxicam in biodegradable particles offer potential advantages over conventional oral delivery. The present study was aimed to develop an alternative to piroxicam-delivery which could overcome the direct contact of the drug at the mucosal membrane and its permeation through the mucosal membrane was studied. To achieve this, the piroxicam was encapsulated in Poly (lactide-co-glycolide) (PLGA) microparticles (size 1–4 μm, encapsulation efficiency 80–85 %) and nanoparticles (size 151.6 ± 28.6 nm, encapsulation efficiency 92.17 ± 3.08 %). Various formulation process parameters were optimised for the preparation of piroxicam-loaded PLGA nanoparticles of optimal size and encapsulation efficiency. Transmucosal permeability of piroxicam-loaded PLGA micro- and nanoparticles through the porcine oesophageal mucosa was studied. Using fluorescently labelled PLGA micro- and nanoparticles, size-dependent permeation was demonstrated. Furthermore, the effect of different permeation enhancers on the flux rate and permeability coefficient for the permeation of nanoparticles was investigated. The results suggested that amongst the permeation enhancers used the most efficient enhancement of permeation was observed with 10 mM sodium dodecyl sulphate.

Differential permeation of piroxicam-loaded PLGA micro/nanoparticles and their in vitro enhancement

Energy Technology Data Exchange (ETDEWEB)

Shankarayan, Raju; Kumar, Sumit; Mishra, Prashant, E-mail: pmishra@dbeb.iitd.ac.in [Indian Institute of Technology Delhi, Department of Biochemical Engineering and Biotechnology (India)

2013-03-15

Piroxicam is a non-steroidal anti-inflammatory drug used for the treatment of musculoskeletal pain. The main problem encountered when piroxicam is administered orally is its gastric side-effect (ulcer, bleeding and holes in the stomach). Transmucosal delivery and encapsulation of piroxicam in biodegradable particles offer potential advantages over conventional oral delivery. The present study was aimed to develop an alternative to piroxicam-delivery which could overcome the direct contact of the drug at the mucosal membrane and its permeation through the mucosal membrane was studied. To achieve this, the piroxicam was encapsulated in Poly (lactide-co-glycolide) (PLGA) microparticles (size 1-4 {mu}m, encapsulation efficiency 80-85 %) and nanoparticles (size 151.6 {+-} 28.6 nm, encapsulation efficiency 92.17 {+-} 3.08 %). Various formulation process parameters were optimised for the preparation of piroxicam-loaded PLGA nanoparticles of optimal size and encapsulation efficiency. Transmucosal permeability of piroxicam-loaded PLGA micro- and nanoparticles through the porcine oesophageal mucosa was studied. Using fluorescently labelled PLGA micro- and nanoparticles, size-dependent permeation was demonstrated. Furthermore, the effect of different permeation enhancers on the flux rate and permeability coefficient for the permeation of nanoparticles was investigated. The results suggested that amongst the permeation enhancers used the most efficient enhancement of permeation was observed with 10 mM sodium dodecyl sulphate.

Differential permeation of piroxicam-loaded PLGA micro/nanoparticles and their in vitro enhancement

Science.gov (United States)

Shankarayan, Raju; Kumar, Sumit; Mishra, Prashant

2013-03-01

Piroxicam is a non-steroidal anti-inflammatory drug used for the treatment of musculoskeletal pain. The main problem encountered when piroxicam is administered orally is its gastric side-effect (ulcer, bleeding and holes in the stomach). Transmucosal delivery and encapsulation of piroxicam in biodegradable particles offer potential advantages over conventional oral delivery. The present study was aimed to develop an alternative to piroxicam-delivery which could overcome the direct contact of the drug at the mucosal membrane and its permeation through the mucosal membrane was studied. To achieve this, the piroxicam was encapsulated in Poly (lactide- co-glycolide) (PLGA) microparticles (size 1-4 μm, encapsulation efficiency 80-85 %) and nanoparticles (size 151.6 ± 28.6 nm, encapsulation efficiency 92.17 ± 3.08 %). Various formulation process parameters were optimised for the preparation of piroxicam-loaded PLGA nanoparticles of optimal size and encapsulation efficiency. Transmucosal permeability of piroxicam-loaded PLGA micro- and nanoparticles through the porcine oesophageal mucosa was studied. Using fluorescently labelled PLGA micro- and nanoparticles, size-dependent permeation was demonstrated. Furthermore, the effect of different permeation enhancers on the flux rate and permeability coefficient for the permeation of nanoparticles was investigated. The results suggested that amongst the permeation enhancers used the most efficient enhancement of permeation was observed with 10 mM sodium dodecyl sulphate.

Scale up, optimization and stability analysis of Curcumin C3 complex-loaded nanoparticles for cancer therapy

Science.gov (United States)

2012-01-01

Background Nanoparticle based delivery of anticancer drugs have been widely investigated. However, a very important process for Research & Development in any pharmaceutical industry is scaling nanoparticle formulation techniques so as to produce large batches for preclinical and clinical trials. This process is not only critical but also difficult as it involves various formulation parameters to be modulated all in the same process. Methods In our present study, we formulated curcumin loaded poly (lactic acid-co-glycolic acid) nanoparticles (PLGA-CURC). This improved the bioavailability of curcumin, a potent natural anticancer drug, making it suitable for cancer therapy. Post formulation, we optimized our process by Reponse Surface Methodology (RSM) using Central Composite Design (CCD) and scaled up the formulation process in four stages with final scale-up process yielding 5 g of curcumin loaded nanoparticles within the laboratory setup. The nanoparticles formed after scale-up process were characterized for particle size, drug loading and encapsulation efficiency, surface morphology, in vitro release kinetics and pharmacokinetics. Stability analysis and gamma sterilization were also carried out. Results Results revealed that that process scale-up is being mastered for elaboration to 5 g level. The mean nanoparticle size of the scaled up batch was found to be 158.5 ± 9.8 nm and the drug loading was determined to be 10.32 ± 1.4%. The in vitro release study illustrated a slow sustained release corresponding to 75% drug over a period of 10 days. The pharmacokinetic profile of PLGA-CURC in rats following i.v. administration showed two compartmental model with the area under the curve (AUC0-∞) being 6.139 mg/L h. Gamma sterilization showed no significant change in the particle size or drug loading of the nanoparticles. Stability analysis revealed long term physiochemical stability of the PLGA-CURC formulation. Conclusions A successful effort towards

Preparation and functional studies of hydroxyethyl chitosan nanoparticles loaded with anti-human death receptor 5 single-chain antibody

Directory of Open Access Journals (Sweden)

Yang J

2014-05-01

Full Text Available Jingjing Yang,1,3,* Xiaoping Huang,1,3,* Fanghong Luo,1 Xiaofeng Cheng,3 Lianna Cheng,3 Bin Liu,4 Lihong Chen,2 Ruyi Hu,1,3 Chunyan Shi,1,3 Guohong Zhuang,1,3 Ping Yin2 1Anti-Cancer Research Center, Medical College, Xiamen University, Fujian, People's Republic of China, 2The Department of Pathology, Zhongshan Hospital, Xiamen University, Xiamen, People's Republic of China, 3Organ transplantation institution, Xiamen University, Xiamen, People's Republic of China, 4Jilin Vocational College of Industry and Technology, Jilin, People's Republic of China  *These authors contributed equally to this work Objective: To prepare hydroxyethyl chitosan nanoparticles loaded with anti-human death receptor 5 single-chain antibody, and study their characteristics, functions, and mechanisms of action. Materials and methods: The anti-human death receptor 5 single-chain antibody was constructed and expressed. Protein-loaded hydroxyethyl chitosan nanoparticles were prepared, and their size, morphology, particle-size distribution and surface zeta potential were measured by scanning electron microscopy and laser particle-size analysis. Mouse H22 hepatocellular carcinoma cells were cultured, and growth inhibition was examined using the CellTiter-Blue cell-viability assay. Flow cytometry and Hoechst 33342 were employed to measure cell apoptosis. Kunming mice with H22 tumor models were treated with protein-loaded hydroxyethyl chitosan nanoparticles, and their body weight and tumor size were measured, while hematoxylin and eosin staining was used to detect antitumor effects in vivo and side effects from tumors. Results: The protein-loaded hydroxyethyl chitosan nanoparticles had good stability; the zeta potential was -24.2±0.205, and the dispersion index was 0.203. The inhibition of the protein-loaded hydroxyethyl chitosan nanoparticles on H22 growth was both time- and dose-dependent. Increased expressions of active caspase 8, active caspase 3, and BAX were detected

Algal testing of titanium dioxide nanoparticles - Testing considerations, inhibitory effects and modification of cadmium bioavailability

DEFF Research Database (Denmark)

Hartmann, Nanna Isabella Bloch; von der Kammer, F.; Hofmann, T.

2010-01-01

The ecotoxicity of three different sizes of titanium dioxide (TiO(2)) particles (primary particles sizes: 10, 30, and 300 nm) to the freshwater green alga Pseudokirchneriella subcapitata was investigated in this study. Algal growth inhibition was found for all three particle types...... surfaces. It is also believed that heteroaggregation, driven by algal exopolymeric exudates, is occurring and could influence the concentration-response relationship. The ecotoxicity of cadmium to algae was investigated both in the presence and absence of 2 mg/LTiO(2). The presence of TiO(2) in algal tests......(II) species, indicating a possible carrier effect, or combined toxic effect of TiO(2) nanoparticles and cadmium. These results emphasize the importance of systematic studies of nanoecotoxicological effects of different sizes of nanoparticles and underline the fact that, in addition to particle toxicity...

Safety profile of solid lipid nanoparticles loaded with rosmarinic acid for oral use: in vitro and animal approaches.

Science.gov (United States)

Madureira, Ana Raquel; Nunes, Sara; Campos, Débora A; Fernandes, João C; Marques, Cláudia; Zuzarte, Monica; Gullón, Beatriz; Rodríguez-Alcalá, Luís M; Calhau, Conceição; Sarmento, Bruno; Gomes, Ana Maria; Pintado, Maria Manuela; Reis, Flávio

2016-01-01

Rosmarinic acid (RA) possesses several protective bioactivities that have attracted increasing interest by nutraceutical/pharmaceutical industries. Considering the reduced bioavailability after oral use, effective (and safe) delivery systems are crucial to protect RA from gastrointestinal degradation. This study aims to characterize the safety profile of solid lipid nanoparticles produced with Witepsol and Carnauba waxes and loaded with RA, using in vitro and in vivo approaches, focused on genotoxicity and cytotoxicity assays, redox status markers, hematological and biochemical profile, liver and kidney function, gut bacterial microbiota, and fecal fatty acids composition. Free RA and sage extract, empty nanoparticles, or nanoparticles loaded with RA or sage extract (0.15 and 1.5 mg/mL) were evaluated for cell (lymphocytes) viability, necrosis and apoptosis, and antioxidant/prooxidant effects upon DNA. Wistar rats were orally treated for 14 days with vehicle (control) and with Witepsol or Carnauba nanoparticles loaded with RA at 1 and 10 mg/kg body weight/d. Blood, urine, feces, and several tissues were collected for analysis. Free and loaded RA, at 0.15 mg/mL, presented a safe profile, while genotoxic potential was found for the higher dose (1.5 mg/mL), mainly by necrosis. Our data suggest that both types of nanoparticles are safe when loaded with moderate concentrations of RA, without in vitro genotoxicity and cytotoxicity and with an in vivo safety profile in rats orally treated, thus opening new avenues for use in nutraceutical applications.

Silver and titanium dioxide nanoparticle toxicity in plants: A review of current research.

Science.gov (United States)

Cox, Ashley; Venkatachalam, P; Sahi, Shivendra; Sharma, Nilesh

2016-10-01

Nanoparticles (NPs) have become widely used in recent years for many manufacturing and medical processes. Recent literature suggests that many metallic nanomaterials including those of silver (Ag) and titanium dioxide (TiO2) cause significant toxic effects in animal cell culture and animal models, however, toxicity studies using plant species are limited. This review examines current progress in the understanding of the effect of silver and titanium dioxide nanoparticles on plant species. There are many facets to this ongoing environmental problem. This review addresses the effects of NPs on oxidative stress-related gene expression, genotoxicity, seed germination, and root elongation. It is largely accepted that NP exposure results in the cellular generation of reactive oxygen species (ROS), leading to both positive and negative effects on plant growth. However, factors such as NP size, shape, surface coating and concentration vary greatly among studies resulting in conflicting reports of the effect at times. In addition, plant species tend to differ in their reaction to NP exposure, with some showing positive effects of NP augmentation while many others showing detrimental effects. Seed germination studies have shown to be less effective in gauging phytotoxicity, while root elongation studies have shown more promise. Given the large increase in nanomaterial applications in consumer products, agriculture and energy sectors, it is critical to understand their role in the environment and their effects on plant life. A closer look at nanomaterial-driven ecotoxicity is needed. Ecosystem-level studies are required to indicate how these nanomaterials transfer at the critical trophic levels affecting human health and biota. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Chitosan nanoparticles as non-viral gene delivery systems: determination of loading efficiency.

Science.gov (United States)

Carrillo, Carolina; Suñé, Josep Maria; Pérez-Lozano, Pilar; García-Montoya, Encarna; Sarrate, Rocío; Fàbregas, Anna; Miñarro, Montserrat; Ticó, Josep Ramon

2014-07-01

Chitosan has been studied for use in particle delivery systems for therapeutic purposes, since one of its most important applications is as a non-viral vector in gene therapy. Due to its positive charge, it is capable of forming DNA complexes (polyplexes) obtained through several methods and with the property of protecting nucleic acids. Two methods for obtaining the nanoparticles of chitosan-nucleic acids are reported in this study: simple complexation (of depolymerized chitosan or of different chitosan salts with plasmid) and ionic gelation (by adsorption of plasmid in the nanoparticles or by encapsulation of plasmid into nanoparticles). The determination of the loading efficiency of chitosan nanoparticles with the plasmid is carried out by electrophoretic mobility of the samples on agarose gel. Furthermore, the nanoparticles have been characterized according to their morphology, size and surface charge using AFM, TEM, laser diffraction and dynamic light scattering techniques. The polyplexes obtained have been found to be spherical and nanometric in size (between 100-230nm) with a zeta potential between 37 and 48mV. Positive results have been obtained by agarose gel electrophoresis for all studied cases: a concentration of between 20 and 30μg/mL of chitosan salts is required while for the remaining chitosan samples studied, 100% loading efficiency does not occur until a concentration equal to 100μg/mL (regardless of previous depolymerisation and the method performed). Chitosan-plasmid nanocapsules have been obtained at the polymer concentrations worked with (between 0.025 and 0.2%). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Ruthenium Dioxide Catalysts for the Selective Oxidation of Benzylamine to Benzonitrile: Investigating the Effect of Ruthenium Loading on Physical and Catalytic Properties

DEFF Research Database (Denmark)

Nordvang, Emily Catherine; Schill, Leonhard; Riisager, Anders

2017-01-01

The oxidative dehydrogenation of benzylamine to benzonitrile was studied in batch and continuous flow processes using ruthenium dioxide catalysts with varying ruthenium loadings. Increased conversions were observed in the continuous flow process compared with the batch process (up to 100% in the ......The oxidative dehydrogenation of benzylamine to benzonitrile was studied in batch and continuous flow processes using ruthenium dioxide catalysts with varying ruthenium loadings. Increased conversions were observed in the continuous flow process compared with the batch process (up to 100......% in the flow process compared with up to 92% in the batch process), with increased selectivity to benzonitrile (82 and 65%, respectively) and benzonitrile yields (84 and 58%, respectively). The major by-product was N-benzylidenebenzylamine. The ruthenium loading in the catalyst was successfully optimised...... and the most active catalyst had a ruthenium loading of 2.5-3.5 wt%....

Curcumin and piperine loaded zein-chitosan nanoparticles: Development and in-vitro characterisation

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Yücel Baspinar

2018-03-01

It was succeeded to prepare curcumin and piperine loaded zein-chitosan nanoparticles having a mean particle size of approximately 500 nm and high encapsulation efficencies for curcumin (89% and piperine (87%. Using a curcumin concentration of 10–25 µg/ml resulted in reduction of the viability of approximately 50% of the neuroblastoma cells. The here developed nanoparticle formulation consisting of solely natural compounds showed good cytotoxic effects and is a promising approach with appropriate properties for final consumption.

Effects of titanium dioxide nanoparticles on human keratinocytes.

Science.gov (United States)

Wright, Clayton; Iyer, Anand Krishnan V; Wang, Liying; Wu, Nianqiang; Yakisich, Juan S; Rojanasakul, Yon; Azad, Neelam

2017-01-01

Titanium dioxide (TiO 2 ) is a ubiquitous whitening compound widely used in topical products such as sunscreens, lotions and facial creams. The damaging health effects of TiO 2 inhalation has been widely studied in rats, mice and humans showing oxidative stress increase, DNA damage, cell death and inflammatory gene upregulation in lung and throat cells; however, the effects on skin cells from long-term topical use of various products remain largely unknown. In this study, we assessed the effect of specific TiO 2 nanoparticles (H 2 TiO 7 ) on a human keratinocyte cell line (HaCaT). We performed a comparative analysis using three TiO 2 particles varying in size (Fine, Ultrafine and H 2 TiO 7 ) and analyzed their effects on HaCaTs. There is a clear dose-dependent increase in superoxide production, caspase 8 and 9 activity, and apoptosis in HaCaTs after treatment with all three forms of TiO 2 ; however, there is no consistent effect on cell viability and proliferation with either of these TiO 2 particles. While there is data suggesting UV exposure can enhance the carcinogenic effects of TiO 2 , we did not observe any significant effect of UV-C exposure combined with TiO 2 treatment on HaCaTs. Furthermore, TiO 2 -treated cells showed minimal effects on VEGF upregulation and Wnt signaling pathway thereby showing no potential effect on angiogenesis and malignant transformation. Overall, we report here an increase in apoptosis, which may be caspase 8/Fas-dependent, and that the H 2 TiO 7 nanoparticles, despite their smaller particle size, had no significant enhanced effect on HaCaT cells as compared to Fine and Ultrafine forms of TiO 2 .

pH and ion strength modulated ionic species loading in mesoporous silica nanoparticles

International Nuclear Information System (INIS)

Liu, Wei; Liu, Jianbo; Yang, Xiaohai; Wang, Kemin; Wang, Qing; Yang, Meng; Li, Li; Xu, Jianguo

2013-01-01

Mesoporous silica nanoparticles (MSN) have emerged as appealing host materials to accommodate guest molecules for biomedical applications, and recently various methods have been developed to modulate the loading of guest molecules in the silica matrix. Herein, it was demonstrated that pH and ion strength showed great influence on the loading of charged species into the nanoparticles, taking MCM-41 as a host MSN model and methylviologen (MV 2+ ) and 1,5-naphthalene disulfonate (NDS 2− ) as typical charged ionic guest molecules. As the pH increased from 3.0 to 8.0, the loading amount of MV 2+ increased gradually, while on the contrary, it decreased gradually for NDS 2− , for the solution pH changed the electrostatic interaction between the silica matrix and the ionic guest molecules. Additionally, the adding of NaCl reduced the electrostatic interaction, which resulted in a decreasing of the electrostatic rejection and electrostatic accumulation for the molecules carrying the same and the opposite charge to the particle respectively. Thus, pH and ion strength can be employed as simple approaches to modulate the loading of charged molecules and permselectivity in MSN. This work has a definite guidance function for molecule loading, transport modulation, controlled release as well as sensors based on MSN. (paper)

Formulation and characterization of solid lipid nanoparticles loaded Neem oil for topical treatment of acne

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V. Vijayan

2013-01-01

Conclusion: The result concluded that Neem oil loaded solid lipid nanoparticles with more lecithin content in their colloid exhibit sustained effect which satisfactorily produced the antibacterial action on Acne microbes. Therefore Neem oil loaded SLN was used successfully for prolonged treatment of Acne.

Assessment of the physico-chemical behavior of titanium dioxide nanoparticles in aquatic environments using multi-dimensional parameter testing

International Nuclear Information System (INIS)

Kammer, Frank von der; Ottofuelling, Stephanie; Hofmann, Thilo

2010-01-01

Assessment of the behavior and fate of engineered nanoparticles (ENPs) in natural aquatic media is crucial for the identification of environmentally critical properties of the ENPs. Here we present a methodology for testing the dispersion stability, ζ-potential and particle size of engineered nanoparticles as a function of pH and water composition. The results obtained from already widely used titanium dioxide nanoparticles (Evonik P25 and Hombikat UV-100) serve as a proof-of-concept for the proposed testing scheme. In most cases the behavior of the particles in the tested settings follows the expectations derived from classical DLVO theory for metal oxide particles with variable charge and an isoelectric point at around pH 5, but deviations also occur. Regardless of a 5-fold difference in BET specific surface area particles composed of the same core material behave in an overall comparable manner. The presented methodology can act as a basis for the development of standardised methods for comparing the behavior of different nanoparticles within aquatic systems. - The behavior of engineered nanoparticles in the aquatic environment can be elucidated using a multi-dimensional parameter set acquired by a semi automated experimental set-up.

Magnetic nanoparticle-loaded alginate beads for local micro-actuation of in vitro tissue constructs.

Science.gov (United States)

Alshehri, Awatef M; Wilson, Otto C; Dahal, Bishnu; Philip, John; Luo, Xiaolong; Raub, Christopher B

2017-11-01

Magnetic nanoparticles (MNPs) self-align and transduce magnetic force, two properties which lead to promising applications in cell and tissue engineering. However, the toxicity of MNPs to cells which uptake them is a major impediment to applications in engineered tissue constructs. To address this problem, MNPs were embedded in millimeter-scale alginate beads, coated with glutaraldehyde cross-linked chitosan, and loaded in acellular and MDA-MB-231 cancer cell-seeded collagen hydrogels, providing local micro-actuation under an external magnetic field. Brightfield microscopy was used to assess nanoparticle diffusion from the bead. Phase contrast microscopy and digital image correlation were used to track collagen matrix displacement and estimate intratissue strain under magnetic actuation. Coating the magnetic alginate beads with glutaraldehyde-chitosan prevents bulk diffusion of nanoparticles into the surrounding microenvironment. Further, the beads exert force on the surrounding collagen gel and cells, resulting in intratissue strains of 0-10% tunable with bead dimensions, collagen density, and distance from the bead. Cells seeded adjacent to the embedded beads are subjected to strain gradients without loss of cell viability over two days culture. This study describes a simple way to fabricate crosslinked magnetic alginate beads to load in a collagen tissue construct without direct exposure of the construct to nanoparticles. The findings are significant to in vitro studies of mechanobiology in enabling precise control over dynamic mechanical loading of tissue constructs. Copyright © 2017 Elsevier B.V. All rights reserved.

PTX-loaded three-layer PLGA/CS/ALG nanoparticle based on layer-by-layer method for cancer therapy.

Science.gov (United States)

Wang, Fang; Yuan, Jian; Zhang, Qian; Yang, Siqian; Jiang, Shaohua; Huang, Chaobo

2018-05-17

Poly (lactic-co-glycolic acid) (PLGA) nanoparticles are an ideal paclitaxel (PTX)-carrying system due to its biocompatibility and biodegradability. But it possessed disadvantage of drug burst release. In this research, a layer-by-layer deposition of chitosan (CS) and sodium alginate (ALG) was applied to modify the PLGA nanoparticles. The surface charges and morphology of the PLGA, PLGA/CS and PLGA/CS/ALG particles was measured by capillary electrophoresis and SEM and TEM, respectively. The drug encapsulation and loading efficiency were confirmed by ultraviolet spectrophotometer. The nanoparticles were stable and exhibited controlled drug release performance, with good cytotoxicity to human lung carcinoma cells (HepG 2). Cumulatively, our research suggests that this kind of three-layer nanoparticle with LbL-coated shield has great properties to act as a novel drug-loaded system.

Titanium Dioxide Nanoparticles Trigger Loss of Function and Perturbation of Mitochondrial Dynamics in Primary Hepatocytes.

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Vaishaali Natarajan

Full Text Available Titanium dioxide (TiO2 nanoparticles are one of the most highly manufactured and employed nanomaterials in the world with applications in copious industrial and consumer products. The liver is a major accumulation site for many nanoparticles, including TiO2, directly through intentional exposure or indirectly through unintentional ingestion via water, food or animals and increased environmental contamination. Growing concerns over the current usage of TiO2 coupled with the lack of mechanistic understanding of its potential health risk is the motivation for this study. Here we determined the toxic effect of three different TiO2 nanoparticles (commercially available rutile, anatase and P25 on primary rat hepatocytes. Specifically, we evaluated events related to hepatocyte functions and mitochondrial dynamics: (1 urea and albumin synthesis using colorimetric and ELISA assays, respectively; (2 redox signaling mechanisms by measuring reactive oxygen species (ROS production, manganese superoxide dismutase (MnSOD activity and mitochondrial membrane potential (MMP; (3 OPA1 and Mfn-1 expression that mediates the mitochondrial dynamics by PCR; and (4 mitochondrial morphology by MitoTracker Green FM staining. All three TiO2 nanoparticles induced a significant loss (p < 0.05 in hepatocyte functions even at concentrations as low as 50 ppm with commercially used P25 causing maximum damage. TiO2 nanoparticles induced a strong oxidative stress in primary hepatocytes. TiO2 nanoparticles exposure also resulted in morphological changes in mitochondria and substantial loss in the fusion process, thus impairing the mitochondrial dynamics. Although this study demonstrated that TiO2 nanoparticles exposure resulted in substantial damage to primary hepatocytes, more in vitro and in vivo studies are required to determine the complete toxicological mechanism in primary hepatocytes and subsequently liver function.

Synthesis and Characterization of BSA Conjugated Silver Nanoparticles (Ag/BSA Nanoparticles) and Evaluation of Biological Properties of Ag/BSA Nanoparticles and Ag/BSA Nanoparticles Loaded Poly(hydroxy butyrate valerate) PHBV Films

Science.gov (United States)

Ambaye, Almaz

Ag/BSA nanoparticles was found to be in a range of 9-13 nm. X-ray photo electron spectroscopy measurements of argon sputtered Ag/BSA nanoparticles provided evidence that the outer and inner region of nanoparticles are mainly composed of BSA and silver, respectively. Having characterized the nanoparticles, the next phase of the study was to evaluate the antibacterial activity and cytotoxicity level of BSA stabilized silver nanoparticles. The antibacterial efficacy of Ag/BSA nanoparticles against E. coli and S. aureus was evaluated, and minimum lethal concentration was found to be 2ppm and 7ppm, respectively. E. coli showed a higher susceptibility to silver nanoparticles than S. aureus, which could be attributed to the difference in the cell wall structure. We have also investigated the cytotoxicity level of Ag/BSA nanoparticles towards MC3T3-E1 osteoblast cells. The minimum bactericidal concentration found for both strains is lower than the silver nanoparticles concentration that was toxic to the osteoblast cells. Preliminary studies of Ag/BSA nanoparticles loaded collagen immobilized PHBV film showed that the Ag/BSA nanoparticles loaded PHBV film inhibit bacterial growth. The findings of our study can be extremely useful in the design of novel scaffold to address the critical needs of bone tissue engineering community.

Investigation of titanium dioxide nanoparticles toxicity and uptake by plants

Energy Technology Data Exchange (ETDEWEB)

Larue, C; Carriere, M [Laboratoire de Structure et Dynamique par Resonance Magnetique UMR 9956 CEA-CNRS-IRAMIS, Gif-sur-Yvette (France); Khodja, H [Laboratoire d' Etude des Elements Legers, UMR 9956 CEA-CNRS-IRAMIS, Gif-sur-Yvette (France); Herlin-Boime, N [Laboratoire Francis Perrin URA 2453 CEA-CNRS-IRAMIS, 91191 Gif-sur-Yvette (France); Brisset, F [Institut de Chimie Moleculaire et des Materiaux d' Orsay, UMR8182 CNRS-University Paris sud, Orsay (France); Flank, A M [LUCIA beamline, SOLEIL synchrotron, Saint-Aubin (France); Fayard, B [Laboratoire de Physique du solide, Orsay, France and ID21 beamline, ESRF, Grenoble (France); Chaillou, S, E-mail: marie.carriere@cea.fr [Unite de Nutrition Azotee des Plantes, INRA, Versailles (France)

2011-07-06

Nanoparticles (NP) are introduced in a growing number of commercial products and their production may lead to their release in the environment. Plants may be a potential entry point for NP in the food chain. Up to now, results describing NP phytotoxical effects and plant accumulation are scarce and contradictory. To increase knowledge on titanium dioxide NP (TiO{sub 2}-NPs) accumulation and impact on plants, we designed a study on three plant species, namely wheat (Triticum aestivum), oilseed rape (Brassica napus) and Arabidopsis thaliana. These plants were exposed in hydroponics to a panel of well-characterized TiO{sub 2}-NPs, with diameters ranging from 12 to 140 nm, either anatase or rutile. Their accumulation in plant tissues is currently being assessed by complementary imaging techniques: scanning electron microscopy (SEM), transmission electron microscopy (TEM), micro-X-ray fluorescence (SR-{mu}-XRF) imaging and micro-particle induced X-ray emission ({mu}-PIXE) imaging. Moreover, the impact of TiO{sub 2}-NP exposure on germination rate, root elongation, dry biomass and evapotranspiration is evaluated. Preliminary results are presented here, with data collected on wheat plants exposed to 12 nm and 25 nm anatase TiO{sub 2}-NPs. These results show that TiO{sub 2}-NPs are taken up by plants, and do not significantly alter their germination and root elongation. These results underline the necessity of deeper evaluation of nanoparticle ecotoxicity, and particularly on their interaction with plants.

Investigation of titanium dioxide nanoparticles toxicity and uptake by plants

International Nuclear Information System (INIS)

Larue, C; Carriere, M; Khodja, H; Herlin-Boime, N; Brisset, F; Flank, A M; Fayard, B; Chaillou, S

2011-01-01

Nanoparticles (NP) are introduced in a growing number of commercial products and their production may lead to their release in the environment. Plants may be a potential entry point for NP in the food chain. Up to now, results describing NP phytotoxical effects and plant accumulation are scarce and contradictory. To increase knowledge on titanium dioxide NP (TiO 2 -NPs) accumulation and impact on plants, we designed a study on three plant species, namely wheat (Triticum aestivum), oilseed rape (Brassica napus) and Arabidopsis thaliana. These plants were exposed in hydroponics to a panel of well-characterized TiO 2 -NPs, with diameters ranging from 12 to 140 nm, either anatase or rutile. Their accumulation in plant tissues is currently being assessed by complementary imaging techniques: scanning electron microscopy (SEM), transmission electron microscopy (TEM), micro-X-ray fluorescence (SR-μ-XRF) imaging and micro-particle induced X-ray emission (μ-PIXE) imaging. Moreover, the impact of TiO 2 -NP exposure on germination rate, root elongation, dry biomass and evapotranspiration is evaluated. Preliminary results are presented here, with data collected on wheat plants exposed to 12 nm and 25 nm anatase TiO 2 -NPs. These results show that TiO 2 -NPs are taken up by plants, and do not significantly alter their germination and root elongation. These results underline the necessity of deeper evaluation of nanoparticle ecotoxicity, and particularly on their interaction with plants.

Preparation of basil seed mucilage aerogels loaded with paclitaxel nanoparticles by the combination of phase inversion technique and gas antisolvent process

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Seyyed Ghoreishi

2017-09-01

Full Text Available Objective(S: In this work, paclitaxel (PX, a promising anticancer drug, was loaded in the basil seed mucilage (BSM aerogels by implementation of supercritical carbon dioxide (SC-CO2 technology. Then, the effects of operating conditions were studied on the PX mean particle size (MPS, particle size distribution (PSD and drug loading efficiency (DLE. Methods: The employed SC-CO2 process in this research is the combination of phase inversion technique and gas antisolvent (GAS process. The effect of DMSO/water ratio (4 and 6 (v/v, pressure (10-20 MPa, CO2 addition rate (1–3 mL/min and ethanol concentration (5-10% were studied on MPS, PSD and DLE. Scanning electron microscopy (SEM and Zetasizer were used for particle analysis. DLE was investigated by utilizing the high-performance liquid chromatography (HPLC. Results: Nanoparticles of paclitaxel (MPS of 82–131 nm depending on process variables with narrow PSD were successfully loaded in BSM aerogel with DLE of 28–52%. Experimental results indicated that higher DMSO/water ratio, ethanol concentration, pressure and CO2 addition rate reduced MPS and DLE. Conclusions: A modified semi batch SC-CO2 process based on the combination of gas antisolvent process and phase inversion methods using DMSO as co-solvent and ethanol as a secondary solvent was developed for the loading of an anticancer drug, PX, in ocimum basilicum mucilage aerogel. The experimental results determined that the mean particle size, particle size distribution, and drug loading efficiency be controlled with operating conditions.

Nutlin-3a and Cytokine Co-loaded Spermine-Modified Acetalated Dextran Nanoparticles for Cancer Chemo-Immunotherapy

DEFF Research Database (Denmark)

Bauleth-Ramos, Tomás; Shahbazi, Mohammad-Ali; Liu, Dongfei

2017-01-01

The combination of chemo- and immunotherapy represents one promising strategy to overcome the existent challenges in the present-day anticancer therapy. Here, spermine-modified acetalated dextran nanoparticles (Sp-AcDEX NPs), co-loaded with the non-genotoxic molecule Nutlin-3a (Nut3a), and the cy......The combination of chemo- and immunotherapy represents one promising strategy to overcome the existent challenges in the present-day anticancer therapy. Here, spermine-modified acetalated dextran nanoparticles (Sp-AcDEX NPs), co-loaded with the non-genotoxic molecule Nutlin-3a (Nut3a...

Biocompatible and colloidally stabilized mPEG-PE/calcium phosphate hybrid nanoparticles loaded with siRNAs targeting tumors.

Science.gov (United States)

Gao, Pei; Zhang, Xiangyu; Wang, Hongzhi; Zhang, Qinghong; Li, He; Li, Yaogang; Duan, Yourong

2016-01-19

Calcium phosphate nanoparticles are safe and effective delivery vehicles for small interfering RNA (siRNA), as a result of their excellent biocompatibility. In this work, mPEG-PE (polyethylene glycol-L-α-phosphatidylethanolamine) was synthesized and used to prepare nanoparticles composed of mPEG-PE and calcium phosphate for siRNA delivery. Calcium phosphate and mPEG-PE formed the stable hybrid nanoparticles through self-assembly resulting from electrostatic interaction in water. The average size of the hybrid nanoparticles was approximately 53.2 nm with a negative charge of approximately -16.7 mV, which was confirmed by dynamic light scattering (DLS) measurements. The nanoparticles exhibited excellent stability in serum and could protect siRNA from ribonuclease (RNase) degradation. The cellular internalization of siRNA-loaded nanoparticles was evaluated in SMMC-7721 cells using a laser scanning confocal microscope (CLSM) and flow cytometry. The hybrid nanoparticles could efficiently deliver siRNA to cells compared with free siRNA. Moreover, the in vivo distribution of Cy5-siRNA-loaded hybrid nanoparticles was observed after being injected into tumor-bearing nude mice. The nanoparticles concentrated in the tumor regions through an enhanced permeability and retention (EPR) effect based on the fluorescence intensities of tissue distribution. A safety evaluation of the nanoparticles was performed both in vitro and in vivo demonstrating that the hybrid nanoparticle delivery system had almost no toxicity. These results indicated that the mPEG-PE/CaP hybrid nanoparticles could be a stable, safe and promising siRNA nanocarrier for anticancer therapy.

Algal testing of titanium dioxide nanoparticles-Testing considerations, inhibitory effects and modification of cadmium bioavailability

International Nuclear Information System (INIS)

Hartmann, N.B.; Von der Kammer, F.; Hofmann, T.; Baalousha, M.; Ottofuelling, S.; Baun, A.

2010-01-01

The ecotoxicity of three different sizes of titanium dioxide (TiO 2 ) particles (primary particles sizes: 10, 30, and 300 nm) to the freshwater green alga Pseudokirchneriella subcapitata was investigated in this study. Algal growth inhibition was found for all three particle types, but the physiological mode of action is not yet clear. It was possible to establish a concentration/dose-response relationship for the three particle sizes. Reproducibility, however, was affected by concentration-dependent aggregation of the nanoparticles, subsequent sedimentation, and possible attachment to vessel surfaces. It is also believed that heteroaggregation, driven by algal exopolymeric exudates, is occurring and could influence the concentration-response relationship. The ecotoxicity of cadmium to algae was investigated both in the presence and absence of 2 mg/L TiO 2 . The presence of TiO 2 in algal tests reduced the observed toxicity due to decreased bioavailability of cadmium resulting from sorption/complexation of Cd 2+ ions to the TiO 2 surface. However, for the 30 nm TiO 2 nanoparticles, the observed growth inhibition was greater than what could be explained by the concentration of dissolved Cd(II) species, indicating a possible carrier effect, or combined toxic effect of TiO 2 nanoparticles and cadmium. These results emphasize the importance of systematic studies of nanoecotoxicological effects of different sizes of nanoparticles and underline the fact that, in addition to particle toxicity, potential interactions with existing environmental contaminants are also of crucial importance in assessing the potential environmental risks of nanoparticles.

Transient loading of CD34+ hematopoietic progenitor cells with polystyrene nanoparticles

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Deville S

2017-01-01

Full Text Available Sarah Deville,1,2 Wahyu Wijaya Hadiwikarta,1 Nick Smisdom,1,2 Bart Wathiong,1,3 Marcel Ameloot,2 Inge Nelissen,1 Jef Hooyberghs1,3 1VITO, Flemish Institute for Technological Research, Mol, Belgium; 2Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium; 3Theoretical Physics, Hasselt University, Diepenbeek, Belgium Abstract: CD34+ hematopoietic progenitor cells (HPCs offer great opportunities to develop new treatments for numerous malignant and non-malignant diseases. Nanoparticle (NP-based strategies can further enhance this potential, and therefore a thorough understanding of the loading behavior of HPCs towards NPs is essential for a successful application. The present study focusses on the interaction kinetics of 40 nm sized carboxylated polystyrene (PS NPs with HPCs. Interestingly, a transient association of the NPs with HPCs is observed, reaching a maximum within 1 hour and declining afterwards. This behavior is not seen in dendritic cells (CD34-DCs differentiated from HPCs, which display a monotonic increase in NP load. We demonstrate that this transient interaction requires an energy-dependent cellular process, suggesting active loading and release of NPs by HPCs. This novel observation offers a unique approach to transiently equip HPCs. A simple theoretical approach modeling the kinetics of NP loading and release is presented, contributing to a framework of describing this phenomenon. Keywords: nanoparticles, hematopoietic progenitor cells, dendritic cells, uptake, release

Development and evaluation of Desvenlafaxine loaded PLGA-chitosan nanoparticles for brain delivery

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Gui-Feng Tong

2017-09-01

Full Text Available Depression is a debilitating psychiatric condition that remains the second most common cause of disability worldwide. Currently, depression affects more than 4 per cent of the world’s population. Most of the drugs intended for clinical management of depression augment the availability of neurotransmitters at the synapse by inhibiting their neuronal reuptake. However, the therapeutic efficacy of antidepressants is often compromised as they are unable to reach brain by the conventional routes of administration. The purpose of the present study was to reconnoiter the potential of mucoadhesive PLGA-chitosan nanoparticles for the delivery of encapsulated Desvenlafaxine to the brain by nose to brain delivery route for superior pharmacokinetic and pharmacodynamic profile of Desvenlafaxine. Desvenlafaxine loaded PLGA-chitosan nanoparticles were prepared by solvent emulsion evaporation technique and optimized for various physiochemical characteristics. The antidepressant efficacy of optimized Desvenlafaxine was evaluated in various rodent depression models together with the biochemical estimation of monoamines in their brain. Further, the levels of Desvenlafaxine in brain and blood plasma were determined at various time intervals for calculation of different pharmacokinetic parameters. The optimized Desvenlafaxine loaded PLGA-chitosan nanoparticles (∼172 nm/+35 mV on intranasal administration significantly reduced the symptoms of depression and enhanced the level of monoamines in the brain in comparison with orally administered Desvenlafaxine. Nose to brain delivery of Desvenlafaxine PLGA-chitosan nanoparticles also enhanced the pharmacokinetic profile of Desvenlafaxine in brain together with their brain/blood ratio at different time points. Thus, intranasal mucoadhesive Desvenlafaxine PLGA-chitosan nanoparticles could be potentially used for the treatment of depression.

Facile hydrothermal preparation of titanium dioxide decorated reduced graphene oxide nanocomposite

Science.gov (United States)

Chang, Betty Yea Sze; Huang, Nay Ming; An’amt, Mohd Nor; Marlinda, Abdul Rahman; Norazriena, Yusoff; Muhamad, Muhamad Rasat; Harrison, Ian; Lim, Hong Ngee; Chia, Chin Hua

2012-01-01

A simple single-stage approach, based on the hydrothermal technique, has been introduced to synthesize reduced graphene oxide/titanium dioxide nanocomposites. The titanium dioxide nanoparticles are formed at the same time as the graphene oxide is reduced to graphene. The triethanolamine used in the process has two roles. It acts as a reducing agent for the graphene oxide as well as a capping agent, allowing the formation of titanium dioxide nanoparticles with a narrow size distribution (~20 nm). Transmission electron micrographs show that the nanoparticles are uniformly distributed on the reduced graphene oxide nanosheet. Thermogravimetric analysis shows the nanocomposites have an enhanced thermal stability over the original components. The potential applications for this technology were demonstrated by the use of a reduced graphene oxide/titanium dioxide nanocomposite-modified glassy carbon electrode, which enhanced the electrochemical performance compared to a conventional glassy carbon electrode when interacting with mercury(II) ions in potassium chloride electrolyte. PMID:22848166

MO-FG-BRA-05: Next Generation Radiotherapy Biomaterials Loaded With Gold Nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Cifter, G; Ngwa, W [Dana Farber Cancer Institute, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (United States); Univ Massachusetts Lowell, Lowell, MA (United States); Sajo, E [Univ Massachusetts Lowell, Lowell, MA (United States); Korideck, H; Cormack, R; Makrigiorgos, G [Dana Farber Cancer Institute, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (United States); Kumar, R [Dana Farber Cancer Institute, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (United States); Northeastern University, Boston, MA (United States); Sridhar, S [Northeastern University, Boston, MA (United States)

2015-06-15

Purpose: It has been proposed that routinely used inert radiotherapy (RT) biomaterials (e.g. fiducials, spacers) can be upgraded to smarter ones by coating/loading them with radiosensitizing gold nanoparticles (GNPs), for sustained in-situ release after implantation to enhance RT. In this work, we developed prototypes of such RT biomaterials and investigated the sustained release of GNPs from the biomaterials as a function of design parameters. Methods: Prototype smart biomaterials were produced by incorporating the GNPs in poly(D,L-lactide-co-glycolide) (PLGA) polymer millirods during the gel phase of production. For comparison, commercially available spacers were also coated with a polymer film loaded with fluorescent GNP. Optical/spectroscopy methods were used to monitor in vitro release of GNPs over time as a function of different design parameters: polymer weighting, type, and initial (loading) GNP concentrations. Inductively coupled plasma mass spectrometry was employed to verify GNP release. Results: Results showed that gold nanoparticles could be successfully loaded in the new RT biomaterial prototypes. Burst release of GNPs could be achieved within 1 to 25 days depending on the preparation approach. Burst release was followed by sustained release profile over time. The amount of released GNP increased with increasing loading concentration as expected. The release profiles could also be customized as a function of polymer weighting, or preparation approaches. Conclusion: Considered together, our results highlight potential for the development of next generation RT biomaterials loaded with GNPs customizable to different RT schedules. Such biomaterials could be employed as needed instead of currently used inert spacers/fiducials at no additional inconvenience to patients, to enhance RT.

MO-FG-BRA-05: Next Generation Radiotherapy Biomaterials Loaded With Gold Nanoparticles

International Nuclear Information System (INIS)

Cifter, G; Ngwa, W; Sajo, E; Korideck, H; Cormack, R; Makrigiorgos, G; Kumar, R; Sridhar, S

2015-01-01

Purpose: It has been proposed that routinely used inert radiotherapy (RT) biomaterials (e.g. fiducials, spacers) can be upgraded to smarter ones by coating/loading them with radiosensitizing gold nanoparticles (GNPs), for sustained in-situ release after implantation to enhance RT. In this work, we developed prototypes of such RT biomaterials and investigated the sustained release of GNPs from the biomaterials as a function of design parameters. Methods: Prototype smart biomaterials were produced by incorporating the GNPs in poly(D,L-lactide-co-glycolide) (PLGA) polymer millirods during the gel phase of production. For comparison, commercially available spacers were also coated with a polymer film loaded with fluorescent GNP. Optical/spectroscopy methods were used to monitor in vitro release of GNPs over time as a function of different design parameters: polymer weighting, type, and initial (loading) GNP concentrations. Inductively coupled plasma mass spectrometry was employed to verify GNP release. Results: Results showed that gold nanoparticles could be successfully loaded in the new RT biomaterial prototypes. Burst release of GNPs could be achieved within 1 to 25 days depending on the preparation approach. Burst release was followed by sustained release profile over time. The amount of released GNP increased with increasing loading concentration as expected. The release profiles could also be customized as a function of polymer weighting, or preparation approaches. Conclusion: Considered together, our results highlight potential for the development of next generation RT biomaterials loaded with GNPs customizable to different RT schedules. Such biomaterials could be employed as needed instead of currently used inert spacers/fiducials at no additional inconvenience to patients, to enhance RT

Doxorubicin Loaded Chitosan-W18 O49 Hybrid Nanoparticles for Combined Photothermal-Chemotherapy.

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Yuan, Shanmei; Hua, Jisong; Zhou, Yinyin; Ding, Yin; Hu, Yong

2017-08-01

Combined treatment is more effective than single treatment against most forms of cancer. In this work, doxorubicin loaded chitosan-W 18 O 49 nanoparticles combined with the photothermal therapy and chemotherapy are fabricated through the electrostatic interaction between positively charged chitosan and negatively charged W 18 O 49 nanoparticles. The in vitro and in vivo behaviors of these nanoparticles are examined by dynamic light scattering, transmission electron microscopy, cytotoxicity, near-infrared fluorescence imaging, and tumor growth inhibition experiment. These nanoparticles have a mean size around 110 nm and show a pH sensitive drug release behavior. After irradiation by the 980 nm laser, these nanoparticles show more pronounced cytotoxicity against HeLa cells than that of free doxorubicin or photothermal therapy alone. The in vivo experiments confirm that their antitumor ability is significantly improved, resulting in superior efficiency in impeding tumor growth and extension of the lifetime of mice. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Titanium dioxide nanoparticles activate the ATM-Chk2 DNA damage response in human dermal fibroblasts

Science.gov (United States)

Prasad, Raju Y.; Chastain, Paul D.; Nikolaishvili-Feinberg, Nana; Smeester, Lisa M.; Kaufmann, William K.; Fry, Rebecca C.

2013-01-01

The use of nanoparticles in consumer products increases their prevalence in the environment and the potential risk to human health. Although recent studies have shown in vivo and in vitro toxicity of titanium dioxide nanoparticles (nano-TiO2), a more detailed view of the underlying mechanisms of this response needs to be established. Here the effects of nano-TiO2 on the DNA damage response and DNA replication dynamics were investigated in human dermal fibroblasts. Specifically, the relationship between nano-TiO2 and the DNA damage response pathways regulated by ATM/Chk2 and ATR/Chk1 were examined. The results show increased phosphorylation of H2AX, ATM, and Chk2 after exposure. In addition, nano-TiO2 inhibited the overall rate of DNA synthesis and frequency of replicon initiation events in DNA combed fibers. Taken together, these results demonstrate that exposure to nano-TiO2 activates the ATM/Chk2 DNA damage response pathway. PMID:22770119

Preparation of Curcumin Loaded Egg Albumin Nanoparticles Using Acetone and Optimization of Desolvation Process.

Science.gov (United States)

Aniesrani Delfiya, D S; Thangavel, K; Amirtham, D

2016-04-01

In this study, acetone was used as a desolvating agent to prepare the curcumin-loaded egg albumin nanoparticles. Response surface methodology was employed to analyze the influence of process parameters namely concentration (5-15%w/v) and pH (5-7) of egg albumin solution on solubility, curcumin loading and entrapment efficiency, nanoparticles yield and particle size. Optimum processing conditions obtained from response surface analysis were found to be the egg albumin solution concentration of 8.85%w/v and pH of 5. At this optimum condition, the solubility of 33.57%, curcumin loading of 4.125%, curcumin entrapment efficiency of 55.23%, yield of 72.85% and particles size of 232.6 nm were obtained and these values were related to the values which are predicted using polynomial model equations. Thus, the model equations generated for each response was validated and it can be used to predict the response values at any concentration and pH.

Fabrication of curcumin-loaded bovine serum albumin (BSA)-dextran nanoparticles and the cellular antioxidant activity.

Science.gov (United States)

Fan, Yuting; Yi, Jiang; Zhang, Yuzhu; Yokoyama, Wallace

2018-01-15

Bovine serum albumin (BSA)-dextran conjugate was prepared with glycation. Self-assembly nanoparticles were synthesized with a green, and facile approach. The effects of dry-heating time on the fabrication and characteristics of BSA-dextran conjugate nanoparticles were examined. Stable nanoparticles (dextran was grafted onto the BSA to provide significant steric hindrance. Particle size decreased with the increase of dry-heating time and the lowest particle size (51.2nm) was obtained after 24h dry-heating. The nanoparticles were stable in a wide pH range (pH 2.0-7.0). The particle size of nanoparticles increased to 115nm after curcumin incorporation and was stable even after one-month storage. TEM results demonstrated that curcumin-loaded nanoparticles displayed a spherical structure and were homogeneously dispersed. Curcumin in BSA-dextran nanoparticle showed better stability, compared to free curcumin. In addition, BSA-dextran nanoparticles can improve the cellular antioxidant activity of curcumin in Caco-2 cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

In Vivo Assessment of Clobetasol Propionate-Loaded Lecithin-Chitosan Nanoparticles for Skin Delivery

Science.gov (United States)

Şenyiğit, Taner; Sonvico, Fabio; Rossi, Alessandra; Tekmen, Işıl; Santi, Patrizia; Colombo, Paolo; Nicoli, Sara; Özer, Özgen

2016-01-01

The aim of this work was to assess in vivo the anti-inflammatory efficacy and tolerability of clobetasol propionate (CP) loaded lecithin/chitosan nanoparticles incorporated into chitosan gel for topical application (CP 0.005%). As a comparison, a commercial cream (CP 0.05% w/w), and a sodium deoxycholate gel (CP 0.05% w/w) were also evaluated. Lecithin/chitosan nanoparticles were prepared by self-assembling of the components obtained by direct injection of soybean lecithin alcoholic solution containing CP into chitosan aqueous solution. Nanoparticles obtained had a particle size around 250 nm, narrow distribution (polydispersity index below 0.2) and positive surface charge, provided by a superficial layer of the cationic polymer. The nanoparticle suspension was then loaded into a chitosan gel, to obtain a final CP concentration of 0.005%. The anti-inflammatory activity was evaluated using carrageenan-induced hind paw edema test on Wistar rats, the effect of formulations on the barrier property of the stratum corneum were determined using transepidermal water loss measurements (TEWL) and histological analysis was performed to evaluate the possible presence of morphological changes. The results obtained indicate that nanoparticle-in-gel formulation produced significantly higher edema inhibition compared to other formulations tested, although it contained ten times less CP. TEWL measurements also revealed that all formulations have no significant disturbance on the barrier function of skin. Furthermore, histological analysis of rat abdominal skin did not show morphological tissue changes nor cell infiltration signs after application of the formulations. Taken together, the present data show that the use of lecithin/chitosan nanoparticles in chitosan gel as a drug carrier significantly improves the risk-benefit ratio as compared with sodium-deoxycholate gel and commercial cream formulations of CP. PMID:28035957

In Vivo Assessment of Clobetasol Propionate-Loaded Lecithin-Chitosan Nanoparticles for Skin Delivery.

Science.gov (United States)

Şenyiğit, Taner; Sonvico, Fabio; Rossi, Alessandra; Tekmen, Işıl; Santi, Patrizia; Colombo, Paolo; Nicoli, Sara; Özer, Özgen

2016-12-26

The aim of this work was to assess in vivo the anti-inflammatory efficacy and tolerability of clobetasol propionate (CP) loaded lecithin/chitosan nanoparticles incorporated into chitosan gel for topical application (CP 0.005%). As a comparison, a commercial cream (CP 0.05% w / w ), and a sodium deoxycholate gel (CP 0.05% w / w ) were also evaluated. Lecithin/chitosan nanoparticles were prepared by self-assembling of the components obtained by direct injection of soybean lecithin alcoholic solution containing CP into chitosan aqueous solution. Nanoparticles obtained had a particle size around 250 nm, narrow distribution (polydispersity index below 0.2) and positive surface charge, provided by a superficial layer of the cationic polymer. The nanoparticle suspension was then loaded into a chitosan gel, to obtain a final CP concentration of 0.005%. The anti-inflammatory activity was evaluated using carrageenan-induced hind paw edema test on Wistar rats, the effect of formulations on the barrier property of the stratum corneum were determined using transepidermal water loss measurements (TEWL) and histological analysis was performed to evaluate the possible presence of morphological changes. The results obtained indicate that nanoparticle-in-gel formulation produced significantly higher edema inhibition compared to other formulations tested, although it contained ten times less CP. TEWL measurements also revealed that all formulations have no significant disturbance on the barrier function of skin. Furthermore, histological analysis of rat abdominal skin did not show morphological tissue changes nor cell infiltration signs after application of the formulations. Taken together, the present data show that the use of lecithin/chitosan nanoparticles in chitosan gel as a drug carrier significantly improves the risk-benefit ratio as compared with sodium-deoxycholate gel and commercial cream formulations of CP.

Alteration of metabolomic profiles by titanium dioxide nanoparticles in human gingivitis model.

Science.gov (United States)

Garcia-Contreras, Rene; Sugimoto, Masahiro; Umemura, Naoki; Kaneko, Miku; Hatakeyama, Yoko; Soga, Tomoyoshi; Tomita, Masaru; Scougall-Vilchis, Rogelio J; Contreras-Bulnes, Rosalia; Nakajima, Hiroshi; Sakagami, Hiroshi

2015-07-01

Although nanoparticles (NPs) has afforded considerable benefits in various fields of sciences, several reports have shown their harmful effects, suggesting the necessity of adequate risk assessment. To clarify the mechanism of titanium dioxide nanoparticles (TiO2 NPs)-enhanced gingival inflammation, we conducted the full-scale metabolomic analyses of human gingival fibroblast cells treated with IL-1β alone or in combination with TiO2 NPs. Observation with transmission electron microscope demonstrated the incorporation of TiO2 NPs into vacuoles of the cells. TiO2 NPs significantly enhanced the IL-1β-induced prostaglandin E2 production and COX-1 and COX-2 protein expression. IL-1β reduced the intracellular concentrations of overall primary metabolites especially those of amino acid, urea cycle, polyamine, S-adenosylmethione and glutathione synthetic pathways. The addition of TiO2 NPs further augmented these IL-1β-induced metabolic changes, recommending careful use of dental materials containing TiO2 NPs towards patients with gingivitis or periodontitis. The impact of the present study is to identify the molecular targets of TiO2 NPs for the future establishment of new metabolic markers and therapeutic strategy of gingival inflammation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enhanced apoptotic and anticancer potential of paclitaxel loaded biodegradable nanoparticles based on chitosan.

Science.gov (United States)

Gupta, Umesh; Sharma, Saurabh; Khan, Iliyas; Gothwal, Avinash; Sharma, Ashok K; Singh, Yuvraj; Chourasia, Manish K; Kumar, Vipin

2017-05-01

Taxanes have established and proven effectivity against different types of cancers; in particular breast cancers. However, the high hemolytic toxicity and hydrophobic nature of paclitaxel and docetaxel have always posed challenges to achieve safe and effective delivery. Use of bio-degradable materials with an added advantage of nanotechnology could possibly improve the condition so as to achieve better and safe delivery. In the present study paclitaxel loaded chitosan nanoparticles were formulated and optimized using simple w/o nanoemulsion technique. The observed average size, pdi, zeta potential, entrapment efficiency and drug loading for the optimized paclitaxel loaded chitosan nanoparticle formulation (PTX-CS-NP-10) was 226.7±0.70nm, 0.345±0.039, 37.4±0.77mV, 79.24±2.95% and 11.57±0.81%; respectively. Nanoparticles were characterized further for size by Transmission Electron Microscopy (TEM). In vitro release studies exhibited sustained release pattern and more than 60% release was observed within 24h. Enhanced in vitro anticancer activity was observed as a result of MTT assay against triple negative MDA-MB-231 breast cancer cell lines. The observed IC 50 values obtained for PTX-CS-NP-10 was 9.36±1.13μM and was almost 1.6 folds (psafe as observed for haemolytic toxicity which was almost 4 folds less (psafe nanoformulation of paclitaxel was developed, characterized and evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhancement of temozolomide stability by loading in chitosan-carboxylated polylactide-based nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Di Martino, Antonio; Kucharczyk, Pavel; Capakova, Zdenka; Humpolicek, Petr; Sedlarik, Vladimir, E-mail: sedlarik@ft.utb.cz [Tomas Bata University in Zlín, Centre of Polymer Systems, University Institute (Czech Republic)

2017-02-15

In the presented work, amphiphilic nanoparticles based on chitosan and carboxy-enriched polylactic acid have been prepared to improve the stability of the pro-drug temozolomide in physiological media by encapsulation. The carrier, with a diameter in the range of 150–180 nm, was able to accommodate up to 800 μg of temozolomide per mg of polymer. The obtained formulation showed good stability in physiological condition and preparation media up to 1 month. Temozolomide loaded inside the carrier exhibited greater stability than the free drug, in particular in simulated physiological solution at pH 7.4 where the hydrolysis in the inactive metabolite was clearly delayed. CS-SPLA nanoparticles demonstrated a pH-dependent TMZ release kinetics with the opportunity to increase or decrease the rate. Mass spectroscopy, UV-Vis analysis, and in vitro cell tests confirmed the improvement in temozolomide stability and effectiveness when loaded into the polymeric carrier, in comparison with the free drug.

In situ effects of titanium dioxide nanoparticles on community structure of freshwater benthic macroinvertebrates.

Science.gov (United States)

Jovanović, Boris; Milošević, Djuradj; Piperac, Milica Stojković; Savić, Ana

2016-06-01

For the first time in the current literature, the effect of titanium dioxide (TiO2) nanoparticles on the community structure of macroinvertebrates has been investigated in situ. Macroinvertebrates were exposed for 100 days to an environmentally relevant concentration of TiO2 nanoparticles, 25 mg kg(-1) in sediment. Czekanowski's index was 0.61, meaning 39% of the macroinvertebrate community structure was affected by the TiO2 treatment. Non-metric multidimensional scaling (NMDS) visualized the qualitative and quantitative variability of macroinvertebrates at the community level among all samples. A distance-based permutational multivariate analysis of variance (PERMANOVA) revealed the significant effect of TiO2 on the macroinvertebrate community structure. The indicator value analysis showed that the relative frequency and abundance of Planorbarius corneus and Radix labiata were significantly lower in the TiO2 treatment than in the control. Meanwhile, Ceratopogonidae, showed a significantly higher relative frequency and abundance in the TiO2 treatment than in the control. Copyright © 2016 Elsevier Ltd. All rights reserved.

X-ray excited luminescence of polystyrene composites loaded with SrF{sub 2} nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Demkiv, T.M.; Halyatkin, O.O.; Vistovskyy, V.V. [Ivan Franko National University of Lviv, 8a Kyryla i Mefodiya St., 79005 Lviv (Ukraine); Hevyk, V.B. [Ivano-Frankivsk National Technical University of Oil and Gas, 15 Karpatska St., 76019 Ivano-Frankivsk (Ukraine); Yakibchuk, P.M. [Ivan Franko National University of Lviv, 8a Kyryla i Mefodiya St., 79005 Lviv (Ukraine); Gektin, A.V. [Institute for Scintillation Materials, NAS of Ukraine, 60 Lenina Ave, 61001 Kharkiv (Ukraine); Voloshinovskii, A.S. [Ivan Franko National University of Lviv, 8a Kyryla i Mefodiya St., 79005 Lviv (Ukraine)

2017-03-01

The polystyrene film nanocomposites of 0.3 mm thickness with embedded SrF{sub 2} nanoparticles up to 40 wt% have been synthesized. The luminescent and kinetic properties of the polystyrene composites with embedded SrF{sub 2} nanoparticles upon the pulse X-ray excitation have been investigated. The luminescence intensity of the pure polystyrene scintillator film significantly increases when it is loaded with the inorganic SrF{sub 2} nanoparticles. The film nanocomposites show fast (∼2.8 ns) and slow (∼700 ns) luminescence decay components typical for a luminescence of polystyrene activators (p-Terphenyl and POPOP) and SrF{sub 2} nanoparticles, respectively. It is revealed that the fast decay luminescence component of the polystyrene composites is caused by the excitation of polystyrene by the photoelectrons escaped from the nanoparticles due to photoeffect, and the slow component is caused by reabsorption of the self-trapped exciton luminescence of SrF{sub 2} nanoparticles by polystyrene.

Cellular Interactions and Biological Responses to Titanium Dioxide Nanoparticles in HepG2 and BEAS-2B Cells: Role of Cell Culture Media

Science.gov (United States)

ABSTRACT We have shown previously that the composition of the biological medium used in vitro can affect the cellular interaction and biological response of titanium dioxide nanoparticles (nano-TiO2) in human lung epithelial cells. However, it is unclear if these effects are co...

Surface properties and dye loading behavior of Zn2SnO4 nanoparticles hydrothermally synthesized using different mineralizers

International Nuclear Information System (INIS)

Annamalai, Alagappan; Eo, Yang Dam; Im, Chan; Lee, Man-Jong

2011-01-01

We present for the first time the influence of different mineralizers on the isoelectric point (IEP) of zinc stannate (Zn 2 SnO 4 ) nanoparticles hydrothermally prepared using three different mineralizers, viz., Na 2 CO 3 , KOH and tert-butyl amine, and the effect of the IEPs on the dye loading behavior of Zn 2 SnO 4 based photoelectrodes in dye sensitized solar cells (DSSCs). To produce highly crystalline, uniform sized Zn 2 SnO 4 nanoparticles, hydrothermal processing parameters, such as reaction temperature, time, and the mineralizers used have been critically adjusted. The structural and morphological features of the as-synthesized Zn 2 SnO 4 nanoparticles have been observed using both scanning and transmission electron microscopy. For the surface state characterization of shape- and size-controlled Zn 2 SnO 4 nanoparticles, the IEPs of Zn 2 SnO 4 surfaces were determined through zeta potential measurements. The IEPs were found to be 5.7, 7.4 and 8.1 for Zn 2 SnO 4 nanoparticles formed using Na 2 CO 3 , KOH and tert-butyl amine, respectively, suggesting that the surface properties of Zn 2 SnO 4 nanoparticles can be manipulated through the choice of the mineralizers used during the hydrothermal reaction. The amount of N719 dye loading on the surfaces of Zn 2 SnO 4 electrodes having different IEPs was also evaluated. It was revealed that the higher the IEP, the higher the dye loading amount, which means that the IEP mainly affects the dye loading at the dye-metal oxide interface. - Highlights: → The effect of various mineralizers on the isoelectric point of Zn 2 SnO 4 was discussed. → The IEP of Zn 2 SnO 4 can be modified by the choice of mineralizer. → Change in IEP affects the surface properties and the morphology of Zn 2 SnO 4 particles. → Modified surface affects the N719 dye loading behaviour of the Zn 2 SnO 4 based DSSCs.

Mixed matrix membranes prepared from high impact polystyrene with dispersed TiO2 nanoparticles for gas separation

Directory of Open Access Journals (Sweden)

P. Safaei

2016-01-01

Full Text Available The current study presents synthesis and characterization of high impact polystyrene - TiO2 nanoparticles mixed matrix membranes for separation of carbon dioxide from nitrogen. The solution-casting method was used for preparation of membranes. The nano mixed matrix membranes were characterized using scanning electron microscopy to ensure the suitable dispersion of nano particles in high impact polystyrene matrix. The effect of TiO2 nanoparticles loading on membrane performance was investigated. The separation performance of synthesized membranes was investigated in separation of CO2 from CO2/N2 mixture. Effect of feed pressure and TiO2 content on separation of CO2 was studied. The results revealed that increase of feed pressure decreases flux of gases through the mixed matrix membrane. The results also confirmed that the best separation performance can be obtained at TiO2 nanoparticles loading of 7 wt.%.

Synthesis of Titanium Dioxide Nanoparticles Using a Double-Slit Curved Wall-Jet Burner

KAUST Repository

Ismail, Mohamed

2016-05-04

A novel double-slit curved wall-jet (DS-CWJ) burner was proposed and utilized for flame synthesis. This burner was comprised of double curved wall-jet nozzles with coaxial slits; the inner slit was for the delivery of titanium tetraisopropoxide (TTIP) precursor while the outer one was to supply premixed fuel/air mixture of ethylene (C2H4) or propane (C3H8). This configuration enabled rapid mixing between the precursor and reactants along the curved surface and inside the recirculation zone of the burner. Particle growth of titanium dioxide (TiO2) nanoparticles and their phases was investigated with varying equivalence ratio and Reynolds number. Flow field and flame structure were measured using particle image velocimetry (PIV) and OH planar laser-induced fluorescence (PLIF) techniques, respectively. The nanoparticles were characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and nitrogen adsorption Brunauer–Emmett–Teller (BET) for surface area analysis. The flow field consisted of a wall-jet region leading to a recirculation zone, an interaction jet region, followed by a merged-jet region. The DS-CWJ burner revealed appreciable mixing characteristics between the precursor and combustion gases near the nozzle regions, with a slight increase in the axial velocity due to the precursor injection. The precursor supply had a negligible effect on the flame structure. The burner produced a reasonably uniform size (13–18 nm) nanoparticles with a high BET surface area (>100 m2/g). The phase of TiO2 nanoparticles was mainly dependent on the equivalence ratio and fuel type, which impact flame height, heat release rate, and high temperature residence time of the precursor vapor. For ethylene flames, the anatase content increased with the equivalence ratio, whereas it decreased in the case of propane flames. The synthesized TiO2 nanoparticles exhibited high crystallinity and the anatase phase was dominant at high equivalence

Biomineralized diamond-like carbon films with incorporated titanium dioxide nanoparticles improved bioactivity properties and reduced biofilm formation.

Science.gov (United States)

Lopes, F S; Oliveira, J R; Milani, J; Oliveira, L D; Machado, J P B; Trava-Airoldi, V J; Lobo, A O; Marciano, F R

2017-12-01

Recently, the development of coatings to protect biomedical alloys from oxidation, passivation and to reduce the ability for a bacterial biofilm to form after implantation has emerged. Diamond-like carbon films are commonly used for implanted medical due to their physical and chemical characteristics, showing good interactions with the biological environment. However, these properties can be significantly improved when titanium dioxide nanoparticles are included, especially to enhance the bactericidal properties of the films. So far, the deposition of hydroxyapatite on the film surface has been studied in order to improve biocompatibility and bioactive behavior. Herein, we developed a new route to obtain a homogeneous and crystalline apatite coating on diamond-like carbon films grown on 304 biomedical stainless steel and evaluated its antibacterial effect. For this purpose, films containing two different concentrations of titanium dioxide (0.1 and 0.3g/L) were obtained by chemical vapor deposition. To obtain the apatite layer, the samples were soaked in simulated body fluid solution for up to 21days. The antibacterial activity of the films was evaluated by bacterial eradication tests using Staphylococcus aureus biofilm. Scanning electron microscopy, X-ray diffraction, Raman scattering spectroscopy, and goniometry showed that homogeneous, crystalline, and hydrophilic apatite films were formed independently of the titanium dioxide concentration. Interestingly, the diamond-like films containing titanium dioxide and hydroxyapatite reduced the biofilm formation compared to controls. A synergism between hydroxyapatite and titanium dioxide that provided an antimicrobial effect against opportunistic pathogens was clearly observed. Copyright © 2017 Elsevier B.V. All rights reserved.

Polycaprolactone Based Nanoparticles Loaded with Indomethacin for Anti-Inflammatory Therapy: From Preparation to Ex Vivo Study.

Science.gov (United States)

Badri, Waisudin; Miladi, Karim; Robin, Sophie; Viennet, Céline; Nazari, Qand Agha; Agusti, Géraldine; Fessi, Hatem; Elaissari, Abdelhamid

2017-09-01

This work focused on the preparation of polycaprolactone based nanoparticles containing indomethacin to provide topical analgesic and anti-inflammatory effect for symptomatic treatment of inflammatory diseases. Indomethacin loaded nanoparticles are prepared for topical application to decrease indomethacin side effects and administration frequency. Oppositely to already reported works, in this research non-invasive method has been used for the enhancement of indomethacin dermal drug penetration. Ex-vivo skin penetration study was carried out on fresh human skin. Nanoprecipitation was used to prepare nanoparticles. Nanoparticles were characterized using numerous techniques; dynamic light scattering, SEM, TEM, DSC and FTIR. Regarding ex-vivo skin penetration of nanoparticles, confocal laser scanning microscopy has been used. The results showed that NPs hydrodynamic size was between 220 to 245 nm and the zeta potential value ranges from -19 to -13 mV at pH 5 and 1 mM NaCl. The encapsulation efficiency was around 70% and the drug loading was about 14 to 17%. SEM and TEM images confirmed that the obtained nanoparticles were spherical with smooth surface. The prepared nanoparticles dispersions were stable for a period of 30 days under three temperatures of 4°C, 25°C and 40°C. In addition, CLSM images proved that obtained NPs can penetrate the skin as well. The prepared nanoparticles are submicron in nature, with good colloidal stability and penetrate the stratum corneum layer of the skin. This formulation potentiates IND skin penetration and as a promising strategy would be able to decline the side effects of IND.

[Development of Inhalable Dry Powder Formulations Loaded with Nanoparticles Maintaining Their Original Physical Properties and Functions].

Science.gov (United States)

Okuda, Tomoyuki

2017-01-01

 Functional nanoparticles, such as liposomes and polymeric micelles, are attractive drug delivery systems for solubilization, stabilization, sustained release, prolonged tissue retention, and tissue targeting of various encapsulated drugs. For their clinical application in therapy for pulmonary diseases, the development of dry powder inhalation (DPI) formulations is considered practical due to such advantages as: (1) it is noninvasive and can be directly delivered into the lungs; (2) there are few biocomponents in the lungs that interact with nanoparticles; and (3) it shows high storage stability in the solid state against aggregation or precipitation of nanoparticles in water. However, in order to produce effective nanoparticle-loaded dry powders for inhalation, it is essential to pursue an innovative and comprehensive formulation strategy in relation to composition and powderization which can achieve (1) the particle design of dry powders with physical properties suitable for pulmonary delivery through inhalation, and (2) the effective reconstitution of nanoparticles that will maintain their original physical properties and functions after dissolution of the powders. Spray-freeze drying (SFD) is a relatively new powderization technique combining atomization and lyophilization, which can easily produce highly porous dry powders from an aqueous sample solution. Previously, we advanced the optimization of components and process conditions for the production of SFD powders suitable to DPI application. This review describes our recent results in the development of novel DPI formulations effectively loaded with various nanoparticles (electrostatic nanocomplexes for gene therapy, liposomes, and self-assembled lipid nanoparticles), based on SFD.

Titanium dioxide nanoparticles exacerbate DSS-induced colitis: role of the NLRP3 inflammasome

Science.gov (United States)

Ruiz, Pedro A; Morón, Belen; Becker, Helen M; Lang, Silvia; Atrott, Kirstin; Spalinger, Marianne R; Scharl, Michael; Wojtal, Kacper A; Fischbeck-Terhalle, Anne; Frey-Wagner, Isabelle; Hausmann, Martin; Kraemer, Thomas; Rogler, Gerhard

2017-01-01

Objective Western lifestyle and diet are major environmental factors playing a role in the development of IBD. Titanium dioxide (TiO2) nanoparticles are widely used as food additives or in pharmaceutical formulations and are consumed by millions of people on a daily basis. We investigated the effects of TiO2 in the development of colitis and the role of the nucleotide-binding oligomerisation domain receptor, pyrin domain containing (NLRP)3 inflammasome. Design Wild-type and NLRP3-deficient mice with dextran sodium sulfate-induced colitis were orally administered with TiO2 nanoparticles. The proinflammatory effects of TiO2 particles in cultured human intestinal epithelial cells (IECs) and macrophages were also studied, as well as the ability of TiO2 crystals to traverse IEC monolayers and accumulate in the blood of patients with IBD using inductively coupled plasma mass spectrometry. Results Oral administration of TiO2 nanoparticles worsened acute colitis through a mechanism involving the NLRP3 inflammasome. Importantly, crystals were found to accumulate in spleen of TiO2-administered mice. In vitro, TiO2 particles were taken up by IECs and macrophages and triggered NLRP3-ASC-caspase-1 assembly, caspase-1 cleavage and the release of NLRP3-associated interleukin (IL)-1β and IL-18. TiO2 also induced reactive oxygen species generation and increased epithelial permeability in IEC monolayers. Increased levels of titanium were found in blood of patients with UC having active disease. Conclusion These findings indicate that individuals with a defective intestinal barrier function and pre-existing inflammatory condition, such as IBD, might be negatively impacted by the use of TiO2 nanoparticles. PMID:26848183

Titanium dioxide nanoparticles exacerbate DSS-induced colitis: role of the NLRP3 inflammasome.

Science.gov (United States)

Ruiz, Pedro A; Morón, Belen; Becker, Helen M; Lang, Silvia; Atrott, Kirstin; Spalinger, Marianne R; Scharl, Michael; Wojtal, Kacper A; Fischbeck-Terhalle, Anne; Frey-Wagner, Isabelle; Hausmann, Martin; Kraemer, Thomas; Rogler, Gerhard

2017-07-01

Western lifestyle and diet are major environmental factors playing a role in the development of IBD. Titanium dioxide (TiO 2 ) nanoparticles are widely used as food additives or in pharmaceutical formulations and are consumed by millions of people on a daily basis. We investigated the effects of TiO 2 in the development of colitis and the role of the nucleotide-binding oligomerisation domain receptor, pyrin domain containing (NLRP)3 inflammasome. Wild-type and NLRP3-deficient mice with dextran sodium sulfate-induced colitis were orally administered with TiO 2 nanoparticles. The proinflammatory effects of TiO 2 particles in cultured human intestinal epithelial cells (IECs) and macrophages were also studied, as well as the ability of TiO 2 crystals to traverse IEC monolayers and accumulate in the blood of patients with IBD using inductively coupled plasma mass spectrometry. Oral administration of TiO 2 nanoparticles worsened acute colitis through a mechanism involving the NLRP3 inflammasome. Importantly, crystals were found to accumulate in spleen of TiO 2 -administered mice. In vitro, TiO 2 particles were taken up by IECs and macrophages and triggered NLRP3-ASC-caspase-1 assembly, caspase-1 cleavage and the release of NLRP3-associated interleukin (IL)-1β and IL-18. TiO 2 also induced reactive oxygen species generation and increased epithelial permeability in IEC monolayers. Increased levels of titanium were found in blood of patients with UC having active disease. These findings indicate that individuals with a defective intestinal barrier function and pre-existing inflammatory condition, such as IBD, might be negatively impacted by the use of TiO 2 nanoparticles. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Gum tragacanth stabilized green gold nanoparticles as cargos for Naringin loading: A morphological investigation through AFM.

Science.gov (United States)

Rao, Komal; Imran, Muhammad; Jabri, Tooba; Ali, Imdad; Perveen, Samina; Shafiullah; Ahmed, Shakil; Shah, Muhammad Raza

2017-10-15

Gold nanoparticles (AuNPs) have attracted greater scientific interests for the construction of drugs loading cargos due to their biocompatibility, safety and facile surface modifications. This study deals with the fabrication of gum tragacanth (GT) green AuNPs as carrier for Naringin, a less water soluble therapeutic molecule. The optimized AuNPs were characterized through UV-vis spectroscopy, FT-IR and atomic force microscope (AFM). Naringin loaded nanoparticles were investigated for their bactericidal potentials using Tetrazolium Microplate assay. Morphological studies conducted via AFM revealed spherical shape for AuNPs with nano-range size and stabilized by GT multi-functional groups. The AuNPs acted as carrier for increased amount of Naringin. Upon loading in AuNPs, Naringin An increased in the bactericidal potentials of Naringin was observed after loading on AuNPs against various tested bacterial strains. This was further authenticated by the surface morphological analysis, showing enhanced membrane destabilizing effects of loaded Naringin. The results suggest that GT stabilized green AuNPs can act as effective delivery vehicles for enhancing bactericidal potentials of Naringin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determining the efficiency of ZSM-5 zeolite impregnated with nanoparticles of titanium dioxide in the photocatalytic removal of styrene vapors

Directory of Open Access Journals (Sweden)

Mojtaba Nakhaei pour

2017-03-01

Full Text Available Introduction: Styrene monomer is a volatile organic compound that has many applications particularly in plastic, rubber and paint industries. According to the harmful effects of these compounds on human and environment, reducing and controling of them seem necessary. Therefore, in this study removal of styrene was investigated using photocatalytic process of titanium dioxide nanoparticles stabilized on ZSM-5. Methods: After stabilization of titanium dioxide nanoparticles on ZSM-5 zeolite, BET, SEM and XRD analysis were used to determine the characteristics of nanoparticles. Experiments were conducted at ambient temperature in laboratory scale. Concentration of produced styrene in the experiments was 50 and 300 ppm, and input flow rate was 1 l/min. Results: images and spectra obtained through XRD and SEM-EDAX showed that  nano-catalysts are well- stabilized. The results showed that by increasing of input concentration of styrene from 50 to 300 ppm, photocatalytic removal efficiency are reduced. Also, adsorption capacity of the catalyst bed in concentrations of 50 and 300 ppm was calculated 16.3 and19.4 mg/gr of adsorbent respectively. Conclusion: The results show that the use of hybrid bed can increase the removal efficiency of contaminants. And due to low cost of application of these systems compared to conventional methods, it is recommended that more comprehensive studies to be done regarding the optimization of the parameters affecting the process of photocatalytic removal.

Synthesis and characterization of folate decorated albumin bio-conjugate nanoparticles loaded with a synthetic curcumin difluorinated analogue.

Science.gov (United States)

Gawde, Kaustubh A; Kesharwani, Prashant; Sau, Samaresh; Sarkar, Fazlul H; Padhye, Subhash; Kashaw, Sushil K; Iyer, Arun K

2017-06-15

Albumin-bound paclitaxel colloidal nanoparticle (Abraxane®) is an FDA approved anticancer formulation available in the market. It is a suspension which is currently used therapeutically for treating cancers of the breast, lung, and pancreas among others. CDF is a novel new and potent synthetic curcumin analogue that is widely used for breast and ovarian cancer. The aim of this study was to use biocompatible albumin as well as folate decorated albumin to formulate colloidal nanoparticles encapsulating curcumin difluorinated (CDF). CDF has demonstrated a 16-fold improvement in stability and remarkable anticancer potency compared to its natural derivative, curcumin. CDF showed marked inhibition of cancer cell growth through down-regulation of multiple miRNAs, up-regulation of phosphatase and tensin homolog (PTEN), and attenuation of histone methyl transferase EZH2. However, CDF is highly hydrophobic and photodegradable with sparing aqueous solubility. In this study, we have formulated albumin nanoparticle using a modified desolvation method, which yielded high CDF loading in a nanoformulation. The physicochemical properties of CDF loaded albumin and folate-decorated albumin nanosuspensions were assessed for particle size, morphology, zeta potential, drug encapsulation efficiency/loading, solubility and drug release. Importantly, the folate ligand decorated albumin nanoparticles were formulated in principle to passively and actively target folate-overexpressing-cancers. In this study, the synthesis and optimization of BSA and folate decorated BSA conjugated CDF nanoparticles are assessed in detail that will be useful for its future clinical translation. Copyright © 2017 Elsevier Inc. All rights reserved.

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

The insertion reactions of zirconium(IV) -butoxide and titanium(IV) -butoxide with a heterocumulene like carbodiimide, carbon dioxide or phenyl isocyanate are compared. Both give an intermediate which carries out metathesis at elevated temperatures by inserting a second heterocumulene in a head-to-head fashion.

Hypericin-loaded nanoparticles for the photodynamic treatment of ovarian cancer.

Science.gov (United States)

Zeisser-Labouèbe, Magali; Lange, Norbert; Gurny, Robert; Delie, Florence

2006-12-01

A photodynamic approach has been suggested to improve diagnosis and therapy of ovarian cancer. As Hypericin (Hy), a natural photosensitizer (PS) extracted from Hypericum perforatum, has been shown to be efficient in vitro and in vivo for the detection or treatment of other cancers, Hy could also be a potent tool for the treatment and detection of ovarian cancer. Due to its hydrophobicity, systemic administration of Hy is problematic. Thus, polymeric nanoparticles (NPs) of polylactic acid (PLA) or polylactic-co-glycolic acid (PLGA) were used as a drug delivery system. Hy-loaded NPs were produced with the following characteristics: (i) size in the 200-300 nm range, (ii) negative zeta potential, (iii) low residual PVAL and (iv) drug loading from 0.03 to 0.15% (w/w). Their in vitro photoactivity was investigated on the NuTu-19 ovarian cancer cell model derived from Fischer 344 rats and compared to free drug. Hy-loaded PLA NPs exhibited a higher photoactivity than free drug. Increasing light dose or incubation time with cells induced an enhanced activity of Hy-loaded PLA NPs. Increased NP drug loading had a negative effect on their photoactivity on NuTu-19 cells: at the same Hy concentration, the higher was the drug loading, the lower was the phototoxic effect. The influence of NP drug loading on the Hy release from NPs was also investigated.

Preparation of curcumin-loaded pluronic F127/chitosan nanoparticles for cancer therapy

International Nuclear Information System (INIS)

Phuc Le, Thi Minh; Pham, Van Phuc; Lua Dang, Thi Minh; Huyen La, Thi; Le, Thi Hanh; Le, Quang Huan

2013-01-01

Nanoparticles (NPs) have been proven to be an effective delivery system with few side effects for anticancer drugs. In this study, curcumin-loaded NPs have been prepared by an ionic gelation method using chitosan (Chi) and pluronic ® F-127 (PF) as carriers to deliver curcumin to the target cancer cells. Prepared NPs were characterized using Zetasizer, fluorescence microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Our results showed that the encapsulation efficiency of curcumin was approximately 50%. The average size of curcumin-loaded PF/Chi NPs was 150.9 nm, while the zeta potential was 5.09 mV. Cellular uptake of curcumin-loaded NPs into HEK293 cells was confirmed by fluorescence microscopy. (paper)

Synthesis of MgO nanoparticle loaded mesoporous Al2O3 and its defluoridation study

International Nuclear Information System (INIS)

Dayananda, Desagani; Sarva, Venkateswara R.; Prasad, Sivankutty V.; Arunachalam, Jayaraman; Parameswaran, Padmanabhan; Ghosh, Narendra N.

2015-01-01

Highlights: • Simple and cost effective preparation of MgO nanoparticles loaded mesoporous Al 2 O 3 . • Adsorbents possess high surface area and mesoporous structure. • Higher fluoride removal capacity of MgO loaded Al 2 O 3 than that of pure Al 2 O 3 . • Faster fluoride adsorption kinetics of MgO loaded Al 2 O 3 from water. - Abstract: MgO nanoparticle loaded mesoporous alumina has been synthesized using a simple aqueous solution based cost effective method for removal of fluoride from water. Wide angle powder X-ray diffraction, nitrogen adsorption desorption analysis, transmission electron microscopy techniques and energy dispersive X-ray spectroscopy were used to characterize the synthesized adsorbents. Synthesized adsorbents possess high surface area with mesoporous structure. The adsorbents have been thoroughly investigated for the adsorption of F − using batch adsorption method. MgO nanoparticle loading on mesoporous Al 2 O 3 enhances the F − adsorption capacity of Al 2 O 3 from 56% to 90% (initial F − concentration = 10 mg L −1 ). Kinetic study revealed that adsorption kinetics follows the pseudo-second order model, suggesting the chemisorption mechanism. The F − adsorption isotherm data was explained by both Langmuir and Freundlich model. The maximum adsorption capacity of 40MgO@Al 2 O 3 was 37.35 mg g −1 . It was also observed that, when the solutions having F − concentration of 5 mg L −1 and 10 mg L −1 was treated with 40MgO@Al 2 O 3 , the F − concentration in treated water became <1 mg L −1 , which is well below the recommendation of WHO

Spanish Broom (Spartium junceum L.) fibers impregnated with vancomycin-loaded chitosan nanoparticles as new antibacterial wound dressing: Preparation, characterization and antibacterial activity.

Science.gov (United States)

Cerchiara, Teresa; Abruzzo, Angela; Ñahui Palomino, Rogers Alberto; Vitali, Beatrice; De Rose, Renata; Chidichimo, Giuseppe; Ceseracciu, Luca; Athanassiou, Athanassia; Saladini, Bruno; Dalena, Francesco; Bigucci, Federica; Luppi, Barbara

2017-03-01

In this work, we propose as new wound dressing, the Spanish Broom fibers impregnated with vancomycin (VM) loaded chitosan nanoparticles. Spanish Broom fibers were extracted by patented method DiCoDe and the morphological, physical and mechanical properties were investigated. Chitosan nanoparticles were prepared by ionic gelation using different weight ratios between chitosan (CH) and tripolyphosphate (TPP). Nanoparticles were characterized in terms of size, zeta potential, yield, encapsulation efficiency, stability and drug release. Finally, the antibacterial activity against Staphylococcus aureus as well as in vitro cytotoxicity on HaCaT cells were evaluated. The best formulation CH/TPP 4:1 was selected based on the encapsulation efficiency and yield. Spanish Broom fibers impregnated with loaded nanoparticles showed an increased antibacterial activity against S. aureus compared to the same fibers containing VM without nanoparticles. Moreover, these fibers were not toxic to HaCaT keratinocytes cells. In conclusion, Spanish Broom fibers impregnated with VM loaded CH/TPP nanoparticles would appear to be a promising candidate for wound dressing application. Copyright © 2016 Elsevier B.V. All rights reserved.

Selective complexometric determination of titanium(IV) using sodium potassium tartrate or ascorbic acid as masking agent

International Nuclear Information System (INIS)

Sreekumar, N.V.; Bhat, N.G.; Narayana, B.; Nazareth, R.A.; Hegde, P.; Manjunatha, B.R.

2003-01-01

A simple, rapid and accurate complexometric method is proposed for the determination of titanium(IV) where sodium potassium tartrate or ascorbic acid were used as masking agents. In the presence of diverse metal ions, titanium is first complexed with excess of EDTA and surplus EDTA is then titrated at pH 5-6 with zinc sulfate, xylenol orange being used as indicator. An excess of 5 % aqueous sodium potassium tartrate is then added to displace the complexed EDTA from the Ti-EDTA complex quantitatively, which is titrated with zinc sulfate. Also, ascorbic acid may be used as the releasing agent. The methods work well in the range 1-53 mg of Ti(IV) for sodium potassium tartrate with relative errors ± 0.28 % and standard deviations 0.16 mg. For ascorbic acid the range is 1.00-30.00 mg of Ti(IV) with relative errors of ± 0.40 % and standard deviations of 0.05 mg. (author)

Resveratrol-loaded glycyrrhizic acid-conjugated human serum albumin nanoparticles wrapping resveratrol nanoparticles: Preparation, characterization, and targeting effect on liver tumors.

Science.gov (United States)

Wu, Mingfang; Lian, Bolin; Deng, Yiping; Feng, Ziqi; Zhong, Chen; Wu, Weiwei; Huang, Yannian; Wang, Lingling; Zu, Chang; Zhao, Xiuhua

2017-08-01

In this study, glycyrrhizic acid-conjugated human serum albumin nanoparticles wrapping resveratrol nanoparticles were prepared to establish a tumor targeting nano-sized drug delivery system. Glycyrrhizic acid was coupled to human serum albumin, and resveratrol was encapsulated in glycyrrhizic acid-conjugated human serum albumin by high-pressure homogenization emulsification. The average particle size of sample nanoparticles prepared under the optimal conditions was 108.1 ± 5.3 nm with a polydispersity index (PDI) of 0.001, and the amount of glycyrrhizic acid coupled with human serum albumin was 112.56 µg/mg. The drug encapsulation efficiency and drug loading efficiency were 83.6 and 11.5%, respectively. The glycyrrhizic acid-conjugated human serum albumin nanoparticles wrapping resveratrol nanoparticles were characterized through laser light scattering, scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetric analyses, and gas chromatography. The characterization results showed that resveratrol in glycyrrhizic acid-conjugated human serum albumin nanoparticles wrapping resveratrol nanoparticles existed in amorphous state and the residual amounts of chloroform and methanol in nanoparticles were separately less than the international conference on harmonization (ICH) limit. The in vitro drug-release study showed that the nanoparticles released the drug slowly and continuously. The inhibitory rate of glycyrrhizic acid-conjugated human serum albumin nanoparticles wrapping resveratrol nanoparticles was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide method. The IC50 values of glycyrrhizic acid-conjugated human serum albumin nanoparticles wrapping resveratrol nanoparticles and resveratrol were 62.5 and 95.5 µg/ml, respectively. The target ability of glycyrrhizic acid-conjugated human serum albumin nanoparticles wrapping resveratrol nanoparticles

Palladium Nanoparticle-Loaded Cellulose Paper: A Highly Efficient, Robust, and Recyclable Self-Assembled Composite Catalytic System.

Science.gov (United States)

Zheng, Guangchao; Kaefer, Katharina; Mourdikoudis, Stefanos; Polavarapu, Lakshminarayana; Vaz, Belén; Cartmell, Samantha E; Bouleghlimat, Azzedine; Buurma, Niklaas J; Yate, Luis; de Lera, Ángel R; Liz-Marzán, Luis M; Pastoriza-Santos, Isabel; Pérez-Juste, Jorge

2015-01-15

We present a novel strategy based on the immobilization of palladium nanoparticles (Pd NPs) on filter paper for development of a catalytic system with high efficiency and recyclability. Oleylamine-capped Pd nanoparticles, dispersed in an organic solvent, strongly adsorb on cellulose filter paper, which shows a great ability to wick fluids due to its microfiber structure. Strong van der Waals forces and hydrophobic interactions between the particles and the substrate lead to nanoparticle immobilization, with no desorption upon further immersion in any solvent. The prepared Pd NP-loaded paper substrates were tested for several model reactions such as the oxidative homocoupling of arylboronic acids, the Suzuki cross-coupling reaction, and nitro-to-amine reduction, and they display efficient catalytic activity and excellent recyclability and reusability. This approach of using NP-loaded paper substrates as reusable catalysts is expected to open doors for new types of catalytic support for practical applications.

BSA nanoparticle loaded atorvastatin calcium--a new facet for an old drug.

Science.gov (United States)

Sripriyalakshmi, S; Anjali, C H; George, Priya Doss C; Rajith, B; Ravindran, Aswathy

2014-01-01

Currently, the discovery of effective chemotherapeutic agents poses a major challenge to the field of cancer biology. The present study focuses on enhancing the therapeutic and anti cancer properties of atorvastatin calcium loaded BSA (ATV-BSA) nanoparticles in vitro. BSA-ATV nanoparticles were prepared using desolvation technique. The process parameters were optimized based on the amount of desolvating agent, stabilization conditions as well as the concentration of the cross linker. The anti cancer properties of the protein coated ATV nanoparticles were tested on MiaPaCa-2 cell lines. In vitro release behavior of the drug from the carrier suggests that about 85% of the drug gets released after 72 hrs. Our studies show that ATV-BSA nanoparticles showed specific targeting and enhanced cytotoxicity to MiaPaCa-2 cells when compared to the bare ATV. We hereby propose that the possible mechanism of cellular uptake of albumin bound ATV could be through caveolin mediated endocytosis. Hence our studies open up new facet for an existing cholesterol drug as a potent anti-cancer agent.

Transient loading of CD34+ hematopoietic progenitor cells with polystyrene nanoparticles.

Science.gov (United States)

Deville, Sarah; Hadiwikarta, Wahyu Wijaya; Smisdom, Nick; Wathiong, Bart; Ameloot, Marcel; Nelissen, Inge; Hooyberghs, Jef

2017-01-01

CD34 + hematopoietic progenitor cells (HPCs) offer great opportunities to develop new treatments for numerous malignant and non-malignant diseases. Nanoparticle (NP)-based strategies can further enhance this potential, and therefore a thorough understanding of the loading behavior of HPCs towards NPs is essential for a successful application. The present study focusses on the interaction kinetics of 40 nm sized carboxylated polystyrene (PS) NPs with HPCs. Interestingly, a transient association of the NPs with HPCs is observed, reaching a maximum within 1 hour and declining afterwards. This behavior is not seen in dendritic cells (CD34-DCs) differentiated from HPCs, which display a monotonic increase in NP load. We demonstrate that this transient interaction requires an energy-dependent cellular process, suggesting active loading and release of NPs by HPCs. This novel observation offers a unique approach to transiently equip HPCs. A simple theoretical approach modeling the kinetics of NP loading and release is presented, contributing to a framework of describing this phenomenon.

Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells

Energy Technology Data Exchange (ETDEWEB)

Joshy, K.S. [Department of Chemistry, CMS College Kottayam, Kerala (India); International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Sharma, Chandra P. [Division of Biosurface Technology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Science and Technology, Poojappura, Thiruvananthapuram, Kerala (India); Kalarikkal, Nandakumar [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Sandeep, K. [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Thomas, Sabu, E-mail: sabuchathukulam@yahoo.co.uk [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Pothen, Laly A. [Department of Chemistry, Bishop Moore College, Mavelikkara, Kerala (India)

2016-09-01

Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66 ± 12.22 nm and modified solid lipid nanoparticles showed an average size of 265.61 ± 80.44 nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. - Highlights: • SLN of AZT-SA, AZT-SA-AV was developed • Better drug loading efficacy • Good uptake.

Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells

International Nuclear Information System (INIS)

Joshy, K.S.; Sharma, Chandra P.; Kalarikkal, Nandakumar; Sandeep, K.; Thomas, Sabu; Pothen, Laly A.

2016-01-01

Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66 ± 12.22 nm and modified solid lipid nanoparticles showed an average size of 265.61 ± 80.44 nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. - Highlights: • SLN of AZT-SA, AZT-SA-AV was developed • Better drug loading efficacy • Good uptake

Synthesis and catalytic properties of Pd nanoparticles loaded nanoporous TiO2 material

International Nuclear Information System (INIS)

Xu, Wence; Zhu, Shengli; Li, Zhaoyang; Cui, Zhenduo; Yang, Xianjin

2013-01-01

In the present work, Pd nanoparticles were loaded on the nanoporous TiO 2 material by a simple chemical deposition. The amount of Pd nanoparticles was determined by the loading times. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and chronoamperometry (CA) methods were used to characterize the surface morphology, composition and electro-catalyst activity of the nanoporous Pd/TiO 2 material. CV and CA results exhibited the excellent methanol electro-oxidation performance of 6 times loaded sample. The effects of methanol concentration, H 2 SO 4 concentration and upper scan limits on the electro-oxidation performance of six times loaded sample were investigated. In the solution with low methanol concentration, electro-oxidation of methanol was influenced by the amount of methanol molecules on Pd active sites. In the solution with high methanol concentration, electro-oxidation of methanol was controlled by intermediates diffusion. With increasing H 2 SO 4 concentration, driving force of methanol oxidation decreased. However, the increase of bisulfate adsorption, the reduction of thermodynamic tendency and solution conductivity would result in the suppression of peak current density. The upper scanning limit had obvious influence on the active sites for the methanol oxidation reaction in the backward scanning stage. The generation of PdO at high potential was undesired for methanol electro–oxidation

Loading technique for preparing radionuclide containing nanoparticles

DEFF Research Database (Denmark)

2011-01-01

associated with leaky blood vessels. The composition and methods of the invention find particular use in diagnosing and imaging cancerous tissue and, in general, pathological conditions associated with leaky blood vessels in a subject. The present invention provides a new diagnostic tool for the utilization......Source: US2012213698A The present invention relates to a novel composition and method for loading delivery systems such as liposome compositions with radionuclides useful in targeted diagnostic and/or therapy of target site, such as cancerous tissue and, in general, pathological conditions...... of positron emission tomography (PET) imaging technique. One specific aspect of the invention is directed to a method of producing nanoparticles with desired targeting properties for diagnostic and/or radio-therapeutic applications....

Hydrothermal synthesis of nanocubes of sillenite type compounds for photovoltaic applications and solar energy conversion of carbon dioxide to fuels

Science.gov (United States)

Subramanian, Vaidyanathan; Murugesan, Sankaran

2014-04-29

The present invention relates to formation of nanocubes of sillenite type compounds, such as bismuth titanate, i.e., Bi.sub.12TiO.sub.20, nanocubes, via a hydrothermal synthesis process, with the resulting compound(s) having multifunctional properties such as being useful in solar energy conversion, environmental remediation, and/or energy storage, for example. In one embodiment, a hydrothermal method is disclosed that transforms nanoparticles of TiO.sub.2 to bismuth titanate, i.e., Bi.sub.12TiO.sub.20, nanocubes, optionally loaded with palladium nanoparticles. The method includes reacting titanium dioxide nanotubes with a bismuth salt in an acidic bath at a temperature sufficient and for a time sufficient to form bismuth titanate crystals, which are subsequently annealed to form bismuth titanate nanocubes. After annealing, the bismuth titanate nanocubes may be optionally loaded with nano-sized metal particles, e.g., nanosized palladium particles.

Polyinosinic:polycytidylic acid loading onto different generations of PAMAM dendrimer-coated magnetic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Khodadust, Rouhollah, E-mail: raoul.1357@gmail.com [Middle East Technical University, Department of Biotechnology (Turkey); Mutlu, Pelin [Middle East Technical University, Central Laboratory, Molecular Biology and Biotechnology R and D Center (Turkey); Yalc Latin-Small-Letter-Dotless-I n, Serap [Ahi Evran University, Department of Food Engineering (Turkey); Unsoy, Gozde; Gunduz, Ufuk, E-mail: ufukg@metu.edu.tr [Middle East Technical University, Department of Biotechnology (Turkey)

2013-08-15

Poly (I:C), which is a synthetic double-stranded RNA, have significant toxicity on tumor cells. The immobilization of Poly (I:C) onto nanoparticles is important for the fabrication of targeted delivery systems. In this study, different generations of newly synthesized PAMAM dendron-coated magnetic nanoparticles (DcMNP) which can be targeted to the tumor site under magnetic field were efficiently loaded for the first time with Poly (I:C). Different generations of DcMNPs (G{sub 2}, G{sub 3}, G{sub 4}, G{sub 5}, G{sub 6}, and G{sub 7}) were synthesized. Poly (I:C) activation was achieved in the presence of EDC and 1-methylimidazole. Loading of Poly (I:C) onto DcMNPs was followed by agarose gel electrophoresis. Acidic reaction conditions were found as superior to basic and neutral for binding of Poly (I:C). In addition, having more functional groups at the surface, higher generations (G{sub 7}, G{sub 6}, and G{sub 5}) of PAMAM DcMNPs were found more suitable as a delivery system for Poly (I:C). Further in vitro and in vivo analyses of Poly (I:C)/PAMAM magnetic nanoparticles may provide new opportunities for the selective targeting and killing of tumor cells.

A Comparative Study Between the Antibacterial Effect of Nisin and Nisin-Loaded Chitosan/Alginate Nanoparticles on the Growth of Staphylococcus aureus in Raw and Pasteurized Milk Samples.

Science.gov (United States)

Zohri, Maryam; Alavidjeh, Mohammad Shafiee; Haririan, Ismaeil; Ardestani, Mehdi Shafiee; Ebrahimi, Seyed Esmaeil Sadat; Sani, Hadi Tarighati; Sadjadi, Seyed Kazem

2010-12-01

The aim of this study was to evaluate the antibacterial effect of nisin-loaded chitosan/alginate nanoparticles as a novel antibacterial delivery vehicle. The nisin-loaded nanoparticles were prepared using colloidal dispersion of the chitosan/alginate polymers in the presence of nisin. After the preparation of the nisin-loaded nanoparticles, their physicochemical properties such as size, shape, and zeta potential of the formulations were studied using scanning electron microscope and nanosizer instruments, consecutively. FTIR and differential scanning calorimetery studies were performed to investigate polymer-polymer or polymer-protein interactions. Next, the release kinetics and entrapment efficiency of the nisin-loaded nanoparticles were examined to assess the application potential of these formulations as a candidate vector. For measuring the antibacterial activity of the nisin-loaded nanoparticles, agar diffusion and MIC methods were employed. The samples under investigation for total microbial counts were pasteurized and raw milks each of which contained the nisin-loaded nanoparticles and inoculated Staphylococcus aureus (ATCC 19117 at 10(6) CFU/mL), pasteurized and raw milks each included free nisin and S. aureus (10(6) CFU/mL), and pasteurized and raw milks each had S. aureus (10(6) CFU/mL) in as control. Total counts of S. aureus were measured after 24 and 48 h for the pasteurized milk samples and after the time intervals of 0, 6, 10, 14, 18, and 24 h for the raw milk samples, respectively. According to the results, entrapment efficiency of nisin inside of the nanoparticles was about 90-95%. The average size of the nanoparticles was 205 nm, and the average zeta potential of them was -47 mV. In agar diffusion assay, an antibacterial activity (inhibition zone diameter, at 450 IU/mL) about 2 times higher than that of free nisin was observed for the nisin-loaded nanoparticles. MIC of the nisin-loaded nanoparticles (0.5 mg/mL) was about four times less than

Influence of charge on FITC-BSA-loaded chondroitin sulfate-chitosan nanoparticles upon cell uptake in human Caco-2 cell monolayers

Directory of Open Access Journals (Sweden)

Hu CS

2012-09-01

Full Text Available Chieh-shen Hu,1 Chiao-hsi Chiang,2 Po-da Hong,1,4,* Ming-kung Yeh1–3,*1Biomedical Engineering Program, Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology; 2School of Pharmacy, National Defence Medical Center; 3Bureau of Pharmaceutical Affairs, Ministry of National Defence Medical Affairs Bureau; 4Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taiwan, Republic of China*These authors contributed equally to this workBackground and methods: Chondroitin sulfate-chitosan (ChS-CS nanoparticles and positively and negatively charged fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA-loaded ChS-CS nanoparticles were prepared and characterized. The properties of ChS-CS nanoparticles, including cellular uptake, cytotoxicity, and transepithelial transport, as well as findings on field emission-scanning electron microscopy, transmission electron microscopy, and confocal laser scanning microscopy were evaluated in human epithelial colorectal adenocarcinoma (Caco-2 fibroblasts. ChS-CS nanoparticles with a mean particle size of 250 nm and zeta potentials ranging from –30 to +18 mV were prepared using an ionic gelation method.Results: Standard cell viability assays demonstrated that cells incubated with ChS-CS and FITC-BSA-loaded ChS-CS nanoparticles remained more than 95% viable at particle concentrations up to 0.1 mg/mL. Endocytosis of nanoparticles was confirmed by confocal laser scanning microscopy and measured by flow cytometry. Ex vivo transepithelial transport studies using Caco-2 cells indicated that the nanoparticles were effectively transported into Caco-2 cells via endocytosis. The uptake of positively charged FITC-BSA-loaded ChS-CS nanoparticles across the epithelial membrane was more efficient than that of the negatively charged nanoparticles.Conclusion: The ChS-CS nanoparticles fabricated in this study were

Formulation and comparative in vitro evaluation of various dexamethasone-loaded pH-sensitive polymeric nanoparticles intended for dermal applications.

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Sahle, Fitsum Feleke; Gerecke, Christian; Kleuser, Burkhard; Bodmeier, Roland

2017-01-10

pH-sensitive nanoparticles have a great potential for dermal and transfollicular drug delivery. In this study, pH-sensitive, dexamethasone-loaded Eudragit ® L 100, Eudragit ® L 100-55, Eudragit ® S 100, HPMCP-50, HPMCP-55 and cellulose acetate phthalate nanoparticles were prepared by nanoprecipitation and characterized. The pH-dependent swelling, erosion, dissolution and drug release kinetics were investigated in vitro using dynamic light scattering and Franz diffusion cells, respectively. Their toxicity potential was assessed by the ROS and MTT assays. 100-700nm nanoparticles with high drug loading and entrapment efficiency were obtained. The nanoparticles bear no toxicity potential. Cellulose phthalates nanoparticles were more sensitive to pH than acrylates nanoparticles. They dissolved in 10mM pH 7.5 buffer and released>80% of the drug within 7h. The acrylate nanoparticles dissolved in 40mM pH 7.5 buffer and released 65-70% of the drug within 7h. The nanoparticles remained intact in 10 and 40mM pH 6.0 buffers (HPMCP nanoparticles dissolved in 40mM pH 6.0 buffer) and released slowly. The nanoparticles properties could be modulated by blending the different polymers. In conclusion, various pH-sensitive nanoparticles that could release differently on the skin surface and dissolve and release in the hair follicles were obtained. Copyright © 2016 Elsevier B.V. All rights reserved.

Preliminary focus on the mechanical and antibacterial activity of a PMMA-based bone cement loaded with gold nanoparticles

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T. Russo

2017-09-01

As reported in the literature, the stress distribution may be altered in bones after the implantation of a total joint prosthesis. Some scientific works have also correlated uncemented TKA to a progressive decrease of bone density below the tibial component. Antibiotic-loaded bone cements are commonly employed in conjunction with systemic antibiotics to treat infections. Furthermore, nanoparticles with antimicrobial activity have been widely analysed. Accordingly, the current research was focused on a preliminary analysis of the mechanical and antibacterial activity of a PMMA-based bone cement loaded with gold nanoparticles. The obtained results demonstrated that nanocomposite cements with a specific concentration of gold nanoparticles improved the punching performance and antibacterial activity. However, critical aspects were found in the optimization of the nanocomposite bone cement.

Titanium Dioxide Nanoparticle-Biomolecule Interactions Influence Oral Absorption.

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Jo, Mi-Rae; Yu, Jin; Kim, Hyoung-Jun; Song, Jae Ho; Kim, Kyoung-Min; Oh, Jae-Min; Choi, Soo-Jin

2016-11-29

Titanium dioxide (TiO₂) nanoparticles (NPs) have been widely applied in various industrial fields, such as electronics, packaging, food, and cosmetics. Accordingly, concerns about the potential toxicity of TiO₂ NPs have increased. In order to comprehend their in vivo behavior and potential toxicity, we must evaluate the interactions between TiO₂ NPs and biomolecules, which can alter the physicochemical properties and the fate of NPs under physiological conditions. In the present study, in vivo solubility, oral absorption, tissue distribution, and excretion kinetics of food grade TiO₂ (f-TiO₂) NPs were evaluated following a single-dose oral administration to rats and were compared to those of general grade TiO₂ (g-TiO₂) NPs. The effect of the interactions between the TiO₂ NPs and biomolecules, such as glucose and albumin, on oral absorption was also investigated, with the aim of determining the surface interactions between them. The intestinal transport pathway was also assessed using 3-dimensional culture systems. The results demonstrate that slightly higher oral absorption of f-TiO₂ NPs compared to g-TiO₂ NPs could be related to their intestinal transport mechanism by microfold (M) cells, however, most of the NPs were eliminated through the feces. Moreover, the biokinetics of f-TiO₂ NPs was highly dependent on their interaction with biomolecules, and the dispersibility was affected by modified surface chemistry.

Mucin secretion induced by titanium dioxide nanoparticles.

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Eric Y T Chen

2011-01-01

Full Text Available Nanoparticle (NP exposure has been closely associated with the exacerbation and pathophysiology of many respiratory diseases such as Chronic Obstructive Pulmonary Disease (COPD and asthma. Mucus hypersecretion and accumulation in the airway are major clinical manifestations commonly found in these diseases. Among a broad spectrum of NPs, titanium dioxide (TiO(2, one of the PM10 components, is widely utilized in the nanoindustry for manufacturing and processing of various commercial products. Although TiO(2 NPs have been shown to induce cellular nanotoxicity and emphysema-like symptoms, whether TiO(2 NPs can directly induce mucus secretion from airway cells is currently unknown. Herein, we showed that TiO(2 NPs (<75 nm can directly stimulate mucin secretion from human bronchial ChaGo-K1 epithelial cells via a Ca(2+ signaling mediated pathway. The amount of mucin secreted was quantified with enzyme-linked lectin assay (ELLA. The corresponding changes in cytosolic Ca(2+ concentration were monitored with Rhod-2, a fluorescent Ca(2+ dye. We found that TiO(2 NP-evoked mucin secretion was a function of increasing intracellular Ca(2+ concentration resulting from an extracellular Ca(2+ influx via membrane Ca(2+ channels and cytosolic ER Ca(2+ release. The calcium-induced calcium release (CICR mechanism played a major role in further amplifying the intracellular Ca(2+ signal and in sustaining a cytosolic Ca(2+ increase. This study provides a potential mechanistic link between airborne NPs and the pathoetiology of pulmonary diseases involving mucus hypersecretion.

Palladium Loaded on Magnetic Nanoparticles as Efficient and Recyclable Catalyst for the Suzuki- Miyaura Reaction

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H. Khojasteh

2015-07-01

Full Text Available Palladium is the best metal catalyst for Suzuki cross coupling reaction for synthesize of unsymmetrical biaryl compounds. But its high cost limits its application in wide scale. Using of nanoscale particles as active catalytic cites is a good approach for reducing needed noble metal. By loading precious nanoparticles on magnetic nanocores as a support, recycling and reusing of catalyst will be possible. Magnetic nanoparticles have super paramagnetic feature and applying an external magnetic field can collect the supported catalyst from reaction milieu simply. In this work new palladium catalyst immobilized on modified magnetic nanoparticles containing NNO donor atoms were synthesized. Then the catalyst characterized by FT-IR spectroscopy, thermogravimetric analysis, X-ray diffraction and ICP. Prepared catalyst showed high activity in the Suzuki– Miyaura cross-coupling reaction of phenylboronic acid with aryl halides. Activity, Pd loading, reusability and Pd leaching of catalyst were studied. Results showed that the supported catalyst has the advantage to be completely recoverable with the simple application of an external magnetic field.

Physical-chemical properties of nanocomposites based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and titanium dioxide nanoparticles

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Braga, Natália F.; da Silva, Ana Paula; Moraes Arantes, Tatiane; Lemes, Ana Paula; Cristovan, Fernando Henrique

2018-01-01

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was reinforced with titanium dioxide (TiO2) in concentrations of 1.0%, 2.5% and 5.0% (m/m) to produce nanocomposites by the solvent casting technique. TiO2 was synthesized by a hydrothermal treatment to produce nanoparticles. The nanostructure of the nanoparticles was studied by x-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The XRD confirmed TiO2 crystalline nanoparticles, with a mixture of anatase and rutile phases. Through TEM analysis, the formation of TiO2 nanorod agglomerates with an average diameter and length of 40 and 12 nm, respectively, was observed. The thermal and mechanical properties of the pure PHBV and nanocomposite films were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis. The DSC analysis showed that the glass transition temperature decreased with the inclusion of TiO2 in the PHBV matrix in relation to pure PHBV. The results of biodegradation assays for the PHBV and nanocomposites in an aqueous medium and in soil showed morphological and structural changes for all samples, indicating a high biodegradation rate for this material. The most important conclusion is that the biodegradation of the PHBV was not affected by the addition of nanoparticles, thus enabling the use of nanocomposites in applications requiring biodegradable materials.

Radioiodination of cyclin dependent kinase inhibitor Olomoucine loaded Fe rate at Au nanoparticle and evaluation of the therapeutic efficacy on cancerous cells

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Takan, Gokhan; Guldu, Ozge Kozgus; Medine, Emin Ilker [Ege Univ., Izmir (Turkey). Dept. of Nuclear Applications

2017-06-01

Magnetic nanoparticles have promising biomedical applications such as drug delivery, novel therapeutics and diagnostic imaging. Magnetic drug delivery combination works on the delivery of magnetic nanoparticles loaded with drug to the target tissue by means of an external magnetic field. Gold coated iron oxide (Fe rate at Au) nanoparticles can provide useful surface chemistry and biological reactivity. Covalent conjugation to the Fe rate at Au nanoparticles through cleavable linkages can be used to deliver drugs to tumor cells, then the drug can be released by an external. In this paper, purine based cyclin dependent kinases (CDKs) inhibitor Olomoucine (Olo) [2-(Hydroxyethylamino)-6-benzylamino-9-methylpurine] was loaded on gold coated iron oxide (Fe rate at Au) nanoparticles and radiolabeled with {sup 131}I to combine magnetic targeted drug delivery and radiotherapy. Fe rate at Au nanoparticles were synthesized by microemulsion method. The characterization of nanoparticles was examined by TEM, VSM and XRD. Amine activation was utilized by cysteamine hydrochloride and then CDI was used for conjugation of Olomoucine. Antiproliferative effect and cytotoxicity of Olomoucine loaded Fe rate at Au nanoparticles (Fe rate at Au-Olo) were investigated on MCF7 and A549 cell lines. Proliferation rate was decreased while uptake of Fe rate at Au-Olo on both cell lines was high in comparison with Olomoucine. Also, enhanced incorporation ratio was observed under external magnetic field.

Radioiodination of cyclin dependent kinase inhibitor Olomoucine loaded Fe rate at Au nanoparticle and evaluation of the therapeutic efficacy on cancerous cells

International Nuclear Information System (INIS)

Takan, Gokhan; Guldu, Ozge Kozgus; Medine, Emin Ilker

2017-01-01

Magnetic nanoparticles have promising biomedical applications such as drug delivery, novel therapeutics and diagnostic imaging. Magnetic drug delivery combination works on the delivery of magnetic nanoparticles loaded with drug to the target tissue by means of an external magnetic field. Gold coated iron oxide (Fe rate at Au) nanoparticles can provide useful surface chemistry and biological reactivity. Covalent conjugation to the Fe rate at Au nanoparticles through cleavable linkages can be used to deliver drugs to tumor cells, then the drug can be released by an external. In this paper, purine based cyclin dependent kinases (CDKs) inhibitor Olomoucine (Olo) [2-(Hydroxyethylamino)-6-benzylamino-9-methylpurine] was loaded on gold coated iron oxide (Fe rate at Au) nanoparticles and radiolabeled with "1"3"1I to combine magnetic targeted drug delivery and radiotherapy. Fe rate at Au nanoparticles were synthesized by microemulsion method. The characterization of nanoparticles was examined by TEM, VSM and XRD. Amine activation was utilized by cysteamine hydrochloride and then CDI was used for conjugation of Olomoucine. Antiproliferative effect and cytotoxicity of Olomoucine loaded Fe rate at Au nanoparticles (Fe rate at Au-Olo) were investigated on MCF7 and A549 cell lines. Proliferation rate was decreased while uptake of Fe rate at Au-Olo on both cell lines was high in comparison with Olomoucine. Also, enhanced incorporation ratio was observed under external magnetic field.

Oxcarbazepine-loaded polymeric nanoparticles: development and permeability studies across in vitro models of the blood-brain barrier and human placental trophoblast.

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Lopalco, Antonio; Ali, Hazem; Denora, Nunzio; Rytting, Erik

2015-01-01

Encapsulation of antiepileptic drugs (AEDs) into nanoparticles may offer promise for treating pregnant women with epilepsy by improving brain delivery and limiting the transplacental permeability of AEDs to avoid fetal exposure and its consequent undesirable adverse effects. Oxcarbazepine-loaded nanoparticles were prepared by a modified solvent displacement method from biocompatible polymers (poly(lactic-co-glycolic acid) [PLGA] with or without surfactant and PEGylated PLGA [Resomer(®) RGPd5055]). The physical properties of the developed nanoparticles were determined with subsequent evaluation of their permeability across in vitro models of the blood-brain barrier (hCMEC/D3 cells) and human placental trophoblast cells (BeWo b30 cells). Oxcarbazepine-loaded nanoparticles with encapsulation efficiency above 69% were prepared with sizes ranging from 140-170 nm, polydispersity indices below 0.3, and zeta potential values below -34 mV. Differential scanning calorimetry and X-ray diffraction studies confirmed the amorphous state of the nanoencapsulated drug. The apparent permeability (Pe ) values of the free and nanoencapsulated oxcarbazepine were comparable across both cell types, likely due to rapid drug release kinetics. Transport studies using fluorescently-labeled nanoparticles (loaded with coumarin-6) demonstrated increased permeability of surfactant-coated nanoparticles. Future developments in enzyme-prodrug therapy and targeted delivery are expected to provide improved options for pregnant patients with epilepsy.

High-density platinum nanoparticle-decorated titanium dioxide nanofiber networks for efficient capillary photocatalytic hydrogen generation

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Zhaodong Li; Chunhua Yao; Yi-Cheng Wang; Solomon Mikael; Sundaram Gunasekaran; Zhenqiang Ma; Zhiyong Cai; Xudong Wang

2016-01-01

Aldehyde-functionalized cellulose nanofibers (CNFs) were applied to synthesize Pt nanoparticles (NPs) on CNF surfaces via on-site Pt ion reduction and achieve high concentration and uniform Pt NP loading. ALD could then selectively deposit TiO2 on CNFs and keep the Pt NPs uncovered due to their drastically different hydro-affinity properties. The...

Risk assessment of titanium dioxide nanoparticles via oral exposure, including toxicokinetic considerations.

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Heringa, Minne B; Geraets, Liesbeth; van Eijkeren, Jan C H; Vandebriel, Rob J; de Jong, Wim H; Oomen, Agnes G

2016-12-01

Titanium dioxide white pigment consists of particles of various sizes, from which a fraction is in the nano range (food as additive E 171 as well as in other products, such as food supplements and toothpaste. Here, we assessed whether a human health risk can be expected from oral ingestion of these titanium dioxide nanoparticles (TiO 2 NPs), based on currently available information. Human health risks were assessed using two different approaches: Approach 1, based on intake, i.e. external doses, and Approach 2, based on internal organ concentrations using a kinetic model in order to account for accumulation over time (the preferred approach). Results showed that with Approach 1, a human health risk is not expected for effects in liver and spleen, but a human health risk cannot be excluded for effects on the ovaries. When based on organ concentrations by including the toxicokinetics of TiO 2 NPs (Approach 2), a potential risk for liver, ovaries and testes is found. This difference between the two approaches shows the importance of including toxicokinetic information. The currently estimated risk can be influenced by factors such as absorption, form of TiO 2 , particle fraction, particle size and physico-chemical properties in relation to toxicity, among others. Analysis of actual particle concentrations in human organs, as well as organ concentrations and effects in liver and the reproductive system after chronic exposure to well-characterized TiO 2 (NPs) in animals are recommended to refine this assessment.

Preparation, characterization, drug release and computational modelling studies of antibiotics loaded amorphous chitin nanoparticles.

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Gayathri, N K; Aparna, V; Maya, S; Biswas, Raja; Jayakumar, R; Mohan, C Gopi

2017-12-01

We present a computational investigation of binding affinity of different types of drugs with chitin nanocarriers. Understanding the chitn polymer-drug interaction is important to design and optimize the chitin based drug delivery systems. The binding affinity of three different types of anti-bacterial drugs Ethionamide (ETA) Methacycline (MET) and Rifampicin (RIF) with amorphous chitin nanoparticles (AC-NPs) were studied by integrating computational and experimental techniques. The binding energies (BE) of hydrophobic ETA, hydrophilic MET and hydrophobic RIF were -7.3kcal/mol, -5.1kcal/mol and -8.1kcal/mol respectively, with respect to AC-NPs, using molecular docking studies. This theoretical result was in good correlation with the experimental studies of AC-drug loading and drug entrapment efficiencies of MET (3.5±0.1 and 25± 2%), ETA (5.6±0.02 and 45±4%) and RIF (8.9±0.20 and 53±5%) drugs respectively. Stability studies of the drug encapsulated nanoparticles showed stable values of size, zeta and polydispersity index at 6°C temperature. The correlation between computational BE and experimental drug entrapment efficiencies of RIF, ETA and MET drugs with four AC-NPs strands were 0.999 respectively, while that of the drug loading efficiencies were 0.854 respectively. Further, the molecular docking results predict the atomic level details derived from the electrostatic, hydrogen bonding and hydrophobic interactions of the drug and nanoparticle for its encapsulation and loading in the chitin-based host-guest nanosystems. The present results thus revealed the drug loading and drug delivery insights and has the potential of reducing the time and cost of processing new antibiotic drug delivery nanosystem optimization, development and discovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gambogic acid-loaded biomimetic nanoparticles in colorectal cancer treatment

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Zhang Z

2017-02-01

Full Text Available Zhen Zhang,1 Hanqing Qian,2 Mi Yang,2 Rutian Li,2 Jing Hu,1 Li Li,1 Lixia Yu,2 Baorui Liu,1,2 Xiaoping Qian1,2 1Comprehensive Cancer Center, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Traditional Chinese Medicine, 2Comprehensive Cancer Center, Nanjing Drum Tower Hospital, Medical School of Nanjing University, Clinical Cancer Institute, Nanjing University, Nanjing, China Abstract: Gambogic acid (GA is expected to be a potential new antitumor drug, but its poor aqueous solubility and inevitable side effects limit its clinical application. Despite these inhe­rent defects, various nanocarriers can be used to promote the solubility and tumor targeting of GA, improving antitumor efficiency. In addition, a cell membrane-coated nanoparticle platform that was reported recently, unites the customizability and flexibility of a synthetic copolymer, as well as the functionality and complexity of natural membrane, and is a new synthetic biomimetic nanocarrier with improved stability and biocompatibility. Here, we combined poly(lactic-co-glycolic acid (PLGA with red blood-cell membrane (RBCm, and evaluated whether GA-loaded RBCm nanoparticles can retain and improve the antitumor efficacy of GA with relatively lower toxicity in colorectal cancer treatment compared with free GA. We also confirmed the stability, biocompatibility, passive targeting, and few side effects of RBCm-GA/PLGA nanoparticles. We expect to provide a new drug carrier in the treatment of colorectal cancer, which has strong clinical application prospects. In addition, the potential antitumor drug GA and other similar drugs could achieve broader clinical applications via this biomimetic nanocarrier. Keywords: gambogic acid, nanocarriers, RBCm-GA/PLGA nanoparticles, colorectal cancer

Design and optimization of novel paclitaxel-loaded folate-conjugated amphiphilic cyclodextrin nanoparticles.

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Erdoğar, Nazlı; Esendağlı, Güneş; Nielsen, Thorbjorn T; Şen, Murat; Öner, Levent; Bilensoy, Erem

2016-07-25

As nanomedicines are gaining momentum in the therapy of cancer, new biomaterials emerge as alternative platforms for the delivery of anticancer drugs with bioavailability problems. In this study, two novel amphiphilic cyclodextrins (FCD-1 and FCD-2) conjugated with folate group to enable active targeting to folate positive breast tumors were introduced. The objective of this study was to develop and characterize new folated-CD nanoparticles via 3(2) factorial design for optimal final parameters. Full physicochemical characterization studies were performed. Blank and paclitaxel loaded FCD-1 and FCD-2 nanoparticles remained within the range of 70-275nm and 125-185nm, respectively. Zeta potential values were neutral and -20mV for FCD-1 and FCD-2 nanoparticles, respectively. Drug release studies showed initial burst release followed by a longer sustained release. Blank nanoparticles had no cytotoxicity against L929 cells. T-47D and ZR-75-1 human breast cancer cells with different levels of folate receptor expression were used to assess anti-cancer efficacy. Through targeting the folate receptor, these nanoparticles were efficiently engulfed by the breast cancer cells. Additionally, breast cancer cells became more sensitive to cytotoxic and/or cytostatic effects of PCX delivered by FCD-1 and FCD-2. In conclusion, these novel folate-conjugated cyclodextrin nanoparticles can therefore be considered as promising alternative systems for safe and effective delivery of paclitaxel with a folate-dependent mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

Solid lipid nanoparticles loaded with insulin by sodium cholate-phosphatidylcholine-based mixed micelles: preparation and characterization.

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Liu, Jie; Gong, Tao; Wang, Changguang; Zhong, Zhirong; Zhang, Zhirong

2007-08-01

Solid lipid nanoparticles (SLNs) loaded with insulin-mixed micelles (Ins-MMs) were prepared by a novel reverse micelle-double emulsion method, in which sodium cholate (SC) and soybean phosphatidylcholine (SPC) were employed to improve the liposolubility of insulin, and the mixture of stearic acid and palmitic acid were employed to prepare insulin loaded solid lipid nanoparticles (Ins-MM-SLNs). Some of the formulation parameters were optimized to obtain high quality nanoparticles. The particle size and zeta potential measured by photon correlation spectroscopy (PCS) were 114.7+/-4.68 nm and -51.36+/-2.04 mV, respectively. Nanospheres observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed extremely spherical shape. The entrapment efficiency (EE%) and drug loading capacity (DL%) determined with high performance liquid chromatogram (HPLC) by modified ultracentrifuge method were 97.78+/-0.37% and 18.92+/-0.07%, respectively. Differential scanning calorimetry (DSC) of Ins-MM-SLNs indicated no tendency of recrystallisation. The core-shell drug loading pattern of the SLNs was confirmed by fluorescence spectra and polyacrylamide gel electrophoresis (PAGE) which also proved the integrity of insulin after being incorporated into lipid carrier. The drug release behavior was studied by in situ and externally sink method and the release pattern of drug was found to follow Weibull and Higuchi equations. Results of stability evaluation showed a relatively long-term stability after storage at 4 degrees C for 6 months. In conclusion, SLNs with small particle size, excellent physical stability, high entrapment efficiency, good loading capacity for protein drug can be produced by this novel reverse micelle-double emulsion method in present study.

Application of zirconium dioxide nanoparticle sorbent for the clean-up step in post-harvest pesticide residue analysis.

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Uclés, Ana; Herrera López, Sonia; Dolores Hernando, Maria; Rosal, Roberto; Ferrer, Carmen; Fernández-Alba, Amadeo R

2015-11-01

The use of yttria-stabilized zirconium dioxide nanoparticles as d-SPE clean-up sorbent for a rapid and sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the determination of post-harvest fungicides (carbaryl, carbendazim, chlorpropham, diphenylamine, ethoxyquin, flutriafol, imazalil, iprodione, methomyl, myclobutanil, pirimiphos-methyl, prochloraz, pyrimethanil, thiabendazole, thiophanate-methyl and tolclofos-methyl) in orange and pear samples has been evaluated and validated. The sample preparation was a modification of the QuEChERS extraction method using yttria-stabilized zirconium dioxide and multi-walled carbon nanotubes (MWCNTs) nanoparticles as the solid phase extraction (d-SPE) clean-up sorbents prior to injecting the ten-fold diluted extracts into the LC system. By using the yttria-stabilized zirconium dioxide extraction method, more recoveries in the 70-120% range were obtained - thus this method was used for the validation. Quantification was carried out using a matrix-matched calibration curve which was linear in the 1-500 µg kg(-1) range for almost all the pesticides studied. The validated limit of quantification was 10 µg kg(-1) for most of the studied compounds, except chlorpropham, ethoxyquin and thiophanate-methyl. Pesticide recoveries at the 10 and 100 µg kg(-1) concentration levels were satisfactory, with values between 77% and 120% and relative standard deviations (RSD) lower than 10% (n=5). The developed method was applied for the determination of selected fungicides in 20 real orange and pear samples. Four different pesticide residues were detected in 10 of these commodities; 20% of the samples contained pesticide residues at a quantifiable level (equal to or above the LOQs) for at least one pesticide residue. The most frequently-detected pesticide residues were: carbendazim, thiabendazole and imazalil-all were below the MRL. The highest concentration found was imazalil at 1175 µg kg

Development of silane grafted ZnO core shell nanoparticles loaded diglycidyl epoxy nanocomposites film for antimicrobial applications.

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Suresh, S; Saravanan, P; Jayamoorthy, K; Ananda Kumar, S; Karthikeyan, S

2016-07-01

In this article a series of epoxy nanocomposites film were developed using amine functionalized (ZnO-APTES) core shell nanoparticles as the dispersed phase and a commercially available epoxy resin as the matrix phase. The functional group of the samples was characterized using FT-IR spectra. The most prominent peaks of epoxy resin were found in bare epoxy and in all the functionalized ZnO dispersed epoxy nanocomposites (ZnO-APTES-DGEBA). The XRD analysis of all the samples exhibits considerable shift in 2θ, intensity and d-spacing values but the best and optimum concentration is found to be 3% ZnO-APTES core shell nanoparticles loaded epoxy nanocomposites supported by FT-IR results. From TGA measurements, 100wt% residue is obtained in bare ZnO nanoparticles whereas in ZnO core shell nanoparticles grafted DGEBA residue percentages are 37, 41, 45, 46 and 52% for 0, 1, 3, 5 and 7% ZnO-APTES-DGEBA respectively, which is confirmed with ICP-OES analysis. From antimicrobial activity test, it was notable that antimicrobial activity of 7% ZnO-APTES core shell nanoparticles loaded epoxy nanocomposite film has best inhibition zone effect against all pathogens under study. Copyright © 2016 Elsevier B.V. All rights reserved.

Functionalized PLA polymers to control loading and/or release properties of drug-loaded nanoparticles.

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Thauvin, Cédric; Schwarz, Bettina; Delie, Florence; Allémann, Eric

2017-11-15

Advantages associated with the use of polylactic acid (PLA) nano- or microparticles as drug delivery systems have been widely proven in the field of pharmaceutical sciences. These biodegradable and biocompatible carriers have demonstrated different loading and release properties depending on interactions with the cargo, preparation methods, particles size or molecular weight of PLA. In this study, we sought to show the possibility of influencing these properties by modifying the structure of the constituting polymer. Seven non-functionalized or functionalized PLA polymers were specifically designed and synthesized by microwave-assisted ring-opening polymerization of d,l-lactide. They presented short hydrophobic and/or hydrophilic groups thanks to the use of C20 aliphatic chain, mPEG1000, sorbitan esters (Spans ® ) or polysorbates (Tweens ® ), their PEGylated analogues, as initiators. Then, seven types of drug-loaded nanoparticles (NP) were prepared from these polymers and compared in terms of physico-chemical characteristics, drug loading and release profiles. Although the loading properties were not improved with any of the functionalized PLA NP, different release profiles were observed in an aqueous medium at 37 °C and over a period of five days. The presence of PEG moieties in the core of PLA-polysorbates NP induced a faster release while the addition of a single aliphatic chain induced a slower release due to better interactions with the active molecule. Copyright © 2017 Elsevier B.V. All rights reserved.

Lipid-drug-conjugate (LDC) solid lipid nanoparticles (SLN) for the delivery of nicotine to the oral cavity - optimization of nicotine loading efficiency.

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Ding, Yuan; Nielsen, Kent A; Nielsen, Bruno P; Bøje, Niels W; Müller, Rainer H; Pyo, Sung Min

2018-03-12

Nicotine, obtained from tobacco leaves, has been used to promote the cessation of smoking and reduce the risk of COPD and lung cancer. Incorporating the active in lipid nanoparticles is an effective tool to minimize its irritation potential and to use the particles as intermediate to produce final products. However, as a hydrophilic active, it is a challenge to prepare nicotine loaded lipid nanoparticles with high drug loading. In this study, lipid-drug-conjugates (LDC) were formed by nicotine and different fatty acids to enable the production of sufficiently loaded nicotine lipid nanoparticles. The encapsulation efficiency of nicotine in LDC-containing SLN was about 50%, which increased at least fourfold compared to the non-LDC formulations (around 10%) due to the increased lipophilicity of nicotine by strong interactions between positively charged nicotine and negatively charged fatty acids (formation of LDCs). The z-average of all formulations (150 to 350 nm) proved to be in the required submicron size range with a narrow size distribution. In summary, nicotine loaded LDC lipid nanoparticles with high drug loading were successfully developed with Kolliwax® S and stearic acid as counter-ion forming the LDC and hydrogenated sunflower oil (HSO) as lipid particle matrix. Copyright © 2018. Published by Elsevier B.V.

Dual drug loaded superparamagnetic iron oxide nanoparticles for targeted cancer therapy.

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Dilnawaz, Fahima; Singh, Abhalaxmi; Mohanty, Chandana; Sahoo, Sanjeeb K

2010-05-01

The primary inadequacy of chemotherapeutic drugs is their relative non-specificity and potential side effects to the healthy tissues. To overcome this, drug loaded multifunctional magnetic nanoparticles are conceptualized. We report here an aqueous based formulation of glycerol monooleate coated magnetic nanoparticles (GMO-MNPs) devoid of any surfactant capable of carrying high payload hydrophobic anticancer drugs. The biocompatibility was confirmed by tumor necrosis factor alpha assay, confocal microscopy. High entrapment efficiency approximately 95% and sustained release of encapsulated drugs for more than two weeks under in vitro conditions was achieved for different anticancer drugs (paclitaxel, rapamycin, alone or combination). Drug loaded GMO-MNPs did not affect the magnetization properties of the iron oxide core as confirmed by magnetization study. Additionally the MNPs were functionalized with carboxylic groups by coating with DMSA (Dimercaptosuccinic acid) for the supplementary conjugation of amines. For targeted therapy, HER2 antibody was conjugated to GMO-MNPs and showed enhanced uptake in human breast carcinoma cell line (MCF-7). The IC(50) doses revealed potential antiproliferative effect in MCF-7. Therefore, antibody conjugated GMO-MNPs could be used as potential drug carrier for the active therapeutic aspects in cancer therapy. Copyright 2010 Elsevier Ltd. All rights reserved.

Carbon dioxide/methanol conversion cycle based on cascade enzymatic reactions supported on superparamagnetic nanoparticles

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CATERINA G.C. MARQUES NETTO

2017-10-01

Full Text Available ABSTRACT The conversion of carbon dioxide into important industrial feedstock is a subject of growing interest in modern society. A possible way to achieve this goal is by carrying out the CO2/methanol cascade reaction, allowing the recycle of CO2 using either chemical catalysts or enzymes. Efficient and selective reactions can be performed by enzymes; however, due to their low stability, immobilization protocols are required to improve their performance. The cascade reaction to reduce carbon dioxide into methanol has been explored by the authors, using, sequentially, alcohol dehydrogenase (ADH, formaldehyde dehydrogenase (FalDH, and formate dehydrogenase (FDH, powered by NAD+/NADH and glutamate dehydrogenase (GDH as the co-enzyme regenerating system. All the enzymes have been immobilized on functionalized magnetite nanoparticles, and their reactions investigated separately in order to establish the best performance conditions. Although the stepwise scheme led to only 2.3% yield of methanol per NADH; in a batch system under CO2 pressure, the combination of the four immobilized enzymes increased the methanol yield by 64 fold. The studies indicated a successful regeneration of NADH in situ, envisaging a real possibility of using immobilized enzymes to perform the cascade CO2-methanol reaction.

Diesel Engine Emission Reduction Using Catalytic Nanoparticles: An Experimental Investigation

Directory of Open Access Journals (Sweden)

Ajin C. Sajeevan

2013-01-01

Full Text Available Cerium oxide being a rare earth metal with dual valance state existence has exceptional catalytic activity due to its oxygen buffering capability, especially in the nanosized form. Hence when used as an additive in the diesel fuel it leads to simultaneous reduction and oxidation of nitrogen dioxide and hydrocarbon emissions, respectively, from diesel engine. The present work investigates the effect of cerium oxide nanoparticles on performance and emissions of diesel engine. Cerium oxide nanoparticles were synthesized by chemical method and techniques such as TEM, EDS, and XRD have been used for the characterization. Cerium oxide was mixed in diesel by means of standard ultrasonic shaker to obtain stable suspension, in a two-step process. The influence of nanoparticles on various physicochemical properties of diesel fuel has also been investigated through extensive experimentation by means of ASTM standard testing methods. Load test was done in the diesel engine to investigate the effect of nanoparticles on the efficiency and the emissions from the engine. Comparisons of fuel properties with and without additives are also presented.

Pro-inflammatory responses of RAW264.7 macrophages when treated with ultralow concentrations of silver, titanium dioxide, and zinc oxide nanoparticles

International Nuclear Information System (INIS)

Giovanni, Marcella; Yue, Junqi; Zhang, Lifeng; Xie, Jianping; Ong, Choon Nam; Leong, David Tai

2015-01-01

Highlights: • Ultralow levels of common nanoparticles exist in environment and consumer products. • Common nanoparticles at ultralow levels induce mild pro-inflammation by macrophages. • The nanoparticles are cytotoxic only at high doses. - Abstract: To cellular systems, nanoparticles are considered as foreign particles. Upon particles and cells contact, innate immune system responds by activating the inflammatory pathway. However, excessive inflammation had been linked to various diseases ranging from allergic responses to cancer. Common nanoparticles, namely silver, titanium dioxide, and zinc oxide exist in the environment as well as in consumer products at ultralow level of 10 −6 –10 −3 μg mL −1 . However, so far the risks of such low NPs concentrations remain unexplored. Therefore, we attempted to screen the pro-inflammatory responses after ultralow concentration treatments of the three nanoparticles on RAW264.7 macrophages, which are a part of the immune system, at both cellular and gene levels. Even though cytotoxicity was only observed at nanoparticles concentrations as high as 10 μg mL −1 , through the level of NF-κB and upregulation of pro-inflammatory genes, we observed activation of the induction of genes encoding pro-inflammatory cytokines starting already at 10 −7 μg mL −1 . This calls for more thorough characterization of nanoparticles in the environment as well as in consumer products to ascertain the health and safety of the consumers and living systems in general

Preparation and in vitro characterization of 9-nitrocamptothecin-loaded long circulating nanoparticles for delivery in cancer patients.

Science.gov (United States)

Derakhshandeh, Katayoun; Soheili, Marzieh; Dadashzadeh, Simin; Saghiri, Reza

2010-08-09

The purpose in this study was to investigate poly(ethylene glycol)-modified poly (d,l-lactide-co-glycolide) nanoparticles (PLGA-PEG-NPs) loading 9-nitrocamptothecin (9-NC) as a potent anticancer drug. 9-NC is an analog of the natural plant alkaloid camptothecin that has shown high antitumor activity and is currently in the end stage of clinical trial. Unfortunately, at physiological pH, these potent agents undergo a rapid and reversible hydrolysis with the loss of antitumor activity. Previous researchers have shown that the encapsulation of this drug in PLGA nanoparticles could increase its stability and release profile. In this research we investigated PLGA-PEG nanoparticles and their effect on in vitro characteristics of this labile drug. 9-NC-PLGA-PEG nanoparticles with particle size within the range of 148.5 ± 30 nm were prepared by a nanoprecipitation method. The influence of four different independent variables (amount of polymer, percent of emulsifier, internal phase volume, and external phase volume) on nanoparticle drug-loading was studied. Differential scanning calorimetry and X-ray diffractometry were also evaluated for physical characterizing. The results of optimized formulation showed a narrow size distribution, suitable zeta potential (+1.84), and a drug loading of more than 45%. The in vitro drug release from PLGA-PEG NPs showed a sustained release pattern of up to 120 hours and comparing with PLGA-NPs had a significant decrease in initial burst effect. These experimental results indicate that PLGA-PEG-NPs (versus PLGA-NPs) have a better physicochemical characterization and can be developed as a drug carrier in order to treat different malignancies.

Effect of process parameters on removal and recovery of Cd(II) and Cu(II) from electroplating wastewater by fixed-bed column of nano-dimensional titanium (IV) oxide agglomerates

CSIR Research Space (South Africa)

Debnath, S

2014-01-01

Full Text Available Removal performances of Cd(II) and Cu(II) from water was investigated using agglomerated nanoparticle of hydrous titanium(IV) oxide (NTO) packed fixed bed. The parameters varied were the bed depth, flow rate and feed solution concentrations...

PEG-PLGA electrospun nanofibrous membranes loaded with Au@Fe2O3 nanoparticles for drug delivery applications

Science.gov (United States)

Spadaro, Salvatore; Santoro, Marco; Barreca, Francesco; Scala, Angela; Grimato, Simona; Neri, Fortunato; Fazio, Enza

2018-02-01

A PEGylated-PLGA random nanofibrous membrane loaded with gold and iron oxide nanoparticles and with silibinin was prepared by electrospinning deposition. The nanofibrous membrane can be remotely controlled and activated by a laser light or magnetic field to release biological agents on demand. The nanosystems were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and thermogravimetric analyses. The drug loading efficiency and drug content percentages were determined by UV-vis optical absorption spectroscopy. The nanofibrous membrane irradiated by a relatively low-intensity laser or stimulated by a magnetic field showed sustained silibinin release for at least 60 h, without the burst effect. The proposed low-cost electrospinning procedure is capable of assembling, via a one-step procedure, a stimuli-responsive drug-loaded nanosystem with metallic nanoparticles to be externally activated for controlled drug delivery.

Antibacterial and anti-adhesion effects of the silver nanoparticles-loaded poly(L-lactide) fibrous membrane

International Nuclear Information System (INIS)

Liu, Shen; Zhao, Jingwen; Ruan, Hongjiang; Wang, Wei; Wu, Tianyi; Cui, Wenguo; Fan, Cunyi

2013-01-01

The complications of tendon injury are frequently compromised by peritendinous adhesions and tendon sheath infection. Physical barriers for anti-adhesion may increase the incidence of postoperative infection. This study was designed to evaluate the potential of silver nanoparticles (AgNPs)-loaded poly(L-lactide) (PLLA) electrospun fibrous membranes to prevent adhesion formation and infection. Results of an in vitro drug release study showed that a burst release was followed by sustained release from electrospun fibrous membranes with a high initial silver content. Fewer fibroblasts adhered to and proliferated on the AgNP-loaded PLLA electrospun fibrous membranes compared with pure PLLA electrospun fibrous membrane. In the antibacterial test, the AgNP-loaded PLLA electrospun fibrous membranes can prevent the adhesion of Gram-positive Staphylococcus aureus and Staphylococcus epidermidis and Gram-negative Pseudomonas aeruginosa. Taken together, these results demonstrate that AgNP-loaded PLLA electrospun fibrous membranes have the convenient practical medical potential of reduction of infection and adhesion formation after tendon injury. - Highlights: ► Silver nanoparticles are directly electrospun into PLLA fibrous membrane. ► Long-lasting release of Ag + ions is achieved. ► Cytotoxicity of silver ions benefits the anti-proliferation of physical barriers. ► Broad anti-microbial effect of drug-loaded fibrous membrane is revealed. ► Antibacterial and anti-adhesion effects of the physical barriers are combined

An efficient targeted drug delivery through apotransferrin loaded nanoparticles.

Directory of Open Access Journals (Sweden)

Athuluri Divakar Sai Krishna

Full Text Available BACKGROUND: Cancerous state is a highly stimulated environment of metabolically active cells. The cells under these conditions over express selective receptors for assimilation of factors essential for growth and transformation. Such receptors would serve as potential targets for the specific ligand mediated transport of pharmaceutically active molecules. The present study demonstrates the specificity and efficacy of protein nanoparticle of apotransferrin for targeted delivery of doxorubicin. METHODOLOGY/PRINCIPAL FINDINGS: Apotransferrin nanoparticles were developed by sol-oil chemistry. A comparative analysis of efficiency of drug delivery in conjugated and non-conjugated forms of doxorubicin to apotransferrin nanoparticle is presented. The spherical shaped apotransferrin nanoparticles (nano have diameters of 25-50 etam, which increase to 60-80 etam upon direct loading of drug (direct-nano, and showed further increase in dimension (75-95 etam in conjugated nanoparticles (conj-nano. The competitive experiments with the transferrin receptor specific antibody showed the entry of both conj-nano and direct-nano into the cells through transferrin receptor mediated endocytosis. Results of various studies conducted clearly establish the superiority of the direct-nano over conj-nano viz. (a localization studies showed complete release of drug very early, even as early as 30 min after treatment, with the drug localizing in the target organelle (nucleus (b pharmacokinetic studies showed enhanced drug concentrations, in circulation with sustainable half-life (c the studies also demonstrated efficient drug delivery, and an enhanced inhibition of proliferation in cancer cells. Tissue distribution analysis showed intravenous administration of direct nano lead to higher drug localization in liver, and blood as compared to relatively lesser localization in heart, kidney and spleen. Experiments using rat cancer model confirmed the efficacy of the formulation in

Freeze-drying of HI-6-loaded recombinant human serum albumin nanoparticles for improved storage stability.

Science.gov (United States)

Dadparvar, Miriam; Wagner, Sylvia; Wien, Sascha; Worek, Franz; von Briesen, Hagen; Kreuter, Jörg

2014-10-01

Severe intoxications with organophosphates require the immediate administration of atropine in combination with acetyl cholinesterase (AChE) reactivators such as HI-6. Although this therapy regimen enables the treatment of peripheral symptoms, the blood-brain barrier (BBB) restricts the access of the hydrophilic antidotes to the central nervous system which could lead to a fatal respiratory arrest. Therefore, HI-6-loaded albumin nanoparticles were previously developed to enhance the transport across this barrier and were able to reactivate organophosphate-(OP)-inhibited AChE in an in vitro BBB model. Since HI-6 is known to be moisture-sensitive, the feasibility of freeze-drying of the HI-6-loaded nanoparticles was investigated in the present study using different cryo- and lyoprotectants at different concentrations. Trehalose and sucrose (3%, w/v)-containing formulations were superior to mannitol concerning the physicochemical parameters of the nanoparticles whereas trehalose-containing samples were subject of a prolonged storage stability study at temperatures between -20°C and +40°C for predetermined time intervals. Shelf-life computations of the freeze-dried HI-6 nanoparticle formulations revealed a shelf-life time of 18 months when stored at -20°C. The formulations' efficacy was proven in vitro by reactivation of OP-inhibited AChE after transport over a porcine brain capillary endothelial cell layer model. Copyright © 2014 Elsevier B.V. All rights reserved.

Plasmonic Titanium Nitride Nanostructures via Nitridation of Nanopatterned Titanium Dioxide

DEFF Research Database (Denmark)

Guler, Urcan; Zemlyanov, Dmitry; Kim, Jongbum

2017-01-01

Plasmonic titanium nitride nanostructures are obtained via nitridation of titanium dioxide. Nanoparticles acquired a cubic shape with sharper edges following the rock-salt crystalline structure of TiN. Lattice constant of the resulting TiN nanoparticles matched well with the tabulated data. Energy...

Smart polymer platforms for in vitro drug screening assays based on drug-loaded nanoparticles

DEFF Research Database (Denmark)

Faralli, Adele

-electrodes for co-localization of drug-loaded nanoparticles (liposomes) and cancer cells. PEGDA hydrogels are widely used in different fields including tissue engineering and in vivo drug delivery. A home-made setup for the fabrication of PEGDA hydrogels through visible-light photopolymerization is described...

Microfluidic platform for dynamic in vitro optimization of methotrexate-loaded lipid nanoparticle delivery for personalized osteosarcoma treatment

Energy Technology Data Exchange (ETDEWEB)

Muñoz-Hernando, M.; Macias, P.; Abella, M.; Desco, M.; Sharpe, S.; Vaquero, J.J.; Muñoz-Barrutia, M.

2016-07-01

Cancer is a leading cause of mortality in the world, with osteosarcoma being one of the most common types among children between 1 and 14 years old. The use of lipid nanoparticles as biodegradable shells for controlled drug delivery shows promise as a more effective and targeted tumor treatment. However, current techniques for in vitro testing of these vehicles have shown little validity due to their static nature, in which nanoparticles sediment onto the bottom of the wells and kill the cells via asphyxiation, hiding the real effect achieved by the nanoparticles. In this work, a microfluidic platform capable of determining the optimum dose of methotrexate-loaded lipid nanoparticles in osteosarcoma treatment is presented as a promising alternative to current nanoparticle characterization assays. (Author)

Heteroaggregation of titanium dioxide nanoparticles with natural clay colloids.

Science.gov (United States)

Labille, Jérôme; Harns, Carrie; Bottero, Jean-Yves; Brant, Jonathan

2015-06-02

To better understand and predict the fate of engineered nanoparticles in the water column, we assessed the heteroaggregation of TiO2 nanoparticles with a smectite clay as analogues for natural colloids. Heteroaggregation was evaluated as a function of water salinity (10(-3) and 10(-1) M NaCl), pH (5 and 8), and selected nanoparticle concentration (0-4 mg/L). Time-resolved laser diffraction was used, coupled to an aggregation model, to identify the key mechanisms and variables that drive the heteroaggregation of the nanoparticles with colloids. Our data show that, at a relevant concentration, nanoparticle behavior is mainly driven by heteroaggregation with colloids, while homoaggregation remains negligible. The affinity of TiO2 nanoparticles for clay is driven by electrostatic interactions. Opposite surface charges and/or high ionic strength favored the formation of primary heteroaggregates via the attachment of nanoparticles to the clay. The initial shape and dispersion state of the clay as well as the nanoparticle/clay concentration ratio also affected the nature of the heteroaggregation mechanism. With dispersed clay platelets (10(-3) M NaCl), secondary heteroaggregation driven by bridging nanoparticles occurred at a nanoparticle/clay number ratio of greater than 0.5. In 10(-1) M NaCl, the clay was preaggregated into larger and more spherical units. This favored secondary heteroaggregation at lower nanoparticle concentration that correlated to the nanoparticle/clay surface area ratio. In this latter case, a nanoparticle to clay sticking efficiency could be determined.

Preparation and characterization of DOX loaded keratin nanoparticles for pH/GSH dual responsive release

Energy Technology Data Exchange (ETDEWEB)

Li, Yanmei; Zhi, Xuelian [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Lin, Jiantao [Guangdong Medical University, Dongguan 523808 (China); You, Xin [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Yuan, Jiang, E-mail: jyuan@njnu.edu.cn [Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China)

2017-04-01

Smart drug carriers are the current need of the hour in controlled drug delivery applications. In this work, pH and redox dual responsive keratin based drug-loaded nanoparticles (KDNPs) were fabricated through two-step strategies. Keratin nanoparticles were first prepared by desolvation method and chemical crosslinking, followed by electrostatic adsorbing doxorubicin (DOX) to afford drug loaded keratin nanoparticles (KDNPs). The size, size distribution, and morphology of the KDNPs were characterized with dynamic light scattering (DLS) and Scan electronic microscope (SEM). Drug delivery profiles showed that KDNPs exhibited pH and glutathione (GSH) dual-responsive characters. Under tumor tissue/cell microenvironments (more acidic and high GSH level), KDNPs tended to accumulate at the tumor region through a potential enhanced permeability and retention (EPR) effect and perform surface negative-to-positive charge conversion. Hemolysis assay indicated that KDNPs had good blood compatibility. Cellular uptake assay demonstrated that KDNPs could be internalized by A 549 cells through endocytosis. Intriguingly, KDNPs were capable of promoting nitric oxide (NO) release from endogenous donor of S-nitrosoglutathione in the presence of GSH. All of these results demonstrated that keratin based drug carriers had potential for drug/NO delivery and cancer therapy in clinical medicine. - Graphical abstract: pH and redox dual responsive keratin based drug-loaded nanoparticles (KDNPs) were fabricated by desolvation with chemical crosslinking, followed by electrostatic adsorbing DOX to afford DOX loaded keratin nanoparticles (KDNPs). Drug delivery profiles showed that KDNPs exhibited pH and GSH dual-responsive characters. Under tumor tissue/cell microenvironments (more acidic and high GSH level), KDNPs tended to accumulate at the tumor region through a potential enhanced permeability and retention (EPR) effect and perform surface negative-to-positive charge conversion. Hemolysis assay

Oxcarbazepine-loaded polymeric nanoparticles: development and permeability studies across in vitro models of the blood–brain barrier and human placental trophoblast

Science.gov (United States)

Lopalco, Antonio; Ali, Hazem; Denora, Nunzio; Rytting, Erik

2015-01-01

Encapsulation of antiepileptic drugs (AEDs) into nanoparticles may offer promise for treating pregnant women with epilepsy by improving brain delivery and limiting the transplacental permeability of AEDs to avoid fetal exposure and its consequent undesirable adverse effects. Oxcarbazepine-loaded nanoparticles were prepared by a modified solvent displacement method from biocompatible polymers (poly(lactic-co-glycolic acid) [PLGA] with or without surfactant and PEGylated PLGA [Resomer® RGPd5055]). The physical properties of the developed nanoparticles were determined with subsequent evaluation of their permeability across in vitro models of the blood–brain barrier (hCMEC/D3 cells) and human placental trophoblast cells (BeWo b30 cells). Oxcarbazepine-loaded nanoparticles with encapsulation efficiency above 69% were prepared with sizes ranging from 140–170 nm, polydispersity indices below 0.3, and zeta potential values below -34 mV. Differential scanning calorimetry and X-ray diffraction studies confirmed the amorphous state of the nanoencapsulated drug. The apparent permeability (Pe) values of the free and nanoencapsulated oxcarbazepine were comparable across both cell types, likely due to rapid drug release kinetics. Transport studies using fluorescently-labeled nanoparticles (loaded with coumarin-6) demonstrated increased permeability of surfactant-coated nanoparticles. Future developments in enzyme-prodrug therapy and targeted delivery are expected to provide improved options for pregnant patients with epilepsy. PMID:25792832

Stability and Antimicrobial Activity of Nisin-Loaded Mesoporous Silica Nanoparticles: A Game-Changer in the War against Maleficent Microbes.

Science.gov (United States)

Behzadi, Faezeh; Darouie, Sheyda; Alavi, S Mehdi; Shariati, Parvin; Singh, Gurvinder; Dolatshahi-Pirouz, Alireza; Arpanaei, Ayyoob

2018-04-25

Antimicrobial agents, such as nisin, are used extensively in the food industry. Here, we investigated various approaches to load nisin onto mesoporous silica nanoparticles (MSNs, 92 ± 10 nm in diameter), to enhance its stability and sustained release. The morphology, size, and surface charge of the as-prepared nanoparticles were analyzed using scanning transmission electron microscopy, dynamic light scattering, and ζ potential measurement. Nisin was either physically adsorbed or covalently attached to the variously functionalized MSNs, with high loading capacities (>600 mg of nisin g -1 of nanoparticles). The results of antibacterial activity analysis of nisin against Staphylococcus aureus showed that, despite the very low antibacterial activity of nisin covalently conjugated onto MSNs, the physical adsorption of nisin onto the unfunctionalized nanoparticles enhances its antimicrobial activities under various conditions, with no significant cytotoxicity effects on mouse fibroblast L929 cells. In conclusion, MSNs can be recommended as suitable carriers for nisin under various conditions.

Starch nanoparticle as a vitamin E-TPGS carrier loaded in silk fibroin-poly(vinyl alcohol)-Aloe vera nanofibrous dressing.

Science.gov (United States)

Kheradvar, Shadi Alsadat; Nourmohammadi, Jhamak; Tabesh, Hadi; Bagheri, Behnam

2018-06-01

Core-sheath nanofibrous mat as a new vitamin E (VE) delivery system based on silk fibroin (SF)/poly(vinyl alcohol) (PVA)/aloe vera (AV) was successfully prepared by the electrospinning method. Initially, VE-loaded starch nanoparticles were produced and then incorporated into the best beadless SF-PVA-AV nanofibers. The successful loading of VE in starch nanoparticles was proved by Fourier-transform infrared spectroscopy. The scanning electron microscopy and transmission electron microscopy indicated that spherical nanoparticles were successfully embedded within the nanofibers. In vitro release studies demonstrated that the release of VE was controlled by Fickian diffusion and was faster in samples containing more nanoparticles. Fibroblast attachment, proliferation, and collagen secretion were enhanced after adding AV and VE to the SF-PVA nanomatrix. Moreover, the incorporation of VE into the nanocomposite dressing enhanced antioxidant activity, which can have a positive effect on wound healing process by protecting the cells from toxic oxidation products. Copyright © 2018 Elsevier B.V. All rights reserved.

Preparation, characterization, and optimization of primaquine-loaded solid lipid nanoparticles

Directory of Open Access Journals (Sweden)

Omwoyo WN

2014-08-01

Full Text Available Wesley Nyaigoti Omwoyo,1,2 Bernhards Ogutu,3,4 Florence Oloo,3,5 Hulda Swai,6 Lonji Kalombo,6 Paula Melariri,6 Geoffrey Maroa Mahanga,2 Jeremiah Waweru Gathirwa3,4 1Department of Chemistry, Maasai Mara University, Narok, Kenya; 2Department of Chemistry, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya; 3Center for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya; 4Kenya Medical Research Institute, Nairobi, Kenya; 5Department of Chemical Sciences and Technology, Technical University of Kenya, Nairobi, Kenya; 6Department of Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa Abstract: Primaquine (PQ is one of the most widely used antimalarial drugs and is the only available drug that combats the relapsing form of malaria. PQ use in higher doses is limited by severe tissue toxicity including hematological- and gastrointestinal-related side effects. Nanoformulation of drugs in an appropriate drug carrier system has been extensively studied and shown to have the potential to improve bioavailability, thereby enhancing activity, reducing dose frequency, and subsequently reducing toxicity. The aim of this work was to design, synthesize, and characterize PQ-loaded solid lipid nanoparticles (SLNs (PQ-SLNs as a potential drug-delivery system. SLNs were prepared by a modified solvent emulsification evaporation method based on a water-in-oil-in-water (w/o/w double emulsion. The mean particle size, zeta potential, drug loading, and encapsulation efficiency of the PQ-SLNs were 236 nm, +23 mV, 14%, and 75%, respectively. The zeta potential of the SLNs changed dramatically, from -6.54 mV to +23.0 mV, by binding positively charged chitosan as surface modifier. A spherical morphology of PQ-SLNs was seen by scanning electron microscope. In vitro, release profile depicted a steady drug release over 72 hours. Differential scanning calorimeter thermograms demonstrated presence

Towards development of novel immunization strategies against leishmaniasis using PLGA nanoparticles loaded with kinetoplastid membrane protein-11

Directory of Open Access Journals (Sweden)

Santos DM

2012-04-01

Full Text Available Diego M Santos1, Marcia W Carneiro1, Tatiana R de Moura1, Kiyoshi Fukutani1, Jorge Clarencio1, Manuel Soto2, Socorro Espuelas3,4, Claudia Brodskyn1,5, Aldina Barral1,5, Manoel Barral-Netto1,5, Camila I de Oliveira1,51Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, BA, Brazil; 2Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Cientificas, Departamento de Biologia Molecular, Universidad Autonoma de Madrid, Madrid; 3Departamento de Farmacia y Tecnología Farmacéutica, 4Instituto de Salud Tropical, Facultad de Farmacia, Universidad de Navarra, Pamplona, Spain; 5Instituto de Investigação em Imunologia, Salvador, BA, BrazilBackground: Vaccine development has been a priority in the fight against leishmaniases, which are vector-borne diseases caused by Leishmania protozoa. Among the different immunization strategies employed to date is inoculation of plasmid DNA coding for parasite antigens, which has a demonstrated ability to induce humoral and cellular immune responses. In this sense, inoculation of plasmid DNA encoding Leishmania kinetoplasmid membrane protein-11 (KMP-11 was able to confer protection against visceral leishmaniasis. However, recently the use of antigen delivery systems such as poly(lactic-co-glycolic acid (PLGA nanoparticles has also proven effective for eliciting protective immune responses.Methods: In the present work, we tested two immunization strategies with the goal of obtaining protection, in terms of lesion development and parasite load, against cutaneous leishmaniasis caused by L. braziliensis. One strategy involved immunization with plasmid DNA encoding L. infantum chagasi KMP-11. Alternatively, mice were primed with PLGA nanoparticles loaded with the recombinant plasmid DNA and boosted using PLGA nanoparticles loaded with recombinant KMP-11.Results: Both immunization strategies elicited detectable cellular immune responses with the presence of both proinflammatory and anti

Carbon dioxide conversion over carbon-based nanocatalysts.

Science.gov (United States)

Khavarian, Mehrnoush; Chai, Siang-Piao; Mohamed, Abdul Rahman

2013-07-01

The utilization of carbon dioxide for the production of valuable chemicals via catalysts is one of the efficient ways to mitigate the greenhouse gases in the atmosphere. It is known that the carbon dioxide conversion and product yields are still low even if the reaction is operated at high pressure and temperature. The carbon dioxide utilization and conversion provides many challenges in exploring new concepts and opportunities for development of unique catalysts for the purpose of activating the carbon dioxide molecules. In this paper, the role of carbon-based nanocatalysts in the hydrogenation of carbon dioxide and direct synthesis of dimethyl carbonate from carbon dioxide and methanol are reviewed. The current catalytic results obtained with different carbon-based nanocatalysts systems are presented and how these materials contribute to the carbon dioxide conversion is explained. In addition, different strategies and preparation methods of nanometallic catalysts on various carbon supports are described to optimize the dispersion of metal nanoparticles and catalytic activity.

Butyrate-Loaded Chitosan/Hyaluronan Nanoparticles: A Suitable Tool for Sustained Inhibition of ROS Release by Activated Neutrophils

DEFF Research Database (Denmark)

Sacco, Pasquale; Decleva, Eva; Tentor, Fabio

2017-01-01

that butyrate inhibits neutrophil ROS release in a dose and time-dependent fashion. Given the short half-life of butyrate, chitosan/hyaluronan nanoparticles are next designed and developed as controlled release carriers able to provide cells with a long-lasting supply of this SCFA. Notably, while the inhibition...... of neutrophil ROS production by free butyrate declines over time, that of butyrate-loaded chitosan/hyaluronan nanoparticles (B-NPs) is sustained. Additional valuable features of these nanoparticles are inherent ROS scavenger activity, resistance to cell internalization, and mucoadhesiveness. B-NPs appear...

Biodegradable starch/poly (vinyl alcohol) film reinforced with titanium dioxide nanoparticles

Science.gov (United States)

Hejri, Zahra; Seifkordi, Ali Akbar; Ahmadpour, Ali; Zebarjad, Seyed Mojtaba; Maskooki, Abdolmajid

2013-10-01

Biodegradable starch/poly (vinyl alcohol)/nano-titanium dioxide (ST/PVA/nano-TiO2) nanocomposite films were prepared via a solution casting method. Their biodegradability, mechanical properties, and thermal properties were also studied in this paper. A general full factorial experimental approach was used to determine effective parameters on the mechanical properties of the prepared films. ST/PVA/TiO2 nanocomposites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results of mechanical analysis show that ST/PVA films with higher contents of PVA have much better mechanical properties. In thermal analysis, it is found that the addition of TiO2 nanoparticles improves the thermal stability of the films. SEM micrographs, taken from the fracture surface of samples, illustrate that the addition of PVA makes the film softer and more flexible. The results of soil burial biodegradation indicate that the biodegradability of ST/PVA/TiO2 films strongly depends on the starch proportion in the film matrix. The degradation rate is increased by the addition of starch in the films.

Effect of titanium dioxide nanoparticles on zebrafish embryos and developing retina

Directory of Open Access Journals (Sweden)

Ya-Jie Wang

2014-12-01

Full Text Available AIM:To investigate the impact of titanium dioxide nanoparticles (TiO2 NPs on embryonic development and retinal neurogenesis. METHODS:The agglomeration and sedimentation of TiO2 NPs solutions at different dilutions were observed, and the ultraviolet-visible spectra of their supernatants were measured. Zebrafish embryos were experimentally exposed to TiO2 NPs until 72h postfertilization (hpf. The retinal neurogenesis and distribution of the microglia were analyzed by immunohistochemistry and whole mount in situ hybridization. RESULTS: The1 mg/L was determined to be an appropriate exposure dose. Embryos exposed to TiO2 NPs had a normal phenotype. The neurogenesis was initiated on time, and ganglion cells, cones and rods were well differentiated at 72 hpf. The expression of fms mRNA and the 4C4 antibody, which were specific to microglia in the central nervous system (CNS, closely resembled their endogenous profile. CONCLUSION:These data demonstrate that short-term exposure to TiO2 NPs at a low dose does not lead to delayed embryonic development or retinal neurotoxicity.

Risk assessment of amorphous silicon dioxide nanoparticles in a glass cleaner formulation

Science.gov (United States)

Scheel, Julia; Karsten, Stefan; Stelter, Norbert; Wind, Thorsten

2013-01-01

Since nanomaterials are a heterogeneous group of substances used in various applications, risk assessment needs to be done on a case-by-case basis. Here the authors assess the risk (hazard and exposure) of a glass cleaner with synthetic amorphous silicon dioxide (SAS) nanoparticles during production and consumer use (spray application). As the colloidal material used is similar to previously investigated SAS, the hazard profile was considered to be comparable. Overall, SAS has a low toxicity. Worker exposure was analysed to be well controlled. The particle size distribution indicated that the aerosol droplets were in a size range not expected to reach the alveoli. Predictive modelling was used to approximate external exposure concentrations. Consumer and environmental exposure were estimated conservatively and were not of concern. It was concluded based on the available weight-of-evidence that the production and application of the glass cleaner is safe for humans and the environment under intended use conditions. PMID:22548260

No evidence of the genotoxic potential of gold, silver, zinc oxide and titanium dioxide nanoparticles in the SOS chromotest.

Science.gov (United States)

Nam, Sun-Hwa; Kim, Shin Woong; An, Youn-Joo

2013-10-01

Gold nanoparticles (Au NPs), silver nanoparticles (Ag NPs), zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO2 NPs) are widely used in cosmetic products such as preservatives, colorants and sunscreens. This study investigated the genotoxicity of Au NPs, Ag NPs, ZnO NPs and TiO2 NPs using the SOS chromotest with Escherichia coli PQ37. The maximum exposure concentrations for each nanoparticle were 3.23 mg l(-1) for Au NPs, 32.3 mg l(-1) for Ag NPs and 100 mg l(-1) for ZnO NPs and TiO2 NPs. Additionally, in order to compare the genotoxicity of nanoparticles and corresponding dissolved ions, the ions were assessed in the same way as nanoparticles. The genotoxicity of the titanium ion was not assessed because of the extremely low solubility of TiO2 NPs. Au NPs, Ag NPs, ZnO NPs, TiO2 NPs and ions of Au, Ag and Zn, in a range of tested concentrations, exerted no effects in the SOS chromotest, evidenced by maximum IF (IFmax) values of below 1.5 for all chemicals. Owing to the results, nanosized Au NPs, Ag NPs, ZnO NPs, TiO2 NPs and ions of Au, Ag and Zn are classified as non-genotoxic on the basis of the SOS chromotest used in this study. To the best of our knowledge, this is the first study to evaluate the genotoxicity of Au NPs, Ag NPs, ZnO NPs and TiO2 NPs using the SOS chromotest. Copyright © 2012 John Wiley & Sons, Ltd.

Synthesis, characterization and in vitro studies of doxorubicin-loaded magnetic nanoparticles grafted to smart copolymers on A549 lung cancer cell line.

Science.gov (United States)

Akbarzadeh, Abolfazl; Samiei, Mohammad; Joo, Sang Woo; Anzaby, Maryam; Hanifehpour, Younes; Nasrabadi, Hamid Tayefi; Davaran, Soodabeh

2012-12-18

The aim of present study was to develop the novel methods for chemical and physical modification of superparamagnetic iron oxide nanoparticles (SPIONs) with polymers via covalent bonding entrapment. These modified SPIONs were used for encapsulation of anticancer drug doxorubicin. At first approach silane-grafted magnetic nanoparticles was prepared and used as a template for polymerization of the N-isopropylacrylamide (NIPAAm) and methacrylic acid (MAA) via radical polymerization. This temperature/pH-sensitive copolymer was used for preparation of DOX-loaded magnetic nanocomposites. At second approach Vinyltriethoxysilane-grafted magnetic nanoparticles were used as a template to polymerize PNIPAAm-MAA in 1, 4 dioxan and methylene-bis-acrylamide (BIS) was used as a cross-linking agent. Chemical composition and magnetic properties of Dox-loaded magnetic hydrogel nanocomposites were analyzed by FT-IR, XRD, and VSM. The results demonstrate the feasibility of drug encapsulation of the magnetic nanoparticles with NIPAAm-MAA copolymer via covalent bonding. The key factors for the successful prepardtion of magnetic nanocomposites were the structure of copolymer (linear or cross-linked), concentration of copolymer and concentration of drug. The influence of pH and temperature on the release profile of doxorubicin was examined. The in vitro cytotoxicity test (MTT assay) of both magnetic DOx-loaded nanoparticles was examined. The in vitro tests showed that these systems are no toxicity and are biocompatible. IC50 of DOx-loaded Fe3O4 nanoparticles on A549 lung cancer cell line showed that systems could be useful in treatment of lung cancer.

Laser-produced plasma EUV source using a colloidal microjet target containing tin dioxide nanoparticles

Science.gov (United States)

Higashiguchi, Takeshi; Dojyo, Naoto; Sasaki, Wataru; Kubodera, Shoichi

2006-10-01

We realized a low-debris laser-produced plasma extreme ultraviolet (EUV) source by use of a colloidal microjet target, which contained low-concentration (6 wt%) tin-dioxide nanoparticles. An Nd:YAG laser was used to produce a plasma at the intensity on the order of 10^11 W/cm^2. The use of low concentration nanoparticles in a microjet target with a diameter of 50 μm regulated the neutral debris emission from a target, which was monitored by a silicon witness plate placed 30 cm apart from the source in a vacuum chamber. No XPS signals of tin and/or oxygen atoms were observed on the plate after ten thousand laser exposures. The low concentration nature of the target was compensated and the conversion efficiency (CE) was improved by introducing double pulses of two Nd:YAG lasers operated at 532 and 1064 nm as a result of controlling the micro-plasma characteristics. The EUV CE reached its maximum of 1.2% at the delay time of approximately 100 ns with the main laser intensiy of 2 x10^11 W/cm^2. The CE value was comparable to that of a tin bulk target, which, however, produced a significant amount of neutral debris.

Preparation and in vitro characterization of 9-nitrocamptothecin-loaded long circulating nanoparticles for delivery in cancer patients

Directory of Open Access Journals (Sweden)

Katayoun Derakhshandeh

2010-07-01

Full Text Available Katayoun Derakhshandeh1, Marzieh Soheili1, Simin Dadashzadeh2, Reza Saghiri31Department of Pharmaceutics, Faculty of Pharmacy, University of Medical Science, Kermanshah 67145-1673, Iran; 2Department of Pharmaceutics, Faculty of Pharmacy, Shaheed Beheshti University of Medical Science, Tehran, Iran; 3Deptartment of Biochemistry, Pasteur Institute, Tehran, IranAbstract: The purpose in this study was to investigate poly(ethylene glycol-modified poly (d,l-lactide-co-glycolide nanoparticles (PLGA-PEG-NPs loading 9-nitrocamptothecin (9-NC as a potent anticancer drug. 9-NC is an analog of the natural plant alkaloid camptothecin that has shown high antitumor activity and is currently in the end stage of clinical trial. Unfortunately, at physiological pH, these potent agents undergo a rapid and reversible hydrolysis with the loss of antitumor activity. Previous researchers have shown that the encapsulation of this drug in PLGA nanoparticles could increase its stability and release profile. In this research we investigated PLGA-PEG nanoparticles and their effect on in vitro characteristics of this labile drug. 9-NC-PLGA-PEG nanoparticles with particle size within the range of 148.5 ± 30 nm were prepared by a nanoprecipitation method. The influence of four different independent variables (amount of polymer, percent of emulsifier, internal phase volume, and external phase volume on nanoparticle drug-loading was studied. Differential scanning calorimetry and X-ray diffractometry were also evaluated for physical characterizing. The results of optimized formulation showed a narrow size distribution, suitable zeta potential (+1.84, and a drug loading of more than 45%. The in vitro drug release from PLGA-PEG NPs showed a sustained release pattern of up to 120 hours and comparing with PLGA-NPs had a significant decrease in initial burst effect. These experimental results indicate that PLGA-PEG-NPs (versus PLGA-NPs have a better physicochemical characterization

Antibacterial performance on plasma polymerized heptylamine films loaded with silver nanoparticles

Science.gov (United States)

Lin, Yu-Chun; Lin, Chia-Chun; Lin, Chih-Hao; Wang, Meng-Jiy

2017-01-01

The antibacterial performance of the plasma-polymerized (pp) heptylamine thin films loaded with silver nanoparticles was evaluated against the colonization of Escherichia coli and Staphylococcus aureus. The properties including the thickness and chemical composition of the as deposited HApp films were modulated by adjusting plasma parameters. The acquired results showed that the film thickness was controlled in the range of 20 to 400 nm by adjusting deposition time. The subsequent immersion of the HApp thin films in silver nitrate solutions result in the formation of amine-metal complexes, in which the silver nanoparticles were reduced directly on the matrices to form Ag@HApp. The reduction reaction of silver was facilitated by applying NaBH4 as a reducing agent. The results of physicochemical analyses including morphological analysis and ellipsometry revealed that the silver nanoparticles were successfully reduced on the HApp films, and the amount of reduced silver was closely associated which the thickness of the plasma-polymerized films, the concentration of applied metal ions solutions, and the time of immobilization. Regarding the antibacterial performance, the Ag@HApp films reduced by NaBH4 showed antibacterial abilities of 70.1 and 68.2% against E. coli and S. aureus, respectively.

Photocatalytic degradation of phenol by iodine doped tin oxide nanoparticles under UV and sunlight irradiation

Energy Technology Data Exchange (ETDEWEB)

Al-Hamdi, Abdullah M.; Sillanpää, Mika [Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Dutta, Joydeep, E-mail: dutta@squ.edu.om [Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 17, 123 Al-Khoudh (Oman)

2015-01-05

Highlights: • A sol–gel method used to synthesize tin oxide nanoparticles. • Nanoparticles of tin oxide doped with different iodine concentrations. • Degradation studies carried up with UV–vis, TOC, HPLC and GC instruments. • 1% iodine doped tin dioxide showed maximum photodegradation efficiency. - Abstract: Iodine doped tin oxide (SnO{sub 2}:I) nanoparticles were prepared by sol–gel synthesis and their photocatalytic activities with phenol as a test contaminant were studied. In the presence of the catalysts, phenol degradation under direct sunlight was comparable to what was achieved under laboratory conditions. Photocatalytic oxidation reactions were studied by varying the catalyst loading, light intensity, illumination time, pH of the reactant and phenol concentration. Upon UV irradiation in the presence of SnO{sub 2}:I nanoparticles, phenol degrades very rapidly within 30 min, forming carboxylic acid which turns the solution acidic. Phenol degradation rate with 1% iodine doped SnO{sub 2} nanoparticles is at least an order of magnitude higher compared to the degradation achieved through undoped SnO{sub 2} nanoparticles under similar illumination conditions.

Photocatalytic degradation of phenol by iodine doped tin oxide nanoparticles under UV and sunlight irradiation

International Nuclear Information System (INIS)

Al-Hamdi, Abdullah M.; Sillanpää, Mika; Dutta, Joydeep

2015-01-01

Highlights: • A sol–gel method used to synthesize tin oxide nanoparticles. • Nanoparticles of tin oxide doped with different iodine concentrations. • Degradation studies carried up with UV–vis, TOC, HPLC and GC instruments. • 1% iodine doped tin dioxide showed maximum photodegradation efficiency. - Abstract: Iodine doped tin oxide (SnO 2 :I) nanoparticles were prepared by sol–gel synthesis and their photocatalytic activities with phenol as a test contaminant were studied. In the presence of the catalysts, phenol degradation under direct sunlight was comparable to what was achieved under laboratory conditions. Photocatalytic oxidation reactions were studied by varying the catalyst loading, light intensity, illumination time, pH of the reactant and phenol concentration. Upon UV irradiation in the presence of SnO 2 :I nanoparticles, phenol degrades very rapidly within 30 min, forming carboxylic acid which turns the solution acidic. Phenol degradation rate with 1% iodine doped SnO 2 nanoparticles is at least an order of magnitude higher compared to the degradation achieved through undoped SnO 2 nanoparticles under similar illumination conditions

Pro-inflammatory responses of RAW264.7 macrophages when treated with ultralow concentrations of silver, titanium dioxide, and zinc oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Giovanni, Marcella [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585 (Singapore); Yue, Junqi; Zhang, Lifeng [PUB, 40 Scotts Road, Singapore 228231 (Singapore); Xie, Jianping [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585 (Singapore); Ong, Choon Nam [Saw Swee Hock School of Public Health, National University of Singapore, 12 Science Drive 2, Singapore 117549 (Singapore); NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, Singapore 117411 (Singapore); Leong, David Tai, E-mail: cheltwd@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585 (Singapore)

2015-10-30

Highlights: • Ultralow levels of common nanoparticles exist in environment and consumer products. • Common nanoparticles at ultralow levels induce mild pro-inflammation by macrophages. • The nanoparticles are cytotoxic only at high doses. - Abstract: To cellular systems, nanoparticles are considered as foreign particles. Upon particles and cells contact, innate immune system responds by activating the inflammatory pathway. However, excessive inflammation had been linked to various diseases ranging from allergic responses to cancer. Common nanoparticles, namely silver, titanium dioxide, and zinc oxide exist in the environment as well as in consumer products at ultralow level of 10{sup −6}–10{sup −3} μg mL{sup −1}. However, so far the risks of such low NPs concentrations remain unexplored. Therefore, we attempted to screen the pro-inflammatory responses after ultralow concentration treatments of the three nanoparticles on RAW264.7 macrophages, which are a part of the immune system, at both cellular and gene levels. Even though cytotoxicity was only observed at nanoparticles concentrations as high as 10 μg mL{sup −1}, through the level of NF-κB and upregulation of pro-inflammatory genes, we observed activation of the induction of genes encoding pro-inflammatory cytokines starting already at 10{sup −7} μg mL{sup −1}. This calls for more thorough characterization of nanoparticles in the environment as well as in consumer products to ascertain the health and safety of the consumers and living systems in general.

Optimization of methazolamide-loaded solid lipid nanoparticles for ophthalmic delivery using Box-Behnken design.

Science.gov (United States)

Wang, Fengzhen; Chen, Li; Jiang, Sunmin; He, Jun; Zhang, Xiumei; Peng, Jin; Xu, Qunwei; Li, Rui

2014-09-01

The purpose of the present study was to optimize methazolamide (MTZ)-loaded solid lipid nanoparticles (SLNs) which were used as topical eye drops by evaluating the relationship between design factors and experimental data. A three factor, three-level Box-Behnken design (BBD) was used for the optimization procedure, choosing the amount of GMS, the amount of phospholipid, the concentration of surfactant as the independent variables. The chosen dependent variables were entrapment efficiency, dosage loading, and particle size. The generated polynomial equations and response surface plots were used to relate the dependent and independent variables. The optimal nanoparticles were formulated with 100 mg GMS, 150 mg phospholipid, and 1% Tween80 and PEG 400 (1:1, w/v). A new formulation was prepared according to these levels. The observed responses were close to the predicted values of the optimized formulation. The particle size was 197.8 ± 4.9 nm. The polydispersity index of particle size was 0.239 ± 0.01 and the zeta potential was 32.7 ± 2.6 mV. The entrapment efficiency and dosage loading were about 68.39% and 2.49%, respectively. Fourier transform infrared spectroscopy (FT-IR) study indicated that the drug was entrapped in nanoparticles. The optimized formulation showed a sustained release followed the Peppas model. MTZ-SLNs showed significant prolonged decreasing intraocular pressure effect comparing with MTZ solution in vivo pharmacodynamics studies. The results of acute eye irritation study indicated that MTZ-SLNs and AZOPT both had no eye irritation. Furthermore, the MTZ-SLNs were suitable to be stored at low temperature (4 °C).

CdS nanoparticle sensitized titanium dioxide decorated graphene for enhancing visible light induced photoanode

International Nuclear Information System (INIS)

Yousefzadeh, S.; Faraji, M.; Nien, Y.T.; Moshfegh, A.Z.

2014-01-01

Highlights: • CdS nanoparticles were deposited on TiO 2 /graphene film by different SILAR cycles. • The visible light absorption increased due to graphene and CdS nanoparticles. • The highest photocurrent density was achieved for nanocomposite with 30 CdS cycles. • A mechanism has been suggested for nanocomposite photoanodes, significantly. - Abstract: CdS/TiO 2 /graphene (CTG) nanocomposite thin films were synthesized by a facile production route. The TiO 2 /graphene (TG) nanocomposite was initially fabricated by sol-gel method in such a way that TiO 2 nanoparticles loaded on graphene oxide (GO) sheet via photocatalytic process. Then, CdS nanoparticles were deposited on the TG thin film by successive ion layer adsorption and reaction process (SILAR) approach. Based on atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, the TG thin film possessed a larger surface area as compared with the pure TiO 2 thin film due to presence of graphene sheet. UV/visible spectroscopy exhibited that visible absorption of the CTG samples increased with increasing CdS SILAR deposition cycle (n). Enhanced photocurrent response of the CTG(n) photoanodes measured as compared with the TG and T photoanodes due to good electrical conductivity and large surface area of graphene as well as the visible light-harvesting ability of CdS nanoparticles. Maximum photocurrent density of about 4.5 A/m 2 and electron life time of about 5 s was measured for the CTG(30) photoanodes

CdS nanoparticle sensitized titanium dioxide decorated graphene for enhancing visible light induced photoanode

Energy Technology Data Exchange (ETDEWEB)

Yousefzadeh, S.; Faraji, M. [Physics Department, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Nien, Y.T. [Department of Materials Science and Engineering, National Formosa University, Taiwan (China); Moshfegh, A.Z., E-mail: moshfegh@sharif.edu [Physics Department, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 14588-89694, Tehran (Iran, Islamic Republic of)

2014-11-30

Highlights: • CdS nanoparticles were deposited on TiO{sub 2}/graphene film by different SILAR cycles. • The visible light absorption increased due to graphene and CdS nanoparticles. • The highest photocurrent density was achieved for nanocomposite with 30 CdS cycles. • A mechanism has been suggested for nanocomposite photoanodes, significantly. - Abstract: CdS/TiO{sub 2}/graphene (CTG) nanocomposite thin films were synthesized by a facile production route. The TiO{sub 2}/graphene (TG) nanocomposite was initially fabricated by sol-gel method in such a way that TiO{sub 2} nanoparticles loaded on graphene oxide (GO) sheet via photocatalytic process. Then, CdS nanoparticles were deposited on the TG thin film by successive ion layer adsorption and reaction process (SILAR) approach. Based on atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, the TG thin film possessed a larger surface area as compared with the pure TiO{sub 2} thin film due to presence of graphene sheet. UV/visible spectroscopy exhibited that visible absorption of the CTG samples increased with increasing CdS SILAR deposition cycle (n). Enhanced photocurrent response of the CTG(n) photoanodes measured as compared with the TG and T photoanodes due to good electrical conductivity and large surface area of graphene as well as the visible light-harvesting ability of CdS nanoparticles. Maximum photocurrent density of about 4.5 A/m{sup 2} and electron life time of about 5 s was measured for the CTG(30) photoanodes.

Low-debris, efficient laser-produced plasma extreme ultraviolet source by use of a regenerative liquid microjet target containing tin dioxide (SnO2) nanoparticles

Science.gov (United States)

Higashiguchi, Takeshi; Dojyo, Naoto; Hamada, Masaya; Sasaki, Wataru; Kubodera, Shoichi

2006-05-01

We demonstrated a low-debris, efficient laser-produced plasma extreme ultraviolet (EUV) source by use of a regenerative liquid microjet target containing tin-dioxide (SnO2) nanoparticles. By using a low SnO2 concentration (6%) solution and dual laser pulses for the plasma control, we observed the EUV conversion efficiency of 1.2% with undetectable debris.

Low-debris, efficient laser-produced plasma extreme ultraviolet source by use of a regenerative liquid microjet target containing tin dioxide (SnO2) nanoparticles

International Nuclear Information System (INIS)

Higashiguchi, Takeshi; Dojyo, Naoto; Hamada, Masaya; Sasaki, Wataru; Kubodera, Shoichi

2006-01-01

We demonstrated a low-debris, efficient laser-produced plasma extreme ultraviolet (EUV) source by use of a regenerative liquid microjet target containing tin-dioxide (SnO 2 ) nanoparticles. By using a low SnO 2 concentration (6%) solution and dual laser pulses for the plasma control, we observed the EUV conversion efficiency of 1.2% with undetectable debris

Mediatorless Impedance Studies with Titanium Dioxide Conjugated Gold Nanoparticles for Hydrogen Peroxide Detection

Directory of Open Access Journals (Sweden)

Nur Hamidah Abdul Halim

2017-09-01

Full Text Available An impedimetric-based biosensor constructed using gold nanoparticles (AuNP entrapped within titanium dioxide (TiO2 particles for hydrogen peroxide (H2O2 detection is the main feature of this research. The matrix of the biosensor employed the surface of TiO2, which was previously modified with an amine terminal group using 3-Aminopropyltriethoxysilane (APTS at a low temperature to create a ready to immobilise surface for the biosensor application. Hemoglobin (Hb, which exhibits peroxidase-like activity, was used as the bioreceptor in the biosensor to detect H2O2 in solution. The analysis was carried out using an alternative impedance method, in which the biosensor exhibited a wide linear range response between 1 × 10−4 M and 1.5 × 10−2 M and a limit of detection (LOD of 1 × 10−5 M without a redox mediator.

Surface properties and dye loading behavior of Zn{sub 2}SnO{sub 4} nanoparticles hydrothermally synthesized using different mineralizers

Energy Technology Data Exchange (ETDEWEB)

Annamalai, Alagappan; Eo, Yang Dam [Department of Advanced Technology Fusion, Konkuk University, 1 Hwayang-dong, Kwangjin-gu, Seoul 143-701 (Korea, Republic of); Im, Chan [Department of Chemistry, Konkuk University, 1 Hwayang-dong, Kwangjin-gu, Seoul 143-701 (Korea, Republic of); Lee, Man-Jong, E-mail: leemtx@konkuk.ac.kr [Department of Advanced Technology Fusion, Konkuk University, 1 Hwayang-dong, Kwangjin-gu, Seoul 143-701 (Korea, Republic of)

2011-10-15

We present for the first time the influence of different mineralizers on the isoelectric point (IEP) of zinc stannate (Zn{sub 2}SnO{sub 4}) nanoparticles hydrothermally prepared using three different mineralizers, viz., Na{sub 2}CO{sub 3}, KOH and tert-butyl amine, and the effect of the IEPs on the dye loading behavior of Zn{sub 2}SnO{sub 4} based photoelectrodes in dye sensitized solar cells (DSSCs). To produce highly crystalline, uniform sized Zn{sub 2}SnO{sub 4} nanoparticles, hydrothermal processing parameters, such as reaction temperature, time, and the mineralizers used have been critically adjusted. The structural and morphological features of the as-synthesized Zn{sub 2}SnO{sub 4} nanoparticles have been observed using both scanning and transmission electron microscopy. For the surface state characterization of shape- and size-controlled Zn{sub 2}SnO{sub 4} nanoparticles, the IEPs of Zn{sub 2}SnO{sub 4} surfaces were determined through zeta potential measurements. The IEPs were found to be 5.7, 7.4 and 8.1 for Zn{sub 2}SnO{sub 4} nanoparticles formed using Na{sub 2}CO{sub 3}, KOH and tert-butyl amine, respectively, suggesting that the surface properties of Zn{sub 2}SnO{sub 4} nanoparticles can be manipulated through the choice of the mineralizers used during the hydrothermal reaction. The amount of N719 dye loading on the surfaces of Zn{sub 2}SnO{sub 4} electrodes having different IEPs was also evaluated. It was revealed that the higher the IEP, the higher the dye loading amount, which means that the IEP mainly affects the dye loading at the dye-metal oxide interface. - Highlights: {yields} The effect of various mineralizers on the isoelectric point of Zn{sub 2}SnO{sub 4} was discussed. {yields} The IEP of Zn{sub 2}SnO{sub 4} can be modified by the choice of mineralizer. {yields} Change in IEP affects the surface properties and the morphology of Zn{sub 2}SnO{sub 4} particles. {yields} Modified surface affects the N719 dye loading behaviour of the Zn{sub 2

Drug loading to lipid-based cationic nanoparticles

International Nuclear Information System (INIS)

Cavalcanti, Leide P.; Konovalov, Oleg; Torriani, Iris L.; Haas, Heinrich

2005-01-01

Lipid-based cationic nanoparticles are a new promising option for tumor therapy, because they display enhanced binding and uptake at the neo-angiogenic endothelial cells, which a tumor needs for its nutrition and growth. By loading suitable cytotoxic compounds to the cationic carrier, the tumor endothelial and consequently also the tumor itself can be destroyed. For the development of such novel anti-tumor agents, the control of drug loading and drug release from the carrier matrix is essential. We have studied the incorporation of the hydrophobic anti-cancer agent Paclitaxel (PXL) into a variety of lipid matrices by X-Ray reflectivity measurements. Liposome suspensions from cationic and zwitterionic lipids, comprising different molar fractions of Paclitaxel, were deposited on planar glass substrates. After drying at controlled humidity, well ordered, oriented multilayer stacks were obtained, as proven by the presence of bilayer Bragg peaks to several orders in the reflectivity curves. The presence of the drug induced a decrease of the lipid bilayer spacing, and with an excess of drug, also Bragg peaks of drug crystals could be observed. From the results, insight into the solubility of Paclitaxel in the model membranes was obtained and a structural model of the organization of the drug in the membrane was derived. Results from subsequent pressure/area-isotherm and grazing incidence diffraction (GID) measurements performed with drug/lipid Langmuir monolayers were in accordance with these conjectures

Integrated titanium dioxide (TiO_2) nanoparticles on interdigitated device electrodes (IDEs) for pH analysis

International Nuclear Information System (INIS)

Azizah, N.; Gopinath, Subash C. B.; Nadzirah, Sh.; Farehanim, M. A.; Fatin, M. F.; Ruslinda, A. R.; Hashim, U.; Arshad, M. K. Md.; Ayub, R. M.

2016-01-01

Titanium dioxide (TiO_2) nanoparticles based Interdigitated Device Electrodes (IDEs) Nanobiosensor device was developed for intracellular biochemical detection. Fabrication and characterization of pH sensors using IDE nanocoated with TiO_2 was studied in this paper. In this paper, a preliminary assessment of this intracellular sensor with electrical measurement under different pH levels. 3-aminopropyltriethoxysilane (APTES) was used to enhance the sensitivity of titanium dioxide layer as well as able to provide surface modification by undergoing protonation and deprotonation process. Different types of pH solution provide different resistivity and conductivity towards the surface. Base solution has the higher current compared to an acid solution. Amine and oxide functionalized TiO_2 based IDE exhibit pH-dependent could be understood in terms of the change in surface charge during protonation and deprotonation. The simple fabrication process, high sensitivity, and fast response of the TiO_2 based IDEs facilitate their applications in a wide range of areas. The small size of semiconductor TiO_2 based IDE for sensitive, label-free, real time detection of a wide range of biological species could be explored in vivo diagnostics and array-based screening.

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

Increased cellular uptake of lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles due to surface modification with folic acid.

Science.gov (United States)

Feuser, Paulo Emilio; Arévalo, Juan Marcelo Carpio; Junior, Enio Lima; Rossi, Gustavo Rodrigues; da Silva Trindade, Edvaldo; Rocha, Maria Eliane Merlin; Jacques, Amanda Virtuoso; Ricci-Júnior, Eduardo; Santos-Silva, Maria Claudia; Sayer, Claudia; de Araújo, Pedro H Hermes

2016-12-01

Lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles surface modified with folic acid were synthesized by miniemulsion polymerization in just one step. In vitro biocompatibility and cytotoxicity assays on L929 (murine fibroblast), human red blood, and HeLa (uterine colon cancer) cells were performed. The effect of folic acid at the nanoparticles surface was evaluated through cellular uptake assays in HeLa cells. Results showed that the presence of folic acid did not affect substantially the polymer particle size (~120 nm), the superparamagnetic behavior, the encapsulation efficiency of lauryl gallate (~87 %), the Zeta potential (~38 mV) of the polymeric nanoparticles or the release profile of lauryl gallate. The release profile of lauryl gallate from superparamagnetic poly(methyl methacrylate) nanoparticles presented an initial burst effect (0-1 h) followed by a slow and sustained release, indicating a biphasic release system. Lauryl gallate loaded in superparamagnetic poly(methyl methacrylate) nanoparticles with folic acid did not present cytotoxicity effects on L929 and human red blood cells. However, free lauryl gallate presented significant cytotoxic effects on L929 and human red blood cells at all tested concentrations. The presence of folic acid increased the cytotoxicity of lauryl gallate loaded in nanoparticles on HeLa cells due to a higher cellular uptake when HeLa cells were incubated at 37 °C. On the other hand, when the nanoparticles were incubated at low temperature (4 °C) cellular uptake was not observed, suggesting that the uptake occurred by folate receptor mediated energy-dependent endocytosis. Based on presented results our work suggests that this carrier system can be an excellent alternative in targeted drug delivery by folate receptor.

Study on synthesis and properties of nanoparticles loaded with amaryllidaceous alkaloids

Directory of Open Access Journals (Sweden)

Duan Lihong

2017-11-01

Full Text Available Alzheimer’s disease (AD is the most common disease among the elderly people and a major social and medical problem. Amaryllidaceous alkaloids, acting as acetylcholinesterase inhibitors, represent a potential treatment of AD. However, they also have some deficiencies, such as extensive toxicity and widespread side effects. In order to improve the bioavailability and reduce the toxic and side effects, brain targeting of amaryllidaceous alkaloids was enhanced by considering low density lipoprotein (LDL receptors of blood-brain barrier (BBB endothelial cells as therapeutic targets. Amaryllidaceous alkaloids were highly selectively and quantitatively riveted to the surface of low density lipoproteins by using a new method - mild click chemistry. The structure of products has been characterized by NMR, FT-IR, and other methods. In addition, drug loading rate, encapsulation rate, and drug release by the nanoparticles were determined to assess the quality of the nanoparticles.

Evaluation of radiolabeled curcumin-loaded solid lipid nanoparticles usage as an imaging agent in liver-spleen scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Ayan, Arif Kursad [Department of Nuclear Medicine, Ataturk University, 25240 Erzurum (Turkey); Yenilmez, Ayse, E-mail: yenilmez2014@gmail.com [Department of Nanoscience and Nanoengineering, Ataturk University, 25240 Erzurum (Turkey); Department of Molecular Biology and Genetics, Erzurum Technical University, 25240 Erzurum (Turkey); Eroglu, Hayrettin [Department of Biomedical Engineering, Ataturk University, 25240 Erzurum (Turkey)

2017-06-01

Curcumin-loaded solid lipid nanoparticles (C-SLNs) were prepared using micro emulsion and ultrasonication methods in the first stage of this study to determine the role of C-SLN on liver-spleen scintigraphy. It was concluded that the curcumin that was encapsulated in solid lipid nanoparticles had a β′ polymorph structure according to the X-ray diffraction (XRD) analysis. İt was concluded that these particles were at nano scale according to the laser diffraction (LD) analysis. Fourier transform infrared spectroscopy (FT-IR) analysis suggested an interaction between the curcumin and the solid lipid matrix, and the curcumin was loaded on the solid lipid nanoparticles. Moreover, the particles were concluded to be spherical and at nanoscale according to the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. On the other hand, thermogravimetric analysis (TGA) suggested that the curcumin loaded solid nanoparticles were stable against the temperature. C-SLNs were labeled with Technetium-99 m ({sup 99m}Tc) radioisotope in the second stage of the study, then using scintigraphic methods in-vivo studies were performed on New Zealand rabbit and made a comparison with Phytate colloid, routinely used in liver-spleen scintigraphy. After analyzing the images and the biological distributions obtained from the experiments, uptake was observed in the liver and the spleen. Following from the experiment results, {sup 99m}Tc-labeled C-SLNs was concluded to be a possible imaging agent. In particular, it could be a new radiopharmaceutical alternative to {sup 99m}Tc-labeled compounds that are used in liver and spleen imaging in colloid scintigraphy. - Graphıcal abstract: Display Omitted - Hıghlıghts: • Curcumin-loaded solid lipid nanoparticles (C-SLNs) were prepared and examined characterization studies. • The C-SLNs were labeled with {sup 99m}Tc and made a comparison with Phytate colloid, routinely used in liver-spleen scintigraphy. • In vivo

Treatment Efficiency of Free and Nanoparticle-Loaded Mitoxantrone for Magnetic Drug Targeting in Multicellular Tumor Spheroids

Directory of Open Access Journals (Sweden)

Annkathrin Hornung

2015-09-01

Full Text Available Major problems of cancer treatment using systemic chemotherapy are severe side effects. Magnetic drug targeting (MDT employing superparamagnetic iron oxide nanoparticles (SPION loaded with chemotherapeutic agents may overcome this dilemma by increasing drug accumulation in the tumor and reducing toxic side effects in the healthy tissue. For translation of nanomedicine from bench to bedside, nanoparticle-mediated effects have to be studied carefully. In this study, we compare the effect of SPION, unloaded or loaded with the cytotoxic drug mitoxantrone (MTO with the effect of free MTO, on the viability and proliferation of HT-29 cells within three-dimensional multicellular tumor spheroids. Fluorescence microscopy and flow cytometry showed that both free MTO, as well as SPION-loaded MTO (SPIONMTO are able to penetrate into tumor spheroids and thereby kill tumor cells, whereas unloaded SPION did not affect cellular viability. Since SPIONMTO has herewith proven its effectivity also in complex multicellular tumor structures with its surrounding microenvironment, we conclude that it is a promising candidate for further use in magnetic drug targeting in vivo.

Development of Dorzolamide Loaded 6-O-Carboxymethyl Chitosan Nanoparticles for Open Angle Glaucoma

OpenAIRE

Shinde, Ujwala; Ahmed, Mohammed Hadi; Singh, Kavita

2013-01-01

Chitosan (CS) is a biodegradable, biocompatible, and mucoadhesive natural polymer soluble in acidic pH only and can be irritating to the eye. Objective of the study was to synthesize water soluble 6-O-carboxymethyl (OCM-CS) derivative of CS, and to develop CS and OCM-CS nanoparticles (NPs) loaded with dorzolamide hydrochloride (DRZ). CS was reacted with monochloroacetic acid (MCA) ...

Antimicrobial and cell viability measurement of bovine serum albumin capped silver nanoparticles (Ag/BSA) loaded collagen immobilized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) film.

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Bakare, Rotimi; Hawthrone, Samantha; Vails, Carmen; Gugssa, Ayele; Karim, Alamgir; Stubbs, John; Raghavan, Dharmaraj

2016-03-01

Bacterial infection of orthopedic devices has been a major concern in joint replacement procedures. Therefore, this study is aimed at formulating collagen immobilized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) film loaded with bovine serum albumin capped silver nanoparticles (Ag/BSA NPs) to inhibit bacterial growth while retaining/promoting osteoblast cells viability. The nanoparticles loaded collagen immobilized PHBV film was characterized for its composition by X-ray Photoelectron Spectroscopy and Anodic Stripping Voltammetry. The extent of loading of Ag/BSA NPs on collagen immobilized PHBV film was found to depend on the chemistry of the functionalized PHBV film and the concentration of Ag/BSA NPs solution used for loading nanoparticles. Our results showed that more Ag/BSA NPs were loaded on higher molecular weight collagen immobilized PHEMA-g-PHBV film. Maximum loading of Ag/BSA NPs on collagen immobilized PHBV film was observed when 16ppm solution was used for adsorption studies. Colony forming unit and optical density measurements showed broad antimicrobial activity towards Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa at significantly lower concentration i.e., 0.19 and 0.31μg/disc, compared to gentamicin and sulfamethoxazole trimethoprim while MTT assay showed that released nanoparticles from Ag/BSA NPs loaded collagen immobilized PHBV film has no impact on MCTC3-E1 cells viability. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells.

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K S, Joshy; Sharma, Chandra P; Kalarikkal, Nandakumar; Sandeep, K; Thomas, Sabu; Pothen, Laly A

2016-09-01

Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66±12.22nm and modified solid lipid nanoparticles showed an average size of 265.61±80.44nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. Copyright © 2016 Elsevier B.V. All rights reserved.

Microfluidic generation of droplets with a high loading of nanoparticles.

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Wan, Jiandi; Shi, Lei; Benson, Bryan; Bruzek, Matthew J; Anthony, John E; Sinko, Patrick J; Prudhomme, Robert K; Stone, Howard A

2012-09-18

Microfluidic approaches for controlled generation of colloidal clusters, for example, via encapsulation of colloidal particles in droplets, have been used for the synthesis of functional materials including drug delivery carriers. Most of the studies, however, use a low concentration of an original colloidal suspension (60 wt %) particle concentrations. Three types of microfluidic devices, PDMS flow-focusing, PDMS T-junction, and microcapillary devices, are investigated for direct encapsulation of a high concentration of polystyrene (PS) nanoparticles in droplets. In particular, it is shown that PDMS devices fabricated by soft lithography can generate droplets from a 25 wt % PS suspension, whereas microcapillary devices made from glass capillary tubes are able to produce droplets from a 67 wt % PS nanoparticle suspension. When the PS concentration is between 0.6 and 25 wt %, the size of the droplets is found to change with the oil-to-water flow rate ratio and is independent of the concentration of particles in the initial suspensions. Drop sizes from ~12 to 40 μm are made using flow rate ratios Q(oil)/Q(water) from 20 to 1, respectively, with either of the PDMS devices. However, clogging occurs in PDMS devices at high PS concentrations (>25 wt %) arising from interactions between the PS colloids and the surface of PDMS devices. Glass microcapillary devices, on the other hand, are resistant to clogging and can produce droplets continuously even when the concentration of PS nanoparticles reaches 67 wt %. We believe that our findings indicate useful approaches and guidelines for the controlled generation of emulsions filled with a high loading of nanoparticles, which are useful for drug delivery applications.

Stability and antimicrobial effect of amikacin-loaded solid lipid nanoparticles

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Solmaz Ghaffari

2010-12-01

Full Text Available Solmaz Ghaffari1, Jaleh Varshosaz1, Afrooz Saadat2, Fatemeh Atyabi21Department of Pharmaceutics, Faculty of Pharmacy and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran; 2Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, IranAbstract: Solid lipid nanoparticles (SLNs of amikacin were designed in this study for pulmonary delivery to reduce the dose or its administration intervals leading to reduction of its toxicities especially in long term treatment. Nanoparticles of amikacin were prepared from cholesterol by solvent diffusion technique and homogenization. The size, zeta potential, loading efficiency, and release profile of the nanoparticles were studied. The conventional broth macrodilution tube method was used to determine the minimum inhibitory concentration (MIC and minimum bacteriostatic concentration (MBC of amikacin SLNs with respect to Pseudomonas aeruginosa in vitro. To guarantee the stability of desired SLNs, they were lyophilized using cryoprotectants. Results showed that considering the release profile of amikacin from the studied nanocarrier, MIC and MBC of amikacin could be about two times less in SLNs of amikacin compared to the free drug. Therefore, fewer doses of amikacin in SLNs can clear the infection with less adverse effects and more safety. Particle size enlargement after lyophilization of desired SLNs after two months storage was limited in comparison with non-lyophilized particles, 996 and 194 nm, respectively. Zeta potential of lyophilized particles was increased to +17 mV from +4 mV before lyophilization. Storage of particles in higher temperature caused accelerated drug release.Keywords: amikacin, antimicrobial effects, Pseudomonas aeruginosa, solid lipid nanoparticles, stability

Microfluidic generation of droplets with a high loading of nanoparticles

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Wan, Jiandi; Shi, Lei; Benson, Bryan; Bruzek, Matthew J.; Anthony, John E.; Sinko, Patrick J.; Prudhomme, Robert K.; Stone, Howard A.

2012-01-01

Microfluidic approaches for controlled generation of colloidal clusters, e.g., via encapsulation of colloidal particles in droplets, have been used for the synthesis of functional materials including drug delivery carriers. Most of the studies, however, use a low concentration of an original colloidal suspension ( 60 wt%) particle concentrations. Three types of microfluidic devices, PDMS flow-focusing, PDMS T-junction, and microcapillary devices, are investigated for direct encapsulation of a high concentration of polystyrene (PS) nanoparticles in droplets. In particular, it is shown that PDMS devices fabricated by soft lithography can generate droplets from a 25 wt% PS suspension, whereas microcapillary devices made from glass capillary tubes are able to produce droplets from a 67 wt% PS nanoparticle suspension. When the PS concentration is between 0.6 and 25 wt%, the size of the droplets is found to change with the oil-to-water flow rate ratio and is independent of the concentration of particles in the initial suspensions. Drop sizes from ~12 to 40 μm are made using flow rate ratios Qoil/Qwater from 20 to 1, respectively, with either of the PDMS devices. However, clogging occurs in PDMS devices at high PS concentrations (> 25 wt%) arising from interactions between the PS colloids and the surface of PDMS devices. Glass microcapillary devices, on the other hand, are resistant to clogging and can produce droplets continuously even when the concentration of PS nanoparticles reaches 67 wt%. We believe that our findings indicate useful approaches and guidelines for the controlled generation of emulsions of microparticles that are filled with a high loading of nanoparticles and which are useful for drug delivery applications. PMID:22934976

Nanoparticles as potential clinical therapeutic agents in Alzheimer's disease: focus on selenium nanoparticles.

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Nazıroğlu, Mustafa; Muhamad, Salina; Pecze, Laszlo

2017-07-01

In etiology of Alzheimer's disease (AD), involvement of amyloid β (Aβ) plaque accumulation and oxidative stress in the brain have important roles. Several nanoparticles such as titanium dioxide, silica dioxide, silver and zinc oxide have been experimentally using for treatment of neurological disease. In the last decade, there has been a great interest on combination of antioxidant bioactive compounds such as selenium (Se) and flavonoids with the oxidant nanoparticles in AD. We evaluated the most current data available on the physiological effects of oxidant and antioxidant nanoparticles. Areas covered: Oxidative nanoparticles decreased the activities of reactive oxygen species (ROS) scavenging enzymes such as glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase in the brain of rats and mice. However, Se-rich nanoparticles in small size (5-15 nm) depleted Aβ formation through decreasing ROS production. Reports on low levels of Se in blood and tissue samples and the low activities of GSH-Px, catalase and SOD enzymes in AD patients and animal models support the proposed crucial role of oxidative stress in the pathogenesis of AD. Expert commentary: In conclusion, present literature suggests that Se-rich nanoparticles appeared to be a potential therapeutic compound for the treatment of AD.

Lysozyme-loaded lipid-polymer hybrid nanoparticles: preparation, characterization and colloidal stability evaluation.

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Devrim, Burcu; Kara, Aslı; Vural, İmran; Bozkır, Asuman

2016-11-01

Lipid-polymer hybrid nanoparticles (LPNPs) are polymeric nanoparticles enveloped by lipid layers, which have emerged as a potent therapeutic nanocarrier alternative to liposomes and polymeric nanoparticles. The aim of this work was to develop, characterize and evaluate LPNPs to deliver a model protein, lysozyme. Lysozyme-loaded LPNPs were prepared by using the modified w/o/w double-emulsion-solvent-evaporation method. Poly-ɛ-caprolactone (PCL) was used as polymeric core material and tripalmitin:lechitin mixture was used to form a lipid shell around the LPNPs. LPNPs were evaluated for particle size distribution, zeta potential, morphology, encapsulation efficiency, in vitro drug release, stability and cytotoxicity. The DLS measurement results showed that the particle size of LPNPs ranged from 58.04 ± 1.95 nm to 2009.00 ± 0.52 nm. The AFM and TEM images of LPNPs demonstrate that LPNPs are spherical in shape. The protein-loading capacity of LPNPs ranged from 5.81% to 60.32%, depending on the formulation parameters. LPNPs displayed a biphasic drug release pattern with a burst release within 1 h, followed by sustained release afterward. Colloidal stability results of LPNPs in different media showed that particle size and zeta potential values of particles did not change significantly in all media except of FBS 100% for 120 h. Finally, the results of a cellular uptake study showed that LPNPs were significantly taken up by 83.3% in L929 cells. We concluded that the LPNPs prepared with PCL as polymeric core material and tripalmitin:lechitin mixture as lipid shell should be a promising choice for protein delivery.

Iontophoresis on minoxidil sulphate-loaded chitosan nanoparticles accelerates drug release, decreasing their targeting effect to hair follicles

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Breno N. Matos

Full Text Available The experiments described in this paper tested the hypothesis whether iontophoresis applied on a chitosan nanoparticle formulation could combine the enhanced drug accumulation into the follicular casts obtained using iontophoresis and the sustained drug release, reducing dermal exposure, provided by nanoparticles. Results showed that even though iontophoresis presented comparable minoxidil targeting potential to hair follicles than passive delivery of chitosan-nanoparticles (4.1 ± 0.9 and 5.3 ± 1.0 µg cm-2, respectively, it was less effective on preventing dermal exposure, since chitosan-nanoparticles presented a drug permeation in the receptor solution of 15.3 ± 4.3 µg cm-2 after 6 h of iontophoresis, while drug amounts from passive nanoparticle delivery were not detected. Drug release experiments showed particles were not able to sustain the drug release under the influence of a potential gradient. In conclusion, the application of MXS-loaded chitosan nanoparticles remains the best way to target MXS to the hair follicles while preventing dermal exposure.

Magnetic loading of TiO2/SiO2/Fe3O4 nanoparticles on electrode surface for photoelectrocatalytic degradation of diclofenac

International Nuclear Information System (INIS)

Hu, Xinyue; Yang, Juan; Zhang, Jingdong

2011-01-01

Highlights: ► Magnetic TSF nanoparticles are immobilized on electrode surface with aid of magnet. ► Magnetically attached TSF electrode shows high photoelectrochemical activity. ► Diclofenac is effectively degraded on TSF-loaded electrode by photoelectrocatalysis. ► Photoelectrocatalytic degradation of diclofenac is monitored with voltammetry. - Abstract: A novel magnetic nanomaterials-loaded electrode developed for photoelectrocatalytic (PEC) treatment of pollutants was described. Prior to electrode fabrication, magnetic TiO 2 /SiO 2 /Fe 3 O 4 (TSF) nanoparticles were synthesized and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and FT-IR measurements. The nanoparticles were dispersed in ethanol and then immobilized on a graphite electrode surface with aid of magnet to obtain a TSF-loaded electrode with high photoelectrochemical activity. The performance of the TSF-loaded electrode was tested by comparing the PEC degradation of methylene blue in the presence and absence of magnet. The magnetically attached TSF electrode showed higher PEC degradation efficiency with desirable stability. Such a TSF-loaded electrode was applied to PEC degradation of diclofenac. After 45 min PEC treatment, 95.3% of diclofenac was degraded on the magnetically attached TSF electrode.

Sensors based on Ag-loaded hematite (α-Fe2O3 nanoparticles for methyl mercaptan detection at room temperature

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Daniel Garcia

2017-06-01

Full Text Available Sensors based on Ag/α-Fe2O3 nanoparticles have been prepared by the coprecipitation method for sensing methyl mercaptan at room temperature. X-ray diffraction patterns of samples matched perfectly with characteristic peaks of hematite with no peaks assigned to Ag even at the highest concentration. STEM images and EDX analysis revealed the presence of Ag nanoparticles (from 2 to 5 nm which were highly dispersed onto α-Fe2O3 surface with an Ag/Fe ratio from 0.014 to 0.099. The Ag nanoparticles were deposited on the hematite surface. Sensing tests of Ag-loaded hematite nanoparticles showed much higher response signal than the unmodified sensor. Hematite loaded with 3%(Wt Ag showed the highest response with a linear dependence from 20 to 80 ppm. The sensor also depicted a good selectivity and stability during 4 days with short recovery time. The high dispersion of reduced Ag evaluated by XPS analysis played an important chemical role in the sensing mechanism that favored the contact of CH3SH with oxygen.

Dual-affinity peptides to generate dense surface coverages of nanoparticles

International Nuclear Information System (INIS)

Del Re, Julia; Blum, Amy Szuchmacher

2014-01-01

Graphical abstract: - Highlights: • Stable nanoparticles were created with the Flg-A3 fusion peptide as a ligand. • Interactions of transition metal ions with Flg control aggregation of the nanoparticles in solution. • The QBP1-A3 fusion peptide improves surface attachment of gold nanoparticles. • Solution pre-aggregation of nanoparticles results in dense surface coverage. - Abstract: Depositing gold nanoparticles is of great interest because of the many potential applications of nanoparticle films; however, generating dense surface nanoparticle coverage remains a difficult challenge. Using dual-affinity peptides we have synthesized gold nanoparticles and then pre-aggregated the particles in solution via interactions with metal ions. These nanoparticle aggregates were then deposited onto silicon dioxide surfaces using another dual-affinity peptide to control binding to the substrate. The results demonstrate that when divalent ions like Zn 2+ or Ni 2+ are used, densely packed gold nanoparticle monolayers are formed on the silicon dioxide substrate, which may have applications in fields like molecular electronics

Errantum: Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins

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Lai JCK

2010-12-01

Full Text Available Lai JCK, Ananthakrishnan G, Jandhyam S, et al. Treatment of human astrocytoma U87 cells with silicon dioxide nanoparticles lowers their survival and alters their expression of mitochondrial and cell signaling proteins. Int J Nanomedicine. 2010;5:715–723.The wrong image was used in Figure 5 on page 719.

Docetaxel-loaded multilayer nanoparticles with nanodroplets for cancer therapy

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Oh KS

2016-03-01

Full Text Available Keun Sang Oh,1,* Kyungim Kim,1,* Byeong Deok Yoon,1 Hye Jin Lee,1 Dal Yong Park,1 Eun-yeong Kim,1 Kiho Lee,1 Jae Hong Seo,2 Soon Hong Yuk1,2 1College of Pharmacy, Korea University, Sejong, 2Biomedical Research Center, Korea University Guro Hospital, Guro-gu, Seoul, Republic of Korea *These authors contributed equally to this work Abstract: A mixture of docetaxel (DTX and Solutol® HS 15 (Solutol transiently formed nanodroplets when it was suspended in an aqueous medium. However, nanodroplets that comprised DTX and Solutol showed a rapid precipitation of DTX because of their unstable characteristics in the aqueous medium. The incorporation of nanodroplets that comprised DTX and Solutol through vesicle fusion and subsequent stabilization was designed to prepare multilayer nanoparticles (NPs with a DTX-loaded Solutol nanodroplet (as template NPs core for an efficient delivery of DTX as a chemotherapeutic drug. As a result, the DTX-loaded Solutol nanodroplets (~11.7 nm were observed to have an increased average diameter (from 11.7 nm to 156.1 nm and a good stability of the hydrated NPs without precipitation of DTX by vesicle fusion and multilayered structure, respectively. Also, a long circulation of the multilayer NPs was observed, and this was due to the presence of Pluronic F-68 on the surface of the multilayer NPs. This led to an improved antitumor efficacy based on the enhanced permeation and retention effect. Therefore, this study indicated that the multilayer NPs have a considerable potential as a drug delivery system with an enhanced therapeutic efficacy by blood circulation and with low side effects. Keywords: multilayer nanoparticles, Solutol, Pluronic F-68, docetaxel, cancer therapy

Uniform deposition of ternary chalcogenide nanoparticles onto mesoporous TiO{sub 2} film using liquid carbon dioxide-based coating

Energy Technology Data Exchange (ETDEWEB)

Nursanto, Eduardus Budi [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Park, Se Jin [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Jeon, Hyo Sang; Hwang, Yun Jeong [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Kim, Jaehoon, E-mail: jaehoonkim@skku.edu [School of Mechanical Engineering, Sungkyunkwan University, 2066, Seobu-Ro, Jangan-Gu, Suwon, GyeongGi-Do 440–746 (Korea, Republic of); SKKU Advanced Institute of Nano Technology (SAINT), 2066, Seobu-Ro, Jangan-Gu, Suwon, GyeongGi-Do 440–746 (Korea, Republic of); Min, Byoung Koun, E-mail: bkmin@kist.re.kr [Clean Energy Research Center, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136–791 (Korea, Republic of); Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology,217, Gajeong-ro, Yuseong-gu, Daejeon 305–333 (Korea, Republic of); Green School, Korea University, 145,Anam-ro, Seongbuk-gu, Seoul 136–713 (Korea, Republic of)

2014-08-28

We report the simultaneous deposition of two different metal precursors dissolved in liquid carbon dioxide (l-CO{sub 2}), aiming to the synthesis of ternary chalcopyrite (e.g. CuInS{sub 2}) nanoparticles on a mesoporous TiO{sub 2} film. The l-CO{sub 2}-based deposition of Cu and In precursors and subsequent reaction with a dilute H{sub 2}S gas resulted in Cu{sub x}In{sub y}S{sub z} nanoparticles uniformly deposited across the entire thickness of a mesoporous TiO{sub 2} film. Further heat treatment (air annealing and sulfurization) led to the formation of more stoichiometric CuInS{sub 2} nanoparticles. The formation of CuInS{sub 2} on TiO{sub 2} was confirmed by scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. The crystal growth of CuInS{sub 2} was also found to be controllable by adjusting the number of coating cycles of the l-CO{sub 2}-based deposition. - Highlights: • Simultaneous deposition of two different metal precursors dissolved in l-CO{sub 2}. • Uniform deposition of CuInS{sub 2} nanoparticles across mesoporous TiO{sub 2} film. • Highly crystalline CuInS{sub 2} formed on mesoporous TiO{sub 2} film. • Nearly stoichiometric ratio of Cu:In:S was obtained.

Curcumin loaded poly(2-hydroxyethyl methacrylate) nanoparticles from gelled ionic liquid--in vitro cytotoxicity and anti-cancer activity in SKOV-3 cells.

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Kumar, Sathish Sundar Dhilip; Surianarayanan, Mahadevan; Vijayaraghavan, R; Mandal, Asit Baran; MacFarlane, D R

2014-01-23

The main focus of this study is to encapsulate hydrophobic drug curcumin in hydrophilic polymeric core such as poly(2-hydroxyethyl methacrylate) [PHEMA] nanoparticles from gelled ionic liquid (IL) to improve its efficacy. We have achieved 26.4% drug loading in a biocompatible hydrophilic polymer. Curcumin loaded PHEMA nanoparticles (C-PHEMA-NPs) were prepared by nano-precipitation method. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis showed that the prepared nanoparticles were spherical in shape and free from aggregation. The size and zeta potential of prepared C-PHEMA-NPs were about 300 nm and -33.4 mV respectively. C-PHEMA-NPs were further characterized by FT-IR spectroscopy which confirmed the existence of curcumin in the nanoparticles. X-ray diffraction and differential scanning calorimetry studies revealed that curcumin present in the PHEMA nanoparticles were found to be amorphous in nature. The anticancer activity of C-PHEMA-NPs was measured in ovarian cancer cells (SKOV-3) in vitro, and the results revealed that the C-PHEMA-NPs had better tumor cells regression activity than free curcumin. Flow cytometry showed the significant reduction in G0/G1 cells after treatment with C-PHEMA-NPs and molecular level of apoptosis were also studied using western blotting. Toxicity of PHEMA nanoparticles were studied in zebrafish embryo model and results revealed the material to be highly biocompatible. The present study demonstrates the curcumin loaded PHEMA nanoparticles have potential therapeutic values in the treatment of cancer. Copyright © 2013 Elsevier B.V. All rights reserved.

Cancer therapy with drug loaded magnetic nanoparticles-magnetic drug targeting

International Nuclear Information System (INIS)

Alexiou, Christoph; Tietze, Rainer; Schreiber, Eveline; Jurgons, Roland; Richter, Heike; Trahms, Lutz; Rahn, Helene; Odenbach, Stefan; Lyer, Stefan

2011-01-01

The aim of magnetic drug targeting (MDT) in cancer therapy is to concentrate chemotherapeutics to a tumor region while simultaneously the overall dose is reduced. This can be achieved with coated superparamagnetic nanoparticles bound to a chemotherapeutic agent. These particles are applied intra arterially close to the tumor region and focused to the tumor by a strong external magnetic field. The interaction of the particles with the field gradient leads to an accumulation in the region of interest (i.e. tumor). The particle enrichment and thereby the drug-load in the tumor during MDT has been proven by several analytical and imaging methods. Moreover, in pilot studies we investigated in an experimental in vivo tumor model the effectiveness of this approach. Complete tumor regressions without any negative side effects could be observed. - Research Highlights: →Iron oxide nanoparticles can be enriched in tumors by external magnetic fields. → Histology evidences the intravasation of particles enter the intracellular space. → Non-invasive imaging techniques can display the spatial arrangement of particles. → HPLC-analysis show outstanding drug enrichment in tumors after MDT.

Cancer therapy with drug loaded magnetic nanoparticles-magnetic drug targeting

Energy Technology Data Exchange (ETDEWEB)

Alexiou, Christoph, E-mail: c.alexiou@web.d [Department of Oto-rhino-laryngology, Head and Neck Surgery, University Hospital Erlangen, Section for Experimental Oncology and Nanomedicine at the Else Kroener-Fresenius-Stiftung-Professorship (Germany); Tietze, Rainer; Schreiber, Eveline [Department of Oto-rhino-laryngology, Head and Neck Surgery, University Hospital Erlangen, Section for Experimental Oncology and Nanomedicine at the Else Kroener-Fresenius-Stiftung-Professorship (Germany); Jurgons, Roland [Franz Penzoldt Center, University Hospital Erlangen (Germany); Richter, Heike; Trahms, Lutz [PTB Berlin (Germany); Rahn, Helene; Odenbach, Stefan [TU Dresden, Chair of Magnetofluiddynamics, 01062 Dresden (Germany); Lyer, Stefan [Department of Oto-rhino-laryngology, Head and Neck Surgery, University Hospital Erlangen, Section for Experimental Oncology and Nanomedicine at the Else Kroener-Fresenius-Stiftung-Professorship (Germany)

2011-05-15

The aim of magnetic drug targeting (MDT) in cancer therapy is to concentrate chemotherapeutics to a tumor region while simultaneously the overall dose is reduced. This can be achieved with coated superparamagnetic nanoparticles bound to a chemotherapeutic agent. These particles are applied intra arterially close to the tumor region and focused to the tumor by a strong external magnetic field. The interaction of the particles with the field gradient leads to an accumulation in the region of interest (i.e. tumor). The particle enrichment and thereby the drug-load in the tumor during MDT has been proven by several analytical and imaging methods. Moreover, in pilot studies we investigated in an experimental in vivo tumor model the effectiveness of this approach. Complete tumor regressions without any negative side effects could be observed. - Research Highlights: Iron oxide nanoparticles can be enriched in tumors by external magnetic fields. Histology evidences the intravasation of particles enter the intracellular space. Non-invasive imaging techniques can display the spatial arrangement of particles. HPLC-analysis show outstanding drug enrichment in tumors after MDT.

Silicone rubbers for dielectric elastomers with improved dielectric and mechanical properties as a result of substituting silica with titanium dioxide

DEFF Research Database (Denmark)

Yu, Liyun; Skov, Anne Ladegaard

2016-01-01

One prominent method of modifying the properties of dielectric elastomers (DEs) is by adding suitable metal oxide fillers. However, almost all commercially available silicone elastomers are already heavily filled with silica to reinforce the otherwise rather weak silicone network and the resulting...... and dynamic viscosity. Filled silicone elastomers with high loadings of nano-sized titanium dioxide (TiO2) particles were also studied. The best overall performing formulation had 35 wt.% TiO2 nanoparticles in the POWERSIL® XLR LSR, where the excellent ensemble of relative dielectric permittivity of 4.9 at 0...

Effect of Titanium Dioxide Nanoparticles on The Amount of Blood Cells and Liver Enzymes in Wistar Rats

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Rezaei Zarchi

2011-11-01

Full Text Available Introduction: Considering the development of nanotechnology and extensive use of nano-materials are in different fields of industry, it is necessary to investigate their destructive effects on biological systems. Titanium dioxide(TiO2 is used in the production of different dyes, cosmetics, ceramics, photocatalysts, water and sewage treatment and a lot of other products. In the present study, the effect of TiO2 on the number of blood cells and the activity of liver enzymes of rat was assessed. Methods: Concentrations of 50, 100 and 500 mg/Kg TiO2 nanoparticles (25 nm size in distilled water were administered orally to Wistar rats for 14 days and some blood factors were studied on the blood samples collected. Results: Results showed that TiO2 nanoparticles cause different changes in blood cells, and the changes were significant for some of them such as white blood cells (lymphocytes, monocytes, eosinophils and basophils. Decreased number of red blood cells and increased level of liver enzymes was also observed after the administration of different concentrations of TiO2, which proves the toxic effects of TiO2 on the body. Conclusion: Results of the present study proved the toxicity of TiO2 nanoparticles on the living organisms. So, further studies are recommended to predict TiO2 toxicity.

Guided bone regeneration with asymmetric collagen-chitosan membranes containing aspirin-loaded chitosan nanoparticles

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Zhang J

2017-12-01

Full Text Available Jiayu Zhang,1 Shiqing Ma,1 Zihao Liu,1 Hongjuan Geng,1 Xin Lu,1 Xi Zhang,1 Hongjie Li,1 Chenyuan Gao,2 Xu Zhang,1 Ping Gao1 1School of Dentistry, Hospital of Stomatology, Tianjin Medical University, Tianjin, 2Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, People’s Republic of China Introduction: Membranes allowing the sustained release of drugs that can achieve cell adhesion are very promising for guided bone regeneration. Previous studies have suggested that aspirin has the potential to promote bone regeneration. The purpose of this study was to prepare a local drug delivery system with aspirin-loaded chitosan nanoparticles (ACS contained in an asymmetric collagen-chitosan membrane (CCM. Methods: In this study, the ACS were fabricated using different concentrations of aspirin (5 mg, 25 mg, 50 mg, and 75 mg. The drug release behavior of ACS was studied. Transmission electron microscopy (TEM and scanning electron microscopy (SEM were used to examine the micromorphology of ACS and aspirin-loaded chitosan nanoparticles contained in chitosan-collagen membranes (ACS-CCM. In vitro bone mesenchymal stem cells (BMSCs were cultured and critical-sized cranial defects on Sprague-Dawley rats were made to evaluate the effect of the ACS-CCM on bone regeneration.Results: Drug release behavior results of ACS showed that the nanoparticles fabricated in this study could successfully sustain the release of the drug. TEM showed the morphology of the nanoparticles. SEM images indicated that the asymmetric membrane comprised a loose collagen layer and a dense chitosan layer. In vitro studies showed that ACS-CCM could promote the proliferation of BMSCs, and that the degree of differentiated BMSCs seeded on CCMs containing 50 mg of ACS was higher than that of other membranes. Micro-computed tomography showed that 50 mg of ACS-CCM resulted in enhanced bone regeneration compared with the control group.Conclusion: This

Effects of Titanium Dioxide Nanoparticles on Red Clover and Its Rhizobial Symbiont.

Science.gov (United States)

Moll, Janine; Okupnik, Annette; Gogos, Alexander; Knauer, Katja; Bucheli, Thomas D; van der Heijden, Marcel G A; Widmer, Franco

2016-01-01

Titanium dioxide nanoparticles (TiO2 NPs) are in consideration to be used in plant protection products. Before these products can be placed on the market, ecotoxicological tests have to be performed. In this study, the nitrogen fixing bacterium Rhizobium trifolii and red clover were exposed to two TiO2 NPs, i.e., P25, E171 and a non-nanomaterial TiO2. Growth of both organisms individually and their symbiotic root nodulation were investigated in liquid and hydroponic systems. While 23 and 18 mg l-1 of E171 and non-nanomaterial TiO2 decreased the growth rate of R. trifolii by 43 and 23% respectively, P25 did not cause effects. Shoot length of red clover decreased between 41 and 62% for all tested TiO2 NPs. In 21% of the TiO2 NP treated plants, no nodules were found. At high concentrations certain TiO2 NPs impaired R. trifolii as well as red clover growth and their symbiosis in the hydroponic systems.

Effects of Titanium Dioxide Nanoparticles on Red Clover and Its Rhizobial Symbiont.

Directory of Open Access Journals (Sweden)

Janine Moll

Full Text Available Titanium dioxide nanoparticles (TiO2 NPs are in consideration to be used in plant protection products. Before these products can be placed on the market, ecotoxicological tests have to be performed. In this study, the nitrogen fixing bacterium Rhizobium trifolii and red clover were exposed to two TiO2 NPs, i.e., P25, E171 and a non-nanomaterial TiO2. Growth of both organisms individually and their symbiotic root nodulation were investigated in liquid and hydroponic systems. While 23 and 18 mg l-1 of E171 and non-nanomaterial TiO2 decreased the growth rate of R. trifolii by 43 and 23% respectively, P25 did not cause effects. Shoot length of red clover decreased between 41 and 62% for all tested TiO2 NPs. In 21% of the TiO2 NP treated plants, no nodules were found. At high concentrations certain TiO2 NPs impaired R. trifolii as well as red clover growth and their symbiosis in the hydroponic systems.

Multifunctional PEG modified DOX loaded mesoporous silica nanoparticle@CuS nanohybrids as photo-thermal agent and thermal-triggered drug release vehicle for hepatocellular carcinoma treatment

Science.gov (United States)

Wu, Lingjie; Wu, Ming; Zeng, Yongyi; Zhang, Da; Zheng, Aixian; Liu, Xiaolong; Liu, Jingfeng

2015-01-01

The combination of a multi-therapeutic mode with a controlled fashion is a key improvement in nanomedicine. Here, we synthesized polyethylene glycol (PEG)-modified doxorubicin (DOX)-loaded mesoporous silica nanoparticle (MSN) @CuS nanohybrids as efficient drug delivery carriers, combined with photothermal therapy and chemotherapy to enhance the therapeutic efficacy on hepatocellular carcinoma (HCC). The physical properties of the nanohybrids were characterized by transmission electron microscopy (TEM), N2 adsorption and desorption experiments and by the Vis-NIR absorption spectra. The results showed that the doxorubicin could be stored in the inner pores of mesoporous silica nanoparticles; the CuS nanoparticles, which are coated on the surface of a mesoporous silica nanoparticle, could serve as efficient photothermal therapy (PTT) agents; the loaded drug release could be easily triggered by NIR irradiation. The combination of the PTT treatment with controlled chemotherapy could further enhance the cancer ablation ability compared to any of the single approaches alone. Hence, the reported PEG-modified DOX-loaded mesoporous silica nanoparticle@CuS nanohybrids might be very promising therapeutic agents for HCC treatment.

Determination of Histamine in Silages Using Nanomaghemite Core (γ-Fe2O3-Titanium Dioxide Shell Nanoparticles Off-Line Coupled with Ion Exchange Chromatography

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Natalia Cernei

2016-09-01

Full Text Available The presence of biogenic amines is a hallmark of degraded food and its products. Herein, we focused on the utilization of magnetic nanoparticles off-line coupled with ion exchange chromatography with post-column ninhydrin derivatization and Vis detection for histamine (Him separation and detection. Primarily, we described the synthesis of magnetic nanoparticles with nanomaghemite core (γ-Fe2O3 functionalized with titanium dioxide and, then, applied these particles to specific isolation of Him. To obtain further insight into interactions between paramagnetic particles’ (PMP surface and Him, a scanning electron microscope was employed. It was shown that binding of histamine causes an increase of relative current response of deprotonated PMPs, which confirmed formation of Him-PMPs clusters. The recovery of the isolation showed that titanium dioxide-based particles were able to bind and preconcentrate Him with recovery exceeding 90%. Finally, we successfully carried out the analyses of real samples obtained from silage. We can conclude that our modified particles are suitable for Him isolation, and thus may serve as the first isolation step of Him from biological samples, as it is demonstrated on alfalfa seed variety Tereza silage.

Effective Removal of Congo Red by Triarrhena Biochar Loading with TiO2 Nanoparticles

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Peng Yu

2018-01-01

Full Text Available A composite of pyrolytic Triarrhena biochar loading with TiO2 nanoparticles has been synthesized by the sol-gel method. The composite shows a well-developed hollow mesoporous and macropore structure as characterized by XRD, BET, and SEM. When used as an absorbent to remove Congo red from aqueous solution, it was found that as-prepared composite performed better absorption capacity than single biochar or TiO2. The results suggest that biochar loading with TiO2 could be promisingly implemented as an environmentally friendly and inexpensive adsorbent for Congo red removal from wastewater.

Recombinant IκBα-loaded curcumin nanoparticles for improved cancer therapeutics

International Nuclear Information System (INIS)

Banerjee, Subhamoy; Ghosh, Siddhartha Sankar; Sahoo, Amaresh Kumar; Chattopadhyay, Arun

2014-01-01

The field of recombinant protein therapeutics has been evolving rapidly, making significant impact on clinical applications for several diseases, including cancer. However, the functional aspects of proteins rely exclusively on their structural integrity, in which nanoparticle mediated delivery offers unique advantages over free proteins. In the present work, a novel strategy has been developed where the nanoparticles (NPs) used for the delivery of the recombinant protein could contribute to enhancing the therapeutic efficacy of the recombinant protein. The transcription factor, NFκB, involved in cell growth and its inhibitor, IκBα, regulates its proliferation. Another similar naturally available molecule, which inhibits the function of NFκB, is curcumin. Hence, we have developed a ‘green synthesis’ method for preparing water-soluble curcumin nanoparticles to stabilize recombinant IκBα protein. The NPs were characterized by UV–vis and fluorescence spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering before administration into human cervical carcinoma (HeLa) and glioblastoma (U87MG) cells. Experimental results demonstrated that this combined module had enhanced therapeutic efficacy, causing apoptotic cell death, which was confirmed by cytotoxicity assay and flowcytometry analyses. The expression of apoptotic genes studied by semi-quantitative reverse transcription PCR delineated the molecular pathways involved in cell death. Thus, our study revealed that the functional delivery of recombinant IκBα-loaded curcumin NPs has promise as a natural-product-based protein therapeutics against cancer cells. (paper)

Recombinant IκBα-loaded curcumin nanoparticles for improved cancer therapeutics

Science.gov (United States)

Banerjee, Subhamoy; Sahoo, Amaresh Kumar; Chattopadhyay, Arun; Sankar Ghosh, Siddhartha

2014-08-01

The field of recombinant protein therapeutics has been evolving rapidly, making significant impact on clinical applications for several diseases, including cancer. However, the functional aspects of proteins rely exclusively on their structural integrity, in which nanoparticle mediated delivery offers unique advantages over free proteins. In the present work, a novel strategy has been developed where the nanoparticles (NPs) used for the delivery of the recombinant protein could contribute to enhancing the therapeutic efficacy of the recombinant protein. The transcription factor, NFκB, involved in cell growth and its inhibitor, IκBα, regulates its proliferation. Another similar naturally available molecule, which inhibits the function of NFκB, is curcumin. Hence, we have developed a ‘green synthesis’ method for preparing water-soluble curcumin nanoparticles to stabilize recombinant IκBα protein. The NPs were characterized by UV-vis and fluorescence spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering before administration into human cervical carcinoma (HeLa) and glioblastoma (U87MG) cells. Experimental results demonstrated that this combined module had enhanced therapeutic efficacy, causing apoptotic cell death, which was confirmed by cytotoxicity assay and flowcytometry analyses. The expression of apoptotic genes studied by semi-quantitative reverse transcription PCR delineated the molecular pathways involved in cell death. Thus, our study revealed that the functional delivery of recombinant IκBα-loaded curcumin NPs has promise as a natural-product-based protein therapeutics against cancer cells.

Preparation of silica doped titania nanoparticles with thermal stability and photocatalytic properties and their application for leather surface functionalization

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Carmen Gaidau

2017-11-01

Full Text Available Doped nanoparticles based on titanium dioxide are of interest for their multifunctional properties and enlarged photocatalytic activity in visible domain. Silica doped titanium dioxide nanoparticles were prepared by hydrothermal method and their structural characteristics and photocatalytic activity were determined, in order to be used for leather coating as alternative to halogen based flame retardants and dry cleaning solvents. A range of concentrations from 2% to 20% silica doped titanium dioxide nanoparticles (% denotes the theoretical weight percent of Si was synthesized and characterized by ICP-OES, FT-IR, UV-vis spectroscopy, XRD, HRTEM and DLS. Titanium dioxide network penetration was supported by Si-O-Ti and OH identification in FT-IR spectra mainly on surface of 10% and 20% silica doped titanium dioxide nanoparticles. The increase of Si-O-Ti bonds with Si dopant concentration acts as efficient barriers against sinterization and growth of TiO2 particles and explains the low particle size identified in HRTEM analyses as compared to undoped TiO2NPs. UV-vis diffuse reflectance spectra of doped titanium dioxide nanoparticles showed the shifting of absorption band to visible domain for 10% silica doped titanium dioxide nanoparticles. The crystallite sizes were calculated from XRD spectra, ranging between 16.2 and 18.1 nm. HRTEM measurement of hydrothermally synthesized titanium dioxide nanoparticles showed anatase crystallites in the range of 8.8–27 nm, while in the 20% silica doped titanium dioxide nanoparticle sample smaller crystallite with sizes between 2.7 nm and 3.5 nm was identified due to the constraints of the SiO2-based amorphous matrix. Nano sizes of 64 nm and 72 nm were found in water dispersions of 10% and 20% silica doped titanium dioxide nanoparticles and the Zeta potentials were of −53.6 mV and −52.9 mV, which indicate very good stabilities. The leather surface treated with composites of film forming polymers

Engineering of budesonide-loaded lipid-polymer hybrid nanoparticles using a quality-by-design approach.

Science.gov (United States)

Leng, Donglei; Thanki, Kaushik; Fattal, Elias; Foged, Camilla; Yang, Mingshi

2017-08-25

Chronic obstructive pulmonary disease (COPD) is a complex disease, characterized by persistent airflow limitation and chronic inflammation. The purpose of this study was to design lipid-polymer hybrid nanoparticles (LPNs) loaded with the corticosteroid, budesonide, which could potentially be combined with small interfering RNA (siRNA) for COPD management. Here, we prepared LPNs based on the biodegradable polymer poly(dl-lactic-co-glycolic acid) (PLGA) and the cationic lipid dioleyltrimethylammonium propane (DOTAP) using a double emulsion solvent evaporation method. A quality-by-design (QbD) approach was adopted to define the optimal formulation parameters. The quality target product profile (QTPP) of the LPNs was identified based on risk assessment. Two critical formulation parameters (CFPs) were identified, including the theoretical budesonide loading and the theoretical DOTAP loading. The CFPs were linked to critical quality attributes (CQAs), which included the intensity-based hydrodynamic particle diameter (z-average), the polydispersity index (PDI), the zeta-potential, the budesonide encapsulation efficiency, the actual budesonide loading and the DOTAP encapsulation efficiency. A response surface methodology (RSM) was applied for the experimental design to evaluate the influence of the CFPs on the CQAs, and to identify the optimal operation space (OOS). All nanoparticle dispersions displayed monodisperse size distributions (PDIPLGA increases when increasing the initial amount of budesonide. The OOS was modeled by applying the QTPP. The OOS had a budesonide encapsulation efficiency higher than 30%, a budesonide loading above 15μg budesonide/mg PLGA, a zeta-potential higher than 35mV and a DOTAP encapsulation efficiency above 50%. This study shows the importance of systematic formulation design for understanding the effect of formulation parameters on the characteristics of LPNs, eventually resulting in the identification of an OOS. Copyright © 2017 Elsevier B

Chlorogenic acid loaded chitosan nanoparticles with sustained release property, retained antioxidant activity and enhanced bioavailability

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Ilaiyaraja Nallamuthu

2015-06-01

Full Text Available In this study, chlorogenic acid (CGA, a phenolic compound widely distributed in fruits and vegetables, was encapsulated into chitosan nanoparticles by ionic gelation method. The particles exhibited the size and zeta potential of 210 nm and 33 mV respectively. A regular, spherical shaped distribution of nanoparticles was observed through scanning electron microscopy (SEM and the success of entrapment was confirmed by FTIR analysis. The encapsulation efficiency of CGA was at about 59% with the loading efficiency of 5.2%. In vitro ABTS assay indicated that the radical scavenging activity of CAG was retained in the nanostructure and further, the release kinetics study revealed the burst release of 69% CGA from nanoparticles at the end of 100th hours. Pharmacokinetic analysis in rats showed a lower level of Cmax, longer Tmax, longer MRT, larger AUC0–t and AUC0–∞ for the CGA nanoparticles compared to free CGA. Collectively, these results suggest that the synthesised nanoparticle with sustained release property can therefore ease the fortification of food-matrices targeted for health benefits through effective delivery of CGA in body.

The potential of follicle-stimulating hormone peptide-modified triptolide-loaded nanoparticles to induce a mouse model of premature ovarian insufficiency

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Chen XY

2015-04-01

Full Text Available Xiu-Ying Chen,1–3 Wu-Lian Chen,4 Min Ma,1–3 Chao Gu,1,2 Xi-Rong Xiao,1,2 Bin Li1,2 1Obstetrics and Gynecology Hospital, Fudan University, 2Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, 3Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, 4State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, People’s Republic of ChinaAbstract: The use of triptolide (TP is limited by its poor water solubility and severe toxicity. In this study, we developed an active drug delivery system (TP-loaded nanoparticles that could help improve the water solubility of TP and decrease its toxicity. Then, we investigated whether TP-loaded nanoparticles could be used to establish a novel premature ovarian insufficiency mouse model. The mice treated with TP-loaded nanoparticles for 35 days displayed normal growth, decreased serum antimullerian hormone, prominent ovarian fibrosis and vacuolar changes, fewer follicles and corpus lutea, increased collapsed oocytes and follicle apoptosis, and sterility. In conclusion, this model appears to show the reproductive characteristics associated with premature ovarian insufficiency in women and will allow us to study the mechanism of the effects of traditional Chinese medicine on gonadal toxicity. Keywords: peptide, nanoparticles, drug delivery, premature ovarian insufficiency, animal model

The influence of supercritical carbon dioxide (SC-CO2) processing conditions on drug loading and physicochemical properties.

Science.gov (United States)

Ahern, Robert J; Crean, Abina M; Ryan, Katie B

2012-12-15

Poor water solubility of drugs can complicate their commercialisation because of reduced drug oral bioavailability. Formulation strategies such as increasing the drug surface area are frequently employed in an attempt to increase dissolution rate and hence, improve oral bioavailability. Maximising the drug surface area exposed to the dissolution medium can be achieved by loading drug onto a high surface area carrier like mesoporous silica (SBA-15). The aim of this work was to investigate the impact of altering supercritical carbon dioxide (SC-CO(2)) processing conditions, in an attempt to enhance drug loading onto SBA-15 and increase the drug's dissolution rate. Other formulation variables such as the mass ratio of drug to SBA-15 and the procedure for combining the drug and SBA-15 were also investigated. A model drug with poor water solubility, fenofibrate, was selected for this study. High drug loading efficiencies were obtained using SC-CO(2), which were influenced by the processing conditions employed. Fenofibrate release rate was enhanced greatly after loading onto mesoporous silica. The results highlighted the potential of this SC-CO(2) drug loading approach to improve the oral bioavailability of poorly water soluble drugs. Copyright © 2012 Elsevier B.V. All rights reserved.

Inkjet Printing of Drug-Loaded Mesoporous Silica Nanoparticles-A Platform for Drug Development.

Science.gov (United States)

Wickström, Henrika; Hilgert, Ellen; Nyman, Johan O; Desai, Diti; Şen Karaman, Didem; de Beer, Thomas; Sandler, Niklas; Rosenholm, Jessica M

2017-11-21

Mesoporous silica nanoparticles (MSNs) have shown great potential in improving drug delivery of poorly water soluble (BCS class II, IV) and poorly permeable (BCS class III, IV) drugs, as well as facilitating successful delivery of unstable compounds. The nanoparticle technology would allow improved treatment by reducing adverse reactions of currently approved drugs and possibly reintroducing previously discarded compounds from the drug development pipeline. This study aims to highlight important aspects in mesoporous silica nanoparticle (MSN) ink formulation development for digital inkjet printing technology and to advice on choosing a method (2D/3D) for nanoparticle print deposit characterization. The results show that both unfunctionalized and polyethyeleneimine (PEI) surface functionalized MSNs, as well as drug-free and drug-loaded MSN-PEI suspensions, can be successfully inkjet-printed. Furthermore, the model BCS class IV drug remained incorporated in the MSNs and the suspension remained physically stable during the processing time and steps. This proof-of-concept study suggests that inkjet printing technology would be a flexible deposition method of pharmaceutical MSN suspensions to generate patterns according to predefined designs. The concept could be utilized as a versatile drug screening platform in the future due to the possibility of accurately depositing controlled volumes of MSN suspensions on various materials.

G-CSF loaded nanofiber/nanoparticle composite coated with collagen promotes wound healing in vivo.

Science.gov (United States)

Tanha, Shima; Rafiee-Tehrani, Morteza; Abdollahi, Mohamad; Vakilian, Saeid; Esmaili, Zahra; Naraghi, Zahra Safaei; Seyedjafari, Ehsan; Javar, Hamid Akbari

2017-10-01

Sustained release of functional growth factors can be considered as a beneficial methodology for wound healing. In this study, recombinant human granulocyte colony-stimulating factor (G-CSF)-loaded chitosan nanoparticles were incorporated in Poly(ε-caprolactone) (PCL) nanofibers, followed by surface coating with collagen type I. Physical and mechanical properties of the PCL nanofibers containing G-CSF loaded chitosan nanoparticles PCL/NP(G-CSF) and in vivo performance for wound healing were investigated. G-CSF structural stability was evaluated through SDS_PAGE, reversed phase (RP) HPLC and size-exclusion chromatography, as well as circular dichroism. Nanofiber/nanoparticle composite scaffold was demonstrated to have appropriate mechanical properties as a wound dresser and a sustained release of functional G-CSF. The PCL/NP(G-CSF) scaffold showed a suitable proliferation and well-adherent morphology of stem cells. In vivo study and histopathological evaluation outcome revealed that skin regeneration was dramatically accelerated under PCL/NP(G-CSF) as compared with control groups. Superior fibroblast maturation, enhanced collagen deposition and minimum inflammatory cells were also the beneficial properties of PCL/NP(G-CSF) over the commercial dressing. The synergistic effect of extracellular matrix-mimicking nanofibrous membrane and G-CSF could develop a suitable supportive substrate in order to extensive utilization for the healing of skin wounds. © 2017 Wiley Periodicals Inc. J Biomed Mater Res Part A: 105A: 2830-2842, 2017. © 2017 Wiley Periodicals, Inc.

Effect of PEG biofunctional spacers and TAT peptide on dsRNA loading on gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Sanz, Vanesa; Conde, Joao; Hernandez, Yulan [Universidad de Zaragoza, Instituto de Nanociencia de Aragon (Spain); Baptista, Pedro V. [Universidade Nova de Lisboa, Departamento de Ciencias da Vida, Faculdade de Ciencias e Tecnologia, Centro de Investigacao em Genetica Molecular Humana (Portugal); Ibarra, M. R.; Fuente, Jesus M. de la, E-mail: jmfuente@unizar.es [Universidad de Zaragoza, Instituto de Nanociencia de Aragon (Spain)

2012-06-15

The surface chemistry of gold nanoparticles (AuNPs) plays a critical role in the self-assembly of thiolated molecules and in retaining the biological function of the conjugated biomolecules. According to the well-established gold-thiol interaction the undefined ionic species on citrate-reduced gold nanoparticle surface can be replaced with a self-assembled monolayer of certain thiolate derivatives and other biomolecules. Understanding the effect of such derivatives in the functionalization of several types of biomolecules, such as PEGs, peptides or nucleic acids, has become a significant challenge. Here, an approach to attach specific biomolecules to the AuNPs ({approx}14 nm) surface is presented together with a study of their effect in the functionalization with other specific derivatives. The effect of biofunctional spacers such as thiolated poly(ethylene glycol) (PEG) chains and a positive peptide, TAT, in dsRNA loading on AuNPs is reported. Based on the obtained data, we hypothesize that loading of oligonucleotides onto the AuNP surface may be controlled by ionic and weak interactions positioning the entry of the oligo through the PEG layer. We demonstrate that there is a synergistic effect of the TAT peptide and PEG chains with specific functional groups on the enhancement of dsRNA loading onto AuNPs.

Efficient production of nanoparticle-loaded orodispersible films by process integration in a stirred media mill.

Science.gov (United States)

Steiner, Denise; Finke, Jan Henrik; Kwade, Arno

2016-09-25

Orodispersible films possess a great potential as a versatile platform for nanoparticle-loaded oral dosage forms. In this case, poorly water-soluble organic materials were ground in a stirred media mill and embedded into a polymer matrix. The aim of this study was the shortening of this manufacturing process by the integration of several process steps into a stirred media mill without facing disadvantages regarding the film quality. Furthermore, this process integration is time conserving due to the high stress intensities provided in the mill and applicable for high solids contents and high suspension viscosities. Two organic materials, the model compound Anthraquinone and the active pharmaceutical ingredient Naproxen were investigated in this study. Besides the impact of the film processing on the crystallinity of the particles in the orodispersible film, a particle load of up to 50% was investigated with the new developed processing route. Additionally, a disintegration test was developed, combining an appropriate amount of saliva substitute and a clear endpoint determination. In summary, high nanoparticle loads in orodispersible films with good particle size preservation after film redispersion in water as well as a manufacturing of the film casting mass within a few minutes in a stirred media mill was achieved. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of PEG biofunctional spacers and TAT peptide on dsRNA loading on gold nanoparticles

International Nuclear Information System (INIS)

Sanz, Vanesa; Conde, João; Hernández, Yulán; Baptista, Pedro V.; Ibarra, M. R.; Fuente, Jesús M. de la

2012-01-01

The surface chemistry of gold nanoparticles (AuNPs) plays a critical role in the self-assembly of thiolated molecules and in retaining the biological function of the conjugated biomolecules. According to the well-established gold–thiol interaction the undefined ionic species on citrate-reduced gold nanoparticle surface can be replaced with a self-assembled monolayer of certain thiolate derivatives and other biomolecules. Understanding the effect of such derivatives in the functionalization of several types of biomolecules, such as PEGs, peptides or nucleic acids, has become a significant challenge. Here, an approach to attach specific biomolecules to the AuNPs (∼14 nm) surface is presented together with a study of their effect in the functionalization with other specific derivatives. The effect of biofunctional spacers such as thiolated poly(ethylene glycol) (PEG) chains and a positive peptide, TAT, in dsRNA loading on AuNPs is reported. Based on the obtained data, we hypothesize that loading of oligonucleotides onto the AuNP surface may be controlled by ionic and weak interactions positioning the entry of the oligo through the PEG layer. We demonstrate that there is a synergistic effect of the TAT peptide and PEG chains with specific functional groups on the enhancement of dsRNA loading onto AuNPs.

Recent Advances in Antimicrobial Hydrogels Containing Metal Ions and Metals/Metal Oxide Nanoparticles

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Fazli Wahid

2017-11-01

Full Text Available Recently, the rapid emergence of antibiotic-resistant pathogens has caused a serious health problem. Scientists respond to the threat by developing new antimicrobial materials to prevent or control infections caused by these pathogens. Polymer-based nanocomposite hydrogels are versatile materials as an alternative to conventional antimicrobial agents. Cross-linking of polymeric materials by metal ions or the combination of polymeric hydrogels with nanoparticles (metals and metal oxide is a simple and effective approach for obtaining a multicomponent system with diverse functionalities. Several metals and metal oxides such as silver (Ag, gold (Au, zinc oxide (ZnO, copper oxide (CuO, titanium dioxide (TiO2 and magnesium oxide (MgO have been loaded into hydrogels for antimicrobial applications. The incorporation of metals and metal oxide nanoparticles into hydrogels not only enhances the antimicrobial activity of hydrogels, but also improve their mechanical characteristics. Herein, we summarize recent advances in hydrogels containing metal ions, metals and metal oxide nanoparticles with potential antimicrobial properties.

Influence of Conductive and Semi-Conductive Nanoparticles on the Dielectric Response of Natural Ester-Based Nanofluid Insulation

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M. Z. H. Makmud

2018-02-01

Full Text Available Nowadays, studies of alternative liquid insulation in high voltage apparatus have become increasingly important due to higher concerns regarding safety, sustainable resources and environmentally friendly issues. To fulfil this demand, natural ester has been extensively studied and it can become a potential product to replace mineral oil in power transformers. In addition, the incorporation of nanoparticles has been remarkable in producing improved characteristics of insulating oil. Although much extensive research has been carried out, there is no general agreement on the influence on the dielectric response of base oil due to the addition of different amounts and conductivity types of nanoparticle concentrations. Therefore, in this work, a natural ester-based nanofluid was prepared by a two-step method using iron oxide (Fe2O3 and titanium dioxide (TiO2 as the conductive and semi-conductive nanoparticles, respectively. The concentration amount of each nanoparticle types was varied at 0.01, 0.1 and 1.0 g/L. The nanofluid samples were characterised by visual inspection, morphology and the dynamic light scattering (DLS method before the dielectric response measurement was carried out for frequency-dependent spectroscopy (FDS, current-voltage (I-V, and dielectric breakdown (BD strength. The results show that the dielectric spectra and I-V curves of nanofluid-based iron oxide increases with the increase of iron oxide nanoparticle loading, while for titanium dioxide, it exhibits a decreasing response. The dielectric BD strength is enhanced for both types of nanoparticles at 0.01 g/L concentration. However, the increasing amount of nanoparticles at 0.1 and 1.0 g/L led to a contrary dielectric BD response. Thus, the results indicate that the augmentation of conductive nanoparticles in the suspension can lead to overlapping mechanisms. Consequently, this reduces the BD strength compared to pristine materials during electron injection in high electric

N-Trimethyl chitosan (TMC) nanoparticles loaded with influenza subunit antigen for intranasal vaccination : Biological properties and immunogenicity in a mouse model

NARCIS (Netherlands)

Amidi, Maryam; Romeijn, Stefan G.; Verhoef, J. Coos; Junginger, Hans E.; Bungener, Laura; Huckriede, Anke; Crommelin, Daan J. A.; Jiskoot, Wim

2007-01-01

In this study, the potential of N-trimethyl chitosan (TMC) nanoparticles as a carrier system for the nasal delivery of a monovalent influenza subunit vaccine was investigated. The antigen-loaded nanoparticles were prepared by mixing a solution containing TMC and monovalent influenza A subunit H3N2

Review of titanium dioxide nanoparticle phototoxicity: Developing a phototoxicity ratio to correct the endpoint values of toxicity tests

Science.gov (United States)

2015-01-01

Abstract Titanium dioxide nanoparticles are photoactive and produce reactive oxygen species under natural sunlight. Reactive oxygen species can be detrimental to many organisms, causing oxidative damage, cell injury, and death. Most studies investigating TiO2 nanoparticle toxicity did not consider photoactivation and performed tests either in dark conditions or under artificial lighting that did not simulate natural irradiation. The present study summarizes the literature and derives a phototoxicity ratio between the results of nano‐titanium dioxide (nano‐TiO2) experiments conducted in the absence of sunlight and those conducted under solar or simulated solar radiation (SSR) for aquatic species. Therefore, the phototoxicity ratio can be used to correct endpoints of the toxicity tests with nano‐TiO2 that were performed in absence of sunlight. Such corrections also may be important for regulators and risk assessors when reviewing previously published data. A significant difference was observed between the phototoxicity ratios of 2 distinct groups: aquatic species belonging to order Cladocera, and all other aquatic species. Order Cladocera appeared very sensitive and prone to nano‐TiO2 phototoxicity. On average nano‐TiO2 was 20 times more toxic to non‐Cladocera and 1867 times more toxic to Cladocera (median values 3.3 and 24.7, respectively) after illumination. Both median value and 75% quartile of the phototoxicity ratio are chosen as the most practical values for the correction of endpoints of nano‐TiO2 toxicity tests that were performed in dark conditions, or in the absence of sunlight. Environ Toxicol Chem 2015;34:1070–1077. © 2015 The Author. Published by SETAC. PMID:25640001