oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Hair dye-incorporated poly-γ-glutamic acid/glycol chitosan nanoparticles based on ion-complex formation  [cached]
Lee HY,Jeong YI,Choi KC
International Journal of Nanomedicine , 2011,
Abstract: Hye-Young Lee1,*, Young-IL Jeong2,*, Ki-Choon Choi31Anyang Science University, Anyang, Gyeonggi, South Korea; 2Chonnam National University Hwasun Hospital, Jeonnam, South Korea; 3Grassland and Forages Research Center, National Institute of Animal Science, Rural Development Administration, Chungnam, South Korea*These authors contributed equally to this work.Background: p-Phenylenediamine (PDA) or its related chemicals are used more extensively than oxidative hair dyes. However, permanent hair dyes such as PDA are known to have potent contact allergy reactions in humans, and severe allergic reactions are problematic.Methods: PDA-incorporated nanoparticles were prepared based on ion-complex formation between the cationic groups of PDA and the anionic groups of poly(γ-glutamic acid) (PGA). To reinforce PDA/PGA ion complexes, glycol chitosan (GC) was added. PDA-incorporated nanoparticles were characterized using field-emission scanning electron microscopy, Fourier-transform infrared (FT-IR) spectroscopy, dynamic light scattering, and powder X-ray diffractometry (XRD).Results: Nanoparticles were formed by ion-complex formation between the amine groups of PDA and the carboxyl groups of PGA. PDA-incorporated nanoparticles are small in size (<100 nm), and morphological observations showed spherical shapes. FT-IR spectra results showed that the carboxylic acid peak of PGA decreased with increasing PDA content, indicating that the ion complexes were formed between the carboxyl groups of PGA and the amine groups of PDA. Furthermore, the intrinsic peak of the carboxyl groups of PGA was also decreased by the addition of GC. Intrinsic crystalline peaks of PDA were observed by XRD. This crystalline peak of PDA was completely nonexistent when nanoparticles were formed by ion complex between PDA, PGA, and GC, indicating that PDA was complexed with PGA and no free drug existed in the formulation. During the drug-release experiment, an initial burst release of PDA was observed, and then PDA was continuously released over 1 week. Cytotoxicity testing against HaCaT human skin keratinocyte cells showed PDA-incorporated nanoparticles had lower toxicity than PDA itself. Furthermore, PDA-incorporated nanoparticles showed reduced apoptosis and necrosis reaction at HaCaT cells.Conclusion: The authors suggest that these microparticles are ideal candidates for a vehicle for decreasing side effects of hair dye.Keywords: p-phenylenediamine, keratinocyte, PDA, PGA
5-aminolevulinic acid-incorporated nanoparticles of methoxy poly(ethylene glycol)-chitosan copolymer for photodynamic therapy  [cached]
Chung CW,Chung KD,Jeong YI,Kang DH
International Journal of Nanomedicine , 2013,
Abstract: Chung-Wook Chung,1,* Kyu-Don Chung,2,* Young-Il Jeong,1 Dae Hwan Kang,1 1National Research and Development Center for Hepatobiliary Disease, Pusan National University Yangsan Hospital, Gyeongnam, Republic of Korea; 2Department of Anesthesiology and Pain Medicine, College of Medicine, The Catholic University, Seoul, Republic of Korea*These authors contributed equally to this workPurpose: The aim of this study was to make 5-aminolevulinic acid (5-ALA)-incorporated nanoparticles using methoxy polyethylene glycol/chitosan (PEG-Chito) copolymer for application in photodynamic therapy for colon cancer cells.Methods: 5-ALA-incorporated (PEG-Chito-5-ALA) nanoparticles were prepared by ion complex formation between 5-ALA and chitosan. Protoporphyrin IX accumulation in the tumor cells and phototoxicity induced by PEG-Chito-5-ALA nanoparticles were assessed using CT26 cells in vitro.Results: PEG-Chito-5-ALA nanoparticles have spherical shapes with sizes diameters 200 nm. More specifically, microscopic observation revealed a core-shell structure of PEG-Chito-5-ALA nanoparticles. 1H NMR spectra showed that 5-ALA was incorporated in the core of the nanoparticles. In the absence of light irradiation, all components such as 5-ALA, empty nanoparticles, and PEG-Chito-5-ALA nanoparticles did not affect the viability of cells. However, 5-ALA or PEG-Chito-5-ALA nanoparticles induced tumor cell death under light irradiation, and the viability of tumor cells was dose-dependently decreased according to the increase in irradiation time. In particular, PEG-Chito-5-ALA nanoparticles induced increased phototoxicity and higher protoporphyrin IX accumulation into the tumor cells than did 5-ALA alone. Furthermore, PEG-Chito-5-ALA nanoparticles accelerated apoptosis/necrosis of tumor cells, compared to 5-ALA alone.Conclusion: PEG-Chito-5-ALA nanoparticles showed superior delivery capacity of 5-ALA and phototoxicity against tumor cells. These results show that PEG-Chito-5-ALA nanoparticles are promising candidates for photodynamic therapy of colon cancer cells.Keywords: 5-ALA, photosensitizer, chitosan, nanoparticles, colon cancer, protoporphyrin IX
5-aminolevulinic acid-incorporated nanoparticles of methoxy poly(ethylene glycol)-chitosan copolymer for photodynamic therapy
Chung CW, Chung KD, Jeong YI, Kang DH
International Journal of Nanomedicine , 2013, DOI: http://dx.doi.org/10.2147/IJN.S39615
Abstract: minolevulinic acid-incorporated nanoparticles of methoxy poly(ethylene glycol)-chitosan copolymer for photodynamic therapy Original Research (598) Total Article Views Authors: Chung CW, Chung KD, Jeong YI, Kang DH Published Date February 2013 Volume 2013:8 Pages 809 - 819 DOI: http://dx.doi.org/10.2147/IJN.S39615 Received: 26 October 2012 Accepted: 19 January 2013 Published: 25 February 2013 Chung-Wook Chung,1,* Kyu-Don Chung,2,* Young-Il Jeong,1 Dae Hwan Kang,1 1National Research and Development Center for Hepatobiliary Disease, Pusan National University Yangsan Hospital, Gyeongnam, Republic of Korea; 2Department of Anesthesiology and Pain Medicine, College of Medicine, The Catholic University, Seoul, Republic of Korea *These authors contributed equally to this work Purpose: The aim of this study was to make 5-aminolevulinic acid (5-ALA)-incorporated nanoparticles using methoxy polyethylene glycol/chitosan (PEG-Chito) copolymer for application in photodynamic therapy for colon cancer cells. Methods: 5-ALA-incorporated (PEG-Chito-5-ALA) nanoparticles were prepared by ion complex formation between 5-ALA and chitosan. Protoporphyrin IX accumulation in the tumor cells and phototoxicity induced by PEG-Chito-5-ALA nanoparticles were assessed using CT26 cells in vitro. Results: PEG-Chito-5-ALA nanoparticles have spherical shapes with sizes diameters 200 nm. More specifically, microscopic observation revealed a core-shell structure of PEG-Chito-5-ALA nanoparticles. 1H NMR spectra showed that 5-ALA was incorporated in the core of the nanoparticles. In the absence of light irradiation, all components such as 5-ALA, empty nanoparticles, and PEG-Chito-5-ALA nanoparticles did not affect the viability of cells. However, 5-ALA or PEG-Chito-5-ALA nanoparticles induced tumor cell death under light irradiation, and the viability of tumor cells was dose-dependently decreased according to the increase in irradiation time. In particular, PEG-Chito-5-ALA nanoparticles induced increased phototoxicity and higher protoporphyrin IX accumulation into the tumor cells than did 5-ALA alone. Furthermore, PEG-Chito-5-ALA nanoparticles accelerated apoptosis/necrosis of tumor cells, compared to 5-ALA alone. Conclusion: PEG-Chito-5-ALA nanoparticles showed superior delivery capacity of 5-ALA and phototoxicity against tumor cells. These results show that PEG-Chito-5-ALA nanoparticles are promising candidates for photodynamic therapy of colon cancer cells.
Effect of polyethylene glycol on characteristics of chitosan membranes
Puthai, W.,Wanichapichart, P.,Kaewpiboon A.
Songklanakarin Journal of Science and Technology , 2005,
Abstract: This work reports the influence of polyethylene glycol (PEG) on characteristics of chitosan membranes. Parameters used for membrane characterization were hydraulic permeability (Lp), molecular weight cut off (MWCO), and membrane impedance (Z). The results obtained from LP and Z imply that larger a amount of PEG addition enhances membrane porosity and enlarges the pore size. The prepared membranes were ultrafiltration type, with MWCO slightly greater than 35 kDa. Membranes without PEG additioncould be nanofiltration type with Lp value of 0.4x10-11 m3 N-1 s-1, 10-20 times smaller than the other.
Semi-interpenetrating polymer networks of chitosan and poly(ethylene glycol)  [PDF]
Milosavljevi? Nedeljko B.,Kalagasidis-Kru?i? Melina T.,Filipovi? Jovanka M.
Hemijska Industrija , 2008, DOI: 10.2298/hemind0806345m
Abstract: Chitosan is a natural polycationic polymer that possesses useful properties such as bioactivity, biocompatibility, non-toxicity and non-antigenicity. On the other hand, its mechanical properties are not good for some biomedical application. They may be improved by preparing semi-interpenetrating polymer networks (semi-IPNs), when the hydrogel network is prepared in the presence of a previously made polymer such as poly(ethylene glycol). This paper deals with synthesis and characterization of the semi-interpenetrating polymer networks of chitosan and poly(ethylene glycol) with different Ch/PEG ratio and crosslinking degree. The degree of deacetylation of chitosan was determined by potentiometric titration, titration and elemental analysis. The semi-IPNs were characterized by swelling kinetics, mechanical properties and thermal analysis. It was found that PEG content and crosslinking agent concentration significantly influence the swelling behaviour of semi-IPNs. Water uptake was higher for lower crosslinking agent concentrations and PEG contents, up to PEG/Ch = 0,75. Better mechanical strength of semi-IPNs was obtained for higher PEG content and crosslinking agent concentration. SEM analysis confirmed the porous structure of semi-IPNs. Increasing the degree of crosslinking and PEG content up to PEG/Ch = 0,75, the pore size decreased. Based on the pore size, the investigated semi-IPNs can be regarded as macroporous. Thermogravimetric analysis showed that thermal stability of the semi-IPNs depends on the degree of crosslinking, as well as on the PEG content.
Synthesis, characterization and antibacterial activity of superparamagnetic nanoparticles modified with glycol chitosan  [cached]
Baskaran Stephen Inbaraj, Tsung-Yu Tsai and Bing-Huei Chen
Science and Technology of Advanced Materials , 2012,
Abstract: Iron oxide nanoparticles (IONPs) were synthesized by coprecipitation of iron salts in alkali media followed by coating with glycol chitosan (GC-coated IONPs). Both bare and GC-coated IONPs were subsequently characterized and evaluated for their antibacterial activity. Comparison of Fourier transform infrared spectra and thermogravimetric data of bare and GC-coated IONPs confirmed the presence of GC coating on IONPs. Magnetization curves showed that both bare and GC-coated IONPs are superparamagnetic and have saturation magnetizations of 70.3 and 59.8 emu g 1, respectively. The IONP size was measured as ~8–9 nm by transmission electron microscopy, and their crystal structure was assigned to magnetite from x-ray diffraction patterns. Both bare and GC-coated IONPs inhibited the growths of Escherichia coli ATCC 8739 and Salmonella enteritidis SE 01 bacteria better than the antibiotics linezolid and cefaclor, as evaluated by the agar dilution assay. GC-coated IONPs showed higher potency against E. coli O157:H7 and Staphylococcus aureus ATCC 10832 than bare IONPs. Given their biocompatibility and antibacterial properties, GC-coated IONPs are a potential nanomaterial for in vivo applications.
Morphology and Thermal Stability of Chitosan and Methoxy Poly (ethylene glycol)-b-Poly (ε-caprolactone)/Poly(D, L-lactide) Nanocomposite Films  [PDF]
Supawut Khamhan,Yodthong Baimark
Journal of Applied Sciences , 2009,
Abstract: The objective of this study was to prepare biodegradable chitosan nanocomposite films contained dispersed nanoparticles of methoxy poly(ethylene glycol)-b-poly( μ-caprolactone) (MPEG-b-PCL) or methoxy poly(ethylene glycol)-b-poly(D,L-lactide) (MPEG-b-PDLL) diblock copolymers by solvent evaporation of nanoparticle suspension-chitosan solution. The nanoparticles were firstly produced in the chitosan solution by modified-spontaneous emulsification solvent diffusion method without any surfactants before film casting. The dispersed nanoparticles with approximately 100 and 300 nm in sizes for MPEG-b-PDLL and MPEG-b-PCL, respectively can be observed throughout the chitosan film matrices. Nanoparticle morphology was spherical shapes with smooth surfaces. The nanoparticles of MPEG-b-PDLL were smaller than the MPEG-b-PCL. The possible interactions between the chitosan film matrices and the nanoparticles were evaluated by thermogravimetry. Thermal stability of the chitosan film matrices were enhanced by nanoparticle incorporating. The chitosan/MPEG-b-PCL nanocomposite films had lower film transparency and moisture uptakes than the chitosan/MPEG-b-PDLL nanocomposite films. The both film transparency and moisture uptakes decreased as the diblock copolymer ratio increased.
Physicochemical, Antimicrobial and Antioxidant Properties of Chitosan Films Incorporated with Carvacrol  [PDF]
Marco A. López-Mata,Saul Ruiz-Cruz,Norma P. Silva-Beltrán,José de Jesús Ornelas-Paz,Paul B. Zamudio-Flores,Silvia E. Burruel-Ibarra
Molecules , 2013, DOI: 10.3390/molecules181113735
Abstract: Chitosan films (CF) with carvacrol (CAR) [0.5%, 1.0% and 1.5% v/v] were prepared by the emulsion method. The retained CAR, water solubility, water vapor permeability (WVP), optical, mechanical properties, antibacterial and antioxidant capacity of films were analyzed. The results indicate that the retention of CAR in the CF was ≈50%. The incorporation of CAR to CF decreased the water solubility, the WVP, the yellowing and transparency and the tensile strength, but increased the stiffness. Microcapsules with diameters of 2 to 7 μm were found on the surface CF-CAR. The CF-CAR with highest CAR concentrations showed antibacterial activity against S. t yphimurium and E. coli O157:H7. The CF-CAR had higher antioxidant capacity and an increased protective effect against oxidation of erythrocytes in different grades. These results suggest potential applications of CF-CAR as active packaging to preserve food products.
HAIR DYE POISONING (AN EMERGING EMERGENCY FOR AIRWAY SURGEON- A CASE REPORT)  [cached]
Karthikeyan Arjunan,Yahiah Basith,Balasubramanian Thiagarajan
Otolaryngology Online Journal , 2013,
Abstract: Super-Vasmol, a cheap, freely-available hair dye is emerging as a major cause of suicidal poisoning in India. It contains potential toxins including paraphenylene diamine, resorcinol, sodium ethylenediaminetetraacetic acid and propylene glycol which can result in multiorgan dysfunction2 .This case report is an attempt to throw light on this emerging problem.
Preliminary Study of Conformation and Drug Release Mechanism of Doxorubicin-Conjugated Glycol Chitosan, via cis-Aconityl Linkage, by Molecular Modeling  [PDF]
Thongchai Srinophakun,Jirapat Boonmee
International Journal of Molecular Sciences , 2011, DOI: 10.3390/ijms12031672
Abstract: An investigation of the structure and drug release mechanism of a drug delivery system is proposed on the basis of semi-empirical and ab initio computations in vacuum stage. Cis-aconityl linkage is used to improve the interaction between an anti-cancer agent, doxorubicin, and a glycol chitosan biopolymer. It has been found that the doxorubicin-conjugated glycol chitosan carrier has more stability. The stability is increased when the lengths of the polyethylene glycol (PEG) chains in the glycol chitosan biopolymer are increased. Cis-aconityl can release doxorubicin under appropriate environmental conditions. Relative energies of this mechanism in an acid condition, as determined by B3LYP/6-31G//PM3, are 122.41, 119.27, 160.18 and 222.22 kcal/mol, and by the B3LYP/6-31G//HF/6-31G method are 54.23, 109.28, 219.98 and 980.49 kcal/mol, with mono-, di-, tri-, and quanta-ethylene glycol, respectively. In a normal condition, the relative energies are above 300 kcal/mol for all reactions. Therefore, cis-aconityl will release doxorubicin in an acid solution but not in a normal condition. The glycol chitosan polymer can be degraded in an acid solution as well. Long PEG chains influence the release mechanism of doxorubicin. The proposed length of the PEG chain is di-ethylene glycol. These simulation results agree well with various reported experimental data.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.