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Biodegradable polymeric nanoparticles acting as drug carrier have important potential applications such as site-specific drug delivery and controllable drug delivery. However, these carriers cannot generally be used because they are eliminated by the reticulo-endothelial system within seconds or minutes after intravenous injection. To overcome this limitation, more and more researchers introduce hydrophilic polyethylene glyeol(PEG) to modify polymeric nanoparticles for avoiding their uptake by reticulo-endothelial system. Introducing PEG not only changes polymer nanoparticles' biodegradation in vivo, but also influences drug's properties such as drug release, in vivo biodistribution, et. al. In this paper are reviewed the researches of PEG-modified copolymer nanoparticles, including their preparation and size distribution, stability, drug incorporation, drug release, in vivo biodistribution, in vitro cytotoxicty. A prospect for the researches and developments of the PEG-modified copolymer nanoparticles was also made.
Subject(s)
Animals , Drug Carriers , Pharmacokinetics , Drug Compounding , Methods , Drug Delivery Systems , In Vitro Techniques , Nanotechnology , Polyethylene Glycols , Chemistry , Polymers , ChemistryABSTRACT
Purpose The aim is to sulfonize Hunai polysaccharide fr om p leurotus tuber-rigium(Fr.)Sing. and to evaluate the antioxidative activities of the sulfated po lysaccharide (S-HNP).Methods S-HNP was prepared by the reacti on of Hunai polysaccharide with chlorosulfonic acid-Pyridine. The antioxidative activities o f S-HNP were evaluated as follows: (1) the inhibition effects on Fe2+- Vc inducing the injury of rat liver mitochondria in vitro, (2) the protectiv e ef fect on CuSO4 -Phen-Vc-H2O2 inducing the damage of DNA, (3) the scaven ging effect on O*-2. Results S-HNP could protect mitochondria from lipid peroxidation induced by Fe2+-Vc, i ncluding the inhibitions of the increase of TBARS content, the swelling of mitoc hondria and the decrease of membrane fluidity, and protect DNA from the damage induced by CuSO4-Phen-Vc-H2O2， and scavenge O*-2 generated in the sel f-oxidation of pyrogallic acid. Conclusion S-HNP exhibi ted marked antioxidative activities.
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Objective: To examine effects of Platycodon grandiflorum (JG), Glycyrrhiza uralensis Fisch (GC) or the compound of JG with GC on the growth of cariogenic and periodontopathic bacteria in vitro . Methods: JG,GC and the compound were extracted with ?=65% ethanol respectively. The minimal inhibitory concentration(MIC)and minimal bactericidal concentration (MBC) of JG, GC or compound against S.mutans MT818, S. sobrinus 6715, P.gingivalis 381 and B.forsythus 43037 were measured by drug sensetivity test.Results: JG showed no effect on the growth of oral pathogens tested;GC inhibited S.mutans MT 8418 and S.sobrinus 6715 with MIC of 3.91 mg/ml.The compound inhibited the microorganisms with the MIC of 1.96 mg/ml against S.mutans MT8148 or S.sobrinus 6715, 3.91 mg/ml against P.gingivalis 381, 7.81 mg/ml against B.forsythus 43037 respectively.Conclusion: The compound of JG and GC has stronger inhibition and bactericidal effects on oral pathogens than the single medicine.
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Object To study the mechanism of triptolide solid lipid nanoparticle (TP-SLN) for decreasing liver toxicity of triptolide (TP). Methods With ig three doses of TP-SLN to mice for 60 d, the A LT, AST activities in serum and superoxide dismutase (SOD), glutathione peroxida se (GSH-Px) activites and malondialdehyde (MDA) contents in liver were determin ed. Results The activities of ALT, AST, SOD, GSH-Px and conten t of MDA between experimental group and blank group did not have remarkable diff e rence. However, the activites of ALT, AST, SOD, GSH-Px for the middle- (20 ?g /kg) and high-dose (30 ?g/kg) group were higher and the contents of MDA were lower than the experimental group. Conclusion TP-SLN can decrease the liver toxicity of TP.
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AIM: To establish the simultaneous determination of camphor,menthol,synthetic borneol and methyl salicylate in Shexiang Zhuanggu Plaster(Camphor,Mentholum,Borneolum Syntheticum,etc). by GC. METHODS: The sample solution was distilled in volatile oil determination apparatus.Naphthalene was used for the internal standard.The GC system consisted of capillary column,PEG-20M as the stationary phase,nitrogen as the carrier gas,FID as the detector.The programmed temperature-GC and internal standard method was employed to determine four kinds of components in Shexiang Zhuanggu Plaster. RESULTS: Camphor,menthol,synthetic borneol(borneol and isoborneol) and methyl salicylate in Shexiang Zhuanggu Plaster and naphthalene have been separated well under the same chromatographic condition.The average recovery of camphor,menthol,synthetic borneol and methyl salicylate were 96.92%(RSD=2.42%),98.03%(RSD=1.81%),99.02%(RSD=1.47%) and 98.15%(RSD=1.59%),respectively. CONCLUSION: The method is simple,accurate and separable,and can be used to control the quality of Shexiang Zhuanggu Plaster
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AIM: To investigate the influence of three dimentional printing processes(3DP) on the release of controlled-release helicid tablet. METHODS: Parameters of 3DP,such as skeleton polymer,binder,thickness of powder layering,number of spray painting,subregion ser up and diameter of aperture,were selected in the preparation of donut-shape multilayer controlled-release helicid tablet.Dissolution tests in vitro were carried out to analyse the effect of technological parameters on the release of helicid. RESULTS: Under the condition of fixed subregion and diameter of aperture,the selections of binders and thickness of spray painting were key factors concerning the release period of helicid. CONCLUSION: 3DP processes shows high flexibility and efficacy in the preparation of controlled-release tablets.