bFGF-PLGA微球促进随意皮瓣早期断蒂

目的 :探讨碱性成纤维细胞生长因子 -聚乳酸 /聚乙醇酸 (bFGF PLGA)微球促进随意皮瓣早期断蒂。方法 :通过复乳溶剂挥发法制备bFGF PLGA微球 ,采用60 Co辐照灭菌。将bFGF PLGA微球注入大鼠背部随意皮瓣下方 ,4d后断蒂 ,断蒂后 10d观察皮瓣成活率、新生微血管数量。并与单独使用bFGF组进行对比。结果 :皮瓣成活率A组为 (89 2± 2 6 0 ) %,B组为 (85 6± 2 9 7) %,C组为 (76 6± 3 2 2 ) %。新生血管数A组为 2 9 7,B组为 2 4 6,C组为 12。经统计学分析 ,各组间存在显著差异。结论 :bFGF PLGA微球能够更好地促进随意皮瓣的早期断蒂。     

骨碎补/聚乳酸-羟基乙酸共聚物微囊复合自固化磷酸钙治疗家兔股骨缺损模型的实验研究

目的 探讨骨碎补/聚乳酸-羟基乙酸共聚物(DR-PLGA)微囊与自固化磷酸钙人工骨(CPC)复合物对家兔股骨骨缺损的影响.方法 将8只新西兰大白兔数字随机分为实验组(n=4)和对照组(n=4),制备家兔股骨骨缺损模型,分别植入DR-PLGA/CPC复合体与不含骨碎补的PLGA/CPC骨支架,分别于术后4周、8周通过X线、大体解剖、组织学观察评价其提高成骨活性、促进骨折愈合的效果.结果 术后4周、8周X线及组织学观察显示实验组促进骨愈合、提高成骨活性均优于对照组.结论 DR-PLGA/CPC复合体可诱导新生骨形成,促进骨愈合.     

利培酮长效注射微球的制备及体外释放的研究

目的：制备利培酮长效注射微球并考察其体外释放行为。方法：使用乳酸-羟基乙酸共聚物（PLGA）为材料,采用乳化-溶剂挥发法制备利培酮微球,观察微球的形态及粒径,测定微球的载药量和包封率,考察微球的体外释放情况。结果：利培酮微球表面圆整,粒径集中在40～80μm之间。微球的包封率较高,达到80％以上,以低分子量PLGA（50：50）制备的微球,体外突释很高达到40％以上;以高分子量PLGA（75：25）制备的微球,在高载药量时突释较小,可持续释放达3周以上。结论：以高分子量PLGA制备的高载药量的利培酮微球,体外突释较小可缓释达3周以上。     

Fabrication of biodegradable spheroidal microparticles for drug delivery applications

Particle shape, in addition to size, is becoming increasingly recognized as important in the design of drug carriers for in vivo use. However, few methods exist for fabricating non-spherical particles from biodegradable polymers. This work describes for the first time the fabrication of biodegradable spheroidal microparticles using the simple oil-in-water emulsion solvent evaporation technique (O/W ESE). Unloaded and paclitaxel-loaded spheroids were fabricated from poly(lactic-co-glycolic acid) (PLGA), and the shape and size of fabricated spheroids were manipulated by controlling fabrication process parameters including stir speed, aqueous and oil phase viscosity, aqueous phase pH, and the polymer molecular weight and end group. The presented data show that high aqueous phase viscosity, basic aqueous phase pH and hydrophilic polymer side chains and end groups are all conditions that favor the formation of spheroidal particles. The described technique is advantageous over methods currently described in the literature in its simplicity in setup, high particle yield and adaptability to a wide range of biodegradable polymers and therapeutics.     

Preparation and in vitro evaluation of thienorphine-loaded PLGA nanoparticles

Poly (d,l-lactic-co-glycolide) nanoparticles (PLGA-NPs) have attracted considerable interest as new delivery vehicles for small molecules, with the potential to overcome issue such as poor drug solubility and cell permeability. However, their negative surface charge decreases bioavailability under oral administration. Recently, cationically modified PLGA-NPs has been introduced as novel carriers for oral delivery. In this study, our aim was to introduce and evaluate the physiochemical characteristics and bioadhesion of positively charged chitosan-coated PLGA-NPs (CS-PLGA-NPs), using thienorphine as a model drug. These results indicated that both CS-PLGA-NPs and PLGA-NPs had a narrow size distribution, averaging less than 130?nm. CS-PLGA-NPs was positively charged (+42.1?±?0.4?mV), exhibiting the cationic nature of chitosan, whereas PLGA-NPs showed a negative surface charge (?2.01?±?0.3?mV). CS-PLGA-NPs exhibited stronger bioadhesive potency than PLGA-NPs. Furthermore, the transport of thienorphine-CS-PLGA-NPs by Caco-2 cells was higher than thienorphine-PLGA-NPs or thienorphine solution. CS-PLGA-NPs were also found to significantly enhance cellular uptake compared with PLGA-NPs on Caco-2 cells. An evaluation of cytotoxicity showed no increase in toxicity in either kind of nanoparticles during the formulation process. The study proves that CS-PLGA-NPs can be used as a vector in oral drug delivery systems for thienorphine due to its positive surface charge and bioadhesive properties.     

乳酸/羟基乙酸共聚物的分子量及其单体组成比例对利培酮微球性质的影响

目的:制备利培酮-乳酸(LA)/羟基乙酸(GA)共聚物(R-PLGA)缓释微球,并对微球的性质及释放效果进行评价。方法:采用单乳溶剂蒸发法制备R-PLGA缓释微球;对微球的粒径分布、载药量、包封率、突释、体外释放等指标进行测定,考察PL-GA不同分子量和LA/GA不同单体组成比例对微球性质的影响。结果:所制微球外观圆整,分散良好。PLGA的单体组成比例以及分子量对微球性质尤其是释放速度有明显的影响。结论:可通过调节PLGA的分子量和LA/GA单体组成比例改变微球性质,以达到控制微球释放速率等预期目的。