载药蛋白质/聚苯硼酸复合纳米微球制备及其释药性能研究

Preparation of the Protein/Polyphenylboronic Acid Nanospheres for Drug Loading and Unloading

蛋白质纳米颗粒具有良好的生物相容性和生物降解性,易于进行额外的表面修饰,用作药物输送系统提高了生物利用度,减少了药物分子的毒副作用.本工作在利用苯硼酸基团与再生桑蚕丝蛋白(RSF)上相关侧基之间具有路易斯酸-碱配对反应的基础上,通过3-丙烯酰胺苯硼酸(APBA)在RSF水溶液中原位聚合,使RSF分子链重排形成微球并在表面负载抗炎中药,制备了载药丝蛋白/聚苯硼酸纳米微球.此尺寸分布均匀的微球直径约为550~600nm,表面光滑且在水中的分散性能良好;对乔松素、杜鹃素和地奥司明三种药物的负载率分别为7.8%,11.9%和13.4%,包封率分别为75.0%,89.1%和93.7%.载药微球控制释放约7d,且缓释行为具有pH响应性.丝蛋白/聚苯硼酸纳米微球与主体药物协同作用提高了自由基清除速度和清除效率,优于直接给药组.与此同时,将RSF改换为牛血清白蛋白或明胶蛋白,采用此方法也能制成尺寸分别为260和100nm的白蛋白/聚苯硼酸微球或明胶蛋白/聚苯硼酸微球.由此,三种不同尺寸、电性和药物释放速率的蛋白质/聚苯硼酸纳米微球有望适应多种静脉注射和皮下或腹腔注射药物传输的需求.

Protein nanoparticles(NPs),biocompatible and biodegradable,can be easily surface modified.In particular,amphiphilic proteins act as“surfactants”that help form microparticles while undergoing molecular chain rearrangement.These NPs have been successfully used as drug delivery systems,improving bioavailability and reducing the toxic effects of drug molecules.The use of regenerated silk protein(RSF)with m-acrylamidophenylboronic acid(APBA)composites as drug carriers for loading anti-inflammatory herbal extracts was reported.Firstly,a simple and rapid method was used to prepare silk protein/polyphenylboronic acid nanospheres,in brief,RSF solution and a certain amount of initiator were added to APBA solution,and the pH was adjusted by NaOH,and the polymerization was initiated by heating at 90℃under nitrogen protection with stirring at 500 r/min.After 2 h of reaction,a milky solution was obtained,which formed silk protein/benzeneboronic acid nanospheres with hydrophobic interior and hydrophilic surface.The drug-loaded silk protein/polyphenylboronic acid nanospheres with an average size of 550 to 600 nm were prepared by mixing with the drug solution after dialysis and stirring at room temperature for 12 h to load the drug by adsorption.By the same method,drug-loaded albumin/polyphenylboronic acid microspheres and collagen/polyphenylboronic acid microspheres with sizes around 260 nm and 100 nm,respectively,could be prepared.The results observed by scanning and projection electron microscopy and dynamic light scattering showed that the drug-loaded silk protein/polyphenylboronic acid nanomicrospheres displayed regular spherical shape indicating smoothness and good dispersion with no obvious aggregation.The highest drug loading rate was about 13.4%,and the encapsulation rate was over 90%.Also,such drug-loaded nanospheres could achieve controlled release for about seven days and their slow release behavior was pH-responsive,with faster drug release in buffer solution at pH=5.5 than in buffer solution at pH=7.4.In addition,the synergistic interaction of the silk protein/polyphenylboronic acid nanomicrospheres with the subject drug improved its free radical scavenging rate and scavenging efficiency,which was superior to that of the direct drug delivery group.Thus,three protein/polyphenylboronic acid nanomicrospheres with different sizes,electrical properties and drug release rates may be adaptable to a wide range of intravenous and subcutaneous or intraperitoneal drug delivery needs and have great potential for clinical applications.