【作者】 张金凤；

【导师】 陈立江；

【作者基本信息】 辽宁大学 ， 药物化学， 2018， 硕士

【摘要】 “理想药物传递系统”是既获得了完全生物相容性表面,还可以通过对合成载体内核的设计实现药物的靶向性、环境响应应答等特性。前期的研究已经合成了多种“生物类+合成类”的复合类药物载体,其中基于红细胞膜合成的复合型药物载体,具有降低免疫原性、可生物降解及生物相容性好等优点,可有效躲避免疫系统的吞噬。但是传统的红细胞/纳米粒子复合载体由于尺寸较大,不利于体内循环,此外,由于红细胞的变异性大,存在难以实现标准化制备、运输比较困难等问题,极大地限制了红细胞载体的应用。因此我们设计了一种具有高度生物相容性的,并且可以实现环境响应特异性地释放药物的新型药物传递体系——纳米红细胞膜小体包裹纳米粒(RBCm-derived vesicles coated nanoparticles,RDV-NPs),期待其成为新型的药物载体。本课题首先设计并合成了纳米粒内核。选择索拉非尼(Sorafenib,SFN)为模型药物,以二硫键链接的两亲性共聚物聚丙烯酸-胱胺二盐酸盐-维生素E琥珀酸酯(PAAssVES)为材料,采用乳化-溶剂挥发法制备得到了具有还原响应特性的纳米粒内核(SFN-PAAssVES),同时,该纳米粒还具有良好生物可降解性。并对该纳米粒的处方工艺进行了优化筛选。结果表明,SFN-PAAssVES纳米粒粒径为96.8 nm左右,且分布均匀,Zeta电位为-22.3 mV,具有类圆形的形态。其次,通过低渗透析法以及机械挤压法制备得到纳米红细胞小体(RBC-membrane-derived vesicles,RDVs),最大限度地保留了红细胞膜的结构与功能,同时又兼具纳米粒子的特性。对红细胞膜纳米小体的制备条件,如聚碳酸酯膜孔径、挤压次数等进行了优化,同样对其进行粒径、表面电位及基本形态等表征,结果显示,红细胞膜纳米小体尺寸较小,粒径为113.5 nm,Zeta电位接近红细胞的电位值,为-10.7 mV。然后通过机械挤出的方法将红细胞膜纳米小体与SFN-PAAssVES纳米粒子共混,制备得到纳米级复合载体。对复合载体的制备条件,例如共同挤压次数进行了优化,制备得到了分布均匀的纳米红细胞膜小体包裹纳米粒。通过粒径、表面电位及TEM等表征,证明了纳米红细胞膜小体包裹纳米粒的成功合成,同时该复合载体具有良好的稳定性及缓释性能。采用MTT法,选取BGC-823细胞及MKN-45细胞对RDV-NPs的体外抗肿瘤活性进行了研究。结果表明,RDV-NPs具有缓释性,可以长时间缓慢释放药物,最终显示出较高的体外抗肿瘤活性。为了研究RDV-NPs的体内药动学情况,本文选取SD雄性大鼠为模型进行了药代动力学研究,实验结果表明,RDV-NPs经尾静脉注射给药后,血药浓度明显高于未进行红细胞膜纳米小体包裹的制剂组与原药组,可以有效延长药物在体内的循环时间,提高生物利用度。更多还原

【Abstract】 The ideal drug delivery systems is able to achieve optimal biocompatible,drug targeting and environmental response through the design of synthetic drug carrier.In many studies,"bio-synthetic" hybrid drug carriers,especially erythrocyte membrane-based drug delivery systems,have been developed to achieve high biodegradability and biocompatibility,reduce immunogenicity and effectively evade phagocytosis of the immune system.However,the application of conventional hybrid drug carriers composed of red blood cells and nanoparticles are limited by rapid clearance in the body due to their large sizes.In addition,it is difficult to achieve standardized preparation and transport due to the high variability of red blood cells.Therefore,we design RBC membrane-derived vesicles coated nanoparticles(RDV-NPs)to deliver drugs.The novel RBC membrane-based nano-drug delivery system achived high biocompatibility and release drugs in response to the environment.Firstly,the nanoparticles were designed and prepared by emulsification and solvent volatilization method as the core of the hybrid drug delivery system.In the present study,poly(acrylic acid)-cystamine hydrochloride-D-α-tocopherol succinate(PAAssVES)was used to load the model drug,Sorafenib(SFN).The nanoparticles were biodegradable and redox responsive.The prescription and process were optimized by using the particle size,encapsulation efficiency as evaluation index.The DLS results showed that the particle size of SFN-PAAssVES was uniform,about 96.8 nm,and the Zeta potential was-22.3 mV.The TEM images showed that SFN-PAAssVES were spherical.In order to obtain RBC membrane-derived vesicles(RDVs),red blood cells collected from SD male rats were treated with hyponotic swelling and mechanical extrusion,and the vesicles maintained the membrane structure and function of erythrocyte membrane.The preparation condition of RBCm-derived vesicles,such as pore size of polycarbonate membrane,extrusion cycles,were optimized.The particle size,surface Zeta potential and morphology of RBCm-derived vesicles were also characterized.The results showed that the size of RDVs was 113.5 nm,and the Zeta potential was-10.7 mV,which was close to the value of erythrocyte.Then,RBCm-derived vesicles and SFN-PAAssVES nanoparticles were mixed together and extruded through polycarbonate membrane to prepare the RBC membrane-derived vesicles coated nanoparticles.The preparation conditions of the hybrid drug delivery system,such as the extrusion cycles,were optimized.The RBC membrane-derived vesicles coated nanoparticles were evaluated by dynamic light scattering(DLS)and transmission electron microscopy(TEM).The result of particle size,Zeta potential and TEM images showed that the nanoparticles were coated by RBCm-derived vesicles successfully.Besides,the stability experiments showed good stability.And the sustained release of encapsulated drug of the hybrid drug delivery system was investigated in vitro.In addition,the cytotoxicity of RDV-NPs was elvluated by MTT assay in vitro on BGC-823 cells and MKN-45 cells.The results showed that RDV-NPs released encapsulated drug slowly in a long time and showed high anti-tumor activity in vitro.In order to investigate the pharmacokinetics of RDV-NPs in vivo,SD male rats were given RDV-NPs via intravenous injection at the tail vein.The plasma concentration-time profile of RDV-NPs was significantly higher than that of the SFN-PAAssVES group and the bulk drug.This indicated that RDV-NPs could effectively prolong the circulation time of the drug in vivo and improve bioavailability.更多还原