Preparation And Evaluation Of Long Circulating Erythrocyte Membrane-cloaked Anticancer Drug Delivery System

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.