Studies On The Biomembrane-coated Nano-preparations As Anticancer Agents Delivery Vehicle For Oral Administration

With intensive investigations,the advantages of nano-preparations in cancer treatment have been widely recognized.In order to improve therapeutic effect and decrease adverse reactions,nano-preparations such as polymeric micelles,nanocrystals and other dosage forms have been widely studied and applied clinically,due to their attributes in solubility enhancement and targeting properties.Intravenous injection(I.V.)is usually the first choice as the route of administration,on the other hand,it is equally important to use oral administration,because it is capable of improving patient compliance as well as reducing the cost of treatment.“Hybrid drug delivery vehicles” are novel structures fabricated by unique topdown approach for drug delivery in recent years,which combine advantages of natural cell membrane and synthetic biomaterials.It is characterized by the selection of different natural biomaterials with specific characteristics according to different treatment requirements,which can be used to cloak the existing synthetic nanopreparations to greatly improve performances of the corresponding hybrid preparations,and to achieve the desired therapeutic purpose.Herein,OMVs was chosen as the biomaterial to fuse with micelles,nanoparticles and other nanopreparations(NPs).It is expected to construct a new type of drug delivery vehicle that could be used for suitable nano-preparations of oral administration.In the present work,E.Coli DH5? was cultured in Luria Broth as the parent cell.Using OD value as monitoring index of colony growth status,OMVs were collected and purified by ultrafiltration-centrifugation method.The particle size and surface Zeta potential of OMVs were measured by dynamic light scattering(DLS).Measurements showed that the collected vesicles had heterogeneous size distribution with diameters ranging from 30 to 300 nm with a surface Zeta potential of-20 mV.Transmission electron microscopy(TEM)images were taken to examine the structure of the OMVs and showed that all OMVs had a clear spherical structure.Albumin Bound Nanoparticle Paclitaxel and Paclitaxel-PLGA micelles were prepared by high-pressure homogenization and solvent displacement process,respectively,and the corresponding nanoparticles were verified using TEM,DLS in morphology,Zeta potential and particle size distribution.Through high-pressure extrusion process,OMVs were fused with NPs,translocating the entire OMVs onto surfaces of NPs to form OMVs-coated NPs(OMVs-NPs).Particle size distribution,Zeta potential and morphology of the corresponding OMVs-NPs were measured by dynamic DLS and TEM.Characteristics of intermediate products and final products were compared in order to examine the feasibility of formulation and preparation process.Drug release studies from drug loaded OMVs-NPs and drug loaded NPs in simulated intestinal fluid were performed to evaluate the stability in oral administration.Drug delivery capacities of NPs and OMVs-NPs were evaluated in a CaCo-2-transwell system.Cellular uptake of OMVs-NPs and NPs by HT-29 cell were performed by utilizing laser scanning confocal microscope.The capacity of OMVs-NPs delivering drugs into blood stream was comprehensively evaluated by above experimental results.The results demonstrated that the NPs can be fused with OMVs appropriately through the high-pressure extrusion process.DLS measurements showed that the diameter of NPs increased slightly upon OMVs coating.Under the transmission electron microscopy,OMVs-NPs showed a clear spherical core-shell structure.Zeta potential measurements showed that the value of OMVs-NPs was closer to OMVs.The stability investigation showed that NPs had higher degree and speed than OMVsNPs in drug release profiles.Confocal microscopy showed that NPs fused with OMVs could be internalized by HT-29 cells,in contrast,the bare NPs were barely internalized.Compared with NPs,OMVs-NPs delivered more therapeutic agents to the basal side in the Caco-2-transwell system,indicating that OMVs can promote the absorption of coated NPs by intestinal epithelium.Taken together,compared with bare NPs,OMVs-NPs can promote the stability and absorption of coated NPs in the intestinal.The vehicle established in the present study combine the advantages of nano-preparations and the existing hybrid drug delivery vehicles and is expected to become an oral nano drug delivery system with the prospect of clinical application.