PLGA Nanoparticle-based Biomimetic Dendritic Cell Preparation Method

Nanoparticles are highly modifiable and controllable,and can also be used to encapsulate drugs with different hydrophilic properties,so they are often used to design various functional nanodrugs or drug-loading systems.In order to prepare dendritic cell(DC)nanoparticles,this paper first stimulates DC through bacterial cell fusion material to achieve DC activation and antigen presentation,and characterizes and verifies the function of the material,the specific contents are: 1.The preparation method of the material and the required reagents and equipment are described in detail;2.Transmission electron microscopy(TEM)and dynamic light scattering(DLS)were used to characterize the materials,and the results showed that the fusion materials were relatively regular spherical and the size was about 200nm;3.The protein of the material was separated by protein gel electrophoresis,and the protein was analyzed by Coomassie brilliant blue staining and western blotting,and the results showed that the fusion material successfully fused bacteria with cells;4.The activation degree of DC after stimulation by fusion materials was analyzed by flow cytometry and enzyme-linked immunosorbent experiment,and the effects of normal and starvation culture on DC activation were discussed.5.The extraction and treatment methods of cell membranes and cytokines were introduced,which provided a raw material basis for the preparation of biomimetic nanoparticles.Poly(lactic-co-glycolic acid)(PLGA)nanoparticles coated with cytokines were prepared by re-emulsification,and the influence of different parameters on the physical properties and encapsulation rate of nanoparticles was briefly explored,and the optimal parameters were preliminarily selected.Then,the cell membrane was coated on the surface of the nanoparticles by physical extrusion,and the ratio of nanoparticles to cell membranes was explored by detecting the surface potential to determine the final cell membrane dosage,and biomimetic nanoparticles were prepared.The nanoparticles were characterized by DLS and TEM,and their physical properties were observed,which preliminarily proved the successful coating of cell membranes.The successful inheritance of cell membrane proteins was preliminarily demonstrated by protein electrophoresis and Coomassie brilliant blue staining,and the biomimetic nanoparticles were further proved to be bioactive by antibody pull-down experiments.Finally,the targeting ability and immunostimulatory ability of biomimetic nanoparticles are verified in mice,and the results show that biomimetic nanoparticles can actively and specifically target mouse lymph nodes and activate specific immunity to tumor cells.