Study On The Mechanism Of Interaction Between Nanoparticles And Cell Membrane Based On Biofilm

Cell membrane is the first barrier for nanoparticles to contact and enter cells.The interaction between nanoparticles and cell membrane may affect the normal life activities of cells and produce cytotoxicity.Understanding the interaction between nanoparticles and cell membrane is of great significance for the design of safe and effective nanopharmaceuticals.The third chapter synthesized hydrophobic gold nanoparticles(LPNs and SNPs)larger than and smaller than the film thickness,and studied the effect of nanoparticle loading on membrane fluidity by fluorescence bleaching recovery experiment and fluorescence spectrum experiment.The experimental results show that LPNs and SNPs affect the lateral motion of phospholipids through steric hindrance and change of phospholipid ordering degree.The results provide a reference for the construction of functional nanoparticle phospholipid assembly and the regulation of biomimetic membrane function by nanomaterials.In the fourth chapter,the in vitro endocytosis of porous silicon nanoparticles encapsulated by negative phospholipid membrane with different lateral fluidity was investigated.There were differences in endocytosis between high flow liquid phospholipid package and low flow gel state phospholipid package.The endocytosis efficiency of high flow liquid phospholipid package is higher than that of low flow gel state phospholipid package.Derjaguin-Landau-Verway-Overbeek theoretical analysis shows that the former phospholipid spatial rearrangement can promote the fusion of biofilm and cell membrane and particle endocytosis,while the latter has a high energy barrier in the process of membrane fusion,which can only passively enter the cell in the form of cellular drink.This part of the study deepens the understanding of the endocytosis process of coated particles and provides a new idea and reference for the subsequent design of complex nano-carriers.The adsorption of nanoparticles on biofilm surface is very important for biomedical application.In this part,the adsorption kinetics of gold nanorods on the surface of supporting films with different solution heights were characterized by positive and inverted quartz electron microbalance and dissipation coefficient measurements.It is found that the gold rod produces uneven concentration of solution in gravity field.The increase of aspect ratio can increase the hydrodynamic size of gold rod,delay the uneven redistribution process of gold rod,and maintain the consistency of surface adsorption of biofilm at different solution height.At the same time,because of the uneven degree of concentration,the adsorption capacity of short rod,medium rod and long rod at different solution heights is also changed.The adsorption capacity of the short rod at the bottom of the solution is the largest,and the adsorption capacity of the rod at the top of the solution is the largest.In this part,the physical factors regulating the adsorption of nanoparticles on biofilm surface are investigated,which provides a reference for the medical application of nanomaterials.Finally,the work done in this paper is summarized,and combined with some experimental research results,the future research direction is prospected.