The Study Of Targeted Nanoparticle Binding And Uptake Based On Dissipative Particle Dynamics

Nanoparticles(NPs) are promising carriers for targeted drug delivery, photodynamic therapy and imaging probes. In particular, it is promising to realize targeted nano-medicines in nano biomaterial area. Besides, their transporting efficiency carrying DNA to nucleus is of eight times higher than polyethylenimine. In biomedicine, it is a hotpot to design the funcional nanoparticle and optimize the efficiency of NPs through changing their shapes, sizes and material characters. A fundamental understanding of the dynamics of polymeric nanoparticle targeting to receptor-coated vascular surfaces and uptaking is great important to enhance the design of nanoparticles toward improving binding ability.Based on molecular dynamics simulation and coarse grain principles,this thesis employed dissipative particle dynamics to proceed the research of nanoparticle bonding.A fundamental understanding of the dynamics of polymeric NP targeting to bilayer membranes is important to enhance the design of NPs for better adhesion, stability and efficiency. In this study, dissipative particle dynamics simulations are applied to investigate the adhesion and uptake process of rod and spherical NPs with various shaped ligands to cell membranes. Striped ligands are found to prevent NPs from rotating, which minimizes collateral damage caused by shearing force and improves the penetration rate to 100%. We further optimize striped NPs to a more stabilized structure. The warping percentage, binding percentage and uptake processes of NPs with different configurations are thoroughly investigated in our simulations, and the binding efficiencies are compared for different NPs. These findings provide crucial guidelines for patterned nanoparticle design and are important for fabricating new NPs for biomedical applications.Although the effects of particle size and shear flow on the binding of nanoparticles to a vessel wall have been studied at the particulate level, a computational model to investigate the details of the binding process at the molecular level has not been developed. In this research, dissipative particle dynamics simulations are used to study nanoparticles with diameters of several nanometers binding to receptors on vascular surfaces under shear flow. Shear flow velocities ranging from 0 to 2000 s-1 have no effect on the attachment process of nanoparticles very close to the capillary wall. Increased binding energy between the ligands and wall caused a corresponding linear increase in bonding ability. Our simulations also indicate that larger nanoparticles and those of rod shape with a higher aspect ratio have better binding ability than those of smaller size or rounder shape.