Dynamics Research Of Nanoparticles Carrieer

Nowadays with the rapid development of nanomaterials, people have paidy attention to the applications of nanomaterials, which is undoubtedly the fastest development in the field of nano medicine, such as drug delivery, gene therapy, imaging and clinical diagnosis and treatment. For most cell, the basic unit of lives, most of them contain cell membrane (except some virus). Cell membrane plays an important role in protecting cells, and controlling of materials in and out of the cell, which neither let the useful material arbitrarily exude cells, nor let harmful substances easily enter the cell. In addition, it can exchange information between cells. So it is of great significance for us to study the interaction between nanoparticles and the cell membrane.Nanoparticles enter cells, mainly through infiltration and endocytosis. Compared to endocytosis, nanoparticles penetration is still unknown. Due to the limitations of experimental methods, more and more studies begin with the aid of the computer technology. In this work, we use dissipative particle dynamics method to study nanoparticles internalizing into vesicles, and analyze effects of different factors such as the number, size, shape and the interaction between nanoparticle and. Iipid molecules.Our results show that the process of nanoparticles penetration can divide into three pathways, including infiltration, short chain penetration and special penetration. When nanoparticles have a strong attraction with lipid head, nanoparticles penetrate as short chains.In addition, nanoparticle penetration rate is about 45%, indicating that the short chain penetration is less efficiency than direct penetration. For infiltration of short chains, the number of the nanoparticles need to reach to a certain concentration so that nanoparticles can form short chains, then penetrate into the vesicles.For non-spherical nanoparticles, the internalization is non-endocytosis. In the process of their internalization, we can see phospolopid molecules adhesion on the surface of nanoparticles, it is the reason that nanoparticles have a strong attraction with lipid head. From the point of view of energy analysis of this phenomenon, due to the binding energy between nanoparticles and phospolipid molecules is higher than the bending energy, which prompts phospholipid molecules encapsulate nanoparticles, but the postitive surface tension make it difficult encapsulating nanoparticles. When we increase of the radius,height and radius of curvature of the nanoparticles which means encapsulating nanoparticles need more time. These factors can affect the encapsulating.We also need to pay attention to the nanoparticle aggregation and the aggregation induced vesicle deformation, such as the budding and even vesicle rupture. In this process, vesicle appeared to budding and other special structures. Nanoparticles cytotoxicity is a big challenge for us, and we also determine the critical nanoparticle number that cause vesicle rupture.