树形大分子与金纳米颗粒复合体系构型与结合强度的分子动力学研究

Molecular dynamic study of conformation and binding strength of dendrimer-gold complex systems

通过在PAMAM型树形大分子上搭载不同尺寸的金纳米颗粒构建树形大分子-金纳米颗粒复合体系,采用经典分子动力学方法考察了金纳米颗粒尺寸、搭载数量及树形大分子聚乙二醇化修饰对复合体系构型、结合强度及在水中扩散系数的影响。结果表明,PAMAM型树形大分子经过聚乙二醇化修饰可负载更多的金纳米颗粒,使得有效包埋金纳米颗粒的同时自身尺寸未产生明显膨胀。研究结果为探索新型多功能造影剂在生物医药领域的应用具有重要意义。

Three different sizes of ligands have been employed to build PAMAM dendrimer-gold complex systems via PAMAM dendrimer entrapping. Classical molecular dynamics simulations are carried out to systematically investigate interactions between PAMAM dendrimers and gold nanoparticles （Au NPs）, which were initially encapsulated inside PEG-cored PAMAM dendrimers. In particular, effects of sizes and surface PEGylation func-tionalization of PAMAM dendrimers as well as the number and sizes of Au NPs are investigated to explore ener-getic stabilities and diffusion behaviors of the complex systems. Results show that surface PEGylation helps PAMAM dendrimers to carry more Au NPs with greater strength without considerable volumetric expansion. This study is of great significance for exploring the new multifunction contrast media in the field of biomedicine application.