Enthalpy-driven self-assembly of amphiphilic Janus dendrimers into onion-like vesicles: Janus particle model
作者：F.-F. Hu, Y.-W. Sun, Y.-L. Zhu, Y.-N. Huang, Z.-W. Li, Z.-Y. Sun
關鍵字：Janus particle model
論文來源：期刊
具體來源：Nanoscale, 2019,11, 17350-17356
發表時間：2019年
Synthetic vesicles by amphiphilic Janus dendrimers are known as dendrimersomes. The understanding of the conditions and formation mechanism of dendrimersomes is meaningful for further controlling structures. Herein, characteristics on the self-assembly of amphiphilic Janus dendrimer/water solutions into unilamellar and onion-like dendrimersomes are studied by molecular dynamics simulations via a spherical single-site Janus particle model. The model with two distinct surfaces, one hydrophobic side and another hydrophilic side, describes the amphiphilic nature of Janus dendrimers. By reducing the dendrimers with complex architectures to be simple Janus particles, we investigate the concentration-dependent self-assembled structures as well as the enthalpy-driven forming process of onion-like dendrimersomes, in contrast to the entropy-mediated self-assembly of amphiphilic flexible chains. Three typical equilibrium morphologies including linear micelles, lamellar structures and vesicles are found upon varying Janus balance and dendrimer concentration. It is observed that the dendrimersomes consisting of the dendrimers with neglectable molecular configuration entropy become very stable, which agrees well with experimental observation. Specifically, different from many lipidsomes and polymersomes which could spontaneously merge, the size of dendrimersomes will not grow through mutual fusion, once the well-defined onion-like structure is formed. Moreover, the discharging of water is achieved by water diffusion fasion in our simulations, instead of the "peeling-one-onion-layer-at-a-time" fashion. Our study combined with the previous ones using flexible chain models could depict a complete picture of dendrimersomes in favor of the applications in drug and gene delivery.