Structure-controlling Of PH And Temperature Dual-responsive Core-shell Nanoparticles And Its Effect On Controlled Drug Release

Core-shell structure nanoparticles have attracted wide attention as drug carriers, due to easily functionalization, stability, and dispersibility, controllable structure and other advantages. However, the structural effect of these dual-stimuli responsive nanoparticles on their drug-loading and controlled release has not been demonstrated by now. Therefore, PMAA/PNIPAM nanoparticles with different structures were prepared to investigate the influence of structure on the drug-loading and controlling release performance.Due to the different swelling degree of the PMAA nanoparticles in acetonitrile and water, the core-shell structured PMAA/PNIPAM nanoparticles were prepared by two kinds of methods, distillation precipitation and emulsion precipitation copolymerization. The structure and particle size distribution were by investigated FT-IR, SEM, and DLS. The two kinds of nanoparticles were dispersed into different pH solution for loading anticancer drug DOX, then DOX-loaded nanoparticles were placed into different temperature and pH in PBS buffer solution, and the structure effects about adsorption and release of DOX were studied. The results showed that the nanoparticles prepared with fully-swelling PMAA were beneficial to the drug-loading and controlled release.The yolk/shell PMAA/PNIPAM nanoparticles were prepared by distillation precipitation copolymerization, sol-gel solution, emulsion precipitation and selective etching method. The structure and particle size distribution were by investigated FT-IR, SEM, and DLS. The yolk/shell PMAA/PNIPAM nanoparticles were dispersed into pH=7.4 solution as the model drug-carriers to investigate the effects of the diameters of the cavity of the middle layers, thicknesses and crosslinking degrees of the PNIPAM shells on the temperature sensitive drug-loading and pH responsive controlled release characteristics, with doxorubicin (DOX) as a model drug. The results showed that the smaller cavity and the lower PNIPAM crosslinking degree were beneficial to the drug-loading and controlled release.The core-shell and flower structured PMAA/PNIPAM nanoparticles were prepared by emulsion precipitation. The structure and particle size distribution were by investigated FT-IR, SEM, and DLS. The two kinds of nanoparticles were dispersed into different pH solution for loading anticancer drug DOX, and DOX-loaded nanoparticles were placed in different temperature and pH in PBS buffer solution, and the structure effects about drug-loading and release of DOX were investigated. The results showed that the folwer structure of PMAA/PNIPAM nanoparticles were beneficial to the drug-loading and controlled release.