Effect of PNIPAM Formulation on Fabrication of Nanogels Containing Gold Nanoparticles

Abstract

Gold nanoparticles (AuNPs) have been investigated for various biomedical applications such as biosensors and genes or proteins delivery. Recently, they were modified with peptides or incorporated with polymers to increase cell penetration, specificity to targets, and stability in aqueous medium. In this study, we prepared poly(N-isopropylacrylamide) (PNIPAM) based nanogels systems containing AuNPs and examined the effect of PNIPAM formulation on the formation of AuNPs encapsulated in nanogels by using different comonomers. AuNPs were embedded into nanogels through the reduction of HAuCl4 at different pHs after PNIPAM-based nanogels were formed by a conventional radical polymerization. The morphology characterized by transmission electron microscopy (TEM) confirmed multiple non-aggregated AuNPs in PNIPAM based nanogels. Dynamic light scattering (DLS) showed the size of nanogels containing AuNPs changed with temperature and pH. UV-Vis measurements exhibited different intensity depending on PNIPAM formulations, since different amounts of gold nanoparticles were embedded in nanogels.