Biocompatible, Antifouling, and Thermosensitive Core−Shell Nanogels Synthesized by RAFT Aqueous Dispersion Polymerization

Reversible addition−fragmentation chain transfer (RAFT) aqueous dispersion polymerization was used to synthesize a novel type of core−shell nanogel containing linear poly(ethylene glycol) (PEG) and/or nonlinear polymers with oligo(ethylene glycol) side chains. These nanogels with low polydispersities were synthesized efficiently with tunable sizes and thermosensitivities. The nanogels containing nonlinear polymers with oligo(ethylene glycol) side chains as the shell had enhanced stability during freeze−thawing process and in biologically relevant solutions including 1.5 M NaCl, 1% bovine serum albumin (BSA) and 100% fetal bovine serum (FBS) solutions. Aminolysis and hydrolysis of the chain transfer agents (CTAs) in the nanogels were studied and the nanogels exhibited enhanced stability in comparison with molecularly dissolved polymers. The chemical stability of the CTAs in the nanogels was well-correlated with the in vitro cell viability studies of the nanogels using lung cancer cells.