Preparation of functional nanoparticles of mPEG-b-P(DMA-co-HA) copolymers via polymerization-induced thermal self-assembly

Abstract

Self-assembled polymeric nanoparticles have been of great interest for various biological applications such as drug delivery, catalysis, and biosensing. In this regard, polymerization-induced self-assembly (PISA) has been widely explored as a more efficient technique than conventional self-assembly methods as it can be conducted in one pot and does not require harsh conditions. Recently, a method known as polymerization-induced thermal self-assembly (PITSA) has emerged, exploiting the inherent phase transition behavior of thermoresponsive polymers at a critical temperature point to generate thermoresponsive nanoparticles in situ. However, the narrow range of monomers suitable for PITSA limits the design of diverse thermoresponsive nanoparticles, and therefore this process has not yet been explored to its fullest capacity. In this study, we demonstrate the preparation of thermoresponsive nanoparticles based on hydrophilic N,N-dimethyl acrylamide (DMA) and hydrophobic hexyl acrylate (HA) monomers. This is particularly interesting as these monomers produce non-responsive homopolymers but display thermoresponsive behavior when copolymerized. The nanoparticles obtained were crosslinked to enable their characterization at room temperature, and further functionalized with a short synthetic antibacterial peptide (WR)3 to demonstrate proof-of-concept potential as antimicrobial agents. Overall, this work expands the library of monomers amenable to PITSA for the production of thermoresponsive nanoparticles, contributing to the design of new functional nanoparticles for therapeutic purposes.