Poly(2-oxazoline)-Based Microgel Particles for Neuronal Cell Culture

An increasing number of in vivo and in vitro neuro-engineering applications are making use of colloidal particles as neuronal cell carriers. Recent studies highlight the shortcomings of commercial glass particles and stress the benefit of using soft microgel particles (MGPs) instead. This study describes first the fabrication of MGPs from telechelic poly(2-methyl-2-oxazoline)s (PMeOx) cross-linkers and hydrophilic neutral (hydroxyethyl)methacrylate (HEMA) or charged 2-methacryloxyethyltrimethylammonium (METAC) monomers by emulsion polymerization, and it discusses their ability to support cell growth. It establishes that uncharged copolymers lead to MGPs with nonfouling properties inappropriate for cell culture, and it provides a protocol to amend their surface properties to enable cell adhesion. Finally, it demonstrates that the introduction of positive charges by METAC is necessary to obtain surface properties suitable for neuronal cell development. Through the optimization of the PMeOx30 MGP properties, this work provides general guidelines to evaluate and tune MGP chemistry to obtain microcarriers for neuro-engineering applications.