Synthetic polycations with controlled charge density and molecular weight as building blocks for biomaterials

Abstract

A series of polycations prepared by RAFT copolymerization of N-(3-aminopropyl)methacrylamide hydrochloride (APM) and N-(2-hydroxypropyl)methacrylamide, with molecular weights of 15 and 40 kDa, and APM content of 10–75 mol%, were tested as building blocks for electrostatically assembled hydrogels such as those used for cell encapsulation. Complexation and distribution of these copolymers within anionic calcium alginate gels, as well as cytotoxicity, cell attachment, and cell proliferation on surfaces grafted with the copolymers were found to depend on composition and molecular weight. Copolymers with lower cationic charge density and lower molecular weight showed less cytotoxicity and cell adhesion, and were more mobile within alginate gels. These findings aid in designing improved polyelectrolyte complexes for use as biomaterials.

Keywords:

• Polycation
• RAFT
• polyelectrolyte complexes
• anti-fouling
• biocompatibility
• encapsulation

Acknowledgments

We would like to thank NSERC (Discovery Grant and CREATE IDEM programs) for funding, and acknowledge Christine Di Cresce, Emilia Bakaic, Ivana Postic, and Bahareh Sayyar for their help with cell cultures and assays, Iwona Wenderska for helping with statistical analysis, and Dr. Heather Sheardown and Dr. Gonzalo Hortelano for providing access to their cell culture facilities.

Disclosure statement

No potential conflict of interest was reported by the authors.