A Degradable and Antimicrobial Surface‐Attached Polymer Hydrogel

Abstract

Surface‐attached, degradable polymer hydrogels with potential antimicrobial activity are reported. They are obtained by ring‐opening metathesis copolymerization (ROMP) of a monomer with potential bioactivity and a monomer that carries a benzophenone cross‐linker and a hydrolyzable group. The hydrolyzable group is either an ester or an anhydride group. The copolymers thus obtained are spin‐coated onto silicon wafers and UV‐irradiated to induce C,H cross‐linking of the benzophenone groups and obtain the target polymer networks. Immersion of these networks into aqueous media triggers network degradation. The degradation speed depends on the nature of the intended break points (ester or anhydride groups), the number of cross‐links per polymer chain, and the surrounding medium. By releasing bioactive polymer fragments to the medium (“leaching”) and by regenerating the hydrogel surface during the degradation process, the hydrogels potentially have two ways to prevent biofilm formation on their surface.

Self‐Regenerating Antimicrobial Polymer Surfaces via Multilayer‐Design—Sequential and Triggered Layer Shedding under Physiological Conditions

“…Thus, when placed within a polymer multilayer stack, this antimicrobial layer could be self‐polishing. [11a,29] However, this was not the focus of the here presented study.…”

“…For example, the antimicrobial polymer network A itself could serve as one further regeneration layer, since the built‐in diazo ester crosslinker contains hydrolytically cleavable groups. We recently demonstrated the degradability of a similar network . Thus, when placed within a polymer multilayer stack, this antimicrobial layer could be self‐polishing.…”

“Just Antimicrobial is not Enough” Revisited—From Antimicrobial Polymers to Microstructured Dual‐Functional Surfaces, Self‐Regenerating Polymer Surfaces, and Polymer Materials with Switchable Bioactivity

“…As an alternative, we investigated antimicrobial materials featuring various surface self-regeneration mechanisms. [25,41,42] In particular, we developed antimicrobial materials that were polymer multilayer stacks. These were made from discrete, tens to hundreds of nanometer thick individual polymer layers (not to be confused with PEMs, as discussed in the Introduction).…”

“…Following this approach, degradable antimicrobial, or protein-repellent polymer surfaces have been developed, where hydrolytic or enzymatic degradation of the polymer would renew the material surface. [15,[23][24][25] These are often called "self-polishing" coatings and have been long known, for example in the context of the prevention of marine biofouling, as summarized previously. [26,27] Historically, "self-polishing" coatings contained heavy metals, in particular organo-substituted tin (e.g., tributyl tin, which is now banned for environmental reasons) or copper particles embedded into degradable polymer matrices.…”

Fast-Acting Antibacterial, Self-Deactivating Polyionene Esters

“…Antimicrobial polymers attached to surfaces , or at least cross-linked toward hydrogels − kill adhering bacterial cells. The groups of Lienkamp, Herdick, Yang, and our group reported on different degradable antimicrobial surface-attached polymers and hydrogels. − …”