Peptide-functionalized poly[oligo(ethylene glycol) methacrylate] brushes on dopamine-coated stainless steel for controlled cell adhesion

The modification of the surface of surgical implants with cell adhesion ligands has emerged as a promising approach to improve biomaterial-host interactions. However, these approaches are limited by the non-specific adsorption of biomolecules and uncontrolled presentation of desired bioactive ligands on implant surfaces. This leads to sub-optimal integration with host tissue and delayed healing. Here we present a strategy to grow non-fouling polymer brushes of oligo(ethylene glycol) methacrylate by atom transfer radical polymerization from dopamine-functionalized clinical grade 316 stainless steel. These brushes prevent non-specific adsorption of proteins and attachment of cells. Subsequently, the brushes can be modified with covalently tethered adhesive peptides that provide controlled cell adhesion. This approach may therefore have broad application to promote bone growth and improvements in osseointegration.

STATEMENT OF SIGNIFICANCE

Stainless steel (SS) implants are widely used clinically for orthopaedic, spinal, dental and cardiovascular applications. However, non-specific adsorption of biomolecules onto implant surfaces results in sub-optimal integration with host tissue. To allow controlled cell-SS interactions, we have developed a strategy to grow non-fouling polymer brushes that prevent protein adsorption and cell adhesion and can be subsequently functionalized with adhesive peptides to direct cell adhesion and signaling. This approach has broad application to improve osseointegration onto stainless steel implants in bone repair.

Surface-Initiated Controlled Radical Polymerization: State-of-the-Art, Opportunities, and Challenges in Surface and Interface Engineering with Polymer Brushes

The generation of polymer brushes by surface-initiated controlled radical polymerization (SI-CRP) techniques has become a powerful approach to tailor the chemical and physical properties of interfaces and has given rise to great advances in surface and interface engineering. Polymer brushes are defined as thin polymer films in which the individual polymer chains are tethered by one chain end to a solid interface. Significant advances have been made over the past years in the field of polymer brushes. This includes novel developments in SI-CRP, as well as the emergence of novel applications such as catalysis, electronics, nanomaterial synthesis and biosensing. Additionally, polymer brushes prepared via SI-CRP have been utilized to modify the surface of novel substrates such as natural fibers, polymer nanofibers, mesoporous materials, graphene, viruses and protein nanoparticles. The last years have also seen exciting advances in the chemical and physical characterization of polymer brushes, as well as an ever increasing set of computational and simulation tools that allow understanding and predictions of these surface-grafted polymer architectures. The aim of this contribution is to provide a comprehensive review that critically assesses recent advances in the field and highlights the opportunities and challenges for future work.