For many materials and devices, the physicochemical properties and functionalities of their surfaces are vitally important for their performance. Traditional methods for surface modification utilize covalent strategies, such as grafting "from/to", or non-covalent strategies, such as layer-by-layer deposition. However, these methods suffer from critical drawbacks, such as low grafting density, non-biocompatibility, or the requirement for specific surface chemistries and geometries. In this talk, we present our work on leveraging the self-assembly of silk fibroins, a class of network-forming structural proteins, at solid-liquid interfaces as a versatile "chemical-free" approach towards functionalizing surfaces. Our studies have shown that in conditions which balance protein-protein and protein-surface interactions, interfacial silk fibroin self-assembly can yield adherent, defect-free coatings on a wide range of organic and inorganic substrates. These coatings transform the physicochemical properties of surfaces and endow new functionality without requiring covalent chemistry, adhesion motifs, specific substrate geometries, or surface pre-activation. Due to the amphiphilicity of silk fibroins, our coating strategy tolerates both hydrophobic and hydrophilic surfaces, including PTFE, PDMS, TiO2, stainless steel, and other common materials. The properties and morphologies of self-assembled coatings depend on the silk fibroin sequence. For example, coatings assembled from <i>Bombyx mori</i> silk fibroin improve cell adhesion and neurite extension, while coatings assembled from recombinant spidroin inhibit cellular attachment. Furthermore, we have recently found that macromolecular "payloads" can be incorporated into coatings via interfacial co-assembly with silk fibroin. Thus, whereas fouling of surfaces by proteins has long been considered an undesirable but unavoidable problem, our research utilizes this robust phenomenon the basis of a modular and versatile bottom-up approach for creating multifunctional surfaces.

Interfacial protein assembly as a chemical-free strategy towards surface functionalization

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.