CAREER: Functional Fouling of Surfaces by Interfacial Silk Fibroin Self-Assembly

NON-TECHNICAL SUMMARY

The tendency of proteins in water to adhere randomly to nearby surfaces is a ubiquitous phenomenon in nature. This phenomenon, known as “fouling,” is usually considered a confounding problem which can lead to a wide range of issues, such as clinical failure of biomedical implants and undesirable attachment of marine organisms to ship hulls. However, this project aims to leverage the persistence of protein fouling as the basis of a new, highly versatile approach for creating multifunctional surfaces.

Using silk fibroins, a class of biocompatible proteins derived from or inspired by the main component of natural silk, this project will develop methods for creating robust nanometer-thin coatings on a variety of surfaces without requiring hazardous chemicals or complex instrumentation. Towards this goal, the project will seek to gain a fundamental understanding of the fouling behavior of silk fibroins as they undergo self-assembly – an aggregation process which underlies the spinning of silk threads by insects and spiders.

Through a combination of synthetic biology and surface-sensitive material characterization techniques, this project will also reveal fundamental insights about how proteins and other biomacromolecules in nature are able to adhere tenaciously to surfaces without specific chemical reactions. Furthermore, this project will develop a bio-inspired strategy by which the function of surfaces, such as biocompatibility or therapeutic activity, can be modified for applications in human healthcare and sustainability.

To facilitate the dissemination of complex scientific findings from this project to a global public audience, the Merian Studio for Visual Communication will be founded at Rensselaer Polytechnic Institute. This technology-equipped workspace will enable students to produce compelling visual educational tools, such as 2D/3D graphics and animations. As part of this visual communication effort, the project will also support an interdisciplinary team of art and engineering students to create an interactive video game that intuitively teaches the fundamental concepts of natural protein assembly and fouling phenomena.

TECHNICAL SUMMARY

This proposal aims to develop a powerful bottom-up strategy for creating multifunctional thin-film coatings that leverages the unique self-assembly behavior of silk fibroins at solid-liquid interfaces. Such interfacial behavior, where adsorption occurs concurrently with protein-protein assembly, is a type of robust “fouling” which has not been sufficiently studied to date, despite being an important aspect underlying natural biomacromolecular adhesion.

Furthermore, whereas fouling of surfaces by proteins has long been considered an undesirable but unavoidable problem, interfacial silk fibroin self-assembly can be used as a versatile non-covalent approach for modifying a variety of surfaces under mild, biocompatible conditions without complex chemistries or advanced instrumentation. This project will seek to gain a fundamental understanding of the growth of adherent and defect-free coatings via interfacial protein self-assembly by 1) relating silk fibroin adsorption on high and low surface energy substrates to tunable solution-phase assembly phenomena, 2) determining the role of protein sequence and size on coating formation using de novo designed recombinant silk fibroins, 3) visualizing the effects of nanoscale substrate topography on coating formation, and 4) exploring co-assembly of enzymes and growth factors with silk fibroins as a one-pot method for creating therapeutically active surfaces.

The project will generate a comprehensive model for interfacial assembly of network-forming proteins, such as silk fibroins, in terms of protein-protein and protein-surface interactions. Moreover, this work will establish a new non-covalent approach towards functionalizing surfaces for a variety of materials applications. To facilitate the dissemination of complex scientific findings from the proposed research to a broad lay audience, the project will establish the “Merian Studio for Visual Communication” at Rensselaer Polytechnic Institute, which will be a technology-equipped workspace enabling students to produce compelling visual educational tools, such as 2D/3D graphics and animations.

The project will also support an interdisciplinary team of art and engineering undergraduate students to create an interactive video game that teaches fundamental concepts in protein adsorption and assembly related to the proposed research for use in global outreach.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.