Development of Adhesive Elastomeric Proteins for Surgical Adhesive Applications

This project focuses on the development and characterization of a recombinant protein that functions as a surgical adhesive.  Surgical adhesives provide a promising alternative to the stiff sutures and staples that often result in external tissue damage when used to close wounds.  Ideal surgical adhesives are biocompatible, able to set well and remain sticky in moist conditions, possess strong adhesive and cohesive properties, and exhibit mechanical properties that mimic those of the surrounding tissue. Unfortunately, the commercial adhesives available today are unable to meet all of these criteria.  We created a modular protein that combines the adhesive properties of mussel proteins, which are able to strongly adhere to nearly any surface, with the mechanical properties of elastin, a protein that provides flexibility to soft tissues in the body.  Thus far, our recombinant protein was successfully cloned into E. coli and overexpressed in a 10 L fermentor.  The protein was then purified using immobilized metal affinity chromatography, and the pre-adhesive region of the protein was enzymatically converted to impart adhesive properties. 

We were able to use crosslinking chemistry to form hydrogels from a model protein and show that the gelation time and mechanical properties can be tuned by altering the crosslinker concentration and pH.  The mechanical properties of protein hydrogels are being characterized using controlled-force tensile testing.  Our preliminary results demonstrate that our model protein has a Young’s modulus that is similar to that of soft tissues and may be of interest in surgical applications.