Collagen affinity coating for surface binding of decorin and other biomolecules: Surface characterization

The development of biomaterials that promote tissue reconstruction and regeneration can reduce the low level, chronic inflammation and encapsulation that impact the performance of today's medical devices. Specifically, in the case of implantable sensors, the host response often leads to poor device performance that discourages permanent implantation. Our goal is to present on medical implants bioactive molecules that can promote healing rather than scarring. Localized delivery of these molecules would also minimize the possibility of adverse tissue reactions elsewhere in the body. Toward this end, the authors have developed a collagen affinity coating that binds a number of potential healing molecules and can be attached to the surface of an implanted biomaterial. This allows the creation of a wide variety of natural surface coatings that can be evaluated and tailored to promote the desired healing response. To demonstrate the efficacy of this collagen affinity coating to biospecifically bind promising healing molecules to type I collagen in vivo, the antifibrotic proteoglycan decorin was utilized. Decorin binds and renders ineffective the protein transforming growth factor beta (TGFβ) that induces collagen scar production. Thus, an assembled, supramolecular structure of biomaterial-collagen-decorin-TGFβ is formed. A decorin surface coating was created and characterized, illustrating the potential of this type I collagen affinity coating for widespread use with a variety of promising healing molecules. Future studies will test the implant efficacy of this type of coating.