Synthetic and naturally occurring polymers are an important element in new strategies for producing therapeutic and diagnostic devices. Synthetic materials have been obvious potential candidates for such applications since their chemical and physical properties can be controlled. However, these materials lack the ability to predictably signal (orchestrate) fundamental cellular processes (e.g., adhesion, migration, differentiation, and proliferation). Therefore, one of our research foci has been on the development of biomaterials involving naturally-occurring polymers. The laboratories of J.Paul Robinson and S.L. Voytik-Harbin have worked as part of a collaborative team of physicians, engineers, and life scientist toward investigating novel tissue-derived biomaterials for tissue replacement and restoration. An integrative approach involving analytical biochemistry, cell biology, animal experimentation, traditional and advanced microscopy, and flow cytometry is being used to characterize the biological, compositional, biomechanical, and architectural properties of biomaterials. The results from these studies imply that extracellular matrix ("the stuff that surrounds cells") does not just provide an inert architectural template for tissue regrowth but rather this complex macromolecular assembly actively participates in signaling of host cells. In addition to its obvious utility as a therapeutic biomaterial, these biomaterials can be viewed as a "biological tool" which could contribute to the answering of complex questions regarding the role of ECM in mammalian morphogenesis, regeneration, and repair.
In addition, to the study of intact extracellular matrices, the biological and biophysical properties of individual extracellular matrix components is being investigated. Interestingly, many molecules of the extracellular matrix exhibit the ability to form complex supramolecular assemblies spontaneously in vitro, a process known as "self-assembly". Although cells are known to play an important role in guiding the assembly process in vivo, it is apparent that much of the information that determines the proper structure of these assembly products is contained with the macromolecules that form these structures. This property can be exploited to engineer biomaterials (e.g., gels and matrices) from polymers, which are natural to the body. Therefore, another active research area involves the study of fundamental interactions between the macromolecules of extracellular matrix (e.g., collagens, proteoglycans, and growth factors) that contribute to the synthesis of matrices and biomaterials with defined architecture, mechanical properties, and biological signaling capacity.