AVS 56th International Symposium & Exhibition
    Biomaterial Interfaces Monday Sessions
       Session BI-MoA

Paper BI-MoA6
Design of Protein Polymers as Novel Tissue Engineering Scaffolds

Monday, November 9, 2009, 3:40 pm, Room K

Session: Protein and Cell Interactions at Interfaces I
Presenter: D. Sengupta, Stanford University
Authors: D. Sengupta, Stanford University
S.C. Heilshorn, Stanford University
Correspondent: Click to Email
The ability to tailor specific cell-matrix interactions in biomaterials is now recognized as an important method to control cell behaviour. Biomaterial adhesivity and elasticity are important determinants of cell adhesion, proliferation, and differentiation; and a coordinated cell response to these different material inputs results in complex signaling crosstalk. Independent modification of these biomaterial properties is thus extremely important, but difficult to achieve with current synthetic as well as natural biomaterials. While natural biomaterials such as collagen and Matrigel do not allow for the independent tuning of multiple biomaterial properties, synthetic biomaterials such as PEG and acrylates can be toxic and immunogenic. An alternative approach to natural as well as synthetic materials is the use of protein polymers made with recombinant protein engineering technology. By templating protein synthesis using the genetic code, we have exact molecular-level control over our material. Using this strategy, we have engineered a family of tunable and biodegradable protein-engineered biomimetic materials that incorporate critical elements of the natural extracellular matrix. The materials are manufactured using a modular design strategy, resulting in a fusion protein comprised of multiple peptide domains that provide cell adhesion and matrix elasticity. Specifically, the elastic modulus of the material can be tuned (from ~43-1200 kPa) independently of RGD ligand density (from 0-9300 cell adhesion sites/μm2), enabling optimization of the biomaterial interface for specific tissue engineering applications. Additionally, these interfaces can be easily micro-molded to incorporate micro- or nanoscale topographical features that induce cell alignment. Human embryonic stem cell-derived cardiomyocytes as well as mouse embryonic stem cells cultured on our protein-engineered biomaterials demonstrate viability, proliferation, differentiation, and morphology comparable to positive gelatin controls, providing a viable alternative to commonly used materials. The molecular-level design strategy of these protein polymers allows for unprecedented control over the biomaterial-cell interface for regenerative medicine applications.