(150e) INVITED: Protein Block-Copolymers as Organic-Inorganic Hybrid Biomaterials

As cell-based regenerative therapies advance, there is a push to move from 2 dimensional (2D) to 3 dimensional (3D) culture systems and biomaterials. Here we describe protein engineering tools to fabricate 3D hybrid cell culture systems for eventual translation into clinical use. A modular design strategy allows the concept of a block copolymer to be applied to protein materials. By treating the protein's amino acid sequence as a series of functional blocks, we are able to achieve a variety of independently tunable functionalities in a single polymer strand. We have designed a family of elastin-based protein materials, each of which contains an elastin-like structural domain and a variety of biomimetic domains, including cell adhesive ligands, proteolytically degradable cleavage sites, and sites for the nucleation of inorganic materials such as hydroxy apatite. These materials support the 3D culture of rat mesenchymal stem cells and human adipocyte stem cells and are ideal platforms for studies of cell-biomaterial interactions.