Surface-initiated assembly of protein nanofabrics.

Cells and tissues are self-organized within an extracellular matrix (ECM) composed of multifunctional, nano- to micrometer scale protein fibrils. We have developed a cell-free, surface-initiated assembly technique to rebuild this ECM structure in vitro. The matrix proteins fibronectin, laminin, fibrinogen, collagen type I, and collagen type IV are micropatterned onto thermosensitive surfaces as 1 to 10 nm thick, micrometer to centimeter wide networks, and released as flexible, free-standing nanofabrics. Independent control of microstructure and protein composition enables us to engineer the mechanical and chemical anisotropy. Fibronectin nanofabrics are highly extensible (>4-fold) and serve as scaffolds for engineering synchronously contracting, cardiac muscle; demonstrating biofunctionality comparable to cell-generated ECM.