Mechanical properties of biocompatible protein polymer thin films

A silklike protein with fibronectin functionality (SLPF) (ProNectin F(R), P rotein Polymer Technologies, Inc.) is a genetically engineered protein poly mer containing structural and biofunctional segments. The mechanical proper ties and deformation mechanisms of electrostatically deposited SLPF thin fi lms were examined by scratch testing, tensile testing, and nanoindentation, Scanning electron microscopy and scanned probe microscopy revealed that th e macroscopic properties were a sensitive function of microstructure. The S LPF films were relatively brittle in tension, with typical elongation-to-br eak values of 3%. Nanoindentation data were fit to a power law relationship .