Electromechanical properties of dried tendon and

Assembling artificial collagenous tissues with structural, functional, and mechanical properties, which mimic natural tissues, is of vital importance for many tissue engineering applications. While the electromechanical properties of collagen are thought to play a role in, e.g., bone formation and remodeling, this functional property has not been adequately addressed in engineered tissues. Here, the electromechanical properties of rat tail tendon are compared with those of dried iso-electrically focused collagen hydrogels using piezoresponse force microscopy in ambient conditions. In both the natural tissue and the engineered hydrogel, D-periodic, type I collagen fibrils are observed, which exhibit shear piezoelectricity. While both tissues also exhibit fibrils with parallel orientation, Fourier transform analysis has revealed that the degree of parallel alignment of the fibrils in the tendon is three times that of the dried hydrogel. The results obtained demonstrate that iso-electrically focused collagen has similar structural and electromechanical properties to that of tendon, which is relevant for tissue engineering applications.