Bioactive scaffolds based on collagen filaments with tunable physic-chemical and biological features

Native tissues such as nerve bundle, blood vessel and tendon have extracellular matrix with characteristic orientation, which cannot be fully achieved with current technology in the development of regenerative biomaterials. In this study, bioactive and oriented collagen filaments were fabricated by combination of wet-spinning and carbodiimide-based crosslinking. The wet-spinning techniques, including the extrusion and collection rates, and their influences on collagen filaments were studied and optimized. The diameter of attained collagen filaments could be adjusted from 30 μm to 650 μm. The further characterizations, such as circular dichroism, scanning electron microscopy, small-angle X-ray scattering and Fourier transform infrared spectra analysis, showed the native structure of the collagen was greatly preserved after the filament preparation process. The measurements of weight swelling ratio and degradation rate indicated that the crosslinking method can efficiently regulate the physico-chemical properties of collagen filaments, including water absorption and degradation behavior. Particularly, the mechanical strength of collagen filaments can be greatly improved via crosslinking. In addition, cells can adhere and spread on collagen filaments with well-aligned patterns, showing suitable biological features. It can be concluded that the bioactive collagen filaments with tunable properties may enjoy superiority to develop tissue engineering scaffolds with characteristic orientation feature. With further study on interaction between collagen filaments and cells, it may shed a light on the development of collagen based biomaterials and would benefit to the fields.