Optimized Bio-Degradability and Biocompatibility of a Biogenic Collagen Membrane by Cross-Linking and Nznha Doping

Biogenic collagen membranes have been widely used as soft tissue barriers in guided bone regeneration (GBR) and guided tissue regeneration (GTR). Nevertheless, their clinical performance remains unsatisfactory yet because of their low mechanical strength and fast degradation rate in vivo. Although cross-linking with chemical agents is effective and reliable to prolong the degradation time of collagen membranes, some adverse effects including potential cytotoxicity and undesirable tissue integration have been observed during this process. As a nutritionally fundamental trace element, zinc plays an active role in promoting the growth of cells and regulating the degradation of collagen matrix. Herein, a biogenic collagen membrane was cross-linked with glutaraldehyde-alendronate to prolong its degradation time, of which the physiochemical and biological properties were enhanced by the incorporation of a zinc doped nano-hydroxyapatite (nZnHA), with the native structure of collagen preserved. Specifically, the cross-linking combined with the incorporation of 1% and 2% nZnHA seemed to endow the membrane with the best biocompatibility and tissue integration capability, as well as a degradation period of six weeks in a rat subcutaneous model. Thus, it is a promising strategy to improve the clinical performance of biogenic collagen membranes by cross-linking together with the incorporation of nZnHA.