Study on the cross-linking effect of a natural derived oxidized chitosan oligosaccharide on the porcine acellular dermal matrix

The purpose of this study is to investigate the cross-linking interaction between a natural derived oxidized chitosan oligosaccharide (OCOS) and the porcine acellular dermal matrix (pADM), and further evaluate the varying properties of the pADM after cross-linked. The shrinkage temperature (T-s) and cross-link density study indicate that the amino groups of lysine or hydroxylysine side groups of collagen could predominantly react with the available aldehyde group of OCOS to form a more stable Schiff's base leading to the improved hydrothermal stability of pADM. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and atomic force microscopy (AFM) analysis indicate that the structural integrity of collagen (i.e. D-periodicity structure and triple helix) is still maintained after the OCOS treatment. Meanwhile, the mechanical properties, hydrophilicity, collagenase degradation and cytotoxicity of pADM after cross-linking have been all promoted obviously. Above all, the cytocompatibility analysis implies that when the dosage of OCOS is less than 8%, introducing OCOS into pADM might be favorable for cell adhesion, growth and proliferation. Taken as a whole, the present study demonstrates that OCOS could serve as an ideal cross-linker for the chemical fixation of pADM, which are compatible with its potential applications in biomaterials.