Abstract
Sodium hyaluronate (SH) is recognized as the strongest natural humectant, since it contains a large number of hydroxyl and carboxyl groups in its structure, and can absorb 1000 times its own weight of water. The porcine acellular dermal matrix (pADM) has been widely used in biological materials for its biological activities, such as promoting cell proliferation and promoting wound healing. Enhancing the hydrophilic and moisturizing properties of the pADM is expected to further improve its ability to promote wound healing. However, there are no strong chemical bonds between SH and pADM. Therefore, SH was oxidized by sodium periodate in this study, and was further used to cross-link it with pADM. The microstructure, hydrophilicity, moisture retention, degradation and cytotoxicity of pADM cross-linked with different oxidation degrees of oxidized sodium hyaluronate (OSH) were studied. The results show that OSH-pADM maintained the secondary structure of natural collagen, as well as the good microporous structure of native pADM after cross-linking. With increasing oxidation degree, the surface hydrophilicity and moisture retention capacities of OSH-pADM increased; among them, OSH-pADM cross-linked with 40% oxidation degree of OSH was found to have the strongest moisture retention capacity. The hygroscopic kinetics at 93% RH were conformed to the second-order hygroscopic kinetics equation, indicating that the hygroscopic process was controlled by chemical factors. The degradation resistance of OSH-pADM also increased with increasing oxidation degree, and the cytotoxicity of OSH-pADM was acceptable. The in vivo full-thickness wound healing experiments showed that OSH-pADM had an obvious ability to promote wound healing. It can be speculated that OSH-pADM, with its good hydrophilic and moisturizing properties, physicochemical properties and biocompatibility, has great potential for facilitating wound repair.