Preparation and evaluation of heparinized sponge based on collagen and chitosan for wound healing

The wound dressing can temporarily replace the skin and play a protective role in the process of wound healing, preventing wound infection and inflammation, and providing a favorable environment for wound healing. In this study, a mixture of collagen and chitosan was lyophilized to be the host material of the sponge. This sponge was soaked into 1-ethyl-(dimethylaminopropyl) carbodiimide/N-hydroxy sulfosuccinimide cross-linking solution containing heparin and experienced secondary lyophilization to prepare the heparinized sponge (CT-CL/Hp). The surface morphology and structural characterization of the sponge was characterized by scanning electron microscope and Fourier transform infrared spectrometer, respectively. Relatively favorable water absorption capability were observed by measuring the physical properties. Satisfactory antibacterial properties against various bacteria and microbial isolation performance were observed by the antibacterial effect analysis in vitro. The sustained-release property of heparin from the sponges was measured using Alcian Blue assay. Experiments in vitro and in vivo showed that the sponges had satisfactory biocompatibility and lower sensitization. Moreover, the effect of sponge on early stages of wound healing was evaluated by guinea pigs wound healing models. Analysis of wound healing rates and histological examination showed satisfactory results. CT-CL/Hp enhanced expression of growth factors, particularly VEGF and EGF at day 7. These results demonstrated that CT-CL/Hp-treated sponges benefit to wound skin healing and regeneration.