Cross-linked collagen-chondroitin sulfate-hyaluronic acid imitating extracellular matrix as scaffold for dermal tissue engineering.

The objective of this study was to develop a novel scaffold imitating the ingredients and their ratios of natural dermal matrix and to evaluate its biological activity. We applied different ratios and different synthetic methods to fabricate nine kinds of cross-linked (CL) collagen/chondroitin sulfate/hyaluronic acid (Co/CS/HA) scaffolds for dermal tissue engineering. On the basis of comparison among the morphology, mechanical properties, and biodegradation rates of scaffolds, we selected the novel scaffold that was fabricated under unique procedures. In the procedures, Co, CS, and HA were firstly synthesized together in the ratio of 9:1:1 to form a membrane that was then CL with 5 mM of 1-ethyl-3-3-dimethylaminopropylcarbodiimide hydrochloride (EDC) (Co-CS-HA/CL 9:1:1). From the results of comparison, we also found that the ratio of 9:1:1 was better than other ratios. So the scaffold of Co-CS-HA/CL 9:1:1 was used as experimental group with the scaffolds of Co-HA/CS CL 9:1:1 and Co-CS/HA CL 9:1:1 as control groups to evaluate their characteristics in vitro. A control group of an open wound without scaffold was supplemented to evaluate their effects on promoting wound healing in vivo. Morphological observation showed that the novel Co-CS-HA/CL 9:1:1 scaffold had uniform and widely interconnected pores with mean diameters of 109 +/- 11 microm and adequate porosity of about 94%. Mechanical property and biodegradation assessment indicated that it had more degradation-resistant and higher elastic modulus than other scaffolds. Metabolic activity assay showed that it could more strongly promote cellular attachment and proliferation. When scaffolds were seeded with allogenic skin fibroblasts and implanted on the dorsum of Sprague-Dawley rats for 6 weeks, the novel Co-CS-HA/CL 9:1:1 skin equivalent could more successfully repair full thickness skin defects in Sprague-Dawley rats. The histology was more approximate to normal skin than those of the controls within 6 weeks. These results demonstrated that the novel CoCS-HA/CL 9:1:1 tri-copolymer has the potential to be used as a scaffold for dermal tissue engineering.