Physical and biological properties of collagen/gelatin scaffolds

Abstract

Biocompatible gelatin was used as a base material to produce a scaffold and to substitute a large portion of collagen, which is an expensive biomaterial mainly used in skin substitute. The collagen/gelatin scaffolds with various blending compositions were fabricated by freeze drying and dehydrothermal (DHT) crosslinking techniques. The effects of gelatin type, solution concentration, blending composition and DHT treatment time on the chemical and physical properties of the scaffolds were investigated. It was found that crosslinking degree of the scaffolds, determined by 2,4,6-trinitrobenzene sulphonic acid (TNBS) method, mainly depended on gelatin type and DHT treatment time. The different scaffolds provided different morphology depending on gelatin type, solution concentration and collagen content. In addition, compressive modulus of gelatin scaffolds could be improved by collagen blending up to 10 kPa. Swelling property of the scaffolds directly related to the morphology and compressive modulus. The in vitro biodegradation test by lysozyme showed that collagen blending could decrease the degradation rate of gelatin scaffolds. Crosslinked gelatin scaffolds degraded within a day while crosslinked collagen/gelatin scaffolds could remain up to 3 weeks in lysozyme solution at 37°C. The results from in vitro cell culture revealed that mouse fibroblasts could proliferate on all scaffolds. At 48th h after the culture, the number of proliferated cells on collagen/gelatin scaffolds prepared from different blending compositions was comparable to that on pure collagen scaffolds. The results proved that gelatin could be used to partly replace collagen by 70-90% for scaffold fabrication. Therefore, a large amount of collagen used in scaffold fabrication could be reduced leading to a much lower cost of biomaterials used.