Characterizations of polyanionic collagen prepared by linking additional carboxylic groups

We have successfully attempted to characterize the polyanionic collagen (PAC) intended for biomaterial and tissue engineering applications. PAC was obtained from type I collagen by chemically linking additional carboxylic groups to the reactive free amino groups. These changes do not affect the α chains morphology and conformation in collagen. Pure type I collagen obtained from bovine Achilles tendons was allowed to react slowly at pH 9 with succinic anhydride to attain 96% conversion into PAC confirmed by trinitrobenzenesulfonic acid (TNBS) assay. Electrophoretic mobility pattern of α, β and γ components of PAC shifted to higher molecular weight by 16,300 Da indicating modification of collagen. Similarly, FTIR, CD and DSC indicated retention of triple helical conformation of PAC. Novelty of PAC lies in its swelling behavior resulting in dissolution thus offering transparency in neutral pH buffer. The results obtained here give us an opportunity to use PAC as an injectable device for tissue engineering applications as its up-regulatory efficiency for cytoproliferation validates its biocompatibile potentials.