Effect of carboxymethylcellulose on fibril formation of collagen in vitro

The effect of carboxymethylcellulose (CMC) on the fibril formation of collagen in vitro was studied by turbidity measurements and atomic force microscopy (AFM). The kinetics curves of fibril formation indicated that the rate of collagen fibrillogenesis was decreased with the addition of CMC, meanwhile the final turbidity was obviously increased as the CMC/collagen ratio reached 30%. The AFM images of collagen-CMC solutions showed that the number of nucleation sites of collagen fibrillogenesis was significantly increased with the presence of CMC, while the diameter of immature collagen fibrils was obviously decreased. Moreover, the thermal stability of collagen fibril hydrogels was obviously improved with the presence of CMC. In addition, the morphologies of collagen fibrils observed by AFM revealed that the adjacent fibril segments or fibrils were intertwisted and even tightly merged, probably due to the hydrogen bonding and molecular entanglement interactions between CMC and collagen molecules.