Composite aerogels based on dialdehyde nanocellulose and collagen for potential applications as wound dressing and tissue engineering scaffold

Nanocellulose and collagen are all natural polymer materials, and their combination could expand the mode and scope of applications. Employing a mild chemical purification together with the subsequent ultrasonic treatment, the nanocellulose fibers (NCFs) were isolated from wood powder, and were then oxidized into dialdehyde NCFs by sodium periodate, which offers active sites for introducing collagen. The dialdehyde NCFs and collagen were crosslinked together through the bonds of Schiff base. The dialdehyde NCFs act as matrix to guide the growth of collagen, and through the chemical crosslinkage, collagen grew along dialdehyde NCFs and formed the composite aerogels. The as-prepared NCF/collagen composite aerogels, consisting of the membranes interwoven by NCF/collagen composite fibers, exhibited low-densities between 0.02 and 0.03 g cm−3, high-porosities ranged from 90% to 95%, and strong water absorption up to 4000%. The aerogels also exhibited good biocompatibility as well as high level of cell activity and proliferation, which may be suitable for biological wound dressings and tissue engineering scaffolds.