The Analysis of Keratins/Chitosan Photocrosslinked Biomaterials for Bone Tissue Repairing

Bone tissue engineering has gained increasing attention among the medical society recently due to the aging population in developed countries. Issues of bone repair clinically is very popular, especially regeneration of large traumatic bone defects. The materials used in bone tissue engineering were dominant by either inorganic ceramic compounds or synthesis polymers. But natural polymers are also of great interest of researchers in this biomaterial field since they posses intrinsic biocompatibility, biodegradability and with little immune response. These types of natural polymers, for example, collagen, keratin, alginate and chitosan, are being extensively studied for their potentials in tissue engineering recently.

Keratin has intrinsic biocompatibility and contains several peptide-binding motifs that support the attachment of a wide variety of cell types. Based on our previous study, we have proved that keratin extracted from human hair can promote cell adhesion and proliferation for 3T3 fibroblasts, MG63 osteoblasts and human adipose stem cells (hASCs). Despite the advantages of keratin in bioactivity, the fragile mechanical properties of keratin will face challenges in the field of bone tissue engineering. To overcome this problem, we decided to combined keratin with chitosan by induction of azide functional group as a photocrosslinker, in order to enhance the mechanical strength.

In this research we will analyze the properties of the Keratin/Chitosan composites, and prove that the following films can maintained good adhesion and proliferation of human adipose stem cells. Most importantly, this biomaterial could promote the differentiation to osteoblast. Also, we will show that by lyophilizing the keratin chitosan mixtures, a scaffold of highly interconnected porous structure can be made, which may produce an ideal environment for tissue engineering. .

We believe that the keratin/chitosan composite biomaterials can be used in surface modification, and the crosslinkable properties can make scaffold fabrication of these natural polymers for bone tissue engineering possible in the near future.