Biological Assemblies Provide Novel Templates for the Synthesis of Biocomposites and Facilitate Cell Adhesion

Abstract

Mechanical mismatch and the lack of interactions between implants and the natural tissue environment are the major drawbacks in bone tissue engineering. Biomaterials mimicking the self-assembly process and the composition of the bone matrix should provide new route for fabricating biomaterials possessing novel osteoconductive and osteoinductive properties for bone repair. In the present study, we employ bio-inspired strategies to design de novo self-assembled chimeric protein hydrogels comprising leucine zipper motifs flanked by dentin matrix protein 1 domain, which was characterized as a mineralization nucleator. Results showed that this chimeric protein could function as a hydroxyapatite nucleator in pseudo-physiological buffer with the formation of highly oriented apatites similar to biogenic bone mineral. It could also function as an inductive substrate for osteoblast adhesion, promote cell surface integrin presentation and clustering, and modulate the formation of focal contacts. Such biomimetic "bottom-up" construction with dual osteoconductive and osteoinductive properties should open new avenues for bone tissue engineering.Mechanical mismatch and the lack of interactions between implants and the natural tissue environment are the major drawbacks in bone tissue engineering. Biomaterials mimicking the self-assembly process and the composition of the bone matrix should provide new route for fabricating biomaterials possessing novel osteoconductive and osteoinductive properties for bone repair. In the present study, we employ bio-inspired strategies to design de novo self-assembled chimeric protein hydrogels comprising leucine zipper motifs flanked by dentin matrix protein 1 domain, which was characterized as a mineralization nucleator. Results showed that this chimeric protein could function as a hydroxyapatite nucleator in pseudo-physiological buffer with the formation of highly oriented apatites similar to biogenic bone mineral. It could also function as an inductive substrate for osteoblast adhesion, promote cell surface integrin presentation and clustering, and modulate the formation of focal contacts. Such biomimetic "bottom-up" construction with dual osteoconductive and osteoinductive properties should open new avenues for bone tissue engineering.