Collagen Binding Peptide Modified-injectable Scaffold for New Bone Formation

Objectives: The objective of this study was to investigate whether the developed injectable scaffold containing tyrosine residues as a latch between the polymer and the peptide can provide in vivo physically and chemically complete microenvironment for new bone formation.
Methods: To induce biomineralization, collagen binding peptide identified from Osteopontin, that is the non-collageneous protein to make minerals with collagens in extracellular matrix around bone. The peptide was prepared by using F-moc solid phase peptide synthesis. The peptide conjugated hydrogel was easily formulated by enzyme reaction and that could inject to fit the targeted site on calvarial defected model. In vitro osteogenesis and in vivo bone formation efficacy of peptide modified hydrogel including human dental derived stem cells was investigated by calcium staining, immunofluorescent staining and micro-CT. Moreover, the expression of genes and proteins as osteogenic markers were also confirmed on 3D cultured cells.
Results: First of all, the peptide modified injectable scaffold developed by the authors was easily/quickly formed 3D structure which can help to survive and change stem cells to osteoblasts. The engineered osteoinducing system could lead to osteogenesis by increasing osteogenic markers and accumulate hydroxyapatite like minerals. Furthermore, the restoration ability on defected bones was confirmed on animal models by X-ray images and calcium stained tissue sections.
Conclusions: The osteoinductive scaffold might be a potent bone regenerative material due to easier collaboration with bioactive molecules and stem cells and more adjustable application on target tissues than conventional regenerative biomaterials.