Densified collagen-fibril biomaterials for bone tissue engineering

Watkins, Lauren E. M.S.B.M.E., Purdue University, May 2016. Densified Collagen-Fibril Biomaterials for Bone Tissue Engineering. Major Professor: Sherry Voytik-Harbin. Millions of craniofacial bone defects occur annually as a result of trauma, congenital defects, disease, or tooth extraction1, 2. When present in the oral cavity, these defects are associated with adverse impacts on speech, mastication, and aesthetics3, 4. Thus, there is a clinical need for interventional strategies to restore and preserve alveolar bone mass to improve the success of future treatment options intended to reestablish functionality and aesthetics. Guided bone regeneration using bone grafts and a membrane represent the current standard of care for repairing alveolar bone defects, but face a number of limitations related to resorption time and structural integrity. Improvements may be directed toward the development of bone graft substitutes that are patient-specific, provide structural support to the defect, and promote rapid bone regeneration. Here, we describe the design of a densified, oligomer collagen-fibril bone regeneration template inspired by the natural progression of bone defect healing. As the dominant component of the bone organic matrix and the soft callus formed first during bone fracture healing, type I collagen provides a physiologically-relevant material for promoting bone regeneration. The polymerizable oligomer collagen formulation preserves fibrillar and suprafibrillar microstructures necessary for directing mineral deposition and also facilitates cellular encapsulation with minimal shape distortion. The densified oligomer collagen-fibril materials promote accelerated and enhanced mineralization by encapsulated human adipose-derived stem cells in vitro when compared to conventional collagen-based bone regeneration