Localization of adenosine to promote fracture healing

ABSTRACT Bone fracture is a very common injury, and there has been a dramatic increase in trauma-induced fractures with the increase in active lifestyle. Despite the regenerative ability of bone, bone injuries often suffer from delayed healing or non-unions. The prevalence of bone fracture and the cost of repair is on the rise primarily due to aging of the population. The profound negative impact on the patient’s quality of life and the economic burden of fracture treatment following trauma or age-related fragility fractures warrants the development of efficient and cost-effective fracture-healing adjuvants to accelerate the healing rate and improve the quality of healing. The proposed research focuses on biomaterial-assisted local delivery of adenosine to promote bone healing of aged bone tissues by rejuvenating the endogenous tissue environment and reparative cells. We hypothesize that local delivery of adenosine at the injury site will induce a pro-regenerative immune environment and promote regeneration of aging bone tissues through enhanced osteoblastogenesis and angiogenesis. These hypotheses will be tested through the following aims. Aim 1 will determine the effect of local delivery of adenosine to promote bone regeneration in aged mice by using two injury models: transverse tibial fracture and critical-sized segmental femoral defect. Aim 2 will determine the role of adenosine delivery on immunomodulation leading to enhanced bone regeneration. Successful completion of the proposed studies will have a significant impact in public health by establishing a new therapeutic intervention for promoting bone regeneration.