Elucidation of the mechanism of the promotion of bone fracture healing by mature osteoblast transplantation and its application to development of novel therapeutic methods

Abstract

Research underway in the Department of Orthopaedic and Spinal Surgery at Tokyo Medical and Dental University aims to develop a new treatment method for osteoporosis related fracture and implement a novel system to enhance fall prevention for osteoporosis patients. The team consists of more than 200 orthopaedic surgeons involved in a wide range of research. Dr Koji Fujita, an associate professor with extensive expertise in osteoporosis, is the leader of one of the research group within the Department which is conducting innovative studies focused on developing new drugs and clinical research for fall prevention as well as surgery of the upper extremity. "In Japan, osteoporosis and related bone fractures are a major concern because this country experiences population aging that is unprecedented anywhere in the world," he highlights. "Therefore, urgent countermeasures to prevent osteoporosis and to cure the fragility fracture are necessary." The primary focus of Fujita's research involves the development of a novel way to enhance and optimise bone union following fractures in osteoporotic patients. His initial incentive for the new research direction was that current treatments for fragility fractures are lacking efficiency when it comes to fulfilling the optimal bone union. Hence, Fujita has been focusing on mature human osteoblasts that are large cells responsible for the synthesis and mineralisation of bone during both its primary formation and fracture healing. "In this method, we will isolate human mature osteoblasts from the iliac crest of patients with fracture, then transplant into the fracture site," he explains. "Currently, isolation of human mature osteoblast from bone chip is about four hours including collagenase digestion, Magnetic cell sorting and Fluorescence-activated cell sorter (FACS). We are trying to shorten this duration to one hour, which will enable us to both isolate and transplant at the same time while the patient is in the operating theatre.