A new strategy for repairing large bone defects using an interventional micro-circulation system

Repairing large bone defects remains a difficult clinical problem because of the variability in the defects. The traditional methods, such as autograft, allograft bone and biological filler material transplantation are still facing difficulties in clinical application nowadays. Tissue engineering technology has the potential to solve this problem, and it has thus become a popular research topic. However, ideal solutions for engineering large pieces of bone tissue with vascularization and other key technical problems have not been found to date. Using conventional repair approaches for large bone defects also faces enormous challenges. In order to circumvent these difficulties, we proposed and established a new method called the interventional micro-circulatory system (IMCS) for repairing large-segment bone defects in situ. On the one hand, the system provides nutrition and removes inflammatory cytokines, oxygen free radicals, and toxic metabolites to improve the ischemic injury microenvironment; on the other hand, seed cells are supplied dynamically, and their biological behavior ability such as the migration, proliferation, differentiation, and directional distribution are promoted. We demonstrate the repair of large bone defects in an animal model using this system. Compared with conventional reconstruction methods, this strategy has the potential to provide a new approach to clinical stem cell transplantation for the treatment of large bone defects.