Cellularized bone grafts for point-of-care complex craniofacial reconstructions

Epibone, Inc., Jersey City NJ

Investigators

Abstract

DESCRIPTION (provided by applicant): EpiBone is a company engineering living, anatomically precise and functionally mature bone grafts from autologous stem cells derived from fat aspirates. In the United States alone, there are over 400,000 emergency visits per year due to facial trauma, with ~20% of facial fractures being complex and involving more than one bone. Our goal with this SBIR is to develop the epiBone-CMF product: a unique class of stem cell- infused grafts that can be prepared within <7 days and are thus suitable for trauma patients requiring cranio- maxillofacial (CMF) repair. In past research, we have established a technology for engineering anatomically shaped living bone grafts using our proprietary bioreactor, stem cells and decellularized bone scaffolds, and showed excellent bone healing in a porcine model of craniofacial repair with grafts conditioned for 3 weeks in vitro. We now propose to establish rapid bioreactor conditioning of the cells in scaffolds, in order to develop a product suitable for treating trauma patients with complex CMF injuries. The graft will be produced by infusing stem cells freshly isolated from a sample of the patient's fat tissue into decellularized bone scaffolds A key component of the production process is our bioreactor, which will be used for cell seeding and conditioning. We will first develop a semi-automated system for cell seeding of scaffolds. Stromal vascular fraction (SVF) cells extracted from adipose tissue will be infused into bone scaffolds using a bioreactor system optimized for providing spatially uniform perfusion during culture. We will determine the optimal cell density and cell carrier (culture medium, fibrin gel, o collagen gel). We will then determine the duration of cell conditioning in perfused culture for stable cell attachment and expression of osteogenic markers. Finally, we will demonstrate utility of these cellularized bone grafts for bone reconstruction, in the nude rat calvarial defect model using human SVF stem cells, over a period of 6 weeks. The osteogenic quality of bone grafts, filling of the defect, mechanical properties and integrative strength of the graft-bone interface (benchmark: >0.5 MPa) will be monitored using imaging (uCT) and endpoint assays (histology, biomechanics). We expect to establish a system for rapid production of complex bone constructs suitable for image-guided reconstructions in the CMF complex. The outcomes of this study will be the starting point for a large animal study of anatomically shaped epiBone-CMF grafts, towards eventual clinical application. If successful, epiBone-CMF would revolutionize the current standard of treatment of CMF injuries, and help improve patient outcomes for the numerous CMF procedures involving complex fractures.