Crosslinkable Tissue Particles for Regenerating Craniofacial Bone in an Ovine Model

PROJECT SUMMARY The overall goal of this application is the translation of a new crosslinkable bone void filler that will allow surgeons to better heal patients after craniofacial bone loss. The bone void filler designed is unique in that it can be implanted as a paste then quickly transition to a solid after initiation with blue light. The ability to transition into a solid after placement is unique to bone fillers that regenerate bone rather than filling the defect with a synthetic material such as bone cement. The motivation to improve upon the current state of the art was inspired by a clear gap identified by plastic surgeons and neurosurgeons, to be filled by an off-the-shelf material that can be molded to a patient’s contours, crosslink or “set” after placement to retain material, quickly transition to a solid when desired by the user (i.e., no working time restriction), and be completely biodegradable so the material will be replaced with the patient’s bone over time. To create the exact craniofacial bone void filler to meet the needs of surgeons, multiple material designs were evaluated in over 200 rats to develop the photocrosslinking bone void filler, BoneLink, proposed in the SBIR Phase I project.Our team is uniquely positioned to accomplish the goals set forth in the project and have multiple years of cumulative experience working together. The team is comprised of a plastic surgeon, craniomaxillofacial surgeon, pathologist, regulatory consultant, biostatistician, and biomedical engineers providing the necessary skills to successfully complete the translational large animal (sheep) model testing proposed. The project is highly focused with a single Specific Aim: To demonstrate improved bone regeneration in critical-size cranial bone defects using a crosslinkable tissue particle implant. We will test the hypothesis that BoneLink will lead to improved bone regeneration in a large defect compared to DBX®. Successful completion of this SBIR Phase I project will pave the way for an FDA Q-Submissions meeting, which will in turn shape a future Phase II project to bring BoneLink closer to the clinic.Compared to clinically available bone products, BoneLink offers surgeons a new option for craniofacial bone defect repair by combining the moldability of current products with the ability to set after placement, creating a solid structure to regenerate bone. For multiple reasons, the current focus is on translation of the technology to the craniofacial space where the material’s inherent capabilities will be the most advantageous and marketable. The desired initial indication for use will be a craniofacial bone void filler with the intention to expand indications later after 510(k) clearance to the extremities, pelvis, and spine. Successful translation of BoneLink offers a paradigm shift for the treatment of large size craniofacial bone defects by potentially replacing the need for bone autografts since commercially available products cannot. The clinical impact (Phase II project) will be the introduction of a new product that regenerates bone rather than simply filling the defect, eliminates follow-up surgeries, and ultimately improves quality of life for patients.NARRATIVE The proposed bone void filler technology is designed to offer surgeons new capabilities for regenerating craniofacial bone by offering a material than can be implanted as a paste-like material, molded to any size or shape, then crosslinked in place for material retention. Clinically available bone regenerating products behave as pastes or putties; however, they do not set after placement and are prone to material migration outside the defect. The advantage of our crosslinkable design offers an implantable material that can transition to a solid after placement for better overall bone regeneration.