MUSSEL ADHESIVE PROTEIN-INSPIRED BONE GLUE FOR INTEROSSEOUS ADHESION AND HEALING

Purpose: According to the National Ambulatory Medical Care Survey & American Academy of Orthopaedic Surgeons approximately 1 in 40 people in the USA fracture a bone each year. A rapid return to ambulation is not only desirable from a patient and caregiver perspective, but also immediate weight bearing following bone fracture is believed to promote faster healing and it shortens hospital stays. A variety of bone fillers and cements currently exist, but none of them are capable of gluing broken bones back together. Our goal is to create a technology that is not a filler but rather a biocompatible glue with adhesive properties found in nature. This technology will allow us to glue bones together or bones and surgical implants such as metal plates. Unlike current bone cements, we seek to develop a technology that does not require a high curing temperature or drying of surfaces prior to its application. Inspired by the underwater adhesive properties demonstrated by the glue proteins of aquatic mussels (mollusk bivalves), we are developing an adhesive substance with biomimetic properties capable of accelerated interosseous healing in an aqueous environment similar to that encountered during orthopedic surgical intervention. This would be achieved while still providing the strength and structure of current more invasive techniques. Methods: Similar to mussel glue proteins, we exploited catechol-like chemistries to achieve adhesion to wetted bone. To demonstrate proof-of-concept, a variety of free-flowing liquid prototype adhesives were applied to the ends of moist transversely sectioned long bones from chickens and sheep. These were then allowed to cure at room temperature with the application of minimal compression. Results: We are currently engaged in molecular tailoring of adhesive functionalities to optimize the molecular properties of our glues. Important parameters include adhesive strength and elastic modulus similar to bone. Conclusions: Through the application of our bioinspired bone adhesive, the healing process following various orthopedic injuries can be accelerated by significantly decreasing the time required before weight bearing and ambulation. This coat and stick technology can be delivered via a syringe or other minimally invasive device and thus has the potential to decrease post-surgical infection rates along with other common complications associated with open reduction with internal fixation procedures.