(626c) Dual Growth Factor Delivery for Craniomaxillofacial Bone Repair Using Layer-By-Layer Technology

Osteogenic (BMP-2) and angiogenic growth factors (PDGF and VEGF) delivered locally from synthetic implants have been shown to improve healing outcomes in craniomaxillofacial bone defects in vivo by modulating bone and blood vessel growth at the defect site. Layer-by-layer (LBL) technology has been demonstrated to incorporate these growth factors at an unusually high weight percent into ultrathin coatings on the surfaces of defect-relevant implant scaffolds. These films can be engineered to deliver multiple proteins with tunable release kinetics and sequences by careful selection of polymeric carriers in the LBL film and film assembly conditions. Specifically, engineering through manipulation of polymer degradation rate, extent of interlayer diffusion, and rate of water penetration into the film can be used to tune the release kinetics of these potent growth factors to deliver physiologically-relevant doses over predetermined periods of time, reducing the risk of growth factor-associated side effects. However, it is still unclear as to the optimal combination, sequence, and delivery window of these growth factors for craniomaxillofacial defect repair. This project aims to leverage LBL technology to answer these questions by carefully tuning delivery rates of one or multiple growth factors and comparing therapeutic efficacy in an in vivo rat calvarial defect model. Results from a pilot study demonstrate ability to track in vivo release kinetics as well as promising bone growth in a BMP-2-eluting LBL-coated scaffold, compared to an uncoated scaffold.