Role of Combination of Bioceramics and FGF 18 on Craniofacial Bone Regeneration using an Injectable Chitin PLGA Gel

Abstract

Craniofacial bone regeneration following trauma, infection, and tumorectomy remains a formidable challenge in the clinical scenario. The current treatment mainly involves autologous transplantation, which is considered as the gold standard for bone regeneration. However, limited availability, donor-site morbidity, contour irregularities etc. are the bottlenecks in this approach, necessitating the clinicians and researchers to explore alternative treatment methods. Synthetic bone grafts such as calcium sulfate (CS) and hydroxyapatite (HAP) are widely used in clinics because of their biocompatibility and osteoconductivity. However, their limited osteogenic potential and inability to induce angiogenesis are the major limitations in using them for large craniofacial defects. Because of all these attributes, they show a moderate effect on the development of new bone tissue. newlineThe major inorganic component of bone is hydroxyapatite, which is not homogenous. Bone incorporates various trace elements (Mg2+, Si4+, Na+, Zn2+, etc.) that play an important role in the formation, growth and repair of bone. Among various trace elements, Si4+ and Mg2+ ions enhance both osteogenesis and angiogenesis. Among the Mg2+ incorporated bioceramics, whitlockite was promising material as it is the second most abundant inorganic component in bone (occupying up to 25%). With Si4+ incorporated bioceramics, bioglass was selected as it was also found to be a promising candidate. Further, considering the critical-sized defects in the craniofacial region (CFR), besides bioceramics, growth factors would augment bone regeneration. Bone morphogenetic protein-2 (BMP-2) is an osteoinductive molecule and has been approved to be used in the sinus wall and alveolar ridge augmentation in the CFR. However, the evidence doesn t support the usage of BMP-2 in maxillary sinus wall augmentation, calvarial reconstruction, or mandibular reconstruction. Alternatively, fibroblast growth factor-18 (FGF-18), a potent BMP-2 signalling molecule, is found to direct ..