Garret Hisle

 Introduction: The process of bone repair and the healing of bone fractures caused by trauma or disease has a significant clinical relevance due to the limited effectiveness in current treatment options. Among the Osteoinductive growth factors used for bone tissue stimulation, bone morphogenetic proteins (BMPs) are the most widely studied (5). BMPs induce the process of bone healing by recruiting bone-forming cells to the lesion (5)(8)(9)(11). While although BMP biologics have limited approved use, extensive research has continued to push the boundaries for new applications and techniques. Methods: Several studies using animal models with different delivery mechanisms of BMPs were analyzed and compared. In the TMJ-OA explant treated mouse model, BMP-2 treatment was analyzed in its effects on matrix turnover in the condyle (1). In the Canine model BMP-2 was delivered to mandible defects via an injectable hydrogel system with sustained release of BMP-2 to induce vertical bone regeneration (4). In the study of posterior lateral spinal fusion in rabbits, new gene transfer approaches were studied using baculovirus as a vector to mediate gene/cell therapy to improve bone healing (3). Other systematic reviews and research articles with a focus on BMPs application to favor bone regeneration in bone fractures, non union, with adequate evidence were also analyzed. Results: It was shown in the TMJ-OA mice model that up regulation of both anabolic and catabolic genes occurred in both sets of mice treated with BMP-2, thus suggesting that BMP increases matrix turnover in the condyle and further more that Bgn and Fmod have protective roles in this process (1). In the Canine hydrogel delivery system model, significant bone generation at the implant site in the hydrogel treatment was shown, demonstrating the effectiveness of BMP-2 hydrogel system (4). In the rabbit mesenchymal stem cell model expressing Baculovirus-engineered BMP-2 showed a new feasible approach to the treatment model, and also showed the positive effects of BMP-2 in bone healing (3). Conclusion: Studies have shown that the application of BMPs for bone healing in the clinical setting has potential. Promising results in animals with varying delivery techniques only further demonstrate the utility of BMP-2 as an effective orthobiologic. However clinical evidence is still rather controversial due to varying results from several studies as well as the dangers of these growth factors having the capacity to produce ectopic ossification. Continued research is needed to better understand the true potential of more affective and safe approaches with using BMPs biologics.

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3. Fu, T.-S., Chang, Y.-H., Wong, C.-B., Wang, I.-C., Tsai, T.-T., Lai, P.-L., … Chen, W.-J. (2015). Mesenchymal stem cells expressing baculovirus-engineered BMP-2 and VEGF enhance posterolateral spine fusion in a rabbit model. The Spine Journal, 15(9), 2036–2044.
4. Seo, B.-B., Chang, H.-I., Choi, H., Koh, J.-T., Yun, K.-D., Lee, J.-Y., & Song, S.-C. (2017). New approach for vertical bone regeneration using in situ gelling and sustained BMP-2 releasing poly(phosphazene) hydrogel system on peri-implant site with critical defect in a canine model. Journal of Biomedical Materials Research Part B: Applied Biomaterials.
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