An Evaluation of Novel AMP2-Coated Electrospun Composite Scaffolds for Intraoral Bone Regeneration: A Proof-of-Concept In Vivo Study

Blaire V. Slavin ¹ Shangtao Wu ¹ Savanah R. Sturm ¹ Kevin K. Hwang ¹ Ricky Almada ² Nicholas A. Mirsky ¹ Vasudev Vivekanand Nayak ² Lukasz Witek ^3,4,5* Paulo G. Coelho ^2,6

• ¹ Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, United States
• ² Department of Biochemistry and Molecular Biology, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, United States
• ³ College of Dentistry, New York University, New York, United States
• ⁴ Department of Plastic Surgery, Grossman School of Medicine, New York University, New York City, New York, United States
• ⁵ Department of Biomedical Engineering, Tandon School of Engineering, New York University, Brooklyn, New York, United States
• ⁶ Division of Plastic Surgery, DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, United States

Background: Alveolar ridge preservation by guided bone regeneration (GBR) is a surgical procedure that can be performed prior to implant placement to increase the likelihood of survival. Autogeneic, allogeneic, or xenogeneic derived bone are frequently placed in conjunction with a barrier membrane for GBR; however, advancements in tissue engineering have led to the development ofpromising synthetic alternatives. This study aimed to evaluate the in vivo performance of a novel electrospun composite scaffold coated in a recombinant variant of human bone morphogenetic protein-2 (OsteoAdapt) relative to a porcine derived xenograft regularly utilized in clinical practice. Methods: Four-walled mandibular defects were created in each adult beagle dog (n=4 defects perdog; n=4 dogs). Each defect received one of three experimental (test) groups: (i) OsteoAdapt without membrane (OA), (ii) OsteoAdapt with porcine membrane (OA/ZM), (iii) OsteoAdapt mixed with porcine particulate xenograft (Zcore™) with porcine membrane (OA/P/ZM) and compared to a positive control -Zcore™ with porcine membrane (CTRL). After 4-weeks in vivo, bone regeneration was assessed through qualitative volumetric reconstruction, qualitative and quantitative histomorphologic analyses. Results: Histomorphometric analysis at 4-weeks in vivo revealed percent regenerated bone (33.26% ± 15.98 [OA], 28.64% ± 13.48 [OA/ZM], 20.11% ± 3.35 [OA/P/ZM], 18.18% ± 8.88 [CTRL]) or soft tissue presence (66.74% ± 15.98 [OA], 71.36% ± 13.48 [OA/ZM],75.00% ± 2.58 [OA/P/ZM], 74.69 ± 9.11 [CTRL] within defects, with no significant differences between groups. Qualitative analysis of the histological micrographs demonstrated advanced bone healing in defects treated with OA relative to the CTRL. Bone overgrowth beyond the limits of defect borders was observed in groups treated with OA and a barrier membrane, namely OA/ZM and OA/P/ZM. In contrast to the treatment groups, minimal woven bone was visualized in the CTRL group. Conclusion: In contrast to defects treated with porcine-derived particulate and barrier membrane, defects filled with OA exhibited bone regeneration throughout the defect, with bone overgrowth when covered by a barrier membrane at 4weeks in vivo. This suggests that the novel combination of AMP-2 and a bioceramic/synthetic polymer based electrospun scaffold is suitable candidate for GBR procedures, without a barrier membrane to secure its place within a defect.