PTH 1-34-functionalized bioactive glass improves peri-implant bone repair in orchiectomized rats: Microscale and ultrastructural evaluation

• Autor(a) principal: Gomes-Ferreira, Pedro Henrique Silva [UNESP]
• Data de Publicação: 2022
• Outros Autores: Micheletti, Chiara, Frigério, Paula Buzo [UNESP], Batista, Fábio Roberto de Souza [UNESP], Monteiro, Naara Gabriela [UNESP], Bim-júnior, Odair [UNESP], Lisboa-Filho, Paulo Noronha [UNESP], Grandfield, Kathryn, Okamoto, Roberta [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.msec.2022.112688; http://hdl.handle.net/11449/240817
• topic: Bioactive glass; Bone regeneration; Dental implants; Local drug delivery; Osteoporosis; Parathyroid hormone

The objective of this work was to investigate the use of Biogran® functionalized with parathyroid hormone (PTH) 1–34 by sonochemistry for the local delivery of this anabolic agent to the implant site. The effects of Biogran® and topical administration of PTH 1–34 on peri-implant bone regeneration were evaluated from the microscale to ultrastructural levels in healthy (SHAM) and orchiectomized (ORQ). While some animals only received a titanium implant in their tibial metaphyses (CLOT group), in others the peri-implant defect was first filled with Biogran® either without or with PTH 1–34 functionalization (BG and BGPTH groups, respectively) prior to implant installation. Osseointegration was characterized from a biomechanical perspective by measuring the removal torque with the counter-torque technique. Micro-CT was used to evaluate the percentage of bone volume, trabecular thickness, number and separation, and bone-implant contact (BIC). Dynamics of new bone formation were assessed by measuring fluorochrome area, daily mineral apposition rate, and neoformed bone area using confocal laser microscopy. RT-PCR was performed to evaluate ALP and osteocalcin expression. The interface between newly formed bone and Biogran® was examined using scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) at the micro-and nanoscale, respectively, while elemental analyses were completed in SEM with energy-dispersive X-ray spectroscopy (EDS). STEM imaging demonstrated the intimate attachment of bone to Biogran® (nanoscale level). Overall, the results suggest that the effectiveness of the topical administration of PTH 1–34 at the implant site seems enhanced in osteoporotic bone, promoting peri-implant bone regeneration to comparable levels in healthy conditions.