Bioactive Glass-Inspired Coating for Implants via Plasma Electrolytic Oxidation: A Preclinical Approach to Enhance Bone Repair in Healing-Impaired Conditions Associated with Diabetes.
Stéfany Barbosa Alves da Cruz, Raphael Cavalcante Costa, Francieli da Silva Flores, Maria Helena R Borges, Doris Hissako Matsushita, Martinna Bertolini, Nilson Cristino da Cruz, João Gabriel S Souza, Edilson Ervolino, Valentim A R Barão, Leonardo P Faverani
Abstract
Open AccessDiabetes mellitus is a globally prevalent metabolic disorder that impairs wound healing and bone regeneration, compromising outcomes in implant therapies that rely on osseointegration. Advances in precision medicine and bioengineering have driven the development of functionalized implant surfaces to overcome these limitations. Among them, bioactive glass (BG) coatings have emerged as promising candidates to enhance biological responses. Building upon this rationale, we unveiled the osteoinductive potential of a BG-based coating synthesized via plasma electrolytic oxidation (PEO) and its effects on peri-implant bone regeneration in a diabetic rat model. Titanium implants were treated with PEO using a formulation mimicking BG composition (∼45.0 Si, 24.5 Ca, 24.5 Na, 6.0 P; m/v %), and the resulting coating was characterized. Implants with a sandblasted and acid-etched (SLA) surface served as the control. In vivo evaluation was conducted in Wistar rats with streptozotocin-induced diabetes mellitus, followed by tibial implant placement. At 14 and 28 days postimplantation, samples were harvested for histological, immunohistochemical, micro-CT, and histomorphometric analyses. Physicochemical characterization confirmed the synthesis of the PEO-BG coating, which exhibited enhanced surface roughness and wettability compared to SLA controls. A significantly greater area of newly formed bone, increased bone-implant contact, and favorable bone turnover were noted in the PEO-BG group. The expression profiles of BMP-2, RANKL, OPG, and OCN indicated modulation of osteogenic and inflammatory pathways consistent with accelerated bone repair. These findings demonstrate that PEO-BG coating confers robust osteoinductive potential, enhancing peri-implant bone regeneration under compromised diabetic conditions, and highlight its potential for translational application in high-risk populations.