DEVELOPMENT AND EVALUATION OF CELL-FREE BONE SUBSTITUTE FOR THE TREATMENT OF CRITICAL BONE LESIONS

BALAÑA , MARÍA EUGENIA; KOKUBU, SABRINA; KOKUBU, GABRIEL; MANDALUNIS, PATRICIA; HAGELIN, KARIN; MONTANER, ALEJANDRO; LEIROS, GUSTAVO JOSÉ

MAr del Plata

Congreso; LXVIII Reunión Anual SAIC; 2023

SAIC

Autologous or allogeneic bone grafts used in case of bone loss, provide osteogenic cells and factors but they have certain limitations.Metallic or ceramic implants provides mechanical support but showpoor integration. Therefore, it is crucial to develop bone substitutesbased on a biocompatible and osteogenic matrix. The aim of thisstudy was to generate a cell-free bone substitute using collagenmatrices (MCol) loaded with BMP-2, IMT-504 oligonucleotide, ora combination of both, to promote bone regeneration in critical lesions. Lesions of 6mm in diameter were created in Wistar rat calvaria and grafted with MCol combined with the following treatments:MCol+BMP-2, MCol+IMT-504, MCol+BMP-2+IMT-504. A matrix-only (Control) and an untreated lesion control (Control Abs) were alsoincluded. Previously we reported no differences among the groupsin radiographic studies 10 days after graft while all groups exhibiteda significant decrease in lesion size after 40 days. Only MCol-BMP2and the Control group showed better lesion closure than the absolute Control, whereas MCol+IMT-504 got worse wound closure compared to the Control. This effect was partially reversed by BMP-2 inthe MCol+BMP-2+IMT-504 group. In this work, histological studiesconducted 40 days after graft demonstrated that BMP-2 improvedosteoconductive and osteoinductive effects of collagen matrix. Notably, the presence of newly formed bone exhibited a continuousand more organized structure throughout the lesion compared to theControl Abs, which only showed new bone at the edges or comparedto the Control group, which displayed “islands” of new bone. Conversely, IMT-504 exhibited diminished efficacy for bone regenerationthan the Control Abs, potentially attributed to its anti-inflammatoryeffect upon topical application.