Enriched mesoporous bioactive glass scaffolds as bone substitutes in critical diaphyseal bone defects in rabbits

Abstract

In the field of orthopedic surgery, there is an increasing need for the development of bone replacement materials for the treatment of bone defects. One of the main focuses of biomaterials engineering are ad- vanced bioceramics like mesoporous bioactive glasses (MBG´s). The present study compared the new bone formation after 12 weeks of implantation of MBG scaffolds with composition 82,5SiO2 –10CaO–5P2 O5 - x 2.5SrO alone (MBGA), enriched with osteostatin, an osteoinductive peptide, (MBGO) or enriched with bone marrow aspirate (MBGB) in a long bone critical defect in radius bone of adult New Zealand rab- bits. New bone formation from the MBG scaffold groups was compared to the gold standard defect filled with iliac crest autograft and to the unfilled defect. Radiographic follow-up was performed at 2, 6, and 12 weeks, and microCT and histologic examination were performed at 12 weeks. X-Ray study showed the highest bone formation scores in the group with the defect filled with autograft, followed by the MBGB group, in addition, the microCT study showed that bone within defect scores (BV/TV) were higher in the MBGO group. This difference could be explained by the higher density of newly formed bone in the os- teostatin enriched MBG scaffold group. Therefore, MBG scaffold alone and enriched with osteostatin or bone marrow aspirate increase bone formation compared to defect unfilled, being higher in the osteo- statin group. The present results showed the potential to treat critical bone defects by combining MBGs with osteogenic peptides such as osteostatin, with good prospects for translation into clinical practice.