Mesoporous bioactive glass/e-polycaprolactone scaffolds promote bone regeneration in osteoporotic sheep

TL;DR

This study demonstrates that mesoporous bioactive glass and PCL scaffolds significantly promote bone regeneration in osteoporotic sheep, with enhanced vascularization and cellular activity, and explores the effects of zoledronic acid incorporation.

Contribution

The paper introduces a novel robocasted scaffold combining mesoporous bioactive glass and PCL that effectively promotes bone regeneration in osteoporotic models and examines drug release effects.

Findings

Scaffolds promote new bone formation and vascularization.

Zoledronic acid-loaded scaffolds inhibit osteoclast differentiation.

Zoledronic acid induces inflammation and impairs bone healing.

Abstract

Macroporous scaffolds made of a SiO2-CaO-P2O5 mesoporous bioactive glass (MBG) and epolycaprolactone (PCL) have been prepared by robocasting. These scaffolds showed an excellent in vitro biocompatibility in contact with osteoblast like cells (Saos 2) and osteoclasts derived from RAW 264.7 macrophages. In vivo studies were carried out by implantation into cavitary defects drilled in osteoporotic sheep. The scaffolds evidenced excellent bone regeneration properties, promoting new bone formation at both the peripheral and the inner parts of the scaffolds, thick trabeculae, high vascularization and high presence of osteoblasts and osteoclasts. In order to evaluate the effects of the local release of an antiosteoporotic drug, 1% (%wt) of zoledronic acid was incorporated to the scaffolds. The scaffolds loaded with zoledronic acid induced apoptosis in Saos 2 cells, impeded osteoclast differentiation in a time dependent manner and inhibited bone healing, promoting an intense inflammatory response in osteoporotic sheep.