Early-stage bone regeneration of hyaluronic acid supplemented with porous 45s5 bioglass-derived granules: an injectable system

In the present study, an injectable bone substitute system which utilized porous bioglass (BG)-derived granules supplemented with hyaluronic acid (Hya), was evaluated. Hya plays ultimate role in wound healing, promoting cell motility. The BG were synthesized by a simple and low sintering temperature process without any foreign phase incorporation. Furthermore, the physical properties in the porous scaffold were optimized to investigate the in vitro and in vivo performance. The porous BG60 scaffolds system showed excellent bioactivity in an in vitro simulated body fluid test in which the ions dissolved from the composite materials influenced apatite growth, countered the acidic pH, and increased material degradation. In an in vitro study with pre-osteoblasts cells (MC3T3-E1), the porous scaffold supported cell adhesion and proliferation. A post-implantation study conducted in femoral defects showed implant degradation and surprisingly fast bone formation just after 2 weeks of implantation. Initial in vivo degradation of Hya promotes releasing ions which regulates the bone forming cells, clues to tissue repair, and regeneration. On the other hand it also prevent the scattering of BG granule after grafting at implant site. The faster dissolution of the porous BG scaffold increased the resorption of the composite material and hence, facilitated bone tissue regeneration. Our findings suggest that the porous BG scaffold could potentially be used as an injectable bone substitute for fast, early bone regeneration applications. (paper)