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Bone reconstruction in the oral and maxillofacial region presents particular challenges related to the development of biomaterials with osteoinductive properties and suitable physical characteristics for their surgical use in irregular bony defects. In this work, the preparation and bioactivity of chitosan-gelatin (ChG) hydrogel beads loaded with either bioactive glass nanoparticles (nBG) or mesoporous bioactive glass nanospheres (nMBG) were studied. In vitro testing of the bionanocomposite beads was carried out in simulated body fluid, and through viability and osteogenic differentiation assays using dental pulp stem cells (DPSCs). In vivo bone regenerative properties of the biomaterials were assessed using a rat femoral defect model and compared with a traditional maxillary allograft (Puros®). ChG hydrogel beads containing homogeneously distributed BG nanoparticles promoted rapid bone-like apatite mineralization and induced the osteogenic differentiation of DPSCs in vitro . The bionanocomposite beads loaded with either nBG or nMBG also produced a greater bone tissue formation in vivo as compared to Puros® after 8 weeks of implantation. The osteoinductivity capacity of the bionanocomposite hydrogel beads coupled with their physical properties make them promissory for the reconstruction of irregular and less accessible maxillary bone defects., (© 2021 IOP Publishing Ltd.)

Bionanocomposite scaffolds based on aliphatic polyurethane (PU) and bioactive glass nanoparticles were produced by using a one-step in situ polymerization method. Bioactive glass nanoparticles (nBG) or mesoporous BG nanospheres (nMBG) were incorporated during the polymerization reaction to produce simultaneous formation and foaming of porous nanocomposite scaffolds. The in vitro bioactivity of the scaffolds was assessed in simulated body fluid (SBF), and through cytocompatibility and osteogenic differentiation assays with stem cells. Bone regeneration properties of the scaffold materials were in vivo assessed by using a critical-sized femoral defect model in rat. The scaffold nanocomposites showed excellent cytocompatibility and ability to accelerate the crystallization of bone-like apatite in vitro. nBG/PU bionanocomposite scaffold exhibited the higher capacity to stimulate osteogenic cell differentiation as judged by an increased ALP activity and the presence of mineralized nodules associated with the stem cells. nBG (5%)/PU scaffold significantly also produces in vivo a denser and more significant amount of new bone after 8 weeks of implantation, which is attributed to the more rapid dissolution rate of nBG into osteogenic ionic products compared to nMBG. The results of this work show that the in situ polymerization method combined with the use of nanodimensional BG particles enable the production of PU - based scaffolds with enhanced bioactive properties to stimulate the bone tissue regeneration., (Copyright © 2018 Elsevier B.V. All rights reserved.)