Improved physical and osteoinductive properties of demineralized bone matrix by gelatin methacryloyl formulation

Abstract

The demineralized bone matrix (DBM) is the most widely used bone allograft, which is obtained by removing the mineral component of bone, leading to exposure of the proteins responsible for osteoinduction. For clinical use, DBM shall be formulated with a carrier that provides consistency and improves its osteoinduction. In this study, three DBM formulations with glycerol (Gly), hyaluronic acid (HA), and gelatin methacryloyl (GelMA) were evaluated measuring their physicochemical properties (microstructure, compressive strength, and serum cohesivity) and their osteoinductive capacity both in vitro using C2C12 cells and umbilical cord human mesenchymal stem cells and in vivo in an ectopic bone formation model in athymic mice. To assess the effectiveness of DBM in vitro in inducing the differentiation into osteoblasts, alkaline phosphatase (ALP) activity was assessed in combination with a cytotoxicity assay. In vivo, new bone formation was assessed by histological and radiological analysis. In the compression and in the serum cohesive assays, the GelMA DBM formulation showed its superiority over the other formulations. In addition, GelMA showed a more compact structure analysed by scanning electron microscopy. Higher cell toxicity was observed on Gly formulations in vitro, whereas GelMa and HA showed very low toxicity. All formulations significantly improved ALP activity compared with control. In the in vivo studies, GelMA showed the greatest osteoinductive potential with a higher percentage of new bone and bone marrow formation. Our results suggest GelMA is useful as a carrier for DBM designed to promote the formation of the new bone.

Biomedical application of photo-crosslinked gelatin hydrogels

“…GelMA/DBM C2C12 It shows higher cell toxicity,low toxicity,greatest osteoinductive potential with a higher percentage of new bone and bone marrow formation. [93] GelMA microspheres BMSCs This kind of microspheres can maintain the vitality of stem cells, promote cell proliferation, enhance osteogenesis and mineralization.…”

3D printed hybrid bone constructs of PCL and dental pulp stem cells loaded GelMA

“…GelMA hydrogel has also been used widely in osteochondral applications since it induces osteogenic differentiation and calcium deposition in vitro and enhances endochondral bone formation in vivo. 36‐40 The rheological properties of GelMA can be adjusted to 3D bioprinting applications by modifying the methacrylation and reaction conditions 41‐44 …”

“…34,35 GelMA hydrogel has also been used widely in osteochondral applications since it induces osteogenic differentiation and calcium deposition in vitro and enhances endochondral bone formation in vivo. [36][37][38][39][40] The rheological properties of GelMA can be adjusted to 3D bioprinting applications by modifying the methacrylation and reaction conditions. [41][42][43][44] Structural stability and high mechanical strength of 3D constructs required for bone tissue have generally been provided by synthetic polymers such as poly(lactic acid) (PLA), poly(glycolic acid) (PGA), and their random copolymers poly(lactic acid-co-glycolic acid) (PLGA), 45 poly(propylene fumarate) (PPF), 46 and poly(ε-caprolactone) (PCL).…”