[Bone transplantation or biomaterials? : An analysis of 99,863 surgical procedures in orthopedic and trauma surgery in Germany from 2018]

Hydrogel Use in Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is a vascular disease of unknown etiology and can be categorized mainly into two types: non-traumatic and traumatic ONFH. Thus, understanding osteogenic-angiogenic coupling is of prime importance in finding a solution for the treatment of ONFH. Hydrogels are biomaterials that are similar to the extracellular matrix (ECM). As they are able to mimic real tissue, they meet one of the most important rules in tissue engineering. In ONFH studies, hydrogels have recently become popular because of their ability to retain water and their adjustable properties, injectability, and mimicry of natural ECM. Because bone regeneration and graft materials are very broad areas of research and ONFH is a complex situation including bone and vascular systems, and there is no settled treatment strategy for ONFH worldwide, in this review paper, we followed a top-down approach by reviewing (1) bone and bone grafting, (2) hydrogels, (3) vascular systems, and (4) ONFH and hydrogel use in ONFH with studies in the literature which show promising results in limited clinical studies. The aim of this review paper is to provide the reader with general information on every aspect of ONFH and to focus on the hydrogel used in ONFH.

Injectable Photo-Crosslinked Bioactive BMSCs-BMP2-GelMA Scaffolds for Bone Defect Repair

Injectable hydrogels offer a new therapy option for irregular bone deformities. Based on gelatin methacryloyl (GelMA), bone marrow mesenchymal stem cells (BMSCs), and bone morphogenetic protein 2 (BMP2), we created a photo-crosslinked composite bioactive scaffold. The composite scaffolds had appropriate mechanical properties for stem cells adhesion and proliferation, as well as good biocompatibility and the ability to stimulate BMSCs osteogenic differentiation in vitro. The synergistic effect of BMSCs and BMP2 enabled the composite bioactive scaffold to exhibit higher osteogenic potential in vivo than scaffolds loaded alone with BMSCs or BMP2, according to imaging and histology studies. In conclusion, by promoting the osteogenic differentiation of BMSCs, the composite bioactive scaffold based on BMSCs-BMP2-GelMA has demonstrated remarkable application potential in bone regeneration and bone defects repair.