Abstract
Bone graft substitutes and bone void fillers are predominantly used to treat bone defects and bone fusion in orthopaedic surgery. Some aragonite-based scaffolds of coralline exoskeleton origin exhibit osteoconductive properties and are described as useful bone repair scaffolds. The purpose of this study was to evaluate the in vitro osteogenic potential of the bone phase of a novel aragonite-based bi-phasic osteochondral scaffold (Agili-C™, CartiHeal Ltd.) using adult human bone marrow-derived mesenchymal stem cells (MSCs). Analyses were performed at several time intervals: 3, 7, 14, 21, 28 and 42 days post-seeding. Osteogenic differentiation was assessed by morphological characterisation using light microscopy after Alizarin red and von Kossa staining, and scanning electron microscopy. The transcript levels of alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), bone gamma-carboxyglutamate (BGLAP), osteonectin (SPARC) and osteopontin (SPP1) were determined by quantitative PCR. Proliferation was assessed by a thymidine incorporation assay and proliferating cell nuclear antigen (PCNA) immunocytochemistry. Our results demonstrate that the bone phase of the bi-phasic aragonite-based scaffold supports osteogenic differentiation and enhanced proliferation of bone marrow-derived MSCs at both the molecular and histological levels. The scaffold was colonized by differentiating MSCs, suggesting its suitability for incorporation into bone voids to accelerate bone healing, remodelling and regeneration. The mechanism of osteogenic differentiation involves scaffold surface modification with de novo production of calcium phosphate deposits, as revealed by energy dispersive spectroscopy (EDS) analyses. This novel coral-based scaffold may promote the rapid formation of high quality bone during the repair of osteochondral lesions.
Highlights
The repair of joint lesions requires the reconstruction of both subchondral bone and articular cartilage
Bone-like nanocomposite scaffolds made of sericin and hydroxyapatite crystals promote the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (BM-MSCs) (Yang et al, 2015a,b)
Cells cultured in growth medium maintained the expression of cell surface markers characteristic to human mesenchymal stem cell (hMSC); they were found to be positive for CD90, CD73, CD105, CD146, CD47 and CD29; and negative for CD45, CD117 and CD34 (Dominici et al, 2006) (Fig. 2)
Summary
The repair of joint lesions requires the reconstruction of both subchondral bone and articular cartilage. The optimal osteogenic scaffold should allow bone repair in damaged areas by means of migration, proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) into the graft (Ciocca et al, 2015). Bone-like nanocomposite scaffolds made of sericin (a silk worm-protein) and hydroxyapatite crystals promote the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (BM-MSCs) (Yang et al, 2015a,b). Biomineralized hydroxyapatite small intestinal submucosa scaffolds were found to promote the osteogenic differentiation of MSCs in basal media without osteogenic supplements due to the presence of hydroxyapatite crystals in the scaffolds (Yang et al, 2015a,b). To facilitate scaffold vascularisation and incorporation, a novel strategy involving a “smart matrix” composed of three key components (RGD-phage; porous bone-like biphasic calcium phosphate scaffold and MSCs) has been developed. Due to the presence of the RGD-phage nanofibres, the novel matrix can regulate endothelial cell migration and adhesion to induce vascularisation and simultaneously activate osteoblastic differentiation of MSCs, and induce both osteogenesis and angiogenesis in vivo (Wang et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
