In vitro differentiation and biocompatibility of mesenchymal stem cells on a novel platelet releasate‐containing injectable composite

Abstract

Underlying changes in subchondral and cancellous bone precede joint degeneration in spinal discs, knees, hips, and other joints. We hypothesize that an early bone remodeling intervention therapy may alleviate or postpone the later manifestation of joint failure. Utilization of a novel biomaterial for injection deliverability to the underlying subchondral and cancellous bone during the onset of osseous changes, before severe cartilaginous damage, is proposed. In this preliminary study, we introduced novel platelet releasate-containing alginate/calcium phosphate composites for this intervention therapy and evaluated them in vitro through mesenchymal stem cell biocompatibility and induction of osteochondral differentiation. DNA quantification and gene expression profiles suggested mesenchymal stem cells were directed along an osteochondral differentiation pathway, more specifically, to the immature nonhypertrophic chondrocyte phenotype. These conclusions were based on reduced mitogenic activity, a rapid upregulation followed by suppression of Runx2 transcription factor mRNA, sustained upregulation of Sox9 transcription factor mRNA and the absence of late marker expressions for both mature articular chondrocytes and osteoblasts over the course of 14 days. Initial findings in regard to the use of these materials for bone remodeling were positive and support the execution of future studies evaluating the inflammatory and angiogenic aspects of the materials. In this study, we have considered one of the many aspects of the endochondral ossification process; neovascularization and resorption of bone with an irregular physiology need to be evaluated.

Induction of the early inflammatory‐mediated cellular responses of fracture healing in vitro using platelet releasate‐containing alginate/CaPO4 biomaterials for early osteoarthritis prevention

“…This study and our prior work suggest that osteochondral differentiation, 8,9 inflammatorymediated responses associated with cellular driven tissue/ implant resorption, and osteo-and angiogenic growth factors are deliverable from the composite biomaterials. Our proposed implant system is modeled after natural and implant-assisted fracture healing and presents a bioresorbable osteoconductive scaffold after an initial, short-term delivery of growth factors.…”

“…Our proposed implant system is modeled after natural and implant-assisted fracture healing and presents a bioresorbable osteoconductive scaffold after an initial, short-term delivery of growth factors. This study and our prior work suggest that osteochondral differentiation, 8,9 inflammatorymediated responses associated with cellular driven tissue/ implant resorption, and osteo-and angiogenic growth factors are deliverable from the composite biomaterials. The included bioactive agents for these composites have been obtained through a blood processing protocol which is customary within the clinical setting, 10 allowing for a low-cost autologous source.…”

Human platelet releasates combined with polyglycolic acid scaffold promote chondrocyte differentiation and phenotypic maintenance

“…A possible justification to this behaviour can be found in the different content of growth factors and signalling proteins between FCS and PRPr supplementations. PRPr represents an invaluable non-expensive source of growth factors (McCanless et al 2012). Among these, PDGF isoforms have been demonstrated to upregulate chondrocytes proliferation and ECM production (Matsiko et al 2013), while TGF-β is thought to be of great relevance in maintaining nonhypertrophic chondrocyte phenotype by inducing the upregulation of sox9 (McCanless et al 2012).…”

“…PRPr represents an invaluable non-expensive source of growth factors (McCanless et al 2012). Among these, PDGF isoforms have been demonstrated to upregulate chondrocytes proliferation and ECM production (Matsiko et al 2013), while TGF-β is thought to be of great relevance in maintaining nonhypertrophic chondrocyte phenotype by inducing the upregulation of sox9 (McCanless et al 2012). In fact, throughout the experiment, in our cell model (5% PRPr) TGF-β is present at a concentration that is consistent with the one required in chondrocyte differentiation studies (5 ng/mL) and almost 5-fold higher than in control cultures (5% FCS).…”

Hematoma-inspired alginate/platelet releasate/CaPO4 composite: initiation of the inflammatory-mediated response associated with fracture repair in vitro and ex vivo injection delivery

“…The following work completes a series of in vitro experiments; prior investigations demonstrated biocompatibility and osteochondrogenic potential for the biocomposites using murine mesenchymal stem cells, angiogenic characteristics using human umbilical vein endothelial cells (HUVECs), and chemo/haptotactic abilities using HUVECs and an immortalized murine monocyte line (which, additionally, is used in the current study) [12][13][14]. While earlier findings are promising, neovascularization and activated immune cell-mediated resorption of damaged and irregular mineralized tissue and the bone graft substitute systems are also essential processes for osseous tissue rejuvenation.…”