40 research outputs found
From nucleus pulposus mesenchymal stem cells towards neural differentiation: an interesting prospect
Regenerative medicine arouses great interest for the treatment of many neurological diseases. Since nucleus pulposus of the invertebral discs is a postembryonic vestige of the notochord, it has been hypothesized that mesenchymal stem cells (MSCs) isolated from nucleus pulposus (NP-MSCs) can more easily differentiate into neurons. In this study, MSCs from nucleus pulposus were successfully isolated and characterized. Then, neural differentiation was induced by using a medium consisted of DMEM/F12 supplemented with B27 and the growth factors FGF and EGF for 10 days. Immunocytochemistry, molecular studies, SEM and TEM microscopy analyses were performed. NP-MSCs exhibited the typical features of MSCs, revealing spindle-shape morphology, specific immunophenotype attributable to MSCs and the ability to differentiate in osteogenic and chondrogenic lineages. After neurodifferentiation induction, compared to NP-MSCs in only DMEM/F12, proliferation rate decreased and cells changed morphology acquiring an increased number of the so-called neural-like extensions. Neural progenitor marker NESTIN and mature neuronal marker ENOLASE-2 were up-regulated, while GFAP was not detected. Moreover, cells after differentiation were small rounded and fusiform, with tendency to organize in clumps; they had elongated extrusions containing oriented cytoskeletal elements, classifiable as microtubules and intermediate filaments, as visualized by SEM and TEM microscopy. Dense vesicles similar to lipid droplet were also observed. NP-MSCs in differentiation medium were able to form neurospheres. In conclusion, even if more analysis have to be done and the way to treat neurodegenerative disease with regenerative medicine is still long, NP-MSCs represent a promising resource
Periosteum derived stem cells for regenerative medicine proposals: boosting current knowledge
Periosteum is a thin fibrous layer that covers most bones. It resides in a dynamic mechanically loaded environment and provides a niche for pluripotent cells and a source for molecular factors that modulate cell behaviour. Elucidating periosteum regenerative potential has become a hot topic in orthopaedics. This review discusses the state of the art of osteochondral tissue engineering rested on periosteum derived progenitor cells (PDPCs) and suggests upcoming research directions. Periosteal cells isolation, characterization and migration in the site of injury, as well as their differentiation, are analysed. Moreover, the role of cell mechanosensing and its contribution to matrix organization, bone microarchitecture and bone stenght is examined. In this regard the role of periostin and its upregulation under mechanical stress in order to preserve PDPC survival and bone tissue integrity is contemplated. The review also summarized the role of the periosteum in the field of dentistry and maxillofacial reconstruction. The involvement of microRNAs in osteoblast differentiation and in endogenous tissue repair is explored as well. Finally the novel concept of a guided bone regeneration based on the use of periosteum itself as a smart material and the realization of constructs able to mimic the extracellular matrix features is talked out. Additionally, since periosteum can differentiate into insulin producing cells it could be a suitable source in allogenic transplantations. That innovative applications would take advantage from investigations aimed to assess PDPC immune privilege
Emerging Biomedical Applications of Nano-Chitins and Nano-Chitosans Obtained via Advanced Eco-Friendly Technologies from Marine Resources
The present review article is intended to direct attention to the technological advances made in the 2010–2014 quinquennium for the isolation and manufacture of nanofibrillar chitin and chitosan. Otherwise called nanocrystals or whiskers, n-chitin and n-chitosan are obtained either by mechanical chitin disassembly and fibrillation optionally assisted by sonication, or by e-spinning of solutions of polysaccharides often accompanied by poly(ethylene oxide) or poly(caprolactone). The biomedical areas where n-chitin may find applications include hemostasis and wound healing, regeneration of tissues such as joints and bones, cell culture, antimicrobial agents, and dermal protection. The biomedical applications of n-chitosan include epithelial tissue regeneration, bone and dental tissue regeneration, as well as protection against bacteria, fungi and viruses. It has been found that the nano size enhances the performances of chitins and chitosans in all cases considered, with no exceptions. Biotechnological approaches will boost the applications of the said safe, eco-friendly and benign nanomaterials not only in these fields, but also for biosensors and in targeted drug delivery areas
Smart scaffolds for osteoporosis treatment
Osteoporosis is a well known, worldwide spread disease with a rapidly growing incidence as the population ages; it results in bone loss and deterioration and in a decreased bone strength involving an increase in the risk of fractures. This disease has a very high frequency in people over 50 and it has been calculated that 1 in 5 men and 1 in 3 women over 50 will experience an osteoporotic fracture in their lifetime.
The main clinical consequences of this disease are bone fractures, which are associated with significant morbidity and mortality. Antiresorptive agents such as bisphosphonates are mainstays of the therapy for osteoporosis and currently four of these agents have received FDA approval for clinical treatment. The perfect solution to treat osteoporosis is still not within grasp and recently attention was drawn to the negative outcome of some drugs clinically used to treat osteoporosis. In the frame of the ERC-consolidator grant BOOST, a scaffold purposely developed for osteoporosis treatment will be developed.
In the present work, healthy and early osteoporotic bone geometries will be obtained from tomographic scans of human bone tissues discarded from surgery on healthy and early-stage osteoporotic patients. Smart scaffolds will be biofabricated by means of a purposely developed multimaterial platform which will combine different rapid prototyping techniques. To manufacture the scaffolds collagen will be used as a matrix and mesoporous bioactive glass as reinforcing and bioactive phase. The fabricated scaffolds will then be tested in suitable bioreactors by means of a co-culture of osteoblasts and osteoclasts in order to codify the influence of both chemical and topographical stimuli on the osteoblast-osteoclast coupling
Evidence Supporting a Paracrine Effect of IGF-1/VEGF on Human Mesenchymal Stromal Cell Commitment
Skeletal defect healing is strictly dependent on osteogenesis and efficient vascularization of engineered scaffolds. Insulin-like Growth Factor-1(IGF-1) and Vascular Endothelial Growth Factor (VEGF) are both involved in these processes. The in vitro administration of IGF-1 and VEGF association is able to modulate the osteoblastic or endothelial commitment of Mesenchymal Stromal Cells (MSCs) of different origin (e.g. periosteum and skin). In the present study, in order to deepen a possible paracrine effect of IGF-1 and VEGF on Periosteum Derived Progenitor Cells (PDPCs) and Skin-derived Mesenchymal Stromal Cells (S-MSCs) a transwell co-culture approach was used. We explored genes involved in endothelial and osteoblastic differentiation, those modulating mitogen-activated protein kinases (MAPK) and Phosphatidylinositol 3’-kinase (PI3K)-AKT signalling pathways as well as genes implicated in stemness (i.e. Sox2, Oct4 and Nanog). Periosteal cells, which are typically committed toward osteoblastogenesis, are driven in the direction of endothelial gene expression when influenced by S-MSCs. The latter, once influenced by PDPCs, lose their endothelial commitment and increase the expression of osteoblast associated genes. PI3K/AKT and MAPK signalling pathways seem to be markedly involved in this behaviour. Our results evidence that paracrine signals between MSCs may differently modulate their commitment in a bone microenvironment, opening stimulating viewpoints for skeletal tissue engineering strategies coupling angiogenesis and osteogenesis processes
TOTAL KNEE PROSTHESE POLYETHYLENE WEAR REDUCTION BY A NEW METAL PART FINISHING METHOD
Purpose: The purpose of this study was to evaluate a new metal component finishing designed to improve total knee prosthesis durability. Wear of ultrahigh molecular-weight polyethylene (UHMWPE), with generation of submicrometer- and micrometer-sized particles, has been associated with osteolysis and artificial joint failure. Wear extent is influenced by several factors, some of which are related to manufacturing.
Methods: UHMWPE wear was assessed in metal prosthesis components finished with the Microloy® technology and in traditionally finished components by wear simulation experiments (pin on disk and knee simulator tests) and analysis of wear debris.
Results: Microloy®-finished prosthesis showed a 48,5% reduction in UHMWPE total weight loss compared with traditional components (P=0.002). A significant (p<0.05) reduction of UHMWPE debris were detected from the Microloy®-finished compared with the traditional-finished components.
Conclusions: These findings suggest the Microloy® metal finishing may enhance the long-term performance of knee prostheses