Up to now, the gingiva-derived mesenchymal stem cells (GMSCs) as a new postnatal stem cells have been isolated and characterized with multipotential differentiation capabilities in vitro. However, the in vivo efficacy of utilizing the GMSCs in bone regeneration remains obscure. First of all, we identified canonical MSCs in human gingival tissue, which possessed homogenous immunophenotype (CD34(-)CD45(-)CD29(+)CD105(+)CD90(+) STRO-1(+)) and had tri-lineage differentiation potential (osteoblasts, adipocytes, and chondrocytes). Next, we examined the efficacy of utilizing these stem cells in bone tissue regeneration; the enhanced green fluorescent protein-labeled GMSCs seeded on type I collagen gel were implanted into the mandibular defects as well as the critical-sized calvarial defects in Sprague Dawley rats. We first demonstrated that GMSCs could repair the mandibular wounds and calvarial defects at 2 months in rats postsurgical reconstruction. Histomorphological analysis and image of fluorescence microscope certified that new bone in the defect areas was derived from the transplanted GMSCs. Immunohistochemical analysis of green fluorescent protein, human collagen I, and osteopontin further confirmed our conclusion. The above results implied that mesenchymal stem cells derived from gingival tissue could be a novel source for stem cell-based therapy in bone reconstruction in clinical applications.

Background: A nanohydroxyapatite-coated chitosan scaffold has been developed in recent years, but the effect of this composite scaffold on the viability and differentiation of periodontal ligament stem cells (PDLSCs) and bone repair is still unknown. This study explored the behavior of PDLSCs on a new nanohydroxyapatite-coated genipin-chitosan conjunction scaffold (HGCCS) in vitro as compared with an uncoated genipin-chitosan framework, and evaluated the effect of PDLSC-seeded HGCCS on bone repair in vivo. Methods: Human PDLSCs were cultured and identified, seeded on a HGCCS and on a genipinchitosan framework, and assessed by scanning electron microscopy, confocal laser scanning microscopy, MTT, alkaline phosphatase activity, and quantitative real-time polymerase chain reaction at different time intervals. Moreover, PDLSC-seeded scaffolds were used in a rat calvarial defect model, and new bone formation was assessed by hematoxylin and eosin staining at 12 weeks postoperatively. Results: PDLSCs were clonogenic and positive for STRO-1. They had the capacity to undergo osteogenic and adipogenic differentiation in vitro. When seeded on HGCCS, PDLSCs exhibited significantly greater viability, alkaline phosphatase activity, and upregulated the bone-related markers, bone sialoprotein, osteopontin, and osteocalcin to a greater extent compared with PDLSCs seeded on the genipin-chitosan framework. The use of PDLSC-seeded HGCCS promoted calvarial bone repair. Conclusion: This study demonstrates the potential of HGCCS combined with PDLSCs as a promising tool for bone regeneration.

Stem cells, such as adult stem cells or embryonic stem cells, are the most important seed cells employed in tooth tissue engineering. Even though dental-derived stem cells are a good source of seed cells for such procedures, they are not often used in clinical applications because of the limited supply. Induced pluripotent stem (iPS) cells, with their high proliferation and differentiation ability, are now considered a promising alternative. The objectives of this study were to assess the role of iPS cells in tooth tissue engineering. We used real-time polymerase chain reaction to confirm that mouse iPS (miPS) cells can be induced to express both odontogenic and osteogenic gene profiles. We then established a tooth germ model and transplanted the recombinant tooth germ into a mouse subrenal capsule for 4 weeks to reproduce early-tooth organogenesis. After 4 weeks, hematoxylin and eosin staining results showed newly formed bone-like and dental pulp-like areas. Further immunohistochemical staining confirmed that osteopontin was present in the apical part of the tooth-like structure. These results demonstrate that miPS cells have the potential to differentiate into odontogenic cells, confirming that they could be a new source of seed cells for use in tooth tissue engineering.

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A binary nanoporous‐SixSb alloy is prepared successfully as electrode for lithium‐ion batteries (LIBs) by a one‐step chemical dealloying method. The sample morphology can be controlled by adjusting the content of Al and the molar ratio of Si and Sb in the alloy precursors. Structural and morphological characterizations reveal the presence of uniformly‐distributed nanopores which can effectively accommodate the volume change and provide massive diffusion channels for Li‐ions during charging/discharging. Electrochemical experiments show that the nanoporous Si15Sb15 (np‐Si15Sb15) anode can deliver excellent performance with a specific capacity of 647.40 mAh g−1 after 90 cycles at a current density of 100 mA g−1. This simple approach may be further extended to the design of novel nanoporous materials, providing a guideline for mass production of high‐performance electrochemical energy storage devices.

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Fe78Si9B13 amorphous particles with high saturation magnetization, low remanence and low coercivity are applied in preparing magnetorheological fluids.