Evaluation of the cytotoxic effects of sodium hypochlorite on human dental stem cells

Purpose: To investigate the influence of sodium hypochlorite (NaOCl) on human dental stem cell proliferation and differentiation.Method: Dental pulp stem cells (DPSCs), periodontal ligament stem cell (PDLSCs), and gingival mesenchymal stem cells (GMSCs) were treated with NaOCl. Cell viability was evaluated with cellular counting kit-8 (CCK8), and cellular adenosine triphosphate (ATP) levels were analyzed by bromodeoxyuridine (BrdU) incorporation and subsequent flow cytometry. Quantitative polymerase chain reaction (qPCR) and western blotting were performed to detect the expressions of differentiation markers.Results: The viability and ATP levels of all three stem cells types were impaired by NaOCl in a concentration- and time-dependent manners. However, the decrease ATP in GMSCs was less than the other two stem cell population (p < 0.05). NaOCl treatment significantly suppressed the proliferation of dental stem cells (p < 0.05). With regard to differentiation marker expression levels, the decrease in Stro-1 was greater in treatment groups when compared to control on Day 7, while increase in levels of dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), and osteocalcin (OC) was smaller (p < 0.05). The expressional changes of Stro-1, DSPP, BSP, and OC were more prominent in DPSMs and PDLSCs than in GMSCs.Conclusion: NaOCl dose-dependently impairs the viability, proliferation and differentiation of dental stem cells. Thus, its toxicity to dental stem cells needs to be considered in clinical application.Keywords: Dental stem cells, Sodium hypochlorite, Viability, Proliferation, Differentiatio

Biocompatibility and Toxicity of Nanoparticles and Nanotubes

In recent years, nanoparticles (NPs) have increasingly found practical applications in technology, research, and medicine. The small particle size coupled with their unique chemical and physical properties is thought to underline their exploitable biomedical activities. Its form may be latex body, polymer, ceramic particle, metal particles, and the carbon particles. Due to their small size and physical resemblance to physiological molecules such as proteins, NPs possess the capacity to revolutionise medical imaging, diagnostics, therapeutics, as well as carry out functional biological processes. But these features may also underline their toxicity. Indeed, a detailed assessment of the factors that influence the biocompatibility and toxicity of NPs is crucial for the safe and sustainable development of the emerging NPs. Due to the unique structure, size, and shape, much effort has been dedicated to analyzing biomedical applications of nanotubes.This paper focuses on the current understanding of the biocompatibility and toxicity of NPs with an emphasis on nanotubes

Conservation and diversification of the miR166 family in soybean and potential roles of newly identified miR166s

Identity between pre-miR166s in soybean. (TIF 5906 kb

Implantation of neural stem cells embedded in hyaluronic acid and collagen composite conduit promotes regeneration in a rabbit facial nerve injury model

The implantation of neural stem cells (NSCs) in artificial scaffolds for peripheral nerve injuries draws much attention. NSCs were ex-vivo expanded in hyaluronic acid (HA)-collagen composite with neurotrophin-3, and BrdU-labeled NSCs conduit was implanted onto the ends of the transected facial nerve of rabbits. Electromyography demonstrated a progressive decrease of current threshold and increase of voltage amplitude in de-innervated rabbits after implantation for one, four, eight and 12 weeks compared to readouts derived from animals prior to nerve transection. The most remarkable improvement, observed using Electrophysiology, was of de-innervated rabbits implanted with NSCs conduit as opposed to de-innervated counterparts with and without the implantation of HA-collagen, NSCs and HA-collagen, and HA-collagen and neurotrophin-3. Histological examination displayed no nerve fiber in tissue sections of de-innervated rabbits. The arrangement and S-100 immunoreactivity of nerve fibers in the tissue sections of normal rabbits and injured rabbits after implantation of NSCs scaffold for 12 weeks were similar, whereas disorderly arranged minifascicles of various sizes were noted in the other three arms. BrdU+ cells were detected at 12 weeks post-implantation. Data suggested that NSCs embedded in HA-collagen biomaterial could facilitate re-innervations of damaged facial nerve and the artificial conduit of NSCs might offer a potential treatment modality to peripheral nerve injuries

Sponge spicules as blueprints for the biofabrication of inorganic–organic composites and biomaterials

While most forms of multicellular life have developed a calcium-based skeleton, a few specialized organisms complement their body plan with silica. However, of all recent animals, only sponges (phylum Porifera) are able to polymerize silica enzymatically mediated in order to generate massive siliceous skeletal elements (spicules) during a unique reaction, at ambient temperature and pressure. During this biomineralization process (i.e., biosilicification) hydrated, amorphous silica is deposited within highly specialized sponge cells, ultimately resulting in structures that range in size from micrometers to meters. Spicules lend structural stability to the sponge body, deter predators, and transmit light similar to optic fibers. This peculiar phenomenon has been comprehensively studied in recent years and in several approaches, the molecular background was explored to create tools that might be employed for novel bioinspired biotechnological and biomedical applications. Thus, it was discovered that spiculogenesis is mediated by the enzyme silicatein and starts intracellularly. The resulting silica nanoparticles fuse and subsequently form concentric lamellar layers around a central protein filament, consisting of silicatein and the scaffold protein silintaphin-1. Once the growing spicule is extruded into the extracellular space, it obtains final size and shape. Again, this process is mediated by silicatein and silintaphin-1, in combination with other molecules such as galectin and collagen. The molecular toolbox generated so far allows the fabrication of novel micro- and nanostructured composites, contributing to the economical and sustainable synthesis of biomaterials with unique characteristics. In this context, first bioinspired approaches implement recombinant silicatein and silintaphin-1 for applications in the field of biomedicine (biosilica-mediated regeneration of tooth and bone defects) or micro-optics (in vitro synthesis of light waveguides) with promising results

Measurement of the cross section of e+e−→Ξ−Ξˉ+e^+e^-\rightarrow\Xi^{-}\bar\Xi^{+} at center-of-mass energies between 3.510 and 4.843 GeV

Using $e^+e^-$ collision data corresponding to a total integrated luminosity of 12.9 $fb^{-1}$ collected with the BESIII detector at the BEPCII collider, the exclusive Born cross sections and the effective form factors of the reaction $e^+e^-\rightarrow\Xi^{-}\bar\Xi^{+}$ are measured via the single baryon-tag method at 23 center-of-mass energies between 3.510 and 4.843 GeV. Evidence for the decay $\psi(3770)\rightarrow\Xi^{-}\bar\Xi^{+}$ is observed with a significance of 4.5$\sigma$ by analyzing the measured cross sections together with earlier BESIII results. For the other charmonium(-like) states $\psi(4040)$, $\psi(4160)$, $Y(4230)$, $Y(4360)$, $\psi(4415)$, and $Y(4660)$, no significant signal of their decay to $\Xi^-\bar \Xi^+$ is found. For these states, upper limits of the products of the branching fraction and the electronic partial width at the 90% confidence level are provided.Comment: 18 pages, 10 pages, 4 table

First Observation of a Three-Resonance Structure in e+e−→e^+e^-\rightarrow{non-open} Charm Hadrons

We report the measurement of the cross sections for $e^+e^-$$\rightarrow${nOCH} (nOCH stands for non-open charm hadrons) with improved precision at center-of-mass energies from 3.645 to 3.871 GeV. We observe for the first time a three-resonance structure in the energy-dependent lineshape of the cross sections, which are $\mathcal R(3760)$, $\mathcal R(3780)$ and $\mathcal R(3810)$ with significances of $9.4\sigma$, $15.7\sigma$, and $9.8\sigma$, respectively. The $\mathcal R(3810)$ is observed for the first time. We found two solutions in analysis of the cross sections. For solution I [solution II], we measure the mass, the total width and the product of electronic width and nOCH decay branching fraction to be $(3805.8 \pm 1.1 \pm 2.7)$ [$(3805.8 \pm 1.1 \pm 2.7)$] MeV/$c^2$, $(11.6 \pm 2.6 \pm 1.9)$ [$(11.5 \pm 2.5 \pm 1.8)$] MeV, and $(10.8\pm 3.2\pm 2.3)$ [$(11.0\pm 2.9\pm 2.4)$] eV for the $\mathcal R(3810)$, respectively. In addition, we measure the branching fractions ${\mathcal B}({\mathcal R}(3760)$$\rightarrow${nOCH}$)=(24.5 \pm 13.4 \pm 27.4)\% [(6.8 \pm 5.4 \pm 7.6)\%]$ for the first time, and ${\mathcal B}(\mathcal R(3780)$$\rightarrow${nOCH}$)=(11.6 \pm 5.8 \pm 7.8)\% [(10.3 \pm 4.5 \pm 6.9)\%]$. Moreover, we determine the open-charm (OC) branching fraction ${\mathcal B}({\mathcal R}$$(3760)\rightarrow${OC}$)=(75.5 \pm 13.4 \pm 27.4)\% [(93.2 \pm 5.4 \pm 7.6)\%]$, which supports the interpretation of $\mathcal R(3760)$ as an OC pair molecular state, but contained a simple four-quark state component. The first uncertainties are from fits to the cross sections, and the second are systematic