Development of a Current Collector with a Graphene Thin Film for a Proton Exchange Membrane Fuel Cell Module.

This paper constructs planar-type graphene thin film current collectors for proton exchange membrane fuel cells (PEMFCs). The present planar-type current collector adopts FR-4 as the substrate and coats a copper thin film using thermal evaporation for the electric-conduction layer. A graphene thin film is then coated onto the current collector to prevent corrosion due to electrochemical reactions. Three different coating techniques are conducted and compared: Spin coating, RF magnetron sputtering, and screen printing. The corrosion rates and surface resistances are tested and compared for the different coating techniques. Single cell PEMFCs with the developed current collectors are assembled and tested. A PEMFC module with two cells is also designed and constructed. The cell performances are measured to investigate the device feasibility.

The Application of Three-Dimensional Printing Model and Platelet-Rich Fibrin Technology in Guided Tissue Regeneration Surgery for Severe Bone Defects.

A 36-year-old male patient diagnosed with severe chronic periodontitis was treated with novel surgery for his maxillary right lateral incisor. Preoperatively, a 3D printer was used, based on CBCT datasets, to produce a photosensitive resin bony anatomy replica. The patient's blood was centrifuged to obtain advanced platelet-rich fibrin (A-PRF) and injected platelet-rich fibrin (I-PRF), then mixed with Bio-Oss and packed onto the 3D replica to form the ideal shape. The replica was positioned at the planned sites without changes. The A-PRF membrane was applied over the replica as well as a Bio-Gide collagen membrane. Fifteen months after the surgery, clinical and radiographic followup revealed greatly reduced pocket depths and significant 3D alveolar bone fill at the treatment site. Based on these short-term results, the initial 3D printing surgical temple assisted guided tissue regeneration method resulted in significant clinical and radiographic improvements; A-PRF/I-PRF should be considered an ideal biomaterial for regenerative periodontal therapy.

LncRNA papillary thyroid carcinoma susceptibility candidate 3 (PTCSC3) regulates the proliferation of human periodontal ligament stem cells and toll-like receptor 4 (TLR4) expression to improve periodontitis.

BACKGROUND: LncRNA PTCSC3 is a known tumor suppressor, while its roles in other human diseases are unclear. METHODS: All participants were admitted by The second Affiliated Hospital, School of Medicine, Zhejiang University from January 2016 to January 2018. RT-qPCR, Vectors, cell transfection, In vitro cell proliferation assay and western blot were using to carry out the experiment. RESULTS: In this study we found that PTCSC3 was downregulated, while toll-like receptor 4 (TLR4) was upregulated in periodontal ligament stem cells (PDLSCs) isolated from periodontitis affected teeth that in PDLSCs isolated from healthy teeth. Expression levels of PTCSC3 and TLR4 were only significantly and inversely correlated in PDLSCs isolated from periodontitis affected teeth but not in PDLSCs isolated from healthy teeth. PTCSC3 overexpression led to the downregulation of TLR4 in PDLSCs isolated from periodontitis affected teeth, while TLR4 overexpression failed to significantly affect PTCSC3. PTCSC3 overexpression also led to the inhibited proliferation of periodontitis-affected PDLSCs. CONCLUSIONS: Therefore, lncRNA PTCSC3 may regulate the proliferation of PDLSCs and TLR4 expression to improve periodontitis.

Th17 and Th1 Lymphocytes Are Correlated with Chronic Periodontitis.

T cells are involved in the homeostasis of periodontal tissues and mediate bone loss in periodontitis, but the involvement of T-helper cells in chronic periodontitis (CP) in a Chinese population is still unclear. This study aimed to assess the distribution of peripheral and local T helper (Th17) and Th1 in CP. Sixty-eight patients with CP and 43 healthy controls were recruited from April 2012 to July 2014 at the Department of Stomatology, People's Hospital of Xinjiang Uygur Autonomous Region (China). The proportions of Th17 (CD3(+)CD4(+)IL-17(+)) and Th1 (CD3(+)CD4(+)IFN-γ(+)) T-cells in peripheral blood samples were assessed by flow cytometry. Immunohistochemistry was used to quantify interleukin-17 (IL-17) and interferon-gamma (IFN-γ) protein levels in gingival biopsy samples. mRNA levels of IL-17, IFN-γ RORγt, and T-bet in gingival biopsy samples were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The proportions of circulating Th17 cells and Th1 cells were both more abundant in CP patients than in controls (Th17: 1.05% ± 0.87% vs. 0.62% ± 0.49%, P < 0.01; Th1: 13.93% ± 7.94% vs. 8.22% ± 4.50%, P < 0.001). Positive correlations were obtained between the proportion of circulating Th17 cells and probing depth (PD) (r = 0.320, P = 0.001) and between the proportion of circulating Th1 cells and PD (r = 0.372, P < 0.001). IL-17 and IFN-γ protein levels in gingival biopsy samples were markedly increased in CP compared to controls (both P < 0.05). Relative IFN-γ, IL-17A, and T-bet mRNA levels in CP biopsies were higher compared to controls (all P < 0.05). These results suggest that elevated peripheral and local Th17 and Th1 cells might be involved in the pathogenesis of CP.

Low-level Nd:YAG laser inhibiting inflammation and oxidative stress in human gingival fibroblasts via AMPK/SIRT3 axis.

OBJECTIVE: Photobiomodulation is extensively employed in the management of chronic inflammatory diseases such as periodontitis because of its anti-inflammatory and antioxidant effects. This study used low-level Nd:YAG laser to investigate the mechanism of photobiomodulation as well as the role of adenosine monophosphate-activated protein kinase (AMPK) and Sirtuins (SIRT) 3 in it, providing new clues for the treatment of periodontitis. METHODS: Human gingival fibroblasts (HGFs) were extracted from gingiva and stimulated with LPS. The suitable parameters of Nd:YAG laser were chosen for subsequent experiments by detecting cell viability. We assessed the level of inflammation and oxidative stress as well as AMPK and SIRT3. The mechanism for AMPK targeting SIRT3 modulating the anti-inflammatory and antioxidant effects of photobiomodulation was explored by the AMPK inhibitor (Compound C) test, cell transfection, western blot, and immunofluorescence. RESULTS: HGFs were isolated and identified, followed by the identification of optimal Nd:YAG laser parameters (60 mJ, 15 Hz, 10s) for subsequent experimentation. With this laser, inflammatory factors (IL-6, TNF-α, COX2, and iNOS) decreased as well as the phosphorylation and nuclear translocation of NFκB-P65. SOD2 was up-regulated but reactive oxygen species (ROS) was down-regulated. The laser treatment exhibited enhancements in AMPK phosphorylation and SIRT3 expression. The above effects could all be reversed by Compound C. Silencing AMPK or SIRT3 by siRNA, the down-regulation of COX2, iNOS, and ROS by laser was inhibited. SIRT3 was down-regulated when the AMPK was silenced. CONCLUSION: Low-level Nd:YAG laser activated AMPK-SIRT3 signaling pathway, facilitating the anti-inflammatory and antioxidative activity.

Osteoclast-Derived Exosomal miR-5134-5p Interferes with Alveolar Bone Homeostasis by Targeting the JAK2/STAT3 Axis.

Background: In chronic periodontitis, exosomes transport various informative substances between osteoclasts and osteoblasts in alveolar bone. Herein, we aimed to investigate the effect of exosomal micro-ribonucleic acid (miRNA/miR)-5134-5p derived from osteoclasts on osteoblastic proliferation and differentiation and the development of periodontitis in vivo and in vitro. Methods: The effects of OC-Exos on the proliferation and differentiation of osteoblasts were identified by Real-time quantitative reverse polymerase chain reaction (qRT-PCR), Western blot(WB), alkaline phosphatase(ALP) staining, etc. Exosomal miRNA expression was analyzed by sequencing. The sites of miRNA action were predicted through TargetScan and tested by double luciferase assay. After transfecting miR-5134-5p mimic/inhibitor into osteoblasts, we measured the proliferation and differentiation of osteoblasts by ALP staining and WB, etc. Furthermore, OC-Exos were injected into the gingival sulcus at the ligation site. Inflammation was observed by Hematoxylin-eosin (H&E) staining, the expression of inflammatory factors were detected by qRT-PCR, the resorption of alveolar bone was observed by Micro CT. Results: Osteoblastic proliferation and differentiation were negatively regulated by OC-Exos in vitro. miRNA sequencing analysis revealed that miR-5134-5p expression was significantly elevated in OC-Exos, which also increased in osteoblasts following OC-Exo intervention. The dual-luciferase assay revealed that miR-5134-5p and Janus kinase 2 (JAK2) had binding sites. miR-5134-5p-mimics could upregulate miR-5134-5p expression in osteoblasts while downregulating Runt-related transcription factor 2(Runx2), phosphorylated-JAK2 (p-JAK2), and phosphorylated-signal transducer and activator of transcription 3 (p-STAT3) expression and inhibited osteogenic differentiation. However, miR-5134-5p-inhibitor had the opposite effect. In vivo, the OC-Exo group demonstrated morphological disruption of periodontal tissue, massive inflammatory cell infiltration, upregulation of inflammatory factors mRNA expression, a significant decrease in BV/TV, and an increase in the cementoenamel junction and alveolar bone crest distance. Conclusion: Osteoclast-derived exosomal miR-5134-5p inhibits osteoblastic proliferation and differentiation via the JAK2/STAT3 pathway. OC-Exos exacerbate periodontal tissue inflammation and accelerate alveolar bone resorption in mice with experimental periodontitis.

Current levels and composition profiles of microplastics in irrigation water.

Land-based sources have been considered the most important sources of microplastic pollution to the coastal and marine environment. The number of research studies examining microplastic pollution in freshwater and inland water systems is increasing, but most research focuses on rivers, reservoirs, and lakes. This study investigated the spatial-temporal distribution, characteristics, sources, and risks of microplastics in irrigation water in Taiwan. The results showed that microplastics were widely and unevenly distributed along the irrigation system and were abundant at sites surrounded by a dense population and sites that received lateral canal and urban runoff input. The abundance of microplastics ranged from 1.88 items/L to 141 items/L, and samples collected in May had the highest microplastic concentrations. Polypropylene, polyethylene, and polystyrene were identified as the predominant polymers. Fibers (36-64%) were the most typical and abundant shape, and 333-1000 µm size (49-63%) and white/transparent (45-51%) were the dominant size and colors among all samples. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to assess the impact of the rainy season and typhoons and addressed the dramatic changes in distinct population densities. The polymer risk index was calculated to evaluate the environmental risk of microplastics in irrigation water, and the results revealed a high microplastic risk throughout the year except in November and January. This study provided a valuable reference and impetus for a better understanding of the microplastic profile and source apportionment in irrigation water, which was important for environmental management.

Inflamm-Aging-Related Cytokines of IL-17 and IFN-γ Accelerate Osteoclastogenesis and Periodontal Destruction.

Periodontal disease (PD), as an age-related disease, prevalent in middle-aged and elderly population, is characterized as inflammatory periodontal tissue loss, including gingival inflammation and alveolar bone resorption. However, the definite mechanism of aging-related inflammation in PD pathology needs further investigation. Our study is aimed at exploring the effect of inflamm-aging-related cytokines of interleukin-17 (IL-17) and interferon-γ (IFN-γ) on osteoclastogenesis in vitro and periodontal destruction in vivo. For receptor activator of nuclear factor-κB ligand- (RANKL-) primed bone marrow macrophages (BMMs), IL-17 and IFN-γ enhanced osteoclastogenesis, with the expression of osteoclastogenic mRNA (TRAP, c-Fos, MMP-9, Ctsk, and NFATc1) and protein (c-Fos and MMP-9) upregulated. Ligament-induced rat models were established to investigate the role of IL-17 and IFN-γ on experimental periodontitis. Both IL-17 and IFN-γ could enhance the local inflammation in gingival tissues. Although there might be an antagonistic interaction between IL-17 and IFN-γ, IL-17 and IFN-γ could facilitate alveolar bone loss and osteoclast differentiation.

Biphasic ceramic biomaterials with tunable spatiotemporal evolution for highly efficient alveolar bone repair.

Alveolar bone defects, which are characterized by a relatively narrow space and location adjacent to the cementum, require promising substitute biomaterials for their regeneration. In this study, we introduced novel yolk-shell biphasic bio-ceramic granules with/without a customized porous shell and evaluated their biological effect together with structural transformation. Firstly, a self-made coaxial bilayer capillary system was applied for the fabrication of granules. Secondly, thorough morphological and physicochemical characterizations were performed in vitro. Subsequently, the granules were implanted into critical-size alveolar bone defects (10 × 4 × 3 mm) in New Zealand white rabbits, with Bio-Oss® as the positive control. Finally, at 2, 4, 8, and 16 weeks postoperatively, the alveolar bone specimens were harvested and assessed via radiological and histological examination. Our results showed that the yolk-shell biphasic bio-ceramic granules, especially those with porous shells, exhibited a tunable ion release performance, improved biodegradation behavior and satisfactory osteogenesis compared with the homogeneously hybrid and Bio-Oss® granules both in vitro and in vivo. This study provides the first evidence that novel yolk-shell bio-ceramic granules, on account of their adjustable porous microstructure, have great potential in alveolar bone repair.