Effects of Sapindus mukorossi Seed Oil on Bone Healing Efficiency: An Animal Study.

Natural products have attracted great interest in the development of tissue engineering. Recent studies have demonstrated that unsaturated fatty acids found in natural plant seed oil may exhibit positive osteogenic effects; however, few in vivo studies have focused on the use of plant seed oil for bone regeneration. The aim of this study is to investigate the effects of seed oil found in Sapindus mukorossi (S. mukorossi) on the osteogenic differentiation of mesenchymal stem cells and bone growth in artificial bone defects in vivo. In this study, Wharton-jelly-derived mesenchymal stem cells (WJMSCs) were co-cultured with S. mukorossi seed oil. Cellular osteogenic capacity was assessed using Alizarin Red S staining. Real-time PCR was carried out to evaluate ALP and OCN gene expression. The potential of S. mukorossi seed oil to enhance bone growth was assessed using an animal model. Four 6 mm circular defects were prepared at the parietal bone of New Zealand white rabbits. The defects were filled with hydrogel and hydrogel-S. mukorossi seed oil, respectively. Quantitative analysis of micro-computed tomography (Micro-CT) and histological images was conducted to compare differences in osteogenesis between oil-treated and untreated samples. Although our results showed no significant differences in viability between WJMSCs treated with and without S. mukorossi seed oil, under osteogenic conditions, S. mukorossi seed oil facilitated an increase in mineralized nodule secretion and upregulated the expression of ALP and OCN genes in the cells (p < 0.05). In the animal study, both micro-CT and histological evaluations revealed that new bone formation in artificial bone defects treated with S. mukorossi seed oil were nearly doubled compared to control defects (p < 0.05) after 4 weeks of healing. Based on these findings, it is reasonable to suggest that S. mukorossi seed oil holds promise as a potential candidate for enhancing bone healing efficiency in bone tissue engineering.

The power of heteronemin in cancers.

Heteronemin (Haimian jing) is a sesterterpenoid-type natural marine product that is isolated from sponges and has anticancer properties. It inhibits cancer cell proliferation via different mechanisms, such as reactive oxygen species (ROS) production, cell cycle arrest, apoptosis as well as proliferative gene changes in various types of cancers. Recently, the novel structure and bioactivity evaluation of heteronemin has received extensive attention. Hormones control physiological activities regularly, however, they may also affect several abnormalities such as cancer. L-Thyroxine (T4), steroid hormones, and epidermal growth factor (EGF) up-regulate the accumulation of checkpoint programmed death-ligand 1 (PD-L1) and promote inflammation in cancer cells. Heteronemin suppresses PD-L1 expression and reduces the PD-L1-induced proliferative effect. In the current review, we evaluated research and evidence regarding the antitumor effects of heteronemin and the antagonizing effects of non-peptide hormones and growth factors on heteronemin-induced anti-cancer properties and utilized computational molecular modeling to explain how these ligands interacted with the integrin αvß3 receptors. On the other hand, thyroid hormone deaminated analogue, tetraiodothyroacetic acid (tetrac), modulates signal pathways and inhibits cancer growth and metastasis. The combination of heteronemin and tetrac derivatives has been demonstrated to compensate for anti-proliferation in cancer cells under different circumstances. Overall, this review outlines the potential of heteronemin in managing different types of cancers that may lead to its clinical development as an anticancer agent.

Antioxidants protect against gingival overgrowth induced by cyclosporine A.

OBJECTIVE: We investigated the importance of reactive oxygen species (ROS) on developing gingival overgrowth (GO) and then introduced the antioxidant strategy to prevent, or even reduce GO. BACKGROUND: Gingival overgrowth is a common side effect of the patients receiving cyclosporine A (CsA), an immune suppressant. Although it has been broadly investigated, the exact pathogenesis of the induced GO is still uncertain. METHODS: We cultured human primary gingival fibroblasts and used animal model of GO to investigate the ameliorative effects of antioxidants on CsA-induced GO. To examine the CsA-induced oxidative stress, associated genes and protein expression, and the overgrown gingiva of rats by using immunocytochemistry, confocal laser scanning microscopy, real-time PCR, ELISA, gelatin zymography, gingival morphological, and immunohistochemical analysis. RESULTS: We found for the first time that ROS was responsible for the CsA-induced oxidative stress and TGF-ß1 expression in human primary gingival fibroblasts, as well as the GO of rats. The antioxidants (oxidative scavenger of vitamin E and an antioxidative enzyme inducer of hemin) ameliorated CsA-induced pathological and morphological alterations of GO without affected the CsA-suppressed il-2 expression in rats. CsA-induced oxidative stress, HO-1, TGF-ß1, and type II EMT were also rescued by antioxidants treatment. CONCLUSIONS: We concluded that CsA repetitively stimulating the production of ROS is the cause of CsA-GO which is ameliorated by treating antioxidants, including vitamin E and sulforaphane. Furthermore, the immunosuppressive effect of CsA is not interfered by antioxidant treatments in rats. This finding may thus help the clinician devise better prevention strategies in patients susceptible to GO.

Combined Treatment of Heteronemin and Tetrac Induces Antiproliferation in Oral Cancer Cells.

BACKGROUND: Heteronemin, a marine sesterterpenoid-type natural product, possesses an antiproliferative effect in cancer cells. In addition, heteronemin has been shown to inhibit p53 expression. Our laboratory has demonstrated that the thyroid hormone deaminated analogue, tetrac, activates p53 and induces antiproliferation in colorectal cancer. However, such drug mechanisms are still to be studied in oral cancer cells. METHODS: We investigated the antiproliferative effects by Cell Counting Kit-8 and flow cytometry. The signal transduction pathway was measured by Western blotting analyses. Quantitative PCR was used to evaluate gene expression regulated by heteronemin, 3,3',5,5'-tetraiodothyroacetic acid (tetrac), or their combined treatment in oral cancer cells. RESULTS: Heteronemin inhibited not only expression of proliferative genes and Homo Sapiens Thrombospondin 1 (THBS-1) but also cell proliferation in both OEC-M1 and SCC-25 cells. Remarkably, heteronemin increased TGF-ß1 expression in SCC-25 cells. Tetrac suppressed expression of THBS-1 but not p53 expression in both cancer cell lines. Furthermore, the synergistic effect of tetrac and heteronemin inhibited ERK1/2 activation and heteronemin also blocked STAT3 signaling. Combined treatment increased p53 protein and p53 activation accumulation although heteronemin inhibited p53 expression in both cancer cell lines. The combined treatment induced antiproliferation synergistically more than a single agent. CONCLUSIONS: Both heteronemin and tetrac inhibited ERK1/2 activation and increased p53 phosphorylation. They also inhibited THBS-1 expression. Moreover, tetrac suppressed TGF-ß expression combined with heteronemin to further enhance antiproliferation and anti-metastasis in oral cancer cells.

Damping ratio analysis of tooth stability under various simulated degrees of vertical alveolar bone loss and different root types.

BACKGROUND: The purpose of this study was to evaluate the feasibility of using damping ratio (DR) analysis combined with resonance frequency (RF) and periotest (PTV) analyses to provide additional information about natural tooth stability under various simulated degrees of alveolar vertical bone loss and various root types. METHODS: Three experimental tooth models, including upper central incisor, upper first premolar, and upper first molar were fabricated using Ti6Al4V alloy. In the tooth models, the periodontal ligament and alveolar bone were simulated using a soft lining material and gypsum, respectively. Various degrees of vertical bone loss were simulated by decreasing the surrounding bone level apically from the cementoenamel junction in 2-mm steps incrementally downward for 10 mm. A commercially available RF analyzer was used to measure the RF and DR of impulse-forced vibrations on the tooth models. RESULTS: The results showed that DRs increased as alveolar vertical bone height decreased and had high coefficients of determination in the linear regression analysis. The damping ratio of the central incisor model without a simulated periodontal ligament were 11.95 ± 1.92 and 27.50 ± 0.67% respectively when their bone levels were set at 2 and 10 mm apically from the cementoenamel junction. These values significantly changed to 28.85 ± 2.54% (p = 0.000) and 51.25 ± 4.78% (p = 0.003) when the tooth model was covered with simulated periodontal ligament. Moreover, teeth with different root types showed different DR and RF patterns. Teeth with multiple roots had lower DRs than teeth with single roots. CONCLUSION: Damping ratio analysis combined with PTV and RF analysis provides more useful information on the assessment of changes in vertical alveolar bone loss than PTV or RF analysis alone.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-glucoside Isolated from Polygoni Multiflori Ameliorates the Development of Periodontitis.

Periodontitis, a chronic infection by periodontopathic bacteria, induces uncontrolled inflammation, which leads to periodontal tissue destruction. 2,3,5,4'-Tetrahydroxystilbene-2-O-beta-glucoside (THSG), a polyphenol extracted from Polygoni Multiflori, reportedly has anti-inflammatory properties. In this study, we investigated the mechanisms of THSG on the Porphyromonas gingivalis-induced inflammatory responses in human gingival fibroblasts and animal modeling of ligature-induced periodontitis. Human gingival fibroblast cells were treated with lipopolysaccharide (LPS) extracted from P. gingivalis in the presence of resveratrol or THSG to analyze the expression of TNF-α, IL-1ß, and IL-6 genes. Increased AMP-activated protein kinase (AMPK) activation and SirT1 expression were induced by THSG. Treatment of THSG decreased the expression of LPS-induced inflammatory cytokines, enhanced AMPK activation, and increased the expression of SirT1. In addition, it suppressed the activation of NF-κB when cells were stimulated with P. gingivalis LPS. The anti-inflammatory effect of THSG and P. Multiflori crude extracts was reproduced in ligature-induced periodontitis animal modeling. In conclusion, THSG inhibited the inflammatory responses of P. gingivalis-stimulated human gingival fibroblasts and ameliorated ligature-induced periodontitis in animal model.

Cell-based semiquantitative assay for sulfated glycosaminoglycans facilitating the identification of chondrogenesis.

Glycosaminoglycans (GAGs), in particular chondroitin sulfate, are an accepted marker of chondrogenic cells. In this study, a cell-based sulfated GAG assay for identifying the chondrogenesis of mesenchymal stem cells was developed. Based on fluorescent staining using safranin O and 4',6-diamidino-2-phenylindole (DAPI), this method was highly sensitive. The results were both qualitative and quantitative. The method is suitable for identifying the chondrogenic process and also for screening compounds. The method may be helpful for discovering novel bioactive compounds for cartilage regeneration.

Concentration effects of grape seed extracts in anti-oral cancer cells involving differential apoptosis, oxidative stress, and DNA damage.

BACKGROUND: Grape seeds extract (GSE) is a famous health food supplement for its antioxidant property. Different concentrations of GSE may have different impacts on cellular oxidative/reduction homeostasis. Antiproliferative effect of GSE has been reported in many cancers but rarely in oral cancer. METHODS: The aim of this study is to examine the antioral cancer effects of different concentrations of GSE in terms of cell viability, apoptosis, reactive oxygen species (ROS), mitochondrial function, and DNA damage. RESULTS: High concentrations (50-400 µg/ml) of GSE dose-responsively inhibited proliferation of oral cancer Ca9-22 cells but low concentrations (1-10 µg/ml) of GSE showed a mild effect in a MTS assay. For apoptosis analyses, subG1 population and annexin V intensity in high concentrations of GSE-treated Ca9-22 cells was increased but less so at low concentrations. ROS generation and mitochondrial depolarization increased dose-responsively at high concentrations but showed minor changes at low concentrations of GSE in Ca9-22 cells. Additionally, high concentrations of GSE dose-responsively induced more γH2AX-based DNA damage than low concentrations. CONCLUSIONS: Differential concentrations of GSE may have a differentially antiproliferative function against oral cancer cells via differential apoptosis, oxidative stress and DNA damage.

Static magnetic field increases survival rate of dental pulp stem cells during DMSO-free cryopreservation.

Successful and efficient cryopreservation of living cells and organs is a key clinical application of regenerative medicine. Recently, magnetic cryopreservation has been reported for intact tooth banking and cryopreservation of dental tissue. The aim of this study was to assess the cryoprotective effects of static magnetic fields (SMFs) on human dental pulp stem cells (DPSCs) during cryopreservation. Human DPSCs isolated from extracted teeth were frozen with a 0.4-T or 0.8-T SMF and then stored at -196 °C for 24 h. During freezing, the cells were suspended in freezing media containing with 0, 3 or 10% DMSO. After thawing, the changes in survival rate of the DPSCs were determined by flow cytometry. To understand the possible cryoprotective mechanisms of the SMF, the membrane fluidity of SMF-exposed DPSCs was tested. The results showed that when the freezing medium was DMSO-free, the survival rates of the thawed DPSCs increased 2- or 2.5-fold when the cells were exposed to 0.4-T or 0.8-T SMFs, respectively (p < 0.01). In addition, after exposure to the 0.4-T SMF, the fluorescence anisotropy of the DPSCs increased significantly (p < 0.01) in the hydrophilic region. These results show that SMF exposure improved DMSO-free cryopreservation. This phenomenon may be due to the improvement of membrane stability for resisting damage caused by ice crystals during the freezing procedure.

Long-term stimulation of areca nut components results in increased chemoresistance through elevated autophagic activity.

BACKGROUND: We previously demonstrated the autophagy-inducing activity in the crude extract of areca nut (ANE) and its 30-100 kDa fraction (ANE 30-100 K). This study aimed to analyze whether chronic ANE and ANE 30-100 K stimulations lead to higher stress resistance and autophagic activity in oral cells, and whether the resulting autophagic status in stimulated cells correlates with stress resistance. MATERIALS AND METHODS: Malignant cells from the mouth oral epidermoid carcinoma Meng-1 (OECM-1) and blood (Jurkat T) origins were stimulated with non-cytotoxic ANE and ANE 30-100 K for 3 months. Sensitivity to anticancer drugs of and autophagy status in stimulated cells, analyzed respectively by XTT assay and calculating microtubule-associated protein 1 light chain 3-II LC3-II/ß-actin ratios from Western blot, were compared to non-treated cells. Autophagy inhibitors, 3-methyladenine (3-MA) and chloroquine (CQ), were used to assess whether autophagy inhibition interferes the altered chemoresistance. RESULTS: Areca nut extract-stimulated (ANE-s) and ANE 30-100 K-stimulated (30-100 K-s) OECM-1 and Jurkat T cells generally exhibited higher cisplatin and 5-fluorouracil (5-FU) resistances, compared to non-stimulated cells. Most stimulated cells expressed significantly higher levels of LC3-II and Atg4B proteins. Interestingly, these cells also showed stronger tolerances against hypoxia environment and expressed higher LC3-II levels under glucose-deprived and hypoxia conditions. Finally, both 3-MA and CQ alleviated, albeit to different degrees, the increased chemoresistance in ANE-s and/or 30-100 K-s cells. CONCLUSIONS: Chronic stimulations of ANE or ANE 30-100 K may increase tolerance of oral cancer and leukemia T cells to anticancer drugs, as well as to glucose deprivation and hypoxia conditions, and cause an elevation of autophagy activity responsible for increased drug resistance.

Evaluation of the efficiency, trueness, and clinical application of novel artificial intelligence design for dental crown prostheses.

OBJECTIVE: The unique structure of human teeth limits dental repair to custom-made solutions. The production process requires a lot of time and manpower. At present, artificial intelligence (AI) has begun to be used in the medical field and improve efficiency. This study attempted to design a variety of dental restorations using AI and evaluate their clinical applicability. METHODS: Using inlay and crown restoration types commonly used in dental standard models, we compared differences in artificial wax-up carving (wax-up), artificial digital designs (digital) and AI designs (AI). The AI system was designed using computer calculations, and the other two methods were designed by humans. Restorations were made by 3D printing resin material. Image evaluations were compared with cone beam computed tomography (CBCT) by calculating the root mean squared error. RESULTS: Surface truth results showed that AI (68.4 µm) and digital-designed crowns (51.0 µm) had better reproducibility. Using AI for the crown reduced the time spent by 400% (compared to digital) and 900% (compared to wax-up). Optical microscopic and CBCT images showed that AI and digital designs had close margin gaps (p < 0.05). The margin gap of the crown showed that the wax-up group was 4.1 and 4.3 times greater than those of the AI and digital crowns, respectively. Therefore, the utilization of artificial intelligence can assist in the production of dental restorations, thereby enhancing both production efficiency and accuracy. SIGNIFICANCE: It is expected that the development of AI can contribute to the reproducibility, efficiency, and goodness of fit of dental restorations.

Effect of various post-curing light intensities, times, and energy levels on the color of 3D-printed resin crowns.

Background/purpose: Current 3D-printing technology has been widely used for creating dental resin restorations. This study aimed to evaluate the effect of light intensity, time, and energy post-curing on the surface color of 3D-printed resin crowns. However, the influences of post-curing parameters on the restoration after printing still need to be explored. Therefore, this project investigates the effect of post-cure conditions on resin color. Materials and methods: Specimens from single-crown (SC) and pontic (PO) specimens underwent post-curing at various light intensities (105, 210, 420, 630, and 860 mW/cm2) for 5, 10, and 15 min. Specimens were observed at three predetermined points and measured using a commercial spectrophotometer that utilizes the CIE Lab∗ color space. Subsequently, samples were analyzed for color differences (ΔE). Results: ΔE color differences in evaluated samples were influenced by the light intensity, time, and energy post-curing. SC samples showed a significant color difference (P < 0.05), with the lowest value at 5 min of 16 (860 mW/cm2), while 10 and 15 min had a difference of 4 (210 mW/cm2). PO samples exhibited a significant decrease in the color difference (P < 0.05) at 5 and 10 min of 16 (860 mW/cm2), and at 15 min of 12 (630 mW/cm2). Conclusion: The results of this study indicate that exposing a resin crown to a high light intensity results in color stability and allows shorter post-curing times.

Applying machine learning to assess the morphology of sculpted teeth.

Background/purpose: Producing tooth crowns through dental technology is a basic function of dentistry. The morphology of tooth crowns is the most important parameter for evaluating its acceptability. The procedures were divided into four steps: tooth collection, scanning skills, use of mathematical methods and software, and machine learning calculation. Materials and methods: Dental plaster rods were prepared. The effective data collected were to classify 121 teeth (15th tooth position), 342 teeth (16th tooth position), 69 teeth (21st tooth position), and 89 teeth (43rd tooth position), for a total of 621 teeth. The procedures are divided into four steps: tooth collection, scanning skills, use of mathematical methods and software, and machine learning calculation. Results: The area under the curve (AUC) value was 0, 0.5, and 0.72 in this study. The precision rate and recall rate of micro-averaging/macro-averaging were 0.75/0.73 and 0.75/0.72. If we took a newly carved tooth picture into the program, the current effectiveness of machine learning was about 70%-75% to evaluate the quality of tooth morphology. Through the calculation and analysis of the two different concepts of micro-average/macro-average and AUC, similar values could be obtained. Conclusion: This study established a set of procedures that can judge the quality of hand-carved plaster sticks and teeth, and the accuracy rate is about 70%-75%. It is expected that this process can be used to assist dental technicians in judging the pros and cons of hand-carved plaster sticks and teeth, so as to help dental technicians to learn the tooth morphology more effectively.

Aquaporin-8 promotes human dermal fibroblasts to counteract hydrogen peroxide-induced oxidative damage: A novel target for management of skin aging.

The skin is subjected to various external factors that contribute to aging including oxidative stress from hydrogen peroxide (H2O2). This study investigated the distribution of aquaporin-8 (AQP8), a protein that transports H2O2 across biological membranes, in skin cells, and its effects in mitigating H2O2-induced oxidative damage. Human dermal fibroblasts were treated with increasing concentrations of H2O2 to evaluate oxidative damage. Cell viability, reactive oxygen species (ROS) generation, and the expression of specific genes associated with skin aging (IL-10, FPR2, COL1A1, KRT19, and Aggrecan) were evaluated and AQP8 expression was assessed via quantitative polymerase chain reaction and western blotting. Small-interfering RNA was used to silence the AQP8 gene and evaluate its significance. The results show that H2O2 treatment reduces cell viability and increases ROS generation, leading to oxidative damage that affects the expression of target molecules. Interestingly, H2O2-treated cells exhibit high levels of AQP8 expression and gene silencing of AQP8 reverses high levels of ROS and low levels of COL1A1, KRT19, and Aggrecan expression in stressed cells, indicating that AQP8 plays a vital role in preventing oxidative damage and consequent aging. In conclusion, AQP8 is upregulated in human dermal fibroblasts during H2O2-induced oxidative stress and may help prevent oxidative damage and aging. These findings suggest that AQP8 could be a potential therapeutic target for skin aging. Further research is necessary to explore the feasibility of using AQP8 as a preventive or therapeutic strategy for maintaining skin health.

Development of a zinc chloride-based chemo-mechanical system for potential minimally invasive dental caries removal system.

Background/purpose: The chemo-mechanical caries-removal technique is known to offer advantages of selective dentin caries treatment while leaving healthy dental tissues intact. However, current sodium hypochlorite based reagents usually excessively damage dentin collagen. Therefore, the purpose of this study was to develop a novel chemo-mechanical caries-removal system to preserve the collagen network for subsequent prosthetic restorations. Materials and methods: The calfskin-derived collagen was chosen as a model system to investigate the dissolution behavior of collagen under different operating conditions of chemical-ultrasonic treatment systems. The molecular weight, triple-helix structure, the morphology, and functional group of collagen after treatment were investigated. Results: Various concentrations of sodium hypochlorite or zinc chloride together with ultrasonic machinery were chosen to investigate. The outcomes of circular dichroism (CD) spectra demonstrated stability of the triple-helix structure after treatment of a zinc chloride solution. In addition, two apparent bands at molecular weights (MWs) of 130 and 121 kDa evidenced the stability of collagen network. The positive 222 nm and 195 nm negative CD absorption band indicated the existence of a triple-helix structure for type I collagen. The preservation of the morphology and functional group of the collagen network on the etched dentin surface were investigated by in vitro dentin decalcification model. Conclusion: Unlike NaOCl, the 5 wt% zinc chloride solution combined with ultra-sonication showed dissolution rather than denature as well as degradation of the dentin collagen network. Additional in vivo evaluations are needed to verify its usefulness in clinical applications.

Cryopreservation of human embryonic stem cells by a programmed freezer with an oscillating magnetic field.

Human embryonic stem cells (hESCs), due to their self-renewal capacity and pluripotency, are an important source of cells for regenerative medicine. The immediate obstacles that need to be addressed are the poor cell survival rate of hESCs and their cell quality after cryopreservation. In this study, we used the Cell Alive System (CAS) which combines a programmed freezer with an oscillating magnetic field to reduce cryo-injury during the freezing process. The hESC clumps suspended in freezing medium were divided into three groups: (i) cells frozen by a conventional freezing container, Mr. Frosty and kept in a -80 °C freezer (MF); (ii) cells frozen to -32 °C by CAS, and then transferred to a -80 °C freezer (CAS); (iii) cells frozen to -32 °C by CAS, and then transferred to a pre-cooled Mr. Frosty and kept in a -80 °C freezer (CAS-MF) for overnight. All cryovials were placed in liquid nitrogen for one week, and hESCs were then thawed and cultured on feeder for 7 days. The results of alkaline phosphatase (AP) staining showed that the attachment efficiency of the cells cryopreserved by CAS and CAS-MF was significantly higher (29.0% and 44.0%) than in the MF method (7.0%). Furthermore, we confirmed the cells cryopreserved using CAS-MF could be subcultured while expressing pluripotent markers, differentiate into three germ layers, and maintain a normal karyotype. These results demonstrate that the use of CAS-MF offers an efficient method of hESC banking.

Surface modification of zirconia ceramics through cold plasma treatment and the graft polymerization of biomolecules.

Background/purpose: Although zirconia ceramics were highly versatile as dental implants, their long-term presence in the human body may slow down healing and impede cell growth in the past. To enhance the cytocompatibility of zirconia ceramics, surface activation modification was used to immobilize biopolymers such that a biomimetic environment was created. Materials and methods: Hexamethyldisilazane thin films were deposited onto the surface of inorganic zirconia through cold plasma treatment under various power and deposition time settings to form an organosilane interface layer. Next, oxygen plasma treatment was performed to activate the free radicals on the surface. Subsequently, ultraviolet light was employed to graft and polymerize acrylic acid for generating carboxyl groups on the surface. This was followed by a condensation reaction with biopolymers (chitosan, chitosan/poly-γ-glutamic acid, and gelatin). Results: Under a 20-min deposition time at 40 W and 150 mTorr, the thin films had a maximum graft density of 2.1 mg/cm2. MG-63 cells (human osteosarcoma cells) were employed to evaluate cell compatibility. Chitosan and chitosan/poly-γ-glutamic acid promoted the compatibility of MG-63 cells (a human osteosarcoma cell line) with zirconia ceramics, whereas gelatin reduced this compatibility. Conclusion: The findings confirm that cold plasma treatment and graft polymerization can promote the immobilization of biomolecules and improve the biocompatibility of zirconia ceramics. This approach can be applied to the modification of zirconia ceramic implants.

Comparative analysis of bonding strength between enamel and overlay of varying thicknesses following an aging test.

Abstract: Background/purpose: Overlay restorations can be used clinically as a treatment option to preserve natural dentine. However, whether the residual enamel thickness and overlay thickness affect the adhesion between the restoration and tooth is still unknown. This study was to investigate effects of the overlay thickness and residual enamel thickness on bonding strength. Materials and methods: Overlays of different thicknesses were prepared with natural teeth which had 2, 4, and 6 mm of occlusal reduction (n = 10). Specimens were subjected to 10,000 cycles in water at 5-55 °C, and finally compressive strength tests were used to evaluate the bonding strength. Results: All groups showed good bond strength (P > 0.05). The overlay restorations of different thicknesses reduced the preparation amount by 30.3%-7.2% and significantly preserved more of the tooth structure (P < 0.005). Compared to the control group, the overlay restoration increased the marginal fitness by about 0.67-0.88 times. The thermal cycling indicated that the decrease in the maximum bearing stress was due to the aging of the ceramic itself. Therefore, the thickness of the overlay had a greater influence on the compressive strength than the bond strength. Conclusion: Based on the above this study recommends an overlay thickness of at least 2 mm in clinical practice. The aging test confirmed that adhesion between the overlay and teeth was quite firm and stable. This shows that a stable adhesive effect of the overlay can be used as a treatment option for preserving a greater amount of a tooth's structure.

Integrins and Actions of Androgen in Breast Cancer.

Androgen has been shown to regulate male physiological activities and cancer proliferation. It is used to antagonize estrogen-induced proliferative effects in breast cancer cells. However, evidence indicates that androgen can stimulate cancer cell growth in estrogen receptor (ER)-positive and ER-negative breast cancer cells via different types of receptors and different mechanisms. Androgen-induced cancer growth and metastasis link with different types of integrins. Integrin αvß3 is predominantly expressed and activated in cancer cells and rapidly dividing endothelial cells. Programmed death-ligand 1 (PD-L1) also plays a vital role in cancer growth. The part of integrins in action with androgen in cancer cells is not fully mechanically understood. To clarify the interactions between androgen and integrin αvß3, we carried out molecular modeling to explain the potential interactions of androgen with integrin αvß3. The androgen-regulated mechanisms on PD-L1 and its effects were also addressed.

Magnetic cryopreservation for dental pulp stem cells.

Magnetic cryopreservation has been successfully used for tooth banking with satisfactory implantation outcomes, suggesting that the method preserves human periodontal ligament cells and dental pulp stem cells (DPSCs). Therefore, magnetic cryopreservation may be applied for the preservation of DPSCs; however, this method has not been evaluated yet. A reliable cryopreservation method for live-cell preservation is important for the clinical applications of regenerative medicine. The conventional slow-freezing procedure with 10% dimethylsulfoxide (DMSO) may not be appropriate for stem cell-based therapies because DMSO is cytotoxic. The objective of this study was to investigate whether magnetic cryopreservation can be applied for DPSC cryopreservation. Cells isolated from human dental pulp were subjected to magnetic cryopreservation. Postthawing cell viability, adhesion, proliferation, expression of markers for mesenchymal stem cells (MSCs), differentiation ability of magnetically cryopreserved DPSCs and DNA stability were compared to those of cells subjected to the conventional slow-freezing method. The results indicated that a serum-free cryopreservation medium (SFM) containing 3% DMSO is optimal for magnetic cryopreservation. Post-thaw magnetically cryopreserved DPSCs express MSC markers, and perform osteogenesis and adipogenesis after induction similarly to fresh MSCs. No significant DNA damage was found in magnetically cryopreserved DPSCs. Magnetic cryopreservation is thus a reliable and effective method for storage of DPSCs. The smaller amount of DMSO required in SFM for cryopreservation is beneficial for the clinical applications of post-thaw cells in regenerative medicine.