Inducing cyclooxygenase-2 expression, prostaglandin E2 and prostaglandin F2α production of human dental pulp cells by activation of toll-like receptor-3, mitogen-activated protein kinase kinase/extracellular signal-regulated kinase and p38 signaling.

Background/purpose: Bacterial infection was the major etiology for pulpal/root canal infection. This study aimed to investigate the activation of toll-like receptor-3 (TLR) on cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) and PGF2α production of human dental pulp cells (HDPCs) and associated signaling. Materials and methods: HDPCs were exposed to different concentrations of Poly (I:C) (a TLR3 activator). Cell viability was determined by 3- (4,5-Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay and alkaline phosphatase (ALP) activity was evaluated by ALP staining. Activation of extracellular signal-regulated kinase (ERK) and p38 by Poly (I:C) was determined by immunofluorescent staining. The COX-2 protein expression was analyzed by Western blot. PGE2 and PGF2α production was measured by enzyme-linked immunosorbent assay. The mRNA expression was studied by real-time polymerase-chain reaction. Moreover, HDPCs were exposed to Poly(I:C) with/without U0126 or SB203580 treatment and analysis of COX-2 expression and prostanoid production were conducted. Results: Poly (I:C) showed little effect on ALP activity, but decreased viability of HDPCs. It stimulated COX-2 mRNA and protein expression. Poly (I:C) induced PGE2 and PGF2α production of HDPCs. Poly (I:C) activated p-ERK, and p-p38 protein expression. Treatment by U0126 (a mitogen-activated protein kinase kinase (MEK)/ERK inhibitor) and SB203580 (a p38 inhibitor) attenuated Poly (I:C)-induced COX-2 mRNA and protein expression as well as PGE2 and PGF2α production. Conclusion: TLR3 activation is involved in the infection and inflammatory responses of pulp tissues, via MEK/ERK, and p38 signaling to mediate COX-2 expression as well as PGE2 and PGF2α production, contributing to the pathogenesis and progression of pulpal/periapical diseases.

Biomechanical stress distribution of medical inelastic fabrics with different porosity structures.

Clothing fit and pressure comfort play important role in clothing comfort, especially in medical body sculpting clothing (MBSC). In the present study, different body movements (forward bending, side bending, and twisting) were adopted to simulate and investigate the biomechanical stress distribution of the human body with three kinds of porosity inelastic MBSCs through the finite element analysis method. The elastic modulus of the investigated MBSCs was also measured by means of tensile testing. Analytical results showed that in the compression region during body movements, the investigated inelastic MBSCs endured less compression stress, and most of the stress was transmitted to the human body. Moreover, the stresses on the body surface were decreased with the porosity increasing. However, most of the von Mises stresses on the human body were in the desired pressure comfort range. Therefore, these results could provide potential information in the modification of MBSC for medical applications.

Inducing cathepsin L expression/production, lysosomal activation, and autophagy of human dental pulp cells by dentin bonding agents, camphorquinone and BisGMA and the related mechanisms.

Camphorquinone (CQ) and resin monomers are included in dentin bonding agents (DBAs) and composite resin to restore tooth defects due to abrasion, crown fracture, or dental caries. DBAs, CQ, and bisphenol A-glycidyl methacrylate (BisGMA) applications influence the biological activities of the dental pulp. The current investigation aimed to delineate the effect of DBAs, CQ, and BisGMA on cathepsin L production/expression, lysosomal activity, and autophagy induction in human dental pulp cells (HDPCs). HDPCs were exposed to DBAs, CQ, or BisGMA with/without inhibitors for 24 h. Enzyme-linked immunosorbent assay was employed to determine the cathepsin L level in culture medium. The cell layer was utilized to measure cell viability by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl -tetrazolium bromide (MTT) assay. Real-time PCR was used to evaluate the mRNA expression. Western blotting or immunofluorescent staining was used to study protein expression. Lysosomal density was evaluated by lysotracker red staining. We found that DBAs, CQ, and BisGMA stimulated cathepsin L mRNA, protein expression, and production in HDPCs. In addition, CQ and BisGMA induced lysosomal activity, Beclin1, ATG12, LC3B, Bax, and p53 expression in HDPCs, indicating the stimulation of autophagy. Glutathione (GSH) prevented CQ- and BisGMA-induced cytotoxicity. Moreover, E64d, cathepsin L inhibitor (two cathepsin inhibitors), and Pifithrin-α (a p53 inhibitor) showed little preventive effect toward CQ- and BisGMA-induced cytotoxicity. Autophagy inhibitors (NH4Cl, Lys05) mildly enhanced the CQ- and BisGMA-induced cytotoxicity. These results indicate that DBAs stimulated cathepsin L, possibly due to their content of CQ and BisGMA that may induce cathepsin L in HDPCs. CQ and BisGMA stimulated lysosomal activity, autophagy, and apoptosis, possibly via induction of Beclin 1, ATG12, LC-3B, Bax, and p53 expression. In addition, CQ and BisGMA cytotoxicity was related to redox change and autophagy. These events are important role in pulpal changes after the restoration of tooth decay using CQ- and BisGMA-containing DBAs and resin composite.

The potential of the three-dimensional printed titanium mesh implant for cranioplasty surgery applications: Biomechanical behaviors and surface properties.

The aim of the present study was to investigate the biomechanical behaviors of the pre-shaped titanium (PS-Ti) cranial mesh implants with different pore structures and thicknesses as well as the surface characteristics of the three-dimensional printed Ti (3DP-Ti) cranial mesh implant. The biomechanical behaviors of the PS-Ti cranial mesh implants with different pore structures (square, circular and triangular) and thicknesses (0.2, 0.6 and 1 mm) were simulated using finite element analysis. Surface properties of the 3DP-Ti cranial mesh implant were performed by means of scanning electron microscopy, X-ray diffraction and static contact angle goniometer. It was found that the stress distribution and peak Von Mises stress of the PS-Ti cranial mesh implants significantly decreased at the thickness of 1 mm. The PS-Ti mesh implant with the circular pore structure created a relatively lower Von Mises stress on the bone defect area as compared to the PS-Ti mesh implant with the triangular pore structure and square pore structure. Moreover, the spherical-like Ti particle structures were formed on the surface of the 3DP-Ti cranial mesh implant. The microstructure of the 3DP-Ti mesh implant was composed of α and rutile-TiO2 phases. For wettability evaluation, the 3DP-Ti cranial mesh implant possessed a good hydrophilicity surface. Therefore, the 3DP-Ti cranial mesh implant with the thickness of 1 mm and circular pore structure is a promising biomaterial for cranioplasty surgery applications.

The application of silver nano-particles on developing potential treatment for chronic rhinosinusitis: Antibacterial action and cytotoxicity effect on human nasal epithelial cell model.

Chronic rhinosinusitis (CRS) has raised attentions both in many countries due to its high relapsing rate and the resistance of certain treatments especially antibiotics application on both acute and chronic bacterial rhinosinusitis. The aim of this research is stressing on developing an effective alternative treatment for treating CRS and reducing the use of antibiotics to avoid further resistance forming. The antibacterial functions of silver nano-particles (AgNPs) are well known according to previous reports and studies. However, for developing a suitable treatment for further clinical application, a variety of AgNPs cell cytotoxicity experiments and AgNPs antibacterial properties experiments were examined in vitro in this study. For imitating the clinical condition of CRS, the human nasal epithelial cell line (RPMI2650) has chosen as experimental model. Moreover, Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) were selected for antibacterial function experiments. The analytical results demonstrated that 5ppm of AgNPs not only maintains >80% of cell activity to RPMI2650, but also possesses >80% of antibacterial function to S. aureus and 100% of antibacterial function to E. coli. Therefore, 5ppm of AgNPs might be considered as a promising antibacterial agent for treating CRS.

Change of scaling-induced proinflammatory cytokine on the clinical efficacy of periodontitis treatment.

Proinflammatory cytokines are key inflammatory mediators in periodontitis. This study aimed to investigate the relationship between proinflammatory cytokines in saliva and periodontal status. To investigate the usefulness of cytokines in the therapeutic approach for periodontal disease, the relationship between stimulated cytokine changes and the periodontitis treatment outcome was investigated in this study. Saliva was obtained from 22 patients diagnosed by dentists as having chronic periodontitis. The proinflammatory cytokine (interleukin-1α (IL-1α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor α (TNF-α), and tumor necrosis factor ß (TNF-ß)) levels were determined using a commercially available kit. The IL-1ß and IL-6 levels increased, whereas the TNF-ß levels decreased with the severity of periodontitis (4 mm pocket percentage). Poststimulation IL-1α, IL-6, and IL-8 levels were higher in patients who had an improved treatment outcome. The differences of IL-6 levels (cut point: 0.05 µg/g) yielded a sensitivity and specificity of 90.0% and 81.82%, respectively, for predicting the periodontitis treatment outcome. Among the proinflammatory cytokines, stimulated IL-6 was an excellent marker for predicting the periodontitis treatment outcome.

Scaling-stimulated salivary antioxidant changes and oral-health behavior in an evaluation of periodontal treatment outcomes.

AIM: Our goal was to investigate associations among scaling-stimulated changes in salivary antioxidants, oral-health-related behaviors and attitudes, and periodontal treatment outcomes. MATERIALS AND METHODS: Thirty periodontitis patients with at least 6 pockets with pocket depths of >5 mm and more than 16 functional teeth were enrolled in the study. Patients were divided into three groups: an abandoned group (AB group), a nonprogress outcome group (NP group), and an effective treatment group (ET group). Nonstimulated saliva was collected before and after scaling were received to determine superoxide dismutase (SOD) and the total antioxidant capacity (TAOC). RESULTS: Salivary SOD following scaling significantly increased from 83.09 to 194.30 U/g protein in patients who had irregular dental visit patterns (<1 visit per year). After scaling, the TAOC was significantly higher in patients who had regular dental visits than in patients who had irregular dental visits (3.52 versus 0.70 mmole/g protein, P < 0.01). The scaling-stimulated increase in SOD was related to a higher severity of periodontitis in the NP group, while the scaling-stimulated increase in the TAOC was inversely related to the severity of periodontitis in the AB group. CONCLUSIONS: These results demonstrate the importance of scaling-stimulated salivary antioxidants as prognostic biomarkers of periodontal treatment.

Enhancement of biomechanical behavior on osseointegration of implant with SLAffinity.

The purpose of this study was to investigate stresses resulting from different thicknesses of hydroxyapatite- and titanium dioxide (TiO(2))-treated layers at the interface between temporomandibular joint (TMJ) implants and bones using three-dimensional finite element models. For ensuring osseointegration of implant treatment, one must examine the stresses of interface between implant and bone tissue. Treated layers on TMJ implants are a very important factor in clinical application. Several studies have investigated finite element models for TMJs, but few have examined a model for TMJ implants with treated layers. In this study, TMJ models were reconstructed using computer tomography data, and the effects of treated layer thickness on the stress field during jaw movement were investigated; this index has not yet been reported with respect to TMJ implant. The maximum stresses in the bone occurred at the position of the first screw. Data analysis indicated a greater decrease in this stress in the case of using TMJ implants with TiO(2)-treated layers, and the stresses decreased with increasing layer thicknesses. Results confirmed that the treated layers improve biomechanical properties of the TMJ implants and release abnormal stress concentration in them. The results of our study offer the potential clinical benefit of inducing superior biomechanical behavior in TMJ implants.