Evaluation of viscoelastic properties, hardness, and glass transition temperature of soft denture liners and tissue conditioner.

Soft denture liners and tissue conditioners are widely used for the denture patients to cushion masticatory force and condition abused tissues, respectively. This study assessed methods for the evaluation of the viscoelasticity and glass transition temperature (Tg) of the silicone permanent soft liner, acrylic permanent soft liner, and tissue conditioner. Three rheological parameters of storage modulus (E'), loss modulus (E''), and loss tangent ([Formula: see text]), Tg, and hardness were determined using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and the Shore A0 hardness test. Five specimens were measured for each material. The time-temperature superposition principle was applied to produce master curves of E', E'', and [Formula: see text] for the tested materials at a reference temperature of 37 °C. The acrylic permanent soft liner and tissue conditioner exhibited viscoelastic behavior and sensitivity to frequency, especially at lower frequencies. The silicone permanent soft liner showed elastic behavior and was frequency-independent. Tg for the acrylic permanent soft liner was higher than that for the tissue conditioner, which in turn was higher than that for the silicone permanent soft liner for both DMA and DSC. In DMA, a higher frequency led to higher Tg values. A positive linear relationship was found between Shore A0 hardness and E' values, but not E'' and [Formula: see text] values. Shore hardness reflects elasticity, but not viscosity. The results of the present study can be used to improve methods for evaluating the viscoelasticity and Tg of soft denture liners and tissue conditioners.

Antitumor and Antiangiogenic Activities of Lenvatinib in Mouse Xenograft Models of Vascular Endothelial Growth Factor-Induced Hypervascular Human Hepatocellular Carcinoma.

High expression of vascular endothelial growth factor (VEGF) in patients with hepatocellular carcinoma (HCC) is associated with poor prognosis. Here, we investigated the antitumor activity of lenvatinib, a multiple receptor tyrosine kinase inhibitor, in VEGF-overexpressing HCC models. In human umbilical vein endothelial cells, lenvatinib showed potent inhibitory activities against VEGF-induced proliferation and VEGF/basic fibroblast growth factor-induced tube formation. In VEGF-overexpressing HCC xenograft models, characterized by aggressive tumor growth and hypervascularity, lenvatinib had significant antitumor and antiangiogenic activities. These results suggest that potent activity of lenvatinib against VEGF signaling underlies its antitumor and antiangiogenic activities in the hypervascular HCC models.

Immunomodulatory activity of lenvatinib contributes to antitumor activity in the Hepa1-6 hepatocellular carcinoma model.

Angiogenesis inhibitors such as lenvatinib and sorafenib, and an immune checkpoint inhibitor (ICI), nivolumab, are used for anticancer therapies against advanced hepatocellular carcinoma (HCC). Combination treatments comprising angiogenesis inhibitors plus ICIs are promising options for improving clinical benefits in HCC patients, and clinical trials are ongoing. Here, we investigated the antitumor and immunomodulatory activities of lenvatinib (a multiple receptor tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor 1-3, fibroblast growth factor receptor 1-4, platelet-derived growth factor receptor α, KIT and RET) and the combined antitumor activity of lenvatinib plus anti-programmed cell death 1 (PD-1) antibody in the Hepa1-6 mouse HCC syngeneic model. We found that the antitumor activities of lenvatinib and sorafenib were not different in immunodeficient mice, but lenvatinib showed more potent antitumor activity than sorafenib in immunocompetent mice. The antitumor activity of lenvatinib was greater in immunocompetent mice than in immunodeficient mice and was attenuated by CD8+ T cell depletion. Treatment with lenvatinib plus anti-PD-1 antibody resulted in more tumor regression and a higher response rate compared with either treatment alone in immunocompetent mice. Single-cell RNA sequencing analysis demonstrated that treatment with lenvatinib with or without anti-PD-1 antibody decreased the proportion of monocytes and macrophages population and increased that of CD8+ T cell populations. These data suggest that lenvatinib has immunomodulatory activity that contributes to the antitumor activity of lenvatinib and enhances the antitumor activity in combination treatment with anti-PD-1 antibody. Combination treatment of lenvatinib plus anti-PD-1 antibody therefore warrants further investigation against advanced HCC.

Hsp90 inhibitor geldanamycin attenuates the cytotoxicity of sunitinib in cardiomyocytes via inhibition of the autophagy pathway.

Sunitinib malate (sunitinib) is an orally available, multitargeted tyrosine kinase inhibitor with antitumor and antiangiogenic activities. Although sunitinib is effective for the treatment of patients with gastrointestinal stromal tumor, advanced renal cell carcinoma, or pancreatic neuroendocrine tumor, adverse cardiac events associated with sunitinib administration have been reported. Here, we examined the effect of geldanamycin, an inhibitor of heat shock protein (Hsp) 90, on sunitinib-induced cytotoxicity in cardiomyocytes. First, we found that treatment with geldanamycin or other Hsp90 inhibitors (tanespimycin, ganetespib, or BIIB021) significantly attenuated sunitinib-induced cytotoxicity in rat H9c2 cardiomyocytes, suggesting a drug-class effect of Hsp90 inhibitors. We then examined the mechanisms underlying sunitinib-induced cytotoxicity and found that sunitinib induced autophagy in H9c2 cells and that pretreatment with geldanamycin inhibited the induction of autophagy by promoting degradation of the autophagy-related proteins Atg7, Beclin-1, and ULK1. Pharmacological assessment with autophagy inhibitors confirmed that geldanamycin attenuated the cytotoxicity of sunitinib by interfering with autophagy. In addition, we found that the molecular chaperone Hsp70, which is induced by geldanamycin, was not involved in the attenuation of sunitinib-induced cytotoxicity. Finally, to provide more clinically relevant data, we confirmed that geldanamycin attenuated sunitinib-induced cytotoxicity in human induced pluripotent stem cell-derived cardiomyocytes. Together, these data suggest that geldanamycin attenuates sunitinib-induced cytotoxicity in cardiomyocytes by inhibiting the autophagy pathway. Thus, the further investigation of combination or sequential treatment with an Hsp90 inhibitor and sunitinib is warranted as a potential strategy of attenuating the cardiotoxicity associated with sunitinib administration in the clinical setting.

Identification and optimisation of a series of tetrahydrobenzotriazoles as metabotropic glutamate receptor 5-selective positive allosteric modulators that improve performance in a preclinical model of cognition.

Herein we describe a series of tetrahydrobenzotriazoles as novel, potent metabotropic glutamate receptor subtype 5 (mGlu5) positive allosteric modulators (PAMs). Exploration of the SAR surrounding the tetrahydrobenzotriazole core ultimately led to the identification of 29 as a potent mGlu5 PAM with a low maximal glutamate potency fold shift, acceptable in vitro DMPK parameters and in vivo PK profile and efficacy in the rat novel object recognition (NOR) assay. As a result 29 was identified as a suitable compound for progression to in vivo safety evaluation.

Bioactivity and antibacterial effects of zinc-containing bioactive glass on the surface of zirconia abutments.

OBJECTIVES: This study aimed to enhance gingival fibroblast function and to achieve antibacterial activity around the implant abutment by using a zinc (Zn)-containing bioactive glass (BG) coating. METHODS: 45S5 BG containing 0, 5, and 10 wt.% Zn were coated on zirconia disks. The release of silica and Zn ions in physiological saline and their antibacterial effects were measured. The effects of BG coatings on human gingival fibroblasts (hGFs) were assessed using cytotoxicity assays and by analyzing the gene expression of various genes related to antioxidant enzymes, wound healing, and fibrosis. RESULTS: BG coatings are capable of continuous degradation and simultaneous ion release. The antibacterial effect of BG coatings increased with the addition of Zn, while the cytotoxicity remained unchanged compared to the group without coatings. BG coating enhances the expression of angiogenesis genes, while the Zn-containing BG enhances the expression of antioxidant genes at an early time point. BG coating enhances the expression of collagen genes at later time points. CONCLUSIONS: The antibacterial effect of BG improved with the increase in Zn concentration, without inducing cytotoxicity. BG coating enhances the expression of angiogenesis genes, and Zn-containing BG enhances the expression of antioxidant genes at an early time point. BG coating enhances the expression of collagen genes at later time points. CLINICAL SIGNIFICANCE: Adding 10 wt% Zn to BG could enhance the environment around implant abutments by providing antibacterial, antioxidant, and anti-fibrotic effects, having potential for clinical use.

Ago-allosteric modulators of human glucagon-like peptide 2 receptor.

Glucagon-like peptide 2 (GLP-2) is an intestinotropic peptide that binds to GLP-2 receptor (GLP-2R), a class-B G protein-coupled receptor (GPCR). Few synthetic agonists have been reported so far for class-B GPCRs. Here, we report the first scaffold compounds of ago-allosteric modulators for human GLP-2R, derived from methyl 2-{[(2Z)-2-(2,5-dichlorothiophen-3-yl)-2-(hydroxyimino)ethyl]sulfanyl}benzoate (compound 1).

Influence of monomer type, plasticizer content, and powder/liquid ratio on setting characteristics of acrylic permanent soft denture liners based on poly(ethyl methacrylate/butyl methacrylate) and acetyl tributyl citrate.

We evaluated the influence of monomer type, plasticizer content, and powder/liquid (P/L) ratio on the setting characteristics of light-cured acrylic permanent soft denture liners based on poly(ethyl methacrylate/butyl methacrylate). Two monomers, iso-butyl methacrylate (i-BMA) and 2-ethylhexyl methacrylate (2-EHMA), that contained various concentrations of the plasticizer acetyl tributyl citrate (ATBC) and trace amounts of the photo initiator and reducing agent were used. The P/L ratio was 1.0 or 1.2. The gelation time was measured using a controlled stress rheometer. Materials with i-BMA had shorter gelation times than those for materials with 2-EHMA. The gelation time increased exponentially with increasing plasticizer content. A higher P/L ratio led to a shorter gelation time. The effects of monomer type and plasticizer content were larger than that for the P/L ratio. These results show that 2-EHMA is a suitable monomer for soft denture liners and that the setting characteristics can be controlled via ATBC content.

Multivariate analysis reveals oral health-related quality of life of complete denture wearers with denture adhesives: a multicenter randomized controlled trial.

Purpose To investigate the difference in improvement of oral health-related quality of life (OHR-QoL) depending on the oral and denture conditions of a complete denture wearer when using a cream or powder type denture adhesive in a 10-center parallel randomized clinical trial.Methods Two hundred edentulous subjects who wore complete dentures were allocated to each of the three groups according to denture adhesive type: cream, powder, and control (saline solution). The materials were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention were collected. OHR-QoL was assessed using the Japanese version of the modified Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT-J) scale for outcome. Multivariate analysis was used to investigate improvements in OHR-QoL according to participant characteristics among complete denture wearers using these materials.Results OHIP-EDENT-J scores were significantly decreased in all groups after the intervention (p < 0.05); however, there were no statistically significant differences among the groups. Multiple logistic regression analysis revealed a significant association between the vertical height of the maxillary and mandibular alveolar ridge and OHIP-EDENT-J scores in the cream-type denture adhesive group. In contrast, there were no significant association between participant characteristics and OHIP-EDENT-J scores in the powder-type adhesive and control groups.Conclusions The use of denture adhesives could improve OHR-QoL for complete denture wearers. The cream-type denture adhesives may be expected to improve OHR-QoL in patients with poor residual ridge conditions compared with patients with good residual ridge conditions.

Production of P(3-hydroxybutyrate-co-3-hydroxyhexanoate-co-3-hydroxyoctanoate) terpolymers using a chimeric PHA synthase in recombinant Ralstonia eutropha and Pseudomonas putida.

Recombinant strains of Ralstonia eutropha and Pseudomonas putida harboring a chimeric polyhydroxyalkanoate (PHA) synthase, which consisted of PHA synthases of Aeromonas caviae and R. eutropha, produced 3-hydroxybutyrate (3HB)-based PHA copolymers comprised of 3-hydroxyhexanoate and 3-hydroxyoctanoate units from dodecanoate (87-97 mol % 3HB), indicating that the chimeric PHA synthase possesses desirable substrate specificity leading to the production of 3HB-rich copolymers.

A new beneficial mutation in pseudomonas sp. 61-3 polyhydroxyalkanoate (PHA) synthase for enhanced cellular content of 3-hydroxybutyrate-based PHA explored using its enzyme homolog as a mutation template.

A newly isolated mutation (Gln508Leu) and a combination of it with previously discovered beneficial mutations in polyhydroxyalkanoate synthase 1 from Pseudomonas sp. 61-3 were found to enhance the production of poly(3-hydroxybutyrate) [P(3HB)] and poly(3HB-co-3-hydroxyalkanoate)s in recombinant Escherichia coli.

Effects of denture adhesives and mouth moisturizers to human oral fibroblast and human keratinocyte cells using direct and indirect cell culture systems.

The purpose of this study was to evaluate the effects of commercialized denture adhesives and mouth moisturizers using direct and indirect cell cultures for in vitro examinations with human fibroblast and epithelial cells. Denture adhesives (Faston, Poligrip Powder, New Poligrip Free, Tafugurippu Kurimu, Polident Adhesive, Tafugurippu Tomei) and mouth moisturizers (Concool Mouth Gel, Biotene Oral Balance Gel) were subjected to live and dead detection and pH level determination. The mouth moisturizers showed higher cytotoxicity effects comparing with control on every cell cultures and cells, and pH level did not show any significant differences. However, there was no correlation of type of denture adhesive or mouth moisturizer with cytotoxicity. We concluded that cytotoxicity affects human cells regardless of type of material, though some dependence was noted.

Antibacterial Properties of Nano-Ag Coating on Healing Abutment: An In Vitro and Clinical Study.

Peri-implantitis is an inflammatory disease with a relevant focus on the long-term success of dental implants and implant-supported prostheses. The present study focuses on the antibacterial effect of the silver nanoparticle and investigated the suppression of dental plaque adhesion on implant abutment and/or superstructure by micro-wave assistant nanosilver coating in vivo and in vitro. Nanosilver coating on pure titanium was prepared by microwave-assisted synthesis, and characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. In vitro studies were conducted to analyze biocompatibility using MTS assay and fluorescence microscopy with human gingival fibroblasts to evaluate antibacterial activity. During the in vivo study, nanosilver coating was applied to the healing abutments, and the prevention of plaque accumulation on nanosilver coating was confirmed by a split-mouth randomized clinical trial. The aggregation of nano-sized particles was found on the titanium surface with an antibacterial effect. The coating had no cytotoxic effect on human gingival fibroblasts. The result of the clinical trial showed that the coating suppressed the dental plaque adhesion on the healing abutments. Nanosilver coating is a promising material with antibacterial properties and can be used for implant abutments and prostheses for preventing peri-implantitis.

Use of cellulose nanofibers as a denture immersing solution.

The purpose of this study was to investigate the influence of cellulose nanofibers (CNF) solution on the mechanical and biological properties of denture base resins (DBR). Two types of CNFs obtained from bamboo (BB) and needle-leaved (NB) trees were used in this study. We prepared 18 different CNF solutions based on their fibrillation (A-low, B-middle, and C-high) and concentration (0.05, 0.10, and 0.20 wt%). A heat-polymerized acrylic resin was used as DBR. The contact angles for each specimen were measured after immersion. The flexural properties of the immersed specimens, and the biological properties of the CNF solutions were examined. Specimens immersed in CNF-NB-C-0.05 wt% solution presented with the lowest contact angles. Specimens in CNF-NB-C and CNF-BB-A groups showed higher flexural modulus values. No cytotoxic or antimicrobial effects were observed for the CNF solutions. This study suggest that CNF solution may improve the surface wettability of the DBR without affecting its flexural property.

Chimeric enzyme composed of polyhydroxyalkanoate (PHA) synthases from Ralstonia eutropha and Aeromonas caviae enhances production of PHAs in recombinant Escherichia coli.

Chimeric enzymes composed of polyhydroxyalkanoate (PHA) synthases from Ralstonia eutropha (Cupriavidus necator) (PhaC(Re)) and Aeromonas caviae (PhaC(Ac)) were constructed. PhaC(Re) is known for its potent enzymatic activity among the characterized PHA synthases. PhaCAc has broad substrate specificity and synthesizes short-chain-length (SCL)/medium-chain-length (MCL) PHA. We attempted to create chimeric enzymes inheriting both of the advantageous properties. Among eight chimeras, AcRe12, with 26% of the N-terminal of PhaC(Ac) and 74% of the C-terminal of PhaC(Re), exhibited comparable P(3-hydroxybutyrate) accumulation as parental enzymes in Escherichia coli JM109. Thus, AcRe12 was applied to SCL/MCL PHA production using E. coli LS5218 as the host. AcRe12 accumulated higher amount of PHA (50 wt %) than the parental enzymes. Furthermore, the PHA consisted of 2 mol % 3-hydroxyhexanoate as well as 3-hydroxybutyrate. Therefore, the chimeric PHA synthase, AcRe12, inherited the character of both of the parental enzymes and thus exhibits improved enzymatic properties.

Production of short-chain-length/medium-chain-length polyhydroxyalkanoate (PHA) copolymer in the plastid of Arabidopsis thaliana using an engineered 3-ketoacyl-acyl carrier protein synthase III.

Short-chain-length/medium-chain-length (SCL/MCL) polyhydroxyalkanoate (PHA) was produced in the plastids of Arabidopsis thaliana. Phe87Thr (F87T) mutated 3-ketoacyl-acyl carrier protein (ACP) synthase III (FabH) from Escherichia coli , and Ser325Thr/Gln481Lys (ST/QK) mutated polyhydroxyalkanoate (PHA) synthase (PhaC1) from Pseudomonas sp. 61-3, along with the beta-ketothiolase (PhaA) and acetoacetyl-CoA reductase (PhaB) from Ralstonia eutropha (Cupriavidus necator) genes were introduced into Arabidopsis. The transgenic Arabidopsis produced PHA copolymers composed of monomers consisting of 4-14 carbons. The introduction of the engineered PHA synthase resulted in a 10-fold increase in PHA content compared to plants expressing the wild-type PHA synthase. In addition, expression of the engineered fabH gene in the plastid led to an increase in the amount of the SCL monomer, 3-hydroxybutyrate, incorporated into PHA, and contributed to supply of MCL monomers for PHA production.

Influence of composition and powder/water ratio on adhesion strength and initial viscosity of powder-type denture adhesives based on CMC-Na and PVM-MA.

We evaluated the influence of the composition and powder/water (P/W) ratio of powder-type denture adhesives (DA) based on sodium carboxymethyl cellulose (CMC-Na) and poly(methyl vinyl ether-maleic anhydride) (PVM-MA) on the strength of adhesion to acrylic resin and initial viscosity. Twenty types of DA were prepared by mixing CMC-Na and PVM-MA at various weight ratios with distilled water in P/W ratios ranging from 0.125 to 0.500. Adhesion strength and viscosity were measured using a universal testing machine and a controlled-stress rheometer, respectively. A higher percentage of CMC-Na and higher P/W ratios resulted in higher adhesion strength and viscosity. The effect of the CMC-Na/PVM-MA weight ratio on adhesion strength and viscosity was larger than that of the P/W ratio. DA with higher viscosity had higher adhesion strength. These results suggest that the adhesion strength and initial viscosity of powder-type DA can be controlled via the P/W ratio and the CMC-Na/PVM-MA weight ratio.

Calreticulin and integrin alpha dissociation induces anti-inflammatory programming in animal models of inflammatory bowel disease.

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a chronic intestinal inflammatory condition initiated by integrins-mediated leukocyte adhesion to the activated colonic microvascular endothelium. Calreticulin (CRT), a calcium-binding chaperone, is known as a partner in the activation of integrin α subunits (ITGAs). The relationship between their interaction and the pathogenesis of IBD is largely unknown. Here we show that a small molecule, orally active ER-464195-01, inhibits the CRT binding to ITGAs, which suppresses the adhesiveness of both T cells and neutrophils. Transcriptome analysis on colon samples from dextran sodium sulfate-induced colitis mice reveals that the increased expression of pro-inflammatory genes is downregulated by ER-464195-01. Its prophylactic and therapeutic administration to IBD mouse models ameliorates the severity of their diseases. We propose that leukocytes infiltration via the binding of CRT to ITGAs is necessary for the onset and development of the colitis and the inhibition of this interaction may be a novel therapeutic strategy for the treatment of IBD.

Targeted delivery of anticancer drugs to tumor vessels by use of liposomes modified with a peptide identified by phage biopanning with human endothelial progenitor cells.

As tumor angiogenic vessels are critical for tumor growth and express different molecules on their surface from those on normal vessels, these vessels are expected to be an ideal target for anticancer drug delivery systems. It was previously reported that endothelial progenitor cells (EPCs) are involved in angiogenesis, tumor growth, and metastasis, and that EPCs show gene expression patterns similar to those of tumor endothelial cells. In the present study, a tumor vessel-targeting peptide, ASSHN, was identified from a phage-display peptide library by in vitro biopanning with human EPCs (hEPCs) and in vivo biopanning using angiogenesis model mice prepared by the dorsal air sac method. Phage clones displaying ASSHN peptide showed a marked affinity for hEPCs in vitro, and also for tumor vessels in vivo. PEGylated liposomes modified with the ASSHN peptide (ASSHN-Lip) were designed and prepared for the delivery of anticancer agents. Confocal images showed that ASSHN-Lip clearly bound to hEPCs in vitro and tumor vessels, and also showed extravasation from the vessels. The administration of doxorubicin-encapsulated ASSHN-Lip into Colon26 NL-17-bearing mice significantly suppressed tumor growth compared with doxorubicin-encapsulated PEGylated liposomes. These results suggest that the delivery of anticancer agents with ASSHN-Lip could be useful for targeted cancer therapy.

Deletion analysis of the subunit genes of V-type Na+-ATPase from Enterococcus hirae.

The V1Vo-ATPase from Enterococcus hirae catalyzes ATP hydrolysis coupled with sodium translocation. Mutants with deletions of each of 10 subunits (NtpA, B, C, D, E, F, G, H, I, and K) were constructed by insertion of a chloramphenicol acetyltransferase gene into the corresponding subunit gene in the genome. Measurements of cell growth rates, 22Na+ efflux activities, and ATP hydrolysis activities of the membranes of the deletion mutants indicated that V-ATPase requires nine of the subunits, the exception being the NtpH subunit. The results of Western blotting and V1-ATPase dissociation analysis suggested that the A, B, C, D, E, F, and G subunits constitute the V1 moiety, whereas the V0 moiety comprises the I and K subunits.