Assessment of Antimicrobial Agents, Analgesics, and Epidermal Growth Factors-Embedded Anti-Adhesive Poly(Lactic-Co-Glycolic Acid) Nanofibrous Membranes: In vitro and in vivo Studies.

BACKGROUND: Postoperative tissue adhesion is a major concern for most surgeons and is a nearly unpreventable complication after abdominal or pelvic surgeries. This study explored the use of sandwich-structured antimicrobial agents, analgesics, and human epidermal growth factor (hEGF)-incorporated anti-adhesive poly(lactic-co-glycolic acid) nanofibrous membranes for surgical wounds. MATERIALS AND METHODS: Electrospinning and co-axial electrospinning techniques were utilized in fabricating the membranes. After spinning, the properties of the prepared membranes were assessed. Additionally, high-performance liquid chromatography and enzyme-linked immunosorbent assays were utilized in assessing the in vitro and in vivo liberation profiles of the pharmaceuticals and the hEGF from the membranes. RESULTS: The measured data suggest that the degradable anti-adhesive membranes discharged high levels of vancomycin/ceftazidime, ketorolac, and hEGF in vitro for more than 30, 24, and 27 days, respectively. The in vivo assessment in a rat laparotomy model indicated no adhesion in the peritoneal cavity at 14 days post-operation, demonstrating the anti-adhesive capability of the sandwich-structured nanofibrous membranes. The nanofibers also released effective levels of vancomycin, ceftazidime, and ketorolac for more than 28 days in vivo. Histological examination revealed no adverse effects. CONCLUSION: The outcomes of this study implied that the anti-adhesive nanofibers with sustained release of antimicrobial agents, analgesics, and growth factors might offer postoperative pain relief and infection control, as well as promote postoperative healing of surgical wounds.

Lubricin as a tool for controlling adhesion in vivo and ex vivo.

The ability to prevent or minimize the accumulation of unwanted biological materials on implantable medical devices is important in maintaining the long-term function of implants. To address this issue, there has been a focus on materials, both biological and synthetic, that have the potential to prevent device fouling. In this review, we introduce a glycoprotein called lubricin and report on its emergence as an effective antifouling coating material. We outline the versatility of lubricin coatings on different surfaces, describe the physical properties of its monolayer structures, and highlight its antifouling properties in improving implant compatibility as well as its use in treatment of ocular diseases and arthritis. This review further describes synthetic polymers mimicking the lubricin structure and function. We also discuss the potential future use of lubricin and its synthetic mimetics as antiadhesive biomaterials for therapeutic applications.

Insect Antiadhesive Surfaces Using Electrosprayed Wrinkled Ethyl Cellulose Particles.

A range of plants developed leaves, the surfaces of which prevent or diminish insect adhesion due to their microscopic topography. Well known examples include the leaves of the lychee tree (Litchi chinensis). Here, we report a method to coat substrates with ethyl cellulose microparticles that exhibit wrinkled surfaces, resulting in surface morphologies that closely resemble those of insect repelling plants, i.e., Litchi chinensis. The microparticles were prepared by electrospraying, a method that allowed tuning of the particle size and surface morphology. By measuring the traction forces of Colorado potato beetles walking on these surfaces, the wrinkly microsphere parameters were optimized, resulting in biomimetic surfaces that surpass the antiadhesive properties of the biological role model. This study may pave the way to sustainable, nontoxic insecticide replacements.

An anti-infective hydrogel adhesive with non-swelling and robust mechanical properties for sutureless wound closure.

A non-swelling hydrogel adhesive is urgently needed in clinical application for wound closure; however, preparing a non-swelling hydrogel adhesive with superior mechanical and tissue adhesion properties remains a challenge. In this study, we developed a new family of non-swelling hydrogel adhesives composed of Pluronic F127 diacrylate, poly(ethylene glycol) diacrylate, modified sodium alginate, and tannic acid. Physical and biological properties of the hydrogels were systematically evaluated in vitro/vivo. The results indicated that the hydrogels exhibited non-swelling features, robust mechanical properties and good adhesion abilities toward various tissues. The hydrogels also exhibited good cytocompatibility and strong antibacterial activities against S. aureus and E. coli. Additionally, the hydrogel could be used for sutureless wound closure and displayed better advantages compared to sutures and commercial adhesive pads. The above results demonstrated that our non-swelling hydrogel adhesive with robust mechanical properties holds great promise for applications in clinical surgery.

Engineering an adhesive based on photosensitive polymer hydrogels and silver nanoparticles for wound healing.

Hemostasis, wound closure and prevention of infection are critical to wound healing after an injury. Skin adhesives have been used to seal incisions, thus aiding primary wound healing, as well as creating a barrier to microbes. We constructed a skin adhesive with antibacterial and hemostatic activities (AHAs) for wound management. The adhesive was made by using methacrylated hyaluronan-polyacrylamide (MHA-PAAm) hydrogels, integrated with silver nanoparticles (AgNPs) and bonded to gelatin. Because of the three-dimensional network structure of the hydrogels, nanoscale particles can be encapsulated into their voids; the AgNPs, through sustained delivery of silver ions, endow the adhesives with sustained broad-spectrum antibacterial activity. Furthermore, due to the introduction of MHA which can be crosslinked by visible light, the polyacrylamide hydrogel matrix can be formed through photo crosslinking. In addition, gelatin can be bonded to both the hydrogel matrix and host tissues because of the interaction between carboxyl and amino-moieties. Our animal studies demonstrated that the AHAs which possess tissue adhesive and antibacterial properties were easy to stretch, and were able to stop bleeding in rat tail amputation and liver injury models. AHAs enhance wound granulation tissue formation, vascular tissue formation, and collagen formation, as well as alleviate inflammation. These properties promoted wound closure in rat wound infection models, promising great potential for applying AHAs in clinical uses.

The Role of 17ß-Estrogen in Candida albicans Adhesion on Human Vaginal Epithelial Cells via FAK Phosphorylation.

PURPOSES: To investigate the role of 17ß-estrogen in Candida albicans (C. albicans) adhesion on human vaginal epithelial cells in vulvovaginal candidiasis (VVC). METHODS: The vaginal epithelial cell line, VK2/E6E7, was used to study the estrogen-induced molecular events between C. albicans and cells. An adhesion study was performed to evaluate the involvement of the estrogen-dependent focal adhesion kinase (FAK) activation in cell adhesion. The phosphorylation status of FAK and estrogen receptor α (ERα) upon estrogen challenge was assessed by western blotting. Specific inhibitors for ERα were used to validate the involvement of ERα-FAK signaling cascade. RESULTS: A transient activation of ERα and FAK was observed following the stimulation with 1000 nM estrogen for 48 h, as well as the increased average number of C. albicans adhering to each vaginal epithelial cell. Estrogen-induced activation of ERa and FAK was inhibited by the specific inhibitor of ERα, especially when the inhibitor reached a 10 µM concentration and allowed to act for 12 h. Simultaneously, a decrease in the number of adherent C. albicans was observed. However, this inhibitory effect diminished as the concentration of estrogen increased. CONCLUSION: FAK and ERα signaling cascades were involved in the early interaction between the vaginal epithelial cells and C. albicans, which appeared to be linked with the enhanced cell adhesion leading to VVC and promoted by a certain concentration of estrogen.

Surface, adhesiveness and virulence aspects of Candida haemulonii species complex.

The emerging opportunistic pathogens comprising the Candida haemulonii complex (C. haemulonii [Ch], C. duobushaemulonii [Cd] and C. haemulonii var. vulnera[Chv]) are notable for their intrinsic antifungal resistance. Different clinical manifestations are associated with these fungal infections; however, little is known about their biology and potential virulence attributes. Herein, we evaluated some surface properties of 12 clinical isolates of Ch (n = 5), Cd (n = 4) and Chv (n = 3) as well as their virulence on murine macrophages and Galleria mellonella larvae. Scanning electron microscopy demonstrated the presence of homogeneous populations among the species of the C. haemulonii complex, represented by oval yeasts with surface irregularities able to form aggregates. Cell surface hydrophobicity was isolate-specific, exhibiting high (16.7%), moderate (25.0%) and low (58.3%) hydrophobicity. The isolates had negative surface charge, except for one. Mannose/glucose- and N-acetylglucosamine-containing glycoconjugates were evidenced in considerable amounts in all isolates; however, the surface expression of sialic acid was poorly detected. Cd isolates presented significantly higher amounts of chitin than Ch and Chv. Membrane sterol and lipid bodies, containing neutral lipids, were quite similar among all fungi studied. All isolates adhered to inert surfaces in the order: polystyrene > poly-L-lysine-coated glass > glass. Likewise, they interacted with murine macrophages in a quite similar way. Regarding in vivo virulence, the C. haemulonii species complex were able to kill at least 80% of the larvae after 120 hours. Our results evidenced the ability of C. haemulonii complex to produce potential surface-related virulence attributes, key components that actively participate in the infection process described in Candida spp.

Lycorine Hydrochloride Inhibits the Virulence Traits of Candida albicans.

The human opportunistic fungal pathogen Candida albicans causes a severe health burden while the biofilms formed by C. albicans present a kind of infections that are hard to cure, highlighting the pressing need for new antifungal drugs against C. albicans. This study was to explore the antifungal activities of lycorine hydrochloride (LH) against C. albicans. The minimal inhibitory concentration (MIC) of LH against C. albicans SC5314 was 64 µM. Below its MIC, LH demonstrated antivirulence property by suppressing adhesion, filamentation, biofilm formation, and development, as well as the production of extracellular phospholipase and exopolymeric substances (EPS). The cytotoxicity of LH against mammalian cells was low, with half maximal inhibitory concentrations (IC50) above 256 µM. Moreover, LH showed a synergistic effect with AmB, although its interaction with fluconazole, as well as caspofungin, was indifferent. Thus, our study reports the potential use of LH, alone or in combination with current antifungal drugs, to fight C. albicans infections.

Adhesive alginate for buccal delivery in aphthous stomatitis.

BACKGROUND: Recurrent aphthous stomatitis being the most common chronic disease of the oral cavity affects 5-25% of the population. AIM: This study goals to develop a novel polymeric excipient based on alginate with enhanced mucoadhesion and controlled release for buccal therapy of aphthae. METHODS: Sulfhydryl groups of amino acid cysteine (SH) was anchored on the polymeric backbone of alginate (AL). Furthermore, mucoadhesiveness, stability and release profile as well as permeation of ambroxol through buccal mucosa were examined. RESULTS: Sulfhydryl anchored alginate was successfully synthesized. The stability was 3.52-fold improved in presence of sulfhydryl anchored alginate compared to alginate. Mucoadhesive studies revealed an 11.56-fold augmentation in adhesion time with AL-SH instead of AL. Ambroxol showed a 1.4-fold controlled release in presence of AL-SH and AL, respectively. The permeation profile of ambroxol was 1.89-fold higher in case of AL-SH compared to AL. CONCLUSION: The obtained AL-SH will pave the pathway for the aphthae therapy.

Effect of epigallocatechin-3- gallate solutions on bond durability at the adhesive interface in caries-affected dentin.

Hydrolytic and enzymatic degradation by matrix metalloproteinases (MMPs) reduces the durability of composite resin restorations on caries-affected dentin (CAD). The use of MMP inhibitors such as epigallocatechin-3-gallate (EGCG) could increase the longevity of the bond to dentin. This study aimed to evaluate the use of EGCG at different aqueous concentrations on the resin-dentin microtensile bond strength (µTBS), fracture pattern and nanoleakage (NL) in immediate (IM) time interval and after 12-months of water storage (1Y) when using a two-step etch-and-rinse adhesive system on CAD. Dentin surfaces of 40 human molars were submitted to a microbiological caries induction protocol and randomized into 5 groups (n = 8) (0.02% EGCG; 0.2% EGCG; 0.5% EGCG; 2% Chlorhexidine [CHX] and no treatment as Control Group - [NT]). After acid etching, the solutions were applied for 60 s followed by application of dental adhesive (Adper Single Bond 2, 3 M ESPE) to CAD surfaces. Subsequently, a resin composite (4 mm) block was built on the dentin. After 24 h, the teeth were sectioned into beam-shaped specimens (cross-sectional area of 1 mm2 and 8-mm high). Half of the specimens were tested in IM and the other half after 1Y. Two samples per tooth were submitted to SEM for NL evaluation. Data were statistically analyzed by two-way ANOVA and Tukey tests (α = 0.05). The results showed that use of EGCG and CHX did not affect µTBS in IM (p > 0.05). After 1Y, there was a reduction in µTBS for all experimental groups (p < 0.05). Adhesive fractures predominated in IM in all groups, except for 0.05% EGCG and NT. After 1Y, there was an increase in these adhesive fractures in all groups. For NL, all agents applied reduced NL in comparison with CT (p < 0.001). CHX showed lower NL (p < 0.001), followed by 0.02% and 0.5% EGCG. NT showed highest NL for both time intervals (p < 0.001). Thus, although the use of EGCG at different concentrations and CHX reduced the NL, they were unable to reduce degradation of µTBS to CAD over time.

Localized drug delivery with mono and bilayered mucoadhesive films and wafers for oral mucosal infections.

Local drug delivery into oral cavity offers many advantages over systemic administration in treatment of the oral infections. In this study, monolayer and bilayered mucoadhesive film and wafer formulations were developed as local drug delivery platforms using chitosan and hydroxypropyl methylcellulose (HPMC). Cefuroxime axetil (CA) was used as the model drug. Surface morphology, mechanical strength, water uptake, in vitro adhesion, disintegration and in vitro release properties of the formulations were investigated. Furthermore, antimicrobial activity of the formulations was evaluated against E. coli and S. aureus. HPMC based formulations were found to disintegrate within <30 min whereas chitosan based formulations remained intact up to 6 h. Significantly higher drug release was obtained with wafer formulations. Antimicrobial activity was found to increase in presence of chitosan, and HPMC was also observed to contribute to this action. Bilayered wafer formulation, with adhesive chitosan backing layer and HPMC based drug loaded layer, providing prolonged drug release and suitable adhesive properties, with suitable mechanical strength, would be suggested as a promising local delivery system for treatment of the infections in the oral cavity.

In Vitro Evaluation of Adhesion of Candida albicans on CAD/CAM PMMA-Based Polymers.

PURPOSE: To compare the amount of adherent Candida albicans to different CAD/CAM poly(methyl methacrylate) (PMMA)-based polymers and conventional heat-polymerized PMMA after long-term thermal cycling. MATERIALS AND METHODS: The specimens were subjected to 10,000 thermal cycles (5-55°C) and divided into two groups, uncoated and pellicle-coated. Surface roughness and contact angles of the specimens were measured. The surface morphology was observed with scanning electron microscopy (SEM). An adhesion test was performed by incubating the disk specimens in C. albicans suspensions at 37°C for 2 hours, and the adherent cells were counted under an optical microscope. The data were analyzed statistically using a variance analysis and Tukey HSD post hoc comparison test. The correlation between measurements was tested using a Pearson correlation analysis (α = 0.05). RESULTS: CAD/CAM polymers generally showed statistically significant lowest Ra and contact angle values, whereas conventional PMMA showed the highest Ra and contact angle values in the uncoated group (p < 0.05). Pellicle coating essentially increased contact angle of all materials and reduced the differences in a number of Candida cells on the materials (p < 0.05). Candida adhesion was statistically significantly greatest on conventional PMMA when compared to CAD/CAM polymers. A strong positive correlation was found between the surface roughness of the specimens (p < 0.05) and the amount of adhered cells, whereas no correlation was found between hydrophobicity of the specimens and the amount of adhered cells (p > 0.05). CONCLUSIONS: CAD/CAM PMMA-based polymers may be preferable to reduce Candida-associated denture stomatitis in long-term use.

Influence of nano-hydroxyapatite containing desensitizing toothpastes on the sealing ability of dentinal tubules and bonding performance of self-etch adhesives.

OBJECTIVES: To evaluate the dentinal tubular occlusion of nano-hydroxyapatite (nHAp) containing desensitizing toothpastes and their influence on the resin-dentin bonding performance of two mild self-etch adhesives. MATERIALS AND METHODS: Mid-coronal dentin specimens were prepared from obtained intact human third molars. They were immersed in 1% citric acid for 20 s to expose the dentinal tubules to simulate sensitive teeth and then randomly divided into four groups. The control group received no desensitizing treatment. Experimental groups were treated with two commercial nHAp containing desensitizing toothpastes (Biorepair and Dontodent) and an experimental pure nHAp paste respectively. Each group was further divided into two subgroups and bonded with either G-Bond or Clearfil S3 Bond. The micro-tensile bond strength was tested and failure mode distribution was analyzed. Moreover, the effect of desensitizers on dentinal tubular occlusion was observed by the field-emission scanning electron microscope (FESEM). Resin infiltration of the adhesives labeled by fluorescent Rhodamin B was evaluated under confocal laser scanning microscopy (CLSM). RESULTS: FESEM revealed that all the desensitizers noticeably occluded the dentinal tubules, and the extents were completer after application for 7 days. The majority of the occlusion still preserved even after acid challenge with cola or adhesive. CLSM demonstrated shorter resin tags were produced in the desensitized groups. When bonding with G-Bond, the pure nHAp group showed comparable bond strength to the control group, while Biorepair and Dontodent treatment decreased the bond strength. For groups bonded with Clearfil S3 Bond, all the desensitizers reduced the bond strengths compared to the control and no significant difference was found among the three groups. CONCLUSION: Nano-hydroxyapatite containing desensitizing toothpastes could occlude dentinal tubules effectively with a certain degree of acid resistance, which contributes to the relief of dentin hypersensitivity. While, the application of these nHAp desensitizers comprised the resin infiltration of G-Bond and Clearfil S3 Bond, resulting in decreased bond strengths of the resin-dentin bonding.

A high level of TGF-B1 promotes endometriosis development via cell migration, adhesiveness, colonization, and invasiveness†.

Endometriosis is a prevalent gynecological disorder that eventually gives rise to painful invasive lesions. Increased levels of transforming growth factor-beta 1 (TGF-B1) have been reported in endometriosis. However, details of the effects of high TGF-B1 on downstream signaling in ectopic endometrial tissue remain obscure. We induced endometriotic lesions in mice by surgical auto-transplantation of endometrial tissues to the peritoneal regions. We then treated endometriotic (ectopic and eutopic endometrial tissues) and nonendometriotic (only eutopic endometrial tissues) animal groups with either active TGF-B1 or PBS. Our results demonstrate that externally supplemented TGF-B1 increases the growth of ectopically implanted endometrial tissues in mice, possibly via SMAD2/3 activation and PTEN suppression. Adhesion molecules integrins (beta3 and beta8) and FAK were upregulated in the ectopic endometrial tissue when TGF-B1 was administered. Phosphorylated E-cadherin, N-cadherin, and vimentin were enhanced in the ectopic endometrial tissue in the presence of TGF-B1 in the mouse model, and correlated with epithelial-mesenchymal transition (EMT) in ovarian endometriotic cells of human origin. Furthermore, in response to TGF-B1, the expression of RHOGTPases (RAC1, RHOC, and RHOG) was increased in the human endometriotic cells (ovarian cyst derived cells from endometriosis patient) and tissues from the mouse model of endometriosis (ectopic endometrial tissue). TGF-B1 enhanced the migratory, invasive, and colonizing potential of human endometriotic cells. Therefore, we conclude that TGF-B1 potentiates the adhesion of ectopic endometrial cells/tissues in the peritoneal region by enhancing the integrin and FAK signaling axis, and also migration via cadherin-mediated EMT and RHOGTPase signaling cascades.

Effect of different bonding protocols on degree of monomer conversion and bond strength between orthodontic brackets and enamel.

The objective of the present study was to evaluate the effect of different surface treatments and polymerization protocols on the bond strength of brackets to enamel, and the degree of conversion of the bonding agents. 120 bovine crowns were embedded in acrylic resin blocks and sanded. Next, the blocks were randomly assigned into 12 groups. Metal brackets were bonded to enamel according to the "surface treatment" factor (A: Phosphoric Acid; ATxt: Phosphoric Acid + Transbond XT Primer®; Tse: Transbond Plus Self Etching Primer®; and SBU: Scotchbond Universal®) and "polymerization" factor (R20: Radii-Cal®/20 seconds; V20: Valo Cordless®/20 seconds; and V3: Valo Cordless®/3 seconds). All samples were stored for 6 months (water, 37ºC) and then subjected to a shear bond strength test (SBS). Bond failures were classified according to the Adhesive Remnant Index (ARI) and analyzed with the Kruskal-Wallis and Mann-Whitney tests (5%). Using the same factors, 120 resin discs were made to assess the degree of conversion (DC) of the monomer. Data from the SBS (MPa) and DC (%) were analyzed by analysis of variance (2 factors) and Tukey's test (5%). For the SBS, the factors "polymerization" (R20 = 8.1B; V20 = 13.2A; V3 = 5.2C, p = 0.0001) and "surface treatment" (A = 3.1C; ATxt = 13.6A; Tse = 12.3A; SBU = 6.3B, p = 0.0001) were statistically significant among groups. The highest adhesion value were found for the ATxt/V20 group (22.2A) and the lowest value for the A/R20 group (1.2E). Regarding ARI, score 2 was the most prevalent in groups A, ATxt, V20 and V3, while score 4 was the most prevalent in the Tse, SBU and R20 groups, with no significant difference between them (p = 1.0). Regarding DC, the factors "polymerization" (R20 = 66.6A; V20 = 58.4B; V3 = 45.1C, p = 0.0001) and "surface treatment" (A = 52B, ATxt = 59.7A, Tse = 51.4B, SBU = 63.8A, p = 0.0001) were statistically significant. Tse was more sensitive to the variations in polymerization protocols than the other surface treatments. Treatment A did not present suitable bond strength or degree of conversion.

Physical and biological properties of a novel anti-adhesion material made of thermally cross-linked gelatin film: Investigation of the usefulness as anti-adhesion material.

To create more useful, effective and safer anti-adhesion materials, we developed a thermally cross-linked gelatin film. In this study, we examined the physical properties of the film such as the physical strength and the adhesiveness to reveal the handling properties and biological properties, such as the anti-adhesion effect, the influence on cell proliferation, and the cytotoxicity to reveal the anti-adhesion mechanism, especially in comparison with the conventional hyaluronic acid and carboxymethylcellulose film (the conventional film). A tensile test under dry and wet conditions and shearing stress test showed that the gelatin film has significant higher maximum tensile stress and fracture strain than the conventional film. In the study using a rat model of cecum adhesion, the anti-adhesion effect of the gelatin film was significantly superior to that of the conventional film. In the cell proliferation test, the number of fibroblast cells on the gelatin film increased at each time point, while no cell proliferation was observed on the conventional film. Furthermore, in the cytotoxicity test using a colony assay and Live/Dead assay, the extract of the gelatin film had no cytotoxicity, while the extract of the conventional film had cytotoxicity considerably. These results suggest that the gelatin film provides better handling than the conventional film, due to better physical strength and ductility of the film. In addition, the gelatin film has a significantly greater anti-adhesion effect than the conventional film without any cytotoxicity. Therefore, the gelatin film is quite favorable as an anti-adhesion material. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 689-696, 2018.

Effect of different bonding protocols on degree of monomer conversion and bond strength between orthodontic brackets and enamel

Abstract The objective of the present study was to evaluate the effect of different surface treatments and polymerization protocols on the bond strength of brackets to enamel, and the degree of conversion of the bonding agents. 120 bovine crowns were embedded in acrylic resin blocks and sanded. Next, the blocks were randomly assigned into 12 groups. Metal brackets were bonded to enamel according to the "surface treatment" factor (A: Phosphoric Acid; ATxt: Phosphoric Acid + Transbond XT Primer®; Tse: Transbond Plus Self Etching Primer®; and SBU: Scotchbond Universal®) and "polymerization" factor (R20: Radii-Cal®/20 seconds; V20: Valo Cordless®/20 seconds; and V3: Valo Cordless®/3 seconds). All samples were stored for 6 months (water, 37ºC) and then subjected to a shear bond strength test (SBS). Bond failures were classified according to the Adhesive Remnant Index (ARI) and analyzed with the Kruskal-Wallis and Mann-Whitney tests (5%). Using the same factors, 120 resin discs were made to assess the degree of conversion (DC) of the monomer. Data from the SBS (MPa) and DC (%) were analyzed by analysis of variance (2 factors) and Tukey's test (5%). For the SBS, the factors "polymerization" (R20 = 8.1B; V20 = 13.2A; V3 = 5.2C, p = 0.0001) and "surface treatment" (A = 3.1C; ATxt = 13.6A; Tse = 12.3A; SBU = 6.3B, p = 0.0001) were statistically significant among groups. The highest adhesion value were found for the ATxt/V20 group (22.2A) and the lowest value for the A/R20 group (1.2E). Regarding ARI, score 2 was the most prevalent in groups A, ATxt, V20 and V3, while score 4 was the most prevalent in the Tse, SBU and R20 groups, with no significant difference between them (p = 1.0). Regarding DC, the factors "polymerization" (R20 = 66.6A; V20 = 58.4B; V3 = 45.1C, p = 0.0001) and "surface treatment" (A = 52B, ATxt = 59.7A, Tse = 51.4B, SBU = 63.8A, p = 0.0001) were statistically significant. Tse was more sensitive to the variations in polymerization protocols than the other surface treatments. Treatment A did not present suitable bond strength or degree of conversion.

Thermo-responsive hydroxybutyl chitosan hydrogel as artery intervention embolic agent for hemorrhage control.

This work targeted to investigate the potential of thermo-responsive hydroxybutyl chitosan (HBC) hydrogel using as an embolic material for occlusion of selective blood vessels. HBC hydrogel was prepared via an etherification reaction between chitosan (CS) and 1, 2-butene oxide. The hydroxybutyl groups were introduced into CS backbone, which endowed HBC hydrogel with properties of porous structure, favorable hydrophilia and rapid sol-gel interconvertibility. The gelation temperatures and gelation time respectively decreased from 30.7°C to 11.5°C and 79.60±3.19s to 7.70±1.42s at 37°C, with HBC solutions viscoelasticity increased from 3.0% to 7.0%. HBC hydrogel exhibited noncytotoxic to mouse embryo fibroblasts (MEFs) and excellent hemocompatibility with red blood cells (RBCs). After injection HBC solution into rat renal arteries, HBC solution transformed into hydrogel and attached onto blood vessel inner wall tightly, giving immediate blood vessels embolization. Meanwhile, RBCs could aggregate around HBC hydrogel to form moderate coagulation, which was beneficial to avoid hydrogel migration with blood flow. Above results suggested that HBC hydrogel could be applied as a promising embolic agent for hemorrage in the interventional vascular embolization field.

Inhibition of denture plaque by TiO2 coating on denture base resins in the mouth.

STATEMENT OF PROBLEM: Information is lacking about antiadhesion effect of titanium dioxide (TiO2) coating on denture base resins in the mouth. PURPOSE: The purpose of this clinical study was to investigate the antiadhesion effect of TiO2 coating on denture base resins. MATERIAL AND METHODS: Ten healthy dentate participants (mean 27 ±2 years of age) participated in this study. Disks and palatal appliances were made with denture base resin. They were divided into 2 groups: a TiO2-coated group and an uncoated group. A primer and a top coat containing TiO2 were applied to the surfaces of the resin by means of an air spray. In the denture plaque staining test, resin disks were fixed to the retainer, placed in each participant's mouth for 3 days, and stained with a dental plaque-disclosing solution. The staining rate was calculated. The resin disks and palatal appliances were used to measure the total number of microbes. The resin specimens were placed in each participant's mouth for either 3 or 7 days and swabbed to count the total number of microbes. The chewing gum adherence test was performed both subjectively and objectively. Subjectively, each participant wearing a palatal appliance rated adherence using a visual analog scale. The objective test was performed with a chewing gum adhesion test. The staining rate, the total number of microbes, and the visual analog scale values were statistically analyzed using the Wilcoxon signed rank test, and the adhesive force was statistically analyzed using a Student t test. RESULTS: In the denture plaque staining test, the measurement of microbes, and the resin chewing gum adherence test results, significant differences were observed between the TiO2-coated groups and the uncoated groups. CONCLUSIONS: TiO2 coating of the denture base acrylic resin inhibited the adhesion of microbes, denture plaque, and highly adhesive food.

Effects of trimethylsilane plasma coating on the hydrophobicity of denture base resin and adhesion of Candida albicans on resin surfaces.

STATEMENT OF PROBLEM: Candida-associated denture stomatitis is the most common oral mucosal lesion among denture wearers. Trimethylsilane (TMS) plasma coating may inhibit the growth of Candida albicans on denture surfaces. PURPOSE: The purpose of this in vitro study was to investigate whether TMS plasma coatings can effectively reduce C albicans adhesion on denture base acrylic resin surfaces. MATERIAL AND METHODS: Sixty denture base acrylic resin disks with smooth and rough surfaces were prepared and were either left untreated (control group) or coated with TMS monomer (experimental group) by using plasma. Contact angles were measured immediately after TMS plasma coating. The morphology of C albicans adhesion was observed with scanning electron microscopy (SEM). Energy-dispersive spectroscopy (EDS) was used to characterize the elemental composition of the specimen surface. An adhesion test was performed by incubating the resin disk specimens in C albicans suspensions (1×107 cells/mL) at 37°C for 24 hours and further measuring the optical density of the C albicans by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay test. One-way ANOVA and 2-way ANOVA were followed by a post hoc test analysis (α=.05). RESULTS: The group with TMS coating exhibited a more hydrophobic surface than the control group. EDS analysis revealed successful TMS plasma coating. The difference in the mean contact angles between the uncoated group and the TMS-coated group was statistically significant (P<.05), 79.0 ±2.9 degrees versus 105.7 ±1.5 degrees for the smooth surface and 90.2 ±7.6 degrees versus 131.5 ±2.1 degrees for the rough surface. In SEM analysis, the C albicans biofilm was found to grow more on the surface of the denture base resin without the TMS coating than on the surfaces of the experimental group. In the adhesion test, the amount of C albicans adhering to the surface of denture base resin with the TMS coating was significantly less than that on the surfaces without TMS coating (P<.05). CONCLUSIONS: TMS coating significantly reduced the adhesion of C albicans to the denture base resin and may reduce denture stomatitis.