Analyzing the effects of physical activity levels on aggressive behavior in college students using a chain-mediated model.

This study aims to examine the mediating role of self-efficacy (SE) and self-control (SC) in the relationship between physical activity (PA) and aggressive behaviors (AB) among college students. It provides a basis for the prevention and control of AB among college students. This study employed a survey research methodology, including the PA Level Scale, the General Self-efficacy Scale, the Self-control Scale, and the Chinese Aggressive Behaviors Scale on 950 college students. The chain mediating effect test and Bootstrap analysis were applied. The results were as follows: (1) There was a main effect of PA on SE, SC, and AB as well as all sub-indicators (physical aggression, verbal aggression, anger, hostility, self-directed aggression), i.e., PA had a direct effect on the control of all three; (2) PA level was significantly negatively correlated with AB and significantly positively correlated with SE and SC. That is, the higher the level of PA, the better the SE and SC, and the lower the probability of AB; (3) The three pathways had mediating effects: PA → SE → AB, PA → SC → AB, PA → SE → SC → AB, with effect sizes of 8.78%, 28.63%, and 19.08%, respectively. It is concluded that regular PA is a potent method for decreasing aggressive behavior and psychological issues in university students while additionally promoting self-efficacy and self-control. Increasing the intensity of PA may enhance the effectiveness of these chain benefits.

Dynamic Modulation of Li2O2 Growth in Li-O2 Batteries through Regulating Oxygen Reduction Kinetics with Photo-Assisted Cathodes.

Widely acknowledged that the capacity of Li-O2 batteries (LOBs) should be strongly determined by growth behaviors of the discharge product of lithium peroxide (Li2O2) that follows both coexisting surface and solution pathways. However until now, it remains still challenging to achieve dynamic modulation on Li2O2 morphologies. Herein, the photo-responsive Au nanoparticles (NPs) supported on reduced oxide graphene (Au/rGO) have been utilized as cathode to manipulate oxygen reduction reaction (ORR) kinetics by aid of surface plasmon resonance (SPR) effects. Thus, we can experimentally reveal the importance of matching ORR kinetics with Li+ migration towards battery performance. Moreover, it is found that Li+ concentration polarization caused "sudden death" of LOBs is supposed to be just a form of suspended animation that could timely recover under irradiation. This work provides us an in-depth explanation on the working mechanism of LOBs from a kinetic perspective, offering valuable insights for the future battery design.

High-intensity interval training versus moderate-intensity continuous training on patient quality of life in cardiovascular disease: a systematic review and meta-analysis.

This systematic review and meta-analysis aimed to compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on the quality of life (QOL) and mental health (MH) of patients with cardiovascular disease (CVDs). Web of Science, Medline, Embase, Cochrane (CENTRAL), CINAHL, China National Knowledge Infrastructure, Wanfang, and China Science and Technology Journal databases were searched from their date of establishment to July, 2023. A total of 5798 articles were screened, of which 25 were included according to the eligibility criteria. The weighted mean difference (WMD) and standardized mean difference (SMD) were used to analyze data from the same and different indicator categories, respectively. The fixed-effects model (FE) or random-effects model (RE) combined data based on the between-study heterogeneity. There were no statistically significant differences regarding QOL, physical component summary (PCS), mental component summary (MCS), and MH, including depression and anxiety levels, between the HIIT and MICT groups [SMD = 0.21, 95% confidence interval (CI) - 0.18-0.61, Z = 1.06, P = 0.290; SMD = 0.10, 95% CI - 0.03-0.23, Z = 1.52, P = 0.128; SMD = 0.07, 95% CI - 0.05-0.20, Z = 1.13, P = 0.25; SMD = - 0.08, 95% CI - 0.40-0.25, Z = - 0.46, P = 0.646; WMD = 0.14. 95% CI - 0.56-0.84, Z = 0.39, P = 0.694, respectively]. HIIT significantly improved PCS in the coronary artery disease (CAD) population subgroup relative to MICT. HIIT was also significantly superior to MICT for physical role, vitality, and social function. We conclude that HIIT and MICT have similar effects on QOL and MH in patients with CVD, while HIIT is favorable for improving patients' self-perceived physiological functioning based on their status and social adjustment, and this effect is more significant in patients with CAD.

Hypericin nanoparticles for self-illuminated photodynamic cytotoxicity based on bioluminescence resonance energy transfer.

The purpose of this study was to investigate the self-sensitization of photosensitizer without an external light source to produce a photodynamic therapy (PDT) effect based on the principle of bioluminescence resonance energy transfer (PDT-BRET). First, we demonstrated that HeLa cells could efficiently express firefly luciferase (FLase) after the firefly luciferase gene was transfected with the FLase-gene plasmid (FLase-GP), and proved that FLase could act on the substrate firefly D-luciferin (FLuc) to produce photons. The generated photons activate the photosensitizer hypericin (Hyp) and induce cytotoxicity. Then, we successfully prepared carboxymethyl chitosan-modified poly(lactic-co-glycolic acid) nanoparticles (CPNPs) loaded with FLuc (FLuc-CPNPs) and with loaded Hyp (Hyp-CPNPs). Their physicochemical and pharmaceutical characteristics indicated that they were an excellent drug delivery system. Characterization of the biological effects showed that they could be located in the mitochondrial, had higher ROS generation and stronger cytotoxicity. In vivo results also showed that PDT-BRET was as effective as classic PDT. PDT-BRET and the related drug delivery system are expected to become a new platform for anticancer therapy.

In Situ Fabrication of Porous Cox P Hierarchical Nanostructures on Carbon Fiber Cloth with Exceptional Performance for Sodium Storage.

Superior high-rate performance and ultralong cycling life have been constantly pursued for rechargeable sodium-ion batteries (SIBs). In this work, a facile strategy is employed to successfully synthesize porous Cox P hierarchical nanostructures supported on a flexible carbon fiber cloth (Cox P@CFC), constructing a robust architecture of ordered nanoarrays. Via such a unique design, porous and bare structures can thoroughly expose the electroactive surfaces to the electrolyte, which is favorable for ultrafast sodium-ion storage. In addition, the CFC provides an interconnected 3D conductive network to ensure firm electrical connection of the electrode materials. Besides the inherent flexibility of the CFC, the integration of the hierarchical structures of Cox P with the CFC, as well as the strong synergistic effect between them, effectively help to buffer the mechanical stress caused by repeated sodiation/desodiation, thereby guaranteeing the structural integrity of the overall electrode. Consequently, Cox P@CFC as an anode shows a record-high capacity of 279 mAh g-1 at 5.0 A g-1 with almost no capacity attenuation after 9000 cycles.

Highly Active PdO/Mn3 O4 /CeO2 Nanocomposites Supported on One Dimensional Halloysite Nanotubes for Photoassisted Thermal Catalytic Methane Combustion.

In this work, we have successfully triggered the aqueous auto-redox reactions between reductive Ce(OH)3 and oxidative MnO4 - /Pd2+ ions to form PdO/Mn3 O4 /CeO2 (PMC) nanocomposites. PMC could spontaneously self-assemble into compact encapsulation on the surface of halloysite nanotubes (HNTs) to form the final one dimensional HNTs supported PMCs (HPMC). It is identified that there exists strong synergistic effects among the components of PdO, Mn3 O4 , and CeO2 , and hence HPMC could show excellent performance on photoassisted thermal catalytic CH4 combustion that its light-off temperature was sharply reduced to be 180 °C under visible light irradiation. Based on detailed studies, it is found that the catalytic reaction process well follows the classic MVK mechanism, and adsorption/activation of O2 into active oxygen species (O*) should be the rate-determining step for CH4 conversion.

Oral administration co-delivery nanoparticles of docetaxel and bevacizumab for improving intestinal absorption and enhancing anticancer activity.

In this study, to improve the intestinal absorption of small molecule chemotherapeutic drug docetaxel (DTX) and macromolecular monoclonal antibody drug bevacizumab (BVZ), we designed and prepared a type of co-delivery nanoparticles for the oral administration of DTX and BVZ. Carboxymethyl chitosan (CMC) and poly(lactic-co-glycolic acid) (PLGA) were used as the carrier of DTX nanoparticles (CPNPDTX), and methoxy polyethylene glycol-poly (ß-amino ester) (mPEG-PAE) was used as the carrier of BVZ nanoparticles (PPNPBVZ). Then, the two nanoparticles were physically mixed in mass ratios to form mixed co-delivery nanoparticles, which was named as CPNPDTX&PPNPBVZ. The nanoparticles were characterized with pH-sensitive drug release property. CPNPDTX&PPNPBVZ could significantly increase the bioavailability of DTX and BVZ according to the more cellular uptake in Caco-2 cells and the higher absorption in the intestinal tissue. Compared with free DTX and BVZ, CPNPDTX&PPNPBVZ showed excellent cytotoxic effects on A549 cells. Our study revealed the potential of co-delivery nanoparticles of binary mixture of chemotherapeutic small molecule and macromolecular antibody drug as an oral administration therapeutic system.

Binary blended co-delivery nanoparticles with the characteristics of precise pH-responsive acting on tumor microenvironment.

Although combined chemotherapy had achieved the ideal efficacy in clinical anti-cancer therapeutic, the issues that need to be addressed are non-targeting and toxic-side effects of small molecule chemical drug (SMCD). In this study, we designed and prepared a novel binary blended co-delivered nanoparticles (BBCD NPs) with pH-responsive feature on tumor microenvironment. The BBCD NPs consists of two kind of drug-loaded NPs, in one of which carboxymethyl chitosan (CMC) and Poly (lactic-co-glycolic acid) (PLGA) were chosen as delivery carrier to load anti-cancer drug vincristine (VCR), named CMC-PLGA-VCR NPs (or CPNPVCR); and in the other of which methoxy poly(ethylene glycol)-poly(ß-amino ester) (mPEG-PAE) were chosen as delivery carrier to load anti-fibrotic drug pirfenidone (PFD), named mPEG-PAE-PFD NPs (or PPNPPFD). Then, the two types of NPs (CPNPVCR and PPNPPFD) were physically mixed in mass ratios to form BBCD NPs, which was named CPNPVCR&PPNPPFD. CPNPVCR&PPNPPFD had good encapsulation efficiency and loading capacity, and the particle size distribution was uniform. In cytotoxicity experiments and non-contact co-culture studies in vitro, the model drugs loaded in CPNPVCR&PPNPPFD could respectively target cancer cell and cancer associated fibroblast (CAF) owing to the precise pH-sensitive drug release in the pharmacological targets and show stronger synergism than that of the combined treatment of two free drugs. As a modularity and assemble ability feature in design, BBCD NPs would have the advantages on the terms of concise on preparation process, controllable on quality standard, stable in natural environment storage. The research results can provide scientific evidence for the further development of a novel drug co-delivery system with multi-type cell targets.

Co-delivery nanoparticles of doxorubicin and chloroquine for improving the anti-cancer effect in vitro.

To increase the efficacy of small molecule chemotherapeutic drug (SMCD) and reduce its toxic and side effects, we selected two model drugs doxorubicin (DOX) and chloroquine (CQ). DOX is a SMCD and CQis a chemosensitizer with autophagy inhibition. Poly(lactic-co-glycolic acid) (PLGA) and alpha-tocopherol polyethylene glycol 1000 succinate were chosen as delivery carriers to design and prepare a novel type of drug co-delivery single-nanoparticles by emulsification-solvent volatilisation, named NPDOX+CQ. The physicochemical properties of NPDOX+CQ were characterised. Then A549 cells and A549/Taxol cells were used for the in vitro anti-cancer effect study. At the same time, cellular uptake, intracellular migration and anti-cancer mechanism of nanoparticles were studied. The NPs showed a uniform spherical shape with good dispersibility, and both drugs had good encapsulation efficiency and loading capacity. In all formulations, NPDOX+CQ showed the highest in vitro cytotoxicity. The results showed that NPs could protect drugs from being recognised and excluded by P-glycoprotein (P-gp). Moreover, the results of the mechanistic study demonstrated that NPs were transported by autophagy process after being taken up by the cells. Therefore, during the migration of NPDOX+CQ, CQ could exert its efficacy and block autophagy so that DOX would not be hit by autophagy. Western Blot results showed that NPDOX+CQ had the best inhibition effect of autophagy. It can be concluded that the system can prevent the drug from being recognised and excluded by P-gp, and CQ blocks the process of autophagy so that the DOX is protected and more distributed to the nucleus of multidrug resistance (MDR) cell. The NPDOX+CQ constructed in this study provides a feasible strategy for reversing MDR in tumour cells.

Photothermal-Triggered Controlled Drug Release from Mesoporous Silica Nanoparticles Based on Base-Pairing Rules.

Base-pairing is stable under physiological temperature but broken by heating, which is the basic mechanism for nucleic acid amplification in biology. In this manuscript, a simple controlled-drug-release system was prepared on the basis of this rule and its in vivo activity was studied. Poly adenine (poly A), the tail of the synthesized RNA chain, was exploited as gatekeeper of thymine (T)-modified mesoporous silica nanoparticles (MSN-T) based on the simple A-T base-pairing rules. The gate keeper maintains stability to avoid drug (chemotherapy and photothermal therapy drugs) release during the delivery process but is effectively removed by a photothermal effect to trigger drug release at the tumor tissue by near-infrared (NIR) laser irradiation. In vitro and in vivo experiments indicated that the prepared nanomedicine could effectively suppress tumor growth and activate antitumor immunity.

Co-delivery nanoparticles of anti-cancer drugs for improving chemotherapy efficacy.

To achieve superior therapeutic efficacy, the combination chemotherapy using two or more anticancer drugs in clinical practice has been generally accepted as a feasible strategy. On account of the concept of combination chemotherapy, co-delivery of anticancer drugs with nanotechnology gradually becomes a desired strategy and one of the research frontiers on modern drug delivery. In recent years, nano drug co-delivery system (NDCDS), which loads at least two anticancer drugs with different physicochemical and pharmacological properties into a combination delivery system, has achieved rapid development. NDCDS synergistically inhibited the growth of the tumor compared with the free drugs. In this review, we highlighted the current state of co-delivery nanoparticles and the most commonly used nanomaterial, discussed challenges and strategies, and prospect future development.

Epigallocatechin-3-gallate and Epigallocatechin-3-O-(3-O-methyl)-gallate Enhance the Bonding Stability of an Etch-and-Rinse Adhesive to Dentin.

This study evaluated epigallocatechin-3-gallate (EGCG) and epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG-3Me) modified etch-and-rinse adhesives (Single Bond 2, SB 2) for their antibacterial effect and bonding stability to dentin. EGCG-3Me was isolated and purified with column chromatography and preparative high performance liquid chromatography. EGCG and EGCG-3Me were incorporated separately into the adhesive SB 2 at concentrations of 200, 400, and 600 µg/mL. The effect of cured adhesives on the growth of Streptococcus mutans (S. mutans) was determined with scanning electron microscopy and confocal laser scanning microscopy; the biofilm of bacteria was further quantified via optical density 600 values. The inhibition of EGCG and EGCG-3Me on dentin-originated collagen proteases activities was evaluated with a proteases fluorometric assay kit. The degree of conversion (DC) of the adhesives was tested with micro-Raman spectrum. The immediate and post-thermocycling (5000 cycles) bond strength was assessed through Microtensile Bond Strength (MTBS) test. Cured EGCG/EGCG-3Me modified adhesives inhibit the growth of S. mutans in a concentration-dependent manner. The immediate MTBS of SB 2 was not compromised by EGCG/EGCG-3Me modification. EGCG/EGCG-3Me modified adhesive had higher MTBS than SB 2 after thermocycling, showing no correlation with concentration. The DC of the adhesive system was affected depending on the concentration of EGCG/EGCG-3Me and the depth of the hybrid layer. EGCG/EGCG-3Me modified adhesives could inhibit S. mutans adhesion to dentin-resin interface, and maintain the bonding stability. The adhesive modified with 400 µg/mL EGCG-3Me showed antibacterial effect and enhanced bonding stability without affect the DC of adhesive.

The effect of active components from citrus fruits on dentin MMPs.

OBJECTIVES: This study was aimed to evaluate the anti-matrix metalloproteinases (MMPs) ability of active components from citrus fruits (hesperetin: Hst, hesperidin: Hsd and naringenin: Nge). METHODS: Inactivation effects of citrus flavonoids (Hst, Hsd, Nge) at different concentrations on soluble collagenase were measured using a fluorometric assay. Matrix-bound endogenous MMPs activity was evaluated via dry mass loss and hydroxyproline (HYP) release of demineralized human dentin. Demineralized dentin beams were pretreated with 500µg/mL citrus flavonoids for 10min. Chlorhexidine (CHX) was used as inhibitor control. Beams pretreated with distilled water served as blank control. Dentin slabs were used for in situ zymography and evaluated under confocal microscopy. Ultrastructure of demineralized collagen fibers was exhibited by Transmission Electron Microscopy (TEM). RESULTS: Citrus flavonoids exhibited inactivation function on soluble MMPs and the extent of inactivation increased in a dose-dependent manner. The inactivation percent of citrus flavonoids reached above 90% at the concentration of 500µg/mL. Compared with control group, citrus flavonoids pretreated demineralized dentin beams exhibited less dry mass loss, lower hydroxyproline release and more intact collagen architecture after 15days storage. Dentin samples pretreated with citrus flavonoids showed lower enzymes activities in in situ zymography. CONCLUSIONS: Hst, Hsd or Nge have anti-MMPs ability and can preserve dentin collagen from degradation. CLINICAL SIGNIFICANCE: Hst, Hsd and Nge may have the potential to be used in dentin bonding systems and improve the resin-dentin bonding durability.

Effects of Epigallocatechin-3-gallate (EGCG) on the bond strength of fiber posts to Sodium hypochlorite (NaOCl) treated intraradicular dentin.

This study was to evaluate the effect of Epigallocatechin-3-gallate (EGCG) on the bond strength of two adhesive systems to the Sodium hypochlorite (NaOCl) treated intraradicular dentin. The roots were accepted regular root canal treatments and post space preparations, and further divided into eight groups according to the four post space pretreatments and two dentin adhesives [Single Bond 2 (SB2) and Clearfil SE Bond (CSB)] used. The push-out strength before and after thermocycling in different root region (coronal and apical), DC of the adhesive and morphologic patterns of treated post space were evaluated. NaOCl + EGCG groups showed the highest push-out strength regardless of the adhesive type, root region and time (P < 0.05). NaOCl pretreatment significantly decreased the push-out strengths and DC of CSB (P < 0.05). EGCG could improve the bonding properties of both SB2 and CSB to NaOCl treated intraradicular dentin. The effect of NaOCl on bonding of a fiber post depended on the type of the adhesive.

Occlusion and Disocclusion Time Changes in Single Unit Crowns Designed by Functional Generated Path Technique: A Randomised Clinical Trial.

Although it is believed that implementation of the functional generated path (FGP) technique can facilitate occlusal surface design for restorations, it has not been objectively compared in situ with the conventional fabrication yet. Therefore, in the present study, a single-blind crossover clinical trial was conducted using T-scan to compare changes in occlusion time (OT) and disocclusion time (DT) of single posterior artificial crowns designed differently using FGP technique (FGP), average-value FGP technique (AVR) and conventional fabrication (CON). Each of the 10 participants took part in the study tried three artificial crowns in different sequences according to a computer generated randomization list. The results objectively revealed that changes in OT and DT were significantly smaller for FGP than CON (P < 0.05) and considerably smaller for AVR than CON, respectively. The subjective feedback and the occlusal adjusting time were better and shorter for FGP and AVR than CON (P < 0.05). No harm to the participants occurred. Overall, FGP is an efficient technique showing more physiological harmonious relationship with the articulating system.

Antibacterial Activity and Bonding Ability of an Orthodontic Adhesive Containing the Antibacterial Monomer 2-Methacryloxylethyl Hexadecyl Methyl Ammonium Bromide.

Irreversible white spot lesion (WSL) occurs in up to 50% of patients during orthodontic treatment. Therefore, orthodontic adhesives need to be able to inhibit or reduce bacterial growth in order to prevent or minimize WSL. This study evaluated the antibacterial effect and shear bond strength (SBS) of a resin-based orthodontic adhesive containing the antibacterial monomer 2-methacryloxylethyl hexadecyl methyl ammonium bromide (MAE-HB). MAE-HB was added at three concentrations (1, 3, and 5 wt%) to a commercial orthodontic adhesive Transbond XT, while the blank control comprised unmodified Transbond XT. Their antibacterial effects on Streptococcus mutans were investigated after 0 and 180 days of aging. The SBS of metal brackets bonded to the buccal enamel surface of human premolars was assessed. Compared with the blank control, the MAE-HB-incorporated adhesive exhibited a significant contact inhibitory effect on the growth of S. mutans (P < 0.05), even after 180 days of aging. SBS and adhesive remnant index values revealed that the bonding ability of the experimental adhesive was not significantly adversely affected by the incorporation of MAE-HB at any of the three concentrations. Therefore, orthodontic adhesives with strong and long-lasting bacteriostatic properties can be created through the incorporation of MAE-HB without negatively influencing bonding ability.

Effect of an Experimental Direct Pulp-capping Material on the Properties and Osteogenic Differentiation of Human Dental Pulp Stem Cells.

Effective pulp-capping materials must have antibacterial properties and induce dentin bridge formation; however, many current materials do not satisfy clinical requirements. Accordingly, the effects of an experiment pulp-capping material (Exp) composed of an antibacterial resin monomer (MAE-DB) and Portland cement (PC) on the viability, adhesion, migration, and differentiation of human dental pulp stem cells (hDPSCs) were examined. Based on a Cell Counting Kit-8 assay, hDPSCs exposed to Exp extracts showed limited viability at 24 and 48 h, but displayed comparable viability to the control at 72 h. hDPSC treatment with Exp extracts enhanced cellular adhesion and migration according to in vitro scratch wound healing and Transwell migration assays. Exp significantly upregulated the expression of osteogenesis-related genes. The hDPSCs cultured with Exp exhibited higher ALP activity and calcium deposition in vitro compared with the control group. The novel material showed comparable cytocompatibility to control cells and promoted the adhesion, migration, and osteogenic differentiation of hDPSCs, indicating excellent biocompatibility. This new direct pulp-capping material containing MAE-DB and PC shows promise as a potential alternative to conventional materials for direct pulp capping.

Effect of an Antibacterial Monomer on the Antibacterial Activity of a Pit-and-Fissure Sealant.

Resin-based pit-and-fissure sealants are often used to form a barrier on the occlusal surface of molars to treat caries lesions; however, bacteria can remain in the pit and fissures without detection, increasing the risk of secondary caries. Sealants with antimicrobial properties or microbial repellent actions might be advantageous. The aim of this study was to assess the inhibitory effect of a 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB)-incorporated sealant against Streptococcus mutans. MAE-DB (4% wt) was incorporated into a commercially available sealant, Eco-S resin-based pit-and-fissure sealant (Vericom Co., Ltd., Korea); a sealant without MAE-DB served as a negative control, and Clinpro™ Sealant (3M™ ESPE™), a fluoride-releasing resin, was used as a commercial control. The effects of the cured sealants and their eluents on the growth of S. mutans were determined according to colony-forming unit counts and metabolic tests. The effects of the cured sealants on the adherence and membrane integrity of S. mutans were investigated using confocal laser-scanning microscopy (CLSM) in conjunction with fluorescent indicators. Compared with the negative control and commercial control, the cured MAE-DB-incorporated pit-and-fissure sealant exhibited a significant inhibitory effect on the growth of S. mutans (P < 0.05), whereas the eluents did not show any detectable antibacterial activity. The commercial control also showed no detectable bactericidal activity. Moreover, the aged experimental material retained its property of contact inhibition of biofilm formation. The fluorescence analysis of CLSM images demonstrated that the cured MAE-DB-incorporated sealant could hamper the adherence of S. mutans and exert a detrimental effect on bacterial membrane integrity. The incorporation of MAE-DB can render a pit-and-fissure sealant with contact antibacterial activity after polymerization via influencing the growth, adherence, and membrane integrity of S. mutans. Therefore, MAE-DB-containing pit-and-fissure sealant shows promise for preventing or controlling dental caries on occlusal pit and fissures of molars.

Antibacterial activity of a modified unfilled resin containing a novel polymerizable quaternary ammonium salt MAE-HB.

Resins with strong and long-lasting antibacterial properties are critical for the prevention of secondary dental caries. In this study, we evaluated the antibacterial effect and the underlying mechanism of action of an unfilled resin incorporating 2-methacryloxylethyl hexadecyl methyl ammonium bromide (MAE-HB) against Streptococcus mutans UA159 (S. mutans UA159). MAE-HB was added into unfilled resin at 10 mass%, and unfilled resin without MAE-HB served as the control. Bacterial growth was inhibited on 10%-MAE-HB unfilled resin compared with the control at 1 d, 7 d, 30 d, or 180 d (P < 0.05). The growth inhibitory effect was independent of the incubation time (P > 0.05). No significant differences in the antibacterial activities of eluents from control versus 10%-MAE-HB unfilled resins were observed at any time point (P > 0.05). The number of bacteria attached to 10%-MAE-HB unfilled resin was considerably lower than that to control. Fe-SEM and CLSM showed that 10%-MAE-HB unfilled resin disturbed the integrity of bacterial cells. Expression of the bacterial glucosyltransferases, gtfB and gtfC, was lower on 10%-MAE-HB unfilled resin compared to that on control (P < 0.05). These data indicate that incorporation of MAE-HB confers unfilled resin with strong and long-lasting antibacterial effects against S. mutans.

N-Acetyl Cysteine Depletes Reactive Oxygen Species and Prevents Dental Monomer-Induced Intrinsic Mitochondrial Apoptosis In Vitro in Human Dental Pulp Cells.

PURPOSE: To investigate the involvement of intrinsic mitochondrial apoptosis in dental monomer-induced cytotoxicity and the influences of N-acetyl cysteine (NAC) on this process. METHODS: Human dental pulp cells (hDPCs) were exposed to several dental monomers in the absence or presence of NAC, and cell viability, intracellular redox balance, morphology and function of mitochondria and key indicators of intrinsic mitochondrial apoptosis were evaluated using various commercial kits. RESULTS: Dental monomers exerted dose-dependent cytotoxic effects on hDPCs. Concomitant to the over-production of reactive oxygen species (ROS) and depletion of glutathione (GSH), differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase were detected. Apoptosis, as indicated by positive Annexin V/propidium iodide (PI) staining and activation of caspase-3, was observed after dental monomer treatment. Dental monomers impaired the morphology and function of mitochondria, and induced intrinsic mitochondrial apoptosis in hDPCs via up-regulation of p53, Bax and cleaved caspase-3, and down-regulation of Bcl-2. NAC restored cell viability, relieved oxidative stress and blocked the apoptotic effects of dental monomers. CONCLUSIONS: Dental monomers induced oxidative stress and mitochondrial intrinsic apoptosis in hDPCs. NAC could reduce the oxidative stress and thus protect hDPCs against dental monomer-induced apoptosis.