RESUMO
The prism-interprisms level of the enamel hierarchical microstructure is the largest degree of structural variation and most sophisticated structural adaptation. We studied the effect of the prism-interprisms three-dimension spatial microstructure on the enamel bond strength. We prepared 11 groups of enamel segments: longitudinally sectioned segments with or without a 45-degree bevel (group = 2), horizontally sectioned segments with or without a 45-degree bevel of three regions (the incisal, middle, and cervical) (group = 6), and tangential (labial) sectioned segments of three regions (the incisal, middle, and cervical) (group = 3). The finished surface of each segment was observed by scanning electric microscopy (SEM) before treatment with four self-etch adhesive systems and applied with four corresponding composite resins. Resin-bonded enamel samples were prepared in beams for microtensile bond strength (MTBS) tests. The results were analyzed with a three-way ANOVA followed by Tukey's post-hoc HSD multiple comparisons procedure. SEM observations revealed complex arrangements of prisms and interprisms. MTBS measurement showed that the longitudinally sectioned group had the lowest value, without significant differences between the groups with or without 45-degree bevel. Combining SEM observations and MTBS measurements, the prism-interprisms microstructure varied with the incisor regions, and different prism-interprisms microstructures allowed diverse sectioned surfaces, which could affect the enamel bonding.
Assuntos
Colagem Dentária , Cimentos Dentários , Humanos , Cimentos de Resina/química , Microscopia Eletrônica de Varredura , Resistência à Tração , Esmalte Dentário , Resinas Compostas/química , Teste de Materiais , Propriedades de Superfície , Análise do Estresse DentárioRESUMO
OBJECTIVE: To analyze the effect of occupational noise exposure on hypertension in male steel workers. METHODS: The general information, noise exposure and blood pressure were collected through questionnaires and physical examinations. Chi-square test was used to investigate the prevalence of hypertension under different cumulative noise exposure, and the effect of noise exposure and other factors on hypertension was analyzed by the restrictive cubic spline(RCS) combined with multivariatenon-condition Logistic regression model. RESULTS: The prevalence of hypertension in noise exposure group was higher than that in noise non-exposure group(P<0. 001). After adjusting for multiple factors, the restricted cubic spline model showed a dose-response relationship between cumulative noise exposure(CNE) and hypertension(overall correlation χ~2=75. 76, P<0. 001, and nonlinear χ~2=24. 17, P<0. 001). Compared with the steel workers exposure to lowest dose, the risk of hypertension of steel workers exposure to 82-94 and 95-107 dB(A) in group was 1. 81(95%CI 1. 31-2. 52) times and 2. 60(95%CI 1. 84-3. 68) times. CONCLUSION: There is a non-linear dose-response relationship between cumulative noise exposure and hypertension.
Assuntos
Perda Auditiva Provocada por Ruído , Hipertensão , Ruído Ocupacional , Doenças Profissionais , Exposição Ocupacional , Humanos , Masculino , AçoRESUMO
This study investigated the effects of the prime-and-rinse approach, using a 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing primer, on the short- and long-term dentin microtensile bond strengths (MTBSs) of mild self-etch adhesives. Half of sixty human midcoronal dentin surfaces were polished as control (self-etch approach), and the other half were polished and further treated with a 15% MDP-containing primer and thoroughly sprayed with water as prime-and-rinse approach. The dentin surfaces were treated with a self-etch adhesive, and a composite resin was placed on the surfaces. The following materials were used: Clearfil S3 Bond+Clearfil Majesty; G-Bond+Gradia Direct; Adper Easy One+Z250; and i Bond+Charisma. The MTBS was examined after 24 h and 14 months in water storage. The resin-dentin interfaces were analysed using scanning electron microscopy/transmission electron microscopy. Pretreated dentin surfaces were further analysed using scanning electron microscopy and micro-Raman spectroscopy. Compared with the self-etch approach, the prime-and-rinse approach significantly increased the dentin MTBS, regardless of the duration of storage. The scanning electron microscopy/transmission electron microscopy findings revealed that the prime-and-rinse approach removed most of the dentin smear layer. The Raman spectra of the MDP-treated dentin reveal the characteristic spectra of collagen, hydroxyapatite, and the monomer. Therefore, the prime-and-rinse approach using MDP-containing primers prior to the application of mild self-etch adhesives significantly increases the short- and long-term MTBS of dentin.
Assuntos
Colagem Dentária , Corrosão Dentária , Adesivos Dentinários , Adesivos , Bis-Fenol A-Glicidil Metacrilato , Resinas Compostas , Cimentos Dentários , Dentina , Humanos , Teste de Materiais , Metacrilatos , Microscopia Eletrônica de Varredura , Cimentos de Resina , Resistência à TraçãoRESUMO
This study investigated the regional microtensile bond strength (MTBS) and cohesive strength of bovine enamel. The crowns of bovine incisors were sectioned, either horizontally along incisal and cervical thirds to produce horizontal and tangential segments, or longitudinally along the midline to produce longitudinal segments. Half of the horizontal and longitudinal segments were prepared using a 45° bevel. Then, the differently sectioned enamel surfaces were treated with one- or two-step self-etch adhesives (Clearfil SE Bond or Clearfil S3 Bond) and a composite resin (Clearfil Majesty) was placed. Resin-bonded enamel samples were cut into beams for use in the MTBS tests. Labial horizontal and longitudinal segments of pure enamel beams were prepared for cohesive strength tests. Enamel microstructures were analyzed by scanning electron microscopy. Three-way anova followed by Tukey's post-hoc HSD multiple comparisons procedure showed that a 45° bevel cut did not statistically significantly improve enamel MTBS, which varied with the different regions. The longitudinally sectioned resin-bonded enamel samples had the lowest MTBS, and the horizontal enamel cohesive strength was weaker than that of the longitudinal enamel. The scanning electron microscopy fractographs indicated that rows of parallel prisms were detached from the fractured surfaces. In conclusion, the regional enamel MTBS and the cohesive strength are strongly related to the enamel microstructures and prism orientations.
Assuntos
Resinas Compostas/química , Colagem Dentária/métodos , Esmalte Dentário/química , Adesivos Dentinários/química , Cimentos de Resina/química , Animais , Bovinos , Esmalte Dentário/ultraestrutura , Análise do Estresse Dentário , Técnicas In Vitro , Incisivo , Microscopia Eletrônica de Varredura , Resistência à TraçãoRESUMO
Water dispersible latex particles with randomly mixed shells or chain segregated surface are synthesized from one-pot reversible addition-fragmentation chain transfer heterogeneous polymerization of benzyl methacrylate (BzMA) using a mixture of poly(glycerol monomethacrylate) (PGMA) and poly(2,3-bis(succinyloxy)propyl methacrylate) (PBSPMA) macromolecular chain transfer agents. In methanol, the two in situ synthesized PGMA-b-PBzMA and PBSPMA-b-PBzMA diblock copolymers coaggregate into spherical micelles, which contain PBzMA core and discrete PGMA and PBSPMA nanodomains on the shell. In contrast, in water-methanol mixture (V/V = 9/1), latex particles with homogeneous distribution of PGMA and PBSPMA polymer chains on the shell are obtained. The reasons leading to formation of latex particles with homogenous or chain-segregated surface are discussed, and polymerization kinetics and physical state of PBSPMA in methanol and water-methanol mixtures are ascribed. These polymeric micelles with patterned functional group on the surface are potentially important for application in supracolloidal hierarchical assemblies and catalysis.
Assuntos
Látex/síntese química , Metilmetacrilatos/química , Polimerização , Látex/química , Substâncias Macromoleculares/química , Metacrilatos/química , Micelas , Estrutura Molecular , Água/químicaRESUMO
OBJECTIVE: To analyze the relationship between joint of heat and noise, and metabolic syndrome in a steel rolling factory workers. METHODS: A total of 590 steel workers were selected as subjects by cluster sampling method from workers of a steel factory. They were investigated by face to face way with the unified questionnaire which contents included personal information, occupational history, personal history, habits and other factors. Furthermore, height, weight, waist circumference and blood pressure were measured. Referring to the 2005 International Diabetes Federation (IDF) issued by the metabolic syndrome (MS) worldwide uniform definition combines waist diagnosis MS. A database was built by Epidata 3.0 software, and data was analyzed by SPSS 17.0. RESULTS: 571 steel workers were from 22 to 60 years, mean age (41.2 -7.9) years old. The prevalence of metabolic syndrome in steel workers was 17.9%. The prevalence of metabolic syndrome of those who exposed to high temperature was 18.8%, higher than that of those who did not expose to high temperature (5.3%), there was a statistically significant difference (P < 0.05). The prevalence of metabolic syndrome of those who exposed to noise was 20.6%, higher than that of those who did not exposed to noise (14.0%) (P < 0.05). After adjusting for the effects of confounding factors, the prevalence of MS those who exposed to high temperatures and noise is 1.118 times as high as that of those who did not exposed to high temperatures and noise. CONCLUSIONS: The combined effects of heat and noise is related to the increasing prevalence of MS of steel workers.
Assuntos
Temperatura Alta/efeitos adversos , Síndrome Metabólica/epidemiologia , Metalurgia , Ruído Ocupacional/efeitos adversos , Exposição Ocupacional/efeitos adversos , Adulto , Pressão Sanguínea , Peso Corporal , Humanos , Pessoa de Meia-Idade , Prevalência , Aço , Circunferência da Cintura , Adulto JovemRESUMO
Rattle-like polymer capsules with multicores in one shell are facilely fabricated by oil-in-water Pickering emulsion polymerization for the first time. The oil phase contains hydrophobic silica nanoparticles dispersed in polymerizable monomer, styrene, and unpolymerizable solvent, hexadecane. The multicore rattle-like capsules are facilely produced after the polymerization of monomers in the oil droplets. The key point of this one-pot method lies in the nucleation of hydrophobic silica and the phase separation between the resulting polystyrene and hexadecane. The influences of the contents of silica, hexadecane, cross-linker, and stabilizer on the structure and morphology of rattle-like capsules are systematically investigated. Moreover, functionalization of the rattle-like capsules can be developed easily by varying hydrophobic nucleation nanoparticles in the oil phase. This work opens up a new route to fabricate multilevel capsules or spheres.
Assuntos
Cápsulas/química , Nanopartículas/química , Alcanos/química , Reagentes de Ligações Cruzadas/química , Emulsões/química , Interações Hidrofóbicas e Hidrofílicas , Óleos/química , Polimerização , Poliestirenos/química , Dióxido de Silício/químicaRESUMO
Noncarious lesions, a multifactorial condition encompassing tooth attrition, abrasion, and erosion, have a surge in prevalence and required increased attention in clinical practice. These nonbacterial-associated tooth defects can compromise aesthetics, phonetics, and masticatory functions. When providing full-arch fixed occlusal rehabilitation for such cases, the treatment strategy should extend beyond by restoring dentition morphology and aesthetics. This report details a complex case of erosive dental wear addressed through a fully digital, full-arch fixed occlusal rehabilitation. A 4D virtual patient was created using multiple digital data sources, including intraoral scanning, 3D facial scanning, digital facebow registration, and mandibular movement tracing. With a comprehensive understanding of the masticatory system, various types of microinvasive prostheses were customized for each tooth, including labial veneers, buccal-occlusal veneers, occlusal veneers, overlays, inlays, and full crowns, were customized for each tooth. The reported digital workflow offered a predictable diagnostic and treatment strategy, which was facilitated by virtual visualization and comprehensive quality control throughout the process.
Assuntos
Atrito Dentário , Erosão Dentária , Humanos , Erosão Dentária/patologia , Erosão Dentária/terapia , Tecnologia Digital , Estética Dentária , Restaurações IntracoronáriasRESUMO
The phosphorylated noncollagenous proteins (NCPs) play a vital role in manipulating biomineralization, while the mechanism of phosphorylation of NCPs in intrafibrillar mineralization of collagen fibril has not been completely deciphered. Poly(vinylphosphonic acid) (PVPA) and sodium trimetaphosphate (STMP) as templating analogs of NCPs induce hierarchical mineralization in cooperation with indispensable sequestration analogs such as polyacrylic acid (PAA) via polymer-induced liquid-like precursor (PILP) process. Herein, STMP-Ca and PVPA-Ca complexes are proposed to achieve rapid intrafibrillar mineralization through polyelectrolyte-Ca complexes pre-precursor (PCCP) process. This strategy is further verified effectively for remineralization of demineralized dentin matrix both in vitro and in vivo. Although STMP micromolecule fails to stabilize amorphous calcium phosphate (ACP) precursor, STMP-Ca complexes facilely permeate into intrafibrillar interstices and trigger phase transition of ACP to hydroxyapatite within collagen. In contrast, PVPA-stabilized ACP precursors lack liquid-like characteristic and crystallize outside collagen due to rigid conformation of PVPA macromolecule, while PVPA-Ca complexes infiltrate into partial intrafibrillar intervals under electrostatic attraction and osmotic pressure as evidenced by intuitionistic 3D stochastic optical reconstruction microscopy (3D-STORM). The study not only extends the variety and size range of polyelectrolyte for PCCP process but also sheds light on the role of phosphorylation for NCPs in biomineralization.
Assuntos
Fosfatos de Cálcio , Colágeno Tipo I , Polivinil , Fosfatos de Cálcio/química , Polivinil/química , Colágeno Tipo I/química , Colágeno Tipo I/metabolismo , Polifosfatos/química , Animais , Resinas Acrílicas/química , Dentina/química , Dentina/metabolismo , Fosforilação , Humanos , Compostos de Vinila , OrganofosfonatosRESUMO
To produce an anion-conductive and durable polymer electrolyte for alkaline fuel cell applications, a series of quaternized poly(2,6-dimethyl phenylene oxide)s containing long alkyl side chains pendant to the nitrogen-centered cation were synthesized using a Menshutkin reaction to form comb-shaped structures. The pendant alkyl chains were responsible for the development of highly conductive ionic domains, as confirmed by small-angle X-ray scattering (SAXS). The comb-shaped polymers having one alkyl side chain showed higher hydroxide conductivities than those with benzyltrimethyl ammonium moieties or structures with more than one alkyl side chain per cationic site. The highest conductivity was observed for comb-shaped polymers with benzyldimethylhexadecyl ammonium cations. The chemical stabilities of the comb-shaped membranes were evaluated under severe, accelerated-aging conditions, and degradation was observed by measuring IEC and ion conductivity changes during aging. The comb-shaped membranes retained their high ion conductivity in 1 M NaOH at 80 °C for 2000 h. These cationic polymers were employed as ionomers in catalyst layers for alkaline fuel cells. The results indicated that the C-16 alkyl side chain ionomer had a slightly better initial performance, despite its low IEC value, but very poor durability in the fuel cell. In contrast, 90% of the initial performance was retained for the alkaline fuel cell with electrodes containing the C-6 side chain after 60 h of fuel cell operation.
Assuntos
Álcalis/química , Fontes de Energia Elétrica , Polímeros/química , Ânions/química , Condutividade Elétrica , Estrutura MolecularRESUMO
The hydrodynamics of laminar flow in a microfluidic device has been used to control the continuous self-assembly of gold nanoparticles (NPs) tethered with amphiphilic block copolymers. Spherical micelles, giant vesicles (500 nm-2.0 µm), or disk-like micelles could be formed by varying the flow rates of fluids. Such vesicles can release encapsulated hydrophilic species by using near-IR light.
Assuntos
Preparações de Ação Retardada/química , Nanopartículas Metálicas/química , Polímeros/química , Interações Hidrofóbicas e Hidrofílicas , Micelas , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodosRESUMO
In spite of similar efficacy and safety in pilot studies, compared with the contemporary durable polymer drug-eluting stent (DP-DES), the bioabsorbable polymer drug-eluting stent (BP-DES) may be more superior in promoting blood vessel healing. We sought to compare the safety and efficacy of everolimus-eluting BP-DES (BP-EES) with contemporary DP-DES through a meta-analysis. We performed this meta-analysis to provide further evidence of the safety and efficacy of BP-EES. Medline, Embase and the Cochrane library databases were searched for randomized controlled trials comparing clinical efficacy and safety of BP-EES versus contemporary DP-DES. Fifteen RCTs with a total of 15,572 patients were selected. The rate of MACE was 9.4% in patients receiving BP-EES and 7.3% receiving DP-EES (RR 1.13, 95% CI 0.99-1.29, p = 0.05; I2 = 46%). TLF and MI were also similar in both groups. Based on the available data, this review demonstrates that BP-EES displays a clinically comparable efficacy and safety profile to that of contemporary DP-DES at years of follow-up in patients undergoing PCI.
Assuntos
Stents Farmacológicos , Intervenção Coronária Percutânea , Humanos , Stents Farmacológicos/efeitos adversos , Everolimo , Intervenção Coronária Percutânea/efeitos adversos , Stents , PolímerosRESUMO
HYPOTHESIS: The stability of anti-cancer drugs and the adverse drug reactions (ADRs) caused by drug-drug interactions (DDIs) are two major challenges of combination chemotherapy. In this work, hydrophilic drug loaded lignin-based nanoparticles were applied to stabilize high internal phase Pickering emulsions (HIPPEs) containing hydrophobic drug in the oil phase, which not only improved the stability of anti-cancer drugs, but also reduced the risk of DDIs. EXPERIMENTS: Highly biocompatible enzymatic hydrolysis lignin/chitosan oligosaccharide (EHL/COS-x) nanoparticles were prepared and used to load hydrophilic cytarabine (Ara-C). The morphology, loading capacity, encapsulation efficiency and emulsifying properties of nanoparticles were characterized and predicted. Subsequently, these nanoparticles were applied to stabilize HIPPEs with soybean oil containing hydrophobic curcumin as dispersed phase. The effects of the morphology, amphipathy and concentration of nanoparticles and oil/water ratio on the microstructure and stability of HIPPEs were investigated. Meanwhile, the controlled release, protective performance, cytotoxicity and bio-activity of HIPPEs were also evaluated. FINDINGS: EHL/COS-x nanoparticles loaded with Ara-C could stabilize HIPEs with 85 vol% soybean oil containing curcumin. The two drugs were separately loaded in same delivery system, which effectively lowered the risk of DDIs. Meanwhile, HIPPEs provided outstanding UV, thermal and oxidation protection for these two environmentally sensitive anti-cancer drugs. In addition, HIPPEs displayed a good pH-responsive release in a tumor environment. In vitro experiments show that the killing efficiency of two drugs co-loaded HIPPEs against the leukemia cell is two times higher than that of single drug loaded systems. This strategy can be extended to the synergistic therapy of two or more drugs with different physicochemical properties.
Assuntos
Quitosana , Nanopartículas , Neoplasias , Emulsões , Lignina , Oligossacarídeos , Tamanho da Partícula , Microambiente TumoralRESUMO
OBJECTIVES: To coat a zirconia surface with silica-zirconia using a dip-coating technique and evaluate its effect on resin-zirconia shear bond strength (SBS). METHODS: A silica-zirconia suspension was prepared and used to coat a zirconia surface using a dip-coating technique. One hundred and eighty-nine zirconia disks were divided into three groups according to their different surface treatments (polishing, sandblasting, and silica-zirconia coating). Scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD) were used to analyze the differently treated zirconia surfaces. Different primer treatments (Monobond N, Z-PRIME Plus, and no primer) were also applied to the zirconia surfaces. Subsequently, 180 composite resin cylinders (Filtek Z350) were cemented onto the zirconia disks with resin cement (RelyX Ultimate). The SBS was measured after water storage for 24 h or 6 months. The data were analyzed by two-way analysis of variance (ANOVA). RESULTS: SEM and EDX showed that the silica-zirconia coating produced a porous layer with additional Si, and XRD showed that only tetragonal zirconia was on the silica-zirconia-coating surface. Compared with the control group, the resin-zirconia SBSs of the sandblasting group and silica-zirconia-coating group were significantly increased (P<0.05). The silica-zirconia coating followed by the application of Monobond N produced the highest SBS (P<0.05). Water aging significantly reduced the resin-zirconia SBS (P<0.05). CONCLUSIONS: Dip-coating with silica-zirconia might be a feasible way to improve resin-zirconia bonding.
Assuntos
Colagem Dentária , Zircônio/química , Microscopia Eletrônica de Varredura , Porosidade , Dióxido de Silício , Propriedades de Superfície , Suspensões , Resistência à Tração , Difração de Raios XRESUMO
OBJECTIVE: Multiple dental researches show that bovine teeth are potential alternatives to human teeth. However, whereas cattle are herbivore, humans are omnivorous. Consequently, we sought to compare the enamel microstructures of bovine and human teeth in relation to their functional similarity. MATERIALS AND METHODS: Crowns of human and bovine teeth were first cut longitudinally, horizontally and tangentially. The appearance of enamel microstructures under the three dimensions were then analyzed using a scanning electron microscope (SEM). RESULTS: Human and bovine teeth have relatively different enamel microstructure. Bovine enamel exhibits transitional zones between adjacent HSBs bands. In addition, it has abundant interprisms interwoven with prisms. CONCLUSION: The teeth of the bovine and humans have a similar evolutionary origin, but the differences are attributed to dietary adaptation. Given the closeness of enamel microstructure of two animals' teeth, the bovine teeth could be utilized as an excellent alternative to human teeth in dental researches.
Assuntos
Coroas , Incisivo , Animais , Bovinos , Esmalte Dentário , Humanos , Microscopia Eletrônica de VarreduraRESUMO
AIMS: To investigate the biomimetic fabrication of fibrous-like organic-inorganic hybrid structures via a simple bottom-up approach, viz. self-assembly of simple molecules, and apply fibrous-like composites as a novel primer to improve dentin bond strengths of self-etch adhesives. MATERIALS AND METHODS: The resultants of commercial amorphous calcium phosphate (ACP) nanoparticles and 10-methacryloyloxydecyl dihydrogen phosphate (MDP) ethanol-aqueous solution were analyzed by TEM, SEM, XRD, DLS and AFM. The acid and alkali resistance of abovementioned self-assembled composites were analyzed with TEM. Micro-tensile bond strengths (MTBS) tests were performed after polished dentin surfaces were pretreated with self-assembled composites. The pretreated dentin surfaces and dentin-resin interfaces were characterized by SEM/TEM. KEY FINDINGS: ACP nanoparticles in MDP solution could self-assemble into fibrous-like nanotube structures in 8 nm diameter. Self-assembly and self-proliferation process went from ACP nanoparticles, dissolved ACP nanoparticles (less than 50 nm), twig-like structures and fibrous-like nanotubes to cellular networks. The fibrous-like nanotubes were only detected when the amount of ACP in reaction system were more than 0.01 g. The more ACP interacted with MDP, the more fibrous-like nanotubes were formed. After the dentin surfaces were treated with fibrous-like nanotube composites, MTBS could be significantly improved. Moreover, the fibrous-like nanotube structures could be resistant to acidic challenge, and were stable at least for 3 months. SIGNIFICANCE: The fibrous-like nanotube structures could be self-assembled via a bottom-up approach at certain ratio of MDP and commercial ACP nanoparticles. The application of fibrous-like nanotube composites as a novel primer prior to self-etch adhesives greatly improved dentin bond strengths.
Assuntos
Biomimética/métodos , Dentina/química , Nanotubos/química , Adesivos/química , Fosfatos de Cálcio/química , Humanos , Teste de Materiais/métodos , Metacrilatos/química , Nanopartículas/química , Resistência à Tração/fisiologiaRESUMO
OBJECTIVES: The study investigated the effects of novel prime-&-rinse mode using MDP (10-methacryloyloxydecyl dihydrogenphosphate) and matrix metalloproteinase (MMPs) inhibitors on dentin microtensile bond strengths (MTBS) of self-etch adhesive, resin-dentin interface degradations, and activity of recombinant human (rh) MMP-8, -9. MATERIALS AND METHODS: Eight experimental primers were prepared using 5% and 15% of MDP ethanol-aqueous (1:1) solution in combination with/without MMPs inhibitors (1%benzalkonium chloride (BAC), 1000 µm/mL polyvinylphosphonic acid (PVPA) and 15%proanthocyanidin (PA)). Ninety human mid-coronal dentin surfaces were applied with the experimental primers, water-sprayed and gently air-dried (prime-&-rinse mode), or not (control, self-etch mode). The specimens were bonded with self-etch adhesive (Clearfil S3 Bond) and composite resin (Clearfil Majesty). The resin-bonded specimens were prepared into multiple micro-beams for MTBS tests after 24 h and 1 yr of water storage. The resin-dentin interfaces were analyzed with SEM/TEM. The inhibitory effects of eight primers on rhMMP-8, 9 were determined. The data were analyzed using two-way ANOVA and LSD multiple comparisons tests. RESULTS: Compared with control, all the primers used in prime-&-rinse mode could significantly improve long-term dentin MTBS (P < 0.05), while 5%MDP-BAC, 15%MDP and 15%MDP+MMPs inhibitors could significantly increase the short-term dentin MTBS (P < 0.05). The SEM/TEM findings revealed that the resin-dentin interfaces were stable over time when the prime-&-rinse mode used. Eight primers possessed the high inhibitory ratio of rh MMP-8, 9. CONCLUSIONS: The novel prime-&-rinse mode using 5%MDP-BAC, 15%MDP and 15%MDP+MMPs inhibitors could significantly increase the short- and long-term dentin MTBS of self-etch adhesive. This might be a supplement to contemporary dentin bonding strategies.
Assuntos
Adesivos , Colagem Dentária , Dentina , Adesivos Dentinários , Humanos , Teste de Materiais , Inibidores de Metaloproteinases de Matriz/farmacologia , Microscopia Eletrônica de Varredura , Cimentos de Resina , Propriedades de Superfície , Resistência à TraçãoRESUMO
BACKGROUND: One major limitation of cancer chemotherapy is a failure to specifically target a tumor, potentially leading to side effects such as systemic cytotoxicity. In this case, we have generated a cancer cell-targeting nanoparticle-liposome drug delivery system that can be activated by near-infrared laser light to enable local photo-thermal therapy and the release of chemotherapeutic agents, which could achieve combined therapeutic efficiency. METHODS: To exploit the magnetic potential of iron oxide, we prepared and characterized citric acid-coated iron oxide magnetic nanoparticles (CMNPs) and encapsulated them into thermo-sensitive liposomes (TSLs). The chemotherapeutic drug, doxorubicin (DOX), was then loaded into the CMNP-TSLs, which were coated with an antibody against the epidermal growth factor receptor (EGFR), cetuximab (CET), to target EGFR-expressing breast cancer cells in vitro and in vivo studies in mouse model. RESULTS: The resulting CET-DOX-CMNP-TSLs were stable with an average diameter of approximately 120 nm. First, the uptake of TSLs into breast cancer cells increased by the addition of the CET coating. Next, the viability of breast cancer cells treated with CET-CMNP-TSLs and CET-DOX-CMNP-TSLs was reduced by the addition of photo-thermal therapy using near-infrared (NIR) laser irradiation. What is more, the viability of breast cancer cells treated with CMNP-TSLs plus NIR was reduced by the addition of DOX to the CMNP-TSLs. Finally, photo-thermal therapy studies on tumor-bearing mice subjected to NIR laser irradiation showed that treatment with CMNP-TSLs or CET-CMNP-TSLs led to an increase in tumor surface temperature to 44.7°C and 48.7°C, respectively, compared with saline-treated mice body temperature ie, 35.2°C. Further, the hemolysis study shows that these nanocarriers are safe for systemic delivery. CONCLUSION: Our studies revealed that a combined therapy of photo-thermal therapy and targeted chemotherapy in thermo-sensitive nano-carriers represents a promising therapeutic strategy against breast cancer.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias da Mama/terapia , Lipossomos/administração & dosagem , Nanopartículas de Magnetita/administração & dosagem , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Cetuximab/administração & dosagem , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos , Receptores ErbB/metabolismo , Feminino , Compostos Férricos/química , Humanos , Hipertermia Induzida , Lipossomos/química , Nanopartículas de Magnetita/química , Camundongos Endogâmicos BALB C , Terapia Fototérmica/métodos , Temperatura , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVES: The study investigated the solid reactants of amorphous calcium phosphate (ACP) nanoparticles with 10-methacryloyloxydecyl dihydrogen phosphate (MDP) in ethanol-aqueous solution, and the effect of ACP-MDP suspension as a novel primer on dentin micro-tesnisl bond strengths (MTBS) prior to application of self-etch adhesives. MATERIALS AND METHODS: The ACP nanoparticles were synthesized. The solid reactants of ACP nanoparticles with MDP ethanol-aqueous solution were analyzed by TEM, SEM, XRD and AFM. After the ACP-MDP complexes were attacked by alkaline, acidic and self-etch adhesive challenges, they were analyzed with TEM. The polished mid-coronal dentin surfaces of six third molars were treated with ACP-MDP suspension, 5% MDP solution or not (served as control), and thoroughly water-sprayed. The pretreated dentin surfaces were applied with a self-etch adhesive (Clearfil S3 Bond) and placed with a composite resin (Clearfil Majesty). After 24â¯h, the resin-bonded samples were cut into multiple beams before the MTBS tests were performed. The failure modes were determined by a stereo-microscopy. The pretreated dentin surfaces were analyzed by SEM. The resin-dentin interfaces were analyzed with TEM. RESULTS: The ACP nanoparticles in the MDP ethanol-aqueous solution at certain molar ratio of Ca:MDP (0.12:1) could self-assemble into ACP-MDP complexes consisting of nanolayering structures. The ACP-MDP self-assembly went from ACP nanoparticles, beaded structures, and twig-like structures to networks. The ACP-MDP complexes can be resistant to adhesive challenge, but not to alkaline and acidic challenges. ACP-MDP complexes possessed a similar modulus of elasticity to dentin, and were stable at least for 3 months. Furthermore, the dentin surfaces treated with ACP-MDP suspension could significantly increase the dentin MTBS when compared with control and those treated with 5% MDP solution (Pâ¯<â¯0.05). CONCLUSION: The ACP-MDP suspension at certain molar ratio of Ca:MDP (0.12:1) could be self-assembled into ACP-MDP complexes consisting of nanolayering structures, and could be used as a novel primer to greatly improve the dentin bond strengths.
Assuntos
Fosfatos de Cálcio/química , Dentina/química , Metacrilatos/química , Adesividade , Teste de Materiais , Nanopartículas/química , Propriedades de Superfície , Resistência à TraçãoRESUMO
BACKGROUND: Both periodontal disease and benign prostatic hyperplasia are age-related diseases that affect millions of people worldwide. Hence, this study aimed to investigate the association between periodontal disease and the risk of benign prostatic hyperplasia. METHODS: A total of 4930 participants were selected from an available health examination that was carried out in 2017, only males were considered for further analysis. All eligible males were divided into benign prostatic hyperplasia and normal groups, the benign prostatic hyperplasia group was then divided into prostate volume ≤ 60 g and > 60 g subgroups; all their periodontal status was extracted and then into normal (CPI score of 0), periodontal disease (CPI score between 1 and 4), and periodontitis (CPI score between 3 and 4) groups. The correlation between periodontal disease and benign prostatic hyperplasia was investigated using logistic regression analyses and greedy matching case-control analysis. Subgroup analysis based on prostate volume was also performed. All analyses were conducted with SAS 9.4 software. RESULTS: A total of 2171 males were selected for this analysis. The presence of periodontal disease significantly increased the risk of benign prostatic hyperplasia by 1.68 times (OR = 1.68, 95% CI: 1.26-2.24), and individuals with periodontitis showed a higher risk (OR = 4.18, 95% CI: 2.75-6.35). In addition, among matched cases and controls, this association remained robust (periodontal disease: OR = 1.85, 95% CI: 1.30-2.64; periodontitis: OR = 4.83, 95% CI: 2.57-9.07). Subgroup analysis revealed that periodontal disease significantly increased benign prostate hyperplasia risk as well (for prostate volume ≤ 60 g: OR = 1.64, 95% CI: 1.22-2.20; for volume > 60 g: OR = 2.17, 95% CI: 1.04-4.53), and there was a higher risk in the group with a prostate volume greater than 60 g. CONCLUSION: Periodontal disease is significantly and positively associated with an increased risk of benign prostatic hyperplasia. Further validation studies should be performed to explore the relationship between periodontal treatment and benign prostate hyperplasia.