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1.
PLoS One ; 15(12): e0231606, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33382707

RESUMO

Keratin intermediate filaments are the principal structural element of epithelial cells. Their importance in providing bulk cellular stiffness is well recognized, but their role in the mechanics of cell cortex is less understood. In this study, we therefore compared the cortical stiffness of three keratinocyte lines: primary wild type cells (NHEK2), immortalized wild type cells (NEB1) and immortalized mutant cells (KEB7). The cortical stiffness was measured by lateral indentation of cells with AOD-steered optical tweezers without employing any moving mechanical elements. The method was validated on fixed cells and Cytochalasin-D treated cells to ensure that the observed variations in stiffness within a single cell line were not a consequence of low measurement precision. The measurements of the cortical stiffness showed that primary wild type cells were significantly stiffer than immortalized wild type cells, which was also detected in previous studies of bulk elasticity. In addition, a small difference between the mutant and the wild type cells was detected, showing that mutation of keratin impacts also the cell cortex. Thus, our results indicate that the role of keratins in cortical stiffness is not negligible and call for further investigation of the mechanical interactions between keratins and elements of the cell cortex.


Assuntos
Citoesqueleto de Actina/metabolismo , Filamentos Intermediários/metabolismo , Queratinócitos/metabolismo , Queratinas/metabolismo , Microtúbulos/metabolismo , Citoesqueleto de Actina/ultraestrutura , Linhagem Celular , Citocalasina D/farmacologia , Elasticidade/efeitos dos fármacos , Expressão Gênica , Dureza/efeitos dos fármacos , Humanos , Filamentos Intermediários/ultraestrutura , Queratinócitos/efeitos dos fármacos , Queratinócitos/ultraestrutura , Queratinas/genética , Microtúbulos/ultraestrutura , Pinças Ópticas , Especificidade de Órgãos
2.
Sci Rep ; 10(1): 8127, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415190

RESUMO

The present study aimed to evaluate the efficiency, effectiveness, and biocompatibility of two agents used for the chemomechanical removal of carious dentin. Sixty extracted carious human teeth were treated with a conventional bur (CBG) or chemomechanical agents - Papacarie Duo (PG) and Brix 3000 (BG). Treatment efficiency and effectiveness were assessed by the working time for carious dentin removal and Knoop microhardness values, respectively. Human pulp fibroblasts (FP6) were used to evaluate cytotoxicity by incorporating MTT dye, and genotoxicity was evaluated with the micronuclei test. The carious tissue was removed in a shorter time with CBG (median = 54.0 seconds) than the time required for chemomechanical agents (p = 0.0001). However, the time was shorter for Brix 3000 (BG) than that for Papacarie Duo (PG), showing mean values of 85.0 and 110.5 seconds, respectively. Regarding microhardness testing, all approaches tested were effective (p < 0.05). The final mean microhardness values were 48.54 ± 16.31 KHN, 43.23 ± 13.26 KHN, and 47.63 ± 22.40 KHN for PG, BG, and CBG, respectively. PG decreased cell viability compared to that of BG, but it presented no genotoxicity. Brix 3000 may be a good option for chemomechanical dentin caries removal due to its reduced removal time and lower cytotoxicity compared to the other treatment options.


Assuntos
Cárie Dentária/terapia , Preparo da Cavidade Dentária/métodos , Dentina/química , Fibroblastos/efeitos dos fármacos , Dureza/efeitos dos fármacos , Papaína/farmacologia , Hipoclorito de Sódio/farmacologia , Proliferação de Células , Células Cultivadas , Dentina/efeitos dos fármacos , Fibroblastos/patologia , Humanos , Técnicas In Vitro , Estresse Mecânico
3.
Drug Dev Ind Pharm ; 46(2): 309-317, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31944867

RESUMO

Objective: Develop a child-friendly Fixed Dose Combination (FDC) water-dispersible tablet for Tuberculosis (TB) treatment, with 50, 150, and 75 mg of isoniazid, pyrazinamide and rifampicin respectively. This new formulation must contain the lowest number of excipients accepted for pediatrics and fulfill all the pharmacopeia requirements.Significance: At present, there is no adequate market dosage form available for children. There is, however, one in a prequalification phase by the World Health Organization but its composition contains excipients which may not be suitable for pediatrics. Therefore, this new formulation would cover this therapeutic gap.Methods: A factorial design, based on three quantitative factors (compression force and concentration of AcDiSol® and Explosol®) at three levels each, was performed to elucidate their influence over disintegration time and friability. In addition, the influence of the press speed on disintegration time, friability, tensile strength, fineness of dispersion and content uniformity over the target tablet was tested. A stability test was done following ICH guideline for accelerated conditions.Results: Tablets developed with 9% w/w of Explosol® and a compression force of 16 kN disintegrated in less than 3 min and showed a friability below 1% when 15-mm punches were used. The tableting process could be done up to 25 and 50 cycles/minute ensuring good quality attributes when 15 and 12-mm punches were used, respectively. All APIs remained inside the limit of ± 5% of drug content till 6 months of storage.Conclusion: A high-quality child-friendly FDC water-dispersible tablet was developed improving the treatment of TB in pediatric.


Assuntos
Antituberculosos/administração & dosagem , Antituberculosos/química , Isoniazida/química , Pirazinamida/química , Rifampina/química , Comprimidos/química , Tuberculose/tratamento farmacológico , Química Farmacêutica/métodos , Criança , Composição de Medicamentos/métodos , Excipientes/química , Dureza/efeitos dos fármacos , Humanos , Isoniazida/administração & dosagem , Pediatria/métodos , Pirazinamida/administração & dosagem , Rifampina/administração & dosagem , Solubilidade/efeitos dos fármacos , Comprimidos/administração & dosagem , Resistência à Tração
4.
Int J Pharm ; 574: 118902, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31794786

RESUMO

Tablet quality can be affected by material, configuration and design of the tooling which comprise punches and dies. Much research attention had centred around punches, with very little reported on the dies. Dies with modified bore lining materials or inserts are available for special applications. However, the influence of such die types on tablet properties and the compaction process has not been well studied. Often, the reason for selecting dies with harder lining material is for improved wear resistance. In this study, flat-faced and convex-faced tablets were produced from paracetamol granules using dies with different bore inserts. Tablet properties and response parameters of the compaction process were evaluated to understand the impact of die mechanical and surface properties on the compacts formed. Compaction pressure was found to have the greatest impact on tablet elastic recovery (r ≥ 0.96, p < 0.01 in all bivariate correlations) and thus affecting the tensile strength. Choice of die inserts could impact the mechanical properties of convex-faced paracetamol tablets, particularly at high compaction pressures.


Assuntos
Acetaminofen/química , Comprimidos/química , Composição de Medicamentos/métodos , Excipientes/química , Dureza/efeitos dos fármacos , Pressão , Propriedades de Superfície/efeitos dos fármacos , Resistência à Tração/efeitos dos fármacos
5.
Biomed Mater Eng ; 30(5-6): 487-496, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31594192

RESUMO

BACKGROUND: Many novel biomaterials have been incorporated in toothpastes to promote remineralization of tooth structure. OBJECTIVES: This study was carried out to compare the discrepancies between declared and actual total fluoride (TF) or total soluble fluoride (TSF) concentration of two modern toothpastes containing bioactive glasses; these were also assessed for their remineralization potential. MATERIALS AND METHODS: The TF and TSF concentration were assessed using a fluoride ion selective electrode. Enamel remineralization was evaluated through micro-hardness analysis. Eighteen enamel blocks were divided into three groups: 1 (n = 6; control), 2 (n = 6; Novamin® toothpaste), and 3 (n = 6; BiominF® toothpaste). The specimens were demineralized by 6 wt% citric acid (pH = 2.2). Subsequently, the specimens in group 1 were kept in artificial saliva (AS), while the specimens in groups 2 and 3 were stored in AS + Novamin® and AS + Biomin®, respectively. RESULTS: Both Novamin® or BiominF® showed less TF concentration than their label claims. BiominF® had more TF and TSF compared to Novamin® (p < 0.05). The BiominF® toothpaste presented higher micro-hardness values on remineralization. CONCLUSION: BiominF® toothpaste demonstrated more fluoride content and greater potential to promote remineralization of demineralized human enamel compared to Novamin®.


Assuntos
Cerâmica/farmacologia , Esmalte Dentário/efeitos dos fármacos , Fluoretos/análise , Remineralização Dentária/métodos , Cremes Dentais/farmacologia , Cerâmica/química , Esmalte Dentário/fisiologia , Dureza/efeitos dos fármacos , Humanos , Técnicas In Vitro , Teste de Materiais , Dente Serotino , Tamanho da Partícula , Propriedades de Superfície/efeitos dos fármacos , Cremes Dentais/química
6.
Braz Oral Res ; 33: e037, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31508726

RESUMO

Iontophoresis is a noninvasive technique, based on the application of a constant low-intensity electric current to facilitate the release of a variety of drugs, whether ionized or not, through biological membranes. The objective of this research was to evaluate the effect of iontophoresis using different electric current intensities on the uptake of fluoride in dental enamel with artificial caries lesions. In this in vitro operator-blind experiment, bovine enamel blocks (n = 10/group) with caries-like lesions and predetermined surface hardness were randomized into 6 groups: placebo gel without fluoride applied with a current of 0.8 mA (negative control), 2% NaF gel without application of any current, and 2% NaF gel applied with currents of 0.1, 0.2, 0.4 and 0.8 mA. Cathodic iontophoresis was applied for 4 min. The concentration of loosely bound fluoride (calcium fluoride) and firmly bound fluoride (fluorapatite) was determined. The results were analyzed by the nonparametric Kruskal-Wallis and Dunn tests. Iontophoresis at 0.8 mA, combined with the application of fluoridated gel (2% NaF), increased fluoride uptake in enamel with caries-like lesions, as either calcium fluoride or fluorapatite.


Assuntos
Cariostáticos/farmacologia , Cárie Dentária , Esmalte Dentário/efeitos dos fármacos , Fluoretos/farmacologia , Iontoforese/métodos , Animais , Apatitas/análise , Fluoreto de Cálcio/análise , Bovinos , Modelos Animais de Doenças , Eletricidade , Dureza/efeitos dos fármacos , Distribuição Aleatória , Propriedades de Superfície/efeitos dos fármacos , Resultado do Tratamento
7.
J Pharm Sci ; 108(12): 3859-3869, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31542437

RESUMO

Hydroxypropyl methylcellulose acetate succinate (HPMCAS) has gained popularity as a carrier for amorphous solid dispersion because of its ability to maintain drugs in supersaturated state after dissolution in aqueous media. In part I and II of this series of articles, we have demonstrated that amorphous solid dispersions containing HPMCAS may be prepared using surfactants as plasticizers to reduce processing temperature (Solanki et al., J Pharm Sci. 2019; 108:1453-65), where surfactants also increase dissolution rate and degree of supersaturation (Solanki et al., J Pharm Sci. 2019; 108: 3063-73). The present investigation was undertaken to develop melt extrudates of itraconazole-HPMCAS and itraconazole-surfactant-HPMCAS mixtures into tablets having tensile strength ≥2 MPa, where poloxamer 407 and d-α-tocopherol polyethylene glycol 1000 succinate were used as surfactants. Milled filaments were sieved to collect <212-µm particles, which were then compressed into tablets with different excipients (silicified microcrystalline cellulose [MCC], Avicel PH-102, dicalcium phosphate, lactose, and Starch 1500). Initial screening of various diluents showed that only silicified MCC and Avicel PH-102 could provide the target tensile strength of ≥2 MPa. Tabletability (tensile strength vs. compaction pressure), compressibility (porosity vs. compaction pressure), and compactibility (tensile strength vs. porosity) were then studied for tablet formulations. The desired tensile strength could be obtained at the diluent level of 50%-70%, where silicified MCC provided better hardness than Avicel PH-102. Tablets disintegrated in <2 min, and drug release from tablets was comparable to that of milled filaments.


Assuntos
Itraconazol/química , Metilcelulose/análogos & derivados , Tensoativos/química , Comprimidos/química , Celulose/química , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Excipientes/química , Dureza/efeitos dos fármacos , Tecnologia de Extrusão por Fusão a Quente/métodos , Lactose/química , Metilcelulose/química , Polietilenoglicóis/química , Solubilidade/efeitos dos fármacos , Temperatura , Resistência à Tração/efeitos dos fármacos
8.
Drug Dev Ind Pharm ; 45(10): 1617-1623, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31353966

RESUMO

Context: AS FDSTs will provide an accessible alternative for AS autoinjector (ATROPEN®), and a noninvasive first-aid antidote for the treatment of organophosphate (OP) poisoning and reduce the number of fatalities due to nerve gas attacks or OP pesticide poisoning. Objective: The effects of changing the filler grade on the characteristics of atropine sulfate (AS) fast disintegrating sublingual tablets (FDSTs) and AS sublingual permeability were investigated in order to optimize the formulation of AS FDSTs and, therefore, AS sublingual permeability. Methods: Two batches of AS FDSTs containing AS 8 mg were formulated and manufactured using two different filler grades: microcrystalline cellulose (MCC) UF-702 (formulation A) and MCC PH-301 (formulation B). Several United States Pharmacopeia (USP) and non-USP physical tests were performed to evaluate the AS FDSTs' characteristics. The AS permeability from the two AS FDST batches were evaluated using Franz cells through excised porcine sublingual membranes. Results were statistically compared at p < .05. Results: Both batches passed the content uniformity and friability tests. Formulation A tablets were significantly different from formulation A tablets and resulted in better powder flowability, higher breaking force, faster disintegration, faster dissolution rate, higher water uptake, and higher AS permeability. Conclusion: The selection of the filler grade to be used in the formulation of AS FDSTs can significantly impact their characteristics and significantly affect AS sublingual permeability, which can be used to improve the sublingual delivery of AS and the potential of using AS FDSTs as an alternative dosage form for the first-aid treatment of OP poisoning.


Assuntos
Atropina/química , Comprimidos/química , Administração Sublingual , Celulose/química , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Excipientes/química , Dureza/efeitos dos fármacos , Permeabilidade/efeitos dos fármacos , Pós/química , Solubilidade/efeitos dos fármacos
9.
J Pharm Sci ; 108(10): 3240-3251, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31216450

RESUMO

This work aimed at establishing a framework to screen and understand the product variability deeming from factors that affect the quality features of cream formulations. As per Quality by Design - based approach, cream quality target profile and critical quality attributes were identified, and a risk assessment analysis was conducted to qualitatively detect the most critical variables for cream design and development. A Plackett-Burman design was used to screen out unimportant factors, avoiding collecting large amounts of data. Accordingly, 2 designs of experiments (DoE-1 and DoE-2) were performed, and the effects of independent variables on the cream formulations responses were estimated. At different factor combinations, significant variability was observed in droplet size, consistency, hardness, compressibility, and adhesiveness with values ranging from 2.6 ± 0.9 to 10 ± 6 µm, 7.93 ± 0.05 to 13.53 ± 0.14 mm, 27.6 ± 0.3 to 58.4 ± 1.1 g, 38 ± 6 to 447 ± 37 g.s, and 25.7 ± 2.1 to 286 ± 33 g.s, respectively. The statistical analysis allowed determining the most influent factors. This study revealed the potential of Quality by Design methodology in understanding product variability, recognizing the most critical independent variables for the final product quality. This systematic approach in the pharmaceutical field will yield more robust products and processes, provisioning time and cost effective developments.


Assuntos
Pomadas/química , Química Farmacêutica/métodos , Composição de Medicamentos/métodos , Dureza/efeitos dos fármacos , Tamanho da Partícula , Controle de Qualidade
10.
PLoS One ; 14(4): e0215370, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30978248

RESUMO

Alterations in the structure and mechanical properties of teeth in adult Wistar rats exposed to cadmium were investigated. Analyses were conducted on two sets of incisors from female and male specimens, that were intoxicated with cadmium (n = 12) or belonged to the control (n = 12). The cadmium group was administered with CdCl2 dissolved in drinking water with a dose of 4mg/kgbw for 10 weeks. The oral intake of cadmium by adult rats led to the range of structural changes in enamel morphology and its mechanical features. A significant increase of cadmium levels in the teeth in comparison to the control, a slight shift in the colour and reduction of pigmented enamel length, higher surface irregularity, a decrease of hydroxyapatite crystals size in the c-axis and simultaneous increase in pigmented enamel hardness were observed. The extent of these changes was sex-dependent and was more pronounced in males.


Assuntos
Cádmio/toxicidade , Incisivo/efeitos dos fármacos , Animais , Fenômenos Biomecânicos , Cádmio/administração & dosagem , Cádmio/farmacocinética , Cristalização , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/patologia , Esmalte Dentário/fisiopatologia , Durapatita/química , Durapatita/metabolismo , Feminino , Dureza/efeitos dos fármacos , Incisivo/patologia , Incisivo/fisiopatologia , Masculino , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Minerais/metabolismo , Ratos , Ratos Wistar , Difração de Raios X
11.
PLoS One ; 14(4): e0214948, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30951549

RESUMO

This work aimed to evaluate the roughness, microhardness, ultrastructure, chemical composition and crystalline structure in submitted teeth to a prolonged home bleaching regimen with 10% carbamide peroxide (10% PC) for different periods. The specimens were divided into the following groups: G1: negative control (application of water-soluble gel); G2: tooth whitening group (positive control), under application time recommended by the manufacturer (4h/14 days); G3: prolonged whitening 50%, under prolonged time recommended by the manufacturer in 50% (4h/21 days); G4: excessive whitening 100%, under exceeded manufacturer recommended time by 100% (4h/ 28 days). The results were evaluated descriptively and analytically. There were no changes in the roughness in any of the evaluated groups. However, the microhardness decreased in the G4 group. Scanning electron microscopy showed changes in the enamel surface of groups G2, G3 and G4. Dispersive X-ray spectroscopy identified changes in the concentration of chemical elements O, Mg, P, K in all groups. Thus, this study showed that prolonged home bleaching could cause changes in the ultrastructure, chemical composition and microhardness of the enamel.


Assuntos
Peróxido de Carbamida/farmacologia , Esmalte Dentário , Dureza/efeitos dos fármacos , Clareamento Dental , Animais , Bovinos , Esmalte Dentário/metabolismo , Esmalte Dentário/ultraestrutura , Microscopia Eletrônica de Varredura , Propriedades de Superfície/efeitos dos fármacos
12.
Int J Pharm ; 559: 210-219, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30682448

RESUMO

This paper compares batch and continuous technologies in terms of product quality and process performance in pharmaceutical tablet manufacturing using ethenzamide as the active pharmaceutical ingredient. Batch and continuous processes using wet granulation were investigated by performing experiments on the scale of 5 and up to 100 kg/lot, using the same raw materials. Three technologies were tested and compared: (i) batch technology using fluidized bed granulation, (ii) batch technology using high shear granulation, (iii) continuous technology using high shear granulation. In the full-scale experiment, in all three technologies including continuous technology, the quality of the tablets fulfilled the target values regarding hardness, active pharmaceutical ingredient content, and dissolution. The granules produced by different technologies, however, presented varying attributes regarding granule size distribution, loose bulk density, or scanning electron microscope images. The process performance, more specifically the yield, was slightly better for batch technologies than for the continuous technology, mainly due to losses in the start-up operation. Notably, this study has shown that continuous technology, which is generally believed to not entail scale-up procedures, could in fact, require parameter adjustment for prolonged operation. The results provided suggestions for improvements to implement large-scale continuous technologies in the pharmaceutical industry.


Assuntos
Salicilamidas/química , Comprimidos/química , Química Farmacêutica/métodos , Excipientes/química , Dureza/efeitos dos fármacos , Tamanho da Partícula , Solubilidade/efeitos dos fármacos , Tecnologia Farmacêutica/métodos
13.
Pak J Pharm Sci ; 32(6(Supplementary)): 2811-2816, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32024618

RESUMO

Sugar free chewable tablets are considered to be desired medication for diabetic population having acid reflex problems. The main objective of this study is to develop a patient complaint tablet dosage form which is sugar free, chewable and easy to use. The formulation is designed for hyperglycemic and dysphasic patients along acidity or stomach ulcer. For manufacturing Aluminum Hydroxide (Kyowa Japan), Magnesium Hydroxide (Taurus chemicals India) Simethicone, Povidone (JRS pharma) Sorbitol powder, Magnesium stearate, Dilcalcium phosphate anhydrous, SSG (JRS pharma) and Aspartame were used. The granules formed by wet granulation method and tablets are compressed by rotary compression machine. The pre-formulation studies of granules (Angle of repose, Bulk/Tapped density, Carr's compressibility index and Hausner's ratio), uniformity of content (assay), acid neutralizing capacity, Identification by FTIR spectroscopy all are found within the limits as per USP specifications. All three formulation batches are stable under accelerated and ambient stability conditions for 6 months and 24 months respectively. The formulation development of sugar free oral chewable antacid tablet is pharmaceutically stable and can further analyze for safety and efficacy studies.


Assuntos
Antiácidos/química , Antiácidos/farmacologia , Antiulcerosos/química , Diabetes Mellitus/fisiopatologia , Azia/tratamento farmacológico , Açúcares/química , Comprimidos/química , Antiulcerosos/farmacologia , Química Farmacêutica/métodos , Complicações do Diabetes/tratamento farmacológico , Composição de Medicamentos/métodos , Excipientes/química , Dureza/efeitos dos fármacos , Azia/etiologia , Humanos , Povidona/química , Pós/química , Pós/farmacologia , Solubilidade/efeitos dos fármacos , Sorbitol/química , Comprimidos/farmacologia
14.
Caries Res ; 53(1): 33-40, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29879720

RESUMO

The aim of this in vitro study was to investigate the impact of saliva on the abrasion of eroded enamel using two measuring methods. A total of 80 bovine enamel specimens from 20 bovine incisors were allocated to four experimental groups (n = 20 specimens per group). After baseline surface microhardness (SMH) measurements and profilometry all specimens were subjected to erosion (2 min, 1% citric acid, pH: 3.6, 37°C). SMH was determined again, and the depths of the Knoop indentations were calculated. Thereafter, specimens were incubated in human saliva (group 1 - no incubation/control, group 2 - 0.5 h, group 3 - 1 h, group 4 - 2 h) before toothbrush abrasion was performed. After final SMH measurements and profilometry, indentations were remeasured, and surface loss was calculated. SMH did not return to baseline values regardless of the length of saliva incubation. Further, an irreversible substance loss was observed for all specimens. With the indentation method, significantly (p < 0.05) more substance loss was found for controls (least square means ± standard error of 198 ± 19 nm) than for groups 2-4 (110 ± 10, 114 ± 11, and 105 ± 14 nm). Profilometric assessment showed significantly more substance loss for controls (122 ± 8 nm) than for group 4 (106 ± 5 nm). Intraclass correlation for interrater reliability between measurement methods was low (0.21, CI: 0.1-0.3), indicating poor agreement. Exposure of eroded enamel to saliva for up to 2 h could not re-establish the original SMH. The amount of measured substance loss depended on the measurement method applied.


Assuntos
Esmalte Dentário/fisiopatologia , Dureza/efeitos dos fármacos , Saliva/química , Abrasão Dentária/induzido quimicamente , Erosão Dentária/induzido quimicamente , Animais , Bovinos , Ácido Cítrico/efeitos adversos , Dureza/fisiologia , Humanos , Reprodutibilidade dos Testes , Propriedades de Superfície/efeitos dos fármacos , Remineralização Dentária , Escovação Dentária
15.
Osteoporos Int ; 30(2): 277-285, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30488274

RESUMO

Bone modulus from patients with osteoporosis treated with bisphosphonates for 1 to 20 years was analyzed. Modulus increases during the first 6 years of treatment and remains unchanged thereafter. INTRODUCTION: Bisphosphonates are widely used for treating osteoporosis, but the relationship between treatment duration and bone quality is unclear. Since material properties partially determine bone quality, the present study quantified the relationship between human bone modulus and hardness with bisphosphonate treatment duration. METHODS: Iliac crest bone samples from a consecutive case series of 86 osteoporotic Caucasian women continuously treated with oral bisphosphonates for 1.1-20 years were histologically evaluated to assess bone turnover and then tested using nanoindentation. Young's modulus and hardness were measured and related to bisphosphonate treatment duration by statistical modeling. RESULTS: All bone samples had low bone turnover. Statistical models showed that with increasing bisphosphonate treatment duration, modulus and hardness increased, peaked, and plateaued. These models used quadratic terms to model modulus increases from 1 to 6 years of bisphosphonate treatment and linear terms to model modulus plateaus from 6 to 20 years of treatment. The treatment duration at which the quadratic-linear transition (join point) occurred also depended upon trabecular location. Hardness increased and peaked at 12.4 years of treatment; it remained constant for the next 7.6 years of treatment and was insensitive to trabecular location. CONCLUSIONS: Bone modulus increases with bisphosphonate treatment durations up to 6 years, no additional modulus increases occurred after 6 years of treatment. Although hardness increased, peaked at 12.4 years and remained constant for the next 7.6 years of BP treatment, the clinical relevance of hardness remains unclear.


Assuntos
Osso Esponjoso/efeitos dos fármacos , Difosfonatos/farmacologia , Osteoporose Pós-Menopausa/tratamento farmacológico , Administração Oral , Idoso , Remodelação Óssea/efeitos dos fármacos , Osso Esponjoso/patologia , Osso Esponjoso/fisiopatologia , Estudos Transversais , Difosfonatos/administração & dosagem , Difosfonatos/uso terapêutico , Esquema de Medicação , Módulo de Elasticidade/efeitos dos fármacos , Feminino , Dureza/efeitos dos fármacos , Humanos , Ílio/efeitos dos fármacos , Ílio/patologia , Ílio/fisiopatologia , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/patologia , Osteoporose Pós-Menopausa/fisiopatologia , Fotomicrografia
16.
J Mech Behav Biomed Mater ; 90: 374-380, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30408756

RESUMO

OBJECTIVES: The aim of the study was to evaluate the effect of bioactive glass (45S5 and NbG) suspensions on bond strength (µTBS), hardness, modulus of elasticity, pH and antibacterial activity of the resin-dentin interfaces after 3 months. METHODS: Groups with different concentrations (5% and 20%) of two types of glass (45S5 and NbG), and a control group (distilled water) were studied. Twenty-five extracted human third molars were etched with phosphoric acid. The data from µTBS, hardness and modulus of elasticity data were submitted to two-way ANOVA (suspension vs. time) and Holm-Sidak tests (=0.05). The antimicrobial activity data were analyzed by the Kruskal-Wallis test (α = 5%). RESULTS: The interactions were significant among groups for µTBS (p = 0.033). Significant reductions in µTBS were observed after 3 months storage in PBS for the Control and 5% NbG Groups. Suspensions with 5% and 20% 45S5 glass and 20% NbG resulted in stable µTBS values and increased hardness after 3 months. Both 20% suspensions (45S5 and NbG) increased the elastic modulus. A significant greater reduction in bacterial growth was observed with the use of 20% 45S5. CONCLUSION: Rewetting dentin with the suspension of 20% 45S5 glass prevented the reduction in bond strength; increased hardness; modulus of elasticity of the resin-dentin interface, and demonstrated antibacterial activity against Streptococcus mutans.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Cerâmica/química , Cerâmica/farmacologia , Dentina/efeitos dos fármacos , Vidro/química , Resistência à Tração , Relação Dose-Resposta a Droga , Elasticidade/efeitos dos fármacos , Dureza/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Streptococcus mutans/efeitos dos fármacos , Resistência à Tração/efeitos dos fármacos
17.
J Mech Behav Biomed Mater ; 90: 460-471, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30448560

RESUMO

Titanium alloys (Ti-6Al-4V) are promising materials as bone implants in clinical surgeries owing to their excellent performances. However, wear debris caused by the tribological behavior of the cortical bone and titanium alloy interface were found to be paramount for implant stability. The contact environment between the cortical bone and Ti-6Al-4V in vivo has been considered to affect the tribological behavior. Currently, the tribological behaviors of bone and Ti-6Al-4V in different biolubricants remain elusive. Therefore, in this work, the tribological behaviors of Ti-6Al-4V plates sliding against bovine cortical bone were investigated in dry sliding and in biolubricants of physiological saline (PS), simulated body fluids (SBF), and fetal bovine serum (FBS). Results show that the friction coefficient and wear rate of the bovine cortical bone and Ti-6Al-4V interface exhibit the same sequence as follows: FBS > SBF > PS > dry sliding. These results are attributed to bone hardness variation and corrosion of different biolubricants. Meanwhile, the effects of normal load and velocity on the tribological behavior of bone and Ti-6Al-4V interface were also investigated in dry sliding and three different biolubricants. Results show that as the normal load is increased and the sliding velocity is decreased, the friction coefficient decreases in dry condition, adhering to the Hertz contact theory. However, according to the boundary lubrication theory, the friction coefficient in three biolubricants correlates positively to the normal load and negatively to the sliding velocity. Moreover, the wear rates of the bone samples increase with the increase in normal load and sliding velocity under dry and biolubrication conditions. Finally, the characterization results indicate that the wear mechanisms of the cortical bone and Ti-6Al-4V interface in dry friction are primarily adhesive and abrasive wear. Further, corrosive wear occurs in biolubrications, apart from adhesive and abrasive wear.


Assuntos
Materiais Biocompatíveis/farmacologia , Osso Cortical/efeitos dos fármacos , Lubrificantes/farmacologia , Titânio/farmacologia , Animais , Materiais Biocompatíveis/química , Bovinos , Corrosão , Eletroquímica , Fricção , Dureza/efeitos dos fármacos , Lubrificantes/química , Fenômenos Mecânicos , Propriedades de Superfície , Titânio/química
18.
Food Chem ; 277: 135-144, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30502129

RESUMO

Nitrogen fertilization regimes significantly affect both grain quality and yield. Wheat plants were subjected to different application timing of topdressed nitrogen at the emergence of the top fifth (TL5), top third (TL3) and top first leaf (TL1), respectively. The iTRAQ (isobaric tag for relative and absolute quantitation) technology was adopted to obtain the complete proteome of wheat flour and to identify the differentially expressed proteins (DEPs) as regulated by nitrogen topdressing timing. Collectively, 591 proteins into 17 functional categories in flour of mature grains were identified. In comparison to TL3, 50 and 63 DEPs were identified in TL5 and TL1, respectively. Nine of the DEPs commonly dependent on nitrogen topdressing timing are the γ-gliadins or high-molecular-weight glutenin subunits. Additionally, delaying nitrogen topdressing modified the grain hardness and allergic protein content. The results suggested that altering nitrogen topdressing timing is a potential strategy for pursuing targeted processing quality of wheat flour.


Assuntos
Grão Comestível/efeitos dos fármacos , Grão Comestível/metabolismo , Glutens/metabolismo , Dureza/efeitos dos fármacos , Nitrogênio/farmacologia , Farinha/análise , Qualidade dos Alimentos , Folhas de Planta/metabolismo , Proteômica , Fatores de Tempo
19.
Int J Biol Macromol ; 123: 10-19, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30408455

RESUMO

Assembling between polyphenols and proteins has been freshly spotlighted. We studied the antiglycation and anti-hardening effects of microencapsulated mulberry polyphenols (MMPs) in a high-protein-sugar ball (HPSB) model during storage using multi-dimensional approaches, including UPLC-ESI-MS/MS, SDS-PAGE, MALDI-TOF-MS, FTIR, and a molecular docking study. It was found that MMPs significantly relegated the browning development, AGEs, and/or CML levels of HPSB after 45 d of storage at 45 °C. MMPs also downgraded the protein insolubility, aggregation, oligomerization, and glycoxidation during late-storage. A molecular docking scrutiny proved that cyanidin 3-O-rutinoside and quercetin 3-O-rutinoside interacted with whey proteins subunits via H-bonding and π-π interactions. This binding blocked some glycation residues of whey proteins especially lysyl residues, namely Lys5, 16, 60, 69, 93, 94, and 122. Our data disclosed that MMPs could be valorized as promising antiglycative ingredients to mitigate AGEs-generation and other subsequent unwanted changes in protein-rich food matrices.


Assuntos
Glicosilação/efeitos dos fármacos , Dureza/efeitos dos fármacos , Morus/química , Polifenóis/farmacologia , Açúcares/metabolismo , Proteínas do Soro do Leite/metabolismo , Antocianinas/farmacologia , Frutas/química , Glucosídeos/farmacologia , Simulação de Acoplamento Molecular/métodos , Extratos Vegetais/farmacologia , Quercetina/análogos & derivados , Quercetina/farmacologia , Espectrometria de Massas em Tandem/métodos
20.
Braz Oral Res ; 32: e122, 2018 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-30569972

RESUMO

The effects of tooth brushing could affect the long-term esthetic outcome of composite restorations. This study evaluated the effect of two different emission spectrum light-curing units on the surface roughness, roughness profile, topography and microhardness of bulk-fill composites after in vitro toothbrushing. Valo (multiple-peak) and Demi Ultra (single-peak) curing lights were each used for 10s to polymerize three bulk-fill resin composites: Filtek Bulk Fill Posterior Restorative (FBF), Tetric EvoCeram Bulk Fill (TET) and Surefil SDR Flow (SDR). After 30,000 reciprocal strokes in a toothbrushing machine, the roughness profile, surface roughness, surface morphology, and microhardness were examined. Representative SEM images were also obtained. When light-cured with the Demi Ultra, SDR showed the most loss in volume compared to the other composites and higher volume loss compared to when was light-cured with Valo. The highest surface roughness and roughness profile values were found in SDR after toothbrushing, for both light-curing units tested. FBF always had the greatest microhardness values. Light-curing TET with Valo resulted in higher microhardness compared to when using the Demi Ultra. Confocal and SEM images show that toothbrushing resulted in smoother surfaces for FBF and TET. All composites exhibited surface volume loss after toothbrushing. The loss in volume of SDR depended on the light-curing unit used. Toothbrushing can alter the surface roughness and superficial aspect of some bulk-fill composites. The choice of light-curing unit did not affect the roughness profile, but, depending on the composite, it affected the microhardness.


Assuntos
Resinas Compostas/efeitos da radiação , Luzes de Cura Dentária , Escovação Dentária/efeitos adversos , Análise de Variância , Resinas Compostas/química , Dureza/efeitos dos fármacos , Dureza/efeitos da radiação , Cura Luminosa de Adesivos Dentários/métodos , Teste de Materiais , Microscopia Confocal , Microscopia Eletrônica de Varredura , Polimerização , Reprodutibilidade dos Testes , Propriedades de Superfície/efeitos dos fármacos , Propriedades de Superfície/efeitos da radiação , Fatores de Tempo
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