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1.
Food Chem ; 311: 125918, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31869647

RESUMO

Multilayer materials used in food packaging are commonly manufactured with a polyurethane adhesive layer in its structure that may contain cyclic esters oligomers as potential migrants. However, little is known about their toxicity. In this work, two cyclic esters of polyurethane are evaluated in migration from 20 multilayer packaging samples. They were composed by adipic acid (AA), diethylene glycol (DEG) and isophthalic acid (IPA) and their structure was AA-DEG and AA-DEG-IPA-DEG. The concentration of these compounds in migration exceeded the maximum level established by Regulation EU/10/2011 (10 ng g-1). Bioaccessibility of both compounds was evaluated by studying gastric and intestinal digestion. The studies showed that the concentration of the compounds decreased during digestion and that their hydrolysed molecules increased. Furthermore, endocrine activity in vitro assays were performed. A weak androgen receptor antagonism was identified, whereas no arylhydrocarbon receptor activity or binding to the thyroid hormone transport protein was found.


Assuntos
Adesivos/química , Embalagem de Alimentos/instrumentação , Poliésteres/química , Poliuretanos/química , Adipatos/química , Adipatos/toxicidade , Antagonistas de Receptores de Andrógenos/química , Antagonistas de Receptores de Andrógenos/toxicidade , Linhagem Celular , Etilenoglicóis/química , Etilenoglicóis/toxicidade , Contaminação de Alimentos/análise , Humanos , Ácidos Ftálicos/química , Ácidos Ftálicos/toxicidade , Poliuretanos/toxicidade
2.
Ecotoxicol Environ Saf ; 183: 109461, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31377519

RESUMO

The present work investigated the changes in DNA methylation pattern of Tenebrio molitor mitochondria genome at different development stages, which was fed with polyurethane foam as a sole diet. Polyurethane foam could influence the global methylation levels in mitochondria DNA of Tenebrio molitor. Different leves of 5-methylcytosine appeared at CpG and non-CpG sites of Tenebrio molitor mtDNA while they were fed with polyurethane foam: 10 CpG and 49 non-CpG sites at larval stage, 4 CpG and 31 non-CpG sites at pupa stage, 7 CpG and 56 non-CpG sites at adult stage in general. Moreover, we observed the decreased levels of ATP generation with the mitochondria DNA methylation variation. The results demonstrated that mitochondria DNA gene could be methylated in response to environmental pollutants to modulate stage-specific functions. Moreover, mtDNA methylation of polyurethane-foam-feeding Tenebrio molitor existed discrepancy in the developmental stage. The tentative methylation mechanism of mtDNA might be that polyurethane foam induced oxidative stress and increased the permeability of mitochondrial membranes, which resulted in transmethylase entry into mitochondria.


Assuntos
DNA Mitocondrial/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Epigênese Genética/efeitos dos fármacos , Metamorfose Biológica/efeitos dos fármacos , Poliuretanos/toxicidade , Tenebrio/efeitos dos fármacos , 5-Metilcitosina/metabolismo , Animais , Metilação de DNA/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/genética , Metamorfose Biológica/genética , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Pupa/efeitos dos fármacos , Pupa/genética , Tenebrio/genética , Tenebrio/crescimento & desenvolvimento
3.
Microsc Res Tech ; 82(10): 1768-1778, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31313433

RESUMO

Resin composite-based dental materials can leach certain components into the oral environment, causing potentially harmful gingival biological effect. Gingival tissue is a rich source of mesenchymal stem cells (MSCs) that is easily accessible, and can be used as a complementary approach for the investigation of dental material biocompatibility. Using gingival MSCs (gMSCs), the present study aimed to investigate the cytotoxicity of two classes of restorative dental materials (ormocers and resin composites) used to restore class II cavities close to the gingival margin, in addition to analyzing the leached compounds from these resin composite-based materials. Functionality assays (Colony-forming unit, migratory potential, and proliferation assays) and a viability assay (MTT) were employed. Cells' aspect was observed by scanning electron microscopy (SEM). Leached monomers were also quantitated using high-performance liquid chromatography (HPLC). The cytotoxicity of the biomaterials was highlighted by impaired functionality and diminished viability of gMSCs. Despite being variants of the same commercial material, the two ormocers behaved differently one material having a more negative impact on cell functionality than the other. Cells appeared to attach well to all materials. Main monomer molecules were mostly released by the tested materials. For all samples, an increased elution of monomers was recorded in artificial saliva as compared with culture medium. One composite material has released nearly eight times more urethane dimetacrylate in artificial saliva than in culture medium. Significantly lower gMSC viability scores were recorded for all the investigated samples in comparison with the control.


Assuntos
Resinas Acrílicas/toxicidade , Materiais Biocompatíveis/toxicidade , Resinas Compostas/toxicidade , Gengiva/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Poliuretanos/toxicidade , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Teste de Materiais
4.
Carbohydr Polym ; 216: 86-96, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31047085

RESUMO

Water-activated shape memory bacterial cellulose/polyurethane nanocomposites were prepared by the immersion of bacterial cellulose (BC) wet membranes into waterborne polyurethane (WBPU) dispersions for different times. The high affinity between the hydrophilic BC and water stable polyurethane led to the coating and embedding of the BC membrane into the WBPU, facts that were confirmed by FTIR, SEM and mechanical testing of the nanocomposites. The mechanical performance of the nanocomposites resulted enhanced with respect to the neat WBPU, confirming the reinforcing effect of the BC membrane. An improvement of the shape fixity ability and faster recovery process with the presence of BC was observed. In 3 min, the nanocomposite with highest BC content recovered the 92.8 ± 6.3% of the original shape, while the neat WBPU only recovered the 33.4 ± 9.6%. The obtained results indicated that 5 min of impregnation time was enough to obtain nanocomposites with improved mechanical performance and fast shape recovery for potential biomedical applications. The present work provides an approach for developing environmentally friendly and biocompatible BC/polyurethane based materials with enhanced mechanical and shape memory properties.


Assuntos
Materiais Biocompatíveis/química , Celulose/química , Nanocompostos/química , Poliuretanos/química , Água/química , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/toxicidade , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Celulose/toxicidade , Módulo de Elasticidade , Fibroblastos/efeitos dos fármacos , Gluconacetobacter/química , Camundongos , Nanocompostos/toxicidade , Poliuretanos/toxicidade , Resistência à Tração , Temperatura de Transição
5.
Plast Reconstr Surg ; 143(5): 1285-1292, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30789476

RESUMO

BACKGROUND: The epidemiology and implant-specific risk for breast implant-associated (BIA) anaplastic large cell lymphoma (ALCL) has been previously reported for Australia and New Zealand. The authors now present updated data and risk assessment since their last report. METHODS: New cases in Australia and New Zealand were identified and analyzed. Updated sales data from three leading breast implant manufacturers (i.e., Mentor, Allergan, and Silimed) were secured to estimate implant-specific risk. RESULTS: A total of 26 new cases of BIA-ALCL were diagnosed between January of 2017 and April of 2018, increasing the total number of confirmed cases in Australia and New Zealand to 81. This represents a 47 percent increase in the number of reported cases over this period. The mean age and time to development remain unchanged. The implant-specific risk has increased for Silimed polyurethane (23.4 times higher) compared with Biocell, which has remained relatively static (16.5 times higher) compared with Siltex implants. CONCLUSIONS: The number of confirmed cases of BIA-ALCL in Australia and New Zealand continues to rise. The implant-specific risk has now changed to reflect a strong link to implant surface area/roughness as a major association with this cancer.


Assuntos
Implante Mamário/efeitos adversos , Implantes de Mama/efeitos adversos , Linfoma Anaplásico de Células Grandes/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Adulto , Idoso , Austrália/epidemiologia , Implante Mamário/instrumentação , Feminino , Humanos , Linfoma Anaplásico de Células Grandes/etiologia , Pessoa de Meia-Idade , Nova Zelândia/epidemiologia , Poliuretanos/toxicidade , Complicações Pós-Operatórias/etiologia , Medição de Risco , Propriedades de Superfície , Adulto Jovem
6.
Clin Oral Investig ; 23(1): 133-139, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29603022

RESUMO

OBJECTIVES: Tooth-colored composites have emerged as a standard restorative material in caries therapy and have largely replaced materials such as silver amalgam or glass ionomer cements. In addition to their superior esthetics and desirable mechanical properties, composites also comprise negative characteristics, such as wear, shrinkage, and an adverse biocompatibility. Modifications of classic resin-based dental composites have been developed to overcome these shortcomings. For example, ormocers are innovative inorganic-organic hybrid polymers that form a siloxane network modified by the incorporation of organic groups. Recently, a new ormocer, Admira Fusion (VOCO), was introduced to composite technology. The absence of cytotoxic matrix monomers leads to the hypothesis that ormocers have improved biocompatibility compared to resin-based dental restorative materials. MATERIALS AND METHODS: The aim of this study was to compare the cytotoxic effects of Admira Fusion to a nanohybrid composite (GrandioSO, VOCO) and a nanofiller composite (Filtek Supreme XTE, 3M Espe) on the standard dermal mouse fibroblasts (L929) and human gingival fibroblasts (GF-1) via a Cell Counting Kit-8 (CCK-8) assay. RESULTS: Admira Fusion was significantly less cytotoxic than GrandioSO and Filtek Supreme XTE to both the standard mouse dermal fibroblasts (L929) and human gingival fibroblasts. CONCLUSIONS: Compared to other resin-based dental restorative materials, the ormocer (Admira Fusion) possesses a superior biocompatibility in vitro. Future research studies are needed to confirm our results. CLINICAL SIGNIFICANCE: Clinically, dental practitioners and their patients might benefit from Admira Fusion in terms of reduced adverse biologic reactions compared to resin-based dental restorative materials.


Assuntos
Resinas Acrílicas/toxicidade , Resinas Compostas/toxicidade , Materiais Dentários/toxicidade , Fibroblastos/efeitos dos fármacos , Cerâmicas Modificadas Organicamente/toxicidade , Poliuretanos/toxicidade , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Gengiva/citologia , Humanos , Teste de Materiais , Metacrilatos/toxicidade , Camundongos , Siloxanas/toxicidade
7.
J Mater Sci Mater Med ; 29(11): 161, 2018 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-30357534

RESUMO

Segmented polyurethanes were prepared with polycaprolactone diol as soft segment and various amounts of 4,4´-Methylenebis(cyclohexyl isocyanate) and atorvastatin, a statin used for lowering cholesterol, in order to obtain SPU with different content of rigid segments. Polyurethanes with 35% or 50% of rigid segment content were physicochemically characterized and their biocompatibility assessed with L929 fibroblasts. High concentrations of atorvastatin were incorporated by increasing the content of rigid segments as shown by FTIR, Raman, NMR, XPS and EDX. Thermal and mechanical characterization showed that polyurethanes containing atorvastatin and 35% of rigid segments were low modulus (13 MPa) semicrystalline polymers as they exhibited a glass transition temperature (Tg) at -38 °C, melting temperature (Tm) at 46 °C and crystallinity close to 35.9% as determined by DSC. In agreement with this, X-ray diffraction showed reflections at 21.3° and 23.6° for PCL without reflections for atorvastatin suggesting its presence in amorphous form with higher potential bioavailability. Low content of rigid segments led to highly degradable polymer in acidic, alkaline and oxidative media with an acceptable fibroblast cytotoxicity up to 7 days possibly due to low atorvastatin content.


Assuntos
Atorvastatina/química , Materiais Biocompatíveis/química , Cianatos/química , Poliésteres/química , Poliuretanos/química , Animais , Atorvastatina/toxicidade , Materiais Biocompatíveis/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Estrutura Molecular , Microscopia Óptica não Linear , Poliésteres/toxicidade , Poliuretanos/toxicidade , Espectrofotometria Infravermelho , Temperatura
8.
PLoS One ; 13(10): e0205699, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30372449

RESUMO

Essential oils play an important role in reducing the pain and inflammation caused by bone fracture.In this study, a scaffold was electrospun based on polyurethane (PU), grape seed oil, honey and propolis for bone tissue-engineering applications. The fiber diameter of the electrospun PU/grape seed oil scaffold and PU/grape seed oil/honey/propolis scaffold were observed to be reduced compared to the pristine PU control. FTIR analysis revealed the existence of grape seed oil, honey and propolis in PU identified by CH band peak shift and also hydrogen bond formation. The contact angle of PU/grape seed oil scaffold was found to increase owing to hydrophobic nature and the contact angle for the PU/grape seed/honey oil/propolis scaffold were decreased because of hydrophilic nature. Further, the prepared PU/grape seed oil and PU/grape seed oil/honey/propolis scaffold showed enhanced thermal stability and reduction in surface roughness than the control as revealed in thermogravimetric analysis (TGA) and atomic force microscopy (AFM) analysis. Further, the developed nanocomposite scaffold displayed delayed blood clotting time than the pristine PU in the activated prothrombin time (APTT) and partial thromboplastin time (PT) assay. The hemolytic assay and cytocompatibility studies revealed that the electrospun PU/grape seed oil and PU/grape seed oil/honey/propolis scaffold possess non-toxic behaviour to red blood cells (RBC) and human fibroblast cells (HDF) cells indicating better blood compatibility and cell viability rates. Hence, the newly developed electrospun nanofibrous composite scaffold with desirable characteristics might be used as an alternative candidate for bone tissue engineering applications.


Assuntos
Materiais Biocompatíveis/química , Regeneração Óssea , Substitutos Ósseos/química , Osso e Ossos/fisiologia , Engenharia Tecidual/métodos , Materiais Biocompatíveis/toxicidade , Substitutos Ósseos/toxicidade , Linhagem Celular , Sobrevivência Celular , Eritrócitos , Fibroblastos , Extrato de Sementes de Uva/química , Extrato de Sementes de Uva/toxicidade , Mel , Humanos , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais/métodos , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Nanocompostos/química , Nanocompostos/toxicidade , Nanocompostos/ultraestrutura , Tempo de Tromboplastina Parcial , Tamanho da Partícula , Poliuretanos/química , Poliuretanos/toxicidade , Própole/química , Própole/toxicidade , Espectroscopia de Infravermelho com Transformada de Fourier , Testes de Toxicidade/métodos
9.
J Mech Behav Biomed Mater ; 87: 148-154, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30071485

RESUMO

Over the past years, significant effort has been dedicated to synthesizing low-shrinking formulations, however, development of dental composites with low volumetric shrinkage continues to be challenging. The purpose of this study was to synthesize a bisphenol allylic derivate (BPhADAC) and evaluate its inclusion in the formulation of a photopolymerizable dental composite resin, as a BisGMA diluent. Experimental (BisGMA/BPhADAC) and control (BisGMA/TEGDMA) photopolymerizable composites were prepared. Double bond conversion, polymerization kinetics, volumetric shrinkage, water sorption, solubility, and flexural properties were investigated. The experimental composite showed higher degree of conversion values, less volumetric shrinkage and less water sorption than the control composite (p < 0.05). In addition, flexural strength between the materials was found to be similar. The overall properties prove that the allylic monomer BPhADAC could be potentially useful in the formulation of low-shrinking dental composite resins.


Assuntos
Resinas Acrílicas/química , Ácido Carbônico/química , Ácido Carbônico/síntese química , Resinas Compostas/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Poliuretanos/química , Resinas Acrílicas/toxicidade , Animais , Bis-Fenol A-Glicidil Metacrilato/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Química Sintética , Cor , Resinas Compostas/toxicidade , Composição de Medicamentos , Módulo de Elasticidade , Resistência à Flexão , Cinética , Camundongos , Processos Fotoquímicos , Polimerização , Poliuretanos/toxicidade , Solubilidade , Água/química
10.
Angew Chem Int Ed Engl ; 57(33): 10574-10578, 2018 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-29870140

RESUMO

Sequence-defined oligourethanes were tested as in vivo taggants for implant identification. The oligomers were prepared in an orthogonal solid-phase iterative approach and thus contained a coded monomer sequence that can be unequivocally identified by tandem mass spectrometry (MS/MS). The oligomers were then included in small amounts (1 wt %) in square-centimeter-sized crosslinked poly(vinyl alcohol) (PVA) model films, which were intramuscularly and subcutaneously implanted in the abdomen of rats. After one week, one month, or three months of implantation, the PVA films were explanted. The rat tissues exposed to the implants did not exhibit any adverse reactions, which suggested that the taggants are not harmful and probably not leaching out from the films. Furthermore, the explanted films were immersed in methanol, as a solvent for oligourethanes, and the liquid extract was analyzed by mass spectrometry. In all cases, the oligourethane taggant was detected, and its sequence was identified by MS/MS.


Assuntos
Poliuretanos/química , Álcool de Polivinil/química , Próteses e Implantes , Abdome/patologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Metanol/química , Camundongos , Poliuretanos/toxicidade , Álcool de Polivinil/análise , Ratos , Espectrometria de Massas por Ionização por Electrospray
11.
Cardiovasc Eng Technol ; 9(3): 503-513, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29700782

RESUMO

In this study, a small vascular graft based on polyurethane (PU) blended with chitosan (Ch) nanoparticles was fabricated using electrospinning technique. Initially, the chitosan nanoparticles were synthesized using ionic gelation method. UV-Vis spectrophotometer confirmed the presence of synthesized Ch nanoparticles by exhibiting absorption peak at 288 nm and the Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the existence of the chitosan. Further, the synthesized Ch nanoparticles showed size diameter in the range of 134 ± 58 nm as measured using ImageJ. In the electrospun PU/chitosan graft, the fiber diameter and pore size diameter was found to be reduced compared to the pure PU owing to incorporation of chitosan into PU matrix. The FTIR spectrum revealed the presence of chitosan in the prepared nanocomposite membrane by the formation of the hydrogen bond and peak shift of CH and NH stretching. Moreover, the contact angle measurements revealed that the prepared graft showed decreased contact angle indicating hydrophilic nature compared to the pristine PU. The cytocompatibility studies revealed the non-toxic behavior of the fabricated graft. Hence, the prepared graft exhibiting significant physiochemical and non-toxic properties may be a plausible candidate for cardiovascular graft applications.


Assuntos
Implante de Prótese Vascular/instrumentação , Prótese Vascular , Quitosana/química , Nanopartículas , Nanotecnologia/métodos , Poliuretanos/química , Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/efeitos adversos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Quitosana/análogos & derivados , Quitosana/toxicidade , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Tamanho da Partícula , Poliuretanos/toxicidade , Porosidade , Desenho de Prótese , Propriedades de Superfície
12.
Cardiovasc Eng Technol ; 9(1): 73-83, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29196952

RESUMO

In spite of advances have been made during the past decades, the problems associated with small-diameter vascular grafts, including low patency and compliance mismatch and in consequence of that thrombosis, aneurysm and intimal hyperplasia are still challenges. To address these problems, net polyurethane (PU) and poly (ethylene terephthalate) (PET) polymers and hybrid PU/PET were electrospun to create three different types of small-diameter vascular scaffolds due to their unique physicochemical characteristics: PU, PET, and novel hybrid PU/PET scaffolds. The results show that the PU and PET composite can improve the mechanical properties of the tissue-engineered vascular scaffolds in the range of the native vessels where the non-cytotoxicity characteristic of these well-known polymers is still immutable. The compliance and stiffness factor of the fabricated hybrid scaffolds were 4.468 ± 0.177 and 22.718 ± 0.896%/0.01 mmHg, respectively, which were significantly different with that of the net PU and PET electrospun scaffolds. Other properties such as ultimate tensile stress (UTS) (3.56 ± 1.21 MPa) were also in good accordance with the native vessels. Furthermore, FT-IR analysis testified the presence of both PU and PET in the hybrid scaffolds. Overall, we were able to fabricate a hybrid scaffold as a small-diameter vascular graft that mechanically matched the gold standard of blood vessel substitution.


Assuntos
Implante de Prótese Vascular/instrumentação , Prótese Vascular , Polietilenotereftalatos/química , Poliuretanos/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Elasticidade , Análise de Falha de Equipamento , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Humanos , Teste de Materiais , Nanofibras , Polietilenotereftalatos/toxicidade , Poliuretanos/toxicidade , Porosidade , Desenho de Prótese , Falha de Prótese , Pele/efeitos dos fármacos , Pele/patologia , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração
13.
Chemosphere ; 193: 720-725, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29175399

RESUMO

A series of laboratory experiments were conducted, in which waste furniture polyurethane foam samples containing tris (1-chloro-2-propyl) phosphate (TCIPP) were contacted with a range of leaching fluids, formulated to simulate the composition of landfill leachate. Leaching was examined under a number of different scenarios, such as: dissolved humic matter concentration, pH, and temperature, as well as the effect of agitation, and waste:leaching fluid contact duration. In addition to single batch (no replenishment of leaching fluid), serial batch (draining of leachate and replenishment with fresh leaching fluid at various time intervals) experiments were conducted. Leaching of TCIPP from PUF appears to be a first order process. Concentrations of TCIPP in leachate generated by the experiments in this study ranged from 13 mg L-1 to 130 mg L-1. In serial batch leaching experiments, >95% of TCIPP was depleted from PUF after 168 h total contact with leaching fluid. Our experiments indicate leaching is potentially a very significant pathway of TCIPP emissions to the environment.


Assuntos
Poluição Ambiental , Retardadores de Chama/toxicidade , Decoração de Interiores e Mobiliário , Organofosfatos/química , Poliuretanos/toxicidade , Poluentes Químicos da Água/química , Cinética , Solubilidade , Soluções/química
14.
J Contemp Dent Pract ; 18(9): 771-774, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28874639

RESUMO

AIM: Different biomaterials and techniques have been introduced in the field of prosthetic dentistry with the purpose of replacement and rehabilitation of the edentulous areas. Due to their shorter setting time, the light-activated restorative and prosthetic materials have the capability of releasing few amount of cytotoxic materials in the oral cavity. Polymer materials [urethane dimethacrylate (UDMA) and bis-acryl] are assumed to have high mechanical properties. Polymethyl methacrylate (PMMA) offers numerous advantages of being highly esthetic in nature and at the same time being cost-effective. Hence, this study aimed to assess and compare the water sorption and cytotoxicity of light-activated UDMA denture base resin and conventional heat-activated PMMA resin. MATERIALS AND METHODS: This study included assessment and comparison of water sorption and cytotoxicity of heat-activated PMMA resin and light-activated UDMA denture base system. Fabrication of heat-activated PMMA resin and UDMA specimens was done by investing the wax patterns in stone molds using manufacturer's instructions. Contraction of the specimens was done for assessment of cytotoxicity and water resorption of the UDMA and PMMA resin samples. All the results were analyzed by Statistical Package for the Social Sciences software version 18.0. Chi-square test and one-way analysis of variance tests were used for the assessment of the level of significance; p < 0.05 was taken as significant. RESULTS: Mean lysis score observed in the PMMA and UDMA groups was 0.4 and 0.3 respectively. While observing at the 3 months time, the mean water resorption in the PMMA and UDMA groups was found to be 37.9 and 40.2 respectively. Significant difference in relation to water resorption was observed between the two study groups only at 3 months time. CONCLUSION: Both materials used in this study are nontoxic. Furthermore, UDMA resin materials exhibited lower water resorption after more than 1 month of time of storage. CLINICAL SIGNIFICANCE: Water resorption is similar for different denture base resin systems till 1 months time.


Assuntos
Materiais Dentários/química , Materiais Dentários/toxicidade , Bases de Dentadura , Metacrilatos/química , Metacrilatos/toxicidade , Polimetil Metacrilato/química , Polimetil Metacrilato/toxicidade , Poliuretanos/química , Poliuretanos/toxicidade , Água/química , Adsorção , Técnicas In Vitro , Teste de Materiais
15.
J Dent ; 65: 76-82, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28711338

RESUMO

OBJECTIVES: Dental resin-based materials are widely used in modern dentistry. Especially, resin cements enjoy great popularity and are utilized in many applications. Nevertheless, monomers could be released from the resinous matrix, thus interact with surrounding tissues, cause adverse biological reactions and may lead in cases of implant retained restorations to peri-implant bone destruction. Hence, we performed an in-vitro study to determine cytotoxicity of resin monomers on osteoblast-like cells. METHODS: Three permanent osteoblast-like cell lines from tumor origin (MG-63 and Saos-2) as well as immortalized human fetal osteoblasts (hFOB 1.19) were used and treated with different concentrations of the main monomers: BisGMA, UDMA, TEGDMA and HEMA. The impact on cell viability was monitored using three different cytotoxicity tests: alamarBlue, XTT, and LDH assay. Mean±SEM were calculated and statistical analysis was performed with GraphPad Prism software. RESULTS: All monomers tested caused concentration dependent cytotoxic effects on the three investigated osteoblast-like cell lines. Although all three cell viability assays showed comparable results in cytotoxic ranking of the monomers (BisGMA > UDMA > TEGDMA > HEMA), higher differences in the absolute values were detected by the various test methods In addition, also a cell line dependent influence on cell viability could be identified with higher impact on the immortalized hFOB 1.19 cells compared to both osteosarcoma cell lines (MG-63, Saos-2). CONCLUSIONS: Monomer concentrations detected in elution studies caused toxic effects in osteoblast-like cells. Although the results from in-vitro studies cannot be directly transferred to a clinical situation our results indicate that released monomers from composite resin cements may cause adverse biological effects and thereby possibly lead to conditions favoring peri-implantitis and bone destruction. CLINICAL SIGNIFICANCE: The wide use of composite resin cements especially in implant-prosthetic treatments should be scrutinized to avoid possible clinical implications between eluted resin monomers and bone cells leading to conditions favoring peri-implantitis and bone destruction.


Assuntos
Materiais Dentários/toxicidade , Teste de Materiais , Osteoblastos/efeitos dos fármacos , Cimentos de Resina/toxicidade , Resinas Sintéticas/toxicidade , Linhagem Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Metacrilatos/toxicidade , Polietilenoglicóis/toxicidade , Ácidos Polimetacrílicos/toxicidade , Poliuretanos/toxicidade , Fatores de Tempo
16.
J Dent ; 59: 11-17, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28122255

RESUMO

OBJECTIVE: In this study, we designed and synthesized a novel macromolecule (tetramethyl bisphenol F acrylate, TMBPF-Ac) with low viscosity, excellent mechanical properties, and good biocompatibility. It could be used as a monomer for dental resin composites, which could reduce the risk of human exposure to bisphenol A derivatives in the oral environment. In addition, the monomer could be used without diluent, thereby avoiding the negative effect of a diluent METHODS: TMBPF-Ac was synthesized by a multistep condensation reaction. Its structure was confirmed by 1H NMR spectra. Different resin mixtures were prepared, and then a number of performance and cytotoxicity tests were performed on these specimens. RESULTS: 1H NMR spectra showed that the structure of TMBPF-Ac was in accordance with the design. The viscosity of TMBPF-Ac was obviously lower than that of bisphenol-A diglycidyl methacrylate. The three kinds of resins used in this study were in line with ISO 4049:2009 and ISO 10993-5:2009. TMBPF-Ac-based resin had better physical and biological properties.


Assuntos
Resinas Acrílicas/química , Resinas Acrílicas/síntese química , Resinas Compostas/química , Resinas Compostas/síntese química , Poliuretanos/química , Poliuretanos/síntese química , Viscosidade , Acrilatos/química , Resinas Acrílicas/toxicidade , Compostos Benzidrílicos/química , Compostos Benzidrílicos/toxicidade , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Fenômenos Químicos , Técnicas de Química Sintética , Resinas Compostas/toxicidade , Força Compressiva , Materiais Dentários/síntese química , Materiais Dentários/química , Resinas Epóxi/química , Humanos , Exposição por Inalação , Espectroscopia de Ressonância Magnética , Teste de Materiais , Metacrilatos/síntese química , Metacrilatos/química , Fenóis/química , Fenóis/toxicidade , Polimerização , Poliuretanos/toxicidade , Estresse Mecânico , Resistência à Tração , Água/química
17.
Singapore Med J ; 58(1): 46-49, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26805670

RESUMO

INTRODUCTION: The risk of surgery-related infection is a persistent problem in orthopaedics and infections involving implants are particularly difficult to treat. This study explored the responses of bone and soft tissue to antimicrobial-coated screws. We investigated whether such screws, which have never been used to fix bony tissues, would result in a cytotoxic effect. We hypothesised that the coated screws would not be toxic to the bone and that the likelihood of infection would be reduced since bacteria are not able to grow on these screws. METHODS: Titanium screws were inserted into the left supracondylar femoral regions of 16 rabbits. The screws were either uncoated (control group, n = 8) or coated with a polyvinylpyrrolidone-polyurethane interpolymer with tertiary amine functional groups (experimental group, n = 8). At Week 6, histological samples were obtained and examined. The presence of necrosis, fibrosis and inflammation in the bony tissue and the tissue surrounding the screws was recorded. RESULTS: Live, cellular bone marrow was present in all the rabbits from the experimental group, but was replaced with connective tissue in four rabbits from the control group. Eight rabbits from the control group and two rabbits from the experimental group had necrosis in fatty bone marrow. Inflammation was observed in one rabbit from the experimental group and five rabbits from the control group. CONCLUSION: Titanium surgical screws coated with polyvinylpyrrolidone-polyurethane interpolymer were associated with less necrosis than standard uncoated screws. The coated screws were also not associated with any cytotoxic side effect.


Assuntos
Parafusos Ósseos , Materiais Revestidos Biocompatíveis , Poliuretanos/toxicidade , Povidona/toxicidade , Infecção da Ferida Cirúrgica/prevenção & controle , Animais , Coelhos , Titânio
18.
Carbohydr Polym ; 156: 235-243, 2017 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-27842818

RESUMO

The aim of this study was to provide a convenient surface modification method for polyurethane (PU) membrane and evaluate its influence on hydrophilicity, antibacterial activity and cell functions, which are the most important factors for wound dressings. For this purpose, chitooligosaccharide (COS) was modified onto the surface of PU membrane based on the self-polymerization of dopamine (DOPA). Surface composition, morphology, hydrophilicity and surface energy of the original and modified PU membranes were characterized. Surface roughness and hydrophilicity of the PU membrane were obviously increased by modified with polydopamine (PDOPA) and COS. Antibacterial experiment against Escherichia coli and Staphylococcus aureus indicated that antibacterial activity of PU membrane increased only slightly by modified with PDOPA, but increased significantly by further modified with COS. Cells culture results revealed that COS-functionalized PU membrane is more beneficial to the adhesion and proliferation of NIH-3T3 cells compared to the original and PDOPA-modified PU membranes.


Assuntos
Indóis/farmacologia , Polímeros/farmacologia , Poliuretanos/farmacologia , Adesivos , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quitina/análogos & derivados , Quitina/química , Indóis/toxicidade , Camundongos , Células NIH 3T3 , Polímeros/toxicidade , Poliuretanos/toxicidade , Propriedades de Superfície
19.
J Biomed Mater Res A ; 104(12): 2954-2967, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27448986

RESUMO

Surface state is one of the most important parameters determining the biocompatibility of an implantable medical device, any change on the surface once in contact with body tissues can impact the biological response (cytotoxicity, inflammation, irritation, thrombosis, etc.). In the present study, we use (Pellethane® ) catheter-based polyurethane (PU), because of its many applications in the field of medical devices, to evaluate the impact of additives blooming on the biocompatibility. Four different antioxidants and two anti-ultraviolet stabilizers were included in this study. A comprehensive study was conducted to evaluate the consequences of cellular exposure to theses additives in the following three forms: in dissolved form and after surface blooming, in amorphous and in crystalized ones, and finally in the overall biocompatibility of the native PU. Surface roughness was analyzed with atomic force microscopy. Endothelial cells' viability was studied in contact with all the three physical forms. A preliminary hemocompatibility evaluation was performed through the measurement of whole blood hemolysis, as well as platelet adhesion in contact with the different PU samples. The study of the proinflammatory IL-α and TNF-α production by macrophages in contact with these films is also reported. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2954-2967, 2016.


Assuntos
Antioxidantes/química , Materiais Biocompatíveis/química , Cateteres de Demora , Células Endoteliais/citologia , Poliuretanos/química , Antioxidantes/toxicidade , Materiais Biocompatíveis/toxicidade , Cateteres de Demora/efeitos adversos , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Inflamação/induzido quimicamente , Microscopia de Força Atômica , Poliuretanos/toxicidade , Protetores Solares/química , Protetores Solares/toxicidade , Propriedades de Superfície
20.
Environ Toxicol Pharmacol ; 43: 159-65, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26994444

RESUMO

Estrogen is a steroid hormone that is vital in vertebrate development and plays a role in a variety of developmental processes including cartilage and craniofacial formation. The effects of estrogen can be mimicked by other compounds found in the environment known as xenoestrogens. Bisphenol-A (BPA) is a known xenoestrogen and is combined with glycidyl methacrylate to make Bisphenol A glycidyl methacrylate (Bis-GMA), a major component in dental resin based composites (RBCs). Bis-GMA based RBCs can release their components into the saliva and bloodstream. Exposure to 1µM and 10µM Bis-GMA in Danio rerio embryos results in increased mortality of approximately 30% and 45% respectively. Changes to gross morphology, specifically craniofacial abnormalities, were seen at concentrations as low as 10nM. While the molecular pathways of Bis-GMA effects have not been studied extensively, more is known about one of the components, BPA. Further research of Bis-GMA could lead to a better understanding of xenoestrogenic activity resulting in improved public and environmental health.


Assuntos
Resinas Acrílicas/toxicidade , Bis-Fenol A-Glicidil Metacrilato/toxicidade , Resinas Compostas/toxicidade , Poliuretanos/toxicidade , Peixe-Zebra/embriologia , Animais , Embrião não Mamífero
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