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1.
Acta Odontol Scand ; 83: 327-333, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38801222

RESUMO

OBJECTIVE: Toothpastes are widely used to protect oral and teeth health. This study aims to examine the cytotoxic and antimicrobial effects of whitening toothpastes. METHODS: In this study, extracts were prepared according to ISO 10993-12:2021 standard (0.2 g/mL) using whitening and conventional toothpastes. The prepared extracts were added to human gingival fibroblast cell lines (HGF-1) in different dilutions (1:1, 1:2, 1:4, 1:8, 1:16, and 1:32) and a cytotoxicity test was performed. Antimicrobial analysis of toothpastes was performed on Streptococcus mutans, Staphylococcus aureus, and Candida albicans using the hole-plate diffusion method. Cell viability and microbial analysis data were examined using two-way analysis of variance (ANOVA) and Tukey post-hoc test (p < 0.05). RESULTS: Toothpastes with sodium lauryl sulfate (SLS) in their composition showed statistically more toxic effects (p < 0.05). The activated carbon toothpastes without SLS showed over 90% cell viability after dilution. Although the dilution rate of toothpastes containing SLS increased, cell viability remained below 70%. All toothpastes used in the study showed antimicrobial effects on S. mutans, S. aureus, and C. albicans. Toothpaste containing hydrogen peroxide and SLS produced more antibacterial effects than activated carbon, blue covarine, microparticles, and conventional toothpaste. CONCLUSIONS: SLS-containing toothpastes showed more toxicity on HGF-1 cells. Toothpaste containing hydroxyapatite did not show toxic effects on HGF-1 cells. SLS, sodium lauryl sarcosinate and hydrogen peroxide in toothpastes increase antimicrobial effects.


Assuntos
Anti-Infecciosos , Candida albicans , Staphylococcus aureus , Streptococcus mutans , Cremes Dentais , Cremes Dentais/farmacologia , Humanos , Candida albicans/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Streptococcus mutans/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Linhagem Celular , Técnicas In Vitro , Fibroblastos/efeitos dos fármacos , Clareadores Dentários/toxicidade , Clareadores Dentários/farmacologia
2.
World J Microbiol Biotechnol ; 40(5): 140, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38514578

RESUMO

One of the major environmental problems we have today is dye pollution, primarily caused by the textile industry. This pollution has detrimental effects on aquatic life, soil fertility, and human health. Many microbial biosorbents have been documented in the literature for the removal of a wide range of azo dyes commonly employed in the textile industry. However, Yarrowia lipolytica NBRC1658 is firstly used as both free and immobilized sorbents for the removal of Reactive yellow 18 (RY18), acid red 18 (AR18) and basic blue 41 (BB41) in this study. The effect of experimental conditions such as pH, biosorbent quantity, dye concentration, contact time, and temperature on dye removal capacity are examined. The research findings demonstrate that the adsorption capacity is higher in biomass compared to immobilized cells. The highest adsorption capacities are observed at pH 2 for RY18 and AR18, while pH 9 is optimal for BB41. Increasing the adsorbent dosage and initial concentration significantly improves the adsorption capacity. The Langmuir model best describes the adsorption process, indicating that the dye attaches to the biosorbent in a single layer, with a uniform biosorbent surface. The removal of the dye occurs through a chemical process on the biosorbent surface, as evidenced by the pseudo-second-order kinetic model. According to thermodynamic analysis, higher temperatures promote greater adsorption of dyes. Our study shows the effectiveness of Yarrowia lipolyica NBRC1658 as a biosorbent in the removal of a wide range of industrial dyes.


Assuntos
Naftalenossulfonatos , Poluentes Químicos da Água , Yarrowia , Humanos , Adsorção , Biomassa , Concentração de Íons de Hidrogênio , Termodinâmica , Corantes , Cinética , Compostos Azo
3.
J Biomater Sci Polym Ed ; 35(3): 295-305, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37982375

RESUMO

Intrauterine devices (IUDs) are widely used in preventing fertilization as contracepting devices. In market, they are produced as T-shaped polyethylene (or propylene) and metal (especially copper) composites. Although the metal component is utilized to provide antibacterial efficacy, prolonged implantation and the presence of a wide range of bacteria flora in the intrauterine environment make IUDs susceptible to bacterial contamination, biofilm formation, and unpleasant infection. In the presented study, the propolis, a natural anti-bacterial/-viral product used for different biomedical applications, coating strategy was applied comparatively in three different ways: coating directly on metal components, coating on polymeric material, and using carrying polymer. In addition, antibacterial activity against Gram-positive (Staphylococcus aureus, S. aureus) and Gram-negative (Escherichia coli, E. coli) bacterial strains were investigated by both dynamic bacterial culture (bacterial inhibition activity) and biofilm (biofilm formation resistance) tests. As a result of 48 h of dynamic bacterial culture; it was determined that the antibacterial inhibition efficiency depending on propolis concentration increased up to 99.5% and 98.5% for E. coli and S. aureus, respectively. In addition, the carrying polymer allows IUDs to cover surfaces more homogeneously, as well as improve antibacterial activity. Similarly; it was determined that biofilm formation resistance was improved by 44.33% for E. coli and by 45.99% for S. aureus with both the propolis concentration and the use of carrying polymer. As a result, it has been revealed that propolis will be classified as an alternative, promising, and effective coating agent for improving antibacterial properties and biofilm formation resistance of IUDs.


Assuntos
Dispositivos Intrauterinos , Própole , Feminino , Humanos , Própole/farmacologia , Staphylococcus aureus , Escherichia coli , Antibacterianos/farmacologia , Polímeros/farmacologia , Biofilmes , Testes de Sensibilidade Microbiana
4.
Micromachines (Basel) ; 14(9)2023 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-37763831

RESUMO

Microbial contaminants are responsible for several infectious diseases, and they have been introduced as important potential food- and water-borne risk factors. They become a global burden due to their health and safety threats. In addition, their tendency to undergo mutations that result in antimicrobial resistance makes them difficult to treat. In this respect, rapid and reliable detection of microbial contaminants carries great significance, and this research area is explored as a rich subject within a dynamic state. Optical sensing serving as analytical devices enables simple usage, low-cost, rapid, and sensitive detection with the advantage of their miniaturization. From the point of view of microbial contaminants, on-site detection plays a crucial role, and portable, easy-applicable, and effective point-of-care (POC) devices offer high specificity and sensitivity. They serve as advanced on-site detection tools and are pioneers in next-generation sensing platforms. In this review, recent trends and advances in optical sensing to detect microbial contaminants were mainly discussed. The most innovative and popular optical sensing approaches were highlighted, and different optical sensing methodologies were explained by emphasizing their advantages and limitations. Consequently, the challenges and future perspectives were considered.

5.
Arch Microbiol ; 204(7): 438, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35768731

RESUMO

In this study, the Pb(II) biosorption performance of newly isolated fungal strain, used as a biosorbent, was analyzed. Fungal strain was identified as Backusella circina according to the internal transcribed spacer (ITS) region. Following Pb(II) biosorption, Fourier-transform infrared spectroscopy was performed to compare pristine and Pb(II) biosorped biomass. The effects of pH, fungal biomass amount, temperature, interfering metal ions, initial concentration of Pb(II) and contact time on biosorption performance of B. circina were examined to optimize the biosorption conditions from aqueous solutions. It was observed that optimum Pb(II) biosorption was performed at pH 6.0. Maximum Pb(II) biosorption capacity was found to be 30.69 at 50 mg/L initial concentration of Pb(II) and equilibrium was established after 60 min. It was indicated that the equilibrium data were better fitted to Langmuir isotherm model and it is better to interpret the kinetic data by the pseudo-second-order model. The competitive Pb(II) biosorption capacity was found to be increased in the presence of co-existing metal ions. To the best of knowledge from related literature, Pb(II) biosorption performance of B. circina has not been reported in advance. In conclusion, Pb(II) biosorption performance of B. circina was revealed as an efficient biosorbent in terms of no requirement of modification, ease of preparation and low cost obtainability.


Assuntos
Chumbo , Poluentes Químicos da Água , Biomassa , Concentração de Íons de Hidrogênio , Íons , Cinética , Mucorales , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Methods Mol Biol ; 2466: 249-260, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35585323

RESUMO

Cryogels are defined as polymeric gel matrices with interconnected macropores providing an advantage to be efficient carriers enabling unhindered diffusion of interested molecule. Cryogels could be easily prepared with the combination of molecular imprinting. Molecular imprinting technology provides selective and sensitive recognition for biomolecules. Immunoglobulin G (IgG) is a main effector component in human response. It is recently well recognized that the purification strategies for IgG have intensively gained attention to treat immune defects. Several methods including affinity chromatography have been applied for the purification of IgG from complex media. The purification of IgG plays a crucial role in medical applications using several materials. Among these, cryogels have been widely applied for the purification of several biomolecules. They offer to create low-cost affinity systems with high chemical and physical stability. Above all, temperature sensitive polymers enable a reversible phase transition against small temperature changes, by the way, reversible swelling and shrinking manner is observed.In this chapter, immunoglobulin G imprinted thermosensitive poly(N-isopropylacrylamide-N methacryloyl-(l)-histidine) [p(NIPA-MAH)/IgG-MIP] monolithic cryogel is explained. The preparation and characterization of cryogels are summarized. In addition, IgG binding studies with different parameters are briefly described. Herein, an effective design principle is presented to create imprinted temperature-sensitive cryogels for IgG purification. A p(NIPA-MAH)/IgG-MIP monolithic cryogel was synthesized for IgG purification. Afterward, IgG binding capacity of p(NIPA-MAH)/IgG-MIP cryogels was examined in different experimental conditions. Apart from these, selectivity of the p(NIPA-MAH)/IgG-MIP cryogel was shown by comparing IgG binding capacity of nonimprinted [p(NIPA-MAH)/NIP] one. Finally, the IgG purification ability of the p(NIPA-MAH)/IgG-MIP cryogel from human plasma was demonstrated proving its application in affinity chromatography using real sample.


Assuntos
Criogéis , Impressão Molecular , Acrilamidas , Resinas Acrílicas , Adsorção , Criogéis/química , Humanos , Imunoglobulina G/química , Polímeros
7.
Eng Life Sci ; 22(3-4): 204-216, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35382542

RESUMO

Bio-separation plays a crucial role in many areas. Different polymers are suitable for bio-separation and are useful for applications in applications in both science and technology. Besides biopolymers, there are a broad spectrum of synthetic polymers with tailor-made properties. The synthetic polymers are characterized by their charges, solubility, hydrophilicity/hydrophobicity, sensitivity to environmental conditions and stability. Furthermore, ongoing developments are of great interest on biodegradable polymers for the treatment of diseases. Smart polymers have gained great attention due to their unique characteristics especially emphasizing simultaneously changing their chemical and physical property upon exposure to changes in environmental conditions. In this review, methodologies applied in bio-separation using synthetic polymers are discussed and efficient candidates are focused for the construction of synthetic polymers.

8.
Turk J Chem ; 45(5): 1353-1365, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34849053

RESUMO

In this study, amino acid functionalized poly(2-hydroxyethyl methacrylate-N-methacrylolyl-l-phenylalanine) [PHEMAPA] cryogel discs were prepared. In this respect, phenylalanine containing N-methacryloyl-(L)-phenylalanine methyl ester (MAPA) was polymerized with 2-hydroxyethyl methacrylate (HEMA) without requirement of any activation step. Laccase bound poly(2-hydroxyethyl methacrylate-N-methacryloyl-l-phenylalanine) [Lac-PHEMAPA] cryogel discs were applied for decolorization of Reactive Blue-247 (RB-247). The ability of Lac-PHEMAPA cryogel discs on dye decolorization was found to be as 90% in 2 h and even more within 4h. The decolorization activities of 86% and 73% were observed at relatively low (4°C) and high (60°C) temperatures, respectively. The effect of dye concentration on dye decolorization and 100% decolorization activity was achieved in dye concentration between 50-300 ppm. Lac-PHEMAPA cryogel discs maintained 80% of its decolorization activity after six cycles. Consequently, the PHEMAPA cryogel discs are promising materials for immobilizing laccase. The Lac-PHEMAPA has a rapid dye decolorization in a broad range of temperature. The preparation is furthermore very stable and activity is preserved during storage.

9.
Biosensors (Basel) ; 11(5)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33947112

RESUMO

Over the past few decades, a significant increase in multi-drug-resistant pathogenic microorganisms has been of great concern and directed the research subject to the challenges that the distribution of resistance genes represent. Globally, high levels of multi-drug resistance represent a significant health threat and there is a growing requirement of rapid, accurate, real-time detection which plays a key role in tracking of measures for the infections caused by these bacterial strains. It is also important to reduce transfer of resistance genes to new organisms. The, World Health Organization has informed that millions of deaths have been reported each year recently. To detect the resistant organisms traditional detection approaches face limitations, therefore, newly developed technologies are needed that are suitable to be used in large-scale applications. In the present study, the aim was to design a surface plasmon resonance (SPR) sensor with micro-contact imprinted sensor chips for the detection of Staphylococcus aureus. Whole cell imprinting was performed by N-methacryloyl-L-histidine methyl ester (MAH) under UV polymerization. Sensing experiments were done within a concentration range of 1.0 × 102-2.0 × 105 CFU/mL. The recognition of S. aureus was accomplished by the involvement of microcontact imprinting and optical sensor technology with a detection limit of 1.5 × 103 CFU/mL. Selectivity of the generated sensor was evaluated through injections of competing bacterial strains. The responses for the different strains were compared to that of S. aureus. Besides, real experiments were performed with milk samples spiked with S. aureus and it was demonstrated that the prepared sensor platform was applicable for real samples.


Assuntos
Técnicas Biossensoriais , Staphylococcus aureus/isolamento & purificação , Biomimética , Histidina/análogos & derivados , Humanos , Metacrilatos , Ressonância de Plasmônio de Superfície
10.
Environ Sci Pollut Res Int ; 28(36): 49685-49696, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33942264

RESUMO

This study aims to characterize the microbial community and its relationship with heavy metal pollution in the beaches of Sugözü, an important nesting site for the green turtle. Heavy metal concentrations of sand samples from subregions of Sugözü were determined using ICP-MS. The microbial community was analyzed using the Biolog® EcoPlate. The relationship between microbial catalytic activity and heavy metal levels were analyzed using canonical correspondence analysis. Levels of 27Al, 57Fe, 55Mn, and 52Cr were quite high (4332.34, 13,764.77, 590.98, and 48.21 mg/kg, respectively). The microbial community in subregions with high levels of metals was found to use carboxylic acid as a carbon source. Bioactivity, substrate utilization, diversity, and evenness values indicated negative correlations concentrations of 27Al, 56Fe, and 52Cr (-0.820, -0.508, and -0.560, respectively). It was also found that microbial diversity decreased in the subregions where heavy metal concentration increased. Embryonic deaths were found highest at early stage (0.1 to 0.2 eggs) and lowest at middle stage for whole study sites by inspecting a total 6408 eggs of 63 green turtle nests. The Biolog EcoPlate was firstly applied to determine pollution, and our findings clearly demonstrate the applicability and effectiveness of this method in assessing nesting beaches.


Assuntos
Metais Pesados , Microbiota , Tartarugas , Animais , Poluição Ambiental , Metais Pesados/análise
11.
J Biomater Sci Polym Ed ; 32(8): 980-993, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33492195

RESUMO

Polymethyl methacrylate (PMMA), called as bone cement, has been used in implant surgery, initially in dental practices, then in arthroplasty surgery for decades. Bone cement is a highly preferred chemical in the field of orthopedics due to its bone-like hardness and mechanical strength. Meanwhile, antibiotic-loaded cements are used in joints and similar surgeries are generally due to the risk of infection. In this study, we aimed to demonstrate the effects of borate mineral loading into bone cement on enhancing the antibacterial resistivity and cell integration as well as retaining mechanical properties. Moreover, the incorporation of minerals into bone cements makes them much more cost-friendly biomaterials for surgical operations. Herein, antibacterial properties were evaluated by using vancomycin- and gentamycin-susceptible strains of Enterococcus faecalis and Staphylococcus aureus whereas cell viability tests were performed by osteoblast cell lines. Three sets of the bone cements, plain, calcium borate-, and sodium borate-loaded, were prepared through commercial procedures and subjected to mechanical, antibacterial and cell viability tests. Percentage deformation determined by compression tests under 0.100 MPa pressure was determined in the range of 12.58%-10.67% in respect to the amount of sodium borate mineral loaded whereas that was determined in the range of 12.54%-9.87% in respect to the amount of calcium borate mineral loaded. Micro-CT results also supported good mineral integration and structural features of the composite bone cements. Furthermore, mineral incorporation enhanced the cell viability, in other words, cellular integrity, up to 101.28% for sodium borate-loaded (NB75, 7.5 g mineral) and 72.04% for calcium borate-loaded (CB75, 7.5 g mineral) bone cement according to the negative control group, fresh culture medium. As a conclusion, both of these minerals could be classified as promising alternatives for developing bone cements with better antibacterial resistivity and cellular integration properties.


Assuntos
Boratos , Polimetil Metacrilato , Antibacterianos/farmacologia , Cimentos Ósseos , Minerais
12.
J Biomater Sci Polym Ed ; 32(2): 189-204, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32962559

RESUMO

Antibacterial micron-sized cryogels, so-called microcryogels, were prepared by cryogelation of gelatin and integration of lysozyme. Gelation yield, specific surface area, macro-porosity and swelling degree of the microcryogels were examined in order to characterize their physical properties. MTT method was utilized to measure cell viability of the gelatin microcryogels with a period of 24, 48, and 72 h and no significant decrease was observed at 72 h. Apoptotic staining assay also showed high viability at 24, 48, 72 h in parallel with the control group. The antibacterial performances of the gelatin microcryogels against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli were examined. The results showed that the incorporation of lysozyme into gelatin microcryogels exhibited the antibacterial activity against S. aureus, B. subtilis, and E. coli, that may provide great potential for various applications in the biomedical industry.


Assuntos
Gelatina , Muramidase , Antibacterianos/farmacologia , Escherichia coli , Staphylococcus aureus
13.
Drug Dev Res ; 82(2): 241-250, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33009868

RESUMO

The development of chitosan-gelatin (CS-G) hydrogels embedded with ampicillin-loaded hyaluronic acid nanoparticles (HA-NPs) for wound dressing is proposed. It was aimed to provide controlled ampicillin delivery by incorporation of HA-NPs into biocompatible CS-G hydrogel structure. According to in vitro ampicillin release studies, 55% of ampicillin was released from CS-G/HA-NPs hydrogels after 5 days. Antibacterial performance of CS-G/HA-NPs hydrogels was proven with agar disc diffusion test. For cytotoxicity assay, fibroblast cell viability increased in CS-G/HA-NPs hydrogels compared with CS-G group after 24 hr incubation. Consequently, the potential ability of CS-G/HA-NPs hydrogels as a controlled drug delivery system has been verified.


Assuntos
Antibacterianos/farmacologia , Quitosana/farmacocinética , Liberação Controlada de Fármacos/efeitos dos fármacos , Gelatina/farmacocinética , Ácido Hialurônico/farmacocinética , Nanopartículas/metabolismo , Ampicilina/síntese química , Ampicilina/farmacocinética , Animais , Antibacterianos/síntese química , Quitosana/síntese química , Avaliação Pré-Clínica de Medicamentos/métodos , Liberação Controlada de Fármacos/fisiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Gelatina/síntese química , Humanos , Ácido Hialurônico/síntese química , Hidrogéis/síntese química , Hidrogéis/farmacocinética , Nanopartículas/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia
14.
Appl Biochem Biotechnol ; 184(2): 538-552, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28762007

RESUMO

In this study, two different materials-alginate and glutaraldehyde-activated chitosan beads-were used for the co-immobilization of α-amylase, protease, and pectinase. Firstly, optimization of multienzyme immobilization with Na alginate beads was carried out. Optimum Na alginate and CaCl2 concentration were found to be 2.5% and 0.1 M, respectively, and optimal enzyme loading ratio was determined as 2:1:0.02 for pectinase, protease, and α-amylase, respectively. Next, the immobilization of multiple enzymes on glutaraldehyde-activated chitosan beads was optimized (3% chitosan concentration, 0.25% glutaraldehyde with 3 h of activation and 3 h of coupling time). While co-immobilization was successfully performed with both materials, the specific activities of enzymes were found to be higher for the enzymes co-immobilized with glutaraldehyde-activated chitosan beads. In this process, glutaraldehyde was acting as a spacer arm. SEM and FTIR were used for the characterization of activated chitosan beads. Moreover, pectinase and α-amylase enzymes immobilized with chitosan beads were also found to have higher activity than their free forms. Three different enzymes were co-immobilized with these two materials for the first time in this study.


Assuntos
Alginatos/química , Quitosana/química , Enzimas Imobilizadas/química , Glutaral/química , Peptídeo Hidrolases/química , Poligalacturonase/química , alfa-Amilases/química , Ácido Glucurônico/química , Ácidos Hexurônicos/química
15.
Colloids Surf B Biointerfaces ; 162: 146-153, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29190465

RESUMO

Boronate affinity chromatography is a common purification method used for isolation and purification of cis-diol containing biomolecules. Poly (hydroxyethyl methacrylate-co-vinyl phenyl boronic acid) [P(HEMA-VPBA)] nanoparticles were prepared by miniemulsion polymerization to use in RNA purification methods. The P(HEMA-VPBA) nanoparticles were characterized by particle size distribution, surface area, Fourier transform infrared spectroscopy and atomic force microscopy. The effects of temperature, pH, RNA concentration and different salt types on RNA binding on the P(HEMA-VPBA) nanoparticles were examined. It was observed that RNA binding was increased with the increasing of pH and max RNA binding was obtained at pH 9.0. RNA binding capacity of the P(HEMA-VPBA) nanoparticles was increased from 167mg/g to 601mg/g with addition of BaCl2 to the binding medium. Maximum RNA binding capacity of the P(HEMA-VPBA) nanoparticles was 172mg/g at 1.0mg/mL initial RNA concentration. The P(HEMA-VPBA) nanoparticles were reusable for RNA binding. RNA was also extracted from Escherichia coli cells and purified successfully using the P(HEMA-VPBA) nanoparticles.


Assuntos
Ácidos Borônicos/química , Cromatografia de Afinidade/métodos , Escherichia coli/química , Nanopartículas/química , Poli-Hidroxietil Metacrilato/química , RNA Bacteriano/isolamento & purificação , Compostos de Vinila/química , Compostos de Bário/química , Cloretos/química , Emulsões , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Polimerização , Temperatura
16.
Sensors (Basel) ; 17(6)2017 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-28608810

RESUMO

Identification of pathogenic microorganisms by traditional methods is slow and cumbersome. Therefore, the focus today is on developing new and quicker analytical methods. In this study, a Surface Plasmon Resonance (SPR) sensor with a microcontact imprinted sensor chip was developed for detecting Salmonella paratyphi. For this purpose, the stamps of the target microorganism were prepared and then, microcontact S. paratyphi-imprinted SPR chips were prepared with the functional monomer N-methacryloyl-L-histidine methyl ester (MAH). Characterization studies of the SPR chips were carried out with ellipsometry and scanning electron microscopy (SEM). The real-time Salmonella paratyphi detection was performed within the range of 2.5 × 106-15 × 106 CFU/mL. Selectivity of the prepared sensors was examined by using competing bacterial strains such as Escherichia coli, Staphylococcus aureus and Bacillus subtilis. The imprinting efficiency of the prepared sensor system was determined by evaluating the responses of the SPR chips prepared with both molecularly imprinted polymers (MIPs) and non-imprinted polymers (NIPs). Real sample experiments were performed with apple juice. The recognition of Salmonella paratyphi was achieved using these SPR sensor with a detection limit of 1.4 × 106 CFU/mL. In conclusion, SPR sensor has the potential to serve as an excellent candidate for monitoring Salmonella paratyphi in food supplies or contaminated water and clearly makes it possible to develop rapid and appropriate control strategies.


Assuntos
Salmonella paratyphi A , Histidina/análogos & derivados , Metacrilatos , Impressão Molecular , Nanoestruturas , Polímeros , Staphylococcus aureus , Ressonância de Plasmônio de Superfície
17.
Sensors (Basel) ; 17(4)2017 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-28353629

RESUMO

There is a growing need for selective recognition of microorganisms in complex samples due to the rapidly emerging importance of detecting them in various matrices. Most of the conventional methods used to identify microorganisms are time-consuming, laborious and expensive. In recent years, many efforts have been put forth to develop alternative methods for the detection of microorganisms. These methods include use of various components such as silica nanoparticles, microfluidics, liquid crystals, carbon nanotubes which could be integrated with sensor technology in order to detect microorganisms. In many of these publications antibodies were used as recognition elements by means of specific interactions between the target cell and the binding site of the antibody for the purpose of cell recognition and detection. Even though natural antibodies have high selectivity and sensitivity, they have limited stability and tend to denature in conditions outside the physiological range. Among different approaches, biomimetic materials having superior properties have been used in creating artificial systems. Molecular imprinting is a well suited technique serving the purpose to develop highly selective sensing devices. Molecularly imprinted polymers defined as artificial recognition elements are of growing interest for applications in several sectors of life science involving the investigations on detecting molecules of specific interest. These polymers have attractive properties such as high bio-recognition capability, mechanical and chemical stability, easy preparation and low cost which make them superior over natural recognition reagents. This review summarizes the recent advances in the detection and quantification of microorganisms by emphasizing the molecular imprinting technology and its applications in the development of sensor strategies.


Assuntos
Técnicas Biossensoriais , Materiais Biomiméticos , Impressão Molecular , Nanotubos de Carbono , Polímeros
18.
Biosens Bioelectron ; 87: 807-815, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27657842

RESUMO

In this study, a label-free, selective and sensitive microcontact imprinted capacitive biosensor was developed for the detection of Escherichia coli. The recognition of E. coli was successfully performed by this sensor prepared with the combination of microcontact imprinting method and capacitive biosensor technology. After preparation of bacterial stamps, microcontact-E. coli imprinted gold electrodes were generated using an amino acid based recognition element, N-methacryloyl-L-histidine methylester (MAH), 2-Hydroxyethyl methacrylate (HEMA) as monomers and ethyleneglycol dimethacrylate (EGDMA) as crosslinker under UV-polymerization. Real-time E. coli detection experiments were carried out within the range of 1.0×102-1.0×107CFU/mL. The unique combination of these two techniques provides selective detection with a detection limit of 70CFU/mL. The designed capacitive sensor has high selectivity and was able to distinguish E. coli when present together with competing bacterial strains which are known to have similar shape. In addition, the prepared sensor has the ability to detect E. coli with a recovery of 81-97% in e.g. river water.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Escherichia coli/isolamento & purificação , Histidina/análogos & derivados , Metacrilatos/química , Impressão Molecular/métodos , Rios/microbiologia , Reagentes de Ligações Cruzadas/química , Capacitância Elétrica , Técnicas Eletroquímicas/instrumentação , Eletrodos , Desenho de Equipamento , Infecções por Escherichia coli/microbiologia , Histidina/química , Humanos , Impressão Molecular/instrumentação
19.
Colloids Surf B Biointerfaces ; 134: 461-8, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26257149

RESUMO

The aim of this study was to prepare Concanavalin A (Con A) immobilized magnetic poly(glycidyl methacrylate) (mPGMA) beads for prostate specific antigen (PSA) binding and to study binding capacities of the beads using lectin-glycoprotein interactions. Firstly, iron oxide nanoparticles were synthesized by co-precipitation method and then, beads were synthesized by dispersion polymerization in the presence of iron oxide nanoparticles. Con A molecules were both covalently immobilized onto the beads directly and through the spacer arm (1,6-diaminohexane-HDMA). The total PSA and free PSA binding onto the mPGMA-HDMA-Con A beads were higher than that of the mPGMA-Con A beads. Maximum PSA binding capacity was observed as 91.2 ng/g. Approximately 45% of the bound PSA was eluted by using 0.1 M mannose as elution agent. The mPGMA-HDMA-Con A beads could be reused without a remarkable decrease in the binding capacities after 5 binding-desorption cycles. Serum fractions were analyzed using SDS-PAGE. The mPGMA-HDMA-Con A beads could be useful for the detection of PSA and suggested as a model system for other glycoprotein biomarkers.


Assuntos
Concanavalina A/química , Magnetismo , Ácidos Polimetacrílicos/metabolismo , Antígeno Prostático Específico/metabolismo , Humanos , Masculino , Espectroscopia de Infravermelho com Transformada de Fourier
20.
Braz. arch. biol. technol ; 57(4): 548-553, Jul-Aug/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-712929

RESUMO

Randomly amplified polymorphic DNA (RAPD)-PCR was applied with ten random 10-mer primers to examine the molecular diversity among methicillin resistant Staphylococcus aureus (MRSA) strains in the hospitals and to investigate the epidemiological spread of these strains between different hospitals. The main objective of the study was to identify appropriate primers, which successfully established the clonality of MRSA. Three of the primers yielded particularly discriminatory patterns and they were used to perform the RAPD analysis which revealed different bands ranging from 200 to 1500 bp. Dendogram was created by the un-weighted pair group method using arithmetic (UPGMA) average clustering and it was constructed based on the combination results of the new primers (S224, S232 and S395) which represented a novel approach for rapid screening of the strains and also provided the opportunity for monitoring the emergence and determining clonal dissemination of MRSA strains between the hospitals. Dendogram generated two main groups (Group I and II) with three clusters (A, B and C) and indicated that the strains isolated from the same hospital were closely related and they placed together in the same group. This technique could be of attractive use in controlling the sources and routes of transmission, tracking the spread of strains within hospital and between the hospitals, and especially preventing the nosocomial infections caused by the MRSA.

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