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Avian coccidiosis, a common disease caused by Eimeria species, results in significant losses in global poultry production. Mycotoxins are low-molecular-weight natural products (i.e., small molecules) produced as secondary metabolites by filamentous fungi and they have the potential to economically and significantly affect global poultry production. Little is known about the relationship between mycotoxins and avian coccidiosis, although they often co-occur in the field. This comprehensive review examines the intricate relationship between mycotoxins and avian coccidiosis, in particular how mycotoxins, including aflatoxins, ochratoxins, trichothecenes as well as Fusarium mycotoxins, compromise the health of the poultry flock and open the door to Eimeria parasites in the gut. In addition, this review sheds light on the immunosuppressive effects of mycotoxins, their disruption of cellular signaling pathways, and the consequent exacerbation of coccidiosis infections. The mechanisms of mycotoxin toxicity are also reviewed, emphasizing direct damage to intestinal epithelial cells, impaired nutrient absorption, inflammation, oxidative stress, and changes in the gut microbiota. Finally, the consequences for the prevention and treatment of coccidiosis when mycotoxins are present in the feed are discussed. This review emphasizes the need for effective management strategies to mitigate the combined risks of mycotoxins and coccidiosis and highlights the complexity of diagnosing and controlling these interrelated problems in poultry. The review advocates a holistic approach that includes strict feed management, disease prevention measures and regular monitoring to maintain the health and productivity of poultry against these significant challenges.
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Introduction: The study aimed to evaluate the efficacy of a novel multicomponent substance against combined exposure to the mycotoxins zearalenone (ZEN) and ochratoxin A (OTA) in weaned piglets. Methods: In total, 60 piglets at the age of 28 days were equally allocated to four experimental groups (A-D), consisting of eight female and seven male piglets each (15 animals per group, for a total trial duration of 42 days). Animals from group A received typical weaner feed without mycotoxins or the test product [multicomponent mycotoxin detoxifying agent (MMDA)]. Group B animals received the same weaner feed contaminated with 0.992 mg ZEN/kg feed and 0.531 mg OTA/kg feed without the addition of the MMDA. Animals in group C received the same contaminated feed as group B with the addition of 1.5 g MMDA/kg feed, whereas group D received the same feed as group B with the inclusion of 3 g MMDA/kg feed. Clinical signs and performance parameters [body weight (BW), average daily weight gain (ADWG), and feed conversion ratio (FCR)] were evaluated, while mycotoxin residues were also assessed in the liver and kidney tissues. Results: Findings showed improved FCR in the group that received the greatest dose of the test product (3 g MMDA/kg feed) compared to the group that received the lower dose (1.5 g MMDA/kg feed). A few hematological and biochemical parameters were slightly altered, predominantly within normal limits. The residue analysis demonstrated a reduction of OTA in liver samples, a-ZEL in the liver and total tested samples, and a total of ZEN and metabolite contents in all samples of the group that received the greatest MMDA dose in comparison to the group that received the toxins without the addition of the test product. Discussion: Therefore, a positive effect of the MMDA at the greatest dosage regime on reducing bioavailability and tissue deposition of ZEN and OTA, with a particularly positive effect on FCR in weaned pigs, is suggested under concurrent ZEN and OTA exposure in vivo.
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Maintaining respiratory tract health is crucial for layers, impacting gut health, laying performance, and egg quality. Viral diseases and standard vaccinations can compromise tracheal epithelium function, leading to oxidative stress. This study assessed the impact of a blend of feed additives, predominantly lysozyme (L), essential oils (EO), and vitamins (VIT) (referred to as L + EO + VIT), on young layers during an oral vaccination schedule. The supplementation significantly enhanced antibody titers for Newcastle Disease Virus (NDV) and Infectious Bronchitis Virus (IBV) after vaccination, trachea functionality and intestinal health in the jejunum, increased egg production, and exhibited a trend toward higher egg weight. Although feed intake showed no significant difference, egg quality remained consistent across experimental groups. Moreover, L + EO + VIT supplementation elevated total phenolic content in eggs, improving oxidative stability in both fresh and stored eggs, particularly under iron-induced oxidation. Notably, it substantially reduced yolk lipid peroxidation and albumen protein carbonyls. In conclusion, water supplementation with L + EO + VIT may enhance humoral immune response to IBV and NDV, positively impacting hen productivity. These findings indicate improved tracheal function and enhanced oxidative stability, emphasizing the potential of this blend in promoting overall health and performance in layers.
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Mycotoxins present a significant health concern within the animal-feed industry, with profound implications for the pig-farming sector. The objective of this study was to evaluate the efficacy of two commercial adsorbents, an organically modified clinoptilolite (OMC) and a multicomponent mycotoxin detoxifying agent (MMDA), to ameliorate the combined adverse effects of dietary aflatoxins (AFs: sum of AFB1, AFB2, AFG1, and AFG2), fumonisins (FBs), and zearalenone (ZEN) at levels of nearly 0.5, 1.0, and 1.0 mg/kg, on a cohort of cross-bred female pigs (N = 24). Pigs were randomly allocated into six experimental groups (control, mycotoxins (MTX) alone, MTX + OMC 1.5 kg/ton, MTX + OMC 3.0 kg/ton, MTX + MMDA 1.5 kg/ton, and MTX + MMDA 3.0 kg/ton), each consisting of four individuals, and subjected to a dietary regimen spanning 42 days. The administration of combined AFs, FBs, and ZEN reduced the body-weight gain and increased the relative weight of the liver, while there was no negative influence observed on the serum biochemistry of animals. The supplementation of OMC and MMDA ameliorated the toxic effects, as observed in organ histology, and provided a notable reduction in residual AFs, FBs, and ZEN levels in the liver and kidneys. Moreover, the OMC supplementation was able to reduce the initiation of liver carcinogenesis without any hepatotoxic side effects. These findings demonstrate that the use of OMC and MMDA effectively mitigated the adverse effects of dietary AFs, FBs, and ZEN in piglets. Further studies should explore the long-term protective effects of the studied adsorbent supplementation to optimize mycotoxin management strategies in pig-farming operations.
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Alimentación Animal , Micotoxinas , Animales , Femenino , Aflatoxinas/toxicidad , Contaminación de Alimentos/análisis , Contaminación de Alimentos/prevención & control , Fumonisinas/toxicidad , Micotoxinas/análisis , Micotoxinas/toxicidad , Porcinos , Zearalenona/análisis , Alimentación Animal/efectos adversos , Alimentación Animal/microbiología , Microbiología de AlimentosRESUMEN
The present study was conducted to determine the ability of multicomponent mycotoxin detoxifying agent (MMDA) in feed to prevent the gastrointestinal absorption of aflatoxin B1 (AFB1) and T2-toxin supplemented via spiked maize. For comparisons, hens were fed with uncontaminated basal diet without or with addition of MMDA at 2 g/kg feed. The trial consisted of 105 laying hens (Lohmann Brown) without obvious signs of disease allocated to 7 treatment groups in 35 pens. Responses were demonstrated on laying performance and health status throughout the 42 d experimental period. The results of laying performance indicated significantly decreased egg mass with increasing mycotoxin (AFB1 and T2-toxin) levels up to the maximum tolerated dosage, however simultaneous presence of MMDA laying performance was slightly modified linearly to increasing application. Dose-dependent pathological changes in liver and kidneys and their relative weights, changes in blood parameters and reduced eggshell weights were observed in the hens fed AFB1 and T2-toxin. The pathological changes in the hens fed with diets containing AFB1 and T2-toxin without MMDA were significantly higher as compared with the control group, but eggshell stability was not affected. The contents of AFB1, T2-toxin and their metabolites in liver and kidney tissues were significantly decreased in the hens supplemented with MMDA at 2 and 3 g/kg in feed. MMDA supplementation significantly reduced the deposition of AFB1, T2-toxin and their metabolites in liver and kidneys at the maximum tolerated dosage (2 and 3 g/kg) indicating specific binding to AFB1 and T2-toxin in the digestive tract as compared to the corresponding diets without MMDA. Exposure of AFB1 and T2-toxin indicated significantly decreased egg mass with increasing mycotoxin levels up to the maximum tolerated dosage because of the significantly reduced egg production. Therefore, in this study, MMDA could reduce negative effects of feeding AFB1 and T-2 to laying hens.
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Micotoxinas , Toxina T-2 , Animales , Femenino , Aflatoxina B1/toxicidad , Aflatoxina B1/metabolismo , Alimentación Animal/análisis , Pollos/fisiología , Dieta/veterinaria , Suplementos Dietéticos , Micotoxinas/toxicidad , Óvulo/química , Toxina T-2/toxicidadRESUMEN
This experimental study was conducted to determine the ability of a novel mycotoxins detoxification agent (MR) at a concentration of 0.2% to reduce the toxicity of aflatoxin B1 (AFB1) or T-2 toxin, alone or in combination, and to examine its effect on performance, pathohistological changes (PH) and the residue of these toxins in the tissues of broiler chicks. A total of 96 broiler chicks were divided into eight equal groups: group C, which served as control (without any additives); group MR, which received the novel detoxification agent (supplemented with 0.2%); group E-I (0.1 mg AFB1/kg of diet); group E-II (0.1 mg AFB1/kg of diet + MR 0.2%); group E-III (0.5 mg T-2 toxin/kg of diet); group E-IV (0.5 mg T-2 toxin/kg of diet + 0.2% MR); group E-V (combination of 0.1 mg AFB1/kg, 0.5 mg T-2 toxin/kg of diet); and group E-VI (combination of 0.1 mg AFB1/kg, 0.5 mg T-2 toxin + 0.2% MR). Results indicate that feeds containing AFB1 and T-2 toxin, alone or in combination, adversely affected the health and performance of poultry. However, the addition of MR to diets containing AFB1 and T-2 toxin singly and in combination exerted a positive effect on body weight, feed intake, weight gain, feed efficiency and microscopic lesions in visceral organs. Residual concentration of AFB1 in liver samples was significantly (p < 0.05) decreased when chicks were fed diets supplemented with 0.2% of MR.
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Family VIII esterases present similarities to class C ß-lactamases, which show nucleophilic serines located at the S-X-X-K motif instead of the G-X-S-X-G or G-D-S-(L) motif shown by other carboxylesterase families. Here, we report the crystal structure of a novel family VIII (subfamily VIII. I) esterase (EH7 ; denaturing temperature, 52.6 ± 0.3 °C; pH optimum 7.0-9.0) to deepen its broad substrate range. Indeed, the analysis of the substrate specificity revealed its capacity to hydrolyse nitrocefin as a model chromogenic cephalosporin substrate (40.4 ± 11.4 units·g-1 ), and a large battery of 66 structurally different esters (up to 1730 min-1 ), including bis(2-hydroxyethyl)-terephthalate (241.7 ± 8.5 units·g-1 ) and the mycotoxin T-2 (1220 ± 52 units·g-1 ). It also showed acyltransferase activity through the synthesis of benzyl 3-oxobutanoate (40.4 ± 11.4 units·g-1 ) from benzyl alcohol and vinyl acetoacetate. Such a broad substrate scope is rare among family VIII esterases and lipolytic enzymes. Structural analyses of free and substrate-bound forms of this homooctamer esterase suggest that EH7 presents a more opened and exposed S1 site having no steric hindrance for the entrance of substrates to the active site, more flexible R1, R2 and R3 regions allowing for the binding of a wide spectrum of substrates into the active site, and small residues in the conserved motif Y-X-X containing the catalytic Tyr enabling the entrance of large substrates. These unique structural elements in combination with docking experiments allowed us to gain valuable insights into the substrate specificity of this esterase and possible others belonging to family VIII.
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Esterasas , beta-Lactamasas , beta-Lactamasas/química , Especificidad por Sustrato , Esterasas/metabolismo , Carboxilesterasa/metabolismo , Dominio CatalíticoRESUMEN
This study has examined the pattern of mycotoxin contamination of maize destined for animal feed in different global regions over a period of 3 years (2018-2020) with up to 1000+ samples analysed in each year. Overall, >75% of samples in each of the survey years were contaminated with multiple mycotoxins regardless of the global region (Europe, Africa, Asia, South Americas countries). Using LC-MS/MS, it was possible to quantify the relative contamination present in the samples in each year from the different regions of eight different mycotoxins including aflatoxin B1 (AFB1), ochratoxin A (OTA) deoxynivalenol (DON), fumonisin B1 (FB1) and B2, zearalenone (ZEA), T-2 and HT-2 toxins. The trends in mycotoxin contamination showed that there was a consistent contamination with DON in the 3 sampling years in all four regions. Interestingly, AFB1 contamination was prevalent in all regions in 2018, but more predominant in Europe and in 2019. In contrast, in 2020 it was found to be the major contaminant in Africa only. However, FB1 contamination of maize which was prevalent in Europe in 2018, became more prevalent in Asia and LATAM countries in 2019 and even in African maize in 2020. Comparisons of contamination with different mycotoxins in each of the years globally showed significant differences for AFB1, FB1, DON and ZEA between the different years. These results are discussed in relation to the trends of contamination of maize with mixtures of mycotoxins and the implication for their control in this key commodity used as an important ingredient in animal feed.
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Micotoxinas , Zearalenona , Animales , Cromatografía Liquida , Contaminación de Alimentos/análisis , Micotoxinas/análisis , Espectrometría de Masas en Tándem/métodos , Zea mays , Zearalenona/análisisRESUMEN
The present study was conducted to evaluate the efficacy of the feed additive, a novel multicomponent mycotoxin detoxifying agent (MMDA) containing modified zeolite (clinoptilolite), Bacillus subtilis, B. licheniformis, Saccharomyces cerevisiae cell walls, and silymarin, as detoxifiers of 0.5 mg/kg (0.5 ppm) ochratoxin A (OTA) and 1 mg/kg (1 ppm) T-2 toxin on broiler chickens. A total of 240 1-old broiler chickens (Ross 308) were randomly distributed into five different dietary treatments: (1) control (non-contaminated diet); (2) non contaminated diet + 3 g/kg of MMDA; (3) non-contaminated diet + 0.5 mg/kg OTA + 1 mg/kg T-2 toxin; (4) non-contaminated diet + 0.5 mg/kg OTA + 1 mg/kg T-2 toxin + 1 g/kg MMDA; and (5) non-contaminated diet + 0.5 mg/kg OTA + 1 g/kg T-2 toxin + 3 g/kg MMDA. The results showed that, in the starter period, from 1 to 10 days, the presence of OTA and T-2 mycotoxins reduced the consumption of feed and the growth of the broilers, and no effects of the detoxifying product were observed in the productivity of the chickens, at any of the doses tested, compared to the contaminated control (treatment 3). However, in the growing period, the same negative effect of mycotoxins was registered, but a recovery was observed in the consumption of feed and in the weight of the broilers that consumed 3 g/kg of the MMDA mycotoxin binder, reaching similar values to those of chickens fed uncontaminated control diets. The presence of mycotoxins in feed led to a reduction in the concentration of total proteins and albumin in blood compared to controls, and the presence of the detoxifying product partially reversed this effect. The breast yield of the chickens fed with mycotoxins was lower than that of the animals fed with the control feed and was not affected by the presence of the product tested, at 1 or 3 g/kg. The weight of the different organs (liver, gizzard, kidneys, or spleen), the intestinal pH, the histology of the small intestine, and oral lesions were not affected by the experimental treatments. In summary, the productive parameters and some blood and carcass characteristics of broiler chickens were impaired by the dietary presence of OTA and T-2 toxin. The tested product included at 1 or 3 g/kg feed in contaminated diets improved performance and seems to be effective in partly counteracting the deleterious effects of the tested mycotoxins.
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BACKGROUND: The objective of this study was to evaluate the efficacy of modified clinoptilolite (Minazel Plus®, MZ) as a mycotoxin adsorbent for preventing the negative the effects of ochratoxin A (OTA) on performance, pathohistological changes, and OTA residue in the eggs of laying hens. METHODS: Forty eight (n = 48) laying hens (27 weeks old) were equally divided into six groups and depending on the type of addition were allocated to the following experimental treatments for 7 weeks: E-I group-1 mg/kg OTA; E-II group 0.25 mg/kg OTA; E-III group 1 mg/kg OTA + 0.2% of MZ; E-IV group 0.25 mg/kg OTA + 0.2% of MZ; MZ group supplemented with 0.2% of the adsorbent; and control (K, without feed additive). RESULTS: Overall, the addition of 0.2% MZ to laying hen feed mitigated the harmful effects of OTA on target organs and reduced the presence of OTA residue in eggs. The groups that received 0.2% of MZ achieved better production results in terms of body weight, number of eggs, and feed consumption, compared to the other treatments. CONCLUSIONS: The current findings confirm the efficacy of MZ in preventing performance losses in laying hens exposed to OTA, as well as for improving the welfare and health of food producing animals.
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Alimentación Animal , Suplementos Dietéticos , Ocratoxinas/química , Zeolitas/química , Aflatoxina B1 , Animales , Pollos , Dieta , Huevos , Femenino , Contaminación de Alimentos , MicotoxinasRESUMEN
The present study was designed to determine the efficacy of a novel multicomponent mycotoxin detoxifying agent (MMDA) containing modified zeolite (Clinoptilolite), Bacillus subtilis, B. licheniformis, Saccharomyces cerevisiae cell walls and silymarin against the deleterious effects of Aflatoxin B1 (AFB1) and Ochratoxin A (OTA) in broiler chicks. A total of 160 one-day-old Ross 308® broiler chicks were randomly allocated in four treatment groups, with four replicates, according to the following experimental design for 42 days. Group A received a basal diet; Group B received a basal diet contaminated with AFB1 and OTA at 0.1 mg/kg and 1 mg/kg, respectively; Group C received a basal diet contaminated with AFB1 and OTA and MMDA at 1 g/kg feed, and Group D received a basal diet contaminated with AFB1 and OTA and MMDA at 3 g/kg feed. Results showed that ingested mycotoxins led to significant (p ≤ 0.05) reduction in body weight and feed conversion from 25 days of age, induced histopathological changes, increased the pH of the intestinal content, and altered the biochemical profile of birds with significantly (p ≤ 0.05) increased aspartate aminotransferase (AST) values (p ≤ 0.05). On the other hand, the supplementation of MMDA significantly (p ≤ 0.05) improved the feed conversion ratio (FCR) during the second part of the study, diminished biochemical alterations, reduced pH in jejunal and ileal content, and E. coli counts in the caeca of birds (p ≤ 0.05). It may be concluded that the dietary supplementation of the MMDA partially ameliorated the adverse effects of AFB1 and OTA in broilers and could be an efficient tool in a mycotoxin control program.
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Aflatoxina B1/envenenamiento , Micotoxicosis/tratamiento farmacológico , Ocratoxinas/envenenamiento , Silimarina/administración & dosificación , Zeolitas/administración & dosificación , Alimentación Animal , Animales , Bacillus licheniformis , Bacillus subtilis , Pollos , Micotoxicosis/metabolismo , Micotoxicosis/patología , Distribución Aleatoria , Saccharomyces cerevisiaeRESUMEN
The inconsistency of phytogenic feed additives' (PFA) effects on the livestock industry poses a risk for their use as a replacement for antibiotic growth promoters. The livestock market is being encouraged to use natural growth promotors, but information is limited about the PFA mode of action. The aim of this paper is to present the complexity of compounds present in essential oils (EOs) and factors that influence biological effects of PFA. In this paper, we highlight various controls and optimization parameters that influence the processes for the standardization of these products. The chemical composition of EOs depends on plant genetics, growth conditions, development stage at harvest, and processes of extracting active compounds. Their biological effects are further influenced by the interaction of phytochemicals and their bioavailability in the gastrointestinal tract of animals. PFA effects on animal health and production are also complex due to various EO antibiotic, antioxidant, anti-quorum sensing, anti-inflammatory, and digestive fluids stimulating activities. Research must focus on reliable methods to identify and control the quality and effects of EOs. In this study, we focused on available microencapsulation techniques of EOs to increase the bioavailability of active compounds, as well as their application in the animal feed additive industry.
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Alimentación Animal , Aditivos Alimentarios , Aceites Volátiles , Animales , Aditivos Alimentarios/química , Aditivos Alimentarios/farmacología , Ganado , Aceites Volátiles/química , Aceites Volátiles/farmacologíaRESUMEN
Recent advances in materials sciences have allowed for the development and fabrication of biomaterials that are capable of providing requisite cues to instigate cells to respond in a predictable fashion. We have developed a series of poly(methyl methacrylate)/polystyrene (PMMA/PS) polymer demixed thin films with nanotopographies ranging from nanoislands to nanopits to study the response of human fetal osteoblast cells (hFOBs). When PMMA was in excess in the blend composition, a nanoisland topography dominated, whereas a nanopit topography dominated when PS was in excess. PMMA was found to segregate to the top of the nanoisland morphology with PS preferring the substrate interface. To further ascertain the effects of surface chemistry vs topography, we plasma treated the polymer demixed films using an atmospheric pressure dielectric barrier discharge reactor to alter the surface chemistry. Our results have shown that hFOBs did not have an increased short-term cellular response on pristine polymer demixed surfaces. However, increasing the hydrophilicty/wettability of the surfaces by oxygen functionalization causes an increase in the cellular response. These results indicate that topography alone is not sufficient to induce a positive cellular response, but the underlying surface chemistry is also important in regulating cell function.
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Osteoblastos , Humanos , Polimetil Metacrilato , Poliestirenos , HumectabilidadRESUMEN
Hyaluronic acid (HA) has been immobilised on poly(methyl methacrylate) (PMMA) surfaces using a novel dielectric barrier discharge (DBD) plasma process for the purposes of repelling protein, cellular and bacterial adhesion in the context of improving the performance of ophthalmic devices. Grafting was achieved by the following steps: (1) treatment of the PMMA with a DBD plasma operating at atmospheric pressure, (2) amine functionalisation of the activated polymer surface by exposure to a 3-aminopropyltrimethoxysilane (APTMS) linker molecule and (3) reaction of HA with the surface bound amine. The mechanism and effectiveness of the grafting process was verified by surface analysis. XPS data indicates that the APTMS linker molecule binds to PMMA via the Si-O chemistry and has the required pendant amine moiety. The carboxylic acid moiety on HA then binds with this -NH2 group via standard carbodiimide chemistry. ToF-SIMS confirms the presence of a coherent HA layer the microstructure of which is verified by AFM. The plasma grafted HA coating surfaces showed a pronounced decrease in protein and cellular adhesion when tested with bovine serum albumin and human corneal epithelial cells, respectively. The ability of these coatings to resist bacterial adhesion was established using Staphylococcus aureus NTC8325. Interestingly, the coatings did not repel bacterial adhesion, indicating that the mechanism of adhesion of bacterial cells is different to that for the surface interactions of mammalian cells. It is proposed that this difference is a consequence of the specific HA conformation that occurs under the conditions employed here. Hence, it is apparent that the microstructure/architecture of the HA coatings is an important factor in fabricating surfaces intended to repel proteins, mammalian and bacterial cells.
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Ácido Hialurónico/química , Gases em Plasma , Polimetil Metacrilato/química , Staphylococcus aureus/fisiología , Presión Atmosférica , Línea Celular Transformada , Humanos , Microscopía de Fuerza Atómica , Espectroscopía de Fotoelectrones , Proteínas/metabolismo , Propiedades de SuperficieRESUMEN
This study investigates the role that surface functionalisation of silicone elastomer (SE) by atmospheric pressure plasma induced graft immobilisation of poly(ethylene glycol) methyl ether methacrylate (PEGMA) plays in the attendant biological response. SE is used in modern ophthalmic medical devices and samples of the material were initially plasma treated using a dielectric barrier discharge reactor (DBD) to introduce reactive oxygen functionalities, prior to in situ grafting of two molecular weights of PEGMA (MW 1000 Da: PEGMA(1000), MW 2000 Da: PEGMA(2000)). The variously processed surfaces were characterised by water contact angle analysis, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry and atomic force microscopy. Lens epithelial cells were then cultured on the PEGMA grafted SE surfaces. It was found that cells on the pristine surface were not well spread and had shrunken morphology. On the DBD pre-treated surfaces, the cells were well spread. On the PEGMA(1000) surface, the cells displayed evidence of shrinkage and were on the verge of detaching. Remarkably, on the PEGMA(2000) surface, no cell adhesion was detection. Bacterial adhesion to the surfaces was studied using Staphylococcus aureus NTC8325. There was no difference in the number of bacteria adhering to any of the surfaces studied.
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Materiales Biocompatibles Revestidos/química , Células Epiteliales/efectos de los fármacos , Cristalino/efectos de los fármacos , Metacrilatos/química , Polietilenglicoles/química , Elastómeros de Silicona/química , Adhesión Bacteriana/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Línea Celular , Materiales Biocompatibles Revestidos/farmacología , Células Epiteliales/citología , Humanos , Cristalino/citología , Metacrilatos/farmacología , Microscopía de Fuerza Atómica , Peso Molecular , Espectroscopía de Fotoelectrones , Gases em Plasma , Polietilenglicoles/farmacología , Especies Reactivas de Oxígeno/química , Elastómeros de Silicona/farmacología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Andamios del TejidoRESUMEN
In this work, the surface functionalisation of the commercially available cyclic olefin copolymer (COC) materials, Zeonor and Zeonex, has been studied. The methodology employed involved oxidation in oxygen plasma, functionalisation of the oxidized surface with aminopropyl triethoxy silane and, finally, attachment of antibody using covalent linker molecules. 1,4-Phenylene diisothiocyanate was selected as the most suitable cross-linker for the attachment of protein, as assessed by fluorescent intensity measurements on immobilised FITC-labelled IgG antibody. The modification method was characterised by contact angle measurements, ellipsometry, X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy. The data are consistent with the deposition of a polymeric film of the silane chemisorbed to the oxidised plastic surface. The functionalised surfaces were employed in a sandwich immunoassay format using the reagents goat anti-human IgG (G alphaHIgG) and fluorescently labelled G alphaHIgG (Cy5-G alphaHIgG) as capture and detection antibodies, respectively, and with human IgG (HIgG) as the model analyte. The lowest concentration of HIgG detected was 0.1 ng ml(-1), with a relative standard deviation of 15%. Non-specific binding effects were also assessed. The method and supporting data demonstrate that simple approaches to surface functionalisation can be adapted to plastic-based devices.
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Anticuerpos/química , Técnicas Biosensibles/instrumentación , Cicloparafinas/química , Inmunoensayo/instrumentación , Inmunoglobulina G/análisis , Adsorción , Anticuerpos/inmunología , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Inmunoglobulina G/inmunología , Unión Proteica , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
The nitrile hydratase (Nhase) induced cells of Rhodococcus rhodochrous PA-34 catalyzed the conversion of acrylonitrile to acrylamide. The cells of R. rhodochrous PA-34 immobilized in 2% (w/v) agar (1.76 mg dcw/ml agar matrix) exhibited maximum Nhase activity (8.25 U/mg dcw) for conversion of acrylonitrile to acrylamide at 10 degrees C in the reaction mixture containing 0.1 M potassium phosphate buffer (pH 7.5), 8% (w/v) acrylonitrile and immobilized cells equivalent to 1.12 mg dcw (dry cell weight) per ml. In a partitioned fed batch reaction at 10 degrees C, using 1.12 g dcw immobilized cells in a final volume of 1 l, a total of 372 g of acrylonitrile was completely hydrated to acrylamide (498 g) in 24 h. From the above reaction mixture 87% acrylamide (432 g) was recovered through crystallization at 4 degrees C. By recycling the immobilized biocatalyst (six times), a total of 2,115 g acrylamide was produced.