Magnetic nanoparticles hyperthermia in a non-adiabatic and radiating process.

We investigate the magnetic nanoparticles hyperthermia in a non-adiabatic and radiating process through the calorimetric method. Specifically, we propose a theoretical approach to magnetic hyperthermia from a thermodynamic point of view. To test the robustness of the approach, we perform hyperthermia experiments and analyse the thermal behavior of magnetite and magnesium ferrite magnetic nanoparticles dispersed in water submitted to an alternating magnetic field. From our findings, besides estimating the specific loss power value from a non-adiabatic and radiating process, thus enhancing the accuracy in the determination of this quantity, we provide physical meaning to a parameter found in literature that still remained not fully understood, the effective thermal conductance, and bring to light how it can be obtained from experiment. In addition, we show our approach brings a correction to the estimated experimental results for specific loss power and effective thermal conductance, thus demonstrating the importance of the heat loss rate due to the thermal radiation in magnetic hyperthermia.

Violacein antimicrobial activity on Staphylococcus epidermidis biofilm.

The aim of this study was to evaluate the antimicrobial potential of violacein (VIO) on Staphylococcus epidermidis biofilm. The minimum biofilm inhibition concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were determined, as well as the effect of VIO exposure time on microbial viability in mature biofilm. Violacein showed good antibiofilm action, inhibiting biofilm formation and eradicating mature biofilm of S. epidermidis at concentrations of 20 µg.mL-1 and 160 µg.mL-1, respectively. At concentrations equal to MBEC and 2x MBEC, the biofilm was eradicated in 3 h and 2h30min of incubation, respectively.When evaluating VIO modulating effect on the action of clinically-used drugs (vancomycin, cefepime, ciprofloxacin and meropenem), especial synergism was observed in the violacein-ciprofloxacin association, it can completely erradicated the mature biofilm at the concentration of 1/2xMBEC and 1/4xMBEC, respectively. VIO shows good antimicrobial action on S. epidermidis biofilm and has the potential to synergistically modulate the activity of clinically-used antimicrobials.

Avaliação de dois testes sorológicos comerciais para diagnóstico das infecções pelo FIV e pelo FeLV / Evaluation of two point-of-care tests to diagnosis of FIV and FeLV infections

FIV e FeLV são retrovírus associados principalmente com neoplasias. Dois testes rápidos são disponibilizados no Brasil para o diagnóstico dessas infecções: um kit de imunocromatografia de fluxo bidirecional (SNAP® Combo IDEXX) e um kit de imunocromatografia de fluxo lateral unidirecional (ALERE/BIONOTE Anigen Rapid). O objetivo deste estudo foi comparar o teste SNAP® com o teste ALERE. Amostras de sangue de 178 gatos foram testadas utilizando-se ambos os kits. A reação em cadeia de polimerase em tempo real (qPCR) foi empregada como método confirmatório para todos os resultados. O teste SNAP® apresentou sensibilidade e especificidade de 100% para FIV; a sensibilidade e a especificidade do teste ALERE foram de 96,15% e 98,68%, respectivamente. A sensibilidade e a especificidade para o FeLV foram de 93,02% e 96,30% para o teste SNAP® e de 90,70% e 97,78% para o teste ALERE. Ainda em relação ao FeLV, três amostras com resultado positivo na qPCR obtiveram resultado falso-negativo em ambos os testes. Não houve diferença estatisticamente significante entre os métodos. Considerando a qPCR como padrão-ouro, o teste SNAP® apresentou maior sensibilidade e especificidade para o FIV, e o teste ALERE apresentou maior especificidade para o FeLV. Os resultados mostraram uma boa correlação entre os testes.(AU)

FIV and FeLV are Retrovirus associated mainly with feline neoplasms. Two point-of-care tests are commercially available in Brazil for diagnosis of these infections: a bidirectional flow immunochromatography kit (IDEXX SNAP ® Combo) and a lateral unidirectional flow immunochromatography kit (ALERE/BIONOTE Anigen Rapid). The aim of this study was to compare SNAP ® and ALERE tests. Blood samples obtained from 178 cats were evaluated using both tests. Quantitative real-time polymerase chain reaction (qPCR) was used as confirmatory test for all samples. The sensitivity and specificity of SNAP ® test was 100% for FIV, and for ALERE test was 96.15% and 98.68%, respectively. The sensitivity and specificity for FeLV was 93.02% and 96.30% for SNAP ® test and 90.70% and 97.78% for ALERE test. Three samples with a qPCR positive result for FeLV obtained a false negative result in both SNAP ® and ALERE tests. There was no statistically significant difference between the two methods. Considering qPCR as gold standard method, the SNAP® test showed higher sensitivity and specificity for FIV, and the ALERE test presented higher specificity for FeLV. The results showed good agreement among the tests.(AU)

Violacein antimicrobial activity on Staphylococcus epidermidis and synergistic effect on commercially available antibiotics.

AIMS: The study aimed to assess whether violacein has antimicrobial activity on Staphylococcus epidermidis and synergistically modulates the action of commercially available antimicrobial drugs. METHODS AND RESULTS: Violacein showed excellent antimicrobial activity on biofilm-forming and nonbiofilm-forming S. epidermidis strains (ATCC 35984) (ATCC 12228), with bacteriostatic (MIC = 20 µg ml-1 and 10 µg ml-1 respectively) and bactericidal effects (MBC = 20 µg ml-1 for both strains), observed in short periods of exposure. The violacein bactericidal concentration led to S. epidermidis death after 2-3 h of exposure. Additionally, violacein synergistically modulated the activity of different antimicrobial classes on S. epidermidis ATCC 12228 (81·8%; n = 9) and on S. epidermidis ATCC 35984 (54·5%; n = 6), reducing the MIC of these antibiotics by up to 16-fold. CONCLUSION: Violacein shows excellent antimicrobial activity on S. epidermidis strains. SIGNIFICANCE AND IMPACT OF THE STUDY: Violacein shows the potential for the development of a new drug for the treatment of infections caused by S. epidermidis.

N-Acetylcysteine Use in Hepatic Ischemia/Reperfusion in Rats Minimizing Bowel Injury.

BACKGROUND: The ischemia/reperfusion (I/R) phenomenon can cause the dysfunction of some transplanted organs and other distant organs. Liver surgery success, including transplantations, may depend on the adverse effects of intestinal mucosa injury arising from temporary porta triad occlusion. The study objective was to examine I/R liver effects on the small intestine in rats after N-acetylcysteine (NAC) treatment. METHODS: Twenty-four male Wistar rats were randomly divided into 2 groups. After anesthesia, they underwent 30 minutes of hepatic ischemia by clamping the porta triad, followed by reperfusion for 30 minutes or 6 hours. Each group was divided into 2 subgroups (n = 6), with 1 group receiving 0.9% saline solution (control) and the other receiving 150 mg/kg of NAC, 15 minutes before hepatic ischemia. At the end of reperfusion, blood was collected for enzyme dosage (alanine aminotransferase [ALT], aspartate aminotransferase [AST], lactate dehydrogenase [LDH], alkaline phosphatase [ALP]), and the terminal ileum was resected to study mucosal morphology by optical microscopy, computerized histomorphometry, and immunohistochemical assessment of apoptosis with caspase 3. RESULTS: After 30 minutes of reperfusion, animals receiving NAC had lower injury in the intestinal mucosa compared to the control subgroup (P < .05). After 6 hours, AST was higher in the control subgroup than in the NAC subgroup (P < .05), and AST, ALT and LDH values showed a significant increase in both subgroups (P < .05). CONCLUSION: These findings show the deleterious effects of late (6-hour) reperfusion and the protective effect of NAC at 30 minutes, when evaluating the small intestine impact of I/R liver damage.

Influence of estrogen therapy on immune markers in postmenopausal women.

OBJECTIVE: To evaluate the impact of estrogen therapy on cellular and humoral immune markers in postmenopausal women. METHODS: This prospective, controlled cohort study included 30 patients who used oral estradiol (1 mg) for 14-17 weeks and 28 patients who served as controls. Total leukocytes and leukocyte subtypes were counted and immunophenotyped by flow cytometry. The concentrations of immunoglobulins and pro- and anti-inflammatory cytokines were also measured in the peripheral blood before and after estrogen therapy. Immunoglobulin E level was measured by electrochemiluminescence, and levels of immunoglobulins A, G, and M were measured by nephelometry. Simultaneous quantification of multiple cytokines was performed by chemiluminescence to measure the serum concentrations of interferon gamma, interleukin (IL)-4, IL-6, IL-10, and IL-17. RESULTS: Hematological cellular components were not significantly different before and after the use of estradiol (p = 0.332-0.984). Serum concentrations of immunoglobulins G, M, E, and A also remained stable (p = 0.248-0.845). Finally, cytokines were not modified throughout the 14-17 weeks of follow-up (p = 0.407-0.873). CONCLUSION: Isolated estrogen therapy with 1 mg of estradiol for 14-17 weeks in postmenopausal women did not modify any of the cellular or humoral immune markers analyzed in this study.

GeLC-MS-based proteomics of Chromobacterium violaceum: comparison of proteome changes elicited by hydrogen peroxide.

Chromobacterium violaceum is a free-living bacillus with several genes that enables it survival under different harsh environments such as oxidative and temperature stresses. Here we performed a label-free quantitative proteomic study to unravel the molecular mechanisms that enable C. violaceum to survive oxidative stress. To achieve this, total proteins extracted from control and C. violaceum cultures exposed during two hours with 8 mM hydrogen peroxide were analyzed using GeLC-MS proteomics. Analysis revealed that under the stress condition, the bacterium expressed proteins that protected it from the damage caused by reactive oxygen condition and decreasing the abundance of proteins responsible for bacterial growth and catabolism. GeLC-MS proteomics analysis provided an overview of the metabolic pathways involved in the response of C. violaceum to oxidative stress ultimately aggregating knowledge of the response of this organism to environmental stress. This study identified approximately 1500 proteins, generating the largest proteomic coverage of C. violaceum so far. We also detected proteins with unknown function that we hypothesize to be part of new mechanisms related to oxidative stress defense. Finally, we identified the mechanism of clustered regularly interspaced short palindromic repeats (CRISPR), which has not yet been reported for this organism.

Feed efficiency indexes and their relationships with carcass, non-carcass and meat quality traits in Nellore steers.

Five hundred and seventy-five Nellore steers were evaluated for residual feed intake and residual feed intake and gain and their relationships between carcass, non-carcass and meat quality traits. RFI was measured by the difference between observed and predicted dry matter intake and RIG was obtained by the sum of -1*RFI and residual gain. Efficient and inefficient animals were classified adopting ±0.5 standard deviations from RFI and RIG mean. A mixed model was used including RFI or RIG and contemporary group as fixed effects, initial age as covariate and sire and experimental period as random effects, testing the significance of the regression slope for each evaluated trait. RIG was positively related to longissimus muscle area. Efficient-RFI animals had lower liver and internal fat proportions compared to inefficient-RFI animals. Efficient-RFI and efficient-RIG animals had 11.8% and 11.2% lower extracted intramuscular fat, compared to inefficient-RFI and inefficient-RIG animals, respectively. Efficient-RFI animals had tougher meat compared to inefficient-RFI animals.

Identification and evaluation of polymorphisms in FABP3 and FABP4 in beef cattle.

Single nucleotide polymorphisms (SNPs) were screened in FABP3 and FABP4 by automatic sequencing of pools of DNA from crossbred animals whose phenotypes belonged to the upper and lower extremes for back fat and marbling, as well as of a pool of DNA from sires used for crossbreeding. Five SNPs were identified in FABP3 and another nine SNPs were identified in FAPB4. Of these, only one SNP had no previous registry in the SNAP database (dbSNP). Three polymorphisms were selected for further evaluation of their association with production traits using restriction fragment length polymorphism-PCR (RFLP-PCR) or real-time PCR genotyping. All 3 markers were in Hardy-Weinberg equilibrium at the 5% significance level for all 7 genetic groups analyzed. Significant association was observed between FABP3-G/A with rib eye area (P = 0.035) and the rib eye area/hot carcass weight ratio (P = 0.025) and between FABP4/TasI with marbling (P = 0.052) and meat texture (P = 0.053). No significant association was observed between the FABP4-G/C polymorphism and any of the observed traits. Previous association studies with allelic variants in these genes have shown mixed results, probably because of the small effect of the genes for these traits, which suggests that results should be replicated in other populations.

Is glycated hemoglobin related to other dysmetabolic variables implicated in the increase of cardiovascular risk in polycystic ovary syndrome? A comparative study.

BACKGROUND: In non-PCOS patients the concentration of glycated hemoglobin (HbA1C) has been employed to identify individuals at higher risk for impaired glucose tolerance (IGT) and diabetes mellitus. A few studies have examined the role of HbA1C in PCOS patients and current results are controversial. AIM: To compare the strength of the association between glycated hemoglobin and other predictors of cardiovascular risk in polycystic ovary syndrome (PCOS). METHODS: This cross-sectional study enrolled 197 PCOS patients and 72 non-PCOS women. Transvaginal ultrasound, biochemical and hormone measurement were performed. Glycated hemoglobin (HbA1C) was correlated with other variables related to dysmetabolic/vascular diseases. RESULTS: The HbA1C levels were 6.0±1.4% and 4.9±0.4% in PCOS patients and non-PCOS controls, respectively (p<0.001). The HbA1C levels were≥5.7% in 46.4% of PCOS and in none of the control subjects (OR=90.8). HbA1C was well-correlated with several anthropometric, metabolic and endocrine parameters. Stepwise multiple regression including HbA1C and other known predictors of cardiovascular risk resulted in a significant model in which body mass index (BMI) and free testosterone exhibited the best correlation with HbA1C (adjusted R(2)=0.530; F=39.8; p<0.001). CONCLUSION: HbA1C was elevated and correlated with anthropometric, biochemical and endocrine variables of metabolic/vascular disease risks in PCOS patients. Combined HbA1C, BMI and free testosterone levels provided a significant model with potential use to evaluate metabolic/vascular disease in PCOS patients.

Identification, characterisation and molecular modelling of two AP endonucleases from base excision repair pathway in sugarcane provide insights on the early evolution of green plants.

Unlike bacteria and mammals, plant DNA repair pathways are not well characterised, especially in monocots. The understanding of these processes in the plant cell is of major importance, since they may be directly involved in plant acclimation and adaptation to stressful environments. Hence, two sugarcane ESTs were identified as homologues of AP endonuclease from the base-excision repair pathway: ScARP1 and ScARP3. In order to understand their probable function and evolutionary origin, structural and phylogenetic studies were performed using bioinformatics approaches. The two predicted proteins present a considerable amino acid sequence similarity, and molecular modelling procedures indicate that both are functional, since the main structural motifs remain conserved. However, inspection of the sort signal regions on the full-length cDNAs indicated that these proteins have a distinct organelle target. Furthermore, variances in their promoter cis-element motifs were also found. Although the mRNA expression pattern was similar, there were significant differences in their expression levels. Taken together, these data raise the hypothesis that the ScARP is an example of a probable gene duplication event that occurred before monocotyledon/dicotyledon segregation, followed by a sub-functionalisation event in the Poaceae, leading to new intracellular targeting and different expression levels.

Genome scan for meat quality traits in Nelore beef cattle.

Meat quality traits are economically important because they affect consumers' acceptance, which, in turn, influences the demand for beef. However, selection to improve meat quality is limited by the small numbers of animals on which meat tenderness can be evaluated due to the cost of performing shear force analysis and the resultant damage to the carcass. Genome wide-association studies for Warner-Bratzler shear force measured at different times of meat aging, backfat thickness, ribeye muscle area, scanning parameters [lightness, redness (a*), and yellowness] to ascertain color characteristics of meat and fat, water-holding capacity, cooking loss (CL), and muscle pH were conducted using genotype data from the Illumina BovineHD BeadChip array to identify quantitative trait loci (QTL) in all phenotyped Nelore cattle. Phenotype count for these animals ranged from 430 to 536 across traits. Meat quality traits in Nelore are controlled by numerous QTL of small effect, except for a small number of large-effect QTL identified for a*fat, CL, and pH. Genomic regions harboring these QTL and the pathways in which the genes from these regions act appear to differ from those identified in taurine cattle for meat quality traits. These results will guide future QTL mapping studies and the development of models for the prediction of genetic merit to implement genomic selection for meat quality in Nelore cattle.

Intake and Performance of Yearling Steers Grazing Guineagrass (Panicum maximum cv. Tanzânia) Pasture Supplemented with Different Energy Sources.

The aim of this study was to evaluate the efficiency of supplements containing different energy sources in relation to mineral supplementation of steers grazing guineagrass (Panicum maximum cv Tanzânia) pasture, during the dry season. The experimental design was a randomized block with three treatments and four replications. The treatments consisted of a mineral supplementation and two other supplements, one based on corn seed and the other based on soybean hulls, and provided at 0.8% of body weight. Forty-eight, 12 month-old crossbred steers with an average initial body weight of 267 kg, were assigned to twelve paddocks (1,125 ha) of guineagrass. The animals that were fed with soybean hulls and corn seed presented a greater average daily gain (0.982 and 0.937) when compared with the mineral supplementation. Soybean hulls can be used as a satisfactory food source, replacing corn as an energy source in the supplementation of beef cattle without compromising animal performance.

Candidate genes for production traits in Nelore beef cattle.

Meat quality is an important trait for the beef industry. Backfat thickness, ribeye area, and shear force are traits measured late in life, and the investigation of molecular markers associated with these traits can help breeding programs. In cattle, some polymorphisms have been related to production traits. Thus, the purpose of this study was to assess the presence of polymorphisms in the candidate genes insulin-like growth factor 1 (IGF1), fatty acid-binding protein 4 (FABP4), and peroxisome proliferative active receptor gamma coactivator 1 A (PPARGC1A) and associate them with production traits in reference families of Nelore cattle. We used 270 steers descendent from 20 sires that were chosen to represent variability in this breed. The investigation of marker effects on the traits was performed using a mixed model under the restricted maximum likelihood method. A significant allele substitution effect was found for IGF1 and yearling weight (P ≤ 0.017). The mean allele substitution effect was 6.9 kg, with the 229 allele associated with reduced yearling weight in this Nelore population.

A methodological approach to estimate the lactation curve and net energy and protein requirements of beef cows using nonlinear mixed-effects modeling.

The objective of this study was to evaluate methods to predict the secretion of milk and net energy and protein requirements of beef cows (Bos indicus and B. taurus) after approximately 1 mo postpartum using nonlinear mixed-effect modeling (NLME). Twenty Caracu × Nellore (CN) and 10 Nellore (NL) cows were inseminated to Red Angus bulls, and 10 Angus × Nellore (AN) were bred to Canchim bulls. Cows were evaluated from just after calving (25 ± 11 d) to weaning (220 d). Milk yield was estimated by weighing calves before and after suckling (WSW) and by machine milking (MM) methods at 25, 52, 80, 109, 136, 164, 193, and 220 ± 11 d of lactation. Brody and simple linear equations were consecutively fitted to the data and compared using information criteria. For the Brody equation, a NLME model was used to estimate all lactation profiles incorporating different sources of variation (calf sex and breed of cow, cow as a nested random effect, and within-cow auto-correlation). The CV for the MM method (29%) was less than WSW (45%). Consequently, the WSW method was responsible for reducing the variance about 1.5 times among individuals, which minimized the ability to detect differences among cows. As a result, only milk yield MM data were used in the NLME models. The Brody equation provided the best fit to this dataset, and inclusion of a continuous autoregressive process improved fit (P < 0.01). Milk, energy and protein yield at the beginning of lactation were affected by cow genotype and calf sex (P < 0.001). The exponential decay of the lactation curves was affected only by genotype (P < 0.001). Angus × Nellore cows produced 15 and 48% more milk than CN and NL during the trial, respectively (P < 0.05). Caracu × Nellore cows produced 29% more milk than NL (P < 0.05). The net energy and net protein requirements for milk yield followed a similar ranking. Male calves stimulated their dams to produce 11.7, 11.4, and 11.9% more milk, energy and protein, respectively (P < 0.05). The MM method is better than the WSW technique to detect genetic or environmental differences in milk yield among beef cows. The data obtained by the MM method and analyzed by NLME models allows the inclusion of fixed effects, random effects and an auto-regressive process in lactation equations to describe lactation curves and net energy and protein requirements. The NLME is a powerful tool to describe differences in the secretion of milk due to heterosis and cell mammary external stimulus in beef cows.

A SNP in ASAP1 gene is associated with meat quality and production traits in Nelore breed.

The ASAP1 gene is located in a QTL region for meat production traits and to access the role of the ASAP1 gene, the association between a SNP in this gene and production traits in beef cattle was studied. For this, about 270 steers of reference families of Nelore breed were used. The investigation of marker effects on the traits was performed using a mixed model under the restricted maximum likelihood method. Novel association of a SNP in the ASAP1 gene and shear force measured at 24 h post mortem (P≤0.0083) was described in this population of Nelore cattle. This polymorphism accounted for 1.13% of the total additive variance and 17.51% of total phenotypic variance of the trait, suggesting that this marker could be used in marker assisted selection.

Cellular and humoral immune responses after short-term oral hormone therapy in postmenopausal women.

OBJECTIVE: To evaluate the cellular and humoral immune responses after oral hormone therapy in postmenopausal women. Study design This was a prospective cohort study, with intervention. The main outcome measures were delayed-type IV cell-mediated hypersensitivity, leukocytes, immunoglobulins, interleukin-6 (IL-6) and interleukin-10 (IL-10). METHODS: The delayed-type cell-mediated hypersensitivity was measured by using five common allergens before and after 3 months of hormone therapy. Each type of leukocyte cell was counted before and after hormone therapy. Different subtypes of lymphocytes were determined by flow cytometry. Immunoglobulins G, A and M were measured by nephelometry; immunoglobulin E was measured by electrochemiluminescence. IL-6 and IL-10 concentrations were determined by chemiluminescence. RESULTS: Hormone therapy increased the response to tuberculin antigen without changing the total number of leukocytes, eosinophils, neutrophils, lymphocytes, and CD4 +, CD8 + B cells. Both monocyte number and CD4 + /CD8 + ratio suffered a slight modification (p = 0.057). Immunoglobulins A, M and E remained unchanged and immunoglobulin G decreased (p = 0.029). IL-6 levels remained stable but IL-10 concentrations increased significantly after hormone therapy. CONCLUSION: Short-term oral hormone treatment has no impact on the cellular immune response but, concerning the humoral immune response, immunoglobulin G decreased and the levels of IL-10 were significantly higher.

Risk factors associated with Toxoplasma gondii infection in dairy cattle, state of Rio de Janeiro / Fatores de risco associados à infecção por Toxoplasma gondii em bovinos leiteiros no estado do Rio de Janeiro

Toxoplasmosis is one of the most common parasitic zoonoses throughout the world. Infection in man and animals varies in different geographical areas influenced by many environmental conditions. Seroprevalence of Toxoplasma gondii infection in cattle in Brazil ranges from 1.03 to 71 percent. A cross-sectional survey was carried out in 58 out of 453 farms in the South Fluminense Paraiba Valley, State of Rio de Janeiro, Brazil. Over 3-year-old cattle (n=589) from dairy herds were selected for blood collection and detection of anti-T. gondii antibodies by indirect immunofluorescence reaction (IFA) with initial titration of 1:16; titers > 64 were considered positive. Univariate analysis of risk factors showed that cats in contact with cattle, cats in contact with drinking water, and number of cats were associated with T. gondii seroprevalence. Logistic regression revealed a two-fold increased risk for infection of cattle (p=0.0138) through larger number of cats (>3) compared with low numbers of cats (1-2) on the farm. In contrast, the presence of chickens was considered a protective factor (p=0.025).

Toxoplasmose é uma das mais comuns zoonoses parasitárias do mundo. Infecções em seres humanos e em animais variam nas diferentes áreas geográficas influenciadas pelas condições ambientais. A soroprevalência da infecção por Toxoplasma gondii em bovinos no Brasil varia de 1,03 a 71,0 por cento. O estudo transversal foi realizado em 58 de um total de 453 propriedades na região Sul Fluminense do estado do Rio de Janeiro. Vacas leiteiras acima de 3 anos de idade (n=589) foram selecionadas para coleta de sangue e a detecção de anticorpos anti-T. gondii foi feita pelo teste de imunofluorescência indireta (IFI) com titulação inicial de 1:16 e títulos > 64 foram considerados positivos. Após análise univariada dos fatores de risco, gatos em contato com bovinos, em contato com a água de beber dos animais e o número de gatos foram associados com a soroprevalência de T. gondii. A regressão logística demonstrou que o número maior de gatos (>3) teve um risco duas vezes maior (p=0,0138) que propriedades que tinham um número menor de gatos (1-2). Em contraste, a presença de galinhas foi considerada um fator de proteção (p=0,025).

Stimuli-responsive magnetic particles for biomedical applications.

In recent years, magnetic nanoparticles have been studied due to their potential applications as magnetic carriers in biomedical area. These materials have been increasingly exploited as efficient delivery vectors, leading to opportunities of use as magnetic resonance imaging (MRI) agents, mediators of hyperthermia cancer treatment and in targeted therapies. Much attention has been also focused on "smart" polymers, which are able to respond to environmental changes, such as changes in the temperature and pH. In this context, this article reviews the state-of-the art in stimuli-responsive magnetic systems for biomedical applications. The paper describes different types of stimuli-sensitive systems, mainly temperature- and pH sensitive polymers, the combination of this characteristic with magnetic properties and, finally, it gives an account of their preparation methods. The article also discusses the main in vivo biomedical applications of such materials. A survey of the recent literature on various stimuli-responsive magnetic gels in biomedical applications is also included.