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Nanotechnology involves the utilization of nanomaterials, including polymeric nanocapsules (NCs) that are drug carriers. For modify drug release and stability, nanoformulations can feature different types of polymers as surface coatings: Polysorbate 80 (P80), Polyethylene glycol (PEG), Chitosan (CS) and Eudragit (EUD). Although nanoencapsulation aims to reduce side effects, these polymers can interact with living organisms, inducing events in the antioxidant system. Thus far, little has been described about the impacts of chronic exposure, with Drosophila melanogaster being an in vivo model for characterizing the toxicology of these polymers. This study analyzes the effects of chronic exposure to polymeric NCs with different coatings. Flies were exposed to 10, 50, 100, and 500 µL of NCP80, NCPEG, NCCS, or EUD. The survival rate, locomotor changes, oxidative stress markers, cell viability, and Nrf2 expression were evaluated. Between the coatings, NCPEG had minimal effects, as only 500 µL affected the levels of reactive species (RS) and the enzymatic activities of catalase (CAT) and glutathione S-transferase (GST) without reducing Nrf2 expression. However, NCEUD significantly impacted the total flies killed, RS, CAT, and Superoxide dismutase from 100 µL. In part, the toxicity mechanisms of these coatings can be explained by the imbalance of the antioxidant system. This research provided initial evidence on the chronic toxicology of these nanomaterials in D. melanogaster to clarify the nanosafety profile of these polymers in future nanoformulations. Further investigations are essential to characterize possible biochemical pathways involved in the toxicity of these polymeric coatings.
Assuntos
Drosophila melanogaster , Nanocápsulas , Estresse Oxidativo , Animais , Drosophila melanogaster/efeitos dos fármacos , Nanocápsulas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Polímeros/toxicidade , Polímeros/química , Portadores de Fármacos/química , Portadores de Fármacos/toxicidadeRESUMO
Cardiac medical devices (CMDs) are required when the patient's cardiac capacity or activity is compromised. To guarantee its correct functionality, the building materials in the development of CMDs must focus on several fundamental properties such as strength, stiffness, rigidity, corrosion resistance, etc. The challenge is more significant because CMDs are generally built with at least one metallic and one polymeric part. However, not only the properties of the materials need to be taken into consideration. The biocompatibility of the materials represents one of the major causes of the success of CMDs in the short and long term. Otherwise, the material will lead to several problems of hemocompatibility (e.g., protein adsorption, platelet aggregation, thrombus formation, bacterial infection, and finally, the rejection of the CMDs). To enhance the hemocompatibility of selected materials, surface modification represents a suitable solution. The surface modification involves the attachment of chemical compounds or bioactive compounds to the surface of the material. These coatings interact with the blood and avoid hemocompatibility and infection issues. This work reviews two main topics: 1) the materials employed in developing CMDs and their key characteristics, and 2) the surface modifications reported in the literature, clinical trials, and those that have reached the market. With the aim of providing to the research community, considerations regarding the choice of materials for CMDs, together with the advantages and disadvantages of the surface modifications and the limitations of the studies performed.
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Abstract Introduction: Halting ventilation during cardiopulmonary bypass (CPB) is implemented to operate in a less bleeding setting. It sustains a better visualization of the operation area and helps to perform the operation much more comfortably. On the other hand, it may lead to a series of postoperative lung complications such as atelectasis and pleural effusion. In this study, we investigated the effects of low tidal volume ventilation on inflammatory cytokines during CPB. Methods: Twenty-eight patients undergoing cardiovascular surgery were included in the study. Operation standards and ventilation protocols were determined and patients were divided into two groups: patients ventilated with low tidal volume and non-ventilated patients. Plasma samples were taken from patients preoperatively, perioperatively from the coronary sinus and postoperatively after CPB. IL-6, IL-8, TNF-α and C5a levels in serum samples were studied with enzyme-linked immunosorbent assay (ELISA) kits. Results: C5a, IL-6, IL-8 and TNF-α were similar when compared to the low tidal volume ventilated and non-ventilated groups (P>0.05) Comparing the groups by variables, IL-6 levels were increased during CPB in both groups (P=0.021 and P=0.001), and IL-8 levels decreased in the ventilation group during CPB (P=0.018). Conclusion: Our findings suggest that low tidal volume ventilation may reduce the inflammatory response during CPB. Although the benefit of low tidal volume ventilation in CPB has been shown to decrease postoperative lung complications such as pleural effusion, atelectasis and pneumonia, we still lack more definitive and clear proofs of inflammatory cytokines encountered during CPB.
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INTRODUCTION: Halting ventilation during cardiopulmonary bypass (CPB) is implemented to operate in a less bleeding setting. It sustains a better visualization of the operation area and helps to perform the operation much more comfortably. On the other hand, it may lead to a series of postoperative lung complications such as atelectasis and pleural effusion. In this study, we investigated the effects of low tidal volume ventilation on inflammatory cytokines during CPB. METHODS: Twenty-eight patients undergoing cardiovascular surgery were included in the study. Operation standards and ventilation protocols were determined and patients were divided into two groups: patients ventilated with low tidal volume and non-ventilated patients. Plasma samples were taken from patients preoperatively, perioperatively from the coronary sinus and postoperatively after CPB. IL-6, IL-8, TNF-α and C5a levels in serum samples were studied with enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: C5a, IL-6, IL-8 and TNF-α levels were similar when compared to the low tidal in volume ventilated and non-ventilated groups (P>0.05). Comparing the groups by variables, IL-6 levels were increased during CPB in both groups (P=0.021 and P=0.001), and IL-8 levels decreased in the ventilation group during CPB (P=0.018). CONCLUSION: Our findings suggest that low tidal volume ventilation may reduce the inflammatory response during CPB. Although the benefit of low tidal volume ventilation in CPB has been shown to decrease postoperative lung complications such as pleural effusion, atelectasis and pneumonia, we still lack more definitive and clear proofs of inflammatory cytokines encountered during CPB.
Assuntos
Derrame Pleural , Atelectasia Pulmonar , Humanos , Ponte Cardiopulmonar , Volume de Ventilação Pulmonar , Citocinas , Fator de Necrose Tumoral alfa , Interleucina-6 , Ponte de Artéria Coronária , Interleucina-8 , Pulmão , Complicações Pós-Operatórias/prevenção & controleRESUMO
OBJECTIVE: The goal of the present study was to compare the myocardial protection obtained with histidine-tryptophan-ketoglutarate (HTK) cardioplegic solution (Custodiol®) and with intermittent hypothermic blood solution. METHODS: Two homogenous groups of 25 children with acyanotic congenital heart disease who underwent total correction with mean aortic clamping time of 60 minutes were evaluated in this randomized study. Troponin and creatine kinase-MB curves, vasoactive-inotropic score, and left ventricular function were obtained by echocardiogram in each group. The values were correlated and presented through graphs and tables after adequate statistical treatment. RESULTS: It was observed that values of all the studied variables varied over time, but there was no difference between the groups. CONCLUSION: We conclude that in patients with acyanotic congenital cardiopathies submitted to total surgical correction, mean aortic clamping time around one hour, and cardiopulmonary bypass with moderate hypothermia, the HTK crystalloid cardioplegic solution offers the same myocardial protection as the cold-blood hyperkalemic cardioplegic solution analyzed, according to the variables considered in our study model.
Assuntos
Soluções Cardioplégicas/uso terapêutico , Cardiopatias Congênitas/cirurgia , Análise de Variância , Creatina Quinase Forma MB/análise , Método Duplo-Cego , Ecocardiografia , Feminino , Glucose/uso terapêutico , Cardiopatias Congênitas/fisiopatologia , Humanos , Lactente , Recém-Nascido , Masculino , Manitol/uso terapêutico , Duração da Cirurgia , Cloreto de Potássio/uso terapêutico , Procaína/uso terapêutico , Estudos Prospectivos , Substâncias Protetoras/uso terapêutico , Valores de Referência , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , Fatores de Tempo , Resultado do Tratamento , Troponina/análise , Função Ventricular EsquerdaRESUMO
Abstract Objective: The goal of the present study was to compare the myocardial protection obtained with histidine-tryptophan-ketoglutarate (HTK) cardioplegic solution (Custodiol®) and with intermittent hypothermic blood solution. Methods: Two homogenous groups of 25 children with acyanotic congenital heart disease who underwent total correction with mean aortic clamping time of 60 minutes were evaluated in this randomized study. Troponin and creatine kinase-MB curves, vasoactive-inotropic score, and left ventricular function were obtained by echocardiogram in each group. The values were correlated and presented through graphs and tables after adequate statistical treatment. Results: It was observed that values of all the studied variables varied over time, but there was no difference between the groups. Conclusion: We conclude that in patients with acyanotic congenital cardiopathies submitted to total surgical correction, mean aortic clamping time around one hour, and cardiopulmonary bypass with moderate hypothermia, the HTK crystalloid cardioplegic solution offers the same myocardial protection as the cold-blood hyperkalemic cardioplegic solution analyzed, according to the variables considered in our study model.