RESUMO
Nanoparticles possess a huge potential to be employed in numerous biomedical purposes; their applications may include drug delivery systems, gene therapy, and tissue engineering. However, the in vivo use in biomedical applications requires that nanoparticles exhibit sterility. Thus, diverse sterilization techniques have been developed to remove or destroy microbial contamination. The main sterilization methods include sterile filtration, autoclaving, ionizing radiation, and nonionizing radiation. Nonetheless, the sterilization processes can alter the stability, zeta potential, average particle size, and polydispersity index of diverse types of nanoparticles, depending on their composition. Thus, these methods may produce unwanted effects on the nanoparticles' characteristics, affecting their safety and efficacy. Moreover, each sterilization method possesses advantages and drawbacks; thus, the suitable method's choice depends on diverse factors such as the formulation's characteristics, batch volume, available methods, and desired application. In this article, we describe the current sterilization methods of nanoparticles. Moreover, we discuss the advantages and drawbacks of these methods, pointing out the changes in nanoparticles' biological and physicochemical characteristics after sterilization. Our main objective was to offer a comprehensive overview of terminal sterilization processes of nanoparticles for biomedical applications.
Assuntos
Tecnologia Biomédica , Nanopartículas/química , Esterilização , Filtração , Radiação IonizanteRESUMO
Next-generation 3-Tesla magnetic resonance (MR) scanners offer improved neonatal neuroimaging, but the greater associated radiofrequency radiation may increase the risk of hyperthermia. Safety data for neonatal 3-T MR scanning are lacking. We measured rectal temperatures continuously in 25 neonates undergoing 3-T brain MR imaging and observed no significant hyperthermic threat.
Assuntos
Encéfalo/diagnóstico por imagem , Febre/etiologia , Imageamento por Ressonância Magnética/efeitos adversos , Neuroimagem/efeitos adversos , Febre/diagnóstico , Humanos , Recém-Nascido , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Avaliação de Resultados em Cuidados de Saúde , Estudos Prospectivos , TermometriaRESUMO
Resumo O objetivo desse estudo foi investigar a associação entre exposição a radiações eletromagnéticas não ionizantes da estação radiobase de telefonia celular e sintomas à saúde. Em um estudo transversal realizado em Salvador, Bahia, Brasil, entrevistaram-se 440 indivíduos. Queixas e diagnósticos psiquiátricos constituíram as variáveis dependentes e a distância do domicílio para estação radiobase foi considerada a variável independente principal. Realizou-se análise de regressão logística hierarquizada para avaliação de confundimento e efeito. Observou-se associação entre sintomas psiquiátricos e residir próximo à estação radiobase e formas de uso do telefone celular (sinal de cobertura fraco, perto do corpo, dois ou mais chips e nunca desligar o celular quando dorme) e com uso de outros eletroeletrônicos. Concluiu-se que a exposição à radiação eletromagnética não ionizante de telefonia celular e a outros eletroeletrônicos foi associada aos sintomas psiquiátricos independente do sexo, escolaridade e tabagismo. Recomenda-se a adoção de medidas precaucionárias no sentido de se reduzir este tipo de exposição.
Resumen El objetivo de este estudio fue investigar la asociación entre la exposición a la radiación electromagnética no ionizante de una estación base telefonía móvil y sus efectos sobre la salud. Se trata de un estudio transversal en Salvador, Bahía, Brasil, donde se entrevistaron a 440 personas. Las quejas y diagnósticos psiquiátricos fueron las variables dependientes y la distancia del hogar a la estación base se consideró como la variable independiente principal. Se realizó un análisis de regresión logística jerárquica para evaluar la confusión y modificación de los efectos. Se observó una asociación entre los efectos psiquiátricos y residir cerca de una estación base y formas de uso del teléfono celular (débil cobertura de la señal, cerca del cuerpo dos o más chips y nunca apagar el teléfono cuando se duerme) y uso de otros aparatos electrónicos. Se concluyó que la exposición a radiación no ionizante de la telefonía móvil y otros aparatos electrónicos se asoció con efectos psiquiátricos, independiente de sexo, la educación y el tabaquismo. Se recomienda la adopción de medidas de precaución, con el fin de reducir la exposición.
Abstract The aim of this study was to investigate the association between exposure to non-ionizing electromagnetic radiation from mobile phone base stations and psychiatric symptoms. In a cross-sectional study in Salvador, Bahia State, Brazil, 440 individuals were interviewed. Psychiatric complaints and diagnoses were the dependent variables and distance from the individual’s residence to the base station was considered the main independent variable. Hierarchical logistic regression analysis was conducted to assess confounding. An association was observed between psychiatric symptoms and residential proximity to the base station and different forms of mobile phone use (making calls with weak signal coverage, keeping the mobile phone close to the body, having two or more chips, and never turning off the phone while sleeping), and with the use of other electronic devices. The study concluded that exposure to electromagnetic radiation from mobile phone base stations and other electronic devices was associated with psychiatric symptoms, independently of gender, schooling, and smoking status. The adoption of precautionary measures to reduce such exposure is recommended.