Protein coronas coating polymer-stabilized silver nanocolloids attenuate cytotoxicity with minor effects on antimicrobial performance.

Silver nanoparticles are versatile platforms with a variety of applications in the biomedical field. In this framework, their presence in biological media inevitably leads to the interaction with proteins thus conducting to the formation of biomolecular coronas. This feature alters the identity of the nanomaterial and may affect many biological events. These considerations motivated the investigation of protein adsorption onto the surface of polymer-stabilized AgNPs. The metallic colloids were coated by polyethyleneimine (PEI), polyvinylpyrrolidone (PVP), and poly(2-vinyl pyridine)-b-poly(ethylene oxide) (PEO-b-P2VP), and nanoparticle-protein interaction was probed by using a library of analytical techniques. The experimental data revealed a higher extent of protein adsorption at the surface of AgNPs@PVP whereas PEO-b-P2VP coating conducted to the least amount. The main component of the protein coronas was evidenced to be bovine serum albumin (BSA), which is indeed the protein at the highest abundancy in the model biological media. We have further demonstrated reduced cytotoxicity of the silver colloids coated by biomolecular coronas as compared to the pristine counterparts. Nevertheless, the protein coatings did not notably reduce the antimicrobial performance of the polymer-stabilized AgNPs. Accordingly, although the protein-repelling property is frequently targeted towards longer in vivo circulation of nanoparticles, we herein underline that protein coatings, which are commonly treated as artifacts to be avoided, may indeed enhance the biological performance of nanomaterials. These findings are expected to be highly relevant in the design of polymer-stabilized metallic colloids intended to be used in healthcare.

Methylene blue-covered superparamagnetic iron oxide nanoparticles combined with red light as a novel platform to fight non-local bacterial infections: A proof of concept study against Escherichia coli.

Currently, antimicrobial photodynamic therapy (APDT) is limited to the local treatment of topical infections, and a platform that can deliver the photosensitizer to internal organs is highly desirable for non-local ones; SPIONs can be promising vehicles for the photosensitizer. This work reports an innovative application of methylene blue (MB)-superparamagnetic iron oxide nanoparticles (SPIONs). We report on the preparation, characterization, and application of MB-SPIONs for antimicrobial photodynamic therapy. When exposed to light, the MB photosensitizer generates reactive oxygen species (ROS), which cause irreversible damage in microbial cells. We prepare SPIONs by the co-precipitation method. We cover the nanoparticles with a double silica layer - tetraethyl orthosilicate and sodium silicate - leading to the hybrid material magnetite-silica-MB. We characterize the as-prepared SPIONs by Fourier transform infrared spectroscopy, powder X-ray diffraction, and magnetic measurements. We confirm the formation of magnetite using powder X-ray diffraction data. We use the Rietveld method to calculate the average crystallite size of magnetite as being 14 nm. Infrared spectra show characteristic bands of iron­oxygen as well as others associated with silicate groups. At room temperature, the nanocomposites present magnetic behavior due to the magnetite core. Besides, magnetite-silica-MB can promote ROS formation. Thus, we evaluate the photodynamic activity of Fe3O4-silica-MB on Escherichia coli. Our results show the bacteria are completely eradicated following photodynamic treatment depending on the MB release time from SPIONs and energy dose. These findings encourage us to explore the use of magnetite-silica-MB to fight internal infections in preclinical assays.

Availability of arsenic in rice grains by in vitro and in vivo (humans) assays.

BACKGROUND: Rice grains are consumed by approximately half of the world's population. This cereal has higher arsenic (As) concentrations in grains than wheat or barley. Arsenic determination in food and/or in vitro studies are important for risk assessment; however, it is not enough to assess the real human exposure. METHOD: In vitro bioaccessibility was carried out in husked-rice using gastric and intestinal solutions similar to humans. Also, As naturally found in husked-rice was evaluated by in vivo bioavailability in humans. For this purpose, diets from the 1st and 2nd days were free of foods known to be high in As; 3rd and 4th days the diets were composed by rice and water and; 5th and 6th the diet was similar the 1st and 2nd days. During all experimentation, a representative aliquot of each meal, blood and urine were collected for total As (t-As) determination. Arsenic species were determined in the urine. RESULTS: t-As in husked rice varied from 157.3 ±â€¯30.6 to 240.2 ±â€¯85.2 µg kg-1. The in vitrobioaccessible fractions ranged from 91 to 94%. Inorganic As (i-As) ranged from 99.7 ±â€¯11.2 to 159.5 ±â€¯29.4 µg kg-1. For the in vivo assay, t-As concentrations in the woman and man blood were about 3 µg mL-1 from the 1st to 6th day. Arsenic from the rice ingested was excreted by urine about 72 h after ingestion. The t-As and dimethyl As (DMA) in urine ranged from 3.59 to 47.17 and 1.02 to 2.55 µg g-1 creatinine for the volunteers, indicating a two-fold DMA-increase in urine after ingestion of husked-rice. CONCLUSION: After rice ingestion, As was quickly metabolized. The higher As concentrations were found in urine 72 h after rice ingestion. The main As-specie found in urine was DMA, indicating that methylation of As from rice followed by urine excretion is the main biological pathway for As excretion.

A iontoforese na prática fisioterapêutica / The iontophoresis in the physical therapy practice

Contextualização: A iontoforese é uma técnica que usa corrente galvânica para aumentar a transferência transdermal de fármacos ionizáveis de maneira controlada, segura e sem desconforto sensorial. Assim como outras modalidades, existem poucos estudos clínicos bem documentados que contribuam para prática baseada em evidências em condições comuns na prática fisioterapêutica. No entanto, alguns estudos clínicos randomizados e controlados, estudos não controlados e casos clínicos disponíveis descrevem resultados favoráveis ao tratamento de condições inflamatórias osteomioarticulares e calcificações ectópicas. Objetivos: Propor um roteiro de tomada de decisão clínica e discutir aspectos relevantes para prática adequada para garantir os resultados terapêuticos desejados. Métodos: Foram revisados estudos clínicos, estudos clínicos randomizados e controlados, estudos de casos, artigos de revisão e livros texto de eletroterapia. Resultados: São apresentados os íons e fármacos ionizáveis que possuem mecanismos de ação em condições relacionadas à fisioterapia, a técnica de aplicação, as complicações, cuidados e reações adversas. Também são discutidas as vantagens e as limitações da aplicação de iontoforese. Conclusão: Este artigo de revisão oferece o embasamento teórico para aplicação da iontoforese na prática da fisioterapia.

Background: Iontophoresis is a technique that uses galvanic current to enhance the transdermal drug delivery of ionic therapeutic agents in a controlled, safety and comfort manner. Such other modalities, there are few well-documented clinical trials contributing to practice evidence based in common conditions to physical therapy practice. However, some randomized controlled trials, non-randomized clinical trials, and case reports have advocated suitable results in bone, muscle and joint inflammatory conditions and in ectopic calcifications treated by iontophoresis. Objectives: The aims of this review were to recommend a guide to clinical decision making and discussed relevant issues to suitable practice in order to reach the desirable therapeutic results. Methods: Randomized controlled trials, non-randomized clinical trials, case reports, reviews, and electrotherapy textbooks. Results: Ions and ionic drugs related to clinical conditions common to physical therapy practice, the complications, precautions, and side effects are presented. Advantages and limitations to iontophoresis application are also discussed. Conclusion: This review offers the theoretical background to iontophoresis application in the physical therapy practice.

Impacto da dor na vida de portadores de disfunçäo temporomandibular / Pain impact on life of patients with temporomandibular disorder

Foi realizado um estudo do impacto da dor na vida de indivíduos portadores de disfunçäo da articulaçäo temporomandibular (DTM). Foram estudados 22 pacientes (20 mulheres e dois homens, com idade média de 28 anos) portadores de DTM que procuraram atendimento fisioterapêutico especializado, submetidos a uma versäo brasileira do Questionário McGill de Dor (Br-MPQ), que inclui questöes específicas sobre a qualidade de vida, como: 1) prejuízo social; 2) atividades da vida diária; 3) percepçäo do outro; 4) tolerância à dor; 5) sensaçäo de estar doente; 6) sensaçäo de utilidade; 7) satisfaçäo com a vida. Os resultados mostraram que a dor da DTM prejudicou as atividades do trabalho (59,09 por cento), da escola (59,09 por cento), o sono (68,18 por cento) e o apetite/alimentaçäo (63,64 por cento). Os autores concluíram que a dor da DTM tem um impacto negativo na qualidade de vida do paciente e que o questionário empregado, embora näo específico, permitiu avalia-lo adequadamente

[Pain impact on life of patients with temporomandibular disorder]. / Impacto da dor na vida de portadores de disfunção temporomandibular.

A study on the impact of pain in patients with temporomandibular joint disorder (TMD) was carried out. Twenty two patients (20 women, two men, 28 years of age on average) with TMD who looked for specialized physiotherapy care were submitted to a brazilian version of McGill Pain Questionnaire (Br-MPQ), which includes questions about life quality, as follows: 1) social loss; 2) daily life activities; 3) third party’s perception; 4) pain tolerance; 5) sensation of being sick; 6) sensation of being useless; 7) life satisfaction. The results showed that pain related to the TMD significantly affected work activities (59.09%), school activities (59.09%), sleeping (68.18%) and appetite/feeding (63.64%). The authors conclude that pain from TMD has a negative impact on the patients’ life quality and that, although unspecific, the questionnaire used allowed for an adequate evaluation of the impact.

Estimulacao eletrica neuromuscular do tibial anterior nao altera a morfologia dos musculos soleo(antagonista) e extensor digital longo(sinergista) do rato / Neuromuscular electrical stimulation of tibialis anterior do not change the morphology of soleus(antagonistic) and extensor digitorum longus(synergistic) muscles of rat

A estimulacao eletrica neuromuscular(EENM) e um recurso fisioterapico muito utilizado para produzir fortalecimento e hipertofia muscular. O objetivo deste trabalho foi analisar os efeitos morfologicos da EENM na musculatura sinergista e antagonista ao musculo diretamente estimulado. O musculo tibial anterior(TA) direito de seis ratos (Wistar)foi submetido a eletroestimulacao e os musculos extensor digital longo(EDL) e soleo, sinergista e antagonista ao TA, repectivamente, foram analisados. A EENM foi realizada em uma frequencia de 52 Hz., com ciclo ON-OFF na proporcao de 1/1, rampa de subida de trens de pulso de 2,2 seg. e intensidade de aproximadamente 0,5 mA. Foram produzidas 20 contracoes em cada sessao, 3 vezes por semana, durante 8 semanas. Posteriormente os animais foram anestesiados,e os musculos EDL e soleo direito e esquerdo foram removidos, pesados, congelados, seccionados e corados com Azul de Toluidina, para avaliacao morfologica das fibras musculares. Estudo previo, realizado no TA diretamente estimulado, nao revelou alteracoes morfologicas significativas no peso, area media das fibras e incidencia de sinais de lesao no EDL e no soleo, quando comparados com os musculos da pata controle nao estimulada. Esses resultados indicam que o protocolo utilizado para EENM, nao produziu alteracoes morfologicas significantes nos musculos EDL(sinergista) e soleo(antagonista) apos estimulacao do TA