RESUMO: A Osteoartrite (OA) é uma denominação clínica para uma combinação de condições patológicas que envolvem a degeneração progressiva da cartilagem articular e remodelação de osso subcondral. A curcumina, um potente agente anti-inflamatório, têm sido extensivamente estudada, no entanto não oferece boa biodisponibilidade sistêmica. Nanopartículas de ouro (AuNPs) apresentam aplicações potenciais na administração de substâncias terapêuticas aumentando a eficiência do transporte de fármacos. O objetivo deste estudo foi realizar a síntese e caracterização de um sistema conjugando as AuNPs à curcumina e avaliar seu potencial terapêutico em um modelo experimental de OA em camundongos por desestabilização do menisco medial (DMM). As AuNPs foram conjugadas com curcumina e os sistemas foram caracterizados por espectroscopia no UV-VIS, espalhamento de luz dinâmico (DLS) e determinação do potencial zeta. Formou-se 4 grupos de oito animais cada, denominados A, B, C, D que receberam injeção intra-articular de AuNPs, curcumina, AuNP-curcumina e solução fisiológica, respectivamente. Após 7 semanas, a cartilagem da articulação-femoro- tibio-patelar (AFTP) foi avaliada em uma variação de escore de 0 a 24. A conjugação de AuNP-curcumina mostrou boa estabilidade e aplicação terapêutica, mas não diferiu significativamente (P>0,05) dos grupos A e B, no entanto, mostrou menor valor de escore e significância (P<0,001) em relação ao grupo controle. Os resultados deste trabalho mostram a importância do desenvolvimento de novos nanofármacos. Neste caso a conjugação de AuNPs com a curcumina permitiu a obtenção de um nanofármaco com sugestivo potencial para aplicação no tratamento da OA.

ABSTRACT: Osteoarthritis (OA) is the clinical term for a combination of pathological conditions that involve the progressive degeneration of articular cartilage and subchondral bone remodelling. Curcumin, a potent anti-inflammatory agent, has been extensively studied; however, it does not provide good systemic bioavailability. Gold nanoparticles (AuNPs) have potential applications in the administration of therapeutic substances in order to increase the transport efficiency of drugs. The objectives of this study were to explore the synthesis and characterization of a system combining AuNPs with curcumin and evaluate its therapeutic potential in an experimental model of OA in mice by the destabilization of the medial meniscus (DMM). The AuNPs were conjugated with curcumin and the systems were characterized by UV-VIS spectroscopy, dynamic light scattering (DLS), and zeta potential. Four groups of eight animals each were formed and labelled A, B, C, and D, which received intra-articular injections of AuNPs, curcumin, AuNP-curcumin, and physiologic solution, respectively. After seven weeks, the cartilage of the stifle joint (SJ) was rated on a scale ranging from 0 to 24. Combination of AuNP-curcumin demonstrated good stability and therapeutic applications, but it did not differ significantly (P>0.05) from groups A and B. However, the control group had a significantly lower score (P<0.001). Results of this study demonstrated the importance of developing new nanodrugs. In this case, the combination of AuNPs and curcumin yielded the nanodrug effects suggestive of a potential for application in the treatment of OA.

The recent advances in the development of nanomaterials have opened new and exciting opportunities for their applications in medicine. These applications include molecular imaging, drug-delivery, and photothermal therapy. Despite the progress in medicinal applications of nanomaterials, several key problems remain unaddressed. Recent advances in this area include the enhancement of sensitivity in early diagnosis and therapy, in addition to investigations into the possible toxicity of nanomaterials. However, since little is known about the toxicity of nanomaterials, the regulation of these materials is a slow and complex process. This paper reviews the current scenario in the applications of nanomaterials in medicine as well as the main concerns and regulatory questions.

Polycrystalline ITO films with good optoelectronics characteristics and homogeneous surface has been obtained upon annealing at 550 °C in N² atmosphere using a low-cost chemical vapor deposition (CVD) system. The films were evaluated as pH sensors in separative extended gate field-effect transistor (SEGFET) apparatus, exhibiting a sensitivity of 53 mV/pH, close to the expected Nernstian theoretical value for ion sensitive materials. The use of CVD process to synthesize ITO, as described here, may represent an alternative for fabrication of SEGFET pH sensors at low cost to be used in disposable biosensors since H+ ions are the product of several oxireductase enzymes.

In this work we take advantage of the polyelectrolyte character of some Brazilian native gums to fabricate electrically conductive, nanostructured films. The gums Sterculia urens, (caraia), Sterculia striata (chicha) or Anadenanthera macrocarpa Benth were assembled in conjunction with poly(o-methoxyaniline) (POMA) in the form of layered nanostructured films using the layer-by-layer (LbL) technique. All the LbL films displayed a well-defined electroactivity, as confirmed via cyclic voltammetry. In comparison to POMA LbL films fabricated with conventional polyelectrolytes (viz. poly(vinyl sulfonic acid)-PVS), the presence of the gums in the LbL films increased remarkably the electrochemical stability of the films.

Compósitos condutores elétricos a base de poli(fluoreto de vinilideno) (PVDF) e negro de fumo modificado com polianilina (Eeonomer®) foram preparados através do processamento por fusão. Resultados de reometria de torque indicaram que a presença de polianilina no negro de fumo é vantajosa ao processamento por fusão, reduzindo a viscosidade do fundido em comparação com a aditivação com negro de fumo puro. Compósitos contendo acima de 5% em peso de Eeonomer® apresentaram condutividade da ordem de 10-2 S/cm. Esse valor se manteve estável mesmo após tratamento térmico a 150°C por 170 h em atmosfera ambiente. Análises por calorimetria diferencial de varredura (DSC) e difração de Raios-X mostraram que o tipo e a quantidade de Eeonomer®, assim como a taxa de resfriamento da amostra, podem afetar a temperatura de fusão, o grau de cristalinidade e a fase cristalina do PVDF presente no compósito.

Conductive polymeric composites of poly(vinylidene fluoride) and carbon black modified with polyaniline were prepared via melting processing. The additivation with Eeonomers® is advantageous to the melt processing of the composites reducing the melt viscosity in comparison to the additivation with pure carbon black. The composites containing above 5%wt of Eeonomer® exhibited electrical conductivity around 10-2 S/cm, and this value remains constant even after thermal treatment at 150 ºC during 170 h room atmosphere. Differencial Scanning Calorimetry (DSC) and X-Ray diffraction analyses showed that composites containing the beta phase of PVDF could be obtained via quenching from the melt. It was also shown that the type and amount of Eeonomer® affect the crystallinity and the melting temperature of PVDF present in the composites.