Pesquisa e desenvolvimento de nanomedicamentos: olhar bioético / Nanodrug research and development: a bioethical approach / Investigación y desarrollo de nanomedicinas: desde la mirada bioética

Resumo Nanotecnologia é a utilização de materiais na escala nanométrica, em que estes adquirem características próprias. A área de pesquisa e desenvolvimento de novos nanomedicamentos é uma das mais promissoras atualmente, todavia essas partículas necessitam de avaliação particular e ainda não há consenso referente às testagens específicas a serem seguidas, o que dificulta a formação de uma legislação que garanta a segurança e eficácia destes medicamentos, além de um processo de registro mais eficaz. Assim, é necessária uma abordagem bioética da nanotecnologia e sua utilização em medicamentos, visando garantir que o progresso científico não acarrete impactos irreversíveis. Diante dessa problemática, busca-se promover uma discussão nanoética referente ao processo de pesquisa e desenvolvimento de nanomedicamentos, por meio de estudo qualitativo, exploratório-descritivo e de caráter analítico, utilizando revisão bibliográfica, análise documental e dados quantitativos disponíveis como técnicas de pesquisa.

Abstract Nanotechnology consist of using materials at the nanoscale, in which they acquire specific characteristics. Nanodrug research and development is one of the most promising fields today; however, these particles require particular evaluation. Moreover, studies lack consensus on which specific tests to follow, thus hindering the elaboration of legislation that ensure their safety and efficacy, as well as a more effective registration process. Thus, a bioethical approach to nanotechnology and its use in drug development is necessary to ensure scientific progress without irreversible impacts. Given this scenario, this article proposes a nanoethics discussion regarding nanodrug research and development by means of a qualitative, exploratory and descriptive analysis, based on literature review, documental analysis and quantitative data available.

Resumen La nanotecnología utiliza materiales nanométricos, en que estos adquieren características propias. El área de investigación y desarrollo de nuevas nanomedicinas es una de las más prometedoras en la actualidad, sin embargo, estas partículas requieren de una evaluación particular y aún no existe consenso en cuanto a las pruebas específicas que seguir, lo que dificulta establecer una legislación que garantice la seguridad y eficacia de estos medicamentos, además de un proceso de registro más efectivo. Por lo tanto, se necesita un enfoque bioético de la nanotecnología y su uso en medicamentos para garantizar que el avance científico no tenga impactos irreversibles. Ante esta problemática, se pretende promover el debate sobre la nanoética en el proceso de investigación y desarrollo de nanomedicinas a partir de un estudio cualitativo, exploratorio-descriptivo y analítico, que utiliza como técnicas de investigación la revisión bibliográfica, el análisis de documentos y los datos cuantitativos disponibles.

Mutagenic damage among bronchiectasis patients attending in the pulmonology sector of a hospital in southern Brazil

SUMMARY OBJECTIVE: Bronchiectasis is a chronic respiratory disease characterized by inflammation, irreversible dilation of the bronchi, and recurrent pulmonary infections, with a high morbidity and mortality rate, but is less studied from the point of view of its prevalence and associated factors not directly related to respiratory prognosis. As it is a disease related to the exacerbation of the inflammatory process and oxidative stress, this study searched to investigate the micronucleus frequency in patients with and without bronchiectasis treated at a specialized pulmonology service in a hospital in the extreme south of Brazil. METHODS: Patients with a confirmed tomographic diagnosis of bronchiectasis were defined as cases. Mutagenicity was evaluated by the micronucleus test in patients' oral mucosa cells. Data collection was performed through a questionnaire containing socioeconomic, demographic, lifestyle, and health condition information. RESULTS: Of the 95 patients involved in this study, 21 (22.1%) were diagnosed with bronchiectasis aged between 12 and 89 years. There was no significant difference in the frequency of micronucleus between patients with and without bronchiectasis. There was a significant positive association between age and frequency of micronucleus among patients with bronchiectasis, but this association does not occur among patients without the disease. CONCLUSION: This is the first study to investigate data on the prevalence and clinical and epidemiological aspects of this chronic disease in Brazil, especially those related to the genotoxicity outcome.

In vitro susceptibility of Sporothrix spp. to complexes coordinated with Co(II) and cobalt chloride hexahydrate

Abstract Sporothrix spp. are the major dimorphic fungus associated with a type of subcutaneous mycosis, sporotrichosis. The limitation of antifungal availability and the past reports of in vitro resistance of Sporothrix spp. clinical isolates makes it important to search for new compounds with antifungal activities. In this study, we therefore evaluate the in vitro activities of complexes coordinated with Co(II) and cobalt chloride hexahydrate against clinical isolates of Sporothrix spp. Broth microdilution test was performed as per M38-A2 from CLSI (2008) in duplicate for 31 clinical isolates of Sporothrix spp. (27 S. brasiliensis e 04 S. schenckii stricto sensu). The antifungal activities of the complexes coordinated with Co(II) and cobalt chloride hexahydrate were detected at a concentration range of 32-128 µg/mL for all isolates. None of the compounds demonstrated any cytotoxicity (to macrophage cells) at the concentration of 200 µg/mL. The activity against Sporothrix spp. recorded in this study instigate the continuity of experimental studies with Co(II) to search for the mechanisms of antifungal action as well as to evaluate its interaction with the commercial antifungal drugs.

Thesis and dissertations examining tuberculosis in Brazil between 2013 and 2019: an overview

ABSTRACT Background: Tuberculosis (TB) remains a serious public health problem, with approximately 10 million new cases reported annually. Knowledge about the quantitative evolution of theses and dissertations (T&Ds) examining human TB in Brazil can contribute to generating strategic planning for training professionals in this field and disease control. Therefore, this study highlights the role of T&Ds on TB in national scientific disclosures. Methods: An integrative review related to TB was performed, including T&Ds produced in Brazil and completed between 2013 and 2019. Results: A total of 559,457 T&Ds were produced, of which 1,342 were associated with TB, accounting for 0.24% of the total number of T&Ds in Brazil. This was evidenced by a predominance of themes such as attention/health care, epidemiology, and TB treatment, and 80.2% of the T&Ds on TB were related to the large areas of health and biological sciences. Only 19.7% of T&Ds were associated with groups of patients considered at risk for TB, and 50.9% were produced in southeastern Brazil. The 1,342 T&Ds on TB were developed in 416 postgraduate programs linked to 121 higher education institutions (HEIs). We highlight that 72.7% of T&Ds on TB were produced in federal HEIs, 27.4% in state HEIs, and 8.5% in private HEIs. Conclusions: Strategic themes, such as TB control, require public policies that aim to increase the number of doctors and masters with expertise in TB, with geographic uniformity, and in line with the priorities for disease control.

Drug resistance in helicobacter pylori / A resistência de Helicobacter pylori aos antimicrobianos

ABSTRACT Background Helicobacter pylori has a worldwide distribution and is associated with the pathogenesis of various diseases of the digestive system. Treatment to eradicate this microorganism involves the use of a combination of antimicrobials, such as amoxicillin, metronidazole, clarithromycin, and levofloxacin, combined with proton pump inhibitors. Although the current therapy is effective, a high rate of treatment failure has been observed, mainly because of the acquisition of point mutations, one of the major resistance mechanisms developed by H. pylori. This phenomenon is related to frequent and/or inappropriate use of antibiotics. Conclusion This review reported an overview of the resistance to the main drugs used in the treatment of H. pylori, confirming the hypothesis that antibacterial resistance is a highly local phenomenon and genetic characteristics of a given population can influence which therapy is the most appropriate.

RESUMO Contexto Helicobacter pylori tem uma distribuição a nível mundial, e está associado a patogênese de várias doenças do sistema digestivo. O tratamento para a erradicação deste microrganismo envolve a utilização de uma combinação de agentes antimicrobianos, tais como amoxicilina, metronidazol, claritromicina e levofloxacino, combinados com inibidores da bomba de prótons. Embora a terapia atual seja eficaz, uma elevada taxa de fracasso de tratamento tem sido observada, principalmente devido à aquisição de mutações pontuais, um dos principais mecanismos de resistência desenvolvida por H. pylori, relacionado com o uso frequente e/ou inadequado dos antibióticos. Conclusão Esta revisão abordou uma visão geral da resistência às principais drogas utilizadas no tratamento de H. pylori, confirmando a hipótese de que a resistência bacteriana é um fenômeno altamente local e as características genéticas de uma dada população podem influenciar qual terapia é a mais apropriada.

Antimycobacterial and cytotoxicity activity of microcystins

Background: The present work aimed to evaluate the antimycobacterial activity and cytotoxicity of Microcystis aeruginosa toxins, the MC-LR variant and purified extract of [D-Leu1] microcystin-LR. Methods: The antimicrobial activity of M. aeruginosa extract and microcystin was evaluated by resazurin microtiter assay against Mycobacterium tuberculosis, M. terrae, M. chelonae and M. kansasii. The cytotoxicity assay was performed by trypan blue exclusion against the HTC cell line. Results: Antimicrobial activity was observed in the hexanic extract of M. aeruginosa (RST 9501 strain) against M. tuberculosis, including sensitive and resistant strains with minimal inhibitory concentrations (MIC) between 1.93 μM and 0.06 μM. The high activity of M. aeruginosa hexanic extract could be attributed to the major presence of the toxins MC-LR and [D-Leu1] MC-LR that showed activity at MIC between 53 and 0.42 μM against tested mycobacterial strains. Even at the highest concentration tested, no toxicity of M. aeruginosa extracts was identified against HTC cells. Conclusions: These preliminary results suggest that [D-Leu1] MC-LR is a promising candidate for the development of a new antimycobacterial agent.

Molecular typing of Mycobacterium bovis isolates: a review

Mycobacterium bovis is the main causative agent of animal tuberculosis (TB) and it may cause TB in humans. Molecular typing of M. bovis isolates provides precise epidemiological data on issues of inter- or intra-herd transmission and wildlife reservoirs. Techniques used for typing M. bovis have evolved over the last 2 decades, and PCR-based methods such as spoligotyping and mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) have been extensively used. These techniques can provide epidemiological information about isolates of M. Bovis that may help control bovine TB by indicating possible links between diseased animals, detecting and sampling outbreaks, and even demonstrating cases of laboratory cross-contamination between samples. This review will focus on techniques used for the molecular typing of M. bovis and discuss their general aspects and applications.

Molecular typing of Mycobacterium bovis isolated in the south of Brazil

Bovine tuberculosis is a major infectious disease of the cattle. In this study, 85 M. bovis isolates from 162 lymph nodes, obtained from a herd of cattle on a farm in southern Brazil, were evaluated using spoligotyping and VNTR. The strains were grouped into five clusters and five orphans, showing a heterogenic genetic profile, what could represent diverse geographic origins of the introduced cows and/or the frequent movement of cattle between different properties.

Rational design of diagnostic and vaccination strategies for tuberculosis

The development of diagnostic tests which can readily differentiate between vaccinated and tuberculosis-infected individuals is crucial for the wider utilization of bacillus Calmette-Guérin (BCG) as vaccine in humans and animals. BCG_0092 is an antigen that elicits specific delayed type hypersensitivity reactions similar in size and morphological aspects to that elicited by purified protein derivative, in both animals and humans infected with the tubercle bacilli. We carried out bioinformatics analyses of the BCG_0092 and designed a diagnostic test by using the predicted MHC class I epitopes. In addition, we performed a knockout of this gene by homologous recombination in the BCG vaccine strain to allow differentiation of vaccinated from infected individuals. For that, the flanking sequences of the target gene (BCG_0092)were cloned into a suicide vector. Spontaneous double crossovers, which result in wild type revertants or knockouts were selected using SacB. BCG_0092 is present only in members of the Mycobacterium tuberculosis complex. Eight predicted MHC class I epitopes with potential for immunological diagnosis were defined, allowing the design of a specific diagnostic test. The strategy used to delete the (BCG_0092) gene from BCG was successful. The knockout genotype was confirmed by PCR and by Southern blot. The mutant BCG strain has the potential of inducing protection against tuberculosis without interfering with the diagnostic test based on the use of selected epitopes from BCG_0092.

Investigation of the antimycobacterial activity of 36 plant extracts from the Brazilian Atlantic Forest / Análise da atividade antimicobacteriana de 36 extratos vegetais da Mata Atlântica brasileira

Thirty-six plant extracts from the brazilian Atlantic Forest were tested for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv and M. kansasii, using the method REMA in seriate concentrations of 100 to 0.20 µg/mL. Among the thirty six extracts tested, five were active against M. tuberculosis, and three of these extracts also showed activity against M. kansasii. Cytotoxicity test with VERO cells was performed with the five extracts active against M. tuberculosis. Only the extract of Peschiera affinis was identified as non-toxic in the concentration of 100µg/mL.

Trinta e seis extratos vegetais originários da Mata Atlântica foram testados quanto à sua atividade antimicobacteriana frente ao M. tuberculosis H37Rv e M. kansasii, utilizando o método REMA em concentrações seriadas de 100 a 0,20 µg/mL. Dentre os trinta e seis extratos testados, cinco mostraram atividade frente ao M. tuberculosis, e destes apenas, três mostraram atividade ao M. kansasii, que apresentou susceptibilidade a outros dez. O teste de citotoxicidade com células VERO foi realizado com os cinco extratos ativos frente ao M. tuberculosis em que identificou-se a não toxicidade em apenas um extrato (Peschiera affinis) na concentração de 100 µg/mL.