ABSTRACT Illicit drug abuse to enhance athletic performance undermine integrity of sports. Detecting banned substances is challenging owing to rapid clearance and evasion via masking agents. Chromatography techniques are constrained by cost, analysis times and portability impeding on-site testing. Electroanalytical sensors incorporating carbon nanomaterials demonstrate vast promise as rapid, sensitive and cost-effective complementary screening tools. Exceptional conductivity, electrocatalysis and functionalization potential of graphene, carbon nanotubes and fullerenes allow parts-per-billion detection limits matching immunological assays for stimulants and anabolics. Aptamer integration also imparts target specificity. Nevertheless, translation from lab prototypes to commercial devices needs optimization of green synthesis protocols and surface stabilization for reliable reproducibility. Coupling to microfluidics and machine learning data harmonization can enable automated sampling, multi-marker testing and wireless result archiving at decentralized point-of-care. Overall, miniaturized nanosensors adequately sensitive for divide cutoff concentrations aid anti-doping enforcement through early interventions, chelation therapy and deterrence against proliferation of doping culture among athletes. sports agents cost onsite on site costeffective effective tools conductivity graphene partsperbillion parts per billion anabolics specificity Nevertheless reproducibility sampling multimarker multi marker pointofcare. pointofcare point care. care point-of-care Overall antidoping anti interventions athletes

Abstract The development of fast, specific, ultrasensitive, and accurate techniques for the early detection of important pathogens has been spurred by growing concerns about environmental safety, food safety, and nosocomial infection. Many bacteria, which may be found in foods, water, and medical equipment, cause diseases in humans and plants. In recent years, antibiotic resistance has arisen as a significant concern, as has their contamination as a result of unregulated use. As a result, there is a greater need to quickly establish reliable, simple, and sensitive techniques for evaluating antibiotics and their residues. The majority of bacterial detection procedures are lengthy and take days to provide a result. Aptamers appear to be a potential option for detecting bacteria in food items rapidly and reliably. Because of their high sensitivity, specificity, and selectivity, aptamer-based biosensors (aptasensors) attracted a lot of interest. This article provides a summary of newly discovered antibiotic detection aptasensors. This paper discusses the use of several aptamer assays to identify antibiotics such as sulfonamides, tetracyclines, lincosamide, (fluoro)quinolones, chloramphenicol, anthracyclines, aminoglycosides, and β-lactams.

ABSTRACT Chlorpyrifos (CP) is a widely used pesticide related to various health hazards, and for its ubiquity, its monitoring has become relevant to assess the state and rates of emission to the environment. On the other hand, environmental factors favor the degradation of CP and dissipation in the environment, making it difficult to trace and detect it in the different matrices. Nowadays, the use of biosensors provides promising analytical techniques for the detection of various environmental importance compounds. However, it is unknown if the natural degradation of these compounds would affect the correct recognition by biosensors, influencing their use as a traceability tool. The main objective of this review is to address the recent advances in biosensors for the detection of CP, its challenges in detecting the real sample associated with the degradation of this pollutant, and the future aspects about with the environmental monitoring of this pesticide related to health risks.

RESUMEN El Clorpirifós (CP) es un pesticida ampliamente utilizado, relacionado a diversos daños en salud y dado a su ubicuidad, su monitoreo ha adquirido relevancia para evaluar el estado y tasas de descarga al medioambiente. Por su parte, los factores ambientales favorecen la degradación de CP y disipación en el medio ambiente, dificultando su trazabilidad y detección real en las diversas matrices. En la actualidad, el uso de biosensores proporciona técnicas analíticas prometedoras para la detección de diversos compuestos de importancia ambiental, pero se desconoce si la degradación natural de dichos compuestos afectaría el correcto reconocimiento por parte de los biosensores, influyendo en su uso como herramienta de trazabilidad. El objetivo principal de esta revisión es abordar los recientes avances de biosensores para la detección de CP, sus desafíos en la detección en muestras reales asociados a la degradación de este contaminante y los aspectos futuros asociados al monitoreo ambiental de este pesticida relacionado con riesgos para la salud.

Resumen Los aptámeros son secuencias de ADN o ARN de cadena sencilla que adoptan la forma de estructuras tridimensionales únicas, lo cual les permite reconocer un blanco específico con gran afinidad. Sus usos potenciales abarcan, entre otros, el diagnóstico de enfermedades, el desarrollo de nuevos agentes terapéuticos, la detección de riesgos alimentarios, la producción de biosensores, la detección de toxinas, el transporte de fármacos en el organismo y la señalización de nanopartículas. El pegaptanib es el único aptámero aprobado para uso comercial por la Food and Drug Administration (FDA). Otros aptámeros para el tratamiento de enfermedades están en la fase clínica de desarrollo. En parasitología, se destacan los estudios que se vienen realizando en Leishmania spp., con la obtención de aptámeros que reconocen la proteína de unión a poliA (LiPABP) y que pueden tener potencial utilidad en la investigación, el diagnóstico y el tratamiento de la leishmaniasis. En cuanto a la malaria, se han obtenido aptámeros que permiten identificar eritrocitos infectados e inhiben la formación de rosetas, y otros que prometen ser alternativas para el diagnóstico al detectar de forma específica la proteína lactato deshidrogenasa (PfLDH). Para Cryptosporidium parvuum se han seleccionado aptámeros que detectan ooquistes a partir de alimentos o aguas contaminadas. Para Entamoeba histolytica se han aislado dos aptámeros llamados C4 y C5, que inhiben la proliferación in vitro de los trofozoítos y tienen potencial terapéutico. Los aptámeros contra Trypanosoma cruzi inhiben la invasión de células LLC-MK2 (de riñón de mono) en un 50 a 70 % y aquellos contra T. brucei transportan moléculas tóxicas al lisosoma parasitario como una novedosa estrategia terapéutica. Los datos recopilados en esta revisión destacan los aptámeros como una alternativa para la investigación, el diagnóstico y el tratamiento contra parásitos de interés nacional.

Abstract Aptamers are single-stranded DNA or RNA sequences that adopt unique three-dimensional structures that allow them to recognize a specific target with high affinity. They can potentially be used for the diagnosis of diseases, as new therapeutic agents, for the detection of food risks, as biosensors, for the detection of toxins, and as drug carriers and nanoparticle markers, among other applications. To date, an aptamer called pegaptanib is the only aptamer approved by the Food and Drug Administration (FDA) for commercial use. Other aptamers are in different clinical stages of development for the treatment of different diseases. In parasitology, investigations carried out with parasites such as Leishmania spp. allowed the acquisition of aptamers that recognize the polyA-binding protein LiPABP and may have potential applications in research and diagnosis and even as therapeutic agents. Regarding malaria, aptamers have been obtained that allow the identification of infected erythrocytes or inhibit the formation of rosettes, along with those that provide promising alternatives for diagnosis by specifically detecting the protein lactate dehydrogenase (PfLDH). In Cryptosporidium parvum allow the detection of oocysts in contaminated food or water. In Entamoeba histolytica, two aptamers called C4 and C5, which inhibit the proliferation of trophozoites in vitro and have potential use as therapeutic agents, have been isolated. Aptamers obtained against Trypanosoma cruzi inhibit the invasion of LLC-MK2 (from monkey kidney) cells by 50-70%, and in T. brucei, aptamers with the potential to transport toxic molecules to the parasitic lysosome were identified as a novel therapeutic strategy. The data collected in this review highlight aptamers as a novel alternative in the research, diagnosis, and treatment of parasites of national interest.

ABSTRACT Aflatoxin B1 (AFB1) is one of the most frequent mycotoxins produced by certain species of the fungi Aspergillus, which affects a wide variety of agricultural products such as kiwicha. AFB1 is known to be nephrotoxic, hepatotoxic and carcinogenic, and has led to strict regulation throughout the world and the need to have new rapid, simple and selective methods to detect the mycotoxin. The nanoaptasensors based on gold nanotriangles (AuNTs) emerge as a simple and effective alternative to traditional detection systems. On the one hand, aptamers make the system stable and very selective due to its high affinity, but at a low cost. On the other hand, the exceptional optical properties of gold nanoparticles allow the implementation of the sensor in a simple analytical technique such as UV-Vis-NIR spectroscopy. This development is possible due to the localized surface plasmon resonance (LSPR), which allows monitoring the interaction between the aptamer and the toxin and correlating the spectral changes with the mycotoxin content. The sensitivity of the nanosensors was evaluated in different solvents and buffers within the 0-780 ppbs AFB1 range. Best results were obtained using PBS buffer with MgCl2 pH 7.5 (R2 = 0.98101). Furthermore, the spectral analysis by the partial least squares regression (PLS) method it was possible to achieve a detection limit of 22 ppbs. Finally, the developed nanoaptasensors have shown good responses even in the presence of a complex matrix such as kiwicha.

RESUMEN La aflatoxina B1 (AFB1) es una micotoxina producida por la especie de hongos Aspergillus que afecta a una gran variedad de productos agrícolas como la kiwicha. La AFB1 es conocida por ser nefrotóxica, hepatotóxica y carcinogénica, lo que ha llevado a una estricta regulación en todo el mundo y a la necesidad de tener nuevos métodos que permitan su detección rápida, sencilla y selectiva. Los nanosensores aptaméricos basados en nanotriángulos de oro (AuNTs) surgen como una alternativa simple y eficaz a los sistemas tradicionales de detección. Por una parte, los aptámeros hacen que el sistema sea estable y muy selectivo debido a su gran afinidad, pero a un bajo costo y, por otro, las excepcionales propiedades ópticas de las nanopartículas de oro permiten implementar el sensor en una técnica analítica sencilla como la espectroscopía UV-Vis-NIR. Esto se debe a la resonancia de plasmón superficial localizado (LSPR), que permite monitorear la interacción entre el aptámero y la toxina y relacionar los cambios espectrales con el contenido de micotoxina. Los nanosensores aptaméricos desarrollados en esta investigación fueron evaluados en diferentes solventes y tampones, siendo el mejor de ellos el de PBS pH 7.5 (R2 = 0.98101) logrando detectar AFB1 en el rango de 0-780 ppbs. Adicionalmente, el análisis multivariante por regresión de mínimos cuadrados parciales (PLS) de los espectros logró obtener un límite de detección de 22 ppbs. Finalmente, los nanosensores han demostrado ser lo suficientemente robustos para obtener buenos resultados aun en matrices complejas como extractos de kiwicha.

As a kind of important water pollutant, heavy metal ions have a detrimental effect on the health of human. In this study, Au@Ag core-shell nanoparticles were synthesized by simple reduction of Ag + around Au nanoparticles and functionalized by DNAzyme. Based on thymine-Hg2+-thymine binding mode, a sensitive aptamer biosensor was constructed by utilizing functionalized Au@Ag core-shell nanoparticles as labels, and the sensitivity was enhanced by DNAzyme due to the catalysis toward H2O2. Under optimal conditions, square wave voltammetry was carried out to measure the current derived from Au@Ag nanoparticles labels. The current response of biosensor increased with the increasing of Hg2+ concentration, which presented linear relation in the range of 0.002-20 μg L -1 with limit of detection of 0.006 μg L -1. Meanwhile, the electrochemical biosensor showed superior reversibility, stability, repeatability, and selectivity.

Electrochemical aptasensor arrays have been recently used to detect several proteins reported as disease biomarkers, mainly due to their known advantages, that include high affinity, sensitivity, specificity and low costs, among others. This study describes the development of a label-free electrochemical multi-aptasensor array, for the simultaneous detection of human osteopontin (OPN), using two specific aptamers. To enable multiplexed protein assay, RNA and DNA aptamers were immobilized in the dual-screen-printed gold working electrodes via streptavidin-biotin interaction, and using the [Fe(CN)6]3-/4- as the redox probe for cyclic voltammetry measurements. The multi-aptasensor array herein developed exhibited a good response and selectivity to detect human OPN in the presence of other interfering proteins. Considering these preliminary results, the DNA/RNA dual aptasensor array could potentially be used as an analytical tool for the specific detection of human OPN, and for cancer diagnosis overall.

ABSTRACT Aptamers are short single-stranded RNA or DNA oligonucleotides that are capable of binding various biological targets with high affinity and specificity. Their identification initially relies on a molecular process named SELEX (Systematic Evolution of Ligands by EXponential enrichment) that has been later modified in order to improve aptamer sensitivity, minimize duration and cost of the assay, as well as increase target types. Several biochemical modifications can help to enhance aptamer stability without affecting significantly target interaction. As a result, aptamers have generated a large interest as promising tools to compete with monoclonal antibodies for detection and inhibition of specific markers of human diseases. One aptamer-based drug is currently authorized and several others are being clinically evaluated. Despite advances in the knowledge of parasite biology and host-parasite interactions from "omics" data, protozoan parasites still affect millions of people around the world and there is an urgent need for drug target discovery and novel therapeutic concepts. In this context, aptamers represent promising tools for pathogen identification and control. Recent studies have reported the identification of "aptasensors" for parasite diagnosis, and "intramers" targeting intracellular proteins. Here we discuss various strategies that have been employed for intracellular expression of aptamers and expansion of their possible application, and propose that they may be suitable for the clinical use of aptamers in parasitic infections.

Na contínua busca do diagnóstico precoce e melhores modalidades terapêuticas contra o câncer, com base no constante aumento do conhecimento da biologia do câncer, aptâmeros têm a promessa de expandir o atual sucesso dos anticorpos, e superar alguns dos problemas enfrentados com os anticorpos, como agentes terapêuticos ou como agentes que chegam ao processo neoplásico. Entretanto, como o primeiro aptâmero chegou ao mercado como um inibidor da angiogênese para o tratamento da degeneração macular, aptâmeros tem encontrado apenas aplicações ou interesse limitados em oncologia, e ainda menos como radiofármacos para o diagnóstico por imagem e radioterapia direcionada para tumores. A química para a marcação de aptâmeros e as opções para alterar suas propriedades radiofarmacocinéticas, para torná-los mais adequados para uso como radiofármacos, é agora disponível e os avanços recentes no seu desenvolvimento podem demonstrar que essas moléculas poderiam ser ideais como veículos para o desenvolvimento de radiofármacos sítio-dirigidos que poderiam levar radiação com precisão para o tumor, oferecendo melhores propriedades terapêuticas e reduzidos efeitos indesejados.

In the continuous search for earlier diagnosis and improved therapeutic modalities against cancer, based on our constantly increasing knowledge of cancer biology, aptamers hold the promise to expand on current antibody success, but overcoming some of the problems faced with antibodies as therapeutic or delivery agents in cancer. However, as the first aptamer reached the market as an inhibitor against angiogenesis for the treatment of macular degeneration, aptamers have found only limited applications or interest in oncology, and even less as radiopharmaceuticals for diagnostic imaging and targeted radiotherapy of tumours. Yet, the chemistry for the labelling of aptamers and the options to alter their pharmacokinetic properties, to make them suitable for use as radiopharmaceuticals is now available and recent advances in their development can demonstrate that these molecules would make them ideal delivery vehicles for the development of targeted radiopharmaceuticals that could deliver their radiation load with accuracy to the tumour site, offering improved therapeutic properties and reduced side effects.

A tomografia por emissão de pósitrons (TEP) é uma técnica de imagem não invasiva da medicina nuclear. A TEP utiliza moléculas marcadas com emissores de radiação beta positiva (pósitrons). As radiações gama medidas que resultam do aniquilamento dos pósitrons são detectadas por um sistema de coincidência e mapeadas para produzir uma imagem tridimensional da distribuição do radiotraçador no corpo. A imagem molecular com TEP refere-se ao uso de biomoléculas marcadas com emissor de pósitron que são substratos altamente específicos para alvos como enzimas, proteínas transportadoras ou receptores protéicos. A imagem molecular com TEP produz mapas espaciais e temporais de alvos que estejam sendo avaliados. A imagem molecular é uma importante ferramenta analítica no diagnóstico por imagem em medicina, no monitoramento de terapia e no desenvolvimento de novas drogas. A imagem molecular tem seus fundamentos na biologia molecular. Originalmente, a biologia molecular significava a biologia da expressão gênica, mas atualmente a biologia molecular envolve amplamente a biologia de macromoléculas, a bioquímica de proteínas, carboidratos complexos e ácidos nucléicos. A imagem molecular tem priorizado as proteínas, com ênfase nos anticorpos monoclonais e suas formas derivadas, substratos enzimáticos para pequenas moléculas e componentes de membranas celulares, incluindo os transportadores e elementos envolvidos com a sinalização trans-membrana.

Positron emission tomography (PET) is a non-invasive nuclear imaging technique. In PET, radiolabelled molecules decay by positron emission. The gamma rays resulting from positron annihilation are detected in coincidence and mapped to produce three dimensional images of radiotracer distribution in the body. Molecular imaging with PET refers to the use of positron-emitting biomolecules that are highly specific substrates for target enzymes, transport proteins or receptor proteins. Molecular imaging with PET produces spatial and temporal maps of the target-related processes. Molecular imaging is an important analytical tool in diagnostic medical imaging, therapy monitoring and the development of new drugs. Molecular imaging has its roots in molecular biology. Originally, molecular biology meant the biology of gene expression, but now molecular biology broadly encompasses the macromolecular biology and biochemistry of proteins, complex carbohydrates and nucleic acids. To date, molecular imaging has focused primarily on proteins, with emphasis on monoclonal antibodies and their derivative forms, small-molecule enzyme substrates and components of cell membranes, including transporters and transmembrane signalling elements. This overview provides an introduction to nucleosides, nucleotides and nucleic acids in the context of molecular imaging.

Degeneração macular relacionada à idade (DRMI) é a principal causa de cegueira no mundo ocidental. Várias formas clínicas foram reconhecidas, e membrana neovascular coroideana (MNSR) representa manifestação importante passível de tratamento. O tratamento de MNSR tem sido um foco importante de pesquisa nas últimas décadas e a primeira terapia estabelecida baseada em evidência foi a fotocoagulação a laser, que reduziu o risco de perda visual em lesões extrafoveais. No fim da década de 90 a terapia fotodinâmica foi estabelecida como método eficiente de tratamento de MNSR predominantemente clássicas e ocultas. Terapias adicionais como a translocação macular, cirurgia submacular, e protrombose mediada por indocianina verde estão atualmente em investigação em ensaios clínicos em larga escala. A biologia molecular permitiu recentemente uma melhor compreensão da patogênese da DMRI e o fator de crescimento vascular endotelial foi reconhecido como um mediador-chave na angiogênese da formação de MNSR. Portanto, a abordagem farmacológica surge como opção terapêutica no tratamento da MNSR. O primeiro agente terapêutico aprovado pelo FDA é o aptâmero pegaptanib sódio (Macugen®), que inativa a isoforma fundamental para a angiogênese intra-ocular: VEGF165. Outros inativadores de VEGF como ranibizumab RhuFab V2 (Lucentis®) e bevacizumab (Avastin®) estão em avaliação em estudos clínicos. Resultados impressionantes de bevacizumab intravítreo foram liberados recentemente. Adicionalmente, o derivado de esteróides acetato de anecortave, assim como o corticosteróide acetato de triancinolona têm sido propostos como métodos no tratamento de DMRI-neovascular. Este artigo apresenta os princípios e resultados iniciais na terapia antiangiogênica farmacológica da MNSR na DMRI.

Age-related macular degeneration (ARMD) remains a leading cause of blindness in the western world. Several clinical forms of the disease are recognized, whereas choroidal neovascularization (CNV) represents an important manifestation suitable for treatment. The treatment of CNV has been a major focus of research in the past decades, and the first evidence-based established therapy was laser photocoagulation, which reduces the risk of visual loss in extrafoveal lesions. In the late 90's photodynamic therapy has been established as an efficient method for the treatment of predominantly classic and occult CNV. Additional therapies such as macular translocation, submacular surgery, and indocyanine-mediated prothrombosis are currently under investigation in large-scale clinical trials. Molecular biology has recently provided a better comprehension of the pathogenesis of ARMD, and vascular endothelial growth factor (VEGF) was recognized as key mediator in the angiogenesis of CNV-formation. Therefore, the pharmacological approach rose as a key research area to treat CNV. The first FDA-approved agent for CNV-therapy is aptamer pegaptanib sodium (Macugen®), which inactivates the key angiogenic isoform VEGF165. Additional VEGF-blockers such as ranibizumab RhuFab V2 (Lucentis®) and bevacizumab (Avastin®) are under evaluation in major clinical studies. Impressive results of intravitreal bevacizumab were released recently. Moreover, the steroid-derived anecortave acetate as well as the corticosteroid triamcinolone acetate have been proposed as methods for treatment of wet-ARMD. This paper presents the rationale and principles of the pharmacologic antiangiogenic therapy for CNV in ARMD.