RESUMO
The origin of the term diagnostic comes from the Greek word gnosis, meaning "to know." In medicine, a diagnostic can predict the pathology risk, disease status, treatment, and prognosis, even following therapy. An early and correct diagnosis is necessary for an efficient treatment. Moreover, it is possible to predict if and why a therapy will be successful or fail, enabling the timely application of alternative therapeutic strategies. Available diagnostics are due to the advances in biotechnology; however, more sensitive, low-cost, and noninvasive methodologies are still a challenge. Knowledge about molecular characteristics provide personalized information, which is the goal of future medicine. Today, multiple diagnostic techniques have emerged, with which it is possible to distinguish molecular patterns.In this way, aptamers are the perfect tools to recognize molecular targets and can be easily modified to confer additional functions. Their versatile characteristics and low cost make aptamers ideal for diagnostic applications.This chapter is a review of aptamer-based diagnostics in biomedicine, with a special focus on probe design and molecular imaging. Graphical Abstract.
Assuntos
Aptâmeros de Nucleotídeos , Biotecnologia , Diagnóstico por Imagem , Imagem Molecular , Aptâmeros de Nucleotídeos/química , Diagnóstico por Imagem/métodos , Diagnóstico por Imagem/tendências , Humanos , Imagem Molecular/métodos , Imagem Molecular/tendências , Técnica de Seleção de AptâmerosAssuntos
Imagem Molecular/tendências , Medicina Nuclear/tendências , Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/diagnóstico , Endocrinologia/normas , Europa (Continente) , Humanos , Imagem Molecular/normas , Medicina Nuclear/normas , Sociedades Médicas , Estados UnidosRESUMO
Cardiovascular diseases are the leading cause of death worldwide. Despite preventive efforts, early detection of atherosclerosis, the common pathophysiological mechanism underlying cardiovascular diseases remains elusive, and overt coronary artery disease or myocardial infarction is often the first clinical manifestation. Nanoparticles represent a novel strategy for prevention, diagnosis, and treatment of atherosclerosis, and new multifunctional nanoparticles with combined diagnostic and therapeutic capacities hold the promise for theranostic approaches to this disease. This review focuses on the development of nanosystems for therapy and diagnosis of subclinical atherosclerosis, coronary artery disease, and myocardial infarction and the evolution of nanosystems as theranostic tools. We also discuss the use of nanoparticles in noninvasive imaging, targeted drug delivery, photothermal therapies together with the challenges faced by nanosystems during clinical translation.
Assuntos
Aterosclerose/diagnóstico por imagem , Aterosclerose/terapia , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/terapia , Nanopartículas/administração & dosagem , Nanomedicina Teranóstica/métodos , Animais , Humanos , Imagem Molecular/métodos , Imagem Molecular/tendências , Terapia de Alvo Molecular/métodos , Terapia de Alvo Molecular/tendências , Nanomedicina Teranóstica/tendênciasRESUMO
The pathophysiology of neurodegenerative diseases (ND) such as Alzheimer's disease (AD) and Parkinson's disease (PD) has not yet been completely elucidated. However, in the past few years, there have been great knowledge advances about intra-and extracellular proteins that may display impaired function or expression in AD, PD and other ND, such as amyloid beta (Aβ), α-synuclein, tau protein and neuroinflammatory markers. Recent developments in the imaging techniques of positron emission tomography (PET) and single photon emission computed tomography (SPECT) now allow the non-invasive tracking of such molecular targets of known relevance to ND in vivo. This article summarizes recent findings of PET and SPECT studies using these novel methods, and discusses their potential role in the field of drug development for ND as well as future clinical applications in regard to differential diagnosis of ND and monitoring of disease progression.
A fisiopatologia das doenças neurodegenerativas (DN), tais como a doença de Alzheimer (DA) e a doença de Parkinson (DP), ainda não é completamente compreendida. No entanto, nos últimos anos, houve grandes avanços em termos do conhecimento sobre proteínas intra e extracelulares, tais como beta-amiloide (Aβ), α-sinucleína, proteína tau e marcadores neuroinflamatórios, que podem ter sua função ou expressão prejudicada na DA, DP ou em outras DN. Progressos recentes nas técnicas de tomografia por emissão de pósitrons (PET) e tomografia computadorizada por emissão de fóton único (SPECT) permitem hoje em dia a identificação não invasiva de tais alvos moleculares in vivo. Este artigo resume descobertas recentes de estudos de PET e SPECT cerebral usando esses alvos moleculares inovadores e discute o papel potencial dessas técnicas no campo do desenvolvimento de novos medicamentos para as DN, bem como futuras aplicações clínicas em relação ao diagnóstico diferencial e monitoramento da progressão dessas doenças.
Assuntos
Animais , Humanos , Doenças Neurodegenerativas , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão de Fóton Único , Doença de Alzheimer , Biomarcadores/metabolismo , Imagem Molecular/tendências , Doença de ParkinsonRESUMO
The pathophysiology of neurodegenerative diseases (ND) such as Alzheimer's disease (AD) and Parkinson's disease (PD) has not yet been completely elucidated. However, in the past few years, there have been great knowledge advances about intra-and extracellular proteins that may display impaired function or expression in AD, PD and other ND, such as amyloid beta (Aß), α-synuclein, tau protein and neuroinflammatory markers. Recent developments in the imaging techniques of positron emission tomography (PET) and single photon emission computed tomography (SPECT) now allow the non-invasive tracking of such molecular targets of known relevance to ND in vivo. This article summarizes recent findings of PET and SPECT studies using these novel methods, and discusses their potential role in the field of drug development for ND as well as future clinical applications in regard to differential diagnosis of ND and monitoring of disease progression.
Assuntos
Doenças Neurodegenerativas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão de Fóton Único , Doença de Alzheimer/diagnóstico por imagem , Animais , Biomarcadores/metabolismo , Humanos , Imagem Molecular/tendências , Doença de Parkinson/diagnóstico por imagemRESUMO
The present review is aimed at updating the reader with the current role of computed tomography (CT) and magnetic resonance imaging (MRI) in the evaluation of tumor response, contextualizing the imaging methods advantages and limitations. CT has been the most frequent and widely adopted diagnostic tool. The main advantages of such method include wide availability, high reproducibility, capability to contemporarily evaluate soft tissues, bone and lung parenchyma, besides being easy to perform. Its main limitation is related to the use of ionizing radiation. MRI has emerged as a feasible alternative to CT, particularly in patients with contraindications to the use of iodinated contrast agents, with advantages related to its high soft tissues contrast. The disadvantages are based on its operational complexity and the many technical variables involved which may influence and compromise the reproducibility and broad implementation of the method. New criteria for evaluation of tumor response have recently been proposed, contemplating lately developed drugs and therapeutic strategies that demand the utilization of functional parameters. In this context, the technological developments incorporated in the CT and MRI imaging techniques, such as perfusion analysis, diffusion studies (DW-RM) and MR spectroscopy (MRS), among others, have provided relevant information regarding the tumor response to targeted therapies, anticipating dimensional alterations and guiding physicians in the course of the treatment. Despite such developments, further efforts are needed to establish reproducible protocols, functional response criteria and time intervals for response evaluation in order to allow a definitive incorporation of these new technologies in the assessment of tumor response.
Assuntos
Imageamento por Ressonância Magnética/tendências , Imagem Molecular/tendências , Neoplasias/diagnóstico , Neoplasias/terapia , Avaliação de Resultados em Cuidados de Saúde/tendências , Técnica de Subtração/tendências , Tomografia Computadorizada por Raios X/tendências , Humanos , Espectroscopia de Ressonância Magnética/métodos , Resultado do TratamentoRESUMO
Molecular imaging comprises non-invasive monitoring of functional and spatiotemporal processes at molecular and cellular levels in living systems. Advanced imaging techniques can monitor such processes. Peptide receptors over-expressed in tumours can be targeted by peptides conjugated to radionuclides, near-infrared fluorochromes, metallic nanoparticles or quantum dots for target-specific cancer imaging.