RESUMO
The coronavirus disease 2019 (COVID-19) pandemic has highlighted the need for different types of diagnostics, comparative validation of new tests, faster approval by federal agencies, and rapid production of test kits to meet global demands. In this Perspective, we discuss the utility and challenges of current diagnostics for COVID-19.
Assuntos
Betacoronavirus , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Imunidade Adaptativa , Antígenos Virais/análise , Betacoronavirus/genética , Betacoronavirus/imunologia , COVID-19 , Técnicas de Laboratório Clínico/economia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Custos e Análise de Custo , Reações Cruzadas , Humanos , Imunidade Inata , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , RNA Viral/análise , RNA Viral/genética , SARS-CoV-2 , Testes Sorológicos/métodos , Pesquisa Translacional Biomédica , Estados Unidos/epidemiologia , Carga Viral/imunologiaRESUMO
This study evaluates µNMR technology for molecular profiling of tumor fine needle aspirates and peripheral blood of melanoma patients. In vitro assessment of melanocyte (MART-1, HMB45) and MAP kinase signaling (pERK, pS6K) molecule expression was performed in human cell lines, while clinical validation was performed in an IRB-approved study of melanoma patients undergoing biopsy and blood sampling. Tumor FNA and blood specimens were compared with BRAF genetic analysis and cross-sectional imaging. µNMR in vitro analysis showed increased expression of melanocyte markers in melanoma cells as well as increased expression of phosphorylated MAP kinase targets in BRAF-mutant melanoma cells. Melanoma patient FNA samples showed increased pERK and pS6K levels in BRAF mutant compared with BRAF WT melanomas, with µNMR blood circulating tumor cell level increased with higher metastatic burden visible on imaging. These results indicate that µNMR technology provides minimally invasive point-of-care evaluation of tumor signaling and metastatic burden in melanoma patients.
Assuntos
Melanócitos/patologia , Melanoma/diagnóstico , Células Neoplásicas Circulantes/patologia , Sistemas Automatizados de Assistência Junto ao Leito , Transdução de Sinais , Biópsia por Agulha Fina/métodos , Linhagem Celular Tumoral , Humanos , Imageamento por Ressonância Magnética/métodos , Melanócitos/metabolismo , Melanoma/sangue , Melanoma/metabolismo , Melanoma/patologia , Proteínas Quinases Ativadas por Mitógeno/análise , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Metástase Neoplásica/diagnóstico , Metástase Neoplásica/patologia , Proteínas Proto-Oncogênicas B-raf/análise , Proteínas Proto-Oncogênicas B-raf/metabolismoRESUMO
Low-cost, rapid and accurate detection technologies are key requisites to cope with the growing global cancer challenges. The need is particularly pronounced in resource-limited settings where treatment opportunities are often missed due to the absence of timely diagnoses. We herein describe a Holographic Assessment of Lymphoma Tissue (HALT) system that adopts a smartphone as the basis for molecular cancer diagnostics. The system detects malignant lymphoma cells labeled with marker-specific microbeads that produce unique holographic signatures. Importantly, we optimized HALT to detect lymphomas in fine-needle aspirates from superficial lymph nodes, procedures that align with the minimally invasive biopsy needs of resource-constrained regions. We equipped the platform to directly address the practical needs of employing novel technologies for "real world" use. The HALT assay generated readouts in <1.5 h and demonstrated good agreement with standard cytology and surgical pathology.
Assuntos
Holografia/métodos , Linfoma/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Imagem Óptica/métodos , Smartphone , Coloração e Rotulagem/métodos , Biópsia por Agulha Fina , Linfonodos/patologia , Linfoma/patologia , Microesferas , Fatores de TempoRESUMO
A new nucleic acid detection method was developed for a rapid and cost-effective diagnosis of infectious disease. This approach relies on the three unique elements: 1)â detection probes that regulate DNA polymerase activity in response to the complementary target DNA; 2)â universal reporters conjugated with a single fluorophore; and 3)â fluorescence polarization (FP) detection. As a proof-of-concept, the assay was used to detect and sub-type Salmonella bacteria with sensitivities down to a single bacterium in less than three hours.
Assuntos
Técnicas Biossensoriais/métodos , Doenças Transmissíveis/diagnóstico , DNA Polimerase Dirigida por DNA/química , Corantes Fluorescentes/química , Técnicas de Amplificação de Ácido Nucleico/economia , Técnicas de Amplificação de Ácido Nucleico/métodos , Ácidos Nucleicos/química , Salmonella/química , Sequência de Bases , Análise Custo-Benefício , DNA Polimerase Dirigida por DNA/metabolismo , Polarização de Fluorescência , Ácidos Nucleicos/análise , Ácidos Nucleicos/metabolismoRESUMO
The widespread distribution of smartphones, with their integrated sensors and communication capabilities, makes them an ideal platform for point-of-care (POC) diagnosis, especially in resource-limited settings. Molecular diagnostics, however, have been difficult to implement in smartphones. We herein report a diffraction-based approach that enables molecular and cellular diagnostics. The D3 (digital diffraction diagnosis) system uses microbeads to generate unique diffraction patterns which can be acquired by smartphones and processed by a remote server. We applied the D3 platform to screen for precancerous or cancerous cells in cervical specimens and to detect human papillomavirus (HPV) DNA. The D3 assay generated readouts within 45 min and showed excellent agreement with gold-standard pathology or HPV testing, respectively. This approach could have favorable global health applications where medical access is limited or when pathology bottlenecks challenge prompt diagnostic readouts.
Assuntos
Telefone Celular , Testes de DNA para Papilomavírus Humano/métodos , Infecções por Papillomavirus/diagnóstico , Lesões Pré-Cancerosas/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Alphapapillomavirus/genética , Alphapapillomavirus/fisiologia , Análise Custo-Benefício , Feminino , Interações Hospedeiro-Patógeno , Humanos , Processamento de Imagem Assistida por Computador/economia , Processamento de Imagem Assistida por Computador/instrumentação , Processamento de Imagem Assistida por Computador/métodos , Infecções por Papillomavirus/virologia , Lesões Pré-Cancerosas/virologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Telemedicina/economia , Telemedicina/instrumentação , Telemedicina/métodos , Fatores de Tempo , Neoplasias do Colo do Útero/virologiaRESUMO
The development of faster and more sensitive detection methods capable of identifying specific bacterial species and strains has remained a longstanding clinical challenge. Thus to date, the diagnosis of bacterial infections continues to rely on the performance of time-consuming microbiological cultures. Here, we demonstrate the use of bioorthogonal chemistry for magnetically labeling specific pathogens to enable their subsequent detection by nuclear magnetic resonance. Antibodies against a bacterial target of interest were first modified with trans-cyclooctene and then coupled to tetrazine-modified magnetic nanoprobes, directly on the bacteria. This labeling method was verified by surface plasmon resonance as well as by highly specific detection of Staphylococcus aureus using a miniaturized diagnostic magnetic resonance system. Compared to other copper-free bioorthogonal chemistries, the cycloaddition reaction reported here displayed faster kinetics and yielded higher labeling efficiency. Considering the short assay times and the portability of the necessary instrumentation, it is feasible that this approach could be adapted for clinical use in resource-limited settings.
Assuntos
Espectroscopia de Ressonância Magnética/instrumentação , Infecções Estafilocócicas/diagnóstico , Staphylococcus aureus/isolamento & purificação , Desenho de Equipamento , Humanos , Espectroscopia de Ressonância Magnética/economia , Fatores de TempoRESUMO
We have developed a compact and inexpensive microfluidic chip, the self-assembled magnetic filter, to efficiently remove magnetically tagged cells from suspension. The self-assembled magnetic filter consists of a microfluidic channel built directly above a self-assembled NdFeB magnet. Micrometre-sized grains of NdFeB assemble to form alternating magnetic dipoles, creating a magnetic field with a very strong magnitude B (from the material) and field gradient â½B (from the configuration) in the microfluidic channel. The magnetic force imparted on magnetic beads is measured to be comparable to state-of-the-art microfabricated magnets, allowing for efficient separations to be performed in a compact, simple device. The efficiency of the magnetic filter is characterized by sorting non-magnetic (polystyrene) beads from magnetic beads (iron oxide). The filter enriches the population of non-magnetic beads to magnetic beads by a factor of >10(5) with a recovery rate of 90% at 1 mL h(-1). The utility of the magnetic filter is demonstrated with a microfluidic device that sorts tumor cells from leukocytes using negative immunomagnetic selection, and concentrates the tumor cells on an integrated membrane filter for optical detection.
Assuntos
Separação Imunomagnética/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Animais , Linhagem Celular Tumoral , Desenho de Equipamento , Humanos , Separação Imunomagnética/economia , Leucócitos/citologia , Camundongos , Técnicas Analíticas Microfluídicas/economiaRESUMO
Nanoparticles have emerged as key materials for biomedical applications because of their unique and tunable physical properties, multivalent targeting capability, and high cargo capacity. Motivated by these properties and by current clinical needs, numerous diagnostic and therapeutic nanomaterials have recently emerged. Here we describe a novel nanoparticle targeting platform that uses a rapid, catalyst-free cycloaddition as the coupling mechanism. Antibodies against biomarkers of interest were modified with trans-cyclooctene and used as scaffolds to couple tetrazine-modified nanoparticles onto live cells. We show that the technique is fast, chemoselective, adaptable to metal nanomaterials, and scalable for biomedical use. This method also supports amplification of biomarker signals, making it superior to alternative targeting techniques including avidin/biotin.