Nanoplasmonic Sensor Approaches for Sensitive Detection of Disease-Associated Exosomes

Abstract

Exosomes are abundantly secreted by most cells that carry membrane and cytosolic factors that can reflect the physiologic state of their source cells and thus have strong potential to serve as biomarkers for early diagnosis, disease staging, and treatment monitoring. However, traditional diagnostic or prognostic applications that might use exosomes are hindered by the lack of rapid and sensitive assays that can exploit their biological information. An array of assay approaches have been developed to address this deficit, including those that integrate immunoassays with nanoplasmonic sensors to measure changes in optical refractive indexes in response to the binding of low concentrations of their targeted molecules. These sensors take advantage of enhanced and tunable interactions between the electron clouds of nanoplasmonic particles and structures and incident electromagnetic radiation to enable isolation-free and ultrasensitive quantification of disease-associated exosome biomarkers present in complex biological samples. These unique advantages make nanoplasmonic sensing one of the most competitive approaches available for clinical applications and point-of-care tests that evaluate exosome-based biomarkers. This review will briefly summarize the origin and clinical utility of exosomes and the limitations of current isolation and analysis approaches before reviewing the specific advantages and limitations of nanoplasmonic sensing devices and indicating what additional developments are necessary to allow the translation of these approaches into clinical applications.

A state-of-the-art review of the recent advances in exosome isolation and detection methods in viral infection

“…This was discovered in a recent study that used an asymmetric flow field-flow fractionation approach to isolate vesicles by their relative density and hydrodynamic properties. Distinguishing and isolating these exosome subpopulations, however, requires a labor-intensive workflow that necessitates large samples, expensive equipment, and skilled labor, making clinical applications unlikely absent significant methodological improvement [ 39 , 40 ]. Exosomes may be isolated in sufficient quantities and with adequate purity, thanks to the rapid development of scientific and technological methods.…”

“…There is an excellent potential for exosomes to serve as biomarkers for early diagnosis, illness staging, and therapy monitoring since they are released abundantly by most cells and contain membrane and cytosolic components that might reflect the physiologic condition of their parent cells. Although exosomes may be helpful in conventional diagnostic or prognostic applications, the absence of quick and sensitive tests that may harness their biological information has limited their use [ 40 ]. Exosome research is exploding as a promising biomarker for disease diagnosis, prognosis, and treatment monitoring (in conditions like cancer, infectious diseases, and neurodegenerative diseases).…”

Clinical Impact of Exosomes in Colorectal Cancer Metastasis

“…Exosome-based cancer profiling transformed the liquid biopsy method with higher specificity. − CRC-derived exosomes are a source of cancer biomarkers (Figure ). One study found that the cellular component of exosomes includes microRNA, long noncoding RNA, and proteins that act as biomarkers (diagnostic and prognostic).…”

Autonomous Microlasers for Profiling Extracellular Vesicles from Cancer Spheroids

“…1−3 Besides their pivotal role as biomarkers, exosomes are associated with various biological processes such as cell−cell communication, proliferation, differentiation, and therapeutics. 4,5 However, like all other cell-secreted analytes, exosomes circulate in our tissues and bloodstreams with an inhomogeneous distribution. Origin differences and local concentration differences may also contribute to different levels of biomarker expressions.…”

“…Cell secretion is a fundamental yet critical process in cell biology in which proteins, ions, and metabolites are released into the surrounding extracellular environment. Likewise, exosomes are tiny vesicles known for carrying a multitude of bioactive cargoes (protein, DNA, and RNA) of the parent cells that travel in our body fluids. − Besides their pivotal role as biomarkers, exosomes are associated with various biological processes such as cell–cell communication, proliferation, differentiation, and therapeutics. , However, like all other cell-secreted analytes, exosomes circulate in our tissues and bloodstreams with an inhomogeneous distribution. Origin differences and local concentration differences may also contribute to different levels of biomarker expressions …”