Recent advances in nanotechnology-enabled biosensors for detection of exosomes as new cancer liquid biopsy

Abstract

Cancer liquid biopsy detects circulating biomarkers in body fluids, provides information that complements medical imaging and tissue biopsy, allows sequential monitoring of cancer development, and, therefore, has shown great promise in cancer screening, diagnosis, and prognosis. Exosomes (also known as small extracellular vesicles) are cell-secreted, nanosized vesicles that transport biomolecules such as proteins and RNAs for intercellular communication. Exosomes are actively involved in cancer development and progression and have become promising circulating biomarkers for cancer liquid biopsy. Conventional exosome characterization methods such as quantitative reverse transcription polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) are limited by low sensitivity, tedious process, large sample volume, and high cost. To overcome these challenges, new biosensors have been developed to offer sensitive, simple, fast, high throughput, low sample consumption, and cost-effective detection of exosomal biomarkers. In this review, we summarized recent advances in nanotechnology-enabled biosensors that detect exosomal RNAs (both microRNAs and mRNAs) and proteins for cancer screening, diagnosis, and prognosis. The biosensors were grouped based on their sensing mechanisms, including fluorescence-based biosensors, colorimetric biosensors, electrical/electrochemical biosensors, plasmonics-based biosensors, surface-enhanced Raman spectroscopy (SERS)-based biosensors, and inductively coupled plasma mass spectrometry (ICP-MS) and photothermal biosensors. The future directions for the development of exosome-based biosensors were discussed.

Exploring the Versatility of Exosomes: A Review on Isolation, Characterization, Detection Methods, and Diverse Applications

“…To address this, various signal magnification tactics have been presented to increase sensitivity of detection, such as nanomaterial-based and DNA-based signal amplification . Magnification of specific nucleic acid sequences with high sensitivity, good reproducibility, and fast response properties, including DNA-based signal amplification, hybridization chain reaction, rolling circle magnification, and hyper-branched rolling, can lead to signal amplification . In particular, the use of nanomaterials, which possess high thermal conductivity, high adsorption capacity, high biocompatibility, and high specific surface area, can raise the efficiency of electronic transmission and improve the loading capacity of signal molecules .…”

“…199 Magnification of specific nucleic acid sequences with high sensitivity, good reproducibility, and fast response properties, including DNAbased signal amplification, hybridization chain reaction, rolling circle magnification, and hyper-branched rolling, can lead to signal amplification. 200 In particular, the use of nanomaterials, which possess high thermal conductivity, high adsorption capacity, high biocompatibility, and high specific surface area, can raise the efficiency of electronic transmission and improve the loading capacity of signal molecules. 201 The inception of these signal magnification strategies significantly improves susceptibility, enabling detection of tumor exosomes even at low concentrations, thus making early tumor diagnosis possible.…”

Nanomaterials for Molecular Detection and Analysis of Extracellular Vesicles

“…Among the emerging molecular characterization techniques, nanotechnology is playing an important role, due to the unique structure and functional properties of materials at the nanometer scale [ 26 , 27 , 28 , 29 , 30 , 31 ]. Nanomaterials exhibit exceptional functional properties that are often not available from discrete molecules and bulk materials.…”

The therapeutic bionanoscience interface

“…In this thematic issue, there are six mini-reviews and two original research articles targeting, toxicology, 1 pathogen and exosome detection, 2,3 spinal cord injury, 4 tissue scaffolds, 5 molecular barcoding, 6 RNA biology, 7 and bio-hybrid electronic devices 8 that bridge biology with nanotechnology and the bionanoscience interface.…”

“…Hsu and Wu 3 review nano-enabled biosensors for the detection of cancer exosomes from liquid biopsies. Recent advances in nano-enabled biosensors that can detect cancer-specific exosomal RNAs and proteins will aid in cancer screening, diagnosis, and prognosis.…”