Peptide-based biosensing approaches for targeting breast cancer-derived exosomes.

Exosomes are nanovesicles present in all the biological fluids, making them attractive as non-invasive biomarkers for diseases like cancer, among many others. However, exosomes are complex to separate and detect, requiring comprehensive molecular characterization for their routine use in diagnostics. This study explores the use of peptides as cost-effective and stable alternatives to antibodies for exosome binding.

Magnetic Separation of Cell-Secreted Vesicles with Tailored Magnetic Particles and Downstream Applications.

The analysis of the receptors on the surface of the cell-secreted vesicles provides valuable information of the cell signature and may also offer diagnosis and/or prognosis of a wide range of diseases, including cancer.Due to their low concentration, conventional procedures for extracellular vesicle (EV) detection usually require relatively large sample volumes, involving preliminary purification or preconcentration steps from complex specimens. Here, we describe the separation and preconcentration in magnetic particles of extracellular vesicles obtained from cell culture supernatants from MCF7, MDA-MB-231, and SKBR3 breast cancer cell lines, human fetal osteoblastic cell line (hFOB), and human neuroblastoma SH-SY5Y cell line, as well as exosomes from human serum.

Electrochemical Genosensing of Overexpressed GAPDH Transcripts in Breast Cancer Exosomes.

Exosomes are receiving highlighted attention as new biomarkers for the detection of cancer since they are profusely released by tumor cells in different biological fluids. In this paper, the exosomes are preconcentrated from the serum by immunomagnetic separation (IMS) based on a CD326 receptor as a specific epithelial cancer-related biomarker and detected by glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcripts. Following the lysis of the captured exosomes, the released GAPDH transcripts are amplified by reverse transcription polymerase chain reaction (RT-PCR) with a double-tagging set of primers on poly(dT)-modified-MPs to increase the sensitivity.

Advances in exosome analysis.

There is growing demand for novel biomarkers that detect early stage disease as well as monitor clinical management and therapeutic strategies. Exosome analysis could provide the next advance in attaining that goal. Exosomes are membrane encapsulated biologic nanometric-sized particles of endocytic origin which are released by all cell types.

The activity of alkaline phosphatase in breast cancer exosomes simplifies the biosensing design.

This work addresses a biosensor combining the immunomagnetic separation and the electrochemical biosensing based on the intrinsic ALP activity of the exosomes. This approach explores for the first time two different types of biomarkers on exosomes, in a unique biosensing device combining two different biorecognition reaction: immunological and enzymatic. Besides, the intrinsic activity of alkaline phosphatase (ALP) in exosomes as a potential biomarker of carcinogenesis as well as osseous metastatic invasion is also explored.

Comparative Study of Gold and Carbon Nanoparticles in Nucleic Acid Lateral Flow Assay.

A lateral flow assay (LFA) is a paper-based, point-of-need test designed to detect a specific analyte in complex samples in low-resource settings. Although LFA has been successfully used in different applications, its use is still limited when high sensitivity is required, especially in the diagnosis of an early-stage condition. The limit of detection (LOD) is clearly related to the signal-generating system used to achieve the visual readout, in many cases involving nanoparticles coupled to a biomolecule, which, when combined, provides sensitivity and specificity, respectively.