Monitoring of circulating exosomal immuno checkpoint in the tumor microenvironment

Researchers report the fabrication of ultrasensitive biosensors based on Surface-enhanced Raman Spectroscopy (SERS) to detect the cancer metastasis related programmed death ligand (PD-L1) biomarker.

In this research, scientists at the Hefei Institutes of Physical Science (HFIPS) fabricated highly sensitive and specific aptamer-functionalized probes based on Au/TiO2/Fe3O4 (shell/core) magnetic nanocomposites and Ag/4-ATP/Au (shell/core) SERS nanotags.

Using the “sandwich” approach, they captured the malignant exosomes between magnetic nanocomposites and SERS nanotags with which they could quantitatively measure the PD-L1 biomarker as low as 4.31 ag/mL by analyzing the Raman report signals.

Schematic representation of circulating exosomal PD-L1 detection using SERS-sandwich

In the mice model, the researchers confirmed that the proposed technique could be useful in analyzing time dependent growth of tumors by analyzing enhancement in PD-L1 expression in tumor.

Moreover, the researchers demonstrated the applicability of their work by integrating nanoparticles probes with portable Raman spectrometer to realize the PD-L1 measurement with 95% sensitivity.

Overall, the outcome of this work demonstrates the great clinical significance of PD-L1 biomarker diagnosis which in future would be helpful in monitoring the patients’ health who undergo PD-L1/PD-1 immunotherapy.

Source – Hefei Institutes of Physical Science (HFIPS)

Muhammad M, Shao CS, Liu C, Song G, Zhan J, Huang Q. (2022) Monitoring of circulating exosomal immuno checkpoint in tumor microenvironment through ultrasensitive aptamer-functionalized SERS probes. Biosensors and Bioelectronics [Epub ahead of print]. [article]

Leave a Reply

Your email address will not be published. Required fields are marked *