Zwitterionic immunobeads may serve as an effective tool in cancer diagnostics

Tumor-derived microvesicle-associated miRNAs are found to be important biomarkers in detecting cancer.

Researchers at the Samsung Advanced Institute of Technology (Gyeonggi-do, South Korea), in collaboration with Yonsei University College of Medicine (Seoul, South Korea), have reported on the separation of total plasma and tumor-derived microvesicle (TMV)-associated miRNAs, which have been found to serve as important biomarkers in cancer diagnostics.

To date, due to the technological challenges of isolating TMVs from human plasma, it has not been possible to compare the two types of miRNAs and assess them as potential biomarkers for cancer detection. To address this issue, a team led by Myoyong Lee, a researcher at the Samsung Advanced Institute of Technology, prepared zwitterionic sulfobetaine-conjugated immunobeads using CD83 as a candidate protein marker for breast cancer-derived microvesicles. By suppressing nonspecific protein binding, the zwitterionic immunobeads were capable of isolating TMVs from clinical plasma samples with an efficiency that was found to be tenfold greater than that achieved by conventional immunobeads.

The team discovered that, using the sulfobetaine-modified immunobeads, early-stage breast cancer can be distinguished from benign breast disease more accurately than by conventional immunobeads, which were found to exhibit poor discriminatory performance. In addition, the results of the study indicated that miRNAs in the form of TMVs offer a major improvement over total plasma miRNAs for early cancer detection.

The team concluded that the zwitterionic immunobead platform may constitute a powerful tool for the identification of circulating biomarkers, with the potential to advance blood-based cancer diagnostics.

Source: Kim G, Yong Y, Kang HJ et al. Zwitterionic polymer-coated immunobeads for blood-based cancer diagnostics. Biomaterials 35(1), 294–303 (2013).