Biospecific Monolayer Coating for Multivalent Capture of Circulating Tumor Cells with High Sensitivity

The isolation and detection of rare circulating tumor cells (CTCs) from patient peripheral blood can help to monitor the metastatic spread of carcinoma and evaluate therapeutic outcomes. However, it is technically challenging to isolate CTCs due to extreme rarity in blood. Current techniques typically have to utilize complex instrumentation to capture CTCs, resulting in nonapplicability. Inspired from the mussel adhesion, a polyglycerol-based block polymer is used to fabricate a biospecific and bioinert interface for isolating CTCs with high selectivity and efficiency. Benefitting from the antifouling polyglycerol, the resulting monolayer coating greatly suppresses the nonspecific cells adhesion. Compared with one anti-epithelial cell adhesion molecule (anti-EpCAM), the CTCs' capture efficiency was improved to 95% when multiple receptors, i.e. anti-EpCAM/Human epithelial receptor 2 (Her2)/Epithelial Growth Factor receptor (EGFR) are employed, even for low EpCAM-expressing CTCs. The CTCs detection limit on the presented surface is as low as 1 cell mL(-1). Furthermore, CTCs are isolated from breast cancer patients' blood sample with a high selectivity. Also, the CTCs can be released and still keep proliferation capability for downstream analysis. This multifunctional block polymer surface coating is quite cost effective and highly applicable for CTCs' isolation in the clinic, which can provide a new prospect for designing the next-generation of bio/nanointerfaces for biomedical studies.