Significantly enhanced capture efficiency of cell-imprinted material for circulating tumor cells via a flexible and ultra-strong double-armed phenylboronic acid design

Circulating tumor cells (CTC) have been incontrovertibly regarded as a critically essential detection tool within the realm of cancer combat, being decidedly preferred by oncology clinicians and serving as the preponderant primary targets for single-cell analysis. However, several challenges hinder the effective capture of CTC from blood, including their rarity, heterogeneity across cancer types, the complexity of the blood environment, and potential damage to cell viability. Here we design a flexible double-armed phenylboric acid (DPBA) that targets double-branched sialylated glycans (SGs) on the surface of liver CTC. The binding affinity of DPBA (200 nM) is 33 times greater than that of typical phenylboric acid, as confirmed by glycoproteomics analysis demonstrating a strong prevalence for SGs. By copolymerization of DPBA with polyethylene glycol dimethacrylate (PEGDMA), using SMMC-7721 cells as templates, we developed a cell-imprinted hydrogel featuring compact polymeric networks interconnected by both chemical crosslinking and hydrogen bonding. This hydrogel exhibits an ultra-low swelling capacity of 5 %, effectively preserving the nano- and micro-morphologies of cell imprinting. It also demonstrates low protein adhesion, appropriate elasticity and reversibility, as well as satisfactory blood and cell compatibility. The high affinity for double-branched SGs and clear cell imprinting endow the material with precise capture efficiency for CTC, enabling accurate discrimination between liver cancer patients and healthy individuals, with an excellent area under the curve (AUC) of 0.99 and a high classification accuracy of 96 %. Importantly, the captured CTC could be released alive for genomics analysis. The material costs just 1.98 dollars per sample, which is only 1/200th of the typical medical price. This study highlights the significant potential of flexible double-armed molecular design in the development of CTC capture materials, which will promote downstream single-cell multi-proteomics analysis and facilitate early cancer diagnostics.