High-quantity capture of heterogeneous circulating tumor cells in vivo based on a multinanobody-functionalized carboxymethyl cellulose cryogel

Circulating tumor cells (CTCs) carry multidimensional information from primary tumors, yet current separation strategies lead to insufficient quantity of cells available for robust downstream analyses. To address this issue, we propose an in-vivo capture strategy for high-quantity CTC enrichment based on a multinanobody-functionalized carboxymethyl cellulose cryogel (MNB-PAACcryo). By addressing the trade-off between pore size and mechanical property, the MNB-PAACcryo sets up a sieving barrier in the bloodstream. It allows free passage of blood cells through its interconnected macropores, while enhancing CTC-nanobody interactions, contributing to a high CTC capture efficiency of 72.3 ± 4.5% in the bloodstream. Consequently, up to 2.7 × 103 CTCs could be harvested from 4000 mL blood at 1 CTC/mL using 0.1 cm3 of the MNB-PAACcryo. In vivo experiments on cancer rat models demonstrated that the MNB-PAACcryo could capture diverse CTC subtypes across multiple cancers, and the captured CTCs exhibited consistent information with the primary tumor tissues. With its robust capability for high-quantity CTC enrichment, the proposed strategy will not only improve the reliability of CTC-based cancer analysis, but may also facilitate the establishment of patient-derived tumor organoid, showing great potential to accelerate the development of personalized cancer medicine.