A 'smart' aptamer-functionalized continuous label-free cell catch-transport-release system

Label-free cell sorting devices are of great significance for biomedical research and clinical therapeutics. However, current platforms for label-free cell sorting cannot achieve continuity and selectivity simultaneously, resulting in complex steps and limited reliability. Here, an immunoaffinity-based cell catch-transport-release thermo-chemo-mechanical coupling hydrogel (iCatch) device is reported. It contains a temperature-responsive hydrogel that can generate spatial movement synergically with the reversible binding of affinity handle modified. The functionalized hydrogel is embedded inside a biphasic microfluidic platform to enable cell transportation between the flows. The cell sorting capability and biocompatibility of the iCatch device were validated with CCRF-CEM cells as a proof-of-concept, and CCRF-CEM-specific aptamers with thermo-responsive affinity as well as a hydrogel with temperature-dependent volume were employed accordingly. A cell catching efficiency of similar to 40% and a recovery rate of similar to 70% were achieved. The iCatch device provides a high-throughput (similar to 900 cells mm(-1) s(-1)) platform for cell sorting and is ultimately valuable for downstream biomedical applications.

Automated summary

The iCatch device utilizes a temperature-responsive hydrogel and reversible binding of affinity handle modified to achieve cell capture, transportation, and release. Validated for biocompatibility and cell sorting capability, it achieves high capture efficiency and recovery rate.