Efficient Capture and High Activity Release of Circulating Tumor Cells by Using TiO₂ Nanorod Arrays Coated with Soluble MnO₂ Nanoparticles

Effective capture and release of circulating tumor cells (CTCs) with high viability is still a challenge in medical research. We design a novel approach with efficient yield and high cell activity for the capture and release of CTCs. Our platform is based on TiO2 nanorod arrays coated with transparent MnO2 nanoparticles. We use hydrothermal synthesis to prepare TiO2 nanorod arrays, the MnO2 nanoparticles are fabricated through in situ self-assembly on the substrate to form a monolayer and etched by oxalic acid with low concentration at room temperature. Up to 92.9% of target cells are isolated from the samples using our capture system and the captured cells can be released from the platform, the saturated release efficiency is 89.9%. Employing lower than 2 × 10–3 M concentration of oxalic acid to dissolve MnO2, the viability of MCF-7 cancer cells exceed 90%. Such a combination of the two-dimensional and three-dimensional platforms provides a new approach isolate CTCs from patient blood samples.