Morphology regulation and aminophenylboronic acid-functionalized 1,5-diaminoanthraquinone microrod films for capture of circulating tumor cells

The capture of circulating tumor cells (CTCs) is important for the early diagnosis and prognosis of tumor patients. The most related research is mainly focused on epithelial cell adhesion molecule (EpCAM)-positive CTCs. The capture of EpCAM-negative cells such as HeLa cells need to develop novel strategies to solve. On the other hand, new substrates are needed developed to effectively capture CTCs. In this work, 1,5-diaminoanthraquinone microrods (DAAQ-R) films with different morphologies are prepared via high-temperature sublimation or room-temperature evaporation. The microrod films are modified with polyethyleneimine (PEI) for forming DAAQ-R/PEI films with positive surface potentials. DAAQ-R/PEI films are then used as substrates for capturing HeLa cells. This research shows that the cell capture efficiencies are related to the morphologies of the DAAQ-R/PEI films due to the surface potentials of the substrates depending on their morphologies. Furthermore, to enhance the capture efficiency of HeLa cells, DAAQ-R/PEI films are functionalized with aminophenylboronic acid (APBA) to generate DAAQ-R/PEI/APBA film. The APBA can interact with sialic acid (SA) on the surfaces of cancer cells, resulting in that the capture efficiency of DAAQ-R/PEI/APBA film to HeLa cells reached 85.6 %. This substrate can be used to isolate CTCs in clinic blood samples of cancer patients. This study provides valuable guidance for isolation of CTCs and further study of tumors.