DNA Framework-based Topological Aptamer for Differentiating Subtypes of Hepatocellular Carcinoma Cells

H epatocellular carcinoma(HCC) remains a global health challenge with a growing incidence worldwide. The accurate identification of liver HCC cell subtypes plays crucial roles in precision medicine and prognosis. Nevertheless, simple and efficient methods for cell subtype discrimination still remain an issue to be studied. In this study, we construct topological probes by using a tetrahedral DNA framework(TDF) to topologically engineer the spatial orientations of the aptamers. The three vertexes of a TDF were algebraic topologically anchored with aptamers targeting epithelial cell adhesion molecule(EpCAM), which may express differently on different subtypes of HCC cells. Using the TDF-based topological aptamer(TDF-TA), we accomplish the differentiation of HCC cell subtypes, including high-metastatic, low-metastatic HCC and normal cells based on flow cytometry(FCM) and fluorescence microscope imaging. By replacing the fluorescent indicator modified on aptamers with photoacoustic dyes, we achieve the discrimination of different HCC cells using photoacoustic imaging technology, further demonstrating the feasibility of the TDF-based topological probe for HCC cell subtype discrimination. This TDF-based topological engineering strategy thus provides a flexible means for subtype cell discrimination, which may provide new ideas for achieving accurate diagnosis of HCC.