Metastasis is responsible for most deaths of cancer burdens. Given that metastatic cancer cells are generally
very low in quantity but high in multiplicity, and able to migrate to diverse organs, the diagnosis and intervention of metastatic
cancers face varieties of challenges. For example, the biomarker for early diagnosis, and detection of circulating
tumor cells by way of epithelial cell adhesion molecule, are complicated by the epithelial-mesenchymal-transition (EMT).
Enhanced permeation and retention have been widely explored but with limitations, especially for microscale metastatic
tumors. Furthermore, drug-resistance and side-effects of chemotherapy remain problematic for diverse cancers. Interfaces
of cells play essential roles in many physiological activities including signal transduction and immunological recognition,
which can be exploited for medical application of interfacial materials; indeed, given unique chemical and physical interfacial
properties, numerous micro/nano particles and interfacial materials exhibit great potentials for diagnosis and intervention
of metastatic cancers. Here we highlight current research, opportunities and challenges for application potentials
of biological interfacial engineering in diagnosis and intervention of metastatic cancers.