Facile synthesis of a tumor microenvironment-responsive nanomaterial with metallic polyphenol-encapsulated for enhanced synergistic therapy

The tumor microenvironment (TME) differs from normal tissue cells in its physiological and biochemical characteristics. The construction of TME-responsive nanoplatforms requires a tedious preparation process and complex multicomponent modification. In this work, Er@EGCG-Cu, a TME-responsive nanoplatform, was simply and rapidly synthesized by combining rare earth-doped nanomaterials (NaLuF4:Yb,Er) with EGCG-Cu which is based on the ability of metal ions to coordinate with polyphenols to form a metal-phenolic network (MPN) structure. The MPN structure is then destroyed under an acidic TME, releasing the chemotherapy (CT) drug EGCG, which can cause apoptosis. CuxSy is generated by combining Cu2+ with H2S overexpressed in human colorectal cancer cells and can be used for photothermal therapy (PTT). Cell experiments show that laser irradiation improves the CT/PTT synergistic effect of Er@EGCG-Cu. This study has significance for the construction of TME-responsive nanomedicines with simple and rapid preparation for synergistic therapy.