Antibody–Calixarene Drug Conjugate: A General Drug Delivery Platform for Tumor-Targeted Therapy

Antibody–drug conjugates (ADCs), which combine the precise targeting capabilities of antibodies with the powerful cytotoxicity of small-molecule drugs, have evolved into a promising approach for tumor treatment. However, the traditional covalent coupling method requires the design of a specific linker tailored to the properties of the small-molecule drugs, which greatly limits the development of ADCs and the range of drugs that can be used. Herein, a novel type of antibody–calixarene drug conjugates (ACDCs) that function similarly to ADCs by delivering drugs to their targets using antibodies but without the requirement of covalent conjugation of the drugs with antibodies is presented. By replacement of conventional linkers with supramolecular linkers, the ACDCs can load various chemotherapeutic drugs through host–guest interactions. Furthermore, ACDCs are readily reduced upon reaching the hypoxic microenvironment, resulting in rapid release of the drugs. With this precise drug encapsulation and controlled release mechanism, ACDCs deliver drugs to tumor tissues effectively and achieve a significantly enhanced antitumor effect. Considering that the ACDCs can be easily prepared by combining antibody–calixarene conjugates derived from tumor-targeting antibodies with various small-molecule drugs, ACDCs may provide a promising platform technology to accelerate ADC development and thus improve the therapeutic efficacy of chemotherapy.