Developments of Aptamer–Drug Conjugates for Targeted Cancer Therapy

Conventional cancer treatments have various off-targeted side effects. A specific targeting small molecule, an aptamer, maybe a solution to the off-target side effects of cancer. Aptamer targets can range from small molecules and heavy metal ions to larger ligands such as proteins and the whole cell. Preclinical studies related to cancer therapy suggest that aptamers have target specificity, nonimmunogenicity, and the capability of carrying a payload to the cell. Due to the small size of aptamers, they can be excreted by the kidneys and sometimes have a short half-life in serum, often making them unusable for therapeutic purposes. As a result, several improvements were made to the aptamer to make it more stable and suitable for therapy. Based on the scientific and clinical development of aptamers as drugs, several are currently in clinical trials for cancer treatment. In this chapter, we explore the principle, properties, structure, modifications, and current scenarios of aptamer in onco-therapeutic applications.