Aptamers as Smart Ligands for Targeted Drug Delivery in Cancer Therapy

Undesirable side effects and multidrug tolerance are the main holdbacks to the treatment of cancer in conventional chemotherapy. Fortunately, targeted drug delivery can improve the enrichment of drugs at the target site and reduce toxicity to normal tissues and cells. A targeted drug delivery system is usually composed of a nanocarrier and a targeting component. The targeting component is called a ligand. Aptamers have high target affinity and specificity, which are identified as attractive and promising ligands. Therefore, aptamers have potential application in the development of smart targeting systems. For instance, aptamers are able to efficiently recognize tumor markers such as nucleolin, mucin, and epidermal growth factor receptor (EGFR). Besides, aptamers can also identify glycoproteins on the surface of tumor cells. Thus, the aptamer-mediated targeted drug delivery system has received extensive attention in the application of cancer therapy. This article reviews the application of aptamers as smart ligands for targeted drug delivery in cancer therapy. Special interest is focused on aptamers as smart ligands, aptamer-conjugated nanocarriers, aptamer targeting strategy for tumor microenvironment (TME), and aptamers that are specified to crucial cancer biomarkers for targeted drug delivery.

Automated summary

Undesirable side effects and multidrug tolerance are major challenges in conventional chemotherapy for cancer treatment. Targeted drug delivery using aptamers as smart ligands can enhance drug accumulation at the target site and minimize toxicity to normal tissues and cells. Aptamers have high target affinity and specificity, making them attractive ligands for targeted drug delivery. This article reviews the application of aptamers in cancer therapy, focusing on their use as smart ligands, conjugation with nanocarriers, targeting strategies for the tumor microenvironment, and specific aptamers for crucial cancer biomarkers.