Aptamer-Driven Nanovehicles for Targeted Therapy of HER2 Overexpressing Breast Cancer Cells

Aptamers are single-stranded small nucleotide segments capable of interacting with numerous biomolecules with solid affinity and have gained significant attention in cancer biomarkers and targeted therapy. Recently, a drug delivery nanovehicle incorporating an anticancer compound targeting the HER2 receptor in breast cancer has been developed. This demonstrates how useful aptamer-based nanovehicles are for creating indicators unique to cancer, reducing side effects, and enhancing treatment effectiveness. The interior of the nanovehicle contains a protamine-aptamer complex that binds to epigallocatechin gallate (EGCG: an anticancer medication), while the surface comprises a HER2 affinity aptamer. The nanovehicle is a carrier bound to cancer cells and transports the anticancer medication into them. Our hypothesis is that the HB5 aptamer on the nanovehicle surface interacts with the particular HER2 receptor area to identify HER2+ cancer cells. AlphaFold web server was used for the HER2 receptor 3D structure. We conducted in silico investigations to estimate aptamers' three-dimensional structure and interactions with HER2 and protamine. We discovered that the surface aptamer creates a particular linear shape necessary for HER2 receptor interactions. The inner aptamer is small and forms a patterned structure with the protamine, releasing EGCG into the cytoplasm in the presence of abundant cytoplasmic ATP. These findings would benefit in understanding aptamer-receptor binding, cancer medicine release mechanism, and creating a possible accurate and safe drug-delivery vehicle.