Aptamers are single-stranded DNA or RNA with 20-100 nucleotides in length that
can specifically bind to target molecules via formed three-dimensional structures. These innovative
targeting molecules have attracted an increasing interest in the biomedical field. Compared
to traditional protein antibodies, aptamers have several advantages, such as small size,
high binding affinity, specificity, good biocompatibility, high stability and low immunogenicity,
which all contribute to their wide application in the biomedical field. Aptamers can bind
to the receptors on the cell membrane and mediate themselves or conjugated nanoparticles to
enter into cells. Therefore, aptamers can be served as ideal targeting ligands for drug delivery.
Since their excellent properties, different aptamer-mediated drug delivery systems had been
developed for cancer therapy. This review provides a brief overview of recent advances in
drug delivery systems based on aptamers. The advantages, challenges and future prospectives
are also discussed.