Functionalizing Liposomes with anti-CD44 Aptamer for Selective Targeting of Cancer Cells

CD44 receptor protein is found to be overexpressed by many tumors and is identified as one of the Moist common cancer stem, cell surface markers including tumors affecting colon, brat, pancreas, and head and neck, making this an attractive receptor for therapeutic targeting. In this study, 2'-F-pyrimidine-containing RNA aptamer (Apt1); previously selected against CD44, was successfully conjugated to the surface of PEGylated liposomes using the thiol-maleimide click reaction. The conjugation of Apt1, to the surface of liposomes was confirnied by the change in site and zeta potential and by migration on agarose gel electrophoresis. The binding affinity of Apt1 was improved after Conjugation compared to free-Aptt. The cellular uptake for Aptl-Lip was tested by flow cytometry and confocal imaging using the two CD44(+) cell lines, human lung cancer cells (A549) and human breast cancer cells (MDA-M.13-231), and the CD44(-) cell line, mouse embryonic fibroblast cells,(NIH/3T3). The results showed higher sensitivity and selectivity for Aptl-Lip compared to the blank liposomes (Mal-Lip). In conclusion; we demonstrate a successful conjugation of anti-C44 aptarner to the surface of liposome and binding preference of Aptl-Lip to CD44-expressing cancer cells and conclude to,a promising potency of Aptl-Lip as a specific drug delivery system.