| Pancreatic ductal adenocarcinoma (PDAC) has an extremely dismal 5-year survival rate of only 6%. Highly specific targeting ligands that can aid in early stage diagnosis and improved treatment are urgently needed. To address the challenge, cell-SELEX was used to develop a panel of partially modified, 2'-F RNA aptamers that highly selectively recognize pancreatic ductal adenocarcinoma cells. One of the best aptamers, termed 1502, was optimized to be the shortest target-binding motif that retains the target-binding specificity and affinity, and further chemically synthesized with various 3' and 5' functional groups for characterization and application. Using hyperthermia treatment mediated by gold nanoparticles targeted with this optimized aptamer, it was found that the aptamer recognizes all the eleven pancreatic cancer cell lines we have tested, but not normal pancreas, nor numerous non-pancreatic cancer cells. Additionally, a hybrid lipid-PLGA nanoparticle was developed that can carry small molecule organic dyes or drugs for a therapeutic delivery application. With a 5'-modified variation of aptamer 1502, this nanoparticle was functionalized to target PDAC cells, and subsequently internalized to deliver a cytotoxic drug, resulting in selective cell-killing. We believe that this aptamer can be translated to in vivo delivery models and can be used to identify a putative novel biomarker of pancreatic ductal adenocarcinoma. |
