Folic acid-modified laponite nanodisks for targeted anticancer drug delivery

We report here an effective approach to modifying laponite (LAP) nanodisks with folic acid (FA) for targeted anticancer drug delivery applications. In this approach, LAP nanodisks were first modified with 3-aminopropyldimethylethoxysilane (APMES) to render them with abundant surface amines, followed by conjugation with FA via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) chemistry. The formed FA-modified LAP nanodisks (LM-FA) were then used to encapsulate anticancer drug doxorubicin (DOX). The surface modification of LAP nanodisks and the subsequent drug encapsulation within the LAP nanodisks were characterized via different techniques. We show that the LM-FA is able to encapsulate DOX with an efficiency of 92.1 ± 2.2%, and the formed LM-FA/DOX complexes are able to release DOX in a pH-dependent manner with a higher DOX release rate under acidic pH conditions than under physiological pH conditions. The encapsulation of DOX within LM-FA does not compromise its therapeutic activity. Importantly, the formed LM-FA/DOX complexes are able to specifically target cancer cells overexpressing high-affinity FA receptors as confirmed via flow cytometric analysis and confocal microscopic observation, and exert specific therapeutic efficacy to the target cancer cells. The developed FA-modified LAP nanodisks may hold great promise to be used as an efficient nanoplatform for targeted delivery of different anticancer drugs.