Fabrication of aptamer decorated dextran coated nano-graphene oxide for targeted drug delivery

• Dextran (DEX) was covalently conjugated to the surface of GO sheets.
• Biocompatible dextran coated nano-GO (GO-DEX) was prepared.
• AS1411 aptamer has been introduced to hydroxyl groups of DEX in GO-DEX.
• Curcumin was loaded onto the GO-DEX and GO-DEX-Apt via π-π stacking interactions.
• The GO-DEX-Apt-CUR nano-complex showed significantly higher cytotoxicity.

In the current study, dextran (DEX) was covalently conjugated to the surface of nano-GO sheets, making stable biocompatible dextran coated GO (GO-DEX). The prepared GO-DEX was nontoxic to 4T1 mammary carcinoma cell line at concentrations up to 300 μg/mL.AS1411 aptamer, a ssDNA aptamer which can improve the intracellular uptake by nucleolin recognition, also has been introduced to hydroxyl groups of DEX in GO-DEX to produce GO-DEX-Apt. Moreover, curcumin (CUR), a natural polyphenol, found in the rhizomes of Curcuma longa (turmeric) which shows antineoplastic effects, was loaded onto the GO-DEX and GO-DEX-Apt via π-π stacking interactions with a high loading capacity (∼29 wt%). The GO-DEX-Apt-CUR could efficiently enter into 4T1 and MCF-7 nucleolin over-expressed cancer cells confirmed by fluorescence microscope and flowcytometry, and it also showed significantly higher cytotoxicity. These types of targeted nanoscale drug delivery vehicles on the basis of DEX coated GO may find potential application in cancer chemotherapy.