AMP functionalized curdlan nanoparticles as a siRNA carrier: Synthesis, characterization and targeted delivery via adenosine A receptor.

Receptor-mediated endocytosis has been used for tissue targeted delivery of short interfering RNA (siRNA) drugs. Herein, we investigated adenosine receptor (AR) as a candidate for receptor-mediated siRNA internalization. We synthesized adenosine functionalized cationic curdlan derivatives (denote CuAMP polymers). One of these polymers, CuAMP4, efficiently delivered siRNA to breast cancer cells expressing high level of A receptor. The internalization of siRNA loaded CuAMP4 by cancer cells was inhibited by free AMP as well as endocytosis inhibitors. Moreover, knockdown of AR by siRNA, or pre-treatment of the cells with anti-AR antibody, strongly inhibited the cellular uptake of CuAMP4. Our findings confirmed that AR can be utilized for cell type specific siRNA delivery, and CuAMP4 NP may be a promising delivery system for cancer cell targeted delivery of therapeutic siRNAs.