SPION loaded poly(L-lysine)/hyaluronic acid micelles as MR contrast agent and gene delivery vehicle for cancer theranostics

In this work we evaluated the ability of a SPION (Superparamagnetic iron oxide nanoparticle) loaded micelle system to safely and efficiently transfer foreign DNA into cells with the help of poly(L-lysine) (PLL) as DNA-carrier. Average particle size of PLL coated hyaluronic acid (HA) loaded SPION (PLL-HA-SPION) micelle was approximately 200 nm in size with spherical morphology. PLL-HA-SPION micelle was found to be nontoxic to the NIH3T3 (murine fibroblast cells) and the in vitro uptake was also tested in CT-26 (murine colon cancer cells) by prussian blue staining. Agarose gel retardation study showed the efficient binding of PLL-HA-SPION micelle with plasmid DNA (pLuc). The formed PLL-HA-SPION/pLuc complex could be efficiently transfected into CT-26 cell line. Finally, MR imaging was also used to check uptake property of SPION loaded in PLL-HA-SPION/DNA complex in vitro. The result showed that the PLL-HA-SPION micelle can be applied to MR imagingguided gene therapy in vivo and it is also advantageous for using this system for the magnetic hyperthermia based cancer therapy.