Polymeric Drug Delivery System with Actively Targeted Cell Penetration and Nuclear Targeting for Cancer Therapy

Targeted tumor cell killing using polymeric micelles with active targeting strategies has been demonstrated to be effectively therapeutic for liver cancers. To implement this strategy, enhancing the cellular uptake of the drug delivery system with targeted anticancer drugs, such as doxorubicin toward nuclear targeting, is of vital importance for increasing drug efficiency and reducing the systemic side effects of encapsulated drugs. In this study, a multifunctional polymeric drug delivery system was designed with actively targeted cell penetration and nuclear targeting for efficient cancer therapy. The nanocarriers were self-assembled from poly(ethylene glycol)-block-poly(epsilon-caprolactone), decorated with folic acid (FA-PECL) for active targeting via amide reaction for selective delivery of drugs to tumors. A cell penetration peptide (CPP) was decorated with doxorubicin (DOX), and the conjugate (CPP-DOX) was encapsulated in the carrier system for efficient cell penetration and nuclear targeting of drugs. An in vitro study showed an enhanced in vitro cytotoxicity and showed that the tumor volume decreased more than 5 times compared with the nontargeted system, by utilizing the drug-loaded system (FA-PECL/CPP-DOX) with active tumor cell targeting and subsequent nuclear targeting. The FA-PECL/CPP-DOX drug-loading system was well-targeted and enriched on tumor sites, resulting in significant suppression of the liver tumor growth.