A redox-sensitive micelle-like nanoparticle self-assembled from amphiphilic adriamycin-human serum albumin conjugates for tumor targeted therapy

The application of chemotherapeutic drug adriamycin (ADR) in cancer therapy is limited by its side effects like high toxicity and insolubility. Nanomedicine offers new hope for overcoming the shortcomings. But how to increase in vivo stability and to control intracellular drug release is a key issue for nano-based formulations. Herein, the hydrophobic ADR was successfully linked to the biocompatible human serum albumin (HSA) by disulfide bond 3-(2-pyridyldithio) propionyl hydrazide (PDPH), resulting in amphiphilic HSA-ADR. The novel ADR-HSA micellar NPs which were thus assembled exhibited a well-defined stable core shell structure with glutathione (GSH) sensitive linkers. The stable PDPH linkers at extracellular level were broken by GSH at intracellular level with a controlled ADR release profile. The in vitro cytotoxicity against gastric cancer cells (NCI-N87) was obviously enhanced by such redox-sensitive ADR-HSA NPs. Additionally, as observed by IVIS Lumina II Imaging System (Xenogen), the intratumor accumulation of ADR-HSA NPs was much higher than that of HSA/ADR NPs due to its high stability. Consequently, the in vivo tumor inhibition was significantly promoted after intravenous administration to the Balb/c nude mice bearing gastric tumors. These in vitro/vivo results indicated that disulfide-bond-containing ADR-HSA NPs were an effective nanodrug delivery system for cancer therapy.