Liver-Targeting and pH-Sensitive Sulfated Hyaluronic Acid Mixed Micelles for Hepatoma Therapy

The tumor-targeting ability and pH-sensitive properties of intelligent drug delivery systems are crucial for effective drug delivery and anti-tumor therapy. In this study, sHA-DOX/HA-GA mixed micelles were designed with the following properties: sulfated hyaluronic acid (sHA) was synthesized to block cell migration by inhibiting HAase; sHA-DOX conjugates were synthesized via pH-sensitive hydrazone bond to realize DOX-sensitive release. The introduction of HA-GA conjugate could improve active-targeting ability and cellular uptake. The results showed that the mixed micelles possessed a nearly spherical shape, nanoscale particle size (217.70±0.89 nm), narrow size distribution (PDI=0.07±0.04), negative zeta potential (-31.87±0.61 mV) and pH-dependent DOX release. In addition, the sHA-DOX/HA-GA micelles exhibited concentration-dependent cytotoxicities against liver carcinoma cells (HepG2) and HeLa cells, and were shown to be effectively taken up by HepG2 cells by confocal microscopy analysis. Furthermore, the in vivo anti-tumor study showed that mixed micelles had a superior anti-tumor effect compared to that of free DOX. Further evidence obtained from the hematoxylin-eosin staining and immunohistochemistry analysis also demonstrated that sHA-DOX/HA-GA exhibited stronger tumor inhibition and lower systemic toxicity than free DOX. The sHA-DOX/HA-GA mixed micelles could be a potential drug delivery system for anti-hepatoma therapy.