PEGylated hyaluronidase/NIR induced drug controlled release system for synergetic chemo-photothermal therapy of hepatocellular carcinoma

In recent years, cancer treatment has been facing the challenge of increasing antitumor efficiency and avoiding severe adverse effects simultaneously. In this study, we designed a controlled release drug delivery system , doxorubicin (Dox)-loaded and hyaluronic acid (HA)-modified PEGylated gold nanocages (AuNCs), which was designated as PEG-HAn-AuNCs/Dox (n represented 10 n HA repeating units were modified on each AuNC). In this system, AuNCs were applied as the photothermal cores, Dox was employed as the model drug, HA was applied as the tumor-microenvironment responsive switch to achieve controlled release, and poly (ethylene glycol) (PEG) was used as the stealth polymer to prolong systemic circulation time. Firstly, we evaluated the physical and chemical properties of the PEG-HAn-AuNCs/Dox with different ratios of HA to AuNC and found that PEG-HA4-AuNCs/Dox was the optimal. Secondly, PEG-HA4-AuNCs/Dox revealed the feature of controlled release, namely, the drug release was triggered by hyaluronidase (HAase) and accelerated by the acidic pH and near-infrared (NIR) irradiation. And then PEG-HA4-AuNCs/Dox could be effectively delivered to a cultured SMMC-7721 cell line in vitro and the tumor tissues of the subcutaneous mouse models of hepatocellular carcinoma (HCC) in vivo . Finally, the results demonstrated the synergetic therapy, namely the combination of chemotherapy and photothermal therapy (PTT) (defined as chemo-photothermal therapy) mediated by PEG-HA4-AuNCs/Dox, could efficiently inhibit the tumor growth both in vitro and in vivo . Therefore, the advantages of PEG-HA4-AuNCs/Dox endowed it as a great potential candidate for HCC treatment.