Peroxynitrite (ONOO−) generation from the HA-TPP@NORM nanoparticles based on synergistic interactions between nitric oxide and photodynamic therapies for elevating anticancer efficiency

Due to biological safety and negligible toxicity, nitric oxide (NO) therapy has gained increasing interest in the field of cancer therapy during the past few years. However, individual NO cancer therapy normally exhibited limited therapeutic efficiency. In order to acquire satisfactory therapeutic outcomes, the NO therapy is usually combined with other therapeutic treatments, mostly chemotherapy. Herein, we constructed HA-TPP@NORM nanoparticles based on the co-assembly of an NO donor (NORM) and tetraphenylporphyrin (TPP)-modified hyaluronic acid, which can efficiently generate a highly biocidal molecule of peroxynitrite (ONOO−) via the synergistic interactions of the nitric oxide (NO) therapy and photodynamic therapy (PDT) to enhance the cancer therapeutic efficiency. In addition, MTT results exhibited that without light irradiation, the HA-TPP@NORM nanoparticles have favourable biocompatibility with the cell viability above 95% at the maximum TPP concentration (20 μg mL−1). Under simultaneous irradiation with 365 nm and 650 nm light, ONOO− can be efficiently produced in cancer cells via the direct coupling reaction of the generated NO and superoxide anion radical (O2˙−), which significantly enhanced the anticancer effect, when compared with individual NO therapy or PDT therapy. Therefore, the HA-TPP@NORM nanoparticles may provide a new insight into the design of efficiently NO-related cancer therapeutic systems.