Redox-responsive nano-micelles containing trisulfide bonds to enhance photodynamic efficacy of zinc naphthalocyanine

A novel amphiphilic polymer with the trisulfide bond was developed. The nano-micelles could be formed through the self-assembling of this polymer with hydrophobic zinc naphthalocyanine, a NIR-absorbing photosensitizer. The micelles showed unique rods, high drug loading, high stability, high sensitivity to GSH, and excellent biosafety. The singlet oxygen production quantum yield of micelles was obviously higher than that of free photosensitizers and micelles containing disulphide bonds in the simulated tumor environment. The phototoxicity of micelles in cancer cells was significant. The redox response drug-loaded micelle was promising to enhance the photodynamic efficacy of zinc naphthalocyanine in cancer cells.