Tumour microenvironment-responsive lipoic acid nanoparticles for targeted delivery of docetaxel to lung cancer.

In the present study, we developed a novel type of reduction-sensitive nanoparticles (NPs) for docetaxel (DTX) delivery based on cross-linked lipoic acid NPs (LANPs). The physicochemical properties, cellular uptake and in vitro cytotoxicity of DTX loaded LANPs (DTX-LANPs) on A549 cells were investigated. Furthermore, the in vivo distribution and in vivo efficacy of DTX-LANPs was evaluated. The results showed that DTX-LANPs had a particle size of 110 nm and a negative zeta potential of -35 mv with excellent colloidal stability. LANPs efficiently encapsulated DTX with a high drug loading of 4.51% ± 0.49% and showed remarkable reduction-sensitive drug release in vitro. Cellular uptake experiments demonstrated that LANPs significantly increased intracellular DTX uptake by about 10 fold as compared with free DTX. The cytotoxicity of DTX-LANPs showed significantly higher potency in inhibiting A549 cell growth than free DTX, while blank LANPs had a good biocompatibility. In addition, in vivo experiments demonstrated that DTX-LANPs could enhance tumour targeting and anti-tumour efficacy with low systemic toxicity. In conclusion, LANPs may prove to be a potential tumour microenvironment-responsive delivery system for cancer treatment, with the potential for commercialization due to the simple component, controllable synthesis, stability and economy.