Tumor-targeted and pH-controlled delivery of doxorubicin using gold nanorods for lung cancer therapy

Background: In lung cancer, the efficacy of conventional chemotherapy is limited due to poor drug accumulation in tumors and nonspecific cytotoxicity. Resolving these issues will increase therapeutic efficacy. Methods: GNR-Dox-Tf-NPs (gold nanorod-doxorubicin-transferrin-nanoparticles) were prepared by different chemical approaches. The efficacy of these nanoparticles was carried out by cell viability in lung cancer and primary coronary artery smooth muscle cells. The receptor-mediated endocytosis studies were done with human transferrin and desferrioxamine preincubation. The GNR-Dox-Tf nanoparticles induced apoptosis, and DNA damage studies were done by Western blot, H2AX foci, and comet assay. Results: We developed and tested a gold nanorod-based multifunctional nanoparticle system (GNR-Dox-Tf-NP) that carries Dox conjugated to a pH-sensitive linker and is targeted to the transferrin receptor overexpressed in human lung cancer (A549, HCC827) cells. GNR-DoxTf- NP underwent physicochemical characterization, specificity assays, tumor uptake studies, and hyperspectral imaging. Biological studies demonstrated that transferrin receptor-mediated uptake of the GNR-Dox-Tf-NP by A549 and HCC827 cells produced increased DNA damage, apoptosis, and cell killing compared with nontargeted GNR-Dox-NP. GNR-Dox-Tf-NP-mediated cytotoxicity was greater (48% A549, 46% HCC827) than GNR-Dox-NP-mediated cytotoxicity (36% A549, 39% HCC827). Further, GNR-Dox-Tf-NP markedly reduced cytotoxicity in normal human coronary artery smooth muscle cells compared with free Dox. Conclusion: Thus, GNR-Dox-Tf nanoparticles can selectively target and deliver Dox to lung tumor cells and alleviate free Dox-mediated toxicity to normal cells.