Abstract
Background
Lung cancer is one of the most frequently diagnosed cancer all over the world and a leading cancer-related mortality. The therapy of lung cancer includes surgery, chemotherapy and radiatherapy and mailny depends on the type and stage of lung cancer characterized based on WHO guidelines. Althought the conventional chemotherapy is the main treatment option for small cell lung cancer (SCLC) and a common treatment for non-SCLC it is characterized with lack of specificity resulting to severe toxicities of normal cells and harmful side effects. Therefore, targeted drug delivery (TDD) systems have been used to reduce the systemic toxicity of some conventional chemotherapies in lung cancer. Quantum dots (QDs) are fascinating nanoscale crystals that can serve as nanocarriers in TDD due to their unique physicochemical properties. Therefore, in this paper, the as-desiged QDs, Ag-In-Zn-S-based nanoconjugates for selective doxorubicin (DOX) targeting to lung cancer cells were developed. The QD nanocrystals were modified with 11-mercaptoundecanoic acid (MUA), L-cysteine (Cys) and lipoic acid (LA) used as drug carriers for targeted delivery of DOX to A549 cells through conjugated folic acid (FA) a self-navigation molecule that docks to the folate receptors on cancer cells. The comprechensive physicochemical, cytotoxicity and genotoxicity studies were performed to characterise the novel QD-based nanocaries and their anticancer cargos.
Results
The results from FTIR, DLS and fluorescence quenching evidenced the successful attachment of FA to the QDs nanocrystals and DOX to the QDs-FA nanocarriers. UV-vis analysis determined the amount of FA and DOX covalently anchored to the QDs nanocrystal surface. Biological screeining revealed that QDs-FA-DOX nanoconjugates showed higher cytotoxicity in comparison to other forms of the synthesized QD samples, suggesting the cytotoxic effect of liberated DOX from the QD constructs. QD-MUA-FA-DOX occurred to be the most cytotoxic against A549 cells among nanoconjugates. In vitro scratch assay also revealed significant inhibition of A549 migration only due to treatment with QD-MUA-FA-DOX. Studies evidenced that all the nanoconjugates at IC 50 induced significantly more DNA breaks than that observed in non-treated cells. All in all, significant and the greatest cytotoxicity, genotoxicity together with inhibition of migratory potential of A549 cells was observed for QD-MUA-FA-DOX.
Conclusion
The studies show the therapeutic efficacy of DOX-loaded QD-based cargos suggesting their promising role as novel drug delivery systems navigating to folate receptors in lung cancer cells.
Folate Receptors’ Expression in Gliomas May Possess Potential Nanoparticle-Based Drug Delivery Opportunities
