Abstract
Objective
Indirubin (IND), a natural antitumor alkaloid, exhibits poor solubility, low bioavailability, and non-specific toxicity, limiting its clinical application against lung cancer. This study aimed to construct a polyethylene glycol (PEG)-functionalized single-walled carbon nanotube (SWCNT)-based nanoplatform (IND/SW-PEG) and evaluate its anti-lung cancer efficacy.
Methods
IND/SW-PEG was prepared via non-covalent adsorption and PEG surface modification. Drug loading efficiency, physicochemical properties, and pH-responsive drug release were characterized. Cytotoxicity, photothermal effect, and apoptosis induction were evaluated in A549 lung cancer cells and TC-1 normal lung epithelial cells using CCK-8 assay and flow cytometry.
Results
The optimal SWCNT-to-IND mass ratio was 1:1, yielding a drug loading efficiency of 25.7%. IND/SW-PEG exhibited significantly higher cumulative drug release at pH 5.0 (mimicking tumor microenvironment) than at pH 7.4. The IC
50
value of IND/SW-PEG against A549 cells was 98.2 μg/mL, equivalent to 76.56 μM indirubin. Combined with 808 nm near-infrared light irradiation, its anticancer potency was further improved, and concentration-dependent cell apoptosis was verified experimentally.
Conclusion
The IND/SW-PEG nanoplatform integrates chemotherapy and photothermal therapy, showing selective cytotoxicity, pH-responsive drug release, and potential to overcome current limitations of indirubin-based lung cancer treatment. Further in vivo studies are warranted to support clinical translation.