Facile and green synthesis of pullulan derivative-stabilized Au nanoparticles as drug carriers for enhancing anticancer activity

In this work, we report for the first time AuNPs reduced/stabilized/capped with modified para-aminobenzoic acid-quat188-pullulan (PABA-QP) as excellent nanocarriers for delivery of doxorubicin to enhance the activity and safety of these systems. Spherical AuNPs@PABA-QP obtained by facile and green synthesis under optimum conditions were characterized by UV-VIS, TEM, EDS, SAED, XRD, ATR-FTIR and zeta-potential analyses and showed a narrow size distribution of 13.7 ± 1.9 nm. DOX was successfully loaded onto AuNPs@PABA-QP via intermolecular interactions with high drug loading. DOX-AuNPs@PABA-QP (IC₅₀ = 0.39μM) showed a 2.1-fold higher cytotoxicity against Chago cells than DOX alone (IC₅₀ = 0.82μM), while exhibiting less cytotoxicity against normal cells (Wi-38). Moreover, DOX-AuNPs@PABA-QP also demonstrated high intracellular uptake by endocytosis, arrested in S and G2-M phases of the cell cycle (total S/G2-M increased to approximately 18.0%), induced excellent cytotoxicity, and increased the fraction of late-apoptotic cells (18.6%). Consequently, it is suggested that the novel combination of DOX-AuNPs@PABA-QP has the potential to be developed for human cancer treatment.