ZSM-5/PEG/DOX nanocarrier for pH-responsive doxorubicin release: Kinetic, isothermal, and cytotoxic studies

Abstract

The application of ZSM-5/PEG nanoparticles as a drug carrier for the adsorption and release of doxorubicinas an anti-cancer drug was investigated. ZSM-5 zeolite was pegylated at different ratios, and ZSM-5/PEG with a mass ratio of (10:4) exhibited the best drug loading and loading efficiency of 83 % (14 mg/g). The carrier showed pH-responsive behaviour, releasing 65 % of the drug at pH 5.6 and 21 % at pH 7.4. The differential scanning calorimetry (DSC) approved the thermal stability of ZSM-5/PEG carrier under body conditions. The absorption models revealed that drug absorption onto ZSM-5/PEG followed the Freundlich model ($R^2$ = 0.93), indicating multilayered absorption of DOX on ZSM-5/PEG nanoparticles. Moreover, the results of kinetic studies confirmed that among the different kinetic models, the Korsmeyer-Peppas model effectively described the release behaviour from the carrier. The values of n and K for the Korsmeyer-Peppas model resulted in 0.22 and 0.36, respectively, indicating that doxorubicin release from ZSM-5/PEG nanocarrier had a slow releasing rate and followed Fick's law. MTT assay showed that loading the DOX on the ZSM-5/PEG nanoparticles increased their cytotoxic effects on the HCT-116 cell line by almost 10 times with the lowest IC₅₀ values(38.1, 10.4, and 2.33 μg/ml for 24 h, 48 h, and 72 h after treatment, respectively). The study found that ZSM-5/PEG/DOX has the potential to treat cancer as a pH-sensitive and slow-releasing drug.