pH‐sensitive folic acid/poly(vinyl pyrrolidone) functionalized MnFe₂O₄/single‐walled carbon nanotubes for release of a natural anticancer agent: Chlorogenic acid

Abstract

Despite promising features of chlorogenic acid (CGA) as an antioxidant and anticancer agent, short pharmacological half‐life constrains its application in cancer treatment. This work was aimed at developing a new nanocarrier with pH‐sensitive release behavior for CGA. In this direction, a porous nanohybrid, poly(vinyl pyrrolidone)/MnFe2O4/single‐walled carbon nanotube–folic acid (PVP/MnFe2O4/SWCNT–FA) was prepared by in situ coprecipitation of manganese and iron salts in the oxidized SWCNT suspension, followed by wrapping of PVP and then conjugating of FA on the magnetic SWCNTs. Afterward, the nanohybrid was loaded with CGA to form a carrier. The PVP/MnFe2O4/SWCNT–FA was characterized using Fourier transform infrared spectra, X‐ray diffraction, FE‐SEM/energy dispersive X‐Ray analysis spectroscope, TGA, and BET, confirming a well‐defined porous structure consisting of numerous functional groups. The CGA loading was carried out through the adsorption process. Adsorption equilibrium was reached within 60 min at pH 5.0. The experimental adsorption data showed an excellent nonlinear correlation coefficient with the simplified Elovich kinetic model and two‐step isotherm model. The CGA release was studied in simulated normal physiological fluid (pH 7.4) and simulated acidic tumor fluid (pH 5.6) over 6 h. The release rate from CGA loaded PVP/MnFe2O4/SWCNT–FA achieved 79.5% at pH 5.6, which was much higher than at pH 7.4 (37.2%), reflecting the acidic medium could markedly improve drug release. In addition, the Peppas–Sahlin model was more appropriate than the Higuchi and Korsmeyer–Peppas models to describe CGA release kinetics from the nanocarrier. In vitro cell viability studies indicated that PVP/MnFe2O4–SWCNT–FA had better biocompatibility in comparison with SWCNTs. Our findings indicate that the designed magnetic nanocarrier has acceptable performance to be used as a pH‐sensitive drug system with low toxicity for targeted drug delivery applications.