Synthesis of a chitosan/g-C₃N₅/ferrite carrier and evaluation of its performance in the loading and controlled release of doxorubicin: optimization of the process by RSM

In this research, a compound of chitosan/N-rich graphitic carbon nitride/calcium ferrite (CS/g-C₃N₅/CaFe₂O₄) was synthesized for the targeted delivery and controlled release of the anticancer drug doxorubicin (DOX). Optimization of the loading process through response surface methodology (RSM) revealed that over 76% of DOX was successfully loaded onto CS/g-C₃N₅/CaFe₂O₄ under optimal conditions (60 min contact time, carrier dose of 0.15 g, DOX concentration of 50 mg L^-1, and pH of 7.5). Analysis of the RSM-optimized data using different kinetic and isothermal models demonstrated that the loading of DOX onto CS/g-C₃N₅/CaFe₂O₄ fits well with Ho's pseudo-2nd-order kinetic model (<i>k</i> = 0.02 g mg^-1 min^-1) and the Temkin isotherm model (<i>B</i>₁ = 13.15 mg g^-1 and <i>K</i>_T = 0.19 L g^-1), indicating significant drug-carrier electrostatic interactions. This was inferred by comparing the FT-IR spectra of the carrier before and after drug loading. The drug release study results showed the release of 100% of DOX under simulated cancerous cell conditions (pH 5.6) compared with 33% under physiological conditions (pH 7.4) over a period of 6 h. Pharmacokinetic studies indicated that the release data under pH 5.6 correlated best with the Hixson-Crowell model (<i>k</i> = 0.0041 h^-0.33), suggesting that the drug release is associated with the carrier's dissolution under mildly acidic conditions. Overall, the bionanomagnetic composite created from CS/g-C₃N₅/CaFe₂O₄ serves as a promising platform for drug delivery, thanks to its notable features such as magnetic targeted delivery and pH-controlled release.