Controlled released dynamics of methotrexate from chitosan-based capsules: A detailed energy landscape analysis

Polymeric membranes are extensively used to construct vehicles for various drug delivery applications. In this study, we investigated the potential of chitosan-based membranes as a carrier for the controlled release of methotrexate (MTX), a widely used drug in cancer treatment. The chitosan (CS) chains were cross-linked with sodium tripolyphosphate (STPP) to form a rigid matrix capable of encapsulating MTX. Molecular dynamics simulations were employed to assess the performance of the CS-based membranes in releasing MTX upon exposure to water. We have calculated the potential of mean force to understand the energy landscape in the aqueous medium or ethanol-water solution. We have observed that the free energy in the ethanol-water solution reduced to ∼52.4 kcal/mol as compared to an aqueous solution. In addition, we have shown the effect of the concentration of STPP on the binding of CS with MTX. Understanding how STPP concentration affects MTX release is crucial for designing drug delivery systems. By adjusting the concentration of STPP, one can fine-tune the release profile of the drug. We have also shown the comparative study of energy requirement to release a drug molecule from the CS matrix with and without STPP molecules. The pair correlation displayed that the water molecules have a stronger interaction with the STPP molecules compared to CS chains and MTX molecules. Our findings indicate that the CS nanoparticles exhibit promising characteristics for controlled drug release, making them a potential candidate for improving the efficacy and safety of MTX therapy in cancer treatment. [Display omitted]