Quantum Insights into Partially Molecular Imprinted Microspheres for Anticancer Therapeutics: Experimental and Theoretical Studies.

Abstract

Drug solubility is a determining factor for controlled release, and solubility-dependent release kinetics can be modified by changing the drug's state in the polymer matrix through partial molecular imprinting (PMI), although research in this area remains limited. This novel PMI approach creates nanocavities within the polymer by partially retaining the imprinting molecule and trapping the drug. Such a method holds promise for developing advanced biomaterial-based drug delivery systems for anticancer therapies. In this study, we developed microspheres designed for anticancer drug delivery utilizing PMI to enhance controlled release properties. Poly(vinyl alcohol) (PVA) microspheres were partially imprinted with aspirin (ASP) to create nanocavities for gemcitabine (GEM) molecules, inducing a polymorphic shift of GEM within the polymer matrix. This novel PMI approach enhanced drug release properties by enabling control over the drug crystallinity and release rate. The PVA-ASP-GEM complex showed zero-order release kinetics, releasing 21.6% of GEM over 48 h, maintaining steady state release profile. In contrast, nonimprinted PVA-GEM microspheres exhibited first-order kinetics with a faster release of 46.85% in the same period. Quantum insights from density functional theory (DFT) calculations revealed the superior stability of the PVA-ASP-GEM complex, with a binding free energy of -56.03 kcal/mol, compared to -29.07 kcal/mol for PVA-GEM. Molecular dynamics (MD) simulations demonstrated that ASP's presence created nanocavities that restricted GEM's movement, further contributing to the controlled release. Experimental validation through differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Raman spectroscopy confirmed the polymorphic transitions within the PVA-ASP-GEM complex. This PMI-based approach offers a promising method for modulating drug release kinetics and improving the stability of anticancer therapeutics, paving the way for innovative biomaterial-based drug delivery systems.