ZnO-based nanocarriers for drug delivery applications

The Enhanced Permeability and Retention (EPR) effect is a crucial mechanism in passive tumor targeting, characterized by the selective accumulation of macromolecules in tumor tissues due to the unique vascular networks of tumors.Tumors exhibit hyperpermeable blood vessels, reduced lymphatic drainage, and high interstitial fluid pressure, leading to the retention of therapeutic nanoparticles, ideally up to 100 nm in size.Zinc oxide (ZnO) nanoparticles are promising drug delivery systems due to their unique physicochemical properties and anticancer activity.Surface functionalization with folic acid (FA) enhances their uptake by cancer cells, exploiting the overexpression of folate receptors, minimizing ZnO cytotoxicity to healthy cells, and stabilizing the drug-carrier system.This master thesis investigates the synthesis of ZnO nanoparticles, their surface conjugation with FA, and the encapsulation of these complexes into Poloxamer 407 polymeric nanoparticles.The produced ZnO and ZnO-FA nanoparticles were characterized using FESEM, XRD, FTIR, UV-Vis, PL and DLS.XRD analysis confirmed a crystalline hexagonal structure for ZnO with a crystallite size of 7.1 nm and 4.7 nm for ZnO@FA.DLS analysis revealed nanoparticle sizes of 95.3 nm for ZnO and 134.4 nm for ZnO@FA, with low polydispersity and zeta potentials of -31.8 mV and -19.9 mV, respectively.The functionalization of ZnO with FA was confirmed by FTIR and UV-Vis spectra.Encapsulation in Poloxamer 407 polymeric nanoparticles resulted in improved stability, with particle sizes below 140 nm and enhanced EPR effect, supporting the intravenous delivery of these systems with further optimization for size and stability.