Liposomal encapsulation of thymoquinone for drug delivery system, characterization of stability studies and in vitro anticarcinogenic effect on cervical cancer cells

In this thesis study, the use of thymoquinone (TQ), a biologically active compound derived from black seed oil, as a targeted drug carrier via liposomal systems was investigated. Due to the low water solubility and bioavailability of TQ, liposomal formulations were developed to enhance its stability and therapeutic efficacy. Three different formulations were prepared: blank liposomes, TQ-loaded liposomes (TQ-LP), and chitosan-coated TQ-loaded liposomes (CS-TQ-LP).Phospholipids extracted from egg yolk were used as the main structural components of the formulations. Liposomal structures were prepared using the thin-film hydration technique, followed by sonication and lyophilization. The formulations were characterized by particle size, zeta potential, polydispersity index (PDI), encapsulation efficiency, morphological analysis (TEM), FTIR, DSC, and XRD analyses. Encapsulation efficiency of TQ was determined by UV-vis spectrophotometry. The particle sizes of the blank, TQ-LP, and CS-TQ-LP formulations were measured as 265.1 nm, 222.3 nm, and 277.4 nm, respectively, while the zeta potentials were –27.19 mV, –36.96 mV, and –34.05 mV. Encapsulation efficiencies were over 94%. XRD and DSC analyses confirmed that TQ transitioned to the amorphous phase and was successfully integrated into the carrier matrix. TEM images revealed spherical and heterogeneous structures, while FTIR spectra indicated interactions between the components.Based on the findings, the encapsulated form of TQ demonstrated a more pronounced cytotoxic effect on HeLa cells, a cervical cancer model, indicating that the system offers advantages in terms of both targeted delivery and controlled release. Overall, the results suggest that the liposomal formulation of TQ can enhance its biological activity and represents a promising approach for targeted cancer therapies, particularly for cervical carcinoma.