| Abstract [eng] |
Master thesis of Danielius Nasonkinas, scientific supervisor doc. dr. Nora Šlekienė. Vilnius University. Faculty of Medicine. Institute of Biomedical Sciences. Center of Pharmacy and Pharmacology Title of the study: Investigation of the interactions between different forms of amphotericin B and bovine serum albumin. Amphotericin B is an effective antifungal drug; however, its use is limited by toxicity and its tendency to aggregate in aqueous media. Incorporating the drug into nanocarriers may change its interaction with biological macromolecules; therefore, it is important to evaluate the interaction of different drug forms with serum albumin. Aim of the study: Using the quartz crystal microbalance with dissipation monitoring method, to evaluate the interaction of free, liposomal, and graphene oxide-bound amphotericin B with bovine serum albumin by determining binding kinetics, affinity, and the viscoelasticity of the formed layer. Tasks of the research: 1.To investigate the interaction of amphotericin B with bovine serum albumin by determining the binding kinetics, affinity, and viscoelasticity of the formed layer. 2.To investigate the interaction of liposome-modified amphotericin B with bovine serum albumin by determining the binding kinetics, affinity, and viscoelasticity of the formed layer. 3.To investigate the interaction of a mixture of amphotericin B and graphene oxide with bovine serum albumin, determining the binding kinetics, affinity, and viscoelasticity of the formed layer. 4.Based on quartz crystal microbalance with dissipation monitoring data, compare the interaction characteristics (kinetic constants and viscoelasticity of the formed layer) of different forms of amphotericin B with bovine serum albumin. Methodology of the research: Three amphotericin B systems were used in the study: free, liposomal and graphene oxide-associated amphotericin B. Their optical properties were evaluated using ultraviolet and visible light spectroscopy, while the interaction with an immobilized bovine serum albumin layer was investigated using quartz crystal microbalance with dissipation monitoring. A two-step irreversible mathematical model was applied to calculate kinetic and affinity parameters. Results of the research: Ultraviolet and visible light spectroscopy analysis showed that an absorption signal characteristic of amphotericin B was registered in all systems; however, the spectral parameters differed depending on the carrier and concentration. Quartz crystal microbalance with dissipation monitoring studies showed that free amphotericin B formed a stiffer and less hydrated layer, whereas liposomal and graphene oxide-associated amphotericin B caused greater dissipation changes. Free amphotericin B had the lowest dissociation rate constant (kd = 7.77 × 10⁻⁵ s⁻¹), indicating the formation of the most kinetically stable complex with the investigated protein. The amphotericin B and graphene oxide mixture had the highest association rate constant (ka = 5488.16 M⁻¹s⁻¹), but also the highest dissociation rate (kd = 1.14 × 10⁻³ s⁻¹), indicating the most dynamic interaction. The affinity parameters remained within the same order of magnitude (KD = 1.10–3.14 × 10⁻⁷ M). Conclusion of the research: Liposomes and graphene oxide did not eliminate the interaction of amphotericin B with albumin, but modified its kinetics and the viscoelastic properties of the formed layer. Keywords: amphotericin B, liposomes, graphene oxide, bovine serum albumin, quartz crystal microgravimetry with dissipation monitoring. Participation in conferences: Nasonkinas, Danielius; Šlekienė, Nora. Study of the Interaction of Different Forms of Amphotericin B with Bovine Serum Albumin Using the QCM-D Method. The LXXVIII Conference of the Student Scientific Activity Network: Vilnius, 8 May 2026: conference abstracts. Vilnius University Press (Appendix 1). |
