Investigation of the effects exerted by different physical and chemical agents on biological and model-membranes is of prominent importance. Recently, a general trend can be observed in the formulation of drugs: incorporation of the drugs into liposomes. Knowledge of the molecular interactions between the transporting lipids and the incorporated agents is therefore very important. Nowadays, the increased environmental UV radiation requires investigation of the effects of the UV radiation exerted on biological membranes. Beside of modeling biological effects, studies on the effects of the UV radiation on model membranes can result in new knowledge on the stability of the liposomes containing phototoxic drugs. During my study, three different methods (EPR spectroscopy, DSC and light scattering measurements) have been applied to investigate the molecular interactions between drugs and the lipid molecules. Derivatives of the morphine as well as the (fluoro)quinolones mainly interact with the headgroups of the lipid molecules resulting in an increase of the molecular ordering of the lipids. My observation that drugs with protonable/deprotonable groups can modify the membrane-fluidity due to specific, local interactions with the lipid/stearic acid molecules of a membrane depending on the pH as well, call attention to choose optimal pH-interval for such drug formulations. Investigating the UVA effect on human fibroblast cell line I concluded that a decrease in the membrane fluidity due to UVA radiation can be detected only at doses higher, than 150 kJ/m2, and close to the lipid head groups.
|Number of pages||8|
|Journal||Acta pharmaceutica Hungarica|
|Publication status||Published - Dec 1 2005|
ASJC Scopus subject areas
- Pharmaceutical Science