The aim of the present study was to investigate the interfacial behaviour of model biomembranes in the presence of β-carotene (βC). The Langmuir monolayer technique was used to form the mixed lipid film at the air/water interface. Using the surface pressure-area isotherms, the surface potential-area curves and the Brewster angle microscopy the nature of interactions between carotenoid and lipid components of the monolayers was investigated. The results were obtained for complex models of the lipid bilayer composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and cholesterol (CHOL). It was found that β-carotene affected the membrane stability, fluidity and rigidity, however this influence varied with the DPPC/CHOL ratio. The membrane permeability which is significant for biological functions was found to be affected by the presence of β-carotene in the membrane. The morphology of mixed films visualized by Brewster angle microscopy was similar for DPPC/CHOL and DPPC/CHOL/βC films indicating incorporation of carotenoid into the film. In contrary to previous reports for individual lipids, we did not observed the aggregation of βC in the mixed lipid monolayer. Moreover, from dilatational rheology experiment we concluded about the significant role of β-carotene in modulation of the elastic behaviour of the membrane, especially in physiologically significant surface pressure, i.e. at π = 30 mN/m.

本研究的目的是研究在存在β-胡萝卜素（βC）的情况下模型生物膜的界面行为。Langmuir单层技术用于在空气/水界面处形成混合脂质膜。使用表面压力-面积等温线，表面电位-面积曲线和布鲁斯特角显微镜研究了单层类胡萝卜素和脂质成分之间相互作用的性质。对于由1,2-二棕榈酰-sn-甘油-3-磷酸胆碱（DPPC）和胆固醇（CHOL）组成的脂质双层的复杂模型，获得了结果。发现β-胡萝卜素影响膜的稳定性，流动性和刚度，但是这种影响随DPPC / CHOL比的变化而变化。发现对于生物功能而言重要的膜渗透性受膜中β-胡萝卜素的存在的影响。通过Brewster角显微镜观察的混合膜的形态对于DPPC / CHOL和DPPC / CHOL /βC膜是相似的，表明类胡萝卜素掺入到膜中。与以前关于单个脂质的报道相反，我们没有在混合脂质单层中观察到βC的聚集。此外，从膨胀流变学实验中，我们得出结论，β-胡萝卜素在调节膜的弹性行为方面具有重要作用，特别是在生理上重要的表面压力（即π= 30 mN / m）上。通过Brewster角显微镜观察的混合膜的形态对于DPPC / CHOL和DPPC / CHOL /βC膜是相似的，表明类胡萝卜素掺入到膜中。与以前关于单个脂质的报道相反，我们没有在混合脂质单层中观察到βC的聚集。此外，从膨胀流变学实验中，我们得出结论，β-胡萝卜素在调节膜的弹性行为方面具有重要作用，特别是在生理上重要的表面压力（即π= 30 mN / m）上。通过Brewster角显微镜观察的混合膜的形态对于DPPC / CHOL和DPPC / CHOL /βC膜是相似的，表明类胡萝卜素掺入到膜中。与以前关于单个脂质的报道相反，我们没有在混合脂质单层中观察到βC的聚集。此外，从膨胀流变实验中，我们得出结论，β-胡萝卜素在调节膜的弹性行为方面具有重要作用，尤其是在生理上重要的表面压力（即π= 30 mN / m）上。