DPPC/胆固醇混合LB膜的AFM研究

用LB膜技术将二棕榈酰磷脂酰胆碱(DPPC)和胆固醇的混合液转移到疏水云母上,并利用原子力显微镜(AFM)在空气中表征了LB膜的性质。结果表明,当C(DPPC)∶C(cho lestero l)=2.6∶1,膜压15mN/m时,能形成有缺陷的LB膜。并分析了这种缺陷LB膜的形成过程。此法制得的LB膜接近受损伤的肾上皮细胞膜,用于诱导晶体生长,从而建立受损伤的肾上皮细胞膜导致肾结石形成的化学模型。

AFM STUDIES ON LB FILMS OF MIXED DPPC/CHOLESTEROL

Mixed 1,2-dipalmitoyl-Sn-glycero-3-phosphocholine(DPPC) and cholesterol monolayers have been deposited on mica using the Langmuir-Blodgett(LB) technique and then the films were characterized by atomic force microscopy(AFM).Investigation with AFM revealed that the defects come into being when DPPC to cholesterol equals(2.6) to 1.The defects formation of the mixed LB films is concluded:(a) the mixed LB films rupture and the molecules on the films reform many microsystems when the films are being dried;(b) microsystems coalesce into big microsystems since the liquid molecules always move;(c) the boundary lipids shrink towards circle with interfacial tension,thus the circle defects form.We can orient crystal growth induced by the LB films since they are similar to the pathologic cell membranes of kidney,which provides a few important implications for understanding of renal calculus.