表面修饰富勒烯的聚酰胺-胺树枝状分子与生物膜的相互作用研究

采用粗粒化的分子动力学模拟,研究了末端修饰富勒烯(C60)的聚酰胺-胺(PAMAM)树枝状分子在水溶液中的结构变化以及其与磷脂膜相互作用行为.发现修饰后的PAMAM分子大小随嫁接数目的增多而减小,而形状变化并不明显,分子仍是近球形结构;同时发现C60分子因疏水作用聚集在一起.与膜作用后,因C60分子插入到双层膜内,导致分子由球形稍微向椭球形改变,分子大小也稍微增大.同时发现PAMAM分子紧紧分布在磷脂膜表面,局域膜厚度变小.     

ANALYSIS OF A MIXED FINITE ELEMENT METHOD FOR A PHASE FIELD BENDING ELASTICITY MODEL OF VESICLE MEMBRANE DEFORMATION

In this paper, we study numerical approximations of a recently proposed phase fieldmodel for the vesicle membrane deformation governed by the variation of the elastic bend-ing energy. To overcome the challenges of high order nonlinear differential systems and thenonlinear constraints associated with the problem, we present the phase field bending elas-ticity model in a nested saddle point formulation. A mixed finite element method is thenemployed to compute the equilibrium configuration of a vesicle membrane with prescribedvolume and surface area. Coupling the approximation results for a related linearized prob-lem and the general theory of Brezzi-Rappaz-Raviart, optimal order error estimates for thefinite element approximations of the phase field model are obtained. Numerical results areprovided to substantiate the derived estimates.