双链DNA生物膜弹性模量的蒙特卡罗模拟  

Monte Carlo simulation for elastic modulus of double-stranded DNA biofilm

作　　者：汤恒松 孟玮烈[1] 谭邹卿[1] 张能辉[1,2] 

机构地区：[1]上海市应用数学和力学研究所上海市力学在能源工程中的应用重点实验室,上海200072 [2]上海大学理学院,力学系上海200444

出　　处：《医用生物力学》2014年第5期459-464,共6页Journal of Medical Biomechanics

基　　金：国家自然科学基金资助项目(11272193,10872121);上海市重点学科建设资助项目(S30106)

摘　　要：目的 研究吸附于微悬臂梁基底上双链DNA生物膜的弹性模量.方法 采用基于中观连续介质液晶理论的Parsegian经验势,描述粗粒化DNA圆柱之间相互作用能;采用蒙特卡罗法模拟加载前后DNA链的微观分布模式;采用思想实验法和宏观连续介质压缩弹性杆模型,预测DNA生物膜弹性模量.结果 双链DNA生物膜的弹性模量约为0.1 ～80 MPa.结论 对比随机分布模式,经典的六角形均匀分布假设低估了DNA生物膜的弹性模量;封装密度的增加和缓冲盐溶液浓度的减小均有助于提高DNA生物膜弹性模量.这些结果对进一步认识临床工作中相关DNA生物膜的力学性质及其调控规律具有重要意义.Objective To investigate elastic modulus of double-stranded DNA （dsDNA） biofilm adsorbed on microcantilever substrate.Methods Parsegian＇ s empirical potentials based on mesoscopic continuum liquid crystal theory was employed to describe the interaction energy among coarse-grained DNA cylinders; Monte Carlo method was used to simulate the distribution pattern of DNA chains before and after loading.The thought experiment method combined with the compression bar model in the sense of macroscopic continuum mechanics was adopted to predict the elastic modulus of DNA biofilm.Results The elastic modulus of dsDNA biofilm ranged from 0.1 MPa to 80 MPa.Conclusions It was found out that the classic hypothesis with uniform hexagonal pattern may underestimate the elastic modulus of DNA biofilm when compared with that in random pattern.Moreover,either the increase of packing density or the decrease of buffer salt concentration will help to enhance elastic modulus of DNA biofilm.These results have great significances in further understanding the mechanical properties and regulation rules of DNA biofilm related with clinical work.

关 键 词：双链DNA 生物膜 弹性模量 圆柱模型 蒙特卡罗法 

分 类 号：R318.01[医药卫生—生物医学工程]