DNA吸附膜热膨胀系数对环境条件的依赖性  

The Dependency of Thermal Expansion Coefficient of DNA Adsorption Film on Environmental Conditions

作　　者：吴春霞 张乘胤 谭邹卿[2] 张能辉[1,3] WU Chunxia;ZHANG Chengyin;TAN Zouqing;ZHANG Nenghui(College of Mechanics and Engineering Science,Shanghai University,Shanghai 200444,China;College of Mechanical Engineering,Changzhou University,Changzhou 213164,Jiangsu,China;Shanghai Key Laboratory of Mechanics in Energy Engineering,Shanghai Institute of Applied Mathematics and Mechanics,Shanghai 200027,China)

机构地区：[1]上海大学力学与工程科学学院,上海200444 [2]常州大学机械工程学院,江苏常州213164 [3]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

出　　处：《医用生物力学》2021年第1期136-143,共8页Journal of Medical Biomechanics

基　　金：国家自然科学基金项目(11772182,11272193,10872121);上海市教委重大项目(2019-01-07-00-09-E00018)。

摘　　要：目的研究基底上DNA吸附膜热膨胀系数对环境条件的依赖性。方法将DNA吸附分子视为有预应变的宏观连续介质薄膜,建立了DNA膜-基底等效层合梁模型,预测温度载荷作用下DNA-微悬臂梁挠度;采用Parsegian经验势描述DNA吸附膜的介观自由能,利用DNA液晶-基底多尺度挠度模型、思想实验法和等效变形法,建立DNA吸附膜微观结构与其宏观力学性能的跨尺度关系,预测基底上DNA吸附膜的热膨胀系数。结果在给定离子强度条件下,双链DNA吸附膜的热膨胀系数为(0.3~8.05)×10^(-4)/K,单链DNA吸附膜的热膨胀系数为(1.28~9.33)×10^(-4)/K。结论在微观作用竞争中起主导作用的构型熵变化决定了DNA吸附膜热膨胀系数对环境条件的依赖性;随着温度或离子浓度或DNA种植密度的增加,DNA膜热膨胀系数减小。研究结果对于基因检测及其调控具有指导意义,并为组织工程中组织器官的性能评估提供参考。Objective To investigate the dependency of thermal expansion coefficient of DNA adsorption film on environmental conditions. Methods By treating DNA adsorption film as a macroscopic continuum film with prestrain,an equivalent composite beam model of DNA film-substrate was established to calculate the deflection of DNA-microcantilever beam under temperature loading. By adopting Parsegian’s empirical potential which described the mesoscopic free energy of DNA adsorption film,the DNA liquid crystal-substrate multi-scale deflection model,the thought experiment method and the equivalent deformation method were combined to establish the trans-scale relationship between the microstructure of DNA adsorption film and its macro-scale mechanical properties. The thermal expansion coefficient of DNA adsorption film was predicted. Results Given the ionic strength,the thermal expansion coefficient of double-stranded DNA adsorption film ranged from 0. 3×10^(-4)/K to8. 05× 10^(-4)/K,and that of single-stranded DNA adsorption film ranged from 1. 28 × 10^(-4)/K to 9. 33 × 10^(-4)/K.Conclusions As a leading role in the competition of micro-interactions,the change of configurational entropy determines the dependency of thermal expansion coefficient of DNA adsorption film on environmental conditions;the thermal expansion coefficient of DNA adsorption film decreases with the increase of temperature or ion concentration or DNA packing density. These results are useful for gene detection and its regulation,and provide reference for the evaluation of tissue organ performance in tissue engineering.

关 键 词：DNA吸附膜 热膨胀系数 介观自由能 跨尺度表征 微梁检测 

分 类 号：R318.01[医药卫生—生物医学工程]