全内反射荧光显微研究磷脂支撑膜形成中的片层前沿成长  

Total internal reflection fluorescence microscopy to study sheet front growth in phospholipid supported lipid membrane formation

作　　者：马贝贝 王凡 林玲 朱涛[2] 蒋中英 Ma Bei-Bei;Wang Fan;Lin Ling;Zhu Tao;Jiang Zhong-Ying(Key Laboratory of Micro-Nano Electronic Sensing Technology and Bionic Devices,College of Electronics and Engineering,Yili Normal University,Yining 835000,China;National Laboratory of Solid State Microstructures,Department of Physics,Nanjing University,Nanjing 210093,China;College of Network Security and Information Technology,Yili Normal University,Yining 835000,China)

机构地区：[1]伊犁师范大学电子与工程学院微纳电传感技术与仿生器械重点实验室,伊宁835000 [2]南京大学物理学院固体微结构物理国家重点实验室,南京210093 [3]伊犁师范大学网络安全与信息技术学院,伊宁835000

出　　处：《物理学报》2022年第16期402-409,共8页Acta Physica Sinica

基　　金：新疆自然科学基金联合基金(批准号:2022D01C336);伊犁师范大学科研项目(批准号:2021YSYB087);国家自然科学基金(批准号:11904167,22163011)资助的课题。

摘　　要：基于支撑磷脂双层膜(SLB)的生物传感器越来越多地被用于快速测定抗原、检测细胞色素等.囊泡在衬底的吸附和自发破裂可形成SLB,最近的研究强调在此过程中考察个体囊泡吸附和破裂的重要性.本研究利用全内反射荧光显微镜(TIRFM)实时监测荧光标记的纳米级个体囊泡的吸附、破裂,追踪片层前沿成长动力学过程.结合带耗散的石英晶体微天平(QCM-D)的表征和分析,发现囊泡尺寸对片层前沿成长有显著影响.通过片层前沿平均成长速度(v_(afv))定量分析片层成长,不同尺寸囊泡的v_(afv)存在数量级差异.理论分析小囊泡具有较高的表面浓度(C)和扩散性,加快了片层前沿成长,与实验值能够较好地符合.此外,通过全局成长理论模型,解释了对于相同的片层,前沿加速成长主要取决于C和囊泡破裂时的磷脂丢失率.计算的小囊泡成片层的磷脂丢失率略大于大囊泡,但更大差异的C是片层加速成长程度不同的关键.囊泡供应影响片层前沿成长的机理诠释深化了磷脂在界面再组装的认识.Supported lipid bilayer(SLB) based biosensors possess biomedical applications such as in rapid detection of antigens and cytochromes.It is generally believed that the SLB can be formed by adsorbing and spontaneously rupturing vesicles on substrate.Recent findings highlight the importance of investigating the adsorption and rupture of individual vesicles during the SLB formation.Here,we use total internal reflection fluorescence microscopy(TIRFM) to characterize the spatiotemporal kinetics of the front spreading at patch boundary.Owing to the mixture of labeled and unlabeled vesicles individual vesicle or patch on the surface can be identified.The TIRFM is employed to investigate the adsorption,rupture of vesicles,and spreading of the patch front.Combining quartz crystal microbalance with dissipation monitoring(QCM-D) and TIRFM characterizations,we find that the size of vesicle has a significant effect on the front spreading at the patch boundary.Quantification of the number of patches and patches area displays that smaller vesicles are more prone to the formation of patches.The front spreading at the patch boundary is analyzed quantitatively using the average front growth velocity(vafv),which indicates that the v_(afv) of 40-nm vesicles is one order of magnitude larger than that of the 112 nm vesicles.Both theoretical analysis and experimental observation show that the smaller vesicles can attain the higher concentration on the surface(C) and high diffusivity in the medium.The global growth theoretical model(GGM) presents that for the patches with the same surface area and vesicle exposure time,the growth of the patch depends on C and lipid loss percentage during the vesicle rupture.The calculated lipid loss of the smaller vesicles is slightly higher than that of the larger vesicles,while C plays a dominating role in determining the disparity of the patch growth between the different vesicles.This study promotes the understanding of the growth mechanism of patches on the surface.It demonstates the criteial role o

关 键 词：囊泡尺寸 表面浓度 片层前沿成长 全局成长模型 

分 类 号：Q811[生物学—生物工程] TP212.3[自动化与计算机技术—检测技术与自动化装置]