Peddireddy Karthik R, McGorty Ryan, Robertson-Anderson Rae M
Department of Physics and Biophysics, University of San Diego, 5998 Alcala Park, San Diego, CA 92110, United States.
Department of Physics and Biophysics, University of San Diego, 5998 Alcala Park, San Diego, CA 92110, United States.
Acta Biomater. 2024 Dec;190:410-422. doi: 10.1016/j.actbio.2024.10.042. Epub 2024 Oct 29.
Understanding how polymers deform in response to local stresses and strains, and how strains propagate from a local disturbance, are grand challenges in wide-ranging fields from materials manufacturing to cell mechanics. These dynamics are particularly complex for blends of polymers of distinct topologies, for which several different species-dependent mechanisms may contribute. Here, we use OpTiDDM (Optical Tweezers integrating Differential Dynamic Microscopy) to elucidate deformation fields and propagation dynamics of binary blends of linear, ring and supercoiled DNA of varying sizes. We reveal robust non-monotonic dependence of strain alignment and superdiffusive transport with strain rate. However, peak alignment and superdiffusivity are surprisingly decoupled, occurring at different strain rates resonant with the distinct relaxation rates of the different topologies. Despite this universal resonance, we find that strain propagation of ring-linear blends is dictated by entanglements while supercoiled-ring blends are governed by Rouse dynamics. Our results capture critical subtleties in propagation and deformation dynamics of topological blends, shedding new light on the governing physics and offering a route towards decoupled tuning of response features. We anticipate our approach to be broadly generalizable to mapping the deformation dynamics of polymer blends, with an eye towards bottom-up bespoke materials design. STATEMENT OF SIGNIFICANCE: In biology and in manufacturing, biomaterials are often subject to localized and spatially nonuniform strains and stresses. Yet, understanding the extent to which strains are absorbed, distributed, or propagated across different spatiotemporal scales remains a grand challenge. Here, we combine optical tweezers with differential dynamic microscopy to elucidate deformation fields and propagation dynamics of blends of linear, ring and supercoiled DNA, revealing robust non-monotonic trends and decoupling of strain alignment and superdiffusivity, and capturing critical subtleties in propagation and deformation dynamics. Our results, shedding important new physical insight to guide decoupled tuning of response features, may be leveraged to map the deformation dynamics of wide-ranging systems of biopolymers and other macromolecules, with an eye towards bottom-up bespoke biomaterials design.
理解聚合物如何响应局部应力和应变而变形，以及应变如何从局部扰动传播，是从材料制造到细胞力学等广泛领域的重大挑战。对于具有不同拓扑结构的聚合物共混物而言，这些动力学过程尤为复杂，因为可能有几种不同的物种依赖性机制在起作用。在这里，我们使用光学镊子集成差分动态显微镜（OpTiDDM）来阐明不同大小的线性、环状和超螺旋DNA二元共混物的变形场和传播动力学。我们揭示了应变排列和超扩散输运对应变速率的强烈非单调依赖性。然而，峰值排列和超扩散性令人惊讶地解耦，出现在与不同拓扑结构的不同弛豫速率共振的不同应变速率下。尽管存在这种普遍的共振现象，但我们发现环状 - 线性共混物的应变传播由缠结决定，而超螺旋 - 环状共混物则由劳斯动力学控制。我们的结果捕捉到了拓扑共混物传播和变形动力学中的关键细微之处，为控制物理过程提供了新的见解，并为响应特征的解耦调节提供了一条途径。我们预计我们的方法可广泛应用于绘制聚合物共混物的变形动力学，着眼于自下而上的定制材料设计。
在生物学和制造业中，生物材料常常受到局部和空间上不均匀的应变和应力作用。然而，了解应变在不同时空尺度上被吸收、分布或传播的程度仍然是一个重大挑战。在这里，我们将光学镊子与差分动态显微镜相结合，以阐明线性、环状和超螺旋DNA共混物的变形场和传播动力学，揭示了强烈的非单调趋势以及应变排列和超扩散性的解耦，并捕捉到了传播和变形动力学中的关键细微之处。我们的结果为指导响应特征的解耦调节提供了重要的新物理见解，可用于绘制广泛的生物聚合物和其他大分子系统的变形动力学，着眼于自下而上的定制生物材料设计。
