Size-Dependent Suppression of Molecular Diffusivity in Expandable Hydrogels: A Single-Molecule Study
Size-Dependent Suppression of Molecular Diffusivity in Expandable Hydrogels: A Single-Molecule Study
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可膨胀水凝胶中分子扩散性的尺寸依赖性抑制：单分子研究
DOI：
10.1021/acs.jpcb.3c00761
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Xu, Ke
中科院分区：
文献类型：
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作者：
Park, Ha H.;Choi, Alexander A.;Xu, Ke
通过重新利用最近流行的膨胀显微镜来控制水凝胶的网络尺寸，我们研究了在宽范围的聚合物分数为0.14- 7wt%的所得调谐水凝胶纳米基质中分子扩散率的尺寸依赖性抑制。与我们最近开发的单分子位移/扩散率映射（SMdM）显微镜方法，我们因此表明，与一个固定的网络大小，较大的分子表现出更受阻的扩散，并为同一分子，扩散是逐步更多的抑制作为网络大小减小，这种效果是更突出的较大的分子。此外，我们表明，网络引起的阻碍扩散是解耦的抑制扩散，由于溶液粘度增加。因此，这两种机制，分别是扩散器尺寸依赖性和独立性，可以分别按比例缩小分子扩散率，以产生最终的扩散减缓在复杂的系统，如细胞。
By repurposing the recently popularized expansion microscopy to control the meshwork size of hydrogels, we examine the size-dependent suppression of molecular diffusivity in the resultant tuned hydrogel nanomatrices over a wide range of polymer fractions of ∼0.14–7 wt %. With our recently developed single-molecule displacement/diffusivity mapping (SMdM) microscopy methods, we thus show that with a fixed meshwork size, larger molecules exhibit more impeded diffusion and that, for the same molecule, diffusion is progressively more suppressed as the meshwork size is reduced; this effect is more prominent for the larger molecules. Moreover, we show that the meshwork-induced obstruction of diffusion is uncoupled from the suppression of diffusion due to increased solution viscosities. Thus, the two mechanisms, respectively, being diffuser-size-dependent and independent, may separately scale down molecular diffusivity to produce the final diffusion slowdown in complex systems like the cell.