Hauck Nicolas, Beck Timon, Cojoc Gheorghe, Schlüßler Raimund, Ahmed Saeed, Raguzin Ivan, Mayer Martin, Schubert Jonas, Müller Paul, Guck Jochen, Thiele Julian
Leibniz-Institut für Polymerforschung Dresden e.V., Institute of Physical Chemistry and Polymer Physics D-01069 Dresden Germany
Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden D-01307 Dresden Germany.
Mater Adv. 2022 Jul 5;3(15):6179-6190. doi: 10.1039/d2ma00296e. eCollection 2022 Aug 1.
Stretching individual living cells with light is a standard method to assess their mechanical properties. Yet, heat introduced by the laser light of optical stretchers may unwittingly change the mechanical properties of cells therein. To estimate the temperature induced by an optical trap, we introduce cell-sized, elastic poly(-isopropylacrylamide) (PNIPAAm) microgels that relate temperature changes to hydrogel swelling. For their usage as a standardized calibration tool, we analyze the effect of free-radical chain-growth gelation (FCG) and polymer-analogous photogelation (PAG) on hydrogel network heterogeneity, micromechanics, and temperature response by Brillouin microscopy and optical diffraction tomography. Using a combination of tailor-made PNIPAAm macromers, PAG, and microfluidic processing, we obtain microgels with homogeneous network architecture. With that, we expand the capability of standardized microgels in calibrating and validating cell mechanics analysis, not only considering cell and microgel elasticity but also providing stimuli-responsiveness to consider dynamic changes that cells may undergo during characterization.
用光拉伸单个活细胞是评估其力学特性的标准方法。然而，光镊的激光所引入的热量可能在不知不觉中改变其中细胞的力学特性。为了估算光阱所诱导的温度，我们引入了细胞大小的、弹性的聚（N-异丙基丙烯酰胺）（PNIPAAm）微凝胶，其将温度变化与水凝胶溶胀联系起来。对于其作为标准化校准工具的用途，我们通过布里渊显微镜和光学衍射层析成像分析自由基链增长凝胶化（FCG）和聚合物类似光凝胶化（PAG）对水凝胶网络不均匀性、微力学和温度响应的影响。通过结合定制的PNIPAAm大分子单体、PAG和微流控处理，我们获得了具有均匀网络结构的微凝胶。由此，我们扩展了标准化微凝胶在校准和验证细胞力学分析方面的能力，不仅考虑细胞和微凝胶的弹性，还提供刺激响应性以考虑细胞在表征过程中可能经历的动态变化。
