Boons Rani, Gerber Dominic, Style Robert W, Droux Anouk, Zimmermann Tanja, Nyström Gustav, Siqueira Gilberto, Studart André R
Cellulose & Wood Materials Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland.
Complex Materials, Department of Materials, ETH Zürich, 8093 Zürich, Switzerland.
Soft Matter. 2025 Jul 2;21(26):5359-5370. doi: 10.1039/d5sm00391a.
The proliferation of microorganisms in hydrogels is crucial for the design of engineered living materials and biotechnological processes, and may provide insights into cellular growth in aquatic environments. While the mechanical properties of the gel have been shown to affect the division of entrapped cells, research is still needed to understand the impact and the origin of mechanical forces controlling the growth of microorganisms inside hydrogels. Using diatoms as model microorganisms, we investigate the viability, time to division and growth dynamics of cells entrapped in agar hydrogels with tuneable mechanical properties. Cell culture experiments, confocal optical microscopy and particle tracking velocimetry are performed to uncover the role of stress relaxation and residual stresses in the gel and how these affect diatom proliferation. Our experiments reveal that the interplay between the internal pressure of the dividing cell and the mechanical response of the hydrogel control the proliferation behaviour of the entrapped diatoms. By providing quantitative guidelines for the selection of hydrogels for the entrapment and growth of microorganisms, this study offers new insights on the design of living materials for established and emerging biotechnologies.
水凝胶中微生物的增殖对于工程化生物材料的设计和生物技术过程至关重要，并且可能为水生环境中的细胞生长提供见解。虽然已表明凝胶的机械性能会影响被包裹细胞的分裂，但仍需要开展研究以了解控制水凝胶内微生物生长的机械力的影响及来源。我们以硅藻作为模型微生物，研究了 entrapped 在具有可调机械性能的琼脂水凝胶中的细胞的活力、分裂时间和生长动力学。进行了细胞培养实验、共聚焦光学显微镜和粒子跟踪测速实验，以揭示凝胶中应力松弛和残余应力的作用以及它们如何影响硅藻增殖。我们的实验表明，分裂细胞的内压与水凝胶的机械响应之间的相互作用控制着被包裹硅藻的增殖行为。通过为选择用于包裹和培养微生物的水凝胶提供定量指导方针，本研究为既定和新兴生物技术的生物材料设计提供了新见解。
