Photon Upconversion Hydrogels for 3D Optogenetics
Photon Upconversion Hydrogels for 3D Optogenetics
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DOI：
10.1002/adfm.202010907
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发表时间：
2021-06-04
影响因子：
19
通讯作者：
Campos, Luis M.
中科院分区：
文献类型：
--
作者：
Meir, Rinat;Hirschhorn, Tal;Campos, Luis M.
由于可见光穿透触发光化学过程的物理限制，3D光学诱导生物反应的能力已经相形见绌。然而，许多生物系统对低能量光相对透明，这不能提供足够的能量来诱导3D光化学。为了克服这一挑战，开发了能够在载有细胞的3D支架内将红光或近红外（NIR）光转换为蓝光的水凝胶。然后，上转换的光可以激发细胞中的光学活性蛋白质，以触发光化学反应。水凝胶通过三重态-三重态湮灭上转换来工作。作为原理证明，发现水凝胶通过HeLa细胞的红光/NIR照射触发光遗传学应答，所述HeLa细胞已被工程化以表达蓝光敏感蛋白Cry 2 olig。虽然在3D中用毯式NIR照射光诱导Cry 2 olig的聚集是显著的，但也证明了水凝胶如何以极大的特异性和时空控制触发单细胞内的聚集。原则上，这些水凝胶可以允许在3D支架内对细胞功能进行光化学控制，这可以导致大量的基础研究和生化应用。
The ability to optically induce biological responses in 3D has been dwarfed by the physical limitations of visible light penetration to trigger photochemical processes. However, many biological systems are relatively transparent to low-energy light, which does not provide sufficient energy to induce photochemistry in 3D. To overcome this challenge, hydrogels that are capable of converting red or near-IR (NIR) light into blue light within the cell-laden 3D scaffolds are developed. The upconverted light can then excite optically active proteins in cells to trigger a photochemical response. The hydrogels operate by triplet-triplet annihilation upconversion. As proof-of-principle, it is found that the hydrogels trigger an optogenetic response by red/NIR irradiation of HeLa cells that have been engineered to express the blue-light sensitive protein Cry2olig. While it is remarkable to photoinduce the clustering of Cry2olig with blanket NIR irradiation in 3D, it is also demonstrated how the hydrogels trigger clustering within a single cell with great specificity and spatiotemporal control. In principle, these hydrogels may allow for photochemical control of cell function within 3D scaffolds, which can lead to a wealth of fundamental studies and biochemical applications.