Institute of Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada.
Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada.
ACS Biomater Sci Eng. 2022 Jan 10;8(1):185-195. doi: 10.1021/acsbiomaterials.1c00941. Epub 2021 Dec 3.
Hydrogels are powerful materials that more accurately mimic the cellular microenvironment over static two-dimensional culture. Photochemical strategies enable dynamic complexity to be achieved within hydrogels to better mimic the extracellular matrix; however, many photochemical systems to pattern proteins within hydrogels are complicated by long reaction times to immobilize these proteins wherein the protein can lose activity. As proof-of-concept, we demonstrate an elegant method where photocaged proteins are immobilized in hydrogels and then directly photoactivated. Specifically, we immobilized streptavidin-ortho-nitrobenzyl-modified epidermal growth factor (EGF) to cross-linked hyaluronan hydrogels and cultured two EGF-responsive cancer cells of breast and lung therein. We used light to temporally uncage and control EGF activation, thereby inducing cell death in breast cancer cells and proliferation in lung cancer cells. These results show how temporal, photochemical, protein activation influences cellular response and lays the foundation for further advances in manipulating the environment to control cell fate.
水凝胶是一种强大的材料，能够更准确地模拟细胞微环境，而不是静态二维培养。光化学策略可以在水凝胶内实现动态复杂性，从而更好地模拟细胞外基质；然而，许多用于在水凝胶中对蛋白质进行图案化的光化学系统由于固定这些蛋白质的反应时间较长而变得复杂，在此过程中蛋白质可能会失去活性。作为概念验证，我们展示了一种巧妙的方法，可以将光笼封蛋白质固定在水凝胶中，然后直接光激活。具体来说，我们将链霉亲和素-邻硝基苄基修饰的表皮生长因子（EGF）固定在交联透明质酸水凝胶中，并在其中培养两种对 EGF 有反应的乳腺癌和肺癌细胞。我们用光来暂时解笼并控制 EGF 的激活，从而诱导乳腺癌细胞死亡和肺癌细胞增殖。这些结果表明，时间、光化学、蛋白质激活如何影响细胞反应，并为进一步推进操纵环境以控制细胞命运奠定了基础。
