To provide insight into how cells receive information from their external surroundings, synthetic hydrogels have emerged as systems for assaying cell function in well-defined microenvironments where single cues can be introduced and subsequent effects individually elucidated. However, as answers to more complex biological questions continue to be sought, advanced material systems are needed that allow dynamic alteration of the three-dimensional cellular environment with orthogonal reactions that enable multiple levels of control of biochemical and biomechanical signals. Here, we seek to synthesize one such three-dimensional culture system using cytocompatible and wavelength-specific photochemical reactions to create hydrogels that allow orthogonal and dynamic control of material properties through independent spatiotemporally regulated photocleavage of crosslinks and photoconjugation of pendant functionalities. The results demonstrate the versatile nature of the chemistry to create programmable niches to study and direct cell function by modifying the local hydrogel environment. Cell-laden synthetic hydrogels â formed via a copper-free click reaction between a poly(ethylene glycol) tetra-cyclooctyne and a peptide-diazide â provide a platform to investigate the cells' response to various stimuli during growth. The hydrogel's biochemical aspects are readily controlled by a thiol-ene photocoupling reaction initiated with visible light, whereas the biomechanical properties of the network are altered via a UV-mediated photodegradation.
                                    为了深入了解细胞如何从外部环境中接收信息,合成
水凝胶已成为在定义明确的微环境中检测细胞功能的系统,在这种微环境中,可以引入单个线索并单独阐明随后的影响。然而,随着人们对更复杂的
生物学问题不断寻求答案,需要有先进的材料系统来动态改变三维细胞环境,并通过正交反应实现对
生物化学和
生物力学信号的多层次控制。在这里,我们试图合成这样一种三维培养系统,利用细胞相容性和特定波长的光
化学反应来制造
水凝胶,通过独立的时空调控交联的光裂解和悬垂功能的光共轭,实现对材料特性的正交和动态控制。研究结果表明,这种
化学方法用途广泛,可通过改变局部
水凝胶环境来创建可编程的龛位,从而研究和指导细胞功能。通过聚(
乙二醇)四
环辛炔和肽-
叠氮化物之间的无
铜点击反应形成的细胞负载合成
水凝胶为研究细胞在生长过程中对各种刺激的反应提供了一个平台。
水凝胶的生化特性可通过可见光引发的
硫醇-烯光偶联反应轻松控制,而网络的
生物力学特性则可通过紫外线介导的光降解作用发生改变。