Hydrogels are widely used as scaffold in tissue engineering field because of their ability to mimic the cellular microenvironment. However, mimicking a completely natural cellular environment is complicated due to the differences in various physical and chemical properties of cellular environments. Recently, gradient hydrogels provide excellent heterogeneous environment to mimic the different cellular microenvironments. To create hydrogels with an anisotropic distribution, gradient hydrogels have been widely developed by adopting several gradient generation techniques. Herein, the various gradient hydrogel fabrication techniques, including dual syringe pump systems, microfluidic device, photolithography, diffusion, and bio‐printing are summarized. As the effects of gradient 3D hydrogels with stems have been reviewed elsewhere, this review focuses principally on gradient hydrogel fabrication for multi‐model tissue regeneration. This review provides new insights into the key points for fabrication of gradient hydrogels for multi‐model tissue regeneration.

中文翻译：

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用于组织工程应用的梯度水凝胶制备的最新策略

水凝胶由于其模仿细胞微环境的能力而被广泛用作组织工程领域的支架。然而，由于细胞环境的各种物理和化学性质的差异，模仿完全自然的细胞环境是复杂的。最近，梯度水凝胶提供了出色的异质环境来模仿不同的细胞微环境。为了产生具有各向异性分布的水凝胶，通过采用几种梯度产生技术已经广泛开发了梯度水凝胶。在此，总结了各种梯度水凝胶制造技术，包括双注射器泵系统，微流控设备，光刻，扩散和生物打印。由于梯度3D水凝胶对茎的影响已在其他地方进行了评论，这篇综述主要侧重于梯度水凝胶制备的多模型组织再生。这篇综述提供了用于多模型组织再生的梯度水凝胶制备关键点的新见解。