Background:

Three-dimensional (3D) printing using hydrogel has made great strides when it comes to mimicking 3D artificial tissue in the medical field. However, most structures do not mimic the dynamic movement of the tissues. Without imitating dynamic movements, there are limitations on the extent to which the proper implementation of the tissue's own functions can be achieved.

Method:

In this study, we intend to present an approach to solving this problem using hydroxybutyl methacrylated chitosan (HBC-MA), a photo-crosslinkable/temperature reversible chitosan polymer. In addition, stereolithography-3D (SLA-3D) printing technology was used, which is more likely to mimic the complex microstructure. As a control, a 3D structure made with pristine poly(ethylene glycol) dimethacrylate (PEG-DMA) was created, and a 4D structure was prepared by adding HBC-MA to poly(ethylene glycol) dimethacrylate (PEG-DMAP) resin.

Results:

HBC-MA caused the expansion of water into the polymer matrix at low temperature, and the 4D structure resulted in expansion of the polymer volume, generating dynamic movement due to the expansion of water. Conversely, as the temperature rose, deswelling occurred, followed by a decrease in the volume, showing a shape memory property of returning to the existing structure. Morphological, swelling, and mechanical analysis further confirmed the principle of dynamic movement. In addition, parameters were provided through calculation of the bending ratio angle (θ).

Conclusion:

Through this, it is suggested that HBC-MA can be applied as a core polymer for SLA-4D printing, and has high potential for realizing the dynamic movement of tissue.

中文翻译：

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使用光可交联/温度可逆壳聚糖聚合物和立体光刻 4D 打印技术实现动态运动的水凝胶生产平台。

 背景：

使用水凝胶进行三维 (3D) 打印在医学领域模仿 3D 人造组织方面取得了巨大进步。然而，大多数结构并不模仿组织的动态运动。如果不模仿动态运动，组织自身功能的正确实现的程度就会受到限制。

 方法：

在这项研究中，我们打算提出一种使用甲基丙烯酸羟丁酯壳聚糖（HBC-MA）（一种光交联/温度可逆壳聚糖聚合物）来解决这个问题的方法。此外，还使用了立体光刻3D（SLA-3D）打印技术，更容易模仿复杂的微观结构。作为对照，创建了由原始聚乙二醇二甲基丙烯酸酯 (PEG-DMA) 制成的 3D 结构，并通过将 HBC-MA 添加到聚乙二醇二甲基丙烯酸酯 (PEG-DMAP) 树脂来制备 4D 结构。

 结果：

HBC-MA在低温下引起水膨胀进入聚合物基体，4D结构导致聚合物体积膨胀，由于水的膨胀而产生动力运动。相反，随着温度升高，发生消溶胀，随后体积减小，表现出恢复现有结构的形状记忆特性。形态、膨胀和力学分析进一步证实了动态运动的原理。此外，通过计算弯曲比角（θ）来提供参数。

 结论：

由此表明，HBC-MA可以作为SLA-4D打印的核心聚合物，并且具有实现组织动态运动的巨大潜力。