Applied Chemicals and Materials Division, Material Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA.
Soft Matter. 2020 May 7;16(17):4131-4141. doi: 10.1039/d0sm00052c. Epub 2020 Mar 23.
Understanding the three-dimensional (3D) mechanical and chemical properties of distinctly different, adjacent biological tissues is crucial to mimicking their complex properties with materials. 3D printing is a technique often employed to spatially control the distribution of the biomaterials, such as hydrogels, of interest, but it is difficult to print both mechanically robust (high modulus and toughness) and biocompatible (low modulus) hydrogels in a single structure. Moreover, due to the fast diffusion of mobile species during printing and nonequilibrium swelling conditions of low-solids-content hydrogels, it is challenging to form the high-fidelity structures required to mimic tissues. Here a predictive transport and swelling model is presented to model these effects and then is used to compensate for these effects during printing. This model is validated experimentally by photopatterning spatially distinct hydrogel elastic moduli using a single photo-tunable poly(ethylene glycol) (PEG) pre-polymer solution by sequentially patterning and in-diffusing fresh pre-polymer for further polymerization.
理解截然不同的相邻生物组织的三维（3D）机械和化学性质对于用材料模拟其复杂性质至关重要。3D 打印是一种常用于空间控制感兴趣的生物材料（如水凝胶）分布的技术，但很难在单个结构中同时打印出机械强度高（高模量和韧性）和生物相容性好（低模量）的水凝胶。此外，由于在打印过程中移动物种的快速扩散和低固含量水凝胶的非平衡溶胀条件，很难形成模拟组织所需的高保真结构。这里提出了一个预测传输和溶胀模型来模拟这些效应，然后在打印过程中补偿这些效应。该模型通过使用单种光可调聚乙二醇（PEG）预聚物溶液顺序图案化和内扩散新鲜预聚物以进一步聚合来光图案化空间上不同的水凝胶弹性模量，从而实验验证。
