Lee Yunji, Park Ju An, Tuladhar Tri, Jung Sungjune
Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang-si, Gyeongsangbuk-do, 37673, Republic of Korea.
Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK.
Macromol Biosci. 2023 May;23(5):e2200509. doi: 10.1002/mabi.202200509. Epub 2023 Mar 22.
Inkjet printing enables the mimicry of the microenvironment of natural complex tissues by patterning cells and hydrogels at a high resolution. However, the polymer content of an inkjet-printable bioink is limited as it leads to strong viscoelasticity in the inkjet nozzle. Here it is demonstrated that sonochemical treatment controls the viscoelasticity of a gelatin methacryloyl (GelMA) based bioink by shortening the length of polymer chains without causing chemical destruction of the methacryloyl groups. The rheological properties of treated GelMA inks are evaluated by a piezo-axial vibrator over a wide range of frequencies between 10 and 10 000 Hz. This approach enables to effectively increase the maximum printable polymer concentration from 3% to 10%. Then it is studied how the sonochemical treatment effectively controls the microstructure and mechanical properties of GelMA hydrogel constructs after crosslinking while maintaining its fluid properties within the printable range. The control of mechanical properties of GelMA hydrogels can lead fibroblasts more spreading on the hydrogels. A 3D cell-laden multilayered hydrogel constructs containing layers with different physical properties is fabrictated by using high-resolution inkjet printing. The sonochemical treatment delivers a new path to inkjet bioprinting to build microarchitectures with various physical properties by expanding the range of applicable bioinks.
喷墨打印能够通过高分辨率地对细胞和水凝胶进行图案化处理，来模拟天然复杂组织的微环境。然而，可用于喷墨打印的生物墨水的聚合物含量有限，因为这会导致喷墨喷嘴内的粘弹性增强。本文证明，声化学处理通过缩短聚合物链的长度来控制基于甲基丙烯酰化明胶（GelMA）的生物墨水的粘弹性，同时不会对甲基丙烯酰基造成化学破坏。通过压电轴向振动器在10至10000Hz的宽频率范围内评估经处理的GelMA墨水的流变学性质。这种方法能够有效地将最大可打印聚合物浓度从3%提高到10%。接着研究了声化学处理如何在交联后有效控制GelMA水凝胶构建体的微观结构和力学性能，同时将其流体性质保持在可打印范围内。对GelMA水凝胶力学性能的控制可使成纤维细胞在水凝胶上更易于铺展。通过使用高分辨率喷墨打印制造出一种包含具有不同物理性质层的三维载细胞多层水凝胶构建体。声化学处理为喷墨生物打印开辟了一条新途径，通过扩大适用生物墨水的范围来构建具有各种物理性质的微结构。
