Leu Alexa Rebeca, Iovu Horia, Ghitman Jana, Serafim Andrada, Stavarache Cristina, Marin Maria-Minodora, Ianchis Raluca
Advanced Polymer Materials Group, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania.
Academy of Romanian Scientists, 54 Splaiul Independentei, 050094 Bucharest, Romania.
Polymers (Basel). 2021 Feb 27;13(5):727. doi: 10.3390/polym13050727.
The development of materials for 3D printing adapted for tissue engineering represents one of the main concerns nowadays. Our aim was to obtain suitable 3D-printed scaffolds based on methacrylated gelatin (GelMA). In this respect, three degrees of GelMA methacrylation, three different concentrations of GelMA (10%, 20%, and 30%), and also two concentrations of photoinitiator (I-2959) (0.5% and 1%) were explored to develop proper GelMA hydrogel ink formulations to be used in the 3D printing process. Afterward, all these GelMA hydrogel-based inks/3D-printed scaffolds were characterized structurally, mechanically, and morphologically. The presence of methacryloyl groups bounded to the surface of GelMA was confirmed by FTIR and H-NMR analyses. The methacrylation degree influenced the value of the isoelectric point that decreased with the GelMA methacrylation degree. A greater concentration of photoinitiator influenced the hydrophilicity of the polymer as proved using contact angle and swelling studies because of the new bonds resulting after the photocrosslinking stage. According to the mechanical tests, better mechanical properties were obtained in the presence of the 1% initiator. Circular dichroism analyses demonstrated that the secondary structure of gelatin remained unaffected during the methacrylation process, thus being suitable for biological applications.
开发适用于组织工程的3D打印材料是当今主要关注的问题之一。我们的目标是获得基于甲基丙烯酸化明胶（GelMA）的合适的3D打印支架。在这方面，研究了三种GelMA甲基丙烯酸化程度、三种不同浓度的GelMA（10%、20%和30%）以及两种浓度的光引发剂（I-2959）（0.5%和1%），以开发适用于3D打印过程的合适的GelMA水凝胶油墨配方。之后，对所有这些基于GelMA水凝胶的油墨/3D打印支架进行了结构、力学和形态学表征。通过FTIR和H-NMR分析证实了与GelMA表面结合的甲基丙烯酰基的存在。甲基丙烯酸化程度影响等电点的值，等电点随GelMA甲基丙烯酸化程度降低。如使用接触角和溶胀研究所证明的，较高浓度的光引发剂由于光交联阶段后形成的新键而影响聚合物的亲水性。根据力学测试，在存在1%引发剂的情况下获得了更好的力学性能。圆二色性分析表明，明胶的二级结构在甲基丙烯酸化过程中保持不变，因此适用于生物应用。
