Tissue Engineering and Biomicrofluidics Laboratory, School of Biomedical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India.
J Biomater Appl. 2021 Apr;35(9):1132-1142. doi: 10.1177/0885328220979473. Epub 2020 Dec 30.
The primary goal of this study is to highlight the rheological and mechanical properties of a new blend composed of naturally-derived hydrogel materials- psyllium husk (PH) and gelatin (G) for its potential use in three-dimensional (3D) printing technology. The mixtures were prepared at various weight ratios of 100PH, 75PH + 25G and 50PH + 50G. A suitable selection of the printable ink was made based on the preliminary screening steps of manual filament drop test and layer stacking by 3D printing. Printing of the common features such as hexagon and square grids helped evaluating shape fidelity of the chosen ink. Although 50PH + 50G blend was found meeting most of the criteria for an ideal 3D printable ink, rheological and mechanical characterizations have been performed for all the ratios of polymeric blends. This study documents the correlation between various factors of rheology that should be taken into account while categorizing any biomaterial as a printable ink. Yield stress was measured as 18.59 ± 4.21 Pa, 268.74 ± 13.56 Pa and 109.16 ± 9.85 Pa for 50PH + 50G, 75PH + 25G and 100PH, respectively. Similarly, consistency index (K) and flow index (n) were calculated using the power law equation and found as 49.303 ± 4.17, 530.59 ± 10.92, 291.82 ± 10.53 and 0.275 ± 0.04, 0.05 ± 0.005, 0.284 ± 0.04 for 50PH + 50G, 75PH + 25G and 100PH, respectively. The loss modulus (G″) was observed dominating over storage modulus (G') for 50PH + 50G, that depicts its liquid-like property; whereas storage modulus (G') was found dominating in case of 75PH + 25G and 100PH, indicating their solid-like characteristics. In addition, the loss tangent value (tan δ) of 50PH + 50G was observed exceeding unity (1.05), supporting its plastic behavior, unlike 75PH + 25G (0.5) and 100PH (0.33) whose loss tangent values were estimated less than unity revealing their elastic behavior. Also, 50PH + 50G was found to have the highest mechanical strength amongst the three blends with a Young's modulus of 9.170 ± 0.0881 kPa.
本研究的主要目的是强调由天然来源的水凝胶材料——亚麻籽壳（PH）和明胶（G）组成的新型共混物的流变和力学性能，因为其可能用于三维（3D）打印技术。混合物以 100PH、75PH+25G 和 50PH+50G 的不同重量比进行制备。基于手动细丝滴落测试和 3D 打印的层堆积的初步筛选步骤，选择合适的可打印墨水。打印常见的特征，如六边形和正方形网格，有助于评估所选墨水的形状保真度。尽管发现 50PH+50G 共混物符合理想 3D 可打印墨水的大多数标准，但已对所有聚合物共混物的比例进行了流变学和力学特性分析。本研究记录了流变学各种因素之间的相关性，在将任何生物材料分类为可打印墨水时应考虑这些因素。屈服应力分别为 50PH+50G、75PH+25G 和 100PH 的 18.59±4.21 Pa、268.74±13.56 Pa 和 109.16±9.85 Pa。同样，使用幂律方程计算了稠度指数（K）和流动指数（n），并发现 50PH+50G、75PH+25G 和 100PH 的值分别为 49.303±4.17、530.59±10.92、291.82±10.53 和 0.275±0.04、0.05±0.005、0.284±0.04。50PH+50G 的损耗模量（G″）大于储能模量（G'），表明其具有液体性质；而 75PH+25G 和 100PH 则表现出储能模量（G'）占主导地位，表明它们具有固体性质。此外，50PH+50G 的损耗角正切值（tan δ）超过 1.05，表明其具有塑性行为，而 75PH+25G（0.5）和 100PH（0.33）的损耗角正切值小于 1，表明它们具有弹性行为。此外，发现 50PH+50G 在三种共混物中具有最高的机械强度，杨氏模量为 9.170±0.0881 kPa。
