Yang Feichen, Tadepalli Vaibhav, Wiley Benjamin J
Department of Chemistry, Duke University, Durham, North Carolina 27708, United States.
ACS Biomater Sci Eng. 2017 May 8;3(5):863-869. doi: 10.1021/acsbiomaterials.7b00094. Epub 2017 Apr 14.
This article demonstrates a two-step method to 3D print double network hydrogels at room temperature with a low-cost ($300) 3D printer. A first network precursor solution was made 3D printable via extrusion from a nozzle by adding a layered silicate to make it shear-thinning. After printing and UV-curing, objects were soaked in a second network precursor solution and UV-cured again to create interpenetrating networks of poly(2-acrylamido-2-methylpropanesulfonate) and polyacrylamide. By varying the ratio of polyacrylamide to cross-linker, the trade-off between stiffness and maximum elongation of the gel can be tuned to yield a compression strength and elastic modulus of 61.9 and 0.44 MPa, respectively, values that are greater than those reported for bovine cartilage. The maximum compressive (93.5 MPa) and tensile (1.4 MPa) strengths of the gel are twice that of previous 3D printed gels, and the gel does not deform after it is soaked in water. By 3D printing a synthetic meniscus from an X-ray computed tomography image of an anatomical model, we demonstrate the potential to customize hydrogel implants based on 3D images of a patient's anatomy.
本文展示了一种利用低成本（300美元）3D打印机在室温下3D打印双网络水凝胶的两步法。通过添加层状硅酸盐使其具有剪切变稀特性，从而使第一种网络前体溶液可通过喷嘴挤出进行3D打印。打印并紫外线固化后，将物体浸泡在第二种网络前体溶液中并再次紫外线固化，以形成聚（2-丙烯酰胺-2-甲基丙烷磺酸盐）和聚丙烯酰胺的互穿网络。通过改变聚丙烯酰胺与交联剂的比例，可以调节凝胶刚度和最大伸长率之间的权衡，从而分别产生61.9和0.44 MPa的抗压强度和弹性模量，这些值大于报道的牛软骨的值。凝胶的最大抗压强度（93.5 MPa）和抗拉强度（1.4 MPa）是先前3D打印凝胶的两倍，并且凝胶在水中浸泡后不会变形。通过从解剖模型的X射线计算机断层扫描图像3D打印合成半月板，我们展示了基于患者解剖结构的3D图像定制水凝胶植入物的潜力。
