Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, San Antonio, TX, 78249, USA.
J Mater Sci Mater Med. 2021 Aug 14;32(8):94. doi: 10.1007/s10856-021-06569-9.
Beta-tricalcium phosphate (β-TCP)-based bioinks were developed to support direct-ink 3D printing-based manufacturing of macroporous scaffolds. Binding of the gelatin:β-TCP ink compositions was optimized by adding carboxymethylcellulose (CMC) to maximize the β-TCP content while maintaining printability. Post-sintering, the gelatin:β-TCP:CMC inks resulted in uniform grain size, uniform shrinkage of the printed structure, and included microporosity within the ceramic. The mechanical properties of the inks improved with increasing β-TCP content. The gelatin:β-TCP:CMC ink (25:75 gelatin:β-TCP and 3% CMC) optimized for mechanical strength was used to 3D print several architectures of macroporous scaffolds by varying the print nozzle tip diameter and pore spacing during the 3D printing process (compressive strength of 13.1 ± 2.51 MPa and elastic modulus of 696 ± 108 MPa was achieved). The sintered, macroporous β-TCP scaffolds demonstrated both high porosity and pore size but retained mechanical strength and stiffness compared to macroporous, calcium phosphate ceramic scaffolds manufactured using alternative methods. The high interconnected porosity (45-60%) and fluid conductance (between 1.04 ×10 and 2.27 × 10 ms/kg) of the β-TCP scaffolds tested, and the ability to finely tune the architecture using 3D printing, resulted in the development of novel bioink formulations and made available a versatile manufacturing process with broad applicability in producing substrates suitable for biomedical applications.
β-磷酸三钙（β-TCP）基生物墨水被开发出来，以支持基于直接墨水 3D 打印的大孔支架的制造。通过添加羧甲基纤维素（CMC）来优化明胶：β-TCP 墨水的结合，以最大化 β-TCP 的含量，同时保持可印刷性。烧结后，明胶：β-TCP：CMC 墨水导致颗粒均匀、打印结构均匀收缩，并在陶瓷中包含微孔。随着 β-TCP 含量的增加，墨水的机械性能得到改善。优化机械强度的明胶：β-TCP：CMC 墨水（明胶：β-TCP 为 25：75，CMC 为 3%）用于通过在 3D 打印过程中改变打印喷嘴尖端直径和孔间距来 3D 打印几种大孔支架的结构（抗压强度为 13.1±2.51 MPa，弹性模量为 696±108 MPa）。烧结的大孔β-TCP 支架表现出高孔隙率和孔径，但与使用替代方法制造的大孔磷酸钙陶瓷支架相比，仍保留了机械强度和刚度。测试的β-TCP 支架具有高连通孔隙率（45-60%）和流体传导率（在 1.04×10 和 2.27×10 ms/kg 之间），并且能够使用 3D 打印精细调整结构，从而开发出新型生物墨水配方，并提供了一种多功能制造工艺，在生产适用于生物医学应用的基质方面具有广泛的适用性。
