Gharacheh Hadis, Abaci Alperen, Alkhoury Keven, Choudhury Ediha, Liaw Chya-Yan, Chester Shawn A, Guvendiren Murat
Otto H. York Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA.
Department of Mechanical & Industrial Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA.
Soft Matter. 2025 Jan 29;21(5):844-854. doi: 10.1039/d4sm01197j.
Material extrusion-based three-dimensional (3D) printing is a widely used manufacturing technology for fabricating scaffolds and devices in bone tissue engineering (BTE). This technique involves two fundamentally different extrusion approaches: solution-based and melt-based printing. In solution-based printing, a polymer solution is extruded and solidifies solvent evaporation, whereas in melt-based printing, the polymer is melted at elevated temperatures and solidifies as it cools post-extrusion. Solution-based printing can also be enhanced to generate micro/nano-scale porosity through phase separation by printing the solution into a nonsolvent bath. The choice of the printing method directly affects scaffold properties and the biological response of stem cells. In this study, we selected polycaprolactone (PCL), a biodegradable polymer frequently used in BTE, blended with hydroxyapatite (HA) nanoparticles, a bioceramic known for promoting bone formation, to investigate the effects of the printing approach on scaffold properties and performance using human mesenchymal stem cells (hMSCs). Our results showed that while both printing methods produced scaffolds with similar strut and overall scaffold dimensions, solvent-based printing resulted in porous struts, higher surface roughness, lower stiffness, and increased crystallinity compared to melt-based printing. Although stem cell viability and proliferation were not significantly influenced by the printing approach, melt-printed scaffolds promoted a more spread morphology and exhibited pronounced vinculin staining. Furthermore, composite scaffolds outperformed their neat counterparts, with melt-printed composite scaffolds significantly enhancing bone formation. This study highlights the critical role of the printing process in determining scaffold properties and performance, providing valuable insights for optimizing scaffold design in BTE.
基于材料挤出的三维（3D）打印是骨组织工程（BTE）中用于制造支架和装置的一种广泛使用的制造技术。该技术涉及两种根本不同的挤出方法：基于溶液的打印和基于熔体的打印。在基于溶液的打印中，聚合物溶液被挤出并通过溶剂蒸发固化，而在基于熔体的打印中，聚合物在高温下熔化并在挤出后冷却时固化。基于溶液的打印还可以通过将相分离的溶液打印到非溶剂浴中，从而增强以产生微/纳米级孔隙率。打印方法的选择直接影响支架特性和干细胞的生物学反应。在本研究中，我们选择了聚己内酯（PCL），一种在BTE中常用的可生物降解聚合物，与羟基磷灰石（HA）纳米颗粒混合，羟基磷灰石是一种以促进骨形成而闻名的生物陶瓷，以研究打印方法对使用人间充质干细胞（hMSCs）的支架特性和性能的影响。我们的结果表明，虽然两种打印方法都产生了具有相似支柱和整体支架尺寸的支架，但与基于熔体的打印相比，基于溶剂的打印产生了多孔支柱、更高的表面粗糙度、更低的刚度和增加的结晶度。虽然打印方法对干细胞活力和增殖没有显著影响，但熔体打印的支架促进了更铺展的形态并表现出明显的纽蛋白染色。此外，复合支架优于其纯对应物，熔体打印的复合支架显著增强了骨形成。这项研究强调了打印过程在确定支架特性和性能方面的关键作用，为优化BTE中的支架设计提供了有价值的见解。
