Liquid deposition modeling (LDM) is an evolving three-dimensional (3D) printing approach that mainly utilizes polymer solutions to enable the fabrication of biomedical scaffolds under mild conditions. A deep understanding of the rheological properties of polymer printing inks and the features of yielded scaffolds are critical for a successful LDM based fabrication of biomedical scaffolds. In this work, polymer printing inks comprised of Poly(epsilon-caprolactone) (PCL), sodium chloride (NaCl), and trichloromethane (CHCl₃) were prepared. The rheological properties, including extrudability (shear stress, viscosity, and shear-thinning) and self-supporting ability (viscosity) of all printing inks were analyzed. Then printing performance was evaluated by measuring the die-swell ratio, 2D, and 3D printing fidelities. Finally, a series of porous PCL scaffolds were fabricated using printing inks comprised of different feed ratios (20:80, 40:60, 50:50, 60:40, and 80:20) of NaCl to PCL, and the porosity, mechanical properties, degradation behaviors, and biocompatibility were discussed. The results suggested that the printing ink formulation is greatly affected the printing performances. The increasing NaCl content in printing inks reduced shear force for extrusion, enhanced the shear-thinning behavior, increased the curing time. The dropping temperature and solvent evaporation both enhanced the self-supporting ability of the printing inks and solvent evaporation is a critical factor for the curing of the printing inks. The further evaluation demonstrated that the obtained fabricated porous PCL scaffolds were endowed with good biocompatibility and controllable porosity, mechanical features, and in vitro degradation behavior related to the NaCl content in the printing inks. This study built a fabricating method of porous polymer scaffolds by 3D printing at low temperatures for regeneration medicine researches.

液相沉积建模（LDM）是一种不断发展的三维（3D）打印方法，主要利用聚合物溶液在温和条件下制造生物医学支架。对聚合物印刷油墨的流变性质和所产生支架的特性的深刻理解对于成功地基于LDM的生物医学支架制造至关重要。在这项工作中，聚合物印刷油墨由聚ε-己内酯（PCL），氯化钠（NaCl）和三氯甲烷（CHCl ₃）准备。分析了所有印刷油墨的流变性质，包括可挤出性（剪切应力，粘度和剪切稀化）和自支撑能力（粘度）。然后通过测量模头膨胀率，2D和3D打印保真度来评估打印性能。最后，使用由不同氯化钠与PCL进料比（20：80、40：60、50：50、60：40和80:20）组成的印刷油墨制造了一系列多孔PCL支架，并采用了机械孔隙率性能，降解行为和生物相容性进行了讨论。结果表明，印刷油墨配方极大地影响了印刷性能。印刷油墨中NaCl含量的增加降低了挤出的剪切力，增强了剪切稀化行为，延长了固化时间。下降温度和溶剂蒸发都增强了印刷油墨的自支撑能力，并且溶剂蒸发是固化印刷油墨的关键因素。进一步的评估表明，所制得的多孔PCL支架具有良好的生物相容性和可控的孔隙率，机械性能和与印刷油墨中NaCl含量有关的体外降解行为。这项研究建立了一种在低温下通过3D打印制造多孔聚合物支架的方法，用于再生医学研究。