Li Jin Lan, Cai Yan Li, Guo Yi Lin, Fuh Jerry Ying Hsi, Sun Jie, Hong Geok Soon, Lam Ruey Na, Wong Yoke San, Wang Wilson, Tay Bee Yen, Thian Eng San
Department of Mechanical Engineering, National University of Singapore, Singapore 117576, Singapore.
J Biomed Mater Res B Appl Biomater. 2014 May;102(4):651-8. doi: 10.1002/jbm.b.33043. Epub 2013 Oct 24.
Biodegradable polymeric scaffolds have been widely used in tissue engineering as a platform for cell proliferation and subsequent tissue regeneration. Conventional microextrusion methods for three-dimensional (3D) scaffold fabrication were limited by their low resolution. Electrospinning, a form of electrohydrodynamic (EHD) printing, is an attractive method due to its capability of fabricating high-resolution scaffolds at the nanometer/micrometer scale level. However, the scaffold was composed of randomly orientated filaments which could not guide the cells in a specific direction. Furthermore, the pores of the electrospun scaffold were small, thus preventing cell infiltration. In this study, an alternative EHD jet printing (E-jetting) technique has been developed and employed to fabricate 3D polycaprolactone (PCL) scaffolds with desired filament orientation and pore size. The effect of PCL solution concentration was evaluated. Results showed that solidified filaments were achieved at concentration >70% (w/v). Uniform filaments of diameter 20 μm were produced via the E-jetting technique, and X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopic analyses revealed that there was no physicochemical changes toward PCL. Scaffold with a pore size of 450 μm and porosity level of 92%, was achieved. A preliminary in vitro study illustrated that live chondrocytes were attaching on the outer and inner surfaces of collagen-coated E-jetted PCL scaffolds. E-jetted scaffolds increased chondrocytes extracellular matrix secretion, and newly formed matrices from chondrocytes contributed significantly to the mechanical strength of the scaffolds. All these results suggested that E-jetting is an alternative scaffold fabrication technique, which has the capability to construct 3D scaffolds with aligned filaments and large pore sizes for tissue engineering applications.
可生物降解的聚合物支架已在组织工程中广泛用作细胞增殖和后续组织再生的平台。用于三维（3D）支架制造的传统微挤压方法受其低分辨率的限制。静电纺丝作为一种电流体动力学（EHD）打印形式，是一种有吸引力的方法，因为它能够在纳米/微米尺度上制造高分辨率支架。然而，该支架由随机取向的细丝组成，无法在特定方向上引导细胞。此外，静电纺丝支架的孔隙很小，从而阻止了细胞浸润。在本研究中，开发了一种替代的EHD喷射打印（E-喷射）技术，并用于制造具有所需细丝取向和孔径的3D聚己内酯（PCL）支架。评估了PCL溶液浓度的影响。结果表明，浓度>70%（w/v）时可实现固化细丝。通过E-喷射技术制备了直径为20μm的均匀细丝，X射线衍射和衰减全反射傅里叶变换红外光谱分析表明PCL没有发生物理化学变化。获得了孔径为450μm、孔隙率为92%的支架。一项初步的体外研究表明，活的软骨细胞附着在胶原涂层的E-喷射PCL支架的外表面和内表面。E-喷射支架增加了软骨细胞外基质的分泌，软骨细胞新形成的基质对支架的机械强度有显著贡献。所有这些结果表明，E-喷射是一种替代的支架制造技术，它有能力构建具有排列细丝和大孔径的3D支架用于组织工程应用。
