Neufurth Meik, Wang Xiaohong, Wang Shunfeng, Steffen Renate, Ackermann Maximilian, Haep Natalie D, Schröder Heinz C, Müller Werner E G
ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University, Johann Joachim Becher Weg 13, D-55099 Mainz, Germany.
Acta Biomater. 2017 Dec;64:377-388. doi: 10.1016/j.actbio.2017.09.031. Epub 2017 Sep 28.
Here we describe the formulation of a morphogenetically active bio-ink consisting of amorphous microparticles (MP) prepared from Ca and the physiological inorganic polymer, polyphosphate (polyP). Those MP had been fortified by mixing with poly-ε-caprolactone (PCL) to allow 3D-bioprinting. The resulting granular PCL/Ca-polyP-MP hybrid material, liquefied by short-time heating to 100 °C, was used for the 3D-printing of tissue-like scaffolds formed by strands with a thickness of 400 µm and a stacked architecture leaving ≈0.5 mm-sized open holes enabling cell migration. The printed composite scaffold turned out to combine suitable biomechanical properties (Young's modulus of 1.60 ± 0.1 GPa; Martens hardness of 153 ± 28 MPa), matching those of cortical and trabecular bone, with morphogenetic activity. This scaffold was capable of attracting and promoting the growth of human bone-related SaOS-2 cells as demonstrated by staining for cell viability (Calcein AM), cell density (DRAQ5) and SEM studies. Furthermore, the hybrid material was demonstrated to upregulate the steady-state-expression of the cell migration-inducing chemokine SDF-1α. EDX analysis and FTIR measurements revealed the presence of hydroxyapatite in the mineral deposits formed on the scaffold surface. Based on the results we conclude that granular PCL/Ca-polyP-MP hybrid material is suitable for the fabrication of bioprintable scaffold which comprises not only biomechanical stability but also morphogenetic potential.
In present-day regenerative engineering efforts, biomaterial- and cell-based strategies are proposed that meet the required functional and spatial characteristics and variations, especially in the transition regions between soft (cartilage, tendon or ligament) and hard (bone) tissues. In a biomimetic approach we succeeded to fabricate amorphous Ca-polyP nanoparticles/microparticles which are highly biocompatible. Together with polycaprolactone (PCL), polyP can be bio-printed. This hybrid material attracts the cells, as documented optically as well as by a gene-expression studies. Since PCL is already a FDA-approved organic and inert polymer and polyP a physiological biologically active component this new bio-hybrid material has the potential to restore physiological functions, including bone remodelling and regeneration if used as implant.
在此，我们描述了一种形态发生活性生物墨水的配方，该生物墨水由钙制备的无定形微粒（MP）和生理性无机聚合物聚磷酸盐（polyP）组成。通过与聚ε-己内酯（PCL）混合对这些MP进行强化，以实现3D生物打印。通过短时间加热至100°C液化得到的粒状PCL/Ca-polyP-MP混合材料，用于3D打印由厚度为400μm的细丝形成的组织样支架，其具有堆叠结构并留有约0.5mm大小的开孔以实现细胞迁移。结果表明，打印的复合支架结合了合适的生物力学性能（杨氏模量为1.60±0.1GPa；马氏硬度为153±28MPa），与皮质骨和小梁骨的性能相匹配，同时具有形态发生活性。通过细胞活力染色（钙黄绿素AM）、细胞密度染色（DRAQ5）和扫描电子显微镜研究表明，该支架能够吸引并促进人骨相关SaOS-2细胞的生长。此外，已证明该混合材料可上调细胞迁移诱导趋化因子SDF-1α的稳态表达。能谱分析和傅里叶变换红外光谱测量揭示了在支架表面形成的矿物质沉积物中存在羟基磷灰石。基于这些结果，我们得出结论，粒状PCL/Ca-polyP-MP混合材料适用于制造不仅具有生物力学稳定性而且具有形态发生潜力的生物可打印支架。
在当今的再生工程研究中，人们提出了基于生物材料和细胞的策略，以满足所需的功能和空间特性及变化，特别是在软（软骨、肌腱或韧带）硬（骨）组织之间的过渡区域。我们采用仿生方法成功制备了具有高度生物相容性的无定形Ca-polyP纳米颗粒/微粒。聚磷酸盐与聚己内酯（PCL）一起可进行生物打印。如光学记录以及基因表达研究所证明的，这种混合材料能够吸引细胞。由于PCL已经是一种经美国食品药品监督管理局批准的有机惰性聚合物，而聚磷酸盐是一种生理性生物活性成分，这种新型生物混合材料如果用作植入物，具有恢复生理功能（包括骨重塑和再生）的潜力。
