Wo Jin, Huang Shi-Shu, Wu Dong-Ying, Zhu Jun, Li Zhi-Zhong, Yuan Feng
Jinan University, Guangzhou, Guangdong, China.
Spinal Surgery Department, Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China.
J Appl Biomater Funct Mater. 2020 Jan-Dec;18:2280800020934652. doi: 10.1177/2280800020934652.
In this study, pore size and porosity distribution of porous Ti-6Al-4V scaffolds (pTi) were controlled by 3D printing. The effects of pore size distribution at a constant porosity, or porosity distribution at a constant pore size pertaining to functions of adhesion, proliferation, and differentiation of the mouse embryonic osteoblast precursor (MC3T3-E1) cells were researched separately.
3D printing was used to design five groups of pTi, designated as PS/HP, PS/LP, PS/HP, PS/LP, and PS/HP based on pore size and porosity distribution. MC3T3-E1 cells were cultured on pTi, and non-porous Ti-6Al-4V samples (npTi) were prepared as control. The pTi was characterized with the scanning electron microscopy (SEM). MC3T3-E1 cells were stained AlamarBlue assay and viability and proliferation analyzed. The mRNA levels of alkaline phosphatase (ALP), osteocalcin (OCN), collagentype-1 (Col-1), and runt-related transcription factor 2 (Runx2) in MC3T3-E1 cells were analyzed by real-time PCR analysis.
The average pore size and porosity of pTi were recorded as (301 ± 9 μm, 58.8 ± 1.8%), (300 ± 9 μm, 43.4 ± 1.3%), (501 ± 11 μm, 58.3 ± 1.2%), (499 ± 12 μm, 42.7 ± 1.1%), and (804 ± 10 μm, 58.9 ± 1.3%), respectively. SEM images confirmed active attachment of cells and oriented with the direction of metal rod after pTi/MC3T3-E1 co-culture for 3 and 7 days. In addition, MC3T3-E1 cells grown on the PS/HP displayed significantly higher proliferation compared with each group after 3 days incubation ( < 0.05). Moreover, cells showed some degree of proliferation in all groups, with the highest value recorded for PS/HP after culture for 7 days ( < 0.05). The gene expression pattern of ALP, OCN, Col-1, and Runx2 confirmed that these were down-regulated when pore size increased or porosity decreased of pTi ( < 0.05).
The pTi facilitated the adhesion and differentiation of osteoblast when pore size decreased or porosity increased. The scaffold model resembles physical modification with porous structures, which has potential application in the surface modifications of Ti implant.
在本研究中，通过3D打印控制多孔Ti-6Al-4V支架（pTi）的孔径和孔隙率分布。分别研究了在恒定孔隙率下孔径分布或在恒定孔径下孔隙率分布对小鼠胚胎成骨细胞前体（MC3T3-E1）细胞黏附、增殖和分化功能的影响。
采用3D打印设计了五组pTi，根据孔径和孔隙率分布分别命名为PS/HP、PS/LP、PS/HP、PS/LP和PS/HP。将MC3T3-E1细胞接种在pTi上培养，并制备无孔Ti-6Al-4V样品（npTi）作为对照。用扫描电子显微镜（SEM）对pTi进行表征。采用AlamarBlue法对MC3T3-E1细胞进行染色，并分析细胞活力和增殖情况。通过实时PCR分析MC3T3-E1细胞中碱性磷酸酶（ALP）、骨钙素（OCN）、I型胶原（Col-1）和 runt相关转录因子2（Runx2）的mRNA水平。
pTi的平均孔径和孔隙率分别记录为（301±9μm，58.8±1.8%）、（300±9μm，43.4±1.3%）、（501±11μm，58.3±1.2%）、（499±12μm，42.7±1.1%）和（804±10μm，58.9±1.3%）。SEM图像证实，pTi与MC3T3-E1共培养3天和7天后，细胞能有效黏附并沿金属棒方向排列。此外，在PS/HP上生长的MC3T3-E1细胞在培养3天后的增殖能力明显高于其他各组（P<0.05）。而且，所有组的细胞均有一定程度的增殖，培养7天后PS/HP组的增殖值最高（P<0.05）。ALP、OCN、Col-1和Runx2的基因表达模式证实，当pTi的孔径增大或孔隙率降低时，这些基因表达下调（P<0.05）。
当孔径减小或孔隙率增加时，pTi促进成骨细胞的黏附与分化。该支架模型类似于具有多孔结构的物理改性，在钛植入物表面改性方面具有潜在应用价值。
