Low-temperature deposition manufacturing and property of polylactic-co-glycolic acid composite scaffolds at different ratios

doi:10.3969/j.issn.2095-4344.2015.12.001

Abstract

Abstract:

BACKGROUND: The study confirmed that adding tricalcium phosphate or pearl powder in polylactic-co-glycolic acid can complement the performance of both, which provides a good environment for cells and makes a faster and better growth of cells.
OBJECTIVE: We used polylactic-co-glycolic acid as matrix, composited with pearl powder or tricalcium phosphate to prepare scaffolds by low-temperature deposition manufacturing.
METHODS: Low-temperature deposition manufacturing was utilized to prepare composite scaffold of polylactic-co-glycolic acid/pearl powder or polylactic-co-glycolic acid/tricalcium phosphate at the ratio of 10:0, 5:2, 7:3 and 6:4. Microstructure, contact angle and compression modulus of elasticity of scaffolds were detected. MC3T3-E1 cells basically fused at 1×10⁴/cm³ were seeded in the pure nonporous polylactic-co-glycolic acid scaffold, pure polylactic-co-glycolic acid scaffold with holes, polylactic-co-glycolic acid/pearl powder at 5:2 and polylactic-co-glycolic acid/tricalcium phosphate at 5:2 separately for 1 and 3 hours. Cell adhesion rate was detected using flow cytometry. After incubation for 1, 4 and 7 days, cell proliferation was measured using Alamar Blue method.
RESULTS AND CONCLUSION: Pure polylactic-co-glycolic acid scaffold had cross-linked microporous structure, with pore size of 3-15 μm. Scaffolds of polylactic-co-glycolic acid/pearl powder at 5:2 or polylactic-co-glycolic acid/tricalcium phosphate at 5:2 had good continuous porous structure, with pore size of 10-25 μm. With increased content of pearl powder or tricalcium phosphate, the hydrophilicity of the composite scaffold increased. The addition of pearl powder or tricalcium phosphate could elevate compressive mechanical properties of the composite scaffold. With increased content, the mechanical property of the scaffold enhanced and then reduced. The addition of pearl powder or tricalcium phosphate improved the cellular affinity of polylactic-co-glycolic acid and the biocompatibility of the scaffold. The biocompatibility of polylactic-co-glycolic acid/pearl powder scaffold at 5:2 was the best.

中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

全文链接：

Key words: Calcium Phosphates, Tissue Engineering, Biocompatible Materials

CLC Number:

R318

Hu Tao, Xu Ming-en, Yan Ming, Guo Miao, Shi Ran, Zhou Qing-qing. Low-temperature deposition manufacturing and property of polylactic-co-glycolic acid composite scaffolds at different ratios[J]. Chinese Journal of Tissue Engineering Research, 2015, 19(12): 1805-1811.

Figures/Tables 5

2.4 力学性能实验结果图4所示为试样在压缩应力测量过程，试样测试结束后，记录每个试样检测曲线激活交叉点处于试样应变为5%所对应的压缩应力值，每组材料3个试样，分别记录压缩模量E和压缩屈服应力σy，计算每组平均值和标准偏差，汇总成表2。实验结果表明，加入珍珠粉或磷酸三钙总体上能够提高支架的压缩力学性能。随着珍珠粉含量的增加，支架的压缩弹性模量先增强后减弱，从纯PLGA的22.100 MPa增至5∶2比例的36.097 MPa，增强了71.89%；由5∶2比例增至7∶3比例的36.100 MPa，而6∶4比例相对于5∶2比例减弱了1.377%，降至35.600 MPa。含磷酸三钙的支架，5∶2比例较纯PLGA支架增强了49.02%压缩弹性模量强度，具有最高的压缩性能和抗压强度，与加入珍珠粉材料组一样随着磷酸三钙含量的增加，其力学性能先高于纯PLGA支架后再减弱，7∶3比例较5∶2比例减弱了7.27%，6∶4比例甚至比纯PLGA支架减弱了2.65%。纯PLGA支架与复合珍珠粉的3组比例支架、复合磷酸三钙5∶2比例组差异支架存在显著性意义(P < 0.05)；7组支架材料应力比较差异无显著性意义(P > 0.05)。加入珍珠粉或磷酸三钙能够提高PLGA的力学性能，其压缩力学性能随着珍珠粉或磷酸三钙含量增加先增强后减弱，出现这种现象的原因主要是：随着珍珠粉或磷酸三钙粉末的加入，珍珠粉或磷酸三钙粉末对PLGA基体起到了弥散强化作用，显著提高了材料的压缩力学性能；另一方面，随着珍珠粉或磷酸三钙含量增加到一定程度，珍珠粉或磷酸三钙产生了团聚现象，部分区域珍珠粉或磷酸三钙分布不均匀，破坏了PLGA基体的连续性，实验过程发现复合珍珠粉或磷酸三钙6∶4组在其6 mm左右压缩量时已被粉末性破坏。因此，复合材料支架中珍珠粉或磷酸三钙含量越高并不能提高复合支架的压缩力学性能，随着珍珠粉或磷酸三钙含量的增加，复合材料支架的压缩力学性能呈现先增强后减弱。"

2.5 细胞相容性实验结果细胞黏附率：①MC3T3-E1细胞接种到支架上1 h后：纯PLGA无孔支架细胞黏附数量仅为纯PLGA有孔支架的69.56%(P < 0.01)，表明大孔结构能显著增加支架的表面积，有利于成骨细胞黏附到支架上。而在具有大孔结构的各组支架间，纯PLGA有孔支架细胞黏附率低于PLGA/珍珠粉和PLGA/磷酸三钙复合支架(P < 0.05)，这一结果表明珍珠粉和磷酸三钙的加入，显著改善了支架的亲水性，进而促进了细胞黏附，这与接触角测试的结果一致。而PLGA/珍珠粉和PLGA/磷酸三钙复合支架的细胞黏附率几乎一致，表明两种无机材料的加入对于细胞短时黏附的改善无明显差异，见表3。②MC3T3-E1细胞接种到支架上3 h后：各组支架的细胞黏附率均有20%以上的上升。纯PLGA无孔支架细胞黏附数量仍极显著低于其他有大孔结构的支架(P < 0.01)；而纯PLGA有孔支架与5∶2 PLGA/珍珠粉、5∶2 PLGA/磷酸三钙之间仍存在显著差异(P < 0.05)，而PLGA/珍珠粉和PLGA/磷酸三钙具有良好的细胞亲和力和细胞黏附率，同时两组间的差异无显著性意义(P > 0.05)，见表3。细胞增殖：实验结果表明，从培养第1-7天，纯PLGA有孔支架细胞增殖率比纯PLGA无孔支架分别高出5.39%(P < 0.05)、9.01%(P < 0.01)和5.82%(P < 0.05)，支架的大孔结构加大了细胞黏附表面积，促进了细胞增殖。在具有大孔结构的各组支架间，纯PLGA有孔支架的细胞增殖率低于PLGA/珍珠粉和PLGA/磷酸三钙复合支架，第1天纯PLGA有孔支架细胞增殖率与5∶2比例两组复合支架差异存在非常显著性意义(P < 0.01)，第4，7天差异存在显著性意义(P < 0.05)，珍珠粉和磷酸三钙粉末的加入显著提高了材料的细胞亲和力，不仅提高了细胞黏附率，也获得了比纯PLGA有孔支架高18.69%-44.30%的细胞增殖率。而复合珍珠粉的支架比磷酸三钙支架具有更高的细胞增殖率，从第1-7天分别高出2.57%、0.96%和0.23%，但两者异存无显著性意义(P > 0.05)，见图5。"

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