模拟体液仿生矿化法制备的羟磷灰石-壳聚糖支架的性能研究

Fabrication and evaluation of hydroxyapatite-chitosan scaffold via simulated body fluid biomimetic mineralization

目的应用模拟体液(SBF)仿生矿化法制备羟磷灰石(HA)-壳聚糖支架,探讨矿化时间对HA-壳聚糖支架结构及细胞相容性的影响。方法应用冷冻干燥法制备壳聚糖支架,将该支架应用交替浸泡法进行预钙化,然后浸入SBF中进行矿化,控制矿化时间分别为7、14、21 d,即为3组实验组,以单纯壳聚糖支架为对照组,检测4组支架的理化性质。再将经过成骨诱导后的脂肪基质干细胞(ADSCs)接种到HA-壳聚糖支架上,检测不同矿化时间支架的细胞相容性。结果矿化14 d,HA-壳聚糖支架的矿化物分布均匀,晶体组成符合HA特征,压缩弹性模量随着矿化时间的延长而增强,在矿化21 d时其压缩弹性模量与对照组的差异具有统计学意义(P<0.05)。矿化14 d,ADSCs的增殖量最多,与其他实验组的差异均有统计学意义(P<0.05);其钙离子和Ⅰ型胶原的分泌量也最多。结论SBF仿生矿化法可用于制备HA-壳聚糖骨组织工程支架,该支架在SBF中矿化14 d左右时其生物相容性及理化性质可达到最佳状态。

Objective This research aimed to fabricate a hydroxyapatite （HA）-chitosan scaffold via simulated body fluid （SBF） biomimetic mineralization and determine how mineralization time affects scaffold construction and cell compatibility. Methods The HA-chitosan scaffolds were fabricated by freeze-drying technique and then subjected to precalcification, also known as alternative soaking method. Afterward, precalcificated scaffolds were placed into the SBF to conduct the minerali- zation process. Mineralization time was set at 7, 14, and 21 days, corresponding to three experimental groups. Pure chitosan scaffolds acted as the control group, and the physical and chemical properties of the four groups were tested. Osteogenic- induced adipose-derived stem cells （ADSCs） were seeded into the scaffolds to investigate the scaffolds＇ cell compatibility. Results The mineral substance of the 14-day group exhibited a uniform distribution. The crystal composition of the mineral substance suited the HA＇s features. The compressive elastic modulus increased along with the extension of mineralization time. The 21-day group showed a statistically significant increase in compressive elastic modulus compared with the control group （P〈0.05）. The cell proliferation level of the 14-day group was significantly the highest among the three experimental groups （P〈0.05）. The calcium ion and the type I collagen had the highest secretion amount when the cells were seeded into the 14-day group. Conclusion The SBF biomimetic mineralization method can be used to fabricate HA-chitosan bone-tissue- engineering scaffolds. The biological compatibility, as well as the chemical and physical properties, reached the optimum levels at day 14.