具有定向孔结构的多孔BCP支架的制备与性能

发布时间：2018-07-09 22:07

本文选题：双相磷酸钙陶瓷 + 多孔　；参考：《华南理工大学》2015年硕士论文

【摘要】：本文针对目前冷冻干燥法制备的定向多孔磷酸钙陶瓷材料在孔隙宽度和力学性能上存在的不足,采用冰晶模板-冷冻干燥法制备了具有定向多孔结构的双相磷酸钙(BCP)陶瓷支架材料。通过优化烧成制度;加入Na Cl等添加剂调控孔结构;灌注卵磷脂改性PLGA溶液和添加磷酸盐玻璃(PG)烧结助剂两种方法对支架进行增强,并评价增强支架的细胞行为,从而得到了结构和性能较好的多孔孔双相磷酸钙陶瓷支架。通过将中位径为7.554μm的β-TCP粉末和中位径为12.024μm的HA粉末在去离子水中机械混合制备了较为均匀的BCP料浆,灌注后采用冰晶模板-冷冻干燥法制备了具有定向多孔结构的双相磷酸钙陶瓷材料。通过探究烧成温度(1000~1300°C)和保温时间(2、4、6 h)对支架物相组成、多孔结构以及抗压强度的影响,优化了支架的烧成制度。通过在制备料浆时添加Na Cl溶液显著增大了定向多孔BCP支架垂直于冷冻方向上的孔隙尺寸。当Na Cl的添加量为10 wt.%时,支架垂直于冷冻方向上的平均孔径可达111.27μm,支架的抗压强度也得到显著提高。实验还发现,通过在料浆中加入聚乙二醇(PEG)、聚乙烯吡咯烷酮(PVP)并不能促进冰晶尺寸的增大从而得到较大孔径的多孔支架。采用添加磷酸盐生物玻璃(PG)作烧结助剂和灌注卵磷脂改性的PLGA溶液复合的两种增强方法,通过探究PG的添加量和PLGA溶液的灌注浓度,制备得到了具有良好结构和性能的多孔支架材料。当PG添加量为17.5 wt.%时,支架的抗压强度可达5.7 MPa,孔隙率为55.9%;当PLGA溶液的复合浓度为7.5%时,显著提高了支架的韧性,形变量和抗压强度分别可以达到40%和7.8 MPa,孔隙率为57.3%。同时,对增强支架的体外降解性能和细胞生物学行为的研究结果表明PG/BCP和PLGA/BCP多孔支架材料在PBS中浸泡28天后失重率都较低(10%),没有发生崩解,能保持原有的结构,两种材料都具有良好的生物相容性,细胞在材料上都黏附良好,且具有较好的增殖能力,有望经后续改进后应用于骨缺损修复领域。
[Abstract]:In this paper, the defects in pore width and mechanical properties of directional porous calcium phosphate ceramics prepared by freeze-drying method are pointed out. A biphasic calcium phosphate (BCP) ceramic scaffold with directional porous structure was prepared by freezing drying method. The scaffold was enhanced by optimizing sintering system, adding NaCl and other additives to regulate pore structure, injecting lecithin modified PLGA solution and adding phosphate glass (PG) sintering promoter to enhance the scaffold, and to evaluate the cell behavior of the enhanced scaffold. Thus, porous dual phase calcium phosphate ceramic scaffolds with better structure and performance were obtained. By mixing 尾 -TCP powder with a median diameter of 7.554 渭 m and HA powder with a median diameter of 12.024 渭 m in deionized water, a uniform BCP slurry was prepared. After perfusion, biphasic calcium phosphate ceramics with directional porous structure were prepared by freezing drying method. The sintering process of the scaffold was optimized by investigating the effects of sintering temperature (1000 ~ 1300 掳C) and holding time (2 ~ 4 ~ 6 h) on the phase composition, porous structure and compressive strength of the scaffold. The pore size perpendicular to the freezing direction of the directional porous BCP scaffold was significantly increased by adding NaCl solution in the preparation of slurry. The average pore diameter perpendicular to the freezing direction can reach 111.27 渭 m when the NaCl content is 10 wt.%, and the compressive strength of the scaffold is also significantly increased. It was also found that polyvinylpyrrolidone (PVP) could not promote the increase of ice crystal size by adding polyethylene glycol (PEG) to the slurry to obtain porous scaffolds with large pore size. By adding phosphate bioglass (PG) as sintering promoter and by adding lecithin modified PLGA solution, two reinforcement methods were used to study the dosage of PG and the concentration of PLGA solution. Porous scaffolds with good structure and properties were prepared. When PG was added 17.5 wt.%, the compressive strength and porosity of the scaffold reached 5.7 MPA and 55.90.When the composite concentration of PLGA solution was 7.5, the toughness of the scaffold was significantly improved, the shape variable and compressive strength were 40% and 7.8 MPA, respectively, and the porosity was 57.3 MPA. At the same time, the results of in vitro degradation and cell biological behavior of enhanced scaffolds showed that the weight loss rate of PG- / BCP and PLGA / BCP porous scaffolds after 28 days of immersion in PBS was lower (10%), no disintegration occurred, and the original structure could be maintained. The two materials have good biocompatibility, good adhesion on the material, and good proliferative ability. They are expected to be used in the field of bone defect repair after further improvement.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R318.08

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