二氧化硅/羟基磷灰石晶须多孔陶瓷支架的制备与性能研究

Preparation and properties of silica/hydroxyapatite whiskers porous ceramics scaffold

目的探讨一种新型二氧化硅(SiO_(2))/羟基磷灰石(hydroxyapatite,HAP)晶须多孔陶瓷支架材料的制备及其性能。方法采用St?ber法对HAP晶须表面进行SiO_(2)微球改性,采用不同条件制备3种SiO_(2)/HAP晶须(1号SiO_(2)/HAP晶须正硅酸乙酯、搅拌时间、煅烧温度、保温时间分别为10 mL、12 h、560℃、0.5 h,2号SiO_(2)/HAP晶须分别为15 mL、24 h、650℃、2 h,3号SiO_(2)/HAP晶须分别为20 mL、48 h、750℃、4 h)。对自制HAP晶须和3种SiO_(2)/HAP晶须进行物相与形貌分析(包括X射线衍射分析和扫描电镜观察)。采用机械发泡法结合挤出成型法,以自制HAP晶须和3种SiO_(2)/HAP晶须为原料,低温热处理方式制备多孔陶瓷材料。对多孔陶瓷进行扫描电镜观察及孔隙率和孔径分布检测,并进行轴向抗压强度测定,采用模拟体液检测其生物降解性能,采用细胞计数试剂盒8法对多孔陶瓷浸提液进行细胞毒性实验。结果成功对HAP晶须表面进行SiO_(2)微球改性,并以此为原料制备了多孔陶瓷材料。SiO_(2)/HAP晶须中SiO_(2)微球为非结晶态,球径约200 nm,微球数量可控,分布均匀且附着性较好。SiO_(2)/HAP晶须多孔陶瓷支架的显气孔率约为78%,其孔隙结构由排列整齐的纵向直通孔及大量微纳米级贯通孔构成。与HAP晶须多孔陶瓷相比,SiO_(2)/HAP晶须多孔陶瓷的轴向抗压强度可达1.0 MPa,强度提高了近4倍;其中2号SiO_(2)/HAP晶须多孔陶瓷的轴向抗压强度最大。HAP晶须表面附着的SiO_(2)微球能为磷灰石的沉积提供位点;SiO_(2)微球含量越高,磷灰石的沉积速率越快。制备的多孔陶瓷细胞毒性等级为0~1级,无细胞毒性。结论SiO_(2)/HAP晶须多孔陶瓷具有良好的生物活性、高孔隙率、三维复合孔隙结构、较好的轴向抗压强度以及无细胞毒性,是一种有应用前景的骨组织工程支架材料。

Objective To investigate the preparation and properties of the novel silica(SiO_(2))/hydroxyapatite(HAP)whiskers porous ceramics scaffold.Methods The HAP whiskers were modified by the SiO_(2)microspheres usingthe Stöber method.Three types of SiO_(2)/HAP whiskers were fabricated under different factors(for the No.1 samples,thecontent of tetraethoxysilane,stirring time,calcination temperature,and soaking time were 10 mL,12 hours,560℃,and0.5 hours,respectively;and in the No.2 samples,those were 15 mL,24 hours,650℃,and 2 hours,respectively;while thosein the No.3 samples were 20 mL,48 hours,750℃,and 4 hours,respectively).The phase and morphology of the self-madeHAP whisker and 3 types of SiO_(2)/HAP whiskers were detected by the X-ray diffraction analysis and scanning electronmicroscopy.Taken the self-made HAP whisker and 3 types of SiO_(2)/HAP whiskers as raw materials,various porousceramic materials were prepared using the mechanical foaming method combined with extrusion molding method,andthe low-temperature heat treatment.The pore structure of porous ceramics was observed by scanning electronmicroscopy.Its porosity and pore size distribution were measured.And further the axial compressive strength was measured,and the biodegradability was detected by simulated body fluid.Cell counting kit 8 method was used to conductcytotoxicity experiments on the extract of porous ceramics.Results The SiO_(2)microspheres modified HAP whiskers andits porous ceramic materials were prepared successfully,respectively.In the SiO_(2)/HAP whiskers,the amorphous SiO_(2)microspheres with a diameter of 200 nm,uniform distribution and good adhesion were attached to the surface of thewhiskers,and the number of microspheres was controllable.The apparent porosity of the porous ceramic scaffold wasabout 78%,and its pore structure was composed of neatly arranged longitudinal through-holes and a large number ofmicro/nano through-holes.Compared with HAP whisker porous ceramic,the axial compressive strength of the SiO_(2)/HAPwhisker porous ceramics could reach 1.0 MPa,which increased the strength by nearly 4 times.Among them,the axialcompressive strength of the No.2 SiO_(2)/HAP whisker porous ceramic was the highest.The SiO_(2)microspheres attached tothe surface of the whiskers could provide sites for the deposition of apatite.With the content of SiO_(2)microspheresincreased,the deposition rate of apatite accelerated.The cytotoxicity level of the prepared porous ceramics ranged from0 to 1,without cytotoxicity.Conclusion SiO_(2)/HAP whisker porous ceramics have good biological activity,high porosity,three-dimensional complex pore structure,good axial compressive strength,and no cytotoxicity,which make it apromising scaffold material for bone tissue engineering.