羧甲基壳聚糖稳定无定形磷酸钙的低温合成及稳定期  

Low-temperature synthesis and stabilization of carboxymethyl chitosan stabilized amorphous calcium phosphate

作　　者：王娉婷[1] 祁星颖 Wang Ping-ting;Qi Xing-ying(Tianjin Medical University School ＆ Hospital of Stomatology,Tianjin 300070,China)

机构地区：[1]天津医科大学口腔医院,天津市300070

出　　处：《中国组织工程研究》2018年第22期3467-3473,共7页Chinese Journal of Tissue Engineering Research

基　　金：天津市自然科学基金重点项目(16JCZDJC32800)~~

摘　　要：背景:无定形磷酸钙可作为生物矿化过程中纳米羟磷灰石的前导相及钙和磷酸盐的储备库,但其稳定性受合成环境影响,容易发生相变。目的:采用钙螯合剂羧甲基壳聚糖(carboxymethyl chitosan,CMCS)稳定无定形磷酸钙,分析稳定无定形磷酸钙的羧甲基壳聚糖最低阈值及陈化时间对无定形磷酸钙稳定期的影响。方法:4℃低温下,在含不同CMCS与Ca摩尔比比值(1∶1,1∶2,1∶3,1∶4,1∶5)的溶液中制备CMCS-无定形磷酸钙沉淀,采用扫描电镜观察沉淀的微观结构,X射线衍射和红外光谱检测沉淀的化学成分,求得合成稳定CMCS-无定形磷酸钙的最低CMCS/Ca比值,并用热重量及差热分析得此比值下复合物中的无定形磷酸钙含量。再以此比值经不同陈化时间(10,30,60,90 min)获得CMCS-无定形磷酸钙复合物,将其溶于模拟体液中,采用X射线衍射和扫描电镜监测无定形磷酸钙的相变,探讨陈化时间对无定形磷酸钙稳定期的影响。结果与结论:(1)X射线衍射与红外光谱图谱显示,当CMCS/Ca≥1∶3时,CMCS-无定形磷酸钙沉淀物为非晶体相;(2)扫描电镜显示,当CMCS/Ca≥1∶3时,沉淀物中可见大量分布均匀的无定形磷酸钙颗粒;(3)通过以上实验得出,低温条件下合成稳定CMCS-无定形磷酸钙复合物的CMCS/Ca最低比值为1∶3,在此比值下复合物中无定形磷酸钙的实际量为63.63%;(4)X射线衍射与扫描电镜显示,当陈化时间为10-60 min时,CMCS-无定形磷酸钙复合物的模拟体液浸泡产物为非晶体态,相位转化时间分别为2,6,8 h;当陈化时间为90 min时浸泡产物为晶体态;(5)结果表明,低温条件下合成稳定CMCS-无定形磷酸钙复合物的CMCS/Ca最低比值为1∶3,在该比值下复合物的稳定期随陈化时间延长而延长,在2-8 h范围内变化。BACKGROUND： Amorphous calcium phosphate can serve as a precursor phase of nano-hydroxyapatite and the storage source for calcium and phosphate. However, the stability of amorphous calcium phosphate is greatly influenced by synthetic environments, which is easy to trigger a phase transition.OBJECTIVE： To stabilize amorphous calcium phosphate by carboxymethyl chitosan（CMCS） and to investigate the lowest threshold of CMCS with stabilizing capacity and the effects of aging time on stabilization period. METHODS： CMCS-amorphous calcium phosphate precipitates in different CMCS/Ca molar ratios（1：1, 1：2, 1：3, 1：4, 1：5） were synthesized at 4 ℃. Their microstructures were observed by scanning electron microscopy（SEM） and chemical compositions were analyzed by powder X-ray diffraction（XRD） and Fourier transform infrared spectroscopy（FTIR）. The lowest threshold of CMCS/Ca with stabilizing capacity was thus acquired. The stable complexes at this lowest threshold were investigated by thermogravimetric analysis and differential scanning calorimetry to determine the content of amorphous calcium phosphate. CMCS-amorphous calcium phosphate complexes with the lowest threshold of CMCS/Ca were then synthesized under different aging times（10, 30, 60, 90 minutes） and dissolved in simulated body fluid. Effects of aging time on stabilization period were discussed following the investigation on the phase transition of amorphous calcium phosphate by SEM and XRD. RESULTS AND CONCLUSION：（1） According to the results from XRD and FTIR, CMCS-amorphous calcium phosphate precipitates were amorphous when CMCS/Ca ≥ 1：3.（2） According to the findings of SEM, plenty of evenly distributed amorphous calcium phosphate particles were found in the precipitates when CMCS/Ca ≥ 1：3.（3） The lowest threshold of CMCS/Ca used for synthesizing the stable CMCS-amorphous calcium phosphate complexes at 4 ℃ reached to 1：3, and the actual content of amorphous calcium phosphate was 63.63%.（4） Accordi

关 键 词：纳米管 碳 辅药 磷酸钙类 组织工程 无定形磷酸钙 羧甲基壳聚糖 稳定性 陈化时间 相位转化 混酸回流 纯化 杂质颗粒 分散性 生物相容性 生物材料 

分 类 号：R318[医药卫生—生物医学工程]