改性细菌纤维素/羟基磷灰石复合多孔支架合成方法的研究

Research on the Synthesis of Modified Bacterial Cellulose / Hydroxyapatite Sponges

探讨不同合成方法对改性细菌纤维素/羟基磷灰石复合支架微观结构和性能的影响。采用原位复合法、物理混合法及生物矿化法制备改性细菌纤维素(TBC)与羟基磷灰石(HA)复合多孔支架,利用扫描电镜(SEM)、能谱分析(EDX)、X射线衍射(XRD)、傅里叶红外变换光谱(ATR-FTI)对不同方法合成的产物进行微观结构表征,同时通过力学实验确定不同支架的力学性能参数。SEM和ATR-FTI等结果表明,采用原位复合法、物理混合法及生物矿化法都可以成功地将HA复合在TBC的纳米纤维上,但是复合的机理各不相同。原位复合法中HA纳米颗粒是以螯合键的方式与TBC纳米纤维上的羧基联合,而物理混合和生物矿化法HA纳米颗粒是采用静电吸附的方式复合在TBC纤维上。XRD表明,不同方法合成的支架都出现了明显的(211)峰,但峰的形态有明显的差别。力学测试结果表明,复合后产物的力学性能也有很大的差异,采用原位复合的支架强度最低,复合后支架强度由4.67 MPa迅速减小到1.00 MPa,而用生物矿化复合的支架强度最高,复合后支架强度由4.67 MPa增加到到5.55 MPa。通过对不同方法合成的复合支架微观结构的表征和分析,为骨组织工程支架的设计提供依据。

The purpose of this study is to investigate three kinds of preparation methods for bacterial cellulose and hydroxyapatite sponges and compare the microstructure and characteristics. The modified bacterial cellulose（ TBC） and hydroxyapatite（ HA） sponges were fabricated by in situ formation, physical mixing orbiomineralization. Samples prepared by the different methods were characterized using scanning electron microscopy（ SEM）, energy spectrum analysis（ EDX）,X-ray diffraction（ XRD）, Fourier IR transform spectroscopy（ ATR-FTI）. Furthermore mechanical performance of the sponges prepared with different parameters were tested as well. Experimental results showed that by the in situ formation,physical mixing orbiomineralization HA was successfully deposited on TBC nanofibers,but mechanisms were different. By the in situ formation method,HA nanoparticles took the form of chelate keys associated with TBC nano fibers on the carboxyl. In the physical mixing orbiomineralization methods, HA nanoparticles became electrostatically adsorbed on TBC nanofibers. XRD results showed that there were obvious（ 211） peaks in the scaffolds synthesized by different methods,but there were significant differences in the morphology of the peaks.Mechanical results showed that microstructure and mechanical properties of sponge also had very big difference with different composite methods. By the in situ formation method,the scaffold minimum intensity was reducedfrom 4. 67 MPa to 1. 00 MPa,while by the biomineralization,scaffold maximum intensitywas increased from4. 67 MPa to 5. 55 MPa. Through the analysis of the microstructure and characterization of the scaffolds,our study could provide the basis for their application to bone tissue engineering.