组氨酸改性壳聚糖多孔支架的制备与表征

Preparation and Characterization of Histidine Grafted Chitosan Porous Scaffolds

以1-(3-二甲氨基丙基)–3-乙基碳二亚胺为引发剂,N-羟基琥珀酰亚胺为催化偶联剂,将组氨酸接枝到壳聚糖上,通过改变组氨酸/壳聚糖的物质的量比及壳聚糖的相对分子质量制得不同取代度的N-组氨酸壳聚糖(NHCS)。利用红外光谱(FT-IR)、核磁共振(1H-NMR)、元素分析(EA)、热重分析(TGA)等进行表征。结果表明,随着组氨酸/壳聚糖的物质的量比增大,取代度增高,NHCS支架材料孔径增大,孔径尺寸分布在5μm～120μm之间,孔隙率均大于85%,可以满足组织工程支架材料的要求。随着pH增大,NHCS的Zeta电位从+13.5 mV降至-22.7 mV,表明其具有pH响应性。当组氨酸/壳聚糖的物质的量比为0.5时制得的NHCS支架材料孔径均一,可为生物矿化提供良好的模板。

Usingl-（3- dimethylamino propyl）-3-ethyl carbodiimide as initiator and N-hydroxysuccinimide as the coupler, the histidine was grafted onto chitosan（CS）. A series of histidine modified chitosan （NHCS） with different substitution degrees were prepared by changing the histidine amount and molecular weight of CS. Chemical structure and morphology of NHCS were characterized through Fourier transform infrared spectrometer, 1H-NMR spectroscopy, elemental analysis, thermal gravimetric analyzer and scanning electron microscope. The results indicate that the degree of substitution increases with the histidine dosage increasing, the pore size of NHCS scaffold increases, the pore size distribution is between 5μm～120/μm, the porosity is over 85 %, which can be applied in the fibroblasts, skin tissue reconstruction and bone tissue engineering. Zeta value of NHCS decreases from ＋ 13.5 mV to -22.7 mV with increase of pH value, which indicates that NHCS shows pH responsibility. Moreover, the pore size of the porous scaffold is comparatively uniform with the molar ratio of histidine to CS 0.5, which can provide a good template for biomineralization.