含不同氨基酸反相微乳体系中胆红素钙的形成与稳定性

Synthesis and Stability of Calcium Bilirubinate in Inverse Microemulsions Containing Different Amino Acids

在聚乙二醇辛基苯基醚(OP)/正己醇/环己烷/水反相微乳液和甘氨酸、精氨酸、组氨酸3种含不同氨基酸的反相微乳液体系中成功地制备了胆红素钙,考察了氨基酸对胆红素钙的组成、形貌、配位方式及稳定性的影响。采用透射电子显微镜、表面Zeta电位、红外光谱和紫外光谱等测试技术对样品进行了表征。结果表明,此反相微乳体系中所得球形颗粒为中性胆红素钙,平均粒径80nm,在水分散体系中颗粒的稳定性随分散体系pH值的升高而先降低后增加,当pH=4.9时,颗粒表面Zeta电位值为0。3种亲水性氨基酸的加入促进胆红素钙颗粒的成核,最终影响胆红素钙的微结构、颗粒形貌和稳定性。当加入的氨基酸为组氨酸、甘氨酸时,所得胆红素钙球形颗粒形貌无明显变化,但平均粒径依次减小至60和40nm,其水分散体系中的稳定性明显增加;当加入的氨基酸为精氨酸时,所得胆红素钙颗粒形貌不规则,粒径非常小,不稳定,易形成聚集体。

Triton X-100/n-hexylalcohoL/cyclohexane/water inverse microemulsion, 3 inverse microemulsions containing glycin（Gly）, arginine（Arg） or histidine（His） were selected as the template to induce the formation of calcium bilirubinate（CaBR） nanoparticles and the effects of amino acids were investigated. CaBRs were characterized by transmission electron microscopy（TEM）, Fourier transform infrared spectroscopy （FTIR）, ultraviolet-visible spectroscopy（UV-Vis） and zeta potential, respectively. The results show that the global CaBR nanoparticles with an average diameter of 80 nm were successfully synthesized in the inverse microemulsion systems, and the stability of suspended CaBR nano particles in aqueous solution decreases first and then increases with the increase of solution pH values, and zeta potential absolute value of CaBR particles was 0 mV when the pH of the suspension solution was around 4. 9. The addition of each of three hydrophilic amino acids（AAs） is helpful to the nucleation of CaBR and influences the microstructure, morphology and agglomeration of CaBR. Global CaBR nanoparticles also formed successfully in the microemlulsion and the stability of the aqueous suspended nanoparticles increased with the addition of His or Gly, but the average diameters of them reduced to 60 nm or 40 nm, respectively. Irregular CaBR nanoparticles with the smallest diameter were produced in inverse microemulsion containing Arg and were easy to agglomerate in aqueous suspended solution.