细胞色素c在SBA - 15上吸附的动力学建模
Kinetic modelling of cytochrome c adsorption on SBA-15.
作者信息
Yokogawa Yoshiyuki, Yamauchi Rie, Saito Akira, Yamato Yuta, Toma Takeshi
机构信息
Graduate school of engineering, Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
出版信息
Biomed Mater Eng. 2017;28(1):37-46. doi: 10.3233/BME-171654.
The adsorption capacity of mesoporous silicate (MPS) materials as an adsorbent for protein adsorption from the aqueous phase and the mechanism of the adsorption processes by comparative analyses of the applicability of five kinetic transfer models, pseudo-first-order model, pseudo-second-order model, Elovich kinetic model, Bangham's equation model, and intraparticle diffusion model, were investigated. A mixture of tetraethyl orthosilicate (TEOS) and triblock copolymer as a template was stirred, hydrothermally treated to form the mesoporous SBA-15 structure, and heat-treated at 550°C to form the MPS material, SBA-15. The synthesized SBA-15 was immersed in a phosphate buffered saline (PBS) solution containing cytochrome c for 2, 48, and 120 hours at 4°C. The TEM observations of proteins on/in mesoporous SBA-15 revealed the protein behaviors. The holes of the MPS materials were observed to overlap those of the stained proteins for the first 2 hours of immersion. The stained proteins were observed between primary particles and partly inside the mesoporous channels in the MPS material when it had been immersed for 48 hours. For MPS when it had been immersed for 120 hours, stained proteins were observed in almost all meso-scale channels of MPS. The time profiles for adsorption of proteins can be described well by Bangham's equation model and the intraparticle diffusion model. The Bangham's equation model is based on the assumption that pore diffusion was the only rate controlling step during adsorption, whose contribution to the overall mechanism of cytochrome c adsorption on SBA-15 should not be neglected. The kinetic curves obtained from the experiment for cytochrome c adsorption on SBA-15 could show the three steps: the initial rapid increase of the adsorbed amount of cytochrome c, the second gradual increase, and the final equilibrium stage. These three adsorption steps can be interpreted well by the multi-linearity of the intraparticle diffusion model, proving the significant role of intraparticle diffusion as one of the rate controlling mechanisms.
通过对五种动力学传递模型(伪一级模型、伪二级模型、埃洛维奇动力学模型、班汉姆方程模型和颗粒内扩散模型)适用性的比较分析,研究了介孔硅酸盐(MPS)材料作为从水相中吸附蛋白质的吸附剂的吸附容量以及吸附过程的机制。将正硅酸四乙酯(TEOS)和三嵌段共聚物的混合物作为模板进行搅拌,水热处理以形成介孔SBA - 15结构,并在550°C下热处理以形成MPS材料SBA - 15。将合成的SBA - 15在4°C下浸入含有细胞色素c的磷酸盐缓冲盐水(PBS)溶液中2、48和120小时。对介孔SBA - 15上/内蛋白质的透射电子显微镜观察揭示了蛋白质的行为。在浸入的前2小时内,观察到MPS材料的孔与染色蛋白质的孔重叠。当浸入48小时时,在MPS材料的初级颗粒之间和部分介孔通道内观察到染色蛋白质。对于浸入120小时的MPS,在MPS的几乎所有介观尺度通道中都观察到染色蛋白质。蛋白质吸附的时间曲线可以用班汉姆方程模型和颗粒内扩散模型很好地描述。班汉姆方程模型基于这样的假设,即孔扩散是吸附过程中唯一的速率控制步骤,其对细胞色素c在SBA - 15上吸附的整体机制的贡献不应被忽视。从细胞色素c在SBA - 15上吸附的实验获得的动力学曲线可以显示三个步骤:细胞色素c吸附量的初始快速增加、第二个逐渐增加以及最后的平衡阶段。颗粒内扩散模型的多线性可以很好地解释这三个吸附步骤,证明颗粒内扩散作为速率控制机制之一的重要作用。