Sugiura Shinji, Imano Wataru, Takagi Toshiyuki, Sakai Kiyotaka, Kanamori Toshiyuki
Research Center of Advanced Bionics, National Institute of Advanced Industrial Science and Technology (AIST), Central 5th, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
Biosens Bioelectron. 2009 Jan 1;24(5):1135-40. doi: 10.1016/j.bios.2008.06.038. Epub 2008 Jul 4.
The control of protein adsorption on microchannel surfaces is important for biosensors. In this study, we demonstrated protein adsorption method that is controlled through temperature change, i.e., thermoresponsive protein adsorption, on polydimethylsiloxane (PDMS) microchannel surfaces using a thermoresponsive polymer, poly(N-isopropylacrylamide) (PNIPAAm). To provide general protein adsorption control method, we adopted biotin-streptavidin chemistry and synthesized streptavidin covalently modified with PNIPAAm (PNIPAAm-StAv). Modification of streptavidin, a hydrophilic protein, with PNIPAAm induced successful thermoresponsive adsorption on a PDMS microchannel surfaces: PNIPAAm-StAv adsorbed at 37 degrees C and desorbed at 10 degrees C on the surfaces. We also demonstrated the thermoresponsive adsorption of biotinylated immunoglobulin G (IgG-b) using PNIPAAm-StAv. Conjugation of IgG-b with PNIPAAm-StAv induced successful thermoresponsive IgG-b adsorption on PDMS. Modification of PDMS surfaces with PNIPAAm reduced physical adsorption of the partially hydrophobic IgG-b on the surface and contributed to the high-contrast thermoresponsive adsorption of IgG-b: less than 1% of the IgG-b adsorbed at 37 degrees C was detected after the PNIPAAm-PDMS surface was washed at 10 degrees C. The controllable adsorption of this system is expected to be applied to the regeneration of biosensor chips and to on-chip protein manipulation.
控制蛋白质在微通道表面的吸附对于生物传感器来说至关重要。在本研究中，我们展示了一种通过温度变化控制的蛋白质吸附方法，即热响应性蛋白质吸附，该方法利用热响应性聚合物聚（N - 异丙基丙烯酰胺）（PNIPAAm）在聚二甲基硅氧烷（PDMS）微通道表面实现。为了提供通用的蛋白质吸附控制方法，我们采用了生物素 - 链霉亲和素化学方法，并合成了用PNIPAAm共价修饰的链霉亲和素（PNIPAAm - StAv）。用PNIPAAm修饰亲水性蛋白质链霉亲和素，成功地在PDMS微通道表面诱导了热响应性吸附：PNIPAAm - StAv在37℃时吸附，在10℃时从表面解吸。我们还展示了使用PNIPAAm - StAv对生物素化免疫球蛋白G（IgG - b）的热响应性吸附。IgG - b与PNIPAAm - StAv的结合成功地在PDMS上诱导了热响应性IgG - b吸附。用PNIPAAm修饰PDMS表面减少了部分疏水性IgG - b在表面的物理吸附，并有助于IgG - b的高对比度热响应性吸附：在PNIPAAm - PDMS表面于10℃洗涤后，检测到在37℃吸附的IgG - b中不到1%残留。该系统的可控吸附有望应用于生物传感器芯片的再生和芯片上的蛋白质操作。
