Li Lifu, Nakaji-Hirabayashi Tadashi, Kitano Hiromi, Ohno Kohji, Kishioka Takahiro, Usui Yuki
Department of Advanced Nano- and Biosciences, Graduate School of Innovative Life Sciences, University of Toyama, Toyama 930-8555, Japan.
Department of Advanced Nano- and Biosciences, Graduate School of Innovative Life Sciences, University of Toyama, Toyama 930-8555, Japan; Department of Applied Chemistry, Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan; Frontier Research Core for Life Sciences, University of Toyama, Toyama 930-8555, Japan.
Colloids Surf B Biointerfaces. 2016 Aug 1;144:180-187. doi: 10.1016/j.colsurfb.2016.04.005. Epub 2016 Apr 6.
A self-assembled monolayer (SAM) of a 2-bromoisobutyryl end group-carrying initiator for atom transfer radical polymerization (ATRP) was constructed on the surface of silicon wafer or glass substrates via a silane-coupling reaction. When the initiator SAM was irradiated with UV light at 254nm, the surface density of bromine atoms was reduced by the scission of CBr bonds as observed by XPS. With the surface-initiated ATRP of the zwitterionic vinyl monomer, carboxymethyl betaine (CMB), the surface density of PCMB brushes could be easily varied by changing the irradiation period of UV light prior to the polymerization. Furthermore, by using a UV-cut shutter sliding above the initiator SAM-modified substrate at a constant speed, the degree of bromine atom removal could be linearly varied along the direction of movement of the shutter. Consequently, the amount of both proteins adsorbed and cells adhered to the PCMB brush-covered substrate could easily be controlled by the gradation of the surface density of PCMB brushes, which suppressed protein adsorption and cell adhesion. Such a technique is very simple and useful for the regulation of the surface density of adsorbed proteins and adhered cells on an originally bio-inert surface.
通过硅烷偶联反应，在硅片或玻璃基板表面构建了用于原子转移自由基聚合（ATRP）的带有2-溴异丁酰端基引发剂的自组装单分子层（SAM）。当用254nm的紫外光照射引发剂SAM时，通过XPS观察到，CBr键断裂使溴原子的表面密度降低。通过两性离子乙烯基单体羧甲基甜菜碱（CMB）的表面引发ATRP，在聚合前改变紫外光的照射时间，可以轻松改变PCMB刷的表面密度。此外，通过使用以恒定速度在引发剂SAM修饰的基板上方滑动的紫外线截止快门，溴原子的去除程度可以沿快门的移动方向线性变化。因此，吸附在PCMB刷覆盖基板上的蛋白质数量和粘附在该基板上的细胞数量都可以通过PCMB刷表面密度的梯度轻松控制，这抑制了蛋白质吸附和细胞粘附。这种技术非常简单且有助于调节原本生物惰性表面上吸附蛋白质和粘附细胞的表面密度。
