Thermal modulated interaction of aqueous steroids using polymer-grafted capillaries
Thermal modulated interaction of aqueous steroids using polymer-grafted capillaries
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DOI：
10.1021/la051968h
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发表时间：
2006-01-03
期刊：
影响因子：
3.9
通讯作者：
Okano, T
中科院分区：
文献类型：
--
作者：
Idota, N;Kikuchi, A;Okano, T
采用表面引发原子转移自由基聚合（ATRP）方法，将分子量可控的聚N-异丙基丙烯酰胺（PIPAAm）致密接枝到玻璃毛细管表面。这些温敏刷表面与疏水类固醇的温度依赖性的变化进行了研究，通过利用温敏水的润湿性变化的聚合物改性的表面在微流体系统中。使用CuCl/CuCl 2/三（二甲基氨基乙基）胺（Me 6 TREN）作为ATRP催化剂，在水中于25 ℃下使IPAAm在ATRP引发剂固定的玻璃表面上聚合。通过改变ATRP反应时间来控制PIPAAm接枝层厚度及其在玻璃表面上的均匀性。PIPAAm接枝表面的水润湿性变化对接枝聚合物层厚度和温度的响应急剧变化，尤其是在较低温度下。然后使用毛细管色谱法研究了这些PIPAAm刷在毛细管内壁表面内的温度响应表面性质。在30 ℃以上，没有任何柱填充材料的情况下，观察到疏水类固醇与脱水的、疏水化的PIPAAm接枝的毛细管表面的有效相互作用。类固醇从PIPAAm接枝毛细管的洗脱行为与通过电子束（EB）照射制备的PIPAAm水凝胶接枝多孔整体二氧化硅毛细管的洗脱行为形成鲜明对比，其中在高温下观察到显著的峰增宽，而不管样品疏水性因子（log P值），表明涂覆的整体二氧化硅毛细管中的多步分离模式。总之，ATRP制备的温敏聚合物接枝的毛细管内壁表面表现出有用的温度依赖性的表面性质的改变，有效地调节与生物分子的相互作用，而不需要分离床填充材料内的毛细管内腔。
Poly (N-isopropylacrylamide) (PIPAAm) of controlled molecular weight was densely grafted onto glass capillary lumenal surfaces using surface-initiated atom transfer radical polymerization (ATRP). Temperature-dependent changes of these thermoresponsive brush surfaces with hydrophobic steroids were investigated by exploiting thermoresponsive aqueous wettability changes of the polymer-modified surfaces in microfluidic systems. IPAAm was polymerized on ATRP initiator-immobilized glass surfaces using CuCl/CuCl2/tris(dimethylaminoethyl)amine (Me6TREN) as an ATRP catalyst in water at 25 C. PIPAAm graft layer thickness and its homogeneity on glass surfaces are controlled by changing ATRP reaction time. Aqueous wettability changes of PIPAAm-grafted surfaces responses drastically changed to both grafted polymer layer thickness and temperature, especially at lower temperatures. Temperature-responsive surface properties of these PIPAAm brushes within capillary inner wall surfaces were then investigated using capillary chromatography. Effective interaction of hydrophobic steroids with dehydrated, hydrophobized PIPAAm-grafted capillary surfaces was observed above 30 C without any column packing materials. Steroid elution behavior from PIPAAm-grafted capillaries contrasted sharply with that from PIPAAm hydrogel-grafted porous monolithic silica capillaries prepared by electron beam (EB) irradiation wherein significant peak broadening was observed at high-temperature regardless of sample hydrophobicity factors (log P values), indicating multistep separation modes in coated monolithic silica capillaries. In conclusion, thermoresponsive polymer-grafted capillary inner wall surfaces prepared by ATRP exhibit useful temperature-dependent surface property alterations effective to regulate interactions with biomolecules without requirements for separation bed packing materials within the capillary lumen.