Unravelling the role of polyols with increasing carbon chain length and OH groups on the phase transition behavior of PNIPAM
Unravelling the role of polyols with increasing carbon chain length and OH groups on the phase transition behavior of PNIPAM
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DOI：
10.1039/c8nj02510j
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发表时间：
2018-08
影响因子：
3.3
通讯作者：
Payal Narang;P. Venkatesu
中科院分区：
文献类型：
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作者：
Payal Narang;P. Venkatesu
在制药、农业和生物医学研究的高级应用中，热响应聚合物（TRP）是在给定温度下表现出构象转变的潜在候选者。 TRP 中的构象转变取决于它们与共溶剂的分子间相互作用以及它们自身片段之间的分子内相互作用的变化。 TRP 的转变行为可以在生物相容性渗透剂存在的情况下改变，生物相容性渗透剂被发现存在于所有生物体中。在这项工作中，我们试图阐明具有不同 C 链长度和 OH 基团的多元醇（即甘油、赤藓糖醇和木糖醇）对聚（N-异丙基丙烯酰胺）（PNIPAM）从线圈到球体转变的影响。结果表明，与 PNIPAM 的典型 LCST 相比，在这些添加剂的存在下观察到 PNIPAM 的较低临界溶解温度 (LCST) 有所降低。观察到的结果可能是由于这些渗透剂对与 PNIPAM 表面相关的水分子的极化能力，因此导致 PNIPAM 的疏水缔合或团聚，从而导致溶液浊度高于特定的相变温度。这些渗透剂在低于 PNIPAM LCST 的温度下以浓度依赖性方式促进塌陷的 PNIPAM 的形成。在当前的研究中，我们采用了各种生物物理技术，例如紫外可见光、荧光和傅里叶变换红外 (FTIR) 光谱研究以及动态光散射 (DLS)。这项工作还可能为合成基于 PNIPAM 的设备和药物输送应用开辟新的替代方案。
In advanced applications of pharmaceutical, agricultural and biomedical research, thermoresponsive polymers (TRPs) are potential candidates which show conformational transitions at given temperatures. The conformational transitions in TRPs depend on their intermolecular interactions with co-solvent and intramolecular interaction changes among their own segments. The transition behavior of TRPs can be altered in the presence of biocompatable osmolytes which are found to be present in all living organisms. Here, in this work, we attempted to elucidate the effect of polyols with varying C-chain length and OH groups, namely glycerol, erythritol and xylitol, on the coil-to-globule transition of poly(N-isopropylacrylamide) (PNIPAM). The results indicate that a decrease in lower critical solution temperature (LCST) of PNIPAM is observed in the presence of these additives as compared to the typical LCST of PNIPAM. The observed results may be due to the polarization ability of these osmolytes towards water molecules associated with the PNIPAM surface and so lead to hydrophobic association or agglomeration of PNIPAM that leads to solution turbidity above the specific phase transition temperature. These osmolytes promote the formation of collapsed PNIPAM at temperatures below that of the LCST of PNIPAM in a concentration dependent manner. For the current study, we employed various biophysical techniques such as UV-visible, fluorescence and Fourier-transform infrared (FTIR) spectroscopic studies along with dynamic light scattering (DLS). This work may also open new alternatives for the synthesis of PNIPAM based devices and drug delivery applications.