Hypothesis

The new findings in the field of polymeric materials expanding their applications in improving the quality of health care are of primary concern. Undoubtedly, the alteration in surface properties of polymeric materials on addition of different additives may provide a step forward towards their better implications in many areas of science. In this regard, the interactions of poly(N-isopropylacrylamide) (PNIPAM) with two differently behaving additives may lead to a new method to carry the phase transition temperature of PNIPAM more near to body temperature so that it can be easily used in drug delivery through intravenous or oral insertion.

Experiments

Individually, the addition of sodium dodceylsulfate (SDS) and trimethylamine N-oxide (TMAO) is increasing and decreasing the lower critical solution temperature (LCST) of PNIPAM as compared to classical LCST of PNIPAM in aqueous solution, respectively. In the present study, we try to emphasis the role of mixed SDS and TMAO environment in varying ratios on the phase transition behaviour of PNIPAM. Many biophysical techniques are employed such as UV–visible spectroscopy, fluorescence spectroscopy and dynamic light scattering (DLS), Laser Raman spectroscopy technique and Field emission scanning electron Microscopy (FESEM) for this part of work.

Findings

The SDS is observed to form globules with PNIPAM segments and do not lead to turbidity of solution for the concentration greater than 10 µM. The negatively charged SDS bound PNIPAM globules that do not allow PNIPAM to associate, however; TMAO leads to turbid solution resulted from the hydrophobic association of PNIPAM. SDS is found to be very effective in increasing the LCST up to 62.8 ^°C even at very low (7.5 mM) concentration as compared to decreasing efficiency of TMAO where LCST reaches up to 29.4 ^°C for 0.75 M however, their mixture in specified concentration (1 mM SDS and 0.1 M TMAO) can bring the LCST of PNIPAM very near to body temperature (i.e. ∼36 ^°C) that is quiet promising for its use in target delivery engineering. TMAO ability to counteract the adverse effect of SDS is the main core reason in getting LCST near to body temperature.

中文翻译：

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在两种行为不同的添加剂存在下，用聚（N-异丙基丙烯酰胺）达到生理温度的有效研究

假设

聚合物材料领域的新发现正在扩大其在改善医疗保健质量方面的应用，这是主要关注的问题。无疑，添加不同添加剂后聚合材料表面性能的改变可能会朝着它们在许多科学领域中的更好应用迈出一步。在这方面，聚（N-异丙基丙烯酰胺）（PNIPAM）与两种行为不同的添加剂的相互作用可能导致一种新方法，使PNIPAM的相变温度更接近体温，因此可以轻松地用于药物输送通过静脉或口服插入。

实验

分别地，与水溶液中PNIPAM的经典LCST相比，十二烷基硫酸钠（SDS）和三甲胺N-氧化物（TMAO）的添加分别增加和降低PNIPAM的较低临界溶液温度（LCST）。在本研究中，我们试图强调PNDSAM的相变行为以不同比例混合SDS和TMAO环境的作用。在这部分工作中，采用了许多生物物理技术，例如紫外可见光谱，荧光光谱和动态光散射（DLS），激光拉曼光谱技术和场发射扫描电子显微镜（FESEM）。

发现

观察到SDS会形成带有PNIPAM片段的小球，并且浓度大于10 µM时不会导致溶液混浊。但是，带负电荷的SDS绑定的PNIPAM小球不允许PNIPAM结合。TMAO导致由PNIPAM的疏水缔合导致的混浊溶液。与降低TMAO的效率（在0.75 M下LCST达到29.4 ^° C达到0.75 M ）相比，即使在非常低的浓度（7.5 mM）下，SDS也能有效地将LCST升高至62.8  ^° C。  （1 mM SDS和0.1 M TMAO）可以使PNIPAM的LCST非常接近体温（即〜36  ^°C）非常有希望在目标交付工程中使用。TMAO抵抗SDS不利影响的能力是使LCST接近体温的主要原因。