Gola Agnieszka, Knysak Tomasz, Musial Witold
Department of Physical Chemistry, Pharmaceutical Faculty, Wroclaw Medical University, Borowska 211, 50-556 Wroclaw, Poland.
Molecules. 2016 Dec 26;22(1):23. doi: 10.3390/molecules22010023.
The aim of the study was to monitor the influence of increasing initiator concentrations on the properties of poly--isopropylacrylamide (polyNIPA) nanoparticles obtained via surfactant free precipitation polymerization (SFPP). In all studied systems P-001 to P-1, the same amount of monomer was used, and increasing amounts of potassium persulphate (KPS). The course of each reaction was monitored by measuring the conductivity of the whole system. The resulting composition of products was confirmed by attenuated total reflectance within Fourier transformed infrared spectroscopy (ATR-FTIR) measurements. The hydrodynamic diameters with polydispersity index (PDI) and zeta potential (ZP) were measured in aqueous dispersions of the synthesized polymers in dynamic light scattering (DLS) device (λ = 678 nm), and were found to be for P-1: 20.33 nm (PDI = 0.49) and -7 mV, for P-05: 22.24 nm (PDI = 0.39) and -5 mV, for P-01: 50.14 nm (PDI = 0.49) and -3 mV, for P-005: 62.75 nm (PDI = 0.54) and -3 mV and for P-001: 509.4 nm (PDI = 0.61) and -12 mV at 18 °C, respectively. Initiator concentration affects the size and ZP of particles. The hydrodynamic diameter decreases with initiator concentration increase, whereas the time of the reaction decreases when the initiator concentration increases. This fact is reflected in the observed values of conductivity in the course of the performed reaction. Evaluated volume phase transition temperature in the range of 32 °C enables further research of the nanoparticles as thermosensitive drug carriers.
本研究的目的是监测引发剂浓度增加对通过无表面活性剂沉淀聚合（SFPP）获得的聚异丙基丙烯酰胺（聚NIPA）纳米颗粒性能的影响。在所有研究的体系P - 001至P - 1中，使用相同量的单体，并增加过硫酸钾（KPS）的用量。通过测量整个体系的电导率来监测每个反应的进程。通过傅里叶变换红外光谱（ATR - FTIR）测量中的衰减全反射来确认产物的最终组成。在动态光散射（DLS）装置（λ = 678 nm）中测量合成聚合物在水性分散体中的流体动力学直径以及多分散指数（PDI）和zeta电位（ZP），发现在18℃时，P - 1的流体动力学直径为20.33 nm（PDI = 0.49），ZP为 - 7 mV；P - 05的流体动力学直径为22.24 nm（PDI = 0.39），ZP为 - 5 mV；P - 01的流体动力学直径为50.14 nm（PDI = 0.49），ZP为 - 3 mV；P - 005的流体动力学直径为62.75 nm（PDI = 0.54），ZP为 - 3 mV；P - 001的流体动力学直径为509.4 nm（PDI = 0.61），ZP为 - 12 mV。引发剂浓度影响颗粒的尺寸和ZP。流体动力学直径随引发剂浓度增加而减小，而反应时间随引发剂浓度增加而缩短。这一事实反映在所进行反应过程中观察到的电导率值上。评估的体积相变温度在32℃范围内，这使得对纳米颗粒作为热敏药物载体的进一步研究成为可能。
