Kwon Kyeongnan, Kim Jin-Chul
Department of Medical Biomaterials Engineering, College of Biomedical Science and Institute of Bioscience and Biotechnology, Kangwon National University, 192-1, Hyoja 2 dong, Chuncheon, Kangwon-do 20-701, Republic of Korea.
J Nanosci Nanotechnol. 2018 May 1;18(5):3102-3109. doi: 10.1166/jnn.2018.14690.
A reduction-responsive solid lipid nanoparticles (SLNs) were prepared by an emulsification evaporation and solidification method using stearic acid (SA) and cystamine as constituting materials. The mean hydrodynamic diameter of the SLN decreased from 510.6 nm to 117.0 nm, as the molar ratio of SA to cystamine increased from 1:0 to 1:1. On the TEM photo, negatively stained SLNs were found as black circles and the diameter was tens to hundreds of nanometer. According to the EDS analysis, the sulfur content of SLN was found to be 1.19% (w/w) to 3.62% (w/w), depending on the molar ratio of SA to cystamine (1:0.125 to 1:1) employed in the preparation. According to the differential scanning calorimetric analysis, the melting point decreased gradually from about 52 °C to 50 °C as the molar ratio of SA to cystamine increased from 1:0 to 1:1. Even if cystamine (a disulfide compound) was contained in SLN, the release degree at 25 °C was not significantly affected by dithiothreitol (DTT, a reducing agent). Whereas, the release degree at 37 °C and 52 °C was significantly suppressed by DTT when cystamine was contained in SLN, possibly because cystamine would be more readily reduced to aminoethanethiols in the SLN matrix at the higher temperatures.
以硬脂酸（SA）和胱胺为构成材料，通过乳化蒸发固化法制备了一种还原响应型固体脂质纳米粒（SLN）。随着SA与胱胺的摩尔比从1:0增加到1:1，SLN的平均流体动力学直径从510.6 nm降至117.0 nm。在透射电镜照片上，负染色的SLN呈黑色圆圈，直径为几十到几百纳米。根据能谱分析，根据制备中使用的SA与胱胺的摩尔比（1:0.125至1:1），SLN的硫含量为1.19%（w/w）至3.62%（w/w）。根据差示扫描量热分析，随着SA与胱胺的摩尔比从1:0增加到1:1，熔点从约52℃逐渐降至50℃。即使SLN中含有胱胺（一种二硫化物化合物），25℃下的释放程度也不受二硫苏糖醇（DTT，一种还原剂）的显著影响。然而，当SLN中含有胱胺时，37℃和52℃下的释放程度受到DTT的显著抑制，这可能是因为在较高温度下，胱胺在SLN基质中更容易还原为氨基乙硫醇。
