Wu Szu-Yuan, Debele Tilahun Ayane, Kao Yu-Chih, Tsai Hsieh-Chih
Institute of Toxicology, College of Medicine, National Taiwan University, Taipei 106, Taiwan.
Department of Radiation Oncology, Wan Fang Hospital, Taipei Medical University, Taipei 116, Taiwan.
Int J Mol Sci. 2017 May 19;18(5):1090. doi: 10.3390/ijms18051090.
Here, dual-sensitive fluorescent branched alginate-polyethyleneimine copolymer (bAPSC) nanogels were synthesized from thiolated alginate and stearoyl-derivatized branched polyethyleneimine. The formation of bAPSC conjugates was confirmed through proton nuclear magnetic resonance and Fourier transform infrared spectroscopy, whereas dynamic light scattering was used to measure the particle size and ζ potential of the nanogels. The fluorescent properties of the nanogels were confirmed through fluorescent spectroscopy and microscopy. In addition to the excitation-dependent fluorescence behavior, the fluorescence emission intensity of bAPSC was altered by both pH and γ-irradiation. This intensity was higher at a lower pH than at a higher pH, and it slightly decreased after γ-irradiation. The drug loading and encapsulation efficiency of bAPSC were 25.9% and 11.2 respectively. An in vitro drug release study revealed that the synthesized nanogels release their doxorubicin (Dox) contents in a time-dependent manner, and the drug release was higher after 96 h of incubation. Approximately 43.74% and 88.36% of Dox was released after 96 h of incubation at pH 5.5 in the absence and presence of glutathione (GSH), respectively. However, relatively lower drug release, approximately 21.6% and 16%, was observed in the presence and absence of GSH at pH 7.4, respectively. Fluorescence microscopy confirmed that Dox-loaded bAPSC nanogels were internalized by HeLa cells, and drug distribution was easily tracked using fluorescent materials without additional probing agents. Moreover, cellular cytotoxicity and hemolysis results revealed less cytotoxicity and hemocompatibility of the synthesized nanogels, confirming that they are the most favorable alternative drug carriers for drug delivery systems.
在此，通过硫醇化海藻酸盐和硬脂酰衍生化支化聚乙烯亚胺合成了双敏感荧光支化海藻酸盐-聚乙烯亚胺共聚物（bAPSC）纳米凝胶。通过质子核磁共振和傅里叶变换红外光谱确认了bAPSC缀合物的形成，而动态光散射用于测量纳米凝胶的粒径和ζ电位。通过荧光光谱和显微镜确认了纳米凝胶的荧光特性。除了激发依赖性荧光行为外，bAPSC的荧光发射强度还受pH值和γ射线照射的影响。该强度在较低pH值下高于较高pH值，并且在γ射线照射后略有下降。bAPSC的载药量和包封率分别为25.9%和11.2。体外药物释放研究表明，合成的纳米凝胶以时间依赖性方式释放其阿霉素（Dox）含量，孵育96小时后药物释放量更高。在pH 5.5下，分别在不存在和存在谷胱甘肽（GSH）的情况下孵育96小时后，约43.74%和88.36%的Dox被释放。然而，在pH 7.4下，分别在存在和不存在GSH的情况下观察到相对较低的药物释放，约为21.6%和16%。荧光显微镜证实，负载Dox的bAPSC纳米凝胶被HeLa细胞内化，并且无需额外的探测剂即可使用荧光材料轻松追踪药物分布。此外，细胞毒性和溶血结果显示合成的纳米凝胶具有较低毒性和血液相容性，证实它们是药物递送系统中最有利的替代药物载体。
