a Department of Medical Biomaterials Engineering, College of Biomedical Science and Institute of Bioscience and Biotechnology , Kangwon National University , Chuncheon , Republic of Korea.
J Biomater Sci Polym Ed. 2018 Apr;29(5):476-490. doi: 10.1080/09205063.2017.1422854. Epub 2018 Jan 8.
Redox-responsive solid lipid microparticles were prepared by an emulsification photo-polymerization method. Octadecyl acrylate (ODA) and a cross-linker (i.e. allyl disulfide (ADS) and octadiene (ODE)) were dissolved in dichloromethane, it was emulsified in poly(vinyl alcohol) solution, and the resulting O/W emulsion was irradiated with UV light. On the scanning electron microscope micrographs, the microparticles were sphere-like and they were not markedly different from the oil droplets in size. Using the atomic compositions analyzed by energy dispersive X-ray spectroscopy, the ODA to cross-linker molar ratio of ODA/ADS microparticles and ODA/ODE ones were calculated to be 1:0.13 and 1:0.15, respectively. In the FT-IR spectra of the microparticles, the signal of the vinyl group was hardly detected, implying that the monomer and the cross-linkers participated in the photo-polymerization. In differential scanning calorimetry study, ODA/ADS microparticles and ODA/ODE ones exhibited their endothermic peaks around 42.9 and 41.3 °C, respectively, possibly due to the melting of polymeric ODA. Dithiothreitol (DTT, a reducing agent) concentration had little effect on the release degree of dye loaded in ODA/ODE microparticles. Whereas, DTT concentration had a significant effect on the release degree of dye loaded in ODA/ADS microparticles. The release degree at 26 °C was weakly affected by DTT concentration. When the temperature was 37 °C, DTT concentration had a strong effect on the release degree. The disulfide cross-linker (i.e. ADS) can be broken to thiol compounds by the reducing agent, resulting in an increase in the release degree.
氧化还原响应性固载脂质体微球通过乳化光聚合方法制备。十八烯丙烯酸酯（ODA）和交联剂（即二烯丙基二硫（ADS）和辛二烯（ODE））溶解在二氯甲烷中，乳化在聚乙烯醇溶液中，然后用紫外光照射。在扫描电子显微镜照片中，微球呈球状，与油滴大小无明显差异。通过能量色散 X 射线光谱分析原子组成，计算出 ODA/ADS 微球和 ODA/ODE 微球中 ODA 与交联剂的摩尔比分别为 1:0.13 和 1:0.15。在微球的傅立叶变换红外光谱中，几乎检测不到乙烯基的信号，这意味着单体和交联剂参与了光聚合反应。在差示扫描量热法研究中，ODA/ADS 微球和 ODA/ODE 微球分别在约 42.9 和 41.3°C 处表现出吸热峰，可能是由于聚合 ODA 的熔融。二硫苏糖醇（DTT，一种还原剂）浓度对负载在 ODA/ODE 微球中的染料的释放度影响不大。然而，DTT 浓度对负载在 ODA/ADS 微球中的染料的释放度有显著影响。在 26°C 时，DTT 浓度对释放度的影响较弱。当温度为 37°C 时，DTT 浓度对释放度有很强的影响。还原剂可以将二硫交联剂（即 ADS）断裂成硫醇化合物，导致释放度增加。
