Center for Convergence Bioceramic Materials, Korea Institute of Ceramic Engineering and Technology (KICET), Chungbuk 28160, South Korea.
ACS Appl Bio Mater. 2021 Feb 15;4(2):1350-1359. doi: 10.1021/acsabm.0c01240. Epub 2021 Jan 13.
This work reports the formation of spherical solid silica-encapsulated liposome particles (SLPs) as functions of the concentration of silica precursor, reaction time, temperature, and volume ratios of solvent, respectively. The solid SLPs are more robust and have better drug-loading-efficiency liquid liposomes in carrier formulations. The liquid-state liposomes are hard to handle and have a lower drug-loading efficiency because they are fragile to external stimuli and have narrow hydrophobic phospholipid bilayers. The SLPs were obtained by silicification with tetraethyl orthosilicate (TEOS) in the hydrophilic region of phospholipid bilayers by a sol-gel process. These SLPs were characterized by scanning electron microscopy (SEM), focused ion beam (FIB)-SEM, confocal laser scanning microscopy (CLSM), thermogravimetric analysis (TGA), ζ-potential, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and UV-vis spectroscopy. The obtained SLPs were spherical with an average size of 2-3 μm. The hydrophilic region of the SLP phospholipid bilayers was confirmed using CLSM with green fluorescent fluorescein isothiocyanate (FITC) labeling and FIB-SEM. Furthermore, the drug-loading capacity and in vitro cytotoxicity assessments were performed using several drug compounds and L929 cells. The drug-loading capacity of the SLPs was >95%, and in particular, the hydrophobic drug-loading capacity was 2.3 times higher than that of general liposomes. Moreover, the result of an in vitro cytotoxicity assessment of the SLPs was good, about 99% of cell viability.
本工作分别研究了硅源浓度、反应时间、温度和溶剂体积比对球形固态二氧化硅包覆脂质体粒子（SLPs）形成的影响。固态 SLPs 比液态脂质体更坚固，载体制剂中的载药效率更高。液态脂质体由于对外界刺激敏感且疏水性磷脂双分子层较窄，因此难以处理且载药效率较低。通过在磷脂双层的亲水区中用正硅酸乙酯（TEOS）进行硅烷化反应，通过溶胶-凝胶过程得到 SLPs。通过扫描电子显微镜（SEM）、聚焦离子束（FIB）-SEM、共焦激光扫描显微镜（CLSM）、热重分析（TGA）、ζ-电位、X 射线衍射（XRD）、傅里叶变换红外（FT-IR）光谱和紫外可见光谱对 SLPs 进行了表征。得到的 SLPs 呈球形，平均粒径为 2-3μm。使用带有绿色荧光异硫氰酸荧光素（FITC）标记的 CLSM 和 FIB-SEM 证实了 SLP 磷脂双层的亲水区。此外，还使用几种药物化合物和 L929 细胞进行了载药能力和体外细胞毒性评估。SLPs 的载药能力>95%，特别是疏水性载药能力比普通脂质体高 2.3 倍。此外，SLPs 的体外细胞毒性评估结果良好，细胞存活率约为 99%。
