Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany; Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, 400030 Chongqing, PR China.
Institute for Pharmacy and Food Chemistry, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany.
Biomaterials. 2014 Sep;35(27):7929-39. doi: 10.1016/j.biomaterials.2014.05.062. Epub 2014 Jun 13.
Herein, we describe the delivery of plasmid DNA (pDNA) using silk fibroin (SF) layer-by-layer assembled microcapsules. Deposition of fluorescently labeled SF onto polystyrene (PS) template particles resulted in increasing fluorescence intensity and decreasing surface charge in correlation to SF layer number. After removal of the PS core, hollow, monodisperse, and structurally stable SF microcapsules of variable size and shell thickness were obtained. Plasmid DNA encoding for enhanced green fluorescent protein (eGFP) was loaded onto 1 or 4 μm capsules, either by incorporation of pDNA within the innermost layer of the shell or by adsorption to the microcapsules surface, and in vitro pDNA release, cytotoxicty and eGFP expression were studied. Sustained pDNA release over 3 days was observed using both loading techniques, being accelerated in the presence of protease. DNA loaded SF microcapsules resulted in efficient cell transfection along with low cytotoxicity after 3 days incubation compared to treatment with pDNA/branched polyethylenimine complexes. Among the tested conditions highest transfection efficiencies were achieved using 1 μm capsules where pDNA was adsorbed to the capsule surface. Our results suggest that SF microcapsules are suitable for the localized delivery of pDNA, combining low cytotoxicity and high transfection efficiency.
在此，我们描述了使用丝素蛋白（SF）层层组装微胶囊递送质粒 DNA（pDNA）。荧光标记的 SF 沉积到聚苯乙烯（PS）模板颗粒上，导致荧光强度增加，表面电荷减少，与 SF 层的数量呈正相关。去除 PS 核后，得到了具有不同尺寸和壳层厚度的空心、单分散且结构稳定的 SF 微胶囊。编码增强型绿色荧光蛋白（eGFP）的质粒 DNA 通过将 pDNA 掺入壳层的最内层或吸附到微胶囊表面而被加载到 1 或 4μm 微胶囊上，并研究了体外 pDNA 释放、细胞毒性和 eGFP 表达。使用这两种加载技术均可观察到 3 天内持续的 pDNA 释放，在存在蛋白酶的情况下释放速度加快。与 pDNA/支化聚乙烯亚胺复合物处理相比，与 SF 微胶囊孵育 3 天后，负载 DNA 的 SF 微胶囊可有效转染细胞，同时细胞毒性低。在测试的条件中，使用吸附到胶囊表面的 pDNA 的 1μm 微胶囊可获得最高的转染效率。我们的研究结果表明，SF 微胶囊适合 pDNA 的局部递药，具有低细胞毒性和高转染效率。
