Department of Comparative Biomedicine and Food Science, University of Padua, viale dell'Università 16, 35020 Legnaro, Italy; Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Palacky University in Olomouc, Slechtitelu 27, 783 71 Olomouc, Czech Republic.
Department of Comparative Biomedicine and Food Science, University of Padua, viale dell'Università 16, 35020 Legnaro, Italy.
Biochim Biophys Acta Gen Subj. 2017 Nov;1861(11 Pt A):2802-2810. doi: 10.1016/j.bbagen.2017.07.025. Epub 2017 Aug 2.
Conversely to common coated iron oxide nanoparticles, novel naked surface active maghemite nanoparticles (SAMNs) can covalently bind DNA. Plasmid (pDNA) harboring the coding gene for GFP was directly chemisorbed onto SAMNs, leading to a novel DNA nanovector (SAMN@pDNA). The spontaneous internalization of SAMN@pDNA into cells was compared with an extensively studied fluorescent SAMN derivative (SAMN@RITC). Moreover, the transfection efficiency of SAMN@pDNA was evaluated and explained by computational model.
SAMN@pDNA was prepared and characterized by spectroscopic and computational methods, and molecular dynamic simulation. The size and hydrodynamic properties of SAMN@pDNA and SAMN@RITC were studied by electron transmission microscopy, light scattering and zeta-potential. The two nanomaterials were tested by confocal scanning microscopy on equine peripheral blood-derived mesenchymal stem cells (ePB-MSCs) and GFP expression by SAMN@pDNA was determined.
Nanomaterials characterized by similar hydrodynamic properties were successfully internalized and stored into mesenchymal stem cells. Transfection by SAMN@pDNA occurred and GFP expression was higher than lipofectamine procedure, even in the absence of an external magnetic field. A computational model clarified that transfection efficiency can be ascribed to DNA availability inside cells.
Direct covalent binding of DNA on naked magnetic nanoparticles led to an extremely robust gene delivery tool. Hydrodynamic and chemical-physical properties of SAMN@pDNA were responsible of the successful uptake by cells and of the efficiency of GFP gene transfection.
SAMNs are characterized by colloidal stability, excellent cell uptake, persistence in the host cells, low toxicity and are proposed as novel intelligent DNA nanovectors for efficient cell transfection.
与常见的涂层氧化铁纳米粒子相反，新型裸露表面活性磁赤铁矿纳米粒子（SAMN）可以共价结合 DNA。含有 GFP 编码基因的质粒（pDNA）直接化学吸附到 SAMN 上，形成一种新型 DNA 纳米载体（SAMN@pDNA）。将 SAMN@pDNA 自发内化进入细胞的过程与广泛研究的荧光 SAMN 衍生物（SAMN@RITC）进行了比较。此外，通过计算模型评估和解释了 SAMN@pDNA 的转染效率。
通过光谱和计算方法以及分子动力学模拟制备和表征 SAMN@pDNA。通过电子传输显微镜、光散射和 zeta 电位研究 SAMN@pDNA 和 SAMN@RITC 的大小和流体动力学特性。在马外周血衍生间充质干细胞（ePB-MSCs）上通过共焦扫描显微镜测试这两种纳米材料，并确定 SAMN@pDNA 的 GFP 表达情况。
具有相似流体动力学特性的纳米材料成功地被内化并储存在间充质干细胞中。SAMN@pDNA 发生转染，GFP 表达高于脂质体法，即使在没有外部磁场的情况下也是如此。计算模型表明，转染效率可归因于细胞内 DNA 的可用性。
DNA 直接共价结合到裸露的磁性纳米粒子上，形成了一种极其强大的基因传递工具。SAMN@pDNA 的流体动力学和物理化学性质是其被细胞有效摄取和 GFP 基因转染效率的原因。
SAMN 具有胶体稳定性、优异的细胞摄取能力、在宿主细胞中的持久性、低毒性，并被提议作为新型智能 DNA 纳米载体，用于高效的细胞转染。
