Bouchaala Redouane, Anton Nicolas, Anton Halina, Vandamme Thierry, Vermot Julien, Smail Djabi, Mély Yves, Klymchenko Andrey S
CNRS UMR 7213, Laboratoire de Biophotonique et Pharmacologie, University of Strasbourg,74 route du Rhin, 67401 Illkirch Cedex, France; Laboratory of Photonic Systems and Nonlinear Optics, Institute of optics and fine mechanics, University of Setif 1, 19000 Algeria.
CNRS UMR 7199, Laboratoire de Conception et Application de Molécules Bioactives, University of Strasbourg,74 route du Rhin, 67401 Illkirch Cedex, France.
Colloids Surf B Biointerfaces. 2017 Aug 1;156:414-421. doi: 10.1016/j.colsurfb.2017.05.035. Epub 2017 May 15.
Light is an attractive trigger for release of active molecules from nanocarriers in biological systems. Here, we describe a phenomenon of light-induced release of a fluorescent dye from lipid nano-droplets under visible light conditions. Using auto-emulsification process we prepared nanoemulsion droplets of 32nm size encapsulating the hydrophobic analogue of Nile Red, NR668. While these nano-droplets cannot spontaneously enter the cells on the time scale of hours, after illumination for 30s under the microscope at the wavelength of NR668 absorption (535nm), the dye showed fast accumulation inside the cells. The same phenomenon was observed in zebrafish, where nano-droplets initially staining the blood circulation were released into endothelial cells and tissues after illumination. Fluorescence correlation spectroscopy revealed that laser illumination at relatively low power (60mW/cm) could trigger the release of the dye into recipient media, such as 10% serum or blank lipid nanocarriers. The photo-release can be inhibited by deoxygenation with sodium sulfite, suggesting that at least in part the release could be related to a photochemical process involving oxygen, though a photo-thermal effect could also take place. Finally, we showed that illumination of NR668 can provoke the release into the cells of another highly hydrophobic dye co-encapsulated into the lipid nanocarriers. These results suggest dye-loaded lipid nano-droplets as a prospective platform for preparation of light-triggered nanocarriers of active molecules.
在生物系统中，光对于从纳米载体释放活性分子而言是一种具有吸引力的触发因素。在此，我们描述了在可见光条件下，荧光染料从脂质纳米液滴中光诱导释放的现象。我们利用自动乳化过程制备了尺寸为32nm的纳米乳液液滴，其包裹着尼罗红的疏水类似物NR668。虽然这些纳米液滴在数小时的时间尺度内无法自发进入细胞，但在显微镜下于NR668吸收波长（535nm）处照射30秒后，染料在细胞内迅速积累。在斑马鱼中也观察到了同样的现象，最初使血液循环染色的纳米液滴在光照后释放到内皮细胞和组织中。荧光相关光谱显示，相对低功率（60mW/cm）的激光照射能够触发染料释放到受体介质中，如10%血清或空白脂质纳米载体中。光释放可通过用亚硫酸钠脱氧来抑制，这表明至少部分释放可能与涉及氧气的光化学过程有关，尽管也可能发生光热效应。最后，我们表明照射NR668能够促使共包裹在脂质纳米载体中的另一种高度疏水染料释放到细胞中。这些结果表明，负载染料的脂质纳米液滴是制备活性分子光触发纳米载体的一个有前景的平台。
