Depalo N, De Leo V, Corricelli M, Gristina R, Valente G, Casamassima E, Comparelli R, Laquintana V, Denora N, Fanizza E, Striccoli M, Agostiano A, Catucci L, Curri M L
Istituto per i Processi Chimico-Fisici-CNR UOS Bari, Via Orabona 4, 70125 - Bari, Italy.
J Mater Chem B. 2017 Feb 21;5(7):1471-1481. doi: 10.1039/c6tb02590k. Epub 2017 Jan 31.
Hydrophobic PbS nanocrystals (NCs) emitting in the near infrared spectral region were encapsulated in the core of micelles and in the bilayer of liposomes, respectively, to form polyethylene glycol (PEG)-grafted phospholipids. The phospholipid-based functionalization process of PbS NCs required the replacement of the pristine capping ligand at the NC surface with thiol molecules. The procedures carried out for two systems, micelles and liposomes, using PEG-modified phospholipids were carefully monitored by optical, morphological and structural investigations. The hydrodynamic diameter and the colloidal stability of both micelles and liposomes loaded with PbS NCs were evaluated using Dynamic Light Scattering (DLS) and ζ-potential experiments, and both were satisfactorily stable in physiological media. The cytotoxicity of the resulting PbS NC-loaded nanovectors was assessed by the in vitro investigation on Saos-2 cells, indicating that the toxicity of the PbS NC loaded liposomes was lower than that of the micelles with the same NC cargo, which is reasonable due to the different overall composition of the two prepared nanocarriers. Finally, the cellular uptake in the Saos-2 cells of both the NC containing systems was evaluated by means of confocal microscopy studies by exploiting a visible fluorescent phospholipid and demonstrating the ability of both luminescent nanovectors to be internalized. The obtained results show the great potential of the prepared emitting nanoprobes for imaging applications in the second biological window.
在近红外光谱区域发射的疏水性硫化铅纳米晶体（NCs）分别包裹在胶束的核心和脂质体的双层中，以形成聚乙二醇（PEG）接枝的磷脂。硫化铅NCs基于磷脂的功能化过程需要用硫醇分子取代NC表面的原始封端配体。使用PEG修饰的磷脂对胶束和脂质体这两种体系进行的操作，通过光学、形态学和结构研究进行了仔细监测。使用动态光散射（DLS）和ζ电位实验评估了负载硫化铅NCs的胶束和脂质体的流体动力学直径和胶体稳定性，并且两者在生理介质中均具有令人满意的稳定性。通过对Saos-2细胞的体外研究评估了所得负载硫化铅NC的纳米载体的细胞毒性，结果表明负载硫化铅NC的脂质体的毒性低于具有相同NC负载量的胶束，这是合理的，因为两种制备的纳米载体的整体组成不同。最后，通过利用可见荧光磷脂进行共聚焦显微镜研究，评估了两种含NC体系在Saos-2细胞中的细胞摄取，并证明了两种发光纳米载体均具有内化能力。获得的结果表明，所制备的发光纳米探针在第二生物窗口成像应用中具有巨大潜力。
