Surface PEGylation and biological imaging of fluorescent Tb3+-doped layered double hydroxides through the photoinduced RAFT polymerization.
Surface PEGylation and biological imaging of fluorescent Tb3+-doped layered double hydroxides through the photoinduced RAFT polymerization.
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DOI：
10.1016/j.jcis.2018.08.033
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发表时间：
2018-12
影响因子：
9.9
通讯作者：
Fengjie Deng;Huajian Zhou;Junyu Chen;Hongye Huang;Jianwen Tian;Y. Wen;Qiang Huang;Meiying Liu;Xiaoyong Zhang;Yen Wei
中科院分区：
文献类型：
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作者：
Fengjie Deng;Huajian Zhou;Junyu Chen;Hongye Huang;Jianwen Tian;Y. Wen;Qiang Huang;Meiying Liu;Xiaoyong Zhang;Yen Wei
用水热法合成的Tb3+掺杂层状双氢氧化物(LDHs)具有良好的光学性能、均匀的尺寸和均匀的形貌。然而，由于缺乏官能团和分散性差，这些Tb3+掺杂的荧光水滑石在很大程度上阻碍了其在生物医学领域的应用。本工作以亲水性聚甲基丙烯酸乙二醇酯(PEGMA)为单体，采用光诱导表面引发可逆加成-断裂链转移(RAFT)聚合的方法对Tb3+掺杂的LDH进行表面修饰。通过光引发的无金属表面RAFT聚合，得到了最终的产物。通过透射电子显微镜、傅立叶变换红外光谱、X-射线光电子能谱和热重分析等多种分析技术证实了这些荧光LDH聚合物复合材料(LDH-PEG)的成功制备。此外，利用激光扫描共聚焦显微镜研究了LDH-PEG复合材料的细胞摄取行为，并评价了其在生物医学应用中的潜力。通过无金属光致表面引发RAFT聚合，亲水性单体PEGMA可以很容易地接枝到Tb3+掺杂的LDHs表面。所得LDH-PEG复合材料具有高水分散度、强荧光、低细胞毒性和良好的细胞摄取性能。LDH-PEG复合材料的这些特性表明其在生物医学应用方面具有巨大的潜力。更重要的是，光诱导RAFT聚合具有传统可控活性自由基聚合的优点，可以克服毒性、金属催化剂的荧光猝灭效应和链转移剂的复杂合成等缺点。因此，该方法可作为材料表面改性和制备多功能荧光纳米材料基聚合物复合材料的替代工具。
Tb3+-doped layered double hydroxides (LDHs) exhibit excellent optical characteristics, uniform size and uniform morphologies when synthesized through a hydrothermal method. However, due to their lack of functional groups and poor dispersibility, applications of these fluorescent Tb3+-doped LDHs have been largely impeded especially in the biomedical fields. In this work, a novel strategy was developed for the surface modification of these fluorescent Tb3+-doped LDHs using photoinduced surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization with hydrophilic poly(ethylene glycol) methacrylate (PEGMA) as the monomer. The final products were obtained via the metal free surface-initiated RAFT polymerization with light irradiation. Successful preparation of these fluorescent LDHs polymer composites (LDH-PEG) was confirmed by a number of analytical technologies, such as transmission electron microscopy, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. In addition, laser scanning confocal microscope was employed to examine the cell uptake behavior of the LDH-PEG composites and evaluate their potential for biomedical applications. We demonstrated that the hydrophilic monomer PEGMA could be facilely grafted on the surface of Tb3+-doped LDHs through metal free photoinduced surface-initiated RAFT polymerization. The resultant LDH-PEG composites displayed high water dispersibility, strong fluorescence, low cytotoxicity and a desirable cell uptake performance. These features of the LDH-PEG composites indicated their great potential for biomedical applications. More importantly, photoinduced RAFT polymerization has the advantages of a conventional controlled living radical polymerization, which could overcome drawbacks such as toxicity, the fluorescence quenching effects of metal catalysts and the complex synthesis of chain transfer agents. Therefore, this method could be an alternative tool for the surface modification of materials and fabrication of multifunctional fluorescent nanomaterials based polymer composites.