Nanotechnology. 2014 Apr 18;25(15):155103. doi: 10.1088/0957-4484/25/15/155103.
To date, the application of photodynamic therapy in deep tissue has been severely restricted by the limited penetration depth of excitation light, such as UV light and visible light. In this work, a protocol of upconverting crystal/dextran-g-DOPE nanocomplex (UCN/dextran-g-DOPE) was developed. The nanocomplex was assembled from the hydrophobic upconverting nanoparticle (UCN) core and hydrophilic lipid shell. The photosensitizer zinc phthalocyanine (ZnPc) loaded UCN/dextran-g-DOPE offers possibilities to overcome the problem mentioned above. The UCN core works as a transducer to convert deeply penetrating near-infrared light to visible light to activate ZnPc for photodynamic therapy. The dextran-g-DOPE lipid shell is used for loading ZnPc and protecting the whole system from nonspecific absorbance or corrosion during the transportation. The experiment results show that the nanocomplex is an individual sphere with an average size of 30 nm. The ZnPc was activated to produce singlet oxygen successfully by the upconverting fluorescence emitted from UCN. The nanocomplex has high fluorescence stability in alkaline or neutral buffer solutions. Importantly, the ZnPc loaded UCN/dextran-g-DOPE nanocomplex showed a significant inhibitory effect on tumor cells after NIR exposure. Our data suggest that a ZnPc loaded UCN/dextran-g-DOPE nanocomplex may be a useful nanoplatform for future PDT treatment in deep-cancer therapy based on the upconverting mechanism.
迄今为止，由于激发光（如紫外光和可见光）的穿透深度有限，光动力疗法在深层组织中的应用受到严重限制。在这项工作中，开发了上转换晶体/葡聚糖-g-DOPE 纳米复合物（UCN/葡聚糖-g-DOPE）的方案。该纳米复合物由疏水上转换纳米颗粒（UCN）核和亲水脂质壳组装而成。负载光敏剂锌酞菁（ZnPc）的 UCN/葡聚糖-g-DOPE 提供了克服上述问题的可能性。UCN 核作为换能器，将深穿透近红外光转换为可见光，以激活 ZnPc 进行光动力治疗。葡聚糖-g-DOPE 脂质壳用于负载 ZnPc，并在运输过程中保护整个系统免受非特异性吸收或腐蚀。实验结果表明，该纳米复合物是一个平均粒径为 30nm 的单个球体。ZnPc 成功地被 UCN 发射的上转换荧光激活以产生单线态氧。该纳米复合物在碱性或中性缓冲溶液中具有高荧光稳定性。重要的是，在 NIR 暴露后，负载 ZnPc 的 UCN/葡聚糖-g-DOPE 纳米复合物对肿瘤细胞表现出显著的抑制作用。我们的数据表明，负载 ZnPc 的 UCN/葡聚糖-g-DOPE 纳米复合物可能是基于上转换机制的深部癌症治疗中未来光动力治疗的有用纳米平台。
