Upconverting crystal/dextran-g-DOPE with high fluorescence stability for simultaneous photodynamic therapy and cell imaging

• Published in: Nanotechnology 2014-04, Vol.25 (15), p.155103-10
• Main Authors: Wang, HanJie, Wang, Sheng, Liu, Zhongyun, Dong, Chunhong, Yang, Jiumin, Gong, Xiaoqun, Chang, Jin
• Format: Article
• Language: English
• Subjects: Breast - pathology; Breast Neoplasms - diagnosis; Breast Neoplasms - therapy; Cell Line, Tumor; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Crystals; dextran; Dextrans - chemistry; Drug Carriers - chemistry; Exact sciences and technology; Female; Fluorescence; Fluorescent Dyes - chemistry; Fullerenes and related materials; Humans; Indoles - administration & dosage; Indoles - chemistry; Indoles - therapeutic use; Infrared and raman spectra and scattering; Lipids; Materials science; nanocomplex; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Organometallic Compounds - administration & dosage; Organometallic Compounds - chemistry; Organometallic Compounds - therapeutic use; Phosphatidylethanolamines - chemistry; Photochemotherapy - methods; Photodynamic therapy; Photosensitizing Agents - administration & dosage; Photosensitizing Agents - chemistry; Photosensitizing Agents - therapeutic use; Physics; polymeric lipid; Shells; Stability; upconverting nanocrystal; Zinc
• ISSN: 0957-4484; 1361-6528
• 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.