Abstract
Near-infrared (NIR)-to-visible up-conversion fluorescent nanoparticles have potential to be used for photodynamic therapy (PDT) in deep tissue because NIR light can penetrate thick tissue due to weak absorption in the optical window.Here a uniformlayer ofmesoporous silica is coated ontoNaYF<sub>4</sub> upconverting nanocrystals, with a large surface area of ≈770 m<sup>2</sup> g<sup>-1</sup>and an average pore size of 2 nm. A photosensitizer, zinc phthalocyanine, is incorporated into the mesoporous silica. Upon excitation by a NIR laser, the nanocrystals convert NIR light to visible light, which further activates the photosensitizer to release reactive singlet oxygen to kill cancer cells. The photosensitizer encapsulated in mesoporous silica is protected from degradation in the harsh biological environment. It is demonstrated that the photosensitizers loaded into the porous silica shell of the nanoparticles are not released out of the silica while they continuously produce singlet oxygen upon excitation by a NIR laser. The nanoparticles are reusable as the photosensitizers encapsulated in the silica are removed by soaking in ethanol. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.
| Original language | English |
|---|---|
| Pages (from-to) | 2285-2290 |
| Journal | Small |
| Volume | 5 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - 16 Oct 2009 |
| Externally published | Yes |
Bibliographical note
Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to [email protected].Research Keywords
- Bionanotechnology
- Fluorescent nanoparticles
- Photodynamic therapy
- Photosensitizers
