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Nat Nanotechnol. 2015 Apr;10(4):370-9. doi: 10.1038/nnano.2015.17. Epub 2015 Mar 9.

Breaking the depth dependency of phototherapy with Cerenkov radiation and low-radiance-responsive nanophotosensitizers.

Author information

1
Department of Radiology, Washington University School of Medicine, St Louis, Missouri 63110, USA.

Abstract

The combination of light and photosensitizers for phototherapeutic interventions, such as photodynamic therapy, has transformed medicine and biology. However, the shallow penetration of light into tissues and the reliance on tissue oxygenation to generate cytotoxic radicals have limited the method to superficial or endoscope-accessible lesions. Here we report a way to overcome these limitations by using Cerenkov radiation from radionuclides to activate an oxygen-independent nanophotosensitizer, titanium dioxide (TiO2). We show that the administration of transferrin-coated TiO2 nanoparticles and clinically used radionuclides in mice and colocalization in tumours results in either complete tumour remission or an increase in their median survival. Histological analysis of tumour sections showed the selective destruction of cancerous cells and high numbers of tumour-infiltrating lymphocytes, which suggests that both free radicals and the activation of the immune system mediated the destruction. Our results offer a way to harness low-radiance-sensitive nanophotosensitizers to achieve depth-independent Cerenkov-radiation-mediated therapy.

PMID:
25751304
PMCID:
PMC4393353
DOI:
10.1038/nnano.2015.17
[Indexed for MEDLINE]
Free PMC Article

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