1. Application of Mitochondrially Targeted Nanoconstructs to Neoadjuvant X-ray-Induced Photodynamic Therapy for Rectal Cancer
- Author
-
Deng, W, McKelvey, KJ, Guller, A, Fayzullin, A, Campbell, JM, Clement, S, Habibalahi, A, Wargocka, Z, Liang, L, Shen, C, Howell, VM, Engel, AF, Goldys, EM, Deng, W, McKelvey, KJ, Guller, A, Fayzullin, A, Campbell, JM, Clement, S, Habibalahi, A, Wargocka, Z, Liang, L, Shen, C, Howell, VM, Engel, AF, and Goldys, EM
- Abstract
In this work, we brought together two existing clinical techniques used in cancer treatment-X-ray radiation and photodynamic therapy (PDT), whose combination termed X-PDT uniquely allows PDT to be therapeutically effective in deep tissue. To this end, we developed mitochondrially targeted biodegradable polymer poly(lactic-co-glycolic acid) nanocarriers incorporating a photosensitizer verteporfin, ultrasmall (2-5 nm) gold nanoparticles as radiation enhancers, and triphenylphosphonium acting as the mitochondrial targeting moiety. The average size of the nanocarriers was about 160 nm. Upon X-ray radiation our nanocarriers generated cytotoxic amounts of singlet oxygen within the mitochondria, triggering the loss of membrane potential and mitochondria-related apoptosis of cancer cells. Our X-PDT strategy effectively controlled tumor growth with only a fraction of radiotherapy dose (4 Gy) and improved the survival rate of a mouse model bearing colorectal cancer cells. In vivo data indicate that our X-PDT treatment is cytoreductive, antiproliferative, and profibrotic. The nanocarriers induce radiosensitization effectively, which makes it possible to amplify the effects of radiation. A radiation dose of 4 Gy combined with our nanocarriers allows equivalent control of tumor growth as 12 Gy of radiation, but with greatly reduced radiation side effects (significant weight loss and resultant death).
- Published
- 2020