Nanoparticle Enhanced Radiotherapy - Isis Project No 4465

Using medical x-rays to treat deep-tissue tumours more effectively: a nanoparticle-based technique.

Market Opportunity

Cancer is a class of diseases in which a group of cells display uncontrolled growth, intrusion and destruction of adjacent cells and metastasis. It is the leading cause of death worldwide and, according to the WHO, accounted for 7.9 million deaths in 2007, representing 13% of all deaths. Early cancer diagnosis, in combination with precise cancer therapies could eventually save millions of lives.  It is believed that the Oxford nanoparticles, used in conjunction with conventional X-ray radiotherapy, will enhance cancer treatment.

The Oxford Invention

Researchers at Oxford University have developed a new system to treat cancer cells using Reactive Oxygen Species (ROS) with little or no damage to neighbouring healthy cells, using existing radiotherapy facilities in a minimally invasive procedure.  ROS are generated by nanoparticles excited by x-rays. ROS and free radicals are already known to be effective in killing cancer cells.  A technique known as photodynamic therapy which uses ultraviolet light to stimulate nanoparticles is already used for skin cancers. However, since UV light is not very penetrating, deep tissue tumours have not been treatable by this method until now.

The Oxford solution is based on the administration of doped oxide nanoparticles, which are highly tuned to absorb X-rays and efficiently convert them into ROS to destroy malignant cells.  Nanoparticles are known to passively accumulate within tumour tissue due to the fenestration of the tumour vasculature and the Enhanced Permeability and Retention (EPR) effect.  In addition, short life-times and diffusion distances of ROS permits cancer cell destruction.

 

In a cancer cell treatment model, cells were incubated with nanoparticles and irradiated with a clinically relevant X-ray dose (3 Gy), left to recover for 24 hours and then irradiated once more.  Multiple cell lines have been tested, the example shows results from a Rhabdosarcoma (a highly malignant cancer) cell line. Cells devoid of nanoparticles are damaged by the X-rays but continue to proliferate and return to approximately 80% of their pre-treatment level after 48 hours. In contrast, the cell line incubated with nanoparticles shows 70% cell death with little evidence of cell growth resuming.

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