A new implantable device which aims to maximise the effectiveness of light-sensitive drugs could improve future outcomes for bladder cancer patients.
Engineers and cancer scientists from the University of Glasgow have developed the device, which uses wirelessly powered micro-LEDs to boost the delivery of light through tissue-mimicking models in the lab.
The platform, designed by a team led by Professor David Flynn, is a first step towards a more precise, affordable and comfortable application of photodynamic therapy to treat this type of cancer.
Photodynamic therapy works by using light-sensitive drugs called photosensitisers to selectively destroy cancer cells.
It is commonly used in skin cancer treatment, but its effectiveness is currently constrained by the physical properties of human body tissue. Tissue tends to absorb light, making it more challenging to reach certain tumours growing deeper in the body in organs like the bladder.
To overcome those constraints, today’s photodynamic therapies can require invasive surgeries and bulky, power-hungry external light sources to flood treatment sites with additional light.
The team’s new platform is designed to be flexible and small enough to be implanted next to tumours, allowing light to reach treatment sites more directly while minimising the need for invasive procedures. It also draws power from a wireless source, cutting the need for external systems entirely.
Dr Rolan Mansour, of the University of Glasgow’s James Watt School of Engineering, is the paper’s corresponding author. He said: “In the developed nations, one in three people is expected to develop a form of cancer during their lifetime. Today, bladder cancers cause 16 deaths a day in the UK alone, according to figures from Cancer Research UK.
“However, bladder cancer, like many others, is potentially curable if it is diagnosed and treated early, before metastatic spread or invasion into adjacent organs.
“Given that photodynamic therapy has the potential for less side effects and could improve cancer treatment outcomes, our work is focused on improving its effectiveness by delivering light where it’s most needed, to the photosensitisers which tackle and kill cancer cells.”
A paper published in the journal Opto-Electronic Advances describes how the disc-shaped, 40mm-wide device was designed and fabricated using laser-based fabrication techniques at the University’s James Watt Nanofabrication Centre and tested in the lab.
It uses four micro-LEDs on a flexible substrate made of Parylene C, a biocompatible polymer suitable for use in medical implants. Using power drawn wirelessly via resonant inductive coupling, the LEDs can deliver optical outputs more than five megawatts.
Lab tests using materials designed to closely mimic human tissues showed they were able to send light with minimal loss through slices of synthetic tissues at thicknesses of up to 50mm.
A photosensitiser solution was also used to test how the system could be used to generate singlet oxygen, the highly reactive, cancer-destroying molecule produced by the interaction between photosensitisers and light.
Their results showed that the solution reacted to the light from the LEDs as planned, reliably producing singlet oxygen on demand and demonstrating the potential of the system for use as an implantable device to support photodynamic therapy.
The James Watt School of Engineering’s Professor David Flynn is lead of the EPSRC PATIENT project which delivered these recent results.
He said: “These are very encouraging results, which demonstrate how flexible bioelectronics, wireless power delivery and photonics can be combined to create advanced, minimally invasive treatments, which could improve the clinical outcomes of photodynamic therapies.
“The cost-effective fabrication processes we used in this new technology also have the potential to deliver a scalable and affordable future treatment pathway which can be used in combination with other therapies.
“Although there is still significant further experimental work to be done before the system is ready to be used directly in patient treatments, the results represent a significant step toward next-generation wireless cancer therapies and implantable photonic medical devices.”
The system was recognised at the IET Excellence and Innovation Awards in 2024, where the team received the Health Technology Award.
Researchers from Edinburgh Instruments Ltd also contributed to the research and co-authored the paper. The team’s paper, ‘A Flexible Wireless System for Prospective Photodynamic Therapy Applications ’, is published in the journal Opto-Electronic Advances. The research was supported by funding from UKRI’s Engineering and Physical Sciences Research Council (EPSRC).
