Leigh Canham's discovery of luminescence and biodegradability of nanostructured silicon - the emission of light by a substance and its biocompatibility opened up a world of possibilities for the versatile material, enabling its application in controlled-release drug delivery, targeted cancer therapy, medical imaging, tissue engineering, and improved health and beauty products.
Inventor: Leigh Canham, United Kingdom
Invention: Usage of porous and biodegradable silicon in the biomedical field
Company: pSiMedica, QinetiQ
In 1989, Leigh Canham became fascinated with the untapped potential of nano-engineered silicon as a semiconductor while working at the Defence Research Agency (now QinetiQ) in Malvern, UK.
Canham studied various practical uses of the luminescent properties of this versatile material. But in the end, it was the physicist's idea that the porous substance could be biodegradable in the human body that led to groundbreaking achievements in the biomedical field.
In 1995 the British scientist made a break-through discovery when he found that porous elemental silicon is not only biodegradable, but also biocompatible (non-toxic). This meant the body can absorb silicon safely after it has been nano-engineered.
Canham's new form of porous silicon, called BioSilicon, features a honeycomb structure with nano-sized pockets. These pockets can be filled with drugs, peptides, genes, proteins, radionuclides and other therapeutics or vaccines.
BioSilicon's semiconductor properties enable it to dissolve in the body at a controlled rate while slowly releasing drugs over hours, days, months, or even years.
After the loaded drug is released, all that is left in the body is pure silicon, which dissolves into non-toxic silicic acid and is safely excreted through the kidneys. Doctors have a range of options for introducing drug-loaded BioSilicon into the body: orally, via injection, transdermally, or with a patch, implant or coatings.
Canham's research has also led to the development of biodegradable micropiercers, microneedles and biolistic bullets, which can deliver drugs directly into a selected organ or even a specific cell. This has important implications for many areas of medicine including new potential treatments for cancer and blinding eye disease.
US-based pSivida Corp. is developing medical applications of BioSilicon and was recently named North America's 15th fastest growing technology company by Deloitte. The corporation's products also include Retisert, a rice-sized eye implant treatment for posterior uveitis, and Vitrasert, an eye implant for the treatment of AIDS-related cytomegalovirus retinitis, Iluvien, a tiny injectable device that would be the first FDA approved drug therapy for diabetic macular edema, is also under FDA review.
pSivida conducts its operations from Boston in the United States and Malvern in the United Kingdom. Canham currently serves as Chief Scientific Advisor to pSivida and is the Chief Scientific Officer of Intrinsiq Materials Ltd., another company in Malvern, UK that focuses on nutritional and consumer care applications.