The potential of miniature implants to deliver controlled doses of medicine over many months is expected to revolutionise health care and improve treatment for an increasingly wide range of conditions over the next decade.
Crucial to these delivery systems is the interaction between the medicine and the polymers that form “the backbone” of the implants, says Professor Greg Qiao, deputy head of the Department of Chemical and Biomolecular Engineering at the University of Melbourne.
Professor Qiao says potential applications have been limited because of adverse chemical reactions between many medicines and the polymers available. However, the University of Melbourne recently partnered with the medical technology company PolyActiva to improve the stability of polymers for implants, which will expand treatment options for many diseases.
The PolyActiva project initially focused on a treatment for glaucoma, which is the leading cause of blindness worldwide. The standard treatment involves daily eye drops. “But people often forget to apply their eye drops,” Professor Qiao says. “And only a small portion of the drug ends up at the site of action anyway.”
PolyActiva’s alternative is a small polymer cylinder implant, injected into the eye, to release a controlled daily dose of the drug for up to six months.
“We were able to improve PolyActiva’s polymerisation process with a new method that creates more stable polymers. These can support a wider range of medicines, including the drugs for glaucoma, over six months or even more,” Professor Qiao says.