Researchers at the US Department of Energy’s Pacific Northwest National Laboratory have developed a new polymer-based material with gelling properties that are useful in medical applications ranging from targeted cancer treatment to tissue engineering.
Called a stimuli-sensitive polymer, the material is designed to change immediately from a liquid into a gel in response to stimulus, such as increases in temperature. This feature would enable physicians to inject the mixture of the polymer and a medicinal solution directly into a specific target in the body, where it would warm and instantly gel.
‘Stimuli-sensitive gels show promise for the effective treatment of inoperable tumours,’ said Anna Gutowska, senior research scientist at PNNL and lead developer of the gel. ‘While much more research remains to be done before this becomes an accepted medical procedure, we are very excited about its potential.’
One of the more promising therapeutic applications is targeted delivery of medical isotopes or chemotherapy drugs to treat inoperable or difficult-to-treat solid tumours, such as those of the liver, pancreas, brain, breast and prostate.
This year, approximately 179,000 new cases of prostate cancer will be diagnosed in the US, according to the American Cancer Society. The gel may be applicable as an improved therapy for early-stage prostate cancer.
In this application, the polymer solution would be mixed with a medical isotope or chemotherapy drug, then injected into the tumour where body heat would cause instant gelling. Because the gel holds the therapeutic at the target site, developers anticipate being able to safely deliver a uniform dose to cancer cells while minimising damage to surrounding healthy tissue.
In preliminary tests, the gel appears to hold therapeutic isotopes in place. The gel also appears to be compatible with both beta- and gamma-emitting isotopes, which would enable physicians to select the most effective medical isotope for individual treatment needs.
In related research, PNNL is collaborating with the Medical University of South Carolina to test a biodegradable version of the polymer gel to support repair of articular cartilage, which provides cushioning between joints.