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Gold Nanoparticles Reduce Side-Effects of Arthritis Drug

Gold nanoparticles could be used to build a new class of anti-arthritic drugs that are more effective and have fewer side-effects, according to research published in the Journal of Inorganic Biochemistry.

Gold compounds have been used for the treatment of rheumatoid arthritis for approximately 80 years, and are usually given via intramuscular injection. Its use tapered off in the 1990s due to limited efficacy, slow onset of action and numerous side-effects.

University of Wollongong PhD student Lloyd James tested gold nanoparticles in macrophages, which play a significant role in rheumatoid arthritis. “We found that gold nano­particles were taken up by more cells and in greater quantities than the traditional gold drugs, but without any toxicity which is often associated with negative side-effects in clinical therapy,” he said.

“Effectively, our study found gold nano­particles didn’t kill immune cells. While cell death is something that you look for, for example in cancer therapies, when it comes to rheumatoid arthritis, cell death can be associated with negative side-effects,” Lloyd said.

So why does shrinking the size of gold particles boost effectiveness and decrease side-effects? Lloyd and his supervisors think that it may be partially due to there being more gold available in the cell – thousands of tiny nanoparticles compared with just a handful of larger particles. They are now trying to answer this question, along with the specifics about how small the nanoparticles need to be.

The use of metals for medicinal purposes is quite common. Colloidal silver has been used for centuries as an antiseptic; a bismuth compound has been used to quell stomach problems; and a platinum drug called cisplatin has been a great success story for chemotherapy.

“I think there is a lot of untapped potential in the medicinal properties of metals,” Lloyd said.