Nanoparticles Show Promise in Long-Term Treatment of Rheumatoid Arthritis

Biodegradable polymer nanoparticles to deliver methotrexate may improve rheumatoid arthritis therapy.

Biodegradable polymer nanoparticles (BNPs) may be efficient in the early detection and long-term treatment of rheumatoid arthritis (RA).

For a study presented at the European League Against Rheumatism Annual Congress, researchers used a chronic collagen-induced arthritis mouse model to examine the new method of treating RA.

“Despite dramatic advances in the treatment of RA, currently available therapies can cause several side effects, many patients fail to respond, and true remission is only achieved in a minority,” said lead study investigator Paolo Macor. “This is often due to late diagnosis of the pathology. There is therefore a need to develop a new tool to enable early diagnosis, and also to develop tissue-specific agents able to reduce systemic side effects. This would increase the potency of the drug with lower doses, and also potentially reduce the cost of treatment.”

Researchers coated BNPs with a peptide that only targets inflamed joint tissue, resulting in minimal side effects. An immunofluorescence technique revealed that BNPs targeted the inflamed joint tissue.

In a rat model of antigen-induced arthritis, researchers used a single injection of BNPs combined with methotrexate, and found that the inflammation disappeared. The same dose that did not contain methotrexate was injected into the rat and had no real effect.

“The advantage of being able to deliver methotrexate in this targeted way is to be able to gain the benefits from this key treatment of RA, while reducing the risk of adverse effects that are more frequent at high doses,” Macor said.