New Nanoparticle Treatment Shows Promise for Preventing Rheumatoid Arthritis Flares

Researchers have developed nanoparticles that could slow disease progression and reduce flare severity for rheumatoid arthritis (RA), a chronic condition with no cure. The study authors, who published their findings in ACS Central Science, noted that Agg-CLNP, an immunomodulatory agent composed of nanoparticles containing a key aggrecan peptide and calcitriol, is optimized to be taken up by dendritic cells (DCs) in the lymph nodes near affected joints, preventing RA onset and recurring flares.^1,2

Overview and Symptoms of Rheumatoid Arthritis

RA is an ongoing chronic condition that causes pain, swelling, and irritation in the joints. This inflammation can also damage other parts of the body, including the skin, eyes, lungs, heart, and blood vessels. The condition occurs when the immune system inadvertently attacks the body’s tissues. Symptoms of RA include painful, warm, swollen joints; joint stiffness that worsens in the mornings and after rest periods that can last 45 minutes or longer; and tiredness, fever, and lack of appetite. In its early stages, RA affects only a few joints, often in the hands and feet; however, as the disease progresses, symptoms spread to more joints, including the wrists, elbows, hips, knees, and ankles. While the severity of symptoms varies among individuals, over time, the joints can bend out of shape and shift, which impacts an individual’s daily activities.³

Treatment with disease-modifying antirheumatic drugs (DMARDs), like abatacept, is known to reduce disease activity and slow progression of AD symptoms. Despite this, individuals taking DMARDs continue to experience flare-ups.^1,2

Nanoparticles for Rheumatoid Arthritis

Previous research developed calcitriol-loaded nanoparticles (CLNP) to help manage inflammation in autoimmune joint diseases. To improve these previous findings, researchers created a new version by attaching a protein fragment from aggrecan, a joint protein often mistakenly targeted by the immune system in RA. The study aimed to evaluate whether these modified nanoparticles could treat both RA flares and the predisease state.^1,2

In the study, the researchers optimized a nanoparticle formulation called Agg-CLNP and confirmed that this nanoparticle effectively regulated dendritic cell activity—which is a main immune cell that causes inflammation—in blood samples from both healthy individuals and individuals with RA. The results found that Agg-CLNP suppressed the immune response, which eased RA symptoms.^1,2

Further results in mouse models found that Agg-CLNP was effective as a preventive treatment and delayed inflammation and swelling. When combined with abatacept (Orencia; Bristol Myers Squibb), the standard RA drug, treatment was even greater, delayed disease onset, and significantly reduced joint inflammation and bone damage. Additionally, Agg-CLNP reduced the severity of potential flare-ups in the future when given after corticosteroid treatment. The findings suggest that Agg-CLNP could further treatment options for RA and provide greater relief for individuals who experience painful flares.^1,2

“These findings highlight Agg-CLNP as a potential therapeutic strategy to address critical unmet needs in RA management,” the authors said in the study.¹

REFERENCES

1. Johnson W, Wilkison E, Iyer N. Immunomodulatory Nanoparticles Enable Combination Therapies To Enhance Disease Prevention and Flare Control in Rheumatoid Arthritis. ACS Central Science. 2025. doi.org/10.1021/acscentsci.5c00723

2. Nanoparticles for rheumatoid arthritis prevention, flare control. EurekAlert. News release. August 6, 2025. Accessed August 28, 2025. https://www.eurekalert.org/news-releases/1093150

3. Mayo Clinic. Rheumatoid Arthritis. News release. April 9, 2025. Accessed August 28, 2025. https://www.mayoclinic.org/diseases-conditions/rheumatoid-arthritis/symptoms-causes/syc-20353648