Even though arthritis is a well-known disease, experts believe that it is often misunderstood. There over 100 different kinds of arthritis and related diseases. The most familiar kinds consist of rheumatoid arthritis (RA), osteoarthritis (OA), and psoriatic arthritis (PsA) all of which result in a lot of difficulty for anyone who suffers from them.
However, there may be hope yet. Scientists at University of California (UC), San Diego are working on developing neutrophil nanosponges that can safely absorb and counteract various proteins that have a part in the development of certain types of arthritis.
Primarily, this study has been targeting rheumatoid arthritis. Inflammation is often associated with rheumatoid arthritis. In rheumatoid arthritis, the immune system attacks the outer layer of the joint, the synovial membrane. The synovial membrane makes a fluid called synovial fluid that reduces frictions between the joints so that they can move more efficiently. The attack on the synovial fluid causes inflammation and swelling. But sometimes having too much synovial fluid can also cause inflammation.
Over a period of time, the continuous swelling and inflammation causes the deterioration of ligaments in the joints. In progressive rheumatoid arthritis this waning end up becoming deformities to the hands and feet, for example claw toe or hammer toe. At this moment there are no effective treatments to cure the disease but only treatments that could slow it down. Even though researchers are working on new innovations that could one day be fruitful in curing this disease.
This new research uses a two mouse model system. Two mouse models have been efficiently treated of severe rheumatoid arthritis by shots of these nanosponges. Administering the nanosponges early on also stopped the disease from progressing.
As rheumatoid arthritis is developing, neutrophils enter the joints when cells in the joints produce inflammatory cytokines which signal them to enter. Once inside, cytokines attach itself to the receptors on the neutrophil surfaces, triggering them to release more cytokines, which then make more neutrophils to the joints and so forth. The nanosponges essentially tweak this inflammatory mechanism from happening over and over again. By taking the place of tiny neutrophil, they interrupt cytokines and stop them from alerting more neutrophils to come to the joints, decreasing joint damage and inflammation.
According to the researchers these nanosponges are promising a better alternative to present treatments for rheumatoid arthritis. For example, some monoclonal antibody drugs have aided patients to manage symptoms of the disease, but they only work by neutralizing some particular kinds of cytokines. This is not adequate to treat the disease, because there are so numerous diverse kinds of pathological molecules and cytokines involved.
In order to make the neutrophil nanosponges, first of all the researchers had to develop a technique to isolated neutrophils from whole blood. Then they treated the cells in a solution that made them to swell and burst, leaving behind the membranes. The membranes were then fragmented into much smaller bits. Stirring them with spherical nanoparticles made of biodegradable polymer attached the neutrophil cell membranes on the surfaces of nanoparticle.
Injecting nanosponges in inflamed joints of mice from the mouse models of severe rheumatoid arthritis led to decrease swelling and secure cartilage from more damage. The nanosponges accomplished just as well in treatments in which mice were given a higher dose of monoclonal antibodies. They also worked as a precautionary treatment when given earlier than the start of the disease in another group of mice.
Though this treatment have not been commercialized yet, it shows great promises in the field of medicines.
Source: Paper title: “Neutrophil membrane-coated nanoparticles inhibit synovial inflammation and alleviate joint damage in inflammatory arthritis.” Co-authors include Diana Dehaini, Yue Zhang, Julia Zhou, Xiangyu Chen, Lifen Zhang, Ronnie H. Fang and Weiwei Gao, all at UC San Diego.