Researchers at MIT and Brigham and Women’s Hospital have developed new nanoparticles that can deliver antiobesity drugs directly to tissue. Mice treated with these nanoparticles lost 10% of their body weight over 25 days without showing any negative side effects. Wouldn’t this be great for those of us that are fighting obesity?
These drugs work by transforming white adipose tissue, made of fat-storing cells, into brown adipose tissue that burns fat. These drugs also stimulate the growth of new blood vessels in fat tissue that positively reinforces the nanoparticle targeting and aids in the white-to-brown transformation.
These are not new and not FDA-approved to treat obesity, but researchers developed a new way to deliver them, helping to avoid unwanted side effects in other parts of the body. Now there is a way of targeting it to a particular area and not giving the body systemic effects. Get the positive effect that you want in terms of antiobesity but not the negative ones that can occur. Langer and Omid Farokhzad, director of the Laboratory of Nanomedicine and Biomaterials at Brigham and Women’s Hospital, are the senior authors of the study published in the Proceedings of the National Academy of Sciences.
Langer and his colleagues have previously shown that promoting the growth of new blood vessels, which is known as angiogenesis, can help in transforming adipose tissue to lead to weight loss in mice. Those drugs that promote angiogenesis can, however, be harmful to the rest of the body. That is why Langer and Farokhzad turned to the nanoparticle drug-delivery strategy they have developed to treat cancer and other diseases. The delivery of a powerful dose while minimizing the drug’s accumulations in other areas can now target these particles directly to the disease site. The particles can carry the drugs in their hydrophobic cores, bound to a polymer known as PLGA which is used in many other drug delivery particles and medical devices.
The particles are injected intravenously, possibly making this approach suitable for morbidly obese patients who are at significant risk of obesity-related diseases. They have yet to come up with easier ways to administer these targeted nanoparticles, possibly orally. Delivering nanoparticles orally makes it difficult for them to penetrate the lining of the intestines. Langer and Farokhzad have developed a nanoparticle coated with antibodies that bind to receptors found on surfaces of cells lining the intestine and in turn, allowing the nanoparticles to be absorbed through the digestive tract.
Another orally delivered nanoparticle that uses transferrin, a protein involved in the transport of iron in the body, has also been developed by them. This is to facilitate active transport of nanoparticles across the intestine. They hope to find more specific adipose tissue targets for the nanoparticles that might further reduce the possibility of side effects. Other drugs with lower toxicity may also be investigated.
This is a proof-of-concept approach for selectively targeting the white adipose tissue and “browning it” to allow the body to burn fat. This research was funded by the National Institutes of Health and a Koch-Prostate Cancer Foundation Award in Nanotherapeutics. This could be exceptional news for those fighting their obesity. Isn’t it time we got some help for people working to lose weight and possibly save their lives?
-Dr Fredda Branyon