Nanoparticles are particles that vary in size between 1 and 100 nanometers (1 billionth of a meter). Researchers at MIT (Langer Lab) and Brigham & Women’s Hospital (under Omid Farokhzad) have developed nanoparticles that act as vehicles for transporting anti-obesity drugs directly to adipose or fat tissue. The drugs work by converting White Adipose Tissue (WAT) into Brown Adipose Tissue (BAT).
BAT is especially abundant in newborns and hibernating mammals (it generates body heat). The larger vasculature and iron content is what gives it the brown color. The drugs that would be administered by the aforementioned nanoparticles would induce the growth of new blood vessels (called Angiogenesis), thus turning WAT into BAT. This could be a game changer in fighting obesity, which affects more than a third of the American population. When treating mice that were obese with these nanoparticles, they lost 10 percent of their body weight over 25 days, with no negative side effects.
Normally, drugs that promote angiogenesis can be harmful to other parts of the body. This is where the nanoparticles come in, providing a unique delivery system that can target the diseased area and minimize the drug’s interaction with other areas of the body. Using poly lactic-co-glycolic acid, or PLGA, which has a hydrophobic (water resistant) core containing two different drugs: Rosiglitazone (brand name Avandia) and a synthetic human hormone prostaglandin. Rosiglitazone has been used to treat type-2 diabetes by increasing sensitivity to insulin but has been known to have adverse side effects like weight gain, chest pains, nausea, loss of appetite, and dark urine among others. But if the drug can be localized to just the White Adipose Tissue, it could break new ground in the fight against obesity and diabetes.
At this point, the only method of introducing these nanoparticles into the body is by intravenous injection, but to be more widely applicable an easier method of administration needs to be developed. Oral pills would be the way to go but the challenge therein would be the ability for the nanoparticles to penetrate the intestinal lining. Langer and Farokhzad have previously developed a nanoparticle that was coated with antibodies that bind to receptors found on the cell lining of the intestine, and would allow for the nanoparticles to be absorbed into the digestive tract. The hope is that this specificity would allow for better targeting, more adipose tissue targets, and more effective drugs to win the aggressively uphill battle on obesitySource: MIT News