The risk of obesity and its association with extremely devastating conditions including heart disease, stroke, high blood pressure, diabetes, breathing problems, makes this health condition extremely concerning.
In a joint effort between Researchers at the University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, has successfully discovered a microneedle patch for the treatment of obesity. The degradable microneedles within this polymer patch consist of drug-loaded nanoparticles (NPs) that gradually release rosiglitazone (Rosi) or CL 316243, which is primarily used to treat diabetes.
As a condition that is considered to be largely preventable, the state of obesity describes a person whose excessive fat accumulation causes them to weigh at least 20% more than an normal individual of the same height. Obesity is estimated to affect approximately 600 million adults worldwide, which is about 13% of the population; a number that has more than doubled since 19801.
Obvious treatment options are primarily focused on restricting the amount of the obese individual’s calorie intake through promotion of physical exercise and diet programs, as well as certain surgical options including bariatric surgeries and liposuction. Therapeutic treatment options are limited due to their inability to only target excess fat tissues and not important sites of adipose tissue such as those present within the liver, kidney, stomach and intestines.
Adipose tissue, or fat, can be present within the body as either brown or white adipose tissue. White adipose tissue (WAT) is responsible for storing excess energy as triglycerides, which causes the abnormal weight gain seen in obese individuals, whereas brown adipose tissue (BAT) produces heat to utilize stored energy.
In obesity research, previous work has been done on “browning agents,” which are chemical agents that could potentially transform WAT into BAT, however the limited specificity of these agents has limited their clinical practicality. To develop their patch, the Researchers began with the fabrication of the Rosi- or CL 316243-encapsulated NPs, which where also equipped with glucose oxidase (GOx), an enzyme that converts glucose to gluconic acid, as well as catalase, which is responsible for consuming excess hydrogen peroxide that is produced during the aforementioned glucose conversion reaction.
Once the sizes of the nanoparticles were confirmed with scanning electron microscopy (SEM), the NPs were loaded into silicone tip needles and then embedded into a polymeric transcutaneous microneedle patch2.
To confirm the effectiveness of the drug-loaded microneedle patch, the Researchers utilized an in vivo mouse model to determine induced browning efficacy. Once the safety of the microneedle patch was confirmed following its placement on healthy lean mice, which was confirmed by the absence of any toxicological effects, the Researchers further evaluated the browning agent patches on diet-induced obese mice.
The microneedle patch was placed on one side of the inguinal region and changed every three days for a four-week study period. Antiobesity effects of the microneedle patch were confirmed by measuring the change of normalized body weight of the mice, whereas antidiabetic effects of the patches were confirmed by measuring the blood glucose levels of mice over the treatment course.
Mice that were treated with Rosi or CL 316243 nanoparticle-embedded microneedle patches demonstrated a clear reduction in both body weight as well as blood glucose level.
The highly specific drug delivery of the microneedle patches in this study show a promising future for the treatment of obesity, especially for individuals who are unable to afford large-scale weight reduction procedures. In addition, the microneedle patch approach developed in this study can also be manipulated for the treatment of various other types of diseases in the future.
- “Obesity and overweight” – World Health Organization
- “Locally Induced ASdipose Tissue Browning by Microneedle Patch for Obesity Treatment” Y. Zhang, O. Liu, et al. ACS Nano. (2017). DOI: 10.1021/acsnano.7b04348.