Scientists distill cows milk into nano-capsules for drug delivery

Exosomes are nano-sized biological capsules that cells produce to protect and courier delicate molecules throughout the body. The capsules are hardy enough to withstand enzymatic breakdown, as well as acidic and temperature fluctuations in the gut and bloodstream, making them a prime candidate for drug delivery.

Harvesting them to achieve clinical-grade levels of purity, however, is a complex process. "Exosomes are abundant in cow's milk, yet they're difficult to isolate from other milk proteins and lipids,"  said Rob Gourdie, professor and director of the Center for Vascular and Heart Research at the Fralin Biomedical Research Institute at VTC.

Gourdie's laboratory developed a scalable method to harvest exosomes from unpasteurized cow's milk. Using this purification method, which was published this month in Nanotheranostics, the research team can extract roughly a cup of purified exosomes for every gallon of unpasteurized milk.

"For the first time, we've charted a path toward the industrial scalability of exosome purification for oral drug delivery," said Gourdie, who is also the Commonwealth Research Commercialization Fund Eminent Scholar in Heart Reparative Medicine Research and a professor of biomedical engineering and mechanics in Virginia Tech's College of Engineering.

The research team developed their multi-step, cost-effective purification process, which optimizes filtration methods, and timing of temperature and chemical treatments effecting calcium levels, during the COVID-19 pandemic.