Scientists at the Fralina Institute for Biomedical Research have developed a new method for purifying exosomes from cow’s milk to produce nanosized capsules for drug delivery.
Exosomes are biological nanoscale capsules that cells produce to protect and deliver fragile molecules throughout the body. The capsules are hardy enough to withstand enzymatic breakdown and acid and temperature fluctuations in the intestines and bloodstream, making them a prime candidate for drug delivery. However, collecting them to achieve clinical purity is challenging.
“Exosomes are abundant in cow’s milk, but difficult to isolate from other milk proteins and lipids,” explains Rob Gourdy, professor and director of the Center for Cardiovascular Research at Virginia Tech.
To solve the problem, Gurdi’s lab has developed a scalable method for collecting exosomes from unpasteurized cow’s milk. Using a new purification method, the research team can extract roughly a cup of purified exosomes from every liter of unpasteurized milk. The research team has developed their own multi-stage, economical cleaning process. It optimizes filtration methods and thermal and chemical processing times that affect calcium levels. Scientists have already carried out practical work to develop a patented procedure.
The research results are published in the journal Nanotheranostics.
Exosomes are naturally secreted by almost all cell types in humans and other mammals and are found in large numbers in blood, lymph, urine, and milk. Coated with protective membranes, exosomes send biomolecules, fragments of genetic material, and chemical signals between cells over long distances.
Over the past decade, research into their pharmaceutical use, especially for the delivery of fragile drugs such as peptides and microRNAs, has increased dramatically.
Exosomes can also cross the blood-brain barrier, a membrane that protects the brain from unwanted pathogens and chemicals, presenting a new way of delivering therapeutic agents for neurological diseases and brain cancer. The study authors note that increasing the viability of exosome use opens up a wide range of drug delivery methods with unlimited clinical applications.