To enhance medication absorption, scientists utilize a synthetic protein coating that binds to receptors on the surface of corneal cells.
Topical medication administration to the eyeball, i.e. eye drops, is the most practical solution. However, a naturally occurring component in tears can interfere with the drug delivery system (DDS), preventing the medication from being absorbed and reaching the cells it needs to reach.
Mucin, or MUC, is normally there to protect your eye, but when it comes into contact with a molecule like a lipoplex, a typical type of DDS used in ophthalmological medicines, it binds to it and reduces absorption into the targeted region. Is there any way to get the lipoplex past the MUC, scientists wondered?
Researchers were able to disguise the lipoplexes as something that MUC would disregard by using a manufactured, artificial protein corona (PC). They discovered that Fibronectin (FBN) and a tripeptide of the amino acids Valine, Glycine, and Aspartate (VGA) were both efficient at hiding the lipoplex, avoiding MUC coating, and binding to the corneal epithelium.
Carlo Astarita, Ph.D. candidate at the Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, College of Science and Technology, Temple University, explains that when MUC binds to the lipoplex surface, it changes the size as well as the positive or negative surface charge. “This inhibits medication absorption by primary corneal epithelial cells. So, what can we do to keep MUC from interfering? We cover the liposome with a novel coating that is recognized by receptors on the ocular surface, avoiding the difficulty and delivering the chemical to the targeted tissue more directly.”
The researchers are part of an international partnership involving Temple University's Sbarro Institute for Cancer Research and Molecular Medicine, the University of Pennsylvania's Scheie Eye Institute, and co-authors from numerous Italian universities.
“As a dry eye specialist, I encounter a lot of patients with various surface disease issues,” says Giacomina Massaro, M.D., of the Scheie Eye Institute, Department of Ophthalmology at the University of Pennsylvania's Perelman School of Medicine (i.e. the corneal epithelial cells). A complex mixture of mucus, lipids, proteins, and fluids that bathe the ocular surface prevent the medicines in many conditions. The capacity of medicines to break through this barrier is critical.”
Antonio Giordano, M.D., Ph.D., Founder and Director of the Sbarro Health Research Organization (SHRO) and the Sbarro Institute at Temple University, as well as a joint research programme with the University of Siena, Italy, says, "This study is a quintessential example of our researchers using precision medicine to innovate." “We find an issue that prevents certain sorts of therapies from working, and then we ask, ‘What does the body give as its own remedy in this case?' The answer is there on the surface of the cells in this case: we make the medication to bond with the targeted tissue. Precision medicine offers the possibility to improved efficacy in this approach.
Source - Newswise