Getting Nanoparticles into the Brain
By linking small molecules related to the body’s natural pain killers to a biodegradable polymer, investigators at the University of Modena in Italy have developed nanoparticles capable of crossing into the brain. These polymer nanoparticles could be used to deliver imaging agents and anticancer drugs to brain tumors.
Reporting its work in the Journal of Controlled Release, a team led by Maria Angela Vandelli, Ph.D., created nanoparticles capable of crossing the normally impenetrable blood-brain barrier by turning to molecules called opioid peptides that the body uses as its own natural painkiller. These molecules, which are short pieces of protein, bind to specific receptors on the cells that makeup the blood-brain barrier. The receptors then pull these molecules across the barrier and into the brain’s blood system.
The investigators prepared five different versions of these opioid peptides and linked each on to the polymer poly (D,L-lactide-co-glycoside), or PLGA, a biodegradable material that many investigators have found forms biocompatible nanoparticles capable of carrying drugs and imaging agents within the body. The researchers also attached a fluorescent molecule to the polymer so that they could track the resulting nanoparticles as they circulated in mice.
Using fluorescence microscopy to track the nanoparticles, the investigators showed first that polymer nanoparticles without attached opioid peptides failed to cross the blood-brain barrier. Each of the five different nanoparticles containing the peptides crossed readily into the brain. The investigators also showed that the blood-brain barriers were not damaged in any way by the nanoparticles.
This work is detailed in a paper titled, “Peptide-derivatized biodegradable nanoparticles able to cross the blood-brain barrier.” An abstract is available through PubMed.
Original article posted here.