Soap Bubbles for Treating Stenosed Blood Vessels
Liposomes are currently used as drug delivery vehicles but recognized by the immune system. Scientists from the universities of Basel and Fribourg have shown that special artificial liposomes do not elicit any reaction in human and porcine sera as well as pigs. The study was published in the Journal Nanomedicine: Nanotechnology, Biology, and Medicine.
Liposomes are soap-bubble-like nanocontainers made of a double phospholipid membrane that shields off an inner aqueous compartment. In a lenticular form, as developed by Professor Andreas Zumbühl’s team at the Department of Chemistry at the University of Fribourg, they are promising candidates for drug delivery to constricted coronary arteries. Here, the blood flows through the stenosed artery segments with high velocity and is subjected to enhanced shear forces. Under these conditions, the liposomes open and release their content.
Unfortunately, the immune system does recognize these liposomes as foreign bodies. The activation of the immune system may lead to a pseudo-allergy. Earlier studies have shown that negative effects are found in up to 30 percent of the cases. Even using clinically approved liposomal dugs it is possible to find anaphylactic shocks, which can be highly toxic for the treated patient.
No Reaction in Pig Studies
A team of researchers led by Prof. Bert Müller from the Biomaterials Science Center of the University of Basel and Prof. Andreas Zumbühl from the Department of Chemistry at the University of Fribourg has tested artificial phospholipid vesicles (Pad-PC-Pad vesicles) for their potential as drug delivery nanocontainers. Surprisingly, these liposomes did not spur any reaction neither in blood serum of pigs nor humans.