The drug molecules
(red) are embedded in a water-filled cavity
inside of the
phopholipid vesicle.
(March 11, 2016) 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.