Biomedical Engineering Reference
In-Depth Information
3
Recent Advances with Liposomes as
Drug Carriers
Shravan Kumar Sriraman
1
and Vladimir P. Torchilin
1,
*
1
Center for Pharmaceutical Biotechnology and Nanomedicine,
Northeastern University, Boston, USA
Abstract
Liposomes are artii cially-prepared bilayered phospholipid vesicles. Since their
discovery, they have emerged as a promising vehicle for the ei cient delivery
of active biological compounds. h ey can be loaded with hydrophilic drugs in
their aqueous interior and/or hydrophobic drugs in the lipid membrane while
simultaneously protecting the incorporated drug from degradation or inactiva-
tion and changing drug pharmacokinetics and bio-distribution in a favorable
fashion.
h e coating of the liposome surface with polyethylene glycol (PEG) gave rise
to long-circulating liposomes. h is coating helps prevent liposomal uptake by the
mononuclear phagocyte system. Longer circulation times allow for an increased
concentration of the liposomes in the blood and when combined with active tar-
geting through the attachment of targeting ligands, lead to ei cient liposomal
delivery to the target sites increasing thus drug concentration in the required zone
and decreasing toxicity.
h is chapter aims to provide the reader with a clear understanding of the
advantages and limitations of dif erent types of liposomes and bring to light the
recent advances in the use of liposomes in the i eld of drug delivery.
