Abstract (english) | Liposomes are colloidal particles in which a phosholipid bilayer membrane,
composed from self-assembled amphiphlic molecules encapsulates pare of the aqueous
phase in which they are dispersed. Since their discovery in the mid-1960s, they
were first used to study biological membranes. Due to their biodegradability and
biocompatibility, today, liposomes are useful system for the delivery or targeting of
drugs to specific sites in the body. Liposomes are characterized by their phospholipid
composition, particle size, number of lamellae, and inner/outer aqueous phases, all of
which dictate their stability and inceraction characteristics. They are able to incorporate
almost any drug regardless of solubility, or to carry on their surface cell-specific
ligands. Therefore, liposomes have the potential to be tailored in a variety of ways to
ensure the production of formulations that are optimal far clinical use. Morphologically,
we distinguish between small, medium-sized, large and giant unilamellar, oligoor
multi-lamellar, as well as multivesicular liposomes. With respect to inceraction
properties there are several types of liposomes: conventional liposomes which are
characterized by a nonspecific reactivity of the milieu, sterically stabilized liposomes
that are relatively inert and therefore nonreactive to the environment, immunoliposomes
and polymorphic liposomes which are very reactive towards specific agents. |