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Biomedical subjects

D D Lasic

Publications and source records attributed to D D Lasic.

26 records · Page 2Linked to original sources
PubMed1991

Sterically stabilized liposomes: improvements in pharmacokinetics and antitumor therapeutic efficacy.

The results obtained in this study establish that liposome formulations incorporating a synthetic polyethylene glycol-derivatized phospholipid have a pronounced effect on liposome tissue distribution and can produce a large increase in the pharmacological efficacy of encapsulated antitumor drugs. This effect is substantially greater than that observed previously with conventional liposomes and is associated with a more than 5-fold prolongation of liposome circulation time in blood, a marked decrease in uptake by tissues such as liver and spleen, and a corresponding increased accumulation in implanted tumors. These and other properties described here have expanded considerably the prospects of liposomes as an effective carrier system for a variety of pharmacologically active macromolecules.

Animals↗
PubMed1991

Sterically stabilized liposomes: a hypothesis on the molecular origin of the extended circulation times.

Therapeutic applications of intravenously injected liposomes have been limited by their rapid clearance from the bloodstream and their uptake by the macrophage cells of the liver and spleen (RES). Recently, however, liposomes which substantially evade the rapid uptake by the RES have been introduced. Since these liposomes exhibit dramatically different pharmacokinetics and biodistribution, new therapeutic opportunities have appeared. These include enhanced efficacy of antineoplastic agents against tumors, sites of inflammation, and targeting ligand-coupled liposomes to extravascular targets. Despite extensive experimental work, the mechanism underlying the ability of liposomes to avoid the rapid uptake by the RES is still not fully understood. Our approach is an alternative to seeking the answers in complex differential interactions of liposomes with various components of blood. We believe that the effect can be easily explained, at least in qualitative terms, by the fundamental principles of colloid stability. In this communication, we propose that steric stabilization of liposomes is responsible for their prolonged circulation times. We propose that stabilization results from local surface concentration of highly hydrated groups that sterically inhibit both electrostatic and hydrophobic interactions of a variety of blood components at the liposome surface.

Animals↗
PubMed1985

Size analysis of biological membrane vesicles by gel filtration, dynamic light scattering and electron microscopy.

Biological membrane vesicles are analysed in terms of size and size distribution using gel filtration on Sephacryl S-1000, electron microscopy and quasi-elastic light scattering. The agreement between the three methods is satisfactory particularly for homogeneous dispersions. Gel filtration on Sephacryl S-1000 is a quick and convenient method for the routine size analysis of membrane vesicles up to a diameter of about 250 nm.

Cell Membrane↗