treatment was employed. Phospholipids were purchased from Avanti Polar Lipids. The vcsiclcs (at a phospholipid concentration of 1 mg/ml in 30 mM-Tris/HCI buffer, pH 7.0, containing 0 . I M-NaCI) were prepared by sonication for 30 rnin in a water-bath sonifier at tcmperaturcs above the phasc transition of the corresponding phospholipid. The concentration of a-sarcin was determined by absorbance ...

Carboplatin (CPT) and paclitaxel (PTX) used in combination is one of the most effective treatments for ovarian cancer. However, the traditional combination methods used to co-administrate CPT and PTX showed limited clinical efficacy due to their distinct pharmacokinetics. Although much effort has been devoted to developing nanoparticles capable of encapsulating drugs with different lipophilicit...

Evidence suggesting liposomal delivery into the pilosebaceous unit of the male Syrian hamster ear membrane was found using two fluorescent techniques, quantitative fluorescence microscopy (QFM), and a scraping method where the various tissue strata of treated skin are analyzed using fluorescence spectrophotometry. Whole ears were mounted on Franz diffusion cells and treated for 24 h with 40 mic...

From glycosylated cell surfaces to sterically stabilized liposomes, polymers attached to membranes attract biological and therapeutic interest. Can the scaling laws of polymer "brushes" describe the physical properties of these coats? We delineate conditions where the Alexander-de Gennes theory of polymer brushes successfully fits the intermembrane distance versus applied osmotic stress data of...

The spontaneous colloidal nanostructures formed in water by the zwitterionic phospholipid DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) with the cationic detergent DTAC (n-dodecyltrimethylammonium chloride) were investigated at a fixed DMPC concentration and variable detergent:lipid total molar ratios (D:L). Apparent (neutral-sphere-equivalent) hydrodynamic diameters (Φ(e)) of liposomes an...

Various vesicle structures and lipid compositions have been studied to identify the optimal type of liposome for delivery of the macrophage-activating agent muramyl dipeptide (MDP) to macrophages. Evaluation of the ability of liposomes to be phagocytosed by macrophages established that optimal initial rates of engulfment were obtained when multilamellar vesicles (MLV) composed of distearoylphos...

The effect of liposomal entrapment on oral absorption of drugs was deter~ned from the excretion profiles of entrapped markers after oral administration to rats. Liposomal entrapment does not facilitate the uptake of PEG-4000, a non-absorbable, water-soluble marker. The excretion patterns of hydrocortisone and salicylic acid, when entrapped in L-a-phosphatidylcholine distearoyl/cholesterol or eg...

Meningococcal and gonococcal outer membrane proteins were reconstituted into liposomes using detergent-mediated dialysis. The detergents octyl glucopyranoside (OGP), sodium cholate and Empigen BB were compared with respect to efficiency of detergent removal and protein incorporation. The rate of OGP removal was greater than for cholate during dialysis. Isopycnic density gradient centrifugation ...

Model membrane systems are used extensively in all aspects of membrane research, and freeze-fracture is the preeminent procedure for directly visualizing local structure in these lipid dispersions. Here we describe in detail the formation of liposomes and how freeze-fracture is routinely employed as a complementary technique to biophysical and biochemical procedures in the characterization of m...

Intravenously administered phospholipid liposomes are known to interact with plasma high-density lipoproteins, which remove phospholipid molecules from the bilayers, thus leading to vesicle destabilization. Consequently, drugs that may have been originally entrapped leak out into the circulation to acquire their own clearance rates and tissue distribution. The destabilized liposomes and drugs t...