Abstract: A hydraulic axial piston pump has a rotating cylindrical barrel which defines pumping chambers and pistons reciprocating in the pumping chambers. A swash plate controls the length of travel of the pistons. During a part of each rotation of the barrel a piston will draw fluid into its complementary pumping chamber and during another part of each such rotation the piston will force fluid under pressure out of its complementary pumping chamber. Each chamber has an inlet valve which is closed when the pressure in the chamber exceeds the inlet pressure. Each chamber also has an outlet valve which is closed when the pressure in the outlet exitway exceeds the pressure in the chamber. High pressure fluid from the chambers is fed to shoes that ride on the swash plate to provide a fluid cushion between the shoes and the swash plate thus reducing friction.

Abstract: A liposome gel composition and method of preparing the same. The composition is composed of charged liposomes, at a relatively low lipid concentration, in a low-conductivity medium. The composition preferably contains a zwitterionic compound at its isoelectric point. The liposomes can be designed for cosmetic use, transdermal drug delivery, or enhanced retention on mucosal tissues, such as for ophthalmic use.

Abstract: A liposome composition which contains between 1-20 mole percent of an amphipathic lipid derivatized with a polyalkylether, as exemplified by phosphatidylethanolamine derivatized with polyethyleneglycol. The derivatized lipid enchances the circulation time of the liposomes severalfold, and this enhancement is achieved with either fluid or membrane-rigidifying liposome components. Also disclosed are methods for delivering a drug for slow release from the bloodstream, and for targeting a selected tissue or cells with liposomes, via the bloodstream.

Abstract: A composition and method for treating a wound or surgical incision, by sustained-released delivery of epidermal growth factor (EGF). The composition includes a high-viscosity aqueous dispersion of negatively charged liposomes with liposome-entrapped EGF. The EGF/liposome composition is formed, in one embodiment of the invention, by suspending a lipid mixture typically containing equimolar amounts of neutral and negatively charged phopholipids and cholesterol in a low-conductivity aqueous medium containing EGF and a zwitterionic compound whose isoelectric point is between pH 5.5 and 8.5 to form a gel-like composition. One embodiment of the invention contains EGF entrapped by surface adsorption to the liposomes, for slow release from the composition.

Abstract: A suspension of heterogeneous size liposomes is passed through a polymer filter having a web-like construction providing a network of interconnected, tortuous-path capillary pores, and a membrane thickness of at least about 100 microns. The processed liposomes have a selected average size less than about 0.4 microns, and a narrow size distribution.

Abstract: A method of preparing a concentrated liposome suspension having a lipid concentration of greater than about 250 .mu.m/ml and liposome sizes no greater than about 0.4 microns. A solution of vesicle-forming lipids in a chlorofluorocarbon solvent is injected under selected conditions into an aqueous medium, with continual solvent removal. During the lipid injection and solvent-removal steps, the liposomes formed in the aqueous medium are extruded through a membrane, to reduce liposome sizes to less than about 0.6 microns. The lipid injection, solvent removal, and extrusion steps are continued until a lipid concentration of at least about 150 .mu.m/ml is reached.

Abstract: A method of preparing a suspension of liposomes containing a water-soluble compound predominantly in liposome-encapsulated form. A solution of vesicle-forming lipids in a chlorofluorocarbon solvent is infused under selected conditions into an aqueous medium, with continual solvent removal. The lipid infusion and solvent removal steps are continued until a lipid concentration of at least about 150 .mu.m/ml is reached, at which point more than about half of the compound contained in the resultant liposome suspension is in encapsulated form.

Abstract: A blood fluid composition for use in a complement-mediated cell lysis system. The composition includes a blood fluid, which may be either a serum source of complement, analyte-containing serum, or both, and lipid vesicles capable of reducing the extent of non-specific cell lysis produced when the blood fluid is added to lysable target cells in the system. The vesicles are present in an amount which increases the ratio of ligand-specific to non-specific cell lysis in the system at least 2-fold and preferably 4-fold or more over that achievable in the system in the absence of the vesicles.

Abstract: A suspension of liposomes whose sizes are predominantly greater than about 1 micron is passed through an asymmetric ceramic filter whose inner-surface pore size is about 1 micron. The processed liposomes have a selected average size of about 0.4 microns or less, depending on the number of filter cycles, and a narrow distribution.

Abstract: A viral lysis immunoassay system and method. The system includes hemolytic particles carrying non-viral, anti-analyte molecules, lysable target cells which are devoid of surface molecules capable of binding to endogenous viral surface molecules, and foreign binding molecules added to the target cells. The binding molecules, which may be either analyte molecules or analyte-related molecules attached to the target cell surfaces, function to bind the particles to the cells, to initiate cell lysis and the release of encapsulated reporter molecules from the cells. The analyte to be assayed may be one adapted to bridge the virus particles to analyte-related molecules carried on the cell surfaces, or one which competes with target-cell molecules for binding to the particle anti-analyte molecules.

Abstract: An enhanced agglutination assay method for determination of a multivalent analyte is disclosed. Analyte is added to agglutinatable particles coated with anti-analyte molecules to produce particle agglutination. The extent of agglutination is enhanced by mixing the particles and analyte with an analyte-binding reagent composed of lipid bodies. The reagent bodies act by promoting multiple analyte bridge connections between individual bridged particles and a reagent body. Also disclosed is a kit containing such particles and reagent.

Abstract: An agglutination assay reagent and method. The reagent is composed of liposomes predominantly in the 1 to 20 micron diameter size range. Each liposome has a surface array of laterally mobile ligand molecules, at a surface concentration adapted to produce reagent agglutination within about 5 minutes, when the reagent is incubated at room temperature with a multivalent ligand-binding analyte. A dye in the liposomes allows such agglutination to be visualized easily without magnification.