title: Biocompatibility of lipid microcylinders: effect on cell growth and antigen presentation in culture.
abstract: The authors are developing a lipid-based microcylinder for the controlled release of biological response modifiers and as templates for cellular migration and differentiation. These structures are comprised of a photopolymerizable phosphatidylcholine (1,2-ditricosa-10,12-diynoyl-sn-glycero-3-phosphocholine) and form spontaneously as a result of a thermotropic phase transition in aqueous solution or in a cosolvent solution of 70:30 ethanol:water. The hollow cylinders are helically wrapped lipid bilayers, variable in length (50-250 microns, depending on conditions of formation) and are 0.5-1.0 microns in diameter. The interaction has been examined of three types of lipid microcylinders: (1) monomeric, (2) photopolymerized by exposure to 254 nm light, and (3) surface-modified by incorporation of 6 mol% gangliosides, with different human cell lines and peripheral blood leucocytes to evaluate the biocompatibility of these structures. The proliferative status of U937 (a histiocytic monocyte), K562 (an erythroleukaemic cell), and Jurkat's derivative (a T-lymphoblast) as measured by pulsed tritiated thymidine was unaffected by the presence of up to 100 micrograms/ml of lipid microcylinders after 3 d in culture. Adherent human peripheral blood monocytes were shown to form adhesive contacts with the lipid microcylinders. An 'association' index from this interaction shows that after 3 d in culture, the association was much lower for those microcylinders that had incorporated ganglioside compared with monomeric or polymerized structures. The lipid microcylinders do not activate T-cells isolated from human peripheral blood, nor do they inhibit the activation of T-cells by phorbol esters or other mitogens.(ABSTRACT TRUNCATED AT 250 WORDS)
authors: Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375-5000.
authors: A S
authors: AS
authors: Rudolph
authors: G
authors: G
authors: Stilwell
authors: R O
authors: RO
authors: Cliff
authors: B
authors: B
authors: Kahn
authors: B J
authors: BJ
authors: Spargo
authors: F
authors: F
authors: Rollwagen
authors: R L
authors: RL
authors: Monroy
mesh_terms: D000941:Antigens / Q000502:physiology*; D001672:Biocompatible Materials / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002461:Cell Line, Transformed; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology; D008051:Lipid Bilayers; D008055:Lipids / Q000494:pharmacology*; D008081:Liposomes; D008213:Lymphocyte Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D008832:Microchemistry; D008934:Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D000941:Antigens; D001672:Biocompatible Materials; D008051:Lipid Bilayers; D008055:Lipids; D008081:Liposomes; D008934:Mitogens