title: Synthesis, characterization and inclusion into liposomes of a new cationic pyrenyl amphiphile.
abstract: The aggregation properties of a new cationic fluorescent amphiphile tagged on the hydrophobic tail with a pyrene moiety and bearing two hydroxyethyl functionalities on the polar headgroup were investigated by fluorescence experiments as pure components or in mixed liposomes containing an unsaturated phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine, at different molar ratios. The obtained results put in evidence that the conformation and the miscibility of the lipids in the aggregates strongly influence the excimer/monomer ratio. Mixed monolayers at the same composition were investigated by Langmuir compression isotherms to deepen the understanding of lipid organization and miscibility, both in the polar and in the hydrophobic regions. The presence of two hydroxyethyl functionalities on the polar headgroup of the newly synthesized amphiphile exerts a shielding effect of the charge of the amphiphile increasing the compressibility of lipid components in contrast with the disturbing effect of the unsaturated acyl chains of the phospholipid.
authors: Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell'Aquila, Via Vetoio, 67100 Coppito (Aq), Italy; CNR - Istituto di Metodologie Chimiche, Via Salaria km 29.300, 00016 Monterotondo Scalo (RM), Italy.
authors: Manuela
authors: M
authors: Petaccia
authors: Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell'Aquila, Via Vetoio, 67100 Coppito (Aq), Italy; CNR - Istituto di Metodologie Chimiche, Via Salaria km 29.300, 00016 Monterotondo Scalo (RM), Italy. Electronic address: luisa.giansanti@univaq.it.
authors: Luisa
authors: L
authors: Giansanti
authors: Dipartimento di Biologia Ambientale, Università degli Studi di Roma "La Sapienza", P.le Aldo Moro 5, 00185 Roma, Italy. Electronic address: francesca.leonelli@uniroma1.it.
authors: Francesca
authors: F
authors: Leonelli
authors: Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", P.le Aldo Moro 5, 00185 Roma, Italy.
authors: Angela La
authors: A
authors: Bella
authors: Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", P.le Aldo Moro 5, 00185 Roma, Italy; CNR - Istituto di Metodologie Chimiche, Via Salaria km 29.300, 00016 Monterotondo Scalo (RM), Italy.
authors: Denise
authors: D
authors: Gradella Villalva
authors: CNR - Istituto di Metodologie Chimiche, Via Salaria km 29.300, 00016 Monterotondo Scalo (RM), Italy.
authors: Giovanna
authors: G
authors: Mancini
mesh_terms: D002412:Cations / Q000138:chemical synthesis / Q000737:chemistry; D005997:Glycerylphosphorylcholine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008081:Liposomes / Q000737:chemistry*; D015394:Molecular Structure; D010713:Phosphatidylcholines; D011721:Pyrenes / Q000138:chemical synthesis / Q000737:chemistry*; D013501:Surface-Active Agents / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D002412:Cations; D008081:Liposomes; D010713:Phosphatidylcholines; D011721:Pyrenes; D013501:Surface-Active Agents; D005997:Glycerylphosphorylcholine; C030984:pyrene; C017251:1,2-oleoylphosphatidylcholine
keywords: Excimer/monomer ratio; Langmuir isotherms; Liposomes; Pyrenyl amphiphile