title: Effect of anionic and cationic polyamidoamine (PAMAM) dendrimers on a model lipid membrane.
abstract: In spite of the growing variety of biological applications of dendrimer-based nanocarriers, a major problem of their potential applications in bio-medicine is related to the disruption of lipid bilayers and the cytotoxicity caused by the aggregation processes involved onto cellular membranes. With the aim to study model dendrimer-biomembrane interaction, the self-assembly processes of a mixture of charged polyamidoamine (PAMAM) dendrimers and dipalmitoylphosphatidylcholine (DPPC) lipids were investigated by means of Zeta potential analysis, Raman and x-ray scattering. Zwitterionic DPPC liposomes showed substantially different behaviors during their interaction with negatively charged (generation G=2.5) sodium carboxylate terminated (COO-Na+) dendrimers or positively charged (generation G=3.0) amino terminated (-NH2) dendrimers. More specifically the obtained results evidence the sensitive interactions between dendrimer terminals and lipid molecules at the surface of the liposome, with an enhancement of the liposome surface zeta potential, as well as in the hydrophobic region of the bilayers, where dendrimer penetration produce a perturbation of the hydrophobic alkyl chains of the bilayers. Analysis of the SAXS structure factor with a suitable model for the inter-dendrimers electrostatic potential allows an estimation of an effective charge of 15 ǀeǀ for G=2.5 and 7.6 ǀeǀ for G=3.0 PAMAM dendrimers. Only a fraction (about 1/7) of this charge contributes to the linear increase of liposome zeta-potential with increasing PAMAM/DPPC molar fraction. The findings of our investigation may be applied to rationalize the effect of the nanoparticles electrostatic interaction in solution environments for the design of new drug carriers combining dendrimeric and liposomal technology.
authors: Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico-Fisici, Viale F. S. D'Alcontres 37, 98158 Messina, Italy. Electronic address: lombardo@ipcf.cnr.it.
authors: Domenico
authors: D
authors: Lombardo
authors: Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati, Via Salaria km 29.300, Monterotondo Stazione, 00015 Roma, Italy.
authors: Pietro
authors: P
authors: Calandra
authors: Dipartimento di Scienze chimiche, biologiche, farmaceutiche ed ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy.
authors: Ersilia
authors: E
authors: Bellocco
authors: Dipartimento di Scienze chimiche, biologiche, farmaceutiche ed ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy.
authors: Giuseppina
authors: G
authors: Laganà
authors: Dipartimento di Scienze chimiche, biologiche, farmaceutiche ed ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy.
authors: Davide
authors: D
authors: Barreca
authors: Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy; LE STUDIUM, Loire Valley Institute for Advanced Studies, Orléans & Tours; and CBM (CNRS), rue Charles Sandron, 45071 Orléans, France.
authors: Salvatore
authors: S
authors: Magazù
authors: Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy.
authors: Ulderico
authors: U
authors: Wanderlingh
authors: Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Ulica Joliot-Curie 6, Dubna, Moscow 141980, Russia.
authors: Mikhail A
authors: MA
authors: Kiselev
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry; D050091:Dendrimers / Q000737:chemistry*; D004337:Drug Carriers; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D013816:Thermodynamics
chemical_list: D002264:Carboxylic Acids; D050091:Dendrimers; D004337:Drug Carriers; D008051:Lipid Bilayers; D008081:Liposomes; C104700:PAMAM Starburst; D015060:1,2-Dipalmitoylphosphatidylcholine
keywords: Dendrimers; Lipid membranes; Raman scattering; Small angle x-ray scattering (SAXS); Zeta potential