title: New amphiphilic derivatives of poly(ethylene glycol) (PEG) as surface modifiers of colloidal drug carriers. III. Lipoamino acid conjugates with carboxy- and amino-PEG(5000) polymers.
abstract: Within a research directed to developing new polymeric materials, suitable for decorating the surface of colloidal drug carriers, PEG5000 polymers containing a free carboxyl or amine group at one end were conjugated to an α-lipoamino moiety (LAA). The conjugates were characterized by FT-IR, (1)H-NMR, and MALDI-TOF mass spectrometry. They showed the same profile of solubility as the parent PEGs in water and in some polar and apolar solvents of pharmaceutical use. Representative terms showed to be well tolerated when incubated with Caco-2 or L929 cell cultures. Dedicated differential scanning calorimetry (DSC) studies were performed to prove the interaction of increasing molar fractions of the PEG5000-LAA conjugates with dipalmitoylphosphatidylcholine (DPPC) bilayers, to gain information about their possible incorporation in drug nanocarriers. While the parent PEGs affected only the superficial structure of bilayers, the amphiphilic PEG-LAA conjugates induced a perturbing effect on the thermotropic behavior of DPPC liposomes, according to the structure of the linked LAA residue. A molar concentration of these PEG-LAA between 5 and 10% was individuated as the most suitable to produce stable vesicles.
authors.affiliation: Sezione di Tecnologia Farmaceutica, Dipartimento di Scienze del Farmaco, Università degli Studi di Catania, Catania, Italy. Electronic address: r.pignatello@unict.it.
authors.forename: Rosario
authors.initials: R
authors.lastname: Pignatello
authors.affiliation: Istituto per i Polimeri, Compositi e Biomateriali, Consiglio Nazionale delle Ricerche, Catania, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Impallomeni
authors.affiliation: Sezione di Tecnologia Farmaceutica, Dipartimento di Scienze del Farmaco, Università degli Studi di Catania, Catania, Italy.
authors.forename: Venerando
authors.initials: V
authors.lastname: Pistarà
authors.affiliation: Sezione di Tecnologia Farmaceutica, Dipartimento di Scienze del Farmaco, Università degli Studi di Catania, Catania, Italy.
authors.forename: Sarha
authors.initials: S
authors.lastname: Cupri
authors.affiliation: Sezione di Fisiologia, Dipartimento di Scienze Bio-mediche, Università degli Studi di Catania, Catania, Italy.
authors.forename: Adriana C E
authors.initials: AC
authors.lastname: Graziano
authors.affiliation: Sezione di Fisiologia, Dipartimento di Scienze Bio-mediche, Università degli Studi di Catania, Catania, Italy.
authors.forename: Venera
authors.initials: V
authors.lastname: Cardile
authors.affiliation: Sezione di Tecnologia Farmaceutica, Dipartimento di Scienze del Farmaco, Università degli Studi di Catania, Catania, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Ballistreri
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D001672:Biocompatible Materials; D018938:Caco-2 Cells; D002152:Calorimetry, Differential Scanning; D003102:Colloids; D004337:Drug Carriers; D006801:Humans; D011092:Polyethylene Glycols / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D013055:Spectrophotometry, Infrared; D013057:Spectrum Analysis; D013499:Surface Properties
chemical_list: D000596:Amino Acids; D001672:Biocompatible Materials; D003102:Colloids; D004337:Drug Carriers; D011092:Polyethylene Glycols
keywords: DSC; Lipoamino acid; MTT test; PEG; Polymeric conjugates; Stealth drug carriers