XXXV Reunião Anual da SBBqResumoID:2622


Development and Characterization of Lectinized-Magnetoliposomes

Andrade, C.A.S.1,2*; dos Santos, C.G.3; Oliveira, M.D.L.4; Santos-Magalhães, N.S.2; Correia, M.T.S.2; de Melo, C.P.1,3



1Pós-Graduação em Ciência de Materiais, 2Departamento de Bioquímica, 3Departamento de Física, 4Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil. *E-mail: cesar@df.ufpe.br


The goal of this study was to prepare and characterize lectinized-magnetoliposomes (LML) and to evaluate the interaction of lectin and lipid vesicles. In this framework, interactions that may occur between wheat germ agglutinin lectin (WGA) and phospholipids in mixed monolayers were investigated. WGA (29mM) and phospholipids (1mM dipalmitoylphosphatidylcholine-DPPC, dioleoylphosphatidylcholine-DOPC, dibehenoylphosphatidylcholine-DBPC, and dipalmitoylphosphatidyletanolamine-DPPE) were analyzed using Langmuir technique, fluorescence and impedance spectroscopy. Initially, magnetic nanoparticles (68 ±18 nm) were prepared by co-precipitation of 0.12M FeCl3 and 0.05M FeSO4. Then LML was obtained by the thin film technique, followed by redispersion with colloidal magnetite and WGA solution. Multilamellar liposomes were submitted to sonication to obtain unilamellar vesicles. p–A isotherms showed that WGA had a mean molecular area of 3,800 Å2 and support the existence of its interaction with phospholipids, especially in DOPC mixed films (1,320 Å2/molecule). LML was obtained with 169 ± 72nm mean diameter of vesicles. Fluorescence spectroscopy showed that WGA has low interaction with DPPE-LML. Conversely, WGA has a great interaction with DOPC-LML. The quenching in the WGA fluorescence of DOPC-LML spectra also indicated an interaction between the lectin and the phospholipid bilayer. Low values of the impedance real part of magnetite (Zre=1.98 kW) were detected from dielectric relaxation diagrams, while for WGA and unloaded liposomes Zre is about 105 W. LML presented Zre values similar to unloaded liposomes, preserving the dielectric properties of pure lipids. This feature indicates that magnetite was entrapped into the lipid vesicles. Additionally, the analysis of the hysteresis cycle of magnetite showed that such particles were paramagnetic. From these results we can state that LML were obtained, which has potential application in magnetic resonance imaging and drug delivery systems for cancer therapy.

Supported by: CNPq/MCT, CAPES.