Effect of polymer capped magnetite and their interaction with phospholipid films adsorbed at air / liquid interface

Rosario

Conferencia; L Reunión Anual de la Sociedad Argentina de Biofísica; 2023

Universidad Nacional de Rosario

Magnetic nanoparticles (MNPs) as magnetite (Fe3O4) have been showed a greater potential application in many biological fields as drug delivery, cancer treatment through hyperthermia and magnetic resonance imaging (MRI) contrast enhancement. However, for all these biomedical applications, the MNPs must be coated with hydrophilic and biocompatible molecules like polymers, which avoid aggregation. For this reason, recognized how these coated MNPs interact with lipid films has gained importance. Langmuir isotherms is used to studied the interaction of Fe3O4 coated with two different polymers, chitosan (CHI) and diethylaminoethyl dextran (DEAE-D) commonly used in medical applications, with lipid membranes models (distearoyl phosphatidic acid (DSPA) and distearoyl phosphatidylethanolamine (DSPE), adsorbed at air / liquid interface, here we analized the behaviour of MNPs: lipid mixtures. For the mixture MNPs: DSPE, the two types of nanoparticles induce a decrease in the mean molecular area per lipid in monolayers, being this effect is greater for Fe3O4@CHI, in this case, as the lipid is zwitterionic, hydrophobic interactions are dominants and cause removal of some phospholipid molecules, along with MNPs, outside the monolayer. This same behavior is observed for the MNPs and DSPA mixture, in this case as the lipid is negative charged and the surface of the particles are positive charge, electrostatic interactions become important. For the maximum Fe3O4@CHI:DSPA ratio, the isotherm do not reach the collapse pressure. The greater interaction between DSPA or DSPE:Fe3O4@CHI is probably due to the better availability and accessibility of the polar head of the lipids to the ammonium groups in the polymer chains, since it is a linear polymer while DEAE-D is a branched polymer.Insertion studies of MNPs within monolayers demonstrate that both kind of nanoparticles can penetrate into monolayers above 30 mN m−1, which is the lateral pressure value accepted for a cellular bilayer.