Artículos de revistas
Interaction of O-acylated chitosans with biomembrane models: probing the effects from hydrophobic interactions and hydrogen bonding
Fecha
2014-02Registro en:
Colloids and Surfaces B, Amsterdam : Elsevier BV,v. 114, p. 53-59, Feb. 2014
0927-7765
10.1016/j.colsurfb.2013.09.034
Autor
Pavinatto, Adriana
Souza, Adriano L.
Delezuk, Jorge A. M.
Pavinatto, Felippe José
Campana Filho, Sérgio Paulo
Oliveira Júnior, Osvaldo Novais de
Institución
Resumen
One of the major challenges in establishing the mechanisms responsible for the chitosan action in biomed-ical applications lies in the determination of the molecular-level interactions with the cell membrane. Inthis study, we probed hydrophobic interactions and H-bonding in experiments with O,O -diacetylchitosan(DACT) and O,O -dipropionylchitosan (DPPCT) incorporated into monolayers of distinct phospholipids,the zwitterionic dipalmitoyl phosphatidyl choline (DPPC), and the negatively charged dipalmitoyl phos-phatidyl glycerol (DPPG) and dimyristoyl phosphatidic acid (DMPA). The importance of hydrophobicinteractions was confirmed with the larger effects observed for DACT and DPPCT than for parent chitosan(Chi), particularly for the more hydrophobic DPPCT. Such larger effects were noted in surface pressureisotherms and elasticity of the monolayers. Since H-bonding is hampered for the chitosan derivatives,which have part of their hydroxyl groups shielded by O-acylation, these effects indicate that H-bondingdoes not play an important role in the chitosan-membrane interactions. Using polarization-modulatedinfrared reflection absorption (PM-IRRAS) spectroscopy, we found that the chitosan derivatives wereincorporated into the hydrophobic chain of the phospholipids, even at high surface pressures compara-ble to those in a real cell membrane. Taken together, these results indicate that the chitosan derivativescontaining hydrophobic moieties would probably be more efficient than parent chitosan as antimicrobialagents, where interaction with the cell membrane is crucial.