Lipid Bilayer Fragments and Disks in Drug Delivery

Abstract

Certain lipids can be dispersed as colloidally stable bilayer fragments (BF) or disks with interesting properties for solubilization and delivery of hydrophobic or amphiphilic drugs. They were first observed and characterized as such in the nineties but remained silent in the literature regarding applications for drug delivery. Only recently their potential for delivery of hydrophobic drugs started to be realized. This review deals with electrostatically or sterically stabilized bilayer fragments which provided excellent solubilization sites for antifungal drugs, acted as drugs themselves against bacteria or fungus, could be loaded with amphiphilic drugs or produced lipid-covered drug particles to be delivered as a synergistic formulation in vivo.

Lipid-based Biomimetics in Drug and Vaccine Delivery

“…Electrokinetic properties of the covered particles were very similar to those of vesicles; the mean-z-average diameter of particles in the latex/vesicle mixtures increased of 10 nm, consistently with the increase in diameter expected from deposition of one bilayer on the www.intechopen.com particles (Carmona-Ribeiro & Midmore, 1992). The interaction between lipids and particles has been reviewed over the last two decades in a few review articles and book chapters (Carmona-Ribeiro, 1992;Carmona-Ribeiro and Lessa, 1999;Carmona-Ribeiro, 2001 a,b;Carmona-Ribeiro, 2003;Carmona-Ribeiro et al, 2006;Carmona-Ribeiro, 2006;CarmonaRibeiro, 2007;Petri & Carmona-Ribeiro, 2007;Mamizuka & Carmona-Ribeiro, 2007) and lately other excellent reviews appeared in the literature (Bulte & De Cuyper, 2003;Troutier & Ladavière, 2007;Al-Jammal & Kostarelos). Figure 4 illustrated possible assemblies resulting from the interaction between bilayer-forming lipids and particles as depicted from experimental evidences (Carmona-Ribeiro & Midmore, 1992;Carmona-Ribeiro & Herrington, 1993;Rapuano & Carmona-Ribeiro, 1997;Carmona-Ribeiro & Lessa, 1999;Moura & Carmona-Ribeiro, 2003;Moura & Carmona-Ribeiro, 2005;Moura & Carmona-Ribeiro, 2007).…”

“…Absence of DODAB vesicle disruption upon interaction with the bacteria was depicted from absence of [ 14 C]-sucrose leakage from vesicles in experiments where this marker was used to label the inner water compartment of the vesicles (Martins et al, 1997). The differential cytotoxicity of DODAB lipid was illustrated in Table 2 (adapted from Carmona -Ribeiro, 2003;Carmona-Ribeiro, 2006;Mamizuka & Carmona-Ribeiro, 2007 In conjunction with amphotericin B, DODAB bilayer fragments provided a novel drug formulation with excellent activity against systemic candidiasis in mice (Vieira & CarmonaRibeiro, 2001;Lincopan et al 2003) but low nephrotoxicity (Lincopan et al, 2005) …”

“…On the other hand, cationic lipids electrostatically combine with a vast variety of negatively charged biomolecules or biological structures besides being excellent antimicrobial agents by themselves (CarmonaRibeiro et al, 2006). Silica Carmona-Ribeiro,1997, 2000;Moura and CarmonaRibeiro, 2005, 2006, 2007, latex (Carmona-Ribeiro and Midmore, 1992; or hydrophobic drug particles (Pacheco and Carmona-Ribeiro, 2003;) have been coated with cationic lipids. Optimal cationic bilayer deposition on particles was achieved by coalescence of bilayer fragments at www.intechopen.com adequate experimental conditions for the intervening medium such as pH, ionic strength and concentrations of the interacting components (Moura & Carmona-Ribeiro, 2003;Moura & Carmona-Ribeiro, 2005;Pereira et al, 2004;Pereira et al, 2006).…”

“…Disks compared favourably to uni-and multilamellar liposomes for hydrophilic drug partitioning employing immobilized disks in glass capillaries (Johansson et al, 2005). The major repulsive interactions preventing fusion of bilayer fragments and discs in dispersion are electrostatic, steric and/or eletrosteric (Carmona-Ribeiro, 2006). In particular, probe sonication of the synthetic and cationic lipid dioctadecyldimethylammonium bromide (DODAB) can yield disrupted vesicles: the bilayer fragments, BF, or disks (Carmona-Ribeiro, 2006).…”

Effect of Functional Groups on Incorporation Behavior of Amino Acid-Type Surfactant into Phospholipid Vesicle Membrane

“…The interaction between phospholipid vesicle membrane and surfactant is of great interest from the standpoints of the solubilization and the reconstitution of membrane proteins, and hence, many researchers have reviewed about it [1][2][3][4][5][6] . In general, the nonionic surfactants have been widely used for this purpose [7][8][9][10][11][12][13][14][15][16][17] . On the other hand, anionic surfactants are used as detergents, and then the interaction of anionic surfactants with phospholipid vesicles might be a good research model for the influence of detergent on skin [18][19][20][21] .…”