Biomembrane Phospholipid–Oxide Surface Interactions: Crystal Chemical and Thermodynamic Basis

Electrostatic effects on deposition of multiple phospholipid bilayers at oxide surfaces

“…This allows for a small electrostatic interaction between DPPC bilayers and the oxide surfaces, which drives adsorption of an additional bilayer on positively-charged oxides. An earlier thermodynamic treatment of phosphatidylcholine (PC)-oxide interactions is incomplete because it only accounted for the positively-charged tetramethylammonium moiety in the PC headgroup [27]. Atomic force microscopy (AFM) images of gel-phase DPPC and liquid-crystalline phase ditridecanoylphosphatidylcholine (DTPC) on planar single-crystal surfaces are in qualitative agreement with our adsorption results [60], where increased bilayer stacking is observed on positively-charged compared to negatively-charged oxides (Fig.…”

“…Supported phospholipid bilayers have also been used as a means of templating controlled nano-particle growth [14][15][16], and may be effective agents in preventing biofouling [5], in enhancing oil and ore recovery [17][18][19], and for passivation of hazardous particles in the environment [20,21]. Furthermore, debate continues on the role of lipid-substrate interactions in determining the fate of inhaled mineral dusts in the body [22][23][24][25][26][27][28]; in mediating biomineralization processes such as production of magnetite in bacteria [29], silica and calcite in diatoms and coccoliths, respectively [30,31], or of pathologic mineralization (e.g., calcium oxalate (kidney stones), calcium pyrophosphate dihydrate (pseudogout)) in humans [32,33]; and in the evolution of pre-biotic membranes [34][35][36].…”

Adsorption behavior of DODAB/DPPC vesicles on silica

“…For amorphous silica, the entropic variation was positive, bilayer disruption was limited, even though the total variation in Gibbs free energy was negative [12]. A microcalorimetric approach at pH 7.4, 25 • C and physiological ionic strength found exothermic interactions for bilayer vesicles and SiO 2 or TiO 2 [13].…”

“…The bilayer-oxide surface interaction was evaluated from a crystal chemical and thermodynamic basis predicting the correct sequence of membranolytic ability for the oxides: quartz > amorphous SiO 2 > Al 2 O 3 > Fe 2 O 3 > TiO 2 [12]. For amorphous silica, the entropic variation was positive, bilayer disruption was limited, even though the total variation in Gibbs free energy was negative [12].…”

Modeling apatite nucleation in the human body and in the geochemical environment

“…The field has a profound, albeit largely unnoticed, impact on issues of importance to the general public. To increase the awareness and understanding of biogeochemistry, it is important to stress that universal physicochemical principles fundamentally control the complex interactions of solutions, biomolecules and minerals in the apparently unrelated realms of the human body and the natural geological environment (Sahai, 2002(Sahai, , 2003aAnseau and others, 2005). In both realms, the systems under consideration may have chemical components that are similar and molecular conformations that are critical to understanding specific reaction pathways.…”