Highly stabilized, polymer–lipid membranes prepared on silica microparticles as stationary phases for capillary chromatography

Abstract

The ability to rapidly screen complex libraries of pharmacological modulators is paramount to modern drug discovery efforts. This task is particularly challenging for agents that interact with lipid bilayers or membrane proteins due to the limited chemical, physical, and temporal stability of conventional lipid-based chromatographic stationary phases. Here, we describe the preparation and characterization of a novel stationary phase material composed of highly stable, polymeric-phospholipid bilayers self-assembled onto silica microparticles. Polymer lipid membranes were prepared by photochemical or redox initiated polymerization of 1,2-bis[10-(2′,4′-hexadieoyloxy)decanoyl]-sn-glycero-2-phosphocholine (bis-SorbPC), a synthetic, polymerizable lipid. The resulting polymerized bis-SorbPC (poly(bis-SorbPC)) stationary phases exhibited enhanced stability compared to particles coated with 1,2-dioleoyl-sn-glycero-phosphocholine (unpolymerized) phospholipid bilayers when exposed to chemical (50mM triton X-100 or 50% acetonitrile) and physical (15 min sonication) insults after 30 days of storage. Further, poly(bis-SorbPC)-coated particles survived slurry packing into fused silica capillaries, compared to unpolymerized lipid membranes, where the lipid bilayer was destroyed during packing. Frontal chromatographic analyses of the lipophilic small molecules acetylsalicylic acid, benzoic acid, and salicylic acid showed > 44% increase in retention times (P < 0.0001) for all analytes on poly(bis-SorbPC)-functionalized stationary phase compared to bare silica microspheres, suggesting a lipophilic retention mechanism. Phospholipid membrane-functionalized stationary phases that withstand the chemical and physical rigors of capillary LC conditions can substantially increase the efficacy of lipid membrane affinity chromatography, and represents a key advance towards the development of robust membrane protein-functionalized chromatographic stationary phases.

Interaction between Antibacterial Peptide Apep10 and Escherichia coli Membrane Lipids Evaluated Using Liposome as Pseudo-Stationary Phase

“…ILC has been reported as a promising method to investigate the partitioning of active substances into biomembranes [32], [33]. The thermodynamic parameters were analysed on the basis of capacity factor k , an index to assess the interaction between the liposome stationary phase and peptide (Table 2).…”

Enhanced Fluorescent Protein Activity in Polymer Scaffold-Stabilized Phospholipid Nanoshells Using Neutral Redox Initiator Polymerization Conditions

“…(NH 4 ) 2 S 2 O 8 and NaHSO 3 are used as neutral redox initiator pair. 63 (NH 4 ) 2 S 2 O 8 and NaHSO 3 were dissolved separately in PBS buffer at 10 mg/mL, each immediately before use. (NH 4 ) 2 S 2 O 8 and NaHSO 3 solution (monomer to initiator mole ratio = 5:1) were added to the monomer-doped phospholipid nanoshell solution.…”

“…(NH 4 ) 2 S 2 O 8 and NaHSO 3 are used as neutral redox initiator pair . (NH 4 ) 2 S 2 O 8 and NaHSO 3 were dissolved separately in PBS buffer at 10 mg/mL, each immediately before use.…”

“…(NH 4 ) 2 S 2 O 8 and NaHSO 3 are used as neutral redox initiator pair. 63 Isolation of Polymer Scaffolds. To isolate the polymer scaffold from phospholipid nanoshells, the phospholipid was removed by washing the PSS-phospholipid nanoshells with methanol.…”