Computational modeling and synthesis of lecithin molecularly imprinted polymer for endotoxin removal

Nowadays, the occurrence of endotoxin contamination in several products and environments is ubiquitous as existing endotoxin removal procedures are inadequate. This results in several potentially adverse health effects on humans when exposed to endotoxin residues. Among the common treatments (such as boiling, filtration, and pH treatment), the use of a highly selective recognition material based on the molecularly imprinted technique is introduced as an alternative approach for endotoxin removal. In this study, a lecithin molecularly imprinted polymer (LEC-MIP) for endotoxin removal was developed. Prior to MIP synthesis, computational modeling tools, AutoDock Vina and BIOVIA Discovery Studio, were used to screen the occurrence of H-bonding interactions between twenty functional monomers and phosphate on lipid A moiety. Factors affecting LEC-MIP synthesis were studied in terms of types (e.g., methanol, dichloromethane, acetonitrile, dimethylsulfoxide, acetone, and isopropanol) and amounts of solvents (e.g., 1, 2, 4, 8, and 10 mL) and the stoichiometric ratio between LEC, methacrylic acid (MAA), and ethyleneglycol dimethacrylate (EGDMA) (e.g., 1:4:16 and 1:8:32, respectively). The synthesized MIPs were screened for 24-h binding performance with a 10-EU/mL endotoxin standard solution. Results show that the LEC-MIP synthesized with 4 mL and 6 mL of 30% v/v MeOH in dichloromethane at stoichiometric ratios of 1:4:16 and 1:8:32 for LEC, MAA, and EGDMA, respectively, yielded the optimum binding performance. Finally, the chosen LEC-MIPs were packed in solid-phase cartridges and tested for endotoxin removal. Results also show that the synthesized MIP yields the highest endotoxin removal rate of up to 47%.