Enzymes inside lipid vesicles: preparation, reactivity and applications (original) (raw)

2001, Biomolecular Engineering

There are a number of methods that can be used for the preparation of enzyme-containing lipid vesicles (liposomes) which are lipid dispersions that contain water-soluble enzymes in the trapped aqueous space. This has been shown by many investigations carried out with a variety of enzymes. A review of these studies is given and some of the main results are summarized. With respect to the vesicle-forming amphiphiles used, most preparations are based on phosphatidylcholine, either the natural mixtures obtained from soybean or egg yolk, or chemically defined compounds, such as DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) or POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine). Charged enzyme-containing lipid vesicles are often prepared by adding a certain amount of a negatively charged amphiphile (typically dicetylphosphate) or a positively charged lipid (usually stearylamine). The presence of charges in the vesicle membrane may lead to an adsorption of the enzyme onto the interior www.elsevier.com/locate/geneanabioeng Abbre6iations: Bz-Arg-pNA, benzoyl-L-Arg-p-nitroanilide; DDV, vesicles prepared by the detergent dialysis method; DMPC, 1,2prepared by the dehydration-rehydration method; DRV-MFV, vesicles prepared by microfluidization of DRV; DRV-VET 100 , vesicles prepared by using the dehydration-rehydration method first and then extruding through polycarbonate membranes with a mean pore diameter of 100 nm used in the last extrusion step; DSPE-PEG2000, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[poly(ethylene glycol) 2000 ]; EE, entrapment efficiency= (amount of enzyme entrapped in the vesicles)/(total amount of enzyme) × 100 (%); FAT-VET 200 , vesicles prepared by freeze-thaw cycles, followed by repeated extrusions through polycarbonate membranes with a mean pore diameter of 200 nm used in the last extrusion step; G M1 , monosialoganglioside; GUV, giant unilamellar vesicles; IFV, vesicles prepared by the so-called 'interdigitated-fusion method'; LUV, large unilamellar vesicles; lyso PC, lysophosphatidylcholine; lyso PE, lysophosphatidylethanolamine; lyso PI, lysophosphatidylinositol; MFV, vesicles prepared by using an homogenizer and the Microfluidizer™; MLS, multilamellar spherulites prepared by shearing a lamellar phase; MLV, multilamellar vesicles; MLV-FAT, vesicles prepared by repetitive freezing and thawing a MLV suspension; MLV-MFV, vesicles prepared from MLV by using the Microfluidizer™; MVVprepared by the reverse-phase evaporation method; REV-VET, REV that have been extruded through polycarbonate membranes of a defined pore size; SM, sphingomyelin; SOPC, 1-stearoyl-2-oleoyl-sn-glycero-3phosphocholine; Suc-Ala-Ala-Pro-Phe-pNA: succinyl-L-Ala-L-Ala-L-Pro-L-Phe-p-nitroanilide; SUV, small (sonicated) unilamellar vesicles as obtained by sonifying MLV; T m , main lamellar chain-melting phase transition temperature (also called 'lamellar gel-liquid crystalline phase transition temperature'); VEI, vesicles prepared by the ethanol injection method; VET 100 , vesicles prepared by the extrusion method (without freezing-thawing cycles) using for final extrusions polycarbonate membranes with mean pore diameters of 100 nm; VPL, vesicles prepared by the pro-liposome method; Z-Phe-Val-Arg-pNA, benzyloxycarbonyl-L-Phe-L-Val-L-Arg-p-nitroanilide.