Lysine-Based Biodegradable Surfactants: Increasing the Lipophilicity of Insulin by Hydrophobic Ion Paring

AimThe aim of this study was to evaluate biodegradable cationic surfactants based on lysine.MethodsLysine esterified with cholesterol, oleyl alcohol and 1-decanol resulting in cholesteryl lysinate (CL), (OL) decyl (DL). Esters were investigated regarding their log Dn-octanol/water, critical micelle concentration (CMC) biodegradability. Hemolytic potential CL, OL, DL the already established hexadecyl (HL) determined complexes insulin (INS) formed by hydrophobic ion pairing (HIP). Lipophilic characteristics ion-pairs examined analyzing Pn-butanol/water.ResultsSuccessful synthesis OL confirmed IR, NMR MS. Log D analysis revealed amphiphilic properties for esters a CMC 0.01 mM, 2.0 mM 6.0 found DL, respectively. Biodegradability proven, as over 99% degraded isolated enzymes within 30 min after 3 h 97% CL cleaved membrane bound enzymes. well displayed no hemolytic effect cytotoxicity significantly reduced comparison HL. INS/CL complex exhibited highest lipophilicity.ConclusionCholesterol-amino acid seem be promising agents HIP.