ИСТИНА

Introduction: Selective infiltration of biological active agents (BAA) in target organ is one of the determinant factors whether a BAA will be effective in the treatment of pathology. However most of the exogenous chemical compounds are unable to penetrate into tissues because of the histohematic barrier. Therefore a method which would allow targeted delivery of drugs is to be developed. In order to reduce toxicity of BAA and increase targeting of delivery several types of nanocontainers have been designed for the past decades. One primary way in the field of controlled targeted delivery of BAA to sites of their specific action is the use of liposomes. Liposomes are synthetic models of natural membranes. Objective: Synthesis of cationic liposomes modified with monoclonal antibodies (mAb) and the study of their physicochemical properties. Methods: To synthesize cationic liposomes phospholipids and cholesterol were mixed. Once emulsified into water solution these reagents form fat bubbles which have a bilayer lipid membrane and contain some amount of mechanically entrapped water solution. In this paper 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), cholesterol, distearoylphosphatidylethanolamine (DSPE) conjugated to polyethylene glycol with molecular weight 2000 (PEG-2000), cationic lipid dimethyldioctadecylammonium bromide (DDAB) and DSPE with terminal maleimide group to conjugate to mAb in order to form vector containers were used. Synthesis was carried out in two parts: 1) lipid films were formed and then thoroughly dried; 2) films were dispersed in distilled water and sonicated to constitute monolayer liposomes. Vector groups mAb were mixed with Traut’s reagent (10-fold molar excess, RT), then added to liposomes and left overnight at 4oC. After that liposomes were separated from unlinked mAb by gel chromatography with use of Sepharose CL-4B at the speed of 0.5 ml/min. BAA were loaded by entrapment and passive diffusion. Results: As a result of synthesis stable vector liposomes loaded with BAA were obtained. Their physicochemical characteristics were studied by dynamic light scattering (DLS). Z-potential of nanoparticles was measured to be -9.85 mV, hydrodynamic diameter – 90 nm, polydispersity index - 0,131. Enzyme-linked immunosorbent assay (ELISA) showed that antibodies stayed active after conjugation. The toxicity of specimen was estimated with MTT assay and it was determined that IC50 depends on the quantities of DDAB and BAA used. Conclusion: Cationic liposome nanocontainers for targeted BAA delivery were obtained.