CONICET | Buscador de Institutos y Recursos Humanos

Polymersomes are polymer-based vesicles that formupon hydration of amphiphilic block copolymers and display high stability and durability, dueto their mechanical and physical properties. They have hydrophilic reservoirsas well as thick hydrophobic membranes; allowing to encapsulate bothwater-soluble bioactive agent and hydrophobic drugs. In this study, Polyethylene glycol (PEG3350 and PEG6000) were used as hydrophilic part and PolyVinyl Benzoate (PVBz) as hydrophobic block to synthesizeamphiphilic triblock copolymers (PVBz-b-PEG-b-PVBz).Different proportions of hydrophilic/hydrophobic part were assayed in order toobtain polymersomes by solvent injection method. For the synthesis of thecopolymers, the initial block of PEG, was derived to obtain a macroinitiatorthrough a xanthate functional group (PEGX3 or PEGX6) and the polymerization ofvinyl benzoate was carried out thought reversible addition-fragmentation chaintransfer polymerization (RAFT). Thestructure of PEGX and copolymers was confirmed by Infrared, 1H-NMRand UV-Vis spectrometry, while the average molecular weight (Mw) andpolydispersity index (PI) were determined by size exclusion chromatography(SEC). The structures adopted by the copolymers in aqueous solution byself-assembly were investigated using transmission electron microscopy (TEM) andsmall-angle X-ray scattering (SAXS). Both techniques confirm that polymersomeswere obtained for a fraction of hydrophilic block (f) » 35% ± 10%, with diameter of 38.3 ± 0.3 or 22.5 ± 0.7 nm , according to the Mw of theprecursor block copolymer. In addition, we analyzed thepossible cytotoxicity in view of its potential application as biomedicalnanocarrier. The results suggest that polymersomes seem not induce cytotoxicity during the periods of timetested.

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