POLYUREA HYDROGELS PREPARED BY SOL-GEL CHEMISTRY AS POTENTIAL BIOMATERIALS

Purpose : We report the synthesis of polyurea (PU) hydrogels using polyethylene oxide PEO-1900 as a soft segment and hexamethylene diisocyanate (HDI) as a hard segment as potential biomaterials. Methods : In two separate 25mL flasks, the PEO1900 (4g in 10 mL of acetone) and the crosslinker (0.525 g in 5 mL of acetone) were dissolved. The contents of the two flasks were mixed and ready to put in a glass mold. Finally, cylindrical monolithic xerogels were obtained after drying under vacuum at 70 °C for 24 h. In the case of the samples loaded with curcumin, addition was made of 0.5 % and 1.0 % w/w to 4.0 g to the PEO. Results : The unloaded dry PU are sensitivy to the humidity, it can be seen that the xerogels are opaque or transparent. Moreover, the PUs are a rubbery, flexible and insoluble in aqueous medium. The opaque characteristic of the PU is due to the presence of a cristalinity PEO segment. The macroscopic swelling experiments demostrated the hydration of the matrix, leading to the expansion of the network by the water molecules diffusion into the PEO. The contact angle result  demonstrated a fast absorbtion of the drop water by PU hydrogel, evindencing a very hydrophilic surface. This behavior is due to the fucntional groups (urea and polyether backbone) present in the structure of the PU xerogel. The incorporation of antimicrobial/anticancerous curcumin in the preparation of PU xerogels was successfully obtained. Conclusions : These PU hydrogels show promising applications as biomaterials.