Artigo
Radiation-grafting of thermo- and pH-responsive poly (N-vinylcaprolactam-co-acrylic acid) onto silicone rubber and polypropylene films for biomedical purposes
Fecha
2014-04-01Registro en:
Radiation Physics and Chemistry. Oxford: Pergamon-Elsevier B.V., v. 97, p. 298-303, 2014.
0969-806X
10.1016/j.radphyschem.2013.12.027
WOS:000332052800044
Autor
Ferraz, Caroline C.
Varca, Gustavo H. C.
Ruiz, Juan-Carlos
Lopes, Patricia S. [UNIFESP]
Mathor, Monica B.
Lugao, Ademar B.
Bucio, Emilio
Institución
Resumen
This work focuses on the effects of gamma-ray irradiation conditions on the stimuli-responsiveness of polypropylene (PP) films and silicone (SR) rubber substrates grafted with N-vinylcaprolactam (NVCL) and acrylic acid (AAc). PP films and SR rubber were modified by simultaneous polymerization and grafting of NVCL and AAc, using pre-irradiation oxidative method at a dose rate of 1223 kGy h(-1) and doses ranging from 5 to 70 kGy. NVCL and AAc solutions (1/1, v/v) at 50% monomer concentration (v/v) in toluene were added to the sample substrates, degassed, sealed and heated at 60 and 70 degrees C for 12 h. After grafting, the samples were soaked in ethanol and distilled water for 24 h successively, followed by drying under vacuum. Samples were characterized by FTIR-ATR, DSC and swelling measurements. Critical points (pH critical or LCST) of grafts were obtained in a pH-environment (pH ranges from 2.2 to 9) and in a thermo-environment (temperature ranges from 22 to 50 C). Cytotoxicity evaluation was performed using fibroblast BALB/c 3T3 cells. the relationship between NVCL-co-AAc grafting and radiation dose was different for each substrate, PP and SR. At 50% NVCL/AAc concentration in toluene, grafting values were higher for SR than for PP. Despite the fact that PP-g-(NVCL-co-AAc) membrane presented a cytotoxic profile at the highest experimental concentration assayed, cytotoxicity evaluation revealed noncytotoxic profiles for the membranes synthesized highlighting their applications for biomedical purposes. (C) 2013 Elsevier B.V. All rights reserved.