title: Radiation grafting of N-vinylcaprolactam onto nano and macrogels of chitosan: Synthesis and characterization.
abstract: The aim of this study was to synthesize chitosan hydrogels, in macro- and nano-size, grafted with N-vinylcaprolactam (NVCL) using gamma radiation, and evaluate their potential application as a drug delivery system, using 5-fluorouracil (5-FU) as a model drug. The effect of dose and monomer concentration in the grafting process was studied, and the materials were characterized by FTIR, TGA, DLS, SEM and AFM. Higher grafting percentages were observed for the nanogels system. Although both the grafted macro- and nanogels, (net-CS)-g-NVCL, showed a response to pH (4.75) and temperature (31-33°C), the nanogels showed a better swelling response to both stimuli because of their higher surface area. Both systems were able to load 5-FU in small amounts (2-3.5mgg-1) and the release was sustained for more than 12h, showing that the modified macro and nanogels can be a potential alternative for the administration of drugs.
authors.affiliation: Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad Universitaria, México 04510, D.F., Mexico.
authors.forename: Angélica
authors.initials: A
authors.lastname: Cruz
authors.affiliation: CONACYT Research Fellow at Departamento de Madera Celulosa y Papel-Universidad de Guadalajara, Carretera Guadalajara-Nogales Km. 15.5, Zapopan, Jalisco 45110, Mexico.
authors.forename: Lorena
authors.initials: L
authors.lastname: García-Uriostegui
authors.affiliation: Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad Universitaria, México 04510, D.F., Mexico.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Ortega
authors.affiliation: Nano Medical Engineering Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Isoshima
authors.affiliation: Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad Universitaria, México 04510, D.F., Mexico. Electronic address: burillo@nucleares.unam.mx.
authors.forename: Guillermina
authors.initials: G
authors.lastname: Burillo
keywords: Chitosan grafting; N-vinylcaprolactam; Nanogels of chitosan; Radiation grafting