Attainment and characterization of carboxymethyl chitosan hydrogels by enzymatic cross-linking

Autor(es)

Morandim-Giannetti, Andreia de Araujo ^[1] ; Wecchi, Patrick de Oliveira ^[1] ; Silverio, Paula de Araujo ^[2] ; Carlstron, Regina ^[3] ; Bersanetti, Patricia Alessandra ^[4]

Afiliação do(s) autor(es)

^[1] Ctr Univ FEI, Dept Chem Engn, Sao Paulo, SP - Brazil

^[2] Univ Fed Sao Paulo, Escola Paulista Med, Dept Hlth Informat, Sao Paulo, SP - Brazil

^[3] Univ Fed Sao Paulo, Escola Paulista Med, Dept Ophthalmol & Visual Sci, Sao Paulo, SP - Brazil

^[4] Univ Fed Sao Paulo, Escola Paulista Med, Dept Biochem, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY; v. 138, n. 5, p. 3635-3643, DEC 2019.
• Citações Web of Science: 0

Resumo

In this study, carboxymethyl chitosan hydrogels (CMCH) cross-linked with catechin in the presence of laccase (CMCH-C-L) were obtained. The synthesis and characterization of CMCH were carried out from chitosan (CH) and its cross-linking with catechin (C) in the presence of laccase (L). DSC, ATR-FTIR, and rheological analyses of the CMCH solution and CMCH-C-L hydrogel were carried out. Three main thermal events were observed in the DSC characterization with temperatures and enthalpies related to each event for CMCH: 167.2 degrees C/+523.3 J g(-1), 269.1 degrees C/-35.0 J g(-1), and 333.3 degrees C/-17.6 J g(-1), possibly referring to these processes: polymerization, breaking of electrostatic interactions, and decomposition of the material, respectively. The CMCH-C-L hydrogel presented values of 165.2 degrees C/+376.6 J g(-1), 266.7 degrees C/-47.8 J g(-1), and 333.3 degrees C/-31.5 J g(-1). Conversely, the chitosan presented only one thermal event of decomposition at 302.5 degrees C and enthalpy of -258.5 J g(-1). Rheological properties of the hydrogels (viscosities, consistency values, and flow indices) showed non-Newtonian pseudoplastic rheological behavior and that the viscosity increased approximately 150% after the reaction (134.25 mPa s for CMCH and 342.85 mPa s in CMCH-C-L) confirming the formation of cross-links after the addition of catechin and laccase. Morphological analyses of CMCH and CMCH-C-L films via SEM showed the modification of the material after the reaction with the catechin in the presence of laccase and corroborated with the results, confirming the presence of cross-links. (AU)

• Processo FAPESP: 15/19273-2 - Aplicação de lacase na modificação de biomateriais e tecidos para uso oftalmológico e avaliação da produção da mesma por fungos endofíticos de Manihot Esculenta, Crantz
• Beneficiário: Andreia de Araújo Morandim
• Modalidade de apoio: Auxílio à Pesquisa - Regular