| Full text | |
| Author(s): |
Morandim-Giannetti, Andreia de Araujo
[1]
;
Wecchi, Patrick de Oliveira
[1]
;
Silverio, Paula de Araujo
[2]
;
Carlstron, Regina
[3]
;
Bersanetti, Patricia Alessandra
[4]
Total Authors: 5
|
| Affiliation: | [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
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY; v. 138, n. 5, p. 3635-3643, DEC 2019. |
| Web of Science Citations: | 0 |
| Abstract | |
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) | |
| FAPESP's process: | 15/19273-2 - Laccase application in the modification of biomaterials and tissue for ophthalmic use and evaluation of the production of it by endophytic fungi of Manihot Esculenta, Crantz |
| Grantee: | Andreia de Araújo Morandim |
| Support Opportunities: | Regular Research Grants |