RESUMEN

This work presents electrospun chitosan mats, functionalized with glucose oxidase (GOX) to implement an in-situ hydrogen peroxide (H2O2) generation system. The as spun CTS-PEO mats exhibited a smooth and homogenous morphology in combination with a high specific surface area (5.4m2/g) providing an excellent basis for further functionalization and subsequent glutaraldehyde crosslinking provided them with superior mechanical stability in aqueous environments. GOX was covalently immobilized, as proven by XPS, and resulted in activity recoveries between 20 and 40%. The functional mats generated a steady state concentration of ∼60µM H2O2 per cm2 which resulted in growth inhibition of E. coli and of S. aureus already after two hours of incubation. Additional cytotoxicity tests of the modified mats against mouse fibroblasts did not show an influence on the viability of the cells which proved it a functional biomaterial of great potential for biomedical applications.

Asunto(s)

Antibacterianos/farmacología , Materiales Biocompatibles/farmacología , Quitosano/farmacología , Enzimas Inmovilizadas/metabolismo , Glucosa Oxidasa/metabolismo , Peróxido de Hidrógeno/farmacología , Animales , Antibacterianos/química , Aspergillus niger/enzimología , Materiales Biocompatibles/química , Quitosano/química , Escherichia coli/efectos de los fármacos , Glucosa/metabolismo , Peróxido de Hidrógeno/química , Ratones , Células 3T3 NIH , Nanofibras/química , Porosidad , Staphylococcus aureus/efectos de los fármacos

RESUMEN

Silicate-based microporous materials like zeolites are nano enabled particles and used for various applications including pharmaceutical formulations. This study reports on the chemo-enzymatic functionalization of chitosan-zeolite particles (CTS-zeolites) with caffeic acid (CA) and glucose oxidase (GOX) to impart combined antioxidant and antimicrobial properties. CA was grafted on the chitosan moieties by using laccase generating stable particles (zeta potential -36.7 mV) of high antioxidant activity (44% DPPH inhibition). GOX was immobilized both on CTS-zeolites and on CA modified CTS-zeolites and creating a hydrogen peroxide generation system continuously and in-situ producing this oxidative and antimicrobial agent. The system prevented bacterial growth of E. coli and S. aureus over 24 h whereby a steady-state concentration of around 60 µM hydrogen peroxide in the culture medium was observed. CA and GOX functionalized CTS-zeolite particles additionally showed combinatorial antioxidant and antimicrobial properties providing a powerful bioactive system for medical applications. These particles proved their suitability for incorporation in bioactive formulations which could be used, inter alia, for topical wound treatments.