Adsorption of gentamicin and antibacterial activity of cellulose-based hydrogels modified with β-cyclodextrin and κ-carrageenan

Abstract

Cellulose is a biopolymer with high potential in applications in areas such as textile, food and pharmaceutical. However, the low water solubility makes the applications difficult and can be overcome through structural modifications which include oxidation with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). In addition to improving the solubility, structural changes open opportunities to obtain new materials including hydrogels that can be applied as adsorbents, wound dressings and drug carriers. This work brings an evaluation of the adsorption efficiency of adsorption of gentamicin sulfate as well as of the antibacterial activity of the microcrystalline cellulose-based hydrogels. Cellulose has been previously oxidized upon TEMPO mediation and chemically crosslinked with epichlorohydrin both in the absence and in the presence of modifiers (β-ciclodextryn and κ-carrageenan. Results of infrared spectroscopy evidenced both the success of oxidation and the crosslinking process, while X ray diffractometry showed the predominant non-crystalline character of the hydrogels. Scanning eléctron microscopy images revealed sponge-like morphologies and, finally, evaluation of the antibacterial acctivity through agar diffusion method showed that the hydrogels obtained exhibit high potential as candidates to use as drug carriers.