Synthesis of films based on chitosan and protic ionic liquids to be used as wound dressing on the oral mucosa.

Oral mucosal ulcerations expose connective tissue to different pathogens and this can progress to systemic infection. This study aimed to synthesize environmentally-friendly films with chitosan and protic ionic liquids, possessing mucoadhesive properties, activity against opportunistic microorganisms, enhanced malleability and mechanical resistance to be used as a wound dressing on the oral mucosa. Therefore, films with chitosan and 10, 35, and 50 % (wt/wt) of 2-hydroxy diethylammonium lactate, salicylate, and maleate protic ionic liquids were synthesized. Thickness measurements and mechanical properties analysis were performed. In addition, oral mucoadhesion, antimicrobial activity, and cytotoxicity properties were investigated. Results showed that the addition of 35wt% and 50wt% of all kinds of protic ionic liquids tested presented significant improvements in film thickness and mechanical properties. Films based on chitosan and the protic ionic liquid 2-hydroxy diethylammonium salicylate at percentages of 35 and 50wt% exhibited superior mucoadhesive properties, antimicrobial activity on opportunistic microorganisms and an improvement in their flexibility after immersion in synthetic saliva. Cytotoxicity results suggest that all kinds of chitosan/protic ionic liquids films tested are safe for intra-oral use. Therefore, the results of this study indicate that these materials could be good candidates for efficient and environmentally-friendly wound dressing films on the oral mucosa.

Immobilization of ß-Galactosidases on Magnetic Nanocellulose: Textural, Morphological, Magnetic, and Catalytic Properties.

We describe a process for obtaining nanocrystalline cellulose (NC) by either acidic (H-NC) or alkaline treatment (OH-NC) of microcrystalline cellulose, which was subsequently bonded to magnetic nanoparticles (H-NC-MNP and OH-NC-MNP) and used as support for the immobilization of Aspergillus oryzae (H-NC-MNP-Ao and OH-NC-MNP-Ao) and Kluyveromyces lactis (H-NC-MNP-Kl and OH-NC-MNP-Kl) ß-galactosidases. The mean size of magnetic nanocellulose particles was approximately 75 nm. All derivatives reached saturation magnetizations of 7-18 emu/g, with a coercivity of approximately 4 kOe. Derivatives could be applied in batch hydrolysis of lactose either in permeate or in cheese whey for 30× and it reached hydrolysis higher than 50%. Furthermore, using a continuous process in a column packed-bed reactor, the derivative OH-NC-MNP-Ao had capacity to hydrolyze over 50% of the lactose present in milk or whey after 24 h of reaction. Fungal ß-galactosidases immobilized on magnetic nanocellulose can be applied in lactose hydrolysis using batch or continuous processes.