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Research article - Peer-reviewed, 2021

In Vitro Investigation of Thiol-Functionalized Cellulose Nanofibrils as a Chronic Wound Environment Modulator

Blasi-Romero, Anna; Palo-Nieto, Carlos; Sandstrom, Corine; Lindh, Jonas; Stromme, Maria; Ferraz, Natalia

Abstract

There is currently a huge need for new, improved therapeutic approaches for the treatment of chronic wounds. One promising strategy is to develop wound dressings capable of modulating the chronic wound environment (e.g., by controlling the high levels of reactive oxygen species (ROS) and proteases). Here, we selected the thiol-containing amino acid cysteine to endow wood-derived cellulose nanofibrils (CNF) with bioactivity toward the modulation of ROS levels and protease activity. Cysteine was covalently incorporated into CNF and the functionalized material, herein referred as cys-CNF, was characterized in terms of chemical structure, degree of substitution, radical scavenging capacity, and inhibition of protease activity. The stability of the thiol groups was evaluated over time, and an in vitro cytotoxicity study with human dermal fibroblasts was performed to evaluate the safety profile of cys-CNF. Results showed that cys-CNF was able to efficiently control the activity of the metalloprotease collagenase and to inhibit the free radical DPPH (1,1-Diphenyl-2-picrylhydrazyl radical), activities that were correlated with the presence of free thiol groups on the nanofibers. The stability study showed that the reactivity of the thiol groups challenged the bioactivity over time. Nevertheless, preparing the material as an aerogel and storing it in an inert atmosphere were shown to be valid approaches to increase the stability of the thiol groups in cys-CNF. No signs of toxicity were observed on the dermal fibroblasts when exposed to cys-CNF (concentration range 0.1-0.5 mg/mL). The present work highlights cys-CNF as a promising novel material for the development of bioactive wound dressings for the treatment of chronic wounds.

Keywords

nanocellulose; wound healing; proteases; reactive oxygen species; cysteine; antioxidant properties

Published in

Polymers
2021, volume: 13, number: 2, article number: 249
Publisher: MDPI

Authors' information

Blasi-Romero, Anna
Uppsala University
Palo-Nieto, Carlos
Uppsala University
Swedish University of Agricultural Sciences, Department of Molecular Sciences
Lindh, Jonas
Uppsala University
Stromme, Maria
Uppsala University
Ferraz, Natalia
Uppsala University

UKÄ Subject classification

Polymer Technologies

Publication Identifiers

DOI: https://doi.org/10.3390/polym13020249

URI (permanent link to this page)

https://res.slu.se/id/publ/110534