EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Introduction: Being composed of a long polypeptide backbone on which dense brushes of carbohydrate chains are grafted, mucin represents an appealing macromolecule for tissue regeneration and repair applications. However, its use in this field is still under-exploited.
Scope: This study advances the idea that the methacryloyl derivative of mucin (MuMA) can be used to obtain double–network (DN) systems with improved mechanical properties when compared to their single network (SN) counterparts. We take advantage of (1) MuMA’s ability to form a stable three-dimensional network through the polymerization of the methacryloyl groups on the protein backbone and (2) the ability of the carbohydrate side chains to form a dense network of hydrogen bonds with a natural polyphenol (tannic acid - TA).
Materials and methods: Following the synthesis of MuMA, various SN stable hydrogels were prepared using reaction media with different pH values. The SN hydrogels were converted into DN systems through incubation in TA solution. The affinity for aqueous media of both SN and DN hydrogels was assessed and the mechanical properties of the obtained systems were evaluated both at macro- and micro-scale.
Results: The successful formation of the DN systems was demonstrated by the noteworthy differences in swelling ability (both the time required for attaining the hydration equilibrium and swelling content). The mechanical tests showed that the SN hydrogels break around 30 – 40 % strain, but are able to undergo higher deformation, while the DN systems require a significantly higher stress to be deformed at the same strain value. The rheological tests showed that the supplementary reinforcement of the hydrogel was not accompanied by the stiffening of any chain parts, while the nanoindentation tests revealed an immobilization of the macromolecular chains on the surface of the synthesized materials.
Acknowledgement: The research was supported through project NanoSHAC within PNCDI III, PN-III-P1-1.1-TE-2019-1161