Chitosan Hydrogels Crosslinked by Genipin and Reinforced with Cellulose Nanocrystals: Production and Characterization

Abstract

In this work, chitosan hydrogels crosslinked with genipin and reinforced with cellulose nanocrystals (CNC) were developed and characterized with the aim of future biomedical applications. CNC was produced by acid hydrolysis and characterized by atomic force microscopy (AFM). Chitosan/CNC nanocomposite hydrogels were produced with different CNC concentrations (w/w): 0%, 2%, 4%, and 6%. The genipin was used as a crosslinking agent in a genipin/chitosan molar proportion of 1:8. The hydrogels were characterized by porosity measurements, scanning electron microscopy (SEM), swelling test, and mechanical compression test. No significant differences were observed concerning the porosity of the hydrogels; however, a trend of decreasing porosity was observed with increasing CNC content. The SEM images showed a better pore structure as the CNC concentration increased. A decrease in the swelling degree with increasing CNC content in the chitosan/CNC nanocomposite hydrogel was verified in the swelling tests. An increase in the CNC concentration in the chitosan/CNC nanocomposite hydrogel caused a gradual increase in the maximum stress and maximum strain as observed in the compression tests, showing a significant difference between chitosan/CNC 6 wt % and neat chitosan hydrogel.

Chitosan hydrogel covalently crosslinked by gold nanoparticle: Eliminating the use of toxic crosslinkers

“…The impact of the presence of NPs in polymeric matrix on the porosity and swelling degree was already discussed by other authors. Recently, in the work of Pomari et al 30 increased rigidity and low swelling degree of chitosan hydrogel were afforded by increasing the content of cellulose nanocrystals into the polymeric matrix. Similarly, Montanheiro et al 25 reported on the PHBV scaffolds of low porosity produced by the addition of cellulose nanocrystals.…”

Review of Chitosan Nanomaterials for Metal Cation Adsorption

“…The results showed that the DOI: 10.15259/PCACD. 25.001 use of a low genipin concentration produced well-crosslinked hydrogels. The swelling of crosslinked hydrogels depended strongly on the degree of crosslinking and the pH of the medium.…”

“…Pomari et al focused on pre-treatment in an ultrasonic bath (5 min, room temperature) before mixing the solutions and for a short crosslinking time (1 min) when preparing crosslinked hydrogels from chitosan (MW 190-310 kDa, weight, DD 75-85%) and genipin (8:1 molar ratio) in an aqueous solution of acetic acid (1%) [25]. Crosslinked chitosan hydrogels were then formed at room temperature for 7 days in plastic tubes, where contact was limited to the surface hydrogel with the atmosphere (О 2 ), as suggested by another study [26].…”

“…Shi et al [35] reported the preparation of hydrogels based on quaternized chitosan (HTCC) and chitosan with a MW of 300 kDa and a DD of 95% (based on which the derivative was synthesized), with DOI: 10.15259/PCACD. 25.001 α-β-glycerophosphate (GP). Gels were obtained by ionic interaction of constituent components under ordinary conditions.…”

“…Progress on Chemistry and Application of Chitin and its Derivatives, Volume XXV, 2020 DOI: 10.15259/PCACD 25…”