Enzymatic gelation to prepare chitosan gels: Study of gelation kinetics and identification of limiting parameters for controlled gel morphology

Wlodarczyk, Damien; Méricq, J.P.; Soussan, Laurence; Bouyer, Denis; Faur, Catherine

doi:10.1016/j.ijbiomac.2017.09.097

Cited by 11 publications

(5 citation statements)

References 39 publications

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“…This study demonstrated that time gelation of chitosan hydrogel was dependent of urea and urease concentrations. Similarly, other study observed that higher concentrations of urease and urea caused hydrogel to have faster gelation (Wlodarczyk et al 2018). In addition, the study findings showed that independent of urea and urease concentration, the chitosan hydrogels resulted in a remaining weight of up to 60% after soaking in lysozyme-containing PBS for 60 days.…”

Section: Discussionsupporting

confidence: 63%

Effects of photobiomodulation associated with chitosan viscosupplementation for osteoarthritis: an in vitro and in vivo study

et al. 2020

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The aim of the present study was to investigate the tissue performance of the association of photobiomodulation (PBM) and chitosan hydrogel (Ch), using in vitro and in vivo studies, in culture of chondrocytes and in an experimental model of osteoarthritis (OA) in the knee of rats. Methods The chitosan hydrogel was characterized by pH, gelation time, and degradation rate. For the in vitro study, chondrocyte cells were seeded in the Ch irradiated or not with PBM to assess cell viability and proliferation after 1, 3, and 5 days. For the in vivo study, sixty Wistar rats with OA were randomly distributed: control group (CG), Ch hydrogel injection (Ch), Ch hydrogel injection associated with PBM (Ch/PBM). Results The characterization results revealed that Ch hydrogels can be controlled precisely by variation of the urea and urease concentrations. The in vitro findings demonstrated that Ch and Ch/PBM are biocompatible and noncytotoxic. The in vivo findings showed that PBM associated with Ch prevented articular degeneration by stimulating anabolic factor (TGF-β) and reducing catabolic factor (TNF-α) and increasing the gene related to components of the cartilage extracellular matrix. Conclusion In conclusion, the PBM associated with Ch can be used as a cartilage repair application.

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Section: Discussionsupporting

confidence: 63%

Effects of photobiomodulation associated with chitosan viscosupplementation for osteoarthritis: an in vitro and in vivo study

et al. 2020

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“…Wlodarczyk et al [24] observed higher concentrations of urease caused hydrogel to gelate faster, as it achieves the basal pH for gelation; they also show higher concentrations of urea cause hydrogel to gelate faster until it reaches a certain concentration which beyond it does not interfere; maximum concentrations used in these experiments were 150 mM of urea and 10,5 U/mL of urease. In our study, in order to obtain gelation, urea concentrations used in our experiments were 7,5 M and 10 M, with a minimum urease of 50 U.…”

Section: Discussionmentioning

confidence: 58%

“…The same research shows that higher concentrations of both reagents make hydrogels to gelate faster; also, higher urease concentrations cause hydrogels to degrade in a higher rate in comparison to those with lower concentrations. A second report conducted by Wlodarczyk et al [24] showed the kinetics of chitosan hydrogel gelation and observed the increase in pH that causes chitosan to become a hydrogel, while it is aqueous in lower values of pH -they, however, do not observe differences in hydrogel degradation rates according to variances in urea/urease concentrations.…”

Section: Discussionmentioning

confidence: 98%

Effects of Isolated and Mesenchymal Stem Cells-Loaded Chitosan on Repair of Cranial Critical-Size Defect in Rats

Oliveira

Tim

Martignago

et al. 2019

BJSTR

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“…Thus, urease was evaluated due to its high efficiency in promoting the hydrolysis of urea [76][77][78]. For example, urease has been applied to promote the formation of strong chitosan/urea gels [79,80]. The initial synthesis was carried out without pH adjustment, meaning high pH values around 10-11, and no catalytic activity was observed, i.e., no ureido or ureylene formation.…”

Section: Effect Of Catalystsmentioning

confidence: 99%

Ureido Functionalization through Amine-Urea Transamidation under Mild Reaction Conditions

Guerrero‐Alburquerque

Zhao

Rentsch

et al. 2021

Polymers

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Ureido-functionalized compounds play an indispensable role in important biochemical processes, as well as chemical synthesis and production. Isocyanates, and KOCN in particular, are the preferred reagents for the ureido functionalization of amine-bearing compounds. In this study, we evaluate the potential of urea as a reagent to graft ureido groups onto amines at relatively low temperatures (<100 °C) in aqueous media. Urea is an inexpensive, non-toxic and biocompatible potential alternative to KOCN for ureido functionalization. From as early as 1864, urea was the go-to reagent for polyurea polycondensation, before falling into disuse after the advent of isocyanate chemistry. We systematically re-investigate the advantages and disadvantages of urea for amine transamidation. High ureido-functionalization conversion was obtained for a wide range of substrates, including primary and secondary amines and amino acids. Reaction times are nearly independent of substrate and pH, but excess urea is required for practically feasible reaction rates. Near full conversion of amines into ureido can be achieved within 10 h at 90 °C and within 24 h at 80 °C, and much slower reaction rates were determined at lower temperatures. The importance of the urea/amine ratio and the temperature dependence of the reaction rates indicate that urea decomposition into an isocyanic acid or a carbamate intermediate is the rate-limiting step. The presence of water leads to a modest increase in reaction rates, but the full conversion of amino groups into ureido groups is also possible in the absence of water in neat alcohol, consistent with a reaction mechanism mediated by an isocyanic acid intermediate (where the water assists in the proton transfer). Hence, the reaction with urea avoids the use of toxic isocyanate reagents by in situ generation of the reactive isocyanate intermediate, but the requirement to separate the excess urea from the reaction product remains a major disadvantage.

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Enzymatic gelation to prepare chitosan gels: Study of gelation kinetics and identification of limiting parameters for controlled gel morphology

Cited by 11 publications

References 39 publications

Effects of photobiomodulation associated with chitosan viscosupplementation for osteoarthritis: an in vitro and in vivo study

Effects of photobiomodulation associated with chitosan viscosupplementation for osteoarthritis: an in vitro and in vivo study

Effects of Isolated and Mesenchymal Stem Cells-Loaded Chitosan on Repair of Cranial Critical-Size Defect in Rats

Ureido Functionalization through Amine-Urea Transamidation under Mild Reaction Conditions

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