Enzymatically crosslinked alginate hydrogels with improved adhesion properties

Abstract

Alginate–dopamine (Alg–DA) conjugate, a polymer with catechol side groups instead of phenol groups, gels in situ in the presence of HRP and H2O2. The resulting hydrogels exhibit significantly improved adhesion properties.

Enzymatically Crosslinked Ulvan Hydrogels as Injectable Systems for Cell Delivery

“…[ 19 ] Dextran, alginate, and hyaluronic acid represent so far the most investigated polysaccharides involved in the preparation of in situ gelling precursors containing tyramine. [25][26][27][28][29][30] To the best of our knowledge this strategy has never been applied on sulphated polysaccharides of algal origins. In the present study ulvan was selected as a model material due to the abundance of the Ulva sp biomass used as source of the polysaccharide and its reported bioactivity.…”

“…[ 17 ] The covalent bonds can occur between the carbon atoms in ortho position to the hydroxyl group or the carbon atom in ortho position to the oxygen atom of the phenol group (Scheme 2 ).…”

“…Indeed the present study reports the unexploited preparation of in situ gelling system based on ulvan crosslinked by enzymatic action aimed at the development of injectable hydrogels. [ 17 ] The use of injectable hydrogels is particularly recommended in biomedical applications, since they can be administered in vivo in a minimally invasive manner, are able to properly fi ll irregular shaped defects, can easily encapsulate drugs and cells in the liquid state, and are effective delivery depots after solidifi cation. In situ gelling could be triggered by chemical (crosslinking agents) and physical stimuli (UV light, temperature, pH).…”

“…Accordingly, ulvan was modifi ed with phenol moieties in order to be susceptible to recognition by horseradish peroxidase (HRP) enzyme whose combination with hydrogen peroxide catalyzed gel formation through the covalent coupling between the grafted phenols. [ 17,19 ] The developed polymeric systems were investigated as suitable in situ gelling materials by evaluating their time of gelifi cation, injectability, and rheological properties. The rat pheochromocytomaPC12 cell line, chosen as a model of cells able to proliferation in suspension, was used to preliminary assess the cytocompatibility of the developed hydrogels and their ability to maintain viable cells upon the occurring of the enzymatic cross-linking.…”

Effect of Chemical Crosslinking on Properties of Polymer Microbeads: A Review

“…However, each type of solid-support has own merits and demerits. Over the last two decades, cross-linked polymers are potentially used in different fields such as synthesis [2], extraction [3], tissue engineering [4], drug delivery [5], pharmaceutical [6], and in biomedical applications [7,8] because polymer properties can be significantly improved by cross-linking [9,10]. The properties such as mechanical strength, thermostability, glass transition temperature, swelling, permeability, rigidity, and stiffness can be improved to a remarkable extent [11].…”