Preparation and Properties of Self-Cross-Linking Hydrogels Based on Chitosan Derivatives and Oxidized Sodium Alginate

Abstract

A self-cross-linking and biocompatible hydrogel has wide application potential in the field of tissue engineering. In this work, an easily available, biodegradable, and resilient hydrogel was prepared using a self-cross-linking method. This hydrogel was composed of N-2-hydroxypropyl trimethyl ammonium chloride chitosan (HACC) and oxidized sodium alginate (OSA). A stable and reversible cross-linking network was formed by the Schiff base self-cross-linked and hydrogen bonding. The addition of a shielding agent (NaCl) may weaken the intense electrostatic effect between HACC and OSA and solve the problem of flocculation caused by the rapid formation of ionic bonds, which provided an extended time for the Schiff base self-cross-linked reaction for forming a homogeneous hydrogel. Interestingly, the shortest time for the formation of the HACC/OSA hydrogel was within 74 s and the hydrogel had a uniform porous structure and enhanced mechanical properties. The HACC/OSA hydrogel withstood large compression deformation due to improved elasticity. What's more, this hydrogel possessed favorable swelling property, biodegradation, and water retention. The HACC/OSA hydrogels have great antibacterial properties against Staphylococcus aureus and Escherichia coli and demonstrated good cytocompatibility as well. The HACC/OSA hydrogels have a good sustained release effect on rhodamine (model drug). Thus, the obtained self-cross-linked HACC/OSA hydrogels in this study have potential applications in the field of biomedical carriers.

Cleaner Leather Tanning and Post-Tanning Processes Using Oxidized Alginate as Biodegradable Tanning Agent and Nano-Hydroxyapatite as Potential Flame Retardant

“…In addition, NaCl weakens the strong electrostatic interaction between collagen and OSA, an anionic polysaccharide. NaCl ions shield the charge of polyelectrolytes in solution, disfavoring the electrostatic interactions, and then, the importance of non-electrostatic forces on OSA-collagen interaction increases [ 64 , 65 ]. The use of a limited, but adequate amount of NaCl is therefore peremptory.…”

“…Water is a fundamental component of the collagen hierarchical structure, and several authors have suggested that the short component of the transversal relaxation time is caused by water molecules tightly bound to collagen helices in the interfibrillar space whereas the long component is caused by water molecules bound to microfibrils [64,65,67,68]. As a result, the long component is significantly more mobile, sensitive to the effects of tanning agents, and vulnerable to variations in hydration levels [66] than the short component.…”

Implications of Storage Conditions on the Characteristics of Alginate Dialdehyde and Its Hydrogels

“…Both these properties were due to the ability of borax to form a tetraborate complex with the adjacent hydroxyl groups in ADA. [7] The available aldehyde groups in ADA can form covalent crosslinking with amino groups in gelatin [8,9] and chitosan [10][11][12] or ionic crosslinking in the presence of CaCl 2 , CaCO 3 , CaSO 4, etc. [5,13,14] The addition of borax to the ADA solution also reduces the gelation time.…”

Self-Cross-Linked Oxidized Sodium Alginate/Gelatin/Halloysite Hydrogel as Injectable, Adhesive, Antibacterial Dressing for Hemostasis

“…The rich aldehyde groups of OSA can react with many moieties to form dynamic covalent bonds. For example, Yu et al prepared the hydrogel with high elasticity and compressive deformation resistance (224 kPa) by a self-cross-linking reaction between chitosan derivatives and OSA . Wang et al constructed an injectable, bioresponsive, and self-repairing hydrogel based on OSA and hydrazide-modified polyethylene glycol .…”