Injectable oligomer-cross-linked chitosan hydrogels for biomedical applications

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Conventional chitosan hydrogels for tissue engineering rely on physical gelation, limiting stability and property range.
• Developing injectable hydrogels with tunable mechanical properties and controlled degradation is crucial for advanced biomedical applications.

Purpose of the Study:

• To develop novel injectable chitosan hydrogels via covalent cross-linking for enhanced stability and tunable properties.
• To synthesize and characterize oligomeric cross-linkers with varying compositions for chitosan hydrogel formation.
• To evaluate the mechanical properties, swelling behavior, degradation kinetics, and cytocompatibility of the resulting hydrogels.

Main Methods:

• Synthesis of hydrophilic oligomers containing acryloyl morpholine and maleic anhydride, with optional pentaerythritol diacrylate monostearate.
• Rheological assessment of oligomers for cross-linking chitosan under physiological conditions.
• Characterization of injectable oligomer-cross-linked chitosan hydrogels (iCsgel) for mechanical strength, swelling, degradation, and cytocompatibility.

Main Results:

• Injectable oligomer-cross-linked chitosan hydrogels (iCsgel) achieved significant elastic strength (up to 28 kPa).
• Oligomer cross-linking enabled customization of mechanical properties, swelling, and degradation kinetics.
• Cell-laden iCsgel exhibited excellent cytocompatibility and supported cell proliferation, with potential for fluorescent labeling.

Conclusions:

• The developed injectable oligomer-cross-linked chitosan hydrogels offer a promising platform with tunable properties for tissue engineering.
• This covalent cross-linking approach enhances hydrogel stability and expands their applicability in biomedical fields, including bioprinting.