Photopolymerizable chitosan hydrogels with improved strength and 3D printability

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Chitosan hydrogels are promising for biomedical uses due to biocompatibility and similarity to the extracellular matrix.
• Limitations in 3D printing chitosan hydrogels include poor mechanical properties and formability.

Purpose of the Study:

• To develop a novel chitosan hydrogel with improved properties for 3D printing.
• To investigate the effects of varying thiol/acrylate ratios on hydrogel characteristics.
• To assess the potential of the developed hydrogel in biomedical applications.

Main Methods:

• Synthesized maleic chitosan (MCS) with high acrylate substitution and thiol-terminated poly(ethylene glycol) (TPEG).
• Utilized a step-chain growth photopolymerization approach to create the hydrogel.
• Characterized rheological, microstructural, mechanical, and degradation properties.
• Evaluated 3D printing accuracy, scaffold stability, cytotoxicity, and cell adhesion.

Main Results:

• Photopolymerized MCS/TPEG hydrogel showed significantly enhanced gelling rate (~2-fold) and compressive strength (~10-fold) compared to pure chitosan hydrogel.
• The thiol/acrylate molar ratio effectively regulated hydrogel properties.
• 3D printed chitosan hydrogel scaffolds exhibited printing accuracy and improved stability.
• The hydrogel demonstrated no cytotoxicity and supported L929 cell adherence.

Conclusions:

• The novel MCS/TPEG hydrogel overcomes limitations of traditional chitosan hydrogels for 3D printing.
• The material offers tunable properties and enhanced mechanical performance.
• This 3D printable chitosan hydrogel is a promising candidate for tissue engineering and drug delivery.