Chitosan-anthracene hydrogels as controlled stiffening networks

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Tissue Engineering

Background:

• Chitosan is a versatile biopolymer with potential in biomedical applications.
• Developing biocompatible hydrogels without toxic initiators is crucial for advanced therapies.
• Anthracene functionalization offers unique crosslinking capabilities for hydrogel design.

Purpose of the Study:

• To synthesize single and dual-crosslinked anthracene-functional chitosan hydrogels.
• To investigate the mechanical properties and cell compatibility of these hydrogels.
• To explore the impact of hydrogel crosslinking density on cell behavior.

Main Methods:

• Synthesis of anthracene-functionalized chitosan.
• Dual crosslinking via anthracene dimerization and free radical photopolymerization using riboflavin (vitamin B2).
• Rheological analysis for mechanical properties (Young's modulus) and cell viability assays (CellTiter-Glo) with 3T3-J2 fibroblast cells.

Main Results:

• Successfully synthesized elastic single and dual-crosslinked chitosan hydrogels without toxic initiators.
• Dual-crosslinked hydrogels exhibited significantly higher Young's modulus (26 ± 2.8 kPa) compared to single-crosslinked (9.2 ± 1.0 kPa).
• Dual-crosslinked hydrogels supported a substantially higher volume of cells (2.2 × 10^7 μm^3) than single-crosslinked hydrogels (4.9 × 10^6 μm^3).

Conclusions:

• Anthracene-functional chitosan hydrogels can be synthesized using a non-toxic vitamin B2 initiator.
• Modulating crosslinking density through dual crosslinking enhances hydrogel mechanics and cell proliferation.
• These tunable hydrogels show promise for applications where mechanical properties influence cell morphology and behavior.