Thiolated polymeric hydrogels for biomedical application: Cross-linking mechanisms

Area of Science:

• Polymer Chemistry
• Biomaterials Science

Background:

• Thiomers, polymers functionalized with thiol groups, are investigated for hydrogel formation.
• Thiol groups enable rapid cross-linking and in situ gelling properties.
• Thiomers include hyaluronic acid, chitosan, cyclodextrin, poly(ethylene glycol), and dextran.

Purpose of the Study:

• To review the synthesis of hydrogel networks using thiomers.
• To highlight the cross-linking mechanisms and "click" chemistry approaches.
• To discuss the applications of thiomer hydrogels.

Main Methods:

• Focus on disulfide bond formation for cross-linking.
• Exploration of "click" chemistry reactions: thiol-ene/yne, Michael addition, thiol-epoxy.
• Review of thiolated polymers as hydrogel precursors.

Main Results:

• Thiomers exhibit high reactivity of thiol groups for efficient cross-linking.
• In situ gelling is achieved through inter- and intra-chain disulfide bond formation.
• Various "click" reactions facilitate the fabrication of thiomer hydrogels.

Conclusions:

• Thiomer hydrogels are synthesized using diverse cross-linking strategies.
• These hydrogels demonstrate significant potential in tissue engineering and regenerative medicine.
• Applications extend to diagnostics and advanced drug/protein delivery systems.