Closed-loop biomaterial design: Diels-Alder hydrogels from renewable polymers for biomedical devices

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Guar gum (GG) hydrogels are biodegradable and biocompatible but lack sufficient stability for advanced applications.
• Developing stable and functional hydrogel systems is crucial for drug delivery and biomedical uses.

Purpose of the Study:

• To engineer stable semi-interpenetrating polymeric networks (semi-IPN) based on guar gum.
• To enhance the thermal and mechanical stability of guar gum hydrogels.
• To explore the potential of these novel hydrogels for drug loading and release.

Main Methods:

• Synthesized a Diels-Alder (DA) polymer using difurfuryl (Di-Fur) and dimaleimide (Di-Mal) monomers.
• Developed a novel trifunctional crosslinker (Tri-Fur) from D-ribonolactone.
• Created guar gum-based semi-IPNs (GG-Xr4 and GG-Xr10) with varying crosslinking degrees.
• Characterized material properties using rheology, SEM, and thermal degradation analysis.

Main Results:

• Achieved maximum crosslinking degrees of 4% and 10% with optimized Tri-Fur concentration.
• Demonstrated reversible and self-healing properties due to DA chemistry and Michael addition.
• Confirmed hydrogel stability for 14 days at 25°C and integrity across a temperature range of 24-60°C.
• Observed significant viscosity increase between 24°C and 37°C, indicating suitability for injectable formulations.
• SEM revealed nanoporous structures with a mean pore size of 530 nm for GG-Xr4.
• Materials retained mucoadhesive properties and facilitated drug loading and release.

Conclusions:

• Successfully engineered stable and self-healing guar gum-based semi-IPNs.
• The developed materials exhibit promising rheological properties for injectable applications.
• Enhanced guar gum hydrogels show significant potential for biomedical and pharmaceutical applications, including drug delivery.