Construction of Injectable Self-Healing Macroporous Hydrogels via a Template-Free Method for Tissue Engineering and...

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Drug Delivery

Background:

• Injectable macroporous hydrogels are of significant interest for tissue engineering and drug delivery due to their biocompatibility and ease of use in minimally invasive procedures.
• Self-healing and macroporous properties are desirable for advanced biomaterial scaffolds.

Purpose of the Study:

• To develop in situ forming, injectable, macroporous, self-healing hydrogels using gelatin (GE), oxidized alginate (OSA), and adipic acid dihydrazide (ADH).
• To investigate the physicochemical properties, injectability, self-healing ability, and biological performance of the developed hydrogels for potential applications in tissue engineering and drug delivery.

Main Methods:

• Hydrogels were synthesized using a high-speed shearing treatment and stabilized via Schiff base and acylhydrazone bonds.
• Characterization included rheology, microstructure analysis (SEM, micro-CT, confocal microscopy), porosity, water content, and in vitro biodegradation.
• Biological evaluation involved in vitro cell proliferation assays (CCK-8, LIVE/DEAD) and in vivo biocompatibility assessments.

Main Results:

• The GE/OSA/ADH hydrogel precursors exhibited excellent injectability at room temperature and rapid gelation at body temperature, with tunable gelation times.
• The hydrogels possessed interconnected macroporous structures (60-83% porosity, 125-380 μm pore size) and demonstrated self-healing capabilities.
• In vitro studies showed successful loading and sustained release of human epidermal growth factor with retained bioactivity, alongside excellent cell proliferation and survival.
• In vivo studies confirmed good injectability, in situ gelation, and tissue biocompatibility.

Conclusions:

• The developed GE/OSA/ADH hydrogels are injectable, macroporous, and self-healing, offering tunable properties.
• These hydrogels demonstrate significant potential as safe and effective scaffolds for tissue engineering and vehicles for drug delivery.