Gellan gum-hydroxyapatite composite spongy-like hydrogels for bone tissue engineering

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Developing effective osteoinductive biomaterials for bone grafting remains challenging.
• Ideal bone graft substitutes require a balance of biodegradability, mechanical strength, and biocompatibility.
• Mimicking the natural bone's organic and inorganic phases is a key strategy.

Purpose of the Study:

• To create novel gellan gum (GG)-hydroxyapatite (HAp) spongy hydrogels.
• To mimic the organic (GG) and inorganic (HAp) components of bone.
• To evaluate the structural, mechanical, degradation, and biological properties of these hydrogels for bone regeneration.

Main Methods:

• Synthesis of gellan gum-hydroxyapatite spongy hydrogels.
• Characterization using FTIR, XRD, and TGA to confirm HAp incorporation and thermal stability.
• Assessment of swelling, degradation, porosity, pore size, interconnectivity, and mechanical properties (storage modulus).

Main Results:

• HAp was successfully integrated into GG networks without affecting thermostability.
• Hydrogels exhibited sustained degradation, high swelling, suitable pore sizes (200-300 μm), high porosity (>90%), and interconnectivity (<60%).
• Calcium chloride (CaCl2) and HAp enhanced mechanical properties (storage modulus from 40 KPa to 70-80 KPa) and promoted bioactivity, supporting cell adhesion and spreading for 21 days.

Conclusions:

• Tailorable spongy hydrogels composed of gellan gum and hydroxyapatite were successfully developed.
• Properties like mechanical strength and bioactivity can be tuned by adjusting HAp content and using CaCl2 as a crosslinker.
• These findings provide insights into optimizing biomaterial features for enhanced in vitro cell performance and potential in vivo bone formation.