Hydroxyapatite-loaded macroporous calcium alginate hydrogels: Preparation, characterization, and in vitro evaluation

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Materials Chemistry

Background:

• Natural polysaccharides like alginate are crucial for developing advanced biomaterials.
• Hydrogels offer promising scaffolds for tissue regeneration applications.
• Incorporating hydroxyapatite enhances biomaterial properties for bone tissue engineering.

Purpose of the Study:

• To synthesize hydroxyapatite-loaded macroporous calcium alginate hydrogels using a novel one-step internal gelation technique.
• To characterize the physicochemical properties of the developed composite hydrogels.
• To assess the in vitro biocompatibility and cell proliferation capabilities of the hydrogels.

Main Methods:

• A one-step internal gelation method in water-frozen solutions was employed for hydrogel synthesis.
• Confocal laser scanning microscopy was used to analyze the macroporous structure.
• Swelling behavior and mechanical properties (Young's moduli) were evaluated with varying hydroxyapatite content (5-30 mass%).

Main Results:

• The hydrogels exhibited an interconnected macroporous structure with pore sizes in the tens of microns.
• Swelling behavior and mechanical properties were successfully tuned by adjusting hydroxyapatite content.
• Mouse fibroblasts (L929) demonstrated robust growth and proliferation on the hydrogels during 7-day cultivation.

Conclusions:

• The novel macroporous composite calcium alginate-hydroxyapatite hydrogels possess suitable physicochemical properties for tissue engineering.
• These hydrogels demonstrate excellent biocompatibility and support long-term cell proliferation in vitro.
• The developed hydrogels show significant potential as scaffolds for regenerative medicine applications, particularly in bone tissue engineering.