Injectable cell-laden hybrid bioactive scaffold containing bioactive glass microspheres

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Rising incidence of bone disorders necessitates minimally invasive treatment options.
• Injectable bioactive fillers offer a promising solution for non-load bearing bone defects.
• Thermosensitive chitosan hydrogels are cytocompatible but lack osteoconductivity.

Purpose of the Study:

• To develop and characterize hybrid hydrogels incorporating bioactive ceramic microbeads for enhanced bone defect treatment.
• To overcome the limitations of homogeneous bioactive ceramic addition in chitosan hydrogels.

Main Methods:

• Created hybrid hydrogels with 45S5-Bioglass® (BG) concentrated in chitosan-based microbeads within a chitosan hydrogel matrix.
• Investigated the effect of BG microbead incorporation versus homogeneous BG distribution on hydrogel properties.
• Assessed hydrogel mechanical properties, cell viability, metabolic activity, and in-situ hydroxyapatite formation.

Main Results:

• Hybrid hydrogels with BG microbeads significantly improved compressive modulus compared to homogeneous BG.
• Encapsulated cell survival and metabolic activity were substantially increased in the presence of BG microbeads.
• Evidence of hydroxyapatite formation on BG microbeads suggests osteoconductive potential.

Conclusions:

• The developed hybrid hydrogel system offers a promising injectable, cell-laden, bioactive biomaterial for treating unloaded bone defects.
• The microbead approach mitigates pH-related issues associated with homogeneous bioactive ceramic incorporation.
• Feasibility of storage via freezing and thawing supports potential clinical translation.