Differentiation of osteoclast precursors on Gellan Gum-based spongy-like hydrogels for bone tissue engineering

Bone tissue engineering with cell-scaffold constructs has been attracting a lot of attention, in
particular as a tool for efficient guiding of new tissue formation. However, the majority of the
current strategies used to evaluate novel biomaterials focus on osteoblasts and bone
formation, while osteoclasts are often overlooked. Consequently, there is limited knowledge
about the interaction between osteoclasts and biomaterials. In this study, the ability of gellan
gum and hydroxyapatite reinforced gellan gum spongy-like hydrogels to support
osteoclastogenesis was investigated in vitro. First, gellan gum and hydroxyapatite reinforced
gellan gum spongy-like hydrogels were characterized in terms of microstructure, water uptake
and mechanical properties. Then, bone marrow cells isolated from mice long bones and
cultured in the spongy-like hydrogels were treated with 1,25-dihydroxyvitamin D3 to promote
osteoclastogenesis. It was shown that the addition of HAp to Gellan Gum spongy-like hydrogels
enables the formation of lager pores and thicker walls, promoting an increase in stiffness.
hydroxyapatite reinforced gellan gum spongy-like hydrogels supported the formation of
aggregates of tartrate-resistant acid phosphatase-stained cells and the expression of the genes
encoding DC-Stamp and Cathepsin K, suggesting the differentiation of bone marrow cells into
pre-osteoclasts. The hydroxyapatite reinforced gellan gum spongy-like hydrogels developed in
this work show promise for future use in bone tissue scaffolding applications.