Customized collagen-hydrogel substrates for osteoclast differentiation and culture for development of therapeutics for osteoclast inhibition

Osteoclasts are phagocytic cells that degrade bone as part of its homeostatic regulation. They play a key role in skeletal development and adult bone remodeling. Osteoclasts are also involved in the pathogenesis of various bone diseases. Abnormal osteoclast activation results in bone mass loss and increased risk of fractures. Thus, there is interest in the development of therapeutics for the pharmacological inhibition of osteoclasts as a strategy to counteract excessive bone degradation. Mature osteoclasts are generated through differentiation from peripheral blood mononuclear cells, a technically challenging procedure. Therefore, effective standardized in vitro protocols for osteoclast differentiation, culture and survival are needed to support the pharmacological inhibition studies and to better understand the pathophysiology and regulation of osteoclast function. The aim of this project is to produce customized collagen-hydrogel matrices for use as substrates to facilitate differentiation and culture of osteoclasts from osteoclast precursor cell lines. Our partner company Biogelx manufactures hydrogels that have been successfully used in the culture and differentiation of several pluripotent cell types. We will incorporate into these hydrogels collagen proteins produced using a recombinant technology developed in the University of Manchester. These collagens will be engineered to contain specific sequence motifs recognized by osteoclast precursors. We will investigate possible hydrogel-collagen synergies by modulating the hydrogel stiffness and modification of the specific collagen sequences being incorporated. We will monitor osteoclast differentiation and function by examining their morphology as well as specific gene expression and signaling phosphorylation events. The University of Manchester supervisory team combines extensive expertise in the biology and culture of stem cells, musculoskeletal cells and their interaction with novel biomaterials, and the biochemistry and structural biology of collagen and its interaction with cell-surface receptors.