3D printed osteoporotic bone model validated in dynamic culture

Osteoporosis is a worldwide bone disease characterized by reduced bone mass and an alteration of bone architecture, leading to bone fragility and an increased risk of fractures. Although animal models are still the gold standard for studying and testing new anti-osteoporotic drugs, they are expensive and unable to reproduce the in vivo conditions accurately, thus making their replacement with alternative methods an urgent need. In the field of bone tissue engineering, pathological three-dimensional (3D) in vitro bone models have been recently considered to overcome economic and ethical issues associated with traditional pre-clinical testing methods. As a result, this study aimed to design a 3D in vitro model of osteoporotic bone consisting of 3D printed scaffolds that resemble the architectural and bone mineral content differences between physiological and osteoporotic bone, and pre-osteoblastic cells seeded onto the scaffolds. A physiological 3D in vitro bone model was designed and printed as a control condition. A comprehensive physicochemical characterization of unseeded scaffolds was conducted in terms of mechanical and thermal properties, swelling behaviour, degradation, and morphology examination under scanning electron microscopy. Cell-seeded physiological and osteoporotic bone scaffolds were cultured under mechanical stimulation to mimic the mechanical forces experienced daily by human bones. The application of mechanical stimuli had a significantly positive effect on the osteogenic differentiation of the pre-osteoblastic cells, with cell-seeded osteoporotic scaffolds reporting the lowest values, thus resembling the reduction in bone formation in osteoporotic patients.