OSTEONET aims to (i) build a multidisciplinary research network involving experts of technical and medical disciplines to merge their expertise and exploit possible synergies for the development of reliable and sustainable 3D in vitro cell models of healthy and aged bone tissue and (ii) train a cohort of scientists and technologists in exploiting the model features to increase knowledge on the effects of ageing on bone biology and mechanobiology, and on bone response to drugs, to leverage the use of 3D cell models in clinics and basic/industrial research labs. Bone ageing reduces the quality of life of the elderly and puts social and economic burden on society. Ageing bones fail more easily when challenged mechanically or with toxicants or pollutants, and respond differently to drugs than healthy bone. To personalize therapies and enable better preventive care for the elderly it is essential to develop reliable and sustainable in vitro models of aged bone tissue alternative to animal tests which often fail to capture human-specific features. Several scientific studies support the idea that in vitro models of bone tissue are an outstanding resource for (i) the comprehension of bone physiology, (ii) a better understanding of pathological pathways in most bone dysfunctions, (iii) testing new or repurposed drugs for bone treatment before preclinical trials with animal models. The networking activities planned in OSTEONET will unravel and share knowledge on the mechanisms driving the information transfer from the biochemical and biomechanical levels, which drive osteosynthesis and osseointegration, to the cascade of molecular and cellular events emerging as an elaborated and physiological bone, and on the mechanisms of the different response of healthy and aged bone tissue to mechano-biological stimuli and drugs.