Mind the gap: Standardising preclinical testing of bone-repair biomaterials

The use of bone-repair biomaterials is rapidly expanding to meet the needs of an ageing and increasingly active population, often with compromised bone quality. However, inconsistencies in how materials are assessed preclinically, across animal models, sampling strategies, and analytical techniques, have led to flawed comparisons and misleading claims. Fundamental differences in material properties and the biological responses they elicit are frequently ignored, conflating distinct mechanisms of bone formation. This "apples vs. oranges" problem is magnified by the growing diversity of biomaterials. Here, we call for a more systematic, context-aware approach to biomaterial evaluation that emphasises standardisation and biological relevance.