Gianluca Mazzucco

Introduction . This review examines the impact of ionizing radiation on bone microstructure and mechanical properties in murine models, with particular attention to how different radiation types, total absorbed doses, and dose rates influence skeletal tissue. The topic is highly relevant in both radiotherapy and aerospace research, two different scenarios but that share important skeletal consequences, such as disturbances in bone remodeling, deterioration of trabecular and cortical microarchitecture, and reductions in mechanical strength. Methods . This review was conducted following PRISMA guidelines, with a structured search across Scopus, PubMed, and Google Scholar using predefined keywords and Boolean operators. Experimental murine studies investigating the effects of ionizing radiation in radiotherapy- or spaceflight-simulating settings were considered eligible if they reported at least one bone morphological and one mechanical outcome. After screening and eligibility assessment, 11 studies were included and evaluated for methodological quality based on the robustness of the reported morphological and mechanical analyses. Results . The included studies indicate that radiation exposure in murine bone is associated with dose-, time-, and radiation quality-dependent deterioration, with early, transient effects after single doses and more persistent damage following repeated exposures. Trabecular bone emerged as the most vulnerable compartment, showing reduced trabecular number and increased separation across several studies. Mechanical outcomes appeared to be site-specific: cortical-rich bones often retain strength despite trabecular loss, whereas trabecular-rich sites appeared more susceptible, suggesting microstructural deterioration may contribute to functional impairment even when whole-bone strength is relatively preserved. Conclusions . These findings highlight that trabecular bone is the primary target of radiation-induced damage, with site-specific effects and persistent mechanical deficits, emphasizing the importance of multiscale assessment to understand and mitigate skeletal fragility in clinical and spaceflight contexts. However, a limited number of eligible studies and heterogeneity of experimental designs could reduce the strength of direct comparisons and the generalizability of these conclusions.

Objectives: To analyse and compare the functionality of extraluminal and intraluminal artificial urinary sphincters (AUSs), an in silico procedure has been defined and applied. Design and reliability assessments of the AUS are typically performed using a clinical approach, which does not provide data on mechanical stimulation of urethral tissues. Mechanical stimulation may determine tissue degeneration, such as urethral atrophy or erosion, the main causes of AUS failure. In silico techniques can provide a quantitative description of stress and strain fields due to the interaction between tissues and AUS and allow investigating an extremely large number of situations, considering different configurations of AUS and urethra.Materials and Methods: Computational investigations were carried out to evaluate the mechanical reliability of the main extraluminal and intraluminal AUS, AMS 800 and Relief. The lower urinary tract was modelled based on previous experiments. The AUS models took into account the main components that interact with biological tissues. Urethra and AUS models were coupled and used to investigate mechanical stimulation of urethral tissues.Results: In silico simulations provide quantitative information about the mechanical stimulation of urethral tissue, such as compressive strain and stress and hydrostatic pressure, due to interaction with the AUS. Such mechanical quantities allow a comparison of reliability between extraluminal and intraluminal devices.Conclusions: The activities define and demonstrate the effectiveness of a novel in silico approach to the design and reliability assessment of AUS devices, increasing the investigative possibilities and reducing the time, ethical and economic costs.