From Technological Innovation to Clinical Translation: Progress and Challenges in 3D Bioprinting for the Development of Breast Cancer Bone Metastasis Models.

The construction of 3D in vitro tumor models centered on bioprinting technology represents one of the most anticipated interdisciplinary innovations and medical applications in recent years. Breakthrough research achievements have been made in the construction of 3D-printed models for various tumors, with a small subset of these technologies advancing to the clinical research stage. However, due to the complex behavioral characteristics of breast cancer bone metastasis, traditional research models exhibit significant limitations and yield minimal mechanistic insights into therapeutic interventions. The irreproducible spatiotemporal dynamics and complex, both synergistic and antagonistic, interactions of multicellular and biochemical components within the bone-metastatic breast cancer microenvironment, which remains irreproducible using conventional techniques, are precisely what drive the unique translational value of 3D bioprinting technology in clinical applications. This article systematically reviews recent advances and clinical explorations in 3D bioprinting technology for breast cancer models, with a focused analysis and summary of four key aspects: printable biomaterials, fabrication processes, research advantages, and translational applications. Capitalizing on recent advances in artificial intelligence (AI) technologies, this review provides a cross-disciplinary analysis of the current state of clinically oriented research and identifies critical challenges that must be addressed to achieve breakthroughs. Furthermore, it systematically summarizes the key difficulties and obstacles encountered across various research directions. Through this comprehensive review, we aim to provide biomedical engineers and clinicians with systematic insights and technical references regarding 3D bioprinted models of breast cancer bone metastasis, thereby facilitating the advancement of highly practical research in this field.