ETH Zurich Researchers Create 3D-Printed Models of Breast Tissue

Researchers at ETH Zurich have pioneered the development of 3D-printed models of lactating breast tissue, a significant advancement in the understanding of milk production. The project, led by Professor Marcy Zenobi-Wong, aims to unravel the complexities of lactation, a process that remains poorly understood despite its critical role in infant nutrition.

In a study published in the journal Science Advances on June 1, 2025, researchers successfully isolated cells from human breast milk, including lactocytes—the cells responsible for milk production. These cells were then used to populate tiny, bioprinted structures resembling the milk ducts and alveoli found in human breasts. The volumetric bioprinting technique employed involves using a laser to solidify a liquid material that mimics the components of human breast tissue, derived from bovine udder tissue. According to Amelia Hasenauer, a doctoral student in Zenobi-Wong’s team and the first author of the study, the cells began producing typical milk components like β-casein and milk fat globules when cultured in this innovative environment.

Despite the promising results, Zenobi-Wong and Hasenauer caution that their model does not yet produce complete breast milk, which comprises a complex mixture of proteins, lipids, sugars, and immune cells. The primary goal of this research is to facilitate a better understanding of lactation, which could ultimately assist women who face challenges in breastfeeding. Zenobi-Wong emphasized, "Our model could one day help find answers for many women who have struggled to breastfeed."

The implications of this research extend beyond lactation. The ability to observe and manipulate lactating cells in a controlled laboratory setting opens avenues for studying the effects of medications and chemicals on lactation, as well as providing insights into breast cancer models. Zenobi-Wong noted, "The next step is to increase the throughput of milk collection, something which is achievable through 3D printing."

Moreover, this research highlights the broader issue of underrepresentation in scientific studies related to female biology. Zenobi-Wong pointed out that many important health topics, such as endometriosis and fertility issues, have received insufficient attention. By utilizing cells derived from breast milk, this research method is ethically justifiable and avoids invasive procedures, making it more accessible for a wide range of studies.

As the field evolves, the hope is that these innovative models will not only enhance our understanding of lactation but also shed light on various aspects of women’s health that have long been neglected. The need for increased visibility and research funding in these areas is critical as the medical community seeks to address the myriad of unanswered questions surrounding female biology.

In conclusion, the work conducted at ETH Zurich represents a key step forward in reproductive and lactation science, with the potential to improve both maternal and infant health outcomes. Future developments in this research area could lead to groundbreaking discoveries that benefit countless women and their families worldwide.

Reference: Hasenauer A, Bevc K, McCabe MC, et al. Volumetric printed biomimetic scaffolds support in vitro lactation of human milk-derived mammary epithelial cells. Science Advances. 2025;11(23):eadu5793. doi: 10.1126/sciadv.adu5793.