Broad Consent Practices Face Growing Resistance Over Brain Organoid Research

A new study from Hiroshima University has found that research involving human brain organoids (HBOs) is reshaping how biobanks and medical institutions must approach donor consent. The study, published in Frontiers in Genetics, reported that the Japanese public largely rejects the current system of broad consent when their donated cells could be used to cultivate HBOs. This trend challenges existing recruitment models and supports the need for project-specific consent procedures.

HBOs are three-dimensional, self-organizing cultures derived from human cells that model brain development and disease. While they offer a powerful framework for studying neurological conditions, they raise substantial ethical questions. Professor Tsutomu Sawai, senior author of the study, explained, “HBOs are fraught with controversy, because it is believed with future research that they will develop the capacity to think and have consciousness. It is not unreasonable to conclude that donors could not have imagined this possibility when consenting to donate their cells to science.”

The study explored how the Japanese public perceives these ethical complexities. Sawai and his colleagues surveyed more than 300 residents to assess whether they would donate cells under broad consent conditions. Before the survey, over 90% of respondents had never heard of HBOs. Once they were informed, the results revealed widespread discomfort with broad consent. Thirty-six percent of participants refused to donate their cells when told they might be used for HBO research. Another 37% said their decision would depend on details such as the scientific purpose or safeguards in place. Only 15% said they would give broad consent unconditionally.

Participants expressed that, in morally sensitive research areas, they want to understand the project’s aims, potential benefits, ethical oversight, and the character of researchers before agreeing to take part. These attitudes mirror similar findings from studies conducted in Europe and the United States, suggesting that concerns about brain organoid research cross cultural boundaries.

To preserve public trust and sustain donor participation, the Hiroshima University team concluded that biobanks and research organizations should adopt project-specific consent procedures for ethically complex studies. As first author Masanori Kataoka stated, “This consent empowers the donors with the decision only after fully understanding the details of the research. Importantly, it respects the moral view of the donor, which we believe is more likely to encourage donations.”