A Tale of Two Chimeras: Applying the Six Principles to Human Brain Organoid Xenotransplantation

Regulatory aspects of optogenetic research and therapy for retinitis pigmentosa under EU law

Optogenetics has potentials for a treatment of retinitis pigmentosa and other rare degenerative retinal diseases. The technology allows controlling cell activity through combining genetic engineering and optical stimulation with light. First clinical studies are already being conducted, whereby the vision of participating patients who were blinded by retinitis pigmentosa was partially recovered. In view of the ongoing translational process, this paper examines regulatory aspects of preclinical and clinical research as well as a therapeutic application of optogenetics in ophthalmology. There is no prohibition or specific regulation of optogenetic methods in the European Union. Regarding preclinical research, legal issues related to animal research and stem cell research have importance. In clinical research and therapeutic applications, aspects of subjects' and patients' autonomy are relevant. Because at EU level, so far, no specific regulation exists for clinical studies in which a medicinal product and a medical device are evaluated simultaneously (combined studies) the requirements for clinical trials with medicinal products as well as those for clinical investigations on medical devices apply. This raises unresolved legal issues and is the case for optogenetic clinical studies, when for the gene transfer a viral vector classified as gene therapy medicinal product (GTMP) and for the light stimulation a device qualified as medical device are tested simultaneously. Medicinal products for optogenetic therapies of retinitis pigmentosa fulfill requirements for designation as orphan medicinal product, which goes along with regulatory and financial incentives. However, equivalent regulation does not exist for medical devices for rare diseases.

Beyond consciousness: Ethical, legal, and social issues in human brain organoid research and application

This study aims to provide a comprehensive review of the ethical, legal and social issues in human brain organoid research, with a view to different types of research and applications: in vitro research, transplantation into non-human animals, and biocomputing. Despite the academic and societal attention on the possibility that human brain organoids may be conscious, we have identified diverse issues in human brain organoid research and applications. To guide the complex terrain of human brain organoid research and applications, a multidisciplinary approach that integrates ethical, legal, and social perspectives is essential.

Human Brain Organoid Research and Applications: Where and How to Meet Legal Challenges?

An ethical and legal framework is needed to regulate the rapidly developing human brain organoid research field properly. However, considering the legal issues involved in human brain organoid research remains underdeveloped and scattered. This article reviews the legal issues of human brain organoid research, grouping them into the following five broad themes: (1) consciousness, (2) legal status, (3) consent, (4) ownership, and (5) transplantation. The issues in each topic include both the urgent (e.g., appropriate forms of consent) and the speculative (e.g., protection of conscious human brain organoids). Therefore, we have attempted to be as explicit as possible about the timescale within which each issue will be realized and to prioritize each. Examining these issues has revealed legal issues specific to human brain organoid research and issues common to research in other fields. Further discussion of human brain organoid research from a legal perspective is needed in the future, considering discussions in related fields.

Organoids and chimeras: the hopeful fusion transforming traumatic brain injury research

Research in the field of traumatic brain injury has until now heavily relied on the use of animal models to identify potential therapeutic approaches. However, a long series of failed clinical trials has brought many scientists to question the translational reliability of pre-clinical results obtained in animals. The search for an alternative to conventional models that better replicate human pathology in traumatic brain injury is thus of the utmost importance for the field. Recently, orthotopic xenotransplantation of human brain organoids into living animal models has been achieved. This review summarizes the existing literature on this new method, focusing on its potential applications in preclinical research, both in the context of cell replacement therapy and disease modelling. Given the obvious advantages of this approach to study human pathologies in an in vivo context, we here critically review its current limitations while considering its possible applications in traumatic brain injury research.

Brain organoids and organoid intelligence from ethical, legal, and social points of view

Human brain organoids, aka cerebral organoids or earlier "mini-brains", are 3D cellular models that recapitulate aspects of the developing human brain. They show tremendous promise for advancing our understanding of neurodevelopment and neurological disorders. However, the unprecedented ability to model human brain development and function in vitro also raises complex ethical, legal, and social challenges. Organoid Intelligence (OI) describes the ongoing movement to combine such organoids with Artificial Intelligence to establish basic forms of memory and learning. This article discusses key issues regarding the scientific status and prospects of brain organoids and OI, conceptualizations of consciousness and the mind-brain relationship, ethical and legal dimensions, including moral status, human-animal chimeras, informed consent, and governance matters, such as oversight and regulation. A balanced framework is needed to allow vital research while addressing public perceptions and ethical concerns. Interdisciplinary perspectives and proactive engagement among scientists, ethicists, policymakers, and the public can enable responsible translational pathways for organoid technology. A thoughtful, proactive governance framework might be needed to ensure ethically responsible progress in this promising field.

Ethics and regulation of neuronal optogenetics in the European Union

Neuronal optogenetics is a technique to control the activity of neurons with light. This is achieved by artificial expression of light-sensitive ion channels in the target cells. By optogenetic methods, cells that are naturally light-insensitive can be made photosensitive and addressable by illumination and precisely controllable in time and space. So far, optogenetics has primarily been a basic research tool to better understand the brain. However, initial studies are already investigating the possibility of using optogenetics in humans for future therapeutic approaches for neuronal based diseases such as Parkinson's disease, epilepsy, or to promote stroke recovery. In addition, optogenetic methods have already been successfully applied to a human in an experimental setting. Neuronal optogenetics also raises ethical and legal issues, e.g., in relation to, animal experiments, and its application in humans. Additional ethical and legal questions may arise when optogenetic methods are investigated on cerebral organoids. Thus, for the successful translation of optogenetics from basic research to medical practice, the ethical and legal questions of this technology must also be answered, because open ethical and legal questions can hamper the translation. The paper provides an overview of the ethical and legal issues raised by neuronal optogenetics. In addition, considering the technical prerequisites for translation, the paper shows consistent approaches to address these open questions. The paper also aims to support the interdisciplinary dialogue between scientists and physicians on the one hand, and ethicists and lawyers on the other, to enable an interdisciplinary coordinated realization of neuronal optogenetics.

Ethical, legal and social aspects of human cerebral organoids and their governance in Germany, the United Kingdom and the United States

Human cerebral organoids (HCOs) are model systems that enable researchers to investigate the human brain in ways that had previously been impossible. The emergence of HCOs was accompanied by both expert and layperson discussions concerning the possibility of these novel entities developing sentience or consciousness. Such concerns are reflected in deliberations about how to handle and regulate their use. This perspective article resulted from an international and interdisciplinary research retreat "Ethical, Legal and Social Aspects of Human Cerebral Organoids and their Governance in Germany, the United Kingdom and the United States", which took place in Tübingen, Germany, in August 2022. The retreat focused on whether HCO research requires new ethical and regulatory approaches. It addressed epistemic issues around the detection and theorisation of consciousness, ethical concerns around moral status and research conduct, difficulties for legislation and guidelines managing these entities, and public engagement.

The Ethics of Human Brain Organoid Transplantation in Animals

In this paper, we outline how one might conduct a comprehensive ethical evaluation of human brain organoid transplantation in animals. Thus far, ethical concerns regarding this type of research have been assumed to be similar to those associated with other transplants of human cells in animals, and have therefore not received significant attention. The focus has been only on the welfare, moral status, or mental capacities of the host animal. However, the transplantation of human brain organoids introduces several new ethical issues. Many of these are related to uncertainty regarding whether or not brain organoids might be conscious. While these concerns might not be immediately relevant, they warrant closer scrutiny. We discuss how various ethical issues are relevant to different stages of human brain organoid transplantation and can guide the ethical evaluation of research. Our examination would broaden the horizons of the debate on the transplantation of brain organoids.