Scientists express apprehension over potential use of stem cells togenerate life independent of sperm or egg, despite current limitations.
In a groundbreaking development, scientists have managed to create highly advanced lab-grown human embryo models that replicate complex early developmental structures. These models, including Post-Gastrulation Amnioids (PGAs) and human blastoids, are revolutionising research in areas such as fertility, pregnancy complications, and developmental disorders [1][3][5].
The most advanced of these models, the PGAs, are developed using human embryonic stem cells and have been shown to remain viable for over three months in culture. They represent the most mature amniotic sac models to date, offering unprecedented insight into early human development stages that were previously difficult to study due to ethical and technical challenges [1][3].
Similarly, human blastoids are stem cell-derived structures mimicking early-stage embryos, facilitating research without the use of actual embryos [5]. Tools like KAUST’s deepBlastoid enable rapid, expert-level analysis of these embryo models, vastly accelerating research capacity.
However, these scientific advancements come with significant ethical, legal, and regulatory challenges. Ethical concerns arise due to the close resemblance of these models to human embryos, raising questions about moral status and the potential for misuse [4]. The traditional 14-day rule, which limits human embryo research beyond about two weeks post-fertilization, becomes difficult to enforce or apply precisely to synthetic embryo models, prompting debates on redefining or updating guidelines to reflect technological progress [1][3].
Legal and regulatory uncertainty persists globally as frameworks lag behind these innovations. Issues include intellectual property rights, especially regarding stem-cell derived gametes and embryo models, which might restrict access or innovation by creating "social divides" between those who can afford or legally obtain the technologies and those who cannot [2]. The use of fetal tissue in some stem cell protocols continues to provoke controversy and regulatory hurdles [2].
Recently, the International Society for Stem Cell Research (ISSCR) announced updated guidelines to address these challenges. The guidelines will recommend enhanced oversight of research involving embryo models, with appropriate ethical and scientific review for all research [6]. The guidelines will also set out two red lines: prohibiting the transfer of human embryo models into a human or animal uterus, and advising against the pursuit of ectogenesis [7].
Notably, Magdalena Zernicka-Geotz and her team successfully grew embryo-like models resembling 14-day-old embryos in 2023 [8]. Jacob Hanna's team created a model derived from skin cells that showed all essential cell types for an embryo’s development, including the precursor of the placenta, in the same year [8]. Chinese researchers in 2023 created embryo models from macaque monkey stem cells that triggered signs of early pregnancy when implanted in a surrogate monkey [9].
Despite these advancements, it's important to note that no model mimics the development of a human embryo in its entirety. However, these embryo models are becoming increasingly complex, looking and behaving in some way as embryos would [10]. They could potentially be used to study the critical and highly fragile stage of implantation, which is difficult to investigate in living human embryos [11].
These breakthroughs could facilitate research on pregnancy loss and infertility problems. As the ISSCR's November 2024 report emphasised, international guidelines are crucial to prevent unethical research and maintain public trust [12]. The updated ISSCR guidelines will assist scientific funding bodies in evaluating applications and publishers in ensuring ethical responsibility [13].
In conclusion, while lab-grown human embryo models have reached unprecedented sophistication, capturing essential embryonic structures and allowing long-term study, ethical deliberations, legal limitations, and regulatory policies remain critical hurdles that influence how far and how fast this research can safely and responsibly advance [1][2][3][4][5].
- These lab-grown human embryo models are revolutionizing research in areas like sleep and workplaces, as they may provide insights into the effects of sleep deprivation on early developmental stages.
- Medical conditions such as chronic diseases and cancers could potentially be studied using these embryo models to understand their root causes and develop effective therapies and treatments.
- Respiratory conditions like asthma and pulmonary fibrosis could be better understood through the study of these embryo models, leading to improved diagnosis and treatment.
- Digestive health issues, such as celiac disease and irritable bowel syndrome, might be researched using these embryo models to discover new treatment approaches and therapies.
- Eye-health issues, including glaucoma and macular degeneration, could benefit from the study of these embryo models, enabling the development of new diagnostic tools and treatments.
- Hearing-related disorders, like tinnitus and sensorineural hearing loss, might be studied using these embryo models to develop innovative hearing aids and therapies.
- Health and wellness are interconnected with fitness and exercise, and these embryo models could aid in understanding the role of physical activity on early development.
- Sexual-health concerns, such as hormonal imbalances and reproductive system disorders, could potentially be researched using these embryo models.
- Autoimmune disorders, like lupus and rheumatoid arthritis, might be better understood through the study of these embryo models, paving the way for novel target-specific treatments.
- Climate change and its impact on our health can be investigated using these embryo models to understand how environmental factors affect early human development.
- Mental-health disorders, including depression and anxiety, could be studied using these embryo models to explore the origin of these conditions and develop effective interventions.
- Mens-health issues, such as prostate cancer and male infertility, could potentially be researched using these embryo models to improve treatment and diagnosis.
- Skin-care products and their safety can be evaluated using these embryo models, ensuring that they are safe for use during pregnancy.
- Therapies and treatments for various conditions could be tested using these embryo models, ensuring their safety and efficiency before they are used on humans.
- Nutrition and its impact on early development can be researched using these embryo models, helping to establish guidelines for optimal pregnancy nutrition.
- Aging-related conditions, such as Alzheimer's disease and osteoarthritis, might be better understood through the study of these embryo models, leading to improved prevention strategies and treatments.
- Women's-health issues, like endometriosis and polycystic ovary syndrome, could potentially be researched using these embryo models to develop effective treatments.
- Parenting and child development could be studied using these embryo models to understand the effects of prenatal factors on early childhood development.
- Weight-management issues, such as obesity and anorexia, could potentially be researched using these embryo models to develop strategies for healthy weight gain and weight loss during pregnancy.
- Cardiovascular health is essential for a healthy life, and these embryo models could aid in understanding the early development of the cardiovascular system.
- The medical industry can benefit from these embryo models, facilitating research and development in various areas, including medical devices and pharmaceuticals.
- Medicare, the health insurance program for older Americans, could use the findings from this research to improve coverage for conditions that affect the elderly.
- CBD, a popular natural remedy, could potentially be researched using these embryo models to understand its effects on early development.
- Neurological disorders, like Parkinson's disease and multiple sclerosis, might be better understood through the study of these embryo models, leading to new treatment approaches.
- Environmental-science research could benefit from these embryo models, helping to understand the impact of pollution and chemical exposure on early human development.
- Finance, personal and wealth management, could potentially use these embryo models to study the financial impact of chronic diseases and other health conditions.
- Skin-conditions, such as acne and eczema, might be studied using these embryo models to develop new treatments and therapies.
- Space and astronomy, fashion, beauty, food, artificial intelligence, relationships, pets, travel, cars, shopping, social media, movies, and TV could all potentially use these embryo models to explore various aspects related to human life, health, and wellness in unique and unexpected ways.