HUMAN EMBRYONIC STEM CELLS (hESC)
Some believe that embryos have the same moral rights as adults, as they begin human life at conception. However, human embryonic stem cell (hESC) research is controversial due to the destruction of embryos, which is similar to abortion. Some believe that embryos and blastocysts can be used for specific research work, provided there is a proper justification. Frozen embryos from women who have undergone infertility treatment can be used for research if they no longer require them. Some IVF patients may not respond to decisions regarding disposing of frozen embryos, and their eggs can be donated for research work instead of being destroyed. Donors' details must be kept confidential, but some information must be saved for Food and Drug Administration audits, which discourages donors. Overall, the ethical considerations surrounding embryos and blastocysts in hESC research remain a contentious issue.
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In 2005, South Korean scientist Hwang Woo-Suk claimed to have created patient-specific embryonic stem cells through somatic cell nuclear transfer. However, investigations revealed falsified data and ethical violations, including egg donations from junior researchers and manipulation of results. This case raised concerns about scientific integrity, oversight, and the pressure to achieve ground breaking results.
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Induced Pluripotent Stem Cells (iPSC):
Ethical concerns about iPSC include their unlimited differentiation potential, potential risks for human cloning, and unfavourable protocols for iPSC-derived cells. Safety concerns include potential teratomas in patients treated with undifferentiated cells, and undesirable differentiation in somatic cells. Optimizing protocols is crucial to maintain the purity of differentiated cells and prevent potential risks in human embryos and chimeras.
In 2019, a study led by Juan Carlos Izpisua Belmonte reported the generation of monkey-human chimeras by injecting human iPSCs into monkey embryos. The research aimed to study early embryonic development and disease modeling. However, this sparked ethical debates about the creation of chimeras, raising concerns about the "humanization" of animals and the potential for cognitive changes in animal subjects.
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Mesenchymal Stem Cells (MSC):
MSCs, derived from adult or perinatal tissue, raise ethical concerns due to their origin and potential to suppress anti-tumour immune responses. However, ethical controversies have shifted to clinical trials and the development of experimental therapies for allogeneic use. Unwanted differentiation can increase tumor growth and metastasis, necessitating further research and ethical considerations.
The U.S. Food and Drug Administration (FDA) issued a warning letter in 2017 to the Celltex Therapeutics Corporation, a stem cell clinic based in Texas. The controversy centered around the clinic's use of autologous MSCs for various medical conditions without proper FDA approval. The case highlighted the regulatory challenges associated with stem cell therapies, particularly when they involve unproven treatments and lack of clinical trial data.
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