Table 4 Diverse types of stem cells utilized in human clinical trials for neurodegenerative disorders [40]
From: Stem cell therapy use in patients with dementia: a systematic review
Categories | Cell Types | Source | Advantages | Disadvantages |
|---|---|---|---|---|
Pluripotent stem cells | Human embryonic stem cells (hESCs) | Inner cell mass of the blastocyst | A good source for cell-replacement therapy. | Challenge of phenotype instability, poor survival of transplanted cells and possible tumour formation |
Can generate neuronal phenotypes for clinical treatment of neurological disorders | Progressive research is impeded by regulatory policies due to ethical controversies | |||
Human-induced pluripotent stem cells (hiPSCs) | Epiblast layer of an implanted embryo | Can serve as cell models of neurodegenerative disorders in vitro | Cells are derived from a patient and may carry any genetic defects specific to said patient | |
Induced adult human fibroblasts | Important in autologous transplantation to reduce immunogenicity | |||
Multipotent stem cells | Human neural stem cells (hNSCs) | Foetal, neonatal or adult brain | Useful in treating neurodegenerative disorders | Require the presence of growth factors even in vitro |
Directed differentiation of pluripotent stem cells | Has a lower risk of causing tumour formation | May not yield high proliferative capacity in expansive in vitro stem cell studies | ||
Neural crest stem cells (NCSCs) | Dorsal margins or neural folds during embryogenesis | Do not require immunosuppressants as the patient’s cells can be used | Has limited ability to differentiate and undergo self-renewal | |
Olfactory ensheathing cells (OECs) | Neuroglia of olfactory axon bundles | Capable of repairing neural bundles with myelin defects and regenerating axons | Prospects of clinical use are limited to the CNS | |
Haematopoietic stem cells (HSCs) | Bone marrow | Have the immense capacity to proliferate and differentiate into various cell lineages | Challenges with potency and number of cells obtained, especially when umbilical cord blood is the source | |
Umbilical cord blood | ||||
Foetal tissues (Liver, Spleen) | ||||
Human Mesenchymal Stem Cells (hMSCs) | BMSCs | Adult bone marrow | Secrete various anti-inflammatory and antiapoptotic cytokines, which aid healing and tissue repair in neurological disorders | Challenges with consensus on appropriate dosing and route of administration |
UCB-MSCs | Umbilical cord blood | |||
MSCs-Exos | Peripheral blood | Possess the ability to migrate to injury sites and initiate neurorestorative functions | Underlying mechanisms of action are not fully understood | |
LMSCs | ||||
HB-adMSCs | Adipose tissue | |||
AD-MSCs | ||||
AD-SVF |