1. Cellular Therapy and Stem Cells FAQ on Scientific Research

Cellular Therapy and Stem cells have been a topic of significant interest and research in the medical and scientific communities for decades. These versatile cells have the unique ability to differentiate into various cell types, making them a promising tool for Anti-Aging and Regenerative Medicine. However, with the growing interest in cellular therapy and stem cells comes a multitude of questions. In this article, our Anti-Aging and Regenerative Medicine Center of Thailand aim to address some of the most frequently asked questions about stem cells (stem cells FAQ), providing a comprehensive overview of their potential, applications, and the ongoing research in this field.

Q1: What are stem cells?

Stem cells are unspecialized cells with the ability to develop into various cell types in the body. They can self-renew indefinitely and are categorized into two types: pluripotent stem cells (which include embryonic stem cells and induced pluripotent stem cells) and somatic or adult stem cells, which can form specific tissues or organs.

Q2: When were stem cells first discovered?

Stem cells were first described in 1888 by Theodor Boveri and Valentin Häcker, who used the term to refer to cells committed to give rise to the germline. However, significant advancements in stem cell research occurred in the early 20th century. The concept of blood-forming stem cells was pioneered by Ernest McCulloch and James Till in the early 1960s, who conducted experiments that demonstrated the existence of hematopoietic stem cells (HSCs) in mice. Their landmark findings were published in 1963, establishing the foundation for modern stem cell research. Additionally, the first successful bone marrow transplant, which utilized stem cells, was performed by Georges Mathé in 1958, marking a critical milestone in the application of stem cell therapy.

Q3: What is the difference between embryonic stem cells and adult stem cells?

Embryonic stem cells are derived from human embryos. They are pluripotent, meaning they can give rise to many different cell types in the body.
Adult stem cells are found in tissues like bone marrow, fat, and skin. They are more limited in their ability to differentiate compared to embryonic stem cells. Examples include mesenchymal stem cells and hematopoietic stem cells

Q4: What are the properties of stem cells?

Stem cells have three defining properties:

Self-renewal: Stem cells can divide and renew themselves over long periods in a suitable environment with sufficient nutrients.
Potency/Differentiation: Undifferentiated stem cells can maintain their uncommitted state while also having the ability to differentiate into specialized cell types.
Regeneration/Tissue Genesis: Stem cells can regenerate damaged or diseased tissues, giving rise to more than 200 types of cells and tissues in the body.

Q5: What is Somatic Cell Nuclear Transfer (SCNT)?

SCNT is a technique where the nucleus of a somatic cell is transplanted into an egg cell that has had its nucleus removed. This process is used for cloning and creating stem cells for research, offering potential for therapeutic cloning without the need for fertilized embryos.

Q6: Why are induced pluripotent stem cells (iPS cells) important?

iPS cells are generated by reprogramming adult cells to an embryonic stem cell-like state. They hold promise for creating patient-specific cell lines for disease modeling and potential therapies, though their use in clinical applications is still under research due to concerns about the reprogramming process.

Q7: What Are the Differences Between Autologous and Allogeneic Stem Cell Transplants?

Feature	Autologous Stem Cells	Allogeneic Stem Cells
Source of Stem Cells	Patient’s own fat and bone marrow (usually elderly, diseased stem cells)	Donor cells from cord blood, amniotic membrane, placenta, dental pulp stored in stem cell banks (usually young, healthy stem cells)
GVHD and tumor Risk	None	Low and close to zero
Immune Compatibility	No HLA matching needed	Requires HLA matching but high percentage of compatibility due to low MHC type I and II expressions in allogenic MSCs
Infection Risk	Low	Low due to rigid and stringent microbiology test and infectious panel
Procedure	Complex and time consuming	Complex only in the laboratory setting
Cancer Recurrence Risk	Higher due to potential reintroduction	Lower due to graft-versus-tumor effect
Suitability	Primarily cancer treatment	Blood disorders, genetic diseases, cancers, other degenerative major organ diseases
MHC Class I and II	Immunoprivileged	Immunoprivileged
Stem Cell Quality	Aged, less potent and regenerative capabilities	Young, potent and high regenerative capabilities
Treatment Effectiveness	Less effective	More effective

Q8: What Are the Sources of Stem Cells for Treatment at our center?

Sources of Stem Cells for Treatment

Type of Stem Cells	Source	Description	Usage
Embryonic Stem Cells (ESC)	Early-stage human embryos	Primitive cells with high potential for differentiation but carry risks for uncontrolled cell division and ethical concerns.	Not offered by our center due to ethical issues.
Umbilical Cord Blood Stem Cells (UCBSC)	Umbilical cord at birth	Allogeneic cells used since 1956 by French oncologist Georges Mathé for treating various disorders, considered viable and effective.	Allogeneic therapies, stored during birth.
Bone Marrow Derived Stem Cells (BMSCs)	Bone marrow (usually at iliac creat of the hipbone)	Common adult stem cells requiring invasive extraction, second most common source of mesenchymal cells (MSCs).	Autologous and allogeneic therapies.
Peripheral Blood Stem Cells (PBSCs)	Patient’s bloodstream (apheresis)	Cells isolated through a cell separating mechanism, used exclusively for autologous transplants.	Autologous transplants.
Fat/Adipose Tissue Stem Cells (ADSCs)	Fat tissue (liposuction)	Cells derived from fat, often used in cosmetic treatments, requires minimally invasive extraction.	Autologous therapies, cosmetic treatments.
Dental Pulp Stem Cells (DPSCs)	Teeth (extracted pulp)	Cells sourced from dental pulp, less invasive, potentially useful for regenerative treatments.	Allogenic therapies.
Wharton’s Jelly Stem Cells (WJSCs)	Umbilical cord (Wharton’s jelly)	Rich in mesenchymal stem cells, less ethically contentious, and potent for regenerative applications.	Allogeneic therapies.
Amniotic Membrane Stem Cells (AMSCs)	Amniotic membrane (placenta)	Cells with high regenerative capabilities, obtained without harming the donor.	Allogeneic therapies.
Cord Blood Stem Cells (CBSCs)	Umbilical cord blood	Similar to UCBSC, used for various treatments, easy to collect during birth.	Allogeneic therapies.

Q9: What are key metrics that must be quantified and qualified when preparing stem cells for patient transfusion?

Stem cell count, genetic stability, potency, viability, and other measures are crucial in assessing the quality and efficacy of stem cells before they are transfused into patients.

Stem Cell Potency

Potency refers to the ability of stem cells to differentiate into different cell types. Different stem cells exhibit varying levels of potency:

1. Totipotent: Can differentiate into all cell types, including embryonic and extra-embryonic tissues.

2. Pluripotent: Can differentiate into nearly all cell types derived from the three germ layers (e.g., embryonic stem cells).

3. Multipotent: Can differentiate into multiple cell types within a particular lineage (e.g., hematopoietic stem cells).

Potency refers to the stem cells’ ability to proliferate and engraft, often measured through assays like the CFU (Colony Forming Unit) assay and ATP (adenosine triphosphate) production tests. High ATP levels indicate better viability and potential for successful engraftment.

Other Methods of Measuring Potency

– Clonogenic Assays: Measure the ability of a single cell to proliferate and form colonies. This is often used for epithelial stem cells to assess the formation of holoclones, meroclones, and paraclones, with holoclones being the most potent.

– Differentiation Assays: Evaluate the ability of stem cells to differentiate into specific cell types in vitro. This includes examining the expression of lineage-specific markers.

– Biomarker Analysis: Identifying stem cell-specific markers such as ΔNp63α for epithelial stem cells or other markers like CD34 for hematopoietic stem cells to predict potency and engraftment potential.

Stem Cell Viability

Viability refers to the proportion of live, healthy cells within a stem cell population. This is assessed through:

Viability is determined by whether stem cells can produce any ATP, while specific assays, such as HemoGenix’s HALO-96 PQR, predict engraftment success with over 90% accuracy. These assessments are essential to ensure patient safety and treatment efficacy.

Other Methods of Measuring Viability

– Trypan Blue Exclusion: A dye that only penetrates dead cells, allowing for counting of live (unstained) versus dead (stained) cells.

– Flow Cytometry: Uses fluorescent markers to distinguish live cells from dead cells based on membrane integrity and metabolic activity.

Other Important Measurements

1. Cell Count: Ensuring an adequate number of viable cells is critical for effective transplantation.

2. Genetic Stability: Karyotyping or genomic analysis to ensure that cells do not have chromosomal abnormalities.

3. Functional Assays: Tests like the electric cell-substrate impedance sensing (ECIS) assay can evaluate the functional capacity of cells, such as their ability to invade or adhere, which is important for therapeutic efficacy.

4. Immunophenotyping: Characterizing the surface markers of stem cells using flow cytometry to confirm their identity and purity.

Ensuring Safety and Efficacy

Before clinical application, stem cells must be characterized for their therapeutic potential and safety. Regulatory bodies often require standardized assays for potency and viability to ensure that stem cell products meet stringent quality standards. This helps in predicting clinical outcomes and ensuring consistent therapeutic benefits for patients.

These comprehensive assessments help in ensuring that stem cells used for therapies are both effective and safe for patient use.