STEM CELLS
In many publications stem cells are referred to as either the basic building blocks of human life, the most powerful cells in the human body, or even the "master cells" of the body.
Stem cells have the potential to develop into many different types of tissue in the body. The University of Wisconsin-Madison reports that stem cells can morph into any one of 220 types of cells and tissues in the human body. Nurtured in their undifferentiated state they can proliferate endlessly in culture, and provide vast numbers of cells for research and therapy.
The ability of stem cells to provide us with the only window to the earliest stages of human development is perhaps one of the most important aspects of future stem cell breakthroughs.
It is important to have a fundamental understanding of what stem cells are. In short, stem cells have two distinct characteristics that distinguish them from other cell types.
Firstly, they are unspecialized cells that renew themselves for long periods through cell division.
Secondly, under certain physiologic or experimental conditions, they can be induced to become cells with special function, such as contracting cells of the heart muscle or insulin producing cells of the pancreas.
With special reference to the work of Dr Barry and current and future research to be performed by Lazaron, it is important to note that globally scientists work primarily with three kinds of stem cells i.e. cord blood stem cells, adult stem cells and embryonic stem cells obtained from either animals or humans.
Lazaron's human stem cell division aims to specialize in the prolonged storage of cord blood stem cells collected from the umbilical cord.
CORD BLOOD STEM CELLS
Cord blood is generally defined as blood contained within the umbilical cord and contiguous placental circulation.
This is by far the richest source of stem cells. These stem cells help the embryo in the womb develop into a fully grown baby.
These cells can be harvested from the umbilical cord of newborn babies without any risk to either mother or infant, and is a painless procedure.
The number of stem cells available for storage relates directly to the volume of cord blood that is collected after birth.
The cells can only be collected for a limited period immediately after birth and is therefore not an opportunity to be discarded as it is truly a once in a lifetime opportunity for the new born baby.
This non invasive procedure takes around 5 minutes to perform and is performed by the physician using sterile procedures. The collection can be performed either after natural birth, or after caesarean section.
The risk of viral infection in the stored stem cells for later usage is considered extremely low if adequate screening procedures are performed pre birth.
Once the cord blood has been collected, the stem cells will be harvested at the laboratories of Lazaron and cryogenically stored for the donor's life.
As regards stem cells harvested from cord blood, it is important to note that the stem cells harvested at this critical juncture are the most suitable for donating to other members of the family, and this includes the parents. These cells have the lowest differentiation rate, and consequently the lowest degree of incompatibility with other individuals.
It is reported that in terms of current medical knowledge, the probability of an infant requiring stem cells for a bone marrow transplant is in the order of 1:2700.
The advantage of storing a baby's cord blood stem cells is to be found in the fact that these will always be an exact match for that particular child in the future. It has been found that parents and siblings might also benefit from the stored infant cells, in future, since around 25% of all samples will be a tissue match for those within the same family. If viewed in this context it is reported that the odds that an immediate family member might require the stored cells increases to around 1:1400. It should be kept in mind that any future gene therapy can only be performed with your own cells.
With reference to the storage of cord blood stem cells by Lazaron it is important to note that globally there is substantial research being conducted on umbilical cord blood, to search for ways of expanding the number of HSC's and compare biological properties of cord blood with adult bone marrow stem cells as this is a valuable source of HSC's.
Lazaron aims to explore the current scientific thinking that umbilical cord blood contains stem cells that have the capability of developing multiple germ layers (multi potent), or even all germ layers e.g. endoderm, ectoderm and mesoderm (pluripotent).
ADULT STEM CELLS
Today there is evidence that stem cells are present in far more tissues and organs than once thought and that these cells are capable of developing into more kinds of cells than previously imagined.
Adult stem cells share at least two characteristics with all other stem cells.
First, they can proliferate for long periods of time referred to as long-term self renewal and secondly they can give rise to mature cell types with specialized functions.
Adult stem cells are rare. It is estimated that between 1 in 10 000 to 1 in 15 000 cells in the bone marrow is a haemopoietic (blood forming) stem cell. The primary function of adult stem cells are to maintain the steady state functioning of a tissue type and with limitations replace cells that die because of injury or disease.
In order to be classified an adult stem cell, the cell should be capable of self renewal for the lifetime of the organism.
Adult stem cells while dispersed in tissues throughout the mature animal behave differently depending on their local environment, for instance stem cells in the bone marrow will differentiate into mature types of blood cells.
In contrast stem cells in the small intestine are stationary and are physically separated from the mature cell types they generate.
In summary, while much is known about adult stem cells, much research needs to be done around the question of plasticity (the ability of stem cells from one adult tissue to generate the differentiated cell types of another tissue).
EMBRYONIC STEM CELLSIMPORTANT: Please note that for ethical reasons Lazaron does not conduct any research on human embryonic stem cells.
Embryonic stem cells are undifferentiated cells unlike any specific adult cell. However, they have the ability to form any adult cell.
Because they are undifferentiated, embryonic stem cells can proliferate indefinitely in culture.
They could, therefore, potentially provide an unlimited source of specific, clinically important adult cells, such as bone, muscle, liver or blood cells.
Embryonic stem cells for research purposes are not derived from eggs fertilized in vivo but are derived from embryos developed from egg cells that have been fertilized in vitro - in an in vitro fertilization clinic - and then donated for research purposes with informed consent from the donors. They are not derived from eggs fertilized in a woman's body. The embryos from which human embryonic stem cells are derived are typically four or five days old and are a hollow microscopic ball of cells called the blastocyst. The blastocyst includes three structures: the trophoblast, which is the layer of cells that surrounds the blastocyst; (and will give rise to the placenta); the blastocoel, which is the hollow cavity inside the blastocyst and the inner cell mass, which is a group of approximately 30 cells at one end of the blastocoel.
Growing cells in the laboratory is known as cell culture. Human embryonic stem cells are isolated by transferring the inner cell mass into a plastic laboratory culture dish that contains a nutrient broth know as culture medium. The cells divide and spread over the surface of the dish. The inner surface of the culture dish is typically coated with mouse fetal skin cells that have been treated so they will not divide. This coating layer of cells is called a feeder layer. The reason for having the mouse cells in the bottom of the culture dish is to give the inner cell mass cells a sticky surface on which they can attach. Also, the feeder cells release growth factors into the culture medium. Recently, scientists have begun to devise ways of growing embryonic stem cells without the mouse feeder cells. This is significant scientific advancement because of the risk that viruses or other macromolecules in the mouse cells may be transmitted to the human cells.
Over the course of several days, the cells of the inner cell mass proliferate and begin to grow in the culture dish. When this occurs, they are removed and plated into several fresh culture dishes. The process of replacing the cells is repeated many times and for many months, and is called sub culturing. Each cycle of sub culturing the cells is referred to as a passage. After six months or more, the original 30 cells of the inner cell mass yield millions of embryonic stem cells. Embryonic stem cells that have proliferated in cell culture for six months or more without differentiating, are pluripotent. They appear genetically normal and are referred to as an embryonic stem cell line.
Once cell lines are established, or even before that stage, batches of them can be frozen and shipped to other laboratories for further culture and experimentation.
HISTORY OF STEM CELLS
Already in the mid 19th century scientists began to recognize that cells constituted what can be described as the building blocks of life. This undertaking led to the belief that stem cells give rise to other cells.
By the beginning of the 20th century European scientists realized that all blood cells came from one particular "stem cell". Doctors have been performing bone marrow transplants, which is actually a transplant of stem cells for over 40 years.
Adult stem cells, such as blood forming stem cells in bone marrow, called haemopoietic stem cells or HSC's are currently the only type of stem cells commonly used to treat human diseases.
In early 1998 researchers at the University of Wisconsin-Madison lead by James Thompson published what has been described as a groundbreaking paper showing that stem cells are ephemeral, blank slate cells that occur at the earliest stages of human development and could be isolated, cultured and grown in apparently limitless quantities.
In 2003 Robert J Glovitz chair of the Christopher Columbus fellowship foundation is reported to have said: "Dr Thompson's research is so fundamental to the future of disease treatment and cure, and its potential effects so enormous, that we cannot even contemplate the future benefits that will result from his work".
It can safely be stated that today stem cells have become almost a household name, yet much confusion remains around the ethical issues surrounding stem cells, their origins and the very future of stem cell applications.Today almost six years after the discovery by James Thompson and despite scientists all over the world reporting breakthroughs in stem cell research, much remains unanswered, yet stem cells more than any other field of medical research have the potential to revolutionize the practice of medicine and improve the quality and length of life on earth.
During 1999 and 2000 researchers discovered that the manipulation of adult mouse tissues could yield previously unsuspected cell types. It was reported that for instance bone marrow cells could be turned into nerve or liver cells and that stem cells found in the brain appear to be able to form other kinds of cells.
In the groundbreaking research conducted by Dr Barry and his team from the University of Stellenbosch at the International Space Station under micro-gravity conditions, the most important findings were: cells from the inner cell mass of the blastocyst stage of the mouse and sheep embryos developed more than one layer of cells forming a multi-layered pattern.
Since publication of the findings Dr Barry and his team concentrated on the development of a method to isolate, grow and store stem cells collected form human umbilical cords.
Dr Barry and his team are currently involved in five projects which are focused on maintaining stem cells in an undifferentiated state while simultaneously multiplying the cells.