Introduction to Regenerative Medicine
- Injuries and the Healing Process
- Cells, Tissues, and Organs
- Stem Cells
- The Future
- Additional Resources
The body works as a holistic system, where all its parts have different functions that support each other... In many ways we can compare the function of certain organs to machines, the heart is like a pump that pumps blood, the brain is like a computer that processes throught, etc. But, unlike a machine, the body has a fantastic ability to adapt and heal!
Regenerative medicine works with the body's natural healing processes, so when an injury occurs that is beyond what the body can heal, doctors can intervene and help the healing become faster or use special materials from the laboratory to regrow tissue.
The injuries in question have to do with extensive tissue damage like broken bones, severe burns, heart attacks (damaged heart muscle) and spinal cord injuries. Some of these injuries will take months to heal. Sadly, some injuries will not heal at all.
But some people will get new treatments involving regenerative medicine that help them heal in weeks, not months. Some people will get new treatments that cure them forever, improving and even saving their lives.
Where Natural Healing ends, Regenerative Medicine takes over!..
Our body has a fantastic ability to heal itself! But some injuries are more than the body can handle. Doctors and scientists are working on regenerative medicine to help speed the body's natural healing ability.
Injuries and Healing
When areas of tissue in the body are damaged or destroyed, the body tries to replace them with new tissue by producing cells capable of creating new tissue.
When a tissue like bone is broken, both its cells and its blood vessels may be injured. The body is prepared to heal minor injuries like these, so when trauma occurs the body works to stop any blood letting by clotting, and then starts producing new cells to replace the damaged ones. These new cells are produced in several places in the body, the main one being the marrow in the center of the bone. They travel through the body to the damage site and become new tissue. Also, the body builds new thin blood vessels, called capillaries, to bring nutrients and oxygen to the new cells.
When the damage is too extensive and there is a big gap of missing or dead tissue where no capillaries survive, new cells can't come fill the area because there is no blood reaching them with nutrients and oxygen. Some tissues like the bone and the skin are easier to heal than others. Other tissues in the body, such as skin and heart muscle, can't heal as well and form scars in the places where they were mended.
When the body can't heal the tissue well, it forms scar tissue which is a weaker and more disorganized tissue than the healthy one.
This is where Regenerative Medicine steps in!...
The basic principles are supplying new cells with STEM CELLS and providing structure with SCAFFOLDS!!!
Cells, Tissues, and Organs
All living things are made of cells. Plants, birds, and bacteria are all made of cells.
One Cell or Many Millions – The Complexity of Life
Cells have existed for millions of years. A cell is the basic unit of Life, which means that all living things are made of cells. Some life forms, like bacteria, are only one cell and others, like humans, are made of millions of cells. Single-cell organisms like bacteria are very efficient organisms, some bacteria live in extreme environments where no human could go without special equipment. In more complex organisms, different groups of cells work together to do different functions particularly well like protecting the body from the outside environment or having muscles and legs to allow the organism to be able to move and look for food instead of just waiting for food to come to them. With increased complexity, comes an increased need for energy and an increased capacity to interact with the world around!..
Cells can work together!
Millions of years ago, life consisted mostly of one-celled organisms, but over time a myriad of bigger and more complex organisms emerged. One of the most interesting things scientists have found was that at some point some cells developed the ability to swallow other cells! Some scientists think this was the beginning of eukaryotic cells.
At some point, some cells started to stick together like glue, forming multicellular organisms (organisms with more than one cell). When cells started to work together, cells were able to start focusing on different things:
- Some swallowing cells took over the process of eating for their neighbors, so their neighbors could have time and energy to do other things.
- Some cells on the outside of the group became really though like the skin on a sponge, to protect their neighbors like the eating cells.
- Some cells became really good at moving around in a group of cells and sniffing out bad or dead cells to remove them before they harmed their neighbors.
This kind of cell cooperation happens all over!
- In your immune system, you have special cells called B and T cells that travel through the body and talk to each other to determine whether a newfound particle is good or bad.
- Your neurons send signals from one to another, and so get messages from your brain all the way to your toes and any other part of the body!
Cells and Tissues
In complex organisms like the human being, you can find many kinds of cells: hair cells, bone cells, stomach cells, immune cells, etc, etc! Each kind of cell works together to form a specific tissue, for example there are a few different kinds of skin cells that work together to form the skin. A tissue is made then of one or more types of cells, something called the extracellular matrix which is sort of the glue that holds all the cells together and also blood vessels, that bring oxygen and nutrients to the cells of each tissue.
One of the limitations of the body is that it can only make so many new cells to replace damaged ones. And sometimes, this number isn't big enough and it takes too long! So, doctors give the body more cells with stem cells. These are young cells that can grow into many different kinds of cells, like bone, heart or neuron cells.
Some scientists can harvest stem cells from the body of the injured patient and help them multiply in the laboratory. Then, they can guide their development towards the kind of cell needed by giving them the appropriate signals.
These signals are called growth factors and they are molecules or proteins that the body naturally produces.
But if there is a large area that is damaged, what will these new cells hold on to? The S C A F F O L D.
Regenerative Medicine provides an artificial support structure – a scaffold – to allow the new cells and capillaries to settle and make new tissue.
The scaffold is structurally similar to the tissue that it is trying to help so the body will recognize it. It also must be strong enough to provide support but naturally degradable so that it can eventually be entirely replaced by healthy, new tissue.
In the future, Regenerative Medicine will hopefully be finding cures for all kinds of disease, diabetes, Parkinson's, spinal cord injuries, and replacing and healing entirely organs like bones and hearts.
Additional Website Resources:
Stem Cells: Cells With Potential
An informational website created by the Exploratorium Museum in San Francisco, California. Also contains animated movies about the importance of stem cells and how stem cells move.
Stem Cell Information: Online Resources
Contains a list of additional educational resources beneficial for teachers.
Stem Cells in the Spotlight
A website created by the University of Utah highlighting a great deal of information about stem cells. Can help students and teachers alike find the answers to all their questions about stem cells!
Other Fun Things:
“A Stem Cell Story: Introducing Stem Cells”
A detailed introduction to the world of stem cells created by the European Consortium for Stem Cell Research
Create Stem Cells
Clicking the “Stem Cells” link, students can learn how to make their own models of stem cells using clay or salt dough.
Microscope Imaging Station: Stem Cells
A collection of movies and images compiled by the Exploratorium Museum in San Francisco, California.
“Tissues of Life” Online Comic
Explore an interactive online comic about stem cells. Includes a bonus feature including information about where stem cells are found in the body and how they are gathered.