Iconic Spider-Man villains to mainstream science fiction content, to miraculous healing in real life: Advanced Tissue Engineering is what’s common here!
This fascinating and relatively new piece of technology is one powerhouse of a future leap
Let us first break down ‘advanced tissue engineering’. What’s the most basic unit we get? Cells. We’re all aware of cells; the ‘fundamental unit of life’ is probably what you’ve been taught. It is mostly correct though.
Incredibly small building blocks, rigorously performing complex tasks down to the molecular level, they make up all living things. Each cell is a tiny but mighty factory with specific jobs and functions.
And there are loads of varieties of cells too. There are muscle cells that contract to help us move, nerve cells transmit signals so we can feel emotions and the ruthless heat we faced this summer! We have blood cells that carry oxygen and nutrients around our body.
The point is, that cells work together and communicate to keep your body functioning. They cooperate in complex ways to maintain balance, repair injuries and essentially allow you to grow and develop.
Often, we find a group of cells (preferably located close) that share a common task. In these cases, cells come together to form further specialized structures called tissues. Go teamwork!
Think of tissues as specialized teams within your body, each with a specific job to do. For example, muscle tissue is made up of muscle cells that contract and relax to help you move. Epithelial tissue forms protective layers in our body, like the skin on the outside of the lining of our organs.
There are even cases where tissues come together to form even complex structures called organs! Organs are extremely task-specific.
Take your heart for example. It is an organ made up of muscle tissue that pumps blood to deliver oxygen and nutrients throughout your body. So, if cells are the building blocks, tissues are the specialized teams, and organs are the larger functional units.
3. About Advanced Tissue Engineering
We’ve established that tissues are a group of cells working together to perform a common task.
I suppose we’ll never know how a cell is pre-programmed to do a specific function, but what if there was a way we could program a cell, or better yet a group of cells, to perform a task?
This ‘what if?’ scenario has opened doors to groundbreaking scientific phenomena that we could once only dream of.
Try to count the number of supervillains you’ve read in comics that were a biological anomaly, or perhaps a surgery gone wrong. Let’s say humans can only count so much.
Back to reality, we manipulate the group of cells to perform a function suited for us. Perfect, let us just program cancerous cells to heal themselves! Unfortunately, it is a wee bit more complicated than that.
Tissue engineering involves the application of biological and engineering principles to construct or regenerate functional tissues.
Read on to learn more about some of the most fascinating techniques discovered in the past 50 years.
But let us know some history and look back on the long path we have taken in tissue engineering. Also here is more about regenerative medicine which will also probably fascinate just as much!
3.1 Historical Background and Development
The term ‘tissue engineering’ was coined by Dr. Robert Langer and Dr. Joseph Vacanti in 1983. However, the concept of tissue regeneration and transplantation dates way back to ancient civilizations.
Going a little further back in history, the 16th century saw Ambroise Paré, a French surgeon, come up with methods for treating war-related injuries.
Of all things, real ligaments and tendons were used. We can now see that that is completely unethical.
Notably, successful organ transplants are a remarkable landmark when it comes to advanced tissue engineering. The first successful organ transplant, a kidney, was conducted in 1954.
Further, liver and heart transplants were conducted in the 60s. Around the same time, the world saw a rapid development of cell culture techniques.
This allowed scientists to grow and study cells outside the body. It also was a giant leap toward the advanced tissue engineering we know today.
4. Advanced Tissue Engineering
4.1 Biomaterials and Scaffolds
Biomaterials are effectively the materials that scientists kind of use to ‘catalyze’ cells in growing and building new parts for the body. These materials can be either natural, like substances already found in our bodies, or artificial, like specially designed plastics.
The only thing is that they must be safe for our bodies to interact with. For instance, think about using a soft and gentle material to help with growing new skin after a burn or using a strong and durable material to construct a sturdy bone implant.
Scaffolds serve as the framework or support structure for building tissues. They are primarily made from biomaterials, and their role is to provide a template for cells to grab onto.
Much like how a house needs a solid frame, cells require scaffolds to hold onto while they grow and shape into tissues.
To illustrate, envision scaffolds as the skeletal structure of a building project. Just as construction workers rely on this frame to build floors and walls, cells need scaffolds to cling to and organize themselves while forming tissues.
4.1.3 But How Do These Combine?
They first shape the biomaterial into a scaffold that closely matches the tissue they want to create. It’s akin to crafting a mold for a specific shape, like a cookie cutter. Then, the target cells are ‘planted’ accordingly given they are compatible.
These cells adhere to the scaffold’s structure and rapidly multiply, simulating the human body. Over time, they collaborate and coordinate their actions, gradually building a tissue layer by layer.
This is similar to how seeds in a garden bed grow into plants that fill the available space. For instance, if researchers aim to create new cartilage, they prepare a scaffold designed for cartilage formation using biomaterials.
A little more biology here; cartilage is an adhesive that holds two bones together. We know how bones are the hardest part of the body so you might appreciate the power of this little adhesive!
These cartilages are then introduced into the scaffold. They then attach to the scaffold and replicate, eventually forming a fresh piece of cartilage.
4.2 Biofabrication Techniques
Biofabrication techniques in tissue engineering are like creative ways to build body tissues using cells and special tools. We basically ‘mold’ living cells into desirable structures. Yes, this is real!
With arduinos assisting in your homework *wink* with 3D printers, here we have “3D bioprinters”. It’s like a printer, but instead of ink, it uses tiny living cells to build up layers, just like stacking Lego pieces.
This helps create structures that look and work like real tissues. Another method is “electrospinning.” Imagine using a special machine that sprays tiny threads made of special materials.
These threads further form a kind of scaffold that cells can grow on and make a tissue. And then we have our basic scaffolding mechanism (as we previously discussed) come into effect.
You can hopefully appreciate just how amazing this is so let us look more into 3D bioprinting and electrospinning individually in a little more detail.
4.3 3D Bioprinting
Design: First, scientists design a blueprint or a digital model of the tissue they want to create. It’s like making a plan for a building.
Printing: Then, they load the bioprinter with a special material called “bio-ink.” This bio-ink contains living cells. The bioprinter follows the digital blueprint, layer by layer, depositing tiny droplets of bio-ink.
Growth: Once the layers are deposited, the cells in the bio-ink start to grow and stick together. Over time, they form a complete tissue that functions like the real thing.
Applications: 3D bioprinting is used to make things like artificial organs (heart, liver), skin, and even parts of organs for transplants or research. A well-known limitation of conventional surgery is meeting the compatibility requirements.
And when there is compatibility there are even bigger issues like the donor having to essentially live without the donated organs. Sure, from a medical point of view, doctors only ever advise donating after confirming that the donor can live normally.
But still, there can be potentially long-term effects that probably haven’t been experienced before. The human body, fascinating as it is, is heavily puzzling even after centuries of studies on it.
Anyways, back to reality as boring as it may be, these problems can be eliminated with the aid of tissue engineering! Compatibility can be embedded into the system specifically tailor-made for every patient.
Completely invasive from traditional surgery, this is also in line with medicinal ethics. However, that is a much bigger discussion that we’ll save for later.
Electrospinning in tissue engineering is like a super tiny, high-tech spider spinning incredibly thin threads made of special materials that can help grow new tissues.
Making Threads: Scientists use a machine called an electrospinning machine. It’s a bit like a water gun but with a special liquid that contains the materials needed for tissues.
Creating Fibers: The machine shoots out tiny droplets of this liquid. When these droplets come out, they stretch into really, really thin threads due to an electric charge. Yeah, Mr. White! Science!
Building a Scaffold: These super thin threads pile up on top of each other to form a scaffold. This scaffold is like a microscopic skeleton. Cells grab onto it and grow into a tissue.
Applications: Electrospinning is used to make scaffolds for tissues like blood vessels, nerves, and cartilage.
These scaffolds provide a structure for cells to cling to, which is important for growing tissues and repairing damaged ones. It’s a cool way to create the support structures needed for tissue engineering!
4.5 Organ-on-Chip Technology
Miniature Organ Models: Organ-on-chip technology involves creating tiny versions of human organs, known as “organoids” or “micro-physiological systems,” on microchips or small devices.
These mini-organs are made using human cells and are designed to replicate the structure and function of real organs as closely as possible.
These mini-organs are placed on specially designed chips or devices that mimic the environment and conditions of the human body.
For example: A lung-on-chip might have tiny channels through which air flows, allowing researchers to study how lung cells respond to air pollution or drug treatments.
A heart-on-chip may have miniature pumping chambers to replicate the beating of a real heart.
Disease Modeling: Organ-on-chip technology allows scientists to recreate the conditions of diseases like lung infections or heart diseases in the mini organs.
Drug Testing: Pharmaceutical companies use organ-on-chip models to assess the safety and effectiveness of new drugs before they are tested on humans. This reduces the need for animal testing and speeds up drug development.
Understanding Interactions: Since our organs don’t work in isolation, these mini-organs can be interconnected on a single chip to mimic how different organs interact in the human body. This helps researchers understand complex interactions between organs and tissues.
Personalized Medicine: Organ-on-chip technology holds promise for personalized medicine. By using a patient’s cells to create mini-organs, doctors can test how specific treatments will affect that individual, leading to more tailored and effective therapies.
Reducing Animal Testing: Advanced tissue engineering is, most of the time, trial and error based. Organ-on-chip models have the potential to replace or reduce the need for animal testing, making research more ethical and humane. Rats are probably making super happy noises now.
5. Ethical Concerns and Societal Impact of Advanced Tissue Engineering
5.1 Ethical Concerns
Cell Source and Consent: For advanced tissue engineering procedures, cells are a major prerequisite. It can be either from the patient’s own body or from a donor’s body.
Using someone else’s cells raises questions about informed consent. Are people fully aware of how their cells will be used, and do they agree to it? Ensuring that individuals have a say in how their cells are used is vital.
Genetic Modification: Scientists can modify cells or genes to make them better for tissue engineering. Naturally, it raises ethical questions about whether we should change our genes and, if so, how much is too much.
See it’s much more than Peter Parker nerdifying things like we saw in The Amazing Spider-Man. We do NOT want our biology professor to be a human lizard secretly!
Animal Use: In some cases, animals are used in research to develop tissue engineering techniques. It’s essential to ensure humane practices in research, otherwise ethical concerns are always in the scenario.
5.2 Societal Impacts
Accessibility and Affordability: Advanced tissue engineering has the potential to revolutionize healthcare, but questions arise about who can access these treatments. Making advanced therapies available and affordable for everyone is a significant challenge. Ensuring equitable access is a societal concern.
Identity and Humanity: Replacing body parts with technology, raises concerns and questions on the authenticity of being human. How do these technological advancements change our perception of ourselves and our connection to our bodies?
Regulations and Oversight: Developing robust regulations and oversight mechanisms are essential to ensure the safe and responsible use of tissue engineering. Finding the right balance between innovation and protecting public health is a top priority.
Environmental Impact: The materials used in tissue engineering, such as biomaterials and energy sources, can have environmental consequences. Evaluating and minimizing the environmental footprint of tissue engineering processes is a growing concern.
In summary, ethical and societal considerations in tissue engineering go beyond the laboratory. They are highly connected to identity, consent, fairness, and the impact of technology on the future.
Finding ethical solutions and ensuring responsible practices are essential as we harness the power of tissue engineering to transform healthcare and the human experience.
6. The Current State of Advanced Tissue Engineering
Presently, modern or advanced tissue engineering has led to the creation of heart valves, blood vessels, and skin grafts.
Ongoing research is dedicated to addressing challenges like vascularization of engineered tissues and immune response modulation.
The integration of nanotechnology and regenerative medicine holds promise for exciting advancements.
While all this sounds exciting, tissue engineering still plays a relatively small role in healthcare today. A lot of surgical procedures have been performed on patients such as supplemental trachea, cartilage, and even bladders, however, these procedures are still costly and experimental.
Over the years, a lot of progress has been seen in advanced tissue engineering with improvements done in materials, design, and cell source.
And a lot more practices are being done to develop new tissues that closely match their counterparts.