What Is ECM (Extracellular Matrix)?

There is a mesh filling the space between cells

You have probably heard skin compared to a brick house. If cells are the bricks, there is something that corresponds to the mortar filling the gaps between them. That is ECM, the extracellular matrix.

ECM is a complex of biological macromolecules that fills the space outside cells. It is not merely a filler for empty gaps: it holds cells in place and even serves as a channel through which cells exchange signals. It is thanks to this structure that skin holds its shape and springs back when you press and release it.

What is it made of?

Familiar names belong here. Collagen is the fiber that forms the framework, making up most of the ECM and creating the thickness and support of the skin. Elastin, as its name suggests, is responsible for the elasticity that lets tissue stretch and return. When you press and release the skin and it returns to place, that is elastin's work.

Hyaluronic acid holds water. It can take up hundreds of times its own weight in moisture, keeping tissue hydrated and plump. That is why skin can look dull even with the same amount of collagen once the moisture is gone.

Added to these are adhesion proteins such as fibronectin and laminin. Their role is to hold cells in place. Cells do not simply float anywhere; they anchor themselves to these proteins and stay put.

What creates and maintains these components are the fibroblasts in the dermis. When fibroblasts are active, new material fills in as fast as the old is broken down; when their activity declines, replacement slows.

Why does it decrease over time?

Aging splits into two paths. One is intrinsic aging, which progresses naturally with age. The dermis thins and, as the number and activity of fibroblasts fall, collagen synthesis decreases. Fine lines appearing and the skin becoming thinner belong here.

The other is photoaging caused by ultraviolet light. UVA has a long wavelength and reaches deep into the dermis. It damages collagen fibers directly while also increasing the action of the enzymes that break collagen down. Less is produced and more is broken down.

The repair process is not smooth either. Instead of a normal structure, abnormal elastic fiber material accumulates, thickening the skin and coarsening its texture. Deep, heavy wrinkles come from this side.

Collagen is known to decline gradually from the twenties onward. That means it is underway long before any visible change appears. The process is covered in detail in Why Does Skin Age?

Filling and restoring are not the same

There are several ways to fill in a hollow. There are methods that add volume directly, such as hyaluronic acid fillers, and methods that move your own tissue, such as fat grafting. The advantage of both is that shape is created immediately, in proportion to what is added.

Approaches that work with ECM have a somewhat different grain. Rather than filling volume, they are closer to creating an environment in which fibroblasts go back to work. The explanation is that the injected ECM components support the structure and interact with cells to induce the formation of new collagen.

By analogy, it is closer to the difference between pouring soil into a collapsed spot and rebuilding soil in which plants can take root. The former levels out immediately; the latter takes time.

So the two approaches are not alternatives to each other and are sometimes used together. Where hollowing is pronounced, filling is considered; where the skin itself is thin and lacks strength, working on the foundation is considered.

What is the difference between autologous ECM and commercial products?

ECM products are divided by their source material. There are allogeneic products made by removing cells and immunogenic factors from human skin tissue, and there is autologous ECM extracted from your own fat.

Allogeneic products are characterized by standardization. The component ratios are consistent and they can be used immediately, so the procedure is simple. They are not, however, your own tissue.

Autologous ECM is made by harvesting a small amount of fat and purifying the extracellular matrix components. Gathering adipose-derived stem cells from that same fat gives you SVF, while extracting only the matrix components gives you autologous ECM, so the starting point is the same. There is the burden of requiring a harvesting procedure, but its characteristic is that it is your own tissue, and it can also be stored and used again later. TheLINE Plastic Surgery carries out autologous ECM treatment with extraction and purification performed in our in-house laboratory.

Products such as Rejuran, which use salmon-derived components, belong to a different family from ECM products. They are based on DNA fragments, so the way they act is not the same. This is covered in How Do Skin Boosters Work?

It is not only in the skin

ECM is mentioned most often in connection with skin, but it exists throughout the body. That is because how each tissue holds its shape comes down to how that tissue's ECM is woven.

Cartilage is a prime example. Cartilage has no blood vessels and only sparse cells, yet most of its load-bearing strength comes from the matrix filling the space between cells. The progression of degenerative arthritis is also explained as the process of that matrix wearing away. This is why regeneration is difficult in knee joint treatment.

ECM is also involved in wound healing. A temporary matrix is laid down first to fill the injured site, and cells migrate over it to repair the tissue. If this organization is not smooth, a thick scar remains. That is why scar treatment is approached as a matter of working with the matrix.

The same principle applies to skin. It is the background to why procedures that work with skin ultimately converge on the question of how to handle the matrix.

Points worth knowing

Procedures that work with ECM are one of several ways of approaching the hollowing and loss of firmness caused by aging. The stem cell (SVF) approach of adding cells and the ECM approach of adding matrix have overlapping purposes, so they are sometimes planned together. They are not a way to reverse every change of aging, and where sagging has progressed, lifting surgery is considered alongside them.

Because these are injection procedures, there is a possibility of swelling, bruising, nodules and infection. When the effect appears and how long it lasts vary greatly from person to person, and the treatment is often divided over several sessions. Before the procedure, please check what source material is used and how many sessions are planned.

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