Revisiting The Role Of Extracellular Matrices In Wounds

It is important to understand the role of extracellular matrix when treating complex, chronic wounds. 

The extracellular matrix is the largest component of normal skin, providing skin with its properties of compressibility, elasticity and tensile strength.¹ It is comprised of connective tissues and fibers that provide support but are not part of a cell

The extracellular matrix’s cellular scaffolding signals the direct cells to divide, differentiate and build themselves into a specific form.¹ In healthy skin, the extracellular matrix helps support cells and comprises key components of the basement membrane, which anchors and helps replenish epidermal cells.

Extracellular matrices have a variety of functions including:

• cell communication within tissue and tissue formation

• structural and biochemical support to the surrounding cells

• cell adhesion, cell-to-cell communication and differentiation

• support, segregating tissues from one another, and regulating intercellular communication

• sequestering of a range of cellular growth factors and acts as a local store

• regulation of a cell's dynamic behavior

• being an essential component of processes like cell growth, wound healing and fibrosis

• holding cells together to form a tissue

The components of extracellular matrices include proteins, such as collagens, laminins, fibronectin and elastins. Collagen is the most abundant fibrous protein within the interstitial extracellular matrix and constitutes up to 30 percent of the total protein mass.² Extracellular matrices also include glycoproteins, glycosaminoglycans and proteoglycans.

The extracellular matrix is integral to each phase of wound healing, interacting with cells and growth factors in a dynamic process that eventually results in wound closure. When the extracellular matrix is dysfunctional, wound healing slows or stalls. Chronic wounds contain increased levels of inflammatory cells, giving rise to elevated levels of proteases that appear to degrade the extracellular matrix components, growth factors and receptors that are essential for healing.¹

Understanding of the importance of re-establishing a functional extracellular matrix in chronic wounds has led to technical advances and the development of products that reduce excessive protease levels or contribute functional extracellular matrix proteins, thereby facilitating the healing process. Such products include Oasis Wound Matrix (Smith and Nephew), an intact matrix that is derived naturally from porcine small intestinal submucosa. When one applies extracellular matrix to a wound, it does not trigger an immune response. Instead, when it begins to break down into surrounding tissue, it causes the cells in that tissue to start repairing the damage. Cells divide and rebuild, creating new, normal tissue, not scar tissue.

References

1. Schultz GS, Ladwig G, Wysocki A. Extracellular matrix: review of its roles in acute and chronic wounds. World Wide Wounds. Available at   https://www.worldwidewounds.com/2005/august/Schultz/Extrace-Matric-Acute-Chronic-Wounds.html . Published August 2005. Accessed Jan. 6, 2015.

2. Boundless. An overview of the extracellular matrix found in animal cells. Boundless Anatomy and Physiology. Available at https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/cellular-structure-and-function-3/external-cellular-components-47/an-overview-of-the-extracellular-matrix-found-in-animal-cells-350-11461/ . Published July 3, 2014. Accessed Nov. 26, 2014.

3. Frantz C, Stewart KM, Weaver VM. The extracellular matrix at a glance. J Cell Sci. 2010; 123(Pt 24):4195-4200.