Collagen in Wound Healing

Chronic wounds become "stalled" in the inflammatory phase of wound healing due to an increased development of proteolytic enzymes with degradation of the extracellular matrix (ECM). Wound chronicity is a hyperinflammatory and proteolytic state that impedes healing. For many years, the scientific community has identified collagen as the common element and denominator in the body's natural healing response.

Collagen helps the body heal itself by preparing the wound bed, balancing wound chemistry, causing cell migration and growth, inducing granulation tissue, and improving overall skin strength. Collagen's role in these various chemicals, mechanical and biological factors, forms an environment conducive to wound healing, and ultimately, to wound closure.

Collagen's Role in Healing

Stops bleeding

Hemostasis

  • Collagen binds to fibronectin and specific receptor sites of platelet membranes that cause platelet adhesion, aggregation, therefore releasing substances to initiate hemostasis.

Cleanses the wound

Debridement

  • Collagen is chemotactic to monocytes and leukocytes. Monocytes transform into macrophages which scavenge and phagocytize foreign bodies and debris.
  • Collagen promotes autolysis in wound healing by using the body's enzymes and moisture to rehydrate, liquify devitalized tissues.

Establishes new tissue and blood vessels

Angiogenesis & Granulation

  • Collagen attracts monocytes, which transform into macrophages.
  • Macrophages release substances that result in fibroplasia and angiogenesis.
  • Collagen provides support for the growth of new capillaries. The presence of new capillaries is essential for the deposition of new fibers.

Creates structural matrix

Fibroblastic Activity

  • Collagen binds with fibronectin, which promotes cell binding and fibrillogenesis, influences fibril dimensions, and stimulates fibroblast proliferation and migration.
  • Collagen is chemotactic to fibroblasts, which govern the restoration of new tissue by depositing oriented and organized fibers.
  • Collagen provides a substrate for directed migration and permeation of fibroblasts.

Closes the wound

Reepithelialization

  • The primary goal in wound chronicity is reepithelialization and or wound closure.
  • Collagen directly supports the growth, attachment, differentiation, and migration of keratinocytes.
  • Collagen promotes wound healing by binding with fibronectin, and collagen provides a provisional matrix for keratinocyte migration.

Regains original integrity

Remodeling or Maturation

  • Collagen reduces scarring by depositing oriented and organized fibers and regulating the amount of collagenase expressed by keratinocytes.
  • Collagen is remodeled from type III to type I moving wound to closure.
  • Cells that are used to repair the wound are no longer needed and removed by apoptosis.

Collagen: The Common Denominator in Wound Healing

Wounds should follow the same healing response, but factors such as clinical conditions and complications may alter or halt the ideal healing process. In these cases, collagen-related activity redirects the wound to the normal healing path.


Injury occurs
Normal Healing Path
Healed Wound
  • Clinical Condition/ Complication
  • Symptoms
  • Collagen-Related Activity
  • Coagulating disorder, anticoagulating agents
  • Inadequate hemostasis, delayed healing, poorly formed fibrin network
  • Collagen assists hemostasis
  • Infection, foreign bodies
  • Longer inflammatory response, delayed healing
  • Collagen attracts monocytes, which turn into macrophages that clean and debride the wound
  • Immunocompromised, diabetes, venous insufficiency, pressure pharmacological agents
  • Increased chances of infection, decreased phagocytic activity, altered vascular growth, inhibition of fibroblast formation and collagen synthesis, static wound
  • Collagen increases phagocytic activity, increases fibroblast activity and therefore, collagen synthesis. A dynamic wound environment is created.
  • Poor nutrition, aging, malignancy
  • Slow rate of healing, decreased collagen synthesis
  • Collagen accelerates the rate of healing, increases fibroblast activity, thereby increasing collagen synthesis
  • Genetic defect, collagen disease
  • Loss of vascularity, fragile skin, lack of tissue strength33
  • Collagen helps in formation of a network that can support cell adhesion and tissue integrity 36
  • Unknown complication
  • Chronic wound
  • Research suggests collagen will help in the healing process

Glossary

  • Angiogenesis: The process by which new blood vessels are formed.
  • Chemotactic Factor: Orientation of a cell along a chemical concentration gradient or movement in the direction of the gradient.
  • Collagenase: An enzyme that catalyzes the hydrolysis of pep· tide bonds in triple helical regions of collagen.
  • Epithelium: The covering of internal  and  external   surfaces of the body, including the lining of vessels and other small cavi­ties.
  • Epithelialization: Healing by the growth of epithelium over a denuded surface.
  • Fibroblasts: A connective tissue cell. They differentiate into chondroblasts, collagenoblasts, and osteoblasts, form the fibrous tissues in the body, ten· dons, aponeuroses, supporting and binding tissues of all sorts.
  • Fibronectin: An adhesive gly­ coprotein. Fibronectins are important in connective tissue, where they cross-link to colla­ gen, and they are also involved in aggregation of platelets.
  • Granulation: The process of forming granulation tissue.
  • Granulation Tissue: Small, beadlike masses of tissue formed on the surface of wounds.
  • Hemostasis: The arrest of bleeding, either by the physic logical properties of vasocon­ striction and coagulation or by surgical means.
  • Keratinocytes: The epidermal cell which synthesizes keratin; constitutes 95 percent of the epidermal cells and with melanocyle, forms the binary cell system of the epidermis.
  • Macrophages: Any of the many mononuclear phagocytes found in tissues.
  • Monocytes: A mononuclear phagocytic leukocyte. Formed in the bone marrow from promonocytes, monocytes are transported to tissues, as of the lungs and liver, where they develop into macrophages.
  • Phagocytocis: Endocytosis of particulate material, such as microorganisms or cell fragments.
  • Platelets: a disk-shaped structure, found in the blood of all mammals and chiefly known for its role in blood coagulation.
  • Remodeling: Reorganization or renovation of an old structure. Tissue has regained most of the original tissue strength.