Wound healing is a common concern for most aestheticians. To treat these conditions successfully, many modalities and products are marketed to provide the professional with tools. However, it is imperative to understand the natural wound healing process and how to effectively treat these conditions. This article will review the five phases of wound healing, explore how peptides work in conjunction with the healing process, and provide an effective tool for scarring, inflammatory skin conditions, and wound repair. One study found that wounds of the skin remain challenging in the clinical treatment settings, but bioactive peptides are the potential therapeutic treatment.1
THE STAGES OF WOUND HEALING
There are five overlapping stages in skin repair during wound healing. The first stage is hemostasis. Hemostasis is defined as the clot formation or the interruption of blood flow. Hemostasis takes place immediately and lasts hours after the injury. The earliest signal of tissue injury is the release of adenosine triphosphate and the exposure of collagen on the blood vessel wall.2 During this phase, a clot is formed that acts as a temporary barrier to prevent excess bleeding and limits the spread of pathogens into the blood stream. The clot is formed by a collagen receptor known as glycoproteins. This is the first stage of fibrin formation. Fibrin is a fibrous, non-globular protein involved in forming a clot.3
Inflammation is the next stage and occurs within hours and last several days after the initial wound. During inflammation, a mixture of injured tissue, platelets, erythrocytes, and fibrin, as well as other foreign material, is introduced. Neutrophils are the first responders and migrate to the injured site. Neutrophils’ role is to digest foreign debris and kill bacteria. This lasts for about 24 to 48 hours if decontamination is complete. Macrophage, mast cells, histamines, and other cytokines are other first responders. Macrophages work on removing foreign debris. Mast cells are responsible for the release of histamines to begin the process of cytokine reactions. Histamines are released to enhance blood vessel permeability and to enhance macrophage migration. Monocytes are healing cells and travel to the site to begin the cellular proliferation stage.2
The cellular proliferation and migration stage begin after inflammation and last until wound closure or until a signal to cease is received. Fibroplasia and angiogenesis are co-dependent and must be successfully completed in order to form an evolving extracellular matrix and granulation tissue. The relationship relies on reciprocity between cellular components, matrix proteins, and bioactive molecules.4 The healing or restoration (re-epithelialization) begins 24 to 48 hours as injured keratinocytes detach from the basal layer and produce matrix metalloproteinases attaching to fibronectin and integrins. Fibronectins and integrins are proteins of the extracellular matrix and attach to collagen. However, if the basal layer is damaged by a wound and portions of the dermis are lost, the wound cannot heal by re-epithelialization alone. Fibroblasts are activated and begin to proliferate after three to four days.2 The fibroblasts begin to rebuild the dermis with the formation of the peptides, proteins hyaluronan, and growth factors. Concurrently, the keratinocyte begins to move closer to the wound.
Following the proliferation phase is contraction. Collagen and elastin fibers are contracting and begin to shrink the wound and the remodeling process has begun. Re-epithelialization has been completed.
The remodeling phase is the last and longest phase. This phase may last several weeks to years to complete. The forces between the fibroblasts create tension, which enhances wound closure. It is important to note that hair follicles, sweat glands, and sebaceous glands lost during injury are not regenerated. Type 1 collagen is replaced by type 3 collagen to rebuild the dermal matrix. Studies have reported that only 80% of the strength of the original skin is regained.5
HOW DO PEPTIDES INFLUENCE WOUND HEALING?
In adults, fibroblasts rarely undergo division within connective tissues, unless stimulated by a wound healing process or inflammatory response.5 Collagen must first be produced by the fibroblast and progress through several stages. Bioavailable peptides are compatible with the cellular proliferation and threshold requirements of cells. Essentially, peptides can provide a message to the fibroblast cell, essentially stimulating collagen without wounding the dermis or epidermis.
Bioavailable peptides play a pivotal role in restoring skin integrity at each layer of wound healing. Peptides are natural messengers that initiate cellular activity and aid in the communication of cytokine signaling, fibroblast, and glycosaminoglycan proliferation. Fibroblast stimulation through peptide communication is an effective tool for the aesthetician to implement for extracellular matrix remodeling or replacement of collagen, without injuring the dermis or epidermis.
1 Song, Y., C. Wu, X. Zhang, W. Bian, N. Liu, S. Yin, M. Yang, J. Tang, and X. Yang. “A short peptide potentially promotes the healing of skin wound.” Biosci Rep 39, no. 3 (2019).
2 Stroncek, John D. and W. Monty Reichert. “Chapter 1 Overview of Wound Healing in Different Tissue Types.” Indwelling Neural Implants.
3 Wikipedia, s.v. “Fibrin,” last modified March 19, 2019, www.wikipedia.org/wiki/fibrin.
4 Greaves, N.S., K.J. Ashcroft, M. Baguneid, and A. Bavat. “Current understanding of molecular and cellular mechanisms in fibroplasia and angiogenesis during acute wound healing.” J Dermatol Sci 72, no. 3 (2013): 206-17.
5 Viktoria De’Ann Peptide Cosmeceuticals. viktoriadeann.com.
Susan Wade is a licensed aesthetician joining Viktoria De’Ann in 2015 as the director of education and sales after being in the health and education industry for over 18 years. She has a master’s in higher education administration and enjoys sharing her wealth of knowledge with physicians, clinicians, and students nationwide. Wade has a diverse background beyond aesthetics as a college instructor in kinesiology and business and is an owner of a successful sports conditioning business’ and a nutrition coach. Her passion lies in understanding the complexities of physiology, nutrition, and biology and in educating practitioners on how to incorporate these areas to reach better solutions and successful results with their clients.