Skin rejuvenation using cosmetic products containing growth factors, cytokines, and matrikines: a review of the literature

Abstract

Skin aging is primarily due to alterations in the dermal extracellular matrix, especially a decrease in collagen I content, fragmentation of collagen fibrils, and accumulation of amorphous elastin material, also known as elastosis. Growth factors and cytokines are included in several cosmetic products intended for skin rejuvenation because of their ability to promote collagen synthesis. Matrikines and matrikine-like peptides offer the advantage of growth factor-like activities but better skin penetration due to their much smaller molecular size. In this review, we summarize the commercially available products containing growth factors, cytokines, and matrikines for which there is evidence that they promote skin rejuvenation.

Keywords: aging; cosmetics; cytokine; growth factor; matrikine; skin.

Figure 1

Structure of human skin. Notes: The outer layer of the epidermis, the external layer of human skin, is made up primarily of corneocytes which provide a barrier function. Underlying the corneocytes are viable keratinocytes, which migrate outward and terminally differentiate to become corneocytes. The epidermis is organized into extensions called rete ridges that project between dermal papille (pink) into the underlying connective tissue. Underlying the epidermis is the dermis, which is primarily made up of collagen, elastin fibers, and other extracellular matrix components. Collagen and elastin fibers are synthesized by fibroblasts to provide tensile strength, firmness, and elasticity to the skin. The innermost layer of the skin, the hypodermis, is composed largely of fat cells, which helps provide structure to the skin. Blood capillaries, lymph vessels, sweat glands, sebaceous glands, hair follicles, and lamellar bodies lie within the dermis and hypodermis. Illustration: © www.julius-ecke.de; source: www.skin-care-forum.basf.com.

Figure 2

Changes in the skin with age. Notes: As the skin ages, several changes occur in the epidermis and dermis. In the epidermis, corneocytes (terminally differentiated keratinocytes) accumulate, giving the skin a rough and dull appearance. In the dermis, the collagen content decreases and collagen and elastin fibers become disorganized and fragmented. This weakens the structure underlying the epidermis, leading to wrinkles. Illustration: © Kleinhans RED, source: www.skin-care-forum.basf.com.