Efficacy of novel skin cream containing mixture of human growth factors and cytokines for skin rejuvenation

Journal of Drugs in Dermatology, Feb, 2007 by Michael H. Gold, Mitchel P. Goldman, Julie Biron

Abstract

The crucial role of growth factors and cytokines in cutaneous wound healing is well described, but there has been little investigation into their use for skin rejuvenation. A novel skin cream containing a mixture of human growth factors and cytokines was recently marketed for skin rejuvenation. The mixture was obtained through a biotechnology process using cultured human fetal skin cells, which originate from a dedicated cell bank originally established for the development of products in wound healing. The cream significantly reduced periorbital and perioral wrinkles, as well as improved skin texture of the chin after one month of treatment, which confirms the beneficial use of growth factors and cytokines for skin rejuvenation reported in 2 earlier studies. After 60 days of twice-daily application, 83% of the subject showed an improved average wrinkle score in the eye area, while 50% showed an improved average wrinkle score in the mouth area. In order to exclude a placebo effect, the efficacy of this product should be confirmed with a double-blind, randomized, placebo-controlled study. Also, the difference between mixtures of growth factor and cytokines should be further elaborated.

Introduction

The mechanistic, protective, and restorative properties of skin are impaired with age. (1) Daily exposure to a multitude of environmental stressors including sunlight additionally accentuates cutaneous deterioration related to chronological skin aging. (2) Clinically, aged skin is characterized by dryness, atrophy, roughness, wrinkling, sagging, as well as alterations in pigmentation.

Histologically, aside form the flattening of the dermal-epidermal junction, intrinsically aged skin displays a loss of extracellular matrix and increased levels of collagen-degrading metalloproteinases, loss of fibroblasts, and vascular network. The main histological change in photodamaged skin is dermal elastosis, or the deposition of abnormal amorphous elastic material. (1)

Functional decrements as a result of intrinsic aging include reduced wound healing due to decreased keratinocyte and fibroblast proliferative capacity, (3) decreased cutaneous immune responsiveness, (4) including a reduced cytokine production, (5) decreased fiber synthesis, and delayed recovery of barrier function after damage. (6) For instance, the time required to reconstitute a competent skin barrier after damage is more than double in the elderly compared to young adults. (7) This is further accentuated in photoaged skin.

While the crucial role of growth factors and cytokines in cutaneous wound healing is well described, (8) their use for skin rejuvenation has only recently been studied. (9-11) Growth factors may be beneficial in reducing signs of skin aging due to their capacity in promoting dermal fibroblast and keratinocyte proliferation and in inducing extracellular matrix formation including collagens.

We report the results of a 2-center study with a novel skin cream that contains a mixture of human growth factors and cytokines (Processed Skin Cell Proteins; PSP[R]) for skin rejuvenation. The mixture was obtained through a biotechnology process using cultured human fetal skin cells originating from a dedicated cell bank established for the development of products in wound healing. Along with some other cytokines, the mixture comprises 16 growth factors known to be involved in the regulation of cutaneous wound healing. (12)

Methods

Study Design

The 2-center study was approved by the Western Institutional Review Board. Twenty Caucasian female volunteers between 35 and 65 years of age, who were not nursing or pregnant, were enrolled. They were of Fitzpatrick skin type I to IV and had demonstrable facial wrinkling in the eye and mouth skin area corresponding to grade 2 or higher in Rao-Goldman's 5-point wrinkle scale (see below). Subjects with any active skin disease affecting the face were excluded from the study. Subjects undergoing any microdermabrasion, light and medium skin peels within one month, any nonablative laser, light or radiofrequency treatments in face within 3 months, any dermabrasion, deep skin peels, ablative laser treatments, Botox[R] or filler injections, or cosmetic surgery in the face within 6 months prior to the start of the study were not allowed to participate. In order to provide sun protection, the use of the sunscreen product Coppertone[R] Shade 45 (Schering-Plough HealthCare Products, Inc., Memphis, TN) was allowed when needed.

Study Product and Treatment

The study product, Bio-Restorative Skin Cream containing a proprietary growth factor and cytokine mixture called PSP was obtained from Neocutis, Inc. (San Francisco, CA). The subjects were instructed to administer the cream to their entire randomly designated half-face in the morning and evening over a period of 60 days.

Clinical Evaluations

The following evaluations were performed:

a) Photographic assessment at baseline (day 0), day 30, day 60, and after a 2-week period of wash-out (day 74). The half-face was photographed at an angle of 45[degrees] with the VISIA-CR Imaging System (Canfield Scientific, Inc., Fairfield, NJ).