ABSTRACT
Introduction 349
Pathology of Photoaged Skin 350
Cosmetic Approaches to Photoaged Skin 350
Growth Factors: What Are They? 351
Growth Factors and Wound Healing 351
Growth Factors in Cosmetic Applications 353
Combination Approaches: Laser Plus Topical Growth Factors 356
Risks Associated with Growth Factors 357
Conclusions 358
Acknowledgment 359
References 359
INTRODUCTION
The pathology of photoaged (sun exposed) skin has been likened to that of a
chronic wound in which remodeling is incomplete because of the extensive
surface area involved and the complication of ongoing photodamage (sun
exposure) (1). Indeed, healing wounds serve well as a physiologic “system” by
which factors affecting skin renewal can be studied. Recently, the cosmetics and
aesthetics industries have sought to achieve a rational approach to skin care by
the use of “cosmeceutical” preparations with known physiologic activities. For
example, vitamin A derivatives (retinoids) and vitamin C are common ingredi-
ents in cosmeceuticals, and are known to have activities beneficial to skin
repair. An emerging trend in cosmeceuticals is the modulation of aging
changes by the use of naturally occurring cell regulatory proteins called
growth factors. Growth factors are normally present in tissues to stimulate cell
growth, modulate immunity, and orchestrate cell development. They have been
studied in wound healing systems (in vitro and in vivo) for many years and defini-
tive evidence of proregenerative effects in wound healing have been demon-
strated. Thus, it is reasonable to consider that they would have similar benefits
in skin care applications. This chapter provides the rationale for the use of
growth factors for the modulation of aged and photodamaged skin and includes
some recent clinical trials evidence to support this assumption.
