Introduction
As humans, almost every cell in our body has been replaced countless times over the course of our lives, with a few key exceptions such as brain neuronal cells (1). The complex process of aging results in the gradual decline of the body’s metabolism and its ability to renew, repair, and regenerate, leading to compromised function which further hampers this capability, until the body is no longer able to sustain life. The focus of the rapidly evolving field of regenerative medicine is, “to restore the functionality of tissues, organs, or body parts damaged by trauma, disease or aging.” (2) Regenerative aesthetics is an offshoot of regenerative medicine, harnessing that emerging fields’ concepts to aesthetic ends. These fields are intertwined; advances in one have often led to advances in the other. Much of the rapidly proliferating armamentarium is the same (3). Our nascent understanding that something in the circulation is critical for reversal of aging was ignited by renewed experimentation over the past 15years with heterochronic parabiosis, i.e., surgically attaching a young and an old mouse (4). One experiment showed that even cognitive ability of an old mouse can be improved by sharing young mouses plasma the old mouse gained spatial orientation of a young mouse after they were conjoined (5). The search for identification of the component(s) in the circulation responsible for the youthifying of the older tissues has been active and has focused on stem cells, peptides, growth factors, mRNA, miRNA and other soluble biologically active molecules. There is palpable excitement about the newest component to be identified, exosomes, designated as EVs, that are being categorized and tested in pre-clinical studies as well as early clinical studies. Twenty years ago, revolutionary skin care was introduced that contained the supernatant of a scaffold of cultured neonatal human fibroblasts, ushering in the “biologics” era in topical aesthetics (6). Over 110 active growth factors were identified, and the resulting skin care
