Gary Goldenberg, MD, focused on regenerative techniques in this up-to-date lecture on nonsurgical treatment of hair loss. He started with platelet-rich plasma (PRP), which harnesses the power of platelet products including growth factors, chemokines, and cytokines to promote cell differentiation and proliferation. Specifically, platelet-derived, vascular endothelial, fibroblast, epidermal, insulin-like, and connective tissue growth factors are responsible for these benefits, which explain this treatment’s usefulness in the treatment of androgenetic alopecia. PRP promotes anagen-associated angiogenesis and neovascularization, dermal papilla cell proliferation, and anti-apoptotic effects. The anagen phase of the hair cycle is extended as dermal papilla cells are protected from premature breakdown. Both dosing at 3 monthly sessions with subsequent injections 3 months later or 2 sessions every 3 months lead to statistically significant increases in hair count, though another trial sponsored by a PRP system manufacturer did show increased hair density with monthly injections compared to quarterly. Further, PRP can be effectively used as an adjunct treatment to many other treatments including microneedling and minoxidil. 

He moved on to discuss exosomes which are vesicles for intercellular communication, and beyond growth factors, enzymes, and chemokines, also contain mRNA and miRNA. In and of themselves, exosomes could be good or bad, but those used in dermatology are often derived from mesenchymal stem cells, conveying messages to develop into various connective tissues supporting regenerative functions. In hair loss, in addition to the benefits from growth factors and chemokines given by PRP, exosomes also promote hair matrix cell proliferation to revitalize degenerative follicles. Other examples of multipotent stem cells sources are umbilical cord blood and adipose tissue. However, the number of multipotent stem cells present in adipose tissue depends on host factors such as age and general health. Harnessing these cells for hair loss could be in the form of inducing the generation of CK19 positive cells and hairlike structures from mesenchymal stem cells. There are a few small trials that have used adipose-derived stem cells for alopecia, but larger randomized controlled trials are needed.