Healthy hair growth depends on the health of dermal papillae cells that regulate hair follicle growth cycles. Hair loss treatments can be costly and ineffective, and these approaches can range from an invasive surgery to chemicals that typically will not produce the desired result. Research indicates that hair follicles do not disappear where balding occurs, rather they shrink; thus the theory is that if DP cells could be replenished at balding sites the follicles may recover.
In this study DP cells were cultured alone and in a 3D spheroid environment to investigate how quickly hair regrew on mice treated with 2D cultured DP cells, 3D spheroid cultured DP cell in a keratin scaffolding, and with the commercial hair loss treatment Minoxidil; during the 20 day trial mice treated with the 3D DP cells regained 90% of hair coverage at 15 days.
“The 3D cells in a keratin scaffold performed best, as the spheroid mimics the hair microenvironment and the keratin scaffold acts as an anchor to keep them at the site where they are needed,” Cheng says. “But we were also interested in how DP cells regulate the follicle growth process, so we looked at the exosomes, specifically, exosomal miRNAs from that microenvironment.”
Exosomes are tiny sacs secreted by cells that play an important role in cell to cell communication, those sacs contain miRNAs which are small molecules that regulate gene expression. The miRNAs in exosomes derived from 3D and 2D DP cells were measured; the 3D DP cell derived exosomes were identified to have miR-218-5p miRNA that enhances the molecule pathway responsible for promoting hair follicle growth, and inhibiting it caused the follicles to lose function.
“Cell therapy with the 3D cells could be an effective treatment for baldness, but you have to grow, expand, preserve and inject those cells into the area,” Cheng says. “MiRNAs, on the other hand, can be utilized in small molecule-based drugs. So potentially you could create a cream or lotion that has a similar effect with many fewer problems. Future studies will focus on using just this miRNA to promote hair growth.“
