Human Secretomes, Plant Exosomes, and Hybrid Secretomes Intradermal Injections for Hair Regeneration: Experimental...

Hair follicle regeneration depends on coordinated interactions between different cells and signaling pathways controlling proliferation. Biologically derived injectable formulations, including human secretomes, plant exosomes, and hybrids, are emerging as potential therapeutics, yet their efficacy in intact skin is not understood. The aim of this research was to evaluate and compare the effects of human adipose-derived secretomes, plant-derived exosomes, and a hybrid exosome formulation on hair regeneration in intact skin.

A randomized, blinded, controlled study was conducted in healthy hamsters. Each animal received two intradermal injections of human secretomes, plant exosomes, hybrid secretomes, or saline with untreated animals as baseline controls. Skin biopsies were collected at baseline, 73 days, and 93 days. Histology (H&E) assessed follicular morphology, and immunohistochemistry for Ki67, β catenin, and CD34 quantified proliferation, Wnt activation, and stem cell involvement.

Ki67-positive cells were highest in hybrid secretomes, followed by plant exosomes and human secretomes, with the lowest levels in controls. Nuclear β catenin localization was most pronounced in human secretome-treated follicles, followed by plant exosomes and hybrid secretomes, whereas controls were largely negative. CD34 expression was highest in hybrid secretomes, followed by human secretomes and plant exosomes, with minimal staining in controls.

The hybrid secretomes most effectively stimulated proliferative and stem cell-associated markers, whereas human secretomes showed strong Wnt/β catenin activation, highlighting differential mechanistic effects of these formulations.