Human Derived Exosome Injections (ASCE+ vs. CELLEXOSOME) Enhance Collagen Remodeling and Angiogenesis in Intact Skin: A Comparative Experimental Study.

BACKGROUND: Exosomes derived from human cells have emerged as promising biological agents for enhancing skin quality through stimulation of collagen remodeling and angiogenesis. While their role in wound healing is well established, their effects on intact, non-injured skin remain insufficiently investigated. Their biological activity depends on their molecular cargo, including growth factors, extracellular matrix-modulating proteins, and angiogenic microRNAs. OBJECTIVE: To evaluate the impact of intradermal injection of two human-derived exosome formulations on dermal architecture and vascular density in intact skin. METHODS: A total of 96 adult male Syrian golden hamsters were randomly assigned to four equal groups: untreated control, saline injection, Cell Exosome (0.1 mL), or ASCE+ Exosome (0.1 mL). Skin biopsies were collected at baseline, day 3, day 7, and day 14 post injection, with equal numbers of animals sacrificed per group and time point. Histological analyses (Hematoxylin & Eosin, Masson's Trichrome, Van Gieson) assessed dermal architecture and collagen organization, while CD34 immunohistochemistry quantified microvascular density. Quantitative image analysis was performed using ImageJ, with five high power fields evaluated per specimen. All assessments were performed in a blinded manner. RESULTS: Untreated control and saline groups showed no significant histological or immunohistochemical changes across all time points, consistent with normal tissue architecture. Cell Exosome treatment produced moderate increases in collagen deposition and CD34 positive vessels. Quantitatively, ASCE+ increased collagen density and microvascular counts compared with Cell Exosome (p < 0.05), whereas control and saline groups showed no measurable changes. CONCLUSIONS: Human derived exosomes promote collagen remodeling and angiogenesis in intact skin, with ASCE+ Exosome exhibiting superior efficacy over Cell Exosome. These findings highlight the potential of exosome-based therapies as minimally invasive strategies for skin rejuvenation.