Could tiny cell particles heal skin? first safety test begins

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Healthy adult volunteers aged 18 to 55 years. 2. Able and willing to provide written informed consent. 3. No clinically significant abnormality based on medical history, physical examination, vital signs, and screening laboratory tests. 4. Intact healthy skin at the planned application sites. 5. Willingness to avoid applying other topical products, cosmetics, antiseptics, or irritant substances to the application sites during the study period. 6. Willingness to avoid excessive sun exposure, sauna, swimming pool use, and mechanical irritation of the application sites during the study period. 7. Willingness to comply with all study visits, topical application procedures, local skin assessments, skin photography, safety assessments, and follow-up. 8. For women of childbearing potential, a negative pregnancy test before first application and willingness to use an acceptable method of contraception during the study period. Exclusion Criteria: 1. Any active skin disease, dermatitis, eczema, psoriasis, urticaria, acneiform eruption, skin infection, open wound, scar, tattoo, burn scar, pigmentation disorder, or clinically significant skin abnormality at the planned application sites. 2. History of severe allergy, anaphylaxis, or hypersensitivity to topical liquids, dressings, biological products, exosome-containing products, or any component of the investigational product or vehicle liquid. 3. Current acute illness, fever, or active infection. 4. Known autoimmune disease, immunodeficiency, or current systemic immunosuppressive therapy. 5. Use of systemic corticosteroids, immunomodulatory drugs, biological agents, or investigational products within 30 days before enrollment. 6. Use of topical corticosteroids, topical immunomodulators, topical antibiotics, retinoids, keratolytic agents, or other medicated topical products on or near the planned application sites within 14 days before enrollment. 7. Clinically significant hepatic, renal, cardiovascular, hematologic, endocrine, neurologic, psychiatric, or systemic disease that may increase risk or interfere with interpretation of study results. 8. Known active malignancy or history of malignancy within the past 5 years. 9. Positive screening test for clinically relevant transmissible infection, if required by the protocol. 10. Pregnancy or breastfeeding. 11. Positive pregnancy test at screening or before first application in women of childbearing potential. 12. Participation in another interventional clinical trial within 30 days before enrollment. 13. Blood donation or major blood loss within 30 days before enrollment, if laboratory safety monitoring is included in the protocol. 14. Any condition that, in the investigator's judgment, would make participation unsafe or interfere with interpretation of study results.