Overview

• A suction device applied for about 20 minutes increased permeability in mouse skin and ex vivo human skin by reorienting collagen and opening hair follicles, with the effect lasting roughly 15 minutes after release.
• Stretching activated local immunity in mice, recruiting neutrophils, monocytes, macrophages, and dendritic cells and altering expression of more than 1,000 genes linked to cytokine signaling.
• Topical delivery of an H1N1 flu antigen during stretching produced slow systemic uptake, antigen accumulation in draining lymph nodes, and higher antibody levels than intramuscular injection.
• Including an adjuvant did not improve the skin‑delivered vaccine response, indicating the mechanical stimulus provided sufficient immune activation.
• The Cell Reports authors caution that dosing control, human efficacy, and safety—including possible penetration of toxic compounds, inflammation, or allergies—require evaluation, though the approach could inform diagnostics or cell‑therapy delivery if validated.