Transcutaneous pneumatic injection of glucose solution: a morphometric evaluation of in vivo micropig skin and tissue-mimicking phantom.

ABSTRACT

BACKGROUND: Needle-free, transcutaneous pneumatic injection systems can be used to deliver therapeutic solutions to targeted layers of skin in a minimally invasive manner. METHODS: To evaluate jet infiltration patterns and tissue reactions, 5% isotonic and 20% hypertonic glucose solutions were pneumatically injected into in vivo micropig skin. Gelatin TM phantom was additionally prepared to analyze penetration and dispersion patterns for different experimental settings. RESULTS: As immediate tissue reactions in the in vivo micropig skin, distinct pneumatic injection injury zones (PIIZs) in the dermis, extending from the papillary dermis deep into the dermo-subcutaneous junction, were generated with the 5% and 20% glucose solutions and with pneumatic pressures of 4.64 and 5.7 bars, respectively. PIIZs markedly decreased in appearance at 1 day after treatment, accompanied by inflammatory cell infiltration, and disappeared at 7 days post-treatment with increased collagen and elastin production. In TM phantom study, the PIIZs created by 20% glucose mainly comprised a single, homogenous, round to oval zone, whereas those created by 5% glucose were irregular and multi-lobular. CONCLUSION: The present study suggests that transcutaneous pneumatic injection therapy may exert mechanical stimulatory effects, immediate tissue shrinkage via hypertonic solutions, and late tissue regeneration effects during wound healing.