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

Abstract

Needle-free, transcutaneous pneumatic injection systems can be used to deliver therapeutic solutions to targeted layers of skin in a minimally invasive manner. 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. 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. 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.