Needle-free jet injection of hyaluronic acid improves skin remodeling in a mouse model

Purpose: The purpose of this study was to improve methods of jet injection using a mouse model. We investigated the mechanism of action, efficacy, and safety of the pneumatic device using injection of hyaluronic acid (HA) solution into a mouse model. Methods: We evaluated the efficacy and safety of an INNOJECTOR (TM) pneumatic device that pneumatically accelerates a jet of HA solution under high pressure into the dermis of mouse skin. We examined the treatment effects using skin hybrid model jet dispersion experiments, photographic images, microscopy, and histological analyses. Results: Use of the INNOJECTOR (TM) successfully increased dermal thickness and collagen synthesis in our mouse model. jet dispersion experiments were performed using agarose gels and a polyacrylamide gel model to understand the dependence of jet penetration on jet power. The mechanisms by which pneumatic injection using HA solution exerts its effects may involve increased dermal thickening, triggering of a wound healing process, and activation of vimentin and collagen synthesis. Conclusions: Collagen synthesis and increased dermal thickening were successfully achieved in our mouse model using the INNOJECTOR (TM). Pneumatic injection of HA under high pressure provides a safe and effective method for improving the appearance of mouse skin. Our findings indicate that use of the INNOJECTOR (TM) may induce efficient collagen remodeling with subsequent marked dermal layer thickening by targeting vimentin. (C) 2016 Elsevier B.V. All rights reserved.