520 Micro/Nanobubbles: A Novel Modality for Burn Oxygenation and Healing

Abstract

Oxygen is one of the most important elements in all stages of wound healing. It is involved in killing bacteria during the inflammatory phase, increasing keratinocyte differentiation and reepithelization during the proliferative phase, and supporting myofibroblast differentiation and collagen cross-linking during the maturation phase. Current therapies which deliver oxygen to wounds such Hyperbaric Oxygen Therapy (HBOT) and Topical Oxygen Therapy (TOT) are costly, not portable, and their efficacy is limited to certain wounds. A new innovation, micro/nanobubbles (MNBs), are miniature gaseous voids that allow for oxygenation of wounds. Given their high oxygen carrying capacity, MNBs offer an inexpensive technology for oxygenating burns and can be supplemented a part of hydrotherapy. The aim of this current study was to use MNBs to deliver oxygen to burn wounds and determine their healing potential. For this study, full thickness burns were placed on the dorsum of six Sprague Dawley rats. Three of these rats received a constant topical treatment of saline infused with MNBs for two weeks after burn placement. The remaining three rats received the control treatment of saline without MNBs. Spatial Frequency Domain Imaging (SFDI) was used during and after the treatment course to measure the tissue scattering and oxygenation within the burn wound and surrounding region, and to quantify the progression of burn healing out to 28 days after burn wound placement. The reduced scattering coefficient, an SFDI measured parameter related to light interaction with tissue structure, decreased within the first week after the burn region in both the experimental and control sets. After 9 days of treatment, the value of the scattering parameter within regions treated with MNBs increased more rapidly towards baseline (unburned) scattering values when compared to saline treated controls. Additionally, measurements of tissue oxygen saturation increased in the areas treated with MNBs, but not in the areas treated with the saline control. MNB-treated full thickness burn wounds show improved healing compared to those treated with the saline control. SFDI measurements demonstrate that MNB application increases tissue oxygenation. Measurements of structural changes indicate MNB-treated burns begin to proliferate and remodel at earlier time-points than burns receiving the saline control. Application of micro/nanobubbles to burn wounds and surrounding tissue increases tissue oxygenation, supports and accelerates burn wound healing.