1. Zameer H. Merchant, Joe F. Lo, David T. Eddington Biological Microsystems Lab, Department of Bioengineering, University of Illinois at Chicago Microfluidic Bandage for Localized Oxygen- Enhanced Wound Healing

2. Importance of Oxygen in Wound Healing Oxygen – hyperoxic conditions 1,2 0 2 is converted to Reactive Oxygen Species (ROS) Required for bactericidal activity Key step in wound healing pathway in low concentrations Topical oxygen accelerates angiogenesis by inducing production of Vascular Endothelial Growth Factor (VEGF) Induces collagen deposition and the tensile strength of skin May trigger the differentiation of fibroblasts to myofibroblasts, cells responsible for wound contraction. 1.Franz Michael G, "Chapter 6. Wound Healing" (Chapter). Doherty GM: CURRENT Diagnosis & Treatment: Surgery, 13e: http://www.accessmedicine.com/content.aspx?aID=5211734. http://www.accessmedicine.com/content.aspx?aID=5211734 2.Gordillo, G., & Sen, C. (2003). Revisiting the essential role of oxygen in wound healing. The American Journal of Surgery, 186, 259-263.

3. Oxygen-Enhanced Wound Healing Techniques CurrentFuture 1 Portable device: available bedside and at home Localized to wound site Rapid diffusion of oxygen Inexpensive Can deliver oxygen directly to superficial wounded tissue severed from circulation No risk of multi-organ oxygen toxicity Topical Oxygen Therapy Hyperbaric Oxygen Therapy (HBO) 1.Gordillo, G., & Sen, C. (2003). Revisiting the essential role of oxygen in wound healing. The American Journal of Surgery, 186, 259-263.

4. Microfluidic Bandage

5. Device Fabrication Photolithography

6. Device Fabrication

7. Measuring Oxygen Diffusion Calculation of [O 2 ] after diffusion through PDMS membrane FOXY slide (ruthenium-coated oxygen-sensing chip) O 2 quenches ruthenium fluorescence intensity Calibration curve established by exposing FOXY slide to known oxygen concentrations Data empirically fit to a Stern-Volmer model Oxygen-sensing chip

8. Characterization: Oxygen Modulation

9. Characterization: Oxygen Penetration Determine the “effective” range of oxygen penetration into tissue directly beneath the PDMS membrane Extent of oxygen penetration measured using phantom tissue (3% agarose) Depth of phantom tissue varied between 0.2 and 1.0mm Diffused oxygen concentration measured 5 minutes after device was connected to 100% O 2 gas line Measured diffused oxygen concentration here

10. Characterization: Oxygen Penetration

11. Characterization: Localization of O 2 Delivery in Conformal and Non-conformal Devices Conformal Bandage Non-Conformal Bandage PDMS Membrane Chamber PDMS Obstacle

12. Characterization: Localization of O 2 Delivery in Conformal and Non-conformal Devices

13. SKH1 Mice Wound Healing Day 3Day 7Day 10Day 14 0 Day after wounding Control Device Placebo

14. SKH1 Mice Wound Healing

15. Conclusions Can consistently deliver 0.02 ±0.73 to 99.5± 4.40% O 2 Can maintain localized oxygen delivery to a specified area even with a non-planar irregularity Can deliver ~80% O 2 through 0.8 mm of agar tissue phantom within 5 minutes Device is compatible with normal wound healing Can be used to provide oxygen-enhanced wound treatment

16. Acknowledgments Financial support from the National Science Foundation and Department of Defense, EEC-NSF Grant # 0755115 Professor David T. Eddington – Biological Microsystems Lab, UIC Dr. Joe F. Lo Dr. DiPietro – Center for Wound Healing, UIC Dr. Christos Takoudis and Dr. Greg Jursich