MECHANISM OF ACTION
Procellera® is antimicrobial due to content of silver and zinc. The silver and the zinc are applied in a well characterized dot matrix pattern, creating multiple micro-batteries over the device surface. Procellera is bioelectric by inherent design: in the presence of a conductive fluid, which may come from wound exudate or exogenously administered fluid, a sustained voltage in the range of 0.3 to 0.9 Volts is generated on the surface of the Procellera device (measured current in the order of 10 micro Amperes across nominal tissue load, or “microcurrent”). This microcurrent is non-hazardous and well below the threshold of feeling.
The Role of Microcurrents in Wound Healing
Scientific research evidence indicates that physiologic microcurrents are normally present in human tissue and that these microcurrents are beneficial in the wound healing process.1-3 With skin injury, physiologic electrical activity is created by a differential in electro-chemistry between tissue layers and is generally confined to the wound edges where the current provides a transport mechanism for cells migration. The bioelectric fields that normally occur in injured tissue and in the healing process have been measured in the range of microamperes, dependent upon the resistance of the fluid / tissue.
These endogenous electrical fields direct epithelial cell migration into the wounded region and have a compelling role in enhancing the rate of wound healing. 4-8 The rate of wound re-epithelialization is significantly reduced when these endogenous electric fields are eliminated.
Antimicrobial action is augmented in the presence of a micro-charged field. 9-11
References1. Foulds IS, Barker AT. Human skin battery potentials and their possible role in wound healing, British J of Dermatology 1983; 109: 515-522.
2. Nuccitelli R. A role for endogenous electric fields in wound healing, Curr Top Dev Biol, 2003; 58:1-26.
3. Sheridan DM, Isseroff RR, Nucitelli R. Imposition of a physiologic DC electric current alters the migratory response of human keratinocytes on extracellular matrix molecules. J. Invest. Dermatol 1996; 106: 642- 646.
4. Vanable JW Jr. Integumentary potentials and wound healing. In: Electric Fields in Vertebrate Repair, Borgens RB, Robinson KR, Vanable, JW Jr., and McGinnis, ME eds. New York: Liss, 1989, p. 171-224.
5. Nishimura KY IR, Nuccitelli R. Human keratinocytes migrate to the negative pole in direct current electric fields comparable to those measured in mammalian wounds. Journal of Cell Science 1996; 109:199-207.
6. Pullar CE, Isseroff RR, Nuccitelli R. Cyclic AMP-dependent protein kinase A plays a role in the directed migration of human keratinocytes in a DC electric field. Cell Motil Cytoskeleton 2001; 50: 207-217.
7. Zhao M, Pu J, Forrester JV, McCaig CD. Membrane Lipids, EGF receptors and intracellular signals co-localize and are polarized in epithelial cells moving directionally in a physiological electric field. FASEB J 2002;16(8):857-859
8. Zhao M. “Electrical fields in wound healing—An overriding signal that directs cell migration.” Semin Cell Dev Biol; 20(6):674-82.
9. Becker RO, Spadaro JA. Treatment of Orthopedic Infections with Electrically Generated Silver Ions. Journal of Bone and Joint Surgery 1978; 60-A: 871-81.
10. Huckfeldt R, Flick AB, Mikkelson D, Lowe C, Finley PJ. Wound closure after split-thickness skin grafting is accelerated with the use of continuous direct anodal micro current applied to silver nylon wound contact dressings. Journal of Burn Care & Research 2007; 28:703-707.
11. Chu CS, McManus AT, Pruitt BA, Mason AD. Therapeutic effects of silver nylon dressings with weak direct current on Pseudomonas aeruginosa-infected burn wounds. Journal of Trauma Injury, Infection, and Care 1988; 28: 1488-92.