Page 59 - OxyBand Research Background

OxyBand
Effect of Oxygen Tension on Neutrophil OxyBand TM TM
Mediated Killing of Acinetobacter baumannii the Healing Power of Oxygen
Mark Rollins, MD, PhD; • Joseph Tonna, MD, University of California San Francisco School of Medicine, San Francisco, CA and OxyBand Technologies Inc., San Francisco, CA; • Amie Franklin, PhD, OxyBa
ABSTRACT More Oxygen = Less Bacteria CONCLUSION
The Affect of Increasing Oxygen Tension on 100% O 2
An in vitro study was conducted to determine whether increased oxygen tension (percent The study presented demonstrates from a basic science standpoint that oxygen plays a critical role
oxygen provided by OxyBand™ would increase Neutrophil (PMN) mediated killing of Acinetobacter in resistance to infection by bacteria such as Acinetobacter baumannii. From a clinical standpoint,
baumannii. OxyBand™ has been shown to increase oxygen tension (increase and maintain Neutrophil Mediated Killing of Acinetobacter Baumannii 21% O 2 with significant military relevance, the stud
elevated levels of dissolved oxygen in wounds (PO2) in full thickness wounds for extended periods useful in treating or preventing infections by bacteria such as Acinetobacter present in traumat
of time. A recent in vivo study demonstrated OxyBand™ elevated PO2 in full thickness wounds to and combat wounds. OxyBand™ is an easy to apply topical oxygen dressing that can deliver high
245 – 263 mmHg for twelve hours (when the study was completed) compared to PO2 in wounds 250 0% O 2 levels of oxygen for up to 5 days. It requires no external oxygen source and can be stored f
treated with HBOT and covered with a film dressing that reached a PO2 level of 89 – 125mmHg. prolonged periods in a simple foil wrapper. Preliminary studies demonstrate that it maintains
surface oxygen levels over a wound sufficient to enhance neutrophil bacterial killing for up to
Acinetobacter baumannii has emerged as a major cause of community-associated and nosocomial 5 days. It can be manufactured in any size, including small enough to be carried in a soldier’s
pneumonia. Infections with Acinetobacter have been an increasingly recognized problem for 209.5 backpack, and large enough to treat burn wounds over significant body surface area. OxyBand™
injured military personnel, particularly soldiers returning from Iraq and Afghanistan with burns may be beneficial in preventing or treating infection/contamination with Acinetobacter and MRSA,
and wounds caused by explosives. Studies have found in the case of Acinetobacter baumannii 200 it will have a tremendous potential for widespread military use. It is small enough to replace the
respiratory infections that neutrophils are rapidly recruited to the lungs following i.n. inoculation dressing currently supplied for all troops, and should have significantly more efficacy in hea
of the Acinetobacter baumannii pathogen and decline to baseline level upon clearance of the superficial wounds (thermal and chemical burns, rope burns, scrapes, and de-gloving injuries, for
infection. Depletion of neutrophils using monoclonal antibody RB6-8C5 (in vivo) prior to infection example) and returning injured personnel to active duty.
resulted in an acute lethal infection that was associated with enhanced bacterial burdens in the
lung (P < 0.05) and extrapulmonary dissemination to the spleen.
The study presented in this poster was designed to determine the affect of neutrophils on killing 150
Acinetobacter baumannii by increasing oxygen tension in vitro. The question to be answered was 127 128.75
whether killing of Acinetobacter baumannii by neutrophils would be proportional to local oxygen
tension in vitro. Acinetobacter Baumannii per ml of blood 107.75
Results from the in vitro study confirm that PMNs kill Acinetobacter baumannii in an oxygen 100 98.75 REPRESENTATIVE REFERENCES
dependent fashion. Levels of oxygen provided by OxyBand™, should increase PMNs and
therefore, increase in neutrophil mediated killing of Acinetobacter baumannii. Results suggest 88.5 91.75 83.25 • van Faassen H, KuoLee R, Harris G, Zhao X, Conlan JW, and Chen W, Neutrophil
there is a beneficial effect of increasing oxygen tension on neutrophil mediated killing of
Acinetobacter baumannii. From these data a clinical trial of traumatic and combat wounds seems Role in Host Resistance to Respiratory Infection with Acinetobacter baumannii in Mice, Infection an
Immunity, Dec. 2007, p. 5597–5608.
indicated. 50
OxyBand Technologies Inc. has developed OxyBand™ – a ready to deploy topical oxygen delivery 52.25 • Babior BM. 1978. Oxygen-dependent microbial killing by phagocytes. N Engl J Med. 298(13): 6
system in a dressing that requires no external oxygen source and can be stored for prolonged CFU/ml
periods in a simple foil wrapper. The delivery system is an FDA approved (510k) device which has • Edwards S, Hallett M, Campbell A. 1984. Oxygen-radical production during inflammation may be
limited by oxygen concentration. Biochem J. 217:851-854.
illustrated ability to accelerate wound healing with less pain and without infection. Preliminary
studies demonstrate that OxyBand™ maintains surface oxygen levels over a wound sufficient
to enhance neutrophil bacterial killing for up to 5 days. It can be manufactured in any size, 0 • Paty PB, Graeff RW, Mathes SJ, Hunt TK. 1990. Superoxide production by wound neutrophils. Evid
including small enough to be carried in webbing or a backpack, and large enough to treat wounds for increased activity of the NADPH oxidase. Arch Surg. 125(1):65-69.
over significant body surface area. OxyBand™, if beneficial in preventing or treating infection/ 30 minutes 1 hour 2 hours
contamination with Acinetobacter and potentially MRSA, will have a tremendous potential for • Gabig TG, Bearman SI, Babior BM. 1979. Effects of oxygen tension and pH on the respiratory burst of
Time post onset of oxygen treatment
widespread military use. human neutrophils. Blood. 53(6):1133-1139.
• Moelleken B, Mathes S, Amerhauser A, Scheuenstuhl H, Hunt T. 1991. An adverse wound environment
activates leukocytes prematurely. Arch Surg. 126:225-230.
RESULTS • Rotstein O, Fiegel V, Simmons R, Knighton D. 1988. The deleterious effect of reduced pH and hypoxia
BACKGROUND Table 1 (Selected Results) on neutrophil migration in vitro. J Surg Res.45:298-303.
• Belda FJ, Aguilera L, Garcia de la Asuncion J, et al. 2005. Supplemental perioperative oxygen and the
and wounds caused by explosives. Acinetobacter is naturally sensitive to a small range of antibiotics, and reports
Hyperbaric oxygen has been shown to be effective in improving healing in selected clinical conditions. Similarly, Table 1, shows a trend toward higher oxygen tension effecting the PMN killing of
local oxygen delivery has been shown to provide a stimulus to healing in a manner similar to hyperbaric oxygen. of resistance are increasing. It has been suggested that Acinetobacter is another
The exact mechanism of effect remains an open question for both technologies. Infections affecting wounds killing by neutrophils, but this impression also has not been systematically investigate
causing loss and death of tissue, chronicity, limbs and death represent a significant problem for both patients and macrophage responses. Fed Proc 45: A958.
the military and civilian health care delivery systems. Continued armed conflict and changing demographics of The present study investigates the efficacy of increasing levels of oxygen present in
and treat Acinetobacter by examining the oxygen-dependence of neutrophil-mediated killing of Acinetobacter
most developed societies imply that a dramatic increase in the incidence of wounds including infected and chronic suggest there is a beneficial effect of increasing oxygen tension on neutrophil m
wounds is growing. baumannii, in vitro. of Acinetobacter baumannii. From these data a clinical trial of wounds in clinical settings and in
combat situations seems indicated. • Antibiotics for Pseudomonas aeruginosa. Appl Microbiol. 16(2):260–262.
OxyBand™ Studies & Demonstrated Results: The impact of increasing oxygen concentrations in infections, led OxyBand™ scientists and University of
California San Francisco medical school physicians to ask whether increased oxygen tension would affect • Luongo C, Imperatore F, Matera MG, Mangoni G, Marmo M, Baroni A, C
Neutrophil Mediated Killing of Acinetobacter baumannii. This laboratory trial was conducted at The University of
All studies (in vitro, preclinical, clinical) used the FDA approved device (510k approval number K043063). OxyBand™ 1999. Effect of hyperbaric oxygen therapy in experimental subcutaneous and pul
is a multilayer wound dressing that keeps out water, dirt and germs, and supplies oxygen to the wound. It is California San Francisco, School of Medicine, and consisted of an in vitro study to d
higher oxygen tension would increase the Neutrophil Mediated killing of Acinetobacter baumannii. The results, are
designed to be applied directly over clean skin or wounds for up to 5 days. A study has shown that oxygen levels
rise steadily over a wound area for the first few hours and then maintain at elevated levels through 5 days as long positive in vitro, and warrant testing clinically and in the field. DISCUSSION
as the dressing remains intact and secure around the perimeter. TK, editor. Wound Healing and Wound Infection. Appleton-Century-Crofts,; New York.
Study Methods Wounds and burns remain a common experience of military personnel, whether on active duty or
The present study evaluated the efficacy of oxygen in OxyBand™ on Neutrophil Mediated killing of Acinetobacter Acinetobacter baumannii were cultured and grown in a variety of growth media to opti
baumannii has been seen in wounded soldiers treated since the beginning of OIF and OEF. Multi Drug Resistant minor injuries may also be high, particularly if the wounds become infected. Infectio
Acinetobacter and Acinetobacter Baumannii organisms were the most frequently recovered gram-negative isolate predictable concentration. Human neutrophils (PMN) were then isolated using the Histo
and their concentration, viability and bactericidal activity were determined. An apparatus was built to allow for
from war wounds and the second most frequent bacterium causing bloodstream infection in US Marines with that delays return of military personnel to active duty – or to activities of daily living
extremity wounds during the Vietnam War. control of temperature and oxygen concentration while mixing PMNs and bacteria for various lengths of time to frequently resistant to multiple antibiot
measure their bactericidal activity.
have somewhat limited value. Topical oxygen, however, appears to enhance epithelization.
Resistant Wound Infections • Park MK, Muhvich KH, Myers RA, Marzella L. Hyperoxia prolongs the aminoglycoside-induced
After determining the growth rate of Acinetobacter baumannii and stationary phase concentrations in broth, the Oxygen is important in wound healing, and there is a need to fi
chamber was built to mix the PMNs and bacteria. This involved maintaining a humidified environment where
Wound infections remain the most common complication of trauma, including surgery. They lead to delayed as concentrations to superficial wounds. OxyBand™ as has been shown during in vitro and cli
well as impaired healing and excess cost. Injuries in military personnel carry a particularly high risk of infection. the partial pressure of oxygen could be varied from 10mmHg through >600mmHg
Despite ongoing introduction of more powerful antibiotics, the rate of antibiotic resistance continues to increase. rapid gas exchange between the liquid environment of the reaction and the gas
temperature of 37C. The chamber was configured to allow constant stirring to ensure good mixing and enable
Staphylococcus aureus (MRSA) strains, Acinetobacter baumannii and other bacteria-demonstrating multiple antibiotic inflammation and decrease pain. Microbiology. PR zvMurray et al., eds. ASM Pre
resistant are becoming epidemic. Resistance to infection for Staph aureus in particular has been shown to be Additionally, the apparatus allowed researchers rapid access to remove bacterial samp
without disturbing the environment. After the chamber was designed, built and tested, PMNs were isolated from
dependent upon sufficient oxygen to allow phagocytic killing. Development of resistance to oxidative bacterial This investigation was initiated to determine whether increasing oxygen concentratio
killing has not been described previously. Acinetobacter baumannii, classified as an opportunistic, Gram-negative human volunteers, and then the viability and bactericidal activity were tested. S
coccobacillus although primarily considered a respiratory contaminant that may cause pneumonia or sepsis in reaction at various time points and at various oxygen tensions to determine viability
of PMNs at those environments. After adapting the protocol for Acinetobacter the protocol was repeated 3 times.
civilian life, wound infections with acinetobacter have been an increasingly recognized problem for injured military warrant immediate field testing. Further References upon Request
personnel, particularly those with burns
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