Exoxemis’ scientific team members are active contributors to the field’s body of knowledge in myeloperoxidase (MPO) technology. The publications and presentations listed below represent a partial list.

"Efficacy of the Myeloperoxidase Enzyme System in a Rat Dermal Model for the Prevention of Surgical Site Infection".

Robins, A¹; Denys, G²; Woodhead, S³; Davis, J⁴; Abril-Horpel, O ;Becquerelle, S; Haag, W; Valvani, S; Bond, J ; Medinsky, M.

¹University of Washington, Seattle, WA, ²Clarian Health Partners, Inc., Indianapolis, IN, ³Ricerca Biosciences, Concord, OH, ⁴Exoxemis, Inc., Little Rock, AR

Poster # 1379 presented at Orthopaedic Research Society Conference, Washington, DC, February 20 – 23, 2005

Surgical site infections (SSI) are a major source of morbidity and mortality, and add significant cost to healthcare. An oxidant generating enzyme system containing myeloperoxidase (MPO) has been developed as a new topical/local product to prevent SSI (Exoxemis, Inc., Little Rock, AR). In vitro, the MPO enzyme system is rapidly microbicidal against a broad range of microorganisms, even in the presence of metal implant material. In this study, a rat dermal model has been developed to evaluate the in vivo efficacy of the MPO enzyme system for the prevention of surgical site infection.
 
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“Animal safety profile of pure and formulated porcine myeloperoxidase”

James Bond, Michele Medinsky, Shri Valvani, William Haag, Sophie Bequerelle, Gerald Denys, Obsidiana Abril-Hörpel

Exoxemis, Inc., Little Rock, AR

Poster # 29-5P2 4th International Peroxidase Meeting, Kyoto, Japan
October 27-30, 2004

A cell free oxidant generating system containing porcine myeloperoxidase (MPO) has been developed as a local/topical antimicrobial. The MPO system is rapidly microbicidal against a broad range of bacteria, fungi, spores, and viruses in vitro, and demonstrates rapid decrease in bacterial challenge after application onto wounds in vivo. Excellent efficacy of the MPO system both in vitro and in vivo led us to investigate the safety profile of the pure and formulated MPO. Studies were conducted in rats and rabbits to investigate the safety of pure and formulated MPO. The studies included 14 day oral, dermal and pulmonary toxicity testing and 72 hour dermal and ocular irritation testing. The results showed that pure and formulated MPO were non-toxic in oral, dermal and pulmonary tests and non-irritating to the eyes. In dermal irritation tests, a slight and transient erythema reaction in 1/3 rabbits cleared within 24 hours.
 
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Bactericidal Activity of the Myeloperoxidase Antimicrobial Enzyme System Against Vegetative and Spore Forms of Bacillus cereus, Bacillus thuringiensis, and Bacillus subtilis”

S. Woodhead¹, G. Hill², S. Valvani², O. Abril-Horpel², W. Haag², S. Becquerelle², G. A. Denys^3
1Ricerca Biosciences, ²Exoxemis, Inc., Little Rock, AR, ³Clarian Health Partners, Inc.

Paper#: 56(G) accepted for 2004 ASM Biodefense Research Meeting, Baltimore, MD, March 7 – 10, 2004.

The emergence of new infectious diseases, rise in antibiotic resistance, and threat of bioterriorism and biowarfare have prompted the development of alternative treatment options to antibiotics. A novel enzyme system utilizing myeloperoxidase (MPO) as a potent antimicrobial agent has been developed (Exoxemis, Inc. Little Rock, AR). A study has been performed to investigate the in vitro action of the MPO enzyme system on vegetative and spore forms of Bacillus species closely related to Bacillus anthracis, specifically Bacillus cereus ATCC 10987, Bacillus thuringiensis ATCC 33679, and Bacillus subtilis ATCC 19659. The MPO enzyme system demonstrated rapid and potent bactericidal activity against Bacillus spores (100% kill within 120 minutes) and shows promise for the prevention of anthrax and other infections which may be caused by biowarfare agents.
 
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“Comparison of the Activity of Myeloperoxidase (MPO) Enzyme System to Antibiotics for Irrigation of Implant Material”

Robins A¹, Woodhead S², Denys G^3
1University of Washington, ²Ricerca Biosciences, ³Exoxemis, Inc.

Poster # 1061 accepted for Orthopaedic Research Society Conference, San Francisco, CA, March 7 – 10, 2004.

Residual bacteria at the site of implant surgery can lead to acute and delayed infection. Intra-operative irrigation with antibiotic solutions during implant surgery is common clinical practice despite the lack of evidence of sustained reduction or elimination of residual bacteria at the surgical field. A novel enzyme system utilizing myeloperoxidase (MPO) as a potent antimicrobial agent has been developed (Exoxemis, Inc. Little Rock, AR). The MPO enzyme system exhibited rapid and complete kill of residual S. aureus, even in the presence of implant material. The antibiotic solutions failed to do so and, in fact, showed re-growth of the initial inoculum.
 
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“Microbicidal Activity of the Myeloperoxidase Enzyme System Against Clinically Relevant Bacterial and Fungal Isolates Including Multidrug-Resistant Strains”

Woodhead S¹, Denys G², Harrell L³, Hill G⁴, Valvani S⁴, Abril-Horpel O⁴, Haag W^4
1Ricerca Biosciences, ²Clarian Health Partners, Inc., ³Duke University Medical Center, ⁴Exoxemis, Inc.

The Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). 43rd ICAAC, September 14 - 17, 2003, Chicago, Illinois. Poster #: F-1458.

A novel enzyme system utilizing myeloperoxidase (MPO) as a potent antimicrobial agent has been developed (Exoxemis, Inc. Little Rock, AR). A study has been performed to investigate the in vitro activity of the MPO enzyme system against a broad spectrum of bacterial and fungal isolates implicated in serious infections. The MPO enzyme system demonstrated rapid and potent microbicidal activity against a broad spectrum of bacterial and fungal isolates, and may have prophylactic and therapeutic applications.
 
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“Resistance Selection Studies with the Myeloperoxidase Enzyme System Against Staphylococcus aureus, Enterococcus faecium, and Pseudomonas aeruginosa”

Denys G¹, Woodhead S², Becquerelle S³, Valvani S³, Abril-Horpel O³, Haag W^3
1Clarian Health Partners, Inc., ²Ricerca Biosciences, ³Exoxemis, Inc.

The Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). 43rd ICAAC, September 14 - 17, 2003, Chicago, Illinois. Poster # F-353.

Myeloperoxidase (MPO) plays an important role in the natural host defense system against pathogenic microorganisms. A novel enzyme system utilizing myeloperoxidase (MPO) as a potent antimicrobial agent has been developed (Exoxemis, Inc. Little Rock, AR). To assess the potential for emergence of resistance in clinical use, the selection of resistance was investigated by in vitro serial passage. The MPO enzyme system did not select for resistant variants in S. aureus, E. faecium, and P. aeruginosa. These results suggest that the MPO enzyme system with its unique mechanism of action does not select for resistance.
 
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“A New Approach for the Prevention and Treatment of Staphylococcal Musculoskeletal Infection”

Robins A¹, Woodhead S^2
1University of Washington, ²Ricerca Bioscience

Orthopaedic Research Society, New Orleans, LA, February 2 – 5, 2003.
Poster #1062

Staphylococcus aureus (SA) and coagulase-negative staphylococci (CNS) are the most frequent cause of musculoskeletal infections. Emerging resistance among these organisms to traditional antimicrobial agents makes the management and prevention of infection difficult. A novel enzyme system utilizing myeloperoxidase (MPO) as a potent antimicrobial agent has been developed (Exoxemis, Inc. Little Rock, AR). The MPO system demonstrated both rapid action and complete microbicidal activity in vitro, safety in animals tested, and potential for prophylactic and therapeutic applications against problematic microorganisms associated with musculoskeletal infections.
 
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“Physical-Chemical Characterization of Myeloperoxidase (MPO) and Related Degradation Products”

Scandella C¹, Cunico RL², Gruhn V², Moon J², House M², Taylor E², Jin Y-Q³ and Kiang H³.
¹Exoxemis, Inc., ²Bay Bioanalytical Laboratory, ³PHARMout Laboratories

Analysis of Well Characterized Biotechnology Pharmaceuticals, San Francisco, CA. January 7-10 2003.

A physical-chemical study was performed to render porcine MPO a well-characterized biopharmaceutical. MPO was purified to near homogeneity, formulated, and examined by several methods, including reverse phase HPLC (rp-HPLC), UV spectrometry (UV), size exclusion chromatography (SEC) with refractive index (RI) and laser light scattering (LLS) detection, mass spectrometry (MS), and an enzyme activity assay using guaiacol as a substrate. Stability studies on intact MPO for up to two years revealed that the molecule is stable to prolonged storage, even at temperatures up to 40°C.
 
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