Home

Products
  Pharmaceutical
  Agricultural

Technology
 
Clinical Trial Results
  Journal Articles

Contact Info

Demegen Logo


Selected Journal Articles

Treatment of infected wounds with the antimicrobial peptide D2A21.
Chalekson CP, Neumeister MW, Jaynes J.
Department of Plastic Surgery, Southern Illinois University School of Medicine, Plastic Surgery Institute, Springfield, Illinois 62794-9653, USA.

Journal of Trauma. 2003 Apr;54(4):770-4
Abstract:
BACKGROUND: Infected wounds impose a significantly negative effect on patient care and recovery, as infection hinders normal wound healing, resulting in increased patient morbidity and mortality. More attention is being focused on addressing the problem of multidrug-resistant bacteria and the staggering costs and consequences resulting from this. Recently, newly evaluated antimicrobial peptides have been shown to be active against a wide variety of bacteria in in vitro studies. This study evaluates the use of a particular antimicrobial peptide, D2A21 (Pittsburgh, PA), to combat infection in an acutely infected wound model. METHODS: Forty-eight Wistar rats were used to compare the effects of D2A21 to control vehicle, silver sulfadiazine (SSD), and Sulfamylon in this model. Two 1.5 x 1.5-cm full-thickness defects were created on the rat dorsum and were subsequently inoculated with 108 Pseudomonas aeruginosa. Animals underwent daily treatment with either D2A21 gel, control vehicle, SSD, or Sulfamylon. Animals were evaluated for survival differences. RESULTS: Survival analysis at 21 days for the different treatment groups were as follows: 100% for the D2A21-treated animals, 50% for control-treated animals, 83% for Sulfamylon-treated animals, and 33% for SSD-treated animals. CONCLUSION: D2A21 antimicrobial peptide demonstrates significant activity compared with controls and standards of therapy. The promising effect of this topical peptide is clearly evident as shown by this study, and its further investigation as a potential agent in the fight against infected or chronic wounds is warranted.
PDF file of full article

Inhibitory activity of synthetic peptide antibiotics on feline immunodeficiency virus infectivity in vitro.
Ma J, Kennedy-Stoskopf S, Jaynes JM, Thurmond LM, Tompkins WA
Journal of Virology 2002 Oct 76:9952-61
Abstract:
Natural peptide antibiotics are part of host innate immunity against a wide range of microbes, including some viruses. Synthetic peptides modeled after natural peptide antibiotics interfere with microbial membranes and are termed peptidyl membrane-interactive molecules (peptidyl-MIM [Demegen Inc, Pittsburgh, Pa.]). Sixteen peptidyl-MIM candidates were tested for activity against feline immunodeficiency virus (FIV) on infected CrFK cells. Three of them (D4E1, DC1, and D1D6) showed potent anti-FIV activity in chronically infected CrFK cells as measured by decreased reverse transcriptase (RT) activity, having 50% inhibitory concentrations of 0.46, 0.75, and 0.94 micro M, respectively, which were approximately 10 times lower than their direct cytotoxic concentrations. Treatment of chronically infected CrFK cells with 2 micro M D4E1 for 3 days completely reversed virus-induced cytopathic effect. Immunofluorescence revealed reduced p26 staining in these cells. Treatment of chronically infected CrFK cells with 2 micro M D4E1 suppressed virus production ( approximately 50%) for up to 7 days, The virions from the D4E1-treated culture had impaired infectivity, as measured by the 50% tissue culture infectious dose and nested PCR analysis of proviral DNA. However, these noninfectious virions were able to bind and internalize, suggesting a defect at some postentry step. After chronically infected CrFK cells were treated with D4E1 for 24 h, increased cell-associated mature p26 Gag and decreased extracellular virus-associated p26 Gag were observed by Western blot analysis, suggesting that virus assembly and/or release may be blocked by D4E1 treatment, whereas virus binding, penetration, RNA synthesis, and protein synthesis appear to be unaffected. Synthetic peptide antibiotics may be useful tools in the search for antiviral drugs having a wide therapeutic window for host cells.
PDF file of full article

Improvement in Burn Wound Infection and Survival with Antimicrobial Peptide D2A21 (Demegel)
Charles P. Chalekson, M.D.; Michael W. Neumeister, M.D.; Jesse Jaynes, Ph.D. Springfield, Ill., and Pittsburgh, Pa. From the Plastic Surgery Institute, Southern Illinois University School of Medicine; and Demegen, Inc.
Plastic and Reconstructive Surgery April 2002;109:1338-1343
Abstract:
Naturally occurring antimicrobial peptides have been discovered in both plants and animals. Many of these peptides demonstrate impaired activity or cytotoxicity when applied exogenously. Synthetically engineered antimicrobial peptides have been designed to increase potency and activity against bacteria and fungus yet remain noncytotoxic. The antimicrobial peptide D2A21 (Demegel) has already demonstrated significant activity in vitro against many common hospital pathogens. The purpose of this study was to evaluate the effects of D2A21 in an in vivo infected burn-wound model, examining both quantitative cultures of the wound and survival of the animal. Forty-four Wistar rats were subjected to a 23 percent total body surface area scald burn. Pseudomonas aeruginosa was administered topically with 108 organisms and wounds were then evaluated at day 1, 2, or 3 for eschar and subeschar muscle quantitative culture. The experimental group was treated daily with 1.5% topical D2A21. The control group was treated with control gel. A second group of Wistar rats (n = 14) were burned and given a 107 inoculum of the same Pseudomonas and evaluated to 14 days for survival and weight changes. This group was subdivided into rats receiving either topical D2A21 or control base daily. The quantitative biopsy results demonstrated that D2A21-treated wounds had no bacterial growth in burn eschar at day 2 or 3, whereas control animals demonstrated growth at greater than 105 organisms by day 2. Subeschar muscle cultures also demonstrated significantly less bacterial invasion compared with controls on each day tested. D2A21-treated animals had an 85.7 percent survival compared with 0 percent survival in controls. Furthermore, the D2A21-treated groups demonstrated maintenance of body weights, whereas controls had significant weight loss with time. In conclusion, D2A21 demonstrates significant antibacterial activity against Pseudomonas, sterilizing burn eschar and decreasing subeschar bacterial load, allowing for a markedly significant improvement in survival in this infected burn-wound model.

P-113D, an Antimicrobial Peptide Active against Pseudomonas aeruginosa, Retains Activity in the Presence of Sputum from Cystic Fibrosis Patients 
Umadevi S. Sajjan, Linh T. Tran, Nuria Sole, Christopher Rovaldi, Alan Akiyama, Phillip M. Friden, Janet F. Forstner, and David M. Rothstein 
Antimicrobial Agents and Chemotherapy 2001 December  45:3437-3444
Abstract:
Antimicrobial peptides are a source of novel agents that could be useful for treatment of the chronic lung infections that afflict cystic fibrosis (CF) patients. Efficacy depends on antimicrobial activity against the major pathogens of CF patients, Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae, in the environment of the CF patient's airway. We describe the in vitro efficacies of derivatives of histatins, which are histidine-rich peptides produced by the salivary glands of humans and higher primates. P-113, a peptide containing 12 of the 24 amino acid residues of the parent molecule, histatin 5, retained full antibacterial activity and had a good spectrum of activity in vitro against the prominent pathogens of CF patients. However, P-113 was not active in the presence of purulent sputum from CF patients. In contrast, P-113D, the mirror-image peptide with the amino acid residues in the D configuration, was stable in sputum, was as active as P-113 against pathogens of CF patients in the absence of sputum and retained significant activity in the presence of sputum from CF patients. Recombinant human DNase, which effectively liquefies sputum, enhanced the activity of P-113D in undiluted sputum against both exogenous (added) bacteria and endogenous bacteria. Because of its properties, P-113D shows potential as an inhalant in chronic suppressive therapy for CF patients. 
PDF file of full article

Anticandida activity is retained in p-113, a 12-amino-acid fragment of histatin 5.  
Rothstein DM, Spacciapoli P, Tran LT, Xu T, Roberts FD, Dalla Serra M, Buxton DK, Oppenheim FG, Friden P
Antimicrobial Agents and Chemotherapy 2001 May 45:1367-73
Abstract
:
Through the analysis of a series of 25 peptides composed of various portions of the histatin 5 sequence, we have identified P-113, a 12-amino-acid fragment of histatin 5, as the smallest fragment that retains anticandidal activity comparable to that of the parent compound. Amidation of the P-113 C terminus increased the anticandidal activity of P-113 approximately twofold. The three histidine residues could be exchanged for three hydrophobic residues, with the fragment retaining anticandidal activity. However, the change of two or more of the five basic (lysine and arginine) residues to uncharged residues resulted in a substantial loss of anticandidal activity. A synthetic D-amino-acid analogue, P-113D, was as active against Candida albicans as the L-amino-acid form. In vitro MIC tests in low-ionic-strength medium showed that P-113 has potent activity against Candida albicans, Candida glabrata, Candida parapsilosis, and Candida tropicalis. These results identify P-113 as a potential antimicrobial agent in the treatment of oral candidiasis.
PDF file of full article

In Vitro Microbicidal Activities of Cecropin Peptides D2A21 and D4E1 and Gel Formulations Containing 0.1 to 2% D2A21 against Chlamydia trachomatis
L. M. Ballweber, J. E. Jaynes, W. E. Stamm, and M. F. Lampe
Antimicrobial Agents and Chemotherapy, January 2002, p. 34-41, Vol. 46, No. 1
Abstract:
Topically applied microbicides that eradicate pathogens at the time of initial exposure represent a powerful strategy for the prevention of sexually transmitted infections. To aid in the further development of an effective topical microbicide, we assessed the minimum cidal concentration (MCC) of two cecropin peptides, D2A21 and D4E1, and gel formulations containing 0.1 to 2% D2A21 against Chlamydia trachomatis in vitro. The MCC of peptide D2A21was 5 M (18.32 g/ml), and that of peptide D4E1 was 7.5 M (21.69 g/ml). The MCC of gel formulations containing 2% D2A21 was 0.2 mM (0.7 mg/ml), and that of gel formulations containing 0.5% D2A21 was 0.2 mM (0.7 mg/ml). There was no significant variation in the results when two different C. trachomatis strains were tested, and the addition of 10% human blood did not significantly alter the MCCs. pH values above and below 7 reduced the activity of the D2A21 peptide alone, but the MCC of the 2% D2A21 gel formulation was only slightly altered at the various pHs tested. Ultrastructural studies indicated that C. trachomatis membranes were disrupted after D2A21 exposure, resulting in leakage of the cytoplasmic contents. These in vitro results suggest that these cecropin peptides may be an effective topical microbicide against C. trachomatis and support the need for further evaluation.
PDF file of full article

Use of Intravaginal Microbicides to Prevent Acquisition of Trichomonas Vaginalis Infection in Lactobacillus-Pretreated, Estrogenized Young Mice.
W. B. Lushbaugh, A. C. Blossom, P. H. Shah, A. K. Banga, J. M. Jaynes, J. D. Cleary, and R. W. Finley
The American Journal of Tropical Medicine & Hygiene: Vol. 63, No. 5, 2000,  pp. 284289

Abstract:
D2A21, a novel peptide antibiotic has in vitro activity against a wide spectrum of sexually transmitted diseases (STD). In this study we tested the hypothesis that intravaginal D2A21 would interfere with acquisition of Trichomonas vaginalis infection in a modified mouse model. T. vaginalis infections of estrogenized young mice pre-treated with Lactobacillus vaginalis or Lactobacillus rhamnosus were more frequent and persistent than those in mice pre-treated with Lactobacillus gasseri or Lactobacillus acidophilus. One hundred percent T. vaginalis infection was achieved for 24 days post-challenge when intravaginal L. rhamnosus pre-treatments were given to estrogenized mice 48 hr prior to a single T. vaginalis challenge. Estrogenized mice pre-treated with L. rhamnosus were pre-medicated with intravaginal placebo gel, 0.5% or 2% D2A21 gel, or 500 ug/mL metronidazole gel prior to T. vaginalis challenge. Both 2% D2A21 and metronidazole gels were significantly more efficacious (10% or none infected) than placebo gel (53% infected) in preventing vaginal T. vaginalis infections in mice.

 

Follow this link to obtain the Adobe Acrobat Reader for viewing PDF files:

Download Adobe Acrobat Reader for PDF files