Electrospun fibers loaded with antimicrobial peptides for treatment of wound infections.

The widespread resistance of clinically relevant bacteria against established antibiotics emphasizes the urgent need for novel therapeutics. In this context, wound infections constitute a specific challenge, as most systemically applied antibiotics are insufficiently available at the site of infection. Therefore, the local treatment of infected wounds poses a particular challenge regarding the appropriate release kinetics of actives and their residence time in the wound bed. Consequently, design and development of novel, drug-loaded wound dressings constitute a major research focus for the effective treatment of wound infections. In this study, we employed electrospinning to design drug-loaded wound dressings, incorporating the therapeutically promising antimicrobial peptide tyrothricin. By parallel electrospinning, we combined different ratios of water-soluble polyvinylpyrrolidone and water-insoluble methacrylate copolymer (EudragitE), in order to take advantage of their specific mechanical stability and dissolution properties. We fabricated fiber mats constituting mechanically stable wound dressings with a controlled drug release profile, combining an initial burst release above the minimal inhibitory concentration of known wound pathogens and a subsequent prolonged antimicrobial effect of the active ingredient. Antimicrobial activity against Staphylococcusaureus and Staphylococcusepidermidis was successfully proven, thereby introducing our tyrothricin-loaded fiber mats as a promising prospective therapy against typical wound-associated pathogens.

Efficacy and safety of a triple active sore throat lozenge in the treatment of patients with acute pharyngitis: Results of a multi-centre, randomised, placebo-controlled, double-blind, parallel-group trial (DoriPha).

OBJECTIVE: The aim of this multi-centre, randomised, double-blind, placebo-controlled trial was to compare the efficacy and safety of the fixed combination of 0.5 mg tyrothricin, 1.0 mg benzalkonium chloride, and 1.5 mg benzocaine (study drug marketed as Dorithricin® ) in repeat dosing for 3 days to match placebo lozenges in the treatment of acute pharyngitis in adults. METHODS: Patients (pts, aged ≥18 years) with acute pharyngitis, ie, non-streptococcal sore throat and moderate-to-severe pain (intensity NRS ≥ 7; VAS ≥ 50) were assigned to study drug (n = 160) or matching placebo (n = 161). Efficacy was assessed by investigator for 2 hours post initial dose (p.i.d.), and 3 days later (Visit 2). Primary efficacy endpoint was the complete resolution of throat pain and difficulty in swallowing at Visit 2 (3 days p.i.d.). Safety and local tolerability were also assessed. RESULTS: Seventy-two hours (p.i.d.), complete resolution of throat pain and difficulty in swallowing were achieved by 44.6% patients on study drug compared with 27.2% patients on placebo (difference 17.4% (CI [5.8%; 29.7%]; 64% improvement [GEE, P = 0.0022]). Until 2 hours p.i.d., reduction in symptoms was better with study drug (P < 0.005). Treatment satisfaction was higher with study drug (patients'/investigators' assessment (78.9%/78.9% vs 55.0%/55.6% for placebo) and was well tolerated, overall safety profile was comparable to placebo. CONCLUSION: The strength of this randomised controlled trial lies in the endpoint of complete remission after 3 days p.i.d., especially in the light of other trials addressing acute pharyngitis. The results of this study show a significant benefit of the study drug over placebo in the treatment of acute pharyngitis. Local treatment with the fixed combination (0.5 mg tyrothricin, 1.0 mg benzalkonium chloride, and 1.5 mg benzocaine) provides a rapid analgesic effect and is effective in relieving both severe throat pain as well as difficulty in swallowing associated with acute pharyngitis leading to a 64% improved complete remission within 72 hours. The triple active combination is a suitable treatment option for patients in the self-management of acute pharyngitis and sore throat. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT03323528.

Measuring acne using Coproporphyrin III, Protoporphyrin IX, and lesion-specific inflammation: an exploratory study.

Propionibacterium acnes: (P. acnes) produce Porphyrins; however, fluorescence measurement of Porphyrins from Ultraviolet-A (UVA) images has failed to establish a correlation. Acne clinical research and imaging has ignored the spectral excitation-emission characteristics and the exact pattern of the Porphyrins synthesized by P. acnes. In this exploratory study, for the first time, the possible relationships of Coproporphyrin III (CpIII) and Protoporphyrin IX (PpIX) fluorescence as well as acne lesion-specific inflammation measurements with clinical signs of acne are investigated. Furthermore, the sensitivity of these measurements in tracking and differentiating the known treatment effects of Benzoyl Peroxide (BPO) 5%, and combination of Clindamycin + BPO are also evaluated. Comedonal and papulopustular lesions identified by investigators during a live assessment of 24 mild-to-severe acne subjects were compared with fluorescence and inflammation measurements obtained from analysis of VISIA®-CR images. CpIII fluorescence spots showed a strong correlation (r = 0.69-0.83), while PpIX fluorescence spots showed a weak correlation (r = 0.19-0.27) with the investigators' comedonal lesion counts. A strong correlation was also observed between the investigators' papulopustular lesion counts and acne lesion-specific inflammation (r = 0.76). Our results suggest that CpIII fluorescence and acne lesion-specific-inflammation measurement can provide objective indication of comedonal and papulopustular acne severity, respectively. Furthermore, these measurements may be more sensitive and specific in evaluating treatment effects and early signs of acne lesion progression compared to investigators' lesion counts.

Tyrothricin--An underrated agent for the treatment of bacterial skin infections and superficial wounds?

The antimicrobial agent tyrothricin is a representative of the group of antimicrobial peptides (AMP). It is produced by Bacillus brevis and consists of tyrocidines and gramicidins. The compound mixture shows activity against bacteria, fungi and some viruses. A very interesting feature of AMPs is the fact, that even in vitro it is almost impossible to induce resistances. Therefore, this class of molecules is discussed as one group that could serve as next generation antibiotics and overcome the increasing problem of bacterial resistances. In daily practice, the application of tyrothricin containing formulations is relatively limited: It is used in sore throat medications and in agents for the healing of infected superficial and small-area wounds. However, due to the broad spectrum antimicrobial activity and the low risk of resistance development it is worth to consider further fields of application.

Reduction of Inflammatory and Noninflammatory Lesions with Topical Tyrothricin 0.1% in the Treatment of Mild to Severe Acne Papulopustulosa: A Randomized Controlled Clinical Trial.

BACKGROUND/AIMS: Antibiotic-induced drug resistance requires new approaches in topical acne treatment. Tyrothricin is known to produce no resistance. In this study, it was tested for the first time in topical acne treatment. The efficacy and tolerability of topical tyrothricin 0.1% was evaluated. METHODS: A randomized, active comparator-controlled, exploratory, observer-blind clinical study was conducted in 24 patients with acne papulopustulosa. Randomization on a split-face was either tyrothricin versus clindamycin + benzoyl peroxide (BPO) (n = 12) or tyrothricin versus BPO 5% (n = 12). The main outcome was change in inflammatory and noninflammatory lesion counts. RESULTS: The mean differences in inflammatory lesion counts from baseline were -12.3 (95% CI: -20.5 to -4.1) in clindamycin + BPO, -10.2 (95% CI: -15.3 to -5.0) in BPO 5%, and -7.7 (95% CI: -11.7 to -3.7) in tyrothricin. Tyrothricin reduced noninflammatory lesions (mean difference: -6.5 (95% CI: -11.6 to -1.4) and caused less product-related adverse events (n = 31) compared to BPO (n = 37) and clindamycin + BPO (n = 20). CONCLUSION: The results indicate that tyrothricin might be a candidate for treating acne and it seems to be more tolerable than both comparator treatments.

[INJECTING MATERIAL FOR SKIN REGENERATION LACERTA APPLICATION IN TREATMENT OF TROPHIC ULCERS IN PATIENTS WITH DIABETIC FOOT SYNDROME].

Examined 22 patients with diabetes mellitus (DM) type II of neuropathic form of diabetic foot syndrome (DFS). In 12 patients (comparison group) local povidone-iodine was used main in 10 (study group), except povidone-iodine, in the phase of exudation used tyrothricin in gel form, the granulation and epithelization phase, after cleaning the wounds, were injected intradermally 1 ml of injecting material for skin regeneration Lacerta. Trophic defects in 9 (90%) patients of the main group during the observation period healed completely, in the comparison group complete healing of the ulcer reached in 2 (16.7%) patients, the rest-wounds, although purified, however, were lethargic granulation, epithelization occurred very slowly. Consequently, the use of the proposed method allows to achieve more rapid healing of trophic ulcers that do not heal continued in patients of neuropathic forms of DFS.

Wound healing efficacy of a chitosan-based film-forming gel containing tyrothricin in various rat wound models.

The objective of this study was to evaluate the healing effects of a chitosan-based, film-forming gel containing tyrothricin (TYR) in various rat wound models, including burn, abrasion, incision, and excision models. After solidification, the chitosan film layer successfully covered and protected a variety of wounds. Wound size was measured at predetermined timepoints after wound induction, and the effects of the film-forming gel were compared with negative (no treatment) and positive control groups (commercially available sodium fusidate ointment and TYR gel). In burn, abrasion and excision wound models, the film-forming gel enabled significantly better healing from 1 to 6 days after wound induction, compared with the negative control. Importantly, the film-forming gel also enabled significantly better healing compared with the positive control treatments. In the incision wound model, the breaking strength of wound strips from the group treated with the film-forming gel was significantly increased compared with both the negative and positive control groups. Histological studies revealed advanced granulation tissue formation and epithelialization in wounds treated with the film-forming gel. We hypothesize that the superior healing effects of the film-forming gel are due to wound occlusion, conferred by the chitosan film. Our data suggest that this film-forming gel may be useful in treating various wounds, including burn, abrasion, incision and excision wounds.

Decade-long use of the antimicrobial peptide combination tyrothricin does not pose a major risk of acquired resistance with gram-positive bacteria and Candida spp.

Tyrothricin, an antimicrobial peptide combination produced by Bacillus brevis consisting of gramicidins and tyrocidins commands broad antimicrobial activity against gram-positive bacteria and some yeasts in vitro. The polypeptide and its components have been used therapeutically for about 60 years in the local treatment of infected skin and infected oro-pharyngeal mucous membranes. Though older studies suggest that resistance development of originally susceptible microorganisms towards tyrothricin is a rare event, data concerning recent state of resistance are lacking. In the present in vitro study the susceptibility to tyrothricin of clinical isolates of bacterial and yeast origin from superficial swabs of the skin and mucous membranes of outpatients and inpatients obtained from clinical material in the second half of the year 2003 was determined. Using a microdilution assay, the minimum inhibitory concentration (MIC and MIC90, defined as the concentration that inhibits at least 90 percent of the tested strains) of 20 strains each of Staphylococcus aureus of the variety MSSA (susceptible to methicillin), Staphylococcus aureus of the variety MRSA (methicillin resistant), Staphylococcus haemolyticus, Streptococcus pyogenes, Enterococcus faecalis, Corynebacterium spec., Candida albicans and Candida parapsilosis was determined. All of the tested gram-positive bacteria turned out to be highly susceptible to tyrothricin with MICs ≤ 4mg/l. The tested yeast strains were susceptible to the polypeptide antibiotic as well, but (with MICs of 16 mg/l and 32 mg/l, respectively) to a lesser extent. No acquired resistance of the tested strains was determined, indicating that the risk of resistance development against topically applied tyrothricin is only marginal, if there is any at all. Thus, long-term-, i.e. decade-long use of topically applied tyrothricin and its components in the local treatment of infected skin does not pose a major risk with respect to acquired resistance of originally susceptible gram-positive bacteria and yeasts, not even in the case of Staphylococcus aureus, both with MSSA and MRSA strains. The broad anti-bacterial and anti-fungal activity of tyrothricin combined with its lacking risk for resistance development make the antimicrobial peptide a valuable addition to our therapeutic armamentarium in the treatment of infected skin.

[Tyrothricin powder in the treatment of cutaneous lesions]. / Tyrothricin-Puder bei Hautverletzungen. Reduktion des Wundradius bei infizierten und infektionsgefährdeten Wunden--Eine randomisierte, placebokontrollierte Doppelblind-Studie.

BACKGROUND AND OBJECTIVES: The efficacy and tolerance of an antiseptic wound powder based on the antibiotic tyrothricin was investigated in a prospective, randomized multicenter trial in patients with posttraumatic and surgical cutaneous lesions. PATIENTS AND METHODS: In 5 centers, 131 male and female patients from 18-85 years were included with posttraumatic or surgical cutaneous lesions with infection or in danger of infection (area > or = 200 mm2). In a double-blind study, tyrothricin (n = 62; 0.1 g tyrothricin per 100 g of vehicle) or placebo powder (n = 69) was applied to the wound twice daily for 9 days. The primary aim was to evaluate the average daily reduction of the radius from the lesion area between the start and end of the randomized treatment (alpha = 0.025; one-sided). Secondly, a wound index (range 0-15) was calculated from the assessments of rubor, crusting, exudation, pain and functional impairment. RESULTS: The treatment groups were comparable at baseline. During randomized treatment, the radius of the lesions was reduced at an average of 0.55 +/- 0.31 mm/day (mean +/- SD) for tyrothricin and 0.47 +/- 0.30 mm/day for placebo (p = 0.016; one-sided; intention-to-treat data set). The wound index decreased at an average of 4.2 +/- 1.7 and 3.3 +/- 1.9 points for tyrothricin and placebo, respectively (p = 0.0048; one-sided). 4 adverse events occurred in each group. A causal relationship with the investigational drug could not be excluded in 3 of the placebo group. CONCLUSION: The results confirm the tendency to an acceleration of wound healing by tyrothricin powder (Tyrosur Powder) in case of infection or danger of infection. A superior efficacy compared to placebo was demonstrated. Due to its good tolerability and the absence of a systemic effects tyrothricin powder is appropriate for the treatment of superficial skin lesions.

Avaliaçäo terapêutica do Malvatricin Ginecológico em processo inflamatório nas vulvites e vulvovaginites pré-puberal / Therapeutic evaluation of Malvatricin Ginecológico in infant patients with inflammatory disease in the genital tract

Dezessete pacientes com patologia inflamatória vulvovaginal foram acompanhados com Malvaticin Ginecológico em um estudo aberto, no sexo feminino, näo comparativo, no Estado do Rio de Janeiro, visando avaliar à eficácia e a telerância do fármaco, composto de Quinosol, Tirotricina, Ácido lático e Hidrolato de Malva. Demonstrou ser ificaz e com uma tolerância excelente em 100 por cento dos casos

[The antihistaminic effect of a gel for burns and wounds containing tyrothricin, fomocaine, diphenhydramine and 8-hydroxyquinoline (author's transl)]. / Uber den Antihistamin-Effekt eines Brand- und Wund-Gels mit den Komponenten Tyrothricin, Fomocain, Diphenhydramin und 8-Hydroxychinolin.

The combination of fomocaine and diphenhydramine as active constituents of a new burn and wound gel (Herit) guarantees a remarkable antihistaminic effect. The UV-erythema model was a very informative test applied on the dorsal skin of 16 male volunteers.

[Experimental protection with tyrothrizin against herpes simplex virus infections in mice]. / Schutzversuche mit Tyrothricin an der Herpes-simplex-Virus-infizierten Maus.

Using 12-day old baby mice, strain NMRI, the LD50 of a Herpes simplex virus type 1 was calculated. Intragastric inoculation of the mice was carried out applying a stomach tube. Lethality of the mice was reduced from 67% to 23% by pre-incubation of the virus suspension for 30 min at 37 degrees C in the presence of 0.2 mg tyrothricin/ml. The effect was statistically significant and could be produced only after direct contact between tyrothricin and virus. Under the same conditions there was no effect of lysozyme against virus infectivity.

Chronic otitis media and hearing loss in the Eskimo population of Canada.

Chronic otitis media and hearing loss is a major health problem today in the Canadian Eskimo. The subject is reviewed and the findings of projects and a survey that have been carried out recently are discussed. A modality of treatment is proposed which is based upon the findings of the projects, the survey and other information that is available at the present time.

A double-blind comparative study of Otoseptil Ear Drops and Otosporin Ear Drops in otitis externa.

A double-blind comparative study of Otoseptil Ear Drops and Otosporin Ear Drops in otitis externa in fifty-eight patients revealed them both to be equally effective in a series with very few fungal infections. In view of the normally high proportion of infections including fungi, there are obvious advantages in using Otoseptil Ear Drops.