Levofloxacin loaded clove oil nanoscale emulgel promotes wound healing in Pseudomonas aeruginosa biofilm infected burn wound in mice.

Owing to their tolerance to antibiotics, bacterial biofilms continue to pose a threat to mankind and are leading cause for non-healing of burn wounds. Within the biofilm matrix, antibiotics become functionally inactive due to restricted penetration and enzymatic degradation leading to rise of antimicrobial resistance. The objective of present investigation was to develop and characterize levofloxacin (LFX) loaded clove oil nanoscale emulgel (LFX-NE gel) and evaluate its in vivo therapeutic efficacy in Pseudomonas aeruginosa biofilm infected burn wound in mice. The optimized emulgel was found to possess good texture profile and showed shear thinning behavior. In vitro release study demonstrated complete drug release in 8 h and emulgel was found to be stable for 3 months at 25 °C and 40 °C. In vivo study revealed biofilm dispersal, complete wound closure, re-epithelialization and collagen deposition by LFX-NE gel in comparison to various control groups. LFX-NE gel was able to clear the infection within 7 days of treatment and promote wound healing as well. Therefore, administration of LFX-incorporated NE gel could be a beneficial treatment strategy for P. aeruginosa biofilm-infected burn wounds.

pH-Responsive Oxygen and Hydrogen Peroxide Self-Supplying Nanosystem for Photodynamic and Chemodynamic Therapy of Wound Infection.

The combination of photodynamic therapy (PDT) and chemodynamic therapy (CDT) has been continuously explored in the antibacterial aspect and has achieved more effective antibacterial effect than a single therapy. We design a pH-responsive O2 and H2O2 self-supplying zeolitic imidazolate framework-67 (ZIF-67) nanosystem for PDT/CDT of wound infection. Under the acidic inflammatory conditions, ZIF-67 can degrade to produce Co2+ and release CaO2 and graphene quantum dots (GQDs). The exposed CaO2 reacted with water to generate H2O2 and O2. The self-supplied O2 alleviates hypoxia at the site of inflammation and enhances external light-initiated GQD-mediated PDT, while H2O2 was catalyzed by endogenous Co2+ to produce hydroxyl radicals for Co2+-triggered CDT. In vitro and in vivo experiments confirm that CaO2/GQDs@ZIF-67 has a combined PDT/CDT effect. The antibacterial mechanism indicates that bacteria post-treated with CaO2/GQDs@ZIF-67 may be sterilized by reactive oxygen species-mediated oxidative stress and the leakage of bacterial contents. The experiments also find that CaO2/GQDs@ZIF-67 may activate the immune response and enhance the therapeutic effect by activating the cyclic GMP-AMP synthase-stimulator of interferon genes signaling pathway.

Accelerated healing by topical administration of Salvia officinalis essential oil on Pseudomonas aeruginosa and Staphylococcus aureus infected wound model.

BACKGROUND: Salvia officinalis L. (Lamiaceae) is known to have antibacterial properties possibly conducive to the healing process of infected wounds. PURPOSE: The present study aimed to evaluate the effects of an ointment containing Salvia officinalis essential oil (SOO) on an infected wound model. METHODS: Essential oil hydrodistillated from the dried leaves of the plant was analyzed by GC-FID and GC-MS. After creating two full-thickness cutaneous wounds, mice were classified into four groups, control, and animals treated with 2 % mupirocin® (standard positive drug), and 2 % and 4 % (w/w) of SOO. In order to evaluate the effects of SOO on the wound healing phases, the expression levels of interleukin-6 (IL-6), interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), cyclin-D1, Bcl-2, fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factors (VEGF) were analyzed using qRT-PCR. Immunohistochemistry analysis, tissue total antioxidant capacity (TAC) and malondialdehyde (MDA) were further assessed in all groups. RESULTS: Concerning essential oil, the main compounds were found to be cis-thujone (26.8 %), camphor (16.4 %), trans-thujone (14.1 %) and 1,8-cineole (10.8 %). Our findings showed that the topical application of SOO was able to shorten the inflammatory phase and accelerate the cellular proliferation, re-vascularization, collagen deposition and re-epithelialization in comparison to the control group (p < 0.05). Moreover, increased mRNA levels of FGF-2 and VEGF, and up-regulation of cyclin-D1 and Bcl-2 were observed following the topical application of SOO compared to the control group (p < 0.05). The expression levels of IL-6, IL-1ß and TNF-α were reduced in animals treated with SOO on days 3, 7 and 14 (p < 0.05). CONCLUSIONS: Administration of SOO increased the TAC level and reduced the MDA content and levels of IL-1ß and TNF-α. It is concluded that SOO is able to accelerate the wound healing process by regulating the expression of pro-inflammatory cytokines, growth factors, and antioxidant properties.

Polyurethane-biomacromolecule combined foam dressing containing asiaticoside: fabrication, characterization and clinical efficacy for traumatic dermal wound treatment.

Polyurethane combined (PUC) foam dressings with various biomacromolecules were fabricated with the adsorption of asiaticoside and silver nanoparticles for traumatic wound treatment. Biomacromolecules had varying effects on physicochemical and mechanical properties of PU foam. With 2% incorporation, starches, high molecular weight chitosan and gelatin provided stiffer and more porous foams while carboxymethylcellulose had the highest compression strength but the lowest water vapor transmission. High water absorption was from foams with carboxymethylcellulose, alginate, hydroxypropyl methylcellulose and low molecular weight chitosan. Increasing the concentrations up to 12% had more prominent effect. However, powdery surface was noticed with poorer tensile properties that 6% incorporation was selected. FTIR spectra and DSC thermograms suggested interaction of PU formulation with biomacromolecules. EDS analysis confirmed existence of active compounds while acceptable stability was from sterilized PUC foam with alginate. On healthy volunteers, this selected foam dressing caused no skin irritation and retained moisture comparable to commercial product. In patients with traumatic dermal wounds, healing improvement with shorter wound closure time, higher reepithelialization and less pain score were from the selected foam dressing compared to standard gauze soaked with chlorhexidine. This PU-alginate combined foam dressing adsorbed with asiaticoside and silver nanoparticles proved advantages for traumatic dermal wound management.

A murine model of cutaneous aspergillosis for evaluation of biomaterials-based local delivery therapies.

Cutaneous fungal infection is a challenging condition to treat that primarily afflicts immunocompromised patients. Local antifungal therapy may permit the delivery of high concentrations of antifungals directly to wounds while minimizing systemic toxicities. However, the field currently lacks suitable in vivo models. Therefore, a large cutaneous wound was created in immunosuppressed mice and inoculated with Aspergillus fumigatus. We fabricated biodegradable polymer microparticles (MPs) that were capable of locally delivering antifungal and characterized in vitro release kinetics. We compared wound bed size, fungal burden, and histological presence of fungi in mice treated with antifungal-loaded MPs. Mice with a cutaneous defect but no infection, mice with infected cutaneous defect but no treatment, and infected mice treated with blank MPs were used as controls. Infection of large wounds inhibited healing and resulted in tissue invasion in an inoculum-dependent manner. MPs were capable of releasing antifungals at concentrations above A. fumigatus Minimum Inhibitory Concentration (MIC) for at least 6 days. Wounds treated with MPs had significantly decreased size compared with no treatment (64.2% vs. 19.4% wound reduction, p = 0.002) and were not significantly different from uninfected controls (64.2% vs. 58.1%, p = 0.497). This murine model may serve to better understand cutaneous fungal infection and evaluate local biomaterials-based therapies. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1867-1874, 2019.

Improvement in infected wound healing in type 1 diabetic rat by the synergistic effect of photobiomodulation therapy and conditioned medium.

We investigated the effects of photobiomodulation therapy (PBMT) and conditioned medium (CM) of human bone marrow mesenchymal stem cells (hBM-MSC) individually and/or in combination on the stereological parameters and the expression of basic fibroblast growth factor (bFGF), hypoxia-inducible factor (HIF-1α), and stromal cell-derived factor-1α (SDF-1α) in a wound model infected with methicillin-resistant Staphylococcus aureus (MRSA) in diabetic rats. CM was provided by culturing hBM-MSCs. Type 1 diabetes mellitus (T1DM) was induced in 72 rats, divided into four groups, harboring 18 rats each: group 1 served as a control group, group 2 received PBMT, group 3 received CM, and group 4 received CM + PBMT. On days 4, 7, and 15, six animals from each group were euthanized and the skin samples were separated for stereology examination and gene expression analysis by real-time polymerase chain reaction. In the CM + PBMT, CM, and PBMT groups, significant decreases were induced in the number of neutrophils (1460 ± 93, 1854 ± 138, 1719 ± 248) and macrophages (539 ± 69, 804 ± 63, 912 ± 41), and significant increases in the number of fibroblasts (1073 ± 116, 836 ± 75, 912 ± 41) and angiogenesis (15 230 ± 516, 13 318 ± 1116, 14 041 ± 867), compared with those of the control group (2690 ± 371, 1139 ± 145, 566 ± 90, 12 585 ± 1219). Interestingly, the findings of the stereological examination in the CM + PBMT group were statistically more significant than those in the other groups. In the PBMT group, in most cases, the expression of bFGF, HIF-1α, and SDF-1α, on day 4 (27.7 ± 0.14, 28.8 ± 0.52, 27.5 ± 0.54) and day 7 (26.8 ± 1.4, 29.6 ± 1.4, 28.3 ± 1.2) were more significant than those in the control (day 4, 19.3 ± 0.42, 25.5 ± 0.08, 22.6 ± 0.04; day 7, 22.3 ± 0.22, 28.3 ± 0.59, 24.3 ± 0.19) and other treatment groups. The application of PBMT + CM induced anti-inflammatory and angiogenic activities, and hastened wound healing process in a T1 DM model of MRSA infected wound.

Drawbacks of the use of cotrimoxazole in foreign-body infections.

INTRODUCTION: The anti-staphylococcal efficacy of cotrimoxazole in the setting of difficult-to-treat infections seems to be compromised by large amounts of pus and devitalized tissue, and, therefore, high levels of thymidine. Our objective was to evaluate the activity of cotrimoxazole against a staphylococcal foreign-body infection experimental model, which also yields significant quantities of thymidine. MATERIAL AND METHODS: We used a rat tissue-cage model of infection (with high inherent thymidine levels) caused by a strain of methicillin-susceptible Staphylococcus aureus (MSSA; ATCC 29213). MIC values were determined (microdilution method) and compared in the presence or absence of tissue-cage fluid samples. RESULTS: The inefficacy of cotrimoxazole was found to be similar to that of the control group. The MIC of cotrimoxazole was 4-8 fold higher in the presence of rat tissue-cage fluid. CONCLUSIONS: The inefficacy of cotrimoxazole in our foreign-body infection model by MSSA, and the probable negative impact of the presence of thymidine on its efficacy, challenge the use of this drug in acute phases of foreign-body infections. It should be reserved as an alternative treatment when the infection is more controlled.

Topical antimicrobial photodynamic therapy improves angiogenesis in wounds of diabetic mice.

We report the results of our investigations on the effect of antimicrobial photodynamic therapy (APDT) on angiogenesis in wounds of diabetic mice. For this, measurements were made on levels of nitric oxide (NO), vascular endothelial growth factor-A (VEGF-A), and markers of proinflammatory stress (phosphorylated nuclear factor kappa B and p(38) mitogen-activated protein kinase) on day 3 post-wounding. For uninfected and infected wounds, the levels of NO, VEGF-A were lower and the levels of phospho-NF-kB-p65, phospho-p(38)MAPK were higher in diabetic mice compared with that in nondiabetic mice. For infected wounds, multiple APDT (fluence ~60 J/cm(2)) led to increase in NO, VEGF-A levels and a decrease in the phospho-NF-kB-p65, phospho-p(38)MAPK. Further, compared with aminoguanidine, and silver nitrate, multiple APDT was observed to result in a much improved proangiogenic response.

Silver-zinc redox-coupled electroceutical wound dressing disrupts bacterial biofilm.

Pseudomonas aeruginosa biofilm is commonly associated with chronic wound infection. A FDA approved wireless electroceutical dressing (WED), which in the presence of conductive wound exudate gets activated to generate electric field (0.3-0.9V), was investigated for its anti-biofilm properties. Growth of pathogenic P. aeruginosa strain PAO1 in LB media was markedly arrested in the presence of the WED. Scanning electron microscopy demonstrated that WED markedly disrupted biofilm integrity in a setting where silver dressing was ineffective. Biofilm thickness and number of live bacterial cells were decreased in the presence of WED. Quorum sensing genes lasR and rhlR and activity of electric field sensitive enzyme, glycerol-3-phosphate dehydrogenase was also repressed by WED. This work provides first electron paramagnetic resonance spectroscopy evidence demonstrating that WED serves as a spontaneous source of reactive oxygen species. Redox-sensitive multidrug efflux systems mexAB and mexEF were repressed by WED. Taken together, these observations provide first evidence supporting the anti-biofilm properties of WED.

A comparative study of the in vitro permeation characteristic of sulphadiazine across synthetic membranes and eschar tissue.

Infections of burn wounds are the source of significant problems in burn patients. Early excision of eschar tissue is an ideal solution to avoid sepsis. When early excision is not feasible, the application of topical antimicrobial formulations may be used to control burn wound sepsis. An understanding of the barrier properties of eschar tissue is essential for optimal design of topical antimicrobial formulations. To date, little research has been conducted on the permeability of eschar. Silver sulphadiazine (SSD) is the most frequently used topical agent in burn management. In this study, the permeation of sulphadiazine from aqueous saturated solutions of SSD through human full-thickness burn eschar tissue was studied and compared with permeability through silicone and Carbosil as model membranes. The permeation of sulphadiazine through eschar tissue was significantly higher than that through silicone and Carbosil membranes (P < 0.05). Deconvolution of the data showed that the apparent sulphadiazine diffusion coefficient was much higher in eschar tissue and was comparable to transport through an aqueous protein gel. Further studies on a greater number of compounds are suggested to elucidate the utility of such membranes as predictive models of drug permeability through eschar tissue.

Wound pathophysiology, infection and therapeutic options.

Wound healing is a complex and highly regulated process that can be compromised by both endogenous factors (pathophysiological) and exogenous factors (micro-organisms). Microbial colonisation of both acute and chronic wounds is inevitable, and in most situations endogenous bacteria predominate, many of which are potentially pathogenic in the wound environment. The risk of wound infection increases as local conditions favour bacterial growth rather than host defence. Consequently a primary objective in wound management is to redress the host-bacterial balance, and this is most effectively achieved by ensuring that the wound is cleared of devitalised tissue and foreign bodies, the bacterial load and inflammation are controlled, and that adequate tissue perfusion is maintained. Although surgical debridement is the most rapid and effective technique for removing devitalised tissue, topical enzymes, moisture-retentive dressings, biosurgical therapy and vacuum therapy have been used as alternative approaches to wound cleansing and preparation. Topical antimicrobial agents continue to be used widely for preventing wound infection and current interest is focused on alternatives to antibiotics, such as antimicrobial moisture-retentive dressings, honey, essential oils and cationic peptides. In addition to the need to control wound microflora, unregulated inflammation caused by both micro-organisms and underlying abnormal pathophysiological conditions is a major factor associated with poor healing in chronic wounds. Consequently, therapeutic strategies that target chronic inflammatory processes are critical to wound progression. The success of future therapies will be dependent on a growing understanding of the pathophysiological processes and the host-bacterial interactions that significantly influence wound healing.

[Use of pefloxacin in the treatment of infected burn wounds]. / Primenenie pefloksatsina dlia lecheniia infitsirovannykh ozhogovykh ran.

The efficacy of a home-made pefloxacin was estimated in clinico-laboratory trials including 25 patients with wound infection. The fluoroquinolone was used in a dose of 400 mg administered orally twice a day for 4-16 days. Good and satisfactory results were stated in 24 patients (96 per cent). The isolates from the patients were mainly susceptible to the drug (86.2 per cent). The bacteriological efficacy amounted to 92 per cent. No side effects to the use of pefloxacin were observed.

[The immunohistochemical study of suppurative wounds in rats following the application of collagenase from the crab Paralithodes camtschatica]. / Immunogistokhimicheskoe izuchenie gnoinykh ran u krys posle applikatsii kollagenazy kraba Paralithodes camtschatica.

Immunohistochemical study of tissues of purulent wounds in rats after application of the collagenase isolated from the king crab Paralithodes camtschatica has been undertaken. The enzyme therapy resulted in a rapid and efficient removal of necrotic debris. It was accompanied by fibrin elimination from the wound bottom and subsequent formation of new capillaries. Cellular fibronectin with ED-A sequence was identified in the newly formed granulation tissue, which points to its active synthesis in situ. Detection of type I collagen in granulation tissue revealed that wound treatment with crab collagenase had no impact on the development process of the tissue. Polyclonal antibodies against two isozymes of crab collagenolytic protease were obtained. It was shown that after application of both isozymes of the collagenase were accumulated in fibrin deposits at the wound bottom but not penetrated in adherent granulation tissue. These processes underlie the therapeutic effect of the crab collagenase.

[The chemoluminescence of the primary focus of a suppurative infection and of isolated neutrophils exposed to dimephosphon]. / Khemiliuminestsentsiia pervichnogo ochaga gnoinoi infektsii i izolirovannykh neitrofilov pri vozdeistvii dimefosfona.

The influence of dimephosphone at concentrations of 0.001 M-0.75 M on the chemiluminescence of tissues at the focus of purulent infection in the ear of a guinea pig, on the survival rate of the experimental animals injected with the lethal dose of Staphylococcus aureus, as well as on the spontaneous and stimulated chemiluminescence of blood neutrophils in patients with wound infection, was studied. The study showed that different concentrations of dimephosphone oppositely influenced the intensity of the chemiluminescence of neutrophil suspensions and tissues at the focus of infection: low concentrations were found to produce stimulating action and high concentrations, suppressive action. At the highest concentration used in this study (0.75 M) dimephosphone prevented the death of the animals receiving lethal doses of S. aureus.

[The effect of the disodium salt of ethylenediaminetetraacetate on the healing of experimental suppurative wounds]. / Vliianie dinatrievoi soli étilendiaminotetraatsetata na zazhivlenie éksperimental'nykh gnoinykh ran.

EDTA was shown to influence the cicatrisation of experimental purulent wounds. The substance accelerated the wound purification with necrotic tissues elimination. Therapeutic effect increased in cases of combined EDTA and dioxidine application.

[The interrelationship between serotonin and lipid peroxidation products during experimental wound healing]. / Vzaimosviaz' serotonina i produktov lipoperoksidatsii v protsesse zazhivleniia ran v éksperimente.

On 220 male Wistar rats with models of aseptic and contaminated skin wounds the authors studied interrelationship between serotonin and hydroperoxide in the wound tissues and the blood. A comparative analysis of the changes of these indices in the blood and tissues showed that the degree of these disorders on the 1st day after the operation was determined by operational trauma and with the development of purulent inflammation intensive initiation of lipoperoxidation products takes place.

Nutritional care of the injured and/or septic patient.

Nutritional therapy is influence both by disease and nutritional status. In addition, the degree of protein depletion in large part dictates the urgency of aggressive nutritional therapy. The presenceof hypermetabolism where the hormonal substrate response is distinctly antagonistic to replacement therapy precludes effective repair of nutritional depletion. Sepsis further antagonizes efforts at nutritional support. For these reasons no elective or semielective procedure that carries a risk of prolonged stress, hypermetabolism, and sepsis should be performed until adequate nutritional status has been obtained. Enteral feeding programs are to be preferred due to their risk-benefit and cost-benefit ratios. However, impaired digestive function related to disease often limits their use and reliance on parenteral nutrition becomes necessary. While each patient has unique needs and responses, a systematic approach based on objective measurements will most often result in effective nutritional therapy. The accomplished therapist will apply the "modular" approach using the wide variety of products and techniques now available. Ignoring the support of protein synthesis and the preservation of lean body mass can no longer be considered good patient care even in the management of the semistarved state. There is no longer any justification for allowing nosocomial malnutrition to alter the morbidity and mortality of disease. With proper skills in the techniques of protein-calorie therapy and the availability of adequate techniques for nutritional assessment, the science of nutritional therapy now affords the opportunity to provide optimal care for the injured hospitalized patient.