Polyvinyl Sponge Research Articles

Poly (ε-caprolactone) microspheres for prolonged release of selenium nanoparticles

Poly (ε-caprolactone) (PCL) microspheres as a carrier for sustained release of antibacterial agent, selenium nanoparticles (SeNPs), were developed. The obtained PCL/SeNPs microspheres were in the range 1–4 μm with the encapsulation efficiency of about 90%. The degradation process and release behavior of SeNPs from PCL microspheres were investigated in five different degradation media: phosphate buffer solution (PBS), a solution of lipase isolated from the porcine pancreas in PBS, 0.1 M hydrochloric acid (HCl), Pseudomonas aeruginosa PAO1 cell-free extract in PBS and implant fluid (exudate) from the subcutaneously implanted sterile polyvinyl sponges which induce a foreign-body inflammatory reaction. The samples were thoroughly characterized by SEM, TEM, FTIR, XRD, PSA, DSC, confocal microscopy, and ICP-OES techniques. Under physiological conditions at neutral pH, a very slow release of SeNPs occurred (3 and 8% in the case of PBS or PBS + lipase, respectively and after 660 days), while in the acidic environment their presence was not detected. On the other hand, the release in the medium with bacterial extract was much more pronounced, even after 24 h (13%). After 7 days, the concentration of SeNPs reached a maximum of around 30%. Also, 37% of SeNPs have been released after 11 days of incubation of PCL/SeNPs in the implant exudate. These results suggest that the release of SeNPs from PCL was triggered by Pseudomonas aeruginosa PAO1 bacterium as well as by foreign body inflammatory reaction to implant. Furthermore, PCL/SeNPs microspheres were investigated in terms of their biocompatibility. For this purpose, cytotoxicity, the formation of reactive oxygen species (ROS), and genotoxicity were evaluated on HepG2 cell line. The interaction of PCL/SeNPs with phagocytic cell line (Raw 264.7 macrophages) was monitored as well. It was found that the microspheres in investigated concentration range had no acute cytotoxic effects. Finally, SeNPs, as well as PCL/SeNPs, showed a considerable antibacterial activity against Gram-positive bacteria: Staphylococcus aureus (ATCC 25923) and Staphylococcus epidermidis (ATCC 1228). These results suggest that PCL/SeNPs-based system could be an attractive platform for a prolonged prevention of infections accompanying implants.

Warfarin affects acute inflammatory response induced by subcutaneous polyvinyl sponge implantation in rats

Purpose: Warfarin (WF) is an anticoagulant which also affects physiological processes other than hemostasis. Our previous investigations showed the effect of WF which gained access to the organism via skin on resting peripheral blood granulocytes. Based on these data, the aim of the present study was to examine whether WF could modulate the inflammatory processes as well. To this aim the effect of WF on the inflammatory response induced by subcutaneous sponge implantation in rats was examined.Materials and methods: Warfarin-soaked polyvinyl sponges (WF-sponges) were implanted subcutaneously and cell infiltration into sponges, the levels of nitric oxide (NO) and inflammatory cytokines tumor necrosis factor (TNF) and interleukin-6 (IL-6) production by sponge cells were measured as parameters of inflammation. T cell infiltration and cytokine interferon-γ (IFN-γ), interleukin-17 (IL-17) and interleukin-10 (IL-10) were measured at day 7 post implantation.Results: Warfarin exerted both stimulatory and suppressive effects depending on the parameter examined. Flow cytometry of cells recovered from sponges showed higher numbers of granulocytes (HIS48+ cells) at days 1 and 3 post implantation and CD11b+ cells at day 1 compared to control sponges. Cells from WF-sponges had an increased NO production (Griess reaction) at days 1 and 7. In contrast, lower levels of TNF (measured by ELISA) production by cells recovered from WF-soaked sponges were found in the early (day one) phase of reaction with unchanged levels at other time points. While IL-6 production by cells recovered from WF-soaked sponges was decreased at day 1, it was increased at day 7. Higher T cell numbers were noted in WF sponges at day 7 post implantation, and recovered cells produced more IFN-γ and IL-17, while IL-10 production remained unchanged.Conclusions: Warfarin affects some of the parameters of inflammatory reaction induced by subcutaneous polyvinyl sponge implantation. Differential (both stimulatory as well as inhibitory) effects of WF on inflammatory response to sponge implants might affect the course and/or duration of this reaction.

Different role of nitric oxide on adhesiveness and apoptosis of inflammatory granulocytes after burn injury

Event Abstract Back to Event Different role of nitric oxide on adhesiveness and apoptosis of inflammatory granulocytes after burn injury Biljana Draskovic-Pavlovic1, 2*, Dragana Vucevic1, 2, Ivana Majstorovic1, Biljana Bozic3, Gordana Zunic1, 2 and Miodrag Colic2 1 Institute for Medical Research Military Medical Academy, Serbia 2 Medical Faculty of the Military Medical Academy, University of Defense, Serbia 3 Institute for Physiology and Biochemistry, Faculty of Biology, Serbia Nitric oxide (NO) is an important mediator of inflammatory reaction. Our previous studies showed increased production of NO at the wound site after burn injury. At the same time we found decreased adhesiveness and apoptosis rate of inflammatory granulocytes (Gr) ex vivo and in cultures. The aim of this study was to investigate the influence of locally originated NO on adhesion and apoptosis of inflammatory Gr at the wound site after burn injury. Inbred Albino Oxford rats were subjected to non-lethal, full-thickness burn injury. Immediately after injuring, sterile polyvinyl sponges were implanted subcutaneously on the borderline of the burned skin in order to obtain inflammatory Gr. Control group were animals implanted with sterile sponges only. In vivo application of aminoguanidin (AG), a specific inhibitor of inducible nitric oxide synthase (iNOS), resulted in increased apoptosis rate of inflammatory Gr from control animals, while this treatment was ineffective in burn injured animals. In regard to Gr adhesiveness, in vivo AG treatment had an opposite effect manifested by stimulation of inflammatory Gr adhesion from burn injured rats, while adhesiveness of Gr from control animals was unchanged. Cumulatively, these results indicate that locally produced NO contribute to the inhibition of Gr adhesiveness without significant influence on apoptosis rate of these cells at the wound site after burn injury. Acknowledgements This study was supported by the project of Ministry of Defense of the Republic of Serbia (MFVMA/4/12-14). Keywords: Granulocytes, injury, Nitric Oxide, Adhesion, Apoptosis Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Innate immunity Citation: Draskovic-Pavlovic B, Vucevic D, Majstorovic I, Bozic B, Zunic G and Colic M (2013). Different role of nitric oxide on adhesiveness and apoptosis of inflammatory granulocytes after burn injury. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00200 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 11 Mar 2013; Published Online: 22 Aug 2013. * Correspondence: Dr. Biljana Draskovic-Pavlovic, Institute for Medical Research Military Medical Academy, Belgrade, Serbia, biljadp@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Biljana Draskovic-Pavlovic Dragana Vucevic Ivana Majstorovic Biljana Bozic Gordana Zunic Miodrag Colic Google Biljana Draskovic-Pavlovic Dragana Vucevic Ivana Majstorovic Biljana Bozic Gordana Zunic Miodrag Colic Google Scholar Biljana Draskovic-Pavlovic Dragana Vucevic Ivana Majstorovic Biljana Bozic Gordana Zunic Miodrag Colic PubMed Biljana Draskovic-Pavlovic Dragana Vucevic Ivana Majstorovic Biljana Bozic Gordana Zunic Miodrag Colic Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Accumulation of tolerogenic cells at the site of granulomatous foreign-body reaction

Event Abstract Back to Event Accumulation of tolerogenic cells at the site of granulomatous foreign-body reaction Dragana Vucevic1, 2*, Sasa Vasilijic1, 2, Jelena Djokic1, Biljana Bozic3, Ivana Majstorovic1, Sergej Tomic2, Milijana Vasiljevska1, Biljana Draskovic-Pavlovic1, 2 and Miodrag Colic2 1 Institute for Medical Research Military Medical Academy, Serbia 2 Medical Faculty of the Military Medical Academy, University of Defense, Serbia 3 Faculty of Biology, Institute for Physiology and Biochemistry, Serbia The granulomatous foreign-body reaction (GFBR) is a special type of chronic inflammation characterised by infiltration of inflammatory cells (ICs). Using a model of subcutaneous implantation of polyvinyl sponges in rats, we studied the phenotypic and functional characteristics of these cells, with particular reference to the properties of antigen presenting cells and lymphocytes. ICs were isolated from sponge exudates at days 1-21 after implantation. Dendritic cells (DCs) and lymphocytes were purified using a combination of separation gradients, adherence to plastics, and immunomagnetic sorting. We showed that dominant population of ICs at day 1 and 3 were granulocytes, followed by their decrease thereafter. The number of mononuclear cells (MNCs), macrophages and DCs, progressively increased after day 3, reaching maximal values at day 7. Maximal number of lymphocytes was detected at day 10. In addition, total ICs isolated from day 7 till day 10 exerted significant suppressive activity in co-culture with autologous ConA-stimulated thymocytes and alogeneic lymph node T cells. This finding correlated with the increased level of IL-10 in culture supernatants and the increased proportion MHC class II+ IDO+ DCs and CD3+ CD25+ Foxp3+ lymphocytes at day 7 and day 10, respectively. We did not find any significant difference in the number of these cell populations between regional lymph nodes MNCs and peripheral blood MNCs of experimental animals compared to controls. In conclusion, accumulation of cells with tolerogenic characteristics in GFBR might be relevant for the suppression of inflammation and the prevention of unwanted immune response. Keywords: granulomatous foreign-body reaction, Dendritic Cells, regulatory T cells, Lymph Node, chronic inflammation Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Adaptive Immunity Citation: Vucevic D, Vasilijic S, Djokic J, Bozic B, Majstorovic I, Tomic S, Vasiljevska M, Draskovic-Pavlovic B and Colic M (2013). Accumulation of tolerogenic cells at the site of granulomatous foreign-body reaction. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00029 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 Mar 2013; Published Online: 22 Aug 2013. * Correspondence: Prof. Dragana Vucevic, Institute for Medical Research Military Medical Academy, Belgrade, Serbia, draganavucevic@yahoo.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Dragana Vucevic Sasa Vasilijic Jelena Djokic Biljana Bozic Ivana Majstorovic Sergej Tomic Milijana Vasiljevska Biljana Draskovic-Pavlovic Miodrag Colic Google Dragana Vucevic Sasa Vasilijic Jelena Djokic Biljana Bozic Ivana Majstorovic Sergej Tomic Milijana Vasiljevska Biljana Draskovic-Pavlovic Miodrag Colic Google Scholar Dragana Vucevic Sasa Vasilijic Jelena Djokic Biljana Bozic Ivana Majstorovic Sergej Tomic Milijana Vasiljevska Biljana Draskovic-Pavlovic Miodrag Colic PubMed Dragana Vucevic Sasa Vasilijic Jelena Djokic Biljana Bozic Ivana Majstorovic Sergej Tomic Milijana Vasiljevska Biljana Draskovic-Pavlovic Miodrag Colic Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Biocompatibility of orthodontic adhesives in rat subcutaneous tissue

ObjectiveThe objective of the present study was to verify the hypothesis that no difference in biocompatibility exists between different orthodontic adhesives.Material and MethodsThirty male Wistar rats were used in this study and divided into five groups (n=6): Group 1 (control, distilled water), Group 2 (Concise), Group 3 (Xeno III), Group 4 (Transbond XT), and Group 5 (Transbond plus Self-Etching Primer). Two cavities were performed in the subcutaneous dorsum of each animal to place a polyvinyl sponge soaked with 2 drops of the respective adhesive in each surgical loci. Two animals of each group were sacrificed after 7, 15, and 30 days, and their tissues were analyzed by using an optical microscope.ResultsAt day 7, Groups 3 (Transbond XT) and 4 (Xeno III) showed intense mono- and polymorphonuclear inflammatory infiltrate with no differences between them, whereas Groups 1 (control) and 2 (Concise) showed moderate mononuclear inflammatory infiltrate. At day 15, severe inflammation was observed in Group 3 (Transbond XT) compared to other groups. At day 30, the same group showed a more expressive mononuclear inflammatory infiltrate compared to other groups.ConclusionAmong the orthodontic adhesive analyzed, it may be concluded that Transbond XT exhibited the worst biocompatibility. However, one cannot interpret the specificity of the data generated in vivo animal models as a human response.

Increased nitric oxide formation followed by increased arginase activity induces relative lack of arginine at the wound site and alters whole nutritional status in rats almost within the early healing period

Nitric oxide (NO) production and free amino acid fluxes at the wound side during the first 3 days following cutaneous wound were investigated. Experiments were performed on Albino Oxford rats ( n = 18) underwent cutaneous implantation of polyvinyl sponges. Intact animals ( n = 6) were controls. Nitrites, nitrates, free amino acids and urea were measured both in plasma and wound fluids. Inducible nitric oxide synthase (iNOS) gene expressions at wound site were analyzed, too. The highest levels of both iNOS gene expression and its activity (increased wound fluid citrulline and nitrites) were at the first day. Wound fluid nitrates were significantly above plasma levels throughout the whole period, while molar nitrate to nitrite ratio steadily increased. It was associated with gradual increase of both ornithine and urea as well as steadily decreases of arginine and increases of phenylalanine at the wound site. Gradual decrease in glycine to branched-chain molar ratio was observed both in plasma and wound fluids. In conclusion, an early locally induced alterations in Arg metabolism, due to increased NO formation followed by increased arginase activity, produces relative lack of Arg at the wound site and disturbs nutritional status of the whole body almost within early healing period following cutaneous wound in rats. It is likely that NO autoxidation at the wound side is influenced by substrate availability.

THE EFFECT OF NITRO-ASPIRINS (NCX4016 AND NCX4040) ON THE APOPTOSIS OF RAT NEUTROPHILS IN VIVO

Non-steroidal anti-inflammatory drugs (NSAID) are widely used as anti-inflammatory agents, but they have serious side effects. In an attempt to reduce these side effects, a series of new compounds have been recently synthesized in which a nitric oxide (NO)-releasing group has been linked to the parent NSAID. Among them are nitro-aspirins NCX-4016 and NCX-4040. Apoptosis of inflammatory cells is a critical event in the resolution of inflammation and manipulation of the apoptosis could be of therapeutic benefit. We studied the effect of aspirin and its nitro derivatives, NCX4016 and NCX4040, on the apoptosis of the neutrophils in vivo. We used a model of inflammation by implanting polyvinyl sponges under the skin of Albino Oxford (AO) rats. Apoptosis was measured 6 and 24 hours after implantation of the sponges and application of aspirin or nitro-aspirins. Apoptosis was detected by morphological criteria after the fixation and staining the cells with Turk reagent. Also, we measured the production of NO in inflammatory exudate and in supernatants of these cells. We found that inflammatory exudate in vitro in a statistically significant manner, decreased spontaneous apoptosis as well as apoptosis induced by nitro-aspirins. In vivo the NCX4040 induced apoptosis of the neutrophils in lower concentration than NCX4016. These nitro-aspirins could be new powerful drugs for use in human and veterinary medicine.

The effect of a new nitro-aspirin on apoptosis of neutrophil granulocytes

Apoptosis of neutrophil granulocytes is a critical event in the resolution of inflammation. Neutrophils have a short lifespan which can be modulated by aspirin. In this work we studied the effect of a nitroaspirin (NCX4040) on apoptosis of inflammatory granulocytes. This nitro-aspirin has been synthesized in attempt to reduce the side effects of aspirin in the gastrointestinal tract. Inflammatory granulocytes have been isolated from polyvinyl sponges implanted under the skin of Albino Oxford (AO) rats. Inflammatory cells that were isolated 20 hours later were about 95% neutrophil granulocytes. The cells were cultivated 24h with different concentrations of NCX4040 ranging from 0.01 μM to 10μM. After that period, apoptosis of neutrophils was performed by using morphological criteria, as well as by flow cytometry (after staining the cells with propidium iodide). We found that NCX4040 at concentrations from 0.25 to 10 μM induced the apoptosis of rat inflammatory granulocytes in a dose-dependent manner. Also, in these concentrations NCX4040 decreased production of nitric oxide in the cells culture supernatants. In conclusion, our results suggest that antiinflammatory properties of NO-aspirins are additionally potentiated by their proapoptotic effect on granulocytes, which could be a novel mechanism of their action.

In VivoPulmonary Tissue Engineering: Contribution of Donor-Derived Endothelial Cells to Construct Vascularization*

Intrapulmonary engraftment of engineered lung tissues could provide a potential therapeutic approach for the treatment of pediatric and adult pulmonary diseases. In working toward this goal, we report here on in vivo generation of vascularized pulmonary tissue constructs utilizing the subcutaneous Matrigel plug model. Mixed populations of murine fetal pulmonary cells (FPCs) containing epithelial, mesenchymal, and endothelial cells (ECs) were isolated from the lungs of embryonic day 17.5 fetuses. FPCs were admixed to Matrigel and injected subcutaneously into the anterior abdominal wall of adult C57/BL6 mice to facilitate in vivo pulmonary tissue construct formation. Vascularization was enhanced by placing fibroblast growth factor 2 (FGF2)-loaded polyvinyl sponges into the hydrogel. After 1 week, routine histology and immunohistochemical staining for donor-derived epithelial cells and ECs as well as analysis of patent vasculature in the constructs following tail vein injection of fluorescein isothiocyanate-conjugated dextran were performed. In the Matrigel-only controls, some level of host infiltrate, but no measurable vascularization, was detected. In the presence of FPCs, the constructs contained ductal epithelial structures and patent vasculature. In the absence of FPCs, exogenous FGF2 induced the formation of numerous patent blood vessels throughout the entire constructs; in combination with FPCs, it resulted in enhanced capillary density and abundant interfacing between developing epithelial and vascular structures. The significant findings of this study are that distal pulmonary epithelial differentiation (as assessed by the expression of prosurfactant protein C) can be maintained in vivo and that donor-derived ECs contribute to the formation of patent vessels that interface tightly with ductal epithelial structures.

The effect of a nitro-aspirine on apoptosis of neutrophil granulocytes

Apoptosis of neutrophil granulocytes is a critical event in the resolution of inflammation. Neutrophils have a short lifespan which can be modulated by aspirin. In this work we studied the effect of a nitroaspirin (NCX4016) on apoptosis of inflammatory granulocytes. This aspirin analogue has been synthesized to reduce the side effects of aspirin in the gastrointestinal tract. Inflammatory granulocytes have been isolated from polyvinyl sponges implanted under the skin of Albino Oxford (AO) rats. Inflammatory cells that were isolated 20 hours later were about 95% neutrophil granulocytes. The cells were cultivated 24h with different concentrations of NCX4016 ranging from 0.25 μM to 500 μM. After that period, apoptosis of neutrophils was assessed by morphological criteria, as well as by flow cytometry (after staining the cells with propidium iodide). We found that NCX4016 at concentrations from 50 to 500 μM induced the apoptosis of rat inflammatory granulocytes in a dose-dependent manner. However, at concentrations from 1 μM to 10 μM it inhibited apoptosis. In conclusion, our results suggest that anti-inflammatory properties of the NO-aspirin are additionally potentiated by the proapoptotic effect on granulocytes, which could be a novel mechanism of their action.

Vakuumtherapie in der Behandlung desaströser Wundverhältnisse bei Morbus Madelung

A 54 year old patient presented with a Madelung disease. Symmetrically fatty deposits were present on both upper arms, at the abdomen and both thighs. Dermatitis was seen in the axillary fold at the skin bearing surfaces. Shoulder movement was impaired. Liposuction of both upper arms has already been performed, but no significant improvement was obtained. We performed a dermolipectomy of both upper arms. Postoperatively the patient suffered from a severe wound dehiscence with fulminant wound infection and septic clinical condition. Because of the large wound surface ((1/3) of the upper arm circumference) anemia occurred and had to be treated with blood transfusions. Wound exsudation caused a general hypoproteinemia. Multiple surgical debridements were necessary in order to clean the wound from necrotic tissue and afterwards moist dressings were applied. Furthermore the patient received intravenous antibiotic treatment. After stabilisation of the general condition of the patient and the wound situation a polyvinyl sponge and a vacuum-sealing were applied and continuous suction was performed (125 mm Hg). This resulted in a significant improvement of the wound situation in regards to wound cleaning, induction of granulation tissue, diminished wound size, reduction of oedema and pain reduction. After four weeks of vacuum therapy defect coverage was possible and split thickness skin grafting was performed. The skin graft was attached to the wound using a vacuum-dressing. After removal of the vacuum dressing on the fifth day the skin graft has completely healed. Vacuum therapy is suitable for disastrous wound conditions in order to achieve a defect size reduction, pain reduction and create a clean wound with granulation tissue for further surgical defect coverage using skin grafts or flaps.

Die V.A.C.®-Therapie als Behandlungsoption von Wundheilungsstörungen nach Achillessehnenrekonstruktion

The postoperative course after Achilles tendon reconstruction is associated with a high incidence rate of infections and wound healing complications, which can lead to protracted healing process and, hence, limit the clinical outcome. PATIENT-METHODS: A 66-year-old male was referred to our clinic with an Achilles tendon rupture. MRI confirmed the diagnosis, an augmented tenoplasty was performed for tendon reconstruction. 11 weeks after surgery the patient presented himself again with an open wound and local infection signs. The surgical treatment included debridement and jet lavage. The V.A.C.-device with the white polyvinyl sponge at an initial pressure of 200 mm Hg was used. A pathogen organism could not be identified. For infection eradication a broad spectrum systemic antibiosis (cefuroxime and gentamicin) was applied. On 3., 6. and 14. day the dressings were changed and the wound was revised under progredient closure. At beginning formation of granulation tissue the pressure was reduced to 150-100 mm Hg. At decreasing blood inflammation parameters and amelioration of the local wound condition the patient could check out after 3 weeks hospitalization. After further successful ambulant management by means of the V.A.C.-therapy a meshgraft transplantation was performed (enlargement factor 1.5; layer thickness 0.3 mm). The V.A.C.-device was applied again at a pressure of 150 mm Hg with a single dressing change after 5 days. At a follow-up of 31 months no further complications occurred. The V.A.C.-therapy seems to be a valuable tool in the treatment of wounds with a critical local vascularity. After successful wound preconditioning the healing process of skin grafts transplants can be also optimised by means of the V.A.C.-device.

The effects of aspirin on apoptosis of neutrophil granulocytes

Neutrophils are a part of the immune system, and they are involved in host defence against microorganisms. Neutrophil granulocytes have the shortest lifespan among leukocytes, which can be modulated by cytokines and pharmacological agents. The effect of aspirin on apoptosis of inflammatory granulocytes has not been studied in detail yet, and therefore was the chosen subject of this study. Inflammatory granulocytes have been isolated from polyvinyl sponges implanted under the skin of Albino Oxford (AO) rats. Inflammatory cells that were isolated 20 hours later were more than 95% neutrophil granulocytes. The cells were cultivated 24 h with different concentrations of aspirin ranging from 1 µM to 10 mM. After the cultivation period, apoptosis of neutrophils was assessed by morphological criteria, as well as by flow cytometry (after staining the cells with propidium iodide). We found that at concentrations from 0,1 mM to 2,5 mM aspirin inhibited apoptosis of granulocytes, but at 10 mM aspirin induced apoptosis of these cells.

Mechanical and humoral factors in wound healing

Summary As wound contraction can be prevented by full-thickness skin graft and enhanced by licking and since saliva contains growth-promoting macromolecules, we have studied the mechanical and humoral aspects of wound healing. Standardized burn and freeze-produced wounds were produced in rats. Contraction did not occur in wounds caused by freezing (n = 30), while burn wounds (n = 30) contracted to less than one-third of the original size in 3 weeks. If the centres of the freeze-produced wounds (n = 12) were excised, contraction would then occur and proceed at the same rate as open wounds (n = 12). The collagen contents of the burn wounds (n = 24) showed a greater initial loss followed by rapid replacement, while that of the freeze-produced wounds (n = 24) demonstrated a slower removal and more gradual replacement. Submandibular sialadenectomized mice (n = 34) and sham controls (n = 34) had excision of a standard sized patch of sacral skin. Through a separate abdominal incision polyvinyl sponges of known weight were introduced subcutaneously into all the animals. Mice without the submandibular salivary glands showed a slower rate of wound contraction than the sham controls (P<0.001). However, this delay in wound contraction was abolished if sialadenectomized mice were caged with mice having intact salivary glands. Collagen synthesis as determined by the hydroxyproline concentrations in the polyvinyl sponges were the same in both groups of animals irrespective of cage environment. Further standard sacral wounds in submandibular sialadenectomized mice (n = 120) were treated with different salivary components. Only high molecular weight nerve growth factor was able to accelerate wound contraction in these sialadenectomized animals to control values. In conclusion, the degree of wound contraction following injury is dependent on the integrity of the matrix, while the initiation of contraction is likely to be chemically induced.

L-Arginine Improves Wound Healing after Trauma-Hemorrhage by Increasing Collagen Synthesis

Several studies indicate impaired wound healing after trauma and shock. Wound immune cell dysfunction seems to be responsible for altered wound healing after trauma-hemorrhage (T-H). In this respect, administration of the amino acid L-arginine normalized wound immune cell function under those conditions. It remains unknown, however, whether L-arginine improves impaired wound healing after T-H. To study this, male C3H/HeN mice were subjected to a midline laparotomy (i.e., soft tissue trauma induced), and polyvinyl sponges were implanted subcutaneously at the wound site before hemorrhage (35 +/- 5 mm Hg for 90 minutes) or were subjected to sham operation. During resuscitation, mice received 300 mg/kg body weight L-arginine or saline (vehicle). Seven days thereafter, hydroxyproline (OHP), a metabolite of collagen synthesis, was measured in the wound fluid using high-performance liquid chromatography. Collagen types I and III were determined in the wound by Western blot analysis. In addition, wound breaking strength was measured 10 days after T-H or sham operation. The results indicate that OHP was significantly decreased in T-H mice. L-arginine, however, restored depressed OHP in the wound fluid in the T-H animals. Similarly, L-arginine treatment prevented a significant depression of collagen I synthesis after T-H. Collagen III was not significantly affected by T-H or L-arginine. Most important, L-arginine increased maximal wound breaking strength after severe blood loss. Therefore, L-arginine improves wound healing after T-H by increasing collagen synthesis. Because L-arginine improves wound healing, the results suggest that L-arginine might represent a novel and useful adjunct to fluid resuscitation for decreasing wound complications after trauma and severe blood loss.

Phase I/II randomized trial of intrahepatic arterial infusion chemotherapy with cisplatin and chemoembolization with cisplatin and polyvinyl sponge in patients with ocular melanoma metastatic to the liver

Ocular melanoma has a unique metastatic predilection for the liver and is refractory to most forms of therapy. The dual blood supply of the liver with differential perfusion of metastatic lesions and normal hepatocytes by the hepatic artery and portal vein, respectively, has led to the evaluation of intrahepatic chemotherapy and chemoembolization in this disease. Despite suggestion of efficacy in phase II trials, this therapy has not been systematically evaluated. The authors conducted a randomized phase I/II trial evaluating escalating doses of intrahepatic chemotherapy with cisplatin with or without polyvinyl sponge (PVS) in 19 patients with ocular melanoma and liver metastases.

Dendritic cells acquire tolerogenic properties at the site of sterile granulomatous inflammation

Subcutaneous implantation of polyvinyl sponges represents a suitable model for studying the mechanisms of acute and chronic inflammation, granulomatous foreign-body reaction, as well as wound healing. Using such a model in rats, we studied the phenotypic and functional characteristics of dendritic cells (DC). DC were purified from the sponge exudate using a combination of separation gradients, adherence to plastics, and immunomagnetic sorting. We have shown that the number of DC progressively increased in the sponges, reaching maximal values at day 10 after implantation, followed by their decrease thereafter. Inflammatory DC expressed MHC class II molecules and myeloid markers CD11b, CD11c, and CD68. A subset of DC expressed CD4, R-MC46, DEC-205, R-MC17, and CCR1. Compared to DC isolated in the early phase of inflammation (day 6 DC), DC in the late stage of inflammation (day 14 DC) had a lower capability to stimulate the proliferation of allogeneic lymphocytes and CD4+ T cells. This finding correlated with the downregulation of CD80, CD86, and CD54 expression and the increased proportion of plasmacytoid MHC class II+ His 24+ His 48+ DC. The suppression of allogeneic lymphocyte proliferation was abrogated by the treatment of DC with lipopolysaccharide. In addition, day 14 DC exerted tolerogenic capability in co-culture with allogenic CD4+ T cells. These results correlated with the increased levels of IL-10 and TGF-β in culture supernatants and the sponge exudate.

Closed subfascial v.a.C.-therapy in periprosthetic hip infections

Infections after hip arthroplasty can lead to protracted and complicated treatments. A great problem is thereby the persistant secretion after surgical revision. 8 patients (3 x after acetabulum cup replacement, 2 x after Girdlestone hip, 2 x after spacer implantation and one case of rearthroplasty) have been treated with a V.A.C.-therapy after bacterial infection and persistant wound secretion. In all cases a pathogen organism could be identified during the frustrated attempts of sanitation. After meticulous debridement and jet lavage in each case, 1-3 polyvinyl sponges have been placed either periprosthetic or in the resection cavity with a transcutan tube outgoing. The wounds have been closed in layers. Initially a pressure of 200 mm Hg via V.A.C. has been attached. After 48-72 h an alteration from haemorrhagic to serous secret could be observed and afterwards the pressure has been reduced to 150 mm Hg. After a mean period of 11 days (8-13) the infection parameters have been retrogressive, the wound secretion was obviously reduced and the sponges were removed. During the remaining hospitalization of each patient no complications occured. In the mean follow-up of 21 months (2-46) no reinfections have been observed. Although the V.A.C.-therapy does not count to the primary therapy concepts of periprosthetic hip infections, it stands for an effective therapy option in exclusive cases.

Physiological Levels of 5α-Dihydrotestosterone Depress Wound Immune Function and Impair Wound Healing Following Trauma-Hemorrhage

Studies indicate that a depressed wound immune function contributes to an increased rate of wound complications and impaired wound healing following trauma-hemorrhage (T-H). Androgen, ie, 5 alpha-dihydrotestosterone, is responsible for producing the depressed systemic cell-mediated immune responses following T-H in males. The aim of the present study was to determine whether depletion of 5 alpha-dihydrotestosterone in males before T-H has any salutary effects on wound immune cell function and wound healing in male mice following T-H. Mice were castrated or sham castrated 14 days before midline laparotomy (ie, tissue trauma) and subcutaneous polyvinyl sponge implantation, followed by hemorrhage (mean +/- SEM blood pressure, 35 +/- 5 mm Hg for 90 minutes and resuscitation) or sham operation. At 24 hours thereafter, wound immune cells from the sponges were harvested and cultured with lipopolysaccharide A. Release of interleukin 1 beta (IL-1 beta) and IL-6 (in picograms per milliliter) was determined in the supernatants by enzyme-linked immunosorbent assay. In addition, IL-6 was assessed at the wound site by immunohistochemistry. Ten days after T-H, wound-breaking strength was measured. Precastration prevented the significantly suppressed capacity of wound immune cells to release IL-1 beta and IL-6. In addition, precastration normalized the elevated IL-6 expression at the wound site in the T-H mice. Moreover, wound-breaking strength was improved in castrated mice 10 days after T-H. Male sex steroids appear to be responsible for wound immune cell dysfunction following trauma and severe blood loss. Because decreasing androgen levels resulted in improved wound healing, our results suggest that the use of androgen receptor-blocking agents, eg, flutamide, following T-H might represent a novel adjunct for decreasing the rate of wound complications under those conditions.

Foreign body giant cell induction in the CSF-1-deficient osteopetrotic ( op/ op) mouse

The osteopetrosis ( op) mutation in mice is characterized by generalized skeletal sclerosis; reduced numbers of osteoclasts, macrophages, and monocytes; and failure to be cured by bone marrow transplantation. This mutation has been shown to result from an absence of colony-stimulating factor-1 (CSF-1) and reported to be cured by treatment with CSF-1. Macrophage polykaryons are known to be formed by fusion of mononuclear precursors and the presence of subcutaneous implants can elicit the formation of macrophage polykaryons. In order to determine if recruitment of foreign body giant cells is also impaired in osteopetrotic mice, tissue reactions to subcutaneously implanted polyvinyl sponges were studied and compared with normal mice. Our result showed that, in the op mouse, recruitment of macrophages and foreign body giant cells in response to the implants was quantitatively not different from that of normal mice. However, these cells were smaller and did not migrate as deeply into the implant as those seen in normal littermates. In contrast, resident macrophages obtained by peritoneal lavage were significantly reduced in op mice. These data indicate that there is a deficiency in the ability of op mice to mount a foreign body giant cell response to an implanted sponge characterized by a deficiency in the recruitment of precursor cells that are capable of either full development and spreading or migration into the implanted sponge. These data add to the emerging appreciation of the regional differences among macrophage populations in their dependence on CSF-1 for differentiation and survival.