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Development of novel therapeutic approaches for wound healing in diabetes

Moura, Liane
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
66.78%
Diabetes mellitus is one of the chronic diseases that affect more people worldwide. Patients with diabetes are susceptible to develop chronic, non-healing diabetic foot ulcers (DFU) which cause pain, suffering, poor quality of life and, in extreme cases, lower extremities amputations. This fact together with the high prevalence of DFU among the diabetic population (around 15%) increases the necessity to find new and more efficient approaches for DFU treatment. Some neuropeptides, such as Substance P (SP) and Neuropeptide Y (NPY), are known to have an important role in the inflammatory, proliferative and reparative processes after tissue injury. However, little is known about the effect of other neuropeptide, neurotensin (NT), in these processes. Recent studies indicated that some of the above referred neuropeptides may act as inflammatory modulators and that may improve the diabetic wound healing process through topical application into wounds. However, one of the major problems associated to the topical administration of peptides, in general and neuropeptides in particular, are their short half-lives and the corresponding loss of bioactivity in the peptidase-rich wound environment. An alternative strategy to overcome these issues can be the use of biocompatible wound dressings for the sustained delivery of these neuropeptides. Some biopolymers such as collagen and chitosan derivatives may be employed for these purposes mostly due to their well known favorable properties and biological behavior...

Cellular and molecular mechanisms of impaired wound healing in diabetes : understanding the role of substance P and mast cells

Tellechea, Ana Luísa Alves
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
66.8%
Diabetes mellitus (DM) é uma das doenças crónicas mais predominantes no Mundo, representando um grave problema de saúde pública. Uma das complicações mais debilitantes e dispendiosas da DM consiste no desenvolvimento de úlceras crónicas, não cicatrizantes, do pé diabético (DFU). Apesar dos esforços para desenvolver novos tratamentos, as terapias actualmente disponíveis são escassas e de eficácia limitada. Assim, compreender as vias complexas e multifactoriais conducentes à cicatrização deficitária de feridas diabéticas (DM) é crucial para identificar novas estratégias terapêuticas para DFU. A neuropatia diabética periférica (DPN), doença vascular periférica (PVD), reduzida resistência a infecção e anomalias bioquímicas são os principais factores de risco para o desenvolvimento de DFU. Além disso, a inflamação sistémica relacionada com DM e a deficiência em neuropeptídeos associada à DPN, foram recentemente propostos como contribuintes importantes para o insucesso na cicatrização. No entanto, a investigação translacional dos mecanismos subjacentes à fisiopatologia da DFU é escassa. Os principais objectivos desta tese são identificar os mecanismos celulares e moleculares através dos quais a inflamação crónica e a deficiência em neuropeptídeos comprometem a cicatrização na DM...

Neurotensin-loaded collagen dressings reduce inflammation and improve wound healing in diabetic mice

Moura, Liane I. F.; Dias, Ana M. A.; Suesca, Edward; Casadiegos, Sergio; Leal, Ermelindo C.; Fontanilla, Marta R.; Carvalho, Lina; Sousa, Hermínio C. de; Carvalho, Eugénia
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.69%
Impaired wound healing is an important clinical problem in diabetes mellitus and results in failure to completely heal diabetic foot ulcers (DFUs), which may lead to lower extremity amputations. In the present study, collagen based dressings were prepared to be applied as support for the delivery of neurotensin (NT), a neuropeptide that acts as an inflammatory modulator in wound healing. The performance of NT alone and NT–loaded collagen matrices to treat wounds in streptozotocin (STZ) diabetic induced mice was evaluated. Results showed that the prepared dressings were not-cytotoxic up to 72 h after contact with macrophages (Raw 264.7) and human keratinocyte (HaCaT) cell lines. Moreover, those cells were shown to adhere to the collagen matrices without noticeable change in their morphology. NT–loaded collagen dressings induced faster healing (17% wound area reduction) in the early phases of wound healing in diabetic wounded mice. In addition, they also significantly reduced inflammatory cytokine expression namely, TNF-α (p < 0.01) and IL-1β (p < 0.01) and decreased the inflammatory infiltrate at day 3 post-wounding (inflammatory phase). After complete healing, metalloproteinase 9 (MMP-9) is reduced in diabetic skin (p < 0.05) which significantly increased fibroblast migration and collagen (collagen type I...

Increased Vascular Permeability, Angiogenesis and Wound Healing Induced by the Serum of Natural Latex of the Rubber Tree Hevea brasiliensis

MENDONCA, Ricardo Jose; MAURICIO, Vanessa Beatriz; TEIXEIRA, Larissa de Bortolli; LACHAT, Joao Jose; COUTINHO-NETTO, Joaquim
Fonte: JOHN WILEY & SONS LTD Publicador: JOHN WILEY & SONS LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.68%
Increases in vascular permeability and angiogenesis are crucial events to wound repair, tumoral growth and revascularization of tissues submitted to ischemia. An increased vascular permeability allows a variety of cytokines and growth factors to reach the damaged tissue. Nevertheless, the angiogenesis supply tissues with a wide variety of nutrients and is also important to metabolites clearance. It has been suggested that the natural latex from Hevea brasiliensis showed wound healing properties and angiogenic activity. Thus, the purpose of this work was to characterize its angiogenic activity and its effects on vascular permeability and wound healing. The serum fraction of the latex was separated from the rubber with reduction of the pH. The activity of the dialyzed serum fraction on the vascular permeability injected in subcutaneous tissue was assayed according Mile`s method. The angiogenic activity was determined using a chick embryo chorioallantoic membrane assay and its effects on the wound-healing process was determined by the rabbit ear dermal ulcer model. The serum fraction showed evident angiogenic effect and it was effective in enhancing vascular permeability. In dermal ulcers, this material significantly accelerated wound healing. Moreover...

Avaliação da reparação tecidual de excisões realizadas em dorso de ratos submetidas à terapia foto-dinâmica com utilização de corante azul de metileno; Wound healing evaluation of excisions performed on the back of rats and submitted to photodynamic therapy mediated by methylene blue dye

Sperandio, Felipe Fornias
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 03/07/2009 PT
Relevância na Pesquisa
66.73%
A terapia foto-dinâmica consiste na irradiação luminosa de um determinado tecido ou microorganismo previamente exposto à ação de um corante foto-sensibilizador. Ela é eficazmente utilizada em neoplasias e em processos infecciosos. No entanto, poucos estudos avaliam o efeito desta terapia em reparação tecidual. Estes trabalhos mostram resultados que variam entre satisfatórios e não-satisfatórios. Além disso, os estudos que envolvem a terapia com laser em baixa intensidade e a terapia foto-dinâmica em reparação tecidual preocupam-se, na maioria das vezes, com a organização e quantificação dos componentes da matriz extra-celular. Estudar o epitélio, em contrapartida, por meio das proteínas expressas pelos queratinócitos é igualmente importante, sabendo-se que a reparação da ferida depende também da organização e proliferação das células epiteliais. Este trabalho avaliou a reparação tecidual de excisões realizadas em dorso de ratos submetidas à irradiação com laser em baixa intensidade ou terapia foto-dinâmica mediada pelo corante azul de metileno. Para tal, realizou-se a análise morfológica e histomorfológica das feridas em determinados tempos experimentais, além da análise imunoistoquímica das citoqueratinas 10 e 14 e p63. Os resultados mostraram que a reparação tecidual foi favorecida com a irradiação laser em baixa intensidade...

Influência de dieta enteral suplementada com arginina e antioxidantes sobre a cicatrização cutânea experimental; Influence of enteral diet supplemented with arginine and antioxidants on experimental cutaneous wound healing

Pereira, Claudia Cristina Alves
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 21/09/2006 PT
Relevância na Pesquisa
66.69%
Introdução: Arginina e antioxidantes estão associados à melhora funcional de cicatrização. Formulação enteral suplementada com arginina e antioxidantes tem sido proposta para corrigir déficit nutricional e garantir substratos ideais para uma boa cicatrização. Ainda não existem informações disponíveis sobre os possíveis mecanismos envolvidos. Objetivo: Avaliar o efeito da nutrição enteral suplementada com arginina e antioxidantes sobre o processo de cicatrização de feridas cutâneas em ratos nutridos e previamente desnutridos, em termos de avaliação morfo-estrutural, bioquímica e biologia molecular. Método: Ratos isogênicos, machos, adultos com peso entre 250 a 350 g, foram divididos aleatoriamente em seis grupos. Três grupos foram mantidos nutridos com alimentação com dieta padrão AIN-93M e três grupos foram submetidos ao regime de desnutrição por 14 dias, com perda de peso corpóreo entre 12 e 15% em relação ao peso corpóreo inicial. Após esse período, os grupos de ratos nutridos e os previamente desnutridos, foram submetidos à lesão cutânea dorsal padronizada e gastrostomia. A seguir, os ratos receberam aleatoriamente dieta por via oral, dieta enteral padrão ou dieta enteral suplementada com arginina e antioxidantes por via gastrostomia...

Uso do laser ALGaInP na cicatrização de lesões cutâneas experimentais em coelhos=Use of ALGaInP laser in the wound healing of experimental cutaneous lesions in rabbits; Use of ALGaInP laser in the wound healing of experimental cutaneous lesions in rabbits

Beheregaray, Wanessa Kruger; Gianotti, Giordano; Leal, Juliano de Souza; Monteiro, Fabiola de Moraes; Simas, Silvana Mello; Elizeire, Mariane Brascher; Contesini, Emerson Antônio
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
POR
Relevância na Pesquisa
66.71%
Background: Animals with extensive cutaneous lesions remain hospitalized for long periods. In addition to increasing treatment costs, this also causes stress in these animals. Low-power laser is widely used to support tissue repair processes. Its use in the treatment of cutaneous wounds has been studied, as it reduces the wound healing period and the consequences caused by the lesion. The study aimed to evaluat the wound healing process of experimental cutaneous wounds in rabbits with the use of laser therapy. Materials, Methods & Results: Ten healthy New Zealand rabbits were used in the study, which were divided in two groups (n=5). Skin biopsies were carried out on day 16 in Group 1 and on day 8 in Group 2. The animals were under general anesthesia for the experimental cutaneous lesion to be carried out. Two 1 cm2 wounds were made on the back of each animal. The lesions were measured by a pachymeter in the immediate postoperative period, then covered with sterile gauze and maintained with rubber bandages. The animals were treated only with Tramadon 3 mg.kg-1 twice a day, during 3 days. Only the lesions on the right side of the animals were irradiated regularly, on each side of the wound, at a distance of 0.5 cm from the margin. The equipment used was a 660 nm wavelength AlGaInP laser diode (Laserpulse...

Células-tronco mesenquimais e eletroacupuntura na cicatrização de lesões cutâneas experimentais em coelhos; Mesenchymal stem cells and electroacupuncture at experimental wound healing in rabbits

Gianotti, Wanessa Krüger Beheregaray
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
66.75%
Durante as duas últimas décadas, têm ocorrido progressos substanciais a respeito do entendimento da fisiopatologia da cicatrização de feridas, e novas terapias tem sido desenvolvidas. Contudo, acelerar o processo de reparo continua sendo um desafio no campo da cirurgia plástica reconstrutiva. Tratamentos inovadores para melhorar a cicatrização e a regeneração cutânea são necessários e é nesse âmbito que as pesquisas com as células-troncos mesenquimais (MSCs) vêm ganhando espaço na última década. As MSCs foram estudadas em diversas áreas no que diz respeito ao seu efeito sobre a cicatrização de lesões e suas aplicações clínicas. Relatos apontam que tanto as MSCs originárias da medula óssea influenciam beneficamente a cicatrização de feridas, quanto originárias do tecido adiposo (ADSCs). A vantagem das ADSCs está na facilidade de serem coletadas, baixas taxas de morbidade e pelo alto rendimento de MSCs por coleta. Estudos demonstram que a eletroacupuntura (passagem de eletricidade através de agulhas de acupuntura inseridas na pele) pode exercer efeito cicatrizante em feridas cutâneas experimentalmente induzidas por meio do aumento da proliferação e da migração de células epiteliais e do tecido conjuntivo envolvidos no reparo de feridas. Dessa forma...

Evaluation of lipoic acid topical application on rats skin wound healing

Guerreiro, Irene Clemes Külkamp; Souza, Marielly Nunes; Bianchin, Mariana Domingues; Isoppo, Mateus; Freitas, Joana Sachetti; Alves, João Alex; Piovezan, Anna Paula; Pohlmann, Adriana Raffin; Guterres, Silvia Stanisçuaski
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
66.69%
PURPOSE: To evaluate the effects of lipoic acid (thioctic acid) topical application on wound healing on rats skin, and the consequences of lipoic acid nanoencapsulation on this process. METHODS: The model used was the healing activity on wounds induced by surgical incision on rats skin (n = 44). The parameters analyzed (11 days) were wound healing rate and histology (vascular proliferation, polymorphonuclear or mononuclear cells, and collagen synthesis or reepithelialization), after application of free lipoic acid or lipoic acid- loaded nanocapsules. The antioxidant activity of these formulations was evaluated by lipid peroxidation test. RESULTS: It was demonstrated for the first time that the topical application of lipoic acid improves wound healing. On the seventh day after surgery, the animals treated with lipoic acid showed increased healing rate (60.7 ± 8.4%) compared to the negative control group (43.0 ± 17.4%), as so improvement of histological parameters. The nanoencapsulation reverted the pro-oxidant activity presented in vitro by lipoic acid, whereas diminished wound repair. CONCLUSIONS: The topical application of lipoic acid produced an increase in the skin wound healing, which may be related to its pro-oxidant activity. On the other hand...

The effect of low intensity laser therapy on wound healing in Streptozotocin-induced diabetic rats

Rabelo, S. Bicalho; Villaverde, A. Balbin; Salgado, M. A. Castilho; Da Silva Melo, M.; Nicolau, R. Amadei; Pacheco, M. T T
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 29-34
ENG
Relevância na Pesquisa
66.7%
Diabetes Mellitus is a condition that results in a delay of the wound healing process, that is associated with an insufficient production of collagen, a decrease of the amount of collagen fibrils and deficient blood flow in the wound area. It is suggested that Low Intensity Laser Therapy acts by improving wound healing in normal organisms, accelerating tissue regeneration. The aim of this work was to investigate the biostimulatory effect of the HeNe laser irradiation, at 632.8 nm, on wound healing in 15 male rats suffering from diabetes induced by Streptozotocin, compared to 15 control diabetic animals. Irradiation parameters were: laser power of 15mW, exposition time of 17 s., irradiated area of 0.025 cm 2 and laser energy density of 10 J/cm 2. Full-thickness skin squared samples, with 5 mm of non-injured tissue around the wound, were obtained at 4, 7 and 15 days after wounding procedure (5 treated and 5 control animals each time). The histopathologic analysis performed by haematoxylin-eosin staining. Results suggested that the irradiation of diabetic rats was efficient for wound healing. Treated group presented better quality of the wound tissues by the macroscopic observation than control group and the microscopic analysis demonstrated that treated animals had better histopathologic evaluation than non treated.

Evaluation of wound healing activity of Ammannia baccifera and Blepharis maderaspatensis leaf extracts on rats

Rajasekaran,Aiyalu; Sivakumar,Vellaichamy; Darlinquine,Sabarimuthu
Fonte: Sociedade Brasileira de Farmacognosia Publicador: Sociedade Brasileira de Farmacognosia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2012 EN
Relevância na Pesquisa
66.73%
Wound healing activity of the leaf extracts of Ammannia baccifera L., Lythraceae, and Blepharis maderaspatensis (L.) B.Heyne ex Roth., Acanthaceae, was investigated by excision and incision wound healing models in rats. A phytochemical screening was done to determine the major constituents of the chloroform, ethyl acetate and ethanolic fractions of ethanolic leaf extracts. The excision and incision models were used to assess the effect of the plant extracts on wound healing in rats. Phytochemical screening reveals the presence of tannins, saponins, steroids, terpenoids, and flavonoids in the extract. The wound healing effect was comparatively evaluated with a standard drug Framycetin cream. Significant wound healing activity was observed for the creams prepared with 5% ethanol fraction of B. maderaspatensis and 5% chloroform fraction of A. baccifera ethanolic leaf extracts. The results of histopathological evaluation supported the outcome of both incision and excision wound models. Ethanolic fraction of B. maderaspatensis and chloroform fraction of A. baccifera exhibited marked wound healing activity. B. maderaspatensis extract displayed a remarkable wound healing activity compared to A. baccifera.

Evaluation of wound healing activity of Acacia leucophloea bark in rats

Suriyamoorthy,Sembian; Subramaniam,Kalidass; Wahab,Femina; Karthikeyan,G
Fonte: Sociedade Brasileira de Farmacognosia Publicador: Sociedade Brasileira de Farmacognosia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 EN
Relevância na Pesquisa
66.69%
Wound healing activity of the bark extracts of Acacia leucophloea Willd., Fabaceae, was investigated by excision and incision wound healing models in Wistar male rats. Ethanolic extract based ointment of A. leucophloea bark (2 and 5% (w/w)) was formulated and evaluated for its wound healing in Wistar male rats. In comparision with a standard wound healing ointment betadine. A. leucophloea ethanolic extract ointment exhibited marked wound healing activity and significantly enhanced the wound contraction and the period of epithelialization as assessed by wound contraction rate, tensile strength, increasing of DNA, collagen and protein synthesis and histopathological examination. The formulated ointment might well find use as skin repair agent without hazard to human health based on these results.

Wound healing properties and mucilage content of Pereskia aculeata from different substrates

Carvalho,Eber Goulart; Soares,Cristina Pacheco; Blau,Lorena; Menegon,Renato Farina; Joaquim,Walderez Moreira
Fonte: Sociedade Brasileira de Farmacognosia Publicador: Sociedade Brasileira de Farmacognosia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
Relevância na Pesquisa
66.69%
Physiologic growth parameters Wound healing Pereskia aculeata Mill., Cactaceae, is a cactus with high mucilage production, well-known for its nutritional properties. Folk use consists on skin injuries, and mucilage is probably involved in the wound healing activity. This work studied some aspects of its cultivation, specifically regarding soil (substrate), to correlate the effects of nutritional content to mucilage production and to the wound-healing property. Plants were grown under five different soil treatment (sand, crude soil, sand and soil, sand and cattle manure, soil and cattle manure), and after eight months extracts were prepared by turbo-extraction to obtain a crude hydroethanolic extract. We evaluated the effects of these extracts on swelling index, cytotoxicity, and in vitro wound healing property. The results show that the substrate used in cultivation may interfere with mucilage production, but not with cytotoxicity and wound healing, this shows the safety of its use, despite the soil treatment received along the various biomes where P. aculeata is cultivated. Furthermore, morphological studies demonstrated the beneficial effect of the mucilage-containing extract on the fibroblast cell culture, corroborating its folk use for wound healing.

Evaluation of lipoic acid topical application on rats skin wound healing

Külkamp-Guerreiro,Irene Clemes; Souza,Marielly Nunes; Bianchin,Mariana Domingues; Isoppo,Mateus; Freitas,Joana Sachetti; Alves,João Alex; Piovezan,Anna Paula; Pohlmann,Adriana Raffin; Guterres,Sílvia Stanisçuaski
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2013 EN
Relevância na Pesquisa
66.69%
PURPOSE: To evaluate the effects of lipoic acid (thioctic acid) topical application on wound healing on rats skin, and the consequences of lipoic acid nanoencapsulation on this process. METHODS: The model used was the healing activity on wounds induced by surgical incision on rats skin (n = 44). The parameters analyzed (11 days) were wound healing rate and histology (vascular proliferation, polymorphonuclear or mononuclear cells, and collagen synthesis or reepithelialization), after application of free lipoic acid or lipoic acid- loaded nanocapsules. The antioxidant activity of these formulations was evaluated by lipid peroxidation test. RESULTS: It was demonstrated for the first time that the topical application of lipoic acid improves wound healing. On the seventh day after surgery, the animals treated with lipoic acid showed increased healing rate (60.7 ± 8.4%) compared to the negative control group (43.0 ± 17.4%), as so improvement of histological parameters. The nanoencapsulation reverted the pro-oxidant activity presented in vitro by lipoic acid, whereas diminished wound repair. CONCLUSIONS: The topical application of lipoic acid produced an increase in the skin wound healing, which may be related to its pro-oxidant activity. On the other hand...

The Role of Androgen Receptor in Cutaneous Wound Healing

Lai, Jiann-Jyh ; Chang, Chawnshang
Fonte: Universidade de Rochester Publicador: Universidade de Rochester
Tipo: Tese de Doutorado Formato: Number of Pages:161 p.
ENG
Relevância na Pesquisa
66.81%
Thesis (Ph.D.)--University of Rochester. School of Medicine and Dentistry. Dept. of Pathology & Laboratory Medicine, 2009. ; Impaired wound healing, including acute wounds and chronic ulcers, has imposed multi-billion dollar costs on US health service. Especially, it often associates with aging and other pathological conditions, such as diabetes mellitus. More and more evidence shows gender differences in cutaneous wound healing, especially in elderly population. Clinically, cutaneous wounds heal more slowly in elderly men than women, accompanied with more inflammatory cell infiltration and reduced collagen deposition. In other studies, male gender has also been known as a risk factor for impaired wound healing, suggesting that sexual hormones, including androgens, might regulate the repair process. Nevertheless, the underlying mechanisms remain poorly understood. In this thesis, we used conditional androgen receptor (AR) knockout mouse models to dissect AR function in different types of cells involved in the healing process and studied the detailed mechanisms how androgens/AR involves cutaneous wound healing. Interestingly, compared to wild type (WT) controls, we found cutaneous wound healing was accelerated in AR knockout (ARKO) mice...

The effect of topical antifibrinolytics and a novel chitosan gel on haemostasis and wound healing in endoscopic sinus surgery.

Athanasiadis, Theodore
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2009
Relevância na Pesquisa
66.79%
Introduction: Endoscopic sinus surgery (ESS) is at present the gold standard therapeutic modality for chronic rhinosinusitis (CRS) resistant to medical therapy. Whilst results from ESS for CRS are generally good, postoperative bleeding and impaired wound healing with adhesion formation remains a concern. Due to patient discomfort and the detrimental effects on wound healing caused by most packing materials, many surgeons no longer routinely use nasal packing. Surgeons have in the past sought agents which would provide post-operative haemostasis without detrimentally affecting wound healing. Antifibrinolytics have been available for many years, however, their topical application has only been explored in the last few years. Recently different forms of chitosan have separately shown significant promise as powerful haemostatic and anti-adhesion agents. The aim of this thesis was to explore the progressive understanding of the interaction between haemostasis and wound healing with possible development of a novel agent. Methods: The first step to scientifically assess bleeding after sinus surgery was to develop a standardised method of video endoscopy and grading the surgical field during ESS. This was done as a multinational collaborative trial. Once this assessment tool was validated a randomised controlled trial evaluating the effect of two antifibrinolytics (epsilon aminocaproic acid and tranexamic acid) was conducted. Further evaluation was then conducted on other possible hemostatic and antiadhesion substances. This included various combinations of a novel chitosan gel. These gels were trialled in vitro to determine their effect on human nasal fibroblasts derived from CRS patients. Fibroblast adhesion and proliferation as well as closure of standardised wounds were studied. The most promising of these gels was then used in an in vivo sheep model. Once effectiveness of the chitosan-dextran gel was shown in the laboratory...

Tierexperimentelle Untersuchung zur Bedeutung des Stickstoffmonoxids bei strahleninduzierten Wundheilungsstörungen; The role of nitric oxide in radiation impaired wound healing - a rat model

Weimer, Wiebke
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
Relevância na Pesquisa
66.76%
Eine Strahlentherapie kann Wundheilungsstörungen induzieren. Stickstoffmonoxid (NO) wird eine wichtige Mediatorfunktion in der Wundheilung, insbesondere bei der Regulation der Kollagensynthese durch Wundfibroblasten, zugeschrieben. Ziel dieser Arbeit war es, die bisher unbekannte Wirkung einer präoperativen Bestrahlung auf die NO-Synthese und Expression der induzierbaren NO-Synthase (iNOS) in Wunden im Zusammenhang mit ihrer Auswirkung auf die Wundheilung zu untersuchen. Die Teilkörperbestrahlung der Versuchtiere erfolgte mit 4 MeV Elektronen eines Linearbeschleunigers. Die Versuchsgruppen mit jeweils 10 Ratten wurden lokal am Rücken mit Einzeldosen von 12 Gy bzw. 24 Gy bestrahlt, die Kontrollgruppe wurde scheinbestrahlt. Fünf Tage später wurde im Bestrahlungsareal eine Hautinzision gesetzt und Polyvinylalkohol-Schwämme subkutan implantiert. Zehn Tage nach der Operation wurden der Hydroxyprolingehalt des Granulationsgewebes und die Wundreißfestigkeit bestimmt. In der Wundflüssigkeit wurden die Konzentrationen von Nitrat und Nitrit, den stabilen Oxidationsprodukten des NO, gemessen und im Granulationsgewebe die Expression der iNOS immunhistochemisch untersucht. Der Hydroxyprolingehalt des Granulationsgewebes, ein Index der Kollagenablagerung...

Papel do receptor PPAR alfa na cicatrização de feridas cutâneas induzidas experimentalmente; The role the receptor PPAR alpha in wound healing induced experimentally

Guimarães, Francielle Rodrigues
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 12/04/2013 PT
Relevância na Pesquisa
66.71%
Peroxissome proliferator-activated receptor-alfa (PPAR-?) é um fator de transcrição nuclear envolvido na regulação do metabolismo de lipídeos e da inflamação. PPAR? pode estar relacionado com a modulação da cicatrização de feridas cutâneas, que é um processo multifatorial, dependente de mecanismos de sinalização celular e de inflamação. Deste modo, o objetivo deste trabalho foi analisar o papel do receptor PPAR? na cicatrização de feridas cutâneas induzidas experimentalmente e a sua relação com o metabolismo sistêmico após tratamento com agonista do PPAR?. Para tanto, foram realizadas feridas na pele da região dorsal de camundongos 129/SvEv, que foram tratados diariamente com o agonista de PPAR?, Gemfibrozil, por via oral ou tópica. Os animais foram acompanhados durante 240h pós-cirúrgico (p.c.) para a análise do reparo cutâneo e alterações metabólicas que poderiam ser induzidas pela ativação de PPAR?. Os camundongos tratados apresentaram melhor cicatrização após ativação de PPAR? com 100 ou 50 mg/kg/dia de agonista por via oral ou tópica, respectivamente. O tratamento oral induziu cicatrização mais rápida somente após 24h, 48h e 72h p.c., enquanto que os animais tratados com Gemfibrozil tópico apresentaram cicatrização mais precoce em todos os tempos avaliados. A indução de feridas alterou o metabolismo sistêmico dos camundongos que demonstraram significativa perda de peso e redução de triglicérides...

ENHANCED BURN WOUND HEALING THROUGH CONTROLLED AND SUSTAINED DELIVERY OF BIOACTIVE INSULIN FROM ALGINATE SPONGE DRESSINGS

Hrynyk, MICHAEL
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
66.7%
Skin is a dynamic and complex organ that relies on the interaction of different cell types,biomacromolecules and signaling molecules. Upon injury, a cascade of events occurs to quickly restore the skin’s integrity. Depending on the size and severity of the wound, a dressing is used to provide a temporary barrier to protect from dehydration, microorganisms and debris. Current wound dressings however, cannot accelerate wound healing beyond the natural rate, require frequent dressing changes, and cannot be easily removed without triggering additional pain ortissue destruction. Insulin, a peptide used to treat Type 1 diabetes, has been reported to improve the recovery of severe burn wounds. Yet, no one has successfully demonstrated a convenient and effective insulin delivery vehicle that can be used to accelerate burn wound healing. Poly(lactic-co-glycolic acid) microparticles, were shown to release bioactive insulin for a period of 25 days, stimulating human keratinocyte migration in vitro. A wound dressing made from poly(ethylene glycol) and alginate was formulated incorporating the insulin-loaded poly(lactic-co-glycolic acid) microparticles. Bioactive insulin release was achieved for nearly 3 weeks, along with favourable water handling and physical properties conducive for wound healing. Finally...

Biomechanics of corneal wound healing

Ramier, James Charles
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
66.69%
The re-establishment of tissue continuity, function, and mechanical proper ties after a through-and-through incision is an important issue in corneal surgery and trauma. Variations in healing can affect vision and patient activity during the recovery period, which may last up to five years. Growth factors introduced into the open wound have the potential to speed up the wound-healing process. The current investigation is concerned with quantitatively characterizing the mechanical properties of corneal tissue and evaluating the effects of epidermal growth factor (EGF), insulin-like growth factor (IGF), and platelet-derived growth factor (PDGF) on accelerating the wound-healing process as compared to a control group treated with phosphate-buffered saline (PBS). A 30 day topical application period was employed to assess the influence of EGF, IGF, and PDGF versus PBS treated corneas following through-and-through incisions. Corneal test specimens were harvested at 3, 10, and 30 days postoperatively and subjected to uniaxial tension loading (perpendicular to the wound) with load and displacement values recorded. Gross strength properties of fracture toughness, peak tangent modulus, and peak stress were calculated and the stiffness characteristics of the test specimens were obtained through curve fitting of the stress - stretch ratio profile. Comparison of strength properties indicated that IGF application enhanced peak stress...