Neusa Margarida Paulo

Wound Healing and Anti-Inflammatory Effect in Animal Models of Calendula officinalis L. Growing in Brazil.

Calendula officinalis is an annual herb from Mediterranean origin which is popularly used in wound healing and as an anti-inflammatory agent. In this study, the ethanolic extract, the dichloromethane, and hexanic fractions of the flowers from plants growing in Brazil were produced. The angiogenic activity of the extract and fractions was evaluated through the chorioallantoic membrane and cutaneous wounds in rat models. The healing activity of the extract was evaluated by the same cutaneous wounds model through macroscopic, morphometric, histopathologic, and immunohistochemical analysis. The antibacterial activity of the extract and fractions was also evaluated. This experimental study revealed that C. officinalis presented anti-inflammatory and antibacterial activities as well as angiogenic and fibroplastic properties acting in a positive way on the inflammatory and proliferative phases of the healing process.

Angiogenic activity of Calendula officinalis flowers L. in rats

PURPOSE In this work, angiogenic activity of Calendula officinalis L. (Asteraceae) ethanolic extract and dichloromethane and hexanic fractions were evaluated, considering medicinal properties, especially healing activity, are attributed to this plant. METHODS Models using 36 rats and 90 embryonated eggs were used to evaluate healing and angiogenic activities of extracts and fractions of the plant, through the induction of skin wounds and the chorioallantoic membrane, respectively. The effect of vascular proliferation was also tested from the study to verify the intensity of expression of vascular endothelial growth factor (VEGF) in cutaneous wounds in rats. RESULTS The angiogenic activity of the extract and the fractions was evidenced in both experimental models. It was verified that this effect is not directly related to the expression of VEGF and it could be associated to other pro-angiogenic factors. CONCLUSION The healing activity referred to C. officinalis is related, among other factors, to its positive effect on angiogenesis, characterized by the induction of neovascularization.

Use of chitosan membrane associated with polypropylene mesh to prevent peritoneal adhesion in rats.

The correction of wall abdominal defects often requires the use of implants such as polypropylene meshes. In spite of presenting good tissue acceptance, these biomaterials can migrate to adjacent viscera, promote enterocutaneos fistulas, tissue adherence and visceral erosions. In this work, the barrier effect of chitosan films associated with polypropylene meshes on adhesion formation experimentally induced in Wistar rats was evaluated. The animals were divided into two groups with 10 animals each. Animals in the CPP group were implanted with chitosan films associated with polypropylene meshes, whereas the ones in the PP group received only polypropylene meshes. After 8 days, the animals were submitted to euthanasia using CO(2) and a descriptive study focusing adhesion formation, visceral involvement with sutures and mesh peritonization was performed. Also, subimplanted material was collected for histopathology analysis. The results showed that the CPP group presented weak adhesions to the omentum over the stitch knots in eight animals. In all animals, the meshes were peritonized, not allowing their visualization after removing the chitosan films. In the PP group, six animals presented intestinal adhesions to the meshes and, in one of them, hepatic adhesion to the mesh was observed, besides omentum adhesion on more than 50% of the mesh area. The protective effect of chitosan films when sutured over polypropylene meshes, as well as no exacerbation of inflammation associated to the peritoneal lesions was statistically demonstrated. Therefore, chitosan films can indeed minimize the formation of peritoneal adhesions induced by polypropylene meshes in rats.

Healing effect and antibacterial activity of Calendula officinalis L. cultivated in Brazil

Since ancient history medicinal properties are attributed to flowers of Calendula officinalis L. (Asteraceae), mainly concerning its healing activity. Studies about the general activity of medicinal plants in healing wounds have been conducted without specifying in which healing phase the plant acts. In this work, the anti-inflammatory and healing activity of the ethanolic extract of C. officinalis flowers cultured in Brazil was evaluated in cutaneous wounds of Wistar rats through macroscopic and histological evaluation. The antibacterial activity of the extract and dichloromethane and hexane fractions was also evaluated. The anti-inflammatory activity of calendula ethanolic extract led to a reduction in plasmatic exudation, hyperemia, fibrin deposition and epidermal hyperplasia, besides resulting in less edematous crusts. There was also an increase in collagen in the granulation tissue and an antibacterial effect. Therefore, calendula ethanolic extract positively acted on the healing process of cutaneous wounds of rats and presented in vitro antibacterial activity.

Reconstruction of thoracic esophagus with pediculated diaphragmatic flap in dogs

PURPOSE To verify whether pediculated diaphragmatic flaps were suitable to correct iatrogenic wounds in dogs esophagus injuries. METHODS Seven dogs were submitted to resection of a segment of the esophageal wall, which was then corrected by suturing a pediculated diaphragm flap. Endoscopic evaluation of the esophageal wall was done forty days after the surgical procedure. RESULTS Three animals died, one due to implant ischemia, caused by strangulation of the phrenic artery; other due to wound infection; and the last, due to mediastinitis. Scar retraction was observed, however, there was no stenosis, allowing the passage of a 9,8 mm probe with no difficulty. The limits between the implants and the native esophagus were indistinguishable, and the implant was covered by esophageal mucosa. CONCLUSION The diaphragmatic flaps are suitable on the restoring of continuity in dogs thoracic esophagus.

Evaluation of peritoneal adhesions formation and tissue response to polypropylene - poli (2-hydroxyethyl methacrylate)-(polyHEMA) implant on rats' abdominal wall.

PURPOSE To verify if the composit poli (2-hydroxyethyl methacrylate)-PolyHEMA/polypropylene mesh implanted in the female rats abdominal wall could be suitable for the prevention of peritoneal adhesions, and for the evaluation of the tecidual response produced by this biomaterial. METHODS Polypropylene meshes (Group PP, n=20) and polypropylene meshes coated with a layer of poli (2-hydroxyethyl methacrylate)-PolyHEMA (Group PH, n=20) were implanted on the abdominal wall of Wistar female rats. Ten animals from each group were submitted to euthanasia at 15 and 30 days of the postoperative period. RESULTS The animals from the group PP presented visceral adhesions on the mesh surface, which was not observed in the ones from group PH. At the histopathological examination foreign body response was observed in both groups, whilst there was a greater intensity of inflammatory response in group PH on both moments. CONCLUSION The poli (2-hydroxyethyl methacrylate) polyHEMA hydrogel associated to polypropylene mesh reduces visceral adhesion formation in rats, although it may be associated to greater inflammatory reaction.

Reconstrução uretral com retalho autógeno de mucosa bucal após uretrostomia, em cães

OBJETIVO: Verificar se fragmentos de mucosa bucal autogena poderiam ser adequados para reconstrucao uretral na presenca de tecido fibroso, e se tal procedimento poderia determinar a formacao de fistulas e ou saculacoes nos sitios implantares. METODOS: Sete caes adultos foram submetidos a uretrostomia pre-escrotal. Apos 40 dias, a uretrostomia foi corrigida por meio da implantacao de fragmentos de mucosa bucal na parede ventral da uretra. Os animais foram observados durante 40 dias, quando entao, foram submetidos a exames radiograficos e sacrificados para estudo histologico. RESULTADOS: Todos os animais apresentaram cistite e fistulas uretro-cutâneas de duracao media de vinte dias foram observadas em seis deles. O aspecto radiografico aos 40 dias apos a reconstrucao uretral mostrou: continuidade luminal em sete animais e presenca de saculacoes na parede ventral da uretra em seis, sem interferencia na qualidade do jato urinario. As caracteristicas histologicas indicam integracao completa da mucosa bucal ao sitio receptor. CONCLUSAO: O implante em retalho ventral, com fragmentos de mucosa bucal autogena e adequado para correcao de defeito uretral produzido por uretrostomia no cao embora possa ocorrer a formacao de saculacoes no sitio do selamento.

Avaliaçäo da triangulaçäo da anastomose término-terminal de fragmento de mucosa bucal na reconstruçäo uretral: estudo experimental no cäo

Oral mucosa has been considered an excellent alternative method to substitute for urethral tissue. OBJECTIVE: To investigate the results of a triangulation of an end-to-end anastomosis using oral mucosa for urethral reconstruction. METHODS: Twelve healthy dogs of no defined race weighing between 13 and 17 kg were anesthetized and an urethral catheter was maintained during the whole surgery. First, a piece of oral mucosa was removed from the superior lip and kept in saline solution containing aqueous chloramphenicol. Then, a 2 cm fragment of the urethra from the penis was removed and the oral mucosa was used to reconstruct the urethra. RESULTS: After 60 days we observed stenosis in 25% of the dogs. There were also urethral-cutaneous fistulas and constrast leakage at the site of anastomosis. CONCLUSION: The triangulation of an end-to-end anastomosis using oral mucosa for urethral reconstruction does not prevent the occurrence of stenosis.

Acute systemic response to intraperitoneal implantation of polypropylene mesh/chitosan-based film composite in pigs

PURPOSE To assess the systemic response of pigs to the intraperitoneal implantation of polypropylene mesh associated with chitosan-based film with a degree of deacetylation of 95%. METHODS Blood samples were collected 24 hours before, and two and seven days after surgery. Systemic reactions were evaluated based on white blood cell count, C-reactive protein, and total serum protein, albumin and globulin levels. RESULTS The systemic response was proportional to the composite response induced by polypropylene mesh, and the tissue inflammatory response was higher in the PP group (p=0.0033). CONCLUSION The polypropylene mesh/chitosan-based film composite did not elicit a systemic response in pigs.

Evaluation of Cell Growth Characteristics on Chitosan-Alginate Membranes to Assess Their Potential Application on Highly Exuding Skin Lesions and In Vivo Evaluation in Wounded Cat

Chitosan and alginate are non-toxic, biocompatible and biodegradable polysaccharides, used in skin healing. High biocompatibility, ease of production and low cost have increased the interest in the use of both compounds in medical and pharmaceutical sectors, as components of wound dressings. The purpose of this work was to access the use of chitosan and chitosan-alginate membranes for highly exudating wounds, as the ones normally observed in cats, employing Vero cell cul- ture as an initial evaluation step. The achieved results show that the chitosan-alginate membranes stimulated cell proliferation, but not cell adhesion, whereas improving tridimentional growth with the formation of aggregates. Cell concentration both at 24 and 48 h were similar to those observed in the control samples, however, at the 72-h period, the average number of cells was lower than those in the controls. The in vivo performance evaluation of the membranes indicated that they were effective on protecting the wound from external microbial contamination, also stimulating tissue recovery. The lesion was totally healed after 30 days.