RESUMO
BACKGROUND: Skin tissue engineering is a rapidly evolving field of research that effectively combines stem cells and biological scaffolds to replace damaged tissues. Human Wharton's jelly mesenchymal stromal cells (hWJ-MSCs) are essential to generate tissue constructs, due to their potent immunomodulatory effects and release of paracrine factors for tissue repair. Here, we investigated whether hWJ-MSC grown on human acellular dermal matrix (hADM) scaffolds and exposed to a proinflammatory environment maintain their ability to produce in vitro growth factors involved in skin injury repair and promote in vivo wound healing. METHODS: We developed a novel method involving physicochemical and enzymatic treatment of cadaveric human skin to obtain hADM scaffold. Subsequently, skin bioengineered constructs were generated by seeding hWJ-MSCs on the hADM scaffold (construct 1) and coating it with human platelet lysate clot (hPL) (construct 2). Either construct 1 or 2 were then incubated with proinflammatory cytokines (IL-1α, IL-1ß, IL-6, TNF-α) for 12, 24, 48, 72 and 96 h. Supernatants from treated and untreated constructs and hWJ-MSCs on tissue culture plate (TCP) were collected, and concentration of the following growth factors, bFGF, EGF, HGF, PDGF, VEGF and Angiopoietin-I, was determined by immunoassay. We also asked whether hWJ-MSCs in the construct 1 have potential toward epithelial differentiation after being cultured in an epithelial induction stimulus using an air-liquid system. Immunostaining was used to analyze the synthesis of epithelial markers such as filaggrin, involucrin, plakoglobin and the mesenchymal marker vimentin. Finally, we evaluated the in vivo potential of hADM and construct 1 in a porcine full-thickness excisional wound model. RESULTS: We obtained and characterized the hADM and confirmed the viability of hWJ-MSCs on the scaffold. In both constructs without proinflammatory treatment, we reported high bFGF production. In contrast, the levels of other growth factors were similar to the control (hWJ-MSC/TCP) with or without proinflammatory treatment. Except for PDGF in the stimulated group. These results indicated that the hADM scaffold maintained or enhanced the production of these bioactive molecules by hWJ-MSCs. On the other hand, increased expression of filaggrin, involucrin, and plakoglobin and decreased expression of vimentin were observed in constructs cultured in an air-liquid system. In vivo experiments demonstrated the potential of both hADM and hADM/hWJ-MSCs constructs to repair skin wounds with the formation of stratified epithelium, basement membrane and dermal papillae, improving the appearance of the repaired tissue. CONCLUSIONS: hADM is viable to fabricate a tissue construct with hWJ-MSCs able to promote the in vitro synthesis of growth factors and differentiation of these cells toward epithelial lineage, as well as, promote in a full-thickness skin injury the new tissue formation. These results indicate that hADM 3D architecture and its natural composition improved or maintained the cell function supporting the potential therapeutic use of this matrix or the construct for wound repair and providing an effective tissue engineering strategy for skin repair.
Assuntos
Derme Acelular , Células-Tronco Mesenquimais , Geleia de Wharton , Humanos , Animais , Suínos , Proteínas Filagrinas , Vimentina/metabolismo , Derme Acelular/metabolismo , gama Catenina/metabolismo , gama Catenina/farmacologia , Diferenciação Celular , Células-Tronco Mesenquimais/metabolismoRESUMO
The volume of global gross banana exports reached a record of 117.9 million tonnes in 2015 (FAO 2017), which agro-industrial wastes derived as the pseudo-stem, rachis and leaves do not have an industrial application instead they are discarded. This research study applies full factorial design and response surface methodology to determine the effect of pressing temperature and resin content on density (D), moisture (M), water absorption (WA), water swelling (WS), module of rupture (MOR), module of elasticity (MOE) and formaldehyde content (FC) of particle board made of banana pseudo-stem. A 22 factorial design was performed, factors considered were resin and temperature. The low level of resin was 15% in the coarse fiber (CF) and 35% in fine fiber (FF); high level as 25% CF and 45% FF. Temperature levels were 150ºC and 170ºC respectively. The boards met all quality parameters except ones with low resin content that didn't meet WS parameter. Furthermore, resin affected positively on WA, FC and MOE, and decreased D, WS and MOR values. Meanwhile, temperature affected negatively on D, WS, and increased FC, WA, MOE, MOR properties; none of the factors affected M response. Process conditions were optimized to 162.61°C and 43.15% FF, 23.97% CF.
Assuntos
Resíduos Industriais , Teste de Materiais , Musa , Caules de Planta , Eliminação de Resíduos/métodos , Resinas Vegetais/análise , Elasticidade , Temperatura , Resistência à TraçãoRESUMO
Acid burns are not very frequent, occupying between 3% and maximum 14% of all etiologies. They mostly occur at home or at work, however there has been an increase in publications outlining chemical burns where aggression is the cause of this burn. There is a different epidemiological profile between developed countries and developing ones. It seems an ongoing upsurge is occurring in the number of registered attacks within developing countries in recent years. A cross sectional retrospective review of attacks by acid was done in Bogota, Colombia from 1995 to the first trimester 2012. A cumulative number of 35 burn patients were registered during the study period. It is found that the main target, almost the unique target, of this attack are young women belonging to low socioeconomic status with low education degree and high dependence on her partner. The patient's age mean was 22.7 years, ranging from 13 to 41 years. The physical and psychological scars were very severe.
Assuntos
Ácidos , Queimaduras Químicas/epidemiologia , Violência/estatística & dados numéricos , Adolescente , Adulto , Queimaduras Químicas/etiologia , Colômbia/epidemiologia , Estudos Transversais , Traumatismos Faciais/induzido quimicamente , Traumatismos Faciais/epidemiologia , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Lesões do Pescoço/induzido quimicamente , Lesões do Pescoço/epidemiologia , Estudos Retrospectivos , Distribuição por Sexo , Fatores Socioeconômicos , Adulto JovemRESUMO
Se presenta la experiencia del Hospital Kennedy de Bogota en la atencion de algunos pacientes provenientes de la catastrofe de Armero, destacando los problemas que se plantean a diario en los Servicios de Salud del pais: recargo de la consulta de urgencias por erronea utilizacion de los escasos recursos disponibles, referencia tardia e inadecuada de pacientes de alto riesgo y de los que requieren tratamiento especializado; atencion primaria deficiente por falta de recursos humanos y materiales; prolongada hospitalizacion de los pacientes por complicaciones o secuelas iatrogenicas. Se indica la forma como fueron tratados los pacientes, haciendo enfasis en tres aspectos: 1. Manejo de la urgencia con atencion inmediata y cirugia diferida, 2. Tratamiento de las fracturas abiertas de acuerdo con su clasificacion y fase biologica. 3. Utilizacion de membranas placentarias como uno de los mejores apositos biologicos temporales, en nuestro medio, en pacientes politraumatizados con gran destruccion de tejidos blandos.