ABSTRACT
The present study is designed to assess the potential benefits of controlled delivery of silver sulfadiazine from collagen scaffold (SSDM-CS) in infected deep partial thickness burn wounds in which epidermis is lost completely and the entire papillary dermis and most of the recticular layer of the dermis is lost. Infection induced by inoculating 10(7) colony forming units (cfu) of Pseudomonas aeruginosa caused significant increase in wound size (20%) till day 15, which decreased significantly from day 9 by SSDM-CS treatment, showing complete healing by day 27 (control > or = 37 days). Early subsidence of infection (<10(2) cfu, day 9) by SSDM-CS resulted in faster epidermal resurfacing and fibroplasia, whereas heavy microbial load (>10(7) cfu, day 9) in controls caused severe inflammatory cellular infiltration. Persistent infection triggered early expression of proinflammatory cytokines intereukin-6, intereukin 1-beta, and tumor necrosis factor-alpha, lasting until day 9, whereas cytokine level decreased in SSDM-CS-treated group by day 6. Infection exacerbated expression of active matrix metalloproteinases (MMPs)-2 and -9 in controls (day 15), while SSDM-CS positively modulated MMP-2 and -9 with faster decline in their levels (day 12). Inherent nature of the dressing to maintain drug level at equilibrium therapeutic concentration (51.2 microg/mL) for prolonged time (72 h), below systemic toxic limits (20 microg/dL, serum level), accelerated the magnitude and sequence of reparative events.
Subject(s)
Burns/complications , Burns/drug therapy , Silver Sulfadiazine/administration & dosage , Silver Sulfadiazine/therapeutic use , Wound Infection/complications , Wound Infection/drug therapy , Administration, Topical , Animals , Blotting, Western , Body Weight/drug effects , Burns/enzymology , Burns/pathology , Collagen/metabolism , Cytokines/metabolism , Delayed-Action Preparations , Densitometry , Enzyme Activation/drug effects , Hexosamines/metabolism , Inflammation Mediators/metabolism , Matrix Metalloproteinases/metabolism , Rats , Rats, Wistar , Silver Sulfadiazine/pharmacology , Wound Healing/drug effects , Wound Infection/enzymology , Wound Infection/pathologyABSTRACT
Se ha demostrado que el colágeno es un nuevo biomaterial utilizado para la administración de fármacos, la fabricación de apósitos o como sustrato para ingeniería tisular cuya biocompatibilidad y propiedades biodegradables son únicas. El colágeno bovino y porcino tipo I constituyen una fuente fácilmente disponible de material de soporte para diversas aplicaciones biomédicas. Sin embargo, estas fuentes conllevan cierto riesgo potencial de enfermedades infecciosas como la encefalopatía espongiforme bovina o la encefalopatía espongiforme transmisible. Por esta razón, existe una demanda de colágeno tipo I procedente de otras fuentes. En el presente estudio, se utilizan animales acuáticos y, en concreto, especies de tiburón en las que el colágeno tipo I es una proteína principal de la piel y la estructura tiene similitud con la de las especies mamíferas. Se ha intentado utilizar colágeno de piel de tiburón como matriz de soporte con extracto de aloe para mejorar la estabilidad. Estas matrices de soporte se caracterizaron por varias propiedades fisicoquímicas y por la evaluación de biocompatibilidad para facilitar el crecimiento de fibroblastos dérmicos humanos in vitro. La incorporación de extracto de aloe influyó enormemente en la morfología y las propiedades fisicoquímicas de la matriz de soporte. Se observó in vitro que los fibroblastos conservaban la orientación organizada en forma de huso al cultivarse sobre la matriz de soporte de colágeno. Así, la matriz de soporte de colágeno desarrollada con una proporción de 10:1 de colágeno de piel de tiburón y extracto de aloe, respectivamente, sirvió como material biocompatible con una resistencia a la tracción apreciable. La investigación anterior sugiere que la matriz de soporte de colágeno de piel de tiburón desarrollada puede ser una alternativa efectiva al colágeno de mamífero en el campo de la ingeniería tisular y para diversas aplicaciones en la curación de heridas (AU)
Collagen has proven to be a novel biomaterial used for drug delivery, wound cover dressings or as a substrate for tissue engineering with unique biocompatibility and biodegradable properties. Bovine and porcine Type I collagen provide a readily available source of scaffold material for various biomedical applications. However these sources have some potential risk of infectious diseases such as bovine spongiform encephalopathy or transmissible spongiform encephalopathy. Hence there is demand for an alternative Type I collagen from various other sources. The present study utilizes the aquatic animals particularly the shark species in which collagen Type I is a major protein in the skin and the structure has similarity to that of mammalian species. An attempt was made to use shark skin collagen as scaffold with the extract of aloe to improve the stability. These scaffolds were characterized for various physicochemical properties and biocompatibility assessment to support the growth of human dermal fibroblasts in vitro. The incorporation of aloe extract highly influenced the morphology and physicochemical properties of the scaffold. It was observed in vitro that the fibroblasts retained the spindle shape, organized orientation when cultured over collagen scaffold. Thus the developed collagen scaffold at 10: 1 ratio of shark skin collagen and aloe extract respectively served as a biocompatible material with appreciable tensile strength. The above investigation suggests that the developed shark skin collagen scaffold could be an effective alternative for the mammalian collagen for tissue engineering and various wound healing applications (AU)
