A nonadherent chitosan-polyvinyl alcohol absorbent wound dressing prepared via controlled freeze-dry technology.

In modern-day 21st century, the demand has increased for absorbent dressings that are nonadherent and maintain structural integrity without shedding lint in the wound site. This study looks at the development of a blend of polysaccharide chitosan and polyvinyl alcohol (PVA) and its fabrication using a novel controlled freeze-drying process, thus giving it channeled pores. The dressing was assessed for in vitro physical properties such as fluid handling, mechanical integrity, bioadhesion, and blood clotting. Additionally, cytocompatibility and hemocompatibility tests were conducted. An in vitro wound-healing assay was performed to determine the healing response. Furthermore, toxicological safety evaluation tests such as acute systemic toxicity, skin irritation, and sensitization were conducted. The results revealed that the developed dressing was biocompatible with a good absorbency rate of 0.63 ± 0.13 g/cm2, enhanced mechanical integrity, and low bioadhesive strength with good healing characteristics and nontoxic nature, which indicated that it was an ideal nonadherent absorbent wound dressing.

Comparación de dos técnicas de curación en pacientes quemados pediátricos / Comparison of two healing techniques in pediatric burned patients

Introducción: Existen varias curaciones para quemaduras. La sulfadiazina de plata se ha usado por años pero las membranas microporosas son cada vez más preferidas. Objetivos: Comparar la eficiencia de las membrana microporosa (Telfa Clear®) versus sulfadiazina de plata (Platsul®) en menores de 15 años hospitalizados por quemadura. Pacientes y Métodos: Estudio de cohorte retrospectivo de 87 pacientes, dividido en 2 grupos comparables en extensión y profundidad de la quemadura, edad y sexo. Durante enero a diciembre 2007 se curaron 52 pacientes con Platsul® y desde enero a octubre 2008 se curaron 35 con Telfa Clear®. Se evalúa tiempos y extensión de reepitelización, porcentaje de injertos, costos, días de hospitalización, número de curaciones, complicaciones, almacenamiento-estabilidad y costos. Estadística no paramétrica para el análisis univariado y regresión logística multivariado en Stata 11.2. Resultados: Los pacientes curados con Platsul® se injertaron más tardíamente y presentan más curaciones. Platsul® es peor evaluado por su almacenamiento-estabilidad y mayores costos. No hay diferencia en la incidencia de infección. Conclusiones: Ambas Técnicas son eficientes en permitir reepitelización, pero Platsul® puede demorar el injerto. La Telfa Clear® es mejor evaluado por el equipo de salud en cuanto a almacenamiento y estabilidad. El menor costo de Telfa Clear® es una ventaja.

Introduction: There are several dressings for burns. Silver sulfadiazine has been used for years but microporous membranes are increasingly preferred. Objectives: To compare the efficiency of microporous membrane (Telfa Clear®) versus silver sulfadiazine (Platsul®) in children younger than 15 years old hospitalized for burns. Patients and Methodology: Retrospective cohort study of 87 patients, divided into 2 comparable groups in extent and depth of the burn, age and sex. During January to December 2007, in 52 patients Platsul® were use and in 35 patients Telfa Clear® were use from January to October 2008. The time and extent of re-epithelialization, percentage of grafts, costs, length of stay, number of dressing change, complications, storage-stability and costs are evaluated. Non-parametric statistics were used for univariate analysis and logistic regression for multivariate analysis en Stata 11.2. Results: Platsul® was associate to a later graft and had a greater number of dressing changes. Platsul® is worst rated for its storage-stability and higher costs. No difference in infection rate was observed. Conclusions: Both techniques are efficient in allowing re-epithelialization, but burns treated with Platsul® were grafted later than when Telfa Clear® was used. Telfa Clear® is best evaluated by the health team in terms of storage and stability. The cost of Telfa Clear® is presented as an advantage.

Imparting commercial antimicrobial dressings with low-adherence to burn wounds.

The objective of our study was to decrease the wound adherence of commercial silver based wound dressings by depositing a non-adherent layer. Our hypothesis was that this non-adherent layer will lower the dressing's adherence to burn wounds without compromising the antimicrobial activity or increasing the cytotoxicity. A polyacrylamide (PAM) hydrogel layer was grafted on two commercial silver antimicrobial dressings (silver nanocrystal dressing (NC) and silver plated dressing (SP)) using a proprietary technique. The grafted PAM served as the non-adherent layer. Dressing adherence was measured with a previously published in vitro gelatin model using an Instron mechanical force testing instrument. The dressings were challenged with two clinically retrieved bacterial strains (Methicillin-resistant Staphylococcus aureus (MRSA) and multidrug resistant (MDR) Pseudomonas aeruginosa) with both a disk diffusion test, and a suspension antibacterial test. The cytotoxicity of samples to human neonatal fibroblast cells was evaluated with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay. Both untreated dressings showed high peeling energy: 2070±453J/m(2) (NC) and 669±68J/m(2) (SP), that decreased to 158±119J/m(2) (NC) and 155±138J/m(2) (SP) with the PAM deposition. Addition of the PAM caused no significant difference in zone of inhibition (ZOI) (disk diffusion test) or antibacterial kinetics (suspension test) against both bacteria (p>0.05, n=6) in either dressing. Survival of fibroblasts was improved by the PAM grafting from 48±5% to 60±3% viable cells in the case of NC and from 55±8% to 61±4% viable cells in SP (p<0.05, n=12). It was concluded that PAM as a non-adherent layer significantly decreases the adherence of these two commercial antimicrobial dressings in an in vitro gelatin model while preserving their antimicrobial efficacy, and reducing their cytotoxicity.