Characterization of cellulose based sponges for wound dressings

Cellulose based sponges were developed by freeze-drying of regenerated cellulose gels and characterizedas a potential wound dressing. Morphological characteristics were analyzed by means of micro-computedtomography. The results showed that the porosity of the sponges reached 75%, the pores were inter-connected and their size ranged from 10 to 1200 m with a mean pore diameter of 750 m. Due tohydrophilicity of cellulose and high specific surface area (14.5 mm2/mm3) the sponges possess highsorption of simulated wound fluids (approx. 210%) and high water vapour transmission ability. Dif-ferent active compounds, such as polyphenols from Calendula officinalis or Chamomilla recutita extracts(1 day diffusion experiment), silver nanoparticles (1, 2 and 4 days diffusion experiments) were immo-bilized into the sponges in order to improve wound dressing performance. Release kinetics of silvernanoparticles and polyphenols from the sponges were investigated. The sponges incorporated with sil-ver, showed antibacterial activity against Staphylococcus epidermidis. Thus, these cellulose based spongesare promising wound dressing materials for fester and infected wounds