Medicated wound dressings incorporate chemicals which have therapeutic value. The objective of this study
was to investigate the in vitro model drug release from a biodegradable needle web, based on medicated cellulosic hollow
fibres, which self-dissolve in the presence of aqueous solutions.
Cellulose hollow fibres were prepared by a standard dry-wet phase inversion spinning process. Dressings were made using
established techniques in the nonwoven industry. Two sets of hollow fibres were filled with different drug solutions:
One set contained the enzyme cellulase and the second set was filled with either antibacterial Pseudomonas aeruginosaspecific
bacteriophages, or the wound debriding enzyme Krillase®. Both fibre sets were freeze-dried to (i) inactivate the
spontaneous biodegradation of the fibres by cellulase and (ii) to preserve the wound healing activities of the biotherapeutic
model drugs. Needle webs containing different mixing ratios of the two sets of hollow fibres were made. Whereas bacteriophages
were released after rewetting the webs in in-vitro experiments with high burst effect, Krillase® showed a sustained
drug release over 20 h, which was found to be dependent on the mixing ratio of cellulase versus Krillase®-hollow
fibres. Possible release mechanisms and therapeutic benefits are discussed.
In summary, needle webs of medicated cellulosic hollow fibres are a new self-dissolving drug delivery system.