A new anti-infective collagen dressing containing antibiotics.

A new antibacterial dressing for infected wounds was prepared. The dressing was composed of a collagen membrane and collagen sponge; both biomaterials possess good tissue biocompatibility. An active antibacterial layer of limited hydrophobicity was placed between the membrane and the sponge and into the upper part of the sponge. The dressing contained gentamycin or amikacin at concentrations of 0.3 microgram/cm2 (loading level of the drug utilized during preparation of the dressing). Either the antibiotic or its concentration easily can be changed in the dressing by the manufacturer. The dressing was stable for several months. The antibiotic was released slowly from the dressing in in vitro experiments for 3 days. Antibacterial activity of the dressing was tested using a mouse wound model experimentally infected with Pseudomonas aeruginosa. Both dressings, containing either amikacin or gentamycin, reduced the number of living bacterial cells in the infected tissue almost to zero during the course of observation. The new dressing may be effective in the treatment of infected wounds in patients.