Evaluation of angiogenesis, epithelialisation and microcirculation after application of polyhexanide, chitosan and sodium chloride in rodents.

The purpose of this study was to investigate the effect of polyhexanide and a new developed chitin-based wound dressing on skin microcirculation, epithelialisation and angiogenesis. A full-thickness dermal layer extending to the underlying cartilage was excised on the dorsal side of hairless mice (n = 27; 2·3 ± 0·3 mm2 ). A polyhexanide ointment, a chitosan solution and a sodium chloride group as control were analysed using intravital fluorescence microscopy. Angiogenesis, epithelialisation and microcirculatory standard parameters were measured over a time period of 20 days. The non-perfused area is regarded as a parameter for angiogenesis and showed the following results: on days 12, 16 and 20, the sodium chloride group was significantly superior to chitosan solution (P < 0·05) and, on days 8, 12, 16 and 20, the polyhexanide group was superior to chitosan solution (P < 0·05). The epithelialisation was measured significantly faster in the polyhexanide and control group on day 8 versus chitosan solution. Whereas polyhexanide and sodium chloride were nearly completely epithelialised, treatment with chitosan solution showed still an open wound of 11% of the initial wound size. Altogether, we could demonstrate the advantageous effects of a polyhexanide ointment on microcirculation, angiogenesis and epithelialisation. Chitosan solution appears to inhibit angiogenesis and delays epithelialisation. Further studies in different models would be worthwhile to confirm these results.