Expanders coated with N-carboxybutyl chitosan were inserted into surgical wounds in the dorsal skin of rabbits and the formation of capsular tissue was studied by scanning electron microscopy and transmission electron microscopy. N-carboxybutyl chitosan, in the course of the capsular organization, favours and potentiates the correct proliferation and organization of the tissue, rather than sustaining reactive processes leading to scar formation. N-carboxybutyl chitosan stimulates physiologically the tissue repair process and favours angiogenesis, whilst depressing fibrogenesis to a certain extent. Applications are envisaged in the treatment of wounds and in plastic surgery.