**Abstract**

Physical and chemical modifications of chitin and chitosan allow for obtaining new functional properties of the natural polymers. This is a particularly valuable feature for the design and manufacture of new materials for medical applications. Due to their wide and varied biological activity, chitin and chitosan materials are increasingly used as dressing materials with antibacterial and hemostatic properties and as materials accelerating the regeneration of damaged tissues because of stimulation of granulation tissue formation, re-epithelialization and reduction of the formation of scar tissue. In addition, chitosan derivatives have antifungal, antiviral, anticancer activity. The increasing use of chitin and chitosan also has a positive impact on the environment, as it is obtained as a result of chitin deacetylation, usually isolated from shellfish shells. The main source of chitin is waste coating of crustaceans. The annual natural reproducibility of chitin by biosynthesis is estimated at 2–3 billion tons. Our interest in the use of biodegradable biopolymers derived from chitin concerns the design, synthesis in laboratory scale, testing new material properties and the final implementation of new developments for industrial practice of new dressing materials useful in the treatment of bleeding wounds (haemostatic properties) as well as in the regeneration of wounds and ulcers of various etiologies. Examples of chitin-based dressing materials introduced by Tricomed SA are Medisorb R Ag, Medisorb R Membrane, Medisorb R Powder and Tromboguard®.

**Keywords:** chitin, chitosan, chemical modification, biological properties, dressing materials, manufacturing on an industrial scale
