MODERN CHITOSAN-BASED WOUND DRESSINGS IN LOCAL WOUND TREATMENT: PRECLINICAL STUDIES

Abstract

One of the priorities of modern medicine is the development of biomaterials for tissue engineering, transplantation and vascular surgery. Such materials should facilitate the regeneration of damaged body organs and tissues. The problem of regeneration of wound lesions affecting various skin and soft tissues is related to a high rate of secondary infection, deep metabolic shifts in the conditions of severe inflammations, activated oxygen-independent phagocytosis and intensified free-radical response. In patients with wounds of various etiologies, modern clinical practice widely employs numerous wound dressings, where properties are specified in advance according to the stage the wound is going through. The principle of a wound coating is the provision of a moist abacterial environment, which is optimal for accelerated healing. The subjects of our experimental studies were 45 white laboratory rats (males, outbred, each weighing 250-300 g) with soft tissue wounds developed by a specifically designed method. As materials for wound treatment we used chitosan-based multilayer wound dressings of different structure and porosity degree. They were introduced into simulated wounds in the back area between the shoulder blades in rats. The experimental part of the study focused on the sorption capacity of the wound exudate obtained after extraction and weighing of the samples within the control time. The laboratory part of the experiment involved studying the sorption capacity of wound dressing samples in relation to distilled water and blood serum. The morphological assessment of the dressing samples surface was performed on a Helios NanoLab 600electron-ion scanning microscope. It was observed that chitosan-based multilayer wound dressings, had different morphological parameters and molecular structure as well as high sorption activity. Chitosan samples with a so-called loose structure and high porosity should be used in a clean (aseptic) wound at the initial stages of treatment, with no inflammation, where initially high adhesion to surrounding tissues is required, thus, ensuring tightness and keeping a blood clot within the wound. Chitosan samples with a tight-packed structure and a smaller diameter of pores showed good results in purulent inflammation (exudative phase) with a large amount of wound exudate. Due to its dense outer layer, their structure is capable of retaining the skeleton functions for a long time, thus offering effective drainage of the wound.