In the last years, health care professionals faced with an increasing number of patients suffering from wounds, burns and bedsores difficult to treat and heal. During the wound healing process, the dressing protects the injured area and contributes to the recovery of dermal and epidermal tissues. Because their biocompatibility, biodegradability and similarity to macromolecules recognized by the human body, some natural polymers such as polysaccharides (alginates, chitin, chitosan), proteoglycans and proteins (collagen, gelatin, fibrin) are extensively are used in wounds and burns management. The study presents a research of new semi-solid formulations of bio-composites based on chitosan extracted from the stone crab Pachygrapsus Mormoratus found on the Black Sea shores. The bio-composites were obtained from natural polymeric compounds, Chitosan (CT), hyaluronic acid (HA) and lanolin(L), to which silver sulfadiazine (S), was added. Several semi-solid formulations have been performed for which the antimicrobial activity on gram-positive and gram-negative germ cultures and the rheological behavior was studied. The bio-composites that were obtained provide an optimal micro-environment for cell proliferation, migration and differentiation, due to their biocompatibility, biodegradability, peculiar structure and good antimicrobial activity.

Two of the considerably versatile and promising biomaterials are chitin and chitosan. Chitin is known to be the most abundant natural amino mucopolysaccharide, produced annually almost as much as cellulose, and it is found in the structure of a wide number of intervertebrates ( crustaceans' exoskeleton, insects' cuticles) functioning as a structural component that provides strenght and protection to the organisms, and the cell walls of fungi, among others. On the other hand, chitosan only occurs naturally in some fungi (mucoraceae). The composition of chitin is based on β(14)-linked 2-acetamido-2-deoxy-β-D-glucose (N-acetylglucosamine

For many years chitosan has been the subject of interest for its use in different medical fields due to its appealing properties such as biocompatibility, biodegradability, low toxicity and relatively low production cost from abundant natural sources. Chitosan is positively charged at low pH values, so it is spontaneously associated with negatively charged polyions in solution to form polyelectrolyte complexes. These chitosan based polyelectrolyte complexes exhibit favourable physicochemical properties with preservation of chitosan’s biocompatible characteristics. These chitosan based complexes are a good candidate for excipient materials for the design of different types of dosage forms. The aim of this review is to describe polyelectrolyte complexes of chitosan with selected natural polyanions and also to indicate some of the factors that influence the formation and stability of these formed complexes.

Abstract

Abstract