SUMMARY
Healing of burn tissue is a complete process involving reepitelization, granulation tissue formation and extracellular matrix remodeling. Thermal injury produces profound systemic changes, such as oligemic shock, anemia, renal failure and metabolic disorders. This causes direct tissue damages: inflammation and infection reactions. The tissue lesion also leads to increased oxidative stress in cells, as it has been observed by the low activity of endogenous antioxidant enzymatic and nonenzymatic systems. In this context, tissue matrix metalloproteinases (MMP) plays a key role in normal physiology of conjunctive tissue during its development, morphogenesis or wound healing, having an irregular activity and being involved in the patho-physiological processes. The analysis of biological samples, MMP profiles contribute to the characterization of some processes involving tissue remodeling, processes related to wound or burn healing, possibly to the development of new therapies. In this context we studied the proliferative effect of levan, a polysaccharide produced by Gram negative bacteria, Zymomonas mobilis, a microorganism that plays an important role in modern biotechnology to produce substances of great interest in biotechnology, food industry or in biomedicine. Our studies focused on analysis of tissue MMPs profiles from Wistar rats with lesions caused by mechanic processes on skin (wounds) and thermal (burn), treated by hallotherapy inCacica and Dej salt mines, before and after the treatment with levan. The results indicate that levan, a natural polysaccharide produced by wild type Z. mobilis NCIB 11163, as well as other bacterial strains, seems to have real value in the management of wounds and burns, applied individually or in combination with natural or artificial haloteraphy. The way that levan participates in the healing process is unknown, probably by activating the tissue metalloproteinases.