Degradable aliphatic polyesters such as polylactides, polyglycolides and their copolymers are used in several biomedical and pharmaceutical applications. We analyzed the influence of poly(L-lactide-co-glycolide) (PLGA) thin films on the adhesion, proliferation, motility and differentiation of primary human skin keratinocytes and fibroblasts in the context of their potential use as cell carriers for skin tissue engineering. We did not observe visible differences in the morphology, focal contact appearance, or actin cytoskeleton organization of skin cells cultured on PLGA films compared to those cultured under control conditions. Moreover, we did not detect biologically significant differences in proliferative activity, migration parameters, level of differentiation, or expression of vinculin when the cells were cultured on PLGA films and tissue culture polystyrene. Our results indicate that PLGA films do not affect the basic functions of primary human skin keratinocytes and fibroblasts and thus show acceptable biocompatibility in vitro, paving the way for their use as biomaterials for skin tissue engineering.
The objective of this study was to assess the extent of glucuronosyl epimerisation of dermatan sulfate (DS) chains, isolated from the matrix of burned wound bed. Dermatan sulfates were isolated and purified from normal and injured skin of domestic pigs, on days 3, 5, 10, 15, and 21 after the thermal damage. The wounds were treated with Propol T, silver sulfadiazine (SSD), physiological salt solution, and vehicle of Propol T. The isolated DS samples were depolymerised with chondroitinase ABC and chondroitinase B. The assessment of the amount of unsaturated disaccharides, released during DS enzymatic digestion was performed. It was found that in the course of the tissue repair the glucuronosyl epimerisation pattern of DS chains derived from burned wounds was altered as compared with epimerisation of DS isolated from normal skin. Propol T, in contrary to routinely used SSD, exerts a beneficial effect on DS metabolism leading to the formation of iduronate residue number similar to that of normal skin. The obtained results demonstrate that Propol T modulates DS structure resulting in the accelerated repair of burned tissue.
Enterococcus faecalis and Enterococcus faecium are among the main agents associated with nosocomial infections with high mortality in immunocompromised patients. Antibiotic resistance, especially against gentamicin and vancomycin among Enterococci, is a risk factor that could increase the morbidity and mortality rate. 179 Enterococci isolates from burn patients were included in this study. Antibiotic susceptibility testing was done using the disk diffusion test and minimum inhibitory concentration (MIC) was evaluated by agar microdilution. Vancomycin and gentamicin resistance associated genes including vanA, vanB, vanC, aac (6’)-Ie aph(2’’), aph(3’)-IIIa and ant(4’)-Ia were detected by PCR and their statistical relation with antibiotic resistance was evaluated. E. faecalis was the more prevalent strain among our local isolates and showed a higher antibiotic resistance in comparison to E. faecium. Vancomycin had a good antibacterial effect on the Enterococcus spp. isolates; however, resistance to this antibiotic and a high-level gentamicin resistance (HLGR) phenotype were observed. Among van operon genes, vanA was the most prevalent gene and among the gentamicin resistance genes, aph (3’)-IIIa was more frequent. The HLGR Enterococci are a real challenge in nosocomial infections. Vancomycin is a key antibiotic to treat such infections but emergence of VRE in our region could be a real concern and, therefore, phenotypic and molecular surveillance must be considered.