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PURPOSE: The synthesis and physico-chemical characterization of six N-substituted chloroacetylanilines and testing their plant growth regulating activity. MATERIAL/METHODS: The synthesis of the six N-substituted chloroacetylanilines was accomplished by condensation of N-substituted anilines, in an acidic medium, with chloroacetylchloride. Purified compounds obtained were physico-chemical characterized by elemental analysis and spectral analysis. Five different concentrations (0.1%, 0.5%, 0.75%, 1% and 5%) of the compounds solubilized in chloroform were used to analzyed their effects on the germination and mainly on the radicular elongation of wheat caryopses, Triticum aestivum subsp. aestivum (Poaceae), Dropia variety. RESULTS: The N-substituted chloroacetylanilines were solid, differently colored, with high melting temperatures and high yields. Their structure was confirmed both by elemental analysis and by the spectral methods (UV-Vis, FTIR, 1H-NMR, 13C-NMR, GC-MS). CONCLUSIONS: For the six analyzed compounds, at five different concentrations (0.1%, 0.5%, 0.75%, 1% and 5%), the experimental data obtained by the method of linear measurement, in the Triticum assay, showed the inhibition of mean radicular elongation compared with the reference.

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Due to their persistence and resistance to the current therapeutic approaches, Staphylococcus aureus biofilm-associated infections represent a major cause of morbidity and mortality in the hospital environment. Since (+)-usnic acid (UA), a secondary lichen metabolite, possesses antimicrobial activity against Gram-positive cocci, including S. aureus, the aim of this study was to load magnetic polylactic-co-glycolic acid-polyvinyl alcohol (PLGA-PVA) microspheres with UA, then to obtain thin coatings using matrix-assisted pulsed laser evaporation and to quantitatively assess the capacity of the bio-nano-active modified surface to control biofilm formation by S. aureus, using a culture-based assay. The UA-loaded microspheres inhibited both the initial attachment of S. aureus to the coated surfaces, as well as the development of mature biofilms. In vitro bioevalution tests performed on the fabricated thin films revealed great biocompatibility, which may endorse them as competitive candidates for the development of improved non-toxic surfaces resistant to S. aureus colonization and as scaffolds for stem cell cultivation and tissue engineering.

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During the healing process of third-degree skin burns, a very complex response involves different cells and tissues linked together by intra- and extra-cellular mechanisms. For the restoration of damaged tissues, angiogenesis is the key point in the formation of new blood vessels. By their emollient, astringent, antiseptic, anti-inflammatory, biostimulator, epithelizing and cicatrizing effect, active principles from natural products contribute to the acceleration of the wound-healing process. In our study, we investigated the angiogenesis process in experimental model of third-degree skin burns treated with three topical preparations (cold-creams) containing 10% herbal extracts, comparing with 1% sulfadiazine cream and cold-cream base respectively. By their biostimulator, epithelizing and cicatrizing effect, cold-creams with herbal extracts are locally modulators of the cellular response and support the wound healing. The phytocomplex stimulates the favorable evolution of the burnt skin wounds and the development of neoangiogenesis capillaries.

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Skin burns represent a major problem of public health because of their frequency and because of their seriousness, too. The healing process of the burnt wound is extremely complex, as it requires a well-coordinated collaboration among different tissues and cellular strings. From the morphological point of view, the stages of the repairing process of the skin wounds include processes of inflammation, proliferation and tissular remodeling. Angiogenesis has a role of extreme importance within the healing process of third-degree skin burns. That is because the vascularization remake is necessary for feeding the tissue of granulation with nutritive substances and oxygen. The angiogenesis started relatively fast. Three days after the producing of the burn, there could be identified strings of CD34+ endothelial precursor cells at the edges and deep into the wound, all these having contact with the normal blood vessels or with those lees affected by the thermal aggression. After the lumenization of the newly-formed capillary vessels, there appeared the pericytes within their membrane. The CD34+ endothelial precursor cells (EPc), as well as the pericytes, participate at the synthesis of the base membrane of the angiogenesis vessels. The density of the angiogenesis vessels on the surface unit within the tissue of granulation grew from three to 12 days. After that, they reduced progressively while the tissue of granulation was becoming mature. The angiogenesis vessels go through a process of reshuffling and maturation at the same time with the maturation of the tissue of granulation, but these processes did not appear to be finished when the skin was completely healed, and the epidermis was totally recovered.

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Local cellular response plays a major role in restoring skin integrity, in burns with infectious complications, chronic fibrous sequelae, etc. For the study of wound-healing process, different experimental models of skin burn were developed. Mice, rats, rabbits and guinea pigs are the most used laboratory animals, kept under standard conditions of light, temperature, food and water (ad libitum). Commonly, by intramuscular injection, general anesthesia was induced with ketamine hydrochloride. Most times, skin burns were inflicted on the dorsal region of animals. Metal devices with different shapes and weights, heated in water at various temperatures were applied locally, for few seconds. The paper reports on 65 natural medicinal products recommended for the external and internal treatment of skin damages (first- or second-degree burns, various wounds, ulcerations). Some of them are traditionally used in the Romanian ethnopharmacology, supporting the wound-healing process mainly because of their epithelizing, astringent, emollient, demulcent, anti-inflammatory, antimicrobial, immunomodulatory and antioxidant properties.

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Macrophages are some of the innate immune cells with a central role in inflammatory and immune responses. Studies in the last 20 years have shown that these cells have a particular influence in the reparative processes also. Our aim in this study was to evaluate the macrophage response in third-degree skin burns treated with allograft in an experimental model. Macrophages were specifically highlighted by immunohistochemical staining with anti-CD68 antibody. In the first evolutive part of the reparatory process, macrophages rapidly increased both numerically and as a relative area with about 300%, and then decreased progressively along with the granulation tissue maturation. Macrophage overall response curve was similar in animals treated with allograft and in the control group (untreated), which leads us to believe that the allograft does not induce a more ample immune response that could be regarded as pathological.

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Skin burns are a rather high incidence lesions which, depending on their depth and extension, can severely affect not only the skin but the entire organism. Third-degree skin burns extended on over 20% of the body surface often require skin graft. Skin allograft is a therapeutic alternative when autograft cannot be used. We investigated the allograft influence on the angiogenesis process in third-degree skin burns, using an experimental model. We noticed that the allograft induces a stronger inflammatory reaction associated with intense angiogenesis process by about 10-15% compared to control group.

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Pericytes and myofibroblasts are two types of connective cells that appear in large quantities in reparative processes. In order to evaluate their response and any relationships between them, we have inflicted third degree skin burns to seven groups of five common Wistar rats each from which we sampled granulation tissue at three days interval for histological and immunohistochemical studies. Alpha-SMA and CD34 antibodies revealed that granulation tissue myofibroblasts do not express CD34 and do not arise from pericytes. The parallel arrangement of myofibroblasts in relation to the burned wound surface suggests that their main function is mechanical traction on granulation tissue and wound edges.

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In the past 30 years, after the discovery of vascular proliferation factors, angiogenesis is one of the most intensively studied fields. Restoring the vascular network after burn injury is essential for healing, as it brings oxygen and nutrients to injured tissues, improves the contribution of inflammatory cells and prepares the damaged area for repair and tissue regeneration. To study the process of angiogenesis we used seven groups of five animals, each of adult Wistar rats, which were inflicted with third degree skin burns. From each group of animals, we sampled at successive intervals of three days the entire burnt wound with a ring of surrounding normal skin. Sampled skin fragments were processed for paraffin inclusion, sectioned with a microtome and stained with Hematoxylin-Eosin or Masson trichrome. The samples were also analyzed using single chromogenic immunohistochemistry or double immunofluorescence for the presence of CD34 and alpha smooth muscle actin (α-SMA). Angiogenesis process started at about three days after the burn infliction, with the appearance of tubular structures lined by CD34-positive cells. Subsequently, these cells showed intense proliferative activity that generated a network that included progressive neovascularization around the wound surface. Maximum vascular proliferation occurred at 9-15 days after injury, when the number of capillaries reached 229/mm², and the total area of capillary angiogenesis at 100.27 µm² (about 10% of the section area). Subsequently, the process of angiogenesis was gradually reduced, but remained at moderate levels after wound healing. During the process of angiogenesis, there was a very close relationship between CD34-positive cells and pericytes (as α-SMA-positive).

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