Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
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Article Citation - WoS: 96Citation - Scopus: 113Hypericum Perforatum Incorporated Chitosan Films as Potential Bioactive Wound Dressing Material(Elsevier Ltd., 2017) Güneş, Seda; Tıhmınlıoğlu, FundaRecent studies in wound dressing applications offer new therapies and promote wound healing process. The aim of this study was to develop Hypericum perforatum (St John's Wort) oil incorporated chitosan films for wound dressing applications. H. perforatum oil as a potential therapeutic agent was encapsulated in chitosan film to achieve a better wound dressing material. Oil incorporated chitosan films were successfully prepared by solvent casting method in different oil concentrations (0.25–1.5%v/v). Water vapor permeability (WVP), mechanical test, swelling behavior and surface hydrophobicity were performed in order to characterize the prepared films. Antimicrobial test was performed by disc diffusion method and the growth inhibition effects of the films including different amount of H. perforatum oil were investigated on Escherichia coli and Staphylococcus aureus. WVP increased with oil incorporation and the highest value was obtained for 0.25% oil concentration.The highest strain value was obtained in 0.25% oil content films although tensile stress decreased with increasing oil content. H. perforatum oil incorporated films had antimicrobial effect on both microorganisms. Chitosan based films had no cytotoxic effects on NIH3T3fibroblast cells and provided a good surface for cell attachment and proliferation. The results showed that the H. perforatum incorporated chitosan films seems to be a potential and novel biomaterial for wound healing applications.Article Citation - WoS: 44Citation - Scopus: 44Chitosan-Polyoxometalate Nanocomposites: Synthesis, Characterization and Application as Antimicrobial Agents(Springer Verlag, 2014) Fiorani, Giulia; Saoncella, Omar; Kaner, P.; Alsoy Altınkaya, Sacide; Figoli, Alberto; Bonchio, Marcella; Carraro, MauroPolyoxometalates (POMs) were used, together with chitosan (CS), to obtain hybrid nanoaggregates. Three representative POMs were efficiently assembled into nanoparticles of few hundred nm diameter, featuring entangled ribbons substructure. In order to establish suitable preparation and stability conditions, the assemblies were characterized in solution by UV-Vis spectroscopy, dynamic light scattering and ζ-potential. The nanoparticles were tested against E. coli (106 CFU/ml) in aqueous solution, showing a synergic activity of the heteropolyacid H5PMo10V2O40 and CS. For such components, a highly porous and antibacterial film was obtained upon lyophilisation of the colloidal mixture.Article Citation - WoS: 48Citation - Scopus: 58Micro-Encapsulation of Ozonated Red Pepper Seed Oil With Antimicrobial Activity and Application To Nonwoven Fabric(John Wiley and Sons Inc., 2013) Özyıldız, Figen; Karagönlü, S.; Başal, Güldemet; Uzel, Ataç; Bayraktar, OğuzIn recent years, functional fabrics possessing antimicrobial activity have drawn significant interest because antibiotic resistance is becoming widespread among pathogenic micro-organisms. The aim of this study was to produce microcapsules incorporating ozonated red pepper seed oil (ORPSO) with antimicrobial properties and apply them to nonwoven fabrics to prepare functional textiles. Red pepper seed oil (RPSO) was ozonated and micro-encapsulated via a complex coacervation method using gelatin (GE) and gum arabic (GA) as wall materials. While micro-encapsulation yield and oil loading decreased with increases in the amount of surfactant, the mean particle size increased. The antimicrobial activity of the oil was tested via the disc diffusion method. The microcapsules were also tested using the agar well method. While RPSO had no effect on the test micro-organisms, the ORPSO and microcapsules containing ORPSO were found to be active against the test micro-organisms. The microcapsules were then applied to nonwoven fabric using the padding method to produce a disposable functional textile. The microcapsule-impregnated functional fabrics provided a 5 log decrease in 1 h. It is therefore possible to functionalize nonwoven fabrics to have antimicrobial activity against antibiotic-resistant micro-organisms, using microcapsules containing ORPSO.Article Citation - WoS: 22Citation - Scopus: 24Optimization of Extraction Conditions for Active Components in Equisetum Arvense Extract(Ars Docendi, 2013) Uslu, Mehmet Emin; Erdoğan, İpek; Bayraktar, Oğuz; Ateş, MehmetResponse surface methodology was applied to predict optimum conditions for equisetum arvense extraction. Central composite design was used to monitor the effects of temperature, stirring speed, ethanol percent, extraction time, solid-liquid ratio on dependent variables such as, extract yield percent, total phenol content, total antioxidant capacity, silicic acid amount. According to the mathematical models obtained from the analysis, the highest values for yield percent, total phenol content, total antioxidant capacity and silicic acid amount were found to be 18.67 %, 123 mg gallic acid gr-1 dry weight extract, 1608 μM TEAC mg-1 dry weight extract and 0.0049 mg silicic acid mg-1 dry weight extract, respectively. The plant extracts were analyzed with HPLC to determine the phenolic content and compositional differences of extracts obtained at different extraction conditions. Plant extracts were also analyzed for their cytotoxic and antimicrobial activities. The high total antioxidant capacity and total phenolic content resulted in an increased cytotoxic effect on fibroblast cells. Equisetum arvense extracts showed antimicrobial activity against Staphylococcus epidermidis and Escherichia coli bacteria, however showed no effect against Candida albicans. © 2013 University of Bucharest.