Browsing by Subject "Antibacterial activity"
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Item Open Access Antibacterial activity of cyclodextrin-Azo dye inclusion complex encapsulated electrospun polycaprolactone nanofibers(Wiley-VCH Verlag GmbH & Co. KGaA, 2021-10-12) Demirci, Serkan; Çelebioğlu, Aslı; Demirci, S. K.; İdil, Ö.Polycaprolactone (PCL) nanofibers incorporating azo dye/γ-cyclodextrin inclusion complex (Azo/γ-CD-IC) were successfully produced. The characteristics of the Azo/γ-CD-IC and PCL/Azo/γ-CD-IC nanofibers were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Based on the SEM analysis the prepared nanofiber has a smooth surface with a size diameter below 500 nm. Meanwhile, the thermal stability of Azo was further improved after being embedded into Azo/γ-CD-IC and the PCL/Azo/γ-CD-IC nanofibers. Proton nuclear magnetic resonance (1H-NMR) was used to calculate the molar ratio of Azo/γ-CD. The antibacterial activity of the PCL/Azo/γ-CD-IC and PCL/Azo nanofibers was investigated using colony counting method and bacterial strains of Escherichia coli and Staphylococcus aureus were used. The results indicated that PCL/Azo/γ-CD-IC nanofibers have enhanced antibacterial activity against Escherichia coli and Staphylococcus aureus compared to PCL/Azo owing to inclusion complexation. Therefore, these PCL/Azo/γ-CD-IC nanofibers might have potential applications in the biomedical field.Item Open Access Antibacterial electrospun nanofibers from triclosan/cyclodextrin inclusion complexes(Elsevier, 2014) Celebioglu A.; Umu, O. C. O.; Tekinay, T.; Uyar, TamerThe electrospinning of nanofibers (NF) from cyclodextrin inclusion complexes (CD-IC) with an antibacterial agent (triclosan) was achieved without using any carrier polymeric matrix. Polymer-free triclosan/CD-IC NF were electrospun from highly concentrated (160% CD, w/w) aqueous triclosan/CD-IC suspension by using two types of chemically modified CD; hydroxypropyl-beta-cyclodextrin (HPβCD) and hydroxypropyl-gamma-cyclodextrin (HPγCD). The morphological characterization of the electrospun triclosan/CD-IC NF by SEM elucidated that the triclosan/HPβCD-IC NF and triclosan/HPγCD-IC NF were bead-free having average fiber diameter of 520±250nm and 1100±660nm, respectively. The presence of triclosan and the formation of triclosan/CD-IC within the fiber structure were confirmed by 1H-NMR, FTIR, XRD, DSC, and TGA studies. The initial 1:1molar ratio of the triclosan:CD was kept for triclosan/HPβCD-IC NF after the electrospinning and whereas 0.7:1molar ratio was observed for triclosan/HPγCD-IC NF and some uncomplexed triclosan was detected suggesting that the complexation efficiency of triclosan with HPγCD was lower than that of HPβCD. The antibacterial properties of triclosan/CD-IC NF were tested against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. It was observed that triclosan/HPβCD-IC NF and triclosan/HPγCD-IC NF showed better antibacterial activity against both bacteria compared to uncomplexed pure triclosan.Item Open Access Antibacterial electrospun zein nanofibrous web encapsulating thymol/cyclodextrin-inclusion complex for food packaging(Elsevier, 2017-10) Aytac Z.; Ipek, S.; Durgun, Engin; Tekinay, T.; Uyar, TamerThymol (THY)/γ-Cyclodextrin(γ-CD) inclusion complex (IC) encapsulated electrospun zein nanofibrous webs (zein-THY/γ-CD-IC-NF) were fabricated as a food packaging material. The formation of THY/γ-CD-IC (1:1 and 2:1) was proved by experimental (X-ray diffraction (XRD), thermal gravimetric analysis (TGA), 1H NMR) and computational techniques. THY/γ-CD-IC (2:1) exhibited higher preservation rate and stability than THY/γ-CD-IC (1:1). It is worth mentioning that zein-THY/γ-CD-IC-NF (2:1) preserved much more THY as observed in TGA and stability of THY/γ-CD-IC (2:1) was higher, as shown by a modelling study. Therefore, much more THY was released from zein-THY/γ-CD-IC-NF (2:1) than zein-THY-NF and zein-THY/γ-CD-IC-NF (1:1). Similarly, antibacterial activity of zein-THY/γ-CD-IC-NF (2:1) was higher than zein-THY-NF and zein-THY/γ-CD-IC-NF (1:1). It was demonstrated that zein-THY/γ-CD-IC-NF (2:1) was most effective in inhibiting the growth of bacteria on meat samples. These webs show potential application as an antibacterial food packaging material.Item Open Access Cytotoxic and bioactive properties of different color tulip flowers and degradation kinetic of tulip flower anthocyanins(Pergamon Press, 2013) Sagdic, O.; Ekici, L.; Ozturk, I.; Tekinay, T.; Polat, B.; Tastemur, B.; Bayram, O.; Senturk, B.This study was conducted to determine the potential use of anthocyanin-based extracts (ABEs) of wasted tulip flowers as food/drug colorants. For this aim, wasted tulip flowers were samples and analyzed for their bioactive properties and cytotoxicity. Total phenolic contents of the extracts of the claret red (126.55. mg of gallic acid equivalent (GAE)/g dry extract) and orange-red (113.76. mg GAE/g dry extract) flowers were the higher than those of the other tulip flowers. Total anthocyanin levels of the violet, orange-red, claret red and pink tulip flower extracts were determined as 265.04, 236.49, 839.08 and 404.45. mg pelargonidin 3-glucoside/kg dry extract, respectively and these levels were higher than those of the other flowers. The extracts were more effective for the inhibition of Listeria monocytogenes, Staphylococcus aureus and Yersinia enterocolitica compared to other tested bacteria. Additionally, the cytotoxic effects of five different tulip flower extracts on human breast adenocarcinoma (MCF-7) cell line were investigated. The results showed that the orange red, pink and violet extracts had no cytotoxic activity against MCF-7 cell lines while yellow and claret red extracts appeared to be toxic for the cells. Overall, the extracts of tulip flowers with different colors possess remarkable bioactive and cytotoxic properties. © 2013 Elsevier Ltd.Item Open Access Electrospinning of cyclodextrin/linalool-inclusion complex nanofibers: fast-dissolving nanofibrous web with prolonged release and antibacterial activity(Elsevier, 2017-09) Aytac Z.; Yildiz, Z. I.; Kayaci-Senirmak, F.; Tekinay, T.; Uyar, TamerThe volatility and limited water solubility of linalool is a critical issue to be solved. Here, we demonstrated the electrospinning of polymer-free nanofibrous webs of cyclodextrin/linalool-inclusion complex (CD/linalool-IC-NFs). Three types of modified cyclodextrin (HPβCD, MβCD, and HPγCD) were used to electrospin CD/linalool-IC-NFs. Free-standing CD/linalool-IC-NFs facilitate maximum loading of linalool up to 12% (w/w). A significant amount of linalool (45–89%) was preserved in CD/linalool-IC-NFs, due to enhancement in the thermal stability of linalool by cyclodextrin inclusion complexation. Remarkably, CD/linalool-IC-NFs have shown fast-dissolving characteristics in which these nanofibrous webs dissolved in water within two seconds. Furthermore, linalool release from CD/linalool-IC-NFs inhibited growth of model Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria to a great extent. Briefly, characteristics of liquid linalool have been preserved in a solid nanofiber form and designed CD/linalool-IC-NFs confer high loading capacity, enhanced shelf life and strong antibacterial activity of linalool.Item Open Access Evaluation of silver content and antibacterial activities of silver loaded fiber/cotton blended textile fabrics(2010) Üreyen, M. E.; Gök Ö.; Ates, M.; Günkaya G.; Süzer, ŞefikThe aims of this work were to analyze the antibacterial activity and laundering durability of the silver loaded cellulosic fiber/cotton blended antibacterial textile fabrics, to quantify the silver content present in fabrics, and to examine the relationship between the antibacterial activity and silver content. For this aims knitting fabrics consisting of SeaCell® Active, which is the cellulosic fiber incorporated with seaweed and silver ions, and cotton fibers blended with five different ratios were produced. All fabric samples bleached and washed 60 times. The antibacterial efficiency was evaluated according to AATCC 100-1999 method after each ten laundry cycles. Silver content of the fabrics were determined by atomic absorption spectroscopy (AAS). Fiber and fabric surfaces were investigated using Scanning Electron Microscopy (SEM) and by X-Ray Photoelectron Spectroscopy (XPS) views. Antibacterial tests showed that good antibacterial activity can be achieved after several washings even with 3% of SeaCell ® Active fibers in blended fabrics. Significant correlation was found between silver content and bacterial reductionItem Open Access Fast-dissolving, prolonged release, and antibacterial cyclodextrin/limonene-inclusion complex nanofibrous webs via polymer-free electrospinning(American Chemical Society, 2016) Aytac Z.; Yildiz, Z. I.; Kayaci-Senirmak, F.; S. Keskin, N. O.; Kusku, S. I.; Durgun, Engin; Tekinay, T.; Uyar, TamerWe have proposed a new strategy for preparing free-standing nanofibrous webs from an inclusion complex (IC) of a well-known flavor/fragrance compound (limonene) with three modified cyclodextrins (HPβCD, MβCD, and HPγCD) via electrospinning (CD/limonene-IC-NFs) without using a polymeric matrix. The experimental and computational modeling studies proved that the stoichiometry of the complexes was 1:1 for CD/limonene systems. MβCD/limonene-IC-NF released much more limonene at 37, 50, and 75 °C than HPβCD/limonene-IC-NF and HPγCD/limonene-IC-NF because of the greater amount of preserved limonene. Moreover, MβCD/limonene-IC-NF has released only 25% (w/w) of its limonene, whereas HPβCD/limonene-IC-NF and HPγCD/limonene-IC-NF released 51 and 88% (w/w) of their limonene in 100 days, respectively. CD/limonene-IC-NFs exhibited high antibacterial activity against E. coli and S. aureus. The water solubility of limonene increased significantly and CD/limonene-IC-NFs were dissolved in water in a few seconds. In brief, CD/limonene-IC-NFs with fast-dissolving character enhanced the thermal stability and prolonged the shelf life along with antibacterial properties could be quite applicable in food and oral care applications.Item Open Access Molecular encapsulation of cinnamaldehyde within cyclodextrin inclusion complex electrospun nanofibers: fast-dissolution, enhanced water solubility, high temperature stability, and antibacterial activity of cinnamaldehyde(American Chemical Society, 2019) Yıldız, Zehra İrem; Kılıç, Mehmet Emin; Durgun, Engin; Uyar, TamerThe electrospinning of nanofibers (NFs) of cinnamaldehyde inclusion complexes (ICs) with two different hydroxypropylated cyclodextrins (CDs), hydroxypropyl-β-cyclodextrin (HP-β-CD) and hydroxypropyl-γ-cyclodextrin (HP-γ-CD), was successfully performed in order to produce cinnamaldehyde/CD-IC NFs without using an additional polymer matrix. The inclusion complexation between cinnamaldehyde and hydroxypropylated CDs was studied by computational molecular modeling, and the results suggested that HP-β-CD and HP-γ-CD can be inclusion complexed with cinnamaldehyde at 1:1 and 2:1 (cinnamaldehyde/CD) molar ratios. Additionally, molecular modeling and phase solubility studies showed that water solubility of cinnamaldehyde dramatically increases with cyclodextrin inclusion complex (CD-IC) formation. The HP-β-CD has shown slightly stronger binding with cinnamaldehyde when compared to HP-γ-CD for cinnamaldehyde/CD-IC. Although cinnamaldehyde is a highly volatile compound, it was effectively preserved with high loading by the cinnamaldehyde/CD-IC NFs. It was also observed that cinnamaldehyde has shown much higher temperature stability in cinnamaldehyde/CD-IC NFs compared to uncomplexed cinnamaldehyde because of the inclusion complexation state of cinnamaldehyde within the hydroxypropylated CD cavity. Moreover, cinnamaldehyde still has kept its antibacterial activity in cinnamaldehyde/CD-IC NF samples when tested against Escherichia coli. In addition, cinnamaldehyde/CD-IC NF mats were fast-dissolving in water, even though pure cinnamaldehyde has a water-insoluble nature. In brief, self-standing nanofibrous mats of electrospun cinnamaldehyde/CD-IC NFs are potentially applicable in food, oral-care, healthcare, and pharmaceutics because of their fast-dissolving character, enhanced water solubility, stability at elevated temperature, and promising antibacterial activity.Item Open Access Multivalent presentation of cationic peptides on supramolecular nanofibers for antimicrobial activity(American Chemical Society, 2017) Beter, M.; Kara, H. K.; Topal, A. E.; Dana, A.; Tekinay, A. B.; Güler, Mustafa O.Noncovalent and electrostatic interactions facilitate the formation of complex networks through molecular self-assembly in biomolecules such as proteins and glycosaminoglycans. Self-assembling peptide amphiphiles (PA) are a group of molecules that can form nanofibrous structures and may contain bioactive epitopes to interact specifically with target molecules. Here, we report the presentation of cationic peptide sequences on supramolecular nanofibers formed by self-assembling peptide amphiphiles for cooperative enhanced antibacterial activity. Antibacterial properties of self-assembled peptide nanofibers were significantly higher than soluble peptide molecules with identical amino acid sequences, suggesting that the tandem presentation of bioactive epitopes is important for designing new materials for bactericidal activity. In addition, bacteria were observed to accumulate more rapidly on peptide nanofibers compared to soluble peptides, which may further enhance antibacterial activity by increasing the number of peptide molecules interacting with the bacterial membrane. The cationic peptide amphiphile nanofibers were observed to attach to bacterial membranes and disrupt their integrity. These results demonstrate that short cationic peptides show a significant improvement in antibacterial activity when presented in the nanofiber form.Item Open Access Release and antibacterial activity of allyl isothiocyanate/β-cyclodextrin complex encapsulated in electrospun nanofibers(Elsevier, 2014) Aytac Z.; Dogan, S.Y.; Tekinay, T.; Uyar, TamerAllyl isothiocyanate (AITC) is known as an efficient antibacterial agent but it has a very high volatility. Herein, AITC and AITC/β-cyclodextrin (CD)-inclusion complex (IC) incorporated in polyvinyl alcohol (PVA) nanofibers were produced via electrospinning. SEM images elucidated that incorporation of AITC and AITC/β-CD-IC into polymer matrix did not affect the bead-free fiber morphology of PVA nanofibers. 1H-NMR and headspace GC-MS analyses revealed that very low amount of AITC was remained in PVA/AITC-NF because of the rapid evaporation of AITC during the electrospinning process. Nevertheless, much higher amount of AITC was preserved in the PVA/AITC/β-CD-IC-NF due to the CD inclusion complexation. The sustained release of AITC from nanofibers was evaluated at 30°C, 50°C and 75°C via headspace GC-MS. When compared to PVA/AITC-NF, PVA/AITC/β-CD-IC-NF has shown higher antibacterial activity against Escherichia coli and Staphylococcus aureus due to the presence of higher amount of AITC in this sample which was preserved by CD-IC. © 2014 Elsevier B.V.