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1.
Mol Pharm ; 20(5): 2624-2633, 2023 05 01.
Article in English | MEDLINE | ID: mdl-37014780

ABSTRACT

Griseofulvin (GSF) is one of the most widely used antifungal suffering from low water solubility and limited bioavailability. Here, cyclodextrin (CD) derivatives of hydroxypropyl-beta-CD (HPßCD) known for its high-water solubility were used to form inclusion complexes (ICs) with GSF. Here, the molecular modeling study revealed the more efficient complex formation with 1:2 (guest:CD) stoichiometry, so ICs of GSF-HPßCD were prepared using a 1:2 molar ratio (GSF:HPßCD) and then mixed with pullulan (PULL) to generate nanofibers (NFs) using the electrospinning technique. PULL is a nontoxic water-soluble biopolymer and the ultimate PULL/GSF-HPßCD-IC NF was obtained with a defect-free fiber morphology having 805 ± 180 nm average diameter. The self-standing and flexible PULL/GSF-HPßCD-IC NF was achieved to be produced with a loading efficiency of ∼98% corresponding to ∼6.4% (w/w) of drug content. In comparison, the control sample of PULL/GSF NF was formed with a lower loading efficiency value of ∼72% which equals to ∼4.7% (w/w) of GSF content. Additionally, PULL/GSF-HPßCD-IC NF provided an enhanced aqueous solubility for GSF compared to PULL/GSF NF so a faster release profile with ∼2.5 times higher released amount was obtained due to inclusion complexation between GSF and HPßCD within the nanofibrous web. On the other hand, both nanofibrous webs rapidly disintegrated (∼2 s) in the artificial saliva medium that mimics the oral cavity environment. Briefly, PULL/GSF-HPßCD-IC NF can be a promising dosage formulation as a fast-disintegrating delivery system for antifungal oral administration owing to the improved physicochemical properties of GSF.


Subject(s)
Cyclodextrins , Nanofibers , Cyclodextrins/chemistry , 2-Hydroxypropyl-beta-cyclodextrin/chemistry , Nanofibers/chemistry , Griseofulvin , Drug Carriers/chemistry , Antifungal Agents , Solubility , Water/chemistry
2.
J Am Chem Soc ; 144(19): 8848-8860, 2022 05 18.
Article in English | MEDLINE | ID: mdl-35486918

ABSTRACT

Fundamental understanding of catalytic deactivation phenomena such as sulfur poisoning occurring on metal/metal-oxide interfaces is essential for the development of high-performance heterogeneous catalysts with extended lifetimes. Unambiguous identification of catalytic poisoning species requires experimental methods simultaneously delivering accurate information regarding adsorption sites and adsorption geometries of adsorbates with nanometer-scale spatial resolution, as well as their detailed chemical structure and surface functional groups. However, to date, it has not been possible to study catalytic sulfur poisoning of metal/metal-oxide interfaces at the nanometer scale without sacrificing chemical definition. Here, we demonstrate that near-field nano-infrared spectroscopy can effectively identify the chemical nature, adsorption sites, and adsorption geometries of sulfur-based catalytic poisons on a Pd(nanodisk)/Al2O3 (thin-film) planar model catalyst surface at the nanometer scale. The current results reveal striking variations in the nature of sulfate species from one nanoparticle to another, vast alterations of sulfur poisoning on a single Pd nanoparticle as well as at the assortment of sulfate species at the active metal-metal-oxide support interfacial sites. These findings provide critical molecular-level insights crucial for the development of long-lifetime precious metal catalysts resistant toward deactivation by sulfur.


Subject(s)
Oxides , Sulfur , Catalysis , Oxides/chemistry , Spectrum Analysis , Sulfates , Sulfur/chemistry
3.
Chemistry ; 27(35): 8890, 2021 Jun 21.
Article in English | MEDLINE | ID: mdl-34114263

ABSTRACT

Invited for the cover of this issue is the Ferdi Karadas and Ekmel Ozbay groups at Bilkent University and co-workers. The image presents an utopic city in Iron Age, which is powered by an iron photosensitizer that bridges semiconductor buildings (TiO2 nanowires) and the catalyst (cobalt site). Read the full text of the article at 10.1002/chem.202100654.


Subject(s)
Iron , Water , Catalysis , Ferrocyanides , Humans
4.
Chemistry ; 27(35): 8966-8976, 2021 Jun 21.
Article in English | MEDLINE | ID: mdl-33929068

ABSTRACT

The replacement of traditional ruthenium-based photosensitizers with low-cost and abundant iron analogs is a key step for the advancement of scalable and sustainable dye-sensitized water splitting cells. In this proof-of-concept study, a pyridinium ligand coordinated pentacyanoferrate(II) chromophore is used to construct a cyanide-based CoFe extended bulk framework, in which the iron photosensitizer units are connected to cobalt water oxidation catalytic sites through cyanide linkers. The iron-sensitized photoanode exhibits exceptional stability for at least 5 h at pH 7 and features its photosensitizing ability with an incident photon-to-current conversion capacity up to 500 nm with nanosecond scale excited state lifetime. Ultrafast transient absorption and computational studies reveal that iron and cobalt sites mutually support each other for charge separation via short bridging cyanide groups and for injection to the semiconductor in our proof-of-concept photoelectrochemical device. The reorganization of the excited states due to the mixing of electronic states of metal-based orbitals subsequently tailor the electron transfer cascade during the photoelectrochemical process. This breakthrough in chromophore-catalyst assemblies will spark interest in dye-sensitization with robust bulk systems for photoconversion applications.


Subject(s)
Iron , Water , Ferrocyanides , Oxidation-Reduction
5.
Mol Pharm ; 18(12): 4486-4500, 2021 12 06.
Article in English | MEDLINE | ID: mdl-34780196

ABSTRACT

Prednisolone is a widely used immunosuppressive and anti-inflammatory drug type that suffers from low aqueous solubility and bioavailability. Due to the inclusion complexation with cyclodextrins (CDs), prednisolone's drawbacks that hinder its potential during the administration can be eliminated effectively. Here, we have early shown the electrospinning of free-standing nanofibrous webs of CD/prednisolone inclusion complexes (ICs) in the absence of a polymer matrix. In this study, hydroxypropyl-beta-CD (HPßCD) has been used to form ICs with prednisolone and generate nanofibrous webs with a drug loading capacity of ∼10% (w/w). Pullulan/prednisolone nanofibrous webs have been also fabricated as a control sample having the same drug loading (∼10%, w/w). It has been demonstrated that prednisolone has been found in an amorphous state in the HPßCD/prednisolone nanofibrous web due to inclusion complexation, while it has retained its crystal structure in the pullulan/prednisolone nanofibrous web. Therefore, the HPßCD/prednisolone IC nanofibrous web has shown a faster and enhanced release profile and superior disintegration feature in artificial saliva than the pullulan/prednisolone nanofibrous web. The complexation energy calculated using ab initio modeling displayed a more favorable interaction between HPßCD and prednisolone in the case of a molar ratio of 2:1 than 1:1 (CD: drug). Here, the HPßCD/prednisolone IC nanofibrous web has been developed without using a toxic component or solvent to dissolve drug molecules and boost drug loading in amorphous nature. The investigation of IC nanofibrous webs has been conducted to formulate a promising alternative to the orally disintegrating tablet formulation of prednisolone in the market. The nanofibrous structure and the improved physicochemical properties of prednisolone arising with the complexation might ensure a faster disintegration and onset of action against commercially available and orally disintegrating delivery systems during the desired treatment.


Subject(s)
2-Hydroxypropyl-beta-cyclodextrin/chemistry , Nanofibers/chemistry , Prednisolone/chemistry , Administration, Oral , Drug Delivery Systems , Drug Liberation , Magnetic Resonance Spectroscopy , Models, Molecular , Prednisolone/administration & dosage , Solubility
6.
Phys Chem Chem Phys ; 19(42): 28963-28969, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-29063089

ABSTRACT

The realization of buckled monolayer sheets of boron (i.e., borophene) and its other polymorphs has attracted significant interest in the field of two-dimensional systems. Motivated by borophene's tendency to donate electrons, we analyzed the interaction of single halogen atoms (F, Cl, Br, I) with borophene. The possible adsorption sites are tested and the top of the boron atom is found as the ground state configuration. The nature of bonding and strong chemical interaction is revealed by using projected density of states and charge difference analysis. The migration of single halogen atoms on the surface of borophene is analyzed and high diffusion barriers that decrease with atomic size are obtained. The metallicity of borophene is preserved upon adsorption but anisotropy in electrical conductivity is altered. The variation of adsorption and formation energy, interatomic distance, charge transfer, diffusion barriers, and bonding character with the type of halogen atom are explored and trends are revealed. Lastly, the adsorption of halogen molecules (F2, Cl2, Br2, I2), including the possibility of dissociation, is studied. The obtained results are not only substantial for fundamental understanding of halogenated derivatives of borophene, but also are useful for near future technological applications.

8.
Phys Chem Chem Phys ; 17(19): 13013-20, 2015 May 21.
Article in English | MEDLINE | ID: mdl-25913574

ABSTRACT

Two-dimensional (2D) materials have attracted growing interest due to their potential use in the next generation of nanoelectronic and optoelectronic applications. On the basis of first-principles calculations based on density functional theory, we first investigate the electronic and mechanical properties of single layer boron phosphide (h-BP). Our calculations show that h-BP is a mechanically stable 2D material with a direct band gap of 0.9 eV at the K-point, promising for both electronic and optoelectronic applications. We next investigate the electron transport properties of a p-n junction constructed from single layer boron phosphide (h-BP) using the non-equilibrium Green's function formalism. The n- and p-type doping of BP are achieved by substitutional doping of B with C and P with Si, respectively. C(Si) substitutional doping creates donor (acceptor) states close to the conduction (valence) band edge of BP, which are essential to construct an efficient p-n junction. By modifying the structure and doping concentration, it is possible to tune the electronic and transport properties of the p-n junction which exhibits not only diode characteristics with a large current rectification but also negative differential resistance (NDR). The degree of NDR can be easily tuned via device engineering.

9.
Polymers (Basel) ; 16(2)2024 Jan 12.
Article in English | MEDLINE | ID: mdl-38257016

ABSTRACT

In this study, we designed a platform based on a laser-driven approach for fast, efficient, and controllable MOF synthesis. The laser irradiation method was performed for the first time to synthesize Zn-based MOFs in record production time (approximately one hour) compared to all known MOF production methods with comparable morphology. In addition to well-known structural properties, we revealed that the obtained ZnMOFs have a novel optical response, including photoluminescence behavior in the visible range with nanosecond relaxation time, which is also supported by first-principles calculations. Additionally, photocatalytic degradation of methylene blue with ZnMOF was achieved, degrading the 10 ppm methylene blue (MB) solution 83% during 1 min of irradiation time. The application of laser technology can inspire the development of a novel and competent platform for a fast MOF fabrication process and extend the possible applications of MOFs to miniaturized optoelectronic and photonic devices.

10.
RSC Med Chem ; 15(2): 595-606, 2024 Feb 21.
Article in English | MEDLINE | ID: mdl-38389869

ABSTRACT

Naproxen is a well-known non-steroidal anti-inflammatory drug (NSAID) that suffers from limited water solubility. The inclusion complexation with cyclodextrin (CD) can eliminate this drawback and the free-standing nanofibrous film (NF) generated from these inclusion complexes (ICs) can be a promising alternative formula as an orally disintegrating drug delivery system. For this, naproxen/CD IC NFs were generated using the highly water soluble hydroxypropylated derivative of ßCD (HPßCD) with two different molar ratios of 1/1 and 1/2 (drug/CD). The complexation energy calculated by the modeling study demonstrated a more favorable interaction between HPßCD and naproxen for the 1/2 molar ratio than 1/1. HPßCD/naproxen IC NFs were generated with loading concentrations of ∼7-11% and without using toxic chemicals. HPßCD/naproxen IC NFs indicated a faster and enhanced release profile in aqueous medium compared to pure naproxen owing to inclusion complexation. Moreover, rapid disintegration in less than a second was achieved in an artificial saliva environment.

11.
Food Chem ; 423: 136284, 2023 Oct 15.
Article in English | MEDLINE | ID: mdl-37156137

ABSTRACT

Carotenoids act as effective antioxidant defense systems in humans as they scavenge molecular oxygen and peroxyl radicals. However, their poor water solubility and being susceptible to degradation driven by light and oxygen hinder their bioactivity, therefore, they should be stabilized by host matrices against oxidation. Here, ß-carotene was encapsulated in electrospun cyclodextrin (CD) nanofibers to increase its water-solubility and photostability to enhance its antioxidant bioactivity. ß-carotene/CD complex aqueous solutions were electrospun into nanofibers. The bead-free morphology of the ß-carotene/CD nanofibers was confirmed by SEM. The formation of ß-carotene/CD complexes was explored through computational modeling and experimentally by FTIR, XRD and solubility tests. The antioxidant activity of the fibers exposed to UV irradiation was demonstrated via a free radical scavenger assay, where ß-carotene/CD nanofibers revealed protection against UV radiation. Overall, this work reports the water-borne electrospinning of antioxidant ß-carotene/CD inclusion complex nanofibers, which stabilize the encapsulated ß-carotene against UV-mediated oxidation.


Subject(s)
Cyclodextrins , Nanofibers , Humans , Antioxidants , beta Carotene , Carotenoids , Water , Solubility
12.
Int J Pharm ; 623: 121921, 2022 Jul 25.
Article in English | MEDLINE | ID: mdl-35714816

ABSTRACT

Ondansetron (ODS) is an effective antiemetic drug which suffers from limited solubility and bioavailability during oral administration due to first-pass metabolism. However, these limitations can be mitigated through inclusion complexation with cyclodextrins (CDs). In this study, we have reported the electrospinning of polymer-free, free-standing ODS/CD nanofibrous webs (NW), a promising approach for developing a fast-disintegrating delivery system of an antiemetic drug molecule. Highly water soluble hydroxypropyl-beta-cyclodextrins (HPßCD) were used as both complexation agent and electrospinning matrix. The computational study revealed that the 1/2 (drug/CD) stoichiometry was more favorable compared to 1/1. The ODS/HPßCD NW was obtained with higher loading efficiency (∼96 %) compared to the control sample of ODS/polyvinyl alcohol (PVA) NW (∼80 %). The amorphous distribution of ODS raised by complexation and the highly water-soluble nature of HPßCD resulted into faster and better release profile and quite faster disintegration property (∼2 s) in artificial saliva than polymeric ODS/PVA NW. Here, ODS/HPßCD NW was generated in the absence of a toxic solvent or chemical to enable the drug loading in an amorphous state. From all reasons above, ODS/HPßCD NW might be a promising alternative to the polymeric based systems for the purpose of fast-disintegrating oral drug delivery.


Subject(s)
Antiemetics/chemistry , Cyclodextrins/chemistry , Nanofibers , Ondansetron/chemistry , Administration, Oral , Antiemetics/pharmacology , Chemical Phenomena , Cyclodextrins/pharmacology , Drug Delivery Systems , Microscopy, Electron, Scanning , Nanofibers/chemistry , Nanofibers/ultrastructure , Ondansetron/pharmacology
13.
J Colloid Interface Sci ; 610: 321-333, 2022 Mar 15.
Article in English | MEDLINE | ID: mdl-34923270

ABSTRACT

Tetracycline is a widely used antibiotic suffering from poor water solubility and low bioavailability. Here, hydroxypropyl-beta-cyclodextrin (HPßCD) was used to form inclusion complexes (IC) of tetracycline with 2:1 M ratio (CD:drug). Then, tetracycline-HPßCD-IC was mixed with pullulan- a non-toxic, water-soluble biopolymer - to form nanofibrous webs via electrospinning. The electrospinning of pullulan/tetracycline-HPßCD-IC was yielded into defect-free nanofibers collected in the form of a self-standing and flexible material with the loading capacity of âˆ¼ 7.7 % (w/w). Pullulan/tetracycline nanofibers was also generated as control sample having the same drug loading. Tetracycline was found in the amorphous state in case of pullulan/tetracycline-HPßCD nanofibers due to inclusion complexation. Through inclusion complexation with HPßCD, enhanced aqueous solubility and faster release profile were provided for pullulan/tetracycline-HPßCD-IC nanofibers compared to pullulan/tetracycline one. Additionally, pullulan/tetracycline-HPßCD-IC nanofibers readily disintegrated when wetted with artificial saliva while pullulan/tetracycline nanofibers were not completely absorbed by the same simulate environment. Electrospun nanofibers showed promising antibacterial activity against both gram-positive and gram-negative bacteria. Briefly, our findings indicated that pullulan/tetracycline-HPßCD-IC nanofibers could be an attractive material as orally fast disintegrating drug delivery system for the desired antibiotic treatment thanks to its promising physicochemical and antibacterial properties.


Subject(s)
Cyclodextrins , Nanofibers , 2-Hydroxypropyl-beta-cyclodextrin , Anti-Bacterial Agents/pharmacology , Drug Carriers , Drug Delivery Systems , Glucans , Gram-Negative Bacteria , Gram-Positive Bacteria , Solubility , Tetracycline/pharmacology
14.
J Colloid Interface Sci ; 585: 184-194, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33279701

ABSTRACT

HYPOTHESIS: The widespread use of antibacterial electrospun nanofibers is mostly restricted due to their low loading capacity to carry antibiotics and the need to use toxic organic solvents to boost the antibiotic loading capacity. Nanofibers based on natural excipients, such as cyclodextrin (CD)-based nanofibers, can carry larger amounts of antibiotics while achieving better stability via inclusion complexation. EXPERIMENTS: Nanofibers were produced by electrospinning and analyzed by electron microscopy to investigate the morphology of fibers. The formation of inclusion-complexation was analyzed by 1H NMR, FTIR, and XRD. Thermal analysis of the fibers was done using TGA. Ab initio modeling studies were done to calculate the complexation energies of antibiotics with CD. A disk-diffusion assay was used to test the antibacterial activity of the fibers. FINDINGS: Bead-free antibacterial nanofibers with mean diameters between 340 and 550 nm were produced. The formation of inclusion complexes (IC) between the CD and the antibiotics was confirmed by FTIR and 1H NMR, which was further verified by the disappearance of the crystalline peaks of antibiotics as determined by XRD analysis. Thermal analysis of the nanofibers revealed that the formulations showed good antibiotic encapsulation (45-90%). Ab initio simulations revealed that gentamicin had the highest complexation energy, followed by kanamycin, chloramphenicol, and ampicillin. The antibacterial nanofibers rapidly dissolved in water and artificial saliva, successfully releasing the CD antibiotic complexes. The nanofibers showed high antibacterial activity against Gram-negative Escherichia coli.


Subject(s)
Cyclodextrins , Nanofibers , Pharmaceutical Preparations , Anti-Bacterial Agents/pharmacology , Solubility
15.
Nanoscale Adv ; 3(13): 3894-3899, 2021 Jun 30.
Article in English | MEDLINE | ID: mdl-36133020

ABSTRACT

Mechanical properties of transition metal dichalcogenides (TMDCs) are relevant to their prospective applications in flexible electronics. So far, the focus has been on the semiconducting TMDCs, mostly MoX2 and WX2 (X = S, Se) due to their potential in optoelectronics. A comprehensive understanding of the elastic properties of metallic TMDCs is needed to complement the semiconducting TMDCs in flexible optoelectronics. Thus, mechanical testing of metallic TMDCs is pertinent to the realization of the applications. Here, we report on the atomic force microscopy-based nano-indentation measurements on ultra-thin 2H-TaS2 crystals to elucidate the stretching and breaking of the metallic TMDCs. We explored the elastic properties of 2H-TaS2 at different thicknesses ranging from 3.5 nm to 12.6 nm and find that the Young's modulus is independent of the thickness at a value of 85.9 ± 10.6 GPa, which is lower than the semiconducting TMDCs reported so far. We determined the breaking strength as 5.07 ± 0.10 GPa which is 6% of the Young's modulus. This value is comparable to that of other TMDCs. We used ab initio calculations to provide an insight into the high elasticity measured in 2H-TaS2. We also performed measurements on a small number of 1T-TaTe2, 3R-NbS2 and 1T-NbTe2 samples and extended our ab initio calculations to these materials to gain a deeper understanding on the elastic and breaking properties of metallic TMDCs. This work illustrates that the studied metallic TMDCs are suitable candidates to be used as additives in composites as functional and structural elements and for flexible conductive electronic devices.

16.
ACS Nano ; 15(5): 8715-8723, 2021 May 25.
Article in English | MEDLINE | ID: mdl-33973765

ABSTRACT

Ternary metal-oxy-chalcogenides are emerging as next-generation layered semiconductors beyond binary metal-chalcogenides (i.e., MoS2). Among ternary metal-oxy-chalcogenides, especially Bi2O2Se has been demonstrated in field-effect transistors and photodetectors, exhibiting ultrahigh performance with robust air stability. The growth method for Bi2O2Se that has been reported so far is a powder sublimation based chemical vapor deposition. The first step for pursuing the practical application of Bi2O2Se as a semiconductor material is developing a gas-phase growth process. Here, we report a cracking metal-organic chemical vapor deposition (c-MOCVD) for the gas-phase growth of Bi2O2Se. The resulting Bi2O2Se films at very low growth temperature (∼300 °C) show single-crystalline quality. By taking advantage of the gas-phase growth, the precise phase control was demonstrated by modulating the partial pressure of each precursor. In addition, c-MOCVD-grown Bi2O2Se exhibits outstanding electrical and optoelectronic performance at room temperature without passivation, including maximum electron mobility of 127 cm2/(V·s) and photoresponsivity of 45134 A/W.

17.
Colloids Surf B Biointerfaces ; 178: 129-136, 2019 Jun 01.
Article in English | MEDLINE | ID: mdl-30852264

ABSTRACT

Electrospun gelatin nanofibrous matrix encapsulating ciprofloxacin (CIP)/hydroxypropyl-beta-cyclodextrin (HPßCD)-inclusion complex (IC) was produced via electrospinning method. Computational modeling indicated that van der Waals forces are the most significant driving forces for the complexation and hydrophobic moiety (piperazinyl) of CIP, which was included in the cavity of HPßCD. The FTIR and XRD studies indicated the formation of CIP/HPßCD host/guest complexation, FTIR also suggested that hydrophobic moiety of CIP is in the HPßCD cavity in parallel with the computational modeling results. The phase solubility diagram demonstrated that the solubility of CIP was enhanced after complexation with HPßCD. SEM images showed that electrospun gelatin nanofibers encapsulating CIP/HPßCD-IC have bead-free morphology with a diameter of ˜90 nm. The gelatin nanofibrous mat loaded with CIP/HPßCD-IC has exhibited fast-dissolving character in water compared to gelatin/CIP nanofibrous mat due to the enhanced wettability of the nanofibrous mat by HPßCD and improvement achieved in the solubility of CIP.


Subject(s)
Ciprofloxacin/chemistry , Cyclodextrins/chemistry , Gelatin/chemistry , Nanofibers/chemistry , 2-Hydroxypropyl-beta-cyclodextrin/chemistry , Spectroscopy, Fourier Transform Infrared
18.
J Agric Food Chem ; 67(40): 11066-11076, 2019 Oct 09.
Article in English | MEDLINE | ID: mdl-31508948

ABSTRACT

The electrospinning of nanofibers (NFs) of cinnamaldehyde inclusion complexes (ICs) with two different hydroxypropylated cyclodextrins (CDs), hydroxypropyl-ß-cyclodextrin (HP-ß-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-ß-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-ß-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.


Subject(s)
Acrolein/analogs & derivatives , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Drug Compounding/methods , Acrolein/chemistry , Acrolein/pharmacology , Cyclodextrins/chemistry , Drug Compounding/instrumentation , Escherichia coli/drug effects , Escherichia coli/growth & development , Nanofibers/chemistry , Solubility , Temperature
19.
ACS Omega ; 3(2): 1815-1822, 2018 Feb 28.
Article in English | MEDLINE | ID: mdl-30023816

ABSTRACT

The synthesis of atomically thin boron sheets on a silver substrate opened a new area in the field of two-dimensional systems. Similar to hydrogenated and halogenated graphene, the uniform coating of borophene with fluorine atoms can lead to new derivatives of borophene with novel properties. In this respect, we explore the possible structures of fluorinated borophene for varying levels of coverage (B n F) by using first-principles methods. Following the structural optimizations, phonon spectrum analysis and ab initio molecular dynamics simulations are performed to reveal the stability of the obtained structures. Our results indicate that while fully fluorinated borophene (BF) cannot be obtained, stable configurations with lower coverage levels (B4F and B2F) can be attained. Unveiling the stable structures, we explore the mechanical, electronic, and thermal properties of (B n F). Fluorination significantly alters the mechanical properties of the system, and remarkable results, including direction-dependent variation of Young's modulus and a switch from a negative to positive Poisson's ratio, are obtained. However, the metallic character is preserved for low coverage levels, and metal to semiconductor transition is obtained for B2F. The heat capacity at a low temperature increases with an increasing F atom amount but converges to the same limiting value at high temperatures. The enhanced stability and unique properties of fluorinated borophene make it a promising material for various high-technology applications in reduced dimensions.

20.
Food Chem ; 233: 117-124, 2017 Oct 15.
Article in English | MEDLINE | ID: mdl-28530556

ABSTRACT

Thymol (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.


Subject(s)
Nanofibers , Anti-Bacterial Agents , Cyclodextrins , Food Packaging , Thymol , Zein
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