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Oil-in-water nanoemulsion-based ethyl lauroyl arginate nanoparticles exhibit potent antibacterial and antibiofilm activity against oral pathogens
(2026-04-23)
Wongkaewkhiaw, Saharut
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Pairojana, Tanita
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Chansiri, Sirirat
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Tsao, Stephany
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Panmekiate, Soontra
Background. Dental biofilm is a key etiological factor in oral diseases such as dental caries and periodontal disease, and has also been linked to systemic health complications. In this study, ethyl lauroyl arginate nanoparticles (ELANPs) were formulated using an oil-in-water nanoemulsion system to investigate their antibiofilm capacity and cellular cytotoxicity in vitro. Methods. The morphology of ELANPs was examined using transmission electron microscopy (TEM). Particle size, polydispersity index (PDI), and zeta potential were evaluated to assess nanoparticle stability over time. Biofilm matrix reduction was analyzed using confocal laser scanning microscopy (CLSM), and cytotoxicity was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results. ELANPs displayed a spherical morphology with an average diameter of 84.3 ± 2.6 nm. The zeta potential was 46.7 ± 4.6 mV, and the PDI was 0.18 ± 0.01, indicating good colloidal uniformity and stable nanosuspensions. Slight changes in physicochemical properties were observed at days 14 and 30, and overall stability was maintained. ELANPs significantly reduced the biofilm matrix across all tested oral pathogens while maintaining low cytotoxicity toward normal human gingival fibroblasts. Conclusion. The findings indicate that ELANPs are physicochemically stable, capable of inhibiting oral biofilm formation, and exhibit minimal cytotoxicity, supporting their potential as a safe and effective oral healthcare agent.
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Nanoparticles Derived from Active Metabolites of Chaetomium cupreum CC3003 against Phytophthora Rot of Durian
(2022-01-01)
Tongon, Rujira
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Soytong, Kasem
Phytophthora rot of durian (Durio zibetinus L.) is a serious disease wherever the crop has been planted and the disease control customarily uses chemical fungicides reported to be resistant by pathogen. Alternative non-chemical control strategies are being investigated to produce safe food. The main objective of this research was to test the activity of metabolites from Chaetomium cupreum CC3003 in the form of crude materials and nanoparticles to control and induce immunity to Phytophthora palmivora causing rot of durian var. Monthong. The results showed that P. palmivora proved to be pathogenic to durian var. Monthong. C. cupreum CC3003 acted as an antagonist and P. palmivora was confirmed as the pathogen by morphological and molecular genetic identification. Effective doses (ED50) of CC-E, CC-H and CC-M crude metabolites for spore inhibition were 60, 97 and 140 mg.kg-1, respectively. The research findings found that the diameters of nano CC-E, nano CC-H and nano CC-M were 534, 499 and 537 nm, respectively. The nano CC-E, nano CC-H and nano CC-M demonstrated antifungal activity against P. palmivora with ED50 of 11, 13 and 16 mg.kg-1, respectively. The nanoparticles at low concentrations were more effective than crude metabolites at high concentrations. Nano-CC-E used to treat seedlings of durian resulted in the production of scopoletin which served as an immunity agent or elicitor against rot disease of durian. It is concluded that active metabolites derived from C. cupreum significantly inhibited P. palmivora and induced immunity through phytoalexin production
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Electrochemical mechanisms of activated carbon, α-MnO2 and composited activated carbon-α-MnO2 films in supercapacitor applications
(2021-12-30)
Tagsin, Patin
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Suksangrat, Pitphichaya
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Klangtakai, Pawinee
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Srepusharawoot, Pornjuk
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Ruttanapun, Chesta
Pure α-MnO<inf>2</inf> and activated carbon-MnO<inf>2</inf> (AC-MnO<inf>2</inf>) films coated on Ni foam by electrophoretic deposition were applied as a supercapacitor electrode. The specific capacitance of AC-MnO<inf>2</inf> films (155.03 F g−1) surpasses those of the pure AC (110.62 F g−1) and pure MnO<inf>2</inf> film in the 1 M NaOH electrolyte. EDX and XPS detect an increase in the Na content and the reduction of Mn4+ to Mn3+ on the discharged MnO<inf>2</inf> electrode (at 0.0 V), whereas a decrease in the Na content and the oxidation of Mn3+ to Mn4+ were obtained on the charged MnO<inf>2</inf> electrode (at 0.45 V). Computational simulation of the Na inserted α-MnO<inf>2</inf> structure displays the connection of Na to O atoms and the increasing electron density on Mn atoms. EDX of the charged AC-MnO<inf>2</inf> (at −1.0 V) film detects a rise in the Na and a fall in the O contents, but the discharged AC-MnO<inf>2</inf> film (at 0.0 V) shows a decrease in Na and increase in O contents. The AC-MnO<inf>2</inf> film could retain 82.29% of the initial specific capacity after 10,000 cycles. Four series-supercapacitor coin cell assembled from the AC-MnO<inf>2</inf> anode and MnO<inf>2</inf> cathode delivers a power density of 2.79 kW kg−1 and an energy density of 168.8 Wh kg−1.
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Natural product of nano-particles constructed from chaetomium spp. To control rice blast disease caused by magnaporthe oryzae
(2020-01-01)
Song, Jiao Jiao
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Soytong, Kasem
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Kanokmedhakul, Somdej
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Kanokmedhkul, Kwanjai
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Poeaim, Supattra
Nanoparticles containing active compounds derived from Chaetomium cochliodes (CTh05) was tested to control rice blast disease caused by Magnaporthe oryzae isolate PO1. The causal agent of rice blast on leaves of rice var. RD57 was isolated. M. oryzae and C. cochliodes were identified morphologically and confirmed by molecular phylogenetic. M. oryzae was demonstrated to be pathogenic, causing blast of rice var. RD57. Biculture tests demonstrated that C. cochliodes could suppress the growth of M. oryzae. The crude metabolites of C. cochliodes (CCoH, CCoE and CCoM) at the concentrations of 10-1000 ppm expressed antifungal activity against the M. oryzae, resulting in inhibited spore production in 12 days with effective dose (ED<inf>50</inf>) values of 85, 144 and 374 ppm, respectively. The nanoparticles sizes of nano-CCoH, nano-CCoE and nano-CCoM were ranged between 567-611, `422-566 and 415-472 nm, respectively. Nanoparticles derived from C. cochliodes (nano-CCoH, nano-CCoE and nano-CCoM) at concentrations of 3-15 ppm significantly inhibited M. oryzae in 12 days with ED<inf>50</inf> values of 9, 16 and 33 ppm, respectively. In vivo experiments revealed a reduction of 38% in blast disease after application of nanoparticles constructed from crude extract mixtures from C. cochliodes at 10 ppm for 30 days. Tricyclazole resulted in reduction of blast disease by 29%. Rice blast disease was decreased in 30 days after applying nano-CCoM at the concentration of 7 ppm (60% disease reduction), followed by nanoCCoE and nanoCCoH with disease reduction of 58 and 50% respectively, and tricyclazole resulted in a 56% reduction in rice blast.
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Flexible and fully transparent WORM memory devices based on Ag nanoparticles blended with poly(ethylene-co-vinyl acetate)
(2019-12-01)
Onlaor, Korakot
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Thiwawong, Thutiyaporn
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Tunhoo, Benchapol
Silver nanoparticles (Ag NPs) blended with poly(ethylene-co-vinyl acetate) (EVA) were used as an active layer to fabricate flexible and fully transparent memory devices by using the spin-coating method followed by the thermal roll lamination technique with the structure of ITO/EVA:Ag NPs/ITO. The devices exhibited a non-volatile write-once-read-many-times (WORM) memory type and possessed current bi-stability with ON/OFF current ratio within the range of 104-105 at a reading voltage of +1 V. The data continuous read operations reached more than 10 h, which revealed the stability of the memory devices over a long period of time. The conduction mechanisms of the memory device could be explained by theoretical models and proposed by electron trapping at the trapping center of Ag NPs inside the EVA matrix. In addition, the memory device showed a fast response of 231 ns and was fully transparent with maximum transmittance of the device at 83.2%. Further, the devices could be operated under the bending condition of more than 0.83% strain.
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Antiradical properties of chemo drug, carboplatin, in cooperation with ZnO nanoparticles under UV irradiation in putative model of cancer cells
(2019-07-01)
Pairoj, Suttirak
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Damrongsak, Pattareeya
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Damrongsak, Badin
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Jinawath, Natini
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Kaewkhaw, Rossukon
The main objective of this study was to assess the antiradical properties of zinc oxide (ZnO) nanoparticles upon exposure to ultraviolet radiation with carboplatin, an anti-proliferative drug used in the treatment of retinoblastoma. For the purpose of this study, the decomposition of 2,2(diphenyl-1-picryhydrazyl) radical (DPPH*) was used to assess the free radical capacity of antioxidants and was followed by MTT measurements. To test the antiradical capacity, the effective concentration, antiradical power, stoichiometry, and number of reduced DPPH* were investigated. DPPH* has a peak absorbance at a wavelength of 515 nm, which disappears upon the introduction of the antiradical agents. Four agents were reacted with DPPH* and represented the possible reaction kinetic categories. ZnO nanoparticles and carboplatin-loaded ZnO nanoparticles reacted more strongly with DPPH* and approached a saturation state at 420 min. The remaining two antiradical agents, ZnO nanoparticles under UV radiation and carboplatin-loaded ZnO nanoparticles under UV radiation, reacted a bit slower with DPPH* and approached a steady state at 1440 min. Among the different four antiradical agents, carboplatin-loaded ZnO nanoparticles under UV light had the highest antiradical response with the lowest effective concentration value to the reduced DPPH* molecules. ZnO nanoparticles alone were found to be poor antiradical agent. Possible mechanisms were attributed to the number of hydroxyl groups available to decrease the number of DPPH*.
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Optical imaging of artificial latent fingerprints using rhodamine 6G and au-core/Pd-shell nanorods
(2019-01-01)
Locharoenrat, Kitsakorn
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Damrongsak, Pattareeya
Latent fingerprints represent valuable information-storage platforms, which play a key role in the forensic practice and health assessment. Recent works have explored novel image-enhancement methods in latent fingerprinting, which are associated with fluorescence dyes. In this study we improve the quality of fingerprint images, using a combination of fluorescence dyes and bimetallic nanoparticles. We find that Rhodamine 6G can serve as a kind of ‘glue’ adhering well onto Au–Pd core–shell nanorods. This system which employs molecules like α- amylase can be successfully used for recognition of artificial latent fingerprints. The appropriate mechanism can be coupling of localized surface plasmon resonance in the nanorods mentioned above and the emission of Rhodamine 6G. As a result, we observe notable enhancement of the images of artificial latent fingerprints.
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Multilevel conductance switching and carrier transport mechanisms of memory devices based on an ITO/PVK:Ag nanoparticles/Al structure
(2018-01-25)
Onlaor, Korakot
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Thiwawong, Thutiyaporn
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Tunhoo, Benchapol
Multilevel conductance switching was achieved using silver nanoparticles (Ag NPs) embedded in poly(9-vinylcarbazole) (PVK) with a structure of ITO/PVK:Ag NPs/Al. The current-voltage (I-V) curves of the memory devices at low reading voltages showed three distinguished states of current. The memory devices exhibited non-volatile rewritable memory characteristics. The carrier transport mechanisms of the devices in each state were analyzed by theoretical models based on the experimental I-V data. In addition, retention time measurements showed clearly three current states with good data retention properties. From the retention times test, the average values of ON/OFF, ON/intermediate (INTERM) and INTERM/OFF current ratios of the memory devices were 1.7 × 106, 3.5 × 102 and 5.0 × 103, respectively.
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Removal of metals using a ZnO/Au composite under visible-light illumination
(2018-01-01)
Thonglim, P.
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Sirivichai, M.
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Thanjai, O.
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Locharoenrat, K.
Gold nanoparticles embedded into a ZnO film are prepared with a simple spin-coating technique. Photocatalytic performance of the film is studied under irradiation with the visible light. We suggest to increase the amount of Au nanoparticles in the ZnO matrix (from 0 to 400 mg in our particular case) to improve photocatalytic efficiency of the film via a combination of plasmonic-resonance and Schottky-barrier effects. We choose Fe2+ as a model representative of metals available in the wastewater. It is demonstrated that the ZnO/Au films with increased Au content reduce efficiently the amount of ferrum ions in the water solution. In particular, the film with the content ratio ZnO:Au = 1:2 serves as a good absorber for removing Fe2+ in case if their initial concentration is equal to 0.2 mM.
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Rhodamine 6G and Au–Pd core–shell nanorods: Fluorescence enhancement for detection of mercury
(2018-01-01)
Rammarat, Ekkachai
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Kraithong, Sasiwimon
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Wanichacheva, Nantanit
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Swanglap, Pattanawit
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Yindeesuk, Witoon
We show that hybrid organic–inorganic particles are efficient for accurate sensing of mercury ions and following up trace amounts of the mercury pollutions spread in the environment. The process of synthesis of a working substance starts from preparation of rhodamine 6G derivative. Then the dye molecules are bound on the surface of Au–Pd core–shell nanorods. Mercury ions with different concentrations are finally attached onto this fluorescence sensor. Fluorescence emission of the sensor is detected with a luminescence spectrophotometer. The experimental results demonstrate that the fluorescence intensity of one of our sensors, a sensor B, is remarkably enhanced when the mercury-ion concentration increases from 0 to 15.5 µM. The limit of detection of the ions is as low as 20.6 nM. The working mechanism of our fluorescence sensor can be explained through the fluorescence-energy transfer and the plasmonic effect associated with spirolactam forms of rhodamine and conducting bimetallic nanoparticles.

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