| 1. |
- de Oliveira Barud, Hélida Gomes, et al.
(författare)
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Bacterial Nanocellulose in Dentistry: Perspectives and Challenges
- 2021
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Ingår i: Molecules. - : MDPI AG. - 1420-3049 .- 1420-3049. ; 26:1
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Forskningsöversikt (refereegranskat)abstract
- Bacterial cellulose (BC) is a natural polymer that has fascinating attributes, such as biocompatibility, low cost, and ease of processing, being considered a very interesting biomaterial due to its options for moldability and combination. Thus, BC-based compounds (for example, BC/collagen, BC/gelatin, BC/fibroin, BC/chitosan, etc.) have improved properties and/or functionality, allowing for various biomedical applications, such as artificial blood vessels and microvessels, artificial skin, and wounds dressing among others. Despite the wide applicability in biomedicine and tissue engineering, there is a lack of updated scientific reports on applications related to dentistry, since BC has great potential for this. It has been used mainly in the regeneration of periodontal tissue, surgical dressings, intraoral wounds, and also in the regeneration of pulp tissue. This review describes the properties and advantages of some BC studies focused on dental and oral applications, including the design of implants, scaffolds, and wound-dressing materials, as well as carriers for drug delivery in dentistry. Aligned to the current trends and biotechnology evolutions, BC-based nanocomposites offer a great field to be explored and other novel features can be expected in relation to oral and bone tissue repair in the near future.
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| 2. |
- Dias, Diogenes dos Santos, et al.
(författare)
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Large scale manufacturing of puree-only edible films from onion bulb (Allium cepa L.): Probing production and structure–processing–property correlations
- 2020
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Ingår i: Industrial Crops and Products. - : Elsevier BV. - 0926-6690. ; 145:March
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Tidskriftsartikel (refereegranskat)abstract
- The demand for bioplastics from renewable sources for a range of emerging applications has been as extensive as the efforts to find greener routes for their isolation from nature. Surfing this wave, we report on the production of flexible, optically semi-transparent onion-only bioplastics through different all-aqueous film-forming procedures encompassing hydrothermal, grinding, washing, and/or sieving pre-solvent casting steps. The onion bioplastics were extensively characterized targeting correlations among chemical structure, film-forming protocol, and film properties. HPLC evidenced insoluble carbohydrates/polysaccharides in all samples, though at different contents (11–44%) depending on processing, but washing lixiviated all soluble carbohydrates – the presence of ca. 14% of the latter in unwashed samples provided their films with reduced glass transition temperature – from 73–83 to 13 °C, as indicated by DSC; elastic modulus and tensile strength – from 1.5–3.2 GPa to 47 MPa and from 7–21 to 3 MPa, respectively; increased elongation at break – from 0.7–1.6% to 22%; and decreased contact angle with water – from 39-70° to 22° (in comparison with washed samples). Additionally, SEM provided morphological aspects; thermogravimetry indicated thermal stability profile; FTIR led to hydrogen bond energy [kJ] and distance [Å] as well as total crystallinity index (0.43–0.96), lateral order index (0.8–3.2), and hydrogen bonding intensity (13–4.7); and XRD determined the index of crystallinity (21–49%). Finally, the hydrophilic/hydrophobic nature, water barrier, and moisture sorption of the bioplastics were determined. Altogether, we herein depict the production of novel bioplastics made up exclusively of onion and used a range of characterization techniques to come up with relevant structure-processing-property correlations.
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| 3. |
- Lara-Cerón, Jesús A., et al.
(författare)
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Ultrasound-assisted synthesis of organotin compounds and their application as luminescent dye in silk fibroin scaffolds
- 2020
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Ingår i: Inorganica Chimica Acta. - : Elsevier BV. - 0020-1693. ; 505
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we report the green synthesis of four luminescent organotin compounds 1–4 derived from amino acid Schiff bases (1: Naph-Trp-SnPh2, 2: Naph-Tyr-SnBu2, 3: Naph-Tyr-SnPh2, 4: Naph-Phe-SnPh2), obtained by ultrasound-assisted synthesis in short time (~20 min) and good yields (>95%). The molecular structure proposed in solution (1H and 119Sn NMR) was confirmed by X-ray diffraction study for compound 1 where the tin atom resides in trigonal bipyramid geometry. Luminescent silk fibroin scaffolds (SF 1–4) were elaborated with organotin compounds by freeze-drying technique. Photophysical properties of organotin compounds and scaffolds were obtained in solid state, observing bathochromic behaviors in tyrosine derived compounds, suggesting that the tyrosine produce supramolecular interactions across the –OH group that change the fluorescent properties. Scaffolds 1–4 were characterized by FTIR, XDR, TG/DTG, and SEM analysis. In addition, cytotoxic analysis of SF 1 presents high cellular viability, which could be applied as a scaffold in tissue engineering.
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| 4. |
- Pekkari, Anna, 1989, et al.
(författare)
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Synthesis of highly monodisperse Pd nanoparticles using a binary surfactant combination and sodium oleate as a reductant
- 2021
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Ingår i: Nanoscale Advances. - : Royal Society of Chemistry (RSC). - 2516-0230. ; 3:9, s. 2481-2487
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Tidskriftsartikel (refereegranskat)abstract
- This study presents the synthesis of monodisperse Pd nanoparticles (NPs) stabilized by sodium oleate (NaOL) and hexadecyltrimethylammonium chloride (CTAC). The synthesis was conducted without traditional reductants and Pd-precursors are reduced by NaOL. It was confirmed that the alkyl double bond in NaOL is not the only explanation for the reduction of Pd-precursors since Pd NPs could be synthesized with CTAC and the saturated fatty acid sodium stearate (NaST). A quantitative evaluation of the reduction kinetics using UV-Vis spectroscopy shows that Pd NPs synthesized with both stabilizer combinations follow pseudo first-order reaction kinetics, where NaOL provides a faster and more effective reduction of Pd-precursors. The colloidal stabilization of the NP surface by CTAC and NaOL is confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analysis.
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| 5. |
- Bilén, Frida, 1994, et al.
(författare)
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Machine Learning-Based Interpretation of Optical Properties of Colloidal Gold with Convolutional Neural Networks
- 2024
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Ingår i: Journal of Physical Chemistry C. - 1932-7447 .- 1932-7455. ; In Press
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Tidskriftsartikel (refereegranskat)abstract
- Gold nanoparticles are used in a range of applications, but their properties depend on their shape, size, and polydispersity. A quick, easy, and accurate characterization of the particles is therefore of high importance, especially in flow synthesis settings where continuous monitoring of the characteristics is desired. Our hypothesis was that convolutional neural networks can be used to extract detailed information about structural parameters of gold nanoparticles from their UV-vis spectra, and we have shown that this is possible by predicting size distributions from in silico UV-vis spectra for colloidal gold with high accuracy. Here this was done for both spherical and rod-shaped gold nanoparticles. We also show that the addition of noise makes the prediction of diameter polydispersity more challenging, but the average diameter, and for rods also aspect ratio distribution, can be accurately predicted even with the highest evaluated level of noise. The model structure is promising and worthy of implementation to enable predictions beyond in silico generated spectra. The model, for instance, can find application in flow synthesis settings to create a machine learning-driven feedback loop for automated synthesis.
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| 6. |
- Cebrian, Ariane V.S., et al.
(författare)
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Development of Conformable Substrates for OLEDs Using Highly Transparent Bacterial Cellulose Modified with Recycled Polystyrene
- 2022
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Ingår i: Advanced Sustainable Systems. - : Wiley. - 2366-7486. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial cellulose (BC) is a biocompatible and nontoxic biopolymer that has been successfully used as a substrate for flexible organic light emitting diodes (OLEDs). Although BC membranes exhibit excellent mechanical properties and industrial scalability, they are semitransparent, which limits their performance. To improve the optical properties of BC membranes, methods such as the polymerization of different inorganic–organic hybrid materials and petrochemical derivative monomers have been considered; however, these methods require considerable time and effort. In this work, transparent BC membranes for conformable OLEDs substrates are fabricated by spray coating a solution of recycled petrochemical plastics, found in expanded foam package wastes, and d-limonene, which is a green solvent extracted from orange peels. This fabrication approach is highly scalable and can be considered a sustainable technique to develop high performance transparent substrates for photonic applications based on both recovered petrochemical polymers and naturally occurring biopolymers. In terms of the morphological and structural properties, the resulting transparent membranes exhibit a lower roughness than pristine BC. The resulting BC-PS composite is used as a substrate for OLED fabrication. The conformable OLEDs exhibit a current efficiency of up to 5 cd A−1 (16 000 cd m−2) and power density of ≈2.8 mW cm−2.
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| 7. |
- de Campos, Anderson M., et al.
(författare)
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Design and Fabrication of Flexible Copper Sensor Decorated with Bismuth Micro/Nanodentrites to Detect Lead and Cadmium in Noninvasive Samples of Sweat
- 2022
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Ingår i: Chemosensors. - : MDPI AG. - 2227-9040. ; 10:11
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Tidskriftsartikel (refereegranskat)abstract
- The use of economic methods to design and fabricate flexible copper sensors decorated with bismuth micro/nanodentrites for the detection of lead and cadmium in sweat is demonstrated. The flexible copper sensors were constructed with simple and cost-effective materials; namely, flexible and adhesive conductive copper tape, adhesive label containing the design of a three-electrode electrochemical system, and nail polish or spray as a protective layer. The flexible copper device consisted of a working electrode decorated with bismuth micro/nanodentrites using an electrodeposition technique, a copper pseudo-reference and copper counter electrodes. Under optimal experimental conditions, the flexible sensing platform showed excellent performance toward the detection of lead and cadmium using differential pulse anodic stripping voltammetry (DPAdSV) in a wide linear range from 2.0 μM to 50 μM with acceptable reproducibility and repeatability, and limits of detection and quantification of 5.36 and 17.9 μM for Cd2+ ions and 0.76 μM and 2.5 for Pb2+ ions. Studies of addition and recovery in spiked artificial sweat sample were performed, with a recovery of 104.6%. The flexible copper device provides a great opportunity for application in wearable perspiration-based healthcare systems or portable sensors to detect toxic metals in biological samples.
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| 8. |
- Fares, Hssen, et al.
(författare)
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Tuning multicolor emission in AgNCs/Tm3+/Mn2+-doped fluorophosphate glasses
- 2020
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Ingår i: Journal of Non-Crystalline Solids. - : Elsevier BV. - 0022-3093. ; 535
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Tidskriftsartikel (refereegranskat)abstract
- Herein we report the synthesis of highly-doped silver nanocluster in fluorophosphate glasses through the melting-quenching method in order to achieve sensitization with Tm3+ and Mn2+ ions. Blue and red emission belonging to Tm3+ (470 to 490 nm) and Mn2+ (550 to 750 nm) ions could be obtained via non-resonant excitation of Tm3+ and Mn2+. Slight decrease of the fluorescence decay times confirmed an energy transfer as a possible mechanism to explain the Tm3+ and Mn2+ emission. The composition of 5 mol% of AgNO3, 0.4 mol% of Tm2O3 and 0.2 mol% of MnF2 in our sample leads to distance between donor (silver nanoclusters) and acceptor (Tm3+-Mn2+) as short as 11 Å, which suggests that the main mechanism for blue and red emission from Tm3+ and Mn2+ is Förster Resonance Energy Transfer (FRET). The results presented here show that the studied material has potential application for multicolor generation as luminophore in white light emitting diodes (W-LED).
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| 9. |
- Sábio, Rafael M., et al.
(författare)
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Near-Infrared Luminescence from Visible-Light-Sensitized Ruthenium(II)-Neodymium(III) Heterobimetallic Bridged Complexes Containing Alkoxy(silyl) Functional Groups
- 2020
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Ingår i: Journal of the Brazilian Chemical Society. - : Sociedade Brasileira de Quimica (SBQ). - 0103-5053 .- 1678-4790. ; 31:4, s. 694-702
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Tidskriftsartikel (refereegranskat)abstract
- New infrared emitting d-f (ruthenium(II)–neodymium(III)) heterobimetallic complexes with alkoxy(silyl) functional groups have been prepared. Visible excitation evidenced energy transfer processes from the ruthenium(II) donor to neodymium(III) acceptors leading to infrared emission. Energy transfer rates (kEnT) and efficiency of energy transfer (ηEnT) are, respectively, 0.61 × 107 s-1 and 44% for RuL1–NdL3 complex. Larger values of kEnT (3.04 × 107 s-1) and ηEnT (84%) were detected for RuL2–NdL4 complex. RuL1–NdL3 and RuL2–NdL4 complexes were fully characterized by elementary analysis (EA), mass spectrometry (MS), Fourier transform infrared spectroscopy (FTIR) and Fourier transform Raman spectroscopy (FT-Raman). Total correlation spectroscopy (TOCSY1D), 1H{13C} heteronuclear single quantum correlation (HSQC) and 1H{13C} heteronuclear multiple bond correlation (HMBC) nuclear magnetic resonance (NMR) analyses were also carried out to characterize NdL3 and RuL1–NdL3 complexes. The presence of trialkoxysilyl-substituted ligands would allow further grafting onto any silica or silicated surface aiming at applications as new luminescent near infrared (NIR)-emitting biosensors or biomarkers.
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| 10. |
- Sábio, Rafael M., et al.
(författare)
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New insights towards mesoporous silica nanoparticles as a technological platform for chemotherapeutic drugs delivery
- 2019
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Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173 .- 1873-3476. ; 564, s. 379-409
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Forskningsöversikt (refereegranskat)abstract
- Mesoporous silica nanoparticles (MSNs)displays interesting properties for biomedical applications such as high chemical stability, large surface area and tunable pores diameters and volumes, allowing the incorporation of large amounts of drugs, protecting them from deactivation and degradation processes acting as an excellent nanoplatform for drug delivery. However, the functional MSNs do not present the ability to transport the therapeutics without any leakage until reach the targeted cells causing side effects. On the other hand, the hydroxyls groups available on MSNs surface allows the conjugation of specific molecules which can binds to the overexpressed Enhanced Growth Factor Receptor (EGFR)in many tumors, representing a potential strategy for the cancer treatment. Beyond that, the targeting molecules conjugate onto mesoporous surface increase its cell internalization and act as gatekeepers blocking the mesopores controlling the drug release. In this context, multifunctional MSNs emerge as stimuli-responsive controlled drug delivery systems (CDDS)to overcome drawbacks as low internalization, premature release before to reach the region of interest, several side effects and low effectiveness of the current treatments. This review presents an overview of MSNs fabrication methods and its properties that affects drug delivery as well as stimuli-responsive CDDS for cancer treatment.
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