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A simple layer-stacking technique to generate biomolecular and mechanical gradients in photocrosslinkable hydrogels
摘要： Physicochemical and biological gradients are desirable features for hydrogels to enhance their relevance to biological environments for three-dimensional (3D) cell culture. Therefore, simple and efficient techniques to generate chemical, physical and biological gradients within hydrogels are highly desirable. This work demonstrates a technique to generate biomolecular and mechanical gradients in photocrosslinkable hydrogels by stacking and crosslinking prehydrogel solution in a layer by layer manner. Partial crosslinking of the hydrogel allows mixing of prehydrogel solution with the previous hydrogel layer, which makes a smooth gradient profile, rather than discrete layers. This technique enables the generation of concentration gradients of bovine serum albumin in both gelatin methacryloyl (GelMA) and poly(ethylene glycol) diacrylate hydrogels, as well as mechanical gradients across a hydrogel containing varying gel concentrations. Fluorescence microscopy, mechanical testing, and scanning electron microscopy show that the gradient profiles can be controlled by changing both the volume and concentration of each layer as well as intensity of UV exposure. GelMA hydrogel gradients with different Young’s moduli were successfully used to culture human fibroblasts. The fibroblasts migrated along the gradient axis and showed different morphologies. In general, the proposed technique provides a rapid and simple approach to design and fabricate 3D hydrogel gradients for in vitro biological studies and potentially for in vivo tissue engineering applications.
关键词： 3D cell culture,Gelatin methacryloyl,Photocrosslinkable hydrogel,Poly(ethylene glycol) diacrylate,Gradient
更新于2025-11-21 11:24:58
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Ionic Liquid Stabilized Gelatin-Lignin Films: A potential UV Shielding Material with Excellent Mechanical and Antimicrobial Properties
摘要： Significant research is going on to develop environmental friendly UV shielding materials. Herein, we have constructed choline citrate (a bio-based ionic liquid, IL) stabilized homogeneous gelatin-lignin UV shielding films with excellent antimicrobial and mechanical properties. Synthesis procedure of films is less energy demanding, one pot and sustainable in nature. Prepared films are characterized for its mechanical and thermal analysis using UTM and TGA respectively. ATR-IR and PXRD is employed to explore the possible formation of H-bonding between biopolymers and IL and change in crystallinity in films after addition of IL to gelatin-lignin matrix. Surface morphology of prepared films has been studied using optical microscope, AFM and FE-SEM. Optical properties of prepared films are measured using UV-Visible spectroscopy. Antimicrobial activity of prepared films has been tested against Bacillus subtilis.Prepared bio-films have shown sun protection factor (SPF) up to ~ 45.0, large elongation ~200% and tensile strength ~70 MPa, which are as good as exhibited by organic polymeric films, indicating a promising renewable resources-based material for UV-light-blocking.
关键词： UV blocking material,Composite,biomass,lignin gelatin composite,ionic liquids
更新于2025-09-23 15:21:01
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UV-induced macromolecular and optical modifications in gelatin solid films with transition metal chlorides
摘要： Gelatin solid films containing transition metal chlorides (NiCl2·6H2O, CoCl2·6H2O and CrCl3.6H2O) were prepared and UV-irradiated at different exposure times, to study the effect of irradiation on the structural properties at the molecular level, as well as the electronic level, using FT-IR and UV-visible spectroscopies. Results showed that modifications in the molecular and electronic structure due to UV-irradiations were possible even when applying the irradiation treatment to the films in the solid phase. These modifications also differ according to the additive’s type and concentration. The force constant of the CO bond tends to increase, and that for the OH bond tends to decrease, by increasing the irradiation exposure time. The colour difference tends to have higher values for the films with the higher additive concentration and higher exposure times, in the meantime, the brightness tends to increase for Gelatin-NiCl2 and Gelatin-CrCl3 films, and decrease for Gelatin-CoCl2 films. The samples of the Gelatin-NiCl2 group become more yellowish and more greenish by increasing concentrations and exposure times, whereas those of the Gelatin-CoCl2 group tend to become more bluish and more reddish. Moreover, the values of yellowness tend to increase for Gelatin-CoCl2 and Gelatin-NiCl2 films with increasing concentrations and exposure times. Our research concludes that UV-induced modifications in the microstructure and optical properties of the gelatin films are possible in the solid phase due to increasing the crosslinking effects. With the current findings, these films can be used as radiation biosensors.
关键词： UV-vis spectroscopy,Ultraviolet radiation,Transition metals,gelatin,macrostructure,FT-IR
更新于2025-09-19 17:15:36
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Biodegradable Materials for Organic Field-effect Transistors on a Paper Substrate
摘要： Paper-based pentacene organic thin-film transistors (OTFTs) with spin-coated gelatin (G) stacked gate dielectric layers, the Au/pentacene/G/G matrix-embedded iron (FeG)/Al/paper structure, were fabricated. The proposed composite-stacked bio-dielectric layer can be implemented using solutions with the degradable biomaterials. These materials enable a large-area printing of use-and-throw devices. Control devices (Au/pentacene/G/Al and Au/pentacene/FeG/Al structure) were also fabricated for comparison. High performance paper-based OTFT constructed from the stacked gate dielectric layer exhibited a carrier mobility of 8 cm2/Vs, on/off current ratio of approximately 103, subthreshold swing of 0.6 V/dec, and threshold voltage of ?1.4 V. These results are compatible to those OTFTs fabricated on other substrates. Therefore, the emerging biomaterial-based transistors on paper substrates may help in developing low-cost, environment-friendly devices.
关键词： paper,pentacene,gelatin,organic thin-film transistor (OTFT),solution process
更新于2025-09-19 17:15:36
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Controlled Synthesis of Triangular Silver Nanoplates by Gelatin–Chitosan Mixture and the Influence of Their Shape on Antibacterial Activity
摘要： Triangular silver nanoplates were prepared by using the seeding growth approach with the presence of citrate-stabilized silver seeds and a mixture of gelatin–chitosan as the protecting agent. By understanding the critical role of reaction components, the synthesis process was improved to prepare the triangular nanoplates with high yield and e?ciency. Di?erent morphologies of silver nanostructures, such as triangular nanoplates, hexagonal nanoprisms, or nanodisks, can be obtained by changing experimental parameters, including precursor AgNO3 volume, gelatin–chitosan concentration ratios, and the pH conditions. The edge lengths of triangular silver nanoplates were successfully controlled, primarily through the addition of silver nitrate under appropriate condition. As-prepared triangular silver nanoplates were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-Vis, Fourier transform infrared spectroscopy (FT-IR), and X-Ray di?raction (XRD). Silver nanoplates had an average edge length of 65–80 nm depending on experimental conditions and exhibited a surface plasma resonance absorbance peak at 340, 450, and 700 nm. The speci?c interactions of gelatin and chitosan with triangular AgNPs were demonstrated by FT-IR. Based on the characterization, the growth mechanism of triangular silver nanoplates was theoretically proposed regarding the twinned crystal of the initial nanoparticle seeds and the crystal face-blocking role of the gelatin–chitosan mixture. Moreover, the antibacterial activity of triangular silver nanoplates was considerably improved in comparison with that of spherical shape when tested against Gram-positive and Gram-negative bacteria species, with 6.0 ug/mL of triangular silver nanoplates as the MBC (Minimum bactericidal concentration) for Escherichia coli and Vibrio cholera, and 8.0 ug/mL as the MBC for Staphylococcus aureus and Pseudomonas aeruginosa. The MIC (Minimum inhibitory concentration) of triangular Ag nanoplates was 4.0 ug/mL for E. coli, V. cholera, S. aureus, and P. aeruginosa.
关键词： seeding growth approach,triangular silver nanoplates,gelatin,antibacterial activity
更新于2025-09-16 10:30:52
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Tailoring the surface morphology and nanoparticle distribution of laser-induced graphene/Co3O4 for high-performance flexible microsupercapacitors
摘要： Recent trends have witnessed laser induced graphene (LIG) syntheses on various materials from synthetic polymers to natural precursors. Herein, porcine skin derived gelatin was used as a medium to modify the surface morphology and nanoparticle distribution of in situ synthesized Co3O4/LIG on polyimide (PI) film. By varying the applied laser fluence, the surface morphology of LIG transitions from a 3D porous structure to a multilayered structure, Co3O4 progressively distributes from the surface to the inside of the LIG structure, and the structure changes from a sphere to a whisker-like shape. These altered attributes contribute to distinct differences in the double layer capacitance and pseudocapacitance behaviors of Co3O4/LIG, as reflected in its associated electrochemical performance. Additionally, a facile fabrication strategy including simple casting and peeling steps was used to generate stretchable microsupercapacitors (MSCs) on a waterborne polyurethane (WPU) substrate. The as-prepared stretchable MSCs present outstanding areal capacitance and excellent mechanical flexibility, whereas their electrochemical differences are significantly minimized and dominated by their inner structures.
关键词： Co3O4,morphology transition,supercapacitor,laser-induced graphene,gelatin
更新于2025-09-12 10:27:22
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A facile method toward potentially next-generation bacteria detectors using polymer/MWCNT/Au nanocomposite films: A possibility to detecting ability through the shift in resonance frequency
摘要： The global market demands for new disposable wireless sensors for food, clinical, tissue, and drug industries in the near future. Gelatin-based multi-layer films were successfully prepared using a room temperature solution casting method. Anticipating future developments, we have looked at the potential applications of cost-effective passive RFID tags in the detection of bacteria (here trypsin was used for biosensing tests) in body fluids, foods, medicines, and much more. This paper is concerned with the measurement of the dielectric constant of materials remotely by using the frequency shift of RFID tags, in the first step. In continue, we establish a setup along with a novel multi-layer structure of gelatin films determining whether there exists any bacterium in a biological fluid or not, by using a physical approach. For this, penetration of bacterium through gelatin multi-layer films causes the RFID tags to be exposed to the biological fluid changing the dielectric constant, detected as a frequency shift. Samples were characterized utilizing FTIR, XRD, TGA, FESEM, tensile, and VNA analyzes. Our proposed wireless biomimetic sensor is able to detect trypsin within a few minutes. The immediate application of our designed biosensor is for the elderly and infants diapers, but further applications in biomedicine, biomedical engineering, food industry, and things like that can be anticipated.
关键词： Gelatin,Vector Network Analyzer,Au Nanoparticles,Trypsin,Carbon nanotubes
更新于2025-09-10 09:29:36
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Caracteriza??o óptica e estrutural de ortoferritas de lantanio dopadas com cromo e alumínio
摘要： This work aimed to synthesize oxides with the perovskite structure of LaFeO3, LaFe0.8Al0.2O3 and LaFe0.8Cr0.2O3 by proteic sol-gel, in order to use as a ceramic pigment. The resulting powders from the synthesis process were calcined at 600 and 800 °C and then characterized by X-ray diffraction (XRD) with Rietveld refinement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy, and CIE-L*a*b* colorimetry. According to the XRD patterns, all calcined powders were single-phase with orthorhombic perovskite structure. The SEM and TEM images revealed that the powders were porous and nanometric. The pure lanthanum ferrites presented pastel colors, being lighter in aluminum-doped powders. The chromium-doped ferrite presented a light brown color. The colors were more intense with increasing calcination temperature.
关键词： gelatin,pigment,perovskite,ferrite
更新于2025-09-09 09:28:46