Confocal Laser Scanning Microscopy Images Research Articles

Preparation, structure and luminescence properties of Ce3+: Y3(Al,Ga)5O12 translucent glass ceramics for AC-LEDs

Translucent glass ceramics containing Ce3+:Y3(Al,Ga)5O12 microcrystals were prepared by spontaneous crystallization in the SiO2–B2O3–Al2O3–Ga2O3–Y2O3–PbO–CeF3 glass system. The sample exhibits around 45 % transmittance in the range of 500–800 nm. X-ray diffraction patterns confirm the garnet phases. Scanning electron microscope and laser scanning confocal microscopy images suggest that about 5 μm grains are dispersed uniformly in the glass matrix. With increasing Ga/Al ratio in the components, both excitation and emission peaks blue shift. The emission intensity reaches to the maximum at Ga/Al ratio of 8/22, and the optimized Ce3+ content is 0.4 mol%. The sample exhibits yellowish-green persistent luminescence with lifetime of 47.3 ms. The glass ceramic-based device exhibits near standard white light emission with luminous efficiency of 64.7 lm/W, correlated color temperature of 6979 K, color rendering index of 65.4 and flicker index of 76.9 %. It indicates that the Ce3+:Y3(Al,Ga)5O12 glass ceramics are promising in the alternating current directly driven white light-emitting diodes (AC-LEDs).

Pharmacokinetic control of orally dosed cyclosporine A with mucosal drug delivery system.

This study aimed to control the oral absorption of cyclosporine A (CsA) with the use of a mucosal drug delivery system (mDDS). Mucopenetrating nanocarriers (MP/NCs) and mucoadhesive nanocarriers (MA/NCs) were prepared by flash nanoprecipitation employing polystyrene-block-poly(ethylene glycol) and polystyrene-block-poly(N,N-dimethyl aminoethyl methacrylate), respectively. Their particle distribution in the rat gastrointestinal tract were visualized by fluorescent imaging. Plasma concentrations were monitored after oral administration of CsA-loaded MP/NCs (MP/CsA) and MA/NCs (MA/CsA) to rats. MP/NCs and MA/NCs had a particle size below 200nm and ζ-potentials of 4 and 40mV, respectively. The results from in vitro experiments demonstrated mucopenetration of MP/NCs and mucoadhesion of MA/NCs. Confocal laser scanning microscopic images showed diffusion of MP/NCs in the gastrointestinal mucus towards epithelial cells and localization of MA/NCs on the surface of the gastrointestinal mucus layer. In a pH 6.8 solution, rapid and sustained release of CsA were observed for MP/CsA and MA/CsA, respectively. After oral dosing (10 mg-CsA/kg) to rats, amorphous CsA powder exhibited a time to maximum plasma concentration (Tmax) of 3.4h, maximum plasma concentration (Cmax) of 0.12μg/mL, and bioavailability of 0.7%. Compared with amorphous CsA powder, MP/CsA shortened Tmax by 1.1 to 2.3h and increased the bioavailability by 43-fold to 30.1%, while MA/CsA prolonged Tmax by 3.4 to 6.8h with Cmax and bioavailability of 0.65μg/mL and 11.7%, respectively. These pharmacokinetic behaviors would be explained by their diffusion and release properties modulated by polymeric surface modification. The mDDS approach is a promising strategy for the pharmacokinetic control of orally administered CsA.

Preparation and Characterization of Fish Oil Pickering Emulsions Stabilized by Resveratrol-Loaded Gliadin/Chitin Nanocrystal Composite Nanoparticles.

Unsaturated fatty acids present in fish oil offer various physiological benefits to the human body. However, their susceptibility to oxidation severely limits their potential applications. The purpose of this study was to develop Pickering emulsions stabilized from a composite of resveratrol-loaded gliadin nanoparticles and oxidized chitin nanocrystals (GR/OC) to protect fish oil from oxidation. The effects of the GR/OC composite on the characterizations of fish oil Pickering emulsions were investigated, including the microstructure, physicochemical properties (stability and rheological behavior), and digestion properties in vitro. The results revealed that an increased concentration of the GR/OC composite significantly reduced the droplet size and improved the ambient stability of the emulsions (in terms of pH, ionic strength, temperature, and storage time). Confocal laser scanning microscopy images depicted that the GR/OC nanoparticles were uniformly dispersed at the interface between water and fish oil (W-O interface). This distribution formed a protective envelope around the droplets. Remarkably, the addition of 2% GR/OC nanoparticles stabilized the Pickering emulsions and showed the most positive effect on the antioxidant capacity compared to that of the control group. These stabilized emulsions maintained lower peroxide values and acid values, which were 1.5 times less than those of the blank control during the 14 day accelerated oxidation experiment. Furthermore, the Pickering emulsions stabilized by GR/OC nanoparticles exhibited the ability to protect fish oil from contamination by gastric juices and facilitate the intestinal absorption of omega-3 polyunsaturated fatty acids. The findings suggest that these GR/OC-stabilized Pickering emulsions offer a promising alternative for delivering fish oils in various industries, including the food industry.

Multimodal imaging analysis in silver fir reveals coordination in cellulose and lignin deposition.

Despite lignin being a key component of wood, the dynamics of tracheid lignification are generally overlooked in xylogenesis studies, which hampers our understanding of environmental drivers and blurs the interpretation of isotopic and anatomical signals stored in tree rings. Here, we analyzed cell wall formation in silver fir (Abies alba Mill.) tracheids to determine if cell wall lignification lags behind secondary wall deposition. For this purpose, we applied a multimodal imaging approach combining transmitted light microscopy (TLM), confocal laser scanning microscopy (CLSM), and confocal Raman microspectroscopy (RMS) on anatomical sections of wood microcores collected in northeast France on 11 dates during the 2010 growing season. Wood autofluorescence after laser excitation at 405 nm and 488 nm associated with the RMS scattering of lignin and cellulose, respectively, which allowed identification of lignifying cells (cells showing lignified and non-lignified wall fractions at the same time) in CLSM images. The number of lignifying cells in CLSM images mirrored the number of wall-thickening birefringent cells in polarized TLM images, revealing highly synchronized kinetics for wall thickening and lignification (similar timings and durations at the cell level). CLSM images and RMS chemical maps revealed a substantial incorporation of lignin into the wall at early stages of secondary wall deposition. Our results show that most of the cellulose and lignin contained in the cell wall undergo concurrent periods of deposition. This suggests a strong synchronization between cellulose and lignin-related features in conifer tree-ring records, as they originated over highly overlapped time frames.

PEGylated mesoporous silica core–shell redox-responsive nanoparticles for delivering paclitaxel to breast cancer cells

Controlling the drug release and restricting its presence in healthy organs is extremely valuable. In this study, mesoporous silica nanoparticles (MSN) as the core, loaded with paclitaxel (PTX), were coated with a non-porous silica shell functionalized with disulfide bonds. The nanoparticles were further coated with polyethylene glycol (PEG) via disulfide linkages. We analyzed the physicochemical properties of nanoparticles, including hydrodynamic size via Dynamic Light Scattering (DLS), zeta potential, X-ray Diffraction (XRD) patterns, Fourier-Transform Infrared (FTIR) spectra, and imaging through Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). The drug release profile in two distinct glutathione (GSH) concentrations of 2 µM and 10 µM was measured. The cellular uptake of nanoparticles by MCF-7 cell line was determined using Confocal Laser Scanning Microscopy (CLSM) images and flow cytometry. Furthermore, the cell viability and the capability of nanoparticles to induce apoptosis in MCF-7 cell line were studied using the MTT assay and flow cytometry, respectively. Our investigations revealed that the release of PTX from the drug delivery system was redox-responsive. Also, results indicated an elevated level of cellular uptake and efficient induction of apoptosis, underscoring the promising potential of this redox-responsive drug delivery system for breast cancer therapy.

Rheology, physicochemical properties, and microstructure of fish gelatin emulsion gel modified by γ-polyglutamic acid.

In this work, the effect of the addition of γ-polyglutamic acid (γ-PGA) on the rheology, physicochemical properties, and microstructure of fish gelatin (FG) emulsion gel was investigated. Samples of the emulsion gel were evaluated for rheological behavior and stability prior to gelation. The mechanical properties and water-holding capacity (WHC) of the emulsion were determined after gelation. The microstructure of the emulsion gel was further examined using confocal laser scanning microscopy (CLSM). The results indicated a gradual increase in the apparent viscosity and gelation temperature of the emulsion at a higher concentration of γ-PGA. Additionally, frequency scan results revealed that on the addition of γ-PGA, FG emulsion exhibited a stronger structure. The emulsion containing 0.1% γ-PGA exhibited higher stability than that of the control samples. The WHC and gel strength of the emulsion gel increased on increasing the γ-PGA concentration. CLSM images showed that the addition of γ-PGA modified the structure of the emulsion gel, and the droplets containing 0.1% γ-PGA were evenly distributed. Moreover, γ-PGA could regulate the droplet size of the FG emulsion and its size distribution. These findings suggest that the viscoelasticity and structure of FG emulsion gels could be regulated by adjusting the γ-PGA concentration. The γ-PGA-modified FG emulsion gel also exhibited improved rheology and physicochemical properties. The results showed that γ-PGA-modified FG emulsion gel may find potential applications in food, medicine, cosmetics, and other industries.

A Comparative Study of New Fluorescent Anthraquinone and Benzanthrone α-Aminophosphonates: Synthesis, Spectroscopy, Toxicology, X-ray Crystallography, and Microscopy of Opisthorchis felineus.

In this research, we explore the synthesis of and characterize α-aminophosphonates derived from anthraquinone and benzanthrone, focusing on their fluorescence properties and potential applications in confocal laser scanning microscopy (CLSM). The synthesized compounds exhibit notable solvatochromic behavior, emitting fluorescence from green to red across various solvents. Spectroscopic analysis, including 1H-, 13C-, and 31P-NMR, FTIR, and mass spectrometry, confirms the chemical structures. The compounds' toxicity is evaluated using etiolated wheat sprouts, revealing varying degrees of impact on growth and oxidative damage. Furthermore, the study introduces these α-aminophosphonates for CLSM imaging of the parasitic flatworm Opisthorchis felineus, demonstrating their potential in visualizing biological specimens. Additionally, an X-ray crystallographic study of an anthraquinone α-aminophosphonate provides valuable structural insights.

The synergistic effect of lactic acid bacteria fermentation combined with gluten on the starch digestive properties of highland barley

In this study, the synergistic effect of fermentation and gluten on highland barley starch digestibility was investigated, and the possible mechanisms were explored. The addition of gluten during fermentation increased the resistant starch content from 16.03% to 28.57% in highland barley. Both fermentation and the addition of gluten inhibited starch swelling and gelatinization. The combination of fermentation and gluten exhibited the most pronounced synergistic effect. Fermentation, with/without gluten addition, had a significant influence on the long-range ordered structure, while only fermentation with gluten addition influenced the short-range ordered structure. Furthermore, confocal laser scanning microscopy images indicated that fermentation facilitated the interaction between exogenously added gluten and starch, forming a dense protective layer around starch granules. This protective layer limited starch gelatinization and protected the starch from enzymatic attack. The results of rheological analyses suggested that the interaction between gluten and starch was primarily driven by hydrogen bonding. These findings will enrich the theory that the synergistic effect of fermentation and gluten improves the digestive properties of cereal starch and facilitates the development of healthy cereal products.

Exploring the emulsification potential of chitosan modified with phenolic acids: Emulsifying properties, functional activities, and application in curcumin encapsulation

This study successfully grafted caffeic acid and 3,4-dihydroxybenzoic acid into chitosan through a coupling reaction, yielding grafting ratio of 8.93 % for caffeic acid grafted chitosan (CA-GC) and 9.15 % for 3,4-dihydroxybenzoic acid grafted chitosan (DHB-GC) at an optimal concentration of 4 mmol phenolic acids. The characterization of modified chitosans through ultraviolet visible spectrometer (UV–vis), Fourier transform infrared spectrometer (FTIR), proton nuclear magnetic resonance (1H NMR), and x-ray photoelectron spectrometer (XPS) confirmed the successful grafting of phenolic acids. In the subsequent step of emulsion preparation, confocal laser scanning microscope images confirmed the formation of O/W (oil-in-water) emulsions. The phenolic acid-grafted chitosans exhibited better emulsification properties compared to native chitosan, such as reduced droplet size, more uniform emulsion droplet distribution, increased ζ-potential, and enhanced emulsifying activity and stability. Moreover, the modified chitosans demonstrated increased antioxidant activities (evidenced by DPPH and β-carotene assays) and displayed greater antimicrobial effects against E. coli and S. aureus. Its efficacy in curcumin encapsulation was also notable, with improved encapsulation efficiency, sustained release rates, and enhanced storage and photostability. These findings hint at the potential of modified chitosans as an effective emulsifier.

Direct Functionalization of Polysaccharide-Based Xylan Phenyl Carbonate Nanoparticles with Tumor Cell Specific Antibodies.

An efficient and easy-to-use approach is presented for obtaining biocompatible polysaccharide-based nanoparticles (NP) that can act as tumor-specific drug delivery agents. Two antibodies are directly immobilized onto reactive xylan phenyl carbonate (XPC) NP; namely Cetuximab (CTX) that binds to human epidermal growth factor receptor (EGFR) and Atezolizumab (ATZ) that binds to programmed death-ligand 1 (PD-L1). High coupling efficiency (up to 100 %) are achieved without any pre-activation and no aggregation occurs during antibody immobilization. By quartz crystal microbalance experiments with dissipation monitoring (QCM-D), flow cytometry assays, and confocal laser scanning microscopy imaging it is demonstrated that the functionalized XPC-NP specifically bind to cells carrying the corresponding antigens. Moreover, the NP retain the antibody specific bioactivities (growth inhibition for CTX and induction of T-cell cytotoxicity for ATZ).

Microgels from egg white as novel stabilizers of Pickering emulsion

Common preparation of microgels is complex. In this study, we aimed to find a convenient method to prepare microgels without high energy input. We prepared egg white microgel (EWM) by ultrasonic-microwave synergistic treatment (US-MW) and evaluate the ability of EWM to stabilize emulsions. The cavitation effect of ultrasound (US) could avoid excessive aggregation of protein caused by microwave (MW) and achieved the regulation of EWM particle size. Compared with EWM prepared by MW and water bath treatment, EWM treated by US-MW had small particle size (233.23 ± 6.49 nm), high absolute value of zeta potential (−25.27 ± 0.74 mV), high hydrophobicity (505.87 ± 5.22) and large contact angle (78.92°), which made it easier to be adsorbed on water-oil interface with higher emulsification, showing great potential in preparation of Pickering emulsions. Emulsions with EWM concentration >1.5% had good stability and EWM showed great ability to stabilize high volume fraction of oil phase (φ = 0.85). Confocal laser scanning microscopy images showed that EWM was adsorbed on the surface of oil droplets, formed physical barrier to stabilize emulsions. Rheological results showed the emulsions (EWM concentration >1.5% and φ > 0.75) had high apparent viscosity and modulus. This study provided a basis for simple preparation of EWM with high emulsifying capacity, and the EWM could effectively stabilize Pickering emulsions which could be further applied in active substance delivery and fat replacement.

Enhancing the inhibition of dental erosion and abrasion with quercetin-encapsulated hollow mesoporous silica nanocomposites.

Introduction: Dental erosion and abrasion pose significant clinical challenges, often leading to exposed dentinal tubules and dentine demineralization. The aim of this study was to analyse the efficacy of quercetin-encapsulated hollow mesoporous silica nanocomposites (Q@HMSNs) on the prevention of dentine erosion and abrasion. Method: Q@HMSNs were synthesized, characterized, and evaluated for their biocompatibility. A total of 130 dentine specimens (2mm × 2mm × 2mm) were prepared and randomly distributed into 5 treatment groups (n = 26): DW (deionized water, negative control), NaF (12.3mg/mL sodium fluoride, positive control), Q (300μg/mL quercetin), HMSN (5.0mg/mL HMSNs), and Q@HMSN (5.0mg/mL Q@HMSNs). All groups were submitted to in vitro erosive (4 cycles/d) and abrasive (2 cycles/d) challenges for 7days. The specimens in the DW, NaF, and Q groups were immersed in the respective solutions for 2min, while treatment was performed for 30s in the HMSN and Q@HMSN groups. Subsequently, the specimens were subjected to additional daily erosion/abrasion cycles for another 7days. The effects of the materials on dentinal tubule occlusion and demineralized organic matrix (DOM) preservation were examined by scanning electron microscopy (SEM). The penetration depth of rhodamine B fluorescein into the etched dentine was assessed using confocal laser scanning microscopy (CLSM). The erosive dentine loss (EDL) and release of type I collagen telopeptide (ICTP) were measured. The data were analysed by one-way analysis of variance (ANOVA) with post hoc Tukey's test (α = 0.05). Results: Q@HMSNs were successfully synthesized and showed minimal toxicity to human dental pulp stem cells (HDPSCs) and gingival fibroblasts (HGFs). Q@HMSNs effectively occluded the dentinal tubules, resulting in a thicker DOM in the Q@HMSN group. The CLSM images showed more superficial penetration in the HMSN and Q@HMSN groups than in the quercetin, NaF, and DW groups. The Q@HMSN group exhibited a significantly lower EDL and reduced ICTP levels compared to the other groups (p < 0.05). Conclusion: Q@HMSNs hold promise for inhibiting dentine erosion and abrasion by promoting tubule occlusion and DOM preservation.

Rheological properties and microstructure of wheat flour dough systems with enzyme-hydrolyzed mashed potatoes.

The interest in incorporating potatoes into wheat dough is increasing. However, potatoes exhibit significant viscosity during thermal processing, affecting product processing and quality. This study aims to find an effective method to reduce the viscosity of mashed potatoes. We aimed to compare the effects of different enzymes (α-amylase, β-amylase, and flavourzyme) and concentrations (0.01%, 0.05%, and 0.1%) on the micromorphology and rheological properties of mashed potatoes and potato-wheat dough. The impact of flavourzyme was the most significant (p<0.05). When enzyme concentration increased, viscosity decreased, and the degree of structural damage, indicated by increased porosity. Notably, the addition of flavourzyme can increase the content of sweet and umami free amino acids, improving the flavor of mashed potatoes. The scanning electron microscopy and confocal laser scanning microscopy images of potato-wheat dough revealed that enzyme-hydrolyzed mashed potatoes had improved homogeneity, reestablished the dough continuity, and strengthened the three-dimensional structure comprising proteins and starch. Notably, flavourzyme demonstrated the most significant effect on enhancing the protein-starch network structure. This was attributed to the exposure of functional groups resulting from protein hydrolysis, facilitating interaction with starch molecules. Our findings indicate that the addition of 0.1% flavourzyme (500 LAPU/g, pH5.5, 55±2°C, 30min treated) was the most effective in reducing viscosity and reconstructing the gluten network. Enzymatic hydrolysis plays a vital role in the production of high-quality potato products, with particular importance in the baking industry, where flavourzyme exhibits significant potential. PRACTICAL APPLICATION: Enzymatic hydrolysis plays a vital role in the production of high-quality potato products, with particular importance in the baking industry, where flavourzyme exhibits significant potential.

Triamcinolone-loaded self nano-emulsifying drug delivery systems for ocular use: An alternative to invasive ocular surgeries and injections

Inflammation of the posterior segment of the eye is a severe condition and hard to cure as delivery of drugs to the inflammation site is inefficient. Currently, the primary treatment approach is ocular surgery or invasive ocular injections. Herein, we designed and developed a topically self nano-emulsifying drug delivery system (SNEDDs) to deliver triamcinolone acetonide (TCA) to the posterior segment of the eye. A screening based on TCA solubility was conducted on each excipient followed by preparation of various formulations using different ratios of the selected excipients. Vesicles of optimized SNEDDs had less than 100 nm size and spherical morphology. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay showed self-emulsified vesicles have relatively high safety on retinal pigment epithelium (RPE) cell line. Furthermore, efficient cellular uptake of coumarin 6-loaded SNEDDs in RPE using confocal laser scanning microscopy (CLSM) was confirmed.In addition, an in-vivo study using hematoxylin and eosin (H&E) staining revealed that 14 days of topical treatment of albino rabbit eyes with TCA-loaded SNEDDs was safe and no sign of tissue destruction and inflammation was detected in different parts of the eye sections including cornea, sclera, retina, and optic nerve. Also, the CLSM images from topically treated eyes with coumarin 6 (a hydrophobic, fluorescent drug model) loaded SNEDDs, showed that the optimized SNEDDs could properly penetrate toward the posterior segments of the eye especially the retina, posterior parts of the choroid, and sclera. Considering the outstanding results obtained by ocular tissue penetration and low toxicity, prepared SNEDDs, have the potential to be used as a topical administration for treating posterior segment disorders of the eye through an utterly non-invasive route and TCA-loaded SNEDDs could be an alternative for TCA intravitreal and intra conjunctival injections.

Effect of B. subtilis in simulated acid red soil on the corrosion behavior of X80 pipeline steel

The eastern section of China's West-east gas transmission project is laid in acidic red soil. NRB are widespread in soils and play an important role in metal corrosion. In this article, the corrosion failure behavior and mechanism of X80 pipeline steel under the action of NRB in simulated acidic soil were studied. It was found that the biofilm of B. subtilis had significant inhibitory on the overall corrosion of X80 steel. Electrochemical results prove that the corrosion rate of the sterile group after 14 days of immersion was about 4.5 times that of the bacterial group. However, the biofilm promotes the formation of local corrosion pits. Confocal laser scanning microscopy images indicate that that the corrosion pit depth of the bacterial group (46.1 μm) was three times that of the bacterial-free group (15.7 μm) after 14 days. The pH of the acidic environment was slightly improved by B. subtilis. XPS results proved that B. subtilis complicates the corrosion products of X80 steel through its nitrate reduction ability and metabolism.

Two promising Bacillus-derived antifungal lipopeptide leads AF4 and AF5 and their combined effect with fluconazole on the in vitro Candida glabrata biofilms.

Introduction: Candida species are endowed with the ability to produce biofilms, which is one of the causes of pathogenicity, as biofilms protect yeasts from antifungal drugs. Candida glabrata (Nakaseomyces glabrata) is one of the most prevalent pathogenic yeasts in humans and a biofilm producer. Methods: The study was aimed at evaluating the combined effects of two highly promising antifungal biomolecules (AF4 and AF5) lipopeptide in nature, chromatographically purified to homogeneity from Bacillus subtilis (B. subtilis) and the standard antifungal fluconazole (at different concentrations) to demonstrate C. glabrata biofilm formation inhibition. Biofilm production and inhibition were evaluated by quantification of the biofilm biomass and metabolic activity using crystal violet (CV) staining and XTT reduction assays, respectively. Microscopic techniques such as confocal scanning laser microscopy (CSLM) and scanning electron microscopy (SEM) were employed to visualize biofilm formation and inhibition. Results and Discussion: Compared to untreated and fluconazole-treated biofilms, an enhanced in vitro anti-biofilm effect of the antifungal lipopeptides AF4/AF5 alone and their combinations with fluconazole was established. The lipopeptides AF4/AF5 alone at 8 and 16μg/mL exhibited significant biomass and metabolic activity reductions. SEM and CSLM images provided evidence that the lipopeptide exposure results in architectural alterations and a significant reduction of C. glabrata biofilms, whereas (2', 7'-dichlorofluorescin diacetate (DCFDA) and propidium iodide (PI) analyses showed reactive oxygen species (ROS) generation along with membrane permeabilization. The estimation of exopolysaccharides (EPS) in AF4/AF5-treated biofilms indicated EPS reduction. The combinations of fluconazole (64/128μg/mL) and AF4/AF5 lipopeptide (16μg/mL) were found to significantly disrupt the mature (24h) biofilms as revealed by CSLM and SEM studies. The CSLM images of biofilms were validated using COMSTAT. The FTIR-analyses indicate the antibiofilm effects of both lipopeptides on 24h biofilms to support CSLM and SEM observations. The combinations of fluconazole (64/128μg/mL) and AF4/AF5 lipopeptide were found to disrupt the mature biofilms; the study also showed that the lipopeptides alone have the potentials to combat C. glabrata biofilms. Taken together, it may be suggested that these lipopeptide leads can be optimized to potentially apply on various surfaces to either reduce or nearly eradicate yeast biofilms.

Enhancing the textural and rheological properties of fermentation-induced pea protein emulsion gels with transglutaminase.

The aim of this study was to assess how transglutaminase (TG) impacts the microstructure, texture, and rheological properties of fermentation-induced pea protein emulsion gels. Additionally, the study examined the influence of storage time on the functional properties of these gels. Fermentation-induced pea protein gels were produced in the presence or absence of TG and stored for 1, 4, 8, 12, and 16 weeks. Texture analysis, rheological measurements, moisture content and microstructure evaluation with confocal laser scanning microscopy (CLSM) and 3D image analysis were conducted to explore the effects of TG on the structural and rheological properties of the fermented samples. The porosity of the protein networks in the pea gels decreased in the presence of TG, the storage modulus increased and the textural characteristics were significantly improved, resulting in harder and more springy gels. The gel porosity increased in gels with and without TG after storage but the effect of storage on textural and rheological properties was limited, indicating limited structural rearrangement once the fermentation-induced pea protein emulsion gels are formed. Greater coalescence was observed for oil droplets within the gel matrix after 16 weeks of storage in the absence of TG, consistent with these protein structures being weaker than the more structurally stable TG-treated gels. This study shows that TG treatment is a powerful tool to enhance the textural and rheological properties of fermentation-induced pea protein emulsion gels.

A REVIEW ON BENZANTHRONE LUMINOPHORES FOR RAPID AND HIGH-RESOLUTION IMAGING OF PARASITES BY CONFOCAL LASER SCANNING MICROSCOPY

Nowadays, is growing interest in investigation of parasites and their anatomic structure. Most common tools are linked with usage of luminophores and luminescent microscopy techniques. In recent years, a variety of fluorescent probes have been developed and widely used to realize the visualization of certain structures [1]. The benzanthrone compounds captivated a lot of interest as fluorescent probes for biomedical technologies because of remarkable spectral properties and negligible fluorescence in the aqueous phase [2]. Notably, the spectral characteristics of benzanthrone dyes meet the criteria for an ideal bio-imaging agent, featuring a high extinction coefficient, bright fluorescence, photo-, thermo- and chemical stability, and reduced background signal [3]. Fluorescent molecular dyes, currently used to study cell membranes, make lipid structures visible through optical techniques [4] and act as potential fluorescent probes for biomolecules [5]. There are studies in the literature where the benzanthron phosphors have confirmed their application for visualization of biological objects [6-8]. Despite high activity in this field, still it`s huge request for specific fluorescent probes for biological objects. The confocal laser scanning microscope (CLSM) is a powerful tool for providing high-resolution optical sections. CLSM can be used to analyse images of morphological structures and to place organ or organ systems of interest in their anatomical context. Luminescence imaging techniques are increasingly utilized for exploring the structure and properties of biological objects. Laser-induced fluorescence stands out as a sensitive method, capable of detecting even a single-molecule under specific conditions [9], which makes it a powerful bioanalytical tool for life sciences [10 12]. Benzanthrone derivates are used for CLSM imaging as fluorescence probe for various biological objects because benzanthrones render the specimen fluorescent to examine the stained samples by optical sectioning [13,14]. This review provides inputs in utilisation of different benzanthrone luminophores for examination of the parasites.

Dynamic in situ microstructure evaluation of cheese melting: Understanding structure-rheological relationships under controlled temperature sweeps

This study assessed the changes in processed and natural cheese during heating from 5 to 95 °C, at 2 °C per min, using confocal laser scanning microscopy (CLSM), Raman micro-spectroscopy and rheological analysis. The CLSM images showed that the cheese samples varied in fat droplet size and distribution. CLSM micrographs of processed cheese with lower fat content (<10%) showed no substantial structural changes during heating, which were consistent with the absence of cross-over in temperature rheology sweep curves. Cheese containing starch showed uniformly distributed fat and cohesive protein network, leading to reduced cheese flow. At temperatures > 70 °C, cheeses with a fat content ≥ 25% showed greater coalescence of fat globules, which finally merged into large fat pools. The results of this study demonstrate the potential of dynamic in situ CLSM and rheological analysis for evaluating the changes in cheese matrices during heating. The Raman spectral region corresponding to C-H stretching vibrations (2800–3000 cm-1) could be used to track fat melting in cheese samples with minimum 10% fat.

Development, characteristics and biological activities of bilayer composite film based on gelatin/κ-carrageenan loading curcumin and ε-polylysine

Using curcumin and epsilon-polylysine (ε-PL) as functional ingredients, one bilayer composite film was prepared by flow casting method using gelatin and κ-carrageenan as the outer- and inner-film layers, respectively. Compared with the inner κ-carrageenan film loading 3 wt% curcumin and 0.1% ε-PL (01CF) or 3 wt% curcumin and 0.3% ε-PL (03CF), the transparency, tensile, and water contact angle of the bilayer composite film were significantly increased. X-ray diffraction results revealed that the inner film matrix of κ-carrageenan interacted well with curcumin and ε-PL. Scanning electron microscopy observed that the cross-sectional surface of the inner and outer layers in the bilayer composite film was smooth and had good compatibility. In atomic force microscopy image, the inner surface of the bilayer composite film had lower root mean square roughness and average roughness than the outer film surface. The crystallinity of curcumin in the bilayer composite film loading 0.3% ε-PL was dramatically reduced in confocal laser scanning microscope images compared to that of the composite film with 0.1% ε-PL addition. The bilayer composite film demonstrated good scavenging activity on DPPH radical with inhibition rate >65%, and showed strong inhibition effect on the spoilage bacteria derived from Penaeus vannamei. Furthermore, the bilayer composite film showed sensitive response to volatile amines by visible color changes from yellowish to reddish brown. In conclusion, the prepared bilayer composite film could have potential application prospects in the field of natural active food packaging materials for shrimp products.