Morphology Of Microcapsules Research Articles

Enhancement of oral bioavailability of celastrol by chitosan microencapsulated porous starch carriers

Celastrol demonstrates significant potential in immunomodulatory applications; however, its low oral bioavailability presents a substantial obstacle to its clinical translation. Here, we combined porous starch with chitosan to develop an efficacious microencapsulation system aimed at enhancing the oral absorption of celastrol. Microcapsule carrier for celastrol was formulated Through the utilization of chitosan-coated porous starch particle technology and Subsequent evaluations of the morphology and release kinetics of microcapsules. The impact of microencapsulation on the enhanced absorption of celastrol was assessed through Caco-2 cell uptake experiments and in vivo pharmacokinetic studies. FT-IR analysis revealed the stable presence of celastrol in an amorphous state within the microcapsules, facilitated by hydrogen-bonding interactions between celastrol and porous starch. Simulated release experiments indicated that the chitosan coating improved the stability and extended the release of celastrol. Cell experiments, as well as in vivo distribution and pharmacokinetic investigations, demonstrated that the chitosan microencapsulation strategy significantly enhanced cellular uptake and in vivo absorption of celastrol, resulting in notably higher bioavailability compared to conventional formulations. This study successfully demonstrated the remarkable efficacy of chitosan microencapsulated porous starch carriers in enhancing the oral bioavailability of celastrol, revealing novel potential applications for these two food-grade materials in delivery systems.

Pesticide delivery microcapsule based on maleic anhydride‐functionalized cellulose nanocrystals‐stabilized pickering emulsion

AbstractThe efficient use of pesticides is conducive to the harmonious coexistence of humans and nature, and pesticide transport carriers can enhance the utilization value of pesticides. However, design flaws in many pesticide carriers have resulted in numerous environmental and toxicity problems. Therefore, this paper proposed a method for synthesizing pesticide microcapsules using Pickering emulsion templates stabilized by maleic anhydride‐functionalized cellulose nanocrystals‐g‐poly (methyl methacrylate) (MACNCs‐g‐MMA), viz., simple radical polymerization of maleic anhydride‐functionalized cellulose nanocrystals with methyl methacrylate in Pickering emulsion. The structure and morphology of microcapsules were characterized via the FT‐IR, XRD, TG‐DTG, and SEM techniques. The imidacloprid‐loaded MACNCs‐g‐MMA (IMI@MACNCs‐g‐MMA) presented a high encapsulation efficiency (~94.13%) and drug loading efficiency (~24.00%). The release behavior was affected by temperature, viz., higher temperature promoted the release of IMI. Regarding the spread and retention on the leaf surface, the IMI@MACNCs‐g‐MMA demonstrated significant advantages over commercial IMI water‐dispersible granules (CG) (36.9° vs. 104.9° for contact angle, 14.3 vs. 30.0 mg cm−2 for retention). This study provides a promising pesticide formula for sustainable agriculture.

MUF-n-Octadecane Phase-Change Microcapsules: Effects of Core pH and Core-Wall Ratio on Morphology and Thermal Properties of Microcapsules.

Phase change energy storage microcapsules were synthesized in situ by using melamine-formaldehyde-urea co-condensation resin (MUF) as wall material, n-octadecane (C18) as core material and styryl-maleic anhydride copolymer (SMA) as emulsifier. Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and thermogravimetric analysis were used to study the effects of emulsifier type, emulsifier dosage, core-wall ratio and pH on the morphology and thermal properties of microcapsules. The results show that the pH of core material and the ratio of core to wall have a great influence on the performance of microcapsules. SMA emulsifiers and MUF are suitable for the encapsulation of C18. When the pH is 4.5 and the core-wall ratio is 2/1, the latent heat and encapsulation efficiency of phase transition reaches 207.3 J g-1 and 84.7%, respectively. The prepared phase-change microcapsules also have good shape stability and thermal stability.

Polysaccharide-potato protein coacervates for enhanced anthocyanin bioavailability and stability

Anthocyanins (ACNs) possess strong antioxidants, anti-cancer, anti-obesity, anti-diabetic, and anti-inflammatory properties but are limited use by their susceptibility to environmental factors. This study aims to overcome these limitations by developing and assessing a novel coacervate system, consisting of potato protein isolate (PPI) combined with various polysaccharides, to stabilize and encapsulate anthocyanins from black carrot concentrate The polysaccharides included in this system include inulin, gum Arabic, guar gum, pectin, and soluble fiber. The coacervate system's effectiveness in maintaining stability and increasing the bioavailability of anthocyanins was evaluated compared to conventional soybean protein-based systems. The results show that pH considerably influences potato protein solubility, with maximum solubility at strongly acidic (pH 2) conditions. Hygroscopicity and moisture content analysis of the coacervates showed significant variations, with potato protein-guar gum (PPIGG) microcapsules having the lowest moisture content and potato protein gum Arabic (PPIGA) microcapsules having the highest moisture content. SEM imaging illustrated distinct microcapsule morphologies, while FT-IR measurement verified the successful integration of proteins and polysaccharides. The significance of the research reflects its proof that potato protein isolate (PPI) based coacervate systems consists of potato protein with polysaccharides, particularly those containing gum Arabic and pectin, have significant potential for improving anthocyanin stability and bioavailability. These findings guide future studies to investigate other polysaccharides, improve coacervation processes, and explore applications in the food and nutraceutical sectors. It also offers valuable insights for creating efficient encapsulation techniques for bioactive substances.

Evaluation of gum arabic and gelatine coacervated microcapsule morphology and core oil encapsulation efficiency by combining the spreading coefficient and two component surface energy theory

Microcapsules containing various flavour/fragrance oils with different properties were fabricated using gelatine and gum arabic by complex coacervation. The surface properties (surface polarity and the spreading coefficients) of core oils were investigated in order to evaluate their effects on the capsule morphology and encapsulation efficiency based on a spreading coefficient and two component surface energy theory. Contact angles, interfacial tensions, and surface polarities were measured, and results were discussed with respect to the internal structure as well as encapsulation efficiency of different oil microcapsules. The thermodynamic spreading coefficients theory did not give an exactly accurate prediction of capsule morphology using high molecular weight biopolymer as the wall material in this work. Notwithstanding, the morphology predictions for different oil microcapsules are holistically consistent with the values of their encapsulation efficiency. Also, it has been found that the encapsulation efficiency increased with the decreasing surface polarity of the core oil holistically.

Novel eco-friendly nanodiamonds@chitosan hybrid microcapsules via facile electrospraying for self-healing and anticorrosion coating

Nanodiamonds were immobilized into chitosan biopolymer to fabricate hybrid microcapsules via electrospraying technique. Previously optimized electrospraying parameters for the formulation of chitosan microcapsules were adjusted to accommodate the immobilized nanodiamonds and maintain a suitable capsule size for the novel hybrid. The yield and entrapment efficiency of the composite microcapsules, including capsule strength were analyzed. The chemical structure, elemental composition, crystalline phases, size distribution, surface morphology, and thermal stability of microcapsules were assessed by Fourier transform infrared (FTIR) spectroscopy, energy dispersive x-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA), respectively. The results demonstrated a 39 % reduction in the size of composite microcapsules and sphericity improvement after the adjustment. There was a general observation of good yield and immobilization efficiency with the maximum at 96.2 % and 93.8 % for yield and entrapment efficiency, respectively. Characterized composite microcapsules showed desirable morphology, good thermal stability and enhanced mechanical strength, and overall successful fabrication of the hybrid microcapsules. The hybrid microcapsules were subsequently loaded in epoxy resin and coated on a steel substrate to assess their self-healing and anticorrosion abilities. Cross-scratched coating samples were monitored visually for healing efficiency and further analyzed with EIS and potentiodynamic polarization. The self-healing coating showed efficient self-healing and anticorrosion capabilities with a healing efficiency of 97.3 % and a protection efficiency of 99.4 %, confirming the unique feature of the hybrid chitosan-nanodiamonds microparticles for self-healing and anticorrosion purposes.

Augmenting the Quality and Shelf Life of Ras Cheese by Adding Microencapsulated Allspice Berry Extract Nanoemulsion

AbstractThe current study was achieved to increase phenolic compounds and antioxidant content in Ras cheese by microencapsulation of the nanoemulsion of extract from the berries of allspice. The microencapsulation of the extract nanoemulsion from the berries of allspice using maltodextrin, whey protein concentrate, and guar gum was prepared by a freeze-drying process. The extract was cured, and nanoemulsion forms were prepared and evaluated for the antimicrobial effect and phenolic compound content. The morphology of microcapsules was studied by transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FT-IR) analysis. The prepared microcapsules were added to Ras cheese using ratios (1, 2, and 3% (w/w)) and then stored for 120 days for ripening and examined chemically, microbiologically, and organoleptically. The results indicated that the allspice extract in both forms has shown an inhibitory effect on all microorganisms. Moreover, the major phenol compound in allspice berry extract was gallic acid with quantities of 15,991 µg/g. Furthermore, the microcapsule efficiency was recorded at 80.97% and spherical with a diameter of 380 µm, while the nanoemulsion of extract as the core has a size of around 320 nm. The total lactic acid bacteria counts in all samples gradually declined during the ripening period. The mold and yeast count was not detected in fresh cheeses and appeared for cheese control more than in cheese with the extract. Cheese control and treatments contained lower titratable acidity, total nitrogen, soluble nitrogen, and ash ratio than the other cheese with extract treatments. The total volatile fatty acids (TVFAs) were increased through the storage period in all cheese treatments. Correspondingly, Ras cheese acceptability for sensory evaluation increased during the ripening periods in all treatments, whereas cheese supplemented with 1% microcapsules ranked the highest score for flavor and body and texture during storage gaining a high accepted point of 93.62.

Inhibited the walnut oil oxidation through the microcapsules that consisted of (−)-Epigallocatechin gallate and sodium caseinate

(−)-Epigallocatechin gallate (EGCG) possesses potent antioxidant properties and can enhance the encapsulation efficiency and stability of oil microcapsule with sodium caseinate (NaCas). Hence, the present study aimed to investigate the effects of different concentrations of EGCG on the physicochemical properties of walnut oil microcapsules. The impact of EGCG on the morphology, structure, physical attributes, and functional traits of walnut oil microcapsules was characterized through scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, molecular docking, thermogravimetric analysis, etc. Results demonstrated that EGCG interacted with NaCas via hydrogen bonding and hydrophobic interactions to form walnut oil microcapsules, significantly enhancing the encapsulation efficiency up to 86.42%. With increasing concentration of EGCG, the NaCas-EGCG complex displayed heightened DPPH free radical scavenging capacity (up to 68.27 μg Trolox/mL). Furthermore, in vitro digestion indicated that the microcapsules could effectively regulate the release rate of free fatty acids. In conclusion, the present study successfully prepared walnut oil microcapsules with elevated oxidative stability by employing EGCG and NaCas as the wall materials, providing new insight for preparing walnut oil microcapsules with improved stability and release properties.

Characterization of Polyallylamine/Polystyrene Sulfonate Polyelectrolyte Microcapsules Formed on Solid Cores: Morphology.

Polyelectrolyte microcapsules (PMC) based on polyallylamine and polystyrene sulfonate are utilized in various fields of human activity, including medicine, textiles, and the food industry, among others. However, characteristics such as microcapsule size, shell thickness, and pore size are not sufficiently studied and systematized, even though they determine the possibility of using microcapsules in applied tasks. The aim of this review is to identify general patterns and gaps in the study of the morphology of polyelectrolyte microcapsules obtained by the alternate adsorption of polystyrene sulfonate and polyallylamine on different solid cores. First and foremost, it was found that the morphological change in polyelectrolyte microcapsules formed on different cores exhibits a significant difference in response to varying stimuli. Factors such as ionic strength, the acidity of the medium, and temperature have different effects on the size of the microcapsules, the thickness of their shells, and the number and size of their pores. At present, the morphology of the microcapsules formed on the melamine formaldehyde core has been most studied, while the morphology of microcapsules formed on other types of cores is scarcely studied. In addition, modern methods of nanoscale system analysis will allow for an objective assessment of PMC characteristics and provide a fresh perspective on the subject of research.

A new synthesis method of flexible microcapsules applied for electrophoresis display

This study prepared a new type of electrophoretic display microcapsule with flexibility and strength, namely gum arabic/gelatin/urea-formaldehyde resin microcapsule, based on polysaccharides as the reaction starting point, combined with proteins and resins. The composition, morphology and thermal stability of the microcapsules were tested by Fourier transform infrared spectroscopy, stereo fluorescence microscopy, scanning electron microscopy and thermogravimetric analysis. It was found that the morphology and stability of the new microcapsules prepared by the method are better than those prepared by the traditional complex coacervation method or the in-situ polymerization method. At the same time, it showed that the rotational speed was between 1000 rpm and 1200 rpm, the concentrations of gum arabic and gelatin were 3 wt%, the reaction pH between 3 and 3.5, the reaction duration is between 150 min and 180 min, the ammonium chloride was 20 wt%, and resorcinol was 6 wt%, the reaction between the urea-formaldehyde prepolymer and the electro-neutralizer formed by gelatin and gum arabic was sufficient, the microcapsule wall structure was uniform and consistent, with a dense resin based structure on the outer layer and a flexible blend structure inside.

Preparation of UV Topcoat Microcapsules and Their Effect on the Properties of UV Topcoat Paint Film.

An orthogonal experiment was designed to prepare different UV topcoat microcapsules by adjusting the mass ratio of wall material to core material, HLB value of emulsifier, reaction temperature, and reaction time of UV topcoat microcapsule. By testing the morphology and multiple properties of UV topcoat microcapsules, it was found that the biggest factor affecting the synthesis of UV topcoat microcapsules is the emulsifier HLB value. In order to further optimize the performance of UV topcoat microcapsules, a single-factor experiment was conducted with the emulsifier HLB value as the variable, and it was found that the UV topcoat microcapsules achieved the best performance when the emulsifier HLB value was 10.04. The optimal UV topcoat microcapsules were added to the UV topcoat at different amounts to prepare UV topcoat paint films. Through testing the various properties of the UV topcoat paint film, it was determined that the performance of the UV topcoat paint film was optimal when the amount of UV topcoat microcapsules added to the UV topcoat was 4.0%. The optical properties of the UV topcoat paint film were tested, and the effect of UV topcoat microcapsules on the color difference and glossiness of the UV topcoat paint film was not significant. The tensile and self-healing performance of UV topcoat microcapsules were tested. UV topcoat microcapsules can enhance the toughness of the UV topcoat paint film to a certain extent, suppress the generation of microcracks, and have a good self-healing effect. The results provide experimental support for the preparation of microcapsules using UV coatings as core materials for the self-healing of UV coatings.

Evaluation of Bioactive Compounds, Release Profiles, and Toxicity Test from Microcapsules Containing R. tuberosa L. Extracts Utilizing Gum Arabic

This study is essential to analyze the toxicity and release of bioactive compounds in R. tuberosa L. extract microcapsules coated with gum Arabic and to provide information on the use of microcapsules as a drug delivery system with controlled release of active ingredients. Investigations focused on the effect of pH and timing on discharge kinetics, as well as toxicity evaluation. The release of active ingredients from microcapsules was carried out in medium variations, namely pH 2.2 and pH 7.4, with release durations of 30, 60-, 90-, 120-, and 150-min. Bioactive compounds were released by 59.23% at pH 2.2 and 58.21% at pH 7.4 within 150 min. The BSLT (brine shrimp lethal toxicity) assay was used using brine shrimp larvae (Artemia salina L.), resulting in a non-toxic classification as evidenced by an LC50 value of 5729 μg/mL. Microcapsules in optimum conditions were then characterized using FTIR (Fourier-Transform Infrared) and SEM (scanning electron microscopy) instruments. The FTIR analysis showed variations in functional groups in R. tuberosa L. extracts, gum Arabic, and microcapsules. Furthermore, the SEM examination highlighted the morphology of microcapsules that were mostly spherical.

Co-encapsulation of β-D-Galactosidase and Ascorbic Acid in the Milk Protein-Based Microcapsules: Optimization and Characterization

This research is aimed at preparing the β-galactosidase (βg) and vitamin C (VC) cocapsules stabilized by milk proteins. The effect of different independent parameters including core-coating ratio (10-100%), whey protein isolate (0 : 1), sodium caseinate (0 : 1), and ultrasound power (50-150 W) on physicochemical properties of microcapsules was investigated. The response surface methodology (RSM) defined the optimal conditions. Increasing the WPI values had different effects on the particle size and polydispersity index (PDI). The zeta potential values decreased by decreasing SC values. The βg had better encapsulation efficiency in comparison to VC. Increasing the core-coating ratio showed a negative effect on the enzyme activity. Among the test parameters, the core-coating ratio was effective on the viscosity of microcapsules. Two optimum conditions for co-encapsulation were determined as WPI, SC, core-coating ratio, and ultrasound power of 0, 1, 100%, and 79.4 W and 0.2, 0.8, 100%, and 75 W for microcapsules I and II, respectively. In the next step, the structural and morphological properties of the optimum samples were analyzed. The heterogeneous morphology of microcapsules was observed by SEM analysis. The formation of new interactions between wall materials, βg, and VC was confirmed by FT-IR analysis. XRD analysis revealed that the WPI-coated sample had a higher crystallinity index. Generally, the successful co-encapsulation of βg and VC exhibited the potential of the resultant microcapsules for the industrial production of VC fortified and lactose-free milk.

Unveiling antioxidant capacity of standardized chitosan-tripolyphosphate microcapsules containing polyphenol-rich extract of Portulaca oleraceae

The medicinal plant Portulaca oleraceae has a long history of usage in traditional medicine. Plant extracts have several interesting pharmacological effects but have some drawbacks that can be addressed via capsulation with chitosan. This work set out to do just that tally up the antioxidant effects of a polyphenol-rich P. olerace extract and see how capsulation affected them. The reflux extraction and response surface methodology (RSM) were carried out to optimize the phenolic and flavonoid content of P. oleraceae extract. Additionally, high-resolution mass spectrometry was employed to determine the secondary metabolite present in the extract. The microcapsules of extract-loaded chitosan were prepared using the ionic gelation method and characterized in terms of size, encapsulation efficiency (EE), and morphology of microcapsules. Fourier transform infrared (FTIR) was used to observe the successful production of microcapsules with a principal component analysis (PCA) approach. The antioxidant activity of microcapsules was established using the radical scavenging method. According to RSM, the highest amounts of TPC and TFC were obtained at 72.894 % ethanol, 2.031 h, and 57.384 °C. The compounds were employed from the optimized extract of P. oleraceae including phenolics and flavonoids. The microcapsules were secured with a %EE of 43.56 ± 2.31 %. The characteristics of microcapsules were approved for the obtained product's successful synthesis according to the PCA. The microcapsules have antioxidant activity in a concentration-dependent manner (p < 0.0001). The findings of this study underscored the benefits of employing chitosan as a nanocarrier for extract, offering a promising approach to enhance plant-derived therapies.

Preparation and chemical properties of microencapsulation developed with mulberry anthocyanins and silk fibroin

Anthocyanins, as natural pigments with bright color and non-toxic side effect, are widely used in the agricultural products processing field. In the present research, mulberry anthocyanin microcapsules were prepared with silk fibroin and gum arabic as wall materials for the possible application in cosmetics industry. Anthocyanin microcapsule encapsulation efficiency was up to 95.71% in the condition of silk fibroin: gum arabic at 2:1, wall-core ratio of 7.5:1 and solid content at 15%. Microcapsules improved the thermal stability and pH stability of mulberry anthocyanins with higher retention rates. Besides, scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and fourier transform infrared (FTIR) were applied to analyze the surface morphology, structure, crystallinity and thermal properties of mulberry anthocyanin microcapsules. The results indicated that anthocyanins were embedded in the capsules with crystalline structures, good encapsulation and enhanced thermal stability.

Chitosan-TPP microcapsules for controlled drug release

Production of chitosan/sodium tripolyphosphate (CS/TPP) microcapsules via spray drying involves atomizing an emulsion containing CS, TPP, acetic acid (AcOH), and folic acid (FA) into fine droplets exposed to high-temperature, low-pressure gas flow. Solvent evaporation within the drying chamber leads to solid particle formation. Spray drying is valuable for creating solid CS/TPP microcapsules. Precise equipment parameter adjustments, like inlet temperature and gas flow rate, enable the study of microcapsule morphology, size, and properties. This adaptability allows for customization to specific pH dissolution ranges. The production method's impact on CS/TPP microcapsules was studied by modifying spray drier parameters, including inlet temperature and aspirator pressure, to enhance understanding of their behavior in solution under varied production conditions.&#x0D; In chitosan delivery systems, various approaches can encapsulate drug agents like folic acid, an analog to the cancer treatment drug methotrexate. Agents can be added to the chitosan solution pre-crosslinking, incorporated into gelation-inducing agents pre-mixing with chitosan, or included in the crosslinking mixture. Experiments were conducted to assess CS/TPP microcapsules' behavior when encapsulating agents like folic acid. Release profiles were analyzed to understand their drug delivery capabilities and potential as controlled release carriers.

MICROENCAPSULATION BISOPROLOL FUMARATE WITH EUDRAGIT E PO BY SOLVENT EVAPORATION METHOD

Objective: This study aimed to develop and optimize the microcapsule formula of bisoprolol fumarate-Eudragit EPO by double-emulsion solvent evaporation.&#x0D; Methods: The preparation of bisoprolol fumarate-Eudragit EPO microcapsule was done in three different ratios 1: 3 (F1), 1: 4 (F2), and 1: 5 (F3), followed by characterization of each of the microcapsule formula using Fourier transform infrared, scanning electron microscopy, particle size analyzer. Further analysis included investigation of the drug loading, entrapment efficiency, solubility in pH 6.8, and the difference among dissolution profiles of each microcapsule using one-way ANOVA.&#x0D; Results: Infra-red spectrum showed no chemical interaction between bisoprolol fumarate and Eudragit E PO in microcapsules. The morphology and structure of F1 microcapsule was irregular spheres, while F2 and F3 were regular spheres. The average particle distribution of microcapsules was 24.765±0,236 μm (F1), 28.245±0,252 μm (F2), and 40.634±0,218 μm (F3). The drug loading was 7.691±0,087 % (F1), 8.922±0,056 % (F2), and 9.012±0,133% (F3). The encapsulation efficiency was 4.980 % (F1), 5.857%(F2), and 6,285 %(F3). The average amount of bisoprolol fumarate released in pH 6.8 was 2.113±0,289 % (F1), 1.954±0,015 % (F2), and 1.619±0,020 % (F3). The dissolution profile between each formula was statistically different (p value= 0,000).&#x0D; Conclusion: As the low value of drug loading and encapsulation efficiency in each formula, we concluded that the microencapsulation formula with Eudragit EPO by solvent evaporation method is not effective to entrap bisoprolol fumarate.

A unified thermodynamic and kinetic approach for prediction of microcapsule morphologies

Hypothesis: Microcapsule formation, following internal phase separation by solvent evaporation, is controlled by two main factors of thermodynamic and kinetic origin. Morphology prediction has previously focused on the final thermodynamical state in terms of spreading conditions, limiting the prediction accuracy. By additionally considering kinetic effects as the emulsion droplet evolves through the two-phase region of its ternary phase diagram during solvent evaporation, this should enhance prediction accuracy and explain a wider range of morphologies.Experiments: Dynamical interfacial tensions, and thereby spreading coefficients, during the formation of poly(methyl methacrylate) and poly(d,l-lactic-co-glycolic acid) microcapsules were measured by first establishing the boundaries and tie-lines of the ternary system in the emulsion droplets. Kinetic effects during the formation were investigated by varying the solvent evaporation rate and hence the time for polymer shell formation equilibration. The theory was validated by comparing predicted morphologies to microscopic snapshots of intermediate and final morphologies.Findings: The proposed theory explained both intermediate acorn and core–shell morphologies, where a late transition from acorn to core–shell produced microcapsules containing highly off-centered cores. By considering the kinetic factors, the formulation could be altered from yielding kinetically frozen acorns to core–shell and from yielding multicore to single core microcapsules.

The color/shape/flavor of yam gel with double emulsified microcapsules changed synchronously in 4D printing induced by microwave

The feasibility of 3D printing the color, aroma and shape changes of yam gel with microwave heating as stimulus and soybean protein isolate-chitosan-maltodextrin complex coacervated microcapsules rich in water-soluble betacyanin and rose essence as stimulus-response materials was discussed. The morphology of microcapsules presented irregular spherical structure, and the surface was relatively smooth and slightly concave. Microwave heating led to the gradual destruction of microcapsules in yam gel, releasing internal pigments and essence, and enhancing the redness and flavor of printed samples. The release of the water phase and oil phase of the microcapsules and the hot-spot expansion effect of the models made the 3D printed bird models bend and deform, realizing the deformation effect of “spreading of wings”, which realized a three-response synchronous change in color, shape, and flavor of the printed samples within 45 s. In this study, a variety of 4D printed foods with synchronous changes in sensory characteristics were created, which increased sensory enjoyment on the basis of ensuring the nutritional needs of food.

Synthesis and characterisation of microcapsules for self-healing dental resin composites

AimThe purpose of this study was to i) synthesise TEGDMA-DHEPT microcapsules in a laboratory setting; ii) characterise the resultant microcapsules for quality measures.Materials & methodsMicrocapsules were prepared by in situ polymerization of PUF shells. Microcapsules characterisation include size analysis, optical and SEM microscopy to measure the diameter and analyse the morphology of PUF microcapsules. FT-IR spectrometer evaluated microcapsules and benzyl peroxide catalyst polymerization independently.ResultAverage diameter of TEGDMA-DHEPT microcapsules was 120 ± 45 μm (n: 100). SEM imaging of the capsular shell revealed a smooth outer surface with deposits of PUF nanoparticles that facilitate resin matrix retention to the microcapsules upon composite fracture. FT-IR spectra showed that microcapsules crushed with BPO catalyst had degree of conversion reached to 60.3%.ConclusionTEGDMA-DHEPT microcapsules were synthesised according to the selected parameters. The synthesised microcapsules have a self-healing potential when embedded into dental resin composite as will be demonstrated in our future work.Graphical Graphical abstract showing the microcapsule components. The shell contains poly(urea-formaldehyde), and the core consists of TEGDMA-DHEPT healing agents.