Chitosan dual gel-like functionalized with flavonoid extract and cinnamaldehyde oil using dual cross-linking agents: Characterization, antioxidant, and antimicrobial effects.

This study evaluated antioxidant and antimicrobial properties of chitosan gel (Cs-gel) functionalized with cinnamaldehyde oil (CN) and orange peel-derived flavonoid extract (Fs) using the ionic-gelation method. Results showed that the encapsulation efficiencies of CCF-9 and CCN were 83.14 ± 3.34 and 80.56 ± 1.17%, respectively. The interaction of CN or Fs on Cs-gel indicates the presence of H-bonding formation, as observed by UV-vis spectroscopy, Fourier transform infrared spectrophotometry (FTIR), and Raman-spectroscopy showed a good corroboration with Surflex-dock findings. Scanning electron microscopy also showed the integration that occurred between Cs and both ligands, which was further supported with X-ray diffraction and X-Ray photoelectron spectroscopy spectra. The textural properties of CCF-5 gel showed high hardness, chewiness, and gumminess values, indicating that the integration of Fs and CN altered the microstructure of Cs-gel. Chotison-functionalized based gels exhibited higher antioxidant abilities against DPPH and ABTS free radicals than Cs-gel. The CCF-9 gel showed a good inhibition value of 29.91 ± 1.22 and 93.61 ± 2.12% against Penicillium expansum and Alternaria westerdijkiae, respectively. Additionally, CCF-9 inhibition zones against Staphylococcus aureus, Escherichia coli, and Bacillus cerues were 28.65 ± 0.05, 27.69 ± 0.04, and 26.16 ± 0.02 mm, respectively. These findings demonstrated the potential antioxidant and antimicrobial effects of functionalized chitosan gel indicating its potential as a bioactive additive for food preservation.

Development of an alternative method to quantify H2S: application in wine fermentation.

BACKGROUND: A colorimetric method for the quantification of hydrogen sulfide (H2S) produced in microbial fermentations was developed using lead gelled alginate microparticles packed in glass columns. The formation of a lead sulfide complex, between H2S and lead ion (Pb2+) immobilized on the microparticles, allowed simple and accurate quantification by colorimetry. RESULTS: The microparticle-loaded columns were calibrated and showed significant analytical sensitivity. The calibration curve of the system showed a correlation coefficient (r2) of 0.995 and a detection limit of 1.29 ± 0.02 µg L-1. The application of the columns in laboratory wine fermentations was able to detect variations in H2S production from 10.6 to 23.5 µg L-1 by increasing the sugar content in the medium, and from 10.6 to 3.2 µg L-1 with decreasing nitrogen content in the medium. CONCLUSION: Validation of the proposed method was carried out by determining H2S in a vinic fermentation model, the results of which were compared with those obtained using a reference chemical method. The data obtained showed no statistically significant differences between the two methods, confirming the reliability and accuracy of the developed system. © 2024 Society of Chemical Industry.

Synthesis of agro-industrial wastes/sodium alginate/bovine gelatin-based polysaccharide hydrogel beads: Characterization and application as controlled-release microencapsulated fertilizers.

Synthesis of novel agro-industrial wastes/sodium alginate/bovine gelatin-based polysaccharide hydrogel beads, micromeritic/morphometric characteristics of the prepared formulations, greenhouse trials using controlled-release microencapsulated fertilizers, and acute fish toxicity testing were conducted simultaneously for the first time within the scope of an integrated research. In the present analysis, for the first time, 16 different morphometric features, and 32 disinct plant growth traits of the prepared composite beads were explored in detail within the framework of a comprehensive digital image analysis. The hydrogel beads composed of 19 different agro-industrial wastes/materials were successfully synthesized using the ionotropic external gelation technique and CaCl2 as cross-linker. According to micromeritic characteristics, the ionotropically cross-linked beads exhibited 77.86 ± 3.55 % yield percentage and 2.679 ± 0.397 mm average particle size. The dried microbeads showed a good swelling ratio (270.02 ± 80.53 %) and had acceptable flow properties according to Hausner's ratio (1.136 ± 0.028), Carr's index (11.94 ± 2.17 %), and angle of repose (25.03° ± 5.33°) values. The settling process of the prepared microbeads was observed in the intermediate flow regime, as indicated by the average particle Reynolds numbers (169.17 ± 82.81). Experimental findings and non-parametric statistical tests reveal that dried fertilizer matrices demonstrated noteworthy performance on the cultivation of red hot chili pepper plant (Capsicum annuum var. fasciculatum) according to the results of greenhouse trials. Surface morphologies of the best-performing fertilizer matrices were also characterized by Scanning Electron Microscopy. Moreover, the static fish bioassay experiment confirmed that no abnormalities and acute toxic reactions occurred in shortfin molly fish (Poecilia sphenops) fed with dried leaves of red hot chili pepper plants grown with formulated fertilizers. This study showcased a pioneering investigation into the synthesis of microcapsules using synthesized hydrogel beads along with digital image processing for bio-waste management and sustainable agro-application.

Additive-Free Gelation of Graphene Oxide Dispersions via Mild Thermal Annealing: Implications for 3D Printing and Supercapacitor Applications.

Herein, a mild thermal annealing (MTA) process is presented for additive-free gelation of graphene oxide (GO) dispersions. This process transitions the GO from a nematic liquid crystal phase to a random network structure, significantly enhancing its rheological properties by order of magnitude. This transition is facilitated by the diffusion of functional groups on the GO surface, which induces hydrophobic attractions, leading to a stable network structure. Employing rheo-SAXS experiments, detailed insights are provided into the microstructural changes of GO gel under shear stress, establishing a direct correlation between its rheological behavior and microstructure. The distinctive properties of MTA-processed inks are illustrated, seamlessly integrating with 3D printing, to yield a highly porous lattice structure that demonstrates promising potential as a supercapacitor electrode. The MTA process, an additive-free approach to gelation, maintains the inherent dispersion properties of GO while offering scalability. Thus, this method brings significant economic and environmental advantages compared to conventional gelation techniques. The findings not only advance the fundamental understanding of 2D colloidal network gels but also increase the potential of GO for a wide range of applications, from gas and liquid absorbers to electrodes for energy storage and conversion, and biomedical fields.

Fabrication of nanogels to improve the toxicity and persistence of cycloxaprid against Diaphorina citri, the vector of citrus huanglongbing.

INTRODUCTION: Diaphorina citri is the most serious pest of citrus worldwide because it is the natural insect vector of huanglongbing. Cycloxaprid (Cyc) was highly toxic to D. citri. However, the poor solubility and stability had limited its development. OBJECTIVES: In order to improve the insecticidal effect and stability to harsh climatic conditions of Cyc. METHODS: Cyc was chosen as the representative pesticide, 4,4'-methylenebis (phenyl isocyanate), PEG-600 and n-butanol were used to prepare sustained-release nano-gelation particles (Cyc@NGs). RESULTS: Cyc@NGs enhance the toxicity of Cyc more than 3 folds. Furthermore, Cyc@NGs showed excellent anti-rain and anti-UV capacity. After being exposed to ultraviolet light for 12 h, Cyc decreased by 100 %, while the insecticide content of Cyc@NGs only decreased by 25 %. Additionally, Cyc@NGs possessed better wettability on citrus leaves, mainly benefitting from its lower contact angle on citrus leaves. Moreover, FITC-labeled nano-gelation particles (FITC-NGs) exhibited high capability to penetrate and enrich in citrus leaf tissue and D. citri midgut. Consequently, NGs promoted the translocation and durability of insecticides, thereby, increasing the insecticidal activity. The results suggested that nano-gelation particle is a promising platform to deliver insecticides and Cyc@NGs would be the suitable candidate for the effective management of D. citri.

Insight into the effects of ultrasound-assisted intermittent tumbling on the gelation properties of myofibrillar proteins: Conformational modifications, intermolecular interactions, rheological properties and microstructure.

The aim of the present study was to evaluate the effects of ultrasound-assisted intermittent tumbling (UT) at 300 W, 20 kHz and 40 min on the conformation, intermolecular interactions and aggregation of myofibrillar proteins (MPs) and its induced gelation properties at various tumbling times (4 and 6 h). Raman results showed that all tumbling treatments led the helical structure of MPs to unfold. In comparison to the single intermittent tumbling treatment (ST), UT treatment exerted more pronounced effects on strengthening the intermolecular hydrogen bonds and facilitating the formation of an ordered ß-sheet structure. When the tumbling time was the same, UT treatment caused higher surface hydrophobicity, fluorescence intensity and disulfide bond content in the MPs, inducing the occurrence of hydrophobic interaction and disulfide cross-linking between MPs molecules, thus forming the MPs aggregates. Additionally, results from the solubility, particle size, atomic force microscopy and SDS-PAGE further indicated that, relative to the ST treatment, UT treatment was more potent in promoting the polymerization of myosin heavy chain. The MPs aggregates in the UT group were more uniform than those in the ST group. During the gelation process, the pre-formed MPs aggregates in the UT treatment increased the thermal stability of myosin, rendering it more resistant to heat-induced unfolding of the myosin rod region. Furthermore, they improved the protein tail-tail interaction, resulting in the formation of a well-structured gel network with higher gel strength and cooking yield compared to the ST treatment.

Structural Rheology in the Development and Study of Complex Polymer Materials.

The progress in polymer science and nanotechnology yields new colloidal and macromolecular objects and their combinations, which can be defined as complex polymer materials. The complexity may include a complicated composition and architecture of macromolecular chains, specific intermolecular interactions, an unusual phase behavior, and a structure of a multi-component polymer-containing material. Determination of a relation between the structure of a complex material, the structure and properties of its constituent elements, and the rheological properties of the material as a whole is the subject of structural rheology-a valuable tool for the development and study of novel materials. This work summarizes the author's structural-rheological studies of complex polymer materials for determining the conditions and rheo-manifestations of their micro- and nanostructuring. The complicated chemical composition of macromolecular chains and its role in polymer structuring via block segregation and cooperative hydrogen bonds in melt and solutions is considered using tri- and multiblock styrene/isoprene and vinyl acetate/vinyl alcohol copolymers. Specific molecular interactions are analyzed in solutions of cellulose; its acetate butyrate; a gelatin/carrageenan combination; and different acrylonitrile, oxadiazole, and benzimidazole copolymers. A homogeneous structuring may result from a conformational transition, a mesophase formation, or a macromolecular association caused by a complex chain composition or specific inter- and supramolecular interactions, which, however, may be masked by macromolecular entanglements when determining a rheological behavior. A heterogeneous structure formation implies a microscopic phase separation upon non-solvent addition, temperature change, or intense shear up to a macroscopic decomposition. Specific polymer/particle interactions have been examined using polyethylene oxide solutions, polyisobutylene melts, and cellulose gels containing solid particles of different nature, demonstrating the competition of macromolecular entanglements, interparticle interactions, and adsorption polymer/particle bonds in governing the rheological properties. Complex chain architecture has been considered using long-chain branched polybutylene-adipate-terephthalate and polyethylene melts, cross-linked sodium hyaluronate hydrogels, asphaltene solutions, and linear/highly-branched polydimethylsiloxane blends, showing that branching raises the viscosity and elasticity and can result in limited miscibility with linear isomonomer chains. Finally, some examples of composite adhesives, membranes, and greases as structured polymeric functional materials have been presented with the demonstration of the relation between their rheological and performance properties.

Impact of diverse mineral hardness in electrodialysis water on the ionotropic gelation mechanism of low methoxyl pectin.

In this study, the effect of desalinated lava seawater via electrodialysis (ED water) on the formation and properties of low methoxyl pectin (LMP) gels was investigated. Additionally, the syneresis, microstructure, gelation mechanism, and thermostability of the gel samples were analyzed. When the ED water content exceeded 25 %, pectin gels with viscosities and textures that differed from those of the sol were formed. The highest gel hardness (9.38 N) was observed when 50 % ED water was mixed with LMP. However, when 75 % ED water was added, the pore size of the LMP gel became the largest, and excess water was released from the gel, resulting in a weak gel strength (4.98 N). The formation and properties of the gel structure were found to be mainly due to the ionic bonds between the minerals in the ED water and the free carboxyl groups of pectin, and it was confirmed that the hydrogen bonds within the pectin chains also had an effect. These results suggest that the interaction between the ED water and LMP can be widely used in various industrial fields, including low-sugar gels or viscosity-enhancing agents with diverse rheological properties.

Hyaluronic acid promotes heat-induced gelation of ginkgo seed proteins.

This study aimed to investigate how varying concentrations (0.01-0.5 %, w/v) and molecular weights (50, 500, 1500 kDa) of hyaluronic acid (HA) affect the physicochemical properties of heat-induced ginkgo seed protein isolate (GSPI)-HA composite gel. Incorporating HA increased viscosity (up to 14 times) and charge (up to 23 %) of GSPI-HA aggregates, while reducing particle size (up to 31 %) and improving gel texture, particularly with high molecular weight HA. However, high concentrations (0.5 %, w/v) of HA weakened gel texture. Non-covalent bonds primarily drive the formation of a continuous gel network between HA and GSPI, resulting in small pores and enhanced hydration properties. With increasing HA molecular weight, non-covalent interactions between GSPI and HA increased, leading to improved gel thermal stability. Overall, the study suggests that manipulating the molecular weight and concentration of HA can enhance the gelling properties of GSPI, leading to the development of a diverse array of GSPI-HA composite gels with varied properties.

Preservation by ionic gelation encapsulation of the antioxidant activity of protein hydrolysate derived from Lionfish (Pterois volitans, L.) muscle proteins.

The ionic gelation for preserving the antioxidant activity of the protein hydrolysate from encapsulated lionfish (Pterois volitans, L.) muscle was evaluated. A 22 factorial design was used. The factors evaluated were sodium alginate concentration (1.75% and 3.5% w/v) and calcium chloride concentration (3% and 5% w/v). The response variables were encapsulation efficiency and preservation of antioxidant activity. The beads obtained were classified as microcapsules (2-3 mm) and were mostly spherical, with a weight ranging from 12 to 38 mg. Encapsulation efficiency ranged from 37 to 55.47%, while the preservation of antioxidant activity ranged from 43.3 to 64.5%. The best treatment for preserving the in vitro antioxidant activity of the protein hydrolysate was the one with 1.75% w/v sodium alginate and 3% w/v calcium chloride, which showed an encapsulation efficiency of 53.96%, preservation of antioxidant activity of 64.5%, and free radical scavenging (DPPH) of 22.73%.

Sweet potato protein hydrolysates solidified calcium-induced alginate gel for enhancing the encapsulation efficiency and long-term stability of purple sweet potato anthocyanins in beads.

Based on the previous research, this work aimed to reveal the effect of sweet potato protein hydrolysates (SPPHs) with different molecular weights (1000, 3000, and 8000 Da) at 0.5 % on the gelation behavior of calcium-induced sodium alginate (SA), and the encapsulation efficiency and storage stability of purple sweet potato anthocyanins (PSPA) in calcium-induced alginate gel beads was determined. Results indicated that SPPHs with a molecular weight of 8000 Da formed hydrogen bonds and other interactions with SA, which strengthened the internal network connections of the gel, significantly enhanced the gel and effectively filled its pores. The highest encapsulation efficiency was achieved at 87.27 %, compared to 61.73 % without SPPHs. Additionally, stored at 37 °C for 21 days after commercial sterilization, the residual concentration of PSPA with SPPHs was 2.50 times higher than that without SPPHs. SPPHs can enhance the encapsulation efficiency of PSPA and retard their release in gel beads.

Modulation of acid-induced pea protein gels by gellan gum and glucono-δ-lactone: Rheological and microstructural insights.

This study investigated the effect of gellan gum (GG) and glucono-δ-lactone (GDL) on the acid-induced gel properties of pea protein isolate (PPI) pretreated with media milling. The inclusion of GG substantially enhanced the gel hardness of PPI gel from 18.69 g to 792.47 g though slightly reduced its water holding capacity (WHC). Rheological analysis showed that GG increased storage modulus (G') and decreased damping factor of gels in the small amplitude oscillatory shear region and transformed its strain thinning behavior into weak strain overshoot behavior in the large amplitude oscillatory shear region. SEM revealed that GG transformed the microstructure of gel from a uniform particle aggregate structure to a chain-like architecture composed of filaments with small protein particles attached. Turbidity and zeta potential analysis showed that GG promoted the transformation of PPI from a soluble polymer system to an insoluble coagulant during acidification. When GG content was relatively high (0.2 %-0.3 %), high GDL content increased the electrostatic interaction between PPI and GG molecules, causing their rapid aggregation into a dense irregular aggregate structure, further enhancing gel strength and WHC. Overall, GG and GDL can offer the opportunity to modulate the microstructure and gel properties of acid-induced PPI gels, presenting potential for diversifying food gel design strategies through PPI-GG hybrid systems.

Complex influence of structural characteristics of low-methoxyl pectins on rheological properties of semi-solid Ca-gels.

The semi-solid Ca-gels were prepared from low-methoxyl pectins (methoxylation degree DM 4-36 %) of Oberna Behen, Potamogeton natans, Tanacеtum vulgаre, Comarum palustre, Bergenia crassifolia, and Heracleum sosnowskyi. Pectins are characterized by Mw of 77-556 kDa and different content of HG and RG-I. The gels were prepared by addition of Ca2+ ions at varying stoichiometric ratios, R = 2 × [Ca2+]/[COO-], of 0.2-0.6, and a fixed pectin concentration of 10 g/L. It was shown that the presence of certain sets of structural characteristics in low-methoxyl pectins from different sources leads to the formation of gels with similar rheological properties. Pectins with Mw 77-98 kDa, DM 6-14 % form stiffer Ca-gels than pectins with Mw 218-253 kDa, DM 24-36 % at the same R. Pectins with Mw 346-556 kDa form the strongest Ca-gels. Their high Mw compensates for the influence of DM on the properties of Ca-gels. The stability of gels in PBS (pH 7.4) is determined mainly by proportion of 1,4-linked non-methoxylated GalA in pectins. Pectins with DM 4-14 % form more stable Ca-gels in PBS than pectins with DM 21-36 %.

A comprehensive review on freeze-induced deterioration of frozen egg yolks: Freezing behaviors, gelation mechanisms, and control techniques.

Over the years, the production of eggs has increased tremendously, with an estimated global egg production of 9.7 billion by 2050. Further processing of shell eggs to egg products has gained growing popularity. Liquid egg yolks, an innovative form of egg replacement, still suffer from short shelf-life issues, and freezing has been applied to maintain freshness. An undesirable phenomenon called "gelation" was found during the production of frozen egg yolks, which has attracted numerous scholars to study its mechanism and quality control methods. Therefore, we comprehensively reviewed the history of the studies on frozen egg yolks, including the production procedure, the fundamentals of freezing, the gelation mechanism, the factors affecting gelation behaviors, and the techniques to control the gelation behaviors of frozen egg yolks. Reporting the production procedure and freezing fundamentals of frozen egg yolks will give readers a better understanding of the science and technological aspects of frozen egg yolks. Furthermore, a comprehensive summary of the mechanism of egg yolk gel formation induced by freeze-thawing and relevant control techniques will provide insights to researchers and manufacturers in the field of frozen egg processing.

Thermosensitive injectable fibrillar gels based on cellulose nanocrystals grafted with poly(N-isopropylacrylamide) as biocompatible brain implants.

Drug treatment of glioblastoma, the most aggressive and widespread form of brain cancer, is complicated due to the difficulty of penetration of chemotherapeutic drugs through the blood-brain barrier (BBB). Moreover, with surgical removal of tumors, in 90 % of cases they reappear near the original focus. To solve this problem, we propose to use hydrogel based on cellulose nanocrystals grafted with poly(N-isopropylacrylamide) (CNC-g-PNIPAM) as a promising material for filling postoperative cavities in the brain with the release of antitumor drugs. The CNC-g-PNIPAM is formed by "grafting to" method for precise control of molecular weight and grafting density. This colloidal system is liquid under injection conditions (at r. t.) and turns into a gel at human body temperature (when filling the postoperative area). It was shown for the first time that due to the rod-shaped of CNC, the gel has a fibrillar structure and, thus, mechanical properties similar to those of brain tissue, including nonlinear mechanics (strain-stiffening and compression softening). The biocompatibility of the hydrogel with primary brain cells is demonstrated. In addition, the release of the antitumor drug paclitaxel from the hydrogel and its antitumor activity is shown. The resulting nanocolloid system provides an innovative alternative approach to filling postoperative cavities and can be used for postoperative treatment due to the programmable release of drugs, as well as for in vitro modeling of tumor interaction with the BBB affecting drug transport in the brain.

Gelation of gellan induced by trivalent cations and coexisting trivalent with monovalent cations studied by rheological and DSC measurements.

The effect of trivalent cation Fe3+ on the gelation process of a sodium salt form of gellan (DG, deacylated gellan gum) was investigated by rheology and DSC studies. On addition of a fairly low concentration of Fe3+ (1 mM), both the complex modulus (G*) of a 1.0 % DG solution in gel state and the sol-gel transition temperature (Tgel) slightly decreased. At higher Fe3+ concentrations (2 and 3 mM), however, a slight increase in the G* and Tgel was observed. In the coexisting monovalent cation (K+) solutions, addition of Fe3+ always improved the G* in gel state and the Tgel in a concentration-dependent manner. Moreover, for all Fe3+ DG solutions, the ordered structure formation temperature (Torder) was always lower than Tgel and increased with increasing Fe3+ concentration. This finding indicates that the network formation in the DG solutions should occur in advance of the ordered structure formation of the DG chains and that the presence of Fe3+ unfavorably affected the conformational transition of DG. In coexisting cation solution, the presence of K+ ion made a favorable contribution to the binding of Fe3+ to the disordered DG chains and to the subsequent ordered structure formation of the DG chains.

Application of purple basil leaf anthocyanins-loaded alginate-carrageenan emulgel beads in gelatin-based jelly candies.

Jelly candies could be considered promising food matrices for the delivery of bioactive compounds such as anthocyanins (ACNs). In this study, gelatin-based jelly candies were fortified with free ACNs-rich purple basil leaf extract (PBLE) and PBLE-loaded emulgel beads. The interaction between free ACNs and gelatin in the jelly matrix resulted in a lower release of ACNs in the mouth (8.27 %) and gastric stage (74.44 %) compared to those of free extract (24.92 and 86.13 %), as well as some protection in the intestinal stage. The release of ACNs from the jellies enriched with PBLE-loaded emulgel beads only began in the intestinal stage and reached 66.34-70.75 % of the initial load. Compared to those of PBLE-loaded emulgel beads, the introduction of beads within the jelly matrix increased the in vitro release of ACNs. The jelly samples enriched with PBLE-loaded emulgel beads yielded higher hardness, adhesiveness, flexibility, and chewiness compared to samples with free PBLE. While the color and appearance of jellies fortified with encapsulated PBLE were impaired, they got the highest sensory acceptance scores due to the masking of the bitter taste of the free extract. ACNs-loaded emulgel beads could be a viable method for fortifying jelly candies.

Study on co-amorphous emerging solubilization behavior after gelation during dissolution: The importance of complexation and anti-crystallization.

Co-amorphous (CM) is a promising technology for enhancing the aqueous solubility of insoluble drugs, but the gelation phenomenon has often occurred during the dissolution process and seriously threatened their solubility/dissolution performance. Therefore, it's quite important to design favorable CM systems to alleviate or even avoid the adverse effects of gelation phenomenon. In this study, CM systems of taxifolin (TAX) and oxymatrine (OMT) (TAX-OMT CMs) were constructed to improve the solubility and dissolution properties of TAX. Interestingly, TAX-OMT CMs gradually aggregated and obviously gelled during dissolution, but the solubility and dissolution of TAX in TAX-OMT CMs were significantly enhanced compared to crystalline TAX. Consequently, the underlying solubilization mechanisms of TAX-OMT CMs after gelation were systematically explored. For one thing, the complexation between the two components in TAX-OMT CMs was verified by phase solubility, fluorescence spectroscopy and isothermal titration calorimetry. For another, the residual solids of TAX-OMT CMs after dissolution evaluation were thoroughly characterized by means of powder X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscopy, which showed the anti-crystallization property of TAX-OMT CMs. Furthermore, molecular simulation demonstrated the intermolecular interactions of TAX-OMT CMs alone and TAX-OMT complexes in aqueous solution. Finally, pharmacokinetics study in rats suggested that the bioavailability of TAX in TAX-OMT CM (1:2) was approximately 5.5-fold higher than that of crystalline TAX after oral administration. Collectively, this study reveals the importance of complexation and anti-crystallization effects of CM systems on maintaining solubilization behavior after gelation, providing an effective strategy to improve the absorption performance of pharmaceutical CM systems.

Structural evolution of maize starches with different amylose content during pasting and gelation as evidenced by Rapid Visco Analyser.

This study examined multi-scale structural alterations of maize starches varying in amylose content during pasting and gelation, using Rapid Visco Analyser (RVA). At 50 °C, starch granules maintained their morphology with low viscosity. As the temperature increased to 95 °C, helical and crystal structures were destroyed, leading to granule swelling, distortion and porosity, as identified by Wide Angle X-ray Scattering and Fourier Transforms Infrared measurements at 90% moisture. This resulted in increased viscosity and the formation of a loose gel network structure. Subsequently, maintaining the temperature at 95 °C caused a decrease in viscosity as most granules disappeared, forming a reorganized flaky gel structure with larger pores. As the temperature decreased, gel porosity reduced. In high amylose content starch, the viscosity remained low and granules were partially gelatinized since the heating temperature was below the gelatinization temperature. This study is the first to detail starch multilevel structural dynamics during RVA gelatinization.

Exosome Loaded Protein Hydrogel for Enhanced Gelation Kinetics and Wound Healing.

Exosomes are being increasingly explored in biomedical research for wound healing applications. Exosomes can improve blood circulation and endocrine signaling, resulting in enhanced cell regeneration. However, exosome treatments suffer from low retention and bioavailability of exosomes at the wound site. Hydrogels are a popular tool for drug delivery due to their ability to encapsulate drugs in their network and allow for targeted release. Recently, hydrogels have proven to be an effective method to provide increased rates of wound healing when combined with exosomes that can be applied noninvasively. We have designed a series of single-domain protein-based hydrogels capable of physical cross-linking and upper critical solution temperature (UCST) behavior. Hydrogel variant Q5, previously designed with improved UCST behavior and a significantly enhanced gelation rate, is selected as a candidate for encapsulation release of exosomes dubbed Q5Exo. Q5Exo exhibits low critical gelation times and significant decreases in wound healing times in a diabetic mouse wound model showing promise as an exosome-based drug delivery tool and for future hybrid, noninvasive protein-exosome design.