Octenylsuccinylation strategy to construct high-amylose maize starch-myristic acid complexes with high thermal stability, complexation efficiency and anti-retrogradation ability.

Gelatinizing high-amylose maize starch (HAMSt) requires high temperatures to allow complexation with lipids, making it a challenging process. An octenylsuccinylation method was examined as a part of a strategy to decrease the gelatinization temperature of HAMSt, thereby promoting the complexation between HAMSt and myristic acid (MAc). Octenyl succinic anhydride (OSA) modification of HAMSt reduces the onset gelatinization temperature of HAMSt from 71.63 °C to 66.97 °C. Moreover, as the OSA concentration increased from 2 % to 11 %, the degree of substitution and molecular weights of the esterified HAMSt gradually increased from 0.0069 to 0.0184 and from 0.97 × 106 to 1.17 × 106 g/mol, respectively. Fourier transform infrared analysis indicated that the octenyl-succinate groups were grafted onto the HAMSt chains. The formation of HAMSt-MAc complexes improved the thermal stability of OSA-treated HAMSt (peak temperature increased by 0.11 °C-13.95 °C). Moreover, the diffraction intensity of the V-type peak of the 11 % sample was greater than that of other samples. Finally, the anti-retrogradation ability was in the order of OSA-HAMSt-MAc complexes > HAMSt-MAc complexes > HAMSt. Overall, our results indicate that octenylsuccinylation can be an effective strategy to promote the formation of OSA-HAMSt-MAc complexes and delay starch retrogradation.

Overcoming Challenges of Incorporation of Biobased Dibutyl Itaconate in (Meth)acrylic Waterborne Polymers.

Polymeric derivatives of itaconic acid are gaining interest as biobased alternatives to petroleum-based monomers due to their versatility, renewable nature, commercial availability, and cost-effectiveness. Itaconate ester monomer's challenges incorporating in (meth)acrylic waterborne polymers are the low propagation rate, unfavorable reactivity ratios, and the depropagation process. To overcome these challenges, the seeded semibatch emulsion polymerization of 100% biobased dibutyl itaconate, methyl methacrylate, and butyl acrylate was investigated at different temperatures. Consequently, 30 wt % DBI was successfully incorporated within waterborne (meth)acrylates in short reaction times (4 h), obtaining high DBI incorporation (>90%). The results demonstrate that DBI incorporation influences the instantaneous monomer conversion, polymer's microstructure, and mechanical properties. By incorporating a biobased itaconate cross-linker, kinetics and mechanical characteristics of the polymers were improved. This combined approach can be implemented without altering industrial processes, resolving the commercialization dilemma for itaconate monomers to synthesize high-performance biobased polymers for adhesive and coating industries.

Injectable Hydrogel of Chitosan-Octyl Itaconate Conjugate Modulates Inflammatory Response.

Itaconic acid and its derivative 4-octyl itaconate (OI) represent a novel anti-inflammatory medication that has demonstrated efficacy in multiple inflammation models because of its minimal side effects. Recently, natural polymers conjugated with small molecule drugs, known as polymer-drug conjugates (PDCs), have emerged as a promising approach to sustained drug release. In this work, we reported an approach to prepare a PDC containing an OI and make it into an injectable hydrogel. Chitosan (CS) was selected for PDC synthesis because of its abundant free amino groups that can be conjugated with molecules containing carboxyl groups by carbodiimide chemistry. We used an ethanol/water cosolvent system to synthesize a CS-OI conjugate via EDC/NHS catalysis. The CS-OI conjugate had improved water solubility and unique anti-inflammatory activity and did not show compromised antibacterial activity compared with unmodified CS. Beta-glycerophosphate (ß-GP) cross-linked CS-OI hydrogel exhibited good injectability with sustainable OI release and effectively modulated inflammatory response in a rat model. Therefore, this study provides valuable insights into the design of PDC hydrogels with inflammatory modulatory properties.

Computational Insights into SARS-CoV-2 Main Protease Mutations and Nirmatrelvir Efficacy: The Effects of P132H and P132H-A173V.

Nirmatrelvir, a pivotal component of the oral antiviral Paxlovid for COVID-19, targets the SARS-CoV-2 main protease (Mpro) as a covalent inhibitor. Here, we employed combined computational methods to explore how the prevalent Omicron variant mutation P132H, alone and in combination with A173V (P132H-A173V), affects nirmatrelvir's efficacy. Our findings suggest that P132H enhances the noncovalent binding affinity of Mpro for nirmatrelvir, whereas P132H-A173V diminishes it. Although both mutants catalyze the rate-limiting step more efficiently than the wild-type (WT) Mpro, P132H slows the overall rate of covalent bond formation, whereas P132H-A173V accelerates it. Comprehensive analysis of noncovalent and covalent contributions to the overall binding free energy of the covalent complex suggests that P132H likely enhances Mpro sensitivity to nirmatrelvir, while P132H-A173V may confer resistance. Per-residue decompositions of the binding and activation free energies pinpoint key residues that significantly affect the binding affinity and reaction rates, revealing how the mutations modulate these effects. The mutation-induced conformational perturbations alter drug-protein local contact intensities and the electrostatic preorganization of the protein, affecting noncovalent binding affinity and the stability of key reaction states, respectively. Our findings inform the mechanisms of nirmatrelvir resistance and sensitivity, facilitating improved drug design and the detection of resistant strains.

Starch Sodium Octenylsuccinate as a New Type of Stabilizer in the Synthesis of Catalytically Active Gold Nanostructures.

Here, starch derivatives, i.e., sodium starch octenylsuccinate (OSA starch, hereinafter referred to as OSA), were employed as both reducing and stabilizing agents for the unique, inexpensive, and simple synthesis of gold nanoparticles (OSA-AuNPs) in an aqueous solution with gold salt. The obtained OSA-AuNPs were characterized by UV-vis spectrophotometry, transmission electron microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The catalytic activity of the obtained gold colloids was studied in the reduction of organic dyes, including methylene blue (C.I. Basic Blue 9) and rhodamine B (C.I. Basic Violet 10), and food coloring, including tartrazine (E102) and azorubine (E122), by sodium borohydride. Moreover, OSA-AuNPs were utilized as signal amplifiers in surface-enhanced Raman spectroscopy. The obtained results confirmed that gold nanoparticles can be used as effective catalysts in reduction reactions of selected organic dyes, as well as signal enhancers in the SERS technique.

Struvite and ethylenediaminedisuccinic acid (EDDS) enhance electrokinetic-biological permeable reactive barrier removal of copper and lead from contaminated loess.

Removal of heavy metals using the electrokinetic (EK) remediation technology is restricted by soils containing a fraction of clay particles above 12%. Furthermore, it is also affected by hydroxide precipitation (focusing phenomenon) close to the cathode. A modified EK reactor containing a permeable reactive barrier (PRB) was proposed herein where the enzyme-induced carbonate precipitation (EICP) treatment was incorporated into the PRB. Despite that, NH4+-N pollution induced by the urea hydrolysis resulting from the EICP treatment causes serious threats to surrounding environments and human health. There were four types of tests applied to the present work, including CP, TS1, TS2, and TS3 tests. CP test neglected the bio-PRB, while TS1 test considered the bio-PRB. TS2 test based on TS1 test tackled NH4+-N pollution using the struvite precipitation technology. TS3 test based on TS2 test applied EDDS to enhance the removal of Cu and Pb. In CP test, the removal efficiency applied to Cu and Pb removals was as low as approximately 10%, presumably due to the focusing phenomenon. The removal efficiency was elevated to approximately 24% when the bio-PRB and the electrolyte reservoir were involved in TS1 test. TS2 test indicated that the rate of struvite precipitation was 40 times faster than the ureolysis rate, meaning that the struvite precipitate had sequestered NH4+ before it started threatening surrounding environments. The chelation between Cu2+ and EDDS took place when EDDS played a part in TS3 test. It made Cu2+ negatively surface charged by transforming Cu2+ into EDDSCu2-. The chelation caused those left in S4 and S4 to migrate toward the bio-PRB, whereas it also caused those left in S1 and S2 to migrate toward the anode. Due to this reason, the fraction of Cu2+ removed by the bio-PRB and the electrolyte reservoir is raised to 32% and 26% respectively, and the fraction of remaining Cu was reduced to 41%. Also, the removal efficiency applied to Pb removal was raised to 50%. Results demonstrate the potential of struvite and EDDS-assisted EK-PRB technology as a cleanup method for Cu- and Pb-contaminated loess.

Synthesis and characterization of pH-sensitive nanocarrier based chitosan-g-poly(itaconic acid) for ciprofloxacin delivery for anti-bacterial application.

This study aims to develop pH-sensitive and controlled release of ciprofloxacin from ciprofloxacin-loaded grafted chitosan-coated zinc oxide nanoparticles (Cip@Gchit/Zn-NPs) for the treatment of bacterial infections in the human colon. For this aim, first, the chitosan-g-poly(itaconic acid) [Chit-g-poly (Itac)] was synthesized via grafting of itaconic acid onto chitosan in the presence of cerium ammonium nitrate (CAN) under an inert atmosphere using conventional methods, while zinc oxide nanoparticles (Zn-NPs) were prepared via sol-gel technique. Characterization of the synthesized Cip@Gchit/Zn-NPs was analyzed using XRD, FT-IR, SEM, TGA, and zeta potential analysis. The antibacterial efficacy of Cip@Gchit/Zn-NPs against three pathogenic bacteria, namely Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, was superior to that of tetracycline reference drugs, as evidenced by larger inhibition zones. Cytotoxicity assessment of Cip@Gchit/Zn-NPs on the human chondrocyte cell line C28/I2 via MTT assay revealed 100 % cell viability at a concentration of 500 µg/mL. The loading efficiency of ciprofloxacin into Gchit/Zn-NPs was evaluated at various ratios, demonstrating lower loading efficiency; however, sustained release of ciprofloxacin from Cip@Gchit/Zn-NPs was excellent, with 98.13 % release observed at pH 7.2 over 10 h. Kinetic analysis of ciprofloxacin release followed the first-order kinetic models.

Pharmacokinetics and antioxidant activity of dihydrocaffeic acid grafted chitosan nanomicelles loaded with chicoric acid in broilers.

Chicoric acid (CA) is a natural nutrient found in plants, showcasing diverse biological activities, including anti-inflammatory and antioxidant properties. Despite its valuable properties, CA faces limitations in bioavailability and susceptibility to oxidative breakdown during utilization. Previous research introduced synthesized dihydrocaffeic acid grafted chitosan self-assembled nanomicelles (DA-g-CS), demonstrating its potential to enhance CA absorption. This study aims to investigate the pharmacokinetics, tissue distribution, and antioxidant activity of both CA and DA-g-CS loaded CA (DA-g-CS/CA) in broilers. An IPEC-J2 cell model was established and evaluated to delve deeper into the transport mechanism and antioxidant potential. The in vivo pharmacokinetic analysis in broilers highlighted a substantial difference: the maximum plasma concentration (Cmax) of DA-g-CS/CA exceeded CA by 2.6-fold, yielding a notable increased relative bioavailability to 214%. This evidence underscores the significant enhancement in CA's oral absorption, facilitated by DA-g-CS. The collective evaluation outcomes affirm the successful development of the cell model, indicating its suitability for drug transporter experiments. The findings from the intestinal transit analysis revealed that both CA and DA-g-CS/CA underwent passive entry into IPEC-J2 cells. Notably, the cellular uptake rate of DA-g-CS loaded with CA was significantly amplified, reaching 2.1 times higher than that of CA alone. Intracellular transport mechanisms involved microtubules, lysosomes, and the endoplasmic reticulum, with an additional pathway involving the endoplasmic reticulum observed specifically for DA-g-CS/CA, distinguishing it from CA. Moreover, the results from both in vivo and in vitro antioxidant assessments highlight the potent antioxidant activity of DA-g-CS/CA, showcasing its efficacy in preventing and treating cellular damage induced by oxidative stress. In summary, these findings underscore the significant enhancement of CA's efficacy facilitated by DA-g-CS, establishing a robust theoretical foundation for the prospective application of CA within livestock and poultry farming.

High performance poly(L-lactic acid)-based film by one-step synthesis of poly (L-lactic acid-co-butylene itaconate-co-glycolic acid) for efficient preservation of yogurt storage.

Biodegradable poly(L-lactic acid) (PLLA) has seldom used for dairy packaging due to medium permeability and brittleness. Novel PLLA copolymers, poly (L-lactic acid-co-butylene itaconate-co-glycolic acid) (PLBIGA), were developed by integrating glycolic acid (GA) and poly(butylene itaconate) (PBI) into PLLA's structure using low molecular weight PLLA as a key initiator. Then, packaging materials with better barrier and mechanical properties were obtained by blended PLBIGA with PLLA. Both PLLA/PLBIGA films and polyethylene nylon composite film (PE/NY) were used for stirred yogurt packaging and storage at 4 °C for 25 days. Results revealed that yogurt packed by PLLA/PLBIGA films maintained stabler water-holding capacity, color, and viscosity over the storage period. Moreover, the integrity of the gel structure and the total viable count of lactic acid bacteria in yogurt packaged in PLLA/40-PLBIGA8 were also found to be superior to those in PE/NY packages, highlighting its eco-friendly advantages in dairy packaging.

Structural and functional insights of itaconyl-CoA hydratase from Pseudomonas aeruginosa highlight a novel N-terminal hotdog fold.

Itaconyl-CoA hydratase in Pseudomonas aeruginosa (PaIch) converts itaconyl-CoA to (S)-citramalyl-CoA upon addition of a water molecule, a part of an itaconate catabolic pathway in virulent organisms required for their survival in humans host cells. Crystal structure analysis of PaIch showed that a unique N-terminal hotdog fold containing a 4-residue short helical segment α3-, named as an "eaten sausage", followed by a flexible loop region slipped away from the conserved ß-sheet scaffold, whereas the C-terminal hotdog fold is similar to all MaoC. A conserved hydratase motif with catalytic residues provides mechanistic insights into catalysis, and existence of a longer substrate binding tunnel may suggest the binding of longer CoA derivatives.

Composite System of Lauryl Glucoside and Lauryl Glycoside Sulfosuccinate: Properties and Applications in Vitamin E Nanoemulsions.

The synergistic effect of surfactant compounding on performance can be leveraged to enhance product application performance. An investigation of the surface tension and emulsification properties revealed the complex synergistic effect of the composite system comprising lauryl glucoside (LG) and lauryl glycoside sulfosuccinate (LG-SS). The composite system was used as an emulsifier for vitamin E (VE) emulsification. VE nanoemulsions with high VE content were successfully prepared. The nanoemulsion appears homogeneous and transparent and has an average size of approximately 200 nm. It has better temperature and centrifugal stability, an antioxidant capacity 2.89 times that of untreated VE, and is not easily oxidized and deactivated. In this study, we successfully constructed a complex system of LG and its derivatives and applied it to VE emulsification - this is a step toward expanding the effective application of glycosides and their derivative composite systems in food, pharmaceutics, and other industries.

Structural and functional characterization of itaconyl-CoA hydratase and citramalyl-CoA lyase involved in itaconate metabolism of Pseudomonas aeruginosa.

Itaconate is a key anti-inflammatory/antibacterial metabolite in pathogen-macrophage interactions that induces adaptive changes in Pseudomonas aeruginosa-exposed airways. However, the impact and mechanisms underlying itaconate metabolism remain unclear. Our study reveals that itaconate significantly upregulates the expression of pyoverdine in P. aeruginosa and enhances its tolerance to tobramycin. Notably, the enzymes responsible for efficient itaconate metabolism, PaIch and PaCcl, play crucial roles in both utilizing itaconate and clearing its toxic metabolic intermediates. By using protein crystallography and molecular dynamics simulations analyses, we have elucidated the unique catalytic center and substrate-binding pocket of PaIch, which contribute to its highly efficient catalysis. Meanwhile, analysis of PaCcl has revealed how interactions between domains regulate the conformational changes of the active sites and binding pockets, influencing the catalytic process. Overall, our research uncovers the significance and mechanisms of PaIch and PaCcl in the efficient metabolism of itaconate by P. aeruginosa.

Effects of folate-chicory acid liposome on macrophage polarization and TLR4/NF-κB signaling pathway in ulcerative colitis mouse.

BACKGROUND: Chichoric acid (CA) is a major active ingredient found in chicory and Echinacea. As a derivative of caffeic acid, it has various pharmacological effects. PURPOSE: Due to the unclear etiology and disease mechanisms, effective treatment methods for ulcerative colitis (UC) are currently lacking. The study investigated the therapeutic effects of the folate-chicory acid liposome on both LPS-induced macrophage inflammation models and dextran sulfate sodium (DSS)-induced mouse UC models. METHODS: Folate-chicory acid liposome was prepared using the double emulsion ultrasonic method with the aim of targeting folate receptors specifically expressed on macrophages. The study investigated the therapeutic effects of the folate-chicory acid liposome on both LPS-induced macrophage inflammation models and DSS -induced mouse UC models. Furthermore, the effects of the liposomes on macrophage polarization and their underlying mechanisms in UC were explored. RESULTS: The average particle size of folate-chicory acid liposome was 120.4 ± 0.46 nm, with an encapsulation efficiency of 77.32 ± 3.19 %. The folate-chicory acid liposome could alleviate macrophage apoptosis induced by LPS, decrease the expression of inflammatory factors in macrophages, enhance the expression of anti-inflammatory factors, inhibit macrophage polarization towards the M1 phenotype, and mitigate cellular inflammation in vetro. In vivo test, folate-chicory acid liposome could attenuate clinical symptoms, increased colon length, reduced DAI scores, CMDI scores, and alleviated the severity of colonic histopathological damage in UC mice. Furthermore, it inhibited the polarization of macrophages towards the M1 phenotype in the colon and downregulated the TLR4/NF-κB signaling pathway, thereby ameliorating UC in mice. CONCLUSION: Folate-chicory acid liposome exhibited a uniform particle size distribution and high encapsulation efficiency. It effectively treated UC mice by inhibiting the polarization of macrophages towards the M1 phenotype in the colon and downregulating the TLR4/NF-κB signaling pathway.

Misfit and fracture load of implant-supported monolithic crowns in zirconia-reinforced lithium silicate

Abstract Zirconia-reinforced lithium silicate (ZLS) is a ceramic that promises to have better mechanical properties than other materials with the same indications as well as improved adaptation and fracture strength. Objective In this study, marginal and internal misfit and fracture load with and without thermal-mechanical aging (TMA) of monolithic ZLS and lithium disilicate (LDS) crowns were evaluated. Material and methods Crowns were milled using a computer-aided design/computer-aided manufacturing system. Marginal gaps (MGs), absolute marginal discrepancy (AMD), axial gaps, and occlusal gaps were measured by X-ray microtomography (n=8). For fracture load testing, crowns were cemented in a universal abutment, and divided into four groups: ZLS without TMA, ZLS with TMA, LDS without TMA, and LDS with TMA (n=10). TMA groups were subjected to 10,000 thermal cycles (5-55°C) and 1,000,000 mechanical cycles (200 N, 3.8 Hz). All groups were subjected to compressive strength testing in a universal testing machine at a crosshead speed of 1 mm/min until failure. Student's t-test was used to examine misfit, two-way analysis of variance was used to analyze fracture load, and Pearson's correlation coefficients for misfit and fracture load were calculated (α=0.05). The materials were analyzed according to Weibull distribution, with 95% confidence intervals. Results Average MG (p<0.001) and AMD (p=0.003) values were greater in ZLS than in LDS crowns. TMA did not affect the fracture load of either material. However, fracture loads of ZLS crowns were lower than those of LDS crowns (p<0.001). Fracture load was moderately correlated with MG (r=-0.553) and AMD (r=-0.497). ZLS with TMA was least reliable, according to Weibull probability. Conclusion Within the limitations of this study, ZLS crowns had lower fracture load values and greater marginal misfit than did LDS crowns, although these values were within acceptable limits.