Scavenging Rate Research Articles

Direct Evaluation of Salivary Antioxidant Properties in Patients with Down Syndrome for assessment to Periodontal Disease and Premature Aging.

To evaluate oxidative stress involved in Down syndrome periodontal disease and pathological premature aging, reactive oxygen species (ROS) such as superoxide (O2•-) and hydroxyl radical (HO•) in human saliva were measured using electron spin resonance (ESR) spectroscopy. The groups consisted of 20 subjects in the Down syndrome (DS) child (DSC) group (mean age 11.3 ± 4.2 years), 24 subjects in the normal(N) child (NC) group (mean age 8.5 ± 2.0 years), 31 subjects in the DS-adults (DsA) group (mean age 48.9 ± 6.5 years), and 24 subjects in the NA group (mean age 47.1 ± 4.9 years). Comparing DS and N groups, gingivitis index (GI), pocket depth (PD) were higher in group A than in group C depending on age. The salivary O2•- scavenging rate measured by ESR spectroscopy was lower in DS group, and the salivary antioxidant properties such as both O2•- and HO• scavenging rate of DS and N groups, whose GI and PD increased with age, were higher in A group than in C group. These ROS antioxidant properties of saliva suggested the possibility of clinical evaluation for testing for periodontal disease and early aging, which are also characteristics of DS.

Preparation of a biodegradable packaging film by konjac glucomannan/sodium alginate reinforced with nitrogen-doped carbon quantum dots from crayfish shell for crayfish meat preservation.

The development of biomass material is an important approach to alleviating the excessive using of plastic packaging, by which the product could be more environmentally friendly and lower toxicity. In this study, we developed a biodegradable photodynamic antibacterial food packaging film using nitrogen-doped carbon quantum dots (N-CQDs) synthesized from crayfish shells, combined with konjac glucomannan (KGM) and sodium alginate (SA). Casting method was used to prepare the composite film and results indicated that incorporation of N-CQDs significantly enhanced the mechanical and barrier properties of the film by reducing the number of micropores. The N-CQDs endowed the film with strong antioxidant activity and UV resistance. The DPPH scavenging rate of the composite film reached 77.92 %, while the transmittance of ultraviolet (300 nm) was reduced to 16.97 %. Furthermore, under blue light irradiation, the film exhibited excellent photodynamic antibacterial effects against Shewanella putrefaciens and Staphylococcus aureus, achieving inhibition rates of 99.2 % and 98.99 %, respectively. The film solution demonstrated no cytotoxicity, and the composite film preserved crayfish meat for up to 8 days at 4 °C. Furthermore, the film almost completely degrading in soil within 14 days. These findings suggest that the KGM/SA/N-CQD film is a promising degradable antimicrobial material for food packaging applications.

Characterization of gelatin-based composite films loaded with polysaccharide and carbon dots from Stropharia rugosoannulata and their application in pork fresh-keeping.

In this study, bio-based composite films with enhanced barrier, mechanical, antioxidant and antimicrobial properties were prepared by incorporating Stropharia rugosoannulata waste (SP)-derived polysaccharides (SPP) and carbon dots (SPCDs) as an active substance into gelatin (GEL) matrix, which were evaluated for their potential application in pork preservation. The effects of varying concentrations of SPCDs on the morphology, microstructure, and overall performance of the films were systematically investigated. The findings demonstrated that the addition of SPCDs to the GEL/SPP matrix significantly improved the mechanical strength, water vapor permeability, and ultraviolet light blocking ability of the composite films. Specially, the GEL/SPP/SPCDs composite films containing 3 % carbon dots exhibited radical scavenging rates of 53.74 % for DPPH and 73.19 % for ABTS, along with inhibition rates of 58.37 % for E. coli and 70.25 % for S. aureus. Preservation experiments revealed that the prepared GEL/SPP/SPCDs-3 % films provided superior preservation effect on pork, highlighting their potential as eco-friendly active food packaging materials.

High-Accuracy Identification and Structure-Activity Analysis of Antioxidant Peptides via Deep Learning and Quantum Chemistry.

Antioxidant peptides (AOPs) hold great promise for mitigating oxidative-stress-related diseases, but their discovery is hindered by inefficient and time-consuming traditional methods. To address this, we developed an innovative framework combining machine learning and quantum chemistry to accelerate AOP identification and analyze structure-activity relationships. A Bi-LSTM-based model, AOPP, achieved superior performance with accuracies of 0.9043 and 0.9267, precisions of 0.9767 and 0.9848, and Matthews correlation coefficients (MCCs) of 0.818 and 0.859 on two data sets, outperforming existing methods. Compared with XGBoost and LightGBM, AOPP demonstrated a 4.67% improvement in accuracy. Feature fusion significantly enhanced classification, as validated by UMAP visualization. Experimental validation of ten peptides confirmed the antioxidant activity, with LLA exhibiting the highest DPPH and ABTS scavenging rates (0.108 and 0.437 mmol/g, respectively). Quantum chemical calculations identified LLA's lowest HOMO-LUMO gap (ΔE = 0.26 eV) and C3-H26 as the key active site contributing to its superior antioxidant potential. This study highlights the synergy of machine learning and quantum chemistry, offering an efficient framework for AOP discovery with broad applications in therapeutics and functional foods.

Evaluation of Biological Activity of a Lepidium meyenii (Maca) Polysaccharide‐Zinc Complex

ABSTRACTZinc, an important metal element in the human body, fulfills multiple biological roles, such as influence on cell division and differentiation. In this paper, a Maca polysaccharide‐zinc (MPS‐Zn) complex was prepared by water extraction and alcohol precipitation process. A granular MPS‐Zn complex with 0.2360 μg/mg Zn was obtained at 60°C and pH = 3.0 for 60 min. The antioxidant activities of this MPS‐Zn complex were evaluated by the free radical scavenging activity toward DPPH and ABTS. The rate of ABTS free radical scavenging of 4.0 mg/mL MPS‐Zn complex is equal to that of control group (vitamin C). The abilities of this complex against three cancer cell lines including breast cancer MCF‐7, colon cancer SW480, and liver cancer SMMC‐7721 were used to evaluate its antiproliferative activity by MTS assay. The results demonstrate that this complex has an inhibitory effect on the above cancer cell lines. Especially, the inhibitory effect of it on colon cancer SW480 is more effective than that of cisplatin. The toxicity of this complex on human normal pulmonary epithelial cell BEAS‐2B is lower than that of taxol and cisplatin. This complex has the potential use as the zinc‐containing nutritional food and/or anticancer drug.

Flavonoids and other constituents from Jacaranda mimosifolia: In vitro analysis, molecular docking, and molecular dynamic simulations of antioxidant and anti-inflammatory activities.

The investigation of the methanol extract of the flowers of Jacaranda mimosifolia led to the isolation and characterisation of fourteen secondary metabolites (1-14) by the means of chromatographic and spectroscopic analysis. These compounds include eight flavonoids sorted as two flavonols (1-2), three flavones (3, 7-8), and three isoflavones (4, 9-10), two glucoiridoids (5-6), and four triterpenoids sorted as one oleanane (11), one hopane (12), and two lupane (13-14). The in vitro antioxidant potential of all the isolated compounds was evaluated using the ABTS- and FRAP- methods, which demonstrated concentration-dependent activity. Chloroflavonin A (1) and 4',5,7-trihydroxyflavone (2) demonstrated exceptional antioxidant activity, with scavenging rates of 98.63 % and 97.89 %, respectively, at a concentration of 300 μg/mL, and also showed strong ferric-reducing antioxidant power. Chloroflavonin A (1) demonstrated the most potent dual inhibitory effects on Cyclooxigenase-2 (COX-2) and NADPH-Oxidase-5 (NOX-5) enzymes, with binding affinities of -9.7 and -8.2 kcal/mol, respectively, indicating its potential as a strong anti-inflammatory compound. The molecular dynamics simulation, conducted with the Desmond v3.6, demonstrated the stability of the various complexes within the biological system. The findings indicate that compounds derived from Jacaranda mimosifolia may serve as potential therapeutic agents for the management of inflammation and oxidative stress.

Photodynamic inactivation mediated by natural alizarin on bacteria for the safety of fresh-cut apples

Most photosensitizers have limited responsiveness to visible light, however, visible light is a light source with a wide range of wavelengths and the most common in daily life, and making full use of visible light can help to enhance the photodynamic antimicrobial properties of photosensitizers. To tackle this issue, this study confirmed that alizarin has a good absorption capacity for visible light by UV-DRS analysis. Theoretical calculations showed that alizarin might be excited through the charge transfer (CT) mechanism. Under simulated light conditions, alizarin exhibited significant photodynamic inactivation, with a bactericidal efficiency of 99.91 % against S. aureus and L. monocytogenes within 40 min. Meanwhile, the cytolytic rate of alizarin was less than 5 % and the free radical scavenging rate was more than 90 %. To improve the freshness of fresh-cut fruits, we prepared alizarin-pectin (Ali-Pec) coatings using a one-step synthesis method. FT-IR spectroscopic showed the possible presence of hydrogen bonding. It was further found that during storage, the coating-treated fresh-cut apples in the experimental group showed an 8 % reduction in the variation of L-value and a 50 % reduction in the variation of a*-value, and effectively maintained the pH, VC, PPO, and T-AOC levels of the fresh-cut apples, which prolonged the shelf-life of the fresh-cut apples.

High-moisture extrusion of rice bran-peanut proteins: Changes in structural properties and antioxidant activity simulating gastrointestinal digestion.

In this experiment, we investigated the structural properties, digestibility, and variations in antioxidant activity of rice bran-tissue peanut protein (RB-TPP), which was created through high-moisture extrusion between peanut protein powder (PPP) and various additions (0 %, 5 %, 10 %, 15 %, and 20 %) of rice bran (RB). The disulfide bonding and hydrophobic interactions were strengthened, and the hydrogen bonding in the RB-TPP was weakened by adding 5-10 % RB. Additionally, the β-sheet content reached its maximum at RB-10 %, which allowed the hydrophobic groups to be encapsulated ina stable protein network fiber structure, enhancing degree of organization, the thermal stability and digestibility of RB-TPP. On the other hand, RB-10 % showed increased total phenolic content and antioxidant activity, in which the ABTS radical scavenging rate was increased by 22.14 % compared with that of RB-0 %, while the DPPH radical scavenging rate in simulated gastric digestion was increased by 10.59 %. RB addition at 15-20 % hindered the aggregation of proteins, which was not conducive to the rearrangement of protein molecules, and the increase in the irregular curls made the RB-TPP structure loose and disordered. This study provides valuable information for producing tissue proteins with stable fiber network structure and better nutritional and functional properties by adding RB.

Antioxidant activity of herbal medicine Pyrrosia lingua evaluated by electron paramagnetic resonance spectroscopy.

The hydroxyl radical (˙OH) is one of the most reactive and harmful reactive oxygen species in living organisms. In this study, we used electron paramagnetic resonance (EPR) spectroscopy to evaluate the antioxidant activity of herbal medicine Pyrrosia lingua (PL) by measuring its scavenging activity against ˙OH radicals. Using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical as a scavenging model, the PL extract (0.6 mg mL-1) was able to scavenge 95.1% of 0.5 mmol L-1 DPPH radicals, showing a quantitative linear relationship between the DPPH radical concentration and the double integral area under the characteristic peaks of the EPR spectra, with a coefficient of determination R2 = 0.9986. Additionally, we also studied the scavenging activity of the PL extract towards hyperactive ˙OH radicals through the reduction of the intensity of the DMPO-OH˙ adducts. The PL extract (0.5 mg mL-1) showed a high scavenging ability against extremely short-lived ˙OH radicals, with a scavenging rate of 93.6% for ˙OH radicals generated by continuous ultraviolet-irradiation of a 5 mM H2O2 aqueous solution for 30 minutes. This study developed a method based on EPR spectroscopy measurements to detect ˙OH radicals captured by herbal medicine, providing a reference for the application of PL in antioxidant and clinical disease therapies.

Effects of Luteolin Treatment on Postharvest Quality and Antioxidant Capacity of Nanfeng Tangerines.

Postharvest quality deterioration is a major factor affecting the economic value and marketing of Nanfeng tangerines. The objective of this study was to explore the effects of luteolin treatment on the postharvest quality and antioxidant capacity of Nanfeng tangerines. We applied 1 g/L and 3 g/L luteolin to fruit after harvest and evaluated the decay rate, postharvest quality, and antioxidant capacity during a 60-day storage period at room temperature. The results indicated that, compared to untreated fruit, Nanfeng tangerines treated with 3 g/L luteolin exhibited enhanced appearance and flavor quality, as well as delayed disease incidence, during room-temperature storage. Additionally, flavor quality analysis revealed that luteolin treatment maintained high levels of titratable acid (TA) by delaying the degradation of organic acids such as citric, tartaric, succinic, ascorbic, and oxalic acids. Furthermore, luteolin treatment inhibited malondialdehyde (MDA) and H2O2 accumulation by enhancing the content of total phenols and flavonoids content, augmenting antioxidant enzyme activities (peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD)), and elevating the overall antioxidant capacity measured through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging rate. Collectively, these results demonstrate that luteolin has potential as a preservative for promoting postharvest quality and antioxidant capacity. Additionally, our findings elucidate the mechanisms by which plant-derived flavonoids contribute to the preservation of freshness.

L-Cysteine Treatment Delays Leaf Senescence in Chinese Flowering Cabbage by Regulating ROS Metabolism and Stimulating Endogenous H2S Production

Leaf senescence is a major concern for postharvest leafy vegetables, as leaves are highly prone to yellowing and nutrient loss, resulting in reduced commercial value and limited shelf-life. This study aimed to investigate the effect of L-cysteine (L-cys) on postharvest Chinese flowering cabbage stored at 20 °C. The results showed that 0.5 g L−1 L-cys treatment effectively slowed leaf senescence by downregulating chlorophyll degradation genes (BrNYC1, BrNOL, BrPPH, BrPAO, BrNYE, and BrSAGs) and senescence marker gene BrSAG12. Moreover, this treatment exhibited positive influence on the nutritional quality of cabbage. Also, L-cys treatment maintained ROS homeostasis, preventing excessive ROS accumulation and lipid membrane oxidation. L-cys treatment also maintained a higher total antioxidant capacity and scavenging rate of •OH and O2•−. Additionally, L-cys treatment maintained high levels of ascorbate and glutathione and activated antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) and the expression of the encoding genes. Furthermore, L-cys treatment elevated endogenous H2S levels, which are correlated with increased L-cysteine desulfhydrase activity and the upregulation of H2S biosynthesis-related genes. These findings suggest that L-cys can delay leaf senescence by reducing chlorophyll breakdown, maintaining ROS homeostasis, and stimulating endogenous H2S production.

Drug Target Investigation of N-p-Coumaroyl-N’-Caffeoylputrescine, a Naturally-Occurring Alkaloid Derived from Saxifraga tangutica

The exploration of drug targets has always been a priority in new drug research, and this work is even more essential for natural active compounds. Saxifraga tangutica is a traditional Tibetan medicine with excellent antioxidant properties. In this study, an alkaloid, N-p-coumaroyl-N’-caffeoylputrescine (PCC), was first isolated from the plant, Saxifraga tangutica, with a DPPH scavenging rate of 0.936 μg/mL. To further identify its target, the drug affinity responsive target stability technique and multiple public databases were integrated to retrieve a total of 317 common targets from comprehensive screening. A further bioinformatics analysis not only identified 13 hub targets but also indicated PCC as having biological activities against cancer and affecting metabolic diseases. Integrating reverse virtual docking, molecular dynamics simulations, and cellular thermal shift assays ultimately focused on HSP90AA1 as the target of PCC. An in vitro study on liver (HepG2) cells and breast (MCF-7) cancer cells revealed that PCC modulates HSP90AA1, subsequently affecting Mut-p53 expression, triggering a cascade effect that reduced adriamycin-induced drug resistance in cells. Furthermore, a prediction of the absorption, distribution, metabolism, excretion, and toxicity was also applied to evaluate the drug-like properties of PCC. Overall, the integrated strategy used in this study successfully identified the target of PCC, providing a valuable paradigm for future research on the action targets of natural products.

Optimization of Ultrasound-assisted Anthocyanin Extraction from Black Rice Bran for Simultaneous Coloring, UV Protection, and Antioxidant Silk Finishes

This study examined the use of ultrasound to extract anthocyanin from agricultural byproduct black rice bran as a natural colorant and a multifunctional finishing agent for silk fabrics, taking into account the various health advantages linked to anthocyanins. The study employed response surface methodology to identify the optimal extraction process that would yield the highest extraction efficiency for total anthocyanin content. The optimal conditions were 30 Hz ultrasonic power, a liquor-to-material ratio of 21, 60°C an ultrasound temperature, and 30 minutes of an ultrasound time, yielding 173.25 mg/L anthocyanin. Silk fabrics were dyed in a reddish purple tone, and the mordant dyeing method produced a 34% higher color strength value than direct dyeing while displaying good colorfastness (grade ≥ 4) to washing and crocking. The dyed silks also provided excellent UV protection (UPF > 40+) and antioxidant activity, with a DPPH scavenging rate over 80%. Anthocyanins derived from black rice bran could thus be used as a bioactive functional colorant in medical and health-related textiles.

Preparation of Green Tea Polyphenol-Loaded Diacylglycerol Nanostructured Lipid Carrier Hydrogels and Their Activities Related to Skin Protection.

Diacylglycerol (DAG) is a functional oil but is rarely used in the cosmetic industry because low solubility, susceptibility to leakage and low viscosity to skin are still the main hurdles. A novel diacylglycerol nanostructured lipid carrier hydrogel (GTP-DAG-NLC-GEL) loaded with green tea polyphenol (GTP) was designed and successfully prepared to broaden DAG's application in cosmetics, which significantly improved GTP stability and skin stickiness of DAG. The results showed that DAG-NLC-GEL had good viscosity, which was 980 Pa·s when the shear rate was 5 rpm, and its viscosity decreased quickly with the increase in shear rate, making it easily expand on skin. Meanwhile, the encapsulation rate and drug loading of GTP in GDP-DAG-NLC-GEL reached 86.7% and 2.6%, respectively, and the DPPH free radicals scavenging rate and inhibition rate of the advanced glycation end-products (AGEs) were 85.46% and 89.72%, respectively, which indicate that GTP-DAG-NLC-GEL has significant skin sunscreen, antioxidant and anti-glycation activities. The GTP-loaded nanostructured lipid carrier hydrogel can be deemed to have great prospects for skin protection in cosmetics.

Preparation of bioactive film for regulating chlorine dioxide release based on the hygroscopic properties of chitosan and its application in broccoli preservation.

An active packaging film was developed by integrating sodium chlorite (SC) and citric acid (CA) into a Poly(lactic acid)/Poly(butylene adipate-co-terephthalate) (PLA/PBAT) matrix, enabling the controlled release of chlorine dioxide (ClO2) gas. The release of ClO2 was further regulated by introducing chitosan (CS) into the film, leveraging its hygroscopic properties. The results showed that when the addition amount of CS was 4 wt%, the water vapor transmission rate increased by 41.41 %, the water contact angle decreased by 24.4 %, the ClO2 release increased by 2.81 times after 72 h, and the scavenging rate of DPPH free radicals reached 96.26 % after 96 h. When the film was applied to broccoli packaging, it successfully protected the appearance and color of broccoli, effectively inhibited the activity of oxidase and reduced the reduction of active substances, and maintained the marketable quality for up to 8 days. Therefore, this ClO2-releasing active film has application potential in the color protection and preservation of broccoli and other green vegetables.

Multifunctional ZnO-Loaded Colloidosomes with Multiple Synergies as a UV Filter.

ZnO nanoparticles with high safety and stability are often used as active ingredients in sunscreens to protect the skin from ultraviolet rays. However, ZnO nanoparticles are easy to agglomerate, which will significantly affect the ultraviolet absorption and bacteriostatic properties, and the reactive oxygen species induced by the photocatalytic activity may result in irreversible secondary damage to the skin. Herein, the ZnO nanoparticles are dispersed uniformly on the surface of latex particles, and these composite particles are used as shell materials to construct self-assembled colloidosomes by high-gravity technology, which can improve the application properties with synergistic enrichment of the hollow structure. The ultraviolet resistance of colloidosomes is significantly higher than that of the pure ZnO nanoparticles. The higher the loading capacity, the more obvious the inhibition effect of colloidosomes on the growth of Gram bacteria. Furthermore, the antioxidant anthocyanin is in situ encapsulated in colloidosomes, and at a concentration of 2 g/L, the high free radical scavenging rate of 78% can be achieved. The construction of multifunctional colloidosomes provides a route for sunscreen and cosmetics applications.

Bifunctional Electrospun Nanocomposite Dressing: Integrating Antibacterial Efficacy and Controllable Antioxidant Properties for Expedited Wound Healing.

Current wound dressings are insufficient in simultaneously addressing bacterial infections and oxidative stress, which severely affects wound healing outcomes. To solve this problem, we introduced poly(ionic liquid) (PIL) with strong antibacterial properties and cerium oxide nanoparticles (CeO2NPs) with excellent antioxidant capabilities into polyacrylonitrile (PAN) nanofiber membranes to prepare a novel composite dressing. The PIL-CeO2NPs-PAN nanofiber membrane provides sustained antibacterial activity through stably embedded PIL, while the uniformly distributed CeO2NPs achieve controlled release, avoiding safety issues caused by the rapid release of active substances. In vitro and in vivo experiments demonstrated that the membrane exhibits outstanding biocompatibility, significant antibacterial effects (inhibition rates of 88.3% against Escherichia coli and 93.2% against Staphylococcus aureus), and excellent antioxidant performance (64.7% reactive oxygen species scavenging rate). More importantly, PIL-CeO2NPs-PAN achieved a 94.1% wound healing rate within 14 days, significantly superior to traditional treatment methods. The results indicate that this composite membrane significantly improves wound healing by simultaneously resisting infection and oxidative stress, providing a safe and effective new option for clinical applications. Our work offers an innovative design strategy that combines antibacterial and antioxidant mechanisms for wound care.

Correlation Analyses of Amylase and Protease Activities and Physicochemical Properties of Wheat Bran During Solid-State Fermentation.

Solid-state fermentation (SSF) has emerged as an effective method for wheat bran valorization, providing advantages like cost reduction, decreased water usage, and enhanced product quality. In this study, wheat bran was fermented using Rhizopus oryzae to evaluate the extraction yield of soluble dietary fiber, the activities of protease and amylase, and the physicochemical characteristics of wheat bran during SSF. The findings demonstrated that the maximum yield of soluble dietary fiber was achieved after 120 h of fermentation at a moisture content of 55%. Simultaneously, protease activity peaked at 45% moisture content after 120 h, while amylase activity was maximized at 55% moisture content after 96 h. The microstructure result indicated that most of the starch granules degraded after 144 h of fermentation at a moisture content of 55%, exhibiting a smooth outer layer of wheat bran. Furthermore, fermented bran showed a significant rise in total phenols, peaking at 96 h at a moisture content of 55%. Flavonoid content also reached its maximum after 72 h of fermentation at 55% moisture content. The content of alkylresorcinols in fermented wheat bran changed slightly under different moisture content and fermentation time conditions, which was consistent with the change in pH value. The DPPH radical scavenging rate was optimal when the moisture content was 55% after 96 h. The ABTS radical scavenging rate, hydroxyl radical scavenging rate, and reducing ability were optimal at 55% moisture content after 120 h. These findings demonstrate that the optimal conditions for the SSF of wheat bran using Rhizopus oryzae involve maintaining the moisture at 55%, suggesting that this method is effective for enhancing the value of wheat bran.

Study on the Extraction Technology and Antioxidant Capacity of Rhodymenia intricata Polysaccharides.

A red alga named Rhodymenia intricata was explored, and the extraction technology and antioxidant capacity of its polysaccharides were investigated. The crude polysaccharides were extracted using the ultrasound-assisted water extraction method, precipitated by alcohol, and purified using the trichloroacetic acid method. Subsequently, the scavenging rates of polysaccharides on hydroxyl, DPPH, and ABTS free radicals, were determined both prior to and following purification to evaluate their antioxidant activity. Extraction technology was optimized to improve polysaccharide yield, and the optimal parameters were as follows: particle size 100 mesh, material-liquid ratio 1:84 (g/mL), ultrasonic time 30 min, and extraction for 95 min at 80 °C. The maximized extraction rate of crude polysaccharides was 37.78 ± 0.15%. The obtained crude polysaccharides were purified with different concentrations of trichloroacetic acid, and the purification effect was evaluated according to protein removal rate and polysaccharide retention rate, which could reach 62.61 ± 1.82% and 96.10 ± 1.60%, respectively. Infrared spectrum analysis suggested that Rhodymenia intricata polysaccharide might be α-pyranose. The Congo red test illustrated that the polysaccharide contained a triple helix structure. In the antioxidant activity assessment, the scavenging rates of polysaccharide prior to purification for RIP-1 (10 mg/mL) for hydroxyl, DPPH, and ABTS free radicals were observed to achieve maximum values of 94.71 ± 0.13%, 42.80 ± 7.12%, and 76.30 ± 5.20%, respectively. In contrast, the scavenging rates of polysaccharide following purification for RIP-2 (10 mg/mL) for the same free radicals reached maximum values of 94.10 ± 0.27%, 32.37 ± 0.78%, and 98.30 ± 0.34%, respectively. Notably, these scavenging rates exhibited a dose-dependent relationship. These results demonstrated the potential of the extraction method for polysaccharides from Rhodymenia intricata, and for adding value to the by-product for its potential application as an antioxidant in food and pharmaceutical products.

Quaternized Molecular Brush-Grafted Injectable Microgel with Anti-Inflammatory and Drainage Properties for Efficient Therapy of Anal Fistula.

Anal fistula is a common disease with recurrent inflammation and accumulated exudate. Traditional treatments often fail to effectively eliminate inflammation and ensure adequate drainage, leading to prolonged healing time and a high recurrence rate. Herein, a new class of quaternized molecular brush-grafted injectable microgel (denoted as GAA@CNT-g-PVBTMA) is developed through thermal polymerization and mechanical fragmentation to promote the healing process of anal fistula. Benefiting from the fragmented morphology with a porous structure, the microgel can effectively fill the fistula and facilitate the drainage of exudate. Owing to the electrostatic interactions between the positively charged quaternized carbon nanotube molecular brush (CNT-g-PVBTMA) and the negatively charged inflammatory cytokines, GAA@CNT-g-PVBTMA microgel exhibits excellent anti-inflammatory properties with scavenging rates of 92.6% for tumor necrosis factor-α (TNF-α)and 92.5% for interleukin-1β (IL-1β). Rat inflammatory anal fistula model demonstrates that the microgel can effectively reduce inflammation and epithelialization of the fistula, thereby promoting the healing of the anal fistula. By integrating effective filling, adequate drainage, and excellent anti-inflammatory properties, GAA@CNT-g-PVBTMA microgel provides a promising new direction for the treatment of anal fistula.