Reactive Oxygen Species Scavenging Ability Research Articles

Anti-inflammatory cerium-containing nano-scaled mesoporous bioactive glass for promoting regenerative capability of dental pulp cells.

This study aimed to investigate the anti-inflammatory and odontoblastic effects of cerium-containing mesoporous bioactive glass nanoparticles (Ce-MBGNs) on dental pulp cells as novel pulp-capping agents. Ce-MBGNs were synthesized using a post-impregnation strategy based on the antioxidant properties of Ce ions and proposed the first use of Ce-MBGNs for pulp-capping application. The biocompatibility of Ce-MBGNs was analysed using the CCK-8 assay and apoptosis detection. Additionally, the reactive oxygen species (ROS) scavenging ability of Ce-MBGNs was measured using the 2,7-Dichlorofuorescin Diacetate (DCFH-DA) probe. The anti-inflammatory effect of Ce-MBGNs on THP-1 cells was further investigated using flow cytometry and quantitative real-time polymerase chain reaction (RT-qPCR). Moreover, the effect of Ce-MBGNs on the odontoblastic differentiation of the dental pulp cells (DPCs) was assessed by combined scratch assays, RT-qPCR, western blotting, immunocytochemistry, Alizarin Red S staining and tissue-nonspecific alkaline phosphatase staining. Analytically, the secretions of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were detected with enzyme-linked immunosorbent assay (ELISA). Ce-MBGNs were confirmed to effectively scavenge ROS in THP-1-derived macrophages and DPCs. Flow cytometry and RT-qPCR assays revealed that Ce-MBGNs significantly inhibited the M1 polarization of macrophages (Mφ). Furthermore, the protein levels of TNF-α and IL-1β were downregulated in THP-1-derived macrophages after stimulation with Ce-MBGNs. With a step-forward virtue of promoting the odontoblastic differentiation of DPCs, we further confirmed that Ce-MBGNs could regulate the formation of a conductive immune microenvironment with respect to tissue repair in DPCs, which was mediated by macrophages. Ce-MBGNs protected cells from self-produced oxidative damage and exhibited excellent immunomodulatory and odontoblastic differentiation effects on DPCs. As a pulp-capping agent, this novel biomaterial can exert anti-inflammatory effects and promote restorative dentine regeneration in clinical treatment. We believe that this study will stimulate further correlative research on the development of advanced pulp-capping agents.

A hyaluronic acid hydrogel as a mild photothermal antibacterial, antioxidant, and nitric oxide release platform for diabetic wound healing

Hyaluronic acid (HA)-based biopolymer hydrogels are promising therapeutic dressings for various wounds but still underperform in treating diabetic wounds. These wounds are extremely difficult to heal and undergo a prolonged and severe inflammatory process due to bacterial infection, overexpression of reactive oxygen species (ROS), and insufficient synthesis of NO. In this study, a dynamic crosslinked hyaluronic acid (HA) hydrogel dressing (Gel-HAB) loaded with allomelanin (AMNP)-N, N′-dis-sec-butyl-N, N′-dinitroso-1, 4-phenylenediamine (BNN6) nanoparticles (AMNP-BNN6) was developed for healing diabetic wounds. The dynamic acylhydrazone bond formed between hydrazide-modified HA (HA-ADH) and oxidized HA (OHA) makes the hydrogel injectable, self-healing, and biocompatible. The hydrogel, loaded with AMNP-BNN6 nanoparticles, exhibits promising ROS scavenging ability and on-demand release of nitric oxide (NO) under near-infrared (NIR) laser irradiation to achieve mild photothermal antibacterial therapy (PTAT) (∼ 48 °C). Notably, the Gel-HAB hydrogel effectively reduced the oxidative stress level, controlled infections, accelerated vascular regeneration, and promoted angiogenesis, thereby achieving rapid healing of diabetic wounds. The injectable self-healing nanocomposite hydrogel could serve as a mild photothermal-enhanced antibacterial, antioxidant, and nitric oxide release platform for the treatment of diabetic wounds.

Liver Fibrosis Amelioration by Macrophage-Biomimetic Polydopamine Nanoparticles via Synergistically Alleviating Inflammation and Scavenging ROS.

The progression of liver fibrosis is determined by the interaction of damaged hepatocytes, active hepatic stellate cells, and macrophages, contributing to the development of oxidative stress and inflammatory environments within the liver. Unfortunately, the current pharmacological treatment for liver fibrosis is limited by its inability to regulate inflammation and oxidative stress concurrently. In this study, we developed a cell membrane biomaterial for the treatment of liver fibrosis, which we designated as PM. PM is a biomimetic nanomaterial constructed by encapsulating polydopamine (PDA) with a macrophage membrane (MM). It is hypothesized that PM nanoparticles (NPs) can successfully target the site of inflammation, simultaneously inhibit inflammation, and scavenge reactive oxygen species (ROS). In vitro experiments demonstrated that PM NPs exhibited strong antioxidant properties and the ability to neutralize pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β). Moreover, the capacity of PM NPs to safeguard cells from oxidative stress and their anti-inflammatory efficacy in an inflammatory model were validated in subsequent cellular experiments. Additionally, PM NPs exhibited a high biocompatibility. In a mouse model of hepatic fibrosis, PM NPs were observed to aggregate efficiently in the fibrotic liver, displaying excellent antioxidant and anti-inflammatory properties. Notably, PM NPs exhibited superior targeting, anti-inflammatory, and ROS scavenging abilities in inflamed tissues compared to MM, PDA, or erythrocyte membrane-encapsulated PDA. Under the synergistic effect of anti-inflammation and antioxidant, PM NPs produced significant therapeutic effects on liver fibrosis in mice. In conclusion, the synergistic alleviation of inflammation and ROS scavenging by this specially designed nanomaterial, PM NPs, provides valuable insights for the treatment of liver fibrosis and other inflammatory- or oxidative stress-related diseases.

Tomato (Solanum lycopersicum L.) YTH Domain-Containing RNA-Binding Protein (YTP) Family Members Participate in Low-Temperature Treatment and Waterlogging Stress Responses

YT521-B homology (YTH) domain-containing RNA-binding proteins (YTPs) are important N6-methyladenosine (m6A) readers that have crucial roles in determining the destiny of m6A-modified RNAs, which are the most widespread RNA modifications in eukaryotes. Tomatoes (Solanum lycopersicum L.) hold significant importance in both dietary consumption patterns and scientific inquiries. While the YTP gene family has been characterized in tomatoes, their specific reactions to the low temperature and waterlogging stresses remain to be elucidated. In our study, nine tomato SlYTPs could be divided into five subclasses, YTHDFa-c and YTHDCa-b. After gene cloning and measuring their expression levels under stress conditions, it was revealed that SlYTP8 exhibited increased sensitivity to low-temperature treatment, while the expression levels of SlYTP9 were notably upregulated in leaf tissues subjected to waterlogging conditions. As members of the YTHDFc subfamily, SlYTP8 and SlYTP9 are both localized in the cytoplasm. Nevertheless, overexpression (OE) of SlYTP8 increased the sensitivity of tomato plants to low-temperature treatment, which was manifested by a higher accumulation of malondialdehyde (MDA) and hydrogen peroxide (H2O2) and a weaker reactive oxygen species scavenging ability compared to wild-type (WT) tomatoes. However, in comparison to WT plants, the leaves of SlYTP9 OE tomatoes showed higher chlorophyll content and a stronger reactive oxygen species scavenging ability after 3 days of waterlogging treatment, thereby increasing the resistance of tomatoes to waterlogging stress. Moreover, in order to investigate the possible molecular mechanisms underlying their responses to the low temperature and waterlogging stresses, the transcription factors and interacting protein networks associated with SlYTP8/9 promoters and proteins were also predicted, respectively. These results could fill the gap in the understanding of tomato YTPs in response to the low temperature and waterlogging stresses, while also providing a theoretical and experimental basis for subsequent studies on their molecular mechanisms.

Liquid exfoliation of molybdenum metallenes for non-inflammatory photothermal therapy of tumors.

Tissue damage and cell death occurring during photothermal therapy (PTT) for tumors can induce an inflammatory response that is detrimental to tumor therapy. Herein, ultrathin Mo metallene nanosheets with a thickness of <5 nm prepared by liquid phase exfoliation were explored as functional hyperthermia agents for non-inflammatory ablation of tumors. The obtained Mo metallene nanosheets exhibited good photothermal conversion properties and significant reactive oxygen species (ROS) scavenging ability, thus achieving superior cancer cell ablation and anti-inflammatory effects in vitro. For in vivo experiments, 4T1 tumors were ablated while the inflammation-related cytokine levels did not obviously increase, demonstrating that the inflammatory response induced by PTT was inhibited by the anti-inflammatory properties of Mo metallene nanosheets. Moreover, Mo metallene nanosheets depicted good dispersibility and biocompatibility, beneficial for biomedical applications. This work introduces Mo metallenes as promising hyperthermia agents for non-inflammatory PTT of tumors.

Dual-Polymer Functionalized Melanin-AgNPs Nanocomposite with Hydroxyapatite Binding Ability to Penetrate and Retain in Biofilm Sequentially Treating Periodontitis.

Periodontitis is the leading cause of adult tooth missing. Thorny bacterial biofilm and high reactive oxygen species (ROS) levels in tissue are key elements for the periodontitis process. It is meaningful to develop an advanced therapeutic system with sequential antibacterial/ antioxidant ability to meet the overall goals of periodontitis therapy. Herein, a dual-polymer functionalized melanin-AgNPs (P/D-MNP-Ag) with biofilm penetration, hydroxyapatite binding, and sequentially treatment ability are fabricated. Polymer enriched with 2-(Dimethylamino)ethyl methacrylate (D), can be protonated in an acid environment with enhanced positive charge, promoting penetration in biofilm. The other polymer is rich in phosphate group (P) and can chelate Ca2+, promoting the polymer to adhere to the hydroxyapatite surface. Melanin has good ROS scavenging and photothermal abilities, after in situ reduction Ag, melanin-AgNPs composite has sequentially transitioned between antibacterial and antioxidative ability due to heat and acid accelerated Ag+ release. The released Ag+ and heat have synergistic antibacterial effects for bacterial killing. With Ag+ consumption, the antioxidant ability of MNP recovers to scavenge ROS in the inflammatory area. When applied in the periodontitis model, P/D-MNP-Ag has good therapeutical effects to ablate biofilm, relieve inflammation state, and reduce alveolar bone loss. P/D-MNP-Ag with sequential treatment ability provides a reference for developing advanced oral biofilm eradication systems.

Polydopamine Synergizes with Quercetin Nanosystem to Reshape the Perifollicular Microenvironment for Accelerating Hair Regrowth in Androgenetic Alopecia.

Accumulated reactive oxygen species (ROS) and their resultant vascular dysfunction in androgenic alopecia (AGA) hinder hair follicle survival and cause permanent hair loss. However, safe and effective strategies to rescue hair follicle viability to enhance AGA therapeutic efficiency remain challenging. Herein, we fabricated a quercetin-encapsulated (Que) and polydopamine-integrated (PDA@QLipo) nanosystem that can reshape the perifollicular microenvironment to initial hair follicle regeneration for AGA treatment. Both the ROS scavenging and angiogenesis promotion abilities of PDA@QLipo were demonstrated. In vivo assays revealed that PDA@QLipo administrated with roller-microneedles successfully rejuvenated the "poor" perifollicular microenvironment, thereby promoting cell proliferation, accelerating hair follicle renewal, and facilitating hair follicle recovery. Moreover, PDA@QLipo achieved a higher hair regeneration coverage of 92.5% in the AGA mouse model than minoxidil (87.8%), even when dosed less frequently. The nanosystem creates a regenerative microenvironment by scavenging ROS and augmenting neovascularity for hair regrowth, presenting a promising approach for AGA clinical treatment.

Peroxiredoxin II exerts neuroprotective effects by inhibiting endoplasmic reticulum stress and oxidative stress-induced neuronal pyroptosis.

Intracerebral hemorrhage (ICH) is a critical neurological condition with few treatment options, where secondary immune responses and specific cell death forms, like pyroptosis, worsen brain damage. Pyroptosis involves gasdermin-mediated membrane pores, increasing inflammation and neural harm, with the NLRP3/Caspase-1/GSDMD pathway being central to this process. Peroxiredoxin II (Prx II), recognized for its mitochondrial protection and reactive oxygen species (ROS) scavenging abilities, appears as a promising neuronal pyroptosis modulator. However, its exact role and action mechanisms need clearer definition. This research aims to explore Prx II impact on neuronal pyroptosis and elucidate its mechanisms, especially regarding endoplasmic reticulum (ER) stress and oxidative stress-induced neuronal damage modulation. Utilizing MTT assays, Microscopy, Hoechst/PI staining, Western blotting, and immunofluorescence, we found Prx II effectively reduces LPS/ATP-induced pyroptosis and neuroinflammation in HT22 hippocampal neuronal cells. Our results indicate Prx II's neuroprotective actions are mediated through PI3K/AKT activation and ER stress pathway inhibition, diminishing mitochondrial dysfunction and decreasing neuronal pyroptosis through the ROS/MAPK/NF-κB pathway. These findings highlight Prx II potential therapeutic value in improving intracerebral hemorrhage outcomes by lessening secondary brain injury via critical signaling pathway modulation involved in neuronal pyroptosis. Our study not only underlines Prx II importance in neuroprotection but also opens new therapeutic intervention avenues in intracerebral hemorrhage, stressing the complex interplay between redox regulation, ER stress, and mitochondrial dynamics in neuroinflammation and cell death management.

Evaluation of antioxidant activity and fermentation properties of potential probiotic strain Lactiplantibacillus plantarum HY7720 in plant-based materials

People on vegan diets are at risk of being deficient in varied nutrients such as vitamin B12 and certain amino acids. In this study, we investigated vitamin B12-producing lactic acid bacteria (LAB) as well as the probiotic and antioxidant properties. Lactiplantibacillus plantarum HY7720 was screened from 22 strains of LAB that were isolated from different plant foods, and its growth ability and extracellular vitamin B12-producing capacity in vitamin B12-deficient medium were investigated. To determine whether HY7720 functions as a probiotic, survival rate in the simulated gastrointestinal tract and adhesion property to human intestinal epithelial cells of HY7720 were compared with positive control, Lacticaseibacillus rhamnosus GG (LGG). Moreover, the results showed that HY7720 recovered the gene expression levels of tight junction-associated proteins (TJPs), including TJP1, TJP2, occludin (OCLN), and claudin-1 (CLDN1) and inhibited the secretion levels of pro-inflammatory cytokines, including interleukin (IL)-6 and IL-8, in tumor necrosis factor (TNF)-α-stimulated Caco-2 cells. Furthermore, we verified that HY7720 exhibit the antioxidant potential, by showing its intracellular reactive oxygen species (ROS) scavenging ability in hydrogen peroxide (H2O2)-stimulated Caco-2 cells. The ability of HY7720 to ameliorate H2O2-induced cytotoxicity in Caco-2 cells was inhibited by mitogen-activated protein kinase (MAPK) inhibitors, indicating that its antioxidant responses are related to extracellular signal-regulated kinase (ERK) and c-JUN N-terminal kinase (JNK). This study also investigated the nutritional qualities of three plant-based materials (brown rice, white rice, and soy milk) fermented using HY7720. Collectively, HY7720 could be used as a promising probiotic strain for the prevention of nutritional deficiencies among people on vegetarian diets.

A bifunctional biomineralized polyoxometalate enabling efficient Non-Inflammatory NIR-II photothermal tumor therapy

Conventional NIR-I photothermal therapy (PTT) has insufficient penetration depth, and the local tissue damage caused by it often concomitants inflammation. Herein, a bifunctional nanoagent based on bovine serum albumin (BSA) and Mo-polyoxometalate (named as B-POM NPs), was developed via a facile self-assembled method for non-inflammatory near-infrared (NIR)-II PTT of triple-negative breast cancer. Thanks for the BSA modification, the obtained B-POM NPs show excellent biocompatibility with high NIR-II photothermal conversion efficiency of 57.2%. In vivo tumor inhibition efficiency under NIR-II PTT reached up to 87 %. More importantly, it is found that the prepared B-POM NPs also have excellent reactive oxygen species scavenging ability. The inflammatory-related factors, such as TNF-α, IL-6 and IL-1β, are significantly down-regulated, which is much beneficial to reduce side effects of PTT. In brief, this work provides a novel protein-based bifunctional nanoagent to effectively inhibit tumor growth meanwhile alleviate inflammatory post NIR-II PTT, showing good promising in clinical.

A synergistically antimicrobial and antioxidant hyaluronic acid hydrogel for infected wounds

Bacterial infections during wound healing impede the healing process and trigger local or systemic inflammatory reactions. Consequently, there is an urgent need to develop a new material with antimicrobial and antioxidant properties to promote infected wound healing. A synergistically antimicrobial and antioxidant hyaluronic acid hydrogel (HMn) is prepared by employing MnO2 nanosheets into 4ARM-PEG5000-SH crosslinked methacrylated hyaluronic acid (HAMA) network. The coordination between sulfhydryl groups of 4ARM-PEG5000-SH and MnO2 nanosheets ensures entrapment of the nanosheets within the hydrogel, while the interaction between 4ARM-PEG5000-SH and HAMA results in facile gelation through thiol-ene click reaction. MnO2 nanosheets exhibit strong photothermal properties and reactive oxygen species (ROS) scavenging abilities, while hyaluronic acid promotes wound healing. When subjected to near-infrared (NIR) irradiation, the HMn achieves a bactericidal rate of 95.24 % for Staphylococcus aureus and nearly 100 % for Escherichia coli. In animal experiments, treatment with the HMn under NIR irradiation results in the best wound healing outcomes. Both in vitro and vivo biocompatible assays demonstrate that the HMn has rarely cell cytotoxicity and tissue damage. The HMn is easy to prepare and has good biocompatibility as well as efficient antibacterial and antioxidant properties, providing a novel method for the treatment of infected wounds.

ROS-responsive & scavenging NO nanomedicine for vascular diseases treatment by inhibiting endoplasmic reticulum stress and improving NO bioavailability

Vascular diseases seriously threaten human life and health. Exogenous delivery of nitric oxide (NO) represents an effective approach for maintaining vascular homeostasis during pathological events. However, the overproduction of reactive oxygen species (ROS) at vascular injury sites would react with NO to produce damaging peroxynitrite (ONOO−) species and limit the therapeutic effect of NO. Hence, we design a ROS-responsive NO nanomedicine (t-PBA&NO NP) with ROS scavenging ability to solve the dilemma of NO-based therapy. t-PBA&NO NP targets NO and anti-oxidant ethyl caffeate (ECA) to the injury sites via collagen IV homing peptide. The ROS-triggered ROS depletion and ECA release potently alleviate local oxidative stress via ROS scavenging, endoplasmic reticulum and mitochondrial regulation. It subsequently maximizes vascular modulation effects of NO, without production of harmful compounds, reactive nitrogen species (RNS). Therefore, it significantly increases competitiveness of human umbilical vein endothelial cells (HUVECs) over human aortic smooth muscle cells (HASMCs) both in vitro and in vivo. The strategy proved effective in inducing faster re-endothelialization, inhibiting neointimal formation and restoring vascular homeostasis. The synergy between ROS depletion and NO therapy served as a new inspiration for the treatment of cardiovascular diseases and other ROS-associated illnesses.

The OsWRKY72-OsAAT30/OsGSTU26 module mediates reactive oxygen species scavenging to drive heterosis for salt tolerance in hybrid rice.

Hybrid rice (Oryza sativa) generally outperforms its inbred parents in yield and stress tolerance, a phenomenon termed heterosis, but the underlying mechanism is not completely understood. Here, we combined transcriptome, proteome, physiological, and heterosis analyses to examine the salt response of super hybrid rice Chaoyou1000 (CY1000). In addition to surpassing the mean values for its two parents (mid-parent heterosis), CY1000 exhibited a higher reactive oxygen species scavenging ability than both its parents (over-parent heterosis or heterobeltiosis). Nonadditive expression and allele-specific gene expression assays showed that the glutathione S-transferase gene OsGSTU26 and the amino acid transporter gene OsAAT30 may have major roles in heterosis for salt tolerance, acting in an overdominant fashion in CY1000. Furthermore, we identified OsWRKY72 as a common transcription factor that binds and regulates OsGSTU26 and OsAAT30. The salt-sensitive phenotypes were associated with the OsWRKY72paternal genotype or the OsAAT30maternal genotype in core rice germplasm varieties. OsWRKY72paternal specifically repressed the expression of OsGSTU26 under salt stress, leading to salinity sensitivity, while OsWRKY72maternal specifically repressed OsAAT30, resulting in salinity tolerance. These results suggest that the OsWRKY72-OsAAT30/OsGSTU26 module may play an important role in heterosis for salt tolerance in an overdominant fashion in CY1000 hybrid rice, providing valuable clues to elucidate the mechanism of heterosis for salinity tolerance in hybrid rice.

Phenolic Ligand-Metal Charge Transfer Induced Copper Nanozyme with Reactive Oxygen Species-Scavenging Ability for Chronic Wound Healing.

Chronic wounds frequently arise as a complication in diabetic patients, and their management remains a significant clinical hurdle due to their nonhealing nature featured by heightened oxidative stress and impaired healing cells at the wound site. Herein, we present a 2D copper antioxidant nanozyme induced by phenolic ligand-metal charge transfer (LMCT) to eliminate reactive oxygen species (ROS) and facilitate the healing of chronic diabetic wounds. We found that polyphenol ligands coordinated on the Cu3(PO4)2 nanosheets led to a strong charge transfer at the interface and regulated the valence states of Cu. The obtained Cu nanozyme exhibited efficient scavenging ability toward different oxidative species and protected human cells from oxidative damage. The nanozyme enhanced the healing of diabetic wounds by promoting re-epithelialization, collagen deposition, angiogenesis, and immunoregulation. This work demonstrates the LMCT-induced ROS scavenging ability on a nanointerface, providing an alternative strategy of constructing metal-based nanozymes for the treatment of diabetic wounds as well as other diseases.

Using Cu-Based Metal-Organic Framework as a Comprehensive and Powerful Antioxidant Nanozyme for Efficient Osteoarthritis Treatment.

Developing nanozymes with effective reactive oxygen species (ROS) scavenging ability is a promising approach for osteoarthritis (OA) treatment. Nonetheless, numerous nanozymes lie in their relatively low antioxidant activity. In certain circumstances, some of these nanozymes may even instigate ROS production to cause side effects. To address these challenges, a copper-based metal-organic framework (Cu MOF) nanozyme is designed and applied for OA treatment. Cu MOF exhibits comprehensive and powerful activities (i.e., SOD-like, CAT-like, and •OH scavenging activities) while negligible pro-oxidant activities (POD- and OXD-like activities). Collectively, Cu MOF nanozyme is more effective at scavenging various types of ROS than other Cu-based antioxidants, such as commercial CuO and Cu single-atom nanozyme. Density functional theory calculations also confirm the origin of its outstanding enzyme-like activities. In vitro and in vivo results demonstrate that Cu MOF nanozyme exhibits an excellent ability to decrease intracellular ROS levels and relieve hypoxic microenvironment of synovial macrophages. As a result, Cu MOF nanozyme can modulate the polarization of macrophages from pro-inflammatory M1 to anti-inflammatory M2 subtype, and inhibit the degradation of cartilage matrix for efficient OA treatment. The excellent biocompatibility and protective properties of Cu MOF nanozyme make it a valuable asset in treating ROS-related ailments beyond OA.

Multienzyme Active Manganese Oxide Alleviates Acute Liver Injury by Mimicking Redox Regulatory System and Inhibiting Ferroptosis.

Drug-induced liver injury (DILI) is a severe condition characterized by impaired liver function and the excessive activation of ferroptosis. Unfortunately, there are limited options currently available for preventing or treating DILI. In this study, MnO2 nanoflowers (MnO2Nfs) with remarkable capabilities of mimicking essential antioxidant enzymes, including catalase, superoxide dismutase (SOD), and glutathione peroxidase are successfully synthesized, and SOD is the dominant enzyme among them by density functional theory. Notably, MnO2Nfs demonstrate high efficiency in effectively eliminating diverse reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), superoxide anion (O2 •-), and hydroxyl radical (•OH). Through in vitro experiments, it is demonstrated that MnO2Nfs significantly enhance the recovery of intracellular glutathione content, acting as a potent inhibitor of ferroptosis even in the presence of ferroptosis activators. Moreover, MnO2Nfs exhibit excellent liver accumulation properties, providing robust protection against oxidative damage. Specifically, they attenuate acetaminophen-induced ferroptosis by inhibiting ferritinophagy and activating the P62-NRF2-GPX4 antioxidation signaling pathways. These findings highlight the remarkable ROS scavenging ability of MnO2Nfs and hold great promise as an innovative and potential clinical therapy for DILI and other ROS-related liver diseases.

Rapamycin functionalized carbon Dots: Target-oriented synthesis and suppression of vascular cell senescence

Suppression of vascular cell senescence is of great significance in preventing cardiovascular diseases such as hypertension and atherosclerosis. The oxidative stress damage caused by reactive oxygen species (ROS) can lead to cellular senescence. Rapamycin (Rapa) is well known to suppress cell senescence via mammalian target of rapamycin (mTOR) pathway. However, poor water solubility and lack of ROS scavenging ability limit the further development of Rapa. To improve the solubility of Rapa and endow with ROS scavenging ability, Rapa functionalized carbon dots (Rapa-CDs) are target-oriented synthesized via free radical polymerization combination with hydrothermal carbonization. Rapa-CDs improve the solubility of Rapa and show ROS scavenging abilities. The solubility of Rapa-CDs with 9.41 g is improved 3.6 × 104 times higher than that of Rapa (2.6 × 10-4 g). The half maximal inhibitory concentration (IC50) of Rapa-CDs toward hydroxyl radical (•OH) and 2,2-Diphenyl-1-picrylhydrazyl free radical (DPPH•) are 0.18 and 0.17 mg/mL, respectively. Rapa-CDs show anti-oxidative stress effect in HEVECs (Human Umbilical Vein Endothelial Cells) via reducing ROS levels by 87 %. Rapa-CDs alleviate HUVECs senescence by suppressing mTOR overactivation, attenuate the expression of P53, P21 and P16. The study demonstrates the target-oriented synthesis of drugs functionalized CDs with anti-senescence via dual-pathway of anti-oxidative stress and mTOR.

The ABA synthesis enzyme allele OsNCED2T promotes dryland adaptation in upland rice

Upland rice shows dryland adaptation in the form of a deeper and denser root system and greater drought resistance than its counterpart, irrigated rice. Our previous study revealed a difference in the frequency of the OsNCED2 gene between upland and irrigated populations. A nonsynonymous mutation (C to T, from irrigated to upland rice) may have led to functional variation fixed by artificial selection, but the exact biological function in dryland adaptation is unclear. In this study, transgenic and association analysis indicated that the domesticated fixed mutation caused functional variation in OsNCED2, increasing ABA levels, root development, and drought tolerance in upland rice under dryland conditions. OsNCED2-overexpressing rice showed increased reactive oxygen species-scavenging abilities and transcription levels of many genes functioning in stress response and development that may regulate root development and drought tolerance. OsNCED2T-NILs showed a denser root system and drought resistance, promoting the yield of rice under dryland conditions. OsNCED2T may confer dryland adaptation in upland rice and may find use in breeding dryland-adapted, water-saving rice.

Enhanced ROS scavenging and tissue adhesive abilities in injectable hydrogels by protein modification with oligoethyleneimine.

Postsurgical treatment comprehensively benefits from the application of tissue-adhesive injectable hydrogels, which reduce postoperative complications by promoting wound closure and tissue regeneration. Although various hydrogels have been employed as clinical tissue adhesives, many exhibit deficiencies in adhesive strength under wet conditions or in immunomodulatory functions. Herein, we report the development of reactive oxygen species (ROS) scavenging and tissue-adhesive injectable hydrogels composed of polyamine-modified gelatin crosslinked with the 4-arm poly (ethylene glycol) crosslinker. Polyamine-modified gelatin was particularly potent in suppressing the secretion of proinflammatory cytokines from stimulated primary macrophages. This effect is attributed to its ability to scavenge ROS and inhibit the nuclear translocation of nuclear factor kappa-B. Polyamine-modified gelatin-based hydrogels exhibited ROS scavenging abilities and enhanced tissue adhesive strength on collagen casing. Notably, the hydrogel demonstrated exceptional tissue adhesive properties in a wet environment, as evidenced by its performance using porcine small intestine tissue. This approach holds significant promise for designing immunomodulatory hydrogels with superior tissue adhesion strength compared to conventional medical materials, thereby contributing to advancements in minimally invasive surgical techniques.

Overexpression of PbrGA2ox1 enhances pear drought tolerance through regulation of GA3-inhibited reactive oxygen species detoxification and abscisic acid signaling1

Drought stress represents a devastating natural disaster driven by the continuing intensification of global warming, which seriously threats the productivity and quality of several horticultural crops, including pear. Gibberellins (GAs) play crucial roles in plant growth, development, and responses to drought stress. Previous studies have shown significant reductions of GA levels in plants under drought stress; however, understanding of the intrinsic regulation mechanisms of GA-mediated drought stress in pear remains very limited. Here, we show that drought stress could impair the accumulation of bioactive GAs (BGAs), and subsequently identified PbrGA2ox1 as a chloroplast-localized GA deactivation gene, which was significantly induced by drought stress and abscisic acid (ABA) treatment, but was suppressed by GA3 treatment. PbrGA2ox1-overexpressing transgenic tobacco (Nicotiana benthamiana) plants exhibited enhanced tolerance to dehydration and drought stresses, whereas knock-down of PbrGA2ox1 in pear (Pyrus betulaefolia) by virus-induced gene silencing lead to elevated drought sensitivity. Transgenic plants were hypersensitive to ABA, and had a lower BGAs content, enhanced reactive oxygen species (ROS) scavenging ability, and augmented ABA accumulation and signaling under drought stress compared to wild-type plants. However, the opposite effects were observed with PbrGA2ox1 silencing in pear. Moreover, exogenous GA3 treatment aggravated the ROS toxification effect and restrained ABA synthesis and signaling, resulting in the compromised drought tolerance of pear. In summary, our results shed light on the mechanism by which BGAs are eliminated in pear leaves under drought stress, providing a further insight into the mechanism regulating the effects of the GA on the drought tolerance of plants.