查找使用阿拉丁产品的科研文献

Evaluation of tetraalkylammonium amino acid ionic liquids as chiral ligands in ligand-exchange capillary electrophoresis

Song Xue,Siru Ren,Li Wang,Qi Zhang

The application of chiral ionic liquids (ILs) in capillary electrophoresis (CE) for enantioseparation has received considerable attention in the past few years; however, the use of chiral ILs as ligands in ligand-exchange capillary electrophoresis (LE-CE) has been reported only in a few papers. In this work, several tetraalkylammonium amino acid ILs (TAA-AAILs) including tetramethylammonium- l -arginine (TMA- l -Arg), tetramethylammonium- l -proline (TMA- l -Pro) and tetramethylammonium- l -glutamic acid (TMA- l -Glu) were first applied in LE-CE to act as chiral ligands for enantioseparation. The results show that TMA- l -Arg-is an excellent chiral ligand, and able to yield equal or even better resolutions (Rs) in much shorter migration times for most tested analytes compared with previously reported AAILs ligands or free l -Arg-ligand. Parameters of the new TAA-AAILs-based LE-CE system such as the alkane chain length of TAA-AAILs, ILs configuration, ILs concentration, the type and concentration of central metal ion, buffer pH and applied voltage were optimized. Satisfactory enantioseparations were achieved for most selected free- or dansyl-amino acids. The method was then successfully applied to the enantiomeric impurity test of a commercial amino acid sample. This work indicates that the application of TAA-AAILs as chiral ligands in LE-CE is of great potential for enantioseparation.

Single-cell omics reveals arg-1 as a key regulator of age-dependent macrophage-mediated cartilage repair

JianJun Chu,Zhengfa Wen,Wenying Wu,Shoukun Wu

Aging impairs cartilage repair, with young animals exhibiting superior regenerative capacity due to enhanced tissue repairing and reduced inflammation compared to aged counterparts. This study employed single-cell omics to dissect age-dependent immune cell heterogeneity in cartilage injury, revealing a critical deficiency in anti-inflammation macrophage subsets in aged animals. We identified Arg-1 as a central regulator of macrophage polarization, demonstrating that its overexpression rescues impaired repair in aged animals. These findings establish Arg-1 as a novel therapeutic target to counteract age-related declines in cartilage regeneration, offering new insights into macrophage-driven tissue repair mechanisms. The integration of single-cell analysis with functional validation provides a framework for developing precision interventions for age-impaired tissue regeneration.

Synthesis of ethyl (R)-4-chloro-3-hydroxybutyrate by immobilized cells using amino acid-modified magnetic nanoparticles

Yuan Lu,Hongqian Dai,Hanbing Shi,Lan Tang,Xingyuan Sun,Zhimin Ou

Fe 3 O 4 -Arg was selected as the optimal carrier due to its high activity recovery of immobilized cells in the preparation of Fe 3 O 4 -Arg-Cells. The optimal immobilization conditions for the preparation of Fe 3 O 4 -Arg-Cells were 30 °C, 4 h, pH 7, and 3 g dry yeast. The activity recovery of immobilized cells reached 76.8 %. For a batch reduction in a shaker in an alternating magnetic field, Fe 3 O 4 -Arg-Cells were used as a catalyst to gain ethyl ( R )-4-chloro-3-hydroxybutyrate (( R )-CHBE). For further improvement in reduction productivity, a continuous reduction in the magnetic fluidized bed reactor system (MFBRS) was completed. Under their optimal transformation conditions, it took 24 h for Fe 3 O 4 -Arg-Cells to complete the conversion of ethyl 4-chloro-3-oxobutanoate (COBE) (0.8553 mol/L) in the shaker and only 8 h for the batch reduction in an alternating magnetic field. Continuous reduction in MFBRS provided new ideas for the efficient production of ( R )-CHBE; 1.5882 mol/L (10 mL) of COBE can be completely converted in 6 h. The conversion and enantiomeric excess (e.e.) of ( R )-CHBE were 100 % and above 99.9 % respectively, in the three reaction systems mentioned above.

Arg-liposome-amplified colorimetric immunoassay for selective and sensitive detection of cystatin C to predict acute kidney injury

Bing Wang,Lei Zhang,Guo Yin,Jue Wang,Ping Wang,Tiejie Wang,Jiangwei Tian,Xie-an Yu,Huachao Chen

Cystatin C (Cys C) has been considered as a novel biomarker of kidney disease, which is thought to be a better indicator of glomerular filtration rate than creatinine (Scr) in the prediction of acute kidney injury (AKI). Hence, there is strong need to develop a precise, rapid and simple detection method for Cys C. Here we reported a Arg-liposome-amplified colorimetric immunoassay for the detection of Cys C to predict AKI. Cys C antibodies are conjugated on the surface of magnetic beads (MBs) and arginine (Arg)-loaded liposomes to form Ab1-MBs and Ab2-Arg-liposomes, respectively. When Ab1-MBs captured Cys C, Ab2-Arg-liposomes are added and incubated to form the immuno-sandwich complex. After magnetic separation, the surfactant Triton ×100 is added to damage the liposomes, leading to the release of Arg which can induce the gold nanoparticles aggregation. Therefore, the discoloration can be used for visual and quantitative detection of Cys C. Notably, the method has a linear relation in the range of 10–100 μg/L for Cys C with a limit of detection 4.32 μg/L, which is lower than some of the previous reports. In addition, the AKI mice serum samples were tested by the developed method, which were in good agreement with ELISA results. More intriguingly, the results of cisplatin induced acute kidney injury in mice showed that the method could be used to evaluate the protective effect of astragalus membranaceus (AM) on AKI by detecting Cys C in serum, providing a new strategy for screening renal protective drugs. Accordingly, a rapid and highly sensitive Cys C detection system was established with great potential for clinical diagnostics.

Hyaluronic acid and Arg-Gly-Asp peptide modified Graphene oxide with dual receptor-targeting function for cancer therapy

Yufeng Guo,Haixing Xu,Yiping Li,Fengzheng Wu,Yixuan Li,Yun Bao,Xiumei Yan,Zhijun Huang,Peihu Xu

Graphene oxide (GO) modified with hyaluronic acid (HA) and Arg-gly-asp peptide (RGD) was designed as a dual-receptor targeting drug delivery system to enhance the specificity and efficiency of anticancer drug delivery. Firstly, GO-HA-RGD conjugate was characterized to reveal its structure and morphology. Whereafter, doxorubicin (Dox) as a model drug was loaded on GO-HA-RGD carrier, which displayed a high loading rate (72.9%, GO:Dox (w/w) = 1:1), pH-response and sustained drug release behavior. Cytotoxicity experiments showed that GO-HA-RGD possessed excellent biocompatibility towards SKOV-3 and HOSEpiC cells. Additionally, the GO-HA-RGD/Dox had a stronger cytotoxicity for SKOV-3 cells than either GO-HA/Dox (single receptor) or GO/Dox (no receptor). Moreover, celluar uptake studies illustrated that GO-HA-RGD conjugate could be effectively taken up by SKOV-3 cells via a synergic effect of CD44-HA and integrin-RGD mediated endocytosis. Hence, GO-HA-RGD nanocarrier is able to be a promising platform for targeted cancer therapeutic.

Arg−Gly−Asp peptide functionalized poly-amino acid/ poly (p-benzamide) copolymer with enhanced mechanical properties and osteogenicity

Lichao Chen,Bo Wang,Haohao Ren,Yanan Wu,Defu Lyu,Yanan Ouyang,Qiyi Zhang,Yonggang Yan

Poly-amino acid (PAA) is a promising biomaterial in biomedical engineering due to its similar amide bond structure to collagen and excellent biocompatibility, but the lack of osteogenic activity and inferior mechanical strength limit its long-term application in orthopedics. In this study, a poly-amino acid/poly (p-benzamide) (PAA-PBA) copolymer with high mechanical strength was designed and fabricated by the method of solution polymerization. The chain structures, thermal properties and mechanical properties of these polymers were evaluated and results showed that PBA greatly promoted the mechanical properties of PAA, and the copolymer performed the maximum mechanical strengths with compressive strength, bending strength and tensile strength of 123 MPa, 107 MPa and, 95 MPa, respectively. To increase the bioactivity of surface, a bioactive coating that consists of poly-(dopamine) (PDA) nanolayers and tripeptide Arginine-Glycine-Aspartic acid (RGD) on sulfonated PAA-PBA copolymer was created. A porous structure appeared on the surface after modification, the surface roughness and hydrophilicity of copolymer has been improved obviously after introducing PDA and RGD peptide coating. The in vitro bioactivity evaluation demonstrated that the RGD-functionalized sample showed a significantly improved ability to promote bone apatite mineralization, cell adhesion, proliferation and osteogenic differentiation. In a word, such a strategy of material synthesis and surface modification method shows a great potential for broadening the use of PAA in the application of load-bearing bone substitute biomaterials.

PER1 promotes functional recovery of mice with hindlimb ischemia by inducing anti-inflammatory macrophage polarization

Yang Ding,Shengyun Wan,Long Ma,Kaikai Wei,Kun Ye

Hindlimb ischemia (HLI) is an arterial occlusive disease that exposes the patients to the risk of limb gangrene and loss. Polarization of macrophages is related to HLI-induced inflammation. Period circadian regulator 1 (PER1) is a core component of the circadian clock. We first showed, based upon bioinformatics analysis of microarray data, that PER1 expression was reduced in monocytes from patients with critical limb ischemia. The proximal femoral artery in the left hindlimb of male mice was ligated and then the femoral artery and its collateral branches were removed to establish the HLI mouse model. After modeling, a single intramuscular injection of 1 × 10 9  pfu Ad-PER1 was performed at the adductor and gastrocnemius muscles. The gastrocnemius muscle tissues were collected at day 0, 3, 7, 14, 21 post-HLI. There was obvious pathological necrosis, accompanied with reduced expression of PER1 in the muscle tissues of HLI mice. Expression of CD68 and CD31 seemed to be corresponded to PER1 in gastrocnemius muscle, implying the potential of PER1 in regulating macrophage-related inflammation and angiogenesis . PER1 overexpression diminished myocyte damage, promoted blood flow restoration and improved behavioral scores of HLI mice. Immunostaining of CD31 and α-SMA revealed that PER1 upregulation reversed HLI-induced decreases in capillary and arteriole density. In vitro, RAW264.7 cells were cultured in hypoxia (1% O 2 ) for 24 h. The percentage of pro-inflammatory CD86 + macrophages (M1 type) was decreased and that of anti-inflammatory CD206+ macrophages (M2 type) was increased when PER1 was overexpressed. Moreover, the expression levels of TNF-α, IL-6 and M1-type marker iNOS were decreased, and levels of IL-10 and M2-type marker Arg-1 were increased by PER1 in gastrocnemius muscle of HLI mice and hypoxia-treated RAW264.7 cells. PER1 might reduce M1 macrophage polarization and promote M2 macrophage polarization, and thus exert anti-inflammatory and pro-angiogenic actions. Our findings suggest that PER1 overexpression promotes functional recovery of mice with HLI through regulating macrophage polarization.

Hypolipidemic effects and mechanisms of Val-Phe-Val-Arg-Asn in C57BL/6J mice and 3T3-L1 cell models

Xing Zhang,Wen Shi,Hui He,Ruge Cao,Tao Hou

Val-Phe-Val-Arg-Asn (VFVRN) has been identified and screened from lipid-lowering chickpea peptides (ChPs) previously. This work explored its lipid-lowering mechanisms by using a high-fat diet C57BL/6J mice model and 3T3-L1 preadipocyte cell model. Administration of VFVRN to hyperlipidemic mice significantly decreased the levels of total cholesterol (TC) and total triglyceride (TG) in liver and serum (P < 0.05), and increased the fecal triglyceride excretions. The expressions of sterol regulatory element-binding protein (SREBP)-2, liver X receptor (LXR)α, peroxisome proliferator-activated receptors (PPAR)α and their related target genes were regulated via AMP-activated protein kinase (p-AMPK) pathway in liver. Compared with model group, the levels of PPARα and PPARγ in 10 mg/kg VFVRN group were up-regulated by 36.96% and 36.49% in adipose tissues, while LXRα and ATP binding cassette G5/8 transporters (ABGC5/8) were lowered by 87.26% and 145% in small intestine respectively. Moreover, VFVRN promoted 3T3-L1 preadipocyte apoptosis by regulating the expressions of BaX, Caspase-3 and Bcl-2.

Gas Chromatography-Mass Spectrometric Analysis and Insecticidal Activity of Essential Oil of Aerial Parts of Mallotus apelta (Lour.) Muell.-Arg. (Euphorbiaceae)

XC Liu,XB Chen,ZL Liu

Change in microbial community in landfill refuse contaminated with antibiotics facilitates denitrification more than the increase in ARG over long-term

Wu Dong,Chen Guanzhou,Zhang Xiaojun,Yang Kai,Xie Bing

In this study, the addition of sulfamethazine (SMT) to landfill refuse decreased nitrogen intermediates (e.g. N 2 O and NO) and dinitrogen (N 2 ) gas fluxes to <0.5 μg-N/kg-refuse·h −1 , while the N 2 O and N 2 flux were at ~1.5 and 5.0 μg-N/kg-refuse·h −1 respectively in samples to which oxytetracycline (OTC) had been added. The ARG (antibiotic resistance gene) levels in the refuse increased tenfold after long-term exposure to antibiotics, followed by a fourfold increase in the N 2 flux, but SMT-amended samples with the largest resistome facilitated the denitrification (the nitrogen accumulated as NO gas at ~6 μg-N/kg-refuse·h −1 ) to a lesser extent than OTC-amended samples. Further, deep sequencing results show that long-term OTC exposure partially substituted Hyphomicrobium, Fulvivirga , and Caldilinea (>5%) for the dominant bacterial hosts ( Rhodothermus , ~20%) harboring nosZ and norB genes that significantly correlated with nitrogen emission pattern, while sulfamethazine amendment completely reduced the relative abundance of the “original inhabitants” functioning to produce NO x gas reduction. The main ARG carriers ( Pseudomonas ) that were substantially enriched in the SMT group had lower levels of denitrifying functional genes, which could imply that denitrification is influenced more by bacterial dynamics than by abundance of ARGs under antibiotic pressures.

ECM-inspired 3D printed polyetherimide scaffold with Arg-Gly-Asp peptides for the improvement of bioactivity and osteogenic differentiation of osteoblasts

Xinyu Xu,Hao Wang,Shuling Zhang,Xiaohan Mei,Boda Ying,Ruiyan Li,Yanguo Qin

High-performance polymers, such as polyetherimide (PEI), are promising bone biomaterials that meet the mechanical demands of bone defect repair. To achieve better therapeutic outcomes, the osteoinduction of high-performance polymers requires further improvement. In this study, the fused deposition modeling (FDM) 3D printing method was applied to fabricate orthogonal porous PEI scaffolds. Inspired by the simulation of the extracellular matrix (ECM), The polydopamine (PDA) and Arg-Gly-Asp (RGD) peptides were applied to construct an osteogenic microenvironment on PEI/PDA/RGD scaffold. The characterization, bioactivity, and osteogenic differentiation of the scaffolds were systematically investigated. The mechanical properties of the PEI/PDA/RGD scaffold were similar to those of bone tissues with favorable hydrophilicity and no biotoxicity. The adhesion, proliferation, extracellular bone matrix formation, calcium deposition, and alkaline phosphatase (ALP) vitality of MC3T3-E1 osteoblasts was higher in the PEI/PDA/RGD scaffold compared with other scaffolds. The PEI/PDA/RGD scaffold promoted the osteogenic differentiation of MC3T3-E1 osteoblasts by upregulating their gene expression of osteopontin (OPN), runt-related transcription factor 2 (RUNX-2), bone morphogenetic protein (BMP-2), osteocalcin (OCN), ALP, and especially type I collagen (COL-1). The PEI/PDA/RGD scaffold fabricated in this study is a promising bone biomaterial with appropriate mechanical properties and ideal osteogenic microenvironment, which has potential application in the field of bone defect repair. The construction of osteogenic microenvironment on 3D printed porous PEI scaffold could broaden the application of polyetherimide in bone biomaterials.

Engineering a Dual-Regenerative Cascade: Injectable Hydrogel with Zn2+/l-Arg Cross-Linkers and Macrophage-Targeting Carbon Dots for Synergistic CLI Therapy

Haoran Wang,Ning Ding,Mariano Romero,Dominique Mombrú,Alvaro W. Mombrú,Xiaoyu Wang,Chunzhao Liu

Critical limb ischemia (CLI) remains refractory to current revascularization strategies due to its complex pathology. Here, we report an injectable alginate hydrogel that orchestrates a dual-pathway regenerative cascade by simultaneously reprogramming the immune microenvironment and activating direct tissue repair. The system is rationally designed by integrating two functional modules: (i) immunomodulatory carbon dots (PNS-AA@CQDs-COS) that selectively target M1 macrophages and drive them to the M2 phenotype, and (ii) intrinsically bioactive cross-linkers (Zn2+/l-Arg) that serve as sustained-release pro-regenerative signals. Critically, this dual-component architecture enables a synergistic interplay─while the carbon dots establish an anti-inflammatory microenvironment (path 1), the liberated Zn2+ and l-Arg directly activate endothelial cells and muscle satellite cells, thereby initiating coordinated vascular and myogenic regeneration (path 2). In vitro, the hydrogel significantly amplified reparative crosstalk within macrophage-endothelial/myogenic cells’ cocultures. In a murine CLI model, a single injection of the hydrogel resulted in durable recovery of hindlimb perfusion (80.4% by day 14), improved motor function, and enhanced tissue repair. Mechanistic studies revealed that these benefits stem from microenvironment remodeling (M2 polarization and IL-10 upregulation) and modulation of key signaling pathways─suppressing NF-κB while potentiating PI3K/Akt/eNOS. This work presents a material-based strategy that couples immunomodulation with direct cellular activation, offering a synergistic therapeutic platform for CLI and potentially other ischemic diseases.