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1.
Chem Sci ; 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39129776

RESUMO

Fluorination has emerged as a promising strategy in medicinal chemistry to improve the pharmacological profiles of drug candidates. Similarly, incorporating fluorinated non-canonical amino acids into macrocyclic peptides expands chemical diversity and enhances their pharmacological properties, from improved metabolic stability to enhanced cell permeability and target interactions. However, only a limited number of fluorinated non-canonical amino acids, which are canonical amino acid analogs, have been incorporated into macrocyclic peptides by ribosomes for de novo construction and target-based screening of fluorinated macrocyclic peptides. In this study, we report the ribosomal translation of a series of distinct fluorinated non-canonical amino acids, including mono-to tri-fluorinated variants, as well as fluorinated l-amino acids, d-amino acids, ß-amino acids, etc. This enabled the de novo discovery of fluorinated macrocyclic peptides with high affinity for EphA2, and particularly the identification of those exhibiting broad-spectrum activity against Gram-negative bacteria by targeting the BAM complex. This study not only expands the scope of ribosomally translatable fluorinated amino acids but also underscores the versatility of fluorinated macrocyclic peptides as potent therapeutic agents.

2.
Int J Mol Med ; 54(3)2024 09.
Artigo em Inglês | MEDLINE | ID: mdl-38994762

RESUMO

Age­related macular degeneration (AMD) is an ocular disease that threatens the visual function of older adults worldwide. Key pathological processes involved in AMD include oxidative stress, inflammation and choroidal vascular dysfunction. Retinal pigment epithelial cells and Müller cells are most susceptible to oxidative stress. Traditional herbal medicines are increasingly being investigated in the field of personalized medicine in ophthalmology. Triptonide (Tn) is a diterpene tricyclic oxide, the main active ingredient in the extract from the Chinese herbal medicinal plant Tripterygium wilfordii, and is considered an effective immunosuppressant and anti­inflammatory drug. The present study investigated the potential beneficial role of Tn in retinal oxidative damage in order to achieve personalized treatment for early AMD. An oxidative stress model of retinal cells induced by H2O2 and a retinal injury model of mice induced by light and N­Methyl­D­aspartic acid were constructed. In vitro, JC­1 staining, flow cytometry and apoptosis assay confirmed that low concentrations of Tn effectively protected retinal cells from oxidative damage, and reverse transcription­quantitative PCR and western blotting analyses revealed that Tn reduced the expression of retinal oxidative stress­related genes and inflammatory factors, which may depend on the PI3K/AKT/mTOR­induced Nrf2 signaling pathway. In vivo, by retinal immunohistochemistry, hematoxylin and eosin staining and electroretinogram assay, it was found that retinal function and structure improved and choroidal neovascularization was significantly inhibited after Tn pretreatment. These results suggested that Tn is an efficient Nrf2 activator, which can be expected to become a new intervention for diseases such as AMD, to inhibit retinal oxidative stress damage and pathological neovascularization.


Assuntos
Fator 2 Relacionado a NF-E2 , Estresse Oxidativo , Retina , Transdução de Sinais , Estresse Oxidativo/efeitos dos fármacos , Animais , Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Camundongos , Retina/efeitos dos fármacos , Retina/metabolismo , Retina/patologia , Triterpenos/farmacologia , Masculino , Apoptose/efeitos dos fármacos , Humanos , Camundongos Endogâmicos C57BL , Substâncias Protetoras/farmacologia , Linhagem Celular , Peróxido de Hidrogênio
3.
ACS Chem Biol ; 19(7): 1440-1446, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-38901034

RESUMO

Peptide-bile acid hybrids offer promising drug candidates due to enhanced pharmacological properties, such as improved protease resistance and oral bioavailability. However, it remains unknown whether bile acids can be incorporated into peptide chains by the ribosome to produce a peptide-bile acid hybrid macrocyclic peptide library for target-based de novo screening. In this study, we achieved the ribosomal incorporation of lithocholic acid (LCA)-d-tyrosine into peptide chains. This led to the construction of a peptide-LCA hybrid macrocyclic peptide library, which enabled the identification of peptides TP-2C-4L3 (targeting Trop2) and EP-2C-4L5 (targeting EphA2) with strong binding affinities. Notably, LCA was found to directly participate in binding to EphA2 and confer on the peptides improved stability and resistance to proteases. Cell staining experiments confirmed the high specificity of the peptides for targeting Trop2 and EphA2. This study highlights the benefits of LCA in peptides and paves the way for de novo discovery of stable peptide-LCA hybrid drugs.


Assuntos
Ácido Litocólico , Biblioteca de Peptídeos , Peptídeos , Ribossomos , Ácido Litocólico/química , Ácido Litocólico/análogos & derivados , Ácido Litocólico/metabolismo , Ribossomos/metabolismo , Humanos , Peptídeos/química , Peptídeos/metabolismo , Receptor EphA2/metabolismo , Receptor EphA2/química , Descoberta de Drogas , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo
4.
J Transl Med ; 22(1): 561, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38867256

RESUMO

BACKGROUND: Fibrogenesis within ovarian endometrioma (endometrioma), mainly induced by transforming growth factor-ß (TGF-ß), is characterized by myofibroblast over-activation and excessive extracellular matrix (ECM) deposition, contributing to endometrioma-associated symptoms such as infertility by impairing ovarian reserve and oocyte quality. However, the precise molecular mechanisms that underpin the endometrioma- associated fibrosis progression induced by TGF-ß remain poorly understood. METHODS: The expression level of lysine acetyltransferase 14 (KAT14) was validated in endometrium biopsies from patients with endometrioma and healthy controls, and the transcription level of KAT14 was further confirmed by analyzing a published single-cell transcriptome (scRNA-seq) dataset of endometriosis. We used overexpression, knockout, and knockdown approaches in immortalized human endometrial stromal cells (HESCs) or human primary ectopic endometrial stromal cells (EcESCs) to determine the role of KAT14 in TGF-ß-induced fibrosis. Furthermore, an adeno-associated virus (AAV) carrying KAT14-shRNA was used in an endometriosis mice model to assess the role of KAT14 in vivo. RESULTS: KAT14 was upregulated in ectopic lesions from endometrioma patients and predominantly expressed in activated fibroblasts. In vitro studies showed that KAT14 overexpression significantly promoted a TGF-ß-induced profibrotic response in endometrial stromal cells, while KAT14 silencing showed adverse effects that could be rescued by KAT14 re-enhancement. In vivo, Kat14 knockdown ameliorated fibrosis in the ectopic lesions of the endometriosis mouse model. Mechanistically, we showed that KAT14 directly interacted with serum response factor (SRF) to promote the expression of α-smooth muscle actin (α-SMA) by increasing histone H4 acetylation at promoter regions; this is necessary for TGF-ß-induced ECM production and myofibroblast differentiation. In addition, the knockdown or pharmacological inhibition of SRF significantly attenuated KAT14-mediating profibrotic effects under TGF-ß treatment. Notably, the KAT14/SRF complex was abundant in endometrioma samples and positively correlated with α-SMA expression, further supporting the key role of KAT14/SRF complex in the progression of endometrioma-associated fibrogenesis. CONCLUSION: Our results shed light on KAT14 as a key effector of TGF-ß-induced ECM production and myofibroblast differentiation in EcESCs by promoting histone H4 acetylation via co-operating with SRF, representing a potential therapeutic target for endometrioma-associated fibrosis.


Assuntos
Endometriose , Fibrose , Fator de Resposta Sérica , Fator de Crescimento Transformador beta , Adulto , Animais , Feminino , Humanos , Camundongos , Endometriose/patologia , Endometriose/metabolismo , Endométrio/metabolismo , Endométrio/patologia , Histona Acetiltransferases/metabolismo , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Fator de Resposta Sérica/metabolismo , Células Estromais/metabolismo , Células Estromais/patologia , Fator de Crescimento Transformador beta/metabolismo , Regulação para Cima/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo
5.
Front Neurol ; 15: 1341864, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38576530

RESUMO

Background: Autosomal recessive primary microcephaly (MCPH) is a rare neurodevelopmental disorder characterized primarily by congenital microcephaly and intellectual disability but without extra-central nervous system malformations. This investigation aimed to elucidate the genetic underpinnings of microcephaly in a patient from a Chinese consanguineous family. Methods: A comprehensive clinical assessment, including brain magnetic resonance imaging (MRI), electroencephalogram (EEG), and genetic analyses, was conducted to evaluate the patient's condition. Whole-exome sequencing (WES) was employed to identify the causative gene, followed by Sanger sequencing, to confirm the mutation and its segregation within the family. Reverse transcript polymerase chain reaction (RT-PCR) was utilized to detect changes in splicing. Western blot was employed to reveal the difference of protein expression level between the wild-type and mutant WDR62 in vitro. Results: The patient exhibited classic MCPH symptoms, including microcephaly, recurrent epilepsy, delayed psychomotor development, and intellectual disability. Additionally, asymmetrical limb length was noted as a prominent feature. MRI findings indicated reduced brain volume with cortical malformations, while EEG demonstrated heightened sharp wave activity. A molecular analysis uncovered a novel homozygous variant c.4154-6 C > G in the WDR62 intron, and a functional analysis confirmed the pathogenicity of this mutation, resulting in the formation of an abnormal transcript with premature termination codons. Conclusion: This study enhances our understanding of the genetic heterogeneity associated with MCPH and highlights the pivotal role of genetic testing in the diagnosing and managing of rare neurodevelopmental disorders. Furthermore, it highlights the potential of emerging genetic therapies in treating conditions such as MCPH2.

6.
Artigo em Inglês | MEDLINE | ID: mdl-38541298

RESUMO

Most of the studies on the cost of intellectual disability are limited to a healthcare perspective or cohorts composed of individuals where the etiology of the condition is a mixture of genetic and non-genetic factors. When used in policy development, these can impact the decisions made on the optimal allocation of resources. In our study, we have developed a static microsimulation model to estimate the healthcare, societal, and lifetime cost of individuals with familial intellectual disability, an inheritable form of the condition, to families and government. The results from our modeling show that the societal costs outweighed the health costs (approximately 89.2% and 10.8%, respectively). The lifetime cost of familial intellectual disability is approximately AUD 7 million per person and AUD 10.8 million per household. The lifetime costs to families are second to those of the Australian Commonwealth government (AUD 4.2 million and AUD 9.3 million per household, respectively). These findings suggest that familial intellectual disability is a very expensive condition, representing a significant cost to families and government. Understanding the drivers of familial intellectual disability, especially societal, can assist us in the development of policies aimed at improving health outcomes and greater access to social care for affected individuals and their families.


Assuntos
Deficiência Intelectual , Humanos , Deficiência Intelectual/epidemiologia , Deficiência Intelectual/genética , Efeitos Psicossociais da Doença , Austrália/epidemiologia , Atenção à Saúde , Custos de Cuidados de Saúde
7.
Protein Expr Purif ; 218: 106447, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38369031

RESUMO

Diaminopropionate ammonia-lyase transforms D and L isomers of 2,3-diaminopropionate to pyruvate and ammonia. It catalyzes D- and l-serine less effectively. L-2,3-diaminopropionate is a precursor in the biosynthesis of oxalyl diaminopropionate as a neurotoxin in certain legume species. In this work, we cyclized the diaminopropionate ammonia-lyase from Salmonella typhimurium in vitro using the redox-responsive split intein, and identified that backbone cyclization afforded the enzyme with the improved activity, thermal stability and resistance to the exopeptidase proteolysis, different from effects of the incorporated sequence recognized by tobacco vein mottling virus protease at C-terminus. Using analyses of three fluorescent dyes including 8-anilino-1-naphthalenesulfonic acid, N-phenyl-1-naphthylamine, and thioflavin T, the same amounts of the cyclic protein displayed less fluorescence than those of the linear protein upon the heat treatment. The cyclic enzyme displayed the enhanced activity in Escherichia coli cells using the designed novel reporter. In this system, d-serine was added to the culture and transported into the cytoplasm. It was transformed by pre-overexpression of the diaminopropionate ammonia-lyase, and untransformed d-serine was oxidized by the coproduced human d-amino acid oxidase to generate hydrogen peroxide. This oxidant is monitored by the HyPer indicator. The current results presented that the cyclized enzyme could be applied as a better candidate to block the neurotoxin biosynthesis in certain plant species.


Assuntos
Amônia-Liases , Neurotoxinas , Salmonella typhimurium , Humanos , Ciclização , Escherichia coli/genética , Serina
8.
Mov Disord ; 39(1): 152-163, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38014483

RESUMO

BACKGROUND: Hereditary spastic paraplegias (HSP) are neurologic disorders characterized by progressive lower-extremity spasticity. Despite the identification of several HSP-related genes, many patients lack a genetic diagnosis. OBJECTIVES: The aims were to confirm the pathogenic role of biallelic COQ4 mutations in HSP and elucidate the clinical, genetic, and functional molecular features of COQ4-associated HSP. METHODS: Whole exome sequences of 310 index patients with HSP of unknown cause from three distinct populations were analyzed to identify potential HSP causal genes. Clinical data obtained from patients harboring candidate causal mutations were examined. Functional characterization of COQ4 variants was performed using bioinformatic tools, single-cell RNA sequencing, biochemical assays in cell lines, primary fibroblasts, induced pluripotent stem cell-derived pyramidal neurons, and zebrafish. RESULTS: Compound heterozygous variants in COQ4, which cosegregated with HSP in pedigrees, were identified in 7 patients from six unrelated families. Patients from four of the six families presented with pure HSP, whereas probands of the other two families exhibited complicated HSP with epilepsy or with cerebellar ataxia. In patient-derived fibroblasts and COQ4 knockout complementation lines, stable expression of these missense variants exerted loss-of-function effects, including mitochondrial reactive oxygen species accumulation, decreased mitochondrial membrane potential, and lower ubiquinone biosynthesis. Whereas differentiated pyramidal neurons expressed high COQ4 levels, coq4 knockdown zebrafish displayed severe motor dysfunction, reflecting motor neuron dysregulation. CONCLUSIONS: Our study confirms that loss-of-function, compound heterozygous, pathogenic COQ4 variants are causal for autosomal recessive pure and complicated HSP. Moreover, reduced COQ4 levels attributable to variants correspond with decreased ubiquinone biosynthesis, impaired mitochondrial function, and higher phenotypic disease severity. © 2023 International Parkinson and Movement Disorder Society.


Assuntos
Paraplegia Espástica Hereditária , Peixe-Zebra , Animais , Humanos , Ubiquinona/genética , Paraplegia Espástica Hereditária/genética , Mutação/genética , Mutação de Sentido Incorreto , Proteínas Mitocondriais/genética
9.
J Genet Genomics ; 51(2): 184-196, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38159879

RESUMO

CGG repeat expansions in LOC642361/NUTM2B-AS1 have recently been identified as a cause of oculopharyngeal myopathy with leukoencephalopathy. However, since only three patients from a single family were reported, it remains unknown whether their clinicopathological features are typical for CGG repeat expansions in LOC642361/NUTM2B-AS1. Here, using repeat-primed-polymerase chain reaction and long-read sequencing, we identify 12 individuals from 3 unrelated families with CGG repeat expansions in LOC642361/NUTM2B-AS1, typically presenting with oculopharyngodistal myopathy. The CGG repeat expansions range from 161 to 669 repeat units. Most of the patients present with ptosis, restricted eye movements, dysphagia, dysarthria, and diffuse limb muscle weakness. Only one patient shows T2-weighted hyperintensity in the cerebellar white matter surrounding the deep cerebellar nuclei on brain magnetic resonance imaging. Muscle biopsies from three patients show a myopathic pattern and rimmed vacuoles. Analyses of muscle biopsies suggest that CGG repeat expansions in LOC642361/NUTM2B-AS1 may deleteriously affect aggrephagic capacity, suggesting that RNA toxicity and mitochondrial dysfunction may contribute to pathogenesis. Our study thus expands the phenotypic spectrum for the CGG repeat expansion of LOC642361/NUTM2B-AS1 and indicates that this genetic variant typically manifests as oculopharyngodistal myopathy with chronic myopathic changes with rimmed vacuoles and filamentous intranuclear inclusions in muscle fibers.


Assuntos
Doenças Musculares , Distrofias Musculares , Humanos , Debilidade Muscular , Doenças Musculares/genética , Doenças Musculares/patologia , Distrofias Musculares/genética , Distrofias Musculares/patologia
11.
Stem Cell Res ; 74: 103268, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38100910

RESUMO

The human iPS cell line, hiPS-RTT (FJMUi002-A), is derived from peripheral blood mononuclear cells (PBMCs) from a 12-year-old female RTT patient carrying a heterozygous p. R133C (c.397C > T) mutation in the MeCP2 gene. The hiPS-RTT cell line was generated by non-integrative reprogramming vectors encoding OCT3/4, SOX2, KLF4, and c-MYC and was free of genomically integrated reprogramming genes. The hiPS-RTT cell line had a normal karyotype, expressed pluripotency markers, and had capacity to form three germ layers in vitro and in vivo, which offering a useful resource to study the pathogenesis and treatment strategies of RTT.


Assuntos
Células-Tronco Pluripotentes Induzidas , Síndrome de Rett , Criança , Feminino , Humanos , Diferenciação Celular , Linhagem Celular , Células-Tronco Pluripotentes Induzidas/metabolismo , Leucócitos Mononucleares , Mutação/genética , Síndrome de Rett/genética
12.
Cancer Cell Int ; 23(1): 319, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38087309

RESUMO

BACKGROUND: CD56 has been observed in malignant tumours exhibiting neuronal or neuroendocrine differentiation, such as breast cancer, small-cell lung cancer, and neuroblastoma. Abnormal glycosylation modifications are thought to play a role in regulating tumour cell proliferation, migration, and invasion. Nevertheless, the exact roles and molecular mechanisms of CD56 and polysialylated CD56 (PSA-CD56) in the development and progression of clear cell renal cell carcinoma (ccRCC) remain elusive. Here we unveil the biological significance of CD56 and PSA-CD56 in ccRCC. METHODS: In this study, we employed various techniques, including immunohistochemistry (IHC), RT-qPCR, and western blot, to examine the mRNA and protein expression levels in both human ccRCC tissue and cell lines. Lentivirus infection and CRISPR/Cas9 system were utilized to generate overexpression and knockout cell lines of CD56. Additionally, we conducted several functional assays, such as CCK-8, colony formation, cell scratch, and transwell assays to evaluate cell growth, proliferation, migration, and invasion. Furthermore, we established a xenograft tumor model to investigate the role of CD56 in ccRCC in vivo. To gain further insights into the molecular mechanisms associated with CD56, we employed the Hedgehog inhibitor JK184 and the ß-catenin inhibitor Prodigiosin. RESULTS: CD56 was significantly overexpressed in both human ccRCC tissues and renal cancer cell lines compared to adjacent normal tissues and normal renal epithelial cells. In vitro and in vivo experiments revealed that the knockout of CD56 inhibited the proliferation, migration, and invasion capabilities of ccRCC cells, whereas the overexpression of PSA-CD56 promoted these capacities. Finally, PSA-CD56 overexpression was found to activate both the Hedgehog and Wnt/ß-catenin signaling pathways. CONCLUSION: Our findings demonstrate that the oncogenic function of CD56 polysialylation plays a vital role in the tumorigenesis and progression of ccRCC, implying that targeting PSA-CD56 might be a feasible treatment target for ccRCC.

13.
J Am Chem Soc ; 145(51): 28264-28275, 2023 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-38092662

RESUMO

Conserved cysteine frameworks are essential components of disulfide-rich peptides (DRPs), which dominantly define the structural diversity of both naturally occurring and de novo-designed DRPs. However, there are only very limited numbers of conserved cysteine frameworks, and general methods enabling de novo discovery of cysteine frameworks with robust foldability are still not available. Here, we devised a "touchstone"-based strategy that relies on chasing oxidative foldability between two individual disulfide-rich folds on the phage surface to discover new cysteine frameworks from random sequences. Unique cysteine frameworks with a high degree of compatibility with phage display systems and broad sequence tolerance were successfully identified, which were subsequently exploited for the development of multicyclic DRP libraries, enabling the rapid discovery of new peptide ligands with low-nanomolar and picomolar binding affinity. This study provides an unprecedented method for exploring and exploiting the sequence and structure space of DRPs that is not readily accessible by existing strategies, holding the potential to revolutionize the study of DRPs and significantly advance the design and discovery of multicyclic peptide ligands and drugs.


Assuntos
Cisteína , Biblioteca de Peptídeos , Cisteína/química , Ligantes , Peptídeos/química , Dissulfetos/química
14.
Cytotherapy ; 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38054912

RESUMO

Allogeneic hemopoietic cell transplantation remains the goal of therapy for high-risk acute myeloid leukemia (AML). However, treatment failure in the form of leukemia relapse or severe graft-versus-host disease remains a critical area of unmet need. Recently, significant progress has been made in the cell therapy-based interventions both before and after transplant. In this review, the Stem Cell Engineering Committee of the International Society for Cell and Gene Therapy summarizes the literature regarding the identification of high risk in AML, treatment approaches before transplant, optimal transplant platforms and measures that may be taken after transplant to ideally prevent, or, if need be, treat AML relapse. Although some strategies remain in the early phases of clinical investigation, they are built on progress in pre-clinical research and cellular engineering techniques that are already improving outcomes for children and adults with high-risk malignancies.

15.
Molecules ; 28(22)2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-38005308

RESUMO

Aromatic ketones are important pharmaceutical intermediates, especially the pyridin-2-yl-methanone motifs. Thus, synthetic methods for these compounds have gained extensive attention in the last few years. Transition metals catalyze the oxidation of Csp3-H for the synthesis of aromatic ketones, which is arresting. Here, we describe an efficient copper-catalyzed synthesis of pyridin-2-yl-methanones from pyridin-2-yl-methanes through a direct Csp3-H oxidation approach with water under mild conditions. Pyridin-2-yl-methanes with aromatic rings, such as substituted benzene, thiophene, thiazole, pyridine, and triazine, undergo the reaction well to obtain the corresponding products in moderate to good yields. Several controlled experiments are operated for the mechanism exploration, indicating that water participates in the oxidation process, and it is the single oxygen source in this transformation. The current work provides new insights for water-involving oxidation reactions.

16.
Pharmaceuticals (Basel) ; 16(8)2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37631048

RESUMO

A new PES-C/emodin ultrafiltration membrane was prepared by blending natural emodin with phenolphthalein polyethersulfone (PES-C) and was used to purify an acanthopanax senticosus injection in this study. Regarding the purified acanthopanax senticosus injection, its color became lighter, and its clarity increased. On the contrary, for an acanthopanax senticosus injection containing macromolecules, its color deepened, and its turbidity increased. Thermal stability of the purified acanthopanax senticosus injection was the best, followed by the original solution of the acanthopanax senticosus injection, and the acanthopanax senticosus injection containing macromolecules was the worst. The fingerprint spectrum of the purified acanthopanax senticosus injection was similar to the original solution of the acanthopanax senticosus injection, the relative peak area of each single peak was greater than 0.95, and the relative peak area of the total peak was greater than 0.96. Compared with the original solution of the acanthopanax senticosus injection, the histamine release amount and cell degranulation rate of the acanthopanax senticosus injection containing macromolecules increased, while those of the purified acanthopanax senticosus injection decreased, which reduced the risk of allergic reaction to a certain extent. "Inverse proof" confirmed that the acanthopanax senticosus injection containing macromolecules had certain liver and kidney toxicity, which indirectly proved that the liver and kidney toxicity of the purified acanthopanax senticosus injection was effectively reduced.

17.
Theranostics ; 13(12): 4030-4041, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37554273

RESUMO

Rationale: Orbital inflammation is a prevalent and prolonged ocular disease that poses a significant challenge to clinicians. Glucocorticoid Dexamethasone sodium phosphate (Dex) has demonstrated efficacy in the clinical treatment of nonspecific orbital inflammation. However, frequent administration is required due to the short half-life of Dex, which may lead to drug waste and adverse side effects. Methods: In this study, we co-assembled Dex with a weak acid responsive hydrogelator Py-Phe-Phe-Lys-Lys-OH (K) to obtain a novel supramolecular hydrogel Dex/K that could release Dex in a slow manner to treat orbital inflammation. The therapeutic effect of Gel Dex/K on orbital inflammation was verified by in vitro and in vivo experiments. Results: In vitro experiments indicated that co-assembly of Dex with K significantly increased mechanic strength of the hydrogel, enabling a continuous release of 40% of total Dex within 7 days. In vivo experiments further demonstrated that sustained release of Dex from Gel Dex/K could effectively alleviate the infiltration of inflammatory cells and the release of inflammatory factors in the orbit of mice, improving symptoms such as increased intraocular pressure and proptosis. Additionally, Gel Dex/K mitigated the degree of tissue fibrosis and fatty infiltration by reducing the development of local inflammation in the orbit. Conclusions: Our research results indicate that Gel Dex/K could more efficiently achieve responsive drug release in orbit, providing an innovative method for treating orbital inflammation.


Assuntos
Dexametasona , Hidrogéis , Camundongos , Animais , Hidrogéis/farmacologia , Dexametasona/farmacologia , Inflamação/tratamento farmacológico , Olho , Glucocorticoides/farmacologia
18.
Materials (Basel) ; 16(14)2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37512405

RESUMO

Metallurgical slag and dust (MSD) are abundant Zn-containing secondary resources that can partially alleviate the shortage of zinc minerals, with hazardous characteristics and a high recycling value. In this work, the process conditions of recycling Zn from MSD materials leaching by ammonium acetate (NH3-CH3COONH4-H2O) were optimised using response surface methodology (RSM). The influences of liquid/solid ratio, stirring speed, leaching time, total ammonia concentration, and the interactions between these variables on the Zn effective extraction rate during the ammonium acetate leaching process were investigated. Additionally, the predicted regression equation between the Zn effective extraction rate and the four affecting factors was established, and the optimal process parameters were determined with a stirring speed of 345 r/min, leaching temperature of 25 °C, [NH3]/[NH4]+ of 1:1, total ammonia concentration of 4.8 mol/L, liquid/solid ratio of 4.3:1, and leaching time of 46 min. The Zn effective extraction rates predicted by the proposed model and the measured values were 85.25% and 84.67%, respectively, with a relative error of 0.58% between the two values, indicating the accuracy and reliability of the proposed model. XRD and SEM-EDS analysis results showed that Zn2SiO4, ZnS, and ZnFe2O4 were among the main factors affecting the low extraction rate of zinc from metallurgical slag dust. This work established a new technology prototype for the effective and clean extraction of zinc resources, which can provide new routes to effectively utilise Zn-containing MSD materials and lay a foundation for developing other novel techniques for recycling Zn from Zn-containing secondary resources.

20.
Science ; 380(6646): 727-730, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37200424

RESUMO

Breaking the trade-off between activity and selectivity has been a long-standing challenge in the field of catalysis. We demonstrate the importance of disentangling the target reaction from the secondary reactions for the case of direct syngas conversion to light olefins by incorporating germanium-substituted AlPO-18 within the framework of the metal oxide-zeolite (OXZEO) catalyst concept. The attenuated strength of the catalytically active Brønsted acid sites allows enhancing the targeted carbon-carbon coupling of ketene intermediates to form olefins by increasing the active site density while inhibiting secondary reactions that consume the olefins. Thus, a light-olefins selectivity of 83% among hydrocarbons and carbon monoxide conversion of 85% were obtained simultaneously, leading to an unprecedented light-olefins yield of 48% versus current reported light-olefins yields of ≤27%.

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