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1.
Biol Pharm Bull ; 46(2): 338-342, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36724962

RESUMO

Morphinone (MO) is an electrophilic metabolite of morphine that covalently binds to protein thiols via its α,ß-unsaturated carbonyl group, resulting in toxicity in vitro and in vivo. Our previous studies identified a variety of redox signaling pathways that are activated during electrophilic stress. Here, we examined in vitro activation of a signaling pathway involving Kelch-like ECH-associated protein 1 (Keap1) and nuclear factor erythroid 2-related factor 2 (Nrf2) in response to MO. Exposure of HepG2 cells to MO caused covalent modification of Keap1 thiols (evaluated using biotin-PEAC5-maleimide labeling) and nuclear translocation of Nrf2, thereby up-regulating downstream genes encoding ATP binding cassette subfamily C member 2, solute carrier family 7 member 11, glutamate-cysteine ligase catalytic subunit, glutamate-cysteine ligase modifier subunit, glutathione S-transferase alpha 1, and heme oxygenase 1. However, dihydromorphinone, a metabolite of morphine lacking the reactive C7-C8 double bond, had little effect on Nrf2 activation. These results suggest that covalent modification is crucial in the Keap1/Nrf2 pathway activation and that this pathway is a redox signaling-associated adaptive response to MO metabolism.


Assuntos
Glutamato-Cisteína Ligase , Fator 2 Relacionado a NF-E2 , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Glutamato-Cisteína Ligase/genética , Glutamato-Cisteína Ligase/metabolismo , Morfina/farmacologia , Compostos de Sulfidrila
2.
Artigo em Inglês | MEDLINE | ID: mdl-36673825

RESUMO

Although the molecular mechanisms underlying methylmercury toxicity are not entirely understood, the observed neurotoxicity in early-life is attributed to the covalent binding of methylmercury to sulfhydryl (thiol) groups of proteins and other molecules being able to affect protein post-translational modifications from numerous molecular pathways, such as glutamate signaling, heat-shock chaperones and the antioxidant glutaredoxin/glutathione system. However, for other organomercurials such as ethylmercury or thimerosal, there is not much information available. Therefore, this review critically discusses current knowledge about organomercurials neurotoxicity-both methylmercury and ethylmercury-following intrauterine and childhood exposure, as well as the prospects and future needs for research in this area. Contrasting with the amount of epidemiological evidence available for methylmercury, there are only a few in vivo studies reporting neurotoxic outcomes and mechanisms of toxicity for ethylmercury or thimerosal. There is also a lack of studies on mechanistic approaches to better investigate the pathways involved in the potential neurotoxicity caused by both organomercurials. More impactful follow-up studies, especially following intrauterine and childhood exposure to ethylmercury, are necessary. Childhood vaccination is critically important for controlling infectious diseases; however, the safety of mercury-containing thimerosal and, notably, its effectiveness as preservative in vaccines are still under debate regarding its potential dose-response effects to the central nervous system.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Síndromes Neurotóxicas , Vacinas , Humanos , Timerosal/toxicidade , Compostos de Metilmercúrio/toxicidade , Conservantes Farmacêuticos , Síndromes Neurotóxicas/etiologia , Compostos de Sulfidrila
3.
Pediatr Surg Int ; 39(1): 75, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36617603

RESUMO

PURPOSE: This study aimed to examine the diagnostic value of IL-6, thiol-disulfide homeostasis, complete blood count and inflammatory biomarkers in the prediction of acute appendicitis in children. METHODS: The study was designed as a prospective and controlled study in children-the study was conducted at a tertiary referential university hospital between May 2020 and April 2021. Patients were divided between study groups and one control group (CG): 1: confirmed acute appendicitis group (AAP); 2: perforated appendicitis group (PAP); and 3: non-specified abdominal pain (NAP). The age and gender of the patients were determined. The following listed laboratory parameters were compared between groups: TOS: total oxidative status, TAS: total antioxidant status, OSI: oxidative stress index, TT: total thiol, NT (µmol/L): native thiol, DIS: disulfide, IL-6: interleukin 6, TNF-a: tumor necrosis factor-alpha, WBC: white blood cell, NEU: neutrophil, NEU%: neutrophil percentage, LY: lymphocyte, LY%: lymphocyte percentage, PLT: platelet, MPV: mean platelet volume NLR: neutrophil lymphocyte ratio, CRP: C-reactive protein, LCR: lymphocyte CRP ratio, and serum lactate. RESULTS: The TOS level of the PAP group was found to be significantly higher than that in the AAP, NAP and control groups (p = 0.006, < 0.001 and p < 0.001). TAS, TT, and NT levels in the PAP group were significantly lower than those in the AAP, NAP and control groups. OSI was significantly higher in the PAP group than in the other groups. The TT and NT levels of the NAP group were both similar to those of the control group. Serum DIS level was similar between the AAP and PAP groups, AAP and NAP groups, and NAP and control groups. Serum IL-6 and TNF-α levels were found to be significantly higher in the PAP group compared to those in all groups. The WBC, NEU, and NEU% values were found to be significantly higher in the PAP group than those in the NAP and control groups, while LY and LY% values were found to be significantly lower. PAP and AAP groups were found to be similar in terms of WBC, NEU, LYM, NEU%, and LYM% values. PLT and MPV values and serum lactate values did not show a significant difference between the groups. NLR was similar in the AAP and PAP groups. A significant increase in CRP versus a decrease in LCR was detected in the PAP group compared to that in the AAP group. Multivariate analysis demonstrated that only IL-6 has significant estimated accuracy rates as 80% for the control group, 78.8% for AAP, 96.9% for PAP, and 81.6% for NAP. CONCLUSION: Rather than AAP, PAP caused significantly higher oxidative stress (increased TOS and OSI), and lower antioxidation capacity (decreased TT and NT). IL-6 levels can provide a significant stratification. Nevertheless, simply detecting WBC or CRP is not enough to distinguish the specific pathology in acute appendicitis and related conditions.


Assuntos
Apendicite , Interleucina-6 , Humanos , Criança , Apendicite/diagnóstico , Dissulfetos , Compostos de Sulfidrila , Estudos Prospectivos , Biomarcadores , Antioxidantes , Homeostase , Lactatos
4.
Ital J Pediatr ; 49(1): 3, 2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36611205

RESUMO

BACKGROUND: Vitamin B12 is an important vitamin for metabolism and affects many mechanisms in the body including neuronal migration, DNA synthesis, neurotransmitter synthesis, brain and cognitive development. Increased oxidative stress in the body leads to the damage of the child development, but also plays a crucial role in the pathogenesis of many diseases encountered in the childhood period. Our aim is to investigate whether or not B12 deficiency is associated with dynamic thiol/disulfide homeostasis in adolescent patients. METHODS: This is a case-controlled observational study consisting of 45 adolescent patients with vitamin b12 deficiency and a control group consisting of 45 healthy adolescent. Patients between 11 and 18 ages who applied to the outpatient clinic for the first time with one of the complaints of headache were selected due to their decreased school performance, dizziness, and fatigue. Hemogram, vitamin B12, homocysteine levels and oxidative stress parameters such as native and total thiol disulfide levels and ratios of disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol were measured from the patients. RESULTS: Vitamin B12 level was found to be significantly lower in vitamin B12 deficiency group (p < 0.001). The serum disulfide level was found to be 27.5 ± 8.38 in the case group and 20.5 ± 8.36 in the control group (p < 0.001). In the multiple linear regression analysis, it was determined that the independent variables of native thiol, homocysteine and disulfide levels effected of vitamin B12 levels (p < 0.001, p < 0.001, p < 0.005 respectively; R2 = 0.62). CONCLUSION: The results obtained in terms of the effect of vitamin B12 deficiency on oxidative stress in adolescents are remarkable. The increase in oxidative stress parameters in the patient group may also suggest that oxidative stress plays a vital role in vitamin B12 deficiency in adolescence.


Assuntos
Dissulfetos , Deficiência de Vitamina B 12 , Criança , Humanos , Adolescente , Compostos de Sulfidrila , Vitaminas , Deficiência de Vitamina B 12/diagnóstico , Vitamina B 12 , Estresse Oxidativo/fisiologia
5.
Acta Neuropathol Commun ; 11(1): 19, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36691076

RESUMO

We recently discovered that the expression of PRKN, a young-onset Parkinson disease-linked gene, confers redox homeostasis. To further examine the protective effects of parkin in an oxidative stress model, we first combined the loss of prkn with Sod2 haploinsufficiency in mice. Although adult prkn-/-//Sod2± animals did not develop dopamine cell loss in the S. nigra, they had more reactive oxidative species and a higher concentration of carbonylated proteins in the brain; bi-genic mice also showed a trend for more nitrotyrosinated proteins. Because these redox changes were seen in the cytosol rather than mitochondria, we next explored the thiol network in the context of PRKN expression. We detected a parkin deficiency-associated increase in the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) in murine brain, PRKN-linked human cortex and several cell models. This shift resulted from enhanced recycling of GSSG back to GSH via upregulated glutathione reductase activity; it also correlated with altered activities of redox-sensitive enzymes in mitochondria isolated from mouse brain (e.g., aconitase-2; creatine kinase). Intriguingly, human parkin itself showed glutathione-recycling activity in vitro and in cells: For each GSSG dipeptide encountered, parkin regenerated one GSH molecule and was S-glutathionylated by the other (GSSG + P-SH [Formula: see text] GSH + P-S-SG), including at cysteines 59, 95 and 377. Moreover, parkin's S-glutathionylation was reversible by glutaredoxin activity. In summary, we found that PRKN gene expression contributes to the network of available thiols in the cell, including by parkin's participation in glutathione recycling, which involves a reversible, posttranslational modification at select cysteines. Further, parkin's impact on redox homeostasis in the cytosol can affect enzyme activities elsewhere, such as in mitochondria. We posit that antioxidant functions of parkin may explain many of its previously described, protective effects in vertebrates and invertebrates that are unrelated to E3 ligase activity.


Assuntos
Glutationa , Proteínas , Adulto , Camundongos , Humanos , Animais , Dissulfeto de Glutationa/metabolismo , Glutationa/metabolismo , Proteínas/metabolismo , Oxirredução , Estresse Oxidativo , Ubiquitina-Proteína Ligases/genética , Antioxidantes , Cisteína/metabolismo , Encéfalo/metabolismo , Compostos de Sulfidrila/química , Compostos de Sulfidrila/metabolismo , Mamíferos/metabolismo
6.
J Chromatogr A ; 1689: 463774, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36630850

RESUMO

A hydrophilic adsorbent (Cys@poly(AMA)@MAR) was successfully prepared for the enrichment of N-glycopeptides via surface-initiated atom transfer radical polymerization (SI-ATRP) and photo-initiated "thiol-ene" reaction using monodisperse macroporous adsorbent resin (MAR) as adsorption matrix. Due to the presence of electron-deficient acrylic groups and electron-rich vinyl groups in allyl methacrylate (AMA), both of them can participate in free radical reaction. Therefore, the polymerization time of SI-ATRP was optimized. The resulting poly(AMA)@MAR was modified with l-cysteine (L-Cys) via photo-initiated "thiol-ene" reaction, and the amount of vinyl retained was determined by measuring the adsorption of Cu2+. The Cys@poly(AMA)@MAR pendant brushes with high density of amine and carboxyl groups could capture N-glycopeptides from IgG digest and human serum digest by hydrophilic interaction. The 22 N-glycopeptides were identified from IgG digest and the limit of detection reached 10 fmol. The 319 N-glycosylation sites and 583 N-glycopeptides were identified from 2 µL human serum digest and mapped to 147 glycoproteins. It demonstrates great potential and commercialization prospects for the enrichment of N-glycopeptides.


Assuntos
Glicopeptídeos , Compostos de Sulfidrila , Humanos , Polimerização , Química Click/métodos , Adsorção , Cisteína , Imunoglobulina G , Interações Hidrofóbicas e Hidrofílicas
7.
J Chromatogr A ; 1690: 463777, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36640681

RESUMO

Efficient magnetic solid phase extraction using covalent organic frameworks (COFs) can find important applications in food safety. In this work, a sulfonate-functionalized magnetic COF (Fe3O4@COF-SO3Na) was synthesized by self-polycondensation of two-in-one monomer 1,6-bis(4-formylphenyl)-3,8-bis((4-aminophenyl) ethynyl)) pyrene (BFBAEPy) on the surface of aminated Fe3O4 and a thiol-yne click reaction. It was further adopted as an adsorbent for the efficient magnetic solid-phase extraction (MSPE) of basic orange II. The selective adsorption experiment indicated that it displayed selective adsorption ability to basic orange II due to the ion exchange, hydrogen bonds, and π-π interactions. Under the optimized conditions, the proposed MSPE method coupled with HPLC-DAD showed excellent linearity in the range of 0.05-0.5 µg/mL (R2 = 0.9997) for basic orange II. The lower limits of detection (LODs) for basic orange II were 1.0-1.4 µg/L for three food samples: yellow croaker, paprika and dried bean curd. The recoveries were 90.1-98.8% with relative standard deviations (RSDs) below 4.2%. Therefore, this work provides an effective strategy to modify magnetic COFs as absorbents in MSPE. Due to the tunability of functional groups in thiol­yne click reactions, the functional groups of magnetic COFs can be readily designed to enrich their multifunctional applications. Meanwhile, this work proposed a new method to detect trace amounts of basic orange II in food samples.


Assuntos
Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Adsorção , Fenômenos Magnéticos , Extração em Fase Sólida/métodos , Compostos de Sulfidrila , Limite de Detecção , Cromatografia Líquida de Alta Pressão
8.
J Chem Inf Model ; 63(2): 493-506, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36632804

RESUMO

Both reversible noncovalent inhibitors and irreversible covalent inhibitors targeting tyrosine kinases have their disadvantages. The reversible covalent inhibitors with electrophilic group cyanoacrylamide as warheads reacting with cysteine residues could solve the dilemmas. However, there are still several unresolved issues regarding the electrophilic groups. In this manuscript, a series of EGFR inhibitors with double electron-withdrawing substituents introduced into the Cα position on the olefin bond were designed and synthesized. The binding structures and characteristics of inhibitors with the kinase in both the first noncovalent binding phase and the second covalent binding step were explored and combined with molecular docking and molecular dynamics simulations. Then, the reverse ß-elimination reactions of the thiol-Michael adducts were investigated by applying density functional theory calculations. In addition, the effects of different electrophilic substituents of Cα on the binding between the inhibitors and kinase were elucidated. The results suggested that the electrophilicity and size of the electron-withdrawing groups play an important role in the specific interactions during the reaction. The compounds with the electron-withdrawing groups that had medium electrostatic and steric complementarity to the kinase active site could cooperatively stabilize the complexes and showed relatively good potent activities in the kinase assay experiment. The mechanical and structural information in this study could enhance our understanding of the functioning of the electron-withdrawing groups in the covalent inhibitors. The results might help to design efficient cysteine targeting inhibitors in the future.


Assuntos
Cisteína , Compostos de Sulfidrila , Cisteína/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Inibidores de Proteínas Quinases/química
9.
Food Res Int ; 163: 112220, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36596149

RESUMO

pH-responsive in situ gelling properties of thiolated citrus high-methoxyl pectin (TCHMP) were investigated in this study. The gelation capacity results revealed that the in situ gelation behavior of TCHMP only occurred when the pH value was higher than 6.25. The gel strength increased from 26.63 g to 42.77 g as the pH value increased from 7.4 to 8.9. Rheological measurements confirmed that the apparent viscosity and viscoelasticity of TCHMP were highly dependent on pH value and dialysis time. Compared with the control group, the apparent viscosity of TCHMP dialyzed in phosphate-buffered saline (PBS) of pH 8.9 for 180 min increased 695-fold. During the dialysis process of TCHMP at different pH values (7.4-8.9), the final thiol groups content decreased and the final disulfide bonds content increased with the increase in pH value. This illustrates that the mechanism of in situ gelation is mainly the oxidation of thiol-thiol groups to form disulfide bonds. These results can put forward new insights into the pH-responsive in situ gelling properties of TCHMP and provide a theoretical basis for the application of TCHMP in neutral and alkaline gel systems.


Assuntos
Citrus , Compostos de Sulfidrila , Concentração de Íons de Hidrogênio , Géis/química , Compostos de Sulfidrila/química , Pectinas/química , Dissulfetos/química
10.
Environ Sci Technol ; 57(4): 1680-1691, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36642941

RESUMO

Precise and reliable onsite detection of methyl mercaptan (CH3SH) is of great significance for environmental surveillance. Here, we synthesized a novel blue fluorescence nanozyme CeO2@TPE with high peroxidase-like activity by employing aggregation-induced emission (AIE) tetraphenylethene (TPE) to embed into hollow CeO2 nanospheres. In the presence of ethanol oxidase (AOX) and o-phenylenediamine (OPD), we engineered an enzymatic cascade activation ratiometric fluorescence-colorimetric dual-mode system AOX/CeO2@TPE + OPD toward CH3SH. In this design, CH3SH initiated AOX catalytic activity to convert it into H2O2 for activating the peroxidase-like activity of CeO2@TPE, producing •OH for oxidizing the naked-eye colorless OPD into deep yellow 2,3-diaminophenazine (DAP) with an absorption enhancement at ∼425 nm, companied by a new emission peak at ∼550 nm to match with the intrinsic emission at ∼441 nm for observing ratiometric fluorescence response, enabling a ratiometric fluorescence-colorimetric dual-mode analysis. Interestingly, both the ratiometric fluorescence and colorimetric signals could be gathered for being converted into the hue parameter on a smartphone-based sensor, achieving the onsite visual fluorescence-colorimetric dual-mode detection of CH3SH in real environmental media with acceptable results. This study gave a novel insight into designing target-responsive enzymatic cascade activation system-based efficient and reliable dual-mode point-of-care sensors for safeguarding environmental health.


Assuntos
Colorimetria , Smartphone , Colorimetria/métodos , Peróxido de Hidrogênio , Peroxidases , Compostos de Sulfidrila , Limite de Detecção
11.
Anal Chim Acta ; 1240: 340776, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36641156

RESUMO

Histamine is a significant biomarker to assess the freshness of fish products. In this study, a novel MOF-based SERS sensor for histamine determination was synthesized by wrapping PVP-capped Au nanoflowers with a ZIF-67 shell (Au NFs@ZIF-67). The highly branched Au NFs core exhibited a strong electromagnetic field enhancement effect and provided an ultra-sensitive SERS fingerprint spectrum, while ZIF-67 shell was the contributor to enrich the target and stabilize the substrate. The morphology of the core-shell structures can be easily controlled by the concentrations of the capping agent PVP and MOF precursor Co ion. Consequently, 4-MBA pre-grafted on the optimized SERS substrate can act as the Raman internal standard (IS) to eliminate signal fluctuations through standardizing all spectra against its peak at 1074 cm-1. Moreover, as the specific receptor for histamine molecules, 4-MBA helped reach the low detection sensitivity, where the SERS intensity ratio, I1172/I1074 presented a good linear relationship towards the histamine concentrations (10-3-10-7 M) with the LOD of 0.87 × 10-7 M (R2 = 0.9930). Furthermore, the application in monitoring fish spoilage process demonstrated the feasibility and reliability of the developed sensor. This work provided a facile strategy to construct MOF-based SERS substrate as a potential platform for the shelf-life prediction of fish products.


Assuntos
Nanopartículas Metálicas , Nanocompostos , Animais , Histamina , Reprodutibilidade dos Testes , Compostos de Sulfidrila/química , Peixes , Análise Espectral Raman , Ouro/química , Nanopartículas Metálicas/química
12.
ACS Macro Lett ; 12(1): 79-85, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36595222

RESUMO

The synthesis of poly(N-allyl acrylamide) (PNAllAm) as a platform for the preparation of functional hydrogels is described. The PNAllAm was synthesized via organocatalyzed amidation of poly(methyl acrylate) (PMA) with allylamine and characterized by 1H NMR spectroscopy, size exclusion chromatography (SEC), and turbidimetry, which allowed an estimation of the lower critical solution temperature of ∼26 °C in water. The PNAllAm was then used to make functional hydrogels via photoinitiated thiol-ene chemistry, where dithiothreitol (DTT) was used to cross-link the polymer chains. In addition, mercaptoethanol (ME) was added as a functional thiol to modulate the hydrogel properties. A decrease of the volume-phase transition temperature of the resulting hydrogels was observed with increasing ME content. Altogether this work introduces a straightforward way for the preparation of PNAllAm from PMA and demonstrates its value as a reactive polymer platform for the generation of functional hydrogels.


Assuntos
Acrilamida , Hidrogéis , Polímeros/química , Temperatura , Compostos de Sulfidrila
13.
ACS Macro Lett ; 12(1): 107-112, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36603198

RESUMO

Polyolefins compose the majority of plastic waste, but conventional mechanical recycling degrades their properties, thereby reducing their value. We report the functionalization of a model for dehydrogenated polyethylene, polycyclooctene (PCOE), with thiol-ene click chemistry to install pendant hydroxyl ethyl thioethers. Functionalization of PCOE using mercaptoethanol via thiol-ene click chemistry yielded functionalization between 1.4 and 22.9% based on ethylene monomeric units. Reactions were well-controlled by varying the reagent stoichiometry and reaction time. Crystallinity and melting temperature decreased, and glass transition temperature increased with greater functionalization. Contact angle measurements reveal an increase in surface polarity with functionalization. Comparisons with poly(ethylene-co-vinyl alcohol) (EVOH) show comparable surface polarity at similar levels of alcohol functionalization. At 12% functionalization, the ultimate shear stress (USS) of functionalized PCOE in an adhesive configuration is 4.10 ± 0.48 MPa, comparable to EVOH. At >12% functionalization, the failure mode changed from adhesive to mixed adhesive-cohesive, and the USS decreased.


Assuntos
Química Click , Compostos de Sulfidrila , Compostos de Sulfidrila/química
14.
Se Pu ; 41(1): 1-13, 2023 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-36633072

RESUMO

Since Nobel Laureate K. B. Sharpless first introduced the concept of click chemistry in 2001, such reactions have become a powerful modular synthesis tool. Click chemistry reactions have rapidly expanded into many scientific fields, such as materials and life science, owing to their distinct advantages, which include mild conditions, fast reaction rates, high yields, low by-product generation, and simple separation and purification procedures. Nowadays, click chemistry reactions have become an essential means of designing and preparing separation materials; thus, interest in this synthetic technique has quickly grown. Here, the development of click chemistry and its unique advantages are briefly described firstly. The reports on click chemistry-based chromatographic separation materials published in the past five years are then systematically reviewed, focusing on two major separation fields: column chromatography and membrane chromatography. Meanwhile, recent advances in the separation materials obtained from three common types of click reactions, namely, azido-alkyne, thiol-alkene, and thiol-alkyne, are summarized. Finally, an outlook on the future of click chemistry is provided in developing efficient chromatographic separation materials.


Assuntos
Cromatografia , Química Click , Química Click/métodos , Alcinos/química , Compostos de Sulfidrila/química
15.
ACS Appl Mater Interfaces ; 15(2): 2737-2746, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36608274

RESUMO

Digital light processing (DLP) bioprinting is an emerging technology for three-dimensional bioprinting (3DBP) owing to its high printing fidelity, fast fabrication speed, and higher printing resolution. Low-viscosity bioinks such as poly(ethylene glycol) diacrylate (PEGDA) are commonly used for DLP-based bioprinting. However, the cross-linking of PEGDA proceeds via chain-growth photopolymerization that displays significant heterogeneity in cross-linking density. In contrast, step-growth thiol-norbornene photopolymerization is not oxygen inhibited and produces hydrogels with an ideal network structure. The high cytocompatibility and rapid gelation of thiol-norbornene photopolymerization have lent itself to the cross-linking of cell-laden hydrogels but have not been extensively used for DLP bioprinting. In this study, we explored eight-arm PEG-norbornene (PEG8NB) as a bioink/resin for visible light-initiated DLP-based 3DBP. The PEG8NB-based DLP resin showed high printing fidelity and cytocompatibility even without the use of any bioactive motifs and high initial stiffness. In addition, we demonstrated the versatility of the PEGNB resin by printing solid structures as cell culture devices, hollow channels for endothelialization, and microwells for generating cell spheroids. This work not only expands the selection of bioinks for DLP-based 3DBP but also provides a platform for dynamic modification of the bioprinted constructs.


Assuntos
Bioimpressão , Engenharia Tecidual , Engenharia Tecidual/métodos , Bioimpressão/métodos , Compostos de Sulfidrila/química , Norbornanos/química , Polietilenoglicóis/química , Impressão Tridimensional , Hidrogéis/química , Tecidos Suporte/química
16.
J Am Chem Soc ; 145(2): 1053-1061, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36602440

RESUMO

Peptides are steadily gaining importance as pharmaceutical targets, and efficient, green methods for their preparation are critically needed. A key deficiency in the synthetic toolbox is the lack of an industrially viable peptide desulfurization method. Without this tool, the powerful native chemical ligation reaction typically used to assemble polypeptides and proteins remains out of reach for industrial preparation of drug targets. Current desulfurization methods require very large excesses of phosphine reagents and thiol additives or low-abundance metal catalysts. Here, we report a phosphine-only photodesulfurization (POP) using near-UV light that is clean, high-yielding, and requires as little as 1.2 equiv phosphine. The user-friendly reaction gives complete control to the chemist, allowing solvent and reagent selection based on starting material and phosphine solubility. It can be conducted in a range of solvents, including water or buffers, on protected or unprotected peptides, in low or high dilution and on gram scale. Oxidation-prone amino acids, π-bonds, aromatic rings, thio-aminal linkages, thioesters, and glycans are all stable to the POP reaction. We highlight the utility of this approach for desulfurization of industrially relevant targets including cyclic peptides and glucagon-like peptide 1 (GLP-1(7-36)). The method is also compatible with NCL buffer, and we highlight the robustness of the approach through the one-pot disulfide reduction/multidesulfurization of linaclotide, aprotinin, and wheat protein.


Assuntos
Compostos de Sulfidrila , Raios Ultravioleta , Compostos de Sulfidrila/química , Peptídeos/química , Proteínas
17.
Biomacromolecules ; 24(1): 413-425, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36516973

RESUMO

Numerous chemical modifications of hyaluronic acid (HA) have been explored for the formation of degradable hydrogels that are suitable for a variety of biomedical applications, including biofabrication and drug delivery. Thiol-ene step-growth chemistry is of particular interest due to its lower oxygen sensitivity and ability to precisely tune mechanical properties. Here, we utilize an aqueous esterification route via reaction with carbic anhydride to synthesize norbornene-modified HA (NorHACA) that is amenable to thiol-ene crosslinking to form hydrolytically unstable networks. NorHACA is first synthesized with varying degrees of modification (∼15-100%) by adjusting the ratio of reactive carbic anhydride to HA. Thereafter, NorHACA is reacted with dithiol crosslinker in the presence of visible light and photoinitiator to form hydrogels within tens of seconds. Unlike conventional NorHA, NorHACA hydrogels are highly susceptible to hydrolytic degradation through enhanced ester hydrolysis. Both the mechanical properties and the degradation timescales of NorHACA hydrogels are tuned via macromer concentration and/or the degree of modification. Moreover, the degradation behavior of NorHACA hydrogels is validated through a statistical-co-kinetic model of ester hydrolysis. The rapid degradation of NorHACA hydrogels can be adjusted by incorporating small amounts of slowly degrading NorHA macromer into the network. Further, NorHACA hydrogels are implemented as digital light processing (DLP) resins to fabricate hydrolytically degradable scaffolds with complex, macroporous structures that can incorporate cell-adhesive sites for cell attachment and proliferation after fabrication. Additionally, DLP bioprinting of NorHACA hydrogels to form cell-laden constructs with high viability is demonstrated, making them useful for applications in tissue engineering and regenerative medicine.


Assuntos
Ácido Hialurônico , Hidrogéis , Hidrogéis/química , Ácido Hialurônico/química , Polietilenoglicóis/química , Engenharia Tecidual , Ésteres/química , Compostos de Sulfidrila/química
18.
J Chromatogr A ; 1688: 463728, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36566571

RESUMO

Fabricating functional electrospun nanofiber coating for highly selective extraction of microcystin-LR (MC-LR) was of significant importance for water-safety monitoring. Herein, a novel MOF@aptamer functionalized nanofabric was presented via a facile and reliable strategy integrating polydopamine (PDA) mediation and thiol-ene chemistry and applied for specific recognition of the MC-LR model analyte. Using polydopamine (PDA) as the mediating layer, vinyl-UiO-66 MOF was grown in situ, followed by post-synthetic modification (PSM) of Zr4+ with vinyl phosphate and rapid UV-initiated click reaction of aptamers. Uniform deposition of Zr-based MOF (vinyl-UiO-66) on the nanofibers was directly produced, and the tedious co-electrospinning process was abandoned to prevent the aggregation and encapsulation of MOF. Via an efficient "thiol-ene" chemistry, massive thiol-terminated aptamers were grafted on MOF within one step under friendly conditions, rather than the time-consuming nanoparticle adsorption or unfriendly covalent chemical reactions. As a result, the robust MOF@aptamer-coated nano-fabrics were obtained, and a highly selective performance towards MC-LR was illustrated with a limit of detection (LOD) at 0.002 ng/mL, good precision (CV<8.3%), good repeatability (2.2∼6.0%) when coupled with LC-MS. Almost 1∼2 orders of magnitude higher detection sensitivity was exhibited than that of the common non-specific SPE/SPME fiber reported so far. Applied to water samples, the good matrix-resistance ability, and acceptable recovery yields were achieved with high specificity. This strategy might provide a rapid and friendly protocol to efficiently fabricate MOF@aptamer functionalized nano-fabrics through electrospinning and interfacial "thiol-ene" chemistry for highly-selective microextraction.


Assuntos
Aptâmeros de Nucleotídeos , Estruturas Metalorgânicas , Compostos Organometálicos , Arginina , Leucina , Água , Compostos de Sulfidrila
19.
Synapse ; 77(1): e22256, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36200789

RESUMO

The basolateral amygdala (BLA), which is sensitive to stress, is necessary for reward-seeking behavior and addiction. Regular exercise can produce various positive effects by affecting the BLA. Therefore, we aimed to investigate the effects of chronic stress and treadmill running (TR) on anxiety-like behavior, neuronal activity, lipid peroxidation (measured by malondialdehyde (MDA) levels, a marker for oxidative stress), and total thiol in BLA, in morphine-treated rats. Male Wistar rats were restricted in restraint stress and/or ran on the treadmill and treated with morphine (5 mg/kg) for 21 days. Anxiety-like behavior was evaluated using an elevated plus maze (EPM) and open field tests (OFTs), on day 22. On day 23, neuronal activity in BLA was assessed via single-unit recording. Finally, MDA and total thiol were assessed in BLA. Our results showed that chronic administration of morphine (5 mg/kg) did not affect anxiety-like behavior. However, the morphine-treated rats, subjected to chronic stress and exercise, showed fewer anxiety-like behaviors. Morphine increased BLA's MDA levels but it was prevented by TR. Glutamatergic and GABAergic basal neuronal activities were low in morphine-treated rats but after acute morphine application, there was a significant decrease in GABAergic neuronal activities in the morphine-exercise-stress (Mor-Exe-St) group. The results of this study showed that in morphine-treated rats, stress and exercise or their combination could have either co-directional or opposite effects to the chronic effects of morphine. These results indicate the existence of common pathways similar to endogenous opioids.


Assuntos
Complexo Nuclear Basolateral da Amígdala , Ratos , Masculino , Animais , Complexo Nuclear Basolateral da Amígdala/metabolismo , Morfina/farmacologia , Ratos Wistar , Ansiedade , Estresse Oxidativo , Compostos de Sulfidrila/metabolismo , Compostos de Sulfidrila/farmacologia
20.
Int J Pharm ; 631: 122496, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36529356

RESUMO

Epidemiological research has found that between 5 and 12 percent of the population suffers from chronic rhinosinusitis. Patients are dealing with local side effects such as nasal dryness, sporadic sneezing, and nasal pain in addition to the inflammation. The aim of this study was to synthesize a polymer based on hyaluronic acid in order to provide lubrication combined with a ligand leading to a covalent binding on the nasal mucosa. Hyaluronic acid (HA) was modified with L-cysteine ethyl ester hydrochloride (CYS) via amid bond formation. Ellman's assay, together with spectroscopic techniques like IR and 1H NMR, confirmed that HACys had been successfully synthesized. It was demonstrated that HACys is safe for administration on the nasal mucosa. The mucoadhesive potential was determined by 3.26-fold with the rotating cylinder assay and 1.4-fold in terms of bioadhesive examination, respectively. Further, the stability of the modified polymer was improved by 7.6-fold compared to the unmodified polymer. Spraying the formulation on the nasal mucosa, the residence time of a model drug was 1.74-fold prolonged at the site of action compared to unmodified polymer. In light of these findings, modified hyaluronic acid (HACys) displayed compelling properties such as lubricity, targeted application, long-lasting effect, and safety and therefore could be an excellent candidate for nasal application.


Assuntos
Sistemas de Liberação de Medicamentos , Ácido Hialurônico , Humanos , Sistemas de Liberação de Medicamentos/métodos , Ácido Hialurônico/química , Polímeros/química , Células CACO-2 , Mucosa Nasal , Compostos de Sulfidrila/química
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