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Lactate dehydrogenase B (LDHB) reversibly catalyzes the conversion of pyruvate to lactate or lactate to pyruvate and expressed in various malignancies. However, the role of LDHB in modulating immune responses against hepatocellular carcinoma (HCC) remains largely unknown. Here, we found that down-regulation of lactate dehydrogenase B (LDHB) was coupled with the promoter hypermethylation and knocking down the DNA methyltransferase 3A (DNMT 3A) restored LDHB expression levels in HCC cell lines. Bioinformatics analysis of the HCC cohort from The Cancer Genome Atlas revealed a significant positive correlation between LDHB expression and immune regulatory signaling pathways and immune cell infiltrations. Moreover, immune checkpoint inhibitors (ICIs) have shown considerable promise for HCC treatment and patients with higher LDHB expression responded better to ICIs. Finally, we found that overexpression of LDHB suppressed HCC growth in immunocompetent but not in immunodeficient mice, suggesting that the host immune system was involved in the LDHB-medicated tumor suppression. Our findings indicate that DNMT3A-mediated epigenetic silencing of LDHB may contribute to HCC progression through remodeling the tumor immune microenvironment, and LDHB may become a potential prognostic biomarker and therapeutic target for HCC immunotherapy.
Assuntos
Carcinoma Hepatocelular , DNA Metiltransferase 3A , Epigênese Genética , L-Lactato Desidrogenase , Neoplasias Hepáticas , Microambiente Tumoral , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/metabolismo , Microambiente Tumoral/imunologia , Humanos , Animais , Camundongos , L-Lactato Desidrogenase/metabolismo , L-Lactato Desidrogenase/genética , DNA Metiltransferase 3A/metabolismo , Regulação Neoplásica da Expressão Gênica , Metilação de DNA , Isoenzimas/genética , Isoenzimas/metabolismo , Linhagem Celular Tumoral , Inativação Gênica , PrognósticoRESUMO
In implementing the equity incentive system, this paper delves into the listed enterprises' selection of equity incentive models. While previous research has extensively covered the effects, models, and influencing factors of equity incentives, there needs to be more in-depth literature focusing on the diverse incentive models and their impact on corporate performance. Notably, there needs to be more literature on considering entrepreneurial spirit as a mechanism. It aims to explore the relationship between executives' choices under different incentive models, the entrepreneurial spirit fostered by these models, and their combined impact on corporate performance. The findings reveal that adopting the restricted stock incentive model by listed enterprises implementing the equity incentive system significantly positively affects enterprise performance. Mechanistic tests show that when a company implements the restricted stock incentive model, executives prioritize maximizing their interests, leading them to embrace more risk in their investment decisions. This behavior, in turn, stimulates the adventurous spirit of executives, positively impacting enterprise performance, particularly pronounced in companies with more concentrated executive power. Moreover, executives may be more inclined to invest in high-risk, high-reward innovative projects, a behavior indicative of innovation and more prevalent in firms with higher research and development (R&D) investment. However, the limitation of this paper is that the study evaluates the operation of the equity incentive system in China by taking listed companies in China as an example, which is not necessarily suitable for foreign developed capitalist countries. This study contributes to the study of principal-agent problems by exploring the relationship between executives, entrepreneurship and firm performance.
Assuntos
Empreendedorismo , Motivação , Capitalismo , China , InternacionalidadeRESUMO
Thermoresponsive elastin-like peptides (ELPs) have been extensively investigated in biotechnology and medicine, but little attention has been paid to the process by which coacervation causes ELP-decorated particles to aggregate. Using gold nanoparticles (AuNPs) functionalized with a cysteine-terminated 96-repeat of the VPGVG sequence (V96-Cys), we show that the size of the clusters that reversibly form above the ELP transition temperature can be finely controlled in the 250 to 930 nm range by specifying the concentration of free V96-Cys in solution and using AuNPs of different sizes. We further find that the localized surface plasmon resonance peak of the embedded AuNPs progressively red-shifts with cluster size, likely due to an increase in particle-particle contacts. We exploit this fine control over size to homogeneously load precise amounts of the dye Nile Red and the antibiotic Tetracycline into clusters of different hydrodynamic diameters and deliver cargos near-quantitatively by deconstructing the aggregates below the ELP transition temperature. Beyond establishing a key role for free ELPs in the agglomeration of ELP-functionalized particles, our results provide a path for the thermally controlled delivery of precise quantities of molecular cargo. This capability might prove useful in combination photothermal therapies and theranostic applications, and to trigger spatially and temporally uniform responses from biological, electronic, or optical systems.
Assuntos
Ouro , Nanopartículas Metálicas , Peptídeos/química , Ressonância de Plasmônio de Superfície , Elastina/química , TemperaturaRESUMO
In the expanding global digital economy, the digital transformation of businesses has become a critical component of modern operations. This study investigates the relationship between executive incentives and the digital transformation in A-share-listed Chinese companies from 2011 to 2020. Using multi-period DID and linear regression models, we analyzed how equity and compensation incentives influence this transformation. We discovered an inverse U-shaped correlation between executive incentive intensity and corporate digital transformation. Additionally, the relationship between compensation incentives and digital transformation is initially non-positive but transitions to a non-linear positive association beyond a certain threshold. Our research also reveals that digital process innovation and digital business expansion mediate the relationship between executive motivation and digital transformation. These findings highlight the importance of appropriate executive rewards in fostering innovative thinking and advancing digital transformation. This study contributes to the understanding of the drivers and effects of digital transformation and the role of equity incentives in governance. It offers valuable insights for companies aiming to accelerate digital transformation, optimize industrial structure, and promote economic development. Based on this study, further research on this issue can be conducted in the future by refining the personality traits, educational background, and cognitive differences of executives.
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BACKGROUND: Gastric cancer (GC) is a highly heterogeneous disease featuring many various histological and molecular subtypes. Therefore, it is imperative to have well-characterized in vitro models for personalized treatment development. Gastric cancer patient-derived organoids (PDOs), re-capitulating in vivo conditions, exhibit high clinical efficacy in predicting drug sensitivity to facilitate the development of cancer precision medicine. METHODS: PDOs were established from surgically resected GC tumor tissues. Histological and molecular characterization of PDOs and primary tissues were performed via IHC and sequencing analysis. We also conducted drug sensitivity tests using PDO cultures with five chemotherapeutic drugs and twenty-two targeted drugs. RESULTS: We have successfully constructed a PDOs biobank that included EBV+, intestinal/CIN, diffuse/GS, mixed and Her2+ GC subtypes, and these PDOs captured the pathological and genetic characteristics of corresponding tumors and exhibited different sensitivities to the tested agents. In a clinical case study, we performed an additional drug sensitivity test for a patient who reached an advanced progressive stage after surgery. We discovered that the combination of napabucasin and COTI-2 exhibited a stronger synergistic effect than either drug alone. CONCLUSION: PDOs maintained the histological and genetic characteristics of original cancer tissues. PDOs biobank opens up new perspectives for studying cancer cell biology and personalized medicine as a preclinical study platform.
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Antineoplásicos , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Avaliação Pré-Clínica de Medicamentos , Detecção Precoce de Câncer , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , OrganoidesRESUMO
Inflammatory bowel disease (IBD) is a chronic inflammatory disease typically involving the gastrointestinal tract but not limited to it. IBD can be subdivided into Crohn's disease (CD) and ulcerative colitis (UC). Extraintestinal manifestations (EIMs) are observed in up to 47% of patients with IBD, with the most frequent reports of cutaneous manifestations. Among these, pyoderma gangrenosum (PG) and erythema nodosum (EN) are the two most common skin manifestations in IBD, and both are immune-related inflammatory skin diseases. The presence of cutaneous EIMs may either be concordant with intestinal disease activity or have an independent course. Despite some progress in research on EIMs, for instance, ectopic expression of gut-specific mucosal address cell adhesion molecule-1 (MAdCAM-1) and chemokine CCL25 on the vascular endothelium of the portal tract have been demonstrated in IBD-related primary sclerosing cholangitis (PSC), little is understood about the potential pathophysiological associations between IBD and cutaneous EIMs. Whether cutaneous EIMs are inflammatory events with a commonly shared genetic background or environmental risk factors with IBD but independent of IBD or are the result of an extraintestinal extension of intestinal inflammation, remains unclear. The review aims to provide an overview of the two most representative cutaneous manifestations of IBD, describe IBD's epidemiology, clinical characteristics, and histology, and discuss the immunopathophysiology and existing treatment strategies with biologic agents, with a focus on the potential pathophysiological associations between IBD and cutaneous EIMs.
Assuntos
Colite Ulcerativa , Doença de Crohn , Eritema Nodoso , Doenças Inflamatórias Intestinais , Pioderma Gangrenoso , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Colite Ulcerativa/tratamento farmacológico , Pioderma Gangrenoso/terapia , Pioderma Gangrenoso/complicações , Eritema Nodoso/terapia , Eritema Nodoso/complicaçõesRESUMO
The phytochemical investigation of Veratrum mengtzeanum Loes. roots resulted in the isolation and characterization of two novel, namely Mengtzeanines A (1), Mengtzeanines B (2), and eight known steroidal alkaloids (3-10). Their structural properties were assessed though extensive spectroscopic techniques. All constituents 1-10 were analyzed for suppression of NO formation in LPS-induced RAW264.7 macrophages. Among them, constituent 6 (Verazine) showed inhibition against LPS-induced NO production (IC50 = 20.41 µM). Additionally, compound 6 could inhibit the secretion of IL1ß, IL6, and TNFα, and downregulate the productions of iNOS and COX2 in LPS-induced RAW264.7 macrophages. Further experiments revealed that 6 exhibited a potent anti-inflammatory level in LPS-stimulated RAW264.7 macrophages via inhibiting NF-κB, and triggering of Keap1/Nrf2/HO-1 axis, implying that compound 6 may be a promising candidate for treating inflammatory disorders.
Assuntos
Alcaloides , Veratrum , Animais , Camundongos , Veratrum/química , Proteína 1 Associada a ECH Semelhante a Kelch , Lipopolissacarídeos/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Anti-Inflamatórios/farmacologia , Alcaloides/farmacologia , NF-kappa B/metabolismo , Células RAW 264.7 , Óxido Nítrico/metabolismoRESUMO
Parkinson's disease (PD) is a progressive neurodegenerative disease affecting the aging population. Particularly, long non-coding RNAs (lncRNAs) have been demonstrated to play vital roles in PD, while the role of lncRNA SNHG8 in PD remains to be further explored. C57BL/6 mice were induced by rotenone to establish a PD model in vivo, and then the dopaminergic (DA) neuronal damage and locomotor dysfunction in rotenone-treated mice were evaluated. Murine DA cell line MN9D was treated with rotenone to establish a cellular PD model in vitro. Then, the viability, apoptosis, mitochondrial dysfunction, endoplasmic reticulum stress, and autophagy in rotenone-treated MN9D cells were assessed. Expression levels of SNHG8, microRNA-421-3p (miR-421-3p), and sorting nexin 8 (SNX8) in the substantia nigra (SN) of PD mice and rotenone-treated MN9D cells were detected. The interaction between SNHG8 and miR-421-3p, and the targeting relationship between SNX8 and miR-421-3p were confirmed. SNHG8 and SNX8 expression levels were decreased while miR-421-3p expression level was increased in the SN of PD mice and rotenone-treated MN9D cells. Upregulated SNHG8 ameliorated dopaminergic neuron damage and locomotor dysfunction in PD mice. Meanwhile, upregulated SNHG8 enhanced viability, diminished apoptosis, and alleviated mitochondrial dysfunction, endoplasmic reticulum stress, and autophagy in rotenone-treated MN9D cells. Mechanistically, SNHG8 bound to miR-421-3p, and miR-421-3p targeted SNX8. Overexpressed SNHG8 downregulates miR-421-3p to alleviate rotenone-induced dopaminergic neuron injury in PD via upregulating SNX8.
Assuntos
MicroRNAs , Doenças Neurodegenerativas , Doença de Parkinson , Camundongos , Animais , Doença de Parkinson/metabolismo , Neurônios Dopaminérgicos/metabolismo , Rotenona/toxicidade , Doenças Neurodegenerativas/metabolismo , Nexinas de Classificação/metabolismo , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , MicroRNAs/genética , MicroRNAs/metabolismo , Substância Negra/metabolismoRESUMO
Sequence-defined foldamers that self-assemble into well-defined architectures are promising scaffolds to template inorganic mineralization. However, it has been challenging to achieve robust control of nucleation and growth without sequence redesign or extensive experimentation. Here, peptoid nanotubes functionalized with a panel of solid-binding proteins are used to mineralize homogeneously distributed and monodisperse anatase nanocrystals from the water-soluble TiBALDH precursor. Crystallite size is systematically tuned between 1.4 and 4.4 nm by changing protein coverage and the identity and valency of the genetically engineered solid-binding segments. The approach is extended to the synthesis of gold nanoparticles and, using a protein encoding both material-binding specificities, to the fabrication of titania/gold nanocomposites capable of photocatalysis under visible-light illumination. Beyond uncovering critical roles for hierarchical organization and denticity on solid-binding protein mineralization outcomes, the strategy described herein should prove valuable for the fabrication of hierarchical hybrid materials incorporating a broad range of inorganic components.
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Nanopartículas Metálicas , Nanotubos , Peptoides , Peptoides/química , Ouro , Proteínas , Nanotubos/químicaRESUMO
Hierarchical materials that exhibit order over multiple length scales are ubiquitous in nature. Because hierarchy gives rise to unique properties and functions, many have sought inspiration from nature when designing and fabricating hierarchical matter. More and more, however, nature's own high-information content building blocks, proteins, peptides, and peptidomimetics, are being coopted to build hierarchy because the information that determines structure, function, and interfacial interactions can be readily encoded in these versatile macromolecules. Here, we take stock of recent progress in the rational design and characterization of hierarchical materials produced from high-information content blocks with a focus on stimuli-responsive and "smart" architectures. We also review advances in the use of computational simulations and data-driven predictions to shed light on how the side chain chemistry and conformational flexibility of macromolecular blocks drive the emergence of order and the acquisition of hierarchy and also on how ionic, solvent, and surface effects influence the outcomes of assembly. Continued progress in the above areas will ultimately usher in an era where an understanding of designed interactions, surface effects, and solution conditions can be harnessed to achieve predictive materials synthesis across scale and drive emergent phenomena in the self-assembly and reconfiguration of high-information content building blocks.
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Peptídeos , Substâncias Macromoleculares/químicaRESUMO
The Argonaute proteins are present in all three domains of life, which are archaea, bacteria, and eukarya. Unlike the eukaryotic Argonaute proteins, which use small RNA guides to target mRNAs, some prokaryotic Argonaute proteins (pAgos) use a small DNA guide to interfere with DNA and/or RNA targets. However, the mechanisms of pAgo natural function remain unknown. Here, we investigate the mechanism by which pAgo from Natronobacterium gregoryi (NgAgo) targets plasmid and bacteriophage T7 DNA using a heterologous Escherichia coli-based model system. We show that NgAgo expressed from a plasmid linearizes its expression vector. Cotransformation assays demonstrate that NgAgo requires an RNA in trans that is transcribed from the bacteriophage T7 promoter to activate cleavage of a cotransformed plasmid, reminiscent of the trans-RNA function in CRISPR/Cas9. We propose a mechanism to explain how NgAgo eliminates invading foreign DNA and bacteriophage. By leveraging this discovery, we show that NgAgo can be programmed to target a plasmid or a chromosome locus. IMPORTANCE We revealed the mechanism that explains how the NgAgo eliminates the invading foreign DNA and bacteriophage in bacterial cells at 37°C, and by leveraging this discovery, NgAgo can be programmed to target a plasmid or a chromosome locus.
Assuntos
Bacteriófagos , Natronobacterium , Proteínas Argonautas/genética , Bacteriófagos/genética , DNA/metabolismo , Eucariotos/genética , Natronobacterium/genética , Natronobacterium/metabolismo , Células Procarióticas/metabolismo , RNARESUMO
Clustered regulatory interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 nuclease (Cas9), the third-generation genome editing tool, has been favored because of its high efficiency and clear system composition. In this technology, the introduced double-strand breaks (DSBs) are mainly repaired by non-homologous end joining (NHEJ) or homology-directed repair (HDR) pathways. The high-fidelity HDR pathway is used for genome modification, which can introduce artificially controllable insertions, deletions, or substitutions carried by the donor templates. Although high-level knock-out can be easily achieved by NHEJ, accurate HDR-mediated knock-in remains a technical challenge. In most circumstances, although both alleles are broken by endonucleases, only one can be repaired by HDR, and the other one is usually recombined by NHEJ. For gene function studies or disease model establishment, biallelic editing to generate homozygous cell lines and homozygotes is needed to ensure consistent phenotypes. Thus, there is an urgent need for an efficient biallelic editing system. Here, we developed three pairs of integrated selection systems, where each of the two selection cassettes contained one drug-screening gene and one fluorescent marker. Flanked by homologous arms containing the mutated sequences, the selection cassettes were integrated into the target site, mediated by CRISPR/Cas9-induced HDR. Positively targeted cell clones were massively enriched by fluorescent microscopy after screening for drug resistance. We tested this novel method on the amyloid precursor protein (APP) and presenilin 1 (PSEN1) loci and demonstrated up to 82.0% biallelic editing efficiency after optimization. Our results indicate that this strategy can provide a new efficient approach for biallelic editing and lay a foundation for establishment of an easier and more efficient disease model.
Assuntos
Sistemas CRISPR-Cas , Reparo de DNA por Recombinação , Alelos , Reparo do DNA por Junção de Extremidades , Edição de Genes/métodosRESUMO
Zwitterionic polymers exhibit excellent nonfouling performance due to their strong surface hydrations. However, salt molecules may severely reduce the surface hydrations of typical zwitterionic polymers, making the application of these polymers in real biological and marine environments challenging. Recently, a new zwitterionic polymer brush based on the protein stabilizer trimethylamine N-oxide (TMAO) was developed as an outstanding nonfouling material. Using surface-sensitive sum frequency generation (SFG) vibrational spectroscopy, we investigated the surface hydration of TMAO polymer brushes (pTMAO) and the effects of salts and proteins on such surface hydration. It was discovered that exposure to highly concentrated salt solutions such as seawater only moderately reduced surface hydration. This superior resistance to salt effects compared to other zwitterionic polymers is due to the shorter distance between the positively and negatively charged groups, thus a smaller dipole in pTMAO and strong hydration around TMAO zwitterion. This results in strong bonding interactions between the O- in pTMAO and water, and weaker interaction between O- and metal cations due to the strong repulsion from the N+ and hydration water. Computer simulations at quantum and atomistic scales were performed to support SFG analyses. In addition to the salt effect, it was discovered that exposure to proteins in seawater exerted minimal influence on the pTMAO surface hydration, indicating complete exclusion of protein attachment. The excellent nonfouling performance of pTMAO originates from its extremely strong surface hydration that exhibits effective resistance to disruptions induced by salts and proteins.
Assuntos
PolímerosRESUMO
There is considerable interest in the development of hybrid organic-inorganic materials because of the potential for harvesting the unique capabilities that each system has to offer. Proteins are an especially attractive organic component owing to the high amount of chemical information encoded in their amino acid sequence, their amenability to molecular and computational (re)design, and the many structures and functions they specify. Genetic installation of solid-binding peptides (SBPs) within protein frameworks affords control over the position and orientation of adhesive and morphogenetic segments, and a path toward predictive synthesis and assembly of functional materials and devices, all while harnessing the built-in properties of the host scaffold. Here, we review the current understanding of the mechanisms through which SBPs bind to technologically relevant interfaces, with an emphasis on the variables that influence the process, and highlight the last decade of progress in the use of solid-binding proteins for hybrid and hierarchical materials synthesis.
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Proteínas de Transporte , Peptídeos , Peptídeos/metabolismoRESUMO
The prokaryotic Argonaute proteins (pAgos) have been reported to cleave or interfere with DNA targets in a guide-dependent or independent manner. It is often difficult to characterize pAgos in vivo due to the extreme environments favored by their hosts. In the present study, we expressed functional Thermus thermophilus pAgo (TtAgo) in E. coli BL21 (DE3) cells at 37 °C. Initial attempts to express TtAgo in BL21(DE3) cells at 37 °C failed. This was not because of TtAgo mediated general toxicity to the host cells, but instead because of TtAgo-induced loss of its expression plasmid. We employed this discovery to establish a screening system for isolating loss-of-function mutants of TtAgo. The E. colifabI gene was used to help select for full-length TtAgo loss of function mutants, as overexpression of fabI renders the cell to be resistant to the triclosan. We isolated and characterized eight mutations in TtAgo that abrogated function. The ability of TtAgo to induce loss of its expression vector in vivo at 37 °C is an unreported function that is mechanistically different from its reported in vitro activity. These results shed light on the mechanisms by which TtAgo functions as a defense against foreign DNA invasion.
Assuntos
Proteínas Argonautas/metabolismo , Proteínas de Bactérias/metabolismo , Escherichia coli/metabolismo , Proteínas Argonautas/genética , Proteínas de Bactérias/genética , Mutagênese Sítio-Dirigida , Plasmídeos/genética , Plasmídeos/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Thermus thermophilus/metabolismoRESUMO
The high mechanical strength and long-term resistance to the fibrous capsule formation are two major challenges for implantable materials. Unfortunately, these two distinct properties do not come together and instead compromise each other. Here, we report a unique class of materials by integrating two weak zwitterionic hydrogels into an elastomer-like high-strength pure zwitterionic hydrogel via a "swelling" and "locking" mechanism. These zwitterionic-elastomeric-networked (ZEN) hydrogels are further shown to efficaciously resist the fibrous capsule formation upon implantation in mice for up to 1 year. Such materials with both high mechanical properties and long-term fibrous capsule resistance have never been achieved before. This work not only demonstrates a class of durable and fibrous capsule-resistant materials but also provides design principles for zwitterionic elastomeric hydrogels.
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The fabrication of ordered architectures that intimately integrate polymer, protein, and inorganic components remains difficult. Two promising building blocks to tackle this challenge are peptoids, peptide mimics capable of self-assembly into well-defined structures, and solid-binding peptides, which offer a biological path to controlled inorganic assembly. Here, we report on the synthesis of 3.3-nm-thick thiol-reactive peptoid nanosheets from equimolar mixtures of unmodified and maleimide-derivatized versions of the Nbpe6Nce6 oligomer, optimize the location of engineered cysteine residues in silica-binding derivatives of superfolder green fluorescent protein for maleimide conjugation, and react the two components to form protein-peptoid hybrids exhibiting partial or uniform protein coverage on both of their sides. Using 10 nm silica nanoparticles, we trigger the stacking of these 2D structures into a multilayered material composed of alternating peptoid, protein, and organic layers. This simple and modular approach to hierarchical hybrid synthesis should prove useful in bioimaging and photocatalysis applications.
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Nanopartículas , Peptoides , Proteínas de Transporte , PeptídeosRESUMO
Materials that resist nonspecific protein adsorption are needed for many applications. However, few are able to achieve ultralow fouling in complex biological milieu. Zwitterionic polymers emerge as a class of highly effective ultralow fouling materials due to their superhydrophilicity, outperforming other hydrophilic materials such as poly(ethylene glycol). Unfortunately, there are only three major classes of zwitterionic materials based on poly(phosphorylcholine), poly(sulfobetaine), and poly(carboxybetaine) currently available. Inspired by trimethylamine N-oxide (TMAO), a zwitterionic osmolyte and the most effective protein stabilizer, we here report TMAO-derived zwitterionic polymers (PTMAO) as a new class of ultralow fouling biomaterials. The nonfouling properties of PTMAO were demonstrated under highly challenging conditions. The mechanism accounting for the extraordinary hydration of PTMAO was elucidated by molecular dynamics simulations. The discovery of PTMAO polymers demonstrates the power of molecular understanding in the design of new biomimetic materials and provides the biomaterials community with another class of nonfouling zwitterionic materials.
Assuntos
Materiais Biocompatíveis/química , Incrustação Biológica/prevenção & controle , Metilaminas/química , Polímeros/química , Adsorção , Animais , Materiais Biocompatíveis/metabolismo , Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Humanos , Metilaminas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Simulação de Dinâmica Molecular , Células NIH 3T3 , Polímeros/metabolismo , Polímeros/farmacologia , Albumina Sérica/química , Ressonância de Plasmônio de SuperfícieRESUMO
Nerve agents are a class of organophosphorus compounds (OPs) that blocks communication between nerves and organs. Because of their acute neurotoxicity, it is extremely difficult to rescue the victims after exposure. Numerous efforts have been devoted to search for an effective prophylactic nerve agent bioscavenger to prevent the deleterious effects of these compounds. However, low scavenging efficiency, unfavorable pharmacokinetics, and immunological problems have hampered the development of effective drugs. Here, we report the development and testing of a nanoparticle-based nerve agent bioscavenger (nanoscavenger) that showed long-term protection against OP intoxication in rodents. The nanoscavenger, which catalytically breaks down toxic OP compounds, showed a good pharmacokinetic profile and negligible immune response in a rat model of OP intoxication. In vivo administration of the nanoscavenger before or after OP exposure in animal models demonstrated protective and therapeutic efficacy. In a guinea pig model, a single prophylactic administration of the nanoscavenger effectively prevented lethality after multiple sarin exposures over a 1-week period. Our results suggest that the prophylactic administration of the nanoscavenger might be effective in preventing the toxic effects of OP exposure in humans.
Assuntos
Nanopartículas/química , Agentes Neurotóxicos/toxicidade , Substâncias Protetoras/farmacologia , Administração Intravenosa , Animais , Feminino , Cobaias , Masculino , Nanopartículas/administração & dosagem , Paraoxon/toxicidade , Substâncias Protetoras/administração & dosagem , Substâncias Protetoras/farmacocinética , Ratos Sprague-Dawley , Sarina/toxicidade , Análise de Sobrevida , Fatores de Tempo , Distribuição TecidualRESUMO
We report the synthesis of a zwitterionic carboxybetaine disulfide cross-linker (CBX-SS) and biodegradable poly(carboxybetaine) (PCB) hydrogels and nanocages (NCs) made using this cross-linker. The structure of CBX-SS combines zwitterionic carboxybetaine to confer nonfouling properties and a disulfide linkage to facilitate degradation. The physical, mechanical, and fouling characteristics of PCB hydrogels cross-linked with CBX-SS were investigated. Then, the degradation characteristics of CBX-SS-cross-linked hydrogels were evaluated through their weight loss and release of an encapsulated protein in a reducing environment. Furthermore, CBX-SS was applied to prepare degradable PCB NCs. Results show that encapsulating the highly immunogenic enzyme uricase in degradable PCB NCs eliminates or prevents an in vivo immune response to both the protein and polymer.