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1.
Opt Lett ; 49(20): 5803-5806, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-39404542

RESUMEN

We propose a method to prepare optically induced rotating hexagonal and honey-comb photonic lattices by employing the phase modulated three-beam interference in atomic vapors with electromagnetically induced transparency. The phase differences among the three beams are dynamically elaborated to synthesize the circular motion (in transverse dimensions) of waveguides in the photonic lattices. Further, we verify this model experimentally in the case of low-speed modulation. A weak Gaussian probe field is sent into the constructed helical photonic lattices to image their structures under electromagnetically induced transparency (EIT). The motion trajectories of the sites on the discretized output patterns exhibit repeated circles, advocating the formation of rotating lattices. By introducing phase modulations to involved beams, we provide a continent way for producing transverse motions in waveguide arrays with reconfigurability in rotational direction, radius, and speed. This work looks forward to promising applications in topological photonics with great popularity.

2.
Materials (Basel) ; 17(20)2024 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-39459705

RESUMEN

Oxy-steam combustion is a new oxy-fuel combustion technology. This paper focuses on the NO emission characteristics during the combustion of SF (Shen Fu) coal in O2/N2 and O2/H2O mixtures. Experiments were performed in a drop-tube furnace. Combustion tests were carried out in O2/N2 and O2/H2O atmospheres for various O2 concentrations (21%, 30%, 40%, and 60%) at different temperatures (1173 K, 1273 K, and 1373 K). In addition, combustion experiments at different excess oxygen ratios (λ) were conducted in O2/N2 and O2/H2O atmospheres. The influences of the atmosphere, oxygen concentration, temperature, and excess oxygen ratio on NO emissions were analyzed. The results show that the NO concentrations of SF coal combustion in the 21% O2/79% H2O atmosphere were much lower than those in the 21% O2/79% N2 atmosphere at the three temperatures considered. This was because a large amount of NO was decomposed during the SF coal combustion in the O2/H2O atmospheres. The reasons for the decomposition of NO include the selective non-catalytic reaction (SNCR) mechanism and char's important role as a catalyst for the destruction of NO, either directly or by reacting with CO or H2. In oxy-steam combustion, the NO concentrations significantly increased with the increase in the oxygen concentration from 21 vol.% to 60 vol.% and the temperature from 1173 K to 1373 K. The excess oxygen ratio (λ) slightly impacted the NO emissions in the O2/H2O atmosphere.

3.
Anal Chem ; 96(42): 16525-16533, 2024 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-39392424

RESUMEN

What happens to macromolecules in vivo? What drives the structure-activity relationship and in vivo stability for antibody-drug conjugates (ADCs)? These interrelated questions are increasingly relevant due to the re-emerging importance of ADCs as an impactful therapeutic modality and the gaps that exist in our understanding of ADC structural determinants that underlie ADC in vivo stability. Complex macromolecules, such as ADCs, may undergo changes in vivo due to their intricate structure as biotransformations may occur on the linker, the payload, and/or at the modified conjugation site. Furthermore, the dissection of ADC metabolism presents a substantial analytical challenge due to the difficulty in the identification or quantification of minor changes on a large macromolecule. We employed immunocapture-LCMS methods to evaluate in vivo changes in the drug-antibody ratio (DAR) profile in four different lead ADCs. This comprehensive characterization revealed that a critical structural determinant contributing to the ADC design was the linker, and competition of the thio-succinimide hydrolysis reaction over retro-Michael deconjugation can result in superb conjugation stability in vivo. These data, in conjunction with additional factors, informed the selection of AZD8205, puxitatug samrotecan, a B7-H4-directed cysteine-conjugated ADC bearing a novel topoisomerase I inhibitor payload, with durable DAR, currently being studied in the clinic for the potential treatment of solid malignancies (NCT05123482). These results highlight the relevance of studying macromolecule biotransformation and elucidating the ADC structure-in vivo stability relationship. The comprehensive nature of this work increases our confidence in the understanding of these processes. We hope this analytical approach can inform future development of bioconjugate drug candidates.


Asunto(s)
Biotransformación , Inmunoconjugados , Inmunoconjugados/metabolismo , Inmunoconjugados/química , Animales , Ratones , Humanos , Anticuerpos Monoclonales Humanizados/química , Anticuerpos Monoclonales Humanizados/metabolismo , Estabilidad de Medicamentos , Femenino , Camptotecina/análogos & derivados
4.
Rapid Commun Mass Spectrom ; 38(23): e9910, 2024 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-39287024

RESUMEN

RATIONALE: Isomerism can be an important aspect in pharmaceutical drug development. Identification of isomers can provide insights into drug pharmacology and contribute to better design of drug molecules. The general approaches to differentiate isomers include Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and circular dichroism. Additionally, a commonly used method to differentiate isomers is liquid chromatography coupled with mass spectrometry (LC-MS). Notably, LC-MS is routinely applied to leucine and isoleucine differentiation to facilitate protein sequencing. This work focuses on isomer differentiation of widely employed thio-succinimide structure bridging the antibody backbone and linker-payload of antibody-drug conjugates (ADCs). Thio-succinimide hydrolysis stabilizes the payload-protein structure while generating a pair of constitutional isomers: thio-aspartyl and thio-isoaspartyl. METHODS: This paper introduces a hybrid method using ligand binding assay (LBA) and liquid chromatography coupled with tandem MS (LC-MS/MS) to reveal isomerization details of thio-succinimide hydrolysis over time in plasma samples incubated with ADC. Application of two orthogonal dissociation methods, collision-induced dissociation (CID) and electron-activated dissociation (EAD) revealed different MS/MS spectra for this pair of isomers. This observation enables a unique approach in distinguishing thio-succinimide hydrolysis isomers. RESULTS: We observed signature [R1 + Thio + 57 + H]+, [R2 + Succ + H2O - 57 + H]+, and [R2 + Succ + H2O - 44 + 2H]2+ product ions (Succ = succinimide) that differentiated thio-aspartyl and thio-isoaspartyl isomers using EAD. A newly discovered [R2 + ThioSucc + H2O - 44 + 2H]2+ ion also served as additional evidence that further supported our findings. CONCLUSIONS: This study is a first-to-date identification of thio-succinimide hydrolysis isomers without using synthesized reference materials. This approach should be applicable to all thio-succinimide-linked molecules. Correct identification of thio-succinimide hydrolysis isomers may eventually benefit the development of ADCs in the future.


Asunto(s)
Succinimidas , Compuestos de Sulfhidrilo , Isomerismo , Compuestos de Sulfhidrilo/química , Succinimidas/química , Electrones , Espectrometría de Masas en Tándem/métodos , Hidrólisis , Inmunoensayo
5.
Anal Chem ; 96(42): 16475-16480, 2024 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-39298786

RESUMEN

Antibody-drug conjugate (ADC) is a therapeutic modality that aims to improve payload delivery specificity and reduce systemic toxicity. Considering the complex structure of ADCs, various bioanalytical methods by liquid chromatography coupled with mass spectrometry (LC-MS), ligand binding assay (LBA) and hybrid LBA-LC-MS approaches have been established for ADC characterization and quantification. LCMS-based assays enable drug-antibody ratio (DAR) sensitive quantification of the conjugated payload. Typically, for quantitative, DAR-sensitive, assessment by LC-MS/MS,the conjugated payload is enzymatically liberated and quantified. Despite recent advances in ADC bioanalytical methods, the DAR-sensitive quantification of noncleavable linker ADCs by LC-MS/MS remains challenging. Thus, we developed a novel digestion-free middle-down mass spectrometry (DF-MDMS) using a collision-induced dissociation approach for absolute quantification of conjugated payload from four different ADCs in a biological matrix with minimum sample preparation. These results demonstrate that ADCs with different linker-payload structures can be quantified, including a noncleavable linker ADC, trastuzumab emtansine. It also shows that the assay sensitivity is comparable to the conventional ADC quantification method by linker-payload cleavage using enzyme, while the assay dynamic range depends on factors including payload ionization and dissociation efficiency, DAR and its distribution, and species abundance. By demonstrating absolute quantification of both cleavable and noncleavable linker ADCs, this novel middle-down ADC approach demonstrates its potential application in bioanalysis and analytical characterization, especially for early discovery where high-throughput screening is required as the new approach saves time and resources by not requiring enzymatic digestion for cleavable ADCs or development of anti-payload antibodies for noncleavable linker ADCs.


Asunto(s)
Inmunoconjugados , Inmunoconjugados/química , Inmunoconjugados/análisis , Humanos , Espectrometría de Masas en Tándem/métodos , Cromatografía Liquida/métodos , Trastuzumab/química , Trastuzumab/análisis , Espectrometría de Masas/métodos
6.
Pharmaceutics ; 16(8)2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39204440

RESUMEN

Osteochondral defect is a complex tissue loss disease caused by arthritis, high-energy trauma, and many other reasons. Due to the unique structural characteristics of osteochondral tissue, the repair process is sophisticated and involves the regeneration of both hyaline cartilage and subchondral bone. However, the current clinical treatments often fall short of achieving the desired outcomes. Tissue engineering bioscaffolds, especially those created via three-dimensional (3D) printing, offer promising solutions for osteochondral defects due to their precisely controllable 3D structures. The microstructure of 3D-printed bioscaffolds provides an excellent physical environment for cell adhesion and proliferation, as well as nutrient transport. Traditional 3D-printed bioscaffolds offer mere physical stimulation, while drug-loaded 3D bioscaffolds accelerate the tissue repair process by synergistically combining drug therapy with physical stimulation. In this review, the physiological characteristics of osteochondral tissue and current treatments of osteochondral defect were reviewed. Subsequently, the latest progress in drug-loaded bioscaffolds was discussed and highlighted in terms of classification, characteristics, and applications. The perspectives of scaffold design, drug control release, and biosafety were also discussed. We hope this article will serve as a valuable reference for the design and development of osteochondral regenerative bioscaffolds and pave the way for the use of drug-loaded bioscaffolds in clinical therapy.

7.
Artículo en Inglés | MEDLINE | ID: mdl-39120984

RESUMEN

Novel drug-target interaction (DTI) prediction is crucial in drug discovery and repositioning. Recently, graph neural network (GNN) has shown promising results in identifying DTI by using thresholds to construct heterogeneous graphs. However, an empirically selected threshold can lead to loss of valuable information, especially in sparse networks, a common scenario in DTI prediction. To make full use of insufficient information, we propose a DTI prediction model based on Dynamic Heterogeneous Graph (DT-DHG). And progressive learning is introduced to adjust the receptive fields of node. The experimental results show that our method significantly improves the performance of the original GNNs and is robust against the choices of backbones. Meanwhile, DT-DHG outperforms the state-of-the-art methods and effectively predicts novel DTIs. The source code is available at https://github.com/kissablemt/DT-DHG.

8.
Bioact Mater ; 38: 305-320, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38745590

RESUMEN

Osteochondral regeneration involves the highly challenging and complex reconstruction of cartilage and subchondral bone. Silicon (Si) ions play a crucial role in bone development. Current research on Si ions mainly focuses on bone repair, by using silicate bioceramics with complex ion compositions. However, it is unclear whether the Si ions have important effect on cartilage regeneration. Developing a scaffold that solely releases Si ions to simultaneously promote subchondral bone repair and stimulate cartilage regeneration is critically important. Diatomite (DE) is a natural diatomaceous sediment that can stably release Si ions, known for its abundant availability, low cost, and environmental friendliness. Herein, a hierarchical osteochondral repair scaffold is uniquely designed by incorporating gradient DE into GelMA hydrogel. The adding DE microparticles provides a specific Si source for controlled Si ions release, which not only promotes osteogenic differentiation of rBMSCs (rabbit bone marrow mesenchymal stem cells) but also enhances proliferation and maturation of chondrocytes. Moreover, DE-incorporated hierarchical scaffolds significantly promoted the regeneration of cartilage and subchondral bone. The study suggests the significant role of Si ions in promoting cartilage regeneration and solidifies their foundational role in enhancing bone repair. Furthermore, it offers an economic and eco-friendly strategy for developing high value-added osteochondral regenerative bioscaffolds from low-value ocean natural materials.

9.
Front Genet ; 15: 1388015, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38737125

RESUMEN

LncRNAs are an essential type of non-coding RNAs, which have been reported to be involved in various human pathological conditions. Increasing evidence suggests that drugs can regulate lncRNAs expression, which makes it possible to develop lncRNAs as therapeutic targets. Thus, developing in-silico methods to predict lncRNA-drug associations (LDAs) is a critical step for developing lncRNA-based therapies. In this study, we predict LDAs by using graph convolutional networks (GCN) and graph attention networks (GAT) based on lncRNA and drug similarity networks. Results show that our proposed method achieves good performance (average AUCs > 0.92) on five datasets. In addition, case studies and KEGG functional enrichment analysis further prove that the model can effectively identify novel LDAs. On the whole, this study provides a deep learning-based framework for predicting novel LDAs, which will accelerate the lncRNA-targeted drug development process.

10.
CPT Pharmacometrics Syst Pharmacol ; 13(6): 994-1005, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38532525

RESUMEN

Trastuzumab deruxtecan (T-DXd; DS-8201; ENHERTU®) is a human epithelial growth factor receptor 2 (HER2)-directed antibody drug conjugate (ADC) with demonstrated antitumor activity against a range of tumor types. Aiming to understand the relationship between antigen expression and downstream efficacy outcomes, T-DXd was administered in tumor-bearing mice carrying NCI-N87, Capan-1, JIMT-1, and MDA-MB-468 xenografts, characterized by varying HER2 levels. Plasma pharmacokinetics (PK) of total antibody, T-DXd, and released DXd and tumor concentrations of released DXd were evaluated, in addition to monitoring γΗ2AX and pRAD50 pharmacodynamic (PD) response. A positive relationship was observed between released DXd concentrations in tumor and HER2 expression, with NCI-N87 xenografts characterized by the highest exposures compared to the remaining cell lines. γΗ2AX and pRAD50 demonstrated a sustained increase over several days occurring with a time delay relative to tumoral-released DXd concentrations. In vitro investigations of cell-based DXd disposition facilitated the characterization of DXd kinetics across tumor cells. These outputs were incorporated into a mechanistic mathematical model, utilized to describe PK/PD trends. The model captured plasma PK across dosing arms as well as tumor PK in NCI-N87, Capan-1, and MDA-MB-468 models; tumor concentrations in JIMT-1 xenografts required additional parameter adjustments reflective of complex receptor dynamics. γΗ2AX longitudinal trends were well characterized via a unified PD model implemented across xenografts demonstrating the robustness of measured PD trends. This work supports the application of a mechanistic model as a quantitative tool, reliably projecting tumor payload concentrations upon T-DXd administration, as the first step towards preclinical-to-clinical translation.


Asunto(s)
Inmunoconjugados , Receptor ErbB-2 , Trastuzumab , Ensayos Antitumor por Modelo de Xenoinjerto , Animales , Trastuzumab/farmacocinética , Trastuzumab/farmacología , Receptor ErbB-2/metabolismo , Ratones , Humanos , Inmunoconjugados/farmacocinética , Inmunoconjugados/farmacología , Línea Celular Tumoral , Femenino , Camptotecina/análogos & derivados , Camptotecina/farmacocinética , Camptotecina/farmacología , Antineoplásicos Inmunológicos/farmacocinética , Antineoplásicos Inmunológicos/farmacología , Antineoplásicos Inmunológicos/administración & dosificación , Ratones Desnudos
11.
Eur J Radiol ; 175: 111435, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38537606

RESUMEN

PURPOSE: The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is a standardized semi-quantitative scoring system. It is widely used to assess the extent of acute ischemic stroke (AIS). We evaluated the consistency of three automatic software packages with the overall and region-specific manual ASPECTS scores of AIS patients. METHODS: Retrospectively, we gathered patients who presented with stroke symptoms between February 2019 and June 2022, and 174 cases were eventually included in the trial. Two radiologists reviewed the NCCT images independently; After four weeks, the same two radiologists began randomly reviewing the DWI images, discussed different scores and give consistent results as ground truth. RESULTS: Median ASPECTS of the expert consensus reading was 7 (5-9). Good to excellent correlation of ASPECTS total scores among the three software tools (0.70, 0.74 and 0.83). Correlation among ground truth and Rapid-ASPECTS, RealNow-ASPECTS, ShuKun-ASPECTS (ICC = 0.51, Cronbach's α = 0.53), (ICC = 0.60, Cronbach's α = 0.70) and (ICC = 0.52, Cronbach's α = 0.64) respectively. The AUCs for Rapid, RealNow and ShuKun were 0.61, 0.67, and 0.62 respectively. The region-specific results showed a poor to good correlation. The correlations between the non-dominant and dominant cerebral hemispheres and the ground truth were statistically different (P < 0.05). CONCLUSIONS: Overall, the scoring consistency between the three automated scoring software and the ground truth is comparable, with RealNow-ASPECTS being no less consistent and effective than Rapid-ASPECTS and ShuKun-ASPECTS, and even better than both. But the consistency grade that still is developable.


Asunto(s)
Programas Informáticos , Tomografía Computarizada por Rayos X , Humanos , Femenino , Masculino , Estudios Retrospectivos , Anciano , Persona de Mediana Edad , Tomografía Computarizada por Rayos X/métodos , Reproducibilidad de los Resultados , Accidente Cerebrovascular/diagnóstico por imagen , Consenso , Anciano de 80 o más Años , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Adulto
12.
Phytopathology ; 114(7): 1533-1541, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38377011

RESUMEN

Fusarium root rot is usually classified as an extremely destructive soilborne disease. From 2020 to 2021, Fusarium root rot was observed in production areas and seriously affected the yield and quality of Scutellaria baicalensis in Shanxi Province, China. Based on morphological characteristics and combined analysis of the internal transcribed spacer region of ribosomal DNA and translation elongation factor 1-alpha sequences, 68 Fusarium isolates obtained in this work were identified as F. oxysporum (52.94%), F. acuminatum (20.59%), F. solani (16.17%), F. proliferatum (5.88%), F. incarnatum (2.94%), and F. brachygibbosum (1.47%). In the pathogenicity tests, all Fusarium isolates could infect S. baicalensis roots, presenting different pathogenic ability. Among these isolates, F. oxysporum was found to have the highest virulence on S. baicalensis roots, followed by F. acuminatum, F. solani, F. proliferatum, F. brachygibbosum, and F. incarnatum. According to fungicide sensitivity tests, Fusarium isolates were more sensitive to fludioxonil and difenoconazole, followed by carbendazim, thiophanate-methyl, and hymexazol. In brief, this is the first report of Fusarium species (F. oxysporum, F. acuminatum, F. solani, F. proliferatum, F. incarnatum, and F. brachygibbosum) as causal agents of root rot of S. baicalensis in Shanxi Province, China. The fungicide sensitivity results will be helpful for formulating management strategies of S. baicalensis root rot.


Asunto(s)
Fungicidas Industriales , Fusarium , Enfermedades de las Plantas , Raíces de Plantas , Scutellaria baicalensis , Fusarium/genética , Fusarium/efectos de los fármacos , Fusarium/patogenicidad , Fusarium/aislamiento & purificación , Fusarium/fisiología , Scutellaria baicalensis/microbiología , Enfermedades de las Plantas/microbiología , Raíces de Plantas/microbiología , China , Fungicidas Industriales/farmacología , Filogenia , Carbamatos/farmacología , Bencimidazoles
13.
Cell Death Discov ; 10(1): 71, 2024 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-38341418

RESUMEN

Abnormal lipid metabolism is an essential hallmark of glioblastoma. Hormone sensitive lipase (HSL), an important rate-limiting enzyme contributed to lipolysis, which was involved in aberrant lipolysis of glioblastoma, however, its definite roles and the relevant regulatory pathway have not been fully elucidated. Our investigations disclosed high expression of HSL in glioblastoma. Knock-down of HSL restrained proliferation, migration, and invasion of glioblastoma cells while adding to FAs could significantly rescue the inhibitory effect of si-HSL on tumor cells. Overexpression of HSL further promoted tumor cell proliferation and invasion. Bioinformatics analysis and dual-luciferase reporter assay were performed to predict and verify the regulatory role of ncRNAs on HSL. Mechanistically, hsa_circ_0021205 regulated HSL expression by sponging miR-195-5p, which further promoted lipolysis and drove the malignant progression of glioblastoma. Besides, hsa_circ_0021205/miR-195-5p/HSL axis activated the epithelial-mesenchymal transition (EMT) signaling pathway. These findings suggested that hsa_circ_0021205 promoted tumorigenesis of glioblastoma through regulation of HSL, and targeting hsa_circ_0021205/miR-195-5p/HSL axis can serve as a promising new strategy against glioblastoma.

14.
Cancer Immunol Immunother ; 73(2): 39, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38294569

RESUMEN

Adipose-derived stem cells (ASC) or autologous fat transplantation could be used to ameliorate breast cancer postoperative deformities. This study aims to explore the action of ASC and ASC-exosomes (ASC-exos) in breast cancer characterization and tumor microenvironment immunity, which provided a new method into the application of ASC-exos. ASC were extracted from human adipose tissue for the isolation and verification of ASC-exos. ASC-exos were co-cultured with CD4+T cells, CD14+ monocytes and MCF-7 cells, respectively. The tumor formation of nude mice was also constructed. Cell characterization was determined by CCK8, scratch assay, and Transwell. Hematoxylin-eosin (HE), immunohistochemistry (IHC) and immunofluorescence (IF) staining were used to observe the histopathology and protein expression. CD4+T cell and CD14+ monocytes differentiation was detected by flow cytometry. Western blot, qRT-PCR and RNAseq were used to detect the action of ASC-exos on gene and protein expression. CD4+T cells could take up ASC-exos. ASC-exos inhibited Th1 and Th17 differentiation and promoted Treg differentiation of CD4+T cells. ASC-exos inhibited M1 differentiation and promoted M2 differentiation of CD14+ monocytes. ASC-exos promoted the migration, proliferation, and invasion, while inhibited apoptosis of MCF-7 cells. ASC-exos promoted the tumor formation of breast cancer. The effect of ASC-exos on tumor microenvironment immunity was in accordance with the above in vitro results. TOX, CD4 and LYZ1 genes were upregulated, while Mettl7b and Serpinb2 genes were downregulated in ASC-exos group. Human T-cell leukemia virus 1 infection pathway was significantly enriched in ASC-exos. Thus, ASC-exos promoted breast cancer characterization and tumor microenvironment immunosuppression by regulating macrophage and T cell differentiation.


Asunto(s)
Neoplasias de la Mama , Exosomas , Animales , Ratones , Humanos , Femenino , Ratones Desnudos , Adipocitos , Inmunosupresores , Células Madre , Microambiente Tumoral
15.
Opt Lett ; 48(21): 5735-5738, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37910746

RESUMEN

We demonstrate the realization of an anti-parity-time (PT)-symmetric photonic lattice in a coherent three-level Λ-type 85Rb atomic system both experimentally and theoretically. Such an instantaneously reconfigurable anti-PT-symmetric photonic lattice is "written" by two one-dimensional coupling fields, which are arranged alternately along the x direction and can modulate the refractive index of the atomic vapor in a spatially periodical manner via controllable atomic coherence. By properly adjusting the relevant atomic parameters, the phase shift between two adjacent lattice channels occurs in the constructed non-Hermitian photonic system. Such a readily reconfigurable anti-PT-symmetric photonic lattice may open the door for demonstrating the discrete characteristics of the optical waves in periodic anti-PT-symmetric photonic systems.

16.
Opt Lett ; 48(22): 5927-5930, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37966754

RESUMEN

Transparent glass substrates are routinely used in the fabrication of metasurfaces, augmented reality (AR), virtual reality (VR), and holographic devices. While readily compatible with photolithographic patterning methods, when electron beam (E-Beam) techniques are used, field distortion and stitching errors can result due to the buildup of charge. A common approach to overcome this issue is to deposit a thin conductive polymer layer (E-Spacer). However, if high-voltage E-Beam is used to achieve nano-features, the polymer conductivity is not sufficient. We have shown that by using chromium (Cr) as an overcoating conductive layer on the resist, we can achieve accurate and seamless patterning in multiple writing fields and used the method to fabricate on-chip Si3N4 waveguides on SiO2. This technique has the potential to enable the fabrication of large-scale integrated photonic systems on transparent or dielectric substrates.

17.
Antibodies (Basel) ; 12(4)2023 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-37873863

RESUMEN

Deamidation, a common post-translational modification, may impact multiple physiochemical properties of a therapeutic protein. MEDI7247, a pyrrolobenzodiazepine (PBD) antibody-drug conjugate (ADC), contains a unique deamidation site, N102, located within the complementarity-determining region (CDR), impacting the affinity of MEDI7247 to its target. Therefore, it was necessary to monitor MEDI7247 deamidation status in vivo. Due to the low dose, a sensitive absolute quantification method using immunocapture coupled with liquid chromatography-tandem mass spectrometry (LBA-LC-MS/MS) was developed and qualified. We characterized the isomerization via Electron-Activated Dissociation (EAD), revealing that deamidation resulted in iso-aspartic acid. The absolute quantification of deamidation requires careful assay optimization in order not to perturb the balance of the deamidated and nondeamidated forms. Moreover, the selection of capture reagents essential for the correct quantitative assessment of deamidation was evaluated. The final assay was qualified with 50 ng/mL LLOQ for ADC for total and nondeamidated antibody quantification, with qualitative monitoring of the deamidated antibody. The impact of deamidation on the pharmacokinetic characteristics of MEDI7247 from clinical trial NCT03106428 was analyzed, revealing a gradual reduction in the nondeamidated form of MEDI7247 in vivo. Careful quantitative biotransformation analyses of complex biotherapeutic conjugates help us understand changes in product PTMs after administration, thus providing a more complete view of in vivo pharmacology.

18.
J Neurophysiol ; 130(5): 1174-1182, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37702542

RESUMEN

Alzheimer's disease (AD) is a neurodegenerative disorder with insidious onset and progressive development. There is an urgent need to find drugs that prevent and slow AD progression. We focus our attention on 3,6'-disinapoyl sucrose (DISS), an oligosaccharide with antidepressant and antioxidant activities. In this work, APP/PS1 transgenic mice were used to explore the neuroprotective impact of DISS to provide new applications for prevention and therapy of AD. This study aims to assess DISS's neuroprotective impact on learning and memory deficits in APP/PS1 transgenic mice using behavioral tests (Morris water maze, novel object recognition test, and passive avoidance test). Morphological alterations of hippocampus neurons were observed by Nissl staining and neuronal apoptosis was assessed by TUNEL assay. By using ELISA, the expressions of inflammatory factors were evaluated, and Western blotting was used to measure the protein expressions of neuron-related regulators in the hippocampus. DISS significantly ameliorated the cognitive disorder in APP/PS1 transgenic mice, reduced apoptosis by decreasing the ratio of Bax/B-cell lymphoma/leukemia-2 (Bcl-2) in hippocampal neurons, and restored the abnormal secretion of inflammatory factors (IL-2, TNF-α, IL-1ß, and IL-6). Moreover, the gavage of high-dose DISS can boost the expressions of CREB/brain-derived neurotrophic factor (BDNF). Overall, our results indicate that DISS improves cognitive function in APP/PS1 transgenic mice by inhibiting neural apoptosis and activating the CREB/BDNF signal pathway.NEW & NOTEWORTHY In this study, for the first time, DISS was used in APP/PS1 transgenic mice to explore its neuroprotective effect. After gavage DISS for 1 mo, the impairment of learning and spatial memory ability and the loss of neurons in APP/PS1 mice were alleviated. DISS reduced a neuroprotective effect in AD mice via decreasing neuronal apoptosis, enhancing the expressions of CREB phosphorylation and BDNF, pointing to DISS as a new therapeutic target for AD.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Fármacos Neuroprotectores , Ratones , Animales , Ratones Transgénicos , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Fármacos Neuroprotectores/farmacología , Sacarosa/farmacología , Sacarosa/uso terapéutico , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Disfunción Cognitiva/tratamiento farmacológico , Cognición , Modelos Animales de Enfermedad , Aprendizaje por Laberinto
19.
J Med Chem ; 66(17): 12284-12303, 2023 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-37605459

RESUMEN

Poly(ADP-ribose) polymerase inhibitors (PARPi) have significant efficacy in treating BRCA-deficient cancers, although resistance development remains an unsolved challenge. Herein, a series of phthalazin-1(2H)-one derivatives with excellent enzymatic inhibitory activity were designed and synthesized, and the structure-activity relationship was explored. Compared with olaparib and talazoparib, compound YCH1899 exhibited distinct antiproliferation activity against olaparib- and talazoparib-resistant cells, with IC50 values of 0.89 and 1.13 nM, respectively. Studies of the cellular mechanism revealed that YCH1899 retained sensitivity in drug-resistant cells with BRCA1/2 restoration or 53BP1 loss. Furthermore, YCH1899 had acceptable pharmacokinetic properties in rats and showed prominent dose-dependent antitumor activity in olaparib- and talazoparib-resistant cell-derived xenograft models. Overall, this study suggests that YCH1899 is a new-generation antiresistant PARPi that could provide a valuable direction for addressing drug resistance to existing PARPi drugs.


Asunto(s)
Proteína BRCA1 , Proteína BRCA2 , Humanos , Animales , Ratas , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología
20.
CNS Neurosci Ther ; 29(12): 3756-3773, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37309294

RESUMEN

AIM: Exosomal miRNAs derived from glioblastoma stem cells (GSCs) are important mediators of immunosuppressive microenvironment formation in glioblastoma multiform (GBM), especially in M2-like polarization of tumor-associated macrophages (TAMs). However, the exact mechanisms by which GSCs-derived exosomes (GSCs-exo) facilitate the remodeling of the immunosuppressive microenvironment of GBM have not been elucidated. METHODS: Transmission electron microscopy (TME) and nanoparticle tracking analysis (NTA) were applied to verify the existence of GSCs-derived exosomes. Sphere formation assays, flow cytometry, and tumor xenograft transplantation assays were performed to identify the exact roles of exosomal miR-6733-5p. Then, the mechanisms of miR-6733-5p and its downstream target gene regulating crosstalk between GSCs cells and M2 macrophages were further investigated. RESULTS: GSCs-derived exosomal miR-6733-5p induce macrophage M2 polarization of TAMs by positively targeting IGF2BP3 to activate the AKT signaling pathway, which further facilitates the self-renewal and stemness of GSCs. CONCLUSION: GSCs secrete miR-6733-5p-rich exosomes to induce M2-like polarization of macrophages, as well as enhance GSCs stemness and promote malignant behaviors of GBM through IGF2BP3 activated AKT pathway. Targeting GSCs exosomal miR-6733-5p may provide a potential new strategy against GBM.


Asunto(s)
Glioblastoma , MicroARNs , Humanos , Glioblastoma/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Macrófagos/patología , Células Madre/metabolismo , Línea Celular Tumoral , Microambiente Tumoral
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