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Local anesthetics (LA), as part of multimodal analgesia, have garnered significant interest for their role in delaying the initiation of opioid therapy, reducing postoperative opioid usage, and mitigating both hospitalization duration and related expenses. Despite numerous endeavors to extend the duration of local anesthetic effects, achieving truly satisfactory long-acting analgesia remains elusive. Drawing upon prior investigations, vesicular phospholipid gels (VPGs) emerge as promising candidates for extended-release modalities in small-molecule drug delivery systems. Therefore, we tried to use the amphiphilicity of phospholipids to co-encapsulate levobupivacaine hydrochloride and meloxicam, two drugs with different hydrophilicity, to obtain a long-term synergistic analgesic effect. Initially, the physicochemical attributes of the formulation were characterized, followed by an examination of its in vitro release kinetics, substantiating the viability of extending the release duration of the dual drugs. Sequentially, in vivo investigations encompassing pharmacokinetic profiling and assessment of analgesic efficacy were undertaken, revealing a prolonged release duration of up to 120 h and attainment of optimal postoperative analgesia. Subsequently, inquiries into the mechanism underlying synergistic analgesic effects and safety evaluations pertinent to the delivery strategy were pursued. In summation, we successfully developed a promising formulation to achieve long-acting analgesia.
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BACKGROUND: To explore the risk factors of post-traumatic stress disorder (PTSD) among Chinese college students during the COVID-19 pandemic and the construction and validation of risk prediction models. METHODS: A total of 10,705 university students were selected for the study. The questionnaire included the Generalized Anxiety Disorder 7 (GAD-7), Patient Health Questionnaire 9 (PHQ-9), PTSD Checklist for DSM-5 (PCL-5), and self-designed questionnaire. These assessments were conducted to facilitate the survey, construct the predictive model and validate the model's validity. RESULTS: Sex, left-behind experience, poverty status, anxiety score, and depression score were identified as independent risk factors influencing psychological trauma among Chinese college students during the COVID-19 pandemic, while COVID-19 infection emerged as a protective factor against psychological trauma. A column chart was constructed to visualize the six independent risk factors derived from logistic regression analysis. The Hosmer-Lemeshow test results (χ2 = 13.021, P = 0.111) indicated that the risk prediction model fitted well. The receiver operating characteristic (ROC) curve showed an area under the curve (AUC) of 0.864 in the model group and 0.855 in the validation group. The calibration curves of the model closely resembled the ideal curve. Decision curve analysis (DCA) revealed that the model provided net benefit and demonstrated good clinical utility. LIMITATIONS: The validation of the model is currently restricted to internal assessments. However, further confirmation through larger sample sizes, multicenter investigations, and prospective studies is necessary. CONCLUSIONS: The model effectively predicted PTSD risk among Chinese college students during the COVID-19 pandemic, indicating strong clinical applicability.
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COVID-19 , Transtornos de Estresse Pós-Traumáticos , Estudantes , Humanos , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtornos de Estresse Pós-Traumáticos/psicologia , COVID-19/psicologia , COVID-19/epidemiologia , Feminino , Estudantes/psicologia , Estudantes/estatística & dados numéricos , Masculino , China/epidemiologia , Fatores de Risco , Adulto Jovem , Universidades , Adulto , Inquéritos e Questionários , SARS-CoV-2 , Adolescente , Depressão/epidemiologia , Depressão/psicologia , Depressão/diagnóstico , Ansiedade/epidemiologia , Ansiedade/psicologia , Ansiedade/diagnósticoRESUMO
Rheumatoid arthritis (RA) is a chronic inflammatory joint condition characterized by symmetric, erosive synovitis leading to cartilage erosion and significant disability. Macrophages, pivotal in disease progression, release pro-inflammatory factors upon activation. We developed a nanoparticle delivery system (DXP-PSA NPs), based on palmitic acid modified human serum albumin (PSA), to deliver dexamethasone palmitate (DXP) directly to sites of inflammation, enhancing treatment effectiveness and minimizing possible side effects. The system actively targets scavenger receptor-A on activated macrophages, achieving selective accumulation at inflamed joints. In vitro effect and preliminary targeting abilities were investigated on LPS-activated RAW264.7 cells. The in vivo efficacy and safety were evaluated and compared side to side with commercially available lipid emulsion Limethason® in an advanced adjuvant-induced arthritis rat model. DXP-PSA NPs offer a novel approach to RA treatment and presents promising prospects for clinical translation.
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Artrite Experimental , Artrite Reumatoide , Dexametasona , Nanopartículas , Ácido Palmítico , Dexametasona/administração & dosagem , Dexametasona/química , Animais , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/metabolismo , Ácido Palmítico/química , Camundongos , Células RAW 264.7 , Humanos , Nanopartículas/química , Ratos , Artrite Experimental/tratamento farmacológico , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacocinética , Masculino , Albumina Sérica Humana/química , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismoRESUMO
Non-alcoholic fatty liver disease (NAFLD) was a chronic complication of type 2 diabetes mellitus (T2DM), and this comorbid disease lacked therapeutic drugs. Semen Ziziphi Spinosae (SZS) was the seed of Ziziphus jujuba var. Spinosa (Bunge) Hu ex H.F. Chow, and it could alleviate the symptoms of T2DM patients. As a triterpene saponin, Jujuboside A (Ju A) was the main active substance isolated from SZS and could improve hyperglycemia of diabetic mice. However, it was still unknown whether Ju A has protective effects on T2DM-associated NAFLD. Our study showed that Ju A attenuated T2DM-associated liver damage by alleviating hepatic lipid accumulation, inflammatory response, and oxidative stress in the liver of db/db mice, and high glucose (HG) and free fatty acid (FFA) co-stimulated human hepatocellular carcinomas (HepG2) cells. Along with the improved hyperglycemia and liver injury, Ju A restrained Yin Yang 1 (YY1)/cytochrome P450 2E1 (CYP2E1) signaling in vivo and in vitro. YY1 overexpression intercepted the protective effects of Ju A on T2DM-induced liver injury via promoting hepatic lipid accumulation, inflammatory response, and oxidative stress. While, the blocking effect of YY1 overexpression on Ju A's hepatoprotective effect was counteracted by further treatment of CYP2E1 specific inhibitor diethyldithiocarbamate (DDC) in vitro. In-depth mechanism research showed that Ju A through YY1/CYP2E1 signaling promoted hepatic fatty acid ß-oxidation, and inhibited inflammatory response and oxidative stress by activating peroxisome proliferator-activated receptor alpha (PPARα), leading to the improvement of T2DM-associated NAFLD. Ju A might be a potential agent in the treatment and health care of T2DM-associated liver disease, especially NAFLD.
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Citocromo P-450 CYP2E1 , Diabetes Mellitus Tipo 2 , Inflamação , Metabolismo dos Lipídeos , Fígado , Hepatopatia Gordurosa não Alcoólica , Estresse Oxidativo , Transdução de Sinais , Fator de Transcrição YY1 , Estresse Oxidativo/efeitos dos fármacos , Animais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Transdução de Sinais/efeitos dos fármacos , Camundongos , Masculino , Citocromo P-450 CYP2E1/metabolismo , Células Hep G2 , Metabolismo dos Lipídeos/efeitos dos fármacos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Fígado/metabolismo , Fígado/efeitos dos fármacos , Fígado/patologia , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Fator de Transcrição YY1/metabolismo , Camundongos Endogâmicos C57BL , Saponinas/farmacologia , Saponinas/uso terapêuticoRESUMO
Porous chitosan/hydroxyapatite (Chi-HAp) composite microspheres were prepared in an aqueous solution containing chitosan, calcium nitrate, and ammonium dihydrogen phosphate by using a hydrothermal method at various temperatures. The investigation indicated that temperature significantly impacted the final product's appearance. Hydroxyapatite (HAp) coupled with dicalcium phosphate dihydrate (DCPD) flakes were obviously found at 65 and 70 °C, while the latter gradually disappeared at higher temperatures. Conversely, synthesis at 90 °C led to smaller particle sizes due to the broken chitosan chains. The microspheres synthesized at 75 °C were selected for further analysis, revealing porous structures with specific surface areas of 36.66 m2/g, pores ranging from 3 to 100 nm, and pore volumes of 0.58 cm3/g. Vancomycin (VCM), an antibiotic, was then absorbed on and released from the microspheres derived at 75 °C, with a drug entrapment efficiency of 20% and a release duration exceeding 20 days. The bacteriostatic activity of the VCM/composite microspheres against Staphylococcus aureus increased with the VCM concentration and immersion time, revealing a stable inhibition zone diameter of approximately 4.3 mm from 24 to 96 h, and this indicated the retained stability and efficacy of the VCM during the encapsulating process.
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The health-promoting activities of polyphenols and their metabolites originating from germinated quinoa (GQ) are closely related to their digestive behavior, absorption, and colonic fermentation; however, limited knowledge regarding these properties hinder further development. The aim of this study was to provide metabolomic insights into the profile, bioaccessibility, and transepithelial transport of polyphenols from germinated quinoa during in vitro gastrointestinal digestion and Caco-2 cell transport, whilst also investigating the changes in the major polyphenol metabolites and the effects of prebiotics during colonic fermentation. It was found that germination treatment increased the polyphenol content of quinoa by 21.91%. Compared with RQ group, 23 phenolic differential metabolites were upregulated and 47 phenolic differential metabolites were downregulated in GQ group. Compared with RQ group after simulated digestion, 7 kinds of phenolic differential metabolites were upregulated and 17 kinds of phenolic differential metabolites were downregulated in GQ group. Compared with RQ group after cell transport, 7 kinds of phenolic differential metabolites were upregulated and 9 kinds of phenolic differential metabolites were downregulated in GQ group. In addition, GQ improved the bioaccessibilities and transport rates of various polyphenol metabolites. During colonic fermentation, GQ group can also increase the content of SCFAs, reduce pH value, and adjust gut microbial populations by increasing the abundance of Actinobacteria, Bacteroidetes, Verrucomicrobiota, and Spirochaeota at the phylum level, as well as Bifidobacterium, Megamonas, Bifidobacterium, Brevundimonas, and Bacteroides at the genus level. Furthermore, the GQ have significantly inhibited the activity of α-amylase and α-glucosidase. Based on these results, it was possible to elucidate the underlying mechanisms of polyphenol metabolism in GQ and highlight its beneficial effects on the gut microbiota.
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Chenopodium quinoa , Colo , Digestão , Fermentação , Metabolômica , Polifenóis , Prebióticos , Humanos , Polifenóis/metabolismo , Chenopodium quinoa/metabolismo , Células CACO-2 , Colo/metabolismo , Colo/microbiologia , Germinação , Transporte Biológico , Disponibilidade Biológica , Microbioma Gastrointestinal/fisiologiaRESUMO
Colorectal carcinoma (CRC) is a major global health concern, with cancer metastasis being the main cause of patient mortality, and current CRC treatments are challenged by drug resistance. Although natural compounds, especially in foods like hawthorn proanthocyanidin extract (HPOE), have good anticancer activity, their effects on CRC metastasis remain unknown. Therefore, our objective was to investigate the impact and potential mechanisms of HPOE on the movement and infiltration of cells in the HCT116 CRC cells. Firstly, scratch-healing experiments confirmed the anti-migratory and anti-invasive capabilities of HPOE. Then, network pharmacology identified 16 possible targets, including MMP-9. Subsequently, RT-qPCR and Western blotting experiments confirmed that HPOE downregulated epithelial-mesenchymal transition-related factors (N-cadherin and MMP-9) and inhibited Wnt/ß-catenin pathway activation. Finally, these results were experimentally validated using the Wnt pathway activator Licl and inhibitor XAV939. It was confirmed that HPOE had a certain inhibitory effect on the activation of the Wnt signaling pathway caused by the activator Licl and could enhance the inhibitory effect of the inhibitor XAV939. Our findings provide a basis for developing functional foods or dietary supplements, especially positioning HPOE as a functional food raw material for adjuvant treatment of CRC, given its ability to inhibit metastasis through the Wnt/ß-catenin pathway.
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As an output effector of the Hippo signaling pathway, the TEAD transcription factor and co-activator YAP play crucial functions in promoting cell proliferation and organ size. The tumor suppressor NF2 has been shown to activate LATS1/2 kinases and interplay with the Hippo pathway to suppress the YAP-TEAD complex. However, whether and how NF2 could directly regulate TEAD remains unknown. We identified a direct link and physical interaction between NF2 and TEAD4. NF2 interacted with TEAD4 through its FERM domain and C-terminal tail and decreased the protein stability of TEAD4 independently of LATS1/2 and YAP. Furthermore, NF2 inhibited TEAD4 palmitoylation and induced the cytoplasmic translocation of TEAD4, resulting in ubiquitination and dysfunction of TEAD4. Moreover, the interaction with TEAD4 is required for NF2 function to suppress cell proliferation. These findings reveal an unanticipated role of NF2 as a binding partner and inhibitor of the transcription factor TEAD, shedding light on an alternative mechanism of how NF2 functions as a tumor suppressor through the Hippo signaling cascade.
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Via de Sinalização Hippo , Neurofibromina 2 , Proteínas Serina-Treonina Quinases , Transdução de Sinais , Fatores de Transcrição de Domínio TEA , Humanos , Proliferação de Células , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Células HEK293 , Lipoilação , Neurofibromina 2/metabolismo , Neurofibromina 2/genética , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Estabilidade Proteica , Fatores de Transcrição de Domínio TEA/metabolismo , Proteínas Supressoras de Tumor , UbiquitinaçãoRESUMO
Hepatic cirrhosis has become a global public health concern with high mortality and currently lacks effective clinical treatment methods. Activation of hepatic stellate cells (HSCs) and the large number of macrophages infiltrating into the liver play a critical role in the development of liver cirrhosis. This study developed a novel modified nanoparticle system (SRF-CS-PSA NPs) in which Sorafenib (SRF) was encapsulated by palmitic acid-modified albumin (PSA) and further modified with chondroitin sulfate (CS). These modifications enabled the SRF-CS-PSA NPs to effectively target hepatic stellate cells (HSCs) and macrophages. SRF-CS-PSA NPs showed uniform particle size distribution of approximately 120 nm and high loading efficiency of up to 99.5% and can be taken up by HSCs and macrophages via CD44 and SR-A receptors, respectively. In a mouse model of liver cirrhosis, SRF-CS-PSA NPs demonstrated superior targeting and inhibition of HSCs and macrophages, effectively reversing the process of liver cirrhosis. Overall, our study demonstrates the potential of SRF-CS-PSA NPs as a targeted therapy for liver cirrhosis, with promising clinical applications.
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Células Estreladas do Fígado , Nanopartículas , Camundongos , Animais , Cirrose Hepática/tratamento farmacológico , Fígado/patologia , Sorafenibe/uso terapêutico , AlbuminasRESUMO
Surgical removal combined with postoperative chemotherapy is still the mainstay of treatment for most solid tumors. Although chemotherapy reduces the risk of recurrence and metastasis after surgery, it may produce serious adverse effects and impair patient compliance. In situ drug delivery systems are promising tools for postoperative cancer treatment, improving drug delivery efficiency and reducing side effects. Herein, an injectable phospholipid-based in situ forming gel (IPG) was prepared for the co-delivery of antitumor agent pirarubicin (THP) and cyclooxygenase-2 (COX-2) inhibitor celecoxib (CXB) in the surgical incision, and the latter are used extensively in adjuvant chemotherapy for cancer. After injection, the IPG co-loaded with THP and CXB (THP-CXB-IPG) underwent spontaneous phase transition and formed a drug reservoir that fitted the irregular surgical incisions perfectly. In vitro drug release studies and in vivo pharmacokinetic analysis had demonstrated the sustained release behaviors of THP-CXB-IPG. The in vivo therapeutic efficacy was evaluated in mice that had undergone surgical resection of breast cancer, and the THP-CXB-IPG showed considerable inhibition of residual tumor growth after surgery and reduced the incidence of pulmonary metastasis. Moreover, it reduced the systemic toxicity of chemotherapeutic agents. Therefore, THP-CXB-IPG can be a promising candidate for preventing postoperative recurrence and metastasis.
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Neoplasias da Mama , Doxorrubicina/análogos & derivados , Humanos , Camundongos , Animais , Feminino , Celecoxib , Neoplasias da Mama/tratamento farmacológico , Inibidores de Ciclo-Oxigenase 2/farmacologiaRESUMO
A universal platform is developed for dropletizing single cell plate-based multiomic assays, consisting of three main pillars: a miniaturized open Heterogeneous Hydrogel reactor (abbreviated HetHydrogel) for multi-step biochemistry, its tunable permeability that allows Tn5 tagmentation, and single cell droplet barcoding. Through optimizing the HetHydrogel manufacturing procedure, the chemical composition, and cell permeation conditions, simultaneous high-throughput mitochondrial DNA genotyping and chromatin profiling at the single-cell level are demonstrated using a mixed-species experiment. This platform offers a powerful way to investigate the genotype-phenotype relationships of various mtDNA mutations in biological processes. The HetHydrogel platform is believed to have the potential to democratize droplet technologies, upgrading a whole range of plate-based single cell assays to high throughput format.
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DNA Mitocondrial , Hidrogéis , Análise de Célula Única , Hidrogéis/química , DNA Mitocondrial/genética , Humanos , Animais , Mutação , MultiômicaRESUMO
As one of the most significant pathological changes of diabetic nephropathy (DN), tubulointerstitial fibrosis (TIF) had a close relationship with tubulointerstitial inflammation (TI), and the occurrence of TI could have resulted from the disrupted tight junctions (TJs) of renal tubular epithelial cells (RTECs). Studies have demonstrated that sodium butyrate (NaB), a typical short chain fatty acid (SCFA), played an important regulatory role in intestinal TJs and inflammation. In this study, our in vivo and in vitro results showed that accompanied by TI, renal tubular TJs were gradually disrupted in the process of DN-related TIF. In HG and LPS co-cultured HK-2 cells and db/db mice, NaB treatment regained the TJs of RTECs via the sphingosine 1-phosphate receptor-1 (S1PR1)/AMPK signaling pathway, relieving inflammation. Small interfering RNA of S1PR1, S1PR1 antagonist W146 and agonist SEW2871, and AMPK agonist AICAR were all used to further confirm the essential role of the S1PR1/AMPK signaling pathway in NaB's TJ protection in RTECs in vitro. Finally, NaB administration not only improved the renal function and TIF, but also relieved the TI of db/db mice. These findings suggested that the use of NaB might be a potential adjuvant treatment strategy for DN-associated TIF, and this protective effect was linked to the TJ modulation of RTECs via the S1PR1/AMPK signaling pathway, leading to the improvement of TI.
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Diabetes Mellitus , Nefropatias Diabéticas , Camundongos , Animais , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/metabolismo , Ácido Butírico/farmacologia , Ácido Butírico/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Junções Íntimas/metabolismo , Células Epiteliais/metabolismo , Fibrose , Diabetes Mellitus/metabolismoRESUMO
Removal of Expression of Concern for 'Sodium butyrate ameliorated diabetic nephropathy-associated tubulointerstitial inflammation by modulating tight junction of renal tubular epithelial cells' by Tingting Yang et al., Food Funct., 2022, Accepted Manuscript, https://doi.org/10.1039/D2FO00940D.
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Purpose: To understand the detection rate and distribution characteristics of Linezolid-nonsusceptible Enterococcus (LNSE) and analyze the molecular typing and main drug resistance mechanisms of LNSE, providing a theoretical basis for the precision prevention and control of LNSE hospital infections. Methods: A total of 40 LNSE strains isolated from clinical specimens between January 1, 2012, and December 31, 2022, were collected. The LNSE isolates identified by instrument detection were confirmed using a microbroth dilution method. The WHONET 5.0 software was used for statistical analysis of LNSE detection rate, and the LNSE judgment was based on the 2022 CLSI criteria. PCR methods were used to detect 23S rRNA, cfr, optrA, and L3, L4 ribosomal RNA sites for linezolid resistance genes, and gene sequencing was used to verify the amplified PCR products. Multiple locus sequence typing (MLST) was performed to analyze the homology of LNSE strains. Results: A total of 6924 Enterococcus isolates were separated and identified from January 1, 2012, to December 31, 2022, of which 40 were LNSE strains (26 Enterococcus faecalis, 14 Enterococcus faecium), with a detection rate of 0.58% (40/6924). Among them, 28 Linezolid-intermediated Enterococcus(LIE) were detected, accounting for 0.4% (28/6924), and 12 Linezolid-resistant Enterococcus(LRE) were detected, with a detection rate of 0.17% (12/6924). Among the LNSE strains, 23 were resistant to genes. The 40 LNSE strains could be divided into 20 different ST types, with ST16 being the main type, accounting for 12.5% (5/40). Conclusion: The detection of LNSE strains was dominated by Enterococcus faecalis, and the main resistance mechanism of LRE strains was carrying the optrA gene, with 23S rRNA gene mutations also contributing to resistance. New resistance gene phenotypes (optrA +/23S rRNA+) emerged. Most LRE cases were sporadic, and clonal dissemination was observed in some strains.
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In this study, we successfully prepared porous composite microspheres composed of hydroxyapatite (HAp), di-calcium phosphate di-hydrated (DCPD), and chitosan through the hydrothermal method. The chitosan played a crucial role as a chelating agent to facilitate the growth of related calcium phosphates. The synthesized porous composite microspheres exhibit a specific surface area of 38.16 m2/g and a pore volume of 0.24 cm3/g, with the pore size ranging from 4 to 100 nm. Given the unique properties of chitosan and the exceptional porosity of these composite microspheres, they may serve as carriers for pharmaceuticals. After being annealed, the chitosan transforms into a condensed form and the DCPD transforms into Ca2P2O7 at 300 °C. Then, the Ca2P2O7 initially combines with HAp to transform into ß tricalcium phosphate (ß-TCP) at 500 °C where the chitosan is also completely combusted. Finally, the microspheres are composed of Ca2P2O7, ß-TCP, and HAp, also making them suitable for applications such as injectable bone graft materials.
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Tumor metastasis is an intricate multistep process regulated via various proteins and enzymes modified and secreted by swollen Golgi apparatus in tumor cells. Thus, Golgi complex is considered as an important target for the remedy of metastasis. Currently, Golgi targeting technologies are mostly employed in Golgi-specific fluorescent probes for diagnosis, but their applications in therapy are rarely reported. Herein, we proposed a prodrug (INR) that can target and destroy the Golgi apparatus, which consisted of indomethacin (IMC) as the Golgi targeting moiety and retinoic acid (RA), a Golgi disrupting agent. The linker between IMC and RA was designed as a hypoxia-responsive nitroaromatic structure, which ensured the release of the prototype drugs in the hypoxic tumor microenvironment. Furthermore, INR could be assembled with pirarubicin (THP), an anthracycline, to form a carrier-free nanoparticle (NP) by emulsion-solvent evaporation method. A small amount of mPEG2000-DSPE was added to shield the positive charges and improve the stability of the nanoparticle to obtain PEG-modified nanoparticle (PNP). It was proved that INR released the prototype drugs in tumor cells and hypoxia promoted the release. The Golgi destructive effect of RA in INR was amplified owing to the Golgi targeting ability of IMC, and IMC also inhibited the protumor COX-2/PGE2 signaling. Finally, PNP exhibited excellent curative efficacy on 4T1 primary tumor and its pulmonary and hepatic metastasis. The small molecular therapeutic prodrug targeting Golgi apparatus could be adapted to multifarious drug delivery systems and disease models, which expanded the application of Golgi targeting tactics in disease treatment.
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Nanopartículas , Pró-Fármacos , Humanos , Pró-Fármacos/química , Antraciclinas/metabolismo , Antraciclinas/farmacologia , Sistemas de Liberação de Medicamentos , Antibióticos Antineoplásicos/farmacologia , Nanopartículas/química , Hipóxia/tratamento farmacológico , Complexo de Golgi , Linhagem Celular TumoralRESUMO
Repeat-mediated deletion (RMD) rearrangement is a major source of genome instability and can be deleterious to the organism, whereby the intervening sequence between two repeats is deleted along with one of the repeats. RMD rearrangement is likely induced by DNA double-strand breaks (DSBs); however, it is unclear how the complexity of DSBs influences RMD rearrangement. Here, a transgenic Escherichia coli strain K12 MG1655 with a lacI repeat-controlled amp activation was used while taking advantage of particle irradiation, such as proton and carbon irradiation, to generate different complexities of DSBs. Our research confirmed the enhancement of RMD under proton and carbon irradiation and revealed a positive correlation between RMD enhancement and LET. In addition, RMD enhancement could be suppressed by an intermolecular homologous sequence, which was regulated by its composition and length. Meanwhile, RMD enhancement was significantly stimulated by exogenous λ-Red recombinase. Further results investigating its mechanisms showed that the enhancement of RMD, induced by particle irradiation, occurred in a RecA-dependent manner. Our finding has a significant impact on the understanding of RMD rearrangement and provides some clues for elucidating the repair process and possible outcomes of complex DNA damage.
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This paper aims to investigate the guaranteed cost control via dynamic output feedback for nonlinear networked control systems (NCSs) with consideration of hybrid communication mechanism, data dropout and bounded disturbance. Interval type-2 (IT2) Takagi-Sugeno (T-S) fuzzy model is utilized to describe the nonlinear system with parameter uncertainties. To enhance bandwidth utilization and improve control performance, a hybrid communication mechanism involving both event-triggered mechanism (ETM) and time-triggered mechanism (TTM) is proposed. Two Bernoulli processes are invoked to describe the switching between two triggering mechanisms, and the data dropout phenomenon in communication network, respectively. The quadratic boundedness (QB) technique is employed to specify the closed-loop stability of a bounded disturbance networked system. The sufficient conditions for the stability of the system and the presence of a dynamic output feedback guaranteed cost controller are presented. In addition, the problem of controller design is converted to a convex optimization problem that can be tackled by linear matrix inequalities (LMIs) technique. At last, simulation experiment is carried out to explicate the availability and usefulness of the designed controller.