Post-polymerization functionalization of poly(3,4-propylenedioxythiophene) (PProDOT) via thiol–ene “click” chemistry

Publisher's PDFThe surface functionalization of conjugated polymers such as the poly(alkoxythiophenes) poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-propylenedioxythiophene) (PProDOT) provides a potential means for systematically tailoring their physical properties. We previously reported the synthesis of an alkene-functionalized 3,4-propylenedioxy-thiophene (ProDOT) derivative that could be readily modified through thiol–ene “click” chemistry. Here, we investigated the post-polymerization modification of PProDOT surfaces by using a dialkene functionalized variant (ProDOT-diene). The chemical structure of the ProDOT-diene monomer was confirmed by Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared spectroscopy (FTIR). The ProDOT-diene monomer was either chemically or electrochemically polymerized into the PProDOT-diene polymer, and then subsequently modified with alkyl, PEG, or ferrocene moieties via radical-based thiol–ene chemistry. We found that the normally insoluble PProDOT-diene could be converted into a soluble derivative by grafting alkyl groups onto the polymer chains after chemical polymerization. When electrochemically deposited on indium-tin oxide (ITO) glass electrodes, the conductivity, electroactivity and contact angles of the modified PProDOT-diene films could be tuned over a broad range. Scanning Electron Microscopy (SEM) revealed that post-polymerization modification did not significantly alter the surface morphology of the PProDOT-diene films. Overall, this method allows for efficient, facile tuning of the surface chemistry of poly(alkylthiophene) films, making it possible to tailor properties such as conductivity and wettability for different applications.University of Delaware. Department of Materials Science and Engineering.University of Delaware. Department of Biomedical Engineering

A novel intelligent global harmony search algorithm based on improved search stability strategy

Abstract Harmony search (HS) is a new swarm intelligent algorithm inspired by the process of music improvisation. Over the past decade, HS algorithm has been applied to many practical engineering problems. However, for some complex practical problems, there are some remaining issues such as premature convergence, low optimization accuracy and slow convergence speed. To address these issues, this paper proposes a novel intelligent global harmony search algorithm based on improved search stability strategy (NIGHS). In the search process, NIGHS uses the adaptive mean of harmony memory library to build a stable trust region around the global best harmony, and proposes a new coupling operation based on linear proportional relation, so that the algorithm can adaptively adjust the ability of exploration and exploitation in the search process and avoid premature convergence. In addition, the dynamic Gauss fine-tuning is adopted in the stable trust region to accelerate the convergence speed and improve the optimization accuracy. The common CEC2017 test functions are employed to test the proposed algorithm, the results show that NIGHS algorithm has a faster convergence speed and better optimization accuracy compared to the HS algorithm and its improved versions

Significant Enhancement of PEDOT Thin Film Adhesion to Inorganic Solid Substrates with EDOT-Acid

With its high conductivity, tunable surface morphology, relatively soft mechanical response, high chemical stability, and excellent biocompatibility, poly­(3,4-ethylenedioxythiophene) (PEDOT) has become a promising coating material for a variety of electronic biomedical devices. However, the relatively poor adhesion of PEDOT to inorganic metallic and semiconducting substrates still poses challenges for long-term applications. Here, we report that 2,3-dihydrothieno­(3,4-b)­(1,4)­dioxine-2-carboxylic acid (EDOT-acid) significantly improves the adhesion between PEDOT thin films and inorganic solid electrodes. EDOT-acid molecules were chemically bonded onto activated oxide substrates via the chemisorption of the carboxylic groups. PEDOT was then polymerized onto the EDOT-acid modified substrates, forming covalently bonded coatings. The adsorption of EDOT-acid onto the electrode surfaces was characterized by cyclic voltammetry (CV), contact angle measurements, atomic force microscopy, and X-ray photoelectron spectroscopy. The electrical properties of the subsequently coated PEDOT films were studied by electrochemical impedance spectroscopy and CV. An aggressive ultrasonication test confirmed the significantly improved adhesion and mechanical stability of the PEDOT films on electrodes with EDOT-acid treatment over those without treatment

Significant Enhancement of PEDOT Thin Film Adhesion to Inorganic Solid Substrates with EDOT-Acid

With its high conductivity, tunable surface morphology, relatively soft mechanical response, high chemical stability, and excellent biocompatibility, poly­(3,4-ethylenedioxythiophene) (PEDOT) has become a promising coating material for a variety of electronic biomedical devices. However, the relatively poor adhesion of PEDOT to inorganic metallic and semiconducting substrates still poses challenges for long-term applications. Here, we report that 2,3-dihydrothieno­(3,4-b)­(1,4)­dioxine-2-carboxylic acid (EDOT-acid) significantly improves the adhesion between PEDOT thin films and inorganic solid electrodes. EDOT-acid molecules were chemically bonded onto activated oxide substrates via the chemisorption of the carboxylic groups. PEDOT was then polymerized onto the EDOT-acid modified substrates, forming covalently bonded coatings. The adsorption of EDOT-acid onto the electrode surfaces was characterized by cyclic voltammetry (CV), contact angle measurements, atomic force microscopy, and X-ray photoelectron spectroscopy. The electrical properties of the subsequently coated PEDOT films were studied by electrochemical impedance spectroscopy and CV. An aggressive ultrasonication test confirmed the significantly improved adhesion and mechanical stability of the PEDOT films on electrodes with EDOT-acid treatment over those without treatment

Bacteria-Adsorbed Palygorskite Stabilizes the Quaternary Phosphonium Salt with Specific-Targeting Capability, Long-Term Antibacterial Activity, and Lower Cytotoxicity

In order to extend the antibacterial time of quaternary phosphonium salt in bacteria, palygorskite (PGS) is used as the carrier of dodecyl triphenyl phosphonium bromide (DTP), and a DTP-PGS hybrid is prepared. Antibacterial performance of this novel hybrid is investigated for both Gram-positive and Gram-negative bacteria. The results show that the DTP could be absorbed on the surface of PGS which had bacteria-adsorbed capability. The DTP-PGS hybrid, combining the advantages of PGS and DTP, display specific-targeting capability, long-term antibacterial activity, and lower cytotoxicity, suggesting the great potential application as PGS-based antibacterial powder

Direct Imaging of the Electrochemical Deposition of Poly(3,4-ethylenedioxythiophene) by Transmission Electron Microscopy

Conjugated polymers are electronically and ionically active organic materials of interest for use in a variety of devices. Electrochemical deposition is a convenient method for precisely fabricating conjugated polymer thin films, yet a detailed, quantitative understanding of nucleation and growth mechanisms has remained elusive. Here, we report direct imaging of the in situ electrochemical deposition of poly­(3,4-ethylenedioxythiophene) (PEDOT) from an aqueous solution of EDOT monomer using Transmission Electron Microscopy with an electrochemical liquid flow cell. We found that PEDOT deposition began preferentially at the edge of the glassy carbon anodes at the beginning of the reaction. Fluctuating clusters of liquid-like oligomers were observed to form near the electrode surfaces. As the reaction continued, both the nucleation of new domains as well as the growth of pre-existing PEDOT deposits were observed, leading to systematic increases in film thickness and roughness

Clinical and Molecular Characteristics and Antibacterial Strategies of Klebsiella pneumoniae in Pyogenic Infection

ABSTRACT Treatment of Klebsiella pneumoniae causing pyogenic infections is challenging. The clinical and molecular characteristics of Klebsiella pneumoniae causing pyogenic infections are poorly understood, and antibacterial treatment strategies are limited. We analyzed the clinical and molecular characteristics of K. pneumoniae from patients with pyogenic infections and used time-kill assays to reveal the bactericidal kinetics of antimicrobial agents against hypervirulent K. pneumoniae (hvKp). A total of 54 K. pneumoniae isolates were included, comprising 33 hvKp and 21 classic K. pneumoniae (cKp) isolates, and the hvKp and cKp isolates were identified using five genes (iroB, iucA, rmpA, rmpA2, and peg-344) that have been applied as hvKp strain markers. The median age of all cases was 54 years (25th and 75th percentiles, 50.5 to 70), 62.96% of individuals had diabetes, and 22.22% of isolates were sourced from individuals without underlying disease. The ratios of white blood cells/procalcitonin and C-reactive protein/procalcitonin were potential clinical markers for the identification of suppurative infection caused by hvKp and cKp. The 54 K. pneumoniae isolates were classified into 8 sequence type 11 (ST11) and 46 non-ST11 strains. ST11 strains carrying multiple drug resistance genes have a multidrug resistance phenotype, while non-ST11 strains carrying only intrinsic resistance genes are generally susceptible to antibiotics. Bactericidal kinetics revealed that hvKp isolates were not easily killed by antimicrobials at susceptible breakpoint concentrations compared with cKp. Given the varied clinical and molecular features and the catastrophic pathogenicity of K. pneumoniae, it is critical to determine the characteristics of such isolates for optimal management and effective treatment of K. pneumoniae causing pyogenic infections. IMPORTANCE Klebsiella pneumoniae may cause pyogenic infections, which are potentially life-threatening and bring great challenges for clinical management. However, the clinical and molecular characteristics of K. pneumoniae are poorly understood, and effective antibacterial treatment strategies are limited. We analyzed the clinical and molecular features of 54 isolates from patients with various pyogenic infections. We found that most patients with pyogenic infections had underlying diseases, such as diabetes. The ratio of white blood cells to procalcitonin and the ratio of C-reactive protein to procalcitonin were potential clinical markers for differentiating hypervirulent K. pneumoniae strains from classical K. pneumoniae strains that cause pyogenic infections. K. pneumoniae isolates of ST11 were generally more resistant to antibiotics than non-ST11 isolates. Most importantly, hypervirulent K. pneumoniae strains were more tolerant to antibiotics than classic K. pneumoniae isolates

Table_2_Vesicle-mediated transport-related genes are prognostic predictors and are associated with tumor immunity in lung adenocarcinoma.xlsx

BackgroundGlobally, lung adenocarcinoma (LUAD) is the leading cause of cancer-related deaths. It is a progressive disorder that arises from multiple genetic and environmental factors. Dysregulated expression of vesicle-mediated transport-related genes (VMTRGs) have been reported in several cancers. However, the prognostic significance of VMTRGs in LUAD has yet to be established.MethodsThe VMTRG profiling data for 482 LUAD patients and 59 normal controls were downloaded from The Cancer Genome Altas (TCGA). Univariate Cox regression and Least Absolute Shrinkage and Selection Operator (LASSO) regression analyses were performed to construct and optimize the risk model. Several GEO datasets were used to validate the risk model. The roles of these genes were investigated via the Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene ontology (GO) enrichment analyses. Differences in immune cell infiltrations between risk groups were evaluated using five algorithms. “pRRophetic” was used to investigate anti-cancer drug sensitivities in two groups. Expression of these five genes in LUAD samples and adjacent normal tissues were evaluated by qRT-PCR. Colony formation and wound healing assays were performed to assess the significance of CNIH1 and AP3S1 in LUAD cells.ResultsWe identified 85 prognosis-associated VMTRGs that could be constructed a risk model for LUAD patients, indicating their potential importance in LUAD development. The risk model including the five VMTRGs (CNIH1, KIF20A, GALNT2, GRIA1, and AP3S1) was associated with clinical outcomes. Tumor stage and risk score were found to be independent prognostic factors for LUAD patients. The five VMTRGs were also correlated with activation of the Notch and p53 signaling pathways. The risk model was significantly associated with immune responses and with high-level expression of immune checkpoints. High-risk group patients were more sensitive to several chemotherapeutic drugs and Lapatinib. Furthermore, CNIH1 and AP3S1 promoted LUAD cell growth and migration in vitro.ConclusionWe constructed a VMTRG-based risk model for effective prediction of prognostic outcomes for LUAD patients. The risk model was associated with immune infiltration levels. These five hub genes are potential targets for immune therapy combined with chemotherapy in LUAD.</p

Table_3_Vesicle-mediated transport-related genes are prognostic predictors and are associated with tumor immunity in lung adenocarcinoma.xlsx

BackgroundGlobally, lung adenocarcinoma (LUAD) is the leading cause of cancer-related deaths. It is a progressive disorder that arises from multiple genetic and environmental factors. Dysregulated expression of vesicle-mediated transport-related genes (VMTRGs) have been reported in several cancers. However, the prognostic significance of VMTRGs in LUAD has yet to be established.MethodsThe VMTRG profiling data for 482 LUAD patients and 59 normal controls were downloaded from The Cancer Genome Altas (TCGA). Univariate Cox regression and Least Absolute Shrinkage and Selection Operator (LASSO) regression analyses were performed to construct and optimize the risk model. Several GEO datasets were used to validate the risk model. The roles of these genes were investigated via the Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene ontology (GO) enrichment analyses. Differences in immune cell infiltrations between risk groups were evaluated using five algorithms. “pRRophetic” was used to investigate anti-cancer drug sensitivities in two groups. Expression of these five genes in LUAD samples and adjacent normal tissues were evaluated by qRT-PCR. Colony formation and wound healing assays were performed to assess the significance of CNIH1 and AP3S1 in LUAD cells.ResultsWe identified 85 prognosis-associated VMTRGs that could be constructed a risk model for LUAD patients, indicating their potential importance in LUAD development. The risk model including the five VMTRGs (CNIH1, KIF20A, GALNT2, GRIA1, and AP3S1) was associated with clinical outcomes. Tumor stage and risk score were found to be independent prognostic factors for LUAD patients. The five VMTRGs were also correlated with activation of the Notch and p53 signaling pathways. The risk model was significantly associated with immune responses and with high-level expression of immune checkpoints. High-risk group patients were more sensitive to several chemotherapeutic drugs and Lapatinib. Furthermore, CNIH1 and AP3S1 promoted LUAD cell growth and migration in vitro.ConclusionWe constructed a VMTRG-based risk model for effective prediction of prognostic outcomes for LUAD patients. The risk model was associated with immune infiltration levels. These five hub genes are potential targets for immune therapy combined with chemotherapy in LUAD.</p

Image_1_Vesicle-mediated transport-related genes are prognostic predictors and are associated with tumor immunity in lung adenocarcinoma.tif

BackgroundGlobally, lung adenocarcinoma (LUAD) is the leading cause of cancer-related deaths. It is a progressive disorder that arises from multiple genetic and environmental factors. Dysregulated expression of vesicle-mediated transport-related genes (VMTRGs) have been reported in several cancers. However, the prognostic significance of VMTRGs in LUAD has yet to be established.MethodsThe VMTRG profiling data for 482 LUAD patients and 59 normal controls were downloaded from The Cancer Genome Altas (TCGA). Univariate Cox regression and Least Absolute Shrinkage and Selection Operator (LASSO) regression analyses were performed to construct and optimize the risk model. Several GEO datasets were used to validate the risk model. The roles of these genes were investigated via the Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene ontology (GO) enrichment analyses. Differences in immune cell infiltrations between risk groups were evaluated using five algorithms. “pRRophetic” was used to investigate anti-cancer drug sensitivities in two groups. Expression of these five genes in LUAD samples and adjacent normal tissues were evaluated by qRT-PCR. Colony formation and wound healing assays were performed to assess the significance of CNIH1 and AP3S1 in LUAD cells.ResultsWe identified 85 prognosis-associated VMTRGs that could be constructed a risk model for LUAD patients, indicating their potential importance in LUAD development. The risk model including the five VMTRGs (CNIH1, KIF20A, GALNT2, GRIA1, and AP3S1) was associated with clinical outcomes. Tumor stage and risk score were found to be independent prognostic factors for LUAD patients. The five VMTRGs were also correlated with activation of the Notch and p53 signaling pathways. The risk model was significantly associated with immune responses and with high-level expression of immune checkpoints. High-risk group patients were more sensitive to several chemotherapeutic drugs and Lapatinib. Furthermore, CNIH1 and AP3S1 promoted LUAD cell growth and migration in vitro.ConclusionWe constructed a VMTRG-based risk model for effective prediction of prognostic outcomes for LUAD patients. The risk model was associated with immune infiltration levels. These five hub genes are potential targets for immune therapy combined with chemotherapy in LUAD.</p