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2.
Langmuir ; 40(13): 6824-6833, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38498002

RESUMO

The composition and thickness of the passive film formed on the surface of an austenitic Ni-free DIN 1.4456 stainless steel (18% Cr, 18% Mn, and 2% Mo) used in orthodontics were investigated by X-ray photoelectron spectroscopy following contact with three complex artificial saliva solutions containing different organic components. It was found that the synergistic action of low pH and the presence of sodium citrate and lactic acid in the Darvell formulation resulted in thin passive films strongly enriched in chromium phosphates and oxyhydroxides and depleted in iron oxide. The differences in the surface chemistry of the passive film formed upon contact with the different artificial saliva formulations can be related to the more intense alloy dissolution in the active/passive transition, as shown by the polarization curves. Citrates or lactic acid can complex iron and promote alloy dissolution. The corrosion rates diminish with time, and after 16 h, they are found to be about 0.5 µm/year for all saliva formulations examined.

3.
Clin Lymphoma Myeloma Leuk ; 24(5): 323-331, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38369436

RESUMO

BACKGROUND: Intermittent treatment with tyrosine kinase inhibitors (TKIs) is an option for elderly chronic myeloid leukemia (CML) patients who are often candidates for life-long treatment. MATERIALS AND METHODS: The Italian phase III multicentric randomized Optimize TKIs Multiple Approaches (OPTkIMA) study aimed to evaluate if a progressive de-escalation of TKIs is able to maintain the molecular remission (MR)3.0 and to improve Health-Related Quality of Life (HRQoL) in CML elderly patients. RESULTS: A total of 215 patients in stable MR3.0/MR4.0 were randomized to receive an intermittent TKI schedule 1 month ON-1 month OFF for 3 years (FIXED arm; n = 111) vs. a progressive de-escalation TKI dose up to one-third of the starting dose at the 3rd year (PROGRESSIVE arm; n = 104). Two hundred three patients completed the 3rd year of OPTkIMA study. At the last follow-up, MR3.0 loss was 27% vs. 46% (P = .005) in the FIXED vs PROGRESSIVE arm, respectively. None of these patients experienced disease progression. The 3-year probability of maintaining the MR3.0 was 59% vs. 53%, respectively (P = .13). HRQoL globally improved from the baseline to the 3rd year, without any significant difference between the 2 arms. After the 3rd year, the proportion of patients who was address to TKI discontinuation in the 2 arms was 36% (FIXED) vs. 58% (PROGRESSIVE) (P = .03). CONCLUSIONS: The intensification of intermittent TKI therapy is associated with a higher incidence of MR3.0 loss, but those patients who maintain the MR3.0 molecular response at the end of the study have been frequently considered eligible for TFR. The HRQoL generally improved during the de-escalation therapy in both randomization arms.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Inibidores de Proteínas Quinases , Qualidade de Vida , Humanos , Idoso , Masculino , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/farmacologia , Feminino , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Itália , Idoso de 80 Anos ou mais , Resultado do Tratamento
4.
Nanomaterials (Basel) ; 13(22)2023 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-37999287

RESUMO

This study focuses on the dissolution process and surface characterization of amosite fibres following interaction with a mimicked Gamble's solution at a pH of 4.5 and T = 37 °C, up to 720 h. To achieve this, a multi-analytical approach was adopted, and the results were compared to those previously obtained on a sample of asbestos tremolite and UICC crocidolite, which were investigated under the same experimental conditions. Combining surface chemical data obtained by XPS with cation release quantified by ICP-OES, an incongruent behaviour of the fibre dissolution was highlighted for amosite fibres, similarly to asbestos tremolite and UICC crocidolite. In particular, a preferential release of Mg and Ca from the amphibole structure was observed, in agreement with their Madelung site energies. Notably, no Fe release from amosite fibres was detected in our experimental conditions (pH of 4.5 and atmospheric pO2), despite the occurrence of Fe(II) at the M(4) site of the amphibole structure, where cations are expected to be rapidly leached out during mineral dissolution. Moreover, the oxidation of both the Fe centres initially present on the fibre surface and those promoted from the bulk, because of the erosion of the outmost layers, was observed. Since biodurability (i.e., the resistance to dissolution) is one of the most important toxicity parameters, the knowledge of the surface alteration of asbestos possibly occurring in vivo may help to understand the mechanisms at the basis of its long-term toxicity.

5.
J Hazard Mater ; 457: 131754, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37276694

RESUMO

The environmental impact of natural occurrences of asbestos (NOA) and asbestos-like minerals is a growing concern for environmental protection agencies. The lack of shared sampling and analytical procedures hinders effectively addressing this issue. To investigate the hazard posed by NOA, a multidisciplinary approach that encompasses geology, mineralogy, chemistry, and toxicology is proposed and demonstrated here, on a natural occurrence of antigorite from a site in Varenna Valley, Italy. Antigorite is, together with chrysotile asbestos, one of the serpentine polymorphs and its toxicological profile is still under debate. We described field and petrographic analyses required to sample a vein and to evaluate the NOA-hazard. A combination of standardized mechanical stress and automated morphometrical analyses on milled samples allowed to quantify the asbestos-like morphology. The low congruent solubility in acidic simulated body fluid, together with the toxicity-relevant surface reactivity due to iron speciation, signalled a bio-activity similar or even greater to that of chrysotile. Structural information on the genetic mechanism of antigorite asbestos-like fibres in nature were provided. Overall, the NOA site was reported to contain veins of asbestos-like antigorite and should be regarded as source of potentially toxic fibres during hazard assessment procedure.

6.
Viruses ; 15(2)2023 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-36851514

RESUMO

Porcine coronaviruses and reproductive and respiratory syndrome (PRRS) are responsible for severe outbreaks that cause huge economic losses worldwide. In Italy, three coronaviruses have been reported historically: porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV) and porcine respiratory coronavirus (PRCV). Although repeated outbreaks have been described, especially in northern Italy, where intensive pig farming is common, there is a worrying lack of information on the spread of these pathogens in Europe. In this work, we determined the seroprevalence of three porcine coronaviruses and PRRSV in the Campania region, southern Italy. A total of 443 samples were tested for the presence of antibodies against porcine coronaviruses and PRRSV using four different commercial ELISAs. Our results indicated that PEDV is the most prevalent among porcine coronaviruses, followed by TGEV, and finally PRCV. PRRSV appeared to be the most prevalent virus (16.7%). For coronaviruses, seroprevalence was higher in pigs raised in intensive farming systems. In terms of distribution, TGEV is more widespread in the province of Avellino, while PEDV and PRRSV are more prevalent in the province of Naples, emphasizing the epidemic nature of both infections. Interestingly, TGEV-positive animals are more common among growers, while seropositivity for PEDV and PRRSV was higher in adults. Our research provides new insights into the spread of swine coronaviruses and PRRSV in southern Italy, as well as a warning about the need for viral surveillance.


Assuntos
Infecções por Coronavirus , Coronavirus , Síndrome Respiratória e Reprodutiva Suína , Coronavirus Respiratório Porcino , Vírus da Diarreia Epidêmica Suína , Vírus da Síndrome Respiratória e Reprodutiva Suína , Vírus da Gastroenterite Transmissível , Animais , Suínos , Síndrome Respiratória e Reprodutiva Suína/epidemiologia , Estudos Soroepidemiológicos , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/veterinária , Itália/epidemiologia
7.
Leuk Res ; 127: 107023, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36822077

RESUMO

Life expectation of chronic myeloid leukemia patients in the tyrosine kinase inhibitors era is almost equal to that of healthy subjects. On the other hand, their long-term management must take into account a higher risk of adverse events, at least partly related to the treatment. Various studies reported a higher incidence of cardiovascular events in these patients. Clonal hematopoiesis is broadly considered a major independent risk factor for cardiovascular events. Of note, the underlying physiopathological mechanisms connect clonal hematopoiesis with a global proinflammatory status, triggering a vicious circle in which the somatic mutations and inflammation feed each other. All this considered, we investigated the occurrence of clonal hematopoiesis in chronic myeloid leukemia patients developing a cardiovascular event under tyrosine kinase inhibitor therapy.


Assuntos
Doenças Cardiovasculares , Leucemia Mielogênica Crônica BCR-ABL Positiva , Leucemia Mieloide Aguda , Humanos , Hematopoiese Clonal , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucemia Mieloide Aguda/terapia , Doenças Cardiovasculares/genética , Hematopoese/genética , Mutação
8.
Acta Haematol ; 146(1): 37-43, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36195064

RESUMO

INTRODUCTION: Interferon regulatory factor 4 (IRF4) is a transcriptional factor with a key role in the modulation of inflammation and immune surveillance. The IRF4 gene is downregulated in Philadelphia-negative myeloproliferative neoplasms, and its expression is associated with prognosis and response to treatment. METHODS: We evaluated the IRF4 expression kinetics during tyrosine kinase inhibitor (TKI) treatment in a cohort of 116 chronic myeloid leukemia (CML) patients to elucidate its role in the disease course. RESULTS: A relationship between the IRF4 expression and the disease burden was observed at various disease stages. A correlation analysis between the International Scale (IS) and IRF4 values confirmed this close association. A significant increase is detected after 3 months of TKI treatment. Patients achieving an early molecular response (EMR) had higher IRF4 values at both diagnosis and after 3 months of therapy as compared to those failing the EMR target. Patients achieving treatment-free remission did not show IRF4 fluctuations during monitoring, while a decreased IRF4 expression emerged at the time of molecular relapse. CONCLUSION: Our data seem to confirm the relevance of IRF4 in the pathogenesis of CML, suggesting a pivotal role at the disease onset and a predictive value during the CML course.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Leucemia Mieloide , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Doença Crônica , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Expressão Gênica
10.
Hematology ; 27(1): 842-846, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35938951

RESUMO

OBJECTIVES: BCR-ABL1 and JAK2 V617F coexistence in myeloproliferative neoplasms has been described as concomitant or sequential events. Despite this, we present a unique case of chronic myeloid leukemia (CML) not referable to either of the known scenarios. METHODS: BCR-ABL1 molecular monitoring was performed by real-time quantitative PCR (RQ-PCR). At the time of molecular relapse, a targeted next-generation sequencing analysis with a customized panel of 26 genes commonly mutated in myeloid diseases was performed. To investigate the kinetics of the JAK2 variant and its association with the BCR-ABL1 rearrangement, RQ-PCR was performed at different time points during the patient's follow-up. RESULTS: While negative at CML diagnosis, the JAK2 mutation was first detected 9 years later (VAF: 7.2%). The mutational burden of JAK2 remained stable in multiple determinations, with minor fluctuations independent of BCR-ABL1 kinetics. At the last available time point, the patient was in deep molecular response (MR4), the JAK2 mutational burden was 7%, and no clinical-laboratory findings of Ph-MPN were detectable. DISCUSSION: In the presented case, the JAK2variantoccurring during the course of the disease seems to stay in the shadows of CML, just as a bystander. The impact of this event (that may be considered suggestive of clonal hematopoiesis of indeterminate potential) on the disease outcome, even if seemingly irrelevant, has still to be explored.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Transtornos Mieloproliferativos , Proteínas de Fusão bcr-abl/genética , Humanos , Janus Quinase 2/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Mutação , Transtornos Mieloproliferativos/complicações , Transtornos Mieloproliferativos/diagnóstico , Transtornos Mieloproliferativos/genética , Reação em Cadeia da Polimerase em Tempo Real
11.
Front Oncol ; 12: 873896, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35494055

RESUMO

Inflammatory bowel diseases (IBDs) are a group of chronic conditions of the gastrointestinal tract in which nationwide studies have revealed a higher risk of hematological malignancies (HMs). Clonal hematopoiesis (CH) is a premalignant condition defined by the presence of an acquired somatic mutation characterized by a variant allele frequency (VAF) of ≥2%, in a gene frequently associated with HMs. A growing body of evidence suggests a correlation between inflammation and CH; its occurrence in the context of IBD has been previously demonstrated. With the aim to assess CH possible co-occurrence in patients with an IBD associated with HMs, we performed a targeted next-generation sequencing analysis in a cohort of thirteen patients who were referred to our center with IBD associated with HMs. Eleven (85%) patients showed one or more mutations in CH-associated genes; DNMT3A was the most frequently mutated gene, followed by ASXL1 and JAK2. These results may suggest that the mechanisms at the basis of the inflammatory environment could potentially select for the growth of hematopoietic clones harboring specific mutations. In this context, CH emergence may be boosted by the proinflammatory IBD environment, thus acting as a biological link between IBD and the HM onset. If these data are confirmed, IBD patients screened and positive for CH should undergo a hematologic follow-up to assess the risk of developing HM. Future study will clarify the relationship between these conditions.

12.
Chemosphere ; 296: 133897, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35218777

RESUMO

Low-cost and largely available industrial by-products such as calcite (CaCO3) have been considered as sorbents to remediate wastewaters from toxic elements, such as lead, in compliance with the European circular economy strategy. To date few articles are reporting results on lead sorption at the calcite-water solution interface by X-ray photoelectron spectroscopy (XPS) and this investigation aims to clarifying the mechanism of the interaction of Pb2+ model solutions over a wide concentration range, from 0.1 µM to 80 mM, with commercial calcite. X-ray powder diffraction (XRPD), scanning electron microscopy (SEM, EDX) and XPS analysis indicate that when CaCO3 particles are soaked in Pb2+ 0.1 mM and 1 mM solutions, hexagonal platelets of hydrocerussite [(PbCO3)2 Pb(OH)2] precipitate on its surface. When the concentration of Pb2+ is equal or higher than 40 mM, prismatic acicula of cerussite [PbCO3] precipitate. Solution analysis by atomic emission spectroscopy (ICP-AES) and ICP-mass spectrometry (ICP-MS) indicate that Pb2+ removal efficiency is nearly 100%; when the initial Pb2+ concentration was equal to 0.1 µM it was below the limit of detection (LOD) and the efficiency could not be determined. The sorption capacity (qe) increases linearly with increasing initial Pb2+ concentration up to a value of 1680 (20) mg/g when the initial Pb2+concentration is 80 mM. These findings suggest that heterogeneous nucleation and surface co-precipitation occur and calcite can be well considered a very promising sorbent for Pb2+ removal from wastewaters within a wide initial concentration range.


Assuntos
Carbonato de Cálcio , Poluentes Químicos da Água , Adsorção , Carbonato de Cálcio/química , Chumbo , Análise Espectral , Águas Residuárias , Poluentes Químicos da Água/química
13.
Front Oncol ; 12: 835563, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35178353

RESUMO

Tyrosine kinase inhibitors (TKI) may offer a normal life expectancy to Chronic Myeloid Leukemia (CML) patients. However, a higher than expected incidence of arterial occlusive events (AOEs) was observed during treatment with nilotinib. We previously showed an "inflammatory status" during nilotinib that may explain the increased incidence of AOEs. Thus, we conducted this prospective KIARO study involving 186 CML patients (89 imatinib, 59 nilotinib, 38 dasatinib). Interleukin 6 (IL6), interleukin 10 (IL10), Tumor Necrosis Factor-α (TNFα), oxLDL, and high-sensitivity C-reactive protein (hs-CRP) plasma levels were measured at diagnosis and during treatment, with the aim to investigate changes in the inflammatory status favoring AOEs of each patient. Clinical and biochemical pro-atherothrombotic profiles and the 10-year SCORE chart were also evaluated. We showed a pro-inflammatory/pro-oxidative milieu increasing along treatment with nilotinib compared with imatinib or dasatinib, as demonstrated by higher hs-CRP and oxLDL levels and increased IL6/IL10 and TNFα/IL10 ratios only in nilotinib cohort. After median follow-up of 23.3 months starting from TKI, 10/186 patients (5.4%) suffered an AOE. Approximately 5/10 (50%) AOEs occurred during nilotinib treatment despite a lower 10-year SCORE and a lower median age in this subgroup. A longer follow-up is needed to further confirm the active role of nilotinib in AOEs pathogenesis.

16.
ACS Nano ; 15(12): 19256-19265, 2021 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-34817171

RESUMO

A tripod molecule incorporating a C60 photocatalyst into a rigid scaffold with disulfide legs was designed and synthesized for the stable and robust attachment of C60 onto an Au-coated atomic force microscope (AFM) tip. The "tripod-C60" was immobilized onto the tip by forming S-Au bonds in the desired orientation and a dispersed manner, rendering it suitable for the oxidation and scission of single molecules on a countersurface, thereby functioning as "molecular shears". A DNA origami with a well-defined structure was chosen as the substrate for the tip-induced oxidation. The gold-coated, C60-functionalized AFM tip was used for both AFM imaging and oxidation of DNA origami upon visible-light irradiation. The localized and temporally controlled oxidative damage of DNA origami was successfully performed at the single-molecule level via singlet-oxygen (1O2) generation from the immobilized C60 on the AFM tip. This oxidative damage to DNA origami can be carried out under ambient conditions in a fluid cell at room temperature, rendering it well-suited for the manipulation of a variety of species on surfaces via a spatially and temporally controlled oxidation reaction triggered by 1O2 locally generated from the immobilized C60 on the AFM tip.


Assuntos
DNA , Nanotecnologia , Microscopia de Força Atômica , Oxigênio , Espécies Reativas de Oxigênio
17.
Acta Oncol ; 60(11): 1527-1533, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34499575

RESUMO

BACKGROUND: A limited amount of data has been published in chronic-phase chronic myeloid leukemia (CP-CML) patients aged >75 years treated frontline with second-generation tyrosine kinase inhibitors. AIMS: To address this issue in a clinical 'real-life' setting, we retrospectively analyzed 45 CP-CML patients (pts) followed in 20 Italian Centers and treated frontline with dasatinib (DAS). PATIENTS AND METHODS: Median age was 78.4 years (range 75-89.2 years). DAS starting dose was 100 mg QD in 35 pts (77.7%), 80 mg QD in 1 pts (2.2%) and 50 mg QD in 9 pts (20.1%), respectively. The median follow-up was 42.6 months (IQR 20.4 - 63.3). RESULTS: Grade 3 and 4 side effects, both hematological and non-hematological, were detected in 6 (13.3%) and 12 (26.6%) pts, respectively. Pleural effusions of all grades occurred in 13 pts (28.8%) after a median period of DAS exposure of 14.7 months (IQR 3.0 - 33.1). The rates of DAS dose reduction and permanent drug discontinuation were 53.3% and 20.0%, respectively. As the best response, 42/45 patients (93.3%) achieved a complete cytogenetic response (CCyR), 35/45 (77.7%) a major molecular response (MMR) and 24/45 (53.3%) a deep molecular response (both MR 4.0 and MR 4.5). Only 1 patient (2.2%) progressed to the blast phase after 13 months of therapy; 8 deaths were observed (1 CML-related and 7 CML-unrelated). Cumulative event-free survival and overall survival at 36 months were 64.7% (95%, CI 49.4 - 80.0) and 82.3% (95%, CI 70.3-94.3), respectively. CONCLUSION: These findings, although evaluated in a limited and selected cohort of patients, suggest that DAS might be effective in older patients (aged >75 years) affected by CP-CML with acceptable toxicity.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Inibidores de Proteínas Quinases , Idoso , Idoso de 80 Anos ou mais , Dasatinibe/efeitos adversos , Seguimentos , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Inibidores de Proteínas Quinases/efeitos adversos , Estudos Retrospectivos , Resultado do Tratamento
18.
Sci Rep ; 11(1): 14249, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244595

RESUMO

This study aimed at investigating the surface modifications occurring on amphibole asbestos (crocidolite and tremolite) during leaching in a mimicked Gamble's solution at pH of 4.5 and T = 37 °C, from 1 h up to 720 h. Results showed that the fibre dissolution starts with the release of cations prevalently allocated at the various M- and (eventually) A-sites of the amphibole structure (incongruent dissolution). The amount of released silicon, normalized to fibre surface area, highlighted a leaching faster for the crocidolite sample, about twenty times higher than that of tremolite. Besides, the fast alteration of crocidolite promotes the occurrence of Fe centres in proximity of the fibre surface, or possibly even exposed, particularly in the form of Fe(II), of which the bulk is enriched with respect to the oxidized surface. Conversely, for tremolite fibres the very slow fibre dissolution prevents the underlying cations of the bulk to be exposed on the mineral surface, and the iron oxidation, faster than the leaching process, significantly depletes the surface Fe(II) centres initially present. Results of this work may contribute to unravel possible correlations between surface properties of amphibole asbestos and its long-term toxicity.

19.
Nat Nanotechnol ; 16(8): 918-925, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34083772

RESUMO

Minimizing the spread of viruses in the environment is the first defence line when fighting outbreaks and pandemics, but the current COVID-19 pandemic demonstrates how difficult this is on a global scale, particularly in a sustainable and environmentally friendly way. Here we introduce and develop a sustainable and biodegradable antiviral filtration membrane composed of amyloid nanofibrils made from food-grade milk proteins and iron oxyhydroxide nanoparticles synthesized in situ from iron salts by simple pH tuning. Thus, all the membrane components are made of environmentally friendly, non-toxic and widely available materials. The membrane has outstanding efficacy against a broad range of viruses, which include enveloped, non-enveloped, airborne and waterborne viruses, such as SARS-CoV-2, H1N1 (the influenza A virus strain responsible for the swine flu pandemic in 2009) and enterovirus 71 (a non-enveloped virus resistant to harsh conditions, such as highly acidic pH), which highlights a possible role in fighting the current and future viral outbreaks and pandemics.


Assuntos
Amiloide/química , Antivirais/farmacologia , Compostos Férricos/química , Filtros Microporos , Nanopartículas/química , Amiloide/farmacologia , Antivirais/química , Compostos Férricos/farmacologia , Humanos , Lactoglobulinas/química , Filtros Microporos/virologia , Inativação de Vírus/efeitos dos fármacos , Vírus/classificação , Vírus/efeitos dos fármacos , Vírus/isolamento & purificação , Purificação da Água
20.
ACS Appl Mater Interfaces ; 13(24): 29113-29121, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34105349

RESUMO

The efficient and bioorthogonal chemical ligation reaction between potassium acyltrifluoroborates (KATs) and hydroxylamines (HAs) was used for the surface functionalization of a self-assembled monolayer (SAM) with biomolecules. An alkane thioether molecule with one terminal KAT group (S-KAT) was synthesized and adsorbed onto a gold surface, placing a KAT group on the top of the monolayer (KAT-SAM). As an initial test case, an aqueous solution of a hydroxylamine (HA) derivative of poly(ethylene glycol) (PEG) (HA-PEG) was added to this KAT-SAM at room temperature to perform the surface KAT ligation. Quartz crystal microbalance with dissipation (QCM-D) monitoring confirmed the rapid attachment of the PEG moiety onto the SAM. By surface characterization methods such as contact angle and ellipsometry, the attachment of PEG layer was confirmed, and covalent amide-bond formation was established by X-ray photoelectron spectroscopy (XPS). In a proof-of-concept study, the applicability of this surface KAT ligation for the attachment of biomolecules to surfaces was tested using a model protein, green fluorescent protein (GFP). A GFP was chemically modified with an HA linker to synthesize HA-GFP and added to the KAT-SAM under aqueous dilute conditions. A rapid attachment of the GFP on the surface was observed in real time by QCM-D. Despite the fact that such biomolecules have a variety of unprotected functional groups within their structures, the surface KAT ligation proceeded rapidly in a chemoselective manner. Our results demonstrate the versatility of the KAT ligation for the covalent attachment of a variety of water-soluble molecules onto SAM surfaces under dilute and biocompatible conditions to form stable, natural amide bonds.


Assuntos
Boratos/química , Proteínas de Fluorescência Verde/química , Proteínas Imobilizadas/química , Membranas Artificiais , Hidroxilaminas/química , Polietilenoglicóis/química , Estudo de Prova de Conceito
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