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1.
Nanoscale Adv ; 6(9): 2287-2305, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38694476

RESUMO

Coumarins, methylene blue derivatives, as well as related functional organic dyes have become prevalent tools in life sciences and biomedicine. Their intense blue fluorescence emission makes them ideal agents for a range of applications, yet an unwanted facet of the interesting biological properties of such probes presents a simultaneous environmental threat due to inherent toxicity and persistence in aqueous media. As such, significant research efforts now ought to focus on their removal from the environment, and the sustainable trapping onto widely available, water dispersible and processable adsorbent structures such as graphene oxides could be advantageous. Additionally, flat and aromatic bis(thiosemicarbazones) (BTSCs) have shown biocompatibility and chemotherapeutic potential, as well as intrinsic fluorescence, hence traceability in the environment and in living systems. A new palette of graphene oxide-based hierarchical supramolecular materials incorporating BTSCs were prepared, characterised, and reported hereby. We report on the supramolecular entrapping of several flat, aromatic fluorogenic molecules onto graphene oxide on basis of non-covalent interactions, by virtue of their structural features with potential to form aromatic stacks and H-bonds. The evaluations of the binding interactions in solution by between organic dyes (methylene blue and functional coumarins) and new graphene oxide-anchored Zn(ii) derivatised bis(thiosemicarbazones) nanohybrids were carried out by UV-Vis and fluorescence spectroscopies.

2.
Int J Mol Sci ; 25(3)2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38338774

RESUMO

Although calcineurin inhibitors are very effective as immunosuppressants in organ transplantation, complete graft acceptance remains as a challenge. Transfer of genes with immunosuppressant functions could contribute to improving the clinical evolution of transplantation. In this sense, hydrodynamic injection has proven very efficacious for liver gene transfer. In the present work, the hIL-10 gene was hydrofected 'ex vivo' to pig livers during the bench surgery stage, to circumvent the cardiovascular limitations of the procedure, in a model of porcine orthotopic transplantation with a 10-day follow-up. We used IL-10 because human and porcine proteins can be differentially quantified and for its immunomodulatory pleiotropic functions. Safety (biochemical parameters and histology), expression efficacy (RNA transcription and blood protein expression), and acute inflammatory response (cytokines panel) of the procedure were evaluated. The procedure proved safe as no change in biochemical parameters was observed in treated animals, and human IL-10 was efficaciously expressed, with stationary plasma protein levels over 20 pg/mL during the follow-up. Most studied cytokines showed increments (interferon-α, IFN-α; interleukin-1ß, IL-1ß; tumor necrosis factor α, TNFα; interleukin-6, IL-6; interleukin-8, IL-8; interleukin-4, IL-4; and transforming growth factor-ß, TGF-ß) in treated animals, without deleterious effects on tissue. Collectively, the results support the potential clinical interest in this gene therapy model that would require further longer-term dose-response studies to be confirmed.


Assuntos
Hidrodinâmica , Interleucina-10 , Humanos , Animais , Suínos , Interleucina-10/genética , Interleucina-10/metabolismo , Fígado/metabolismo , Citocinas/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Interleucina-6/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-1beta/metabolismo
3.
ACS Bio Med Chem Au ; 3(5): 389-417, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37876497

RESUMO

Nanotechnology advances have the potential to assist toward the earlier detection of diseases, giving increased accuracy for diagnosis and helping to personalize treatments, especially in the case of noncommunicative diseases (NCDs) such as cancer. The main advantage of nanoparticles, the scaffolds underpinning nanomedicine, is their potential to present multifunctionality: synthetic nanoplatforms for nanomedicines can be tailored to support a range of biomedical imaging modalities of relevance for clinical practice, such as, for example, optical imaging, computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET). A single nanoparticle has the potential to incorporate myriads of contrast agent units or imaging tracers, encapsulate, and/or be conjugated to different combinations of imaging tags, thus providing the means for multimodality diagnostic methods. These arrangements have been shown to provide significant improvements to the signal-to-noise ratios that may be obtained by molecular imaging techniques, for example, in PET diagnostic imaging with nanomaterials versus the cases when molecular species are involved as radiotracers. We surveyed some of the main discoveries in the simultaneous incorporation of nanoparticulate materials and imaging agents within highly kinetically stable radio-nanomaterials as potential tracers with (pre)clinical potential. Diversity in function and new developments toward synthesis, radiolabeling, and microscopy investigations are explored, and preclinical applications in molecular imaging are highlighted. The emphasis is on the biocompatible materials at the forefront of the main preclinical developments, e.g., nanoceramics and liposome-based constructs, which have driven the evolution of diagnostic radio-nanomedicines over the past decade.

4.
Front Chem ; 10: 919505, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35646818

RESUMO

[This corrects the article DOI: 10.3389/fchem.2022.830133.].

5.
Front Chem ; 10: 830133, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35494646

RESUMO

We highlight hereby recent developments in the emerging field of theranostics, which encompasses the combination of therapeutics and diagnostics in a single entity aimed for an early-stage diagnosis, image-guided therapy as well as evaluation of therapeutic outcomes of relevance to prostate cancer (PCa). Prostate cancer is one of the most common malignancies in men and a frequent cause of male cancer death. As such, this overview is concerned with recent developments in imaging and sensing of relevance to prostate cancer diagnosis and therapeutic monitoring. A major advantage for the effective treatment of PCa is an early diagnosis that would provide information for an appropriate treatment. Several imaging techniques are being developed to diagnose and monitor different stages of cancer in general, and patient stratification is particularly relevant for PCa. Hybrid imaging techniques applicable for diagnosis combine complementary structural and morphological information to enhance resolution and sensitivity of imaging. The focus of this review is to sum up some of the most recent advances in the nanotechnological approaches to the sensing and treatment of prostate cancer (PCa). Targeted imaging using nanoparticles, radiotracers and biomarkers could result to a more specialised and personalised diagnosis and treatment of PCa. A myriad of reports has been published literature proposing methods to detect and treat PCa using nanoparticles but the number of techniques approved for clinical use is relatively small. Another facet of this report is on reviewing aspects of the role of functional nanoparticles in multimodality imaging therapy considering recent developments in simultaneous PET-MRI (Positron Emission Tomography-Magnetic Resonance Imaging) coupled with optical imaging in vitro and in vivo, whilst highlighting feasible case studies that hold promise for the next generation of dual modality medical imaging of PCa. It is envisaged that progress in the field of imaging and sensing domains, taken together, could benefit from the biomedical implementation of new synthetic platforms such as metal complexes and functional materials supported on organic molecular species, which can be conjugated to targeting biomolecules and encompass adaptable and versatile molecular architectures. Furthermore, we include hereby an overview of aspects of biosensing methods aimed to tackle PCa: prostate biomarkers such as Prostate Specific Antigen (PSA) have been incorporated into synthetic platforms and explored in the context of sensing and imaging applications in preclinical investigations for the early detection of PCa. Finally, some of the societal concerns around nanotechnology being used for the detection of PCa are considered and addressed together with the concerns about the toxicity of nanoparticles-these were aspects of recent lively debates that currently hamper the clinical advancements of nano-theranostics. The publications survey conducted for this review includes, to the best of our knowledge, some of the most recent relevant literature examples from the state-of-the-art. Highlighting these advances would be of interest to the biomedical research community aiming to advance the application of theranostics particularly in PCa diagnosis and treatment, but also to those interested in the development of new probes and methodologies for the simultaneous imaging and therapy monitoring employed for PCa targeting.

6.
Int J Mol Sci ; 23(6)2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35328831

RESUMO

In recent decades, the demand for biomedical imaging tools has grown very rapidly as a key feature for biomedical research and diagnostic applications. Particularly, fluorescence imaging has gained increased attention as a non-invasive, inexpensive technique that allows real-time imaging. However, tissue auto-fluorescence under external illumination, together with a weak tissue penetration of low wavelength excitation light, largely restricts the application of the technique. Accordingly, new types of fluorescent labels are currently being investigated and, in this search, phosphorescent nanoparticles promise great potential, as they combine the interesting size-dependent properties of nanoscale materials with a long-lasting phosphorescence-type emission that allows optical imaging well after excitation (so avoiding autofluorescence). In this work, core-shell structures consisting of SrAlO:Eu,Dy luminescent cores encapsulated within a biocompatible silica shell were prepared, showing a green persistent phosphorescence with an afterglow time of more than 1000 s. A high-energy ball milling procedure was used to reduce the size of the starting phosphors to a size suitable for cellular uptake, while the silica coating was produced by a reverse micelle methodology that eventually allows the excitation and emission light to pass efficiently through the shell. Confocal fluorescence microscopy using HeLa cancer cells confirmed the potential of the all-ceramic composites produced as feasible labels for in vitro optical imaging.


Assuntos
Metais Terras Raras , Nanopartículas , Humanos , Luminescência , Nanopartículas/química , Imagem Óptica , Dióxido de Silício , Estrôncio
7.
ACS Nano ; 16(3): 3934-3942, 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35225592

RESUMO

A macroscopic-assembled graphene oxide (GO) membrane with sustainable high strength presents a bright future for its applications in ionic and molecular filtration for water purification or fast force response for sensors. Traditionally, the bottom-up macroscopic assembly of GO sheets is optimized by widening the interlaminar space for expediting water passage, frequently leading to a compromise in strength, assembly time, and ensemble thickness. Herein, we rationalize this strategy by implanting a superhydrophilic bridge of cobalt-based metal-organic framework nanosheets (NMOF-Co) as an additional water "aisle" into the interlaminar space of GO sheets (GO/NMOF-Co), resulting in a high-strength macroscopic membrane ensemble with tunable thickness from the nanometer scale to the centimeter scale. The GO/NMOF-Co membrane assembly time is only 18 s, 30800 times faster than that of pure GO (154 h). More importantly, the obtained membrane attains a strength of 124.4 MPa, which is more than 3 times higher than that of the GO membrane prepared through filtration. The effect of hydrophilicity on membrane assembly is also investigated by introducing different intercalants, suggesting that, except for the interlamellar spacing, the interlayered hydrophilicity plays a more decisive role in the macroscopic assembly of GO membranes. Our results give a fundamental implication for fast macroscopic assembly of high-strength 2D materials.

8.
Front Chem ; 9: 727574, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34660529

RESUMO

As a primary goal, this review highlights the role of supramolecular interactions in the assembly of new sustainable materials incorporating functional porphyrins and carbon nanoplatforms as building blocks for photovoltaics advancements.

9.
ACS Appl Bio Mater ; 4(5): 4105-4118, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34056563

RESUMO

Existing fluorescent labels used in life sciences are based on organic compounds with limited lifetime or on quantum dots which are either expensive or toxic and have low kinetic stability in biological environments. To address these challenges, luminescent nanomaterials have been conceived as hierarchical, core-shell structures with spherical morphology and highly controlled dimensions. These tailor-made nanophosphors incorporate Ln:YVO4 nanoparticles (Ln = Eu(III) and Er(III)) as 50 nm cores and display intense and narrow emission maxima centered at ∼565 nm. These cores can be encapsulated in silica shells with highly controlled dimensions as well as functionalized with chitosan or PEG5000 to reduce nonspecific interactions with biomolecules in living cells. Confocal fluorescence microscopy in living prostate cancer cells confirmed the potential of these platforms to overcome the disadvantages of commercial fluorophores and their feasibility as labels for multiplexing, biosensing, and imaging in life science assays.


Assuntos
Materiais Biocompatíveis/química , Corantes Fluorescentes/química , Imagem Óptica , Neoplasias da Próstata/diagnóstico por imagem , Linhagem Celular Tumoral , Humanos , Elementos da Série dos Lantanídeos/química , Masculino , Teste de Materiais , Nanopartículas/química , Tamanho da Partícula , Compostos de Vanádio/química , Ítrio/química
10.
Updates Surg ; 72(4): 1041-1051, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32734578

RESUMO

Laparoscopic hemihepatectomy (LHH) may offer advantages over open hemihepatectomy (OHH) in blood loss, recovery, and hospital stay. The aim of this study is to evaluate our recent experience performing hemihepatectomy and compare complications and costs up to 90 days following laparoscopic versus open procedures. Retrospective evaluation of patients undergoing hemihepatectomy at our center 01/2010-12/2018 was performed. Patient, tumor, and surgical characteristics; 90-day complications; and costs were analyzed. Inverse probability of treatment weighting (IPTW) was used to balance covariates. A total of 141 hemihepatectomies were included: 96 OHH and 45 LHH. While operative times were longer for LHH, blood loss and transfusions were less. At 90 days, there were similar rates of liver-specific and surgical complications but fewer medical complications following LHH. Medical complications that arose with greater frequency following OHH were primarily pulmonary complications and urinary and central venous catheter infections. Complications at 90 days were lower following LHH (Clavien-Dindo grade ≥ III OHH 23%, LHH 11%, p = 0.130; Comprehensive Complication Index OHH 20.0 ± 16.1, LHH 10.9 ± 14.2, p = 0.001). While operating costs were higher, costs for hospital stay and readmissions were lower with LHH. Patients undergoing LHH experience a significant reduction in postoperative medical complications and costs, resulting in 90-day cost equity compared with OHH.


Assuntos
Custos e Análise de Custo , Hepatectomia/economia , Hepatectomia/métodos , Laparoscopia/economia , Laparoscopia/métodos , Neoplasias Hepáticas/economia , Neoplasias Hepáticas/cirurgia , Complicações Pós-Operatórias/epidemiologia , Pontuação de Propensão , Idoso , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Feminino , Humanos , Tempo de Internação/economia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/economia , Doenças Respiratórias/economia , Doenças Respiratórias/epidemiologia , Estudos Retrospectivos , Fatores de Tempo
11.
ChemistryOpen ; 9(2): 242-252, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32149034

RESUMO

We report on the design and testing of new graphite and graphene oxide-based extended π-conjugated synthetic scaffolds for applications in sustainable chemistry transformations. Nanoparticle-functionalised carbonaceous catalysts for new Fischer Tropsch and Reverse GasWater Shift (RGWS) transformations were prepared: functional graphene oxides emerged from graphite powders via an adapted Hummer's method and subsequently impregnated with uniform-sized nanoparticles. Then the resulting nanomaterials were imaged by TEM, SEM, EDX, AFM and characterised by IR, XPS and Raman spectroscopies prior to incorporation of Pd(II) promoters and further microscopic and spectroscopic analysis. Newly synthesised 2D and 3D layered nanostructures incorporating carbon-supported iron oxide nanoparticulate pre-catalysts were tested, upon hydrogen reduction in situ, for the conversion of CO2 to CO as well as for the selective formation of CH4 and longer chain hydrocarbons. The reduction reaction was also carried out and the catalytic species isolated and fully characterised. The catalytic activity of a graphene oxide-supported iron oxide pre-catalyst converted CO2 into hydrocarbons at different temperatures (305, 335, 370 and 405 °C), and its activity compared well with that of the analogues supported on graphite oxide, the 3-dimensional material precursor to the graphene oxide. Investigation into the use of graphene oxide as a framework for catalysis showed that it has promising activity with respect to reverse gas water shift (RWGS) reaction of CO2 to CO, even at the low levels of catalyst used and under the rather mild conditions employed at atmospheric pressure. Whilst the γ-Fe2O3 decorated graphene oxide-based pre-catalyst displays fairly constant activity up to 405 °C, it was found by GC-MS analysis to be unstable with respect to decomposition at higher temperatures. The addition of palladium as a promoter increased the activity of the iron functionalised graphite oxide in the RWGS. The activity of graphene oxide supported catalysts was found to be enhanced with respect to that of iron-functionalised graphite oxide with, or without palladium as a promoter, and comparable to that of Fe@carbon nanotube-based systems tested under analogous conditions. These results display a significant step forward for the catalytic activity estimations for the iron functionalised and rapidly processable and scalable graphene oxide. The hereby investigated phenomena are of particular relevance for the understanding of the intimate surface morphologies and the potential role of non-covalent interactions in the iron oxide-graphene oxide networks, which could inform the design of nano-materials with performance in future sustainable catalysis applications.

12.
Transplantation ; 104(10): 2087-2096, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-31978002

RESUMO

BACKGROUND: There is a lack of data on the use of direct-acting antivirals (DAA) on the risk of death and tumoral recurrence in patients with hepatitis C virus (HCV) and hepatocellular carcinoma (HCC) listed for liver transplantation (LT). We aimed to assess the impact of antiviral treatment on mortality and HCC recurrence patients with HCC-HCV. METHODS: This was a retrospective multicenter study of patients with HCC-HCV listed for LT from 2005 to 2015. Patients were divided according to the antiviral treatment received after HCC diagnosis: DAA, interferon (IFN), or no antiviral. Intention-to-treat overall survival and HCC recurrence incidence were compared by the Kaplan-Meier method. Multivariable regression analysis was performed to identify risk factors for outcomes. RESULTS: A total of 1012 HCV-HCC patients were listed for LT during the study period. The median follow-up was 4.0 (interquartile range = 2.3-6.7) years. Mortality was 5.6 (95% confidence interval [CI], 4.3-7.2), 13.1 (95% CI, 11.0-15.7), and 6.2 (95% CI, 5.4-7.2) deaths per 100 person-year among patients treated with DAA, IFN, and antiviral naïve, respectively (P < 0.001). Of the 875 HCV-HCC transplant recipients, the 5-year recurrence-free survival was 93.4%, 84.8%, 73.9% for the pre-LT DAA, pre-LT IFN, and antiviral naïve groups, respectively (P < 0.001). After multivariable regression, the use of pre-LT DAA was not associated to risk of recurrence (hazard ratio = 0.44 [95% CI, 0.19-1.00]). Post-LT DAA was not related to increased risk of recurrence (hazard ratio = 0.62 [95% CI, 0.33-1.16]). CONCLUSIONS: In this multicenter intent-to-treat study, DAA therapy was not found to be a risk factor for mortality or HCC recurrence after adjusting for potential confounders.


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular/terapia , Hepatite C/tratamento farmacológico , Neoplasias Hepáticas/terapia , Transplante de Fígado , Recidiva Local de Neoplasia , Listas de Espera , Antivirais/efeitos adversos , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/secundário , Feminino , Hepatite C/diagnóstico , Hepatite C/mortalidade , Humanos , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Transplante de Fígado/efeitos adversos , Transplante de Fígado/mortalidade , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Listas de Espera/mortalidade
13.
Nanotechnology ; 31(4): 045603, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31589147

RESUMO

Anatase TiO2 has become a material of great interest for photocatalytic production of hydrogen, environmental purification and solar energy conversion. Among the key parameters boosting the photocatalytic efficiency of the anatase nanoparticles, an increased light absorption to expand its optical response to the visible region, together with an improved charge separation of the photo-generated electrons and holes, can be enumerated. In this work, yellow-coloured, single-phase anatase nanoparticles have been obtained using a simple two-step solvothermal routine which requires no external addition of dopants, nor the use of a harassing/aggressive synthesis atmosphere. The obtained powders display a lowered bandgap (<3.0 eV) and significantly reduce the recombination processes, eventually leading to an improved photocatalytic performance under visible light, as exemplified by an enhanced degradation of phenol. This exceptional response is linked to the presence of intrinsic defects in the yellowish particles and, hence, the specific conditions of the proposed methodology become crucial to produce a propitious TiO2-defective nanomaterial capable of photo-degrade the phenol molecule, in contrast with the lack of photocatalytic activity currently exhibited by commercial photocatalysts under visible light.

14.
J Proteomics ; 212: 103581, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-31731051

RESUMO

Nowadays, there are no targeted therapeutic modalities for triple negative breast cancer (TNBC). This disease is associated with poor prognosis and worst clinical outcome because of the aggressive nature of the tumor, delayed diagnosis, and non-specific symptoms in the early stages. Therefore, identification of novel specific TNBC serum biomarkers for screening and therapeutic purposes remains an urgent clinical requirement. New user-friendly and cheap methods for biomarker identification are needed, and nanotechnology offers new opportunities. When dispersed in blood, nanoparticles (NPs) are covered by a protein shell termed "protein corona" (PC). While alterations in protein patterns are challeging to detect by conventional blood analyses, PC acts as a "nano-concentrator" of serum proteins with affinity for NPs' surface. So, the characterization of PC could allow the detection of otherwise undetectable changes in protein concentration at an early stage of the disease or after chemotherapy or surgery. To explore this research idea, serum samples from 8 triple negative breast cancer (TNBC) patients and 8 patients without malignancy were allowed to interact with gold nanoparticles (AuNPs: 10.02 ±â€¯0.91 nm), silver nanoparticles (AgNPs: 9.73 ±â€¯1.70 nm) and magnetic nanoparticles (MNPs: (9.30 ±â€¯0.67 nm). Here, in order to identify biomarker candidates in serum of TNBC patients, these nanomaterials were combined with electrophoretic separation (SDS-PAGE) to performed qualitative and quantitative comparisons of the serum proteomes of TNBC patients (n = 8) and healthy controls (n = 8) by liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis. The results were validated through a sequential window acquisition of all theoretical mass spectra (SWATH) analysis, performed in total serum samples (patients and controls) using this approach as a multiple reaction monitoring (MRM) analysis. SIGNIFICANCE: It is well known that several proteins presented in human serum are important biomarkers for the diagnosis or prognosis of different diseases, as triple negative breast cancer (TNBC). Determining how nanomaterials as gold nanoparticles (AuNPs: 10.02 ±â€¯0.91 nm), silver nanoparticles (AgNPs: 9.73 ±â€¯1.70 nm) and magnetic nanoparticles (MNPs: (9.30 ±â€¯0.67 nm) interact with human serum will assist not only in understanding their effects on the biological system (biocompability and toxicity), but also to obtain information for developing novel nanomaterials with high specificity and selectivity towards proteins with an important biological function (prognostic and diagnostic protein biomarkers).


Assuntos
Biomarcadores Tumorais/sangue , Proteínas Sanguíneas/metabolismo , Nanopartículas Metálicas/análise , Coroa de Proteína/análise , Proteoma/análise , Proteômica/métodos , Neoplasias de Mama Triplo Negativas/diagnóstico , Adulto , Idoso , Estudos de Casos e Controles , Cromatografia Líquida/métodos , Feminino , Ouro/química , Voluntários Saudáveis , Humanos , Ferro/química , Nanopartículas Metálicas/química , Pessoa de Meia-Idade , Prognóstico , Coroa de Proteína/química , Proteoma/metabolismo , Prata/química , Espectrometria de Massas em Tandem/métodos , Neoplasias de Mama Triplo Negativas/sangue
15.
ChemistryOpen ; 8(12): 1383-1398, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31844605

RESUMO

Three-dimensional fluorescent graphene frameworks with controlled porous morphologies are of significant importance for practical applications reliant on controlled structural and electronic properties, such as organic electronics and photochemistry. Here we report a synthetically accessible approach concerning directed aromatic stacking interactions to give rise to new fluorogenic 3D frameworks with tuneable porosities achieved through molecular variations. The binding interactions between the graphene-like domains present in the in situ-formed reduced graphene oxide (rGO) with functional porphyrin molecules lead to new hybrids via an unprecedented solvothermal reaction. Functional free-base porphyrins featuring perfluorinated aryl groups or hexyl chains at their meso- and ß-positions were employed in turn to act as directing entities for the assembly of new graphene-based and foam-like frameworks and of their corresponding coronene-based hybrids. Investigations in the dispersed phase and in thin-film by XPS, SEM and FLIM shed light onto the nature of the aromatic stacking within functional rGO frameworks (denoted rGOFs) which was then modelled semi-empirically and by DFT calculations. The pore sizes of the new emerging reduced graphene oxide hybrids are tuneable at the molecular level and mediated by the bonding forces with the functional porphyrins acting as the "molecular glue". Single crystal X-ray crystallography described the stacking of a perfluorinated porphyrin with coronene, which can be employed as a molecular model for understanding the local aromatic stacking order and charge transfer interactions within these rGOFs for the first time. This opens up a new route to controllable 3D framework morphologies and pore size from the Ångstrom to the micrometre scale. Theoretical modelling showed that the porosity of these materials is mainly due to the controlled inter-planar distance between the rGO, coronene or graphene sheets. The host-guest chemistry involves the porphyrins acting as guests held through π-π stacking, as demonstrated by XPS. The objective of this study is also to shed light into the fundamental localised electronic and energy transfer properties in these new molecularly engineered porous and fluorogenic architectures, aiming in turn to understand how functional porphyrins may exert stacking control over the notoriously disordered local structure present in porous reduced graphene oxide fragments. By tuning the porosity and the distance between the graphene sheets using aromatic stacking with porphyrins, it is also possible to tune the electronic structure of the final nanohybrid material, as indicated by FLIM experiments on thin films. Such nanohybrids with highly controlled pores dimensions and morphologies open the way to new design and assembly of storage devices and applications incorporating π-conjugated molecules and materials and their π-stacks may be relevant towards selective separation membranes, water purification and biosensing applications.

16.
ChemNanoMat ; 4(4): 361-372, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29938196

RESUMO

Molecular imaging has become a powerful technique in preclinical and clinical research aiming towards the diagnosis of many diseases. In this work, we address the synthetic challenges in achieving lab-scale, batch-to-batch reproducible copper-64- and gallium-68-radiolabelled metal nanoparticles (MNPs) for cellular imaging purposes. Composite NPs incorporating magnetic iron oxide cores with luminescent quantum dots were simultaneously encapsulated within a thin silica shell, yielding water-dispersible, biocompatible and luminescent NPs. Scalable surface modification protocols to attach the radioisotopes 64Cu (t1/2=12.7 h) and 68Ga (t1/2=68 min) in high yields are reported, and are compatible with the time frame of radiolabelling. Confocal and fluorescence lifetime imaging studies confirm the uptake of the encapsulated imaging agents and their cytoplasmic localisation in prostate cancer (PC-3) cells. Cellular viability assays show that the biocompatibility of the system is improved when the fluorophores are encapsulated within a silica shell. The functional and biocompatible SiO2 matrix represents an ideal platform for the incorporation of 64Cu and 68Ga radioisotopes with high radiolabelling incorporation.

17.
ChemistryOpen ; 7(2): 144-158, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29435400

RESUMO

The encapsulation of CdSe nanocrystals within single-walled carbon nanotube (SWNT) cavities of varying dimensions at elevated temperatures under strictly air-tight conditions is described for the first time. The structures of CdSe nanocrystals under confinement inside SWNTs was established in a comprehensive study, combining both experimental and DFT theoretical investigations. The calculated binding energies show that all considered polymorphs [(3:3), (4:4), and (4:2)] may be obtained experimentally. The most thermodynamically stable structure (3:3) is directly compared to the experimentally observed CdSe structures inside carbon nanotubes. The gas-phase DFT-calculated energy difference between "free" 3:3 and 4:2 structures (whereby 3:3 models a novel tubular structure in which both Cd and Se form three coordination, as observed experimentally for HgTe inside SWNT, and 4:2 is a motif derived from the hexagonal CuI bulk structure in which both Cd and Se form 4 or 2 coordination) is surprisingly small, only 0.06 eV per formula unit. X-ray powder diffraction, Raman spectroscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray analyses led to the full characterization of the SWNTs filled with the CdSe nanocrystals, shedding light on the composition, structure, and electronic interactions of the new nanohybrid materials on an atomic level. A new emerging hybrid nanomaterial, simultaneously filled and beta-d-glucan coated, was obtained by using pristine nanotubes and bulk CdSe powder as starting materials. This displayed fluorescence in water dispersions and unexpected biocompatibility was found to be mediated by beta-d-glucan (a biopolymer extracted from barley) with respect to that of the individual inorganic material components. For the first time, such supramolecular nanostructures are investigated by life-science techniques applied to functional nanomaterial characterization, opening the door for future nano-biotechnological applications.

18.
Surg Endosc ; 32(5): 2345-2354, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29218665

RESUMO

BACKGROUND: The advantages of laparoscopy over open liver resection in patients with cirrhosis have been widely demonstrated. On the other hand, information on the role of minimally invasive liver surgery in the presence of clinically significant portal hypertension (CSPH) is scarce. The aim of this study was to evaluate the role of laparoscopic liver resection in selected cirrhotic patients with CSPH. METHODS: A retrospective case-control study of cirrhotic patients with hepatocellular carcinoma who were treated with laparoscopic liver resection was conducted from December 2005 to April 2016. A total of 45 patients were included. Patients were divided into two groups according to the presence or absence of clinically significant portal hypertension. Fifteen cirrhotic patients with CSPH were matched with 30 patients without CSPH. RESULTS: Overall, there were no differences in intraoperative results. No conversion to open surgery occurred in the CSPH group, and 3 patients were converted in the Non-CSPH group (0 vs. 10% p = 0.57). Only 2 (7%) patients in the Non-CSPH group and 1 (7%) in the CSPH group had relevant complications (modified Clavien-Dindo classification III). Two patients in the Non-CSPH group and one in the CSPH group developed transient ascites (7 vs. 7%). Postoperative hospital stay was similar in both groups, with a median of 4 days in the CSPH group and 3 days in the Non-CSPH group (p = 0.37). The median follow-up of the entire cohort was 38 months (range 7-100). Overall survival rates at 1 and 3 years were 100 and 87%, respectively. There was no significant difference between the groups in terms of survival (p = 0.8). CONCLUSION: This initial study showed that laparoscopic resection in patients with CSPH can be performed safely in well-selected patients and expand the current surgical indications in patients with CSPH. Prospective trials with a larger sample size are necessary to confirm these results.


Assuntos
Carcinoma Hepatocelular/cirurgia , Hepatectomia/métodos , Hipertensão Portal/complicações , Laparoscopia , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Carcinoma Hepatocelular/mortalidade , Estudos de Casos e Controles , Conversão para Cirurgia Aberta/estatística & dados numéricos , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Cirrose Hepática/complicações , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
19.
Chem Commun (Camb) ; 54(2): 184-187, 2018 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-29220059

RESUMO

We have developed a green and robust fluorogenic (λex = 410 nm, λem = 510 nm) cellulose membrane using graphene oxide (GO) as a construct for simultaneous copper ion recognition and filtration at environmentally relevant levels. The detection limit and removal limit of Cu2+ are 7.3 × 10-7 M and 1000 ppm, respectively. The simplicity and scalability achieved for the detection and removal of metal ions in waste water is particularly noteworthy given the significant problems associated with metal ion pollution of drinking water.


Assuntos
Celulose/análogos & derivados , Celulose/química , Cobre/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Animais , Técnicas Biossensoriais/métodos , Filtração/instrumentação , Fluorescência , Grafite/química , Limite de Detecção , Membranas Artificiais , Naftalimidas/síntese química , Naftalimidas/química , Reciclagem , Água/química , Molhabilidade
20.
Cir Esp ; 95(8): 437-446, 2017 Oct.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-28818290

RESUMO

INTRODUCTION: We analyze major liver resections performed in 10 years, with the objective of evaluating perioperative results. As secondary objectives, factors related to major complications and comparative analyses of 25-year periods are evaluated. METHODS: Retrospective analysis of patients undergoing major hepatic resection (3 or more segments) from January 2005 to December 2014, from pre, intra and postoperative data. The Clavien classification is used for postoperative morbidity. RESULTS: A total of 416 major hepatectomies were performed. Transfusions were performed in 38 patients (9.1%). A Pringle maneuver was used in 47.7% of the cases. Half of the patients had no complications, and only 96 patients (23%) had a major complication. Bile leakage was the most frequent complication (n=72, 17.3% of patients), especially due to malignant disease and biliary reconstruction, high risk ASA (III-IV) and prolonged surgical time. Thirteen patients met criteria for liver failure, of which 7died (5 associated a bacterial infection). The mean hospital stay was 12.5 days, with an 11,8% readmission rate. When comparing 25-year periods, at present more complex patients are operated on, with a lower incidence of transfusions and complications (ns). CONCLUSIONS: Liver surgery has increased significantly in recent years. Surgical management of the liver now allows safe and effective surgery, with a very low complication rate. The limit of resectability depends on the residual hepatic volume.


Assuntos
Hepatectomia , Hepatopatias/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Hepatectomia/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
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