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1.
Materials (Basel) ; 16(4)2023 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-36837351

RESUMEN

The production of glass foams obtained by recycling post-consumer glass and textile industry processing waste is presented. The mechanical, thermal and acoustic properties were characterized as a function of process temperature and time. The results showed that it is possible to produce glass foams with thermal and acoustic insulation properties from a mixture consisting of 96.5% of glass waste, 1% of textile waste and 2.5% of manganese dioxide, processed at temperatures between 800 and 900 °C for a time between 30 and 90 min. The samples had density in the range of 200-300 kg m-3, porosity of 87-92%, thermal conductivity of 85-105 mW m-1 K-1, noise-reducing factors of 0.15-0.40 and compressive strength of 1.2-3.0 MPa. Although their insulation performance was not as outstanding as that of polymer foams, these materials can emerge as competitive candidates for applications requiring non-flammability and high-temperature load bearing capacity in combination with low weight, mechanical strength, and thermal and acoustic insulation properties. The use of secondary raw materials (which accounted for 97.5% by weight of the synthetic blend) limits the energy required compared to that needed for the extraction, transportation and processing of primary raw materials, making these foams attractive also in terms of environmental footprint.

2.
Contrast Media Mol Imaging ; 2021: 6664471, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33880112

RESUMEN

Despite the progress in cardiovascular research, atherosclerosis still represents the main cause of death worldwide. Clinically, the diagnosis of Atherosclerotic Cardiovascular Disease (ASCVD) relies on imaging methodologies including X-ray angiography and computed tomography (CT), which however still fails in the identification of patients at high risk of plaque rupture, the main cause of severe clinical events as stroke and heart attack. Magnetic resonance imaging, which is characterized by very high spatial resolution, could provide a better characterization of atherosclerotic plaque (AP) anatomy and composition, aiding in the identification of "vulnerable" plaques. In this context, hydrogel matrices, which have been demonstrated able to boost relaxometric properties of Gd-based contrast agents (CAs) by the effect of Hydrodenticity, represent a valuable tool towards the precision imaging of ASCVD improving the performance of this class of CAs while reducing systemic toxicity. In particular, hydrogel nanoparticles encapsulating Gd-DTPA can further contribute to providing CA-specific accumulation in the AP by nanoparticle surface decoration triggering an active targeting of the AP with the overall effect of allowing an earlier and more accurate diagnosis. In this work, we tested crosslinked Hyaluronic Acid Nanoparticles (cHANPs) in the complex environment of human atherosclerotic plaque. In addition, the surface of cHANPs was decorated with the antibody anti-CD36 (Ab36-cHANPs) for the active targeting of AP-associated macrophages. Results demonstrate that the Hydrodenticity of cHANPs and Ab36-cHANPs is preserved in this complex system and, preliminarily, that interaction of these probes with the AP is present.


Asunto(s)
Aterosclerosis/diagnóstico por imagen , Imagen por Resonancia Magnética , Nanopartículas/química , Placa Aterosclerótica/diagnóstico por imagen , Aterosclerosis/diagnóstico , Aterosclerosis/patología , Medios de Contraste/química , Medios de Contraste/farmacología , Gadolinio DTPA/farmacología , Humanos , Ácido Hialurónico/química , Ácido Hialurónico/farmacología , Macrófagos/efectos de los fármacos , Microscopía Electrónica de Rastreo , Placa Aterosclerótica/patología
3.
Nanomaterials (Basel) ; 11(3)2021 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-33803884

RESUMEN

Nanoparticles (NPs) are promising platforms for the development of diagnostic and therapeutic tools. One of the main hurdle to their medical application and translation into the clinic is the fact that they accumulate in the spleen and liver due to opsonization and scavenging by the mononuclear phagocyte system. The "protein corona" controls the fate of NPs in vivo and becomes the interface with cells, influencing their physiological response like cellular uptake and targeting efficiency. For these reasons, the surface properties play a pivotal role in fouling and antifouling behavior of particles. Therefore, surface engineering of the nanocarriers is an extremely important issue for the design of useful diagnostic and therapeutic systems. In recent decades, a huge number of studies have proposed and developed different strategies to improve antifouling features and produce NPs as safe and performing as possible. However, it is not always easy to compare the various approaches and understand their advantages and disadvantages in terms of interaction with biological systems. Here, we propose a systematic study of literature with the aim of summarizing current knowledge on promising antifouling coatings to render NPs more biocompatible and performing for diagnostic and therapeutic purposes. Thirty-nine studies from 2009 were included and investigated. Our findings have shown that two main classes of non-fouling materials (i.e., pegylated and zwitterionic) are associated with NPs and their applications are discussed here highlighting pitfalls and challenges to develop biocompatible tools for diagnostic and therapeutic uses. In conclusion, although the complexity of biofouling strategies and the field is still young, the collective data selected in this review indicate that a careful tuning of surface moieties is a pivotal step to lead NPs through their future clinical applications.

4.
J Transl Med ; 17(1): 172, 2019 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-31118074

RESUMEN

BACKGROUND: The aim of the present review is to discuss how the promising field of biobanking can support health care research strategies. As the concept has evolved over time, biobanks have grown from simple biological sample repositories to complex and dynamic units belonging to large infrastructure networks, such as the Pan-European Biobanking and Biomolecular Resources Research Infrastructure (BBMRI). Biobanks were established to support scientific knowledge. Different professional figures with varied expertise collaborate to obtain and collect biological and clinical data from human subjects. At same time biobanks preserve the human and legal rights of each person that offers biomaterial for research. METHODS: A literature review was conducted in April 2019 from the online database PubMed, accessed through the Bibliosan platform. Four primary topics related to biobanking will be discussed: (i) evolution, (ii) bioethical issues, (iii) organization, and (iv) imaging. RESULTS: Most biobanks were founded as local units to support specific research projects, so they evolved in a decentralized manner. The consequence is an urgent needing for procedure harmonization regarding sample collection, processing, and storage. Considering the involvement of biomaterials obtained from human beings, different ethical issues such as the informed consent model, sample ownership, veto rights, and biobank sustainability are debated. In the face of these methodological and ethical challenges, international organizations such as BBMRI play a key role in supporting biobanking activities. Finally, a unique development is the creation of imaging biobanks that support the translation of imaging biomarkers (identified using a radiomic approach) into clinical practice by ensuring standardization of data acquisition and analysis, accredited technical validation, and transparent sharing of biological and clinical data. CONCLUSION: Modern biobanks permit large-scale analysis for individuation of specific diseases biomarkers starting from biological or digital material (i.e., bioimages) with well-annotated clinical and biological data. These features are essential for improving personalized medical approaches, where effective biomarker identification is a critical step for disease diagnosis and prognosis.


Asunto(s)
Bancos de Muestras Biológicas , Atención a la Salud , Bancos de Muestras Biológicas/ética , Recolección de Muestras de Sangre , Bases de Datos como Asunto , Genómica , Humanos , Publicaciones
5.
BMC Infect Dis ; 19(1): 132, 2019 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-30744603

RESUMEN

BACKGROUND: Empirical treatment of tuberculosis (TB) may be necessary in patients with negative or no Xpert MTB/RIF results. In a context with access to Xpert, we assessed mortality in the 6 months after the initial TB consultation among HIV-positive and HIV-negative patients who received empirical TB treatment or TB treatment based on bacteriological confirmation and we compared it with the mortality among those who did not receive TB treatment. METHODS: This prospective cohort study included consecutively adult patients with signs and symptoms of TB attending an outpatient TB clinic in Western Kenya. At the first consultation, patients received a clinical exam and chest X-ray. Sputum was collected for microscopy, Xpert and Mycobacterium tuberculosis complex (MTB) culture. Patients not started on TB treatment were reassessed after 5 days. All patients bacteriologically confirmed (positive Xpert or culture) received TB treatment. Empirical treatment was defined as a decision to start TB treatment without bacteriological confirmation. Patients were reassessed after 6 months. RESULTS: Of 606 patients included, 344/606 (56.8%) were women. Median age was 35 years [Interquartile Range (IQR):27-47] and 398/594 (67.0%) were HIV-positive. In total, 196/606 (32.3%) patients were Xpert- or culture-positive and 331/606 (54.6%) started TB treatment. Overall, 100/398 (25.1%) HIV-positive and 31/196 (15.8%) HIV-negative patients received empirical treatment. Mortality in the 6 months following the first consultation was 1.6 and 0.8/100 patient-months among HIV-positive and HIV-negative patients respectively. In the multivariate analyses, TB treatment - whether empirical or based on bacteriological confirmation- was not associated with increased mortality among HIV-positive patients (aHR:2.51, 95%CI:0.79-7.90 and aHR:1.25, 95%CI:0.37-4.21 respectively). However, HIV-negative patients who received empirical treatment had a higher risk of mortality (aHR:4.85, 95%CI:1.08-21.67) compared to those not started on treatment. HIV-negative patients treated for TB based on bacteriological confirmation did not have a different risk of mortality (aHR:0.77, 95%CI:0.08-7.41). CONCLUSIONS: Our findings suggest that in a context with access to Xpert, clinicians should continue using empirical TB treatment in HIV-positive patients with signs and symptoms of TB and negative Xpert results. However, differential diagnoses other than TB should be actively sought before initiating empirical TB treatment, particularly in HIV-negative patients.


Asunto(s)
Infecciones por VIH/complicaciones , Tuberculosis Pulmonar/mortalidad , Adulto , Instituciones de Atención Ambulatoria , Estudios de Cohortes , Femenino , VIH , Infecciones por VIH/tratamiento farmacológico , Seronegatividad para VIH , Seropositividad para VIH , Humanos , Kenia , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis , Estudios Prospectivos , Sensibilidad y Especificidad , Esputo/microbiología , Tuberculosis Pulmonar/complicaciones , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/tratamiento farmacológico
6.
Nanomedicine (Lond) ; 12(18): 2211-2222, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28814137

RESUMEN

AIM: A high versatile microfluidic platform is proposed to design, in a one-step strategy, PEGylated crosslinked hyaluronic acid nanoparticles (cHANPs) entrapping a magnetic resonance imaging contrast agent and a dye for multimodal imaging applications. MATERIALS & METHODS: Clinically relevant biomaterials were shaped in the form of spherical NPs through a microfluidic flow focusing approach. A comparison between post processing and simultaneous PEGylation is reported to evaluate the potentiality of the chemical decoration of the cHANPs in microfluidics. RESULTS: An accurate control of the NPs in terms of size, PEGylation and loading was obtained. Furthermore, in vitro cell viability is reported and their ability to boost the magnetic resonance imaging signal is also confirmed. CONCLUSION: The proposed microfluidic approach reveals its ability to overcome several limitations of the traditional processes and to become an easy-to-use platform for theranostic applications.


Asunto(s)
Reactivos de Enlaces Cruzados/química , Ácido Hialurónico/química , Técnicas Analíticas Microfluídicas/instrumentación , Nanopartículas/química , Polietilenglicoles/química , Células A549 , Supervivencia Celular , Medios de Contraste/química , Portadores de Fármacos , Estabilidad de Medicamentos , Colorantes Fluorescentes/química , Humanos , Imagen por Resonancia Magnética , Nanomedicina , Imagen Óptica , Tamaño de la Partícula , Propiedades de Superficie
7.
Mol Imaging ; 16: 1536012117706237, 2017 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-28654388

RESUMEN

Strategies to enhance the relaxometric properties of gadolinium (Gd)-based contrast agents (CAs) for magnetic resonance imaging (MRI), without the chemical modification of chelates, have recently had a strong impact on the diagnostic field. We have taken advantage of the interaction between Gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA) and the hydrogel structure of hyaluronic acid to design cross-linked hyaluronic acid nanoparticles down to 35 nm for use in MRI applications. The proposed bioformulations enable the control of the relaxometric properties of CAs, thus boosting the relaxation rate of T1. Our results led us to identify this approach as an adjustable scenario to design intravascularly injectable hydrogel nanoparticles entrapping Gd-DTPA. This approach overcomes the general drawbacks of clinically approved CAs having poor relaxivity and toxic effects.


Asunto(s)
Ácido Hialurónico/química , Imagen por Resonancia Magnética/instrumentación , Microfluídica/métodos , Nanopartículas/química , Medios de Contraste/química , Gadolinio/química
8.
Sci Rep ; 7: 45121, 2017 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-28327584

RESUMEN

Multimodal imaging probes can provide diagnostic information combining different imaging modalities. Nanoparticles (NPs) can contain two or more imaging tracers that allow several diagnostic techniques to be used simultaneously. In this work, a complex coacervation process to produce core-shell completely biocompatible polymeric nanoparticles (HyCoS) for multimodal imaging applications is described. Innovations on the traditional coacervation process are found in the control of the reaction temperature, allowing a speeding up of the reaction itself, and the production of a double-crosslinked system to improve the stability of the nanostructures in the presence of a clinically relevant contrast agent for MRI (Gd-DTPA). Through the control of the crosslinking behavior, an increase up to 6 times of the relaxometric properties of the Gd-DTPA is achieved. Furthermore, HyCoS can be loaded with a high amount of dye such as ATTO 633 or conjugated with a model dye such as FITC for in vivo optical imaging. The results show stable core-shell polymeric nanoparticles that can be used both for MRI and for optical applications allowing detection free from harmful radiation. Additionally, preliminary results about the possibility to trigger the release of a drug through a pH effect are reported.

9.
PLoS One ; 12(1): e0170976, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28125693

RESUMEN

BACKGROUND: Determine-TB LAM assay is a urine point-of-care test useful for TB diagnosis in HIV-positive patients. We assessed the incremental diagnostic yield of adding LAM to algorithms based on clinical signs, sputum smear-microscopy, chest X-ray and Xpert MTB/RIF in HIV-positive patients with symptoms of pulmonary TB (PTB). METHODS: Prospective observational cohort of ambulatory (either severely ill or CD4<200cells/µl or with Body Mass Index<17Kg/m2) and hospitalized symptomatic HIV-positive adults in Kenya. Incremental diagnostic yield of adding LAM was the difference in the proportion of confirmed TB patients (positive Xpert or MTB culture) diagnosed by the algorithm with LAM compared to the algorithm without LAM. The multivariable mortality model was adjusted for age, sex, clinical severity, BMI, CD4, ART initiation, LAM result and TB confirmation. RESULTS: Among 474 patients included, 44.1% were severely ill, 69.6% had CD4<200cells/µl, 59.9% had initiated ART, 23.2% could not produce sputum. LAM, smear-microscopy, Xpert and culture in sputum were positive in 39.0% (185/474), 21.6% (76/352), 29.1% (102/350) and 39.7% (92/232) of the patients tested, respectively. Of 156 patients with confirmed TB, 65.4% were LAM positive. Of those classified as non-TB, 84.0% were LAM negative. Adding LAM increased the diagnostic yield of the algorithms by 36.6%, from 47.4% (95%CI:39.4-55.6) to 84.0% (95%CI:77.3-89.4%), when using clinical signs and X-ray; by 19.9%, from 62.2% (95%CI:54.1-69.8) to 82.1% (95%CI:75.1-87.7), when using clinical signs and microscopy; and by 13.4%, from 74.4% (95%CI:66.8-81.0) to 87.8% (95%CI:81.6-92.5), when using clinical signs and Xpert. LAM positive patients had an increased risk of 2-months mortality (aOR:2.7; 95%CI:1.5-4.9). CONCLUSION: LAM should be included in TB diagnostic algorithms in parallel to microscopy or Xpert request for HIV-positive patients either ambulatory (severely ill or CD4<200cells/µl) or hospitalized. LAM allows same day treatment initiation in patients at higher risk of death and in those not able to produce sputum.


Asunto(s)
Infecciones por VIH/complicaciones , Lipopolisacáridos/análisis , Tuberculosis Pulmonar/diagnóstico , Adulto , Algoritmos , Femenino , Humanos , Kenia , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis , Sistemas de Atención de Punto , Tuberculosis Pulmonar/complicaciones
10.
Sci Rep ; 6: 37906, 2016 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-27901092

RESUMEN

Recent advancements in imaging diagnostics have focused on the use of nanostructures that entrap Magnetic Resonance Imaging (MRI) Contrast Agents (CAs), without the need to chemically modify the clinically approved compounds. Nevertheless, the exploitation of microfluidic platforms for their controlled and continuous production is still missing. Here, a microfluidic platform is used to synthesize crosslinked Hyaluronic Acid NanoParticles (cHANPs) in which a clinically relevant MRI-CAs, gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA), is entrapped. This microfluidic process facilitates a high degree of control over particle synthesis, enabling the production of monodisperse particles as small as 35 nm. Furthermore, the interference of Gd-DTPA during polymer precipitation is overcome by finely tuning process parameters and leveraging the use of hydrophilic-lipophilic balance (HLB) of surfactants and pH conditions. For both production strategies proposed to design Gd-loaded cHANPs, a boosting of the relaxation rate T1 is observed since a T1 of 1562 is achieved with a 10 µM of Gd-loaded cHANPs while a similar value is reached with 100 µM of the relevant clinical Gd-DTPA in solution. The advanced microfluidic platform to synthesize intravascularly-injectable and completely biocompatible hydrogel nanoparticles entrapping clinically approved CAs enables the implementation of straightforward and scalable strategies in diagnostics and therapy applications.


Asunto(s)
Medios de Contraste/química , Ácido Hialurónico/química , Nanopartículas/química , Gadolinio/química , Gadolinio DTPA/química , Imagen por Resonancia Magnética/métodos , Microfluídica/métodos , Nanoestructuras/química
11.
J Acquir Immune Defic Syndr ; 71(4): e89-95, 2016 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-26910386

RESUMEN

INTRODUCTION: The tuberculin skin test (TST) can be used to identify HIV-infected people who would benefit the most from long-term isoniazid preventive therapy (IPT). However, in resource-constrained settings, implementation of the TST can be challenging. The objectives of this study were to assess the feasibility of implementing the TST for IPT initiation and to estimate the proportion of TST-positive incidence among HIV-positive patients in 2 high tuberculosis and HIV burden settings. METHODS: Two prospective observational cohort studies were conducted under programmatic conditions in Mathare, an urban slum of Nairobi, Kenya, and in rural Shiselweni, Swaziland. HIV-positive adults with negative tuberculosis symptomatic screening underwent the TST. Those testing positive were started on 36-month IPT. RESULTS: Of 897 and 1021 patients screened in Mathare and Shiselweni, 550 and 696, respectively, were included. Median age was 38 years, 67.7% were female, and 86.8% were on antiretroviral therapy. Among TST-eligible participants, 88.0% (491/558) and 81.8% (694/848) accepted TST and 74.2% (414/558) and 77.1% (654/858) returned for test reading in Mathare and Shiselweni, respectively. The TST was positive in 49.8% (95% confidence interval: 44.9 to 54.6) in Mathare and 33.2% (95% confidence interval: 29.6 to 36.8) in Shiselweni. The 36-month IPT was accepted by 96.1% (198/206) patients in Mathare and 99.5% (216/217) in Shiselweni. IPT implementation at the clinics was managed with no additional staff or extra space. CONCLUSION: Implementing the TST for IPT initiation was feasible and acceptable in both urban and rural resource-constrained settings. This strategy allows patients who can benefit the most to receive long-term IPT and avoids unnecessarily treating a significant number of patients who do not stand to benefit.


Asunto(s)
Antituberculosos/uso terapéutico , Infecciones por VIH/complicaciones , Isoniazida/uso terapéutico , Prueba de Tuberculina , Tuberculosis/diagnóstico , Tuberculosis/prevención & control , Adulto , Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/uso terapéutico , Antituberculosos/administración & dosificación , Estudios de Cohortes , Esuatini/epidemiología , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Humanos , Kenia/epidemiología , Masculino , Persona de Mediana Edad , Tuberculosis/epidemiología
12.
Microbiol Immunol ; 55(5): 347-56, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21288261

RESUMEN

During neuropathological conditions such as infections and degenerative diseases, astrocytes can be activated by infiltrating immune cells. Activated astrocytes can produce chemokines, cytokines and adhesion molecules. In this study, the production of IL-6 and adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cellular adhesion molecule-1 (VCAM-1) and E-selectin by human astroglioma cells stimulated with Gram-negative surface components was investigated. Haemophilus influenzae type b porin P2 and its selected active peptide, loop L7, were found to induce MEK1-MEK2/ mitogen-activated protein kinase phosphorylation in U87-MG cells as demonstrated by ELISA, and up-regulate cellular adhesion molecule and interleukin-6 (IL-6) production as shown by RT-PCR and ELISA. Using two potent and selective inhibitors of MEK activation by Raf-1 (PD-098059) and p38 (SB-203580), it was also demonstrated that both ERK1/2 and p38 pathways play key roles in the production of IL-6 as well as in ICAM-1, VCAM-1 and E-selectin expression by Hib porin.


Asunto(s)
Astrocitos/metabolismo , Proteínas Bacterianas/inmunología , Moléculas de Adhesión Celular/metabolismo , Haemophilus influenzae/inmunología , Interleucina-6/metabolismo , Porinas/inmunología , Regulación hacia Arriba , Astrocitos/inmunología , Proteínas Bacterianas/farmacología , Moléculas de Adhesión Celular/genética , Línea Celular , Selectina E/genética , Selectina E/metabolismo , Humanos , Molécula 1 de Adhesión Intercelular/genética , Molécula 1 de Adhesión Intercelular/metabolismo , Interleucina-6/genética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosforilación , Porinas/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Molécula 1 de Adhesión Celular Vascular/genética , Molécula 1 de Adhesión Celular Vascular/metabolismo
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