1,721,172 research outputs found
Supramolecular gels by guanine and folic acid: from structural and mechanical properties to biotechnology applications
No full textGuanosine and folic acid-based gels have great potential in developing advanced biomedical and biotechnological applications. Firstly, the study of the chemical-physical properties allows us to explore the structural organisation of gels composed of both guanosine derivatives and folic acid. These two buildings are involved in the spontaneous self-assembling process that ensures the formation of biomaterial termed hydrogels, organogels and ionogels, depending on the type of solvent used. The use of different types of biophysical techniques, such as Small and Wide-Angle X-ray Scattering (SAXS/WAXS), rheology, Fluorescence Recovery After Photobleaching (FRAP) based on the use of confocal microscopy, AFM and SEM based microscopy, infrared spectroscopy and others, offer a complete approach to have an in-depth structural analysis. Moreover, the structural investigation was fundamental in order to choose the best gel samples used for the different applications developed. In this regard, the studied applications belong to a wide range of scientific fields. G-hydrogel was found to be a potential biomaterial used as a 3D bioprinting scaffold for the growth of cells, but also to embed micro crystals proteins as an injectable system to support crystallography experiments (e.g. in a XFEL or synchrotron large-scale facilities). In addition, other uses of this hydrogel concern the formation of nano- and micro-structured gels, for instance for nanomedicine, but also water and surface remediation, for instance for the removal of heavy metals. This latter purpose was studied also for the case of hydrogel based on folic acid, demonstrating its great potential. The improvement of these results could be useful to reach new future milestones in the world of gels for biotechnological applications
Transport Properties of Self-Assembling G-Hydrogels: Evidence for a Tunable Fickian Diffusivity
Full text linkThe mixing of Guanosine (Gua) and Guanosine 5′-monophosphate (GMP) in water in selected compositions yields highly hydrated, transparent, and self-healing self-assembled supramolecular G-hydrogels, attractive for biomedical applications. This work investigates how hydrogel composition affects solute transport, including diffusion, binding, loading, and release properties, using a set of fluorescent probes with varying size and polarity. Although small/wide-angle X-ray scattering techniques showed that no structural changes are induced by probe addition, even when intercalation into G-quadruplexes is expected, the internal mesh structure of the hydrogel, modulated by the Gua:GMP ratio, directly impacts probe diffusivity and loading. Tighter networks (e.g., 1:1) slow diffusion and enhance retention compared to looser configurations (e.g., 1:4). Moreover, UV-visible titrations revealed markedly different binding affinities (Kb ≈ 5.7 × 104 M-1 for DAPI, 8.0 × 103 M-1 for ThT, and 1.4 × 102 M-1 for RhB), which are expected to result in lower diffusion coefficients and slower release, especially for DAPI and ThT. Indeed, diffusion coefficients, obtained via fluorescence recovery after photobleaching and time-resolved fluorescence spectroscopy, reach 90, 20, and 60 μm2/s for FITC-dextran, ThT, and RhB, respectively. Probe release kinetics, modeled via Weibull fitting, indicated sustained release with characteristic times (τ) between 9.6 and 23.2 h and β ≈ 1 in 1× PBS, consistent with predominantly Fickian diffusion. Remarkably, switching to 10× PBS significantly accelerated release (τ reduced by ≈ 40-50%), suggesting that ionic strength and/or pH changes critically affect not only probe-hydrogel interactions but also the internal gel architecture, altering porosity, mesh size, and network tortuosity, thus enhancing molecular mobility. Overall, the G-hydrogel system offers a structurally tunable and composition-dependent platform capable of finely regulating molecular transport and release profiles, making it highly suitable for controlled drug delivery and adaptive biomaterial applications
Acetylcholinesterase inhibitors detection in food-chemically modified electrode (cme) vs biosensor performance
No full textArterial Thrombosis Following Umbilical Artery Catheterization: Visualising Uncommon Neonatal Intensive Care Unit (NICU) Complications
No full textBackground: Right internal iliac artery (RIIA) thrombosis is an extremely rare but serious complication associated with umbilical artery catheter (UAC) malposition in neonates in the Neonatal Intensive Care Unit (NICU). Timely diagnosis and appropriate management are essential to prevent long-term sequelae. Case Report: We present the case of a term neonate with hypoxic–ischaemic encephalopathy (HIE), who developed RIIA thrombosis secondary to UAC malposition, highlighting the role of bedside Doppler ultrasound in diagnosis and monitoring, and the success of a conservative therapeutic approach. Discussion: A term male neonate with HIE was undergoing therapeutic hypothermia when violaceous macular skin lesions appeared on the right buttock and loin shortly after UAC insertion. Imaging confirmed malposition of the catheter in the RIIA. The catheter was promptly removed, and the patient was closely monitored both clinically and with serial Doppler ultrasounds. Approximately 6 h after catheter removal, Doppler ultrasound revealed a clot in the RIIA. The patient was managed conservatively with continuous infusion of unfractionated heparin (10 IU/kg/h) and topical anti-inflammatory therapy. The skin lesions resolved within 36 h, and Doppler at 48 h post-removal confirmed re-established arterial flow. No invasive interventions were required. This case underscores the importance of careful catheter placement and the utility of bedside Doppler ultrasound in detecting and monitoring vascular complications. Moreover, prompt recognition and conservative treatment of arterial thrombosis can result in optimal outcomes, even in neonates with complex clinical conditions such as birth asphyxia
What is the importance of monitoring iron levels in different organs over time with magnetic resonance imaging in transfusion-dependent thalassemia patients?
Full text linkIntroduction
Iron overload is the main pathophysiological driver of organ damage in transfusion-dependent thalassemia (TDT). Magnetic resonance imaging (MRI) provides detailed insights into the distribution and severity of iron accumulation in the different organs.
Areas covered
This special report describes the impact of MRI on clinical and therapeutic management and short- and long-term outcomes in TDT patients. PubMed, Scopus, and Google Scholar databases were searched to identify the relevant studies published before November 2024.
Expert opinion
Cardiac and hepatic MRI are now well-established modalities, integrated into the clinical practice. They have become essential for tailoring iron chelation therapies to the specific patient’s needs and for monitoring treatment efficacy. The improved control of cardiac iron burden has translated into reduced morbidity and mortality. The MRI accessibility remains limited in resource-limited settings and progress in this field relies on educating and training centers to ensure accurate execution and interpretation. The clinicopathological significance, prognostic value, and reproducibility of pancreatic iron levels assessment have been established, charting a path toward its clinical use. There are limited data about renal, adrenal, and pituitary iron deposition, and more research is needed to fully establish the functional significance and to standardize and validate the MRI protocols
Multi-Modality Imaging in Cardio-Rheumatology
No full textPurpose of Review: Our purpose was to discuss the advantages and disadvantages of various noninvasive imaging modalities in the evaluation of cardiovascular disease (CVD) in patients with autoimmune rheumatic diseases (ARDs). The detailed knowledge of imaging modalities will facilitate the diagnosis and follow up of CVD in ARDs. Recent Findings: Autoimmune Rheumatic Diseases (ARDs) are characterized by alterations in immunoregulatory system of the body. Although there is great progress in anti-rheumatic treatment, ARD patients are still at a higher risk for reduced life expectancy, compared with the general population, which is mainly due to the high incidence of CVD. Cardiovascular imaging holds the promise of early, noninvasive diagnosis and follow up of these patients. Summary: Echocardiography (echo), a cost effective, widely available imaging modality, can provide valuable early information about CVD in ARDs and motivate the use of more sophisticated investigations, if needed. Single Photon Emission tomography (SPECT) gives information about myocardial perfusion, while positron emission tomography (PET) gives information about both myocardial perfusion and inflammation with better spatial resolution and less radiation but at a higher financial cost, compared to SPECT. Computed Tomography Coronary Angiography (CTCA) is a reliable tool to rule out the presence of coronary artery disease, which has high incidence in ARD population. Lastly, Cardiovascular Magnetic Resonance (CMR) can perform function and tissue characterization evaluation in the same scan without using radiation and represents the ideal tool for serial evaluation of ARD patients. Lastly, molecular imaging holds the promise for individualized treatment in various ARDs. Cardiovascular imaging is the modern “stethoscope” of the clinicians and therefore they should be familiar with pro and contra of these modalities in order to achieve the best diagnostic and therapeutic target in ARD patients
Nontraditional Cardiovascular Biomarkers and Risk Factors: Rationale and Future Perspectives
Full text linkThe primary prevention of cardiovascular (CV) disease depends on the capacity to identify subjects at higher risk long before the occurrence of CV clinical manifestations. Traditional risk factors do not cover fully prediction of individual risk. Moreover, there is an area of gray for patients at intermediate CV risk, which offers wide margins of improvement. These observations highlight the need for new additive tools for a more accurate risk stratification. An increasing number of candidate biomarkers have been identified to predict CV risk and events, although they generally give only a moderate increase when added to currently available predictive scores. The approach utilizing a relative small number of biomarkers in multiple combinations, but only weakly related to each other or unrelated, thus belonging to independent-pathways, and so able to catch the multidimensional characteristic of atherosclerosis, appears promising. We discuss vitamin D and bone turnover biomarkers, hepatitis C virus, and psycho-emotional factors that may reflect alternative pathways over those generally considered for atherosclerosis (e.g., aspects directly related to inflammation and thrombosis). These new biomarkers could facilitate a more accurate assessment of CV risk stratification if incorporated in the current risk assessment algorithms
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