Luminescence based temperature bio-imaging: Status, challenges, and perspectives

The only way to get thermal images of living organisms without perturbing them is to use luminescent probes with temperature-dependent spectral properties. The acquisition of such thermal images becomes essential to distinguish various states of cells, to monitor thermogenesis, to study cellular activity, and to control hyperthermia therapy. Current efforts are focused on the development and optimization of luminescent reporters such as small molecules, proteins, quantum dots, and lanthanide-doped nanoparticles. However, much less attention is devoted to the methods and technologies that are required to image temperature distribution at both in vitro or in vivo levels. Indeed, rare examples can be found in the scientific literature showing technologies and materials capable of providing reliable 2D thermal images of living organisms. In this review article, examples of 2D luminescence thermometry are presented alongside new possibilities and directions that should be followed to achieve the required level of simplicity and reliability that ensure their future implementation at the clinical level. This review will inspire specialists in chemistry, physics, biology, medicine, and engineering to collaborate with materials scientists to jointly develop novel more accurate temperature probes and enable mapping of temperature with simplified technical mean

Simultaneous endovascular repair of an iatrogenic carotid-jugular fistula and a large iliocaval fistula presenting with multiorgan failure: a case report

<p>Abstract</p> <p>Introduction</p> <p>Iliocaval fistulas can complicate an iliac artery aneurysm. The clinical presentation is classically a triad of hypotension, a pulsatile mass and heart failure. In this instance, following presentation with multiorgan failure, management included the immediate use of an endovascular stent graft on discovery of the fistula.</p> <p>Case presentation</p> <p>A 62-year-old Caucasian man presented to our tertiary hospital for management of iatrogenic trauma due to the insertion of a central venous line into his right common carotid artery, causing transient ischemic attack. Our patient presented to a peripheral hospital with fever, nausea, vomiting, acute renal failure, acute hepatic dysfunction and congestive heart failure. A provisional diagnosis of sepsis of unknown origin was made. There was a 6.5 cm×6.5 cm right iliac artery aneurysm present on a non-contrast computed tomography scan. An unexpected intra-operative diagnosis of an iliocaval fistula was made following the successful angiographic removal of the central line to his right common carotid artery. Closure of the iliocaval fistula and repair of the iliac aneurysm using a three-piece endovascular aortic stent graft was then undertaken as part of the same procedure. This was an unexpected presentation of an iliocaval fistula.</p> <p>Conclusion</p> <p>Our case demonstrates that endovascular repair of a large iliac artery aneurysm associated with a caval fistula is safe and effective and can be performed at the time of the diagnostic angiography. The presentation of an iliocaval fistula in this case was unusual which made the diagnosis difficult and unexpected at the time of surgery. The benefit of immediate repair, despite hemodynamic instability during anesthesia, is clear. Our patient had two coronary angiograms through his right femoral artery decades ago. Unusual iatrogenic causes of iliocaval fistulas secondary to previous coronary angiograms with wire and/or catheter manipulation should be considered in patients such as ours.</p

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure &lt; 100 mmHg (n = 1127), estimated glomerular filtration rate &lt; 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Advances in highly doped upconversion nanoparticles

© 2018 The Author(s). Lanthanide-doped upconversion nanoparticles (UCNPs) are capable of converting near-infra-red excitation into visible and ultraviolet emission. Their unique optical properties have advanced a broad range of applications, such as fluorescent microscopy, deep-tissue bioimaging, nanomedicine, optogenetics, security labelling and volumetric display. However, the constraint of concentration quenching on upconversion luminescence has hampered the nanoscience community to develop bright UCNPs with a large number of dopants. This review surveys recent advances in developing highly doped UCNPs, highlights the strategies that bypass the concentration quenching effect, and discusses new optical properties as well as emerging applications enabled by these nanoparticles

Biological applications of lanthanide doped nanomarkers

Fluorescence is one of the most commonly used methods of biodetection, mainly due to the high sensitivity, non-invasiveness, simplicity, and also due to the availability of the whole range of powerful light sources, a wide range of photodetectors, and numerous and sensitive measuring methods. From the point of view of biodetection and bioimaging, the important characteristics of such fluorophores are large Stokes shift, narrow absorption/emission lines as well as stable and efficient luminescence. Traditional organic dyes applied in biology reveal very fast photobleaching and limited opportunities for simultaneous detection of many biomolecules, what stimulate development of new fluorescent markers. Fast and intensive development of nanotechnology and chemical engineering observed in recent years, aims at designing the nanophosphors or luminescent nanoplatforms, that demonstrate desirable properties and devised functionality. However, new phosphors are not included yet in broad practical applications, mainly because of the need to adapt the measuring apparatus so as to fully exploit their potential. From among the fluorescent nano-particles, silica dye doped nanoparticles, quantum dots, nanocolloidal metallic nanoparticles, and lanthanide doped nanoluminophores show the largest application potential. This article discusses the unique physico-chemical properties of lanthanide doped nanoparticles, which beside very long luminescence lifetimes and narrow emission bands, enable to obtain a visible emission under the near infrared photoexcitation (called anti-Stokes emission), offering improved sensitivity, stability, repeatability and accuracy of the fluorescent biodetection and bioimaging methods. In this review, physico-chemical properties of lanthanide doped nanoluminophores and many examples of their biological applications have been discussed. The first chapter presents spectral characteristics of rare-earth ions with particular regard to the mechanism of energy transfer and up-conversion, which is a fundamental difference and the decisive advantage compared with other known fluorescent markers. The luminescent properties of lantanides are demonstrated based on the most commonly used nanomaterials singly doped with Eu^3+ and Tb^3+ and the codoped matrices, like Yb^3+-Tm^3+, Yb^3+-Er^3+or Yb^3+-Ho^3+ co-doped phosphores. The features of these materials are best suited from the point of view of biodetection and bioimaging. The next chapter gives an overview of the applications of lanthanide doped nanoluminophores in biological sciences. Different types of hetero-/homo-genous tests and luminesce based sensors for pH, CO_2, the level of glucose, and other analytes are presented. Then, basic aspects of bioimaging, photodynamic and thermo-therapy, nanotermometry as well as nano-bio-technology platforms have been summarized. In conclusion suggestions of new research directions and new biological applications of lanthanide doped nanoparticles have been presented

Correlation between the Covalency and the Thermometric Properties of Yb3+/Er3+Codoped Nanocrystalline Orthophosphates

Lanthanide-doped NaYF4 nanoparticles are most frequently studied host materials for numerous biomedical applications. Although efficient upconversion can be obtained in fluoride nanomaterials and good homogeneity of size and morphology is achieved, they are not very predestined for extensive material optimization toward enhanced features and functions. Here, we study the impact of rare-earth metals RE = Y, Lu, La, and Gd ions within Yb3+/Er3+ codoped nanocrystalline REPO4 orthophosphates. The enhanced luminescent thermometry features were found to be in relation to the covalency of RE3+-O2- bonds being modulated by these optically inactive rare-earth ion substitutes. Up to 30% relative sensitivity enhancement was found (from ca. 3.0 to ca. 3.8%/K at -150 °C) by purposefully increasing the covalence of the RE3+-O2- bond. These studies form the basis for intentional optimization thermal couple-based luminescent thermometers such as Yb3+-Er3+ upconverting ratiometric thermometer