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Advances in diagnostic imaging have provided unprecedented opportunities to detect diseases at early stages and with high reliability. Diagnostic imaging is also crucial to monitoring the progress or remission of disease and thus is often the central basis of therapeutic decision-making. Currently, several diagnostic imaging modalities (computed tomography, magnetic resonance imaging, and positron emission tomography, among others) are routinely used in clinics and present their own advantages and limitations. In vivo near-infrared (NIR) fluorescence imaging has recently emerged as an attractive imaging modality combining low cost, high sensitivity, and relative safety. As a preclinical tool, it can be used to investigate disease mechanisms and for testing novel diagnostics and therapeutics prior to their clinical use. However, the limited depth of tissue penetration is a major challenge to efficient clinical use. Therefore, the current clinical use of fluorescence imaging is limited to a few applications such as image-guided surgery on tumors and retinal angiography, using FDA-approved dyes. Progress in fluorophore development and NIR imaging technologies holds promise to extend their clinical application to oncology, cardiovascular diseases, plastic surgery, and brain imaging, among others. Nanotechnology is expected to revolutionize diagnostic in vivo fluorescence imaging through targeted delivery of NIR fluorescent probes using antibody conjugation. In this review, we discuss the latest advances in in vivo fluorescence imaging technologies, NIR fluorescent probes, and current and future clinical applications. [ABSTRACT FROM AUTHOR]

Aims To determine the bioequivalence of several T1 mapping sequences in myocardial characterization of diffuse myocardial fibrosis. Methods and results We performed an intra-individual sequence comparison of three types of T1 mapping sequences [MOdified Look-Locker Inversion recovery (MOLLI), Shortened MOdified Look-Locker Inversion recovery ((sh)MOLLI), and SAturation recovery single-SHot Acquisition (SASHA)]. We employed two model diseases of diffuse interstitial fibrosis [patients with non-ischaemic dilated cardiomyopathy (NIDCM), n = 32] and aortic stenosis [(AS), n = 25)]. Twenty-six healthy individuals served as controls. Relationship with collagen volume fraction (CVF) was assessed using endomyocardial biopsies (EMB) intraoperatively in 12 AS patients. T2 mapping (GraSE) was also performed. Myocardial native T1 with MOLLI and shMOLLI showed, firstly, an excellent discriminatory accuracy between health and disease [area under the curves (P-value): 0.94 (0.88-0.99); 0.87 (0.79-0.94); 0.61 (0.49--0.72)], secondly, relationship between histological CVF [native T1 MOLLI vs. shMOLLI vs. SASHA: r = 0.582 (P = 0.027), r = 0.524 (P = 0.046), r = 0.443 (P = 0.150)], and thirdly, with native T2 [r = 0.628(P < 0.001), r = 0.459 (P = 0.003), r = 0.211 (P = 0.083)]. The respective relationships for extracellular volume fraction with CVF [r = 0.489 (P = 0.044), r = 0.417 (0.071), r = 0.353 (P = 0.287)] were significant for MOLLI, but not other sequences. In AS patients, native T2 was significantly higher compared to controls, and associated with levels of C-reactive protein and troponin. Conclusion T1 mapping sequences differ in their bioequivalence for discrimination between health and disease as well as associations with diffuse myocardial fibrosis." [ABSTRACT FROM AUTHOR]

The unique chemical and functional properties of nanoparticles can be harnessed for the delivery of large quantities of various therapeutic biomolecules. Active targeting of nanoparticles by conjugating ligands that bind to target cells strongly facilitates accumulation, internalization into target cells and longer retention at the target site, with consequent enhanced therapeutic effects. Recombinant antibodies with high selectivity and availability for a vast range of targets will dominate the future. In this review, we systematically outline the tremendous progress in the conjugation of antibodies to nanoparticles and the clear advantages that recombinant antibodies offer in the therapeutic targeting of nanoparticles. The demonstrated flexibility of recombinant antibody coupling to nanoparticles highlights the bright future of this technology for modern therapeutic nanomedicine. [ABSTRACT FROM AUTHOR]

Objective: Stem cell‐based regenerative therapies have been intensively studied with the aim to define an ideal cell type for the treatment of myocardial infarction. We tested systemically delivered, platelet‐targeted induced vascular progenitor cells (iVPCs) to study their potential to salvage damaged myocardium after ischemia‐reperfusion injury. Methods: Using a mouse model of ischemia‐reperfusion injury, we tested the potential of platelet‐targeted iVPCs (1 × 106 targ‐iVPCs) compared to non‐targ‐iVPCs and a saline control. Bioluminescence imaging, echocardiography, and histological analyses were performed. Results: Four weeks after ischemia‐reperfusion injury, systemic delivery of targ‐iVPCs led to reduced fibrosis and infarct size (PBS: 25.7 ± 3.9 vs targ‐iVPC: 18.4 ± 6.6 vs non‐targ‐iVPC: 25.1 ± 3.7%I/LV, P < 0.05), increased neovascularization, and restored cardiac function (PBS: 44.0 ± 4.2 vs targ‐iVPC: 54.3 ± 4.5 vs non‐targ‐iVPC: 46.4 ± 3.8%EF, P < 0.01). Cell tracking experiments revealed entrapment of intravenously injected iVPCs in the pulmonary microvasculature in both cell‐treated groups. Conclusions: Systemic delivery of iVPCs after cardiac ischemia‐reperfusion injury is limited by pulmonary entrapment of the cells. Nevertheless, targ‐iVPCs reduced infarct size, fibrosis, increased neovascularization, and most importantly retained cardiac function. These findings contribute to the mechanistic discussion of cell‐based therapy and ultimately identify activated platelet‐targeted iVPCs as candidates for cell therapy and also describe cell therapy benefits without the necessity of engrafting. [ABSTRACT FROM AUTHOR]

The authors reflect on the role of myocardial T1 mapping as a non-invasive alternative method to tissue diagnosis. Topics include the advantage of cardiovascular magnetic resonance (CMR) compared with other non-invasive imaging methods, late gadolinium enhancement (LGE), and role of CMR in cardiomyopathy diagnosis and treatment.