1,131 research outputs found
A More Flavored Higgs boson in Supersymmetric models
A More flavored Higgs boson arises when the flavor structure encoded in SUSY
extensions of the SM is transmited to the Higgs sector. The flavor-Higgs
transmition mechanism can have a radiative or mixing origin, as it is
illustrated with several examples, and can produce interesting Higgs signatures
that can be probed at future high-energy colliders. Within the MSSM, the flavor
mediation mechanism can be of radiative type, as it is realized trhough
gaugino-slepton loops, which transmit the flavor structture of the
soft-breaking sector to the Higgs bosons. In particular we focus on evaluating
the contributions from the general trilinear terms to the lepton flavor
violating Higgs (LFV) vertices. On the other hand, as an example of flavor
mediation through mixing, we discuss an E_6 inspired multi-Higgs model, with an
abelian flavor symmetry, where LFV as well as lepton flavor conserving Higgs
effects are found to arise, though in this case at tree-level. We find that
Tevatron and LHC can provide information on the flavor structure of these
models through the detection of the LFV higgs mode h-> tau+mu, while NLC can
perform high-precision measurements of the LFC mode h-> tau tau.Comment: 17 pages, 5 tables, 3 figures; corrected mistake in last section,
results changed but conclusions remmai
F-19-nanoparticles: platform for in vivo delivery of fluorinated biomaterials for F-19-MRI
Fluorine-19 (F-19) magnetic resonance imaging (MRI) features one of the most investigated and innovative techniques for quantitative and unambiguous cell tracking, providing information for both localization and number of cells. Because of the relative insensitivity of the MRI technique, a high number of magnetically equivalent fluorine atoms are required to gain detectable signals. However, an increased amount of F-19 nuclei induces low solubility in aqueous solutions, making fluorine-based probes not suitable for in vivo imaging applications. In this context, nanoparticle-based platforms play a crucial role, since nanoparticles may carry a high payload of F-19-based contrast agents into the relevant cells or tissues, increase the imaging agents biocompatibility, and provide a highly versatile platform. In this review, we present an overview of the F-19-based nanoprobes for sensitive F-19-MRI, focusing on the main nanotechnologies employed to date, such as fluorine and theranostic nanovectors, including their design and applications.Cardiovascular Aspects of Radiolog
Assembly of upconversion nanophotosensitizer <i>in vivo</i> to achieve scatheless real-time imaging and selective photodynamic therapy
Upconversion nanoparticle platform for efficient dendritic cell antigen delivery and simultaneous tracking
Upconversion nanoparticles (UCNPs) represent a group of NPs that can convert near-infrared (NIR) light into ultraviolet and visible light, thus possess deep tissue penetration power with less background fluorescence noise interference, and do not induce damage to biological tissues. Due to their unique optical properties and possibility for surface modification, UCNPs can be exploited for concomitant antigen delivery into dendritic cells (DCs) and monitoring by molecular imaging. In this study, we focus on the development of a nano-delivery platform targeting DCs for immunotherapy and simultaneous imaging. OVA 254–267 (OVA24) peptide antigen, harboring a CD8 T cell epitope, and Pam3CysSerLys4 (Pam3CSK4) adjuvant were chemically linked to the surface of UCNPs by amide condensation to stimulate DC maturation and antigen presentation. The OVA24-Pam3CSK4-UCNPs were thoroughly characterized and showed a homogeneous morphology and surface electronegativity, which promoted a good dispersion of the NPs. In vitro experiments demonstrated that OVA24-Pam3CSK4-UCNPs induced a strong immune response, including DC maturation, T cell activation, and proliferation, as well as interferon gamma (IFN-γ) production. In vivo, highly sensitive upconversion luminescence (UCL) imaging of OVA24-Pam3CSK4-UCNPs allowed tracking of UCNPs from the periphery to lymph nodes. In summary, OVA24-Pam3CSK4-UCNPs represent an effective tool for DC-based immunotherapy. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00604-022-05441-z
Functionalized nanoparticles targeting tumor-associated macrophages as cancer therapy
The tumor microenvironment (TME) plays a central role in regulating antitumor immune responses. As an important part of the TME, alternatively activated type 2 (M2) macrophages drive the development of primary and secondary tumors by promoting tumor cell proliferation, tumor angiogenesis, extracellular matrix remodeling and overall immunosuppression. Immunotherapy approaches targeting tumor-associated macrophages (TAMs) in order to reduce the immunosuppressive state in the TME have received great attention. Although these methods hold great potential for the treatment of several cancers, they also face some limitations, such as the fast degradation rate of drugs and drug-induced cytotoxicity of organs and tissues. Nanomedicine formulations that prevent TAM signaling and recruitment to the TME or deplete M2 TAMs to reduce tumor growth and metastasis represent encouraging novel strategies in cancer therapy. They allow the specific delivery of antitumor drugs to the tumor area, thereby reducing side effects associated with systemic application. In this review, we give an overview of TAM biology and the current state of nanomedicines that target M2 macrophages in the course of cancer immunotherapy, with a specific focus on nanoparticles (NPs). We summarize how different types of NPs target M2 TAMs, and how the physicochemical properties of NPs (size, shape, charge and targeting ligands) influence NP uptake by TAMs in vitro and in vivo in the TME. Furthermore, we provide a comparative analysis of passive and active NP-based TAM-targeting strategies and discuss their therapeutic potential.Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas
Redox-sensitive and hyaluronic acid-functionalized nanoparticles for improving breast cancer treatment by cytoplasmic 17 alpha-methyltestosterone delivery
Novel reduction-responsive hyaluronic acid-chitosan-lipoic acid nanoparticles (HACSLA-NPs) were designed and synthesized for effective treatment of breast cancer by targeting Cluster of Differentiation 44 (CD44)-overexpressing cells and reduction-triggered 17 alpha-Methyltestosterone (MT) release for systemic delivery. The effectiveness of these nanoparticles was investigated by different assays, including release rate, 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT), lactate dehydrogenase (LDH), caspase-3 activity, Rhodamine 123 (RH-123), and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). In vitro experiments revealed that Methyltestosterone/Hyaluronic acid-chitosan-lipoic acid nanoparticles (MT/HACSLA-NPs) illustrated a sustained drug release in the absence of glutathione (GSH), while the presence of GSH led to fast MT release. HACSLA-NPs also showed high cellular internalization via CD44 receptors, quick drug release inside the cells, and amended cytotoxicity against positive CD44 BT-20 breast cancer cell line as opposed to negative CD44, Michigan Cancer Foundation-7 (MCF-7) cell line. These findings supported that these novel reduction-responsive NPs can be promising candidates for efficient targeted delivery of therapeutics in cancer therapy.Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas
Combining photodynamic therapy with immunostimulatory nanoparticles elicits effective anti-tumor immune responses in preclinical murine models
Photodynamic therapy (PDT) has shown encouraging but limited clinical efficacy when used as a standalone treatment against solid tumors. Conversely, a limitation for immunotherapeutic efficacy is related to the immunosuppressive state observed in large, advanced tumors. In the present study, we employ a strategy, in which we use a combination of PDT and immunostimulatory nanoparticles (NPs), consisting of poly(lactic-co-glycolic) acid (PLGA)-polyethylene glycol (PEG) particles, loaded with the Toll-like receptor 3 (TLR3) agonist poly(I:C), the TLR7/8 agonist R848, the lymphocyte-attracting chemokine, and macrophage inflammatory protein 3 alpha (MIP3 alpha). The combination provoked strong anti-tumor responses, including an abscopal effects, in three clinically relevant murine models of cancer: MC38 (colorectal), CT26 (colorectal), and TC-1 (human papillomavirus 16-induced). We show that the local and distal anti-tumor effects depended on the presence of CD8(+) T cells. The combination elicited tumor-specific oncoviral- or neoepitope-directed CD8(+) T cells immune responses against the respective tumors, providing evidence that PDT can be used as an in situ vaccination strategy against cancer (neo)epitopes. Finally, we show that the treatment alters the tumor microenvironment in tumor-bearing mice, from cold (immunosuppressed) to hot (pro-inflammatory), based on greater neutrophil infiltration and higher levels of inflammatory myeloid and CD8(+) T cells, compared to untreated mice. Together, our results provide a rationale for combining PDT with immunostimulatory NPs for the treatment of solid tumors.Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas
Enhancing anti-tumor immunity through liposomal oxaliplatin and localized immunotherapy via STING activation
The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is a promising approach for anti-cancer immunotherapy by bridging innate and adaptive immunity. Recent evidence suggests that chemotherapy-induced DNA damage can directly induce dendritic cell (DC) maturation and recruitment, which synergizes with STING activation to enhance anti-tumor effects. As an immunogenic cell death (ICD) inducer, oxaliplatin generates massive double-stranded DNA (dsDNA) crosslinks, release of tumor-associated antigens and promoting the "eat me" signal. STING activation improves antigen immunogenicity, which can promote T cell activation and infiltration. In this study, we developed liposomes encapsulating oxaliplatin and combine this formulation with a STING agonist (ADU-S100) for treating colorectal cancer. The liposomes efficiently inhibited the proliferation of tumor cells while induced ICD in CT26 colorectal cancer cells, which enhanced dendritic cell maturation and phagocytosis in vitro. The liposome-based immunochemotherapy exhibited the strongest efficacy, resulting in complete remission upon tumor inoculation. Mechanistic studies showed this potent anti-cancer effect was related to the significant recruitment of infiltrating CD8 and CD4 T cells, reduction of suppressive Treg cells, and a shift in the phenotype of tumor-associated suppressive macrophages that promote cancer to immune stimulating macrophages. Thus, our study demonstrated the potential of combining oxaliplatin-loaded liposomes with a STING agonist to reduce tumor growth by regulating the immunosuppressive state in the tumor.Horizon 2020 (H2020)777682TumorimmunologyRadiolog
Quark-Squark Alignment Revisited
We re-examine the possibility that the solution to the supersymmetric flavor
problem is related to small mixing angles in gaugino couplings induced by
approximate horizontal Abelian symmetries. We prove that, for a large class of
models, there is a single viable structure for the down quark mass matrix with
four holomorphic zeros. Consequently, we are able to obtain both lower and
upper bounds on the supersymmetric mixing angles and predict the contributions
to various flavor changing neutral current processes. We find that the most
likely signals for alignment are close to the present bound,
significant CP violation in mixing, and shifts of order a few
percent in various CP asymmetries in and decays. In contrast, the
modifications to radiative B decays, to and to
decays are small. We further investigate a new class of
alignment models, where supersymmetric contributions to flavor changing
processes are suppressed by both alignment and RGE-induced degeneracy.Comment: 20 pages, 3 figure
Bacterial cellulose as drug delivery system for optimizing release of immune checkpoint blocking antibodies
Immune checkpoint blocking therapy is a promising cancer treatment modality, though it has limitations such as systemic toxicity, which can often be traced to uncontrolled antibody spread. Controlling antibody release with delivery systems is, therefore, an attractive approach to reduce systemic antibody spread and potentially mitigate the side effects of checkpoint immunotherapy. Here, bacterial cellulose (BC) was produced and investigated as a delivery system for optimizing checkpoint-blocking antibody delivery. BC was produced in 24-well plates, and afterward, the edges were removed to obtain square-shaped BC samples with a surface of similar to 49 mm(2). This customization was necessary to allow smooth in vivo implantation. Scanning electron microscopy revealed the dense cellulose network within BC. Human IgG antibody was included as the model antibody for loading and release studies. IgG antibody solution was injected into the center of BC samples. In vitro, all IgG was released within 24 to 48 h. Cell culture experiments demonstrated that BC neither exerted cytotoxic effects nor induced dendritic cell activation. Antibody binding assays demonstrated that BC does not hamper antibody function. Finally, antibody-loaded BC was implanted in mice, and serum measurements revealed that BC significantly reduced IgG and anti-CTLA-4 spread in mice. BC implantation did not induce side effects in mice. Altogether, BC is a promising and safe delivery system for optimizing the delivery and release of checkpoint-blocking antibodies.Radiolog
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