scholarly journals Highly Potent GalNAc-Conjugated Tiny LNA Anti-miRNA-122 Antisense Oligonucleotides

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 817
Author(s):  
Tsuyoshi Yamamoto ◽  
Yahiro Mukai ◽  
Fumito Wada ◽  
Chisato Terada ◽  
Yukina Kayaba ◽  
...  
Keyword(s):  
Antisense Oligonucleotides ◽  
Ex Vivo ◽  
The Body ◽  
Locked Nucleic Acid ◽  
Imaging Studies ◽  
Phosphodiester Bond ◽  
Chemically Modified ◽  
Ex Vivo Imaging ◽  
Mirna Targeting

The development of clinically relevant anti-microRNA antisense oligonucleotides (anti-miRNA ASOs) remains a major challenge. One promising configuration of anti-miRNA ASOs called “tiny LNA (tiny Locked Nucleic Acid)” is an unusually small (~8-mer), highly chemically modified anti-miRNA ASO with high activity and specificity. Within this platform, we achieved a great enhancement of the in vivo activity of miRNA-122-targeting tiny LNA by developing a series of N-acetylgalactosamine (GalNAc)-conjugated tiny LNAs. Specifically, the median effective dose (ED50) of the most potent construct, tL-5G3, was estimated to be ~12 nmol/kg, which is ~300–500 times more potent than the original unconjugated tiny LNA. Through in vivo/ex vivo imaging studies, we have confirmed that the major advantage of GalNAc over tiny LNAs can be ascribed to the improvement of their originally poor pharmacokinetics. We also showed that the GalNAc ligand should be introduced into its 5′ terminus rather than its 3′ end via a biolabile phosphodiester bond. This result suggests that tiny LNA can unexpectedly be recognized by endogenous nucleases and is required to be digested to liberate the parent tiny LNA at an appropriate time in the body. We believe that our strategy will pave the way for the clinical application of miRNA-targeting small ASO therapy.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

scholarly journals 4081 Quantifying pH buffering capacity and kinetics of tumor and healthy tissue to understand and exploit differences in biology

2020 ◽  
Vol 4 (s1) ◽  
pp. 15-15
Author(s):  
A. Colleen Crouch ◽  
Emily A. Thompson ◽  
Mark D. Pagel ◽  
Erik N.K. Cressman
Keyword(s):  
Tumor Tissue ◽  
Ex Vivo ◽  
Buffering Capacity ◽  
The Body ◽  
Healthy Tissue ◽  
Buffer System ◽  
Bicarbonate Buffer ◽  
Ph Buffering ◽  
Acidocest Mri

OBJECTIVES/GOALS: The purpose of this work is to investigate natural buffering capacity of liver tissue and tumors, to understand and exploit differences for therapy. Using this work, we will determine the concentrations of reagents (acids or bases) used in ablation treatment to optimize treatment by increasing tumor toxicity and minimizing healthy tissue toxicity. METHODS/STUDY POPULATION: For this preliminary study, two methods will be used: benchtop pH experiments ex vivo and non-invasive imaging using acidoCEST MRI in vivo. For ex vivo, two types of tissues will be tested: non-cancerous liver and tumor tissue from HepG2 inoculated mice (n = 10). After mice are euthanized, pH will be measured in tissue homogenates at baseline and then the homogenates will be placed in either acidic (acetic acid) or basic (sodium hydroxide) solutions with varied concentrations (0.5–10M) and time recorded until pH returns to baseline. For in vivo imaging, Mia PaCA-2 flank model mice (n = 10) will be imaged with acidoCEST MRI to quantify pH at baseline. Mice will then be injected intratumorally with (up to 100 μL of) acid or base at increasing concentrations and imaged to quantify pH changes in the tumor. RESULTS/ANTICIPATED RESULTS: For this study, buffering capacity is defined as the concentration threshold for which tissue can buffer pH back to within normal range. Non-cancerous tissue is likely to buffer a wider range of concentrations compared to tumor tissue. From the benchtop experiment, comparison of time-to-buffer will be made for each concentration of acid/base for the two tissue types. AcidoCEST MRI will provide in vivo buffering capacity and potentially demonstrate tumor heterogeneity of buffering capacity. For both experiments, a pH vs. concentration curve for the two tissue types will allow for comparison of ex vivo to in vivo experiments, which will differentiate contributions of local tissue buffering capacity from the full body’s natural bicarbonate buffer system that depends on respiration and blood flow. DISCUSSION/SIGNIFICANCE OF IMPACT: The pH of the body must be maintained within a narrow range. With cancer, impairment in regulation of tumor metabolism causes acidosis, lowering extracellular pH in tumors. It remains unclear if pH plays a role in local recurrence or tumor toxicity. This work will determine if acidoCEST MRI can measure deliberate alteration of pH and how this change affects biology.

Tumor Targeted Nanoparticles Improve Therapeutic Index of BCL2 and MCL1 dual inhibition

Blood ◽  
2020 ◽  
Author(s):  
Neeta Bala Tannan ◽  
Mandana T Manzari ◽  
Laurie Herviou ◽  
Mariana da Silva Ferreira ◽  
Connor J Hagen ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Therapeutic Index ◽  
Drug Dose ◽  
Hematological Toxicity ◽  
Bcl2 Family ◽  
Fold Reduction ◽  
Tumor Killing ◽  
Toxic Drugs ◽  
Ex Vivo Imaging

Cancer and normal cells utilize multiple anti-apoptotic BCL2 proteins to prevent cell death. Therapeutic targeting of multiple BCL2 family proteins enhances tumor killing, but is also associated with increased systemic toxicity. Here, we demonstrate that the dual targeting of MCL1 and BCL2 proteins, using the small molecules S63845 and venetoclax, induces durable remissions in mice harboring human DLBCL tumors but is accompanied by hematological toxicity and weight loss. To mitigate these toxicities, we encapsulated S63845 or venetoclax into nanoparticles targeting P-selectin that is enriched in tumor endothelial cells. In vivo and ex vivo imaging demonstrated preferential targeting of the nanoparticles to lymphoma tumors over vital organs. Mass-spectrometry analyses after nanoparticle drug administration confirmed tumor enrichment of the drug while reducing plasma levels. Furthermore, nanoparticle encapsulation allowed 3.5 to 6.5-fold reduction in drug dose, induced sustained remissions and minimized toxicity. Our results support the development of nanoparticles to deliver BH3 mimetic combinations in lymphoma and in general for toxic drugs in cancer therapy.

In-vivo near-infrared optical imaging of growing osteosarcoma cell lesions xenografted in mice: dual-channel quantitative evaluation of volume and mineralization

2011 ◽  
Vol 52 (9) ◽  
pp. 978-988 ◽  
Author(s):  
Hitoshi Nakayama ◽  
Tomoyuki Kawase ◽  
Kazuhiro Okuda ◽  
Larry F Wolff ◽  
Hiromasa Yoshie
Keyword(s):  
Optical Imaging ◽  
Near Infrared ◽  
Imaging Technique ◽  
Ex Vivo ◽  
Acquisition Time ◽  
Osteosarcoma Cell ◽  
Dual Channel ◽  
Nir Imaging ◽  
Ex Vivo Imaging

Background In a previous study using a rodent osteosarcoma-grafted rat model, in which cell-dependent mineralization was previously demonstrated to proportionally increase with growth, we performed a quantitative analysis of mineral deposit formation using 99mTc-HMDP and found some weaknesses, such as longer acquisition time and narrower dynamic ranges (i.e. images easily saturated). The recently developed near-infrared (NIR) optical imaging technique is expected to non-invasively evaluate changes in living small animals in a quantitative manner. Purpose To test the feasibility of NIR imaging with a dual-channel system as a better alternative for bone scintigraphy by quantitatively evaluating mineralization along with the growth of osteosarcoma lesions in a mouse-xenograft model. Material and Methods The gross volume and mineralization of osteosarcoma lesions were evaluated in living mice simultaneously with dual-channels by NIR dye-labeled probes, 2-deoxyglucose (DG) and pamidronate (OS), respectively. To verify these quantitative data, retrieved osteosarcoma lesions were then subjected to ex-vivo imaging, weighing under wet conditions, microfocus-computed tomography (μCT) analysis, and histopathological examination. Results Because of less scattering and no anatomical overlapping, as generally shown, specific fluorescence signals targeted to the osteosarcoma lesions could be determined clearly by ex-vivo imaging. These data were well positively correlated with the in-vivo imaging data ( r > 0.8, P < 0.02). Other good to excellent correlations ( r > 0.8, P < 0.02) were observed between DG accumulation and tumor gross volume and between OS accumulation and mineralization volume. Conclusion This in-vivo NIR imaging technique using DG and OS is sensitive to the level to simultaneously detect and quantitatively evaluate the growth and mineralization occuring in this type of osteosarcoma lesions of living mice without either invasion or sacrifice. By possible mutual complementation, this dual imaging system might be useful for accurate diagnosis even in the presence of overlapping tissues.

scholarly journals The Opportunities and Use of Imaging to Measure Target Engagement

2019 ◽  
Vol 25 (2) ◽  
pp. 127-136
Author(s):  
Juliana Maynard ◽  
Philippa Hart
Keyword(s):  
Ex Vivo ◽  
Clinical Success ◽  
Receptor Occupancy ◽  
Accurate Information ◽  
Target Engagement ◽  
Drug Molecule ◽  
Drug Discovery And Development ◽  
Ex Vivo Imaging

Lack of efficacy and poor safety outcomes are deemed to be the greatest causes of clinical failure of novel therapeutics. The use of biomarkers that give accurate information on target engagement, providing confidence that pharmacological activity in the target organ is being achieved, is key in optimizing clinical success. Without a measurement of target engagement, it can be very difficult to discern the basis for any lack of efficacy of a drug molecule within the pharmaceutical industry. Target engagement can be measured in both an in vitro and in vivo setting, and in recent years imaging measurements have been used frequently in drug discovery and development to assess target engagement and receptor occupancy in both human and animal models. From this perspective, we assess and look at the advancements in both in vivo and ex vivo imaging to demonstrate the enormous potential that imaging has as an application to provide a greater understanding of target engagement with a correlative therapeutic impact.

Multicolor core/shell silicananoparticles for in vivo and ex vivo imaging

Nanoscale ◽  
2012 ◽  
Vol 4 (3) ◽  
pp. 824-830 ◽  
Author(s):  
Enrico Rampazzo ◽  
Federico Boschi ◽  
Sara Bonacchi ◽  
Riccardo Juris ◽  
Marco Montalti ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Core Shell ◽  
Ex Vivo Imaging

scholarly journals Regional distribution of SGLT activity in rat brain in vivo

2013 ◽  
Vol 304 (3) ◽  
pp. C240-C247 ◽  
Author(s):  
Amy S. Yu ◽  
Bruce A. Hirayama ◽  
Gerald Timbol ◽  
Jie Liu ◽  
Ana Diez-Sampedro ◽  
...  
Keyword(s):  
Rat Brain ◽  
Ex Vivo ◽  
Osmotic Shock ◽  
Regional Distribution ◽  
The Body ◽  
Specific Substrate ◽  
Ex Vivo Autoradiography ◽  
Molecular Imaging Probe ◽  
The Brain

Na+-glucose cotransporter (SGLT) mRNAs have been detected in many organs of the body, but, apart from kidney and intestine, transporter expression, localization, and functional activity, as well as physiological significance, remain elusive. Using a SGLT-specific molecular imaging probe, α-methyl-4-deoxy-4-[18F]fluoro-d-glucopyranoside (Me-4-FDG) with ex vivo autoradiography and immunohistochemistry, we mapped in vivo the regional distribution of functional SGLTs in rat brain. Since Me-4-FDG is not a substrate for GLUT1 at the blood-brain barrier (BBB), in vivo delivery of the probe into the brain was achieved after opening of the BBB by an established procedure, osmotic shock. Ex vivo autoradiography showed that Me-4-FDG accumulated in regions of the cerebellum, hippocampus, frontal cortex, caudate nucleus, putamen, amygdala, parietal cortex, and paraventricular nucleus of the hypothalamus. Little or no Me-4-FDG accumulated in the brain stem. The regional accumulation of Me-4-FDG overlapped the distribution of SGLT1 protein detected by immunohistochemistry. In summary, after the BBB is opened, the specific substrate for SGLTs, Me-4-FDG, enters the brain and accumulates in selected regions shown to express SGLT1 protein. This localization and the sensitivity of these neurons to anoxia prompt the speculation that SGLTs may play an essential role in glucose utilization under stress such as ischemia. The expression of SGLTs in the brain raises questions about the potential effects of SGLT inhibitors under development for the treatment of diabetes.

scholarly journals Supramolecular Encapsulation of Small-Ultra Red Fluorescent Proteins in Virus-Like Nanoparticles for Non-Invasive In Vivo Imaging Agents

2020 ◽  
Author(s):  
Fabian C. Herbert ◽  
Olivia Brohlin ◽  
Tyler Galbraith ◽  
Candace Benjamin ◽  
Cesar A. Reyes ◽  
...  
Keyword(s):  
In Vivo Imaging ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Ex Vivo ◽  
Imaging Agents ◽  
Non Invasive ◽  
Red Fluorescent Proteins ◽  
Ex Vivo Imaging

<div> <div> <div> <p>Icosahedral virus-like particles (VLPs) derived from bacteriophages Qβ and PP7 encapsulating small-ultra red fluorescent protein (smURFP) were produced using a versatile supramolecualr capsid dissassemble-reassemble approach. The generated fluorescent VLPs display identical structural properties to their non-fluorescent analogs. Encapsulated smURFP shows indistinguishable photochemical properties to its unencapsulated counterpart, exhibits outstanding stability towards pH, and produces bright in vitro images following phagocytosis by macrophages. In vivo imaging allows biodistribution to be imaged at different time points. Ex vivo imaging of intravenously administered encapsulated smURFP reveleas localization in the liver and </p> </div> </div> <div> <div> <p>kidneys after 2 h blood circulation and substantial elimination constructs as non-invasive in vivo imaging agents. </p> </div> </div> </div>

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