Natural residues of the dimeric opioid peptide Biphalin were replaced by the corresponding homo-β(3) amino acids. The derivative 1 containing hβ(3) Phe in place of Phe showed good μ- and δ-receptor ...affinities (Ki(δ) = 0.72 nM; Ki(μ) = 1.1 nM) and antinociceptive activity in vivo together with an increased enzymatic stability in human plasma.
Cellular senescence is characterized by an irreversible cell cycle arrest as well as a pro‐inflammatory phenotype, thought to contribute to aging and age‐related diseases. Neutrophils have essential ...roles in inflammatory responses; however, in certain contexts their abundance is associated with a number of age‐related diseases, including liver disease. The relationship between neutrophils and cellular senescence is not well understood. Here, we show that telomeres in non‐immune cells are highly susceptible to oxidative damage caused by neighboring neutrophils. Neutrophils cause telomere dysfunction both in vitro and ex vivo in a ROS‐dependent manner. In a mouse model of acute liver injury, depletion of neutrophils reduces telomere dysfunction and senescence. Finally, we show that senescent cells mediate the recruitment of neutrophils to the aged liver and propose that this may be a mechanism by which senescence spreads to surrounding cells. Our results suggest that interventions that counteract neutrophil‐induced senescence may be beneficial during aging and age‐related disease.
SYNOPSIS
Whether infiltrating immune cells impact on tissue viability during inflammatory response is poorly characterized. Here, activated neutrophils are shown to induce ROS‐dependent acute senescence in adjacent naïve cells, raising the possibility of intercellular senescence crosstalk during ageing and age‐related pathologies.
Neutrophils induce paracrine senescence in neighbouring cells via ROS‐dependent telomere dysfunction.
Neutrophil clearance prevents senescence and telomere dysfunction in a model of acute liver injury.
Senescent cells recruit neutrophils via the senescence‐associated secretory phenotype (SASP) in the aged liver.
Oxidative damage caused by inflammatory neutrophils contributes to neighbouring cell senescence and liver injury.
Nonrandomized data exploring pancreas stereotactic body radiation therapy (SBRT) has demonstrated excellent local control rates and low toxicity. Before commencing a randomized trial investigating ...pancreas SBRT, standardization of prescription dose, dose constraints, simulation technique, and clinical target volume delineation are required.
Specialists in radiation oncology, medical oncology, hepatobiliary surgery, and gastroenterology attended 2 consecutive Australasian Gastrointestinal Trials Group workshops in 2017 and 2018. Sample cases were discussed during workshop contact with specifically invited international speakers highly experienced in pancreas SBRT. Furthermore, sample cases were contoured and planned between workshop contact to finalize dose constraints and clinical target volume delineation.
Over 2 separate workshops, consensus was reached on dose and simulation technique. The working group recommended a dose prescription of 40 Gy in 5 fractions. Treatment delivery during end-expiratory breath hold with triple-phase contrast enhanced computed tomography was recommended. In addition, dose constraints, stepwise contouring guidelines, and an anatomic atlas for pancreatic SBRT were developed.
Pancreas SBRT is emerging as a promising treatment modality requiring prospective evaluation in randomized studies. This work attempts to standardize dose, simulation technique, and volume delineation to support the delivery of high quality SBRT in a multicenter study.
Recent emphasis has focused on the development of rationally designed polymer-based micelle carriers for drug delivery. The current work tests the hypothesis that target specificity can be enhanced ...by micelles with cancer-specific ligands. In particular, we describe the synthesis and characterization of a new gadolinium texaphyrin (Gd-Tx) complex encapsulated in an IVECT micellar system, stabilized through Fe(III) cross-linking and targeted with multiple copies of a specific ligand for the melanocortin 1 receptor (MC1R), which has been evaluated as a cell-surface marker for melanoma. On the basis of comparative MRI experiments, we have been able to demonstrate that these Gd-Tx micelles are able to target MC1R-expressing xenograft tumors in vitro and in vivo more effectively than various control systems, including untargeted or un-cross-linked Gd-Tx micelles. Taken in concert, the findings reported herein support the conclusion that appropriately designed micelles are able to deliver contrast agent payloads to tumors expressing the MC1R.
The field of biosensing would significantly benefit from a disruptive technology enabling flexible manufacturing of uniform electrodes. Inkjet printing holds promise for this, although realizing full ...electrode manufacturing with this technology remains challenging. We introduce a nitrogen-doped carboxylated graphene ink (NGA-ink) compatible with commercially available printing technologies. The water-based and additive-free NGA-ink was utilized to produce fully inkjet-printed electrodes (IPEs), which demonstrated successful electrochemical detection of the important neurotransmitter dopamine. The cost-effectiveness of NGA-ink combined with a total cost per electrode of $0.10 renders it a practical solution for customized electrode manufacturing. Furthermore, the high carboxyl group content of NGA-ink (13 wt%) presents opportunities for biomolecule immobilization, paving the way for the development of advanced state-of-the-art biosensors. This study highlights the potential of NGA inkjet-printed electrodes in revolutionizing sensor technology, offering an affordable, scalable alternative to conventional electrochemical systems.
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Fluorine-19 magnetic resonance imaging (19F MRI) has emerged as a promising noninvasive diagnostic tool, broadening the diagnostic possibilities of commonly used proton MRI. Despite the potential of ...19F MRI, an ideal tracer paving the way toward the entry of this method into common medical practice is yet to be developed. In this study, we report on a series of polymeric systems based on thermoresponsive polyN-(2,2-difluoroethyl)acrylamide (PDFEA), a polymer considered to be an ideal tracer for 19F MRI. The described systems are designed as BAB triblock copolymers, where B corresponds to thermoresponsive PDFEA blocks and A is a hydrophilic poly(ethylene glycol) block. These BAB triblock copolymers are able to form nanoparticles in dilute aqueous solutions, which undergo a transition into physically cross-linked hydrogels upon increasing the polymer concentration. Since thermoresponsive particle- and hydrogel-based systems are applicable in a wide range of biomedical applications, we created a diagnostic system with potential therapeutic properties (theranostic) as a widely tunable platform through straightforward synthesis while serving a multitude of applications. We analyzed the effect of the BAB block ratio on the self-assembly, thermoresponsiveness, and mechanical properties of the studied hydrogels, together with their suitability for 19F MRI. Finally, their biocompatibility was assessed on a relevant cell line.
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We report here the design and synthesis of novel multifunctional ligands that act as (μ/δ) opioid agonists and bradykinin 2 receptor antagonists. These multifunctional ligands were ...designed to interact with the multiple receptors to show an enhanced analgesic effect, with no opioid-induced tolerance. We designed our multifunctional ligands based on the well-known second generation bradykinin 2 receptor antagonist Hoe 140 (DArg-Arg-Pro-Hyp-Gly-Thi-Ser-DTic-Oic-Arg-OH) and the opioid enkephalin analogues Tyr-DAla-Phe, Tyr-DAla-Gly-Phe and Tyr-Pro-Phe. We explored the conjugation of opioid pharmacophore to the Hoe 140 (DArg-Arg-Pro-Hyp-Gly-Thi-Ser-DTic-Oic-Arg-OH) in various positions with and without a linker. These bifunctional ligands showed very good binding affinity towards the both μ and δ opioid receptors. Among these bifunctional ligands 8, 11 and 12 showed excellent and balanced binding affinity at both μ and δ opioid receptors (0.5nM, 2.0nM; 0.3nM, 2nM; 2nM and 3nM), respectively. On the other hand these bifunctional ligands showed very weak and no binding affinity for rat brain bradykinin 2 receptors. Similarly, the Hoe 140 showed very low affinity (>10,000nM and 9000nM) against 3H BK binding in rat brain membranes and in HEK293 cells, respectively. In contrast, the Hoe 140 showed very good binding affinity in guinea pig ileum (0.43nM) similar to that of previously reported. The bradykinin 2 receptors are known to be present in rat brain membrane, guinea pig ileum (GPI) and rabbit jugular vein. Previously the binding affinity of Hoe 140 for bradykinin 2 receptor was reported using guinea pig ileum. The above results suggest that the bradykinin 2 receptors present in rat brain membrane are a different sub type than the bradykinin 2 receptor present in guinea pig ileum (GPI).
Probes for use in time-resolved fluorescence competitive binding assays at melanocortin receptors based on the parental ligands MSH(4), MSH(7), and NDP-α-MSH were prepared by solid phase synthesis ...methods, purified, and characterized. The saturation binding of these probes was studied using HEK-293 cells engineered to overexpress the human melanocortin 4 receptor (hMC4R) as well as the human cholecystokinin 2 receptor (hCCK2R). The ratios of non-specific binding to total binding approached unity at high concentrations for each probe. At low probe concentrations, receptor-mediated binding and uptake was discernable, and so probe concentrations were kept as low as possible in determining Kd values. The Eu-DTPA-PEGO-MSH(4) probe exhibited low specific binding relative to non-specific binding, even at low nanomolar concentrations, and was deemed unsuitable for use in competition binding assays. The Eu-DTPA-PEGO probes based on MSH(7) and NDP-α-MSH exhibited Kd values of 27±3.9nM and 4.2±0.48nM, respectively, for binding with hMC4R. These probes were employed in competitive binding assays to characterize the interactions of hMC4R with monovalent and divalent MSH(4), MSH(7), and NDP-α-MSH constructs derived from squalene. Results from assays with both probes reflected only statistical enhancements, suggesting improper ligand spacing on the squalene scaffold for the divalent constructs. The Ki values from competitive binding assays that employed the MSH(7)-based probe were generally lower than the Ki values obtained when the probe based on NDP-α-MSH was employed, which is consistent with the greater potency of the latter probe. The probe based on MSH(7) was also competed with monovalent, divalent, and trivalent MSH(4) constructs that previously demonstrated multivalent binding in competitive binding assays against a variant of the probe based on NDP-α-MSH. Results from these assays confirm multivalent binding, but suggest a more modest increase in avidity for these MSH(4) constructs than was previously reported.
Together we bind: A series of synthetic heterobivalent ligands containing a fragment of melanocyte stimulating hormone analogue MSH(7) and the δ‐opioid ligand deltorphin‐II has been prepared. These ...ligands bind with higher affinity and with apparent cooperativity to cells expressing both hMC4R and δ‐opioid receptors. Binding affinities were evaluated using a lanthanide‐based in‐cyto time‐resolved fluorescence binding assay.
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Background: With the introduction of Ga68-PSMA PET, a new cohort of androgen-intact men with oligometastatic prostate cancer (PCa) recurrence has been identified. These men have ...normal traditional imaging and a disease-free interval usually measured in years from their definitive treatment. Recent data supports the use of metastasis-directed stereotactic body radiotherapy (SBRT) in oligometastatic PCa. Based on our institutional data in 57 patients treated with SBRT alone in the PSMA era, the median PSA progression free survival (PFS) is 11 months. Despite 100% local control, 80% relapsed by 18 months. Improving the PFS for these men is an important clinical need. Achieving this without the introduction of androgen deprivation therapy (ADT) will likely improve quality of life and minimise the adverse consequences of androgen deprivation. Radiotherapy results in cell stress and release of damage associated molecular patterns (DAMPs) with activation of antigen presenting cells. This stimulates a tumour antigen specific T-cell response and abscopal effect which can be heightened with PD-(L)1 inhibition. Most PD-(L)1 inhibition trials in PCa are in men with a high burden of castrate resistant disease. However, data suggests the castrate state can impair host anti-tumour immune response. PD-(L)1 inhibition combined with SBRT in androgen-intact men may result in improved PFS compared with our historical cohort treated with SBRT alone. Methods: This is a non-randomized, open label, phase II study of durvalumab (1500 mg IV every 4 weeks) starting 1 month prior to SBRT in men with recurrent PCa not immediately requiring ADT and with Ga68-PSMA PET detected oligometastasis. SBRT will be delivered with 30Gy/3# to lymph nodes or 24Gy/2# to bone metastasis. Durvalumab will be continued to a maximum of 12 months. Primary outcomes will be freedom from biochemical failure and toxicity. Secondary objectives include biochemical response rate, magnitude of response, overall survival, time and response to subsequent treatments and quality of life. The study is recruiting at Royal North Shore Hospital in Sydney with 18 of the planned 30 patients enrolled. Clinical trial information: ACTRN12619000097145.
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