In the search for new chemical scaffolds able to afford NLRP3 inflammasome inhibitors, we used a pharmacophore-hybridization strategy by combining the structure of the acrylic acid derivative INF39 with the 1-(piperidin-4-yl)1,3-dihydro-2H-benzo[d]imidazole-2-one substructure present in HS203873, a recently identified NLRP3 binder. A series of differently modulated benzo[d]imidazole-2-one derivatives were designed and synthesised. The obtained compounds were screened in vitro to test their ability to inhibit NLRP3-dependent pyroptosis and IL-1β release in PMA-differentiated THP-1 cells stimulated with LPS/ATP. The selected compounds were evaluated for their ability to reduce the ATPase activity of human recombinant NLRP3 using a newly developed assay. From this screening, compounds 9, 13 and 18, able to concentration-dependently inhibit IL-1β release in LPS/ATP-stimulated human macrophages, emerged as the most promising NLRP3 inhibitors of the series. Computational simulations were applied for building the first complete model of the NLRP3 inactive state and for identifying possible binding sites available to the tested compounds. The analyses led us to suggest a mechanism of protein–ligand binding that might explain the activity of the compounds.
In the last years, research proofs have confirmed that hydrogen sulfide (H2S) plays an important role in various physio-pathological processes, such as oxidation, inflammation, neurophysiology, and cardiovascular protection; in particular, the protective effects of H2S in cardiovascular diseases were demonstrated. The interest in H2S-donating molecules as tools for biological and pharmacological studies has grown, together with the understanding of H2S importance. Here we performed a comparative study of a series of H2S donor molecules with different chemical scaffolds and H2S release mechanisms. The compounds were tested in human serum for their stability and ability to generate H2S. Their vasorelaxant properties were studied on rat aorta strips, and the capacity of the selected compounds to protect NO-dependent endothelium reactivity in an acute oxidative stress model was tested. H2S donors showed different H2S-releasing kinetic and produced amounts and vasodilating profiles; in particular, compound 6 was able to attenuate the dysfunction of relaxation induced by pyrogallol exposure, showing endothelial protective effects. These results may represent a useful basis for the rational development of promising H2S-releasing agents also conjugated with other pharmacophores.
BRAF is a serine/threonine kinase frequently mutated in human cancers. BRAFV600E mutated protein is targeted through the use of kinase inhibitors which are approved for the treatment of melanoma; however, their long-term efficacy is hampered by resistance mechanisms. The PROTAC-induced degradation of BRAFV600E has been proposed as an alternative strategy to avoid the onset of resistance. In this study, we designed a series of compounds where the BRAF kinase inhibitor encorafenib was conjugated to pomalidomide through different linkers. The synthesized compounds maintained their ability to inhibit the kinase activity of mutated BRAF with IC50 values in the 40–88 nM range. Selected compounds inhibited BRAFV600E signaling and cellular proliferation of A375 and Colo205 tumor cell lines. Compounds 10 and 11, the most active of the series, were not able to induce degradation of mutated BRAF. Docking and molecular dynamic studies, conducted in comparison with the efficient BRAF degrader P5B, suggest that a different orientation of the linker bearing the pomalidomide substructure, together with a decreased mobility of the solvent-exposed part of the conjugates, could explain this behavior.
The use of traditional nonsteroidal anti-inflammatory drugs (NSAIDs) and coxibs is effective for the treatment of inflammatory pain and chronic inflammatory conditions. However, their use is associated with enhanced risk of cardiovascular toxicity and thrombotic events, particularly for the latter. The vascular side effects of these drugs could be mitigated by pharmacological inhibition of the thromboxane A2 receptor (TP). Here we describe the development of a new class of dual cyclooxygenase (COX) inhibitors/thromboxane receptor antagonists (COXTRANs) based on the 2-(1,3,4,9-tetrahydropyrano[3,4-b]indol-1-yl)acetic acid scaffold. The in vitro evaluation of 50 newly synthesized compounds resulted in a set of well-balanced compounds exhibiting nanomolar activity on both COX-2 and TP receptor. Further studies in human whole blood and physicochemical profiling allowed the prioritization of 51 (CXT29) as a suitable candidate for in vivo studies. Compound 51, after oral administration, was able to prevent TP receptor-mediated platelet aggregation and to reduce inflammatory pain in mice.
Imaging in the shortwave infrared (SWIR, 1000-1700 nm) region is gaining traction for biomedical applications, leading to an in-depth search for fluorophores emitting at these wavelengths. The development of SWIR emitters, to be used in vivo in biological media, is mostly hampered by the considerable lipophilicity of the structures, resulting from the highly conjugated scaffold required to shift the emission to this region, that limit their aqueous solubility. In this work, we have modulated a known SWIR emitter, named Flav7, by adding hydrophilic moieties to the flavylium scaffold and we developed a new series of Flav7-derivatives, which proved to be indeed more polar than the parent compound, but still not freely water-soluble. Optical characterization of these derivatives allowed us to select FlavMorpho, a new compound with improved emission properties compared to Flav7. Encapsulation of the two compounds in micelles resulted in water-soluble SWIR emitters, with FlavMorpho micelles being twice as emissive as Flav7 micelles. The SWIR emission extent of FlavMorpho micelles proved also superior to the tail-emission of Indocyanine Green (ICG), the FDA-approved reference cyanine, in the same region, by exciting the probes at their respective absorption maxima in phosphate buffered saline (PBS) solution. The availability of optical imaging devices equipped with lasers able to excite these dyes at their maximum of absorption in the SWIR region, could pave the way for implemented SWIR imaging results.
Background/Objectives: Oral insulin continues to constitute a challenge due to its low uptake by the gut wall and degradation by gastrointestinal proteolytic enzymes. Such concerns might be surmounted by means of nanoparticle delivery. Methods: In this study, glargine insulin has been loaded into solid lipid nanoparticles prepared via coacervation from Shea and Mango soaps, due to hydrophobic ion pairing. Subsequently, ex vivo tied-up-gut experiments were performed with fluorescently labeled peptide. Additionally, re-dispersible oral solid dosage forms (powders and tablets) were obtained from nanoparticle suspensions via freeze-drying and spray-drying. Results: Solid lipid nanoparticles are capable of enhancing peptide permeation into different gut sections. Furthermore, spray-drying permits the preparation, which can be scaled up, of a re-dispersible powder from the nanoparticle suspension. Conclusions: This engineered process is suitable for the formulation of solid oral dosage forms, such as granulates and tablets, and presents promising potential for oral insulin delivery, paving the way for the assessment of its pharmacological efficacy in further in vivo studies.
About Me
University of Turin - Department of Drug Science and Technology
University of Turin - Department of Drug Science and Technology