Protein kinase CK2 is the subject of numerous studies in medicinal chemistry due to its involvement in the development of several diseases, primarily cancers. Its overexpression in tumor cells is related to key processes such as tumor immune evasion and cell proliferation. The scientific approach of this study aims to investigate the thermal shift assay (TSA) as a pre-screening tool and to complement it with a co-crystallization approach in post-screening. Therefore, the synthesis of seven small-molecule CK2 inhibitors derived from indeno[1,2-b]indoles was supplemented by 18 related derivatives from our in-house compound library. The 25 molecules belong to four sub-scaffolds, namely 4b,9b-dihydroxy-4b,5,6,7,8,9b-hexahydroindeno[1,2-b]indole-9,10-dione (D-0), 5,6,7,8-tetrahydroindeno[1,2-b]indole-9,10-dione (D-1), 9-hydroxy-5H-indeno[1,2-b]indol-10-one (D-2), and 5H-indeno[1,2-b]indole-6,9,10-trione (D-3). The most active CK2 inhibitors identified by capillary electrophoresis (CE)-based assay belong to the D-1 sub-scaffold. In the TSA, these compounds also generate significant shifts of the melting temperature (Tm) of CK2, indicating a clear correlation between the results of the CE-based assay and those of the TSA. The contribution of co-crystallization in post-screening also demonstrated the effectiveness of D-1 sub-scaffold compared with D-0 sub-scaffold.

CK2α and CK2α’, two paralogous members of the human kinome, are catalytic subunits of protein kinase CK2. Together with the regulatory subunit CK2β, they form heterotetrameric holoenzymes. CK2 is the subject of efforts to develop effective and selective inhibitors. For this, secondary binding sites remote from the canonical ATP/GTP cavity are critical. A crystallographic fragment screening with CK2α’ crystals and an established molecular fragment collection was performed to identify new ligands at known or novel sites. It resulted in fourteen CK2α’/fragment structures. Five fragments were found at the CK2β interface of CK2α’ and three fragments at the established αD pocket, which exhibits subtle differences between CK2α and CK2α’; comparative co-crystallisations with CK2α showed that one of them binds to the αD pocket of CK2α’ exclusively. No fragments bound at the substrate-binding region of CK2α’, but a CK2α’ structure with dp10, a decameric section of the substrate-competitive inhibitor heparin, and the indenoindole-type ATP-competitive inhibitor 4w was determined. A comparison with a published CK2α/dp10 structure revealed features consistent with reports about substrate specificity differences between the isoenzymes: dp10 binds to CK2α’ and CK2α with opposite strand orientations, and the local conformations of the isoenzymes in the helix αD region are significantly different.

Multidrug resistance (MDR) mediated by ATP-binding cassette (ABC) transporters remains a major obstacle to cancer chemotherapy, particularly at later disease stages with metastases. Among the 48 human ABC proteins, P-glycoprotein (P-gp/ABCB1), multidrug resistance-associated protein 1 (MRP1/ABCC1), and breast cancer resistance protein (BCRP/ABCG2) are the most studied ABC transporters associated with MDR. Inhibition of ABC transporters has been considered as one possible strategy to overcome MDR. In this study, twelve N-methylpyrazole derivatives were evaluated as inhibitors of ABCB1, ABCC1, and ABCG2. Several compounds selectively inhibited ABCG2 while showing no activity against ABCB1 or ABCC1. The most potent derivative, 1l, inhibited more than 50% of ABCG2 activity at 10 μM and displayed substrate-independent inhibition, with IC50 values ranging from 1.6 to 3.8 μM depending on the fluorescent probe used. Compound 1l exhibited only mild cytotoxicity and was not transported itself by ABCG2. Mechanistic studies revealed that 1l induced conformational changes in ABCG2, as evidenced by increased binding of the 5D3 conformational antibody. Combination assays with established ABCG2 inhibitors, including chromone 4a and indeno-[1,2-b]indole 5e, showed neither synergistic nor antagonistic effects. Induced-fit docking simulations supported the experimental data, indicating that 1l binds within the central transmembrane cavity of ABCG2, engaging key residues such as Phe439 and stabilizing inward-facing conformations. Finally, co-treatment with 1l restored sensitivity of ABCG2-overexpressing cells to the anticancer drug SN38, effectively reversing the MDR phenotype. Collectively, these results identify N-methylpyrazole derivatives as promising selective inhibitors of ABCG2.

Indeno[1,2-b]indole was shown to be a key scaffold for the design of new bioactive molecules in oncology (e.g., inhibitors of protein kinase CK2 and inhibitors of the breast cancer resistance protein ABCG2). Depending on the synthetic route chosen, a large variety of specific functionalizations can be achieved. In order to develop new indeno[1,2-b]indole-9,10-di ones as CK2 inhibitors, four functionalized indeno[1,2-b]indoles were synthesized using a two-step reaction described in the literature. Given that the reactions reported led to unexpected results, such as incomplete reaction progress, very low yields, and significant formation of by-products, we first optimized the quantities of reagents (AcOH and N,N,N ',N '-tetraethyl sulfurous diamide) and the types of solvents used in the synthetic steps. Then, based on these optimal reaction conditions, a one-pot, two-step reaction was developed to maximize yields and standardize the process, thereby making it more convenient and straightforward.

In this study, we evaluated the ability of three clay minerals and clay-like adsorbents, namely lipophilic organosilicates (OSL), LAPONITE® and montmorillonite (MMT), to extend the duration and released amount of UV filter. With only 4 % of benzophenone-3 (BZ-3), it was possible to obtain new sunscreen formulations stabilized by intercalating BZ-3 within the lamellar structures of the three adsorbents. The kinetics of BZ-3 release was studied through a membrane-free method in sink conditions using four mathematical kinetic models. The kinetics demonstrated that BZ-3 was released from the three adsorbents in a continuous and homogeneous way when powders of BZ-3 and OSL, LAPONITE® or MMT were combined at a similar dosage. We then focused on the effects of adsorbed BZ-3 on OSL particles. The sun protection evaluation tests suggested that the formulation using BZ-3 and OSL was executed accurately and efficiently. The F2 (OSL-BZ-3) showed the most effective broad-spectrum formulation with a higher λc (371) and UVA/UVB ratio (0.57) comparatively to F1 (with only 4% BZ3). Rheological analysis of F2 (OSL-BZ3) showed controlled viscosity, efficient spreadability, and enhanced structural integrity, which are key for uniform UV protection, stability, and consumer acceptability. The OSL-BZ-3 formulation provided an increased protection range and improved sunscreen photostability with respect to current regulations.

Protein kinase CK2 is a promising therapeutic target, especially in oncology. Over the years, various inhibitors have been developed, with polyhalogenated scaffolds emerging as a particularly effective class. Halogens like bromine and chlorine enhance inhibitor stability by forming additional interactions within the ATP pocket. Among halogenated scaffolds, benzotriazole and benzimidazole have led to potent molecules such as 4,5,6,7-tetrabromo-1 H -benzotriazole (IC 50 = 300 nM) and 4,5,6,7-tetrabromo-2-(dimethylamino)benzimidazole (IC 50 = 140 nM). Modifications, including 4,5,6-tribromo-7-ethyl-1 H -benzotriazole (IC 50 = 160 nM), further improved activity. Changing scaffolds while retaining halogens has enabled design of new inhibitors. Flavonols, dibenzofuranones, and the indeno[1,2- b ]indole scaffold are key examples. Halogenation of the reference molecule 5-isopropyl-5,6,7,8-tetrahydroindeno[1,2- b ]indole-9,10-dione ( 4b , IC 50 = 360 nM) significantly boosted potency. The study focused on introducing four halogens, yielding to the compound 1,2,3,4-tetrabromo-5-isopropyl-5,6,7,8-tetrahydroindeno[1,2- b ]indole-9,10-dione ( MC11 ), with an IC 50 of 16 nM. Co-crystallography revealed how bromine atoms enhance binding, and MC11 demonstrated strong in cellulo activity, particularly against leukemic cell lines like IPC-Bcl2.

Aromatase inhibition remains a key therapeutic strategy for hormone-dependent breast cancer (HDBC). Among non-steroidal aromatase inhibitors (NSAIs), letrozole and anastrozole are well-established treatments. To further probe structure-function relationships within the human aromatase active site, we synthesized a library of 42 novel azole derivatives. Several compounds displayed nanomolar inhibitory activity, with potencies approaching that of letrozole in vivo, while maintaining favorable selectivity against other steroidogenic enzymes. Notably, benzoselenazolinone 75 emerged as the most promising candidate, exhibiting potency comparable to letrozole with improved in vitro selectivity, thereby justifying further evaluation in vivo.

Background/Objectives: The ABCG2 transporter actively effluxes anticancer drugs, reducing their efficacy and promoting multidrug resistance (MDR). Developing oral formulations of poorly soluble ABCG2 inhibitors remains challenging due to their low solubility and intestinal permeability. This study aimed to formulate and evaluate an ABCG2 inhibitor using micro- and nanoscale drug delivery systems. Methods: To address the poor solubility and bioavailability of the corresponding active ingredient, a self-nanoemulsifying drug delivery system (SNEDDS) was developed. The SNEDDS was encapsulated into microcapsules using sodium alginate crosslinked with calcium chloride. Five microcapsule formulations were developed, varying in the inclusion of polyvinylpyrrolidone (PVP), Transcutol® HP and SNEDDS. The effects of the excipients on encapsulation efficiency, swelling capacity, enzymatic stability, dissolution, cytocompatibility, and permeability were systematically evaluated. Results: The SNEDDS exhibited monodisperse particle sizes and efficient drug entrapment. Results revealed that formulations incorporating PVP and SNEDDS improved encapsulation efficiency and bioavailability. SNEDDS-containing formulations demonstrated superior enzymatic stability in simulated gastric and intestinal fluids and provided the highest cumulative drug release in vitro. Cytotoxicity studies conducted on Caco-2 and MCF-7 cells demonstrated that our formulations were well tolerated, indicating favorable biocompatibility. Conclusions: Our findings demonstrate that SNEDDS-loaded alginate microcapsules offer an efficient platform for oral delivery of dimeric ABCG2 inhibitors, combining enhanced solubility, stability, and controlled release. The optimized formulation can be regarded as a promising strategy to enhance the oral bioavailability of efflux pump inhibitors and other poorly soluble drugs.

The syntheses of novel 2,4-bis[(substituted-aminomethyl)phenyl]phenylquinazolines 12 and 2,4-bis[(substituted-aminomethyl)phenyl]phenylquinolines 13 are reported here in six steps starting from various halogeno-quinazoline-2,4-(1H,3H)-diones or substituted anilines. The antiproliferative activities of the products were determined in vitro against a panel of breast (MCF-7 and MDA-MB-231), human adherent cervical (HeLa and SiHa), and ovarian (A2780) cell lines. Disubstituted 6- and 7-phenyl-bis(3-dimethylaminopropyl)aminomethylphenyl-quinazolines 12b, 12f, and 12i displayed the most interesting antiproliferative activities against six human cancer cell lines. In the series of quinoline derivatives, 6-phenyl-bis(3-dimethylaminopropyl)aminomethylphenylquinoline 13a proved to be the most active. G-quadruplexes (G4) stacked non-canonical nucleic acid structures found in specific G-rich DNA, or RNA sequences in the human genome are considered as potential targets for the development of anticancer agents. Then, as small aza-organic heterocyclic derivatives are well known to target and stabilize G4 structures, their ability to bind G4 structures have been determined through FRET melting, circular dichroism, and native mass spectrometry assays. Finally, telomerase inhibition ability has been also assessed using the MCF-7 cell line.

A new, convenient and efficient method for the construction of a new polycyclic condensed system containing an azepine and pyrazolophthalazine has been developed in the form of a two-step protocol comprising the condensation reaction of hydroxylamine with 1H-indazolo[1,2-b]phthalazine-1,6,11-trione derivative, followed by a Beckman rearrangement reaction using polyphosphoric acid (PPA) as catalyst. Various substituted substrates were successfully used, affording the azepino phthalazine hybrids in good yields and in short reaction times.

This study articulates the synthesis, spectroscopic characterization, antimicrobial, anti-inflammatory evaluation, theoretical calculations, and molecular docking analysis of a novel α-aminophosphonates derived from aminopyridine as potential antibacterial pharmacophore. The structures of all compounds was established using FTIR, 1H, 13C, 31P NMR spectroscopy. A single crystal of the studied compound 3g was selected for X-ray diffraction analysis, it crystallizes in the monoclinic crystal system with P 21/n space group. Theoretical studies based on density functional theory (DFT) at the B3LYP /6-31G (d, p) level of theory was utilized to investigate the stability and electronic properties electronic of the studied α-aminophosphonates. The ADME/toxicity analyzes carried out by Swiss ADME and OSIRIS software show that all synthesized molecules exhibited good pharmacokinetics, bioavailability and had no toxicity profile.

A series of sulfur-containing tetracycles was designed and evaluated for their ability to inhibit protein kinase DYRK1A, a target known to have several potential therapeutic applications including cancers, Down syndrome or Alzheimer's disease. Our medicinal chemistry strategy relied on the design of new compounds using ring contraction/isosteric replacement and constrained analogy of known DYRK1A inhibitors, thus resulting in their DYRK1A inhibitory activity enhancement. Whereas a good inhibitory effect of targeted DYRK1A protein was observed for 5-hydroxy compounds 4i-k (IC50 = 35-116 nM) and the 5-methoxy derivative 4e (IC50 = 52 nM), a fairly good selectivity towards its known DYRK1B off-target was observed for 4k. In addition, the most active compound 4k, having an ATP-competitive mechanism of action, proved to be also a potent inhibitor of CLK1/CLK4 (IC50 = 20 and 26 nM) and, to a lesser extent, of haspin (IC50 = 76 nM) kinases. In silico docking studies within the DYRK1A, CLK1/CLK4 and haspin ATP binding sites were carried out to understand the interactions of our tetracyclic derivatives 4 with these targets. Antiproliferative activities on U87/U373 glioblastoma cell lines of the most potent compound 4k showed a moderate effect (IC50 values between 33 and 46 μM). Microsomal stabilities of the designed compounds 4a-m were also investigated, showing great disparities, depending on benzo[b]thiophene ring 5-substitution.

The concept of a 'magic bullet' was first introduced by Paul Ehrlich in the early 1900s, he foresaw the advent of targeted therapies and the specific killing of harmful cells and/or microorganisms. However, these therapies were only used in the clinic after the second half of the 20th century with the development of specific monoclonal antibodies. To date, 13 antibody-drug conjugates (ADCs) are commercially available. Many advances have been made by modifying one or several of the three main components of an ADC, namely the antibody, the cleavable or non-cleavable linker or the payload, and by integrating conjugation chemistry. Despite these efforts, some problems have emerged and thus limit their effectiveness. New strategies could overcome these problems and identify the next generation of ADC.

The aim of this study was to formulate and characterize CK2 inhibitor-loaded alginate microbeads via the polymerization method. Different excipients were used in the formulation to improve the penetration of an active agent and to stabilize our preparations. Transcutol® HP was added to the drug–sodium alginate mixture and polyvinylpyrrolidone (PVP) was added to the hardening solution, alone and in combination. To characterize the formulations, mean particle size, scanning electron microscopy analysis, encapsulation efficiency, swelling behavior, an enzymatic stability test and an in vitro dissolution study were performed. The cell viability assay and permeability test were also carried out on the Caco-2 cell line. The anti-oxidant and anti-inflammatory effects of the formulations were finally evaluated. The combination of Transcutol® HP and PVP in the formulation of sodium alginate microbeads could improve the stability, in vitro permeability, anti-oxidant and anti-inflammatory effects of the CK2 inhibitor.

Human breast cancer resistance protein (BCRP), known also as ABCG2, plays a major role in multiple drug resistance (MDR) in tumor cells. Through this ABC transporter, cancer cells acquire the ability of resistance to structurally and functionally unrelated anticancer drugs. Nowadays, the design of ABCG2 inhibitors as potential agents to enhance the chemotherapy efficacy is an interesting strategy. In this context, we have used computer-aided drug design (CADD) based on available data of a large series of potent inhibitors from our groups as an approach in guiding the design of effective ABCG2 inhibitors. We report therein the results on the use of the FLAPpharm method to elucidate the pharmacophoric features of one of the ABCG2 binding sites involved in the regulation of the basal ATPase activity of the transporter. The predictivity of the model was evaluated by testing three predicted compounds which were found to induce high inhibitory activity of BCRP, in the nanomolar range for the best of them.

In the process of developing bioactive small molecules, solubility determination is a crucial step. Many research papers treating problems related to solubility are published, but none of them fully describes the methods and steps for solubility assessment. In addition, in silico prediction tools and databases such as SwissADME, ACD/Percepta, DrugBank and many others offer the possibility to have approximative solubility values based on the structure of the molecule. Although significant differences can be observed depending on the database and the conditions of the experiment such as solvent, pH, temperature… etc. The lack of data can be a barrier to obtaining details on solubility measurement methods. This presentation aims to describe, step by step, the journey of tryptophan solubility determination using high-performance liquid chromatography-diode array detector (HPLC-DAD).

In the present work, elegant modification of halloysite (Hal) by citric acid (CA) was realized. The corresponding novel bio-composite (Hal-CA) was then used as drug carrier. To validate this concept, ketoprofen (KET), a known non-steroidal anti-inflammatory agent, was chosen as drug model. KET has low solubility and a short biological half-life, which can cause some limitations in its therapeutic use. In addition, its use is limited due to gastrointestinal side effects. All Hal, Hal-CA, Hal-KET and Hal-CA-KET samples were characterized using several techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), N2 adsorption-desorption, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The release of KET from the prepared formulations was investigated at pH 1 and 6.8 by means of UV-Visible spectroscopy. In addition, kinetics of the release of KET from inclusion complexes were determined by fitting the release profiles to the first order, Korsmeyer-Peppas and Higuchi models. In order to assess these novel bio-composites, anti-inflammatory and anti-nociceptive activities were also evaluated in vivo. Finally, the ulcerogenic activity and the histopathological effects of all formulations were compared to that of pure KET. This work showed the increase of the anti-inflammatory and antinociceptive potentials of KET loaded in Hal-CA, as well as a maximum protection against ulcers. This suggests that Hal-CA can be considered as a new carrier for pharmaceutical formulations.

Highly pleiotropic and constitutively active protein kinase CK2 is a key target in cancer therapy, but only one small‐molecule inhibitor has reached clinical trials—CX‐4945. In this study, we present the indeno[1,2‐b]indole derivative 5‐isopropyl‐4‐methoxy‐7‐methyl‐5,6,7,8‐tetrahydroindeno[1,2‐b]indole‐9,10‐dione (5a‐2) that decreased the intracellular CK2 activity in A431, A549, and LNCaP tumor cell lines analogous to CX‐4945 (> 75% inhibition at 20 µm) and similarly blocked CK2‐specific Akt phosphorylation in LNCaP cells. Cellular uptake analysis demonstrated higher intracellular concentrations of 5a‐2 (408.3 nm) compared with CX‐4945 (119.3 nm). This finding clarifies the comparable effects of both compounds on the intracellular CK2 activity despite their different inhibitory potency in vitro [IC50 = 25 nm (5a‐2) and 3.7 nm (CX‐4945)]. Examination of the effects of both CK2 inhibitors on cancer cells using live‐cell imaging revealed notable differences. Whereas CX‐4945 showed a stronger pro‐apoptotic effect on tumor cells, 5a‐2 was more effective in inhibiting tumor cell migration. Our results showed that 49% of intracellular CX‐4945 was localized in the nuclear fraction, whereas 71% of 5a‐2 was detectable in the cytoplasm. The different subcellular distribution, and thus the site of CK2 inhibition, provides a possible explanation for the different cellular effects. Our study indicates that investigating CK2 inhibition‐mediated cellular effects in relation to the subcellular sites of CK2 inhibition may help to improve our understanding of the preferential roles of CK2 within different cancer cell compartments.

Background: The toxicological risk of Co-Cr dental alloys is actually a sensitive subject with the European regulatory changes, namely regulation (EU) 2017/745 and annex VI to the CLP regulation (EC) 1972/2008. Objectives: The objective of this review is to conduct a rigorous analysis of the cytocompatibility of cobalt–chromium (Co-Cr) dental alloys. Considering various parameters such as cytotoxicity, type IV hypersensitivity reaction, sensitization, and irritation, we investigated evidence of toxicity of Co-Cr in human dental applications. Data sources: Specific search strategies were performed in three electronic databases, namely Medline, Embase, and Web of Science, using a main restriction in the search regarding the publication date (1995–2022). Study selection: Out of a total of 836 articles, only 21 studies were selected and analyzed according to PRISMA methodology. Results: Among them, 10 in vitro studies using human samples and 11 in vivo studies on human patients were distinguished. Most of the in vitro studies confirmed that Co-Cr alloys have a good cytocompatibility compared to Ni alloys. Regarding the in vivo studies, it appeared that Co-Cr could rarely cause sensitization, irritation, and allergic reactions. Reactions were mainly observed for people allergic to Co or Cr. Nevertheless, titanium-based materials showed better results. Conclusions: This study proposes a new state of the art on Co-Cr dental alloys and will thus be very useful for carrying out additional studies. Relevance: This review will help practitioners in their daily clinical choice.