The effect of water on the large-scale supercritical fluid chromatography purification of two factor XIa active pharmaceutical ingredients.

BMS-962212, a parenteral Factor XIa inhibitor, was scaled-up for toxicity studies. Two steps of supercritical fluid chromatography (SFC) were developed for the chiral resolution of the penultimate and achiral purification of final active pharmaceutical ingredient (API), BMS-962212. A robust SFC process using Chiralcel OD-H with methanol-acetonitrile as modifier in CO2 was established to achieve a stable and uninterrupted operation with reduced mobile phase viscosity and system pressure drop. More than 230 g of the racemic penultimate was chirally resolved to reach >99% chiral purity, ready for final tert-butyl ester deprotection to provide the API. There were a significant number of impurities in BMS-962212 generated from the final step that needed to be removed. In contrast to conventional SFC conditions, an SFC method exploiting water and ammonia as additives in both the mobile phase and sample solution was developed to accomplish purification and desalting (i.e. removing TFA) of the zwitterionic API in one step. Water as an additive eliminated salt precipitation and improved the resolution while ammonia contributed to the desalting, details of which will be discussed in this article. A throughput of 2 g/h was achieved, and >80 g of the crude API was purified. The same strategy was applied to another Factor XIa API (compound A) and its penultimate.

Specifically Eliminating Tumor-Associated Macrophages with an Extra- and Intracellular Stepwise-Responsive Nanocarrier for Inhibiting Metastasis.

Metastasis is the primary cause of death for most cancer patients, in which tumor-associated macrophages (TAMs) are involved through several mechanisms. While hitherto there is still a lack of study on exclusive elimination of TAMs to inhibit metastasis due to the difficulties in specific targeting of TAMs, we construct an extra- and intracellular stepwise-responsive delivery system p-(aminomethyl)benzoic acid (PAMB)/doxorubicin (DOX) to achieve specific TAM depletion for the first time, thereby preventing tumor metastasis. Once accumulated into the tumor, PAMB/DOX would stepwise responsively (hypoxia and reactive oxygen species (ROS) responsively) disintegrate to expose the TAM-targeting ligand and release DOX sequentially, which depletes TAMs effectively in vivo. Owing to the inhibition of extracellular matrix (ECM) degradation, neovascularization, and tumor invasion contributed by TAM depletion, lung metastasis was successfully inhibited. Furthermore, PAMB/DOX showed efficient inhibition against tumor growth as well as spontaneous metastasis formation when combined with additional chemotherapy, representing a safe and efficient nanoplatform to modulate the adverse tumor microenvironment via TAM elimination.

p-Aminobenzoate Organic Salts as Potential Plant Growth Regulators for Tomatoes.

The discovery of environmentally friendly and inexpensive plant growth regulators (PGRs) for agronomically important crops is a necessity and must be considered a priority worldwide. This study provides the synthesis, structure determination and the biological evaluation of two binary organic salts as potential PGRs. New compounds have dual biological activity and are based on natural metabolite p-aminobenzoic acid (pABAH) and different alkanolamines. Studied compounds exhibit hydrogen-bonded 3D supramolecular architectures with different crystal packing due to the formation of one homosynthon and various heterosynthons. The biological profile of new compounds was investigated in laboratory and greenhouse on Solanum lycopersicum L., revealing the efficiency in promoting plant rooting and plant productivity. The results may have a positive impact on agricultural economics, developing new sustainable PGRs for tomatoes.

Cytotoxicity and genotoxicity of DMABEE, a co-photoinitiator of resin polymerization, on CHO-K1 cells: Role of redox and carboxylesterase.

The 4-dimethylaminobenzoic acid ethyl ester (DMABEE) is an important co-initiator for resin polymerization in dental resinous materials. As a radical forming chemical with high lipophilicity, the genotoxicity and cytotoxicity of DMABEE deserve prudent investigation. In this study, we found that DMABEE reduced the viability and proliferation of Chinese hamster ovary (CHO-K1) cells in a dose-dependent manner, and altered cell morphology at higher concentrations. G0/G1 cell cycle arrest was induced by DMABEE at 0.25-0.75 mM, and cell proportion of sub-G0/G1 phase was significantly elevated at 1 mM while cell apoptosis was observed. Genotoxic effect was noted when cells were treated by 0.1 mM DMABEE, as revealed by increase of micronucleus formation. Reactive oxygen species overproduction was observed as cells treated with 0.75 and 1 mM, while elevation of intracellular glutathione was noticeable since 0.1 mM. Contrary to our expectation, pretreatment by N-acetyl-l-cysteine enhanced the toxicity of DMABEE on CHO-K1 cells. Catalase mildly reduced the toxic effect and carboxylesterase showed obvious ability to reverse the toxicity of DMABEE. These findings highlight the mechanism of DMABEE toxicity and provide clues for safety improvement of its application in clinical dental treatment.

Chasing ChEs-MAO B Multi-Targeting 4-Aminomethyl-7-Benzyloxy-2H-Chromen-2-ones.

A series of 4-aminomethyl-7-benzyloxy-2H-chromen-2-ones was investigated with the aim of identifying multiple inhibitors of cholinesterases (acetyl- and butyryl-, AChE and BChE) and monoamine oxidase B (MAO B) as potential anti-Alzheimer molecules. Starting from a previously reported potent MAO B inhibitor (3), we studied single-point modifications at the benzyloxy or at the basic moiety. The in vitro screening highlighted triple-acting compounds (6, 8, 9, 16, 20) showing nanomolar and selective MAO B inhibition along with IC50 against ChEs at the low micromolar level. Enzyme kinetics analysis toward AChE and docking simulations on the target enzymes were run in order to get insight into the mechanism of action and plausible binding modes.

Physicochemical investigations on non-covalent interactions between Padimate O and cyclodextrin receptors in both solution and solid states.

Ultraviolet B (UV-B) radiation is very harmful to human body. It can cause serious health problem mainly skin cancer, sunburn and photo-aging. Padimate O (PMO) is a sunscreen agent. The aim of this work is to form inclusion complexes with α-cyd and ß-cyd in both aqueous environment and solid state that established by UV-Vis, FTIR spectroscopy, mass spectra, powder X-ray diffraction pattern and as α-cyd and ß-cyd are known to us as good drug vehicles, hence, the experimental results suggest that they can be used as good sunscreen agent carrier and photostabilizer additive for increasing the photostability and other properties of PMO. In solution phase, UV-Vis spectroscopy demonstrated that the entire process of formation of complexes is observed with 1:1 stoichiometry which is further justified by mass spectra. Thermodynamic parameters support the whole process in both cases and it is revealed that ß-cyd forms more firmly inclusion complex than α-cyd with PMO. Successful formation of solid inclusion complexes is supported by FTIR spectroscopy and powder-XRD. The enhancement of the thermal stability of the α-cyd/PMO and ß-cyd/PMO complexes is demonstrated by TGA study.

Design and development of novel p-aminobenzoic acid derivatives as potential cholinesterase inhibitors for the treatment of Alzheimer's disease.

Based on the quantitative structure-activity relationship (QSAR), some novel p-aminobenzoic acid derivatives as promising cholinesterase enzyme inhibitors were designed, synthesized, characterized and evaluated to enhance learning and memory. The in vitro enzyme kinetic study of the synthesized compounds revealed the type of inhibition on the respective acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The in vivo studies of the synthesized compounds exhibited significant reversal of cognitive deficits in the animal models of amnesia as compared to standard drug donepezil. Further, the ex vivo studies in the specific brain regions like the hippocampus, hypothalamus, and prefrontal cortex regions also exhibited AChE inhibition comparable to standard donepezil. The in silico molecular docking and dynamics simulations studies of the most potent compound 22 revealed the consensual interactions at the active site pocket of the AChE.

Light curing resin cements containing iodonium salts promote suitable apical bonding of posts to radicular dentin.

The aim of this study was to analyze the efficiency of experimental light-curing resin cements (ERCs) with a ternary photo-initiator system containing diphenyliodonium hexafluorphosphate (DPI) and different amines on retention of glass-fiber posts to dentin (GFP). ERCs formulations: a 1:1 mass ratio of 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenylpropane and triethyleneglycol dimethacrylate. Camphorquinone was used as initiator. Six experimental groups were established according to the amine used: [ethyl-4-(dimethylamino)benzoate-EDMAB or 2-(dimethylamino)ethyl methacrylate-DMAEMA] and the concentration of DPI (0, 0.5 mol%, 1 mol%). The resin cements Variolink II (dual- and light-cured versions) were used as commercial reference. Eighty recently extracted bovine incisors (n = 10) were selected for this study. The roots were prepared and the fiber posts were cemented with the resin cement specified for each experimental group. Specimens from coronal, middle, and apical thirds of the root were subjected to push-out bond strength test 24 hours after bonding. Data were subjected to split-plot ANOVA and the Tukey test (p = 0.05). ERCs containing DPI showed statistically significant higher bond strengths compared with ERCs without DPI. ERCs containing DPI were statistically similar to VARIOLINK II - dual-cured and superior to VARIOLINK II - light-cured (except for EDMAB - 1DPI in the medium third and DMAEMA - 1DPI in the coronal third). Different amines did not influence post retention. The apical root region showed the lowest bond strength for the groups EDAB-0DPI, DMAEMA-0DPI and VARIOLINK II light-cured. Light-cured ERCs containing DPI were efficient for GFP retention to radicular dentin, with similar behaviour to that of dual-curing commercial resin cement.

SPF enhancement provided by rutin in a multifunctional sunscreen.

Unprotected chronic exposure to solar radiation can contribute to premature skin cancer and sunscreens are a key factor to avoid those detrimental effects. Currently, there is a growing interest in the photoprotector and antioxidant potential of bioactive substances, such as rutin, that could increase the sun protection factor (SPF) value and, also, donate multifunctional characteristics to sunscreens. Recent in vitro findings indicated that rutin, when incorporated into sunscreens, can provide antioxidant activity and SPF improvement. However, clinical studies are fundamental to determine this activity, due to the lack of repeatability of in vitro methodology and low correlation with the in vivo data. We aimed at evaluating the clinical safety and in vivo SPF of rutin by comparing sunscreen formulations containing 0.1% (w/w) rutin, 3.0% (w/w) butyl methoxydibenzoylmethane and 8.0% (w/w) octyl dimethyl PABA (2-ethylhexyl 4-(dimethylamino)benzoato) with a similar bioactive-free preparation. Additionally, skin hydration, in vitro SPF and in vitro antioxidant activity of rutin, in association with the ultraviolet (UV) filters, were investigated. The safety profile of the formulations under sun-exposed skin conditions qualified the formulas for clinical efficacy assays. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) test confirmed the antioxidant properties of rutin, revealing around 40% increase in radical scavenging potential when the bioactive compound was present. Rutin in combination with the UV filters robustly elevated the clinical SPF around 70%, when compared with the bioactive-free formulation. To date, this is the first report in the specialized literature of an in vivo SPF measurement of a rutin-containing photoprotective preparation, supporting the claim that rutin is an effective and safe bioactive compound to be used in multifunctional sunscreens.

Long-term bonding efficacy of adhesives containing benzodioxioles as alternative co-initiators.

This study evaluated the three-year lifespan of the bond to dentin of experimental self-etch adhesives containing benzodioxole derivatives - 1,3-benzodioxole (BDO) and piperonyl alcohol (PA) - as co-initiator alternative to amines. Adhesive resins were formulated using Bis-GMA, TEGDMA, HEMA, camphorquinone and different co-initiators: BDO, PA or ethyl 4-dimethylamino benzoate (EDAB - amine). An experimental self-etch primer was used to complete the two-step, self-etch adhesive system. Clearfil SE Bond (CSE) was used as commercial reference. Bond strength to human dentin was assessed by microtensile bond strength (µTBS) test, and failure mode was classified. Morphology of the dentin bonding interface was assessed via scanning electron microscopy (SEM). Irrespective of the dental adhesives evaluated, µTBS was higher after 24 hours compared with that after 1.5 and 3 years (p ≤ 0.001). However, adhesives with BDO and PA as co-initiators showed significantly higher bond strength than the bonding resin with EDAB (p ≤ 0.002), independent of the time evaluated. The commercial adhesive CSE showed similar bond strength compared with the other groups (p ≥ 0.05). Mixed failures were mainly observed after 24 hours, while adhesive failures were more frequently observed after 1.5 and 3 years. No notable differences in homogeneity and continuity along the bonded interfaces were detected among the materials in the SEM analysis. In conclusion, benzodioxole derivatives are feasible alternative co-initiators to tertiary amine in camphorquinone-based self-etching dental adhesive formulations.

Photoactivation of MDM2 Inhibitors: Controlling Protein-Protein Interaction with Light.

Selectivity remains a major challenge in anticancer therapy, which potentially can be overcome by local activation of a cytotoxic drug. Such triggered activation can be obtained through modification of a drug with a photoremovable protecting group (PPG), and subsequent irradiation in the chosen place and time. Herein, the design, synthesis and biological evaluation is described of a photoactivatable MDM2 inhibitor, PPG-idasanutlin, which exerts no functional effect on cellular outgrowth, but allows for the selective, noninvasive activation of antitumor properties upon irradiation visible light, demonstrating activation with micrometer, single cell precision. The generality of this method has been demonstrated by growth inhibition of multiple cancer cell lines showing p53 stabilization and subsequent growth inhibition effects upon irradiation. Light activation to regulate protein-protein interactions between MDM2 and p53 offers exciting opportunities to control a multitude of biological processes and has the potential to circumvent common selectivity issues in antitumor drug development.

Photoprotection or photodamage: a direct observation of nonradiative dynamics from 2-ethylhexyl 4-dimethylaminobenzoate sunscreen agent.

Apart from being an analogue of the prototype for photoinduced intramolecular charge transfer (ICT), 2-ethylhexyl 4-dimethylaminobenzoate (EHDMABA) is also one of the earliest patented and most commonly used sunscreen components. There is, however, little documented information about the photophysics and factors affecting the photophysics of this molecule. Such information is of importance for both the understanding of the ICT reaction and assessing the underlying process of photoprotection, especially in view of the "sunscreen controversy" that has arisen from the contrasting in vivo vs. in vitro photobiological results on this and related UV filters. We report herein a femtosecond broadband time-resolved fluorescence (fs-TRF), complemented by transient absorption (fs-TA) to allow a full probe of the excited state cascades for EHDMABA and two of its derivatives in solvents of varied properties. The results provide direct evidence for a nearly solvent independent inner sphere ICT reaction occurring on the sub-picosecond time scale, and an ensuing solvent dictated deactivation of the ICT state. The ICT state in the aprotic solvent acetonitrile decayed solely through the intrinsic intersystem crossing (ISC) to produce a potentially harmful triplet excited state. In the protic solvent, the solvation and formation of ICT-induced solute-solvent hydrogen (H)-bonding opened the originally inaccessible internal conversion (IC) channel of the ICT state, leading to the rapid reformation of the ground state molecule with a unitary efficiency in the aqueous solution. This H-bonding-mediated IC restrained or eliminated the intrinsic ISC, providing a mechanism at the molecular level for the benign dissipation of the electronic excitation. The precise rate of IC was observed to vary with the alkoxy substituent and its efficiency was affected by the H-bonding capacity of the solvent. The findings of this work demonstrate the pivotal role of the microenvironment and the direct participation of solvent molecules through H-bonding in drastically altering the nonradiative dynamics and promoting or inhibiting photostability and photoprotection. This may assist in developing next-generation UV filters and help in improving formulation design for the optimal efficacy of sunscreen products. The pronounced H-bonding-induced fluorescence quenching and variation in the fluorescence wavelength imply that these molecules may also serve as a sensitive fluorescence probe for the H-bonding properties of the microenvironment.

Synthesis, Structural Characterization, and Antiangiogenic Activity of Polyfluorinated Benzamides.

The introduction of fluorine into bioactive molecules is a matter of importance in medicinal chemistry. In this study, representatives of various chemical entities of fluoroaromatic compounds were synthesized. Depending on the reaction conditions, either tetrafluorophthalimides or ammonium tetrafluorophthalamates are accessible from tetrafluorophthalic anhydride and primary amines. Tetrafluorophthalamic acids undergo thermal decarboxylation to yield tetrafluorobenzamides. These could be successfully converted upon treatment with primary amines, in the course of an aromatic nucleophilic substitution, to 2,3,5-trifluorobenzamides with respective amino substituents at the 4-position. The five structure types were characterized by means of spectroscopic and crystallographic methods. The synthesized compounds were evaluated as inhibitors of angiogenesis by measuring microvessel outgrowth in a rat aortic ring assay. The biological activity was maintained throughout these different polyfluorinated chemotypes.

Highly Potent Clickable Probe for Cellular Imaging of MDM2 and Assessing Dynamic Responses to MDM2-p53 Inhibition.

MDM2 is a key negative regulator of the p53 tumor suppressor. Direct binding of MDM2 to p53 represses the protein's transcriptional activity and induces its polyubiquitination, targeting it for degradation by the proteasome. Consequently, small molecule inhibitors that antagonize MDM2-p53 binding, such as RG7388, have progressed into clinical development aiming to reactivate p53 function in TP53 wild-type tumors. Here, we describe the design, synthesis, and biological evaluation of a trans-cyclooctene tagged derivative of RG7388, RG7388-TCO, which showed high cellular potency and specificity for MDM2. The in-cell reaction of RG7388-TCO with a tetrazine-tagged BODIPY dye enabled fluorescence imaging of endogenous MDM2 in SJSA-1 and T778 tumor cells. RG7388-TCO was also used to pull down MDM2 by reaction with tetrazine-tagged agarose beads in SJSA-1 lysates. The data presented show that RG733-TCO enables precise imaging of MDM2 in cells and can permit a relative assessment of target engagement and MDM2-p53 antagonism in vitro.

Cell- and Tissue-Based Proteome Profiling and Dual Imaging of Apoptosis Markers with Probes Derived from Venetoclax and Idasanutlin.

Venetoclax (ABT-199) and idasanutlin (RG7388) are efficient anticancer drugs targeting two essential apoptosis markers, Bcl-2 and MDM2, respectively. Recent studies have shown that the combination of these two drugs leads to remarkable enhancement of anticancer efficacy, both in vitro and in vivo. In an attempt to disclose the relationships of their protein targets, competitive affinity-based proteome profiling coupled with bioimaging was employed to characterize their protein targets in the same cancer cell line and tumor tissue. A series of protein hits, including ITPR1, GSR, RER1, PDIA3, Apoa1, and Tnfrsf17 were simultaneously identified by pull-down/LC-MS/MS with the two sets of affinity-based probes. Dual imaging was successfully carried out, with the simultaneous detection of Bcl-2 and MDM2 expression in various cancer cells. This could facilitate the novel diagnostic and therapeutic strategies of dual targeting of Bcl-2/MDM2.

Long-term bonding efficacy of adhesives containing benzodioxioles as alternative co-initiators

Abstract This study evaluated the three-year lifespan of the bond to dentin of experimental self-etch adhesives containing benzodioxole derivatives - 1,3-benzodioxole (BDO) and piperonyl alcohol (PA) - as co-initiator alternative to amines. Adhesive resins were formulated using Bis-GMA, TEGDMA, HEMA, camphorquinone and different co-initiators: BDO, PA or ethyl 4-dimethylamino benzoate (EDAB - amine). An experimental self-etch primer was used to complete the two-step, self-etch adhesive system. Clearfil SE Bond (CSE) was used as commercial reference. Bond strength to human dentin was assessed by microtensile bond strength (µTBS) test, and failure mode was classified. Morphology of the dentin bonding interface was assessed via scanning electron microscopy (SEM). Irrespective of the dental adhesives evaluated, µTBS was higher after 24 hours compared with that after 1.5 and 3 years (p ≤ 0.001). However, adhesives with BDO and PA as co-initiators showed significantly higher bond strength than the bonding resin with EDAB (p ≤ 0.002), independent of the time evaluated. The commercial adhesive CSE showed similar bond strength compared with the other groups (p ≥ 0.05). Mixed failures were mainly observed after 24 hours, while adhesive failures were more frequently observed after 1.5 and 3 years. No notable differences in homogeneity and continuity along the bonded interfaces were detected among the materials in the SEM analysis. In conclusion, benzodioxole derivatives are feasible alternative co-initiators to tertiary amine in camphorquinone-based self-etching dental adhesive formulations.

Light curing resin cements containing iodonium salts promote suitable apical bonding of posts to radicular dentin

Abstract The aim of this study was to analyze the efficiency of experimental light-curing resin cements (ERCs) with a ternary photo-initiator system containing diphenyliodonium hexafluorphosphate (DPI) and different amines on retention of glass-fiber posts to dentin (GFP). ERCs formulations: a 1:1 mass ratio of 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenylpropane and triethyleneglycol dimethacrylate. Camphorquinone was used as initiator. Six experimental groups were established according to the amine used: [ethyl-4-(dimethylamino)benzoate-EDMAB or 2-(dimethylamino)ethyl methacrylate-DMAEMA] and the concentration of DPI (0, 0.5 mol%, 1 mol%). The resin cements Variolink II (dual- and light-cured versions) were used as commercial reference. Eighty recently extracted bovine incisors (n = 10) were selected for this study. The roots were prepared and the fiber posts were cemented with the resin cement specified for each experimental group. Specimens from coronal, middle, and apical thirds of the root were subjected to push-out bond strength test 24 hours after bonding. Data were subjected to split-plot ANOVA and the Tukey test (p = 0.05). ERCs containing DPI showed statistically significant higher bond strengths compared with ERCs without DPI. ERCs containing DPI were statistically similar to VARIOLINK II - dual-cured and superior to VARIOLINK II - light-cured (except for EDMAB - 1DPI in the medium third and DMAEMA - 1DPI in the coronal third). Different amines did not influence post retention. The apical root region showed the lowest bond strength for the groups EDAB-0DPI, DMAEMA-0DPI and VARIOLINK II light-cured. Light-cured ERCs containing DPI were efficient for GFP retention to radicular dentin, with similar behaviour to that of dual-curing commercial resin cement.

Discovery of a Parenteral Small Molecule Coagulation Factor XIa Inhibitor Clinical Candidate (BMS-962212).

Factor XIa (FXIa) is a blood coagulation enzyme that is involved in the amplification of thrombin generation. Mounting evidence suggests that direct inhibition of FXIa can block pathologic thrombus formation while preserving normal hemostasis. Preclinical studies using a variety of approaches to reduce FXIa activity, including direct inhibitors of FXIa, have demonstrated good antithrombotic efficacy without increasing bleeding. On the basis of this potential, we targeted our efforts at identifying potent inhibitors of FXIa with a focus on discovering an acute antithrombotic agent for use in a hospital setting. Herein we describe the discovery of a potent FXIa clinical candidate, 55 (FXIa Ki = 0.7 nM), with excellent preclinical efficacy in thrombosis models and aqueous solubility suitable for intravenous administration. BMS-962212 is a reversible, direct, and highly selective small molecule inhibitor of FXIa.

New class of early-stage enterovirus inhibitors with a novel mechanism of action.

4-dimethylamino benzoic acid (compound 12, synonym: 4EDMAB) was identified as an in vitro inhibitor of Coxsackie virus B3 (CVB3) replication in CPE-based assays (EC50 of 9.1 ± 1.5 µM). Next, the activity of twenty-three analogues was assessed, their structure-activity relationship was deduced and a more potent analogue was identified (EC50 of 2.6 ± 0.5 µM). The antiviral activity of 4EDMAB was further confirmed by quantifying viral RNA yield. Time-of-drug-addition assay revealed that 4EDMAB exerts its antiviral activity at the early stages of virus replication. Six compound-resistant viruses were selected and genotyped and all the mutations appeared to be in the capsid protein VP1. Reverse engineering showed that single mutants Y75C, A88V, A98V, D133N and R219K were respectively 15-, 2-, 4-, 17- and 76-fold resistant to 4EDMAB. The compound protected both wild type (WT) CVB3 and the five resistant mutants from heat inactivation. The plaque size produced by the A88V, D133N and R219K mutants was smaller than that of WT and these mutants were also more heat-sensitive than WT in the absence of the compound. These findings suggest that these three mutations increase virion capsid flexibility and compensate for the stabilizing effects of 4EDMAB. Molecular modelling suggests that the compound binds to a small cavity in VP1, which is different from the hydrophobic pocket in the canyon where typical capsid binders (such as pleconaril) bind. Modelling studies also suggest a direct ionic interaction between the negatively charged carboxylic group of 4EDMAB and the positively charged guanidino group of arginine 219. Moreover, the in vitro combination of 4EDMAB and pleconaril resulted in synergistic antiviral effect. In conclusion, 4EDMAB is a novel early-stage inhibitor, which targets VP1 with a mechanism that is different from that of known capsid binders.

Mechanical properties, water sorption characteristics, and compound release of grape seed extract-incorporated resins.

OBJECTIVE: This study evaluated the effect of grape seed extract (GSE) incorporation on the mechanical properties, water sorption, solubility, and GSE release from the experimental adhesive resins. MATERIAL AND METHODS: An experimental comonomer mixture, consisting of 40% Bis-GMA, 30% Bis MP, 28% HEMA, 0.26% camphorquinone and 1% EDMAB, was used to prepare four GSE-incorporated adhesive resins at concentrations of 0.5, 1, 1.5, and 2 wt%. The neat resin without GSE was used as the control. Six resin beams (25 mm x 2 mm x 2 mm) per group were prepared for flexural strength and modulus of elasticity evaluations using a universal testing machine at a crosshead speed of 1 mm/min. Five disks (6 mm in diameter and 2 mm in thickness) per group were used for microhardness measurements using a Leitz micro-hardness tester with Leica Qgo software. Five disks (7 mm in diameter and 2 mm in thickness) per group were prepared and stored in deionized water for 28 days. Water sorption, solubility, and GSE release in deionized water were calculated for each GSE-incorporated adhesive at the end of 28th day. Data was evaluated using one-way ANOVA and Tukey multiple comparisons. RESULTS: Flexural strength, modulus of elasticity and microhardness of GSE-incorporated adhesive decreased significantly with incorporation of 1.5% of GSE (p<0.05). Addition of GSE had no effect on the water sorption of the adhesive resins (p=0.33). The solubility of the resin also increased significantly with incorporation of 1.5% of GSE (p<0.05). Quantities of GSE release increased with increased concentration of GSE in the adhesive resin. CONCLUSION: Up to 1% of GSE can be incorporated into a dental adhesive resin without interfering with the mechanical properties or solubility of the resins.