Wastewater effluents contain a multitude of organic contaminants and transformation products, which cannot be captured by target analysis alone. High accuracy, high resolution mass spectrometric data ...were explored with novel untargeted data processing approaches (enviMass, nontarget, and RMassBank) to complement an extensive target analysis in initial “all in one” measurements. On average 1.2% of the detected peaks from 10 Swiss wastewater treatment plant samples were assigned to target compounds, with 376 reference standards available. Corrosion inhibitors, artificial sweeteners, and pharmaceuticals exhibited the highest concentrations. After blank and noise subtraction, 70% of the peaks remained and were grouped into components; 20% of these components had adduct and/or isotope information available. An intensity-based prioritization revealed that only 4 targets were among the top 30 most intense peaks (negative mode), while 15 of these peaks contained sulfur. Of the 26 nontarget peaks, 7 were tentatively identified via suspect screening for sulfur-containing surfactants and one peak was identified and confirmed as 1,3-benzothiazole-2-sulfonate, an oxidation product of a vulcanization accelerator. High accuracy, high resolution data combined with tailor-made nontarget processing methods (all available online) provided vital information for the identification of a wider range of heteroatom-containing compounds in the environment.
Abstract Objectives The biomodification of dentin is a biomimetic approach, mediated by bioactive agents, to enhance and reinforce the dentin by locally altering the biochemistry and biomechanical ...properties. This review provides an overview of key dentin matrix components, targeting effects of biomodification strategies, the chemistry of renewable natural sources, and current research on their potential clinical applications. Methods The PubMed database and collected literature were used as a resource for peer-reviewed articles to highlight the topics of dentin hierarchical structure, biomodification agents, and laboratorial investigations of their clinical applications. In addition, new data is presented on laboratorial methods for the standardization of proanthocyanidin-rich preparations as a renewable source of plant-derived biomodification agents. Results Biomodification agents can be categorized as physical methods and chemical agents. Synthetic and naturally occurring chemical strategies present distinctive mechanism of interaction with the tissue. Initially thought to be driven only by inter- or intra-molecular collagen induced non-enzymatic cross-linking, multiple interactions with other dentin components are fundamental for the long-term biomechanics and biostability of the tissue. Oligomeric proanthocyanidins show promising bioactivity, and their chemical complexity requires systematic evaluation of the active compounds to produce a fully standardized intervention material from renewable resource, prior to their detailed clinical evaluation. Significance Understanding the hierarchical structure of dentin and the targeting effect of the bioactive compounds will establish their use in both dentin-biomaterials interface and caries management.
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Collagen cross-linkings are determinant of biological tissue stability and function. Plant-derived proanthocyanidins (PACs) mimic different hierarchical levels of collagen cross-links ...by non-enzymatic interactions resulting in the enhancement to the biomechanics and biostability of collagen-rich tissues such as dentin. This study investigated the interaction of PACs from Vitis vinifera grape seed extract with type I collagen in solubilized form and in the demineralized dentin matrix (DDM) by fluorescence spectral analysis; collagen-collagen binding forces in presence of cross-linking solutions by atomic force microscopy (AFM); and spectroscopic analysis of the DDM using attenuated total reflectance Fourier transform-infrared spectroscopy (ATR-FTIR). Glutaraldehyde (GA) and carbodiimide hydrochloride (EDC) with known cross-linking mechanisms were selected for comparative analyses. Changes in fluorescence upon interaction of solubilized type I collagen with PACs, EDC and GA reflected pronounced modifications in collagen conformation. PACs also promoted stronger collagen-collagen fibrils interaction than EDC and GA. A new feature was observed using ATR-FTIR spectroscopic analysis in PACs-treated collagen and DDM. The findings suggest covalent interactions between collagen and PACs. The mechanisms of interaction between PACs-collagen hold attractive and promising tissue-tailored biomedical applications and the binding forces that potentially drive such interaction were characterized.
Connective tissues such as skin, bone and dentin are mainly composed of type I collagen, which is cross-linked to promote tissue stability, strength and function. Novel therapies using substances that mimic cross-links have been proposed to promote repair of collagen-based-tissues. In dentistry, naturally occurring proanthocyanidins (PACs) have the potential to enhance dentin mechanical properties and reduce its enzymatic degradation, but their mechanisms of cross-linking are unclear. The present study investigated the specific interactions between PACs-type I collagen in purified and dentin collagen and compared to the well described cross-linking mechanisms promoted by synthetic chemical substances. Findings reveal that covalent-like bonds are induced by plant PACs in type I collagen as well as in complex dental native tissue, promoting strong collagen-collagen interactions.
To assess the anti-proteolytic effect and potential to inhibit dentin root caries progression of a silver nanoparticle and fluoride solution (CNanoF) in comparison to silver diamine fluoride (SDF).
...48 specimens of root dentin artificial caries lesion were treated with 38% SDF, CNanoF, CNano or F (n = 6 per group). Ph cycling with demineralization and remineralization solutions simulated caries lesion progression. In addition, specimens were incubated with or without bacterial collagenase in the remineralization solution to induce dentin proteolytic degradation. Dentin degradation was assessed by weight loss rate and hydroxyproline (Hyp) release. Changes in cross-sectional microhardness, and lesion permeability and collagen integrity as determined by confocal laser scanning microscopy indicated potential for further demineralization inhibition. The effect of the solutions on the activity of metalloproteinases (MMP) -2 and -9 was also investigated. Statistical analysis consisted of ANOVA, Kruskal-Wallis, and linear mixed models with post-hoc pairwise Tukey, Dunn, and t-tests (α = 0.05).
Treatment with SDF resulted in lower weight loss rate than did other solutions, but all groups showed similar Hyp release (p = 0.183). SDF resulted in greater microhardness at superficial layers of the caries lesions (p<0.05), while there were no differences among CNanoF, CNano, and F. Lesion permeability was similar among all groups after pH cycling (p>0.05), with or without the use of collagenase (p = 0.58). No statistically significant difference was noted among solutions regarding collagen integrity after pH cycling; however, SDF-treated dentin had a significant decrease in collagen integrity when collagenase was used (p = 0.003). Interestingly, only SDF was able to completely inactivate MMP-2 and -9.
CNanoF and SDF both potentially prevent dentin degradation during caries lesion progression in vitro; however, SDF was more effective at inhibiting further tissue demineralization.
Abstract Degradation of the adhesive interface contributes to the failure of resin composite restorations. The hydrophilicity of the dentin matrix during and after bonding procedures may result in an ...adhesive interface that is more prone to degradation over time. This study assessed the effect of chemical modification of the dentin matrix on the wettability and the long-term reduced modulus of elasticity ( E r ) of adhesive interfaces. Human molars were divided into groups according to the priming solutions: distilled water (control), 6.5% Proanthocyanidin-rich grape seed extract (PACs), 5.75% 1-ethyl-3-3-dimethylaminopropyl carbodiimide hydrochloride/1.4% n-hydroxysuccinimide (EDC/NHS) and 5% Glutaraldehyde (GA). The water-surface contact angle was assessed before and after chemical modification of the dentin matrix. The demineralized dentin surface was treated with the priming solutions and restored with One Step Plus (OS) and Single Bond Plus (SB) and resin composite. Er of the adhesive, hybrid layer and underlying dentin was evaluated after 24 h and 30 months in artificial saliva. The dentin hydrophilicity significantly decreased after application of the priming solutions. Aging significantly decreased E r in the hybrid layer and underlying dentin of control groups. E r of GA groups remained stable over time at the hybrid layer and underlying dentin. Significant higher E r was observed for PACs and EDC/NHS groups at the hybrid layer after 24 h. The decreased hydrophilicity of the modified dentin matrix likely influence the immediate mechanical properties of the hybrid layer. Dentin biomodification prevented substantial aging at the hybrid layer and underlying dentin after 30 months storage.
•Plant-derived proanthocyanidins are potent dentin biomodification agents containing high structural diversity.•Unique chemical features in proanthocyanidins hold important clues to the sustained ...interactivity with the dentin matrix components.•This study shows galloylated PAC sources exhibit high initial dentin biomodification, however the effects are not sustainable.•The interflavan monomeric linkages appears to affect the stability, where A-type linkage favors long-term stabilities.
The interactivity of proanthocyanidins (PACs) with collagen modulates dentin matrix biomechanics and biostability. Herein, PAC extracts selected based on structural diversity were investigated to determine key PAC features driving sustained effects on dentin matrices over a period of 18months.
The chemical profiles of PAC-rich plant sources, Pinus massoniana (PM), Cinnamomum verum (CV) and Hamamelis virginiana (HV) barks, as well as Vitis vinifera (VV) seeds, were obtained by diol HPLC analysis after partitioning of the extracts between methyl acetate and water. Dentin matrices (n=15) were prepared from human molars to determine the apparent modulus of elasticity over 18months of aging. Susceptibility of the dentin matrix to degradation by endogenous and exogenous proteases was determined by presence of solubilized collagen in supernatant, and resistance to degradation by bacterial collagenase, respectively. Data were analyzed using ANOVA and Games–Howell post hoc tests (α=0.05).
After 18months, dentin matrices modified by PM and CV extracts, containing only non-galloylated PACs, were highly stable mechanically (p<0.05). Dentin matrices treated with CV exhibited the lowest degradation by bacterial collagenase after 1h and 18months of aging (p<0.05), while dentin matrices treated with PM showed the least mass loss and collagen solubilization by endogenous enzymes over time (p<0.05).
Resistance against long-term degradation was observed for all experimental groups; however, the most potent and long-lasting dentin biomodification resulted from non-galloylated PACs.
Violence in the workplace has important consequences for workers and their own environment. Health and social services professionals are high-risk professional groups. This research has a main aim to ...identify the studies on client violence towards the social worker in Spain. This aim has four specific objectives to understand the phenomenon: (1) to identify those investigations that study the violence of clients against social workers; (2) to analyze the descriptive characteristics of the selected studies; (3) to analyze the methodological characteristics of the selected studies; (4) to identify the variables associated to client violence towards the social worker. In order to achieve these objectives, the method was based on a review of the literature on studies of violence towards social workers in Spain through the PRISMA-S guidelines (Rethlefsen et al., 2021). The results show that this phenomenon effectively exists, and cast a light on a situation that social workers experience in isolation. Exploring the phenomenon in a descriptive way, the review provides information on the variables studied and the current extent of violence towards social workers by clients. The lack of studies on this subject underlines the need to continue researching into the problem from both descriptive and inferential perspectives.
To characterize the interaction of 1-Ethyl-3-3-dimethylaminopropyl carbodiimide Hydrochloride (EDC) with dentin matrix and its effect on the resin-dentin bond.
Changes to the stiffness of ...demineralized dentin fragments treated with EDC/N-hydroxysuccinimide (NHS) in different solutions were evaluated at different time points. The resistance against enzymatic degradation was indirectly evaluated by ultimate tensile strength (UTS) test of demineralized dentin treated or not with EDC/NHS and subjected to collagenase digestion. Short- and long-term evaluations of the strength of resin-dentin interfaces treated with EDC/NHS for 1 h were performed using microtensile bond strength (microTBS) test. All data (MPa) were individually analyzed using ANOVA and Tukey HSD tests (alpha = 0.05).
The different exposure times significantly increased the stiffness of dentin (p < 0.0001, control-5.15 and EDC/NHS-29.50), while no differences were observed among the different solutions of EDC/NHS (p = 0.063). Collagenase challenge did not affect the UTS values of EDC/NHS group (6.08) (p > 0.05), while complete degradation was observed for the control group (p = 0.0008, control-20.84 and EDC/NHS-43.15). EDC/NHS treatment did not significantly increase resin-dentin muTBS, but the values remained stable after 12 months water storage (p < 0.05).
Biomimetic use of EDC/NHS to induce exogenous collagen cross-links resulted in increased mechanical properties and stability of dentin matrix and dentin-resin interfaces.
Proanthocyanidins (PACs) are secondary plant metabolites that mediate nonenzymatic collagen cross-linking and enhance the properties of collagen based tissue, such as dentin. The extent and nature of ...cross-linking is influenced by the composition and specific chemical structure of the bioactive compounds present in certain PAC-rich extracts. This study investigated the effect of the molecular weight and stereochemistry of polyphenol compounds on two important properties of dentin, biomechanics, and biostability. For that, purified phenols, a phenolic acid, and some of its derivatives were selected: PAC dimers (A1, A2, B1, and B2) and a trimer (C1), gallic acid (Ga), its esters methyl-gallate (MGa) and propyl-gallate (PGa), and a pentagalloyl ester of glucose (PGG). Synergism was assessed by combining the most active PAC and gallic acid derivative. Mechanical properties of dentin organic matrix were determined by the modulus of elasticity obtained in a flexural test. Biostability was evaluated by the resistance to collagenase degradation. PACs significantly enhanced dentin mechanical properties and decreased collagen digestion. Among the gallic acid derivatives, only PGG had a significant enhancing effect. The lack of observed C1:PGG synergy indicates that both compounds have similar mechanisms of interaction with the dentin matrix. These findings reveal that the molecular weight of polyphenols have a determinant effect on their interaction with type I collagen and modulates the mechanism of cross-linking at the molecular, intermolecular, and inter-microfibrillar levels.
Highlights • The use of different experimental primers on dentin–resin restorations is proposed. • Experimental primers significantly reduced the enzymatic activity at the dentin–resin interface. • ...Proanthocyanidins from enriched-grape seed extract, chlorhexidine and doxycycline inactivated rMMPs-2 and 9. • Increased enzymatic activity took place under simulated cyclic loading. • Cyclic loading did not have a significant effect on the resin–dentin bond strength.
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