Biofabrication of AuNPs using Coriandrum sativum leaf extract and their antioxidant, analgesic activity.

In this work, Gold nanoparticles (AuNPs) were synthesized by reducing aqueous Au metal ions upon interaction with Coriandrum sativum (C. sativum) leaf extract. The optical absorption peak for the synthesized AuNPs was obtained by using UV-visible spectroscopy within a range of 540-550 nm. The formation of diffraction peaks found at 2θ values of 78.00°, 66.05°, 44.85° and 38.48° that corresponds to the index planes (311), (220), (200), and (111) validate the effective synthesis of AuNPs. Transmission electron microscopy (TEM) was utilized to measure the size range of the spherical shaped nanoparticles, which is obtained to be 32.96 ± 5.25 nm. The peaks obtained from the FTIR results are closely linked to anthocyanins, benzophenones, flavonoids and phenols, which indicated that these biomolecules may serve as reducing agents. Additionally, studies of antioxidant function in vitro revealed that the activities of ABTS (2, 2'-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) were improved dose-dependently. Further, the results of analgesic analysis showed that the cumulative action of AuNPs and the C. sativum leaf extract in pain relief is more efficient than independent C. sativum leaf extract and the aspirin drug.

Immunomodulatory effects of berberine on the inflamed joint reveal new therapeutic targets for rheumatoid arthritis management.

Rheumatoid arthritis (RA) is a chronic inflammatory syndrome designated by synovial joint inflammation leading to cartilage degradation and bone damage as well as progressive disability. Synovial inflammation is promoted through the infiltration of mononuclear immune cells, dominated by CD4+ T cells, macrophages and dendritic cells (DCs), together with fibroblast-like synoviocytes (FLS), into the synovial compartment. Berberine is a bioactive isoquinoline alkaloid compound showing various pharmacological properties that are mainly attributed to immunomodulatory and anti-inflammatory effects. Several lines of experimental study have recently investigated the therapeutic potential of berberine and its underlying mechanisms in treating RA condition. The present review aimed to clarify determinant cellular and molecular targets of berberine in RA and found that berberine through modulating several signalling pathways involved in the joint inflammation, including PI3K/Akt, Wnt1/ß-catenin, AMPK/lipogenesis and LPA/LPA1 /ERK/p38 MAPK can inhibit inflammatory proliferation of FLS cells, suppress DC activation and modulate Th17/Treg balance and thus prevent cartilage and bone destruction. Importantly, these molecular targets may explore new therapeutic targets for RA treatment.

Collagen intrafibrillar mineralization as a result of the balance between osmotic equilibrium and electroneutrality.

Mineralization of fibrillar collagen with biomimetic process-directing agents has enabled scientists to gain insight into the potential mechanisms involved in intrafibrillar mineralization. Here, by using polycation- and polyanion-directed intrafibrillar mineralization, we challenge the popular paradigm that electrostatic attraction is solely responsible for polyelectrolyte-directed intrafibrillar mineralization. As there is no difference when a polycationic or a polyanionic electrolyte is used to direct collagen mineralization, we argue that additional types of long-range non-electrostatic interaction are responsible for intrafibrillar mineralization. Molecular dynamics simulations of collagen structures in the presence of extrafibrillar polyelectrolytes show that the outward movement of ions and intrafibrillar water through the collagen surface occurs irrespective of the charges of polyelectrolytes, resulting in the experimentally verifiable contraction of the collagen structures. The need to balance electroneutrality and osmotic equilibrium simultaneously to establish Gibbs-Donnan equilibrium in a polyelectrolyte-directed mineralization system establishes a new model for collagen intrafibrillar mineralization that supplements existing collagen mineralization mechanisms.

Effects of different sonic activation protocols on debridement efficacy in teeth with single-rooted canals.

OBJECTIVES: The effects of different EndoActivator® (EA) sonic activation protocols on root canal debridement efficacy were examined. METHODS: Root canals in 48 single-rooted teeth were instrumented, irrigated initially with NaOCl and divided into 6 groups (N=8) based on the application time of QMix (antimicrobial calcium-chelating irrigant), and the time and sequence of EA irrigant activation - Positive Control: 90s QMix; Negative Control: 90s saline; Group 1A: 15s QMix+15s QMix with EA-activation; Group 1B: 30s QMix+30s of QMix with EA-activation; Group 2A: 15s QMix with EA-activation+15s QMix; Group 2B: 30s QMix with EA-activation+30s QMix. Split roots were examined with scanning electron microscopy for assignment of smear and debris scores in locations along the coronal, middle and apical thirds of the canals. The overall cleanliness of pooled canal locations in the Positive Control and the 4 experimental groups were compared with chi-square tests. RESULTS: Significant differences were detected among the 5 groups (P<0.001). Post hoc pairwise comparisons indicated that the overall canal cleanliness was in the order (from best to worst): 1B=2B>2A>1A>Positive Control. Completely clean canals could not be achieved due to the absence of continuous irrigant flow for EA to clear intraradicular debris. CONCLUSIONS: Irrespective of the sonic activation sequence, irrigant activation for 30s during a 60-s period of QMix application appears to maximise the smear layer and debris removal potential of the EndoActivator® system. CLINICAL SIGNIFICANCE: Sonic activation of root canal irrigants produces cleaner root canals and reduces the time required for final delivery of a canal wall smear later-removing irrigant when compared to the use of needle irrigation alone.

The role of grape seed extract in the remineralization of demineralized dentine: micromorphological and physical analyses.

OBJECTIVES: Grape seed extract (GSE) is known to have a positive effect on the demineralization and/or remineralization of artificial root caries lesions. The present study aimed to investigate whether biomodification of caries-like acid-etched demineralized dentine, using proanthocyanidins-rich GSE, would promote its remineralization potential. DESIGNS: Dentine specimens were acid-etched for 30s, then biomodified using proanthocyanidin-based preconditioners (at different concentrations and pH values) for 2min, followed by a 15-day artificial remineralization regimen. They were subsequently subjected to microhardness measurements, micromorphological evaluation and X-ray diffraction analyses. Stability of the preconditioners was also analyzed, spectrophotometrically. RESULTS: A concentration-dependent increase was observed in the microhardness of the specimens that were biomodified using GSE preconditioners, without pH adjustment. Field emission scanning electron microscopy revealed greater mineral deposition on their surfaces, which was further identified mainly as hydroxylapatite. The absorbances of preconditioner dilutions at pH 7.4 and pH 10.0 decreased at the two typical polyphenol bands. CONCLUSIONS: Transient GSE biomodification promoted remineralization on the surface of demineralized dentine, and this process was influenced by the concentration and pH value of the preconditioner. GSE preconditioner at a concentration of 15%, without pH adjustment, presented with the best results, and this may be attributed to its high polyphenolic content.

Influence of different adherend materials and combinations on in vitro shear bond strength.

The influence of different adherend and substrate materials on shear bond strength (SBS) test was estimated. Ceramic plates (IPS e.max press) were cut, polished, abraded, and applied with two resin cements (Panavia F/Biscem). The SBS values of 30 groups were measured. The groups consisted of five combinations of adherend and substrate materials for each adhesive system and three different bonded areas (2, 4, and 6 mm diameter) for each combination. The failure modes were examined using a stereomicroscope. Groups with ceramic adherends showed higher SBS values in both adhesive systems and all three bonded areas. Small bonded areas are associated with significantly high SBS values. Groups with similar bonded areas and high SBS values showed more mixed or cohesive failures. Groups with small bonded areas and high SBS values had more interfacial failures. Adherend and substrate material significantly influenced the in vitro SBS value.

Effect of post-space treatment on retention of fiber posts in different root regions using two self-etching systems.

The effect of post-space treatment on the retention of fiber posts in different root regions was evaluated using two self-etching systems. Post spaces were prepared in extracted premolars and then the root canals were subjected to one of the following post-space treatments: (i) water irrigation (control); (ii) etching with 35% phosphoric acid for 30 s; (iii) irrigation with 17% EDTA followed by 5.25% sodium hypochlorite (NaOCl); and (iv) ultrasonic agitation associated with 17% EDTA and 5.25% NaOCl irrigating solutions. The dentin surfaces were examined under scanning electron microscopy (SEM) after different post-space treatments. Fiber posts were then luted in the treated roots using resin cement with either Clearfil SE Bond or Clearfil DC Bond, and the thin-slice push-out test was performed. Scanning electron microscopy showed that all the post-space treatments tested were effective in removal of the smear layer of debris, or sealer/gutta-percha remnants, on the root canal. The apical push-out strength was affected by post-space treatment. Both 35% phosphoric acid etching and ultrasonic agitation in combination with EDTA/NaOCl irrigation improved the apical push-out strength of the fiber post, regardless of the type of self-etching system. A solo irrigation with an EDTA/NaOCl solution resulted in a lower apical push-out strength compared with the other two experimental groups.