Physical properties and bioactivity of Aloe vera modified tricalcium silicate-based cement

Objective: This study compares the physical properties and bioactivity of tricalcium silicate-based cement (Matreva MTA) modified with various concentrations of Aloe vera (AV) solutions and Biodentine cement. Methods: Sixty discs were prepared, and divided into 5 groups (12 discs each) based on the estimated materials: group I: Biodentine, group II: Matreva MTA, group III: Matreva MTA with 10% AV, group IV: Matreva MTA with 20% AV and group V: Matreva MTA with 30% AV. The flow and setting time were assessed following ISO standard 6876:2012 and American Society for Testing and Materials (ASTM) standard C266-21, respectively. The in-vitro bioactivity was evaluated after 1, 14, and 28 days of immersion in Hank\u27s balanced salt solution (HBSS) including pH, calcium ion release, and apatite formation. All data were statistically analyzed. Results: Increasing the AV concentration added to Matreva MTA from 0 to 30% decreased the flow and setting time. Significant high mean pH and calcium ion release values were observed for 20 and 30% AV-modified Matreva MTA cement at 14 and 28 days (P≤ 0.05). Environmental scanning electron microscope/ energy-dispersive X-ray spectroscopy (ESEM/EDX) analysis confirmed calcium phosphate nucleation on the surfaces of 20 and 30% AV-modified Matreva MTA cements after immersion in HBSS. Conclusion: Addition of 20 and 30% AV solutions to Matreva MTA reduced the setting time and improved the handling characteristics as well as the in-vitro bioactivity, resembling the qualities of Biodentine. Both AV-modified Matreva MTA and Biodentine cements had extended alkalinizing activity and calcium ion release. Clinical relevance: AV-modified Matreva MTA can be considered a promising biomaterial for different endodontic applications

Electrospun nano-fibrous bilayer scaffold prepared from polycaprolactone/gelatin and bioactive glass for bone tissue engineering

This work is focused on integrating nanotechnology with bone tissue engineering (BTE) to fabricate a bilayer scaffold with enhanced biological, physical and mechanical properties, using polycaprolactone (PCL) and gelatin (Gt) as the base nanofibrous layer, followed by the deposition of a bioactive glass (BG) nanofibrous layer via the electrospinning technique. Electrospun scaffolds were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy. Surface area and porosity were evaluated using the nitrogen adsorption method and mercury intrusion porosimetry. Moreover, scaffold swelling rate, degradation rate and in vitro bioactivity were examined in simulated body fluid (SBF) for up to 14 days. Mechanical properties of the prepared scaffolds were evaluated. Cell cytotoxicity was assessed using MRC-5 cells. Analyses showed successful formation of bead-free uniform fibers and the incorporation of BG nanoparticles within fibers. The bilayer scaffold showed enhanced surface area and total pore volume in comparison to the composite single layer scaffold. Moreover, a hydroxyapatite-like layer with a Ca/P molar ratio of 1.4 was formed after 14 days of immersion in SBF. Furthermore, its swelling and degradation rates were significantly higher than those of pure PCL scaffold. The bilayer\u27s tensile strength was four times higher than that of PCL/Gt scaffold with greatly enhanced elongation. Cytotoxicity test revealed the bilayer\u27s biocompatibility. Overall analyses showed that the incorporation of BG within a bilayer scaffold enhances the scaffold\u27s properties in comparison to those of a composite single layer scaffold, and offers potential avenues for development in the field of BTE

Amelogenin-inspired peptide, calcium phosphate solution, fluoride and their synergistic effect on enamel biomimetic remineralization: an in vitro pH-cycling model

Abstract Background Several methods were introduced for enamel biomimetic remineralization that utilize a biomimetic analogue to interact and absorb bioavailable calcium and phosphate ions and induce crystal nucleation on demineralized enamel. Amelogenin is the most predominant enamel matrix protein that is involved in enamel biomineralization. It plays a major role in developing the enamel’s hierarchical microstructure. Therefore, this study was conducted to evaluate the ability of an amelogenin-inspired peptide to promote the remineralization potential of fluoride and a supersaturated calcium phosphate solution in treating artificially induced enamel carious lesions under pH-cycling regimen. Methods Fifty enamel slices were prepared with a window (4*4 mm2 ) on the surface. Five samples were set as control healthy enamel and 45 samples were subjected to demineralization for 3 days. Another 5 samples were set as control demineralized enamel and 40 enamel samples were assigned into 8 experimental groups (n=5) (P/I, P/II, P/III, P/AS, NP/I, NP/II, NP/III and NP/AS) according to peptide treatment (peptide P or non-peptide NP) and remineralizing solution used (I; calcium phosphate solution, II; calcium phosphate fluoride solution, III; fluoride solution and AS; artificial saliva). Samples were then subjected to demineralization/remineralization cycles for 9 days. Samples in all experimental groups were evaluated using Raman spectroscopy for mineral content recovery percentage, microhardness and nanoindentation as healthy, demineralized enamel and after pH-cycling. Data were statistically analysed using two-way repeated measures Anova followed by Bonferroni-corrected post hoc test for pairwise multiple comparisons between groups. Statistical significance was set at p= 0.05. Additionally, XRD, FESEM and EDXS were used for crystal orientation, surface morphology and elemental analysis after pH-cycling. Results Nanocrystals clumped in a directional manner were detected in peptide-treated groups. P/II showed the highest significant mean values in mineral content recovery (63.31%), microhardness (268.81±6.52 VHN), elastic modulus (88.74±2.71 GPa), nanohardness (3.08±0.59 GPa) and the best crystal orientation with I002/I300 (1.87±0.08). Conclusion Despite pH changes, the tested peptide was capable of remineralizing enamel with ordered crystals. Moreover, the supplementary use of calcium phosphate fluoride solution with peptide granted an enhancement in enamel mechanical properties after remineralization