A novel injectable boron doped-mesoporous nano bioactive glass loaded-alginate composite hydrogel as a pulpotomy filling biomaterial for dentin regeneration.

BACKGROUND: Different materials have been used as wound dressings after vital pulp therapies. Some of them have limitations such as delayed setting, difficult administration, slight degree of cytotoxicity, crown discoloration and high cost. Therefore, to overcome these disadvantages, composite scaffolds have been used in regenerative dentistry. This study aims to construct and characterize the physicochemical behavior of a novel injectable alginate hydrogel loaded with different bioactive glass nanoparticles in various concentrations as a regenerative pulpotomy filling material. METHODS: Alginate hydrogels were prepared by dissolving alginate powder in alcoholic distilled water containing mesoporous bioactive glass nanoparticles (MBG NPs) or boron-doped MBG NPs (BMBG NPs) at 10 and 20 wt% concentrations. The mixture was stirred and incubated overnight in a water bath at 50 0 C to ensure complete solubility. A sterile dual-syringe system was used to mix the alginate solution with 20 wt% calcium chloride solution, forming the hydrogel upon extrusion. Then, constructed hydrogel specimens from all groups were characterized by FTIR, SEM, water uptake percentage (WA%), bioactivity and ion release, and cytotoxicity. Statistical analysis was done using One-Way ANOVA test for comparisons between groups, followed by multiple pairwise comparisons using Bonferroni adjusted significance level (p < 0.05). RESULTS: Alginate/BMBG loaded groups exhibited remarkable increase in porosity and pore size diameter [IIB1 (168), IIB2 (183) (µm)]. Similarly, WA% increased (~ 800%) which was statistically significant (p < 0.05). Alginate/BMBG loaded groups exhibited the strongest bioactive capability displaying prominent clusters of hydroxyapatite precipitates on hydrogel surfaces. Ca/P ratio of precipitates in IIA2 and IIB1 (1.6) were like Ca/P ratio for stoichiometric pure hydroxyapatite (1.67). MTT assay data revealed that the cell viability % of human gingival fibroblast cells have declined with increasing the concentration of both powders and hydrogel extracts in all groups after 24 and 48 h but still higher than the accepted cell viability % of (˃70%). CONCLUSIONS: The outstanding laboratory performance of the injectable alginate/BMBGNPs (20 wt%) composite hydrogel suggested it as promising candidate for pulpotomy filling material potentially enhancing dentin regeneration in clinical applications.

Throat spray formulated with virucidal pharmaceutical excipients as an effective early prophylactic or treatment strategy against pharyngitis post-exposure to SARS-CoV-2.

Our study aimed to develop a virucidal throat spray using bioactive compounds and excipients, focusing on the preparation of Curcumin (CUR) in a self-nano emulsifying drug delivery system (SNEDDS). Two molecular docking studies against SARS-CoV-2 targets guided the selection of proper oil, surfactant, co-surfactant, and natural bioactive that would maximize the antiviral activity of the throat spray. Two self-nanoemulsifying formulas that were diluted with different vehicles to prepare eight CUR-loaded SNESNS (self-nanoemulsifying self-nanosuspension) formulas. In vitro characterization studies and in vitro anti-SARS-CoV-2 effect revealed that the optimal formula, consisted of 20 % Anise oil, 70 % Tween 80, 10 % PEG 400, and 0.1 %w/w CUR, diluted with DEAE-Dx. Preclinical toxicity tests on male rats confirmed the safety of a mild throat spray dose (5 µg/mL CUR). In a rat model of acute pharyngitis induced by ammonia, post-treatment with the optimal formula of CUR loaded SNESNS for one week significantly reduced elevated proinflammatory markers (TNF-α, IL6, MCP1, and IL8). In conclusion, our CUR-loaded SNESNS formula, at 5 µg/mL concentration, shows promising effect as a prophylactic throat spray against SARS-CoV-2 and as a treatment for pharyngitis.

Nanoparticles fabricated from the bioactive tilapia scale collagen for wound healing: Experimental approach.

The creation of innovative wound-healing nanomaterials based on natural compounds emerges as a top research goal. This research aimed to create a gel containing collagen nanoparticles and evaluate its therapeutic potential for skin lesions. Collagen nanoparticles were produced from fish scales using desolvation techniques. Using SDS PAGE electrophoresis, Fourier transform infrared spectroscopy (FTIR) as well as the structure of the isolated collagen and its similarities to collagen type 1 were identified. The surface morphology of the isolated collagen and its reformulation into nanoparticles were examined using transmission and scanning electron microscopy. A Zeta sizer was used to examine the size, zeta potential, and distribution of the synthesized collagen nanoparticles. The cytotoxicity of the nanomaterials was investigated and an experimental model was used to evaluate the wound healing capability. The overall collagen output from Tilapia fish scales was 42%. Electrophoretic patterns revealed that the isolated collagen included a unique protein with chain bands of 126-132 kDa and an elevated beta band of 255 kDa. When compared to the isolated collagen, the collagen nanoparticles' FTIR results revealed a significant drop in the amide II (42% decrease) and amide III (32% decrease) band intensities. According to SEM analysis, the generated collagen nanoparticles ranged in size from 100 to 350 nm, with an average diameter of 182 nm determined by the zeta sizer. The produced collagen nanoparticles were polydispersed in nature and had an equivalent average zeta potential of -17.7 mV. Cytotoxicity study showed that, when treating fibroblast cells with collagen nanoparticle concentrations, very mild morphological alterations were detected after human skin fibroblasts were treated with collagen nanoparticles 32 µg/ml for 24 hours, as higher concentrations of collagen nanoparticles caused cell detachment. Macroscopical and histological investigations proved that the fabricated fish scale collagen nanoparticles promoted the healing process in comparison to the saline group.