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Nanocomposites based on hydroxyapatite (HAP) are fabricated with/without combining graphene oxide (GO) and silver oxide (Ag2O). All compositions are structurally investigated using x-ray diffraction (XRD). In addition, the lattice parameters were estimated. Lattice constants a and c of hexagonal HAP symmetry are around 9.42 and 6.88 Å, respectively. Further, the lattice constant of Ag2O is around 4.736 Å. Moreover, Fourier-transform infrared (FTIR) spectroscopy is used besides X-ray photoelectron (XPS) to investigate the composition. The morphological study was done with the scanning electron microscope (SEM) and transmission electron microscope (TEM). In this regard, Ag2O is exhibited as nano-spherical grains, while HAP was shown in nanorod grains. The dimensions of HAP decreased from 39 to 16 to 34 and 7 nm for length and diameter. The average roughness parameter (Ra) increased from 23.3 to 67.5 nm from HAP to TNC. The parameters of average maximum height (Rtm), maximum peak height (Rp), and maximum valley depth (Rv) reached 439.3, 261.3, and 251.8 nm respectively. Further, the Ca/P ratio is detected with a value of 1.5. Besides, cell viability of osteoblast cell lines increased from 95.9 ± 3 to 101.2 ± 5%. In addition, the antibacterial behavior increased to 21.6 ± 2.3 and 21.1 ± 1.4 mm for TNC against Escherichia coli and Staphylococcus aureus, respectively.

Bone tissue engineering is the most used technology in recent years for repairing damaged bones. A novel heterogeneous biomaterial is prepared and studied to be suggested as a promising bone substitute biomaterial, based on three different nanoparticles: hydroxyapatite (HAP), boron oxide (B2O3), and graphene oxide (GO) a triple nanocomposite is designed HAP/B2O3/GO. This hybrid scaffold is analyzed with XRD to examine the crystalline structure of HAP/B2O3/GO and shows its crystal planes. Moreover, the interaction between the three nanoparticles and their distinctive active functional groups is illustrated with FTIR analysis. Further, TEM micrographs demonstrate the structural alteration and the uniform incorporation of HAP and B2O3 into GO sheets with an average length of 30 nm and diameter of 6 nm for HAP, and a size of 8 mm for B2O3. Furthermore, SEM micrographs reveal the porous structure of HAP/B2O3/GO with a grain size of 5–10 nm. The maximum roughness average value is obtained by HAP/B2O3/GO which is 11.04 nm. Besides, HAP/B2O3/GO nanocomposite shows the highest cell viability value of 96.1 ± 1.2%. The bacterial toxicity of HAP/B2O3/GO is confirmed with the obtained inhibition zone against Escherichia coli and Staphylococcus aureus of 15.7 ± 1.1 mm and 16.2 ± 0.8 mm respectively. In addition, the hardness of the triple composite is improved showing a maximum value of 3.7 ± 0.3 GPa. Distinctly, the addition of B2O3 to HAP and GO nanosheets alter the morphological properties and enhances the roughness parameters of HAP/B2O3/GO. Besides, HAP/B2O3/GO shows improved porosity, cell viability, and biodegradability. Hence, studying HAP/B2O3/GO nanocomposite with different scans and analyses reveals its porous integrated structure and shows an excellent antibacterial property, so that HAP/B2O3/GO composite can be suggested as a promising bone substitute biomaterial.

Objectives: Endophytic fungi are widely known to reside in plant tissues causing no harm to host plants or even no noticeable change. They may colonize host plants for a part of their life cycle or may complete the entire life cycle since host provide a variety of novel metabolites. Despite being in a close relationship with medicinal host plants, the diversity and metabolic spectrum of endophytic fungi have not been researched well. Their diversity and ecological niche as plant symbionts make them attractive targets in the search for novel biochemicals. Methods: We aimed to isolate, purify, and characterize the endophytic fungal population of medicinal host plants cultivated in Riyadh, Saudi Arabia. The goal was achieved through morphological identification and internal transcribed spacer (ITS) regions in rRNA analyses to determine phylogeny and diversity. Three aromatic and medicinal plants Jasminum sambac, Camellia sinensis, and Ocimum basilicum collected from the Riyadh region, Saudi Arabia were investigated. In total, 84 isolates were purified and they were grouped into 20 operational taxonomic units (OTUs) as per their sequences of ITS regions in rRNA. Results: Twenty species of endophytic fungi were grouped in 12 genera i.e. Neopestalotiopsis, Trichoderma, Fusarium, Colletotrichum, Myrothecium, Chaetomium, Alternaria, Phoma, Curvularia, Cladosporium, Neodidymelliopsis, and Aspergillus and all isolates belonged to Ascomycota phylum. J. sambac was found dominant among other and had a relative frequency of 27%. C. sinensis was next with 18.7% relative frequency. The diversity was prominently recorded in leaf organs over stem and roots while roots exhibited the lowest diversity. Isolates also produced indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase enzyme, and siderophores with variable magnitudes that could be assigned to their wide range of metabolic variations from species to species. Conclusion: Conclusively, J. sambac, C. sinensis, and O. basilicum are a good source of endophytic fungi with certain plant growth-promoting traits. Overall, Alternaria was found as the most predominant genus in terms of colonization rate. Further deternminations are required to screen the beneficial compounds released by these endophytic fungi.

Our study proposed a promising anti-fungal therapy to control Saprolegnia spp. infection in Nile tilapia (Oreochromis niloticus). A Moringa oleifera synthesized silver nanoparticles (MS-AgNPs) showed an in vitro anti-fungal activity against Saprolegnia spp. with an inhibition zone of 18 mm. A total of 220 O. niloticus (45 ± 0.56 g) were used in this study. A preliminary investigation was conducted by using 100 fish for determining the safe dose of MS-AgNPs which was found to be 0.6 mg/L. Another 120 fish were divided into four groups; the first (control) and second groups (G1 and G2) were non-infected and exposed to 0 and 0.6 mg/L MS-AgNPs, respectively. The third and fourth groups (G3 and G4) were infected with Saprolegnia spp. (1.5 × 104 spores/L) and exposed to 0 and 0.6 mg/L MS-AgNPs, respectively. The experiment lasted for 7 days. The infection with Saprolegnia spp. induced immunosuppression expressed by a marked decrease in immunoglobulin M, nitric oxide, complement 3, and lysozyme activity, with a 41 % survival rate. Additionally, a marked decline in the values of hepatic and branchial antioxidant enzymes (superoxide dismutase and catalase) in addition to serum total antioxidant capacity and protein profile indices. In contrast, Saprolegnia spp. infection elevated hepatic and branchial malondialdehyde, hepatic function indicators, and stress biomarkers (cholesterol and triglyceride) with up-regulation of the pro-inflammatory cytokines (IL-1ß and TNF-α), and the anti-inflammatory cytokines (IL-10 and TGF-β). Histopathological findings of the gills and musculature of infected fish showed severe hyperplasia of the epithelial lining with a fusion of secondary lamellae and necrotic myocytes admixed with edema. Interestingly, treatment of the challenged fish with MS-AgNPs at a dose of 0.6 mg/L could improve these variables by enhancing the histological architecture. According to these findings, MS-AgNPs have an ameliorative effect against the harmful effects of Saprolegnia spp. infection on immune-antioxidant status and hepatic functions indices. Consequently, MS-AgNPs at a dose of 0.6 mg/L is a promising option for use in the control of Saprolegnia spp. infection in aquaculture.