This work investigates the effect of adding silver nanoparticles (NPs) in ppm on the bioactivity of hydroxyapatite/polyvinyl alcohol nanocomposites (HAV). HAV prepared by an in situ biomimetic approach was doped with different concentrations of silver NPs (HAV-Ag), and the formed powder samples were characterized by different techniques such as Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-EOS), X-ray diffraction, transmission electron microscope, and Fourier Transform Infrared Spectroscopy. Bioactivity was evaluated in simulated body fluid through studying the kinetics of Ca and P uptake onto the different HAV-Ag nanocomposites. Uptake profiles of Ca and P were well described by a pseudo-second order kinetic model, and the obtained kinetic parameters confirmed that the highest uptake capacities were achieved by adding less than 0.001 ppm of silver NPs which is an amount not detectable by ICP. Furthermore, HAV-Ag nanocomposites were shown to be non-toxic as well as have a strong antibacterial effect. Silver NPs significantly enhanced the bioactivity of HAV nanocomposites and thus the developed nanocomposites promise to be excellent biomaterials for bone and reconstructive surgery applications.

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Ifosfamide is an alkylating oxazaphosphorine antitumor prodrug. Although it is an effective chemotherapeutic agent, it has been shown to induce many side effects. The objective of the present study, therefore, was to investigate the possible protective roles of lecithin and quercetin either singly or combined against ifosfamide-induced molecular structure changes in retina of female rats using Fourier transform infrared spectroscopy (FTIR). Seventy female albino rats were randomly divided into seven groups. Ifosfamide (Ifo; 80mg/kg b.wt.) was administrated for five consecutive days intraperitoneally (i.p.), while quercetin (50mg/kg b.wt.) and lecithin (100mg/kg b.wt) were given orally either singly or in-combination with IFO for six consecutive days. Our results indicate that Ifosfamide was affected on the lipid components of the retina, NH-OH region changes revealed unusual interface/binding mechanism that related to different surrounding environment due to ifosfamide intraperitoneal injection. The co-administration of Lec+Que with the intraperitoneal injection of Ifosfamide preventing the side effect of Ifosfamide. We suggest that synergistic effect of quercetin and lecithin in the combined therapy results in marked neuroprotective effect in part through its antioxidant properties and down regulation of molecular structure in retina.

Background: During cancer chemotherapy, drug-induced oxidative stress can limit therapeutic efficiency and cause a number of side effects. Objectives: Our study aimed to characterize the side effects of an alkylating agent chemotherapy ifosfamide to the retina and if the supplementation of lecithin and or quercetin can diminish its oxidative stress by means of comet assay and FTIR.Methods: Seventy female albino rats divided as control, rats given orally quercetin or lecithin, rats injected with ifosfamide, rats given quercetin or lecithin and in combination of them with ifosfamide injection.Results: Lecithin and quercetin groups indicate a normal comet parameters and distribution of protein secondary structure components content of β-turn, α-helix and β-sheet. After Ifosfamide injection, all comet parameters and β-Turns content were significant increase (p˂0.05) with the same context significant decrease (p˂0.05) of α-helix was observed. Lecithin or quercetin reduces the effect of ifosfamide injection in tail length and percentage tailed DNA. Combined treatment gives more protection against DNA damage. Lecithin role is cleared in returning the normal distribution of β-turn, α-helix, β-sheet and lack of protective effect of quercetin regarding the protein secondary structure of retina was observed.Conclusion: We suggest using lecithin and quercetin in combined treatment to reduce the oxidative stress due to ifosfamide.

Background/aimHumans can beexposed to hydrogen sulfide gas due to either endogenous or exogenous sources. The health effects associated with exposure to hydrogen sulfide is dependent on its concentration and the duration of exposure. It includes -among many other effects-eye irritation, tearing and inflammation. This study aims to clarify the ocular biohazardous effects induced in tear film due to H 2 S exposure by using Ultraviolet spectroscopy. Materials and methods:SixtyChinchilla rabbits wererandomly grouped into six subgroups.Group one served as control. Animals were exposed to hydrogen sulfide gas with concentrations of75, 90,115, 250 and 500 ppm. After exposure, tears were collected from the lower lid using glass micro capillariesand its structural characteristics were investigated immediately with ultraviolet spectroscopy. The curve enhancement procedure using Fourier deconvolution was also applied to resolve the obtained absorption peaks. Results:The control pattern indicates thepresence of three absorption peaks at 203±5 nm, 273±3 nm and 323± 4 nm, which represent the native lipids, trine conjugation and retinolrespectively. After exposure to the specified concentrations of H 2 S the general observation is that the number of detected peaks varied with increasing the H 2 S dose. Conclusion:Tear's lipid is the primary target for hydrogen sulfide; this was associated with changes in the retinol content.