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The acerola non-pomace, a by-product from the juice clarification step and rich in phenolic compounds and ascorbic acid, was investigated for its biological potential through in vitro tests. Extracts were obtained using hydrothermal extraction (HT) at 121°C as well as CO 2 -expanded ethanol (GXL) at 40°C. The GXL extract contained 159 mg/g of ascorbic acid, while the HT extract showed 70 mg/g. Catechin was found only in the HT extract, and quercetin only in the GXL extract. Both extracts exhibited similar antiglycemic potential, but the GXL extract showed twice the neuroprotective potential against acetylcholinesterase (AChE, IC 50 =302 μg/mL) and lipoxygenase (LOX, IC 50 =227 μg/mL) activities. In human breast cancer cells (MDA-MB-231), the GXL extract demonstrated better antitumor potential with an IC 50 of 100 μg/mL compared to 250 μg/mL for the HT extract. [Display omitted] • Acerola non-pomace extracts from hydrothermal (HT) and gas-expanded liquid (GXL) methods. • Ascorbic acid, phenolic compounds and antioxidant activity were determined in the extract. • GXL extract showed better anti-inflammatory and neuroprotective potential. • Both extracts were promising against the metabolic activity of human breast cancer cell. [ABSTRACT FROM AUTHOR]

[Display omitted] • Impedance to assess the biocompatibility and degradation of a cultured cell. • Cardiomyocyte cells seeded into poly(vinyl alcohol) and sodium alginate scaffold. • The dielectric parameters of the PVA/SA ratios to determine the cell impedance. • Three concentrations of PVA/SA were electrospunned: 3.5 wt%, 4 wt%, and 5 wt%. • The 5.0 wt% ratio showed the highest cell number with a more organized network. Achieving continuous cell growth on culture scaffolds indicates biocompatibility features in a biological system. On the other hand, a cell decrease indicates undesirable conditions of the scaffold. This study demonstrates that crushed poly(vinyl-alcohol) and sodium alginate (PVA/SA) scaffolds are detrimental to rat cardiomyocyte culture. The polymeric scaffold was produced by using the electrospinning technique. Three different PVA/SA concentrations were electrospun: 3.5 wt%, 4 wt%, and 5.0 wt%. The electrochemical impedance spectroscopy monitored the dielectric properties of the culture. The cellular study was carried out with Calcein-AM staining, while the architecture morphology was characterized with stereoscopic and optical microscopes. Results showed that the morphology and the cell proliferation rate depended on the PVA/SA concentration. The 5.0 wt% scaffold proved the most effective, given that it developed the highest impedance magnitude and the highest cell number with a more organized network formation. However, crushed scaffolds promoted a rapid cell decrease regardless of the PVA/SA ratio, since the cardiomyocyte cells did not form a biofilm on the electrospun-mats. Therefore, a homogenous scaffold is needed to guarantee biocompatibility features. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Ir(III)-complexes were studied theoretically by using DFT /CAM-B3LYP level. • Molecular electrostatic potentials of the complexes were demonstrated. • CV results showed that the iridium-based variants have different redox potentials. • The compounds had antioxidant, antimicrobial and DNA binding activities. • Complex 6 had antibacterial activity against all test bacteria used. Mononuclear phosphinite Iridium complexes based on ferrocene group have been prepared and characterized by various spectroscopic techniques. The complexes were subjected to cyclic voltammetry studies in order to determine the energies of HOMO and LUMO levels and to estimate their electrochemical and some electronic properties. Organic complex-based memory substrates were immobilized using TiO 2 -modified ITO electrodes, and the memory functions of phosphinite-based organic complexes were verified by chronoamperometry (CA) and open-circuit potential amperometry (OCPA). Extensive theoretical and experimental investigations were directed to gain a more profound understanding of the chemical descriptors and the diverse electronic transitions taking place within the iridium complexes, as well as their electrochemical characteristics. The quantum chemical calculations were carried out for the iridium complexes at the DFT/CAM-B3LYP level of theory in the gas phase. Furthermore, the antioxidant, antimicrobial, DNA binding, and DNA cleavage activities of the complexes were tested. Complex 2 exhibited the highest radical scavenging activity (67.5 ± 2.24 %) at 200.0 mg/L concentration. It was observed that the complexes formed an inhibition zone in the range of 8–15 mm against Gram + bacteria and in the range of 0–13 mm against Gram – bacteria. The agarose gel electrophoresis method was used to determine the DNA binding and DNA cleavage activities of the complexes. All of the tested complexes had DNA binding activity; however, complexes 1, 2 , and 8 showed better binding activity than the others. [ABSTRACT FROM AUTHOR]

[Display omitted] Oats are represented an important source for nutrition, and it have attracted a lot of attention in recent years. In this study we produced oatmeal cookies and oats was added to formula wheat by 50% and 75%. Also, we added cinnamon to treatments 3 and 4 by 5% to increase nutrition value of oatmeal cookies, improvement sensory evaluation and increase antioxidant properties. All the cookies treatments were storage at room temperature. The purposes of this study were to study antioxidant activity for oats and cinnamon. Also determined the chemical composition include (moisture content, protein, ash, total lipids, crude fibers, carbohydrates and total calories) for oats, white flour and oatmeal cookies treatments. In addition evaluated all of sensory evaluation contain (appearance, color, texture, taste and odor) and microbiological evaluation such as (total bacterial count, spore forming bacteria and mold and yeasts count) for oatmeal cookies treatments. Also, biological assays were preformed to measure level of GPT, GOT, urea, creatinine, total cholesterol, triglycerides, HDL, LDL, and glucose. Furthermore, histopathological examination of both liver and kidneys was analyzed. The obtained results were clarified that the antioxidant activity for oats and cinnamon were 52.91% and 87.91%. Moreover, addition of oats and cinnamon to the cookies improve sensory evaluation as made it more acceptable, decreasing microbial load principally treatments 4 (prepared by 75% oats + 5% cinnamon). Biochemical assays were improved in rats with cirrhosis of carbon tetrachloride and their histopathological examination of liver and kidneys. It was clear that the additions ground whole grain oats and cinnamon to wheat flour based cookies improve its nutritional, chemical, and biological functions properties. [ABSTRACT FROM AUTHOR]

The development of new molecules for the treatment of calmodulin related cardiovascular or neurodegenerative diseases is an interesting goal. In this work, we introduce a novel strategy with four main steps: (1) chemical synthesis of target molecules, (2) Förster Resonance Energy Transfer (FRET) biosensor development and in vitro biological assay of new derivatives, (3) Cheminformatics models development and in vivo activity prediction, and (4) Docking studies. This strategy is illustrated with a case study. Firstly, a series of 4-substituted Riluzole derivatives 1–3 were synthetized through a strategy that involves the construction of the 4-bromoriluzole framework and its further functionalization via palladium catalysis or organolithium chemistry. Next, a FRET biosensor for monitoring Ca2+-dependent CaM-ligands interactions has been developed and used for the in vitro assay of Riluzole derivatives. In particular, the best inhibition (80%) was observed for 4-methoxyphenylriluzole 2b. Besides, we trained and validated a new Networks Invariant, Information Fusion, Perturbation Theory, and Machine Learning (NIFPTML) model for predicting probability profiles of in vivo biological activity parameters in different regions of the brain. Next, we used this model to predict the in vivo activity of the compounds experimentally studied in vitro. Last, docking study conducted on Riluzole and its derivatives has provided valuable insights into their binding conformations with the target protein, involving calmodulin and the SK4 channel. This new combined strategy may be useful to reduce assay costs (animals, materials, time, and human resources) in the drug discovery process of calmodulin inhibitors. [Display omitted] • Synthesis, biosensors, cheminformatics, and docking strategy for drug discovery. • Chemical synthesis procedure for Riluzole derivatives from 4-bromoriluzole. • FRET biosensor for Ca2+-dependent CaM-ligands interactions monitoring for drugs. • Predictive model for multiple biological activity parameters in different brain regions. • Docking study of CaM-Riluzole derivatives interaction. [ABSTRACT FROM AUTHOR]

• Biological implications were attributed to FDS ( F elicium d ecipiens S aponin). • Saponins isolated from several plants possess a broad spectrum of biological activities. • 12.8 μg/mL of FDS caused more than 99.9% Aspergillus cell death within 24 h. • The hemolytic activity inhibition of FDS was correlated to the Lectin concentration. Filicium decipiens saponin (FDS) is the first saponin purified from F. decipiens seeds using ion-exchange and gel filtration chromatographies. In the present study, FDS and the aqueous crude extract of F. decipiens seeds were examined for their antifungal properties, hemolytic/cytotoxicity activity. The dried seeds were powdered and homogenized in 10% (w/v) for the preparation of crude extract. Sample obtained from Sephadex-LH-20 demonstrated FDS with a peak at 752.35 g/mol. FDS showed the highest toxicity against Aspergillus flavus , presenting with a low fungicidal concentration at 12.8 μg/mL. Under hemolytic induction, rabbit and cow erythrocytes were more affected by both samples, and the inhibition effect of PpyLL lectin was observed. These characteristics provide fundamental understanding of F. decipiens secondary metabolites, which would benefit future research to prevent dangerous traditional uses and provide agricultural solution. [ABSTRACT FROM AUTHOR]

A straightforward and effective method to chemically conjugate hydroxypropyl cellulose (HPC) to GlcA is described via microwave assisted copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC) between the azide functionalized HPC and the alkynyl functionalized GlcA, reducing reaction times from 24 h to 2 h. Two types of HPC azide derivatives, including an ester (ES) or a carbamate (CB) functional group, were synthesized and characterized by FT-IR and NMR spectroscopy that revealed the efficiency in the incorporation of the azide moieties in the cellulose backbone. These compounds were then conjugated with the alkynyl GlcA by CuAAC, affording the desired glycopolymers, HPA-ES-GlcA and HPA-CB-GlcA in excellent yields. The whole process involved rapid and effective reactions as well as easy purification techniques, using mostly non-toxic solvents, contributing to the sustainability of the synthesis These glycopolymers were characterized by FT-IR, NMR, TGA, DTA and SEM. Furthermore, the cytotoxicity, anti-inflammatory and antibacterial properties of the new glycopolymers were tested and it was found that these new HPC-GlcA conjugates presented low cytotoxicity, good anti-inflammatory and antibacterial properties. Overall, our results showed that HPC-GlcA polymers are suitable as potential GAG mimics for biomedical applications, therefore further investigations will be carried out. • Successful functionalization of cellulose with azide using ester and carbamate linkages. • Successful functionalization of glucuronic acid with an alkyne. • Efficient preparation of glucuronic acid-cellulose glycopolymer using click chemistry. • The glycopolymer had low cytotoxicity, good anti-inflammatory and antibacterial properties. • The new glycopolymer is a potential glycosaminoglycan mimic for biomedical applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Two novel acylthioureas (Ar-CO-NH-CS-NH-R) were synthesized and analyzed spectroscopically. • The crystal packing shows molecules arranged as dimers held by inter-molecular NH⋯S bonds. • The aromatic acyl thioureas could be considered as pseudo amino-enone systems for which the RAHB model is applicable. • One of the studied compounds can be used as agent to avoid surfaces contamination and as a disinfectant. Abstract The study of two new acylthiourea derivatives (Ar-CO-NH-CS-NH-R) are focused on the bonding interactions supported by X-ray, NMR, UV–Vis, Raman and IR spectroscopy, and NBO, AIM and Hirshfeld surface analysis. The RAHB model is proposed to explain some structural properties. The molecules are stabilized by intra-molecular NH⋯O bonds arranged in the lattice as centre-symmetric dimers held by inter-molecular NH⋯S bonds. The dimers are linked to each other through NH⋯O bonds giving rise to a chain, ribbon-like structure in the network. In vitro bacterial growth inhibition, biofilm formation, biosensor and biofilm metabolic activity were tested considering the broad bioactivity of acylthioureas. [ABSTRACT FROM AUTHOR]

In this study, the impact of low-energy (1 keV) Ar+ ion-beam irradiation on the morphology of polycrystalline Ti disks was investigated. Targets were prepared by cutting and mechanically polishing commercial rods. The surface topographies before and after irradiation were characterized by scanning electron microscopy (SEM) and mechanical profilometry. Irradiation was performed using a wide range of incident angles (α i) from normal to grazing geometries at a total dose of 1018 ions/cm2. SEM analysis of the irradiated Ti targets revealed clear texturing with various attainable surface morphologies depending on α i. The surface features varied from ripples within patches with fingerprint-like patterns (0 ≤ α i ≤ 60°) to oriented structures parallel to the direction of the ion beam, such as pillar/tip structures (65 ≤ α i ≤ 75°) and shallow ripples (α i ≈ 80°). This morphological selectivity could be attributed to the competitive diffusive and erosive regimes, where the lateral uniformity of the morphology was affected by the limited size of the crystal grains. Finally, the wettability and biocompatibility of the characteristic topographies were evaluated, and the results indicated improved performance of the ion-beam-textured surfaces compared to the untreated ones. • Commercial pure polycrystalline titanium surfaces have been irradiated with a broad 1 keV Ar+ beam. • Characteristic surface patterns have been produced as a function of the ion incidence angle with respect to the target normal. • The surface morphology is coupled with the intrinsic size of the polycrystalline grains. • The static contact angle (wetting properties) increases for modified surfaces. • Irradiated surfaces display a higher biocompatibility with respect to untreated ones. [ABSTRACT FROM AUTHOR]

• Selective N-allylation on thiazole ring has been achieved by S N 2ꞌ reaction. • The formation of sulphanilimide derivative was confirmed by IR, UV and single crystal studies. • The experimental results and DFT data are in good correlation with each other. • The cation binding characteristics of N-allylated derivative have been predicted by the molecular electrostatic potential (MEP). • The compound has been used for in-silico, in-vitro and in-vivo studies to explore its application. The title compound ethyl (E)-2-(4-aminobenzene-1-sulphonylimino-thiazol-3-yl-methyl)-3-phenyl acrylate (BH-STZ) was synthesized by an S N 2ꞌ reaction between 1:1 ratio of Ethyl 2-(acetoxy phenyl-methyl) acrylate (BH) and 4-amino-N-(1,3-thiazol-2-yl) benzenesulphonamide (STZ). It was characterized by FT-IR, 1H NMR, 13C NMR, DEPT 135, Mass, elemental analysis, and SCXRD. This study investigates the selective allylation of STZ at the secondary amine nitrogen over the primary amine nitrogen. It has been confirmed by the crystal structure of BH-STZ. In the BH-STZ, the hydrogen bonding interaction between primary amine and sulphonyl oxygen (N H...O) forms the β dimer. The photophysical properties (UV absorption and fluorescence emission) of BH-STZ have been studied. The theoretical FT-IR, UV, and SCXRD calculations based on density functional theory correlated well with the experimental results. The HOMO–LUMO energy gap indicated that BH-STZ has good chemical stability and lower hardness. The in vitro antibacterial activity of BH-STZ against a panel of pathogenic bacteria was assayed by the disc diffusion method. These results were compared with molecular docking studies between BH-STZ and the respective target protein from the bacteria. The compound was shown to be non-toxic to normal cells by both in vitro (using bacterial pathogen) and in vivo (using zebrafish) studies. The title compound ethyl (E)-2-(4-aminobenzene-1-sulphonylimino-thiazol-3-yl-methyl)-3-phenyl acrylate (BH-STZ) was synthesized by an S N 2ꞌ reaction between 1:1 ratio of Ethyl 2-(acetoxy phenyl-methyl) acrylate (BH) and 4-amino-N-(1,3-thiazol-2-yl) benzenesulphonamide (STZ). It was characterized by FT-IR, 1H NMR, 13C NMR, DEPT 135, Mass, elemental analysis and SCXRD. This study investigates the selective allylation of STZ at the secondary amine nitrogen over the primary amine nitrogen. It has been confirmed by the crystal structure of BH-STZ. The compound was shown to be non-toxic to normal cells by both in vitro (using bacterial pathogen) and in vivo (using zebrafish) studies. [Display omitted] [ABSTRACT FROM AUTHOR]

Mononuclear transition metal complexes based on ionic liquid have been prepared and the biological properties of the three complexes were evaluated using radical scavenging activity, reducing power, antibacterial effect, DNA binding and cleavage activity. Furthermore, all complexes were determined to have DNA binding and cleavage activities. Moreover, theoretical DFT computations have also been carried out for the cationic complexes to obtain minimum energy configuration of molecules. The effects of the chemical structures of three cationic complex were also studied in relation to the variable property of electron-donating ligands for ruthenium-based complexes and iridium complex and their potential energy levels in ground and excited states HOMO and LUMO were determined. [Display omitted] • Radical scavenging activity, reducing power, antibacterial effect of the complexes. • DNA binding and cleavage activity of the complexes were studied. • Maximum scavenging activity and reducing power activity with (IL-OPPh 2 -Ru-benzene) • Theoretical DFT computations were carried out for cationic parts of the complexes. • HOMO and LUMO levels were calculated. Mononuclear transition metal complexes based on ionic liquid have been prepared and characterized in detail. The biological properties of the three complexes were evaluated using radical scavenging activity, reducing power, antibacterial effect, DNA binding and cleavage activity. Among the complexes, [3-[(2 R)-2-({[dichloro(η6-benzene)ruthenium]diphenylphosphanyl}oxy)-2-phenylethyl]-1-methyl-1H-imidazol-3-ium chloride] (4), demonstrated the highest radical scavenging (64.7 %) and reducing power activity (0.467) at 200 μg/ml concentration. The highest zone of inhibition was obtained from [3-[(2 R)-2-({[dichloro(η6-p-cymene)ruthenium]diphenyl phosphanyl}oxy)-2-phenylethyl]-1-methyl-1H-imidazol-3-ium chloride] (3) , against Bacillus cereus as 14 mm. Furthermore, all complexes were determined to have DNA binding and cleavage activities. Furthermore, theoretical DFT computations have also been carried out for the cationic complexes, to obtain minimum energy configuration of molecules. The effects of the chemical structures of three cationic complexes were also examined in relation to the variable property of electron-donating ligands for ruthenium-based complexes and iridium complex and their potential energy levels in ground and excited states HOMO and LUMO were determined. [ABSTRACT FROM AUTHOR]

Abstract: A series of new docetaxol analogues have been designed and synthesized. And their cytotoxicities against cancer cells have been evaluated by MTT method. Most of these compounds showed selective inhibitions on human cancer cell lines. Among them, compound 8 exhibited higher inhibitory activity than Paclitaxel (Taxol) against several cancer cell lines. This work indicated that appropriate modification at C-7 and C-10 of docetaxel might be a promising approach for this unique class of anticancer compounds. [Copyright &y& Elsevier]

Abstract: A series of new 2-substituted [4-(1,3,4-oxadiazol-2-yl)methyl]phthalazin-1(2H)-one derivatives 7a–h to 9a–h were designed and synthesized from methyl (4-oxo-3,4-dihydrophthalazin-1-yl)acetate (4), which in was turn prepared from phthalic anhydride. The structure of synthesized new compounds were characterized by spectral data and screened for their antimicrobial activities against various bacteria and fungi strains. Several of these compounds showed antimicrobial activity. [ABSTRACT FROM AUTHOR]

A new hydrazide ligand was prepared to synthesize Ni(II), Hg(II) and UO 2 (II) complexes, which elucidated by all possible tools. Accordingly, 1M:2L molar ratio was suggested for Ni(II) and Hg(II) complexes, while UO 2 (II) complex close to 1:1 ratio. The ligand binds as a bidentate or tridentate mode either as a monobasic via deprotonation of azomethine group or as a neutral with Hg(II) complex. A square-planer geometry was suggested for [Ni(L) 2 ], while the other complexes reveal octahedral geometry. The antimicrobial screening was performed as well as the antioxidant and cytotoxic activity test towards Ehrlich ascites cells. The ligand and its Ni(II) complex produce a notable inhibition for microorganisms, while their antioxidant and cytotoxicity are up to the standards themselves. The DFT/B3LYP and Hartree-Fock (HF) methods were used to optimize the structures under suitable basis sets to obtain essential parameters and 3D-maps. Utilizing Swiss-ADME link reveals the positive response of the ligand to blood brain barrier and human intestinal absorption. Moreover, other silico tests were performed via Pharmacophore and Molecular Operating Environmental module (MOE) against different proteins. Finally, the agreement between vitro and silico results was noticed with the ligand and its Ni(II)complex. [ABSTRACT FROM AUTHOR]

Abstract: There is some evidence to suggest that inducible kinin B1 receptors (B1R) may play beneficial and protecting roles in cardiovascular-related pathologies such as hypertension, diabetes, and ischemic organ diseases. Peptide B1R agonists bearing optimized pharmacological features (high potency, selectivity and stability toward proteolysis) hold promise as valuable therapeutic agents in the treatment of these diseases. In the present study, we used solid-phase methodology to synthesize a series of novel peptide analogues based on the sequence of Sar[dPhe8]desArg9-bradykinin, a relatively stable peptide agonist with moderate affinity for the human B1R. We evaluated the pharmacological properties of these peptides using (1) in vitro competitive binding experiments on recombinant human B1R and B2R (for index of selectivity determination) in transiently transfected human embryonic kidney 293 cells (HEK-293T cells), (2) ex vivo vasomotor assays on isolated human umbilical veins expressing endogenous human B1R, and (3) in vivo blood pressure tests using anesthetized lipopolysaccharide-immunostimulated rabbits. Key chemical modifications at the N-terminus, the positions 3 and 5 on Sar[dPhe8]desArg9-bradykinin led to potent analogues. For example, peptides 18 (SarLys[Hyp3,Cha5, dPhe8]desArg9-bradykinin) and 20 (SarLys[Hyp3,Igl5, dPhe8]desArg9-bradykinin) outperformed the parental molecule in terms of affinity, functional potency and duration of action in vitro and in vivo. These selective agonists should be valuable in future animal and human studies to investigate the potential benefits of B1R activation. [Copyright &y& Elsevier]

Abstract: The effect of (2-hydroxypropyl)-β-cyclodextrin (HP-β-CyD) on the solubility properties and spectroscopic features of hesperetin and its 7-rhamnoglucoside, hesperidin, was qualitatively and quantitatively investigated in water, by means of UV–vis absorption and fluorescence spectroscopy. The stoichiometric ratios and stability constants describing the extent of formation of the complexes have been determined by phase-solubility measurements; in both cases type-AL diagrams have been obtained (soluble 1:1 complexes). The higher degree of interaction showed by hesperetin may be attributed to the higher hydrophobicity and smaller size of the aglycone molecule, which therefore exhibits a greater affinity for the CyD and fits better into the cavity. The effect of molecular encapsulation on the two flavanones antioxidant activity was afterwards evaluated by means of different biological assays, concerned to the different mechanisms of in vivo action. The protection efficacy was in all cases higher for the complexed drugs, with respect to the free ones; these results are of great interest for their potential usefulness in pharmaceutics. [Copyright &y& Elsevier]

: PurposeTo analyze some of the limitations to improvement of the outcome of radiotherapy (RT) expected from the introduction of sophisticated treatment planning and delivery technology.: Methods and materialsSeveral recent examples from the literature were analyzed in some detail. Mathematical modeling techniques were used to assess the likely clinical impact of new technologies or biologic principles. The findings of recent randomized controlled trials of RT for prostate, breast, and rectal cancer were analyzed from the perspective of cost-effectiveness and therapeutic gain.: ResultsThe main findings of the analyses may be summarized as follows. Dosimetric precision should aim for a <2% patient-to-patient variability in the delivered dose. Imprecision in clinical target volume definition remains an obstacle for high-precision RT. Functional imaging and novel biologic assays may facilitate a move from a clinical target volume to the real target volume. Improved target volume coverage is mainly important if RT has high effectiveness. Radiation oncology is increasingly becoming evidence based. However, there is still a long way to go. Hypofractionation in adjuvant RT for breast cancer may represent a favorable balance between cost and benefit. Treatment complications are potentially associated with both suffering and high cost. The identification of high-risk patients would improve the cost-effectiveness of high-tech RT aimed at avoiding complications. Conformal RT may allow the introduction of hypofractionation, which, again, could potentially save resources. With improvement in surgery and more screening-detected cancer cases, the number needed to treat increases, and this will directly affect the cost-effectiveness of high-tech RT unless efficient patient selection can be developed.: ConclusionSustained technological refinement is only likely to be cost-effective if the clinical and biologic understanding of patient-to-patient variability in the risk of specific types of failure and the optimal multimodality approach to handle these risks is developed at the same time. Mathematical modeling together with methods from health technology assessment and health economics are useful complements to standard methods from evidence-based medicine. Progress in functional imaging and in basic and clinical cancer biology is likely to provide the tools required for individualized risk-adapted RT. [Copyright &y& Elsevier]

In this work, gamma sterilization was validated, and the impact of this sterilization process on collagen/hydroxyapatite (Col/HAp) composites was investigated. It has been already recognized that the improper sterilization of healthcare products may lead to infection and mortality/morbidity issues in patients. Gamma sterilization has emerged as a promising sterilization method because it shows advantages such as low cost, a small increase in temperature of irradiated materials, and no production of toxic residues. Moreover, gamma rays can reach the products even when contained in sealed packages. The dose of gamma radiation applied in this study ranged from 17.5 to 50 kGy. The studied samples were examined by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG), and differential scanning calorimetry (DSC). No apparent effect of gamma radiation on HAp was observed even when doses as high as 50 kGy were applied. On the other hand, Col was greatly affected by gamma radiation, displaying cross-linking and degradation after sterilization. These structural changes may alter Col's properties, which could, in turn, impact its medical use. As a consequence, it is strongly recommended that the irradiation dose used to sterilize the Col/HAp composites shall be kept as low as possible to mitigate the structural changes induced in Col. It was noticed that a radiation dose of 17.5 kGy was sufficient to sterilize the examined samples because a sterility assurance level (SAL) below 10−6 was detected. Although dramatic structural changes were observed in Col when this dose was applied, the sterilized samples showed no toxicity to human mesenchymal stem cells. Based on these results, we established a VD Max of 17.5 kGy for Col/HAp-based healthcare products. • Collagen/hydroxyapatite (Col/HAp) composites sterilized with gamma radiation. • Samples irradiated with a cobalt-60 source and doses ranging from 17.5 to 50 kGy. • Col was greatly affected by gamma radiation, showing cross-linking and degradation. • We suggest keeping the radiation dose at 17.5 kGy to mitigate structural changes. • Samples exposed to this radiation level showed biocompatibility to human stem cells. [ABSTRACT FROM AUTHOR]

The oxadiazole pharmacophore is considered a viable lead structure for the synthesis of more efficacious and broad spectrum antimicrobial agents. The significance of this study was to prepare various oxadiazole derivatives by introducing the 1,3,4 oxadiazole core into several molecules to explore the possibilities of some altered biological activities. Therefore, the study presents the synthesis, antimicrobial and antioxidant evaluation of a series of 1,3,4 substituted oxadiazole derivatives. Antimicrobial evaluation revealed that eighteen compounds were able to display variable growth inhibitory effects on the tested Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus , Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli and fungal strains Candida albicans and Aspergillus niger . Among the synthesized derivative analogues 6f , 6l and 6r were found to be the most effective antibacterial agents. While the compounds 6c , 6l and 6q were found to be the most promising antifungal agents. On the other hand, all the synthesized compounds 6a–6r were subjected to antioxidant activity but only analogues 6l and 6q were found to exhibit potent antioxidant activity. Further compound 6l containing p -nitro phenyl moiety along with oxadiazole pharmacophore proved to be the most active antimicrobial and antioxidant agent. [ABSTRACT FROM AUTHOR]