Synergistic performance of collagen-g-chitosan-glucan fiber biohybrid scaffold with tunable properties.

Hybrid biocomposite scaffolds (HBS) that serve as a carrier for cell proliferation and differentiation are increasingly used for tissue regeneration. 3D hybrid scaffold based on collagen-grafted-chitosan-glucan fiber (CO-g-CGF-HBS) was prepared by freeze-drying technique. The swelling percentage, hydrolytic stability, and modulus of elasticity of HBS were enhanced after the chemical modification of CO with CGF. Pore size and porosity of HBS were decreased with an increased CGF ratio. HBS exhibits a higher reduction rate against different types of bacteria compared with a control sample. Thus, chemical modification of CO with different ratios of CGF significantly improved the physicochemical, antibacterial properties of HBS.

Assessment of POFA -Cementitious material as backfill barrier in DSRS borehole disposal: 226Ra confinement.

Disused Sealed Radioactive Sources (DSRS) borehole disposal is an innovative concept recommended by international atomic energy agency (IAEA) to improve the safety and security of the management end point for these sources. A green application of Palm Oil Fuel Ash (POFA) as a supplementary material for cementitious backfill barrier in DSRS borehole disposal facility is proposed. Samples with up to 50% POFA replacement complied with the mechanical and hydraulic performance requirements for backfill barriers in retrievable radioactive waste disposal facilities. The structures of one year old OPC and optimum OPC-POFA cement backfills were evaluated using FESEM, XRD, EDXRF, BET, and TGA and their 226 Ra confinement performances were assessed. 30% POFA replacement improved the geochemical conditions by reducing competitive Ca2+ release into the disposal environment. It enhanced 226Ra confinement performance independently on the amount of water intrusion or releases below 2% of 1 Ci source. The improved performance is attributed to the higher fraction of active sites of OPC-POFA backfill compared to that of OPC backfill. 226Ra sorption onto C-S-H is irreversible, spontaneous, endothermic, and independent on the degree of the surface filling. The provided experimental data and theoretical analysis proved the feasibility of this green use of POFA in reducing the radiological hazard of 226Ra.

Assessment of Cyanex 301 impregnated resin for its potential use to remove cobalt from aqueous solutions.

The feasibility of using Cyanex 301 impregnated onto biopolymer resin for removing cobalt from radioactive waste streams is investigated. The emulsion compositions for resin preparation were optimized to ensure compliance with nuclear grade resin specifications on particle size distribution and chemical stabilities using multi-variant analysis. The enhanced chemical stabilities of the resins in different solutions are attributed to the interaction between Cyanex 301 and the emulsifier with alginate via a reaction with the glycosidic bond. The structure and morphology of the three optimized samples were studied using FTIR, SEM, and TGA and their end-of-life cycle treatment was preliminarily investigated. Equilibrium sorption investigations revealed that the sorption is taking place via bi-layers onto two sites on the surface layer independently from the cobalt contamination level and the nature of these sites were characterized by determining the energy barriers and fraction of the weak and strong sites. Cobalt adsorption is chemical spontaneous endothermic reaction and the loaded material spectroscopic analysis and thermodynamics calculations referred to chemical coordination and hydrogen bonding. The enhanced radiological stabilities of the optimum resins at irradiation fields <100 KGy were explained and the relations between the loss of exchange capacity and the doses were quantified. The resins could be regenerated using 0.5 M HCl and the effect of the elution cycles on cobalt uptake was presented.

Chitosan-glucan complex hollow fibers reinforced collagen wound dressing embedded with aloe vera. Part I: Preparation and characterization.

Collagen (CO)/chitosan-glucan complex (CSGC) hollow fibers encapsulated aloe vera (AV) dressing scaffold (CO/CSGC@AV) were fabricated for the first time by the freeze-dried process. Extraction process, morphology, mechanical properties, pore size, porosity, swelling ability, and degradation behavior of composites scaffold were investigated. CSGC hollow fibers were extracted from mycelium of Schizophyllum commune CSGC hollow fiber exhibited inner diameter of (600 ±â€¯250 nm) and outer fiber diameter of (2.5 ±â€¯0.5 µm). The results of swelling and hydrolytic degradation studies demonstrated that the physicochemical of CO/CSGC@AV was significantly enhanced by CSGC in a concentration-dependent manner. The mechanical property of the CO/CSGC@AV was improved after encapsulated AV into CSGC hollow fibers compared with native CO. The pore size and porosity of the CO/CSGC@AV were slightly decreased in the presence of AV. All these results suggested that the new dressing scaffold has a potential for clinical skin regeneration, particularly for infected chronic wounds and ulcers.

Electrospinning of hyaluronan/polyvinyl alcohol in presence of in-situ silver nanoparticles: Preparation and characterization.

Novel nanofibers mats were fabricated by electrospinning of polyvinyl alcohol/hyaluronan (PVA/HA) solutions in the presence of silver nanoparticles (AgNPs). The AgNPs were synthesized by in-situ chemical reduction of silver ions (Ag+) using HA as a reducing and stabilizing agent. Narrow size distribution and spherical shape of AgNPs were achieved by optimizing the initial silver nitrate concentration (0.01 to 1 M) and reaction time (10-60 min). HA-AgNPs nanocomposite and PVA/HA-AgNPs nanofibrous mats were fabricated by electrospinning technique from aqueous solution containing a different mass ratio of PVA and HA-AgNPs and characterized by UV/Vis spectroscopy, SEM, TEM, DLS, XRD, TGA, and ATR-FTIR. Mechanical and rheological properties were also investigated and discussed. The novel nanofibrous mats show great potential in skin regeneration and drug carrier applications.

Optimizing the removal of strontium and cesium ions from binary solutions on magnetic nano-zeolite using response surface methodology (RSM) and artificial neural network (ANN).

The feasibility of using magnetic nano-zeolite (MNZ) to remove cesium and strontium from their binary corrosive solutions was investigated by considering the multi-variant/multi-objective nature of the process. RSM (Response Surface Methodology) and ANN (Artificial Neural Network) were used to model and optimize the removal system and assess sensitive parameters that can affect the process reliability. MNZ is characterized by its high surface area and cation exchange capacity and possesses good regeneration behavior for both elements using citric acid. Its stability is comparable to other sorbents in acidic media and the stability increases in alkaline media, where dissolution rate follow first order reaction on heterogeneous sites. MNZ removes both contaminants simultaneously with small tendency toward Cs, where MNZ is suggested for application in pre-treatment of highly contaminated alkaline solutions. The percentage removal, decontamination factors, and separation factors have different dependency on the effluent/process conditions; this dependency is the same for both contaminants. Sorption kinetics is initially controlled by external mass transfer through the boundaries then intra-particle diffusion dominates the reactions. The process sensitivity to pH changes is attributed to changes in structural elements -species distribution at the solid/aqueous interface. Cs+ and Sr+2 are exchanged with Na+ and H+, regardless the effluent pH value, and with Al and Fe cations at specific pH. Isosteric heat of sorption calculations indicated that the total heat needed to complete the reaction was considerably reduced by operating the process at optimized temperature.

A novel in situ silver/hyaluronan bio-nanocomposite fabrics for wound and chronic ulcer dressing: In vitro and in vivo evaluations.

In-situ formed hyaluronan/silver (HA/Ag) nanoparticles (NPs) were used to prepare composite fibers/fabrics for the first time. Different concentrations of silver nitrate (1, 2mg/100ml) were added at ambient temperature to sodium hyaluronate solution (40mg/ml), then the pH was increased to 8 by adding sodium hydroxide. The in-situ formed HA/Ag-NPs were used to prepare fibers/nonwoven fabrics by wet-dry-spinning technique (WDST). UV/vis spectroscopy, SEM, TEM, DLS, XPS, XRD and TGA were employed to characterize the structure and composition of the nanocomposite, surface morphology of fiber/fabrics, particle size of Ag-NPs, chemical interactions of Ag0 and HA functional groups, crystallinity and thermal stability of the wound dressing, respectively. The resultant HA/Ag-NPs1 and HA/Ag-NPs2 composite showed uniformly dispersed throughout HA fiber/fabrics (SEM), an excellent distribution of Ag-NPs with 25±2, nm size (TEM, DLS) and acceptable mechanical properties. The XRD analysis showed that the in-situ preparation of Ag-NPs increased the crystallinity of the resultant fabrics as well as the thermal stability. The antibacterial performance of medical HA/Ag-NPs fabrics was evaluated against gram negative bacteria E. coli K12, exhibiting significant bactericidal activity. The fibers did not show any cytotoxicity against human keratinocyte cell line (HaCaT). In-vivo animal tests indicated that the prepared wound dressing has strong healing efficacy (non-diabetics/diabetics rat model) compared to the plain HA fabrics and greatly accelerated the healing process. Based on our results, the new HA/Ag-NPs-2mg nonwoven wound dressing fabrics can be used in treating wounds and chronic ulcers as well as cell carrier in different biological research and tissue engineering.

Correlation between toxic organochlorine pesticides and breast cancer.

Organochlorines (OCs) are common environmental pollutants that have been linked to cancer. This work aims to assess the role of OCs as a risk factor for breast cancer and to evaluate the cellular changes induced by exposure to such environmental contaminants. The study included 70 cancer patients subjected to thorough history taking and routine investigations. Samples from tumor and normal adjacent tissue were taken to measure OCs' levels and to perform molecular analysis (some oncogenic and apoptotic markers) by flow cytometry. There were significantly higher concentrations of methoxychlor, dichloro-diphenyl-trichloroethane (DDT), hexa-chlorobenzene (HCB), and chlordane in tumor tissue samples compared to the surrounding normal tissue. There was a positive statistically significant correlation between G2m and dichloro-diphenyl-dichloroethane, DDT, and methoxychlor. There was also a negative correlation between propidium iodide (PI) and heptachlor as well as between PI, B-cell lymphoma 2, and methoxychlor. Annexin showed a negative correlation with HCB and methoxychlor. In conclusion, the higher level of organochlorine pesticides in the tissue specimens of breast cancer and the resultant molecular dysfunction highlight a possible association. Further research is warranted to elucidate the other possible mechanisms involved in the process of carcinogenesis.

Synthesis and Evaluation of 1-Substituted-Biguanide Derivatives as Anti-Diabetic Agents for Type II Diabetes Insulin Resistant.

New 1-substituted-biguanide derivatives 1-3 were synthesized by the reaction of 2,4-dimethoxyaniline, hydrazine and methylhydrazine with dicyandiamide in diluted hydrochloric acid. The resulting biguanide salts were fully characterized by spectroscopic methods. The synthesized compounds were screened for their anti-diabetic activity with standard metformin drug. Oral treatment of hyperglycemic rats with the synthesized biguanide derivatives (200 mg/kg/day) for 2 weeks significantly decreased the elevated blood glucose level. Oral administration of biguanide derivative 2 significantly decreased the level of total cholesterol. While, the triglycerides level was little decreased following administration of biguanide 1 as compared to hyperglycemic rats. Additionally, anti-diabetic properties towards liver function enzyme activities (AST and ALT) and kidney functions (urea and critinine) as well as histopathological studies relative to metformin hydrochloride were investigated and discussed.

Prostate stem cell antigen (PSCA) mRNA expression in peripheral blood in patients with benign prostatic hyperplasia and/or prostate cancer.

The aim of this study was to determine whether detection of prostate stem cell antigen (PSCA) expression in BPH might be associated with the subsequent presence of Prostate cancer (PCa) and also to determine whether detection of PSCA expression has potential for prognosis in PCa. This study was comprised of 112 PCa patients, 111 BPH patients and 120 control subjects. We employed reverse-transcriptase polymerase chain reaction (RT-PCR) to detect PSCA mRNA-bearing cells in peripheral blood. PSCA mRNA was detected in the peripheral blood of 71.4% PCa patients and in 13.5% of patients with BPH by RT-PCR. PSCA was positive in 80% of high-grade diseases compared with 20% of low-grade diseases (P = 0.01). Whereas only 38.8% of prostate-confined diseases were PSCA positive, 61.2% of extraprostatic diseases were PSCA positive (P < 0.001). Patients with a lymphovascular invasion of tumor emboli tended to be PSCA positive (P = 0.02). BPH patients with RT-PCR PSCA positive were significantly more likely to develop prostate cancer (OR = 16, 95% CI = 8.1-31.6, P < 0.001). In conclusion, RT-PCR PSCA positivity is significantly associated with the Gleason score, LV tumor emboli and whether or not the tumor was organ confined. In this study, RT-PCR PSCA detection may be a promising tumor marker of diagnostic and metastasis detection for patients with prostate cancer. Also, it may be an important test for predicting BPH patients who are at high risk of subsequent cancer development.

Modeling the long-term leaching behavior of (137)Cs, (60)Co, and (152,154)Eu radionuclides from cement-clay matrices.

Leaching characteristics of some radionuclides that are commonly encountered in radioactive waste streams from immobilized waste matrices in different cement-clay grouts have been assessed to investigate the influence of the clay additives on the leaching behavior of the solid waste matrices. The International Atomic Energy's Agency (IAEA) standard leach method has been employed to study the leach pattern of (137)Cs, (60)Co, and (152,154)Eu radionuclides immobilized in ordinary Portland cement (OPC), OPC-bentonite, and OPC-red clay grouts. The examination of the leaching data revealed that adding clays to OPC reduces the leach pattern as OPC-bentonite

Synthesis of heterobicyclic nitrogen systems bearing the 1,2,4-triazine moiety as anti-HIV and anticancer drugs, part III.

Some new fused heterobicyclic nitrogen systems such as 1,2,4-triazino[3,4-b] [1,3,4] thiadiazolones/thiadiazinones 4-15 and the related compounds 16-21 have been synthesized from treatment of 4-amino-3-mercapto-6-substituted-1,2,4-triazin-5-ones 1 with bifunctional oxygen and halogen compounds via heterocyclization reactions. Structures of the products have been deduced from their elemental analysis and spectral data. Significant anti-HIV and anticancer activities were observed in vitro for some members of the series, compounds 1e, 4e, 4f, 5, 6 and 16 showing a significant activity in Leukemia, Lung, Breast and CNS anticancer evaluation.

Chemistry of uncondensed 1,2,4-triazines, Part IV. Synthesis and chemistry of bioactive 3-amino-1,2,4-triazines and related compounds--an overview.

Studies on the chemical reactivity of bioactive 3-amino-1,2,4-triazines are reviewed. The synthesis, unique features and pharmacological significance of these constituents are discussed.

Role of uncondensed 1,2,4-triazine derivatives as biocidal plant protection agents--a review.

The role of uncondensed 1,2,4-triazine derivatives and the related compounds as biocidal plant protection agents such as herbicides, bactericidal, fungicidal, antimicrobial, protozacides, anticoccidal, parasiticides, insecticides, acaricdes and pesticides, is reviewed.

Role of uncondensed 1,2,4-triazine compounds and related heterobicyclic systems as therapeutic agents--a review.

The role of uncondensed 1,2,4-triazine compounds and related heterobicyclic systems in AIDS and Cancer is reviewed. Their medicinal applications are also reported.

Chemoselective heterocyclization and pharmacological activities of new heterocycles--a review. Part V-Synthesis of biocidal 4-thiazolidinones derivatives.

4-Thiazolidinones have been reported to possess biological activity especially fungicidal activity. With an intention to prepare some more 4-thiazolidinones as drugs for anti HIV and anticancer activity, we have synthesized some more 4-thiazolidinones by the action of mercaptoacetic acid on Schiff's base and/or heterocyclization of N-substituted thioureas with monochloracetic acid. Characterization of 4-thiazolidinone was deduced upon elemental and spectral analysis.

Synthesis and chemistry of fluorine containing bioactive 1,2,4-triazines--an overview. Chemistry of uncondensed 1,2,4-triazines, Part III.

Studies on the chemical reactivity of fluorine containing bioactive 1,2,4-triazines are reviewed. The synthesis, unique features and biological significance of these constituents are discussed.

Synthesis of some new heterobicyclic nitrogen systems bearing the 1,2,4-triazine moiety as anti-HIV and anti-cancer drugs, Part II.

Some new heterobicyclic nitrogen systems 5-18 and/or thioethers 20, 22 bearing the 1,2,4-triazine moiety have been synthesized via condensation of 3-formylamino-1,2,4-triazine 3 with nitrogen compounds followed by heterocyclization with oxygen reagents. Thioether analogs 20, 22 have been obtained from fusion of compound 19 with 4-chlorothiophenol. The structure of the products have been established by elemental analysis and spectral data. The anti-HIV and anticancer activities of some products have also been investigated where compounds 20a, c and 22b exhibited a moderate activity. The biocidal-structures activity correlation was also studied.

Synthesis of heterobicyclic nitrogen systems bearing the 1,2,4-triazine moiety as anti-HIV and anticancer drugs: Part I.

Some new heterobicyclic nitrogen systems bearing the 1,2,4-triazine moiety (3-22) have been achieved by treatment of 3-amino-5,6-disubstituted-1,2,4-triazines 2a-h with some cyclic and acyclic oxygen compounds followed by heterocyclization. Structures of the products have been deduced by elemental analysis and spectral data. Significant anti-HIV and anticancer activities were observed in vitro for some members of the series, where compounds 5 and 18 showed a moderate activity.

Synthesis and antimicrobial activities of some new 2-substituted benzoxazole/benzothiazole derivatives.

In the search for new antimicrobial compounds, several new sulfur bearing heterobicyclic moieties (4-11) have been synthesized by acylation and alkylation of acetamide, thioacetamide and semicarbazide derivatives. The structure of the products was deduced from elemental analyses as well as spectral data (IR, 1H NMR and MS). Significant antimicrobial activities were obtained for all new compounds especially against Fusarium oxysporum.