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.

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.

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.

Synthesis and anti human immune virus activity of some new fluorine containing substituted -3-thioxo-1,2,4-triazin-5-ones.

Some new fluorine containing substituted 3-thioxo-1,2,4-triazin-5-ones (2-17) have been synthesized and evaluated for in vitro anti human immune virus (HIV) activity. Most of the new compounds displayed a lethal activity, while compounds 2, 6, 7, 10, 11 and 14 displayed a significant antiviral activity. The structures are supported by elemental analysis, IR, UV and 1H-NMR spectral data.

Synthesis of some new fluorine bearing trisubstituted 3-thioxo-1,2,4-triazin-5-ones as potential anticancer agents.

In a search for new anticancer agents fluorine bearing trisubstituted 3-thioxo-1,2,4-triazin-5-ones (2-12) have been prepared and characterized by their elemental analysis, UV, IR and 1H-NMR spectral data. The in vitro anticancer activity of all the compounds has been determined. Compounds 3 and 7 showed a moderate activity against Leukemia/Lymphoma, Small/Non small Cell Lung, Colon carcinoma and Melanoma Cells.

Synthesis of some new thioethers of 1,2,4-triazine-3-hydrazones and assays for their anticancer and anti human immune virus activities.

A number of various thioethers derived from 3-hydrazone-5,6-diphenyl-1,2,4-triazines have been synthesized and evaluated for anticancer and anti HIV activities. The structures are supported by elemental analysis, IR, UV and 1H-NMR spectral data. Most of the tested compounds displayed a significant activity against Leukemia/Lymphoma, CNS, Ovarian and Small cell lung cancer.

Synthesis of some new 4,6-disubstituted-1,2,4-triazin-3,5(2H) diones and related compounds of potential antifungal activity.

The synthesis of 4-substituted amino-6-styryl/alkyl/aryl-1,2,4-triazin- 3,5(2H)diones (4a-d and 15) involving the cyclocondensation of N4-arylaminosemicarbazides(3a-d and 13) with some alpha-ketoacids is described. The behaviour of these triazinones towards amine, hydrazine, isothiocyanate, aromatic aldehyde and gl. acetic acid have been investigated. Structure elucidation of the new compounds has been carried out with the help of elemental analysis, IR, UV and 1H-NMR spectra. The antifungal activity of the prepared compounds has been assayed both in vitro and in vivo against some phytopathogenic fungi associated with wheat grains, were the compound 3b showed a high protection of the grains of wheat against the fungal infection.

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.

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.

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 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.

Synthesis of some new 1,6-dihydro-3-substituted 6-spiro-(9'-fluorene)-1,2,4-triazin-5-(4H)-ones as potential anti HIV and anticancer drugs.

1,6-Dihydro-3(2H)-thioxo-6-spiro-(9'-fluorene)-1,2,4-triazin -5(4H)-one (1) has been used to synthesize several analogous compounds via nucleophilic substitution reactions. Spectroscopic data are given in support of the proposed structures. Some of the new products possessed good anti HIV and anticancer activities.

Synthesis of some new heterobicyclic compounds containing spiro-1,2,4-triazine moiety as potential anti-HIV and anticancer agents.

A number of heterobicyclic compounds such as 1,3,5-thiazine, thiazolidinone, pyrimidine, pyrimidinedione, imidazole, quinazolinone and 1,2,4-triazinone derivatives have been sythesized by reaction of 1,6-dihydro-3(2H)-thioxo-6-spiro-(9'- fluorene)-1,2,4-triazin-5(4H)-one (1) with sulphur/nitrogen compounds in neutral or alkaline media. Structure elucidation of the new compounds have been carried out with the help of elemental analysis and spectral data. Some of these compounds were tested for in vitro anti HIV and anticancer activities.

Synthesis and biological activity of 1,2,4-triazinotriazinone derivatives.

The synthesis of 1,2,4-triazines bearing a 1,2,4-triazinone moiety and of 1,2,4-triazolo[4,3-b]-1,2,4-triazonones have been achieved by reaction of 1,6-dihydro-3-hydrazino-6-spiro- (9-fluorenyl)-1,2,4-triazin-5(4H)-one with various oxo- and halo-compounds. 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.

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 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.

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.

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.