Development of Antibacterial,Degradable and pH-Responsive Chitosan/Guar Gum/Polyvinyl Alcohol Blended Hydrogels for Wound Dressing

The present research is based on the fabrication preparation of CS/PVA/GG blended hydrogel with nontoxic tetra orthosilicate (TEOS) for sustained paracetamol release. Different TEOS percentages were used because of their nontoxic behavior to study newly designed hydrogels’ crosslinking and physicochemical properties. These hydrogels were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and wetting to determine the functional, surface morphology, hydrophilic, or hydrophobic properties. The swelling analysis in different media, degradation in PBS, and drug release kinetics were conducted to observe their response against corresponding media. The FTIR analysis confirmed the components added and crosslinking between them, and surface morphology confirmed different surface and wetting behavior due to different crosslinking. In various solvents, including water, buffer, and electrolyte solutions, the swelling behaviour of hydrogel was investigated and observed that TEOS amount caused less hydrogel swelling. In acidic pH, hydrogels swell the most, while they swell the least at pH 7 or higher. These hydrogels are pH-sensitive and appropriate for controlled drug release. These hydrogels demonstrated that, as the ionic concentration was increased, swelling decreased due to decreased osmotic pressure in various electrolyte solutions. The antimicrobial analysis revealed that these hydrogels are highly antibacterial against Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram negative (Pseudomonas aeruginosa and Escherichia coli) bacterial strains. The drug release mechanism was 98% in phosphate buffer saline (PBS) media at pH 7.4 in 140 min. To analyze drug release behaviour, the drug release kinetics was assessed against different mathematical models (such as zero and first order, Higuchi, Baker–Lonsdale, Hixson, and Peppas). It was found that hydrogel (CPG2) follows the Peppas model with the highest value of regression (R² = 0.98509). Hence, from the results, these hydrogels could be a potential biomaterial for wound dressing in biomedical applications.     

Scarlet Flax Linum grandiflorum (L.) In Vitro Cultures as a New Source of Antioxidant and Anti-Inflammatory Lignans

In vitro cultures of scarlet flax (Linum grandiflorum L.), an important ornamental flax, have been established as a new possible valuable resource of lignans and neolignans for antioxidant and anti-inflammatory applications. The callogenic potential at different concentrations of α-naphthalene acetic acid (NAA) and thidiazuron (TDZ), alone or in combinations, was evaluated using both L. grandiflorum hypocotyl and cotyledon explants. A higher callus induction frequency was observed on NAA than TDZ, especially for hypocotyl explants, with a maximum frequency (i.e., 95.2%) on 1.0 mg/L of NAA. The presence of NAA (1.0 mg/L) in conjunction with TDZ tended to increase the frequency of callogenesis relative to TDZ alone, but never reached the values observed with NAA alone, thereby indicating the lack of synergy between these two plant growth regulators (PGRs). Similarly, in terms of biomass, NAA was more effective than TDZ, with a maximum accumulation of biomass registered for medium supplemented with 1.0 mg/L of NAA using hypocotyls as initial explants (DW: 13.1 g). However, for biomass, a synergy between the two PGRs was observed, particularly for cotyledon-derived explants and for the lowest concentrations of TDZ. The influence of these two PGRs on callogenesis and biomass is discussed. The HPLC analysis confirmed the presence of lignans (secoisolariciresinol (SECO) and lariciresinol (LARI) and neolignan (dehydrodiconiferyl alcohol [DCA]) naturally accumulated in their glycoside forms. Furthermore, the antioxidant activities performed for both hypocotyl- and cotyledon-derived cultures were also found maximal (DPPH: 89.5%, FRAP 866: µM TEAC, ABTS: 456 µM TEAC) in hypocotyl-derived callus cultures as compared with callus obtained from cotyledon explants. Moreover, the anti-inflammatory activities revealed high inhibition (COX-1: 47.4% and COX-2: 51.1%) for extract of hypocotyl-derived callus cultures at 2.5 mg/L TDZ. The anti-inflammatory action against COX-1 and COX-2 was supported by the IC₅₀ values. This report provides a viable approach for enhanced biomass accumulation and efficient production of (neo)lignans in L. grandiflorum callus cultures.     

Phase Transition Behavior of a New Monotropic Liquid Crystal by Inverse GC

A new monotropic liquid crystal with crown ether substituent called Substance M was synthetized and characterized by several methods: ¹H NMR, hot stage polarizing microscopy, differential scanning calorimetry and inverse gas chromatography. Annealing experiments with inverse gas chromatography confirmed the monotropic behavior of the compound. Isothermally in the nematic state, solute probes chosen were chromatographed after different heating times. The changes of the corresponding retention times were studied.     

FTIR analysis of natural and synthetic collagen

Collagen is the most abundant protein in humans and animals, comprising of one third of the total proteins that accounts for three quarters of the dry weight skin in humans. Collagen containing a range of proteins has been reported for tissue engineering applications, but, only a small number of studies related to chemical structure evaluation of collagen are found in the literature. Collagen can be obtained from both the natural and synthetic sources and offers a wide range of biomedical applications due to its excellent biocompatibility and low immunogenicity. Hence, it is important to identify chemical structural properties of collagen and Fourier transform infrared (FTIR) appears to be a technique of choice to study their chemical structure. This review aims to highlight the use of FTIR to study collagen-based biomaterials, using it for characterization of collagen extracted from various sources. Characterization of collagen-based materials used in wound healing, skin substitutes, derma fillers, and aging of skin, collagen containing drug delivery agents, collagen-based materials used in tissue engineering, bone regeneration, and osteogenic differentiation is discussed in detail. FTIR analysis of collagen-containing materials used for dental applications, cleft-palate, and in alveolar-ridge preservation has also been highlighted.     

Influence of rare earth Ce on structural, electrical and magnetic properties of Sr based W-type hexagonal ferrites

A series of single phase W-type Sr_3−xCe_xFe₁₆O₂₇ (x=0, 0.02, 0.04, 0.06, 0.08, 0.10) hexagonal ferrites prepared by the Sol-Gel method was sintered at 1050 °C for 5 h. The X-ray diffraction analysis reveals that all the samples belong to the family of W-type hexagonal ferrites. The c/a ratio falls in the range of W-type hexagonal ferrites. The grain size was measured by SEM varies from 0.7684 to 0.4366 μm which shows that the Ce³⁺ substituted samples have smaller grain size than pure ferrite Sr₃Fe₁₆O₂₇ which results from the difference in ionic radii of Ce³⁺ (1.034 Å) and Sr²⁺ (1.12 Å). The room temperature resistivity of the present samples varies from 6.5×10⁸ to 272×10⁸ Ω-cm. The coercivity increases from 1370 to 1993 Oe which is consistent with the decrease in grain size. The coercivity values indicate that the present samples fall in the range of hard ferrites. The large value of H_c may be due to domain wall pinning at the grain boundaries.     

Synthesis and antiviral screening of some novel pyridazine and triazolopyridazine nucleosides

Some novel cyclic and acyclic pyridazine and triazolopyridazine nucleoside derivatives were prepared. Some of the prepared products were selected and tested for antiviral activity against herpes simplex virus type‐1 (HSV‐1) and hepatitis‐A virus (HAV, MBB‐cell culture adapted strain). Plaque reduction infectivity assay was used to determine virus count reduction as a result of treatment with test compounds. Compound 15 showed the highest effect on the HAV than the other tested compounds. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:274–282, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20296     

Novel functionalized cellulose derivatives fabricated with Cu nanoparticles: synthesis,characterization and degradation of organic pollutants

Cellulose - In this study, microcrystalline cellulose (MCC) was modified to oxidized cellulose (OC), 6-deoxycellulose hydrazide and 6-deoxycellulose (N,N-diethyl)amine (MCC-Hyd and MCC-DEM)...     

Influence of various diet regimens on deterioration of hepatic function and hematological parameters following carbon tetrachloride: a potential protective role of natural honey

The objective was to assess the effects of commercial regular diet as control, total food restriction with honey, commercial regular diet with dextrose, or total food restriction with dextrose, on blood variables after carbon tetrachloride (CCl4) administration. Sprague Dawley albino rats were divided into four groups, 10 rats each; Group 1 rats were on commercial regular diet, Group 2 rats were on commercial regular diet with 50% dextrose, Group 3 rats were on total food restriction with 50% dextrose, and Group 4 rats were on total food restriction with 50% honey. Rats in all the groups were i.m. administered CCL4 (2.4 mL kg b. wt.-1). Blood tests including ALT, AST, serum albumin, serum protein, BUN, blood glucose (BG), hemoglobin (Hb), and white blood cell (WBC) were performed before CCl4 administration and repeated after 48 and 96 h of post-injection. In Group 1, CCl4 caused significant elevation in AST and ALT, and decrease in BS, WBC, and BUN; lower elevation in AST and ALT at 48 h and decreased AST and ALT at 96 h were obtained when dextrose was added to commercial regular diet (Group 2). Using dextrose alone (Group 3), though there was significant elevation of AST and ALT and decrease in BUN and WBC as compared to baseline values, significant decrease in ALT, AST, and BUN as compared to control was obtained. During absolute honey feeding (Group 4), elevation in AST and ALT obtained, following CCl4 administration was significantly less than the values obtained in all other groups; with lower elevation in AST and ALT as compared to baseline values. Honey increased serum albumin, serum protein, BG, and caused lower reduction in Hb. Conclusively, exclusive honey feeding (50% concentration) significantly modifies and ameliorates biochemical and hematological changes obtained after CCl4 injection.     

Biology-oriented drug synthesis (BIODS), in vitro urease inhibitory activity,and in silico studies on ibuprofen derivatives

Molecular Diversity - Novel ibuprofen derivatives 1–19 including ibuprofen hydrazide 1, and substituted thiourea derivatives 2–19 were synthesized and characterized by EI-MS, FAB-MS,...     

Entangled coherent states for quantum information processing

Entangled coherent states (ECSs) with relative phase equal to the phase shift between two coherent states are constructed. We study the degree of entanglement and the nonclassical features exhibited by the so-constructed states keeping in view their role in quantum information processing (QIP).