Madara Jayanetti

The study examined the sustained release of neem from the polymeric carrier system chitosan by varying the drug content, ionic strength of the release medium, and pH. Six different kinetic models, i.e., Korsmeyer–Peppas (KP), Peppas–Sahlin (PS), Higuchi, Hixson–Crowell, Zero order, and First order were used to investigate the drug release kinetics. Based on the R² values, the KP and PS models were chosen from the examined models to study the drug release mechanism from the chitosan biopolymer. The values found for model parameters n and m in the KP and PS models differ noticeably, suggesting that Fickian diffusion and Case II relaxation are important components of the neem release mechanism from chitosan. At lower ionic strengths and lower pH values, neem is released from the composite mostly by Fickian diffusion. The diphenyl-2-picrylhydrazyl assay served to assess the composite’s antioxidant properties. The composite’s antioxidant properties ranged from 3.56 ± 1.89% at 10 μg/mL to 51.28 ± 1.14% at 70 μg/mL. The ability of the composite to inhibit the denaturation of egg albumin was also tested and it ranged from 59.68 ± 0.93% at 25 μg/mL to 187.63 ± 3.53% at 1600 μg/mL. The drug composite has exhibited antibacterial activity against Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, and proved to be highly effective against P. aeruginosa at lower concentrations and against S. aureus at higher concentrations. The resulting inhibition zones for P. aeruginosa at 5 and 10 mg/mL concentrations were 16.5 ± 2.25 mm, and 14.83 ± 0.6 mm, respectively, whereas for S. aureus, it was 16.67 ± 0.33 mm at 20 mg/mL. The neem–chitosan composite’s minimum inhibitory concentration/minimum bactericidal concentration ratio for K. pneumoniae, P. aeruginosa, and S. aureus was greater than 4, suggesting that they trigger bacteriostatic outcomes, whereas for E. coli, it was 4, which means that bactericidal effects were evident.

This study delves into the synergistic amalgamation of Coscinium fenestratum, an Ayurvedic medicinal plant, and chitosan biopolymer. This results in the innovative Venivel Chitosan Composite, which has established a pioneering drug delivery system. Subsequently, the composite material, Venivel Chitosan Composite, was formulated by integrating Coscinium fenestratum extract and chitosan biopolymer. Structural characteristics of Chitosan biopolymer and Venivel Chitosan Composite were determined via scanning electron microscopy (SEM), offering valuable insights into their morphological features. Furthermore, a comprehensive characterization of the composite was achieved through the analysis of X-ray diffraction (XRD) patterns, elucidating its crystalline structure. A meticulous examination of the in vitro drug release profile revealed a predominant diffusion mechanism, indicating the potential suitability of this system for applications in wound healing treatments. In conclusion, integrating Coscinium fenestratum with chitosan biopolymer presents a versatile composite with promising anti bacterial, anti oxidant, and anti - infl ammatory properties, elevating its potential for targeted and controlled ayurvedic drug delivery applications. Keywords: Coscinium fenestratum; Drug delivery; Chitosan

Ilmenite is a mineral whose crystallinity can be altered by chemical treatment, producing TiO2 and iron and titanium-based metal nanocomposites, which are applicable mainly for photocatalysis. Porous and crystalline biomass-derived carbon materials include graphene oxide, reduced graphene oxide, graphitic carbon nitride, catalytically graphitized sucrose and chitosan, and activated carbon. Ilmenite-based metal oxides coupled with biomass-based carbon materials are effective in environmental remediation, especially in dye photodegradation, adsorption, and antibacterial activity. This review summarizes the synthesis and applications of ilmenite and biomass-based composites nanomaterials.

Amaranthus viridis L., belongs to the family Amaranthaceae is a perennial edible plant, and traditionally used for medicinal treatments in South Asia. Despite the significant uses of the plant, availability of scientific data on plant's biological efficiency is lacking in the scientific domain. There is a higher potential and demand for dehydrated value-added products from the local and international market. Hence, the objective of the research was to determine the impact of pretreatments and dehydration on nutritional composition, phytochemical profile, antioxidant activity, and enzyme inhibitory activity of A.viridis leaves. Magnesium oxide 0.1% (w/v), sodium bicarbonate 0.1% (w/v) and potassium metabisulphite 0.5% (w/v) were selected as the best pretreatment based on the experiments. The pretreated leaves were steam blanched (5 min), followed by dehydration at 60 ± 1°C for 12 hours. Protein (21.90 ± 1.01%db), fat (3.70 ± 0.02%db), fiber (5.90 ± 0.05%db), ash (11.30 ± 0.12%db) and carbohydrate (49.24 ± 0.08%db) were determined. Data was statistically analyzed using one-way analysis of variance (ANOVA) test at a 95% confidence level (p < 0.05). A qualitative phytochemical analysis was conducted. The total phenolic content, 5.89 ± 0.30 mg in Gallic acid equivalents per 1g was determined in pretreated, dehydrated powder. FRAP, DPPH radical scavenging activity and ferrous ion chelating activity of the methanolic extract were 20.22 ± 0.45 mg Trolox equivalents, 1.68 ± 0.07 mg in Trolox equivalents and 3.83 ± 0.06 mg EDTA equivalents per 1g of pretreated dehydrated leaf powder, respectively. Methanolic extract (500 μg/mL) showed inhibitory activity of 25.30 ± 0.60% on 5-lipoxygenase, 30.80 ± 0.50% on alpha-amylase and 25.60 ± 0.40% on alpha-glucosidase. Inhibitory activity was not detected against lipase, acetylcholine esterase and butyrylcholinesterase enzymes. In conclusion, pretreated, dehydrated, A. viridis leaves are recommended as a health beneficial food ingredient.

Fabrication of chitosan and ilmenite sand-based novel photocatalysts through the catalytic graphitization of chitosan is reported. Nanocomposites consisted of TiO₂, Fe₂O₃ and Fe nanoparticles dispersed on a nitrogen-doped graphitic carbon framework. The surface area, pore volume and macropore structure of the carbon matrix is disturbed by the heterogeneously distributed nanoparticles. The extent of graphitization expanded with increasing metal loading as indicated by variation in the I_D/I_G ratio. The nanomaterial’s surface consists of Fe³⁺ and Ti⁴⁺, and graphitic, pyridinic and pyrrolic nitrogen were found in the carbon matrix. The band gap values of the composites varied in the 2.06–2.26 eV range. The photocatalytic activity of the synthesized nanomaterials was determined, and the highest rate constant for the photodegradation of methylene blue under sunlight was 4.4 × 10⁻³ min⁻¹, which resulted with 10 mg/L MB and 25 mg of the best-performing catalyst. The rate constant rose with increasing concentrations of persulfate added to the medium. The rate constant greatly diminished with the addition of isopropyl alcohol as it scavenged hydroxyl radicals. The presence of co-pollutants including Pb²⁺, rhodamine B, PO₄³⁻ and Cl⁻ curtailed the rate of reaction. The activity reduced with an increasing number of uses of the catalyst.

Hematite (α-Fe₂O₃) and pseudobrookite (Fe₂TiO₅) suffer from poor charge transport and a high recombination effect under visible light irradiation. This study investigates the design and production of a 2D graphene-like r-GO/GO coupled α-Fe₂O₃/Fe₂TiO₅ heterojunction composite with better charge separation. It uses a simple sonochemical and hydrothermal approach followed by L-ascorbic acid chemical reduction pathway. The advantageous band offset of the α-Fe₂O₃/Fe₂TiO₅ (TF) nanocomposite between α-Fe₂O₃ and Fe₂TiO₅ forms a Type-II heterojunction at the Fe₂O₃/Fe₂TiO₅ interface, which efficiently promotes electron-hole separation. Importantly, very corrosive acid leachate resulting from the hydrochloric acid leaching of ilmenite sand, was successfully exploited to fabricate α-Fe₂O₃/Fe₂TiO₅ heterojunction. In this paper, a straightforward synthesis strategy was employed to create 2D graphene-like reduced graphene oxide (r-GO) from Ceylon graphite. The two-step process comprises oxidation of graphite to graphene oxide (GO) using the improved Hummer’s method, followed by controlled reduction of GO to r-GO using L-ascorbic acid. Before the reduction of GO to the r-GO, the surface of TF heterojunction was coupled with GO and was allowed for the controlled L-ascorbic acid reduction to yield r-GO/GO/α-Fe₂O₃/Fe₂TiO₅ nanocomposite. Under visible light illumination, the photocatalytic performance of the 30% GO/TF loaded composite material greatly improved (1240 Wcm⁻²). Field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) examined the morphological characteristics of fabricated composites. X-ray photoelectron spectroscopy (XPS), Raman, X-ray diffraction (XRD), X-ray fluorescence (XRF), and diffuse reflectance spectroscopy (DRS) served to analyze the structural features of the produced composites.