Differential Scanning Calorimetric Studies Research Articles

Arylazo-3,5-diphenylpyrazole Derivatives: Molecular Probes Exhibiting Reversible Light-induced Phase Transitions for Energy Storage and Direct Photolithographic Patterning.

We report azopyrazole photoswitches decorated with variable N-alkyl and alkoxy chains (for hydrophobic interactions) and phenyl substituents on the pyrazoles (enabling π-π stacking), showing efficient bidirectional photoswitching and reversible light-induced phase transition (LIPT). Extensive spectroscopic, microscopic, and diffraction studies and computations confirmed the manifestation of molecular-level interactions and photoisomerization into macroscopic changes leading to the LIPT phenomena. Using differential scanning calorimetric (DSC) studies, the energetics associated with those accompanying processes were estimated. The long half-lives of Z isomers, high energy contents for isomerization and phase transitions, and the stability of phases over an extended temperature range (-60 to 80 °C) make them excellent candidates for energy storage and release applications. Remarkably, the difference in the solubility of the distinct phases in one of the derivatives allowed us to utilize it as a photoresist in photolithography applications on diverse substrates.

Synthesis of iron loaded jackfruit peel biochar through microwave heating as a stable and active heterogenous Fenton catalyst for dye degradation

Iron-loaded biochar derived from jackfruit peels (Fe-JP) was synthesised by pyrolysis in a microwave furnace and iron was loaded onto the peels prior to pyrolysis, facilitated by sonication. The primary objective of the investigation was to examine the degradation process of methylene blue (MB) dye and Acid Red 1 (AR1) dye by the using Fe-JP biochar as a heterogeneous Fenton catalyst. The investigation encompassed an examination of the impact of different operating parameters, such as pH, catalyst dosage, and H2O2 concentration. The synthesised Fenton catalyst underwent characterization using Field Emission scanning electron microscopy (FESEM), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques, Fourier transform infrared (FTIR) spectra analysis, Raman spectroscopy, Brunauer-Emmet-Teller (BET) analysis. At a pH of 3, using an initial MB dye concentration of 20 mg/L and initial AR1 dye concentration of 50 mg/L, an 8 mM H2O2 concentration, and a catalyst dose of 2 g/L, the maximum dye removal efficiency reached 96.5 % and 98 % respectively, while the total organic carbon (TOC) removal efficiency reached 68.5 % and 75 % respectively. The observed reaction time under the given experimental conditions was 120 min. The thermal stability of the biochar catalyst was found to be excellent based on the Thermogravimetric analysis (TGA) and Differential Scanning Calorimeter (DSC) studies. The catalysts that were developed demonstrated remarkable durability and negligible leaching of iron, hence enabling their repeated usage in subsequent cycles. The findings of the investigation suggest that the primary mechanism responsible for the degradation of the dye was the surface-based heterogeneous Fenton activity. Additionally, the effect of adsorption on the elimination of colour under varying pH conditions was examined, which had a very low influence in dye degradation (<30 %). The conducted scavenging investigations in the research have indicated the major involvement of hydroxyl radicals (OH) in the degradation process, followed by surface-bound hydroxyl radicals (OHsurface), superoxide radicals (O2−) and ultimately by singlet oxygen radicals (1O2). The study's economic analysis demonstrated that using microwave mode of heating for catalyst synthesis is both green and cost-effective. This observation suggests the possibility of practical implications in the domain of dye degradation.

Impact of Ionic Liquids on the Physicochemical Behavior of Vesicles.

The effects of two ionic liquids (ILs), 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) and 1-butyl-1-methyl pyrrolidinium tetrafluoroborate ([bmp]BF4), on a mixture of phospholipids (PLs) 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), and 1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol (DPPG) (6:3:1, M/M/M, 70% PL) in combination with 30 mol % cholesterol (CHOL) were investigated in the form of a solvent-spread monolayer and bilayer (vesicle). Surface pressure (π)-area (A) isotherm studies, using a Langmuir surface balance, revealed the formation of an expanded monolayer, while the cationic moiety of the IL molecules could electrostatically and hydrophobically bind to the PLs on the palisade layer. Turbidity, dynamic light scattering (size, ζ-potential, and polydispersity index), electron microscopy, small-angle X-ray/neutron scattering, fluorescence spectroscopy, and differential scanning calorimetric studies were carried out to evaluate the effects of IL on the structural organization of bilayer in the vesicles. The ILs could induce vesicle aggregation by acting as a "glue" at lower concentrations (<1.5 mM), while at higher concentrations, the ILs disrupt the bilayer structure. Besides, ILs could result in the thinning of the bilayer, evidenced from the scattering studies. Steady-state fluorescence anisotropy and lifetime studies suggest asymmetric insertion of ILs into the lipid bilayer. MTT assay using human blood lymphocytes indicates the safe application of vesicles in the presence of ILs, with a minimal toxicity of up to 2.5 mM IL in the dispersion. These results are proposed to have applications in the field of drug delivery systems with benign environmental impact.

Synthesis, characterization and film preparation of 6FDA-based polyimides with polar groups arranged for thermal crosslinking

Abstract Thermal crosslinking of polyimides is a relevant methodology to increase their chemical resistance. This reaction is induced by heating after polymerization. Although this reaction is considered a viable route to modify polyimides, there is controversy over the specific temperature for the reaction. To contribute to the knowledge of crosslinked structures, we performed a differential scanning calorimetric (DSC) and solubility test studies on a series of polyimides with different molar ratios of carboxylic acid groups. With 3,5-diaminobenzoic acid (DABA) as a source of carboxylic acid groups, the copolyimides were synthesized from 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 4,4ʹ-hexafluoropropylidenebis(p-phenylenoxy)dianiline (6FPA) to form blocks of 6FDA:6FPA (n) and 6FDA:DABA (m) from m = 0–100 %. Flat films were prepared at 50 ± 3 µm with polyimides. In the thermogram of the flat films, a heat absorption zone associated with the decarboxylation reaction was identified with an endothermic minimum at 260 °C, which was assigned to the crosslinking temperature. Furthermore, heating time was varied for 3–36 h to determine the insolubility of the thermally crosslinked polyimide; from 24 h of heating the polyimide were insoluble. The polyimides were thoroughly characterized by ATR-FTIR, 1H NMR, TGA, SEM, the fractional free volume (FFV) was determined by the Bondi’s group contribution method and solubility to different organic solvents. The FFV of crosslinked polyimides increases relative to pristine polyimides by 2 % for those with higher DABA content and 40 % for those with lower DABA content. Finally, also the glass transition temperature increases in the crosslinked polyimides relative to the pristine ones from 280 °C for the lowest DABA content to 402 °C for the highest DABA content, demonstrating the increase in the thermal resistance of the structure.

Structure, Self-Assembly, and Phase Behavior of Neuroactive N-Acyl GABAs: Doxorubicin Encapsulation in NPGABA/DPPC Liposomes and Release Studies.

N-Acylated amino acids and neurotransmitters in mammals exert significant biological effects on the nervous system, immune responses, and vasculature. N-Acyl derivatives of γ-aminobutyric acid (N-acyl GABA), which belong to both classes mentioned above, are prominent among them. In this work, a homologous series of N-acyl GABAs bearing saturated N-acyl chains (C8-C18) have been synthesized and characterized with respect to self-assembly, thermotropic phase behavior, and supramolecular organization. Differential scanning calorimetric studies revealed that the transition enthalpies and entropies of N-acyl GABAs are linearly dependent on the acyl chain length. The crystal structure of N-tridecanoyl GABA showed that the molecules are packed in bilayers with the acyl chains aligned parallel to the bilayer normal and that the carboxyl groups from opposite layers associate to form dimeric structures involving strong O-H···O hydrogen bonds. In addition, N-H···O and C-H···O hydrogen bonds between amide moieties of adjacent molecules within each layer stabilize the molecular packing. Powder X-ray diffraction studies showed odd-even alternation in the d spacings, suggesting that the odd chain and even chain compounds pack differently. Equimolar mixtures of N-palmitoyl GABA and dipalmitoylphosphatidylcholine (DPPC) were found to form stable unilamellar vesicles with diameters of ∼300-340 nm, which could encapsulate doxorubicin, an anticancer drug, with higher efficiency and better release characteristics than DPPC liposomes at physiologically relevant pH. These liposomes exhibit faster release of doxorubicin at acidic pH (<7.0), indicating their potential utility as drug carriers in cancer chemotherapy.

Thermodynamic phase equilibria study of Hythane (methane + hydrogen) gas hydrates for enhanced energy storage applications

Hydrogen blending with natural gas has become an effective technique for incorporating the characteristics of natural gas and facilitating the storage and transportation of hydrogen gas. The transportation of hydrogen and natural gas (methane) blend, also referred to as Hythane, presents numerous challenges, advantages, and disadvantages that differ based on the technology employed. The current research showcased a thorough examination of the thermodynamics involved in studying the three phase equilibrium analysis of gas hydrate technology for storing Hythane gas mixtures. Three different Hythane compositions varying in hydrogen percentage were selected, and the isochoric gas hydrate phase equilibria study was performed. The experimental results of phase equilibria and thermodynamic modelling using CPA EOS in software were compared. A similar study was also conducted in the presence of a 5.56 mol % THF solution to understand the reduction in the pressure requirement for the phase equilibria. Results from the mixed Hythane+THF gas hydrate findings suggested stable gas hydrate formation at much lower pressure requirements, increasing the credibility of storing Hythane mixtures in gas hydrates at moderate conditions. The gas compositions for each experiment were analyzed using gas chromatography to evaluate the presence of the desired gas in the hydrate phase. Heat exchange during the gas hydrate dissociation was analyzed using a high pressure differential scanning calorimeter (DSC). The change in the heat release temperature also indicates the stability of the gas hydrate, and with increasing hydrogen gas in the blend, the gas hydrate stability decreased. The Clausius-Clapeyron equation was employed to compute the heat of gas hydrate dissociation, and a comparison was made with the heat of dissociation obtained from the DSC study. The experimental investigations on Hythane gas hydrates were performed to find the hydrogen storage inside the gas hydrate phase and compare it with the previous studies of pure hydrogen hydrates. To demonstrate the Hythane gas transportation, Hythane gas hydrate pellets were formed, followed by their storage in a controlled environment to observeany changes in pressure and temperature. The Hythane gas hydrate pellets demonstrated exceptional stability of Hythane gas presenting an intriguing prospect for utilizing gas hydrate technology in Hythane gas transportation.

Effect of temperature and pH on the structure and stability of tumor-specific lectin jacalin and insights into the location of its tryptophan residues: CD, DSC and fluorescence studies

Jacalin, the jackfruit seed lectin, exhibits high specificity for the tumor-specific T-antigen and is used in various biomedical and biotechnological applications. Here, we report biophysical studies on the thermal unfolding of jacalin and the effect of pH and temperature on its secondary structure. Differential scanning calorimetric (DSC) studies revealed that native jacalin unfolds at ∼60 °C and that carbohydrate binding stabilizes the protein structure. Circular dichroism spectroscopic studies indicated that the secondary structure of jacalin remains mostly unaffected over pH 2.0–9.0, whereas considerable changes were observed in the tertiary structure. DSC experiments demonstrated that jacalin exhibits two overlapping transitions between pH 2 and 5, which could be attributed to dissociation of the tetrameric protein into subunits and their unfolding. Interestingly, only one transition between pH 6 and 9 was observed, suggesting that the subunit dissociation and unfolding occur simultaneously. While quenching of the protein intrinsic fluorescence by acrylamide increased significantly upon carbohydrate binding, quenching by succinimide is essentially unaffected. We attribute this difference to increased exposure of Trp-123 in the α-chain as it is involved in carbohydrate binding. Both acrylamide and succinimide gave biphasic Stern-Volmer plots, consistent with differential accessibility of the two tryptophan residues of jacalin to them.

Varied optical features and mechanofluorochromism in dicyanovinyl- vs. cyanoacrylicacid-linked twisted π-conjugates: A potential reusable platform for security applications

The dicyanovinyl-linked π-conjugates [DCV, =C(CN)2] are well identified as a stimuli/environment-sensitive fluorophore, while cyanoacrylic acid (CAA) -linked π-conjugates are hardly found. This study focuses on the diversity of solvatochromic, AIE- and mechanofluorochromic (MFC) features between DCV and CAA-linked conformationally twisted small π-conjugates. The creation of MFC-active smart molecules by tuning functionality has received considerable attention owing to its versatile applicability. While DCV-linked fluorophore TCN displays an impressive solvatofluorochromic property, CAA-linked analog TCNA showed no trend due to inter/intramolecular H-bonding. The TCN revealed AIE and a reversible MFC feature upon grinding with a significant bathochromic shift of 51 nm. Moreover, a 32 nm absorption shift was visually detected under ambient light after applying mechanical force (grinding). The non-AIEgen TCNA is emissive in the solid state but exhibited no emission/absorption shift after grinding. All the observed facts were supported by interpreting the molecular structures, crystal packing, powder X-ray diffraction data, and differential scanning calorimetric (DSC) studies. In addition, the DFT/TDDFT calculations were performed to support these outcomes. Finally, TCN is realized as a favorable platform for security writing/piezo patterning for anticounterfeiting applications.

Compressive Stress Dewaterability Limit in Fluid Fine Tailings

Reclamation of fluid fine tailing (FFT) storage facilities to their pre-disturbance equivalent landforms is hampered because micrometer size fines, whose surface-area-to-volume ratio is remarkably high, are occupied with siloxane and hydroxy groups, which bind water strongly. The purpose of this study is to differentiate the forms of water physically distributions in FFT and determine their propensities for dewaterability under compressive stresses. Two thermal and two mechanical methods were used to analyze water distributions in FFT. Dynamic and isothermal thermogravimetric analyses of FFT gave a transition from predominately bulk water to coevolution with water of higher enthalpy of vaporization at 81% (w/w) solids. Differential scanning calorimeter studies were used to determine the non-freezable water amount, with the premise that water that does not freeze by −30 °C is also unlikely to be removable by compressive stresses encountered in tailing treatment processes. The solid weight percent of FFTs with the non-freezable water was 79.6%. A 1D finite-strain model simulation using the constitutive relations of void ratio and effective stress, void ratio, and hydraulic conductivity show that deep-pits filled with such clayey-silt FFT will consolidate to a maximum solids content of 74% (w/w). For separation by centrifugation, the solids content plateaued to a mean of 74% (w/w) for total centrifugal force of ≥30 mega Newtons. These solid contents represent upper thresholds and demonstrate dewatering limit property of an FFT under compressive stresses.

Design and Evaluation of Tretinoin Fatty Acid Vesicles for the Topical Treatment of Psoriasis

The goal of the current study was to explore the potential benefits of Tretinoin (Tre) fatty acid vesicles (Tre-FAV) as a prospective antipsoriatic topical delivery system. This promising system can counteract the drug challenges in terms of its extremely low aqueous solubility, instability, skin irritation, and serious systemic adverse effects. Tre-loaded fatty acid vesicles were successfully developed and entirely characterised. The selected formulation was investigated for in vitro release, ex vivo skin retention and psoriasis efficacy studies. The characterisation results of Tre-FAV showed it has a globular shape with a particle size of 126.37 ± 1.290 nm (0.188 ± 0.019 PDI). The entrapment efficiency and zeta potential were discovered to be 84.26 ± 0.816% and −28.9 ± 1.92 mV, respectively. Encapsulation of the drug in the fatty acid vesicles was also strengthened by differential scanning calorimetric and powder FTIR diffraction studies. In vitro release results showed that Tre-FAV significantly increased skin absorption and retention in comparison to the Tre solution. The topical application of Tre-FAV to a mouse model confirmed that it has superior in vivo antipsoriatic properties in terms of well-demarcated papules, erythema and reduced epidermal thickness in comparison to other treatments. The weight of the spleen and the levels of the cytokines IL-17 and IL-6 decreased after treatment. In conclusion, FAV dramatically increased the water solubility and skin permeability of Tre and its anti-psoriasis activity.

Preparation of chondroitin sulfate and polyvinyl alcohol hydrogels as drug carriers

The chondroitin sulfate/polyvinyl alcohol based pH-sensitive hydrogels (CHS/PVA hydrogels) were synthesized by a free radical polymerization technique for controlled delivery of diclofenac sodium up to 72 h. Polymers chondroitin sulfate and polyvinyl alcohol were crosslinked with monomer acrylic acid by a cross-linker ethylene glycol dimethylacrylate in the presence of initiator ammonium persulfate. The process of polymerization was continued for 24 h at 65 °C. Fourier transform infrared spectroscopy (FTIR) indicated successful polymerization and crosslinking among the hydrogel contents. Differential scanning calorimetric (DSC) and thermogravimetric analysis (TGA) studies demonstrated that fabricated hydrogel has higher thermal stability. The pH sensitivity of designed CHS/PVA hydrogel was investigated by performing dynamic swelling and in vitro drug release tests in pH 1.2, 4.6, and 7.4 medium. Maximum swelling was observed at pH 7.4 when compared to pH 1.2 and 4.6. The sequence of drug release from the developed hydrogel was; pH 7.4 > 4.6 > 1.2. It has been shown that porosity, swelling, and release rate of diclofenac increased with the addition of chondroitin sulfate and acrylic acid, while decreased with increasing PVA composition. Cytotoxicity studies showed that the prepared hydrogel has no toxic effect on T84. Therefore, it can be demonstrated from the results that the CHS/PVA cross-linked hydrogel can be considered as a potential delivery carrier for the controlled release of diclofenac sodium.

Formulation of multicomponent inclusion complex of cyclodextrin-amino acid with Chrysin: Physicochemical characterization, cell viability and apoptosis assessment in human primary glioblastoma cell line

Chrysin (CR) is a water-insoluble drug reported for different therapeutic effects. The microwave irradiation method was used in this study to create a multicomponent inclusion complex (CR-MC) containing CR (drug) and carrier hydroxyl propyl beta cyclodextrin (HP β CD) and L-arginine (LA). The prepared inclusion complex (CR-MC) was evaluated for dissolution study and results were compared with chrysin physical mixture (CR-PM). Further, the samples were assessed for infra-red (IR), nuclear magnetic resonance (NMR), differential scanning calorimeter (DSC), scanning electron microscope (SEM) and molecular docking. Finally, the cell viability, reactive oxygen species and flow cytometer studies were also assessed to check the potential of the prepared inclusion complex on the human primary glioblastoma cell line (U87-MG cell). The phase solubility findings revealed a stability constant (773 mol L−1) as well as a complexation efficiency of 0.027. The dissolution study displayed a significant increase in CR release from CR-MC (99.03 ± 0.39%) > CR-PM (70.58 ± 1.16%) > pure CR (35.29 ± 1.55%). NMR and IR spectral data revealed no interaction between CR and carriers. SEM and DSC study results revealed the conversion into amorphous form. The molecular docking results illustrated a high docking score, which supports the findings of complex formation. The cell viability, reactive oxygen species, and flow cytometry studies results showed enhanced activity from CR-MC against the tested human primary glioblastoma cell line. From the results it has been observed that chrysin solubility significantly increased after complexation and there in vitro activity also enhanced against cancer cell line.

Nano-suspension loaded mucoadhesive mouth dissolving film of meclizine hydrochloride

Meclizine Hydrochloride belongs to class H1 antagonist, antiemetic and anti-vertigo in nature, it is a Biopharmaceutical classification system (BCS) class II drug and is practically insoluble in water. The bottom-up approach was used in the formulation of nanosuspension in which methanol and millipore water was used as solvent and anti-solvent respectively, the stabilizers used for preparation were Polyvinylpyrrolidone K30 (PVP K30) and Hydroxypropyl Methylcellulose E15 (HPMC E15) which were found to be compatible with the formulation after Fourier Transform Infrared (FTIR) and Differential scanning calorimeter (DSC) studies. Mouth dissolving films were formulated by solvent casting method using glycerine lubricated petri dish and were kept for heating in a hot air oven at 45°C overnight. Characterization of nanosuspension-loaded mucoadhesive mouth dissolving films was done by evaluating various characteristics, the highest drug content was found to be 92.43±0.49% in Mouth dissolving film (MDF) 2. In-vitro drug release studies indicate that nanosuspension-loaded mucoadhesive mouth-dissolving film has a rapid drug release rate as compared to plain drug-loaded mouth-dissolving films and marketed tablet formulation.

Relaxor-antiferroelectric hybrids for pyroelectric energy conversion from low-grade heat using flexible PVDF-TrFE-CTFE-NaNbO3 nanocomposite films

Nowadays, researchers focus more on developing smart materials that respond to different stimuli for harvesting energy output. In this paper, the pyroelectric energy harvesting capabilities of smart terpolymer poly(vinylidene-fluoride-trifluoroethylene-chlorotrifluoroethylene) [PVDF-TrFE-CTFE]-based nanocomposites have been investigated. Sodium niobate (NaNbO3) from the perovskite family is selected as the filler. The Sol-gel method is used to synthesise NaNbO3 nanoparticles, and solvent-cast films for different weight fractions (0–20%) of fillers have been fabricated. Structural, morphological, and dielectric properties of the polymer nanocomposite samples were done at room temperature. The ferroelectric properties of the terpolymer is improved with filler addition. The thermal stability of composite films was confirmed using differential scanning calorimetric (DSC) studies. The thermodynamic Olsen cycle was applied to nanocomposites for calculating the harvested energy output. Maximum energy density is obtained for higher filler loading (20 wt % sodium niobate). The operating temperatures were selected at 303 K and 333 K with an applied field of 130 kV/cm. The results show that including NaNbO3 in the relaxor terpolymer matrix considerably enhances the energy harvesting density of the nanocomposites, indicating that they are promising materials for designing thermally stable energy harvesting systems.

Primary structure determination and physicochemical characterization of DSP-3, a phosphatidylcholine binding glycoprotein of donkey seminal plasma

Major proteins of the seminal plasma in a variety of mammals such as bovine PDC-109, equine HSP-1/2, and donkey DSP-1 contain fibronectin type-II (FnII) domains and are referred to as FnII family proteins. To further our understanding on these proteins, we carried out detailed studies on DSP-3, another FnII protein of donkey seminal plasma. High-resolution mass-spectrometric studies revealed that DSP-3 contains 106 amino acid residues and is heterogeneously glycosylated with multiple acetylations on the glycans. Interestingly, high homology was observed between DSP-1 and HSP-1 (118 identical residues) than between DSP-1 and DSP-3 (72 identical residues). Circular dichroism (CD) spectroscopic and differential scanning calorimetric (DSC) studies showed that DSP-3 unfolds at ~45 °C and binding of phosphorylcholine (PrC) – the head group moiety of choline phospholipids – increases the thermal stability. Analysis of DSC data suggested that unlike PDC-109 and DSP-1, which exist as mixtures of polydisperse oligomers, DSP-3 most likely exists as a monomer. Ligand binding studies monitoring changes in protein intrinsic fluorescence indicated that DSP-3 binds lyso-phosphatidylcholine (Ka = 1.08 × 105 M−1) with ~80-fold higher affinity than PrC (Ka = 1.39 × 103 M−1). Binding of DSP-3 to erythrocytes leads to membrane perturbation, suggesting that its binding to sperm plasma membrane could be physiologically significant.

Studies on thermoset blend of bismaleimide having multiple swivel groups and biscyanate ester

The materials 2,2-bis [4-(4-maleimidophenoxy phenyl)] propane (BMIX) and bisphenol-A based cyanate ester (BCY) were synthesized. The monomers BMIX and BCY were physically blended (BMCY) in 1:1 mol ratio. The materials BMIX, BCY and BMCY were thermally polymerized and the structural characterisation of the materials was done using Fourier transform infrared spectrophotometer (FTIR). The curing characteristics of BMIX, BCY and its blend (BMCY) were investigated using differential scanning calorimeter (DSC). The blend BMCY shows considerable differences in the thermal curing behaviour as evidenced by the DSC studies. Blending BCY with BMIX drastically reduces the melting temperature, curing onset temperature and the amount of heat liberated during thermal curing. The thermal stabilities of the crosslinked network polymers (PBMIX, PBCY and PBMCY) were investigated using thermogravimetric analyser (TGA). Detailed TGA studies indicated that the PBMCY shows better thermal stability than the PBMIX and PBCY. The DSC and TG curves indirectly hint about the possible reaction between BMIX and BCY during thermal curing. Woven glass fibre reinforced laminates were prepared using BMIX, BCY and BMCY by solution impregnation followed by drying and compression moulding. The glass laminate having BMCY as the matrix resin showed much better mechanical property (tensile strength) compared to the laminate made using BMIX as the matrix resin.

Transferrin decorated PLGA encumbered moxifloxacin nanoparticles and in vitro cellular studies

Purpose Complicated intra-abdominal infection (cIAI) management involves administering antibiotics that destroy the cell wall and the genesis of bacterial lipopolysaccharide (LPS). During the infectious state, the expression of transferrin receptors upregulates on the intestinal epithelial cells, which are considered the site of infection. In the present research, transferrin decorated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) encapsulated moxifloxacin (MOX) were developed for possible targeting of the receptors in the colon. Significance This study will explore more about the incorporation of transferrin as effective coating material in targeted drug delivery. Methods Nanoparticles were prepared using nano-emulsification and surface modification with transferrin was done by layer-by-layer methodology and evaluated by powder X-ray diffraction (PXRD), differential scanning calorimeter (DSC), FTIR, SEM, antibacterial activity, and cellular uptake studies. Results The formulated NPs exhibit a size of ≈170 nm, PDI ≈ 0.25, zeta potential ≈−4.0 mV, drug loading ≈ 6.8%, and entrapment efficiency of 82%. Transferrin-decorated NPs exhibit tailored release for almost 12 h and in vitro antibacterial activity for 14 h. The cellular uptake studies were done on a RAW264.7 cell line for better determination of transferrin uptake of fabricated NPs. Conclusion The above study circumvents around the preparation of transferrin decorated PLGA encumbered MOX NPs intended for cIAI-induced sepsis. PLGA NPs provide tailored release of MOX with primary burst and followed by sustained release. These observations confines with antibacterial activity studies. The prepared transferrin-coated NPs were stable and effectively uptaken by RAW264.7 cells. However, future studies include the preclinical investigation of these NPs in sepsis-induced murine models.

ENHANCEMENT OF LORATADINE DISSOLUTION BY SURFACE SOLID DISPERSION: THE POTENTIAL USE OF CO-PROCESSED EXCIPIENTS AS ON-SURFACE CARRIERS

Objective: The aim of the work in this study is to enhance the dissolution rate of the poorly water-soluble drug; loratadine employing co-precipitated surface solid dispersions (SSDs) prepared using various hydrophilic on-surface carriers namely; Pearlitol® flash, Parteck® ODT, Prosolv® ODT G2 and Pharmaburst® C1. Methods: Loratadine solid dispersions (SDs) were prepared by co-precipitation method using copovidone, poloxamer 188 and gluconolactone at different ratios. The best formulae were selected, based on dissolution results obtained, to prepare 16 different SSDs. The prepared SSDs were subjected to drug content and in-vitro dissolution studies and the best formulae were further subjected to solid-state characterization, using X-ray powder diffraction (XRPD) and differential scanning calorimeter (DSC). The effect of aging on the best formulae was studied by evaluating the drug content, drug dissolution and the change in the crystalline state using (XRPD). Results: S1 formula, containing drug: poloxamer 188: pearlitol flash at 1:4:1 ratio, and S9 formula, containing drug: poloxamer 188: prosolv ODT at 1:4:1 ratio showed the highest dissolution efficiency. XRPD and DSC studies of S1 and S9 proved a decrease in drug crystallinity and confirmed solid dispersion formation. The stability study of S1 and S9 showed a slight reduction in the dissolution efficiency (DE) of S1 (from 84.6±0.8 to 81.4±0.7 and 81.4±1.3 at ambient and accelerated conditions, respectively) and a higher reduction in DE of S9 (from 83.5±2.4 to 69.6±1.0 and 57.3±2.9 at ambient and accelerated conditions respectively). Conclusion: Results obtained obviously confirmed the potential effect of the surface solid dispersion technique, using poloxamer 188 as a hydrophilic carrier and Pearlitol flash as an on-surface carrier, on improving the dissolution of loratadine.

Phosphate intercalated Mg/Al layered double hydroxide nanosheets as a novel flame retardant for leather: Synthesis, characterization, and application studies

Ammonium polyphosphate (APP) modified Mg/Al layered double hydroxide (LDH) flame retardants (FR) were synthesized by varying the APP concentration between 5 and 15% (PLDH-5, PLDH-10, PLDH-15). Synthesized PLDH (APP modified LDH) were characterized for their microstructural, physicochemical, and thermal properties. FE-SEM images of the PLDH showed agglomerated nanosheets indicating the interaction of APP with the LDH. XRD studies of the PLDH confirmed the intercalation of phosphate ions into the interlayer gallery, leading to an increase in the interlayer distance from 0.76 to 1.07 nm. Emphasis was given to the thermogravimetric (TGA/DTG) and differential scanning calorimetric (DSC) examination of the PLDH, and PLDH treated leathers to understand their thermal insight. The PLDH-treated leathers showed an increase in the thermal stability of the collagen. The endothermic dehydroxylation and decomposition observed in the DSC studies indicated the suitability of the PLDH as flame-retardant material. Application of 3% PLDH during leather making improved the flammability degree of leather by 18.2%. The synthesized PLDH exhibited equivalent or better flame retardant performance as compared to the other flame retardant chemicals reported in the literature for leather applications. The flame retardant mechanism of PLDH was also discussed.

Calorimetric Analysis and Dielectric Properties of Se50Te45Ge5 Chalcogenide Alloy

Abstract In this article, the amorphous structure of chalcogenide alloy Se50Te45Ge5 is confirmed by x-ray diffraction analysis with under-constrained nature. The differential scanning calorimeter study is made for the alloy at different heating rate α. The Tg and Tc of the alloy are found to increase, whereas Tm appears to decrease with increasing α. The mean activation energy for transition and crystallization are found to be around 160 and 150 kJ/mol, respectively. The fragility index is found to decrease with the increase of α. The crystals are established to grow in two dimensions within the glass network. On the other hand, the dielectric constant and loss are studied at frequencies between 30 Hz and 1 MHz and at temperatures between 20 and 300 K. The dielectric modulus of the experimental data is then analyzed using different models. Suitable fitting to the practical data is attained by the application of Davidson–Cole formalism with γ-values ranging from 0.82 to 0.99 with increasing of the temperature.