Colloid and Polymer Science最新文献

Marketed valproic acid formulations use its solid salt forms, which are hygroscopic and difficult to handle. The current study focuses on developing valproic acid nanoemulsion using the physically most stable liquid form of the drug and evaluating its anticancer potential. Valproic acid is a histone deacetylase inhibitor having anticancer potential.The valproic acid nanoemulsion was formulated using a facile and scalable homogenization process. The emulsion stabilization was achieved through viscosity-enhancing polymer polyvinylpyrrolidone K-30 and tween 80. The formulation was optimized using the Box-Behnken model of design of experiments and was evaluated for efficacy and safety in cancer and fibroblast cell lines, respectively.The optimized emulsion showed particle size below 150 nm, polydispersity index below 0.3, zeta potential near − 8.5 mV, density 0.9923 g/cm³, viscosity 2.06 poise, creaming index below 20, drug content 100.37%w/v and acceptable stability at accelerated environmental conditions. Overall, under all the studied conditions of in vitro dissolution and ex vivo permeability, drug release from emulsion was found better than the free drug and comparable to the marketed solution of sodium valproate. The cytotoxicity studies demonstrated improved IC₅₀ values for breast and lung cancer cell lines, with selectivity for cancer cells.The valproic acid nanoemulsion was prepared using its physically stable liquid form. The combination of polymer polyvinylpyrrolidone K-30 and tween 80 demonstrated the desired stabilization of the dispersed phase of the emulsion. The formulated nanoemulsion effectively potentiated valproic acid’s anticancer activity in cell culture assays.

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Acalabrutinib (ACL) was approved in the United States in the year of 2017 and 2019 for the treatment of chronic lymphocytic leukemia (CLL) and relapsed mantle cell lymphoma (MCL). Low-energy method was employed to curate nanoemulsion (NE) for which various components were screened through solubility study and optimization was done through a pseudo-ternary phase diagram. The NE was evaluated for its droplet size, polydispersity index (PDI), transmittance, morphology, rheology, robustness to dilution, the effect of pH, storage stability, and ex vivo permeation study. The optimized ACL-NE demonstrated an appropriate droplet size (94.35 ± 0.3 nm), PDI (0.27 ± 0.03), and an entrapment efficiency of 67.38 ± 2.69%. It showed non-Newtonian (shear thinning behavior) due to reduced viscosity with an increasing shear rate. The apparent permeability was 3.09-fold higher for ACL-NE than ACL suspension. An in vitro drug release study depicted a higher release of ACL (71.10 ± 10.99%) from the optimized NE in a sustained fashion than the suspension (49.01 ± 1.65%). A dose-dependent cytotoxicity was observed in MOLT-4 and HH-cell lines where the IC50 values of ACL were 5.62- and 16.49-fold reduced when encapsulated in oil globules for the respective cell lines. Blank-NE did cause a reduction in cellular toxicity at higher doses. A 7.31- and 5.1-fold increase in C_max and bioavailability was noted between ACL suspension and ACL-NE.

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Visible light-responsive antimicrobial coatings are of importance for antibacterial applications owing to widespread multidrug-resistant infections. Herein, the photocatalytic disinfection performance of an all-organic poly[2,11′-thiophene-ethylene-thiophene-alt-(2,5-(3-carboxyl)-thiophene] (PTET-T-COOH)/polyurethane (PU) coating was synthesized and evaluated. The coating consists of both a protective PU layer and a photoactive layer (PTET-T-COOH), which was prepared using isocyanate groups as linkers, then fabricated by drop-casting. The chemical linkage between PTET-T-COOH and NCO-terminated PU was researched based on ATR-FTIR and XPS analyses. The developed coating demonstrated good photocatalytic bactericidal performance on S. aureus under visible-light irradiation for 6 h. This study provided an effective platform for fabricating environmental-friendly and cheap antimicrobial surfaces.

Flexible strain sensors need to obtain a stable signal as the target undergoes random and repeated deformation. Therefore, excellent mechanical properties, adhesion properties, and electrical conductivity are essential. In this study, a stretchable, self-adhesive, and conductive ionic hydrogel was designed and synthesized. Zwitterionic hydrogels were synthesized by micellar copolymerization of hydrophobic monomer methacrylate stearic acid (C18) with hydrophilic monomers [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide (SBMA) in the presence of sodium dodecyl sulfate (SDS) surfactant. Compared with traditional chemical cross-linked hydrogels, the elongation at break is increased by 934%. The multi-walled carbon nanotubes (MWCNTs) modified with tannic acid (TA) have good dispersibility and stability, which can be added to the hydrogel as a functional filler to enhance the tensile and conductive properties of the sensor. The hydrogel flexible sensor prepared under the synergistic action of various mechanisms has good mechanical properties, bonding properties, and conductive properties. In addition, due to the inherent antibacterial properties of the raw material, the hydrogel has a bactericidal ratio of up to 99% against E. coli and S. aureus under the premise of good biocompatibility in vitro, which has great potential in the field of monitoring human movement and healthcare.

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The degradation and recycling of waste epoxy resins is an urgent environmental problem, encouraging the use of degradable thermosetting epoxies. In this study, a high-performance thermosetting epoxy resin material that can be easily degraded and recycled was prepared using a low-viscosity and high-activity epoxy monomer, tetrahydrophthalic acid diglycidyl ester. Owing to the breakable ester bond in this epoxy monomer, the thermosetting three-dimensional epoxy cross-linked structure can be rapidly degraded using ethylene glycol at atmospheric pressure. After further depolymerization of the epoxy resin/glycol solution with NaOH, sodium cyclohexene-2-carboxylate was obtained. The sodium salt was acidified, epoxidized, and then re-prepared to obtain the epoxy monomer diglycidyl tetrahydrophthalate. The recycled epoxy monomer possesses the same thermal and mechanical properties as the original epoxy monomer, thus realizing the economic and environmentally friendly degradation and recycling of the thermosetting epoxy resin under mild conditions, and this recycling method is applicable to epoxy systems with ester bonding in the cured material.

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This study focused on the thermal stability and the thermal degradation kinetics of two poly(vinyl ethers), PVEs, with different side groups. The objective was to determine how the nature of the side group affects the thermal properties of these materials. Poly(2–Phthalimide Ethyl Vinyl Ether), PPEVE, was derived via zirconocene–mediated cationic homopolymerization, and poly(2–Amino Ethyl Vinyl Ether), PAEVE, was obtained by hydrazinolysis of PPEVE. The thermal stability was investigated by employing thermogravimetric analysis (TGA) and differential thermogravimetry, DTG, at six different heating rates. The thermal decomposition kinetics data were evaluated using the Ozawa–Flynn–Wall, OFW, and Kissinger–Akahira–Sunose, KAS, “model-free” methods to calculate the activation energies, (Ea), and subsequently the appropriate mathematical model or mechanism to describe the thermal decomposition process for each individual homopolymer.

This work investigates the Maxwell fluid flow in the variable porous space of cone and disc influenced by double diffusion on a variable porous space. In this study, the heat and mass transfer is influenced by the combined effects of Fourier’s and Fick’s laws, leading to heat and mass flux assumptions proposed by Cattaneo-Christov to characterize these transfer phenomena. The modeled equations have been converted to dimensionless form by using a suitable set of appropriate variables. This set of dimensionless equations was then solved by using artificial neural networks (ANNs). For this, initially, HAM (homotopy analysis method) has been used for the evaluation of modeled equations, and then, to analyze the dynamics of flow, Levenberg Marquardt Scheme through Neural Network Algorithm (LMS-NNA) has been employed. The optimal performance of the fluid model is observed at the epoch 10, 08, 427, 164, 203, 146, 101, 130, 255, 298, 166, and 222. The proximity to unity is a pivotal observation in this work that has been signifying a high degree of precision in the LMS-NNA design for the proposed model. The porosity factor has opposed the primary velocity profiles and has supported the secondary velocity profiles. Moreover, primary velocity profiles have declined with growth in Maxwell factor while secondary velocity panels have retarded by the upsurge in the retardation time factor. Thermal distribution has been supported by progression in thermophoresis and Brownian motion factors and has been opposed by escalation in the Prandtl number. Concentration distribution has augmented with the upsurge in thermophoresis factor and has declined with the escalation in factor, Schmidt number, and concentration relaxation time factor. It has been also observed in this work that the variable porous space controls the fluid flow and maintains the stability of Maxwell fluid flow between the cone and disc apparatus. The maximum error for testing, training, and validation of the proposed model is achieved for all 12 cases and discussed numerically in tabular form.

A general expression is derived for the Laplace transform of the time dependent transient electrophoretic mobility of spherical colloidal particles in a multi-particle suspension when a step external electric field is suddenly applied to the colloidal suspension. From the general mobility expression, we obtain a simple closed form expression for the Laplace transform of the time-dependent transient electrophoretic mobility of weakly charged spherical colloidal particles in an electrolyte solution. The obtained Laplace transform of the transient electrophoretic mobility of particles does not involve numerical integrations so that its inverse Laplace transform is easily obtained using calculation software.

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Time-dependent transient Henry function for spherical colloidal particles in a multi-particle suspension.