The choice of drug delivery carrier is of paramount importance for the fate of a drug in a human body. In this study, we have prepared the hybrid nanoparticles composed of FDA-approved Eudragit ...L100-55 copolymer and polymeric surfactant Brij98 to load haloperidol-an antipsychotic hydrophobic drug used to treat schizophrenia and many other disorders. This platform shows good drug-loading efficiency and stability in comparison to the widely applied platforms of mesoporous silica (MSN) and a metal-organic framework (MOF). ZIF8, a biocompatible MOF, failed to encapsulate haloperidol, whereas MSN only showed limited encapsulation ability. Isothermal titration calorimetry showed that haloperidol has low binding with the surface of ZIF8 and MSN in comparison to Eudragit L100-55/Brij98, thus elucidating the striking difference in haloperidol loading. With further optimization, the haloperidol loading efficiency could reach up to 40% in the hybrid Eudragit L100-55/Brij98 nanoparticles with high stability over several months. Differential scanning calorimetry studies indicate that the encapsulated haloperidol stays in an amorphous state inside the Eudragit L100-55/Brij98 nanoparticles. Using a catalepsy and open field animal tests, we proved the prolongation of haloperidol release
, resulting in later onset of action compared to the free drug.
Lignin was isolated through mild acidolysis from local wood sources such as beech wood and chestnut wood sawdust, a high-volume side product of wood industries. The lignin fractions were ...characterized by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), Fourier-transform infrared (FTIR), ultraviolet-visible (UV-Vis) and two-dimensional heteronuclear single-quantum correlation nuclear magnetic resonance (2D HSQC NMR) spectroscopies and size exclusion chromatography (SEC). The Klason lignin (KL) content and polysaccharide composition were determined using traditional methods. Lignin nanoparticles (LNPs) were prepared
a non-solvent method involving dialysis and characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and FTIR and UV-VIS spectroscopies. Semi-porous as well as hollow nanoparticles endowed with a spherical shape were observed. The large majority of the LNPs exhibited an average particle diameter of 90–120 nm. Dynamic light scattering (DLS) analysis showed that both distribution and frequency of dimensional classes of LNPs are clearly affected by the lignin solvent system, i.e. solvent selection governs the size distribution of LNPs.
In the current research, the surface of gold nanoparticles (AuNPs) modified using folic acid (FA) as a capping agent for improving their photophysical properties with thionine (TH). The binding ...nature of TH with folic acid stabilized gold nanoparticles (FA-AuNPs) are characterized using absorption, emission, Fourier Transform Infrared Spectroscopy (FT-IR) measurements, High Resolution Transmission Electron Microscopy (HR TEM), Zeta potential and Dynamic Light Scattering (DLS). The outcomes from the spectral studies, FA-AuNPs have the ability to bind with TH and form a ground state complex via electrostatic interaction. Furthermore, electrostatic interaction between TH and FA-AuNPs are confirmed by Zeta potential and FT-IR measurements. Morphological changes of the FA-AuNPs also occur upon the addition of TH and thionine functionalized gold nanoparticles systems (TH-FA-AuNPs) complexes are characterized by DLS and HR TEM analysis. In this scenario, the cytotoxicity of TH and TH-FA-AuNPs are evaluated in human lung cancer cell (A-549) lines (MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay). The compounds TH and TH-FA-AuNPs induced toxicity in A-549 cells under visible light irradiation. TH-FA-AuNPs exhibited more cytotoxicity when compared to free TH. These results indicate that TH-FA-AuNPs is well fitted for therapeutic application including cancer therapy.
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•Folic acid capped gold nanoparticles (FA-Au NPs) are prepared and characterized.•The interaction between TH with FA-Au NPs was investigated.•FA-Au NPs quenches the intrinsic fluorescence of TH by static quenching process.•HR-TEM, DLS, Zeta potential and FT-IR spectral studies are support of the binding study.•In vitro cytotoxicity of TH and TH-FA-Au NPs systems were explored in human lung cancer cell (A-549) lines by MTT assay.
The two part urethane-methacrylate resin RPU 70, used in DLS, seems to have superior material properties. These properties are achieved by a dual curing process of ultraviolet (UV) and thermal ...curing. The temperature influence on the processability of the mixed resin and the resulting mechanical properties are still unknown. It was possible to solidify the liquid RPU 70 resin into an elastomer at 60 °C for 15 h without the influence of UV light by solely harnessing the temperature sensitive crosslinking reaction between part A and part B. The ongoing thermal conversion of the liquid resin into an elastomer was analyzed with viscosity measurements, Fourier-transform infrared spectroscopy (FT−IR), differential scanning calorimetry (DSC) and Photo-DSC. The latter method proved to be effective in tracking the thermal conversion and to identify optimal exposure times for preheated resins. Furthermore, thermogravimetric analysis (TGA) showed a linear evaporation of reactive diluents in RPU 70 over time. In order to investigate the processability and to understand the effects of the thermal curing on mechanical properties, the resin was preheated to 30 °C, 40 °C, 50 °C and 60 °C for one hour before the dual curing DLS process. Even though, the viscosity of the resin was increased by preheating and additionally by the released reaction heat of the photopolymerization during DLS, the build job could be produced with the same part quality as the unheated resin. Tensile tests were conducted on dual cured specimen and the results showed that with a preheating of the resin for one hour at 50 °C, the tensile modulus of RPU 70 increased 19.56%, while tensile strength and elongation at break values remained in the standard deviation range of the comparison group. The preheating at 60 °C improved elongation at break and tensile modulus 47.61% and 5.54% respectively, while at the same time tensile strength dropped −5.02% compared to no preheating. Apart from the possibility to slightly modify the mechanical properties by preheating the resin before DLS, there are two temperature-dependent challenges for RPU 70 during the DLS process, namely evaporation and undesirable thermal curing. However, there are also new innovative ways to utilize the result of this study that RPU 70 resin can be thermally solidified into an elastomer: the creation of parts that have a hard shell and a soft core. The hard shell can be produced by using DLS, the soft core by pouring the liquid resin in the shell and thermally curing both.
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•Mechanical properties can be modified by preheating the resin before DLS.•Reactive diluents evaporate from the resin.•Liquid RPU 70 resin solidifies into an elastomer after 15 h at 60 °C.•Photo-DSC can be used to track the thermal conversion between part A and B.
The solubilisation of methylparaben (MP), an antimicrobial agent used as a food preservative and in cosmetics and personal-care products, in two poloxamines of different Hydrophilic-Lipophilic ...Balance (HLB), namely Tetronic® 904 (T904) and 1107 (T1107), has been studied. The influence of the preservative on the aggregation behaviour of both Tetronics has been analysed by dynamic light scattering (DLS) and small-angle neutron scattering (SANS), while the precise location of the molecule in the aggregates as well as the effects of the micellar solubilisation on the reactivity of the preservative have been elucidated by NMR and UV spectroscopies. The presence of MP reduces the critical micelle temperature (CMT) of any of the poloxamines and induces the formation of larger micelles at room temperature compared to the plain poloxamines; in addition, a remarkable temperature dependent effect on the structure of the micelles has been detected, which progressively evolve from core-shell spheres to rods as the temperature increases. The incorporation of the preservative into the micelles modifies its reactivity against alkaline hydrolysis, resulting in a decrease of its reaction rate constant in which the dominant factor for the reduction in the hydrolysis rate is the incorporation into the micelle core, with a little effect of the length of the hydrophilic polyethylene oxide (PEO) blocks.
•The presence of MP reduces the CMT of the poloxamines and induces the formation of larger micelles at room temperature.•The micelles containing MP evolve from spheres to rods and to wormlike micelles as the temperature increases.•The predominant location of MP in the PPO core of the micelles has been probed by 2D-NOESY experiments.•The incorporation of MP into the micelles results in a decrease of its alkaline hydrolysis rate constant.
Moving towards a real mass vaccination in the context of COVID-19, healthcare professionals are required to face some criticisms due to limited data on the stability of a mRNA-based vaccine ...(Pfizer-BioNTech COVID-19 Vaccine in the US or Comirnaty in EU) as a dose in a 1 mL-syringe. The stability of the lipid nanoparticles and the encapsulated mRNA was evaluated in a “real-life” scenario. Specifically, we investigated the effects of different storing materials (e.g., syringes vs. glass vials), as well as of temperature and mechanical stress on nucleic acid integrity, number, and particle size distribution of lipid nanoparticles. After 5 h in the syringe, lipid nanoparticles maintained the regular round shape, and the hydrodynamic diameter ranged between 80 and 100 nm with a relatively narrow polydispersity (<0.2). Samples were stable independently of syringe materials and storage conditions. Only strong mechanical stress (e.g., shaking) caused massive aggregation of lipid nanoparticles and mRNA degradation. These proof-of-concept experiments support the hypothesis that vaccine doses can be safely prepared in a dedicated area using an aseptic technique and transferred without affecting their stability.
Cephalopod ink is a complex mixture of bioactive substances with technical properties of interest in many fields (e.g., biophysics, ecology, environment, biomedicine, food technology, cosmetics, or ...fine arts). It was previously reported that organic nanoparticles may naturally appear in this mixture. Thus, the particle size determination of these biopolymers is interesting from the point of view of food nanotechnology and nanotoxicology. In this work, the particle size of purified eumelanin microspheres from commercial sepia ink was successfully measured by three techniques: Scanning electron microscopy (SEM), dynamic light scattering (DLS), and asymmetric-flow field-flow fractionation linked to multi-angle laser-light scattering (AF4-MALLS). This study shows the potential and differences of the application of these techniques in terms of sample preparation, conditioning, introduction, and principles for particle size characterization of natural organic nanoparticles in foods. Thus, this methodology can be a model for the characterization of other natural and engineered organic nanoparticles in this matrix type. DLS and AF4-MALLS provide the size corresponding to the hydrodynamic diameter, which is usually larger than the size of the dense core provided by SEM (without hydration or solvation layer). Additionally, SEM informs about the particles morphology, showing a quasi-spherical shape for particles between 100 and 140 nm. DLS and AF4-MALLS indicate particles of hydrodynamic diameter in the range of 180–260 nm. Furthermore, the absolute molar mass of particles has been measured by MALLS.
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► Interaction of ILs with Pluronic micelles is proposed. ► Interaction studied by DLS, SANS, NMR technique. ► NOESY indicates PPO block interaction with alkyl group of IL. ► Through ...this kind of interactions, Cnmim BF4 and P103 can form mixed micelles.
The effect of three ionic liquids (ILs) 1-alkyl 3-methyl imidazlolium tetraflouroborates (Cnmim BF4n=4, 6, 8) on micellar solutions of an ethylene oxide-propylene oxide block copolymer (PEO–PPO–PEO), Pluronic® P103 was examined from scattering and NMR techniques. The ILs alter the cloud point and micelle size dependant on their alkyl chain length and the results are discussed in terms of their behavior as cosolvent/cosurfactant. Cloud point data support the hydrogen bonding between the imidazolium cation and P103 while dynamic light scattering (DLS) and small angle neutron scattering (SANS) reveal that presence of ionic liquid is not conducive to the micelle formation of P103. The selective nuclear Overhauser effect (NOESY) indicates that the PPO block of the P103 interacts with the alkyl group of the Cnmim+ cation by hydrophobic interaction. Through this kind of interactions, Cnmim BF4 and P103 can form mixed micelles. This result indicates that the presence of ILs hinders the micelle formation of P103 in solution and promotes P103 to orient at air/water interface.
E‐learning, as a complex system, includes distance learning, teaching materials in various forms and shapes, group and individual learning processes, as well as interactive and tutorial work. To ...increase the effectiveness and efficiency of the e‐learning system, it is necessary first of all to consider the characteristics of students and their learning styles. Based on the data collected in various ways, in surveys, using the distance learning dystem (DLS) Moodle, based on the subjective assessment of the subject teachers, as well as based on data from the business information system, the student preferences are determined. Then, based on these data, an adaptation is made, a process that adapts the work of the DLS based on student knowledge. The primary goals that can be achieved through the adjustment of the e‐learning system are to improve the design and usefulness of the course, help with finding information on the course, more efficient searching and placement of search results in the context of students' interest, as well as increasing students' loyalty to a higher education institution.
A simple environmentally friendly method for the synthesis of different shaped gold nanoparticles (AuNPs) using silk fibroin (SF) as a reducing, shape tailoring, chapping and subsequent stabilizing ...agent is reported. In this study, neither external reducing agents nor high temperature are used for the synthesis of nanoparticles. The nanoparticles formed in SF solution was probed by considering the changes in position and intensity of the localized surface plasmon resonance (LSPR) peak using UV–Visible spectroscopy (UV–Vis). Nano crystalline structure and FCC crystal family was established by X-ray diffraction (XRD) measurement. The size and shape evolution of the nanoparticles was inspected using transmission electron microscope (TEM) which confirmed the formation of different shaped nanoparticles. The average particles size of AuNPs in colloidal solution was scrutinized using dynamic light scattering (DLS) experiment. Synthesized gold nanoparticles were sense as potential ammonia detector.
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