Average Particle Size Research Articles

Celastrol-loaded polymeric mixed micelles shows improved antitumor efficacy in 4 T1 bearing xenograft mouse model through spatial targeting.

In this study, we have proposed a novel approach that combines hyaluronic acid (HA), folic acid (FA), and celastrol (CLS) within a polymeric micelle system (HF-CLS/MLs), offering a dual-action strategy against breast cancer. Polymeric mixed micelles were prepared through the thin-film hydration method, and comprehensive quality control parameters were established, encompassing particle size, polydispersity index, zeta potential, surface morphology, encapsulation efficiency, drug content, in vitro drug release, and storage stability assessment. The average particle size of CLS-HF/MLs micelles was found to be 120 nm and their drug loading and encapsulation efficiencies were 15.9 % and 89.52 %, respectively. The in vitro release data showed that the CLS-HF/MLs targeted mixed micelles displayed a prolonged release profile compared to the free drug. Additionally, the stability of the developed polymeric mixed micelles was maintained for up to 8 weeks of storage in terms of particle size and drug content. Furthermore, both flow cytometry and confocal laser scanning microscopy studies indicated a significant enhancement in the cellular uptake efficiency and cytotoxicity of CLS-HF/MLs mixed micelles against MCF-7 cell line. In terms of pharmacokinetic analysis, the half-life and AUC values of CLS-HF/MLs mixed micelles were found to be approximately 4.71- and 7.36-folds higher than the values of free drug (CLS), respectively. The CLS-HF/MLs micelles exhibited remarkable antitumor efficacy (almost complete ablation of the 4 T1-cell bearing tumor xenografts mouse model) due to the dual receptor (CD44 and folate) targeting effects with minimal side effects. When considering the cumulative findings of our present research, it becomes evident that mixed micelles designed for chemotherapy offer a promising and potentially effective therapeutic avenue for the treatment of breast cancer.

Non-pigmented laser hair removal mediated via Sepia melanin nanoparticles: in vivo study on albino mice.

Objectives Melanin is considered the main chromophore for laser hair removal. Due to a lack of laser-absorbing chromophores, removing non-pigmented hair with laser is quite problematic with unsatisfactory outcomes. This problem could be solved by delivering more melanin to the area around the hair follicle and enhancing that area as a target for light absorption. The insolubility of Sepia melanin as an exogenous dye, in most solvents, limits its bioavailability and thus its clinical use.Methods In our study, to overcome the solubility problems and increase the bioavailability of melanin for biomedical and cosmetic applications, natural sepia melanin was loaded in different nano-delivery systems (spanlastics and transfersomes) to be delivered to the hair follicles. The different formulations of melanin were prepared and characterized. In vivo skin deposition and histopathological studies were conducted on albino mice.Results Transmission electron microscopy (TEM) showed the spherical shape of the prepared vesicles with an average particle size of 252 and 262 nm and zeta potential of -22.5 and -35 mV for melanin spanlastics and melanin transfersomes, respectively. Histopathological examination of hair follicles and pilosebaceous glands for the irradiated and non-irradiated albino mice skin was studied post the application of the prepared formulations topically and subcutaneously. Qualitative statistical analysis was conducted and melanin transfersomes and melanin spanlastics showed significant damage to pilosebaceous glands and hair follicles with a p-value of 0.031 and 0.009 respectively.Conclusion Melanin nanovesicles as transfersomes and spanlastics could be considered a promising approach for the removal of non-pigmented hair.

Catharanthus roseus-mediated CuAl2O4 Nanocomposites for Evaluation of Killing Kinetics.

The present article portrayed on the killing kinetic of human pathogenic bacteria using bioinspired mesoporous CuAl2O4 nanocomposites (NCs). The NCs was fabricated using leaf extract of medicinal plant Catharanthus roseus (CR) as a green reducer and stabilizer. As bio-fabricated material was calcined at 800 °C and characterized by several analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-DRS), Energy Dispersive X-Ray Spectroscopy (EDS), X-Ray Photoelectron Spectroscopy (XPS), Raman, Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) to authenticate its structure, phase, chemical bonding, chemical state, size and morphology behaviors. XRD and TEM revealed a reduced crystallite and nanoscale sizes of biosynthesized NCs. Moreover, XRD study exposed a cubic-structure of material, while transmission electron microscopy rendered an average particles size in range 10-15 nm. However, BET profile advocates a mesoporous nature of the particles. An effective biological molecular docking modulation assessed by substituting natural inhibitor by bioinspired NCs, while the protein PDB ID 4Z8D FabH as a receptor site for the present investigation. After assessment of molecular docking examination, the antibacterial activity of bioinspired NCs were performed against Staphylococcus aureus, Bacillus subtillis, Klebsiella pneumoniae and Escherichia coli using agar-well method. The broth culture method was employed on different pathogenic strains by kinetic growth assays and colony forming unit.

Calcipotriol Nanosuspension-Loaded Trilayer Dissolving Microneedle Patches for the Treatment of Psoriasis: In Vitro Delivery and In Vivo Antipsoriatic Activity Studies.

Psoriasis, affecting 2-3% of the global population, is a chronic inflammatory skin condition without a definitive cure. Current treatments focus on managing symptoms. Recognizing the need for innovative drug delivery methods to enhance patient adherence, this study explores a new approach using calcipotriol monohydrate (CPM), a primary topical treatment for psoriasis. Despite its effectiveness, CPM's therapeutic potential is often limited by factors like the greasiness of topical applications, poor skin permeability, low skin retention, and lack of controlled delivery. To overcome these challenges, the study introduces CPM in the form of nanosuspensions (NSs), characterized by an average particle size of 211 ± 2 nm. These CPM NSs are then incorporated into a trilayer dissolving microneedle patch (MAP) made from poly(vinylpyrrolidone) and w poly(vinyl alcohol) as needle arrays and prefrom 3D printed polylactic acid backing layer. This MAP features rapidly dissolving tips and exhibits good mechanical properties and insertion capability with delivery efficiency compared to the conventional Daivonex ointment. The effectiveness of this novel MAP was tested on Sprague-Dawley rats with imiquimod-induced psoriasis, demonstrating efficacy comparable to the marketed ointment. This innovative trilayer dissolving MAP represents a promising new local delivery system for calcipotriol, potentially revolutionizing psoriasis treatment by enhancing drug delivery and patient compliance.

Tracking success of interaction of green-synthesized Carbopol nanoemulgel (neomycin-decorated Ag/ZnO nanocomposite) with wound-based MDR bacteria

Abstract Multidrug-resistant wound infections are a global health threat and a leading cause of death, persisting despite available treatments due to antibiotic resistance, biofilms, and ineffective drug delivery systems. The aim of this study is to (i) formulate an innovative nano-drug delivery system (NDDS) based on a Carbopol nanoemulgel (NEG) co-loaded with neomycin-silver/zinc oxide nanocomposite (NC) that could fight clinical MDR and treat biofilm-forming wound pathogens through topical application, and (ii) assess its in vivo wound-healing potential. The silver/zinc oxide (Ag/ZnO) NC was synthesized by co-inoculating the metabolites of Aspergillus welwitschiae and Meyerozyma guilliermondii. The synthesized NC was then conjugated with neomycin and loaded into a Carbopol NEG for efficient topical delivery. The resulting Neo-Ag/ZnO NEG was characterized physicochemically (e.g., UV-visible [UV-Vis] spectrophotometry, field emission scanning electron microscopy, X-ray diffraction, and Fourier transform infrared [FTIR] spectroscopy), biologically (e.g., in vitro antimicrobial, antibiofilm, and hemolytic activities), and pharmacologically (e.g., drug content, ex vivo drug release behavior, and in vivo wound-healing potential). The physicochemical analysis confirmed the successful mycosynthesis of the Carbopol NEG-loaded Neo-Ag/ZnO NC. SEM depicted a crystalline polyhedral shape of the small NC (average particle size of 38 nm). FTIR studies showed a slight interaction with the drug and other bioactive moieties in the Carbopol NEG. The Neo content in the Carbopol NEG was as high as 98%, and a maximum release of 81% for Neo, Ag, and ZnO ions was noticed after 12 h. The NDDS appeared hemocompatible and displayed a minimal inhibition concentration of 0.002 µg/mL with the greatest antimicrobial potential against S. aureus (an inhibition zone of 46 mm) compared to other tested wound microbes (p < 0.05). Statistically significant wound-healing activity was found for NDDS (p = 0.0001) in comparison to the control at a concentration of 100 mg/mL. The results showed that this newly developed Carbopol NEG-loaded neo-Ag/ZnO NC appeared promising for controlling resistant skin infections and boosting wound regeneration.

Self-assembly of the porphyrin monomer on the surface of Fe/graphene material: a novel sensing material for the detection of chloramphenicol antibiotic in aqueous solution.

Currently, electrochemical sensors are in the process of being developed and widely used in various fields, and new materials are being explored to enhance the precision and selectivity of the sensors.The Fe/graphene nanoparticles were synthesized utilizing a green approach, wherein leaf extract was employed as the reducing agent. The resulting materials underwent comprehensive characterization utilizing a range of contemporary techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy. The findings of the study revealed that the nanocomposites of Fe/graphene/porphyrin comprised zero-valent iron nanoparticles, exhibiting an average particle size ranging from 15 to 60 nm. These nanoparticles were seen to be evenly dispersed across the graphene sheets. The presence of nanostructure porphyrin nanofibers, measuring 20 nm in diameter, was also shown to exhibit strong integration with the surface of the Fe/graphene nanomaterials. The electrochemical properties of the Fe/graphene/porphyrin nanocomposite were also investigated, demonstrating that the prepared material could be effectively employed as a sensing electrode in the electrochemical sensor for detecting Chloramphenicol (CAP) through CV, EIS, and DPV techniques using a three-electrode electrochemical system. Under optimal conditions, Fe/graphene/porphyrin exhibited a high current response when detecting CAPs.

N-Doping CQDs as an Efficient Fluorescence Probe Based on Dynamic Quenching for Determination of Copper Ions and Alcohol Sensing in Baijiu.

To address an accurate detection of heavy metal ions in Baijiu production, a nitrogen-doping carbon quantum dots (N-CQDs) was prepared by hydrothermal method from citric acid and urea. The as-prepared N-CQDs had an average particle size of 2.74 nm, and a large number of functional groups (amino, carbonyl group, etc.) attached on its surface, which obtained a 9.6% of quantum yield (QY) with relatively high and stable fluorescence performance. As a fluorescent sensor, the fluorescence of N-CQDs at 380 nm excitation wavelength could be quenched quantitatively by adding Cu2+, due to the dynamic quenching of electron transfer caused by the binding of amine groups and Cu2+, which showed excellent sensitivity and selectivity to Cu2+ in the range of 0.5-5 μM with a detection limit (LOD) of 0.032 μM. In addition, the N-CQDs as well as could be applied to quantitative determine alcohol content in the range of 10-80 V/V% depending on the fluorescence enhancement. Upon the experiment, the fluorescent mechanism was studied by Molecular dynamics (MD) simulations, which demonstrated that solvent effect played an influential role on sensing alcohol content in Baijiu. Overall, the work provided a theoretically guide for the design of fluorescence sensors to monitor heavy metal ion in liquid drinks and sense alcohol content.

Fullerene C60 Conjugate with Folic Acid and Polyvinylpyrrolidone for Targeted Delivery to Tumor Cells

The use of targeted drug delivery systems, including those based on selective absorption by certain receptors on the surface of the target cell, can lead to a decrease in the minimum effective dose and the accompanying toxicity of the drug, as well as an increase in therapeutic efficacy. A fullerene C60 conjugate (FA-PVP-C60) with polyvinylpyrrolidone (PVP) as a biocompatible spacer and folic acid (FA) as a targeting ligand for tumor cells with increased expression of folate receptors (FR) was obtained. Using 13C NMR spectroscopy, FT-IR, UV-Vis spectrometry, fluorometry and thermal analysis, the formation of the conjugate was confirmed and the nature of the binding of its components was established. The average particle sizes of the conjugate in aqueous solutions and cell culture medium were determined using dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA). The FA-PVP-C60 showed antiradical activity against •DPPH, •OH and O2•−, but at the same time, it was shown to generate 1O2. It was found that the conjugate in the studied concentration range (up to 200 μg/mL) is non-toxic in vitro and does not affect the cell cycle. To confirm the ability of the conjugate to selectively accumulate through folate-mediated endocytosis, its uptake into cells was analyzed by flow cytometry and confocal microscopy. It was shown that the conjugate is less absorbed by A549 cells with low FR expression than by HeLa, which has a high level of expression of this receptor.

Parameters Optimization and Physicochemical Properties Characterization of Nanobiochar Prepared from Apple Branches by Ball Milling

Nanobiochar exhibits promising applications across a spectrum of fields due to its exceptional physicochemical properties. Ball milling, a prominent nanobiochar synthesis method, is influenced by process factors and biochar pretreatments, yet dominant controls still remain uncertain. In this study, the apple branch bulk biochar (pyrolyzed under 350[Formula: see text] C) was ball milled under different milling speeds, ball-to-powder mass ratios, and milling durations to investigate the optimal process parameter combinations for ball milling method. Then, we evaluated the impact of pyrolysis temperature and pretreatment temperature of bulk biochar on ball milling effect using optimized parameter combinations. Subsequently, the physicochemical properties of the bulk biochar and nanobiochar were measured. The results showed that high speed with low ball-to-powder mass ratio, low speed with high ball-to-powder mass ratio, and high pyrolysis temperature could significantly decrease the particle sizes of nanobiochar. Ball milling duration and pretreatment temperature had no significant effect on the particle sizes of biochar. The optimal combination of the rotational speed, ball-to-powder mass ratio and milling duration was 400 RPM, 100:1, 2 h and 700 RPM, 20:1, 2 h. The bulk biochar pyrolyzed at 550[Formula: see text] C could be milled into biochar nanoparticles with an average particle size smaller than 100 nm via above parameters. Nanobiochar shows improved properties such as specific surface area, cation exchange capacity, and surface functional groups over bulk biochar. This study provides a scientific basis for the widespread application of ball milling in the field of preparing nanobiochar.

Quantitative characterization of microstructure and research on spatial variation characteristics of loess of different strata in Luochuan, Shaanxi, China.

The complete sequence of loess strata in Luochuan has become a typical section in loess strata, and is the main focus of research for many scholars studying loess. We were based on the theory of aeolian loess and established a set of quantitative index parameters for loess microstructure through our previous research, such as equivalent diameter, sphericity, morphology ratio, orientation angle Phi, orientation angle Theta, pore Eq-Radius, throat Eq-Radius and throat channelLength. Through the quantitative characterization of various index parameters of the Luochuan loess, we found that the probability density of each index parameter meets a specific distribution well, and in terms of spatial dimension, it shows that as the depth of the strata increases, the average particle size and the mode of pore Eq-Radius, throat Eq-Radius and throat channelLength generally increase, while the mode of particle morphology ratio generally decreases. In addition, loess particles in deeper strata are less prone to vertical sedimentation and tend to deposit gently or horizontally. Most particles in different strata are distributed in a northwest or southwest direction. During the formation period of strata, the main cause for spatial differences is the material carrying force. We conducted a statistical analysis on the correlation between the macroscopic physical properties of loess and its microstructure index parameters. Specifically, we found a positive correlation between loess density and the average particle size and the mode of particle equivalent diameter, Additionally, we found a negative correlation between loess liquid limit and plastic limit, and the mode of particle morphology ratio. Furthermore, there was a negative correlation between permeability coefficient and the mode of pore Eq-Radius, throat Eq-Radius, and throat channelLength.

Cadmium oxide nanoparticles from new organometallic Cd(II)-Schiff base complex and in vitro biological potentials: dual S. aureus and E. coli DNA gyrase inhibition by the precursors via in silico binding modes’ study

AbstractAt the nanoscale level, several biological processes take place, owing to the potential that engineered nanomaterials might interrelate with bio-molecules and cellular procedures. This study aimed to synthesize cadmium oxide nanoparticles via a one-step calcination process of tetradentate Schiff base-Cd(II) complex at different temperature ranges. The as-synthesized compounds were carried out via a viz UV–visible, elemental analysis, 1H NMR, molar conductivity, transmission electron microscopy (TEM), FT-IR spectroscopy, and X-ray diffraction (PXRD). The band gap energy and average particle sizes of the CdO particles are respectively (2.69 eV, 3.54 eV), 26.88 nm for CdO@250, and (3.20 eV, 3.57 eV), 25.67 nm for CdO@300, while CdO@350 exhibited the 3.78 eV and 28.42 nm values. The antioxidant accomplishments of the test samples through the scavenging activity of DPPH radicals showed CdO@300 to possess (IC50 = 5.18 ± 0.56 µg/mL). Similarly, the as-synthesized CdO nanoparticles exhibited higher antibacterial activities against S. aureus and E. coli as compared to the corresponding Cd-HMB and ligand (HMB), while ciprofloxacin acted as a standard antibiotic. Furthermore, HMB and its complex Cd-HMB were docked against the DNA gyrase enzymes of S. aureus (PDB IDs: 5CDQ) and E. coli (PDB IDs: 6F86) as receptors. The binding sites docking results showed that the binding energies of HMB and Cd-HMB to 5CDQ ranged from − 3.44 to − 4.99 kcal/mol and from − 6.45 to − 6.64 kcal/mol, while the binding energies related to the target 6F86 are in the ranges of (− 3.64, − 4.76) kcal/mol and (− 6.08, − 6.09) kcal/mol respectively. Therefore, the significant antioxidant and antibacterial activities of the ligand (HMB), Cd-HMB, and CdO NPs review the broad application prospects of these compounds as therapeutic agents for wide-ranging biomedical applications.

Combined helical-blade-strengthened co-flow focusing and high-throughput screening for the synthesis of highly homogeneous nanoliposomes

Nanoliposomes have been widely employed as promising drug delivery vehicles for the treatment of various diseases. However, the large-scale synthesis of drug-loaded nanoliposomes manifesting a highly uniform particle size is impeded by several unmet challenges. Herein a novel helical-blade-strengthened co-flow focusing (HBSCF) device was developed by installing multiple parallel helical blades in a commonly used co-flow focusing microfluidic device. This transformation in the microchannel structure may accelerate the mixing of aqueous and lipid streams in a radial direction, thereby affording the production of nanoliposomes with a significantly lower polydispersity index (PDI) value in terms of particle size. Moreover, a high-throughput experimental platform was developed by employing HBSCF device alongside its integration with various automation modules, which afforded 672 distinct experimental schemes for the synthesis and size characterization of drug-loaded nanoliposomes within 40 h. Afterwards, based on the above obtained large data set of nanoliposomes, a typical machine learning (ML) model pertaining to particle size was established to predict candidate synthesis schemes for the desired average particle size. Therefore, by narrowing the screening ranges through ML, the final synthesis scheme capable of producing liposomes with the desired particle size along with minimum PDI value can be precisely and rapidly obtained using automated experiments based on the same platform. Taken together, an effective integration of the HBSCF synthesis along with an automated high-throughput experimental platform may have broad implications for the industrialization and clinical application of nanomedicine.

Environmentally Friendly Synthesis of Polymer Nanoparticles in a Packed Reactor Using Glass Beads

AbstractPolymeric particles less than 100 nm in size (polymer nanoparticles), which are useful in the fields of medicine and so on, are synthesized through emulsion polymerization, wherein surfactants are essential for maintaining their dispersion stability, contaminating particle surfaces and causing high environmental pollution. The soap‐free emulsion polymerization (SFEP) of styrene in a packed reactor using microglass beads enables the synthesis of polymer nanoparticles without surfactants. Ultraviolet irradiation is used for radical polymerization using an initiator during the SFEP of styrene. The reaction space in the packed reactor is controlled by the size of glass beads to be filled in the reactor. A decrease in the size of the glass beads narrows the reaction space, causing the average polystyrene particle size to reach 27.3 nm and suppress convection flow by the wall of the glass beads, thereby limiting particle motion and preventing particle growth through particle collisions.This article is protected by copyright. All rights reserved

Iron(III) Monoglycerolate: A Potential Hemostatic Agent for Topical Application

Background: Glycerolates of biogenic elements are of interest because of their pharmacological activity. Some of them are used as active substances in agents for topical application and as biocompatible precursors in sol-gel synthesis of bioactive materials. Objective: In this work, morphostructural feature, ability to hydrolyze, and the pharmacological activity of previously synthesized iron(III) monoglycerate were studied. Methods: Analytical techniques, including SEM, TEM, XRD, TGA, IR spectroscopy, DLS and ELS, were used. Hemostatic activity was studied in vivo, and primary toxicological studies were carried out on experimental animals. Antimicrobial activity was studied using the agar diffusion method. Results: When dispersed in glycerol, solid crystalline iron(III) monoglycerolate transforms into an amorphous state, forming aggregates with an average particle size of 250 nm (according to DLS data). It slowly hydrolyzes in water at room temperature, while hydrolysis does not take place in an aqueous glycerol media. Iron(III) monoglycerolate is nontoxic and exhibits pronounced hemostatic activity and low antibacterial activity (relative to the strain S. аureus). Conclusion: Iron(III) monoglycerolate can be considered a potential hemostatic agent, showing promise for topical application in medical and veterinary practice, as well as a novel biocompatible precursor in the sol-gel synthesis of practically useful substances.

Synthesis, characterization, and implementation of BaNiO3 perovskite nanoparticles as thin film supercapacitor electrode

AbstractThis work is the first attempt to explore the supercapacitor applications of Barium nickelate (BaNiO3) perovskite nanoparticles. The nanoparticles are synthesized using a simple combustion method and their morphology, elemental composition, and so forth are studied using standard characterization methods such as x‐ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FESEM), and so forth. The nanoparticles were found to be hexagonal in shape, with an average particle size of 16 nm, and the elemental analysis confirms the successful synthesis of the BaNiO3 perovskite nanoparticles. For electrochemical studies, the electrodes are fabricated over a wearable and flexible conductive fabric (CF) substrate. A slurry paste of the synthesized BaNiO3 nanoparticles is applied over CF and dried overnight, thereby forming a thin film electrode. The fabricated electrode acts as a positive electrode with a high specific capacitance of 508.64 F g−1 at 2.2 A g−1 current density. Upon increasing the current density, the electrode maintains 60% of its specific capacitance and displays 97% cyclic stability over 5000 cycles. The electrochemical impedance spectroscopy (EIS) study indicates excellent conductivity of the electrode, with a bulk resistance of 3.2 Ohms. The electrochemical performance of the fabricated electrode is also compared with various previously reported works and the electrode displays higher specific capacitance and better cyclic stability. These findings suggest that the BaNiO3 perovskite nanoparticles‐based electrode holds promise for utilization as an anode material in supercapacitor applications.

Synthesis and drug release kinetics of ciprofloxacin from polyacrylamide/dextran/carbon quantum dots (PAM/Dex/CQD) hydrogels

Sustainable release of drug by utilizing β-cyclodextrin (β-CD) based inclusion complex (IC) is the prime objective of the present work. Herein, polyacrylamide/dextran containing carbon quantum dots (PAM/Dex/CQD) nanocomposite hydrogels are prepared by in situ polymerization of acrylamide. The incorporation of CQD triggers the change in orientation of the PAM/Dex polymeric chains to result the formation of stacked surface morphology of the hydrogel. The average particle size of CQD is found to be 4.13 nm from HRTEM analysis. As-synthesized nanocomposite hydrogel exhibits an optimum swelling ratio of 863 % in aqueous medium. The cytotoxicity study is conducted on HeLa cells by taking up to 2 μM concentration of the prepared nanocomposite hydrogel demonstrate 78 % cell viability. In present study, ciprofloxacin (Cipro) is taken as model drug that achieves release of 64.15 % in 32 h from β-Cipro@PAM/Dex/CQD hydrogels in acidic medium. From theoretical study, release rate constants, R2, Akaike information criterion (AIC) and model selection criterion (MSC) are computed to determine the best fitted kinetics model. Peppas-Sahlin model is the best fitted kinetics model for β-Cipro@PAM/Dex/CQD and concluded that the release of Cipro follows Fickian drug diffusion mechanism in acidic medium.

Zwitterionic targeting nanodrugs prepared from poly(propyleneimine) dendrimers for enhanced anti-tumor therapy

Development of targeting and high drug loading drug delivery system has been gaining great interest. Zwitterionic modification of the terminal amine groups on G2 poly(propyleneimine) (G2 PPI) dendrimers was achieved via the thiol-ene click reaction, followed by the introduction of the anti-cancer drug paclitaxel and targeting peptides c(RGDfC), then the micelles were formed through self-assembly behavior, subsequently doxorubicin was encapsulated internally, finally the targeting drug-loaded micelles PPIMPRC-DOX were synthesized. The PPIMPRC-DOX micelles were irregular spherical with good monodispersity. The average particle size from TEM image was 63.05 nm and the hydrodynamic size was 93.1 nm, both of which were relatively uniform. The critical micelle concentration was 48.52 μg/mL, the total drug loading efficiency was 32.45 %. In vitro release experiments revealed that within the mildly acidic environment of tumors, PPIMPRC-DOX micelles exhibited enhanced release efficiency and increased accumulation of DOX. The anti-nonspecific protein adsorption experiment proved that the interaction between the PPIMPRC-DOX micelles and fibrinogen was very weak, and they had good anti-nonspecific protein adsorption ability. The cytotoxicity assessments using the MTT assay on HeLa cells and A549 cells revealed obvious cytotoxic effects of PPIMPRC-DOX micelles on both cells. Hence, the utilization of zwitterionic G2 PPI dendrimers in constructing PPIMPRC-DOX micelles holds promise as a prospective nanodrug delivery system.

Design and Study of a Sediment Erosion Test Device for a Single-Flow Channel in the Guide Apparatus of a Reaction Hydraulic Turbine

Sediment erosion damage is one of the main causes of structural failure in reaction turbine units. To study the mechanism through which sediment erosion affects the water-guiding mechanism of a reaction turbine unit, this study obtained the average concentration and particle size of sediment during the flood season based on the statistics of the measured sediment data from the power station. Additionally, the characteristics of the solid–liquid two-phase flow of the diversion components of the reaction hydraulic turbine were numerically calculated. Based on the velocity triangle change in the guide apparatus and the flow similarity principle, a flow-around wear test device for the guide apparatus of the reaction turbine was designed. Furthermore, the similarity of the sand–water flow field between the guide apparatus of the prototype unit and the test device was compared and analyzed. The results demonstrated that the sand–water flow field of the diversion components of the prototype unit was axisymmetric and exhibited a potential flow distribution. Additionally, uniform sand–water flow occurred within the guide apparatus, with a small sand–water velocity gradient near the wall of the stay vanes (SV) and the guide vanes (GV). The maximum volume fraction of sediment particles was observed in the tailing area of the spiral casing, indicating an enrichment phenomenon of sediment particles. The velocity of the sediment particles on the surface of the guide vane in the single-channel sediment wear test device and prototype unit ranged from 6.2 to 7.8 m/s, and the velocity of the sediment particles on the surface of the stay vane ranged from 5.1 to 14.6 m/s, and the difference of the sediment particles’ velocity near the wall was 1 to 3 m/s. The trailing vorticity of the guide vane reached a maximum of 120 s−1. Consequently, the single-channel sediment erosion test device can unveil the sediment erosion mechanism of the guide apparatus of a reaction turbine.

Development of posaconazole nanocrystalline solid dispersion: preparation, characterization and in vivo evaluation

Objective: Posaconazole (PCZ) is an antifungal drug, which acts by inhibiting the lanosterol-14α-demethylase enzyme. It is a biopharmaceutical classification system class II drug with its bioavailability being limited by poor aqueous solubility. The aim of this study was to improve the oral bioavailability of PCZ by preparing nanocrystalline solid dispersion (NCS). Methods: PCZ-NCS was prepared by a combination of precipitation and high-pressure homogenization followed by freeze-drying. Several different surfactants and polymers were screened to produce NCS with smaller particle size and higher stability. Results: The optimized NCS formulation containing 0.2% Eudragit S100 and 0.2% SLS was found to provide the average particle size of 73.31 ± 4.7 nm with a polydispersity index of 0.23 ± 0.03. Scanning electron microscopy revealed the preparation of homogeneous and rounded particles. Differential scanning calorimetry and X-ray diffraction confirmed crystalline nature of NCS. Nanonization increased the saturation solubility of PCZ by about 18-fold in comparison with the neat drug. Intrinsic dissolution study showed 93% dissolution of PCZ within the first 10 min. In vivo pharmacokinetic study in Wistar rats showed that Cmax and AUC total of PCZ-NCS increased by 2.58 and 2.64-fold compared to the marketed formulation. Conclusion: PCZ-NCS formulation presents a viable approach for enhancing the oral bioavailability of PCZ.

ENHANCING NOSE- TO- BRAIN DELIVERY OF PIRIBEDIL: DEVELOPMENT OF A NANOSUSPENSION DISPERSED IN NASAL IN-SITU GELLING SYSTEM

Objective: This study focuses on improving the delivery of Piribedil, a poorly soluble drug, to the brain through the nasal route using a nanosuspension in a nasal in-situ gel. Methods: The nanosuspension was prepared using the sonoprecipitation method. Quality-by-Design (QbD) principles were used to optimize both the formulation and process parameters. The optimal process parameters were determined as sonication time (7.09 min), sonication amplitude (83.44%), and infusion rate (2.41 mL/min) with a desirability value of 0.970. Results: The nanosuspension exhibited an average particle size ranging from 46.7 nm to 50.1 nm, and polydispersity index values between 0.393 and 0.425. Zeta potential values ranged from -33.78 ± 1.86 mV to -35.06 ± 2.12 mV, indicating favorable stability. FTIR studies revealed molecular interactions between Piribedil and stabilizers. XRPD and DSC analyses showed the transition from a crystalline to an amorphous state in the nanosuspension. Dissolution studies demonstrated significantly accelerated dissolution for the Piribedil nanosuspension, attributed to its nanosize and improved wettability. Stability assessments confirmed the robustness of the nanosuspension. Conclusion: This innovative approach offers potential solutions for drug solubility challenges and blood-brain barrier penetration, holding promise for effective brain-targeted treatments.