• Journal of Pharmaceutical Investigation
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• v.26 no.4
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• pp.245-256
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• 1996

Solid lipid nanoparticles (SLN) have been developed as a new drug delivery system. Although many particulate drug carriers, such as microsphere, liposome, niosome, emulsion, etc. have been introduced, they have some disadvantage; low efficiency of incorporation and stability, lack of reproducibility, and so on. Meanwhile, SLN as a new drug delivery system is known to entrap rugs with a high efficiency and a good reproducibility. Moreover, small size SLN can circulate in blood for a prolonged time. Although many preparation methods were introduced, microfluidization method is recommended to be the most useful. This study was attempted to prepare and evaluate ketoprofen-incorporated SLNs (keto-SLN), which were prepared by two methods, ultrasonication and microfluidization. Keto-SLN was evaluated by measurement of particle size and zeta potential, efficacy of entrapment, sedimentation volume, in virto release pattern. The mean particle size was about $0.1\;{\mu}m$, and the size was dependent on the type and the amount of emulsifier. Zeta potential was negative, $-9{\sim}-13mV$ and entrapment efficacy was very high and stability was good for at least 60 days in the respect of particle size and sedimentation volume ratio. Analgesic effect was also determined as well as pharmacokinetic parameters. The former was comparable to that of that of ketoprofen loaded suspension (keto-sus) and the latter revealed that consistent with the delayed release of keto-SLN. $T_{max}$ was longer than keto-sus. Therefore, keto-SLN was favourable dosage forms in the field of drug delivery system such as anti-cancer, analgesics and anti-inflammatory agents.

• Journal of Biomedical Engineering Research
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• v.40 no.1
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• pp.7-14
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• 2019

The microencapsulation of nifedipine (NF) with 4 wt% of poly(${\varepsilon}-caprolactone$) (PCL)/polyvinylpyrollidone (PVP) or PCL/polyethylene glycol (PEG) was carried out by solvent evaporation method in oil in water emulsion system to investigate the effect of PVP and PEG addition on drug release behavior of the microcapsules. The PVA (emulsifier) concentration of 1.0 wt% was chosen for the formation of PCL capsule having an average size of $154{\pm}25{\mu}m$ due to nearly spherical shape with a narrow size distribution. As PCL/PVP and PCL/PEG ratios were raised from 10/0 to 6/4, the capsule size increased gradually from $154{\pm}25{\mu}m$ to $236{\pm}32{\mu}m$ and $248{\pm}56{\mu}m$, respectively. The drug release rate of PCL/PVP and PCL/PEG capsules increased dramatically from 0 to 4 h at the beginning and then reached the plateau region from 20 h. As the concentration of PVP or PEG increased, the amount of drug release increased, suggesting that the larger capsule size was attributed to the higher drug content. However, the drug release behavior remained almost constant. The PCL capsules exhibited no evidence of causing cell lysis or toxicity regardless of NF loading, implying that the microcapsules are clinically suitable for use as drug delivery systems.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.17-22
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• 2019

In this study, cationic gemini surfactants were synthesized by increasing the length of the hydrophobic chain and using 1,4-butanediol as a spacer, and the result was confirmed by $^1H-NMR$. The synthesized surfactant was a white powder, and Kraffts point was below $0^{\circ}C$. Surface tension measurements revealed that the evaluated critical micelle concentration (c.m.c) was $1.8{\times}10^{-3}{\sim}6.5{\times}10^{-4}mol/L$ with a surface tension of 22.5~26.1 dyne/cm at the c.m.c. The initial foam height for CG 14-6E-14 estimated by Ross-Miles method was 16 cm and after 5 minutes the height was 14 cm. It was confirmed that the initial foam force and foam stability were the highest. The foam test and emulsion stability of synthesized gemini cationic surfactants were also compared to those of cetyltrimethylammonium bromide (CTAB), a commoly used surfactant.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.102-107
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• 2019

Anionic surfactants were synthesized by using an sarcosine, taurine and fatty alcohol with varying the carbon chain length. The structure of synthesized surfactants was confirmed by $^1H$ NMR analysis. The critical micelle concentration of the synthetic anionic surfactant was $10^{-2}{\sim}10^{-4}mol/L$ and the surface tension value at the critical micelle concentration was between 21 and 39 mN/m. It was confirmed by the Ross-Miles method that the synthetic surfactant with the carbon chain of 12 showed a good foaming power and stability. In addition, the surfactant using the sacosine was found to have a good affinity in soybean oil while that using taurine in benzene. The physical properties of synthesized surfactants were determined by measuring the critical micelle concentration, foaming power and emulsifying stability.

• Journal of Pharmacopuncture
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• v.22 no.2
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• pp.102-108
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• 2019

Objectives: Esophageal squamous cell carcinoma (ESCC) is considered as a deadly medical condition that affects a growing number of people worldwide. Targeted therapy of ESCC has been suggested recently and required extensive research. With cyclin D1 as a therapeutic target, the present study aimed at evaluating the anticancer effects of doxorubicin (Dox) or Hypericum perforatum L. (HP) extract encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles on the ESCC cell line KYSE30. Methods: Nanoparticles were prepared using double emulsion method. Cytotoxicity assay was carried out to measure the anti-proliferation activity of Dox-loaded (Dox NPs) and HP-loaded nanoparticles (HP NPs) against both cancer and normal cell lines. The mRNA gene expression of cyclin D1 was evaluated to validate the cytotoxicity studies at molecular level. Results: Free drugs and nanoparticles significantly inhibited KYSE30 cells by 55-73% and slightly affected normal cells up to 29%. The IC50 of Dox NPs and HP NPs was ~ 0.04-0.06 mg/mL and ~ 0.6-0.7 mg/mL, respectively. Significant decrease occurred in cyclin D1 expression by Dox NPs and HP NPs (P < 0.05). Exposure of KYSE-30 cells to combined treatments including both Dox and HP extract significantly increased the level of cyclin D1 expression as compared to those with individual treatments (P < 0.05). Conclusion: Dox NPs and HP NPs can successfully and specifically target ESCC cells through downregulation of cyclin D1. The simultaneous use of Dox and HP extract should be avoided for the treatment of ESCC.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.596-610
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• 2021

For application in adsorption process, we synthesized silica nanospheres by Stober method, and silica particles with wrinkled surface as well as macroporous silica particles were also fabricated by utilizing emulsion droplet as micro-reactors, followed by modification of the particle surface using suitable coupling agents containing amine groups. These particles exhibited improved adsorption capacity for heavy metal ions and anionic dyes, which were difficult to be removed by conventional silica particles without surface modification. Anionic dye, methyl orange could be removed almost completely by adsorption using porous silica particles modified using APTES. The adsorption efficiency of heavy metal like copper ions was close to 100%, when porous silica was used as adsorbent particles modified with AAPTS.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.662-668
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• 2021

The aim of the present study was to design ascorbyl glucoside (AG) loaded solid lipid nanoparticles (SLNs) to improve skin penetration of AG. AG loaded SLNs were prepared using double emulsion method. The prepared AG loaded SLNs investigated particle characteristics (particle size, polydispersity index, zeta potential, loading capacity). Skin penetration study was carried out using SkinEthic RHE as one of the reconstructed human epidermis models. The mean particle size and zeta potential of SLNs were 172.65 - 347.19 nm and -22.90 - -41.20 mV, respectively. The loading capacity of AG loaded SLNs demonstrated that loading efficiency and loading amount were ranged from 44.18% to 57.77% and 12.83% to 16.15%, respectively. The results of penetration showed that all SLNs enhanced the skin penetration of AG and the amount of AG from SLNs were approximately 3.7 - 7.4 times higher than that from AG solution. Therefore, AG loaded SLN might be a promising topical drug delivery system.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.508-519
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• 2021

In this study, a model was developed to predict the peak particle velocity (PPV) that affects people and the surrounding environment during blasting. Four machine learning models using the k-nearest neighbors (kNN), classification and regression tree (CART), support vector regression (SVR), and particle swarm optimization (PSO)-SVR algorithms were developed and compared with each other to predict the PPV. Mt. Yogmang located in Changwon-si, Gyeongsangnam-do was selected as a study area, and 1048 blasting data were acquired to train the machine learning models. The blasting data consisted of hole length, burden, spacing, maximum charge per delay, powder factor, number of holes, ratio of emulsion, monitoring distance and PPV. To evaluate the performance of the trained models, the mean absolute error (MAE), mean square error (MSE), and root mean square error (RMSE) were used. The PSO-SVR model showed superior performance with MAE, MSE and RMSE of 0.0348, 0.0021 and 0.0458, respectively. Finally, a method was proposed to predict the degree of influence on the surrounding environment using the developed machine learning models.

• Food Science of Animal Resources
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• v.42 no.3
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• pp.536-555
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• 2022

The most abundant Orthoptera in Mexico is a small grasshopper (Sphenarium purpurascens) which is considered a food source with increased nutritional value due to its high protein content. Insect proteins have gained relevance because of their high potential as gelling, texturing, and extender agents in the food industry. The objective of this study was to evaluate the effect of substituting meat with a soluble protein extract from grasshopper obtained by alkalisation or alkalisation-piezoelectric ultrasound, on the techno-functional, physicochemical, and sensory characteristics of cooked meat models (sausages). The soluble protein was extracted in NaHCO₃ pH 8 and a piezoelectric ultrasound 5-mm sonotrode at 20 kHz with 99% amplitude. Different formulations with meat substitution: 0%, 5%, 10%, and 15% were prepared and characterised for their rheological behaviour, emulsion stability, weight loss by cooking, total protein content, colour, and texture. Sensory evaluation was conducted with consumers using a test involving check-all-that-apply and overall liking. The alkalisation-piezoelectric ultrasound method improved the solubility and the techno-functional properties of the soluble grasshopper protein when applied in sausages at maximum levels of 10% meat substitution. The sensory evaluation indicated that the formulation with 5% meat substitution exhibited the same acceptability as the control sample. Given these results, the soluble protein treated with alkalisation and piezoelectric ultrasound could be used as an extender in meat products.

• Resources Recycling
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• v.32 no.2
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• pp.33-42
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• 2023

Metal emulsions have been studied for several decades as a method of increasing the efficiency of the steelmaking process. This study was performed using a water model, observable at room temperature, to compensate for the disadvantages of the high-temperature experiment, the results of which are difficult to observe visually. As a substitute for metal-in-slag emulsions, experiments were conducted by dropping distilled water into silicone oil and comparing the results with the results of a calculation by momentum balance equations. The descending velocity of the water droplet decreased as the diameter of the droplet and viscosity of the fluid (silicon oil) increased. To simulate the descending velocity of a water droplet in silicon oil under stirring conditions, the flow rate of the fluid (silicon oil) was measured by particle image velocimetry (PIV) methods. The calculation of the descending velocity of the water droplet was in good agreement with the measured values, with and without stirring a viscous silicone oil.