• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.684-689
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• 2012

Poly(acrylic acid) (PAA) microspheres is one of the widely-used polymeric materials for the bio-field application and the electric materials. For the synthesis of PAA microspheres, the polymerization technique using surfactants is applied. After the synthesis, the purification and separation processes are required for the removal of surfactant. When general organic solvents were used, many problems, such as huge amount of waste solvent, additional separation processes, and the possibility of residual media, were occurred. Thus, High-pressure Soxhlet extraction using liquid $CO_2$ was developed to solve these problems. In this study, High-pressure Soxhlet extraction of the synthesized PAA microspheres using liquid $CO_2$ was conducted for the removal of Monasil PCA which is used for the dispersion polymerization of acrylic acid in compressed liquid Dimethyl ether (DME). The morphology of the extracted PAA particles was checked by field emission scanning electron microscopy (FE-SEM) and the residual concentration of Monasil PCA was analyzed by inductively coupled plasma - Optical Emission Spectrometer (ICP-OES). For studying the effect of the solvent effect, Soxhlet extraction was conducted using n-hexane, liquid DME, and liquid $CO_2$. In case of n-hexane, some extracted PAA microspheres were produced. However, deformation was also occurred due to the high thermal energy of n-hexane vapor. Liquid DME could not remove Monasil PCA. When using liquid $CO_2$, the extracted PAA microspheres which were free for the residual solvent were produced without deformation. For finding the optimum operating condition, high-pressure Soxhlet extraction was conducted for 8 hours with changing the temperature of reboiler and condenser. When the extractor temperature is $19.6{\pm}0.2^{\circ}C$ and the pressure is $51.5{\pm}0.5$ bar, the best removal efficiency was obtained.

• Korean Journal of Veterinary Research
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• v.32 no.2
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• pp.175-179
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• 1992

To develope the methods for isolation and enumeration of lymphocyte subpopulations in pigs, we carried out the rosette-assay using sheep erythrocytes(SRBC) and Korean native goat erythrocytes(GRBC) as a target cells. To enumerate T lymphocytes, E-rosette methods were applied with RBC treated with various concentration of polymers such as Aet and Dex, singly or in combination. And to enumerate B lymphocytes, EAand EAC-rosette assay was adopted. The results were as follows; 1. E-RFR with polymer-untreated SRBC and GRBC was $32.9{\pm}7.9%$ and $31.3{\pm}9.4%$, respectively. On the other hand, RFR with 0.1M Aet plus 8% Dex treated SRBC and GRBC was increased about two-fold($67.8{\pm}7.4%$ and $69.8{\pm}8.5%$), respectively. 2. EA-RFR with SRBC and GRBC were $ 39.1{\pm}10.2%$ and $32.6{\pm}6.1%$, respectively. 3. EAC-RFR with SRBC and GRBC were $27.6{\pm}7.0%$ arld $21.0{\pm}3.2%$, respectively. These results showed that both SRBC and GRBC could be recommanded as a binding cells for rosetteassay to isolate of lymphocyte-subpopulations in pigs.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.1-23
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• 2001

Chitosan is biodegradable natural polymer that has been demonstrated its ability to improve wound healing, and calcium metaphosphate(CMP) is a unique class of phosphate minerals having a polymeric structure. In this study, chitosan/CMP and platelet derived growth factor(PDGF-BB) loaded chitosan/CMP sponges were developed, and the effect of the sponges on bone regeneration and their possibility as scaffolds for bone formation by three-dimensional osteoblast culture were examined. PDGF-BB loaded chitosan/CMP sponges were prepared by freeze-drying of a mixture of chitosan solution and CMP powder, and soaking in a PDGF-BB solution. Fabricated sponge retained its 3-dimensional porous structure with $100-200\;{\mu}m$ pores. The release kinetics of PDGF-BB loaded onto the sponge were measured in vitro with $^{125}I-labeled$ PDGF-BB. In order to examine their possibility as scaffolds for bone formation, fetal rat calvarial osteoblastic cells were isolated, cultured, and seeded into the sponges. The cell-sponge constructs were cultured for 28 days. Cell proliferation, alkaline phosphatase activity were measured at 1, 7, 14 and 28 days, and histologic examination was performed. In order to examine the effect on the healing of bone defect, the sponges were implanted into rat calvarial defects. Rats were sacrificed 2 and 4 weeks after implantation and histologic and histomorphometrical examination were performed. An effective therapeutic concentration of PDGF-BB following a high initial burst release was maintained throughout the examination period. PDGF-BB loaded chitosan/CMP sponges supported the proliferation of seeded osteoblastic cells as well as their differentiation as indicated by high alkaline phosphatase activities. Histologic findings indicated that seeded osteoblastic cells well attached to sponge matrices and proliferated in a multi-layer fashion. In the experiments of implantation in rat calvarial defects, histologic and histomorphometric examination revealed that chitosan/CMP sponge promoted osseous healing as compared to controls. PDGF-BB loaded chitosan/CMP sponge further echanced bone regeneration. These results suggested that PDGF-BB loaded chitosan/CMP sponge was a feasable scaffolding material to grow osteoblast in a three-dimentional structure for transplantation into a site for bone regeneration.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.702-711
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• 2015

This study was conducted to determine the feasibility of using Gastrodia elata Blume as a cosmetic raw material by investigating the physiological activities of its extracts, varying the concentration, solvent, and fermentation method (non-fermentation and fermentation using lactic acid bacteria and effective microorganisms). Of the extracts in three different solvents-water, EtOH, and 70% EtOH-at four different concentrations (0.725, 1.25, 2.5, and 5 mg/mL), the EtOH extracts demonstrated the highest contents of antioxidants (flavonoids, polyphenols, and DPPH free radical scavengers). The DPPH free radical scavenging activity in the EtOH extracts of EM-fermented Gastrodia elata Blume increased from $27.08{\pm}0.5%$ at 1.25 mg/mL to $35.89{\pm}0.8%$ at 2.5 mg/mL. The tyrosinase inhibitory activity test was performed to measure skin-whitening capacity and revealed the LB-fermented EtOH extracts to be the most efficacious ($39.1{\pm}0.4%$ at 0.725 mg/mL, $62.8{\pm}1.5%$ at 2.5 mg/mL). Viability was found to exceed 85% in RAW 264.7 cells treated with all extracts (water, EtOH, 70% EtOH at 10, 25, $50{\mu}L$, fermented and non-fermented), thus proving that Gastrodia elata Blume extracts do not cause inflammation. When RAW 264.7 cells were stimulated with lipopolysaccharide as positive controls under the same conditions to determine the antioxidant activity in the presence of reactive oxygen species (ROS), EM-fermentation was found to impart excellent antioxidant capacity. This study verified the physiological activities of fermented Gastrodia elata Blume extracts that are best suited for cosmetic ingredients, such as antioxidants, tyrosinase inhibitors and anti-inflammatory agents.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.154-163
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• 1989

This studies were designed to improve the productivity of L-lysine by protoplast fusion and immobilized system of fusants using strains of Brevibacterium flavum ATCC 21528, Brevibacterium lactofermentum ATCC 21086 and Corynebacterium glutamicum 820. Mutants were isolated with concentration method of $300{\mu}g/ml$ penicillin-G after treatment of $250{\mu}g/ml$ N-methyl-N-nitro-N-nitrosoguanidine. B. flavum $37-2(Hos^-,\;Kan^r,\;AEC^r)$, B. lactofermentum $6-2(Ile^-,\;Val^-,\;Str^r,\;AEC^r)$ and C. glutamicum 57-5$(Met^-,\;Thr^-,\;Rif^r,\;AEC^r)$ were isolated from mutants. Protoplasts were induced by being incubated with $500{\mu}g/ml$ lysozyme of lysis solution for 6 hr and the ratio of protoplast formation and regeneration were ranging from 97-99% and 33-37%, respectively. Fusion frequencies of fusants of BBFL 21, BCFG 37 and BCLG 59 were shown in the range from $1.25{\times}10^{-6}\;to\;5.83{\times}10^{-7}$ under the optimum conditions. The fusant BBFL 21 showed the highest productivity of $411.1\;ng/ml{\cdot}hr$ L-lysine in the lysine productivity broth at $30^{\circ}C$ for 72hr. In the immobilization systems, fusant BBFL 21 was employed in various polymer matrices such as sodium alginate, polyacrylamide, agar and ${\alpha}-carrageena$. The immobilization of sodium alginate showed the highest productivity of $413\;ng/ml{\cdot}hr$ L-lysine in the batch system. Continuous fermentation of immobilization system by using tube fermentor was produced the highest productivity $416.7\;ng/ml{\cdot}hr $ L-lysine under optimum condition.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.1
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• pp.1-8
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• 2009

This research was performed to assess a Fenton-like oxidation using naturally present iron in the field to treat remained oils throughout silty clay residues which finally resided even after a series of soil washing process. Biodegradability was thus tested for reaction products to investigate a possible treatment of the Fenton-like oxidation coupled with a biological treatment process. For those purposes, two types of field soil samples (e.g., dewatered cake after conditioning with a polymer and not-dewatered residue) were tested to remove TPH by adding the various concentration of hydrogen peroxide ($H_2O_2$). Moreover the biodegradability of treated samples was observed based on the ratio of $BOD_5/COD_{Cr}$ after Fenton-like oxidation. The Highest removal of TPH was at 1% of hydrogen peroxide ($H_2O_2$) when hydrogen peroxide ($H_2O_2$) was continuously injected for a period of time rather than that of spot introduction with the same amount of it. For the dewatered cake, TPH was effectively treated when the ratio of solid and water was mixed at 1 : 2. Employing cooking oil could increase solubility of TPH due to enhanced surface-active escalating TPH desorption from silty clay. Nonetheless, the biodegradability was decreased as long as the oxidation duration being extended regardless of operational conditions. It was therefore proved that Fenton-like oxidation using $H_2O_2$ and natural iron minerals was able to remove adsorbed oils in silty clay but the removal efficiency of TPH was low. And if a biological treatment process followed after Fenton-like oxidation, microorganisms would need enough time for acclimation.