• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.398-402
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• 2004

Safrolechitosan (SaCs) and eugenolchitosan (EuCs) were synthesized and characterized to increase water solubility and functionality of chitosan. Product impurities were removed by Soxhlet apparatus using methanol to obtain final product with high purity. Using Ubbelohde viscometer, molecular weights of chitosan, EuCs, and SaCs were determined as $1.2{\times}10^{5}\;Da,\;7.8{\times}10^{5},\;and\;7.5{\times}10^{5}\;Da,\;respectively$. IR spectrum of SaCs revealed chemical shift of amide II band ($1,553cm^{-1}$) of chitosan grafted by safrole caused by generation of covalent bond between primary amino of chitosan and double bond of safrole. Due to graft reaction of safrole onto chitosan, vinyl bands ($1,611\;and\;1,442cm^{-1}$) of safrole disappeared. In graft reaction of eugenol onto chitosan, shift of amide II band ($1,553cm^{-1}$) and disappearance of vinyl band were observed. On $^{1}H-NMR$ spectrum of EuCs, $H_{2}C=CH-$ peak in eugenol (monomer) disappeared, whereas $-H_{2}C-CH_{2}-$ peak appeared. Above results indicate safrole and eugenol were successfully grafted onto chitosan.

• Analytical Science and Technology
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• v.12 no.1
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• pp.7-12
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• 1999

The cation-exchange adsorbent (CEA) was prepared by radiation-induced grafting of glycidyl methacrylate (GMA) onto polypropylene (PP) fabric and its subsequently phosphonation. The adsorption characteristics of $Pb^{2+}$, $Cu^{2+}$ and $Co^{2+}$ for the CEA were discussed. In the grafting of GMA onto PP fabric, the degree of grafting (%) increased with increasing reaction time, reaction temperature, and pre-irradiation dose. The maximum grafting yield was observed around 60% GMA concentration. The content of phosphoric acid ranges from 2.5 to 3.5 mmol/g with the 85% phosphoric acid. The adsorption of $Pb^{2+}$, $Cu^{2+}$ and $Co^{2+}$ by the CEA was enhanced with increasing phosphoric acid content. The order of adsorption capacity of CEA was $Pb^{2+}$>$Co^{2+}$>$Cu^{2+}$.

• Archives of Pharmacal Research
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• v.14 no.3
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• pp.217-224
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• 1991

One of water and/or methanol extracts from 14 herbal deugs which were screened using murine splenocytes showed immunosuppressive activities previously. After water extract from Xanthium strumarium was treated with chloroform. $100 \mu{g/ml}$ of water layer (XS-WCI) has very strong immunosimulating activities tested by $^3H$-thmidine incorporation (control as $100 \mu{g/ml}$, 26345 cpm was 69515 cpm). MLR also appears to be simulated strongly (control vs $100 \mu{g/ml}$, 4962 cpm vs 78688 cpm). When $100 \mu{g/ml}$ of XS-WCI and $0.8 \mu{g/ml}$ of concanavalin a (ConA) were added. more $^3H$-thymidine were incorporated significantly, compared with $0.8 \mu{g/ml}$ of ConA only. In contrast with ConA. results from $5 \mu{/ml}$ of lipopolysaccharide (LPS) and $100 \mu{g/ml}$ of XS-WCI were not different. compared with $5\mu{/ml}$of LPS only. These results indicated the responses of XS-WCI to B cell and T cell may be different. XS-WCI was injected intraperitoneally (10 mg/kg. 50mg/kg/ 100 mg/kg) for 4 days or 10 days and tested secretion of IgM or IgG by direct and indirect hemolytic plaque-forming cell assays, respectively. Numbers of hemolytic plaques for both IgM and IgG were increased significantly. Especially, secretion of IgGs was increased more than 10 times. After administration of XS-WCI for 7 days (50 mg/kg. 100 mg/kg) splenomegaly deu to graft vs host reaction was observed. Human lymhocytes separated from whole blood by Ficoll-Hypaque method were also proliferated after treatment of $10 \mu{g/ml}$ and $50 \mu{g/ml}$ of XS-WCI. As seen in murine lymphocytes, human lymphocyte proliferation was increased synergistically after treatment with both of XS-WCI and phytohemagglutinin (PHA). It appears that XS-WCI may have potential immunosimulating activities and that it remains to be purified further for isolation of active components.

• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.318-323
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• 2014

In order to analyze the effect of maleic anhydride (MAH) content and styrene monomer (SM)/MAH mole ratio on reactive extrusion of maleic anhydride grafted random polypropylenes (MAH-g-rPP), MAH-g-rPPs were prepared by using a twin screw extruder. MAH contents were 0.5, 1.0, 3.0, and 5.0 phr and SM/initiator mole ratio was 0.0, 1.0, and 2.0. Dicumyl peroxide (DCP) was used as an initiator. The graft degree of MAH was confirmed by the existence of carbonyl group (C = O) stretching peak at $1700cm^{-1}$ from FT-IR spectrum. The degree of graft reaction increased up to 3.0 phr MAH and showed the optimum value at 1.0 SM/MAH mole ratio from the area ratio of C = O and C-H stretching peak. Thermal and crystallization properties of MAH-g-rPP and PP/MAH-g-rPP/pulp composites were investigated by DSC, TGA, XRD, and POM. There was a decrease in non-isothermal crystallization temperature of PP/MAH-g-PP/pulp composites. Based on tensile properties and SEM pictures for the fractured surface of PP/MAH-g-PP/pulp composites, MAH content of 1.0 wt% and SM/MAH mole ratio of 1.0 were the optimum formulation as the compatibilizer. The rheological properties of the composites were measured by dynamic Rheometer to compare the processability of the composites with and without compatibilizer. The power law index showed slightly low value at the composites with compatibilizer.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1146-1152
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• 2005

Graft copolymers were synthesized from methylcellulose(MC) and acrylic acid(AA) with active carboxyl groups in the presence of potassium persulfate($K_2S_2O_8$) initiator to enhance adsorption capacity of toxic heavy metal such as $Pb^{2+}$ and $Cu^{2+}$ from wastewater. The resulting grafted copolymers(MC-g-AA/PAA) were mixture of the graft copolymers from MC and AA(MC-g-AA) and polyacrylic acid homopolymers(PAA). The degree of palling was increased with rising concentration of monomer and initiator under the reaction conditions at $60^{\circ}C$, 3 hrs. The water insoluble property of MC-g-AA showed more than 19.7% degree of grafting. So that it could be an adsorbent of heavy metals. Adsorption characteristics of the MC-g-AA were evaluated depending on the degree of grading, pH of wastewater, adsorption time, dosage of MC-g-AA and concentration of heavy metals in the different conditions. Degree of grafting, and initial concentration of heavy metal ions increased, the adsorption amount of $Pb^{2+}$ and $Cu^{2+}$ increased, but added MC-g-AA increased, the adsorption amount per unit weight of $Pb^{2+}$ and $Cu^{2+}$ decreased. The MC-g-AA showed the high $Pb^{2+}$ and $Cu^{2+}$ adsorption amount in the range pH $4{\sim}6$. Also all of $Pb^{2+}$ and $Cu^{2+}$ ions reached in adsorption equilibrium in neighborhood 4 hours. The adsorption of heavy metals described by Freundlich isotherm, it was determined the value of l/n of $Pb^{2+}$ and $Cu^{2+}$ that 0.4294 and 0.3453, respectively.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.3
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• pp.279-285
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• 2009

The purpose of this study was to evaluate histologic result of bone substituting materials on extraction sockets. We compare the histologic findings of control, $MBCP^{(R)}$, $Polybone^{(R)}$. Mandibular premolar teeth of Beagle dogs were extracted available for bone filling. All alveolar extraction sockets were thoroughly debrided with surgical curet to remove the periodontal ligament. The graft materials were filled into the extraction sockets. The animals were sacrified 90 days after implantation. Both treated and control mandibular sites were histologically evaluated with light microscopy. Histological observation at 90 days revealed that control and experimental sites were healed uneventfully without any adverse tissue reaction. Regenerated new bone formation ratio is 34.5% for control, 28.4% for $MBCP^{(R)}$, 23.8% for $Polybone^{(R)}$. From this results, it was suggested that $MBCP^{(R)}$, $Polybone^{(R)}$ are promising bone substituting materials to promote normal tissue healing and new bone formation.

• Journal of Periodontal and Implant Science
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• v.24 no.3
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• pp.671-689
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• 1994

The purpose of this study was to compare effects of various bone grafts on periodontal regeneration of alveolar bone defects in dogs. Seven adult dogs aged 12 to 18 months were used in this study. Experimental alveolar bone defects were created surgically with a #1/2 round bur at the furcation area of the buccal surface of the mandibular 3rd, 4th premolars and 1st molar. Each experimental alveolar bone defects were grafted with dense hydroxyapatite, natural coral, and decalcified freeze-dried bone, and respectively divided into DHA, NC, DFDB group. An area without bone graft was divided into control group. At 1,2,4,6, and 12 weeks, dogs were serially sacrificed and specimens were prepared with Hematoxylin-Eosin stain and Mallory stain for light microscopic evaluation. The results of this study were as follows : 1. In control group, the matrix change of granulation tissue was observed at 1 week. And in experimental groups, the appearance of connective tissue around graft materials was loosely formed at 1 week, but densely formed at 2 weeks. 2. In every group, the slight formation of new trabecular bone was seen from remaining bone at 1 week. 3. The DHA and NC particles were gradually encapsulated by new trabecular bone from remaining bone, and the osteoid tissue was directly induced from DFDB particles. 4. The presence of osteoblasts was first observed at 1 week in control group and at 2 weeks in NC group, but at 6 weeks in DHA group. 5. In DHA group, the resorption of particles was not observed until 12 weeks. But in NC and DFDB group, the particles were resorbed at 6 weeks and replaced by new bone. And the amount and size of particles were reduced, and their border represented irregular form. In summary, in three experimental groups the inflammatory or foreign body reaction were slight, but the regeneration of new osteoid tissue and the matrix change of dense connective tissue fiber were observed. Especially, NC and DFDB materials were considered as the biocompatible graft materials which were effective in the regenertion of new bone.

• Archives of Plastic Surgery
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• v.32 no.3
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• pp.335-342
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• 2005

This study was undertaken to investigate possibility of the allogenic type I collagen inducing osteoinduction or osteoconduction at critical sized bone defect in the rabbit. Twenty Newzealand white rabbit, weighted from 2.8 kg to 3.5 kg, were used in this study. The skull was exposed and two bony defects were created with diameter of 10 mm. Group I(n=10), the bony defects was grafted from the other side bone. Group II(n=10), the bony defects was grafted by the allogenic type I collagen with bone morphogenic protein(BMP). Group III(n=10), the bony defects was grafted by the allogenic type I collagen only. Group IV(n=10), the bony defects was lefted with no grafts. The grafted bones and allogenic type I collagen were investigated with radiologic densitometry, histologic analysis and immunohistochemistry after 12 weeks. No major difference was observed in the gross finding between Group I, II, III, but dura mater was exposed in bony defect,the Group IV. The radiologic study demonstrated more bony opacity in the Group I, but the other groups did not demonstrate a significant difference. In the histologic study, grafted bone edge was completely consolidated with original bone in group I and new bone ingrew into the grafted allogenic type I collagen(group II, III),but there is no bone regeneration from the original bony edge in the group IV. The percent of the new bone formation by cross-sectional area was considered statistically significant at a p value of less than 0.05(p<0.05). In the immunohistochemistry study about BMP antibodies, the group IV demonstrated osteogenic activity in front of advancing original bone edge, in which the osteoblast stained strongly for BMP antibodies, but other group does not demonstrated any osteoblastic expression. There was no immunologic rejection. In conclusion, this results do not demonstrate that the allogenic type I collagen is useful for bone substitute, but the characters of the collagen, such as pliability, easy-handling, sponge-like structure, are useful in interpositional bone graft substitutes. The further evaluation of long term results about the resorption, immunologic tissue reaction, response of applied tissue growth factor to the allogenic collagen is needed.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.343-348
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• 2010

The surface of low density polyethylene (LDPE) film was oxyfluorinated under different reaction conditions to introduce hydroperoxide groups and change surface characteristics. Hydroperoxide functional groups created by oxyfluorination were used as active sites for graft polymerization with hydrophobic monomer, acryl amide (AM), and hydrophilic monomer, methyl methacrylate (MMA) to carry out the second modification of the LDPE film surface. The surface properties of the OFPE films and grafted OFPE films were characterized by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method, ATR-IR, contact angle measurement and DSC. From the results of DPPH method, the amount of hydroperoxide groups on the oxyfluorinated LDPE film continuously increased as the total pressure in the oxyfluorination and the partial pressure of fluorine gas increased. The water contact angle and surface free energy measurements showed that hydrophilic liquid (water) contact angle on LDPE film surface decreased with hydrophilic AM grafting and hydrophobic liquid (methylene diiodide) contact angle on LDPE film surface decreased with hydrophobic MMA grafting. These were attributed to AM or MMA monomer grafting and the wettability of LDPE filmsurface to hydrophilic and hydrophobic liquids were improved.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.1-26
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• 1996

This study was performed to estimate the effects of cultured bone cell inoculated on porous type hydroxyaptite for the regeneration of the artificial alveolar bone defect. In this experiment 3 beagle dogs were used, and each of them were divided into right and left mandible. Every surgical intervention were performed under the general anesthesia by using with intravenous injection of Pentobarbital sodium(30mg/Kg). To reduce the gingival bleeding during surgery, operative site was injected with Lidocaine hydrochloride(l:80,000 Epinephrine) as local anesthesia. After surgery experimental animal were feeded with soft dietl Mighty dog, Frisies Co., U.S.A.) for 1 weeks to avoid irritaion to soft tissue by food. 2 months before surgery both side of mandibular 1st premolar were extracted and bone chips from mandibular body were obtained from all animals. Bone cells were cultured from bone chips obtained from mandible with Dulbecco's Modified Essential Medium contained with 10% Fetal Bovine Serum under the conventional conditions. Porous type hydroxyapatite were immerse into the high concentrated cell suspension solution, and put 4 hours for attachin the cells on the surface of hydroxyapatite. Graft material were inserted on the artificial bone defect after 3 days of culture. Before insertion of cellinoculated graft material, scanning electronic microscopic observation were performed to confirm the attachment and spreading of cell on the hydroxyapatite surface. 3 artificial bone defects were made with bone trephine drill on the both side of mandible of the experimental animal. First defect was designed without insertion of graft material as negative control, second was filled with porous replamineform hydroxyapatite inoculated with cultured bone marrow cells as expermiental site, and third was filled with graft materials only as positive control. The size of every artificial bone defect was 3mm in diameter and 3mm in depth. After the every surgical intervention of animals, oral hygiene program were performed with 1.0% chlorhexidine digluconate. All of the animals were sacrificed at 2, 4, 6 weeks after surgery. For obtaining histological section, tissus were fixed in 10% Buffered formalin and decalcified with Planko - Rycho Solution for 72hr. Tissue embeding was performed in paraffin and cut parallel to the surface of mandibular body. Section in 8um thickness of tissue was done and stained with Hematoxylin - Eosin. All the specimens were observed under the light microscopy. The following results were obtained : 1. In the case of control site which has no graft material, less inflammatory cell infiltration and rapid new bone forming tendency were revealed compared with experimental groups. But bone surface were observed depression pattern on defect area because of soft tissue invasion into the artificial bone defect during the experimental period. 2. In the porous hydroxyapatite only group, inflammatory cell infiltration was prominet and dense connective tissue were encapsulated around grafted materials. osteoblastic activity in the early stage after surgery was low to compared with grafted with bone cells. 3. In the case of porous hydroxyapatite inoculated with bone cell, less inflammatory cell infiltration and rapid new bone formation activity was revealed than hydroxyapatite only group. Active new bone formation were observed in the early stage of control group. 4. The origin of new bone forming was revealed not from the center of defected area but from the surface of preexisting bony wall on every specimen. 5. In this experiment, osteoclastic cell was not found around grafted materials, and fibrovascular invasion into regions with no noticeable foreign body reaction. Conclusively, the cultured bone cell inoculated onto the porous hydroxyapatite may have an important role of regeneration of artificial bone defects of alveolar bone.