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Lee D.Y.,Anyang University, South Korea | Cheon C.,Anyang University, South Korea | Son S.,Anyang University, South Korea | Kim Y.-Z.,Vericom Co. | And 3 more authors.
Polymer (Korea) | Year: 2015

1,4-Butanediol diglycidyl ether (BDDE) crosslinked hyaluronic acid (HA) suspended in three different HAs (697, 1058, 1368 kDa) were prepared to investigate the effect of HA molecular weight on swelling property and elastic modulus of the hydrogels. The amount of the residual BDDE after final dialysis was less than 0.5 ppm. The highest swelling ratio was observed for the uncrosslinked HA having the largest molecular weight. The expansion capacity of HA rose with increasing the amount of pure HA and was inversely proportional to the crosslinking degree due to an increased number of coiled HA chain interactions. Elastic modulus (G') of monophasic fillers having different ratios of 1.0 w/v% BDDE crosslinked HAs to pure HA (1368 kDa) were within 152 and 325 Pa. 178 Pa was observed for the biphasic fillers consisting of 15% crosslinked HA (697 kDa) nanoparticles suspended in 85% of uncrosslinked HA (1368 kDa). © 2015 The Polymer Society of Korea. All rights reserved.

Kim J.-T.,Anyang University, South Korea | Lee D.Y.,Anyang University, South Korea | Kim E.-J.,Health Science University | Jang J.-W.,Cellumed Co. | Cho N.-I.,Sun Moon University
Tissue Engineering and Regenerative Medicine | Year: 2014

Hyaluronic acid hydrogels (HAHs) were synthesized by immersing the HA microbeads crosslinked with divinyl sulfone in phosphate buffered saline solution to assess the responses of tissues to the implant by means of the subchronic systemic toxicity and the intradermal implant test. The HAHs, prepared by the microbeads with an average diameter of 140 μm and a swelling rate of 800 to 1200%, exhibited a porous network channeled with 10 μm pores. The HAHs retained their space and structure by maintaining over 95% of the initial volume 12 weeks after injection to a rabbit. The histological analysis indicated that an acute inflammation, occurred in the rabbit 4 weeks after injection, was alleviated dramatically after 8 weeks. No capsule was formed. The HAHs had no subchronic systemic toxicity under the condition of this study and were considered non-irritant. The implants were excellent in biological synthesis and transplantation as evidenced by non-capsule reaction and disappearance of inflammatory cells. It can be concluded that the implants of HAHs are clinically safe and effective.

Son S.,Anyang University, South Korea | Choi J.-E.,Anyang University, South Korea | Cho H.,Anyang University, South Korea | Kang D.,Anyang University, South Korea | And 3 more authors.
Polymer (Korea) | Year: 2015

Poly(ε-caprolactone) (PCL) nanofibers and PCL/silica membranes were synthesized by sol-gel derived electrospinning and casting, respectively. Smooth PCL nanofibers were obtained from the precursor containing N,N-dimethylformamide (DMF). PCL/silica membranes were prepared by varying the tetraethyl orthosilicate (TEOS) contents from 0 to 40 vol% to investigate the effect of silica addition on mechanical properties and cytotoxicity of the membranes. Although the strength of the membranes decreased from 12 to 8 MPa with increasing the silica content, the strength remained almost constant 7 weeks after dipping in phosphate buffered saline solution (PBS). The strength reduction was attributed to the presence of a patterned surface pores and micro-pores present in the walls between pores. The crystal structure of the membranes was orthorhombic and the crystallite size decreased from 57 to 18 nm with increasing the silica content. From the agar overlay test, the PCL/silica membranes exhibited neither deformation and discoloration nor lysis of L-929 fibroblast cells. © 2015 The Polymer Society of Korea. All rights reserved.

Shim Y.-B.,CHA Medical University | Jung H.-H.,Yonsei University | Jang J.W.,Cellumed Co. | Yang H.S.,Dankook University | And 4 more authors.
Journal of Industrial and Engineering Chemistry | Year: 2016

Hollow porous poly(d,. l-lactide-co-glycolide) microspheres (HP-PLGA-MS) were manufactured using the water-in-oil-in-water double emulsion solvent evaporation method with sucrose as a novel porogen. Dexamethasone (DEX) was dissolved in the oil phase and loaded during the preparation of the HP-PLGA-MS. Bone morphogenetic protein-2 (BMP2) with type I collagen (Col1) was incorporated into HP-PLGA-MS using a simple immersion method. The release rate of BMP2 could be controlled by the amount of Col1. DEX and BMP2 showed a sustained release profile. These results showed that the HP-PLGA-MS could be fabricated successfully using sucrose and showed great potential as a controlled dual drug delivery system. © 2016 The Korean Society of Industrial and Engineering Chemistry.

Wang X.,Seoul National University | Kim J.-R.,Seoul National University | Lee S.-B.,Cellumed Co. | Kim Y.-J.,Gwangju Institute of Science and Technology | And 3 more authors.
BMC Complementary and Alternative Medicine | Year: 2014

Background: Alzheimer's disease (AD) is the most common type of presenile and senile dementia. The human β-amyloid precursor cleavage enzyme (BACE-1) is a key enzyme responsible for amyloid plaque production, which implicates the progress and symptoms of AD. Here we assessed the anti-BACE-1 and behavioral activities of curcuminoids from rhizomes of Curcuma longa (Zingiberaceae), diarylalkyls curcumin (CCN), demethoxycurcumin (DMCCN), and bisdemethoxycurcumin (BDMCCN) against AD Drosophila melanogaster models.Methods: Neuro-protective ability of the curcuminoids was assessed using Drosophila melanogaster model system overexpressing BACE-1 and its substrate APP in compound eyes and entire neurons. Feeding and climbing activity, lifespan, and morphostructural changes in fly eyes also were evaluated.Results: BDMCCN has the strongest inhibitory activity toward BACE-1 with 17 μM IC50, which was 20 and 13 times lower than those of CCN and DMCCN respectively. Overexpression of APP/BACE-1 resulted in the progressive and measurable defects in morphology of eyes and locomotion. Remarkably, supplementing diet with either 1 mM BDMCCN or 1 mM CCN rescued APP/BACE1-expressing flies and kept them from developing both morphological and behavioral defects. Our results suggest that structural characteristics, such as degrees of saturation, types of carbon skeleton and functional group, and hydrophobicity appear to play a role in determining inhibitory potency of curcuminoids on BACE-1.Conclusion: Further studies will warrant possible applications of curcuminoids as therapeutic BACE-1 blockers. © 2014 Wang et al.; licensee BioMed Central Ltd.

Kwon D.Y.,Ajou University | Tai G.Z.,Ajou University | Park J.H.,Ajou University | Lee B.K.,Ajou University | And 6 more authors.
Journal of Polymer Research | Year: 2014

To compare methoxy poly (ethylene glycol) (MPEG)-b-poly (ε-caprolactone) (M7C10L0) and MPEG-bpoly (L-lactide) (M7C0L10), we performed block copolymerization of ε-caprolactone (CL) and L-lactide (LA) to synthesize block copolymers composed of MPEG-b-poly (ε- caprolactone-co-L-lactide) (MxCyLz). The obtained MxCyLz, M7C10L0, and M7C0L10 had molecular weights close to the theoretical values calculated from the CL and/or LA to MPEG molar ratios and exhibited monomodal gel permeation chromatography (GPC) curves. The micellar characterization of MxCyLz block copolymers in an aqueous phase was carried out by using NMR, dynamic light scattering (DLS), and fluorescence techniques. The diameters of micelles, measured by DLS, were 30-370 nm. The critical micelle concentration (CMC) and partition equilibrium constant (Kv) depended on the block lengths and compositions of block copolymers. The degradation of theMxCyLz block copolymers mainly depends on both the length of hydrophilic MPEG segments and the proportion of the CL and LA in the hydrophobic segments present in their structure. We confirmed that MxCyLz block copolymers formed biodegradable micelles suitable for biomedical applications. © Springer Science+Business Media Dordrecht 2014.

PubMed | Cellumed Co.
Type: Comparative Study | Journal: Regulatory toxicology and pharmacology : RTP | Year: 2015

Sequentially chemical-treated bovine bone was not only evaluated by mechanical and chemical analyses but also implanted into the gluteal muscles of rats for 12 weeks to investigate potential local pathological effects and systemic toxicities. The test (chemical treated bone) and control (heat treated bone) materials were compared using scanning electron microscope (SEM), x-ray diffraction pattern, inductively coupled plasma analysis, and bending strength test. In the SEM images, the micro-porous structure of heat-treated bone was changed to sintered ceramic-like structure. The structure of bone mineral from test and control materials was analyzed as100% hydroxyapatite. The ratio of calcium (Ca) to potassium (P), the main inorganic elements, was same even though the Ca and P percentages of the control material was relatively higher than the test material. No death or critical symptoms arose from implantation of the test (chemical treated bone) and control (physiological saline) materials during 12 weeks. The implanted sites were macroscopically examined, with all the groups showing non-irritant results. Our results indicate that chemical processed bovine bone has a better mechanical property than the heat treated bone and the implantation of this material does not produce systemic or pathological toxicity.

Park J.H.,Ajou University | Kang H.J.,Ajou University | Kwon D.Y.,Ajou University | Lee B.K.,Ajou University | And 5 more authors.
Journal of Materials Chemistry B | Year: 2015

To develop an appropriate drug carrier for drug delivery systems, we prepared random poly(lactide-co-glycolide-co-ε-caprolactone) (PLGC) copolymers in comparison to commercial poly(lactic acid-co-glycolic acid) (PLGA) grades. The molecular weights of PLGC copolymers varied from 20k to 90k g mol-1 in the total polyester segments, when poly-l-lactic acid (PLLA), polyglycolic acid (PGA), and polycaprolactone (PCL) compositions were kept constant. The lengths of PLGC copolymers varied from 10:10:80 to 40:40:20 in the PLLA:PGA:PCL segments, when the molecular weights of the total polyester segments were kept constant. The crystalline properties of the PLGA copolymers can be changed to amorphous by the incorporation of PCL segments. In vitro and in vivo degradation behavior can be easily tuned from a few days to a few weeks by changing the chemical composition of the PLGC copolymers. The in vivo inflammation associated with the PLGC implants was less pronounced than that associated with PLGA. In this study, as drug delivery carriers for locally implantable paclitaxel (Ptx) dosages, Ptx-loaded PLGC and PLGA films showed in vitro and in vivo Ptx release for 35 days. The orders of Ptx release showed profiles similar to those of in vitro and in vivo degradation of PLGC. Using near-infrared (NIR) fluorescence imaging, we confirmed the sustained release of NIR over an extended period from IR-780-loaded PLGC and PLGA implanted in live animals. In conclusion, we confirmed that compared to PLGA, PLGC effectively acts as a drug carrier for drug delivery systems. © The Royal Society of Chemistry 2015.

Provided is a method of manufacturing an allogeneic soft-tissue transplant having autologous stem cells transplanted therein using an allogeneic soft-tissue support that is obtained from an allogeneic organism. In this regard, an allogeneic soft-tissue transplant that can replace a damaged soft-tissue of a human body is manufactured.

PubMed | Ajou University, Cellumed Co. and Korea Institute of Science and Technology
Type: | Journal: Biomaterials research | Year: 2015

Hydrolyzed polyacrylonitrile (HPAN) has attracted much attention as a hydrogel for a broad range of biomedical applications. Therefore, in this study, we prepared HPAN derivatives with controllable compositions by the radical polymerization of acrylonitrile (AN), methacrylic acid (MAA) and N-isopropylacrylamide (NIPAM) monomers.The prepared poly(AN-co-MAA-co-NIPAM) copolymers had different ratios of AN, MAA, and NIPAM and molecular weights ranging from 2000 to 50,000. The copolymers were prepared as films to examine their properties. The prepared copolymer films showed different solubilities, contact angles, and swelling ratios. The properties of the copolymer films were affected by the hydrophobic PAN segments and the hydrophilic PMAA or PNIPAM segments.Thus, we conclude that introducing PMAA and PNIPAM segments with different ratios and lengths into PAN segments could represent a method of controlling the hydrogel properties of copolymers.

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