• Asian Pacific Journal of Cancer Prevention
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• 제16권5호
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• pp.1725-1728
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• 2015

Objective: To explore effects of paclitaxel-loaded poly lactic-co-glycolic acid (PLGA) particles on the viability of human hepatocellular carcinoma (HCC) HepG2 cells. Materials and Methods: The viability of HepG2 cells was assessed using MTT under different concentrations of prepared paclitaxel-loaded particles and paclitaxel (6.25, 12.5, 25, 50, and 100 mg/L), and apoptosis was analyzed using Hochest33342/Annexin V-FITC/PI combined with an IN Cell Analyzer 2000. Results: Paxlitaxel-loaded nanoparticles were characterized by narrow particle size distribution (158.6 nm average particle size). The survival rate of HepG2 cells exposed to paclitaxel-loaded PLGA particles decreased with the increase of concentration and time period (P<0.01 or P<0.05), the dose- and time-dependence indicating sustained release (P<0.05). Moreover, apoptosis of HepG2 cells was induced, again with an obvious dose- and time-effect relationship (P<0.05). Conclusions: Paclitaxel-loaded PLGA particles can inhibit the proliferation and induce the apoptosis of HCC HepG2 cells. This new-type of paclitaxel carrier body is easily made and has low cost, good nanoparticle characterization and sustained release. Hence, paclitaxel-loaded PLGA particles deserve to be widely popularized in the clinic.

• 대한두개안면성형외과학회지
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• 제21권2호
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• pp.99-105
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• 2020

Background: Due to the different handling properties of unsintered hydroxyapatite particles/poly-L-lactic acid (uHA/PLLA) and polycaprolactone (PCL), we compared the surgical outcomes and the postoperative implantation accuracy between uHA/PLLA and PCL meshes in orbital fracture repair. Methods: Patients undergoing orbital wall reconstruction with PCL and uHA/PLLA mesh, between 2017 and 2019, were investigated retrospectively. The anatomical accuracy of the implant in bony defect replacement and the functional outcomes such as diplopia, ocular motility, and enophthalmos were evaluated. Results: No restriction of eye movement was reported in any patient (n= 30 for each group), 6 months postoperatively. In the PCL group, no patient showed diplopia or enophthalmos, while the uHA/PLLA group showed two patients with diplopia and one with enophthalmos. Excellent anatomical accuracy of implants was observed in 27 and 22 patients of the PCL and uHA/PLLA groups, respectively. However, this study showed that there were neither any significant differences in the surgical outcomes like diplopia and enophthalmos nor any complications with the two well-known implants. Conclusion: PCL implants and uHA/PLLA implants are safe and have similar levels of complications and surgical outcomes in orbital wall reconstruction.

• 한국염색가공학회지
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• 제20권6호
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• pp.1-7
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• 2008

The effects of $TiO_2$ contents and UV irradiation treatment on the surface properties of PLA films embedded with $TiO_2$ nanoparticle were investigated. Whereas UV irradiation decreased reflectance of the treated PLA films proportionally with increasing UV energy, the reflectance of PLA/$TiO_2$ films increased with increasing UV energy. The UV irradiation treatment caused PLA/$TiO_2$ blend films more polar as indicated in the generation of new carbonyl group and decrease in zeta potentials, which was more pronounced with the introduction of $TiO_2$. Upon UV irradiation, $TiO_2$ particles appeared on the film surface as observed in SEM images. The PLA/$TiO_2$ blend films showed photocatalytic properties such as photobleaching of methylene blue, deodorization of ammonia and antimicrobial activity in comparison with pure PLA films.

• Carbon letters
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• 제13권3호
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• pp.139-150
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• 2012

Poly-L-lactic acid (PLLA), PLLA/hydroxyapatite (HA), PLLA/multiwalled carbon nanotubes (MWNTs)/HA, PLLA/trifluoroethanol (TFE), PLLA/gelatin, and carbon nanofibers (CNFs)/${\beta}$-tricalcium phosphate (${\beta}$-TCP) composite membranes (scaffolds) were fabricated by electrospinning and their morphologies, and mechanical properties were characterized for use in bone tissue regeneration/guided tissue regeneration. MWNTs and HA nanoparticles were well distributed in the membranes and the degradation characteristics were improved. PLLA/MWNTs/HA membranes enhanced the adhesion and proliferation of periodontal ligament cells (PDLCs) by 30% and inhibited the adhesion of gingival epithelial cells by 30%. Osteoblast-like MG-63 cells on the randomly fiber oriented PLLA/TEF membrane showed irregular forms, while the cells exhibited shuttle-like shapes on the parallel fiber oriented membrane. Classical supersaturated simulated body fluids were modified by $CO_2$ bubbling and applied to promote the biomineralization of the PLLA/gelatin membrane; this resulted in predictions of bone bonding bioactivity of the substrates. The ${\beta}$-TCP membranes exhibit good biocompatibility, have an effect on PDLC growth comparable to that of pure CNF membrane, and can be applied as scaffolds for bone tissue regeneration.

• Advanced Composite Materials
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• 제16권4호
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• pp.361-376
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• 2007

Disposing of conventional fiber-reinforced polymers (FRPs) poses an environmentally challenging problem. Disposal of FRPs by combustion discharges carbon dioxide in the air because the resin of FRPs is made of fossil fuel. When they are disposed of in the ground, FRPs remain semipermanently without decomposing. In response to these problems, green composites are now being developed and are extensively studied as a material that produces a lower environmental burden. In this paper, green composites using kenaf fiber yarn bundles and PLA (poly(lactic acid)) are fabricated and their tensile properties are evaluated in the experiment. The tensile Young's modulus of all of the laminations is larger than that of PLA alone and the tensile strength of some laminations is larger than that of PLA alone. In particular, the value of UD composite of $0^{\circ$ shows double the tensile strength of PLA alone. Furthermore, the molding conditions for fabricating with a hot press are investigated and the heat resistant tensile properties of green composites are also reported.

• Journal of Biosystems Engineering
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• 제32권1호
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• pp.50-56
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• 2007

Highly porous composite bioceramic bone scaffolds were developed using sintered gnotobiotic pig bones. These scaffolds consisted of poly-D,L-lactic acid (P(D,L)LA) and bioceramic materials of pig bone powder. The bone scaffolds were able to promote biocompatibility and possess interconnected pores that would support cell adhesion and proliferation adequately. The composite scaffolds were tested with dental pulp stem cells for cytotoxicity test. Cells seeded on the composite scaffolds were readily attached, well proliferated, as confirmed by cytotoxicity test, and cell adhesion assessment. The composite bone scaffold had no toxicity in cytotoxicity test on the extract of 0.013 g scaffold to 2 ml culture medium. The cells on the composite bone scaffold proliferated better than cells on the P(D,L)LA scaffolds.

• 펄프종이기술
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• 제43권2호
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• pp.66-71
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• 2011

Biocomposites were fabricated with biodegradable polymers and natural fibers. Biocomposites have benefits of low cost, low density, and biodegradability over inorganic fiber composite, and give comparable strength properties. Hydrophobic polymer used for sizing in paper industry, AKD (Akenyl Keten Dimer), was applied to natural fibers, red algae fibers (RAF) in this study, to make fiber surfaces more compatible to hydrophobic nature of matrix polymers. Composites with RAF, kenaf, glass fibers, and carbon fibers have been fabricated by a compression molding method and their thermo-mechanical properties have been studied. Also, the thermal dimensional stability test was done from at 30 to $100^{\circ}C$. The storage moduli and the thermo-mechanical stabilities of polypropylene and poly lactic acid based biocomposites were improved by reinforcing with the RAF and much more with AKD treated fibers. Dimensional stability of biocomposite was also markedly improved by AKD pretrement on RAF.

• 한국지반신소재학회논문집
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• 제9권3호
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• pp.67-75
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• 2010

본 연구에서는 생분해성 수지를 이용한 연직배수재에 대해 다양한 성능 평가방법을 적용하여 생분해성 플라스틱배수재의 공학적 특성을 분석하였다. 생분해성 플라스틱으로 제작한 연직배수재는 기존 합성수지 연직배수재에 비해 낮은 인장변형률을 가지며 상대적으로 낮은 인장강도를 갖지만, 연직배수재로서 가져야 할 최소한의 인장강도는 발휘하는 것으로 나타났다. 생분해성 플라스틱으로 제작한 필터는 투수성이 좋고 유효구멍크기가 작아 필터의 성능으로 매우 적합한 것으로 나타났다. 또한 생분해성플라스틱 배수재의 통수능은 필터의 강성을 개선하는 경우 국내 시방기준에도 만족할 수 있는 성능을 갖는 것으로 나타났다.

• Macromolecular Research
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• 제16권4호
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• pp.345-352
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• 2008

Poly(lactic-co-glycolic acid) (PLGA) tubes (5 mm in diameter) were fabricated using an electro spinning method and used as a scaffold for artificial blood vessels through the hybridization of smooth muscle cells (SMCs) and endothelial cells (ECs) differentiated from canine bone marrow under previously reported conditions. The potential clinical applications of these artificial blood vessels were investigated using a canine model. From the results, the tubular-type PLGA scaffolds for artificial blood vessels showed good mechanical strength, and the dual-layered blood vessels showed acceptable hybridization behavior with ECs and SMCs. The artificial blood vessels were implanted and substituted for an artery in an adult dog over a 3-week period. The hybridized blood vessels showed neointimal formation with good patency. However, the control vessel (unhybridized vessel) was occluded during the early stages of implantation. These results suggest a shortcut for the development of small diameter, tubular-type, nanofiber blood vessels using a biodegradable material (PLGA).

• Macromolecular Research
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• 제15권3호
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• pp.205-210
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• 2007

Collagen is the major structural protein of connective tissues. It can be used as a prosthetic biomaterial applicable to artificial skin, tendon, ligaments, and collagen implants. The objective of this study is to investigate the possibility of realizing wound dressing medical products by the synthesis of composite materials with collagen and a biodegradable polymer, PLLA, via a surface modification process. Type I collagen was obtained from pig skin by a separation process. The structural characteristics of the extracted collagen were confirmed by SDS-polyacrylamide (PAcr) gel electrophoresis (PAGE) and FTIR. Also, PLLA-g-PAcr was synthesized by the radical polymerization of acrylamide initiated by AIBN in the presence of PLLA. The surface of PLLA was modified by the presence of the acrylamide residues. The structural characteristics of the copolymer were analyzed by FTIR, $^1H-NMR$ and contact angle measurements. The water uptake and WVTR of the collagen/PLLA-g-PAcr composite tended to increase with increasing collagen concentration and with decreasing EDC concentration.