• Korean Chemical Engineering Research
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• 제58권1호
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• pp.36-43
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• 2020

생분해성 금속인 마그네슘 합금 와이어를 이용하여 담관용 스텐트를 제작하였다. 생체 내에서 마그네슘 합금의 문제점인 빠른 분해 및 부식을 제어하기 위하여 마그네슘 합금 와이어를 생분해성 고분자인 polycaprolactone (PCL), poly(propylene carbonate) (PPC), poly(L-lactic acid) (PLLA), poly(D,L-lactide-co-glycolide) (PLGA) 등으로 코팅하였다. 표면분해가 이루어지는 고분자인 PPC의 경우는 전분해 거동을 보이는 다른 고분자들(PCL, PLLA, PLGA)에 비해 크랙이나 박리가 없어 가장 효율적으로 마그네슘 와이어의 분해 속도를 지연시켰다. 또한 생분해성 고분자 코팅이 마그네슘 합금 스텐트의 기계적 물성인 축 방향 힘에 미치는 영향에 대하여 조사하였다. 대부분의 생분해성 고분자(PCL, PLLA, PLGA)로 코팅된 스텐트는 코팅되지 않은 스텐트에 비해 축 방향의 힘이 증가하여 스텐트의 유연성을 감소시켰으나, PPC로 코팅된 스텐트는 코팅되지 않은 스텐트와 비슷한 축 방향의 힘을 나타내 스텐트의 유연성을 감소시키지 않았다. 이상의 결과로부터 PPC가 가장 효율적인 생분해성 고분자로 판단된다.

• Advances in nano research
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• 제12권3호
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• pp.301-317
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• 2022

Many studies have shown that Mg-Nd-Zn-Zr (abbreviated as JDBM) alloy has good biocompatibility and biodegradability as well as promotion of cell adhesion, proliferation and differentiation, and Wnt/β-catenin signaling pathway may play a unique role in joint tissue by controlling the function of chondrocytes, osteoblasts and synoviocytes. However, it is not clear whether the JDBM alloy induces osteochondral repair through Wnt/β-catenin signaling pathway. This study aims to verify that JDBM alloy can repair osteochondral defects in rats, which is realized by Wnt/β-catenin signaling pathway. In this study, the osteochondral defect model of the right femoral condyle non-weight-bearing area in rats was established and randomly divided into three groups: Control group, JDBM alloy implantation group and JDBM alloy implantation combined with signaling pathway inhibitor drug ICRT3 injection. It was found that after JDBM alloy implantation, the bone volume fraction (BVF) became larger, the bone trabeculae were increased, the relative expression of osteogenesis gene Runx2, Bmp2, Opn, Ocn and chondrogenesis gene Collagen II, Aggrecan were increased, and the tissue repair was obvious by HE and Masson staining, which could be inhibited by ICRT3.

• Corrosion Science and Technology
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• 제17권3호
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• pp.91-100
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• 2018

Development of biodegradable implants for treatment of complex bone fractures has recently become one of the priority areas in biomedical materials research. Multifunctional corrosion resistant and bioactive coatings containing hydroxyapatite $Ca_{10}(PO_4)_6(OH)_2$ and magnesium oxide MgO were obtained on Mg-Mn-Ce magnesium alloy by plasma electrolytic oxidation. The phase and elemental composition, morphology, and anticorrosion properties of the coatings were investigated by scanning electron microscopy, energy dispersive spectroscopy, potentiodynamic polarization, and electrochemical impedance spectroscopy. The PEO-layers were post-treated using superdispersed polytetrafluoroethylene powder. The duplex treatment considerably reduced the corrosion rate (>4 orders of magnitude) of the magnesium alloy. The use of composite coatings in inducing bioactivity and controlling the corrosion degradation of resorbable Mg implants are considered promising. We also applied the plasma electrolytic oxidation method for the formation of the composite bioinert coatings on the titanium nickelide surface in order to improve its electrochemical properties and to change the morphological structure. It was shown that formed coatings significantly reduced the quantity of nickel ions released into the organism.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 추계학술대회 논문집
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• pp.228-229
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• 2015

생체재료로 사용되는 마그네슘 합금은 인체 내에서 매우 빠른 부식을 가지고 있고, 초기 빠른 부식으로 수소기체를 발생하여 피부나 골조직의 괴사를 일의는 문제점을 가지고 있다. 또한 부식이 진행되어 생긴 부식 산화물의 소량은 체외로 배출 되지만, 일부는 체 내에 남아 다양한 문제를 일으킨다. 이번 연구를 통해 이러한 문제점을 해결하고 생체재료로 마그네슘 합금을 안전하게 사용하기 위하여, 마그네슘 합금의 부식 거동을 확인 하고 마그네슘 표면처리 연구를 진행하였다.

• Corrosion Science and Technology
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• 제15권3호
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• pp.120-124
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• 2016

The effect of alloying element Ca (0, 1, and 2 wt%) on corrosion resistance and bioactivity of the as-received and anodized surface of rolled plate AM60 alloys was investigated. A plasma electrolytic oxidation (PEO) was carried out to form anodic oxide film in $0.5mol\;dm^{-3}\;Na_3PO_4$ solution. The corrosion behavior was studied by polarization measurements while the in vitro bioactivity was tested by soaking the specimens in Simulated Body Fluid (1.5xSBF). Optical micrograph and elemental analysis of the substrate surfaces indicated that the number of intermetallic particles increased with Ca content in the alloys owing to the formation of a new phase $Al_2Ca$. The corrosion resistance of AM60 specimens improved only slightly by alloying with 2 wt% Ca which was attributed to the reticular distribution of $Al_2Ca$ phase existed in the alloy that might became barrier for corrosion propagation across grain boundaries. Corrosion resistance of the three alloys was significantly improved by coating the substrates with anodic oxide film formed by PEO. The film mainly composed of magnesium phosphate with thickness in the range $30-40{\mu}m$. The heat resistant phase of $Al_2Ca$ was believed to retard the plasma discharge during anodization and, hence, decreased the film thickness of Ca-containing alloys. The highest apatite forming ability in 1.5xSBF was observed for AM60-1Ca specimens (both substrate and anodized) that exhibited more degradation than the other two alloys as indicated by surface observation. The increase of surface roughness and the degree of supersaturation of 1.5xSBF due to dissolution of Mg ions from the substrate surface or the release of film compounds from the anodized surface are important factors to enhance deposition of Ca-P compound on the specimen surfaces.