• Title/Summary/Keyword: Biocompatibility materials

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The Mechanical Properties and Biocompatibility of Functionally Graded Coatings(FGC) of Hydroxyapatite(HA) and Metallic Powders - Functionally Gradient Coatings of Thermal Spray in Air- (Hydroxyapatite (HA)와 금속 분말 경사 코팅의 기계적 특성 및 생체 적합성 - 대기 열용사 경사코팅 -)

  • Kim, Eun-Hye;Kim, Yu-Chan;Han, Seung-hee;Yang, Seok-Jo;Park, Jin-Woo;Seok, Hyun-Kwang
    • Korean Journal of Metals and Materials
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    • v.47 no.1
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    • pp.13-20
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    • 2009
  • This work presents functionally graded coatings (FGC) of hydroxyapatite (HA) and metallic powders on Ti-6Al-4V implants using plasma spray coating method. HA has been the most frequently used coating material due to its excellent compatibility with human bones. However, because of the abrupt changes in thermomechanical properties between HA and the metallic implant across an interface, and residual stress induced on cooling from coating temperture to room temperature, debonding at the interface occurs in use sometimes. In this work, FGC of HA and Ti or Ti-alloy powders is made to mitigate the abrupt property changes at the interface and the effect of FGC on residual stress release is investigated by evaluating the mechanical bond strength between the implant and the HA coating layers. Thermal annealing is done after coating in order to crystallize the HA coating layer which tends to have amorphous structure during thermal spray coating. The effects of types and compositional ratio of metallic powders in FGC and annealing conditions on the bond strength are also evaluated by strength tests and the microstructure analysis of coating layers and interfaces. Finally, biocompatibility of the coating layers are tested under ISO 10993-5.

Injection Molding of Vertebral Fixed Cage Implant

  • Yoo, Kyun Min;Lee, Seok Won;Youn, Jae Ryoun;Yoon, Do Heum;Cho, Yon Eun;Yu, Jae-Pil;Park, Hyung Sang
    • Fibers and Polymers
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    • v.4 no.2
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    • pp.89-96
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    • 2003
  • A vertebral cage is a hollow medical device which is used in spine forgery. By implanting the cage into the spine column, it is possible to restore disc and relieve pressure on the nerve roots. Most cages have been made of titanium alloys but they detract the biocompatibility. Currently PEEK (polyether ether ketone) if applied to various implants because it has good properties like heat resistance, chemical resistance, strength, and especially biocompatibility. A new shape of vertebral cage is designed and injection molding of PEEK is considered for production. Before injection molding of the cage, it is needed to evaluate process conditions and properties of the final product. Variables affecting the shrinkage of the cage are considered, e.g., injection time, packing pressure, mold temperature, and melt temperature. By using the numerical simula-tion program, MOLDFLOW, several cases are studied. Data files obtained by MOLDFLOW analysis are used for stress anal-ysis with ABAQUS, and shrinkage and residual stress fields are predicted. With these results, optimum process conditions are determined.

Effect of Nitrogen Ion Implantation on Wear Behavior of Biocompatible Ti Implant (질소이온 주입이 생체적합성 티타늄 임플란트의 마모특성에 미치는 영향)

  • Byeon, Eung-Seon;Kim, Dong-Su;Lee, Gu-Hyeon;Jeong, Yong-Su
    • 연구논문집
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    • s.30
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    • pp.137-145
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    • 2000
  • Since the concept of osseointegration was introduced, titanium and titanium-based alloy materials have been increasingly used for bone-anchored metal in oralmaxillofacial and orthopedic reconstruction. Successful osseointegration has been attributed to biocompatibility and surface condition of metal implant among other factors. Although titanium and titanium alloys have an excellent over the metal ion release and biocompatibility, considerable controversy has developed over the metal ion and wear debris in vivo and vitro. In this study, nitrogen ion implantation technique was used to improve the corrosion resistance and wear property of titanium materials, ultimately to enhance the tissue reaction to titanium implants As ion implantation energy was increased, projected range of nitrogen ion the Ti substrate was gradually increased. Under condition of constant ion energy. atomic concentration of nitrogen was also increased with ion doses. The friction in Hank's solution was increased with ion doses. The friction coefficient of ion implanted specimens in HanK's solution was increased from 0.39, 0.47 to 0.52, 0.65 respectively under high energy and ion dose conditions. As increasing ion energies and ion dose, amount of wear was reduced.

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Effect of Surface Treatment on Bioactivity of Ti-Ni Shape Memory Alloys (Ti-Ni형상기억합금의 생체활성에 미치는 표면처리의 영향)

  • Choi, Mi-Seon;Nam, Tae-Hyun
    • Korean Journal of Metals and Materials
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    • v.47 no.12
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    • pp.881-886
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    • 2009
  • Research into the replacement of injured systems and tissue in the human body is advancing rapidly. Recently, Ti-Ni shape memory alloys have shown excellent biofunctionality related to their shape memory effect and superelasticity. In this study, the effect of an acid or an alkali treatment on the bioactivity in 49Ti-Ni and 51.5Ti-48.5Ni alloys is investigated in an effort to utilize Ti-Ni alloy as a biomaterial. In addition, the biocompatibility in a SBF solution is assessed through in vitro testing. A porous surface was formed on the surface of both alloys after a chemical treatment. According to the in vitro test, apatite formed on the surfaces of both alloys. The forming rate of apatite in the Ti-rich alloy was faster that in the Ni-rich alloy. The formation of apatite provided proof of the bioactivity of the Ti-Ni alloy. A small quantity of Ni was eluted at the initial stage, whereas Ni was not found for 12 days in the Ti-rich alloy and for 8 days in the Ni-rich alloy. In the case of the treated 51.5Ti-Ni alloy, the shape memory property was worsened but the biocompatibility was improved.

Effects of Wollastonite Coating on Surface Characteristics of Plasma Electrolytic Oxidized Ti-6Al-4V Alloy (플라즈마 전해 산화처리된 Ti-6Al-4V합금의 표면특성에 미치는 울라스토나이트 코팅효과)

  • Jaeeun Go;Jong Kook Lee;Han Cheol Choe
    • Corrosion Science and Technology
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    • v.22 no.4
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    • pp.257-264
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    • 2023
  • Ti-6Al-4V alloys are mainly used as dental materials due to their excellent biocompatibility, corrosion resistance, and chemical stability. However, they have a low bioactivity with bioinertness in the body. Therefore, they could not directly bond with human bone. To improve their applications, their bone bonding ability and bone formation capacity should be improved. Thus, the objective of this study was to improve the bioinert surface of titanium alloy substrate to show bioactive characteristics by performing surface modification using wollastonite powder. Commercial bioactive wollastonite powder was successfully deposited onto Ti-6Al-4V alloy using a room temperature spray process. It was found that wollastonite-coated layer showed homogeneous microstructure and uniform thickness. Corrosion resistance of Ti-6Al-4V alloy was also improved by plasma electrolytic oxidation treatment. Its wettability and bioactivity were also greatly increased by wollastonite coating. Results of this study indicate that both plasma electrolytic oxidation treatment and wollastonite coating by room temperature spray process could be used to improve surface bioactivity of Ti-6Al-4V alloy substrate.

Microstructure and Mechanical Properties of Ti-35Nb-7Zr-XCPP Biomaterials Fabricated by Rapid Sintering

  • Woo, Kee-Do;Park, Sang-Hoon;Kim, Ji-Young;Kim, Sang-Mi;Lee, Min-Ho
    • Korean Journal of Materials Research
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    • v.22 no.3
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    • pp.150-154
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    • 2012
  • Ti-6Al-4V ELI (Extra Low Interstitial) alloy have been widely used as alternative to bone due to its excellent biocompatibility, although it still has many problems such as high elastic modulus and toxicity. Therefore, biomaterials with low elastic modulus and non toxic characteristics have to be developed. A novel ${\beta}$ Ti-35wt%Nb-7wt%Zr-Calcium pyrophosphate (CPP) composite that is a biocompatible alloy without elemental Al or V was fabricated by spark plasma sintering (SPS) at $1000^{\circ}C$ under 70 MPa using high energy mechanical milled (HEMM) powder. The microstructure and phases of the milled powders and the sintered specimens were studied using SEM, TEM, and XRD. Ti-35wt%Nb-7wt%Zr alloy was transformed from ${\alpha}$ phase to ${\beta}$ phase in the 4h-milled powder by sintering. The sintered specimen using the 4h-milled powder showed that all the elements were distributed very homogeneously and had higher density and hardness. ${\beta}$ Ti alloy-CPP composite, which has nanometer particles, was fabricated by SPS using HEMMed powder. During the sintering process, $CaTiO_3$, TixOy, and CaO were formed because of the reaction between Ti and CPP. The Vickers hardness of the composites increases with the increase of the milling time and the addition of CPP. The biocompatibility of the Ti-Nb-Zr alloys was improved by addition of CPP.

Relative Biocompatibility Evaluation of Anodized Titanium Specimens in vivo and in vitro (In vivo와 in vitro 에서 양극산화 처리한 타이타늄 시편의 상대적인 생체적합성 평가)

  • Lee Yu-Mi;Lee Eun-Jung;Yeom Dong-Sun;Kim Do-Soon;Yee Sung-Tae;Kim Byung-Il;Cho Hyun-Wook
    • Journal of Life Science
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    • v.16 no.2 s.75
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    • pp.302-309
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    • 2006
  • To evaluate the biocompatibility of untreated and anodized titanium specimens, the specimens were implanted in the subcutaneous tissue of the abdominal region of female mice for two weeks. The reaction of connective tissue to specimens was histologically studied. The implants were encapsulated by fibrous connective. tissue consisting of fibroblast, fibrocyte and other cellss including neutroophil, macrophage and giant multinucleated cell. some newly formed blood vessels were located in the fibrous capsule surrounding the implant. Giant multinucleated cells were observed at the fibrous capsule adjacent to the implant. Kind of cell types and the thickness of fibrous capsules were examined quantitatively. Most of cell types located in the fibrous capsule were fibroblast and fibrocyte. The average thickness of fibrous capsules for the anodized specimens was much thinner than that of the untreated titanium specimen. Biocompatibility of titanium specimens were also studied by using cell culture method. The number of MG-63 cells was significantly increased on the anodized titanium specimens in vitro experiment. Our observations suggest that anodized titanium specimens are more effective for the improvement of biocompatibility in vivo and in vitro.

Biocompatibility of 13-93 Bioactive Glass-SiC Fabric Composites

  • Park, Jewon;Na, Hyein;Choi, Sung-Churl;Kim, Hyeong-Jun
    • Journal of the Korean Ceramic Society
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    • v.56 no.2
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    • pp.205-210
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    • 2019
  • Bioactive glass (BG) finds limited use as a bone replacement material owing to its low mechanical properties. In order to solve this problem, the micro-sized 13-93 BG was prepared as a fabric composite with SiC microfibers, and its mechanical properties and biocompatibility were investigated in this study. The tensile strengths of BG-SiC fiber-bundle composites increased in proportion to the number of SiC fibers. In particular, even when only one SiC fiber was substituted, the tensile strength increased by 81% to 1428 MPa. In the early stage of the in-vitro test, a silica-rich layer was formed on the surface of the 13-93 BG fibers. With time, calcium phosphate grew on the silica-rich layer and the BG fibers were delaminated. On the other hand, no products were observed on the SiC fibers for 7 days, therefore, SiC fibers are expected to maintain their strength even after transplantation in the body.

Preparation and Biocompatibility of Composite Bone Scaffolds Using Gnotobiotic Pig Bones (무균돼지뼈를 이용한 복합 골지지체의 제조와 생체적합성 평가)

  • Im, Ae-Lee;Chung, Jong-Hoon;Lim, Ki-Taek;Choung, Pill-Hoon;Hong, Ji-Hyang
    • Journal of Biosystems Engineering
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    • v.32 no.1 s.120
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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.

Surface Characteristics and Biocompatibility of MoS2-coated Dental Implant (MoS2 코팅된 치과용 임플란트의 표면특성과 생체적합성)

  • Min-Ki Kwon;Jun-Sik Lee;Mi Eun Kim;Han-Cheol Choe
    • Corrosion Science and Technology
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    • v.23 no.1
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    • pp.72-81
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    • 2024
  • The Ti-6Al-4V alloy is widely used as an implant material due to its higher fatigue strength and strengthto-weight ratio compared to pure titanium, excellent corrosion resistance, and bone-like properties that promote osseointegration. For rapid osseointegration, the adhesion between the titanium surface and cellular biomolecules is crucial because adhesion, morphology, function, and proliferation are influenced by surface characteristics. Polymeric peptides and similar coating technologies have limited effectiveness, prompting a demand for alternative materials. There is growing interest in 2D nanomaterials, such as MoS2, for good corrosion resistance and antibacterial, and bioactive properties. However, to coat MoS2 thin films onto titanium, typically a low-temperature hydrothermal synthesis method is required, resulting in the synthesis of films with a toxic 1T@2H crystalline structure. In this study, through high-temperature annealing, we transformed them into a non-toxic 2H structure. The implant coating technique proposed in this study has good corrosion resistance and biocompatibility, and antibacterial properties.