가토에서 골가루와 hydroxyapatite가루의 혼합에 의한 골이식

권건영,강진성,송중원,한기환,오재훈 大韓成形外科學會 1992 Archives of Plastic Surgery Vol.19 No.1

When bone grafts are used to reconstruct skeletal defects, autogenous bone graft has been the method of choice. Autogenous bone graft, however, has disadvantages of unpredictable longterm resorption and the added morbidity to the patient from the harvesting of bone. Because of these problems, synthetic inorganic ceramic biomaterial, hydroxyapatite, has been developed and made available for craniofacial reconstructive procedures. Hydroxyapatite is biocompatible, and does not stimulate a foreign body reaction, and demonstrates osseous union with bone ingrowth, osteoconduction, and has not been reported to resorb. The purpose of our study is to make a new bone : a mixture of bone & hydroxyapatite which is able to generate new bone formation by a number of mechanisms such as osteogenesis, osteoinduction and osteoconduction and is unresorbable by the characteristics of unresorbable hydroxyapatite. In 20 rabbits, four full thickness bony defects were created on the frontoparietal bone and they were treated in 4 different ways : Group Ⅰ: the bony defect was left without graft. Group Ⅱ: the bony defect was filled with bone dust. Group Ⅲ: the bony defect was filled with a mixture of bone dust and hydroxyapatite particles. Group Ⅳ: the bony defect was filled with hydroxyapatite particles. Specimens were retrieved at 4, 8, 12, and 24 weeks posttoperatively. They were carefully examined grossly and microscopically. The results at 24 weeks postoperatively are as follows. Volume percentage : Group Ⅱ 74.27±2.048%, Group Ⅲ 121.39±3.284%, Group Ⅳ 119.48±9.173%. Hardness : Group Ⅰ42.20±0.367%, Group Ⅱ 57.28±0.549%, Group Ⅲ 71.14±1.151%, Group Ⅳ 65.69±0.571% X-ray study : In group Ⅱ, central osteoporotic changes, on the contrary marginal osteosclerotic changes were noted. In groups Ⅲ and Ⅳ, nearly complete osteosclerotic changes were noted. Histologic findings : regenerations of the bone, such as the presence of osteoblast, lamination those in group Ⅲ and Ⅳ. In goup Ⅲ, regeneration of bone was found more than in group Ⅳ but bone resorptive change was found less than in group Ⅱ. A mixture of bone and hydroxyapatite induces more bone regeneration than hydroxyapatite but is less resorbable than bone. These results suggest that the combination of bone and hydroxyapatite can improve the unpredictable resorbability of the bone and add bone induction ability to the hydroxyapatite so it amy provide an excellent alternative to autogenous bone graft.

Si 치환 Hydroxyapatite의 소결 특성에 관한 연구

이윤주,김영희,김수룡,정상진,류도형,송희,전무진,Lee, Yoon-Joo,Kim, Young-Hee,Kim, Soo-Ryong,Jung, Sang-Jin,Riu, Do-Hyung,Song, Hee,Jun, Moo-Jin 한국세라믹학회 2003 한국세라믹학회지 Vol.40 No.11

생체친화성이 증진된 생체재료를 얻기 위하여 실리콘 원료로 tetraethyl orthosilicate를 사용하여 실리콘이 치환된 hydroxyapatite를 합성하였으며 FT-IR, XRD, 그리고 ICP 분석결과로부터 실리콘이 hydroxyapatite 구조내에 치환되어 있음을 확인하였다. 성분분석 결과 2 wt%까지의 실리콘을 함유하는 hydroxyapatite인 경우는 120$0^{\circ}C$에서 소결 후에도 원래의 hydroxyapatite 구조를 잘 유지하고 있는 것이 XRD와 HRTEM으로 확인되었으나 그 이상의 실리콘을 함유하는 hydroxyapatite인 경우는 110$0^{\circ}C$에서 부터 상분리가 일어나 XRD에서 tricalcium phosphate와 calcium phosphate silicate상이 검출되기 시작하였다. Si -substituted hydroxyapatite has been prepared to obtain biomaterials having an improved biocompatibility. From FT-IR, XRD, and ICP analyses, it was confirmed that the single-phase of hydroxyapatite substituted by Si has formed. Si- substituted hydroxyapatite of up to 2 wt% for Si keeps its original structures intact for the sintering temperatures of up to 1200$^{\circ}C$. However, it is observed that the ion substitutions by the amount higher than the above ratios for the hydroxyapatite leads to destabilize original structures of the hydroxyapatite and to produce tricalcium phosphate and calcium phosphate silicate phases when the samples were sintered at 1l00$^{\circ}C$ or higher.

Hydroxyapatite로 재건한 Orbital Blow-out fracture의 임상적 분석

황욱배,배용찬,황소민,황성호,김동헌,전재용 大韓成形外科學會 1998 Archives of Plastic Surgery Vol.25 No.6

The blow-out fracture can be reconstructed by various autogeneous and alloplastic material. Particulate, nonresorbable hydroxyapatite is currently one of the choice of implant material available for reconstruction of blow-out fracture. Hydroxyapatite is radiopaque ceramic, physically and chemically similar to enamel and cortical bone. It is a biomaterial derived from natural corals to use as a bone graft substitute. And we looked into the clinical usefulness of 2 type of hydroxyapatite with their advantages and disadvantages in reconstruction of blow-out fracture. 183 patients with blow-out fracture who underwent surgical reconstruction with two types of hydroxyapatite from March 1933 to July 1977 have been analyzed the results of surgical reconstructions, and have been followed up for more than a year. And the condition of formerly inserted hydroxyapatite was observed in the patients who needed 2nd surgical reconstruction due to the enophthalmos. The disadvantages of hydroxyapatite are fragility, size and contour limitations. In spite of these demerits, hydroxyapatite can be one of the prospective materials to reconstruct orbital floor. Through the clinical experiences for 5 years, we have not found any of complications of exposure, infection, and foreign body reaction. Low rates of diplopia, limitation of ocular movement, and enophtalmos was observed. Hydroxyapatite was well adherent to adjacent orbital bone in most patients who needed secondary reconstruction for enopthalmos. In conclusion, our study shows that the availability of hydroxyapattite in reconstruction of blow-out fracture is recommendable, with low complication rates. Hydroxyapatite important appears to be well tolerated, and provides useful alloplastic prosthesis with few problems in reconstruction of blow-out fracture.

Hydroxyapatite/Titania Hybrid Coatings on Titanium by Sol-Gel Process

임기형,김광만,김민철,강동국,김경남,이용근 한국생체재료학회 2006 생체재료학회지 Vol.10 No.4

Sol-gel thin films of hydroxyapatite and titania have received a great deal of attention in the area of bioactive surface modification of titanium implants. Sol-gel process offers lots of advantages over other coating techniques, e.g. increased homogeneity due to atomic level mixing; finer grain microstructure and lower temperature of the crystallization. In this study, we fabricated hydroxyapatite/titania hybrid coatings on titanium by sol-gel method to combine advantages of both materials: the adhesion strength of the titanium dioxide on the substrate and the bioactivity of the hydroxyapatite. Sol-gel coatings of pure hydroxyapatite and titania, and four hydroxyapatite composites with 10~70 mol% titania were developed on titanium substrates. The characteristics of coatings, such as crystallinity, roughness and composition of surface, were observed. The composite coatings showed the characteristic peaks of pure hydroxyapatite and titania with anatase and rutile structures. When the titania amounts adding into the hydroxyapatite sol increased, the surface of the composite coatings became slightly rougher. The critical load strength between coating and substrate slightly increased to 3.151, 4.168, and 5.389 N when the amount of titania added into hydroxyapatite sol increased to 30, 50, and 70 mol%, respectively. For bioactivity test, calcium phosphate deposits were observed on the film surfaces after the soaking in SBF for 1 week, except of titania coated-substrate. The in vitro cellular responses to the coatings were assessed in terms of cell attachment and proliferation. Hydroxyapatite composite coating with 70 mol% titania had the most excellent attachment of MG63 cells as cells tend to attach more readily to surfaces with a rougher microtopography. Statistically analysis revealed that there were no significant differences between the proliferation of osteoblastic cells on the various materials (p>0.05).

Effect of yttria on thermal stability, mechanical and in vitro bioactivity properties of hydroxyapatite/alumina composite

Serdar PAZARLIOĞLU,Serdar SALMAN 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.1

The phase stability, mechanical and in vitro bioactivity properties of hydroxyapatite/alumina composite with and withoutyttria were investigated. Hydroxyapatite without additives decomposed at 1300 oC to beta- and alpha-tricalcium phosphateand calcium oxide phases. Although alumina contributed to the mechanical properties of hydroxyapatite, it not only decreasedthe decomposition temperature of hydroxyapatite from 1200 oC to 900 oC and it’s in vitro bioactivity property but alsoincreased the decomposition ratio of hydroxyapatite. An improvement in the properties of hydroxyapatite/alumina compositewas provided by yttria via inhibiting the solid-state reactions between hydroxyapatite and alumina via the formation of yttriumaluminum oxide and calcium yttrium trialuminum oxide phases. The maximum fracture toughness of 2.178 ± 0.251 MPam1/2,microhardness of 4.947 ± 0.191 GPa, a compressive strength of 227.75 ± 27.87 MPa, and a three-point bending strength of90.15 ± 6.93 MPa were achieved for hydroxyapatite/alumina composite containing 1.5 wt% yttria at the sintering temperatureof 1200 oC. The relative density of 92.94 ± 0.11% was also attained. This ternary composite can potentially be used in thehuman body for load-bearing applications because of its sufficient mechanical and in vitro bioactivity properties with adecomposition ratio of 9.4%.

수산화아파타이트(HAp)를 이용한 치아 수복제에 관한 연구

류수착,Ryu, Su-Chak 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.10

Hydroxyapatite powder was injected into the tooth after decayed tooth clinic. The microstructure of tooth was observed after a tooth extraction in the body. The hydroxyapatite powder was stiffened and the junction of hydroxyapatite powder and tooth was observed. The Ca/P atomic ratio of hydroxyapatite-tooth boundary was higher than hydroxyapatite matrix. And microhardness of hydroxyapatite matrix was 92.4 Hv. The junction of hydroxyapatite powder and tooth was due to the $Ca^{2+}$ ion shift of hydroxyapatite or the firm waxy body was due to setting of hydroxyapatite powder.

Formation of Oriented Hydroxyapatite Rods by Hydrothermal Treatment of Calcite Single Crystal

Kim, Ill-Yong,Kikuta, Koichi,Ohtsuki, Chikara Materials Research Society of Korea 2012 한국재료학회지 Vol.22 No.8

Morphological control on hydroxyapatite crystals has attractive prospects in research to clarify the effects of crystal planes on biological performance. Hydrothermal processing is known as a typical type of processing for fabricating well-grown crystals with unique morphology. The purpose of the present study is to examine the feasibility of well-crystallized crystals with oriented structures through hydrothermal treatment of calcite. A single crystal of calcite was applied to hydrothermal treatment in a phosphate solution at $160^{\circ}C$. Rod-shaped hydroxyapatite crystals with micrometer-size were formed on the {100} face of calcite after treatment, while nanometer-sized hydroxyapatite crystals were formed on the (111). The hydroxyapatite crystals formed on each plane were not morphologically changed with increasing treatment periods. An oriented structure of rod-shaped hydroxyapatite was constructed after hydrothermal treatment of {100} planes on the calcite single, while such orientation was not observed on the (111) plane after the treatment. The layer of hydroxyapatite formed on the {100} plane was thicker than that of the (111) plane. The {100} plane of calcite shows a higher reactivity than that of the (111) plane, which results in rapid crystal growth of hydroxyapatite. The difference in the morphology of the formed hydroxyapatite was governed by the reactivity of each crystal plane exposed to the surrounding solution.

Hydroxyapatite/poly(<i>ε</i>-caprolactone) double coating on magnesium for enhanced corrosion resistance and coating flexibility

Jo, Ji-Hoon,Li, Yuanlong,Kim, Sae-Mi,Kim, Hyoun-Ee,Koh, Young-Hag SAGE Publications 2013 Journal of biomaterials applications Vol.28 No.4

<P>Hydroxyapatite was deposited on pure magnesium (Mg) with a flexible poly(ε-caprolactone) interlayer to reduce the corrosion rate of Mg and enhance coating flexibility. The poly(ε-caprolactone) interlayer was uniformly coated on Mg by a spraying method, followed by hydroxyapatite deposition on the poly(ε-caprolactone) using an aerosol deposition method. In scanning electron microscopy observations, inorganic/organic composite-like structure was observed between the hydroxyapatite and poly(ε-caprolactone) layers, resulting from the collisions of hydroxyapatite particles into the poly(ε-caprolactone) matrix at the initial stage of the aerosol deposition. The corrosion resistance of the coated Mg was examined using potentiodynamic polarization tests. The hydroxyapatite/poly(ε-caprolactone) double coating remarkably improved the corrosion resistance of Mg in Hank’s solution. In the in vitro cell tests, the coated Mg showed better cell adhesion compared with the bare Mg due to the reduced corrosion rate and enhanced biocompatibility. The stability and flexibility of hydroxyapatite/poly(ε-caprolactone) double coating was investigated by scanning electron microscopy inspections after the coated Mg was deformed. The hydroxyapatite coating on the poly(ε-caprolactone) interlayer revealed enhanced coating stability and flexibility without cracking or delamination during bending and stretching compared with the hydroxyapatite single coating. These results demonstrated that the hydroxyapatite/poly(ε-caprolactone) double coating significantly improved the surface corrosion resistance of Mg and enhanced coating flexibility for use of Mg as a biodegradable implant.</P>

Hydroxyapatite와 TiNx의 복합체의 제조

김성진,박성범,조경식,박노진,권원일,오영환,박도언,J.F. Schackelford,Z. A. Munir 한국생체재료학회 2005 생체재료학회지 Vol.9 No.2

The composites of hydroxyapatite-TiNx were prepared using a spark plasma sintering(SPS) apparatus. Density of hydroxyapatite-1%TiNx composite was decreased with increasing content of TiNx in order of 0.1%, 05% and 1.0% but density of hydroxyapatite-1%~10%TiNx composite was increased with increasing content of TiNx inorder of 1%, 5% and 10%. The maximum biaxial strength of hydroxyapatite and TiNx of composites was achieved by SPS with a composition of 0.1% TiNx at 900oC. The decomposition of composites hydroxyapatite and TiNx composites were not detected by XRD at the range of 900oC to 1100oC, this means the decomposition of hydroxyapatite was restrained easily by addition of TiNx.

Birnessite와 Hydroxyapatite에 의한 납과 카드뮴 오염퇴적토의 독성저감 평가

이승배,정재웅,김영진,남경필,Lee, Seung-Bae,Jung, Jae-Woong,Kim, Young-Jin,Nam, Kyoung-Phile 한국지하수토양환경학회 2012 지하수토양환경 Vol.17 No.4

The success of stabilization treatment in heavy metal contaminated sediment depends on the heavy metal bioavailability reduction through the sequestration of the heavy metals. This study was performed to assess the changes in the bioavailability of Pb or Cd in the Pb or Cd contaminated sediments by using birnessite and hydroxyapatite as stabilizing agents. The toxicity tests were carried out using a microorganism (Vibrio fischeri), an amphipod (Hyalella azteca) and an earthworm (Eisenia foetida). With Vibrio fischeri, the toxicities of both Pb and Cd were reduced by more than ten times in the presence of birnessite and hydroxyapatite compared to that of in the absence of birnessite and hydroxyapatite. The concentrations of Pb and Cd in the contaminated sediments were lethal to Hyalella azteca, however, in the presence of birnessite and hydroxyapatite more than 90%, on average, of Hyalella azteca survived. With Eisenia foetida, the bioaccumulated concentrations of both Pb and Cd were reduced by more than 75%, on average, lower with the addition of birnessite and hydroxyapatite to the contaminated sediments. These results show that the addition of birnessite and hydroxyapatite can reduce the bioavailability of Pb and Cd in contaminated sediments. In addition, the in situ and ex situ performance of birnessite and hydroxyapatite as stabilizing agents can be verified using the toxicity tests with Hyalella azteca and Eisenia foetida, respectively.