Papers by Author: Hee Joong Kim

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Authors: Hyun Joo Son, Dong Wook Han, H.H. Kim, Hee Joong Kim, In Seop Lee, Jeong Koo Kim, Jong Chul Park
Abstract: In this study, human dermal fibroblast behaviors onto non-porous PLGA (75:25) films immobilized with 1, 10 and 100 µg/ml collagen (CN) or fibronectin (FN) were investigated according to different cell-seeding densities (1,000, 10,000 and 100,000 cells/ml). Cell attachment and proliferation were assessed using water soluble tetrazolium salt. The results indicated that 1 µg/ml of FN-immobilized PLGA film demonstrated significantly (p < 0.05) superior cellular attachment to the intact PLGA film after 4 hr of incubation. Moreover, the number of attached cells was shown to be directly proportional to that of initially seeded cells. After 48 hr, the cells showed significantly (p < 0.05) higher proliferation onto 1 or 10 µg/ml of FN-immobilized PLGA films than onto other PLGA films, regardless of the initial cell-seeding density. In terms of CN-immobilization, cell proliferation was appreciably increased but it was relatively lower than FN-immobilization. These results suggested that ECM-immobilization can enhance the cell affinity of hydrophobic scaffolds and be used to potential applications for tissue engineering by supporting cell growth.
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Authors: Hee Song, Soo Ryong Kim, S.J. Jung, J.K. Lee, Hee Joong Kim, Y. Kim
Abstract: Silicon containing self setting bone cement has been prepared by adding silicon containing hydroxyapatite whisker to obtain a biomaterial having an improved resorption properties. Silicon containing calcium phosphate bone cement was composed of a-TCP: TeCP: DCPD: Si-HA whisker with a NH4H2PO4 as a setting liquid. From the XRD analysis, it was confirmed that calcium deficient hydroxyapatite phase appeared when it immersed in PBS solution. The dissolution rate of silicon containing calcium phosphate cement was measured in PBS solution and showed high dissolution rate. Based on in-vivo test, silicon containing self setting bone cement can be considered a useful material for bone bonding materials.
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Authors: Sang Hoon Rhee, Yong Keun Lee, Bum Soon Lim, Jae Il Lee, Jeong Joon Yoo, Hee Joong Kim
Abstract: Bioactive poly(e-caprolactone)-siloxane hybrid material was newly developed and its in vitro and in vivo evaluations were made for the potential application as a bone substitute. The polymer precursor, triethoxysilane end capped poly(e-caprolactone) was prepared by the reaction with a,w-hydroxyl poly(e-caprolactone) and 3-isocyanatopropyl triethoxysilane with 1,4-diazabicyclo [2,2,2] octane as a catalyst and toluene as a solvent. The triethoxysilane end capped poly(e-caprolactone) was hydrolyzed and condensed to yield a hybrid sol-gel material. The gelation was carried out for 1 week at ambient condition in a covered Teflon mold with a few pinholes and then dried under vacuum at room temperature for 48 h. Its bioactivity was evaluated by examining the apatite formation on its surface in the SBF and its osteoconductivity was assessed in the tibia of white rabbit. The hybrid material showed apatite-forming ability in the SBF within 1 week soaking. Besides, new bone was formed on the surface of a cylindrical shaped specimen with no histologically demonstrable intervening non-osseous tissue after 6 weeks implantation. There was no evidence of inflammation or foreign body reaction. From the results, it can be concluded that this newly developed hybrid material has osteoconductivity and is likely to be used for the application as a bone graft substitute.
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Authors: Jeong Joon Yoo, Kwang Woo Nam, Kyung Hoi Koo, Kang Sup Yoon, Hee Joong Kim
Abstract: The unique characteristics of cell surface molecules on human bone marrow stromal cells (hBMSCs) have not been clearly elucidated. The authors characterized 19 cell surface molecules on culture-expanded hBMSCs obtained from 10 human donors, by flow cytometry, calculated the averages and standard deviations of the expression frequencies of individual surface molecules, and evaluated their expression patterns with respect to donor-dependent variations. Surface molecules expressed at frequencies of more than 80% on cells included, CD49e, CD29, CD90, CD73, CD44, CD105, and CD146, those expressed at frequencies of 20-80% included, Stro-1, CD51, CD54, CD31, CD106, CD163, and CD34, whereas CD49d, CD14, CD144, CD11b, and CD45 were expressed at less than 20%. Substantial donor-dependent variations (>10% standard deviation in expression percentage) were observed in the expressions of CD105, Stro-1, CD51, CD54, CD31, CD106, CD163, and CD34. Our results demonstrate that CD49e, CD29, CD90, CD73, and CD44 can be used as a positive marker for hBMSCs, and that CD144, CD11b, and CD45 could be used as a highly selective negative marker. However, the expressions of CD54, CD31, and CD106 observed in the present study, contradicted prior reports and thus, their expressions remain controversial.
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Authors: In Hyung Moon, Hee Joong Kim, Kyu Young Kim, K.M. Lee, S.C. Yoo, J. Choi
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Authors: Jeong Joon Yoo, Jeon Hyun Bang, Kyung Hoi Koo, Kang Sup Yoon, Hee Joong Kim
Abstract: The relationships between donor age and gender and initial isolation yield and the osteogenic potentials of human bone marrow stromal cells (hBMSCs) have not been clearly elucidated. The authors investigated whether isolation yields and the osteogenic differentiation potentials of hBMSCs are indeed dependent on donor age or gender. Fresh bone marrow was aspirated from iliac crest of 72 donors (mean age 54.1 years; range, 23-84 years; 39 men and 33 women) undergoing total hip arthroplasty. Numbers of mononuclear cells, numbers of colony forming unit-fibroblasts (CFU-Fs) and alkaline phosphatase (ALP)-positive CFU-Fs, and numbers of BMSCs after isolation culture were not found to be significantly dependent on donor age or gender. Moreover, no significant age- or gender-related differences were observed in terms of the proliferation activities, ALP activities, and calcium contents of BMSCs during in vitro osteogenic differentiation. The data obtained from 72 human donors revealed no significant age- or genderrelated differences among hBMSCs in terms of isolation yields, proliferation activities, and osteogenic potentials.
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Authors: Jeong Joon Yoo, Hee Joong Kim, Young Min Kim, Kang Sup Yoon, Kyung Hoi Koo, Kwang Woo Nam, Yong Lae Kim
Abstract: Medial placement of a cementless acetabular component into or beyond the medial wall of a shallow, dysplastic acetabulum is a technique to enhance its coverage during difficult total hip arthroplasty (THA). Dysplastic hips almost always need small size of acetabular component, so an accelerated polyethylene wear can occur when a conventional bearing surface is used. Modern alumina-on-alumina couplings can be an alternative for these patients. We evaluated the clinical results of 43 medially placed cementless acetabular components (PLASMACUP®SC) incorporating a modern alumina bearing surface (BIOLOX® forte). Acetabular components were inserted medially beyond the ilioischial line and, therefore, beyond the level of the cortical bone of the cotyloid notch, and followed up for more than 5 years (range, 60 – 93 months). In 14 hips, the medial acetabular wall was perforated purposefully and the medial aspect of the cup was placed beyond both the ilioischial and the iliopubic line on radiographs. The mean Harris hip score improved from 55.3 points preoperatively to 94.5 points postoperatively. Postoperatively, the hip center migrated 12.1 mm medially and 1.5 mm inferiorly. The average amount of cup protrusion beyond the ilioischial and the iliopubic line was 3.1 mm and 1.9 mm, respectively. The average superolateral coverage of the cup was 98.5 percent. During follow-up, no osteolysis or loosening of acetabular components was observed and no revision was required. Medial placement of a cementless acetabular component into or beyond the medial acetabular wall offers predictable clinical results and durable fixation in modern alumina-on-alumina THA.
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Authors: Jeong Joon Yoo, Hee Joong Kim, Sang Hoon Rhee
Abstract: Previous study showed that the novel poly(ε-caprolactone)–organosiloxane nano-hybrid material (SiOPCL) had bioactivity, biodegradability, and mechanical properties comparable to those of human cancellous bone. In this study, hydroxyl carbonate apatite layer (HCA) was preformed on the surface of SiOPCL, which mimicked the events likely to occur in vivo, and cellular behaviors of human bone marrow stromal cells (hBMSCs) were investigated during the osteogenic differentiation on its surface (SiOPCL/HCA). Initial attachment, proliferation, and ALP activities of hBMSCs were comparable to those on tissue culture plates (TCPs), while the calcium content in the cell layer showed significantly higher value. It means that this novel bioactive nano-hybrid material is likely to be a promising candidate for bone grafting materials because of good hBMSCs responses as well as apatite forming ability in the simulated body fluid.
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Authors: Jeong Joon Yoo, Hee Joong Kim, Young Min Kim, Kang Sup Yoon, Kyung Hoi Koo, Kwang Woo Nam, Sang Ik Shin
Abstract: Limitation in liner and head options available to the surgeon may be the most practical disadvantage of alumina-on-alumina total hip arthroplasty (THA). This may be more problematic in the revision THA. We evaluated the results of 57 revision THAs (average, 46.2 years old) performed with a contemporary alumina-on-alumina bearing surface after a 5-year minimum follow-up (average, 67 months; range, 60-85 months). A third generation alumina-on-alumina bearing (BIOLOX® forte, CeramTec AG) and a cementless PLASMACUP®-BiCONTACT® hip revision system (AESCULAP AG & Co.) had been used in all patients. Alumina bearing was chosen for a relatively young active patient in whom an acetabular bone defect was not severe and an extremely long neck of artificial head was not required for the restoration of hip joint mechanics. The average Harris hip score improved from 65.0 points to 88.9 points. No implant loosened, no stem or cup was re-revised, and no additional reoperations were required. Ceramic wear was undetectable in 14 hips where differentiation of the femoral head from the cup was possible on radiographs and no osteolysis was observed. During the follow-up period, no hip demonstrated signs of infection or ceramic failure. Short-term results of revision THAs performed with analumina-on-alumina bearing are encouraging. We believe that physiological age and activity level of a patient, severity of acetabular bone loss, and availability of alumina head and liner options required for the restoration of proper limb length and joint stability should be considered to choose this alumina bearing surface during the revision THA.
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Authors: Jeong Joon Yoo, Hee Joong Kim, Young Min Kim, Kang Sup Yoon, Kyung Hoi Koo, Kwang Woo Nam, Yong Lae Kim, Hyuk Jin Lee
Abstract: Total hip arthroplasty (THA) in patients with sequelae of the hip joint infection is a technically challenging procedure. In addition, the majority of such patients are less than fifty years old, so it has been reported that they have higher prevalence of complication and failure of component fixation. Alumina-on-alumina couplings are an attractive alternative and may offer a promising option for such young active patients. We analyzed 33 primary cementless alumina-onalumina THAs (PLASMACUP®SC-BiCONTACT® system incorporating BIOLOX® forte) that had been performed in patients who had sequelae of the hip joint infection. The average age of the patients was 37.8 years (range, 19-68 years) and 26 patients were younger than 50 years old. They were followed-up for more than 5 years (average, 74 months; range, 60-93 months). All hips had no recurrence of hip joint infection. The mean Harris hip score improved from 59.8 points to 93.5 points. All of the implants had radiographic evidence of a bone ingrowth and no radiological loosening was found. During the follow-up period, no cup or stem was revised and no periprosthetic osteolysis was observed. Nonunion of the osteotomized greater trochanter occurred in one hip, but no postoperative infection or ceramic failure was observed. The 5-year minimum follow-up clinical results of modern alumina-on-alumina THAs performed in patients with sequelae of the hip joint infection were encouraging with regard to osteolysis and implant stability. Our findings show that this alternative articulation offers a reliable solution for these young patients with long-standing anatomic abnormalities of the bone and soft tissues.
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