bluuebunny/crossref_metadata_2025_split huggingface dataset:
The bone formation in vitro and mandibular defect repair using PLGA porous scaffolds
Authors: Ren Tianbin , Ren Jie , Jia Xiaozhen , Pan Kefeng 
Published: July 2005

AbstractHighly porous scaffolds of poly(lactide‐co‐glycolide) (PLGA) were prepared by solution‐casting/salt‐leaching method. The in vitro degradation behavior of PLGA scaffold was investigated by measuring the change of normalized weight, water absorption, pH, and molecular weight during degradation period. Mesenchymal stem cells (MSCs) were seeded and cultured in three‐dimensional PLGA scaffolds to fabricate in vitro tissue engineering bone, which was investigated by cell morphology, cell number and deposition of mineralized matrix. The proliferation of seeded MSCs and their differentiated function were demonstrated by experimental results. To compare the reconstructive functions of different groups, mandibular defect repair of rabbit was made with PLGA/MSCs tissue engineering bone, control PLGA scaffold, and blank group without scaffold. Histopathologic methods were used to estimate the reconstructive functions. The result suggests that it is feasible to regenerate bone tissue in vitro using PLGA foams with pore size ranging from 100–250 μm as scaffolding for the transplantation of MSCs, and the PLGA/MSCs tissue engineering bone can greatly promote cell growth and have better healing functions for mandibular defect repair. The defect can be completely recuperated after 3 months with PLGA/MSCs tissue engineering bone, and the contrastive experiments show that the defects could not be repaired with blank PLGA scaffold. PLGA/MSCs tissue engineering bone has great potential as appropriate replacement for successful repair of bone defect. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Surface characterizations and corrosion resistance of nickel–titanium orthodontic archwires in artificial saliva of various degrees of acidity
Authors: Huang Her‐Hsiung 
Published: July 2005

AbstractThis study investigated the surface characterizations and corrosion resistance of as‐received commercial nickel–titanium (NiTi) dental orthodontic archwires from different manufacturers using a cyclic potentiodynamic test in artificial saliva with various acidities. An atomic force microscope was used to evaluate the surface topography of the NiTi wires. The surface chemical analysis of the passive film on the NiTi wires was characterized using X‐ray photoelectron spectroscopy and Auger electron spectroscopy. A scanning electron microscope, together with an energy‐dispersive spectrometer, was used to analyze the surface characterizations of the NiTi wires before and after the corrosion tests. Two‐way analysis of variance was used to analyze the corrosion‐resistance parameters with the factors of wire manufacturer and solution pH. The results showed that the surface structure of the passive film on the tested NiTi wires were identical, containing mainly TiO2, with small amounts of NiO. A different surface topography was observed on the NiTi wires from various manufacturers. The corrosion tests showed that both the wire manufacturer and solution pH had a statistically significant influence on the corrosion potential, corrosion rate, passive current, breakdown potential, and crevice‐corrosion susceptibility. The difference in the corrosion resistance among these NiTi dental orthodontic archwires did not correspond with the surface roughness and pre‐existing defects. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Indomethacin‐loaded methoxy poly(ethylene glycol)/poly(D,L‐lactide) amphiphilic diblock copolymeric nanospheres: Pharmacokinetic and toxicity studies in rodents
Authors: Kim So Yeon , Lee Young Moo , Kang Ju Seop 
Published: July 2005

AbstractBiodegradable methoxy poly(ethylene glycol)/poly(D,L‐lactide) amphiphilic block copolymeric nanospheres were prepared for application as a particulate drug carrier. Drug‐loaded nanospheres (ML50) showed a narrow size distribution with the average diameter of <200 nm. When the feed weight ratio of indomethacin (IMC) to polymer was 1:1, the ML50 nanosphere having a relatively high drug‐loading efficiency of about 33.0% could be obtained. To investigate pharmacokinetic characteristics of IMC in rats, the IMC concentration in plasma was analyzed using a high‐performance liquid chromatography system after intravenous bolus injection of free IMC and IMC‐loaded ML50 nanospheres. ML50 nanosphere system exhibited a significant potential for sustained release of drug and showed slow clearance of IMC, but there was no significant effect on metabolism of IMC in the rats. Median lethal dose (LD50) and major organs (e.g., heart, lung, liver, and kidney) toxicities were determined using ICR mice to estimate the acute toxicity of ML50 nanospheres. The LD50 of ML50 nanospheres determined by Litchfield‐Wilcoxon method was about 1.54 g/kg. After the mice were intraperitoneally administered with a half dose of LD50 for 7 days, no significant histopathologic changes were observed in ML50‐treated mice compared with normal mice in the light and electron microscopic observations of major organs. This indicates that ML50 nanospheres might be a useful candidate as a novel sustained drug carrier for hydrophobic drugs. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Enhanced fixation of implants by bone ingrowth to titanium fiber mesh: Effect of incorporation of hydroxyapatite powder
Authors: Tsukeoka Tadashi , Suzuki Masahiko , Ohtsuki Chikara , Tsuneizumi Yoshikazu , Miyagi Jin , Sugino Atsushi , Inoue Takayuki , Michihiro Ryouichi , Moriya Hideshige 
Published: July 2005

AbstractTight fixation between bone and implant materials is of great importance for a successful outcome of procedures such as total knee arthroplasty (TKA) and total hip arthroplasty (THA). Titanium fiber mesh is an attractive structure for the establishment of tight fixation between bone and implant by bone ingrowth into the spaces among the fibers. Enhancement of bone ingrowth is desired not only for tight fixation but also for a fast recovery. Our hypothesis is that just the presence of hydroxyapatite (HA) particles ensures improved bone ingrowth, and that long‐term stability can be obtained by mechanical anchoring of bone in the spaces among titanium fibers. In this study, we examine our hypothesis by in vivo experiment using dog femur. HA particles were incorporated in titanium fiber mesh coated on titanium alloy rod by dipping in a slurry of HA with hydroxy‐propyl‐cellulose in an ethanol solution. Specimens were implanted for 3, 5, and 8 weeks, and were then compared with the results from specimens without the use of HA. Bonding strength was evaluated by push‐out test, and histomorphometric measurements were made with analysis software to calculate the average value of bone ingrowth. A significantly higher bonding strength was observed for the specimens with HA‐incorporated implant at 3 and 5 weeks, and larger bone ingrowth deep inside the titanium fiber mesh was measured at 3 weeks. Our proposed method has the additional advantage of not requiring a high temperature that may result in changes in characters of HA powder such as phase transition, grain growth, and decomposition. Moreover, this technique of HA powder incorporation without high‐temperature treatment allows the use of several types of metallic fiber mesh, as well as the application to fiber mesh made of organic polymers. We conclude that this simple modification of titanium fiber mesh with HA powder can improve the fixation of implant to bone in the initial stage after operation. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Tissue engineering of articular cartilage using an allograft of cultured chondrocytes in a membrane‐sealed atelocollagen honeycomb‐shaped scaffold (ACHMS scaffold)
Authors: Masuoka Kazunori , Asazuma Takashi , Ishihara Masayuki , Sato Masato , Hattori Hidemi , Ishihara Miya , Yoshihara Yasuo , Matsui Takemi , Takase Bonpei , Kikuchi Makoto , Nemoto Koichi 
Published: July 2005

AbstractThe aim of this study was to investigate with tissue engineering procedures the possibility of using atelocollagen honeycomb‐shaped scaffolds sealed with a membrane (ACHMS scaffold) for the culturing of chondrocytes to repair articular cartilage defects. Chondrocytes from the articular cartilage of Japanese white rabbits were cultured in ACHMS scaffolds to allow a high‐density, three‐dimensional culturing for up to 21 days. Although the DNA content in the scaffold increased at a lower rate than monolayer culturing, scanning electron microscopy data showed that the scaffold was filled with grown chondrocytes and their produced extracellular matrix after 21 days. In addition, glycosaminoglycan (GAG) accumulation in the scaffold culture was at a higher level than the monolayer culture. Cultured cartilage in vitro for 14 days showed enough elasticity and stiffness to be handled in vivo. An articular cartilage defect was initiated in the patellar groove of the femur of rabbits and was subsequently filled with the chondrocyte‐cultured ACHMS scaffold, ACHMS scaffold alone, or nonfilled (control). Three months after the operations, histological analysis showed that only defects inserted with chondrocytes being cultured in ACHMS scaffolds were filled with reparative hyaline cartilage, and thereby highly expressing type II collagen. These results indicate that implantation of allogenic chondrocytes cultured in ACHMS scaffolds may be effective in repairing articular cartilage defects. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Fabrication and evaluation of a new composite composed of tricalcium phosphate, gelatin, and Chinese medicine as a bone substitute
Authors: Yao Chun‐Hsu , Tsai Hung‐Ming , Chen Yueh‐Sheng , Liu Bai‐Shuan 
Published: July 2005

AbstractThis study investigates the biological effects of traditional Chinese medicines on the activities of bone cells using rat bone cells. Then, a mixture of a GGT composite, that is, a novel biodegradable composite containing genipin crosslinked gelatin and tricalcium phosphate, and traditional Chinese medicine (TCM) was prepared as a GGT–TCM composite. A cultured neonatal rat calvarias organ was used to measure the potential of GGT–TCM composite for use in promoting the regeneration of defective bone tissue. The mitochondria activity of the bone cells following exposure to various concentrations of crude extracts of five herbal Chinese medicines was measured by colorimetric assay. Biochemical markers, such as alkaline phosphatase (ALP) and tartrate‐resistant acid phosphatase (TRAP) titers were analyzed to evaluate the activities of bone cells. Finally, we examined the organ culture units, which were maintained in cultured medium for 5 weeks. Morphology of tissue was observed, and the quantitative evaluation of the regenerated bone was determined. In a bone cells culture experiment, adding Cuscuta chinensis Lam. (TCM‐5) to the bone cells culture clearly promoted the proliferation and differentiation of the osteoblasts from their precursor cells; but the reduced amount of TRAP indicated that the medicine significantly inhibited the osteoclasts activities. Opposite bone cell responses were observed when Loranthus parasiticus Merr. (TCM‐3) and Achyranthes bidentata Bl. (TCM‐4) were added to the bone cells culture. Eucommia ulmoides Oliv. (TCM‐1) and Dipsacus asper Wall. (TCM‐2) potentially influence the proliferation and differentiation of the osteoblasts from their precursor cells, but they did not affect the osteoclasts activities. The finding from the organ culture indicated that Chinese medicine effectively increased the rate of tissue regeneration of damaged bones. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Evaluation of different scaffolds for BMP‐2 genetic orthopedic tissue engineering
Authors: Xu X. Leon , Lou Jueren , Tang Tingting , Ng Kenneth Wayman , Zhang Junhui , Yu Chaofeng , Dai Kerong 
Published: July 2005

AbstractTo better understand the effects of scaffold materials for bone morphogenetic protein 2 (BMP‐2) genetic tissue engineering in vivo, several gels, including alginate, collagen, agarose, hyaluronate, fibrin, or Pluronic, were mixed with adenovirus‐mediated human BMP‐2 gene (Adv‐hBMP‐2) transduced bone marrow stromal cells (BMSCs) and injected into the muscles of athymic mice to evaluate the resulting osteogenesis and chondrogenesis. These gel and gene‐transduced BMSC mixtures were also loaded onto β‐TCP/HAP biphasic calcined bone (BCB) and observed under scanning electron microscopy (SEM). In addition, these composite scaffolds were implanted into the subcutaneous site of athymic mice to construct tissue‐engineered bone. After injection, collagen, hyaluronate, or alginate gel mixed with gene‐transduced BMSCs induced more bone formation than a cell suspension in α‐MEM. The agarose‐gene‐transduced BMSC gel was found to contain much more hyaline cartilage. SEM showed the BMSCs could survive in alginate, agarose, and collagen gel in vitro for up to 8 d. After implantation of tissue‐engineered bone, the alginate, collagen, and agarose gel could promote new bone formation within a BCB in vivo. Little or no bone formed after injection of fibrin or Pluronic gel mixed with BMSCs or implantation with BCB. These findings help to elucidate the effects of various scaffold materials for future research in orthopedic tissue engineering using BMP‐2 transduced cells. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Magnetic force‐based mesenchymal stem cell expansion using antibody‐conjugated magnetoliposomes
Authors: Ito Akira , Hibino Eri , Shimizu Kazunori , Kobayashi Takeshi , Yamada Yoichi , Hibi Hideharu , Ueda Minoru , Honda Hiroyuki 
Published: July 2005

AbstractRecently, there has been an accumulation of evidence indicating that human mesenchymal stem cells (MSCs, multipotent cells resident in the bone marrow) are useful for autologous cell transplantation. However, only small numbers of MSCs have been obtained in bone marrow aspirates. We have developed a novel methodology for enriching and proliferating MSCs from bone marrow aspirates using antibody‐conjugated magnetoliposomes (AMLs). The AMLs are liposomes conjugated to anti‐CD105 antibody (immunoliposomes) and contain magnetite nanoparticles (diameter 10 nm). In the present study, the AMLs were added to a small volume (1 mL) of human bone marrow aspirate. After a 1‐h incubation period, the bone marrow aspirates containing AMLs were seeded into 10‐cm tissue culture dishes, and a disk‐shaped magnet (diameter 2.2 cm; height 1 cm; 4000 Gauss) was positioned under the dish to enrich MSCs by magnetic force. The MSCs proliferated, forming colonies at the site where the magnet was positioned. In contrast, no colonies and very few viable cells were observed in ordinary culture based on plastic‐adherent tendencies of cells without use of AMLs. These results suggest that this AML culture method can rapidly and efficiently expand a small number of MSCs into numbers suitable for clinical application. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
The growth improvement of porcine esophageal smooth muscle cells on collagen‐grafted poly(DL‐lactide‐co‐glycolide) membrane
Authors: Zhu Yabin , Chan‐Park Mary B. , Sin Chian Kerm 
Published: July 2005

AbstractSynthetic polyester and the extracellular matrix component collagen are among the most widely used materials in tissue engineering. However, the integration of collagen into polyester scaffolds without loss of its biological function is a problem that has not been fully solved. This article investigates the covalent immobilization of collagen onto poly(DL‐lactide‐co‐glycolide) (PLGA) membrane surfaces via a bridge of 1,8‐diaminooctane and with glutaraldehyde as crosslinking agent. X‐ray photoelectron spectroscopy (XPS) and fluorescence measurements confirmed the presence of bonded collagen. The effect of collagen grafting on cell behavior was investigated by comparing collagen‐PLGA with unmodified PLGA sample and tissue culture polystyrene (TCPS) plates by using porcine esophageal smooth muscle cells (ESMC). DNA analysis showed that collagen‐modified PLGA improved the overall proliferation of the ESMCs compared with unmodified PLGA and TCPS plates. Cells seeded on collagen‐modified PLGA also showed a more extended morphology. Thus, we believe that collagen‐modified PLGA shows good potential to be used as a scaffold material for tissue engineering of the esophagus. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Laser‐layered microfabrication of spatially patterned functionalized tissue‐engineering scaffolds
Authors: Mapili Gazell , Lu Yi , Chen Shaochen , Roy Krishnendu 
Published: July 2005

AbstractUnderstanding cell behavior inside complex, three‐dimensional (3D) microenvironments with controlled spatiotemporal patterning of physical and biochemical factors would provide significant insights into the basic biology of organ development and tissue functions. One of the fundamental limitations in studying such behavior has been the inability to create patterned microenvironments within 3D scaffold structures. Here a simple, layer‐by‐layer stereolithography (SL) method that can precisely pattern ligands, extracellular‐matrix (ECM) components, and growth factors, as well as controlled release particles inside a single scaffold, has been developed. The process also allows fabrication of predesigned internal architectures and porosities. Photocrosslinkable poly(ethylene glycol) dimethacrylate (PEGDMA) was used as the basic structural component of these microfabricated scaffolds. PEG acrylates, covalently modified with the cell adhesive peptide arginine‐glycine‐aspartic acid (RGD) or the ECM component heparan sulfate, was incorporated within the scaffolds to facilitate cell attachment and to allow spatial sequestration of heparan‐binding growth factors. Fluorescently labeled polymer microparticles and basic fibroblast growth factor (FGF‐2) were chosen to illustrate the capability of SL to spatiotemporally pattern scaffolds. The results demonstrate that a precise, predesigned distribution of single or multiple factors within a single 3D structure can be created, and specific internal architectures can be fabricated. Functionalization of these scaffolds with RGD is demonstrated, and heparan sulfate allows efficient cell attachment and spatial localization of growth factors. Such patterned scaffolds might provide effective systems to study cell behavior in complex microenvironments and could eventually lead to engineering of complex, hybrid tissue structures through predesigned, multilineage differentiation of a single stem‐cell population. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Interleukin‐1‐β gene, but not the interleukin‐1 receptor antagonist gene, is associated with graves' disease
Authors: Chen Rong‐Hsing , Chen Wen‐Chi , Chang Chwen‐Tzuei , Tsai Chang‐Hai , Tsai Fuu‐Jen 
Published: July 2005

AbstractInterleukin‐1 (IL‐1) is considered to be involved in the pathogenesis of Graves' disease. The aim of this study was to test whether the IL‐1‐β gene promoter region and exon 5 and IL‐1 receptor antagonist (IL‐1Ra) gene intron 2 polymorphisms could be useful genetic markers for susceptibility to Graves' disease. A normal control group of 163 healthy people and another group of 95 patients with Graves' disease were examined. Polymerase chain reaction (PCR) was used to analyze the variable number of tandem repeats (VNTRs) at intron 2 of the IL‐1Ra gene for the polymorphism. PCR‐based restriction analysis was done for the IL‐1‐β gene polymorphisms of the promoter region and exon 5 using endonucleases AvaI and TaqI, respectively. We found significantly increased frequencies of the C/C homozygous genotype (χ2 test, P=0.038; odds ratio (OR)=2.558, 95% confidence interval (CI)=1.205–5.430) and the C allele (χ2 test, P=0.011; OR=1.589, 95% CI=1.094–2.309) in the IL‐1‐β gene promoter (−511 C/T polymorphism) in Graves' disease patients compared to normal controls. There were no significant differences in polymorphisms of IL‐1‐β gene exon 5 and IL‐1Ra gene intron 2 between the patient and normal control groups. A subgroup analysis also demonstrated no association between the severity of the disease and any polymorphism of IL‐1‐related genes. We suggest that the IL‐1‐β gene promoter polymorphism can be used as a genetic marker for susceptibility to Graves' disease. It is worthwhile to study the cytokine genes further because of the association between cytokines and Graves' disease. J. Clin. Lab. Anal. 19:133–138, 2005. © 2005 Wiley‐Liss, Inc.
Development of PCR‐ELISA for the detection of hepatitis B virus x gene expression and clinical application
Authors: Kim Jong‐Wan , Shim Jung‐Hyun , Park Joo‐Won , Jang Won‐Cheol , Chang H.K. , Song Il Han , Baek Sun‐Young , Lee Seok‐Ho , Yoon Do‐Young , Park Sue‐Nie 
Published: July 2005

AbstractThe presence of hepatitis B virus x (HBx) antigen/antibody is known to correlate with the well‐established serological markers of ongoing viral replication in the chronic phase of HBV infection, and strongly suggests that the level and duration of HBx expression may influence the outcome of the chronic infection. In this research, we developed a polymerase chain reaction enzyme‐linked immunosorbent assay (PCR‐ELISA) method for the detection of HBx gene expression. We also investigated its relationship to the progress of the disease in HBV‐related patients. Peripheral blood mononuclear cells (PBMCs) were purely isolated, and reverse transcription‐PCR (RT‐PCR) was performed for improved sensitivity. The PCR products were determined by ELISA, and we investigated the relationship of the proposed method to the clinical status of the patients. The PCR‐ELISA used in this work was found to be at least 100 times more sensitive than the conventional PCR method, and even 8,000‐fold diluted PCR products could be detected. The HBx concentrations significantly differed among control subjects (0.36±0.09, [P<0.01] and patients with chronic hepatitis (1.13±0.34 [P<0.01 compared to control]), liver cirrhosis (LC; 1.37±0.28 [P<0.01 compared to control]), and hepatocellular carcinoma (HCC; 1.48±0.95 [P<0.01 compared to control]). These findings suggest that monitoring of HBx could be useful for early diagnosis and prognosis in patients with chronic HBV infection, LC, and HCC. J. Clin. Lab. Anal. 19:139–145, 2005. © 2005 Wiley‐Liss, Inc.