Publications (31)66.33 Total impact
-
Article: A novel rotating electrochemically anodizing process to fabricate titanium oxide surface nanostructures enhancing the bioactivity of osteoblastic cells.
[show abstract] [hide abstract]
ABSTRACT: Titanium oxide (TiO(2) ) surface layers with various surface nanostructures (nanotubes and nanowires) have been developed using an anodizing technique. The pore size and length of TiO(2) nanotubes can be tailored by changing the anodizing time and applied voltage. We developed a novel method to transform the upper part of the formed TiO(2) nanotubes into a nanowire-like structure by rotating the titanium anode during anodizing process. The transformation of nanotubes contributed to the preferential chemical dissolution of TiO(2) on the areas with intense interface tension stress. Furthermore, we further compared the effect of various TiO(2) surface nanostructures including flat, nanotubes, and nanowires on bioactive applications. The MG-63 osteoblastic cells cultured on the TiO(2) nanowires exhibited a polygonal shape with extending filopodia and showed highest levels of cell viability and alkaline phosphatase activity (ALP). The TiO(2) nanowire structure formed by our novel method can provide beneficial effects for MG-63 osteoblastic cells in attachment, proliferation, and secretion of ALP on the TiO(2) surface layer.Journal of Biomedical Materials Research Part A 03/2012; 100(7):1687-95. · 2.63 Impact Factor -
Article: Cartilage fragments from osteoarthritic knee promote chondrogenesis of mesenchymal stem cells without exogenous growth factor induction.
[show abstract] [hide abstract]
ABSTRACT: Extracellular matrix (ECM) is thought to participate significantly in guiding the differentiation process of mesenchymal stem cells (MSCs). In this study, we hypothesized that cartilage fragments from osteoarthritic knee could promote chondrogenesis of MSCs. Nonworn parts of cartilage tissues were obtained during total knee arthroplasty (TKA) surgery. Cartilage fragments and MSCs were wrapped into fibrin glue; and the constructs were implanted subcutaneously into nude mice. Histological analysis showed neocartilage-like structure with positive Alcian blue staining in the cartilage fragment-fibrin-MSC constructs. However, constructs with only MSCs in fibrin showed condensed appearance like MSCs in the pellet culture. Gene expression of type II collagen in the constructs with 60 mg cartilage fragments were significantly elevated after 4 weeks of implantation. Conversely, the constructs without cartilage fragments failed to express type II collagen, which indicated MSCs did not differentiate into a chondrogenic lineage. In conclusion, we demonstrated the effect of cartilage fragments from osteoarthritic knee in promoting chondrogenic differentiation of MSCs. This may be a favorable strategy for MSC chondrogenesis without exogenous growth factor induction.Journal of Orthopaedic Research 03/2012; 30(3):393-400. · 2.81 Impact Factor -
Article: Tissue engineering-based cartilage repair with mesenchymal stem cells in a porcine model.
[show abstract] [hide abstract]
ABSTRACT: This in vivo pilot study explored the use of mesenchymal stem cell (MSC) containing tissue engineering constructs in repair of osteochondral defects. Osteochondral defects were created in the medial condyles of both knees of 16 miniature pigs. One joint received a cell/collagen tissue engineering construct with or without pretreatment with transforming growth factor β (TGF-β) and the other joint from the same pig received no treatment or the gel scaffold only. Six months after surgery, in knees with no treatment, all defects showed contracted craters; in those treated with the gel scaffold alone, six showed a smooth gross surface, one a hypertrophic surface, and one a contracted crater; in those with undifferentiated MSCs, five defects had smooth, fully repaired surfaces or partially repaired surfaces, and one defect poor repair; in those with TGF-β-induced differentiated MSCs, seven defects had smooth, fully repaired surfaces or partially repaired surfaces, and three defects showed poor repair. In Pineda score grading, the group with undifferentiated MSC, but not the group with TGF-β-induced differentiated MSCs, had significantly lower subchondral, cell morphology, and total scores than the groups with no or gel-only treatment. The compressive stiffness was larger in cartilage without surgical treatment than the treated area within each group. In conclusion, this preliminary pilot study suggests that using undifferentiated MSCs might be a better approach than using TGF-β-induced differentiated MSCs for in vivo tissue engineered treatment of osteochondral defects.Journal of Orthopaedic Research 05/2011; 29(12):1874-80. · 2.81 Impact Factor -
Article: Nanoparticles prepared from the water extract of Gusuibu (Drynaria fortunei J. Sm.) protects osteoblasts against insults and promotes cell maturation.
[show abstract] [hide abstract]
ABSTRACT: Our previous study showed that Gusuibu (Drynaria fortunei J. Sm.) can stimulate osteoblast maturation. This study was further designed to evaluate the effects of nanoparticles prepared from the water extract of Gusuibu (WEG) on osteoblast survival and maturation. Primary osteoblasts were exposed to 1, 10, 100, and 1000 μg/mL nanoparticles of WEG (nWEG) for 24, 48, and 72 hours did not affect morphologies, viability, or apoptosis of osteoblasts. In comparison, treatment of osteoblasts with 1000 μg/mL WEG for 72 hours decreased cell viability and induced DNA fragmentation and cell apoptosis. nWEG had better antioxidant bioactivity in protecting osteoblasts from oxidative and nitrosative stress-induced apoptosis than WEG. In addition, nWEG stimulated greater osteoblast maturation than did WEG. Therefore, this study shows that WEG nanoparticles are safer to primary osteoblasts than are normal-sized products, and may promote better bone healing by protecting osteoblasts from apoptotic insults, and by promoting osteogenic maturation.International Journal of Nanomedicine 01/2011; 6:1405-13. · 3.13 Impact Factor -
Article: Inhibitory effects of Lactobacillus casei subsp. rhamnosus on Salmonella lipopolysaccharide-induced inflammation and epithelial barrier dysfunction in a co-culture model using Caco-2/peripheral blood mononuclear cells.
[show abstract] [hide abstract]
ABSTRACT: In this study, we investigated the anti-inflammatory and reinforcing barrier effects of Lactobacillus casei subsp. rhamnosus (Lcr35) on Caco-2 intestinal epithelial cells already exposed to Salmonella LPS. Using the Transwell co-culture model, Salmonella LPS was apically added to polarized Caco-2 cells co-cultured with peripheral blood mononuclear cells (PBMCs) in the basolateral compartment. LPS-stimulated Caco-2 cells were incubated with Lcr35 for 1, 6, 24 or 48 h. Apical inoculation of Lcr35 after 48 h significantly inhibited the basolateral secretion of interleukin-8 (IL-8) in the Caco-2/PBMC co-culture. The PCR analysis showed that Lcr35 significantly downregulated mRNA expression of monocyte chemoattractant protein 1 (MCP-1) (P<0.05) and had a trend of decreasing mRNA expression of IL-8 (P=0.05), but did not alter mRNA expression of transforming growth factor-beta1 in LPS-stimulated Caco-2 cells at 48 h after addition of Lcr35. Compared to non-LPS-pretreated controls, transepithelial electrical resistance (TEER) of the polarized Caco-2 cell monolayers pretreated with LPS for 48 h was decreased by 9.9 % (P<0.05). Additionally, compared to those cells only treated with LPS, apical co-incubation with Lcr35 showed biphasic TEER levels increased by 12.1 % (P<0.001), 5.7 % (P<0.05) and 86.8 % (P<0.001) in the Caco-2 cell monolayers compared to those without Lcr35 treatment after 1, 6 and 48 h, respectively. In conclusion, Lcr35 can exert anti-inflammatory effects and ameliorate barrier dysfunction in the Salmonella LPS-pretreated inflamed intestinal epithelium in vitro.Journal of Medical Microbiology 05/2010; 59(Pt 5):573-9. · 2.50 Impact Factor -
Article: A poly(propylene fumarate)--calcium phosphate based angiogenic injectable bone cement for femoral head osteonecrosis.
[show abstract] [hide abstract]
ABSTRACT: Osteonecrosis of the femoral head commonly occurs when the blood supply to bone was disrupted. The general treatment for early stages of necrosis in the femoral head is core decompression. However, the long-term outcome of this operation is usually compromised due to collapse of the necrotic bone. In this study, poly(propylene fumarate) (PPF) and calcium phosphate cement (CPC) were combined to provide appropriate mechanical strength after core-decompressed femoral heads and offer the properties of osteoconductivity. Effects of different ratios of CPC to PPF on mechanical and cytotoxicity were investigated. Results show that bone cement is less cytotoxic with the C/P ratio raise, and the increment of the CPC proportion also strengthens the mechanical strength, reduces the crosslinking temperature and diminishes excessive swelling of the cement. With addition of ginsenoside Rg1 the bone cement composite can also offer angiogenic effect. The drug release profiles were analyzed and the angiogenecity of released Rg1 was confirmed by the assay of tube formation in human umbilical vein endothelial cells (HUVECs). In summary, the newly developed angiogenic bone cement composite possesses remarkable development potential for application to treating osteonecrosis of the femoral head.Biomaterials 02/2010; 31(14):4048-55. · 7.40 Impact Factor -
Article: Dose-dependent effect of Lactobacillus rhamnosus on quantitative reduction of faecal rotavirus shedding in children.
[show abstract] [hide abstract]
ABSTRACT: Beneficial effects of probiotics in acute infectious diarrhoea in children are mainly seen in watery diarrhoea and viral gastroenteritis. Lactobacillus rhamnosus, one the most extensively studied probiotic strains, is effective in shortening courses of acute diarrhoea in children. However, the dose-dependent effect of Lactobacillus upon quantification of faecal rotavirus shedding in humans remains little known. Thus, an open-label randomized trial in 23 children with acute rotaviral gastroenteritis was undertaken by randomly allocating patients to receive one of the three regimens for 3 days: daily Lactobacillus rhamnosus 35 (Lcr35) with 0 CFU/day to six patients in the control group, 2 x 10(8) CFU/day to nine patients in the low-dose group, and 6 x 10(8) CFU/day to eight patients in the high-dose group. Faecal samples were collected before and after the 3-day regimen for measurements of rotavirus concentrations by ELISA. There was no statistically significant change in faecal rotavirus concentrations in either the control group (119.2 x 10(5) particles/ml vs. 23.7 x 10(5) particles/ml, p = 0.075) or the low-dose group (36.1 x 10(5) particles/ml vs. 73.5 x 10(5) particles/ml, p = 0.859). However, the high-dose group had a significant reduction of faecal rotavirus concentration (64.2 x 10(5) particles/ml vs. 9.0 x 10(5) particles/ml, p = 0.012). Without any exception, the faecal rotavirus concentrations of all eight patients in the high-dose Lcr35 group declined by 86% after 3 days when compared with those before Lcr35 administration. In conclusion, this is the first report to provide quantitative evidence of the dose-dependent effect of Lactobacillus rhamnosus, a minimal effective dose of 6 x 10(8) CFU for 3 days, upon the faecal rotavirus shedding in paediatric patients.Journal of Tropical Pediatrics 03/2009; 55(5):297-301. · 1.39 Impact Factor -
Article: Can low frequency electromagnetic field help cartilage tissue engineering?
[show abstract] [hide abstract]
ABSTRACT: To understand whether a low-frequency pulsed electromagnetic field (EMF) could help cartilage tissue repair in the scope of tissue engineering, we tested how EMF affected collagen gel properties and the behaviors of chondrocyte cells embedded in collagen constructs. Collagen gel and primary chondrocytes embedded in collagen were exposed to EMF for 24 h. Gel and cells that were not exposed to EMF served as controls. Collagen gel exposed to EMF was more hydrophobic and less susceptible to enzymatic degradation (both p < 0.05) than control. Three weeks after EMF exposure, chondrocytes showed higher proliferation and lower glycosaminoglycan (GAG) production (both p < 0.05) than control. By the end of the third week, aggrecan, type I, II, and X collagen mRNA expressions in the EMF group were 1.8 times higher (p < 0.05), except for type II collagen) than control. The increase in gene expression did not show up in aggrecan histological staining and type II and type X collagen immunohistochemical staining. Cells from both groups kept a normal polygonal shape through out the test period. Our results suggested that one-time EMF exposure could promote collagen-embedded chondrocytes proliferation and their gene expressions. It also promoted short-term (week 1) GAG production and lacuna formation. No apparent GAG and type II collagen production was seen in histological staining three weeks after the EMF exposure.Journal of Biomedical Materials Research Part A 03/2009; 92(3):843-51. · 2.63 Impact Factor -
Article: Development and biological evaluation of C(60) fulleropyrrolidine-thalidomide dyad as a new anti-inflammation agent.
[show abstract] [hide abstract]
ABSTRACT: Research studies in the field of C(60) fullerene derivatives have significantly increased due to the broad range of biological activities that were found for these compounds. We designed and prepared a new C(60) fullerene hybrid bearing thalidomide as a potential double-action anti-inflammatory agent, capable of simultaneous inhibition of LPS-induced NO and TNF-alpha production. The C(60) fulleropyrrolidine-thalidomide dyad, CLT, was an effective agent to suppress the release of NO and TNF-alpha by the LPS-stimulated macrophages RAW 264.7. Ten micromolars of CLT effectively inhibited LPS-induced NO and TNF-alpha production by 47.3+/-4.2% and 70.2+/-4% with respected to the control, respectively. Furthermore, preliminary biochemical investigation revealed that CLT was a potent agent to suppress both LPS-induced intracellular ROS production and iNOS expression, and CLT also inhibited the phosphorylation of ERK which is an important protein kinase involved in the activation of TNF-alpha synthesis in LPS-activated macrophages. We believed that the studies herein would hold promise for future development of a new generation of potent anti-inflammatory agents.Bioorganic & medicinal chemistry 09/2008; 16(18):8619-26. · 2.82 Impact Factor -
Article: Modulation of gene expression of rabbit chondrocytes by dynamic compression in polyurethane scaffolds with collagen gel encapsulation.
[show abstract] [hide abstract]
ABSTRACT: Chondrocytes have been demonstrated to be sensitive to mechanical stimuli, such as compression, tension, shear force, and hydrostatic pressure. The responses of chondrocytes to mechanical compression have been often studied in vitro with cartilage and chondrocyte/hydrogel systems. The aim of this study was to investigate the effects of dynamic compression on gene expression of rabbit chondrocytes which were seeded in elastic polyurethane scaffolds with or without collagen gel encapsulation. Dynamic compression of 20% or 30% strain with 0.1 Hz frequency was applied to the cell-seeded scaffolds for 4, 8, 12, or 24 h, and then the expression of the three genes related to chondrogenic phenotype, type I and II collagens and aggrecan, was analyzed by RT-PCR. We also investigated the gene expression of the compressed chondrocytes, which had experienced 12-h 30% strain dynamic loading, during the post-compression resting period. We found that the expression of type II collagen did not seem to respond to cyclic compression. On the other hand, aggrecan gene was stimulated by dynamic compression. The stimulatory effect disappeared gradually after the dynamic compression was ceased. Furthermore, the mechano-response of the chondrocytes to aggrecan expression was delayed by collagen gel encapsulation. The expression of type I collagen was enhanced by collagen gel. We found that collagen gel encapsulation prolonged the expression of aggrecan and type I collagen during post-compression resting period. We demonstrated that mechanical and biochemical stimuli modulate the gene expression of chondrocytes.Journal of Biomaterials Applications 09/2008; 23(4):347-66. · 2.08 Impact Factor -
Article: Evaluation of multi-target and single-target liposomal drugs for the treatment of gastric cancer.
[show abstract] [hide abstract]
ABSTRACT: We studied the effects of multi- and single-target liposomal drugs on human gastric cancer cell AGS both in vitro and in vivo. The cytotoxic effect of dihydrotanshinone I was significantly enhanced by treatment with octreotide-polyethylene glycol(PEG)-liposome, Arg-Gly-Asp(RGD)-PEG-liposome, and RGD/octreotide-PEG-liposome encapsulated with 0.5 mug/ml of dihydrotanshinone I to AGS cell for 24 h, compared to control. Furthermore, the AGS cell survival rate for multi-target versus single target liposomal drugs was significantly suppressed. Microscopic examination revealed that significant cell death occurred in the multi- and single-target liposomal encapsulated drug groups. Significant suppression of tumor growth in AGS cell xenograft nude mice given octreotide-PEG-liposome, RGD/octreotide-PEG-liposome encapsulated drug, versus those given a free drug was noted after 13 d of experimentation with the multi-targeted liposome: up to 60.75% and 41.2% reduction of tumor volume as compared to dimethylsulfoxide (DMSO) control and the free drug groups respectively. The treated animals showed no gross signs of toxicity. The results have potential clinical application.Bioscience Biotechnology and Biochemistry 07/2008; 72(6):1586-94. · 1.28 Impact Factor -
Article: Quantitative analysis of osteoblast-like cells (MG63) morphology on nanogrooved substrata with various groove and ridge dimensions.
[show abstract] [hide abstract]
ABSTRACT: Nanotextured silicon substrata with parallel ridges separated by grooves with equal width from 90 to 500 nm, were fabricated by electron beam lithography and dry etching techniques. Osteoblast-like cells, MG-63, were cultured on the sterilized nanopatterned substrata for 4 or 24 h, and then imaged by scanning electron microscopy. The influence of substrate topography on cell morphology was analyzed by image software. We found the initially cells spread faster on the nanopatterned surfaces than on the flat surface, suggesting that surface anisotropic feature facilitates initial cell extension along its direction. However, because of inhibition of cell lateral expansion across nanogrooved surfaces, the cells on the nanogrooved surface did not further expand laterally, and cell spreading area was less than that on the flat surface after 24 h of incubation. Cells elongated and aligned along the direction of grooves on all the nanopatterned substrata. Furthermore, fluorescence staining of cell nuclei indicated that the nuclei of the cells cultured on the nanopatterned surfaces also displayed a more elongated and aligned morphology along the direction of the grooves. Since cell shape and orientation influence cell functions and alignment of extracellular matrix secreted by cells, our results may provide the information regarding responses of osteoblasts to the nanostructure of collagen fibrils, and benefit bone tissue engineering and surface design of orthopedic implants.Journal of Biomedical Materials Research Part A 07/2008; 90(3):629-40. · 2.63 Impact Factor -
Article: Chondrogenesis from immortalized human mesenchymal stem cells: comparison between collagen gel and pellet culture methods.
[show abstract] [hide abstract]
ABSTRACT: Human mesenchymal stem cells (hMSCs) can differentiate into cells of connective tissue lineages, including cartilage. To overcome the limiting autogenous chondrocyte populations available in cartilage repair, various methods have been developed to maximize chondrogenesis of hMSCs in vitro, most of which use cells derived from primary culture. In this study, we compared chondrogenesis of immortalized hMSCs embedded in collagen gel to those grown in pellet culture. The hMSCs in collagen scaffolds expressed more glycosaminoglycan than those in pellet culture. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) analysis demonstrated that the expression of genes encoding sox-9, aggrecan, and types I and II collagen increased in pellet culture over time. However, in the collagen cultures, only type II collagen and aggrecan expression increased over time, whereas sox-9 expression remained unchanged and type I collagen expression decreased. These results indicate that the immortalized hMSC line is a promising tool for further in vitro chondrogenic studies.Artificial Organs 07/2008; 32(7):561-6. · 2.00 Impact Factor -
Article: Chondrocyte acting as phagocyte to internalize polyethylene wear particles and leads to the elevations of osteoarthritis associated NO and PGE2.
[show abstract] [hide abstract]
ABSTRACT: It remains a mystery about the role of chondrocyte or cartilage on the co-existence of ultra-high molecular weight polyethylene (UHMWPE) wear particles from partial joint arthroplasty. An inverted co-culture system was performed to investigate the interactions between chondrocytes and UHMWPE wear particles. It was first time observed that chondrocytes can engulf UHMWPE particles and release osteoarthritis associated pro-inflammatory factors. TEM observation and flow cytometric analysis demonstrated the phagocytosis of particles by chondrocytes. It was found that polyethylene particles may reduce the viability of chondrocytes, and enhance the secretion of nitric oxide (NO) and PGE(2). In conclusion, all these phenomena may contribute to further cartilage degeneration after partial joint arthroplasty surgery. It is first identified in this study that the chondrocyte acts as phagocyte to internalize wear particles and leads to the elevations of precursor mediators of osteoarthritis.Biochemical and Biophysical Research Communications 06/2008; 369(3):884-8. · 2.48 Impact Factor -
Article: Accelerated wear testing with a microfabricated surface to evaluate the lubrication ability of biomolecules on polyethylene
[show abstract] [hide abstract]
ABSTRACT: Wear of ultrahigh-molecular-weight polyethylene (UHMWPE) and wear-particle-induced osteolysis and bone resorption are the major factors causing the failure of total joint replacements. It is feasible to improve the lubrication and reduce the wear of artificial joints. We need further understanding of the lubrication mechanism of the synovial fluid. The objective of this study is to evaluate the lubricating ability of three major components in the synovial fluid: albumin, globulin, and phospholipids. An accelerated wear testing procedure in which UHMWPE is rubbed against a microfabricated surface with controlled asperities has been developed to evaluate the lubrication behavior. An analysis of the wear particle dimensions and wear amount of the tests has provided insights for comparing their lubrication performance. It is concluded that the presence of biomolecules at the articulating interface may reduce friction. A higher concentration of a biological lubricant leads to a decrease in the wear particle width. In addition, in combination with the wear results and mechanical analysis, the roles of individual biomolecules contributing to friction and wear at the articulating interface are discussed. These results can help us to identify the role of the biomolecules in the boundary lubrication of artificial joints, and further development of lubricating additives for artificial joints may be feasible. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008Journal of Applied Polymer Science 02/2008; 108(4):2428 - 2437. · 1.29 Impact Factor -
Article: Synthesis and anti-inflammation evaluation of new C60 fulleropyrrolidines bearing biologically active xanthine.
[show abstract] [hide abstract]
ABSTRACT: We designed and prepared the new C60 fullerene hybrids bearing a xanthine moiety as potential double-action anti-inflammatory agents, capable of simultaneous inhibition of LPS-induced NO and TNF-alpha production. The 10 microM of fulleropyrrolidine-xanthine dyad 2a and b were effective in suppressing LPS-induced NO production by 55.1+/-2.1% and 58.6+/-2.6%, respectively, but only 2b was also effectively in suppressing LPS-induced TNF-alpha production by 34.0+/-2.7%. We believed that the agents synthesized herein would hold promise for future development of a new generation of potent anti-inflammatory agents.Bioorganic & medicinal chemistry letters 02/2008; 18(1):99-103. · 2.65 Impact Factor -
Article: Chemical chaperone and inhibitor discovery: potential treatments for protein conformational diseases.
[show abstract] [hide abstract]
ABSTRACT: Protein misfolding and aggregation cause a large number of neurodegenerative diseases in humans due to (i) gain of function as observed in Alzheimer's disease, Huntington's disease, Parkinson's disease, and Prion's disease or (ii) loss of function as observed in cystic fibrosis and alpha1-antitrypsin deficiency. These misfolded proteins could either lead to the formation of harmful amyloids that become toxic for the cells or to be recognized and prematurely degraded by the protein quality control system. An increasing number of studies has indicated that some low-molecular-weight compounds named as chemical chaperones can reverse the mislocalization and/or aggregation of proteins associated with human conformational diseases. These small molecules are thought to non-selectively stabilize proteins and facilitate their folding. In this review, we summarize the probable mechanisms of protein conformational diseases in humans and the use of chemical chaperones and inhibitors as potential therapeutic agents against these diseases. Furthermore, recent advanced experimental and theoretical approaches underlying the detailed mechanisms of protein conformational changes and current structure-based drug designs towards protein conformational diseases are also discussed. It is believed that a better understanding of the mechanisms of conformational changes as well as the biological functions of these proteins will lead to the development and design of potential interfering compounds against amyloid formation associated with protein conformational diseases.Perspectives in Medicinal Chemistry 01/2008; 1:39-48. -
Article: Molecular dynamics simulations of human cystatin C and its L68Q varient to investigate the domain swapping mechanism.
[show abstract] [hide abstract]
ABSTRACT: Human cystatin C variant (L68Q), one of the amyloidgenic proteins, has been shown to form dimeric structure spontaneously via domain swapping and easily cause amyloid deposits in the brains of patients suffering from Alzheimer's disease or hereditary cystatin C amyloid angiopathy. The monomeric L68Q and wild-type (wt) HCCs share similar structural feature consisting of a core with a five-stranded anti-parallel beta-sheet (beta-region) wrapped around a central helix. In this study, various molecular dynamics simulations were conducted to investigate the conformational fluctuations of the monomeric L68Q and wt HCCs at various combinations of temperature (300 and 500K) and pH (2 and 7) to gain insights into the domain swapping mechanism. The results show that elevated temperature accelerates the disruption of the hydrophobic core and acidic condition promotes the destruction of three salt bridges between beta2 and beta3 in both HCCs. The results also indicate that the interior hydrophobic core of the L68Q variant is relatively unstable, leading to domain swapping more readily comparing to wt HCC under conditions favoring this process. However, these two monomeric HCCs adopt the same mechanism of domain swapping as follows: (i) first, the interior hydrophobic core is disrupted; (ii) subsequently, the central helix departs from the beta-region; (iii) then, the beta2-L1-beta3 hairpin structure unfolds following the so-called "zip-up" mechanism; and (iv) finally, the open form HCC is generated.Journal of biomolecular structure & dynamics 11/2007; 25(2):135-44. · 4.99 Impact Factor -
Article: Tribological process induced conformational transformation of protein may change the friction of cartilage
[show abstract] [hide abstract]
ABSTRACT: In-vitro testing procedures have been successfully developed to investigate the effects of tribological process induced transformation of protein-based lubricant on the friction change of articular cartilages. Serum and albumin solutions were the biological lubricants used in this study. The results indicated that the lubricating ability for cartilages deteriorates after the biological lubricants were articulated between polyethylene and stainless steel materials. In addition, the secondary structure change of the albumin molecule has been characterized after the molecules were articulated by the artificial joint materials. We have provided evidence that the conformational change of protein lubricants leads to the friction increase of articular cartilage.01/2007; -
Article: Structural analysis of human lysozyme using molecular dynamics simulations.
[show abstract] [hide abstract]
ABSTRACT: In this study, various molecular dynamics simulations were conducted to investigate the effects of ethanol and temperature on the conformational changes of human lysozyme, which may lead insights into amyloidosis. The analyses of some important structural characteristics, such as backbone root-mean-square deviation, secondary structural stability, radius of gyration, accessible surface area, and hydrophobic contact of the hydrophobic core all show that ethanol tends to destabilize human lysozyme at high temperatures. It can be attributed to that higher temperatures result in the destruction of the native structure of this protein, leading to the exposure of the interior hydrophobic core. At this stage, ethanol plays a role to destroy this region by forming hydrophobic interactions between protein and solvent due to its lower polarity comparing to water. Such newly formed intermolecular interactions accelerate the unfolding of this protein, starting from the core between the alpha- and beta-domains. Our results are in good agreement with the previous hypothesis suggesting that the distortion of the hydrophobic core at the alpha- and beta-interface putatively results in the formation of the initial "seed" for amyloid fibril. Although the present results cannot directly be linked to fibril formation, they still provide valuable insights into amyloidosis of human lysozyme.Journal of biomolecular structure & dynamics 01/2007; 24(3):229-38. · 4.99 Impact Factor
Top co-authors
Top Journals
Institutions
-
2012
-
Far Eastern Memorial Hospital
Taipei, Taipei, Taiwan
-
-
2006–2010
-
National Taipei University of Technology
- Institute of Biotechnology
Taipei, Taipei, Taiwan
-
-
2009
-
Taiwan Adventist Hospital
Taipei, Taipei, Taiwan
-
-
2003
-
University of Maryland, College Park
College Park, MD, USA
-
