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1.
Biochem Biophys Res Commun ; 512(2): 250-255, 2019 04 30.
Article in English | MEDLINE | ID: mdl-30879771

ABSTRACT

Gastric cancer (GC) is the fourth most common type of malignant tumor that affects humans worldwide, but few targeted therapies for it have been considered that are based on redox systems. Peroxiredoxin2 (Prx2) functions as a reactive oxygen species (ROS)-mediated signaling regulator that controls H2O2 in mammalian cells, and it is involved in the survival of various malignant tumors. In human GC cells, Prx2 depletion markedly reduced the ß-catenin levels and expression of ß-catenin target genes and proteins. Cell-based assays demonstrated that Prx2 knockdown significantly ablates the cell viability, invasive activity, and colony-forming ability of both AGS and SNU668 cells. Furthermore, an experiment using conoidinA, a Prx2 inhibitor, revealed that Prx2 inhibition can overcome 5-FU resistance in GC cells. Thus, this study suggests that Prx2 plays a crucial role in regulating Wnt/ß-catenin signaling in GC cells.


Subject(s)
Gene Expression Regulation, Neoplastic , Peroxiredoxins/genetics , Stomach Neoplasms/genetics , Wnt Signaling Pathway , Cell Line, Tumor , Gene Expression Regulation, Neoplastic/drug effects , Gene Knockdown Techniques , Humans , Peroxiredoxins/antagonists & inhibitors , Peroxiredoxins/metabolism , Quinoxalines/pharmacology , Stomach Neoplasms/drug therapy , Stomach Neoplasms/metabolism , Wnt Signaling Pathway/drug effects , beta Catenin/metabolism
2.
Int J Mol Sci ; 20(21)2019 Oct 24.
Article in English | MEDLINE | ID: mdl-31653087

ABSTRACT

The ubiquitin-proteasome system is an essential regulator of several cellular pathways involving oncogenes. Deubiquitination negatively regulates target proteins or substrates linked to both hereditary and sporadic forms of cancer. The deubiquitinating enzyme ubiquitin-specific protease 14 (USP14) is associated with proteasomes where it trims the ubiquitin chain on the substrate. Here, we found that USP14 is highly expressed in patients with lung cancer. We also demonstrated that USP14 inhibitors (IU1-47 and siRNA-USP14) significantly decreased cell proliferation, migration, and invasion in lung cancer. Remarkably, we found that USP14 negatively regulates lung tumorigenesis not only through apoptosis but also through the autophagy pathway. Our findings suggest that USP14 plays a crucial role in lung tumorigenesis and that USP14 inhibitors are potent drugs in lung cancer treatment.


Subject(s)
Autophagy/drug effects , Lung Neoplasms/pathology , Pyrroles/pharmacology , Ubiquitin Thiolesterase/metabolism , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Cell Transformation, Neoplastic/drug effects , Humans , Lung Neoplasms/metabolism , RNA Interference , RNA, Small Interfering/metabolism , Ubiquitin Thiolesterase/antagonists & inhibitors , Ubiquitin Thiolesterase/genetics
3.
Clin Immunol ; 183: 158-166, 2017 10.
Article in English | MEDLINE | ID: mdl-28847516

ABSTRACT

S100A9 is an endogenous danger signal that promotes and exacerbates the neutrophilic inflammatory response. To investigate the role of S100A9 in neutrophilic asthma, S100A9 levels were measured in sputum from 101 steroid-naïve asthmatics using an ELISA kit and the levels were significantly correlated with percentages of neutrophils in sputum. Intranasal administration of recombinant S100A9 markedly increased neutrophil numbers at 8h and 24h later with concomitant elevation of IL-1ß, IL-17, and IFN-γ levels. Treatment with an anti-S100A9 antibody restored the increased numbers of neutrophils and the increased airway resistance in OVA/CFA mice toward the levels of sham-treated mice. Concomitantly, the S100A9 and neutrophil elastase double positive cells were markedly reduced with attenuation of IL-1ß, IL-17, and IFN-γ levels by the treatment with the anti-S100A9 antibody. Our data support a role of S100A9 to initiate and amplify the neutrophilic inflammation in asthma, possibly via inducing IL-1ß, IL-17 and IFN-γ.


Subject(s)
Asthma/immunology , Calgranulin B/immunology , Neutrophils/immunology , Adult , Animals , Antibodies, Neutralizing/pharmacology , Asthma/physiopathology , Disease Models, Animal , Female , Humans , Inflammation , Interferon-gamma/drug effects , Interferon-gamma/immunology , Interleukin-17/immunology , Interleukin-1beta/drug effects , Interleukin-1beta/immunology , Leukocyte Elastase/metabolism , Male , Mice , Middle Aged , Neutrophils/drug effects , Sputum/chemistry , Sputum/immunology
4.
Ann Allergy Asthma Immunol ; 111(4): 268-275.e1, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24054362

ABSTRACT

BACKGROUND: Neutrophilic airway inflammation is frequently observed in severe uncontrolled asthma (UA) and controlled asthma (CA). However, there is no sputum biomarker to differentiate the 2 conditions. OBJECTIVE: To identify biomarkers of severe uncontrolled asthma with neutrophilic airway inflammation. METHODS: Sputum with a neutrophil content larger than 70% was pooled from 5 patients with severe UA and from 10 patients with CA. Two-dimensional electrophoresis was adopted for differential display proteomics, and candidate proteins were identified using matrix-assisted laser adsorption/ionization-time of flight mass spectrometric analysis. S100 calcium binding protein A9 (S100A9) was identified by western blot and its level was measured in sputum from asthmatics with varying disease severity, patients with chronic obstructive lung disease, and normal controls using enzyme-linked immunosorbent assay. RESULTS: Fourteen protein spots exhibited differences in relative intensity between patients with severe UA and those with CA. Matrix-assisted laser adsorption/ionization-time of flight/time of flight of these spots showed an increase in human neutrophil peptide-2, S100A9, ß-amylase, neutrophil gelatinase-associated lipocalin, 4-aminobutyrate transaminase, and cystatin SA in patients with UA compared with patients with CA. There was a decrease in the plunc precursor, complement C3 component, immunoglobulin heavy-chain variable region, glial fibrillary acidic protein isoform-1, IgM κIIIb SON, MLL-AF4 der(11) fusion protein, cytokeratin-8, and recombinant IgG4 heavy chain. S100A9 was detected at a higher level in western blots of neutrophilic sputum from patients with severe UA vs CA. S100A9 levels were significantly increased, as measured by enzyme-linked immunosorbent assay, in neutrophilic UA compared with CA, eosinophilic UA and CA, and chronic obstructive lung disease. CONCLUSION: S100A9 in sputum may be a biomarker of neutrophilic inflammation in severe UA.


Subject(s)
Asthma/immunology , Calgranulin B/immunology , Eosinophilia/immunology , Neutrophils/immunology , Sputum/immunology , Adult , Aged , Aged, 80 and over , Biomarkers , Female , Humans , Inflammation/immunology , Male , Middle Aged , Proteome/analysis , Pulmonary Disease, Chronic Obstructive/immunology , Young Adult
5.
Micromachines (Basel) ; 14(2)2023 Jan 23.
Article in English | MEDLINE | ID: mdl-36837997

ABSTRACT

MoS2, owing to its advantages of having a sheet-like structure, high electrical conductivity, and benign environmental nature, has emerged as a candidate of choice for electrodes of next-generation supercapacitors. Its widespread use is offset, however, by its low energy density and poor durability. In this study, to overcome these limitations, flower-shaped MoS2/graphene heterostructures have been deployed as electrode materials on flexible substrates. Three-electrode measurements yielded an exceptional capacitance of 853 F g-1 at 1.0 A g-1, while device measurements on an asymmetric supercapacitor yielded 208 F g-1 at 0.5 A g-1 and long-term cyclic durability. Nearly 86.5% of the electrochemical capacitance was retained after 10,000 cycles at 0.5 A g-1. Moreover, a remarkable energy density of 65 Wh kg-1 at a power density of 0.33 kW kg-1 was obtained. Our MoS2/Gr heterostructure composites have great potential for the development of advanced energy storage devices.

6.
J Hum Genet ; 57(4): 247-53, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22377711

ABSTRACT

Aspirin-exacerbated respiratory diseases (AERD) are associated with the metabolism of arachidonic acid. FPR2 (formyl peptide receptor2) is a high-affinity ligand receptor for potent anti-inflammatory lipid metabolites: lipoxins. Thus, functional alterations of the FPR2 may contribute to AERD. We investigated the relationship between single-nucleotide polymorphisms (SNPs) in the FPR2 and AERD. Asthmatics were categorized into AERD <15% decreases in forced expiratory volume in one second (FEV(1)), and/or naso-ocular reactions after oral aspirin challenge (n=170) and aspirin-tolerant asthma (ATA, n=268). In all, 11 SNPs were genotyped. FPR2 protein expressions on CD14-positive monocytes in peripheral blood were measured using flow cytometric analysis. We performed RT-PCR of the FPR2 mRNA expressed by peripheral blood mononuclear cells. Logistic regression analysis showed that the minor allele frequency of FPR2 -4209T>G (rs1769490) in intron 2 was significantly lower in the AERD group (n=170) than in the ATA group (n=268) (P=0.006, P(corr)=0.04, recessive model). The decline of FEV(1) after aspirin challenge was significantly lower in the subjects with GG homozygotes of FPR2 -4209T>G than those with the other genotypes (P=0.0002). Asthmatic homozygotes for FPR2 -4209T>G minor allele exhibited significantly higher FPR2 protein expression in CD14-positive monocytes than did those with the common allele of FPR2 -4209T>G allele (P=0.01). There was no difference in the expression of the wild form and the exon 2 deleted variant form of FPR2 gene according to the genotypes of FPR2 -4209T>G. The minor allele at FPR2 -4209T>G may have a protective role against the development of AERD, via increase of FPR2 protein expression in inflammatory cells.


Subject(s)
Aspirin/adverse effects , Asthma, Aspirin-Induced/genetics , Receptors, Formyl Peptide/genetics , Receptors, Lipoxin/genetics , Adolescent , Adult , Aged , Asthma, Aspirin-Induced/metabolism , Asthma, Aspirin-Induced/pathology , Body Mass Index , Case-Control Studies , Child , Female , Flow Cytometry , Forced Expiratory Volume/drug effects , Gene Expression , Gene Frequency , Homozygote , Humans , Introns , Leukocytes, Mononuclear/cytology , Lipopolysaccharide Receptors/genetics , Lipopolysaccharide Receptors/metabolism , Logistic Models , Male , Middle Aged , Polymorphism, Single Nucleotide , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Formyl Peptide/metabolism , Receptors, Lipoxin/metabolism , Vital Capacity , Young Adult
7.
ACS Appl Mater Interfaces ; 13(23): 27575-27585, 2021 Jun 16.
Article in English | MEDLINE | ID: mdl-34085809

ABSTRACT

The outcomes of the study of plant surfaces, such as rice leaves or bamboo leaves, have led to extensive efforts being devoted to fabricating anisotropic arrays of micro/nanoscale features for exploring anisotropic droplet spreading. Nonetheless, precise engineering of the density and continuity of three-phase contact lines for anisotropic wetting remains a significant challenge without resorting to chemical modifications and costly procedures. In this work, we investigated secondary electrohydrodynamic instability in polymer films for producing secondary nanosized patterns between the micrometer-sized grooves by controlling the timescale parameter, 1/τm (>10-4 s-1). We experimentally demonstrated facile morphological control of anisotropic wettability without the use of any chemical modifications. Thus, anisotropic hydrophilic surfaces fabricated by the secondary phase instability of polymer films are advantageous for both droplet condensation and removal, thereby outperforming the water collection efficiency of conventional (isotropic) hydrophilic surfaces in water harvesting applications (∼200 mg·cm-2·h-1) with excellent durability.

8.
Cell Death Differ ; 28(6): 1790-1803, 2021 06.
Article in English | MEDLINE | ID: mdl-33328571

ABSTRACT

Tripartite motif-containing 28 (TRIM28) is an E3 ubiquitin ligase harboring multiple cellular functions. We found that the TRIM28 protein is frequently overexpressed in patients with lung cancer. The stable overexpression of TRIM28 in lung cancer cells and xenograft models significantly increased the proliferation, migration, and invasiveness, whereas knockdown of TRIM28 had the opposite effect. We further observed that TRIM28 regulates the ubiquitin ligases RLIM and MDM2 to target the p53 levels during lung tumorigenesis. These data provide new insights into lung cancer development and potential new therapeutic targets for this disease.


Subject(s)
Lung Neoplasms/genetics , Proto-Oncogene Proteins c-mdm2/metabolism , Tripartite Motif-Containing Protein 28/metabolism , Tumor Suppressor Protein p53/metabolism , Ubiquitin-Protein Ligases/metabolism , Animals , Carcinogenesis , Humans , Male , Mice , Mice, Nude , Transfection , Ubiquitination
9.
Pharmaceuticals (Basel) ; 13(9)2020 Aug 24.
Article in English | MEDLINE | ID: mdl-32847004

ABSTRACT

Hypoxia-inducible factor (HIF)-1α plays an important role in cancer progression. In various cancers, including thyroid cancer, overexpression of HIF-1α is related to poor prognosis or treatment response. However, few studies have investigated the role of HIF-1α inhibition in thyroid cancer progression. We evaluated the utility of the HIF-1α inhibitor IDF-11774 in vitro utilizing two thyroid cancer cell lines, K1 and BCPAP. Both cell lines were tested to elucidate the effects of IDF-11774 on cell proliferation and migration using soft agar and invasion assays. Here, we found that a reduction of HIF-1α expression in BCPAP cells was observed after treatment with IDF-11774 in a dose-dependent manner. Moreover, cell proliferation, migration, and anchorage-independent growth were effectively inhibited by IDF-11774 in BCPAP cells but not in K1 cells. Additionally, invasion of BCPAP but not K1 cells was controlled with IDF-11774 in a dose-dependent manner. Our findings suggest that promoting the degradation of HIF-1α could be a strategy to manage progression and that HIF-1α inhibitors are potent drugs for thyroid cancer treatment.

10.
J Microbiol Biotechnol ; 17(1): 29-36, 2007 Jan.
Article in English | MEDLINE | ID: mdl-18051350

ABSTRACT

The xynA gene encoding the xylanase A of Paenibacillus sp. DG-22 was isolated with a DNA probe obtained by PCR amplification, using degenerated primers deduced from the amino acid residues of the known N-terminal region of the purified enzyme and the conserved region in the family 11 xylanases. The positive clones were screened on the LB agar plates supplemented with xylan, by the Congo-red staining method. The xynA gene consists of a 630-bp open reading frame encoding a protein of 210 amino acids, and the XynA preprotein contains a 28-residues signal peptide whose cleavage yields a 182-residues mature protein of a calculated molecular weight of 20,000 Da and pI value of 8.77. The cloned DNA fragment also has another ORF of 873 nucleotides that showed 76% identity to the putative transcriptional activator of Bacillus halodurans C-125. Most of the xylanase activity was found in the periplasmic space of E. coli. The xynA gene was subcloned into pQE60 expression vector to fuse with six histidine-tag. The recombinant xylanase A was purified by heating and immobilized metal affinity chromatography. The optimum pH and temperature of the purified enzyme were 6.0 and 60 degrees C, respectively. This histidine-tagged xylanase A was less thermostable than the native enzyme.


Subject(s)
Bacteria/enzymology , Bacteria/genetics , Endo-1,4-beta Xylanases/genetics , Genes, Bacterial , Amino Acid Sequence , Base Sequence , Blotting, Southern , Cloning, Molecular , DNA Primers/genetics , DNA, Bacterial/genetics , Endo-1,4-beta Xylanases/chemistry , Endo-1,4-beta Xylanases/metabolism , Enzyme Stability , Escherichia coli/genetics , Gene Expression , Hydrogen-Ion Concentration , Isoelectric Point , Molecular Sequence Data , Molecular Weight , Polymerase Chain Reaction , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid , Temperature
11.
ACS Biomater Sci Eng ; 3(9): 2054-2058, 2017 Sep 11.
Article in English | MEDLINE | ID: mdl-33440558

ABSTRACT

We elucidated the proper routes for injecting lipid-DNA micelles formulated with an oligonucleotide immune adjuvant in naïve and tumor-bearing mice. We report herein that after assessing six ways of administering an immunostimulatory nanoparticle (INP), several of the injection routes effectively induced dendritic cell-mediated immune-stimulation in vivo, making them amenable to cancer immunotherapies and vaccines using such DNA materials.

12.
Expert Rev Respir Med ; 11(1): 29-40, 2017 01.
Article in English | MEDLINE | ID: mdl-27918221

ABSTRACT

INTRODUCTION: Neutrophilic airway inflammation represents a pathologically distinct form of asthma and frequently appears in symptomatic adulthood asthmatics. However, clinical impacts and mechanisms of the neutrophilic inflammation have not been thoroughly evaluated up to date. Areas covered: Currently, distinct clinical manifestations, triggers, and molecular mechanisms of the neutrophilic inflammation (namely Toll-like receptor, Th1, Th17, inflammasome) are under investigation in asthma. Furthermore, possible role of the neutrophilic inflammation is being investigated in respect to the airway remodeling. We searched the related literatures published during the past 10 years on the website of Pub Med under the title of asthma and neutrophilic inflammation in human. Expert commentary: Epidemiologic and experimental studies have revealed that the neutrophilic airway inflammation is induced by a wide variety of stimuli including ozone, particulate matters, cigarette smoke, occupational irritants, endotoxins, microbial infection and colonization, and aeroallergens. These triggers provoke diverse immune and inflammatory responses leading to progressive and sometimes irreversible airway obstruction. Clinically, neutrophilic airway inflammation is frequently associated with severe asthma and poor response to glucocorticoid therapy, indicating the need for other treatment strategies. Accordingly, therapeutics will be targeted against the main mediators behind the underlying molecular mechanisms of the neutrophilic inflammation.


Subject(s)
Airway Obstruction/immunology , Asthma/immunology , Inflammation/immunology , Neutrophils/immunology , Airway Remodeling/immunology , Humans , Inflammasomes/immunology , Respiratory System/immunology , Th17 Cells/immunology
13.
Lung Cancer ; 90(2): 346-51, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26342550

ABSTRACT

OBJECTIVES: Interleukin (IL)-33 protects against infection and inflammation; however, few studies have explored the relevance of IL-33 in lung cancer patients. We evaluated relation of plasma IL-33 levels with development and progression of lung cancer. MATERIALS AND METHODS: A total of 160 patients with lung cancer and 160 controls with normal lungs were enrolled. Plasma IL-33 levels were measured using a specific sandwich ELISA; these levels were followed-up in 18 patients who underwent surgery and in 14 patients treated with chemotherapy. Malignant lesions and normal lung tissues from 10 cancer patients were subjected to immunohistochemical staining for IL-33. RESULTS: IL-33 levels were significantly lower in cancer patients than normal controls (0.08 vs. 0.38 ng/mL, p=0.005). Among cancer patients, IL-33 decreased in a stage-dependent manner from 0.76 ng/mL in stage I patients to 0.25 ng/mL in those with stage II, 0.08 ng/mL in those with stage III, and 0.08 ng/mL in those with stage IV (p=0.002). The levels were higher at stage I (p=0.041) and markedly lower at stages III and IV than those of controls (p=0.005 and p=0.001, respectively). A similar pattern was observed when IL-33 levels were analyzed by T stage; the levels were 0.39 ng/mL at T1/T2 vs. 0.08 ng/mL at T3/T4 (p=0.001). However, no difference was noted when stage N1 levels were compared with N2 and N3 levels (p=0.058), or between stage M0 and M1 levels (p=0.147). IL-33 levels gradually decreased after surgical resection of malignant lesions (from 1.075 to 0.756 ng/mL, p=0.006), but were unchanged after chemotherapy (0.705 vs. 0.829 ng/mL, p=0.875). On immunohistochemical staining, bronchial epithelial and vascular endothelial cells of normal lung tissues mainly expressed IL-33. CONCLUSIONS: Plasma IL-33 levels are associated inversely with progression of lung cancer. The observed decreases may be attributed to lung volume reduction containing bronchial epithelium and vascular endothelium as the sources of IL-33.


Subject(s)
Interleukin-33/blood , Lung Neoplasms/blood , Lung Neoplasms/pathology , Aged , Case-Control Studies , Disease Progression , Female , Humans , Lung/pathology , Male , Middle Aged , Neoplasm Staging/methods , Pneumonectomy/methods
14.
Asia Pac Allergy ; 4(4): 187-96, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25379478

ABSTRACT

Human airways contact with pathogen-associated molecular patterns and danger-associated molecular patterns present in many environments. Asthmatic's airways may be more susceptible to these patterns and lead to inflammasome activation; however, the participation of inflammasome in the development and exacerbation of asthma is not fully understood and remains controversial. Asthma is a heterogeneous group composed of different airway inflammation patterns with different underlying immune mechanisms. One mechanism is neutrophilic airway inflammation based on the axis of inflammasome activation, interleukin (IL) 1ß/IL-18 production, T helper 17 activation, IL-8/IL-6 overproduction, and neutrophilic inflammation. The role of inflammasome activation has been highlighted in experimental asthma models and some evidence of inflammasome activation has been recently demonstrated in human neutrophilic asthmatic airways. In addition to caspase-1 activation, proteinase 3 and other protease from activated neutrophils directly cleave pro-IL-1ß and pro-IL-18 to IL-1ß and IL-18, which contribute to the phenotype of subsequent adaptive immune responses without inflammasome activation. Data suggests that neutrophilics in asthmatic airways may have an additional effect in initiating inflammasome activation and amplifying immune responses. Among the mediators from neutrophils, S100A9 seems to be one candidate mediator to explain the action of neutrophils in amplifying the airway inflammation in concert with inflammasome.

15.
Toxicology ; 284(1-3): 12-8, 2011 Jun 18.
Article in English | MEDLINE | ID: mdl-21439344

ABSTRACT

Environmental pollutant exposure is associated with adverse respiratory outcomes. The phosphorylation of enzymes activates or deactivates many cellular processes and is related to the development of lung diseases such as asthma and chronic obstructive pulmonary disease. However, little is known about protein phosphorylation of bronchial epithelial cells in response to airborne particulates. Herein, we screened differentially phosphorylated proteins in TiO2-treated epithelial cells and validated the change in GSTP1 protein phosphorylation. Two-dimensional electrophoresis was adopted for differential display proteomics of TiO2-treated BEAS-2B cell lysates. Phosphoproteins were screened using Pro-Q® Diamond phosphoprotein gel stain and identified by MALDI-TOF/TOF analysis. Immunoprecipitation and immunoblotting were performed for quantitative measurement of GSTP1 phosphorylation in cell lysates. Normalized relative intensities of nine phosphorylated proteins increased after TiO2 treatment, whereas those of 12 proteins decreased in the BEAS-2B cell lysates. From gene ontology and pathway analysis, proteins involved in signal transduction were commonly identified, followed by cytoskeletal proteins, proteins from oxidation and antioxidation pathways, proteins catalyzing reductions, and those involved in cellular process, transport, and modification. Immunoblotting with anti-GSTP1 antibody demonstrated no change in GSTP1 protein levels in the lysates of BEAS-2B cells after treatment with TiO2 particles; blotting with anti-phosphoserine and anti-phosphotyrosine antibodies showed dose-dependent decreases in phosphoserine and phosphotyrosine proteins. Stimulation with particulates phosphorylated and dephosphorylated several proteins in epithelial cells, and serine and tyrosine protein phosphorylation of GSTP1 decreased. These data indicate that airborne particles affect the pattern of phosphorylation of proteins involved in defense or apoptosis of respiratory epithelium.


Subject(s)
Epithelial Cells/enzymology , Glutathione S-Transferase pi/metabolism , Respiratory Mucosa/enzymology , Cell Line , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Humans , Particle Size , Phosphorylation/drug effects , Phosphorylation/physiology , Respiratory Mucosa/metabolism , Titanium/metabolism , Titanium/toxicity
16.
Tissue Eng Part A ; 15(9): 2595-604, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19195987

ABSTRACT

The authors devised a novel biphasic scaffold combining hyaluronic acid and atelocollagen for the chondral phase and combining hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP) for the osseous phase. The biphasic scaffold was fabricated by placing the freeze-dried chondral phase over the HA/beta-TCP scaffold prewetted with hyaluronate/atelocollagen solution. Chondrocytes were isolated in 28 rabbits, expanded, injected inside the chondral phase of the biphasic scaffold, and then cultured in chondrogenic medium. After 2 weeks of in vitro culture, chondrocytes had evenly infiltrated inside the chondral phase and produced extracellular matrix. For in vivo study, a large osteochondral defect was made on the patellar groove of the right distal femur and managed using one of the following methods: filling with cell-biphasic scaffold composite (group I); implanting only biphasic scaffold (group II); placing the removed osteochondral fragments back into the defect (group III, positive control); leaving empty (group IV, negative control). Seven rabbits were allocated to each group. After 12 weeks, the International Cartilage Repair Society Macroscopic Score was highest in group III, followed by group I, group II, and lastly group IV. Depression of the defect was greatest in group IV. There were three rabbits (two in group I and one in group II) that were completely denuded of the chondral phase. The junction to adjacent native cartilage was distinct in rabbits of all groups. The International Cartilage Repair Society Visual Histological Score was highest in group III, followed by groups II and I, and lastly group IV. In conclusion, our results suggest that a biphasic osteochondral composite using a chondral phase consisting of hyaluronate and atelocollagen and an osseous phase consisting of HA and beta-TCP holds the promise for repair of osteochondral defects.


Subject(s)
Bone Diseases/pathology , Collagen/pharmacology , Hyaluronic Acid/pharmacology , Hydroxyapatites/pharmacology , Tissue Scaffolds/chemistry , Wound Healing/drug effects , Animals , Chondrocytes/drug effects , Chondrocytes/pathology , Chondrocytes/ultrastructure , Chondrogenesis/drug effects , Models, Biological , Rabbits
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