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1.
Artigo em Inglês | MEDLINE | ID: mdl-33119482

RESUMO

A Gram-stain-negative, non-pigmented, non-spore-forming, motile, strictly aerobic bacterial strain, designated CAU 1492T, was isolated from a coastal sand dune and its taxonomic position was examined using a polyphasic approach. Cells of strain CAU 1492T grew optimally at 30 °C, pH 7.0 and in 3 % (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence of CAU 1492T showed that it formed a distinct lineage within the family Rhodobacteraceae as a separate deep branch, with 96.8 % or lower sequence similarity values to representatives of the genera Marivita, Donghicola, Sulfitobacter, Marinovum, Phaeobacter, Primorskyibacter, Roseovarius and Aestuariihabitans. Strain CAU 1492T was closely related to Marivita geojedonensis DPG-138T (96.8 %), Donghicola eburneus SW-277T (96.7 %), Sulfitobacter porphyrae SCM-1T (96.7 %), Marinovum algicola FF3T (96.6 %) and Aestuariihabitans beolgyonensis BB-MW15T (96.4 %) based on 16S rRNA gene sequences. The major cellular fatty acids of strain CAU 1492T were cyclo-C19 : 0 ω8c and summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c). The polar lipid pattern was composed of phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid and an unidentified aminolipid. The strain contained Q-10 as the sole respiratory quinone. The draft genome of strain CAU 1492T was 4.63 Mb with a DNA G+C content of 63.1 mol%. The genome includes 4292 protein-coding genes and a five rRNA operons. On the basis of the phenotypic, chemotaxonomic and genomic data, strain CAU 1492T represents a novel genus in the family Rhodobacteraceae for which the name Arenibacterium halophilum gen. nov., sp. nov. is proposed. The type strain of Arenibacterium halophilum is CAU 1492T (=KCTC 62998T=NBRC 113696T).

2.
Sci Transl Med ; 12(567)2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33115953

RESUMO

Meniscus tears are common knee injuries and a major osteoarthritis (OA) risk factor. Knowledge gaps that limit the development of therapies for meniscus injury and degeneration concern transcription factors that control the meniscus cell phenotype. Analysis of RNA sequencing data from 37 human tissues in the Genotype-Tissue Expression database and RNA sequencing data from meniscus and articular cartilage showed that transcription factor Mohawk (MKX) is highly enriched in meniscus. In human meniscus cells, MKX regulates the expression of meniscus marker genes, OA-related genes, and other transcription factors, including Scleraxis (SCX), SRY Box 5 (SOX5), and Runt domain-related transcription factor 2 (RUNX2). In mesenchymal stem cells (MSCs), the combination of adenoviral MKX (Ad-MKX) and transforming growth factor-ß3 (TGF-ß3) induced a meniscus cell phenotype. When Ad-MKX-transduced MSCs were seeded on TGF-ß3-conjugated decellularized meniscus scaffold (DMS) and inserted into experimental tears in meniscus explants, they increased glycosaminoglycan content, extracellular matrix interconnectivity, cell infiltration into the DMS, and improved biomechanical properties. Ad-MKX injection into mouse knee joints with experimental OA induced by surgical destabilization of the meniscus suppressed meniscus and cartilage damage, reducing OA severity. Ad-MKX injection into human OA meniscus tissue explants corrected pathogenic gene expression. These results identify MKX as a previously unidentified key transcription factor that regulates the meniscus cell phenotype. The combination of Ad-MKX with TGF-ß3 is effective for differentiation of MSCs to a meniscus cell phenotype and useful for meniscus repair. MKX is a promising therapeutic target for meniscus tissue engineering, repair, and prevention of OA.

3.
Arch Microbiol ; 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33057911

RESUMO

A Gram-stain-negative, slightly curved, rod-shaped bacterial strain CAU 1517T was isolated from marine sediment in Busan, the Republic of Korea. The taxonomic position of strain CAU 1517T was investigated via a polyphasic approach comprising phenotypic, chemotaxonomic and phylogenetic properties. Strain CAU 1517T grew optimally at 30 °C, pH 7.5 and in the presence of 7% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that strain CAU 1517T belongs to the genus Halarcobacter and is most closely related to Halarcobacter bivalviorum LMG 26154T (96.5% similarity). The average nucleotide identity and digital DNA-DNA hybridization values between strain CAU 1517T and members of genus Halarcobacter ranged from were 76.7-78.0% and 19.5-21.2%, respectively. The strain contained menaquinone-6 (MK-6) as the only respiratory quinone, and C16:0, summed feature 3 (C16:1 ω7c/C16:1 ω6c), and summed feature 8 (C18:1ω7c/C18:1ω6c) as the major fatty acids. The polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylethanolamine, and two unidentified aminophospholipids. The G+C content was 28.2 mol%. Therefore, it has been demonstrated that the isolate represents a novel species of the genus Halarcobacter, for which the name Halarcobacter arenosus sp. nov., is proposed. The type strain is CAU 1517T (=KCTC 72232T =NBRC 113955T).

4.
Nanomedicine (Lond) ; 15(25): 2517-2538, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32975146

RESUMO

The knee menisci are critical to the long-term health of the knee joint. Because of the high incidence of injury and degeneration, replacing damaged or lost meniscal tissue is extremely clinically relevant. The multiscale architecture of the meniscus results in unique biomechanical properties. Nanofibrous scaffolds are extremely attractive to replicate the biochemical composition and ultrastructural features in engineered meniscus tissue. We review recent advances in electrospinning to generate nanofibrous scaffolds and the current state-of-the-art of electrospun materials for meniscal regeneration. We discuss the importance of cellular function for meniscal tissue engineering and the application of cells derived from multiple sources. We compare experimental models necessary for proof of concept and to support translation. Finally, we discuss future directions and potential for technological innovations.

5.
Ultrasound Med Biol ; 46(12): 3379-3392, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32917469

RESUMO

Fifty years of research on the nature of backscatter from tissues has resulted in a number of promising diagnostic parameters. We recently introduced two analyses tied directly to the biophysics of ultrasound scattering: the H-scan, based on a matched filter approach to distinguishing scattering transfer functions, and the Burr distribution for quantification of speckle patterns. Together, these analyses can produce at least five parameters that are directly linked to the mathematics of ultrasound in tissue. These have been measured in vivo in 35 rat livers under normal conditions and after exposure to compounds that induce inflammation, fibrosis, and steatosis in varying combinations. A classification technique, the support vector machine, is employed to determine clusters of the five parameters that are signatures of the different liver conditions. With the multiparametric measurement approach and determination of clusters, the different types of liver pathology can be discriminated with 94.6% accuracy.

6.
Ultrasound Med Biol ; 46(12): 3369-3378, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32907773

RESUMO

The non-invasive quantification of tumor burden and the response to therapies remain an important objective for imaging modalities. To characterize the performance of two newly optimized ultrasound-based analyses, we applied shear wave and H-scan scattering analyses to repeated trans-abdominal ultrasound scans of a murine model of metastatic pancreatic cancer. In addition, bioluminescence measurements were obtained as an alternative reference. The tumor metastases grow aggressively and result in death at approximately 4 wk if untreated, but longer for those treated with chemotherapy. We found that our three imaging methods (shear wave speed, H-scan, bioluminescence) trended toward increasing output measures with time during tumor growth, and these measures were delayed for the group receiving chemotherapy. The relative sensitivity of H-scan tracked closely with bioluminescence measurements, particularly in the early to mid-stages of tumor growth. The correlation between H-scan and bioluminescence was found to be strong, with a Spearman's rank correlation coefficient greater than 0.7 across the entire series. These preliminary results suggest that non-invasive ultrasound imaging analyses are capable of tracking the response of tumor models to therapeutic agents.

7.
Res Aging ; : 164027520948833, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32856513

RESUMO

To date, knowledge of the association between social-relational patterns and health among rural elders in non-Western social and cultural contexts is scant. Using regional population data in rural South Korea, this study examines comprehensive social relations among rural elders, and the extent to which heterogeneous patterns of social relations were associated with cognitive impairment and depression. Using comprehensive social-relational indicators with (a) the structure of social relations (b) the quality of social relations, we applied latent class analysis identified four subgroups of social relations among rural older adults: Restricted, Spouse Focused-Ambivalent, Community Engaged-Positive, and Diverse. We found that the Community-Engaged group was less likely to be depressed as well as have co-ocurring problems of cognitive impairment and depression.

8.
Arch Microbiol ; 202(10): 2655-2661, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32715322

RESUMO

A Gram stain-negative, aerobic, non-motile, short, rod-shaped bacterial strain CAU 1482T was isolated from coal mine wastewater in Hongcheon, Korea. It grew well at 30 °C, pH 8.5, 2% NaCl (w/v). 16S rRNA-based phylogeny indicated that CAU 1482T forms a distinct lineage within Aureimonas with high similarity to Aureimonas frigidaquae CW5T (98.2%), Aureimonas altamirensis S21BT (98.0%), and Aureimonas glaciei B5-2T (96.3%). The predominant cellular fatty acids were C18:1 2-OH, C16:0, C18:1 ω7c, and/or C18:1 ω6c (summed feature 8), with Q-10 as the major isoprenoid quinone. The polar lipid profile comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, two unidentified aminolipids, and three unidentified lipids. The 3.9-Mb genome included 8 contigs and 3599 protein-coding genes with a 56.7 mol% G + C content. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain CAU 1482T and closely related strains of A. frigidaquae CW5T and A. altamirensis S21BT were 72.2‒72.4% and 18.7‒18.8%, respectively. These phenotypic, chemotaxonomic, and phylogenetic data support CAU 1482T as a novel Aureimonas species, for which the name Aureimonas fodinaquatilis sp. nov. is proposed. The type strain is CAU 1482T (= KCTC 62995T = NBRC 113692T).


Assuntos
Alphaproteobacteria/classificação , Filogenia , Águas Residuárias/microbiologia , Alphaproteobacteria/genética , Alphaproteobacteria/isolamento & purificação , Composição de Bases , Carvão Mineral , Ácidos Graxos/análise , Genoma Bacteriano/genética , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Especificidade da Espécie
9.
J Org Chem ; 85(15): 9727-9736, 2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32614179

RESUMO

The controversial single-electron-transfer process, frequently proposed in many 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-mediated reactions, was investigated experimentally and theoretically using the oxidative cyclization of aroylhydrazone with DDQ. DDQ-mediated oxadiazole formation involves several processes, including cyclization to form an oxadiazole ring and N-H bond cleavage, either by proton, hydride, or hydrogen atom transfer. The detailed mechanistic study using the M06-2X density functional theory, and the 6-31+G(d,p) basis set, suggests that the pathways involving radical ion pair (RIP) intermediates, which resulted from single-electron transfer (SET), were found to be energetically nearly identical to the pathway without the SET. The substituent-dependent reactivity of oxadiazole formation was consistent with the free energy profiles of both pathways, with or without the SET. This result indicates that in addition to the electron-transfer pathway, the nucleophilic addition/elimination pathway for DDQ should be considered as a possible mechanism of the oxidative transformation reaction using DDQ.

10.
Int J Syst Evol Microbiol ; 70(8): 4562-4568, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32618560

RESUMO

A Gram-stain-negative, yellow-pigmented, non-spore-forming, non-motile, rod-shaped, catalase-positive, strictly aerobic bacterial strain, designated CAU 1491T, was isolated from seawater and its taxonomic position was examined using a polyphasic approach. Cells of strain CAU 1491T grew optimally at 30 °C, pH 7.5 and in 2.0 % (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence of CAU 1491T showed that it formed a distinct lineage within the family Flavobacteriaceae as a separate deep branch, with 97.0 % or lower sequence similarity to representatives of the genera Lacinutrix, Gaetbulibacter and Aquibacter. The major cellular fatty acids of strain CAU 1491T were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH and summed feature 3. The polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylserine, phosphatidylethanolamine and an unidentified phospholipid. The strain contained MK-6 as the sole respiratory quinone. Genome sequencing revealed that strain CAU 1491T has a genome size of 3.13 Mbp and a G+C content of 32.4 mol%. On the basis of the phenotypic, chemotaxonomic and genomic data, strain CAU 1491T represents a new genus and species in the family Flavobacteriaceae for which the name Pontimicrobium aquaticum gen. nov., sp. nov. is proposed. The type strain of Pontimicrobium aquaticum is CAU 1491T (=KCTC 72003T=NBRC 113695T).


Assuntos
Flavobacteriaceae/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacteriaceae/isolamento & purificação , Fosfolipídeos/química , Pigmentação , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
11.
FEMS Microbiol Lett ; 367(13)2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32589213

RESUMO

A Gram stain-negative, aerobic, motile, rod-shaped bacterial strain, designated CAU 1509T, was isolated from marine sediment, and its taxonomic position was determined using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CAU 1509T formed a distinct lineage within the genus Sinimarinibacterium with the highest 16S rRNA gene sequence similarity to Sinimarinibacterium flocculans NH6-24T (97.0%). Similar to another member of Sinimarinibacterium, ubiquinone-8 (Q-8) was the predominant quinone, whereas C16:0, summed feature 3 (C16:1ω7c/ω6c) and summed feature 8 (C18:1ω7c/ω6c) were the major cellular fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid, four unidentified glycolipids and three unidentified aminolipids. Strain CAU 1509T has a genome of 4.54 Mb, including 4251 coding sequences, 6 rRNAs and 50 tRNAs, with a genomic DNA G+C content of 63.2 mol%. Based on its phenotypic, chemotaxonomic and phylogenetic properties, strain CAU 1509T should be classified as a novel species of the genus Sinimarinibacterium, for which the name Sinimarinibacterium arenosum sp. nov. is proposed. The type strain is CAU 1509T (= KCTC 72000T = NBRC 113698T).

12.
FEMS Microbiol Lett ; 367(13)2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32578849

RESUMO

A novel proteobacterial bacterium, designated strain CAU 1489T, was isolated from Jeju Island, Republic of Korea. Cells were strictly anaerobic, Gram stain-negative, cream-pigmented, non-spore-forming, motile and short rod-shaped. Strain CAU 1489T exhibited the highest 16S rRNA gene sequence similarity (98.2%) to Nitratireductor mangrovi SY7T. Multilocus sequence analysis of 16S rRNA and four housekeeping genes (rpoB, rpoC, gyrB and dnaK) indicated that CAU 1489T represents a distinct branch within Nitratireductor. The whole genome was 4.8 Mb with a G + C content of 64.7 mol%, including protein-coding genes related to the function terms amino acids and derivatives, nucleotides and nucleosides, protein metabolism, carbohydrates and cofactors, vitamins, prosthetic groups and pigments. The major fatty acids were 11-methyl C18:1ω7c, cyclo- C19:0ω8c, iso-C17:0 and summed feature 8 (C18:1ω6c and/or C18:1ω7c), and the predominant respiratory quinone was Q-10. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unidentified phospholipids. Digital DNA-DNA hybridization and average nucleotide identity values were 19.4-22.0% and 72.4-79.1%, respectively. On the basis of taxonomic characterization, strain CAU 1489T constitutes a novel species, for which the name Nitratireductor arenosus sp. nov. is proposed. The type strain is CAU 1489T ( = KCTC 62997T = NBRC 113694T).

13.
Int J Syst Evol Microbiol ; 70(5): 3055-3061, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32195650

RESUMO

A Gram-stain-negative, aerobic, non-motile, rod-shaped bacterial strain, designated CAU 1488T, was isolated from tidal flat sediment, and its taxonomic position was investigated using a polyphasic approach. The organism grew optimally at a temperature of 30 °C, at pH 7.0-7.5 and in the presence of 0-6 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CAU 1488T forms a lineage distinct from Ruegeria marisrubri ZGT 118T (97.9 %), Ruegeria marina ZH17T (97.6 %), Ruegeria lacuscaerulensis ITI 1157T (97.5 %), Ruegeria pomeroyi DSS-3T (97.1 %), Ruegeria profundi ZGT108T (97.0 %), Ruegeria intermedia CC-GIMAT-2T (96.8 %), Ruegeria atlantica CECT 4292T (96.7 %) and Ruegeria kandeliae J95T (95.9 %). Genome sequencing revealed that CAU 1488T had a genome size of 4.23 Mbp and a G+C content of 63.2 mol%. Overall genome related indexes including average nucleotide identity and digital DNA-DNA hybridization values were 75.0-83.0 % and 26.2 %, which are below the cutoffs of 95 and 70 %, respectively, indicating that strain CAU 1488T represents a distinct species from the members of the genus Ruegeria. The predominant quinone was ubiquinone-10 (Q-10). The major fatty acids were summed feature 8 (C18 : 1 ω7c/ω6c; 60.7 %) and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and unidentified aminolipids. On the basis of phenotypic, chemotaxonomic and genomic data, strain CAU 1488T constitutes a novel species of the genus Ruegeria, for which the name Ruegeria sediminis sp. nov. is proposed. The type strain is CAU 1488T (=KCTC 62996T=NBRC 113693T).


Assuntos
Sedimentos Geológicos/microbiologia , Filogenia , Rhodobacteraceae/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Rhodobacteraceae/isolamento & purificação , Água do Mar/microbiologia , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/química
14.
Nanomedicine ; 23: 102090, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31493556

RESUMO

Mimicking the ultrastructural morphology of the meniscus with nanofiber scaffolds, coupled with controlled growth-factor delivery to the appropriate cells, can help engineer tissue with the potential to grow, mature, and regenerate after in vivo implantation. We electrospun nanofibers encapsulating platelet-derived growth factor (PDGF-BB), which is a potent mitogen and chemoattractant in a core of serum albumin contained within a shell of polylactic acid. We controlled the local PDGF-BB release by adding water-soluble polyethylene glycol to the polylactic acid shell to serve as a porogen. The novel core-shell nanofibers generated 3D scaffolds with an interconnected macroporous structure, with appropriate mechanical properties and with high cell compatibility. Incorporating PDGF-BB increased cell viability, proliferation, and infiltration, and upregulated key genes involved in meniscal extracellular matrix synthesis in human meniscal and synovial cells. Our results support proof of concept that these core-shell nanofibers can create a cell-favorable nanoenvironment and can serve as a system for sustained release of bioactive factors.


Assuntos
Becaplermina , Menisco/fisiologia , Nanofibras/química , Regeneração/efeitos dos fármacos , Tecidos Suporte/química , Adolescente , Adulto , Becaplermina/química , Becaplermina/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacologia , Feminino , Humanos , Masculino , Poliésteres/química , Poliésteres/farmacologia , Engenharia Tecidual
15.
Biomed Phys Eng Express ; 6(4): 045012, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-33444273

RESUMO

The H-scan approach ('H' denoting hue, or Hermite) is a recent matched filter methodology that aims to add information to the traditional ultrasound B-scan. The theory is based on the differences in the echoes produced by different classes of reflectors or scatterers. Matched filters can be created for different types of scatterers, whereby the maximum output indicates a match, and color schemes can be used to indicate the class of scatterer responsible for echoes, providing a visual interpretation of the results. However, within the theory of weak scattering from a variety of shapes, small changes in the size of the inhomogeneous objects will create shifts in the scattering transfer function. In this paper, we argue for a general power law transfer function as the canonical model for transfer functions from most normal soft vascularized tissues, at least over some bandpass spectrum illuminated by the incident pulse. In cases where scatterer size and distributions change, this produces a corresponding shift in center frequency, along with time and frequency domain characteristics of echoes, and these are captured by matched filters to distinguish and visualize in color the major characteristics of scattering types. With this general approach, the H-scan matched filters can be set to elicit more fine grain shifts in scattering types, commensurate with more subtle changes in tissue morphology. Compensation for frequency-dependent attenuation is helpful for avoiding beam softening effects with increasing depths. Examples from phantoms and normal and pathological tissues are provided to demonstrate that the H-scan analysis and displays are sensitive to scatterer size and morphology, and can be adapted to conventional imaging systems.

16.
Tissue Eng Part A ; 25(23-24): 1577-1590, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30950316

RESUMO

Electrospinning is an attractive method of fabricating nanofibers that replicate the ultrastructure of the human meniscus. However, it is challenging to approximate the mechanical properties of meniscal tissue while maintaining the biocompatibility of collagen fibers. Our objective was to determine if functionalizing polylactic acid (PLA) nanofibers with collagen would enhance their biocompatibility. We therefore used coaxial electrospinning to generate core-shell nanofibers with a core of PLA for mechanical strength and a shell of collagen to enhance cell attachment and matrix synthesis. We characterized the nanostructure of the engineered scaffolds and measured the hydrophilic and mechanical properties. We assessed the performance of human meniscal cells seeded on coaxial electrospun scaffolds to produce meniscal tissue by gene expression and histology. Finally, we investigated whether these cell-seeded scaffolds could repair surgical tears created ex vivo in avascular meniscal explants. Histology, immunohistochemistry, and mechanical testing of ex vivo repair provided evidence of neotissue that was significantly better integrated with the native tissue than with the acellular coaxial electrospun scaffolds. Human meniscal cell-seeded coaxial electrospun scaffolds may have potential in enhancing repair of avascular meniscus tears. Impact Statement The success of any tissue-engineered meniscus graft relies on its ability to mimic native three-dimensional microstructure, support cell growth, produce tissue-specific matrix, and enhance graft integration into the repair site. Polylactic acid scaffolds possess the desired mechanical properties, whereas collagen scaffolds induce better cell attachment and enhanced tissue regeneration. We therefore fabricated nanofibrous scaffolds that combined the properties of two biomaterials. These novel coaxial scaffolds more closely emulated the structure, mechanical properties, and biochemical composition of native meniscal tissue. Our findings of meniscogenic tissue generation and integration in meniscus defects have the potential to be translated to clinical use.


Assuntos
Menisco/patologia , Nanofibras/química , Tecidos Suporte/química , Cicatrização , Adulto , Animais , Bovinos , Forma Celular , Sobrevivência Celular , Colágeno/metabolismo , DNA/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Interações Hidrofóbicas e Hidrofílicas , Masculino , Teste de Materiais , Nanofibras/ultraestrutura , Poliésteres/química , Termogravimetria , Adulto Jovem
17.
Acta Biomater ; 76: 126-134, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29908335

RESUMO

The aim of this study was to examine the potential of platelet-derived growth factor (PDGF)-coated decellularized meniscus scaffold in mediating integrative healing of meniscus tears by inducing endogenous cell migration. Fresh bovine meniscus was chemically decellularized and covalently conjugated with heparin and PDGF-BB. In vitro PDGF release kinetics was measured. The scaffold was transplanted into experimental tears in avascular bovine meniscus explants and cultured for 2 and 4 weeks. The number migrating and proliferating cells at the borderline between the scaffold and injured explant and PDGF receptor-ß (PDGFRß) expressing cells were counted. The alignment of the newly produced ECM and collagen was analyzed by Safranin-O, picrosirius red staining, and differential interference contrast (DIC). Tensile testing of the explants was performed after culture for 2 and 4 weeks. Heparin conjugated scaffold showed immobilization of high levels of PDGF-BB, with sustained release over 2 weeks. Insertion of the PDGF-BB treated scaffold in defects in avascular meniscus led to increased PDGFRß expression, cell migration and proliferation into the defect zone. Safranin-O, picrosirius red staining and DIC showed tissue integration between the scaffold and injured explants. Tensile properties of injured explants treated with PDGF-BB coated scaffold were significantly higher than in the scaffold without PDGF. In conclusion, PDGF-BB-coated scaffold increased PDGFRß expression and promoted migration of endogenous meniscus cells to the defect area. New matrix was formed that bridged the space between the native meniscus and the scaffold and this was associated with improved biomechanical properties. The PDGF-BB-coated scaffold will be promising for clinical translation to healing of meniscus tears. STATEMENT OF SIGNIFICANCE: Meniscus tears are the most common injury of the knee joint. The most prevalent forms that occur in the inner third typically do not spontaneously heal and represent a major risk factor for the development of knee osteoarthritis. The goal of this project was to develop an approach that is readily applicable for clinical use. We selected a natural and readily available decellularized meniscus scaffold and conjugated it with PDGF, which we had previously found to have strong chemotactic activity for chondrocytes and progenitor cells. The present results show that insertion of the PDGF-conjugated scaffold in defects in avascular meniscus led to endogenous cell migration and proliferation into the defect zone with tissue integration between the scaffold and injured explants and improved tensile properties. This PDGF-conjugated scaffold will be promising for a translational approach to healing of meniscus tears.


Assuntos
Materiais Revestidos Biocompatíveis , Traumatismos do Joelho , Menisco , Fator de Crescimento Derivado de Plaquetas , Engenharia Tecidual , Tecidos Suporte/química , Animais , Bovinos , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacocinética , Materiais Revestidos Biocompatíveis/farmacologia , Humanos , Traumatismos do Joelho/metabolismo , Traumatismos do Joelho/terapia , Fator de Crescimento Derivado de Plaquetas/química , Fator de Crescimento Derivado de Plaquetas/farmacocinética , Fator de Crescimento Derivado de Plaquetas/farmacologia
18.
Tissue Eng Part A ; 24(1-2): 81-93, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28463545

RESUMO

Hydrogel and electrospun scaffold materials support cell attachment and neotissue development and can be tuned to structurally and mechanically resemble native extracellular matrix by altering either electrospun fiber or hydrogel properties. In this study, we examined meniscus tissue generation from different human cell sources including meniscus cells derived from vascular and avascular regions, human bone marrow-derived mesenchymal stem cells, synovial cells, and cells from the infrapatellar fat pad (IPFP). All cells were seeded onto aligned electrospun collagen type I scaffolds and were optionally encapsulated in a tricomponent hydrogel. Single or multilayered constructs were generated and cultivated in defined medium with selected growth factors for 2 weeks. Cell viability, cell morphology, and gene-expression profiles were monitored using confocal microscopy, scanning electron microscopy, and quantitative polymerase chain reaction (qPCR), respectively. Multilayered constructs were examined with histology, immunohistochemistry, qPCR, and for tensile mechanical properties. For all cell types, TGFß1 and TGFß3 treatment increased COL1A1, COMP, Tenascin C (TNC), and Scleraxis (SCX) gene expression and deposition of collagen type I protein. IPFP cells generated meniscus-like tissues with higher meniscogenic gene expression, mechanical properties, and better cell distribution compared to other cell types studied. We show proof of concept that electrospun collagen scaffolds support neotissue formation and IPFP cells have potential for use in cell-based meniscus regeneration strategies.


Assuntos
Colágeno/química , Menisco/citologia , Engenharia Tecidual/métodos , Tecidos Suporte/química , Adulto , Contagem de Células , Células Cultivadas , Feminino , Humanos , Masculino , Microscopia Eletrônica de Varredura
19.
J Physiol Anthropol ; 36(1): 11, 2017 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-28126038

RESUMO

BACKGROUND: Several studies have used functional magnetic resonance imaging (fMRI) to show that neural activity is associated with driving. fMRI studies have also elucidated the brain responses associated with driving while performing sub-tasks. It is important to note that these studies used computer mouses, trackballs, or joysticks to simulate driving and, thus, were not comparable to real driving situations. In order to overcome these limitations, we used a driving wheel and pedal equipped with an MR-compatible driving simulator (80 km/h). The subjects drove while performing sub-tasks, and we attempted to observe differences in neuronal activation. METHODS: The experiments consisted of three blocks and each block consisted of both a control phase (1 min) and a driving phase (2 min). During the control phase, the drivers were instructed to look at the stop screen and to not perform driving tasks. During the driving phase, the drivers either drove (driving only condition) or drove while performing an additional sub-task (driving with sub-task condition) at 80 km/h. RESULTS: Compared to when the drivers were focused only on driving, when the drivers drove while performing a sub-task, the number of activation voxels greatly decreased in the parietal area, which is responsible for spatial perception. Task-performing areas, such as the inferior frontal gyrus and the superior temporal gyrus, showed increased activation. Performing a sub-task simultaneously while driving had affected the driver's driving. The cingulate gyrus and the sub-lobar region (lentiform nucleus, caudate, insula, and thalamus), which are responsible for error monitoring and control of unnecessary movements (e.g., wheel and pedal movements), showed increased activation during driving with sub-task condition compared to driving only condition. CONCLUSIONS: Unlike simple driving simulators (joysticks, computer mouses, or trackballs) used in previous research, the addition of a driving wheel and pedals (accelerator and brake) to the driving simulator used in this study closely represents real driving. Thus, the number of processed movements was increased, which led to an increased number of unnecessary movements that needed to be controlled. This in turn increased activation in the corresponding brain regions.


Assuntos
Condução de Veículo , Encéfalo/fisiologia , Imagem por Ressonância Magnética/métodos , Adulto , Humanos , Masculino , Modelos Teóricos , Análise e Desempenho de Tarefas
20.
Tissue Eng Part A ; 22(5-6): 436-48, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26842062

RESUMO

The self-healing capacity of an injured meniscus is limited to the vascularized regions and is especially challenging in the inner avascular regions. As such, we investigated the use of human meniscus cell-seeded electrospun (ES) collagen type I scaffolds to produce meniscal tissue and explored whether these cell-seeded scaffolds can be implanted to repair defects created in meniscal avascular tissue explants. Human meniscal cells (derived from vascular and avascular meniscal tissue) were seeded on ES scaffolds and cultured. Constructs were evaluated for cell viability, gene expression, and mechanical properties. To determine potential for repair of meniscal defects, human meniscus avascular cells were seeded and cultured on aligned ES collagen scaffolds for 4 weeks before implantation. Surgical defects resembling "longitudinal tears" were created in the avascular zone of bovine meniscus and implanted with cell-seeded collagen scaffolds and cultured for 3 weeks. Tissue regeneration and integration were evaluated by histology, immunohistochemistry, mechanical testing, and magentic resonance imaging. Ex vivo implantation with cell-seeded collagen scaffolds resulted in neotissue that was significantly better integrated with the native tissue than acellular collagen scaffolds or untreated defects. Human meniscal cell-seeded ES collagen scaffolds may therefore be useful in facilitating meniscal repair of avascular meniscus tears.


Assuntos
Colágeno/farmacologia , Menisco/patologia , Engenharia Tecidual/métodos , Tecidos Suporte/química , Cicatrização/efeitos dos fármacos , Animais , Bovinos , Células Cultivadas , Colágeno/ultraestrutura , Modelos Animais de Doenças , Módulo de Elasticidade/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Imagem por Ressonância Magnética , Fenótipo , Resistência à Tração/efeitos dos fármacos
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