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1.
Org Lett ; 2020 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-32202432

RESUMO

A Brønsted base and Lewis acid cooperatively catalyzed 1,3-dipolar cycloaddition is reported through chiral dinuclear zinc catalysts. An asymmetric exo'-selective [3 + 2] cycloaddition of CF3-containing N-unprotected isatin-derived azomethine ylides is realized. In the presence of 10 mol % of catalyst, azomethine ylides react efficiently with methyleneindolinones, giving a series of trifluoromethyl-substituted 2,3-pyrrolidinyl dispirooxindoles with highly enantio- (up to 99% ee) and exo'-selectivity (>20:1 dr). Up to four contiguous stereogenic centers, including two adjacent spiro quaternary stereocenters, are constructed in one step.

2.
J Org Chem ; 85(6): 4195-4206, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32083864

RESUMO

An asymmetric Michael/hemiketalization and Fridel-Crafts reaction has been reported through a one-pot reaction. A number of structurally novel tetrahydrofuran spirooxindoles are synthesized in the presence of a 10 mol % dinuclear zinc catalyst with diastereomer ratios (dr) of 3:1-13:1 and an enantiomeric excess (ee) of 75-99%. The reaction can be performed on a gram scale without impacting its efficiency. The absolute configuration of products is confirmed by X-ray single crystal structure analysis, and a possible mechanism is proposed.

3.
Life Sci ; 242: 117240, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31891722

RESUMO

Lycium barbarum polysaccharides (LBP) are derived from Wolfberry and have antioxidant activities. This study aimed to evaluate the efficacy of LBP for kidney injury in a rat model of sepsis. Male rats were divided randomly to control group (Con), LPS group (LPS), ulinastatin group (ULI), low dose LBP group (LBP-1), middle dose LBP group (LBP-2) and high dose LBP group (LBP-3). After intraperitoneal injection of LPS (5 mg/kg) to make sepsis model (LPS group), 10,000 U/kg ulinastatin were given in ULI group, and 200, 400 and 800 mg/kg LBP was given in LBP-1, -2, -3 group, respectively. Serum IL-1ß, IL-6, IL-8, TNF-α and NF-κB levels were measured by ELISA. Nrf2, Keap1, NF-κB, HO-1 and NQO1 expression levels were detected by PCR and Western blot analysis. We found that LBP decreased the levels of NF-κB and pro-inflammatory cytokines while attenuated kidney injury. In addition, LBP regulated Keap1-Nrf2/ARE signaling pathway in the kidney. In conclusion, LBP attenuates inflammation injury in the kidney via possible regulation of Keap1-Nrf2/ARE signaling.


Assuntos
Lesão Renal Aguda/prevenção & controle , Elementos de Resposta Antioxidante/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Sepse/complicações , Transdução de Sinais/efeitos dos fármacos , Animais , Western Blotting , Citocinas/metabolismo , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real
4.
Mater Sci Eng C Mater Biol Appl ; 106: 110253, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753332

RESUMO

The application of photoresponsive surface molecularly imprinted polymers based on azobenzene is limited by the UV light source required and their poor water solubility. Reducing the phototoxicity and solvent toxicity of the polymers therefore presents a challenge. In this work, an NIR-light-responsive surface molecularly imprinted polymer was fabricated by atom transfer radical polymerization using up-conversion nanoparticles as the core, a hydrophilic green-light-responsive azobenzene derivative as the functional monomer, and a drug as the template. The up-conversion nanoparticles core emitted green fluorescence in the range of 520-550 nm upon NIR irradiation (980 nm, 5 W cm-2), which was absorbed by the azobenzene containing molecularly imprinted polymers layer on the up-conversion nanoparticles surface. This caused the azobenzene chromophores to undergo trans→cis isomerization in phosphate buffered solution (pH = 7.4), thus resulting in NIR-light-induced drug release. The up-conversion fluorescence spectra were used to study the interaction mechanism between the azobenzene monomer and NIR light. Compared with structural analogues of the template (antifebrin and phenacetin), the NIR-light-responsive surface molecularly imprinted polymer showed excellent specificity of recognition for the template drug (paracetamol). The maximum adsorption capacity of the NIR-light-responsive surface molecularly imprinted polymer for loading of paracetamol was 16.80 µmol g-1. The NIR-light-responsive surface molecularly imprinted polymer was applied for NIR-light-induced paracetamol release in phosphate buffered solution (pH = 7.4) through porcine tissue. This work demonstrates the potential of drug delivery systems based on molecularly imprinted polymers for application in deep tissue delivery.

5.
Mater Sci Eng C Mater Biol Appl ; 96: 661-668, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30606579

RESUMO

The trans to cis isomerization of the azobenzene chromophore in most azobenzene-based photoresponsive molecularly imprinted polymers (MIPs) is initiated by UV irradiation. This limits the application of these materials in cases where UV light toxicity is an issue, such as in biological systems, food monitoring, and drug delivery. Herein we report a tetra-ortho-methyl substituted azobenzene, (4-[(4-methacryloyloxy)-2,6-dimethyl phenylazo]-3,5-dimethyl benzenesulfonic acid (MADPADSA). The photoswitching of MADPADSA could be induced by visible-light irradiation (550 nm for trans to cis and 475 nm for cis to trans) in 4-hydroxyethylpiperazineethanesulfonic acid (HEPES) buffer-ethanol (4:1, v/v) at pH 7.0, however, the photoisomerization was slow. With the use of MADPADSA as a functional monomer, NaYF4:Yb3+,Er3+ as a substrate, 4-ethylphenol (4-EP) as a template, a novel photoresponsive surface molecularly imprinted polymer NaYF4:Yb3+,Er3+@MIP was obtained. The NaYF4:Yb3+,Er3+@MIP displayed rapid visible-light-induced photoswitching. The NaYF4:Yb3+,Er3+ substrate could efficiently increase the trans to cis isomerization rate of the photoresponsive MIP on its surface, which was faster than that of the corresponding azobenzene monomer MADPADSA. Possible reasons for this effect were investigated by fluorescence spectroscopy. NaYF4:Yb3+,Er3+@MIP displayed good specificity toward 4-EP with a specific binding constant (Kd) of 3.67 × 10-6 mol L-1 and an apparent maximum adsorption capacity (Qmax) of 10.73 µmol g-1, respectively. NaYF4:Yb3+,Er3+@MIP was applied to determine the concentration of 4-EP in red wine with good efficiency and a limit of detection lower than the value that could cause an unpleasant off-flavor.


Assuntos
Fenóis/análise , Processos Fotoquímicos , Raios Ultravioleta , Vinho/análise , Espectrometria de Fluorescência
6.
Mater Sci Eng C Mater Biol Appl ; 92: 365-373, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30184762

RESUMO

A new photoresponsive surface molecularly imprinted polymer shell (PMIPS) was developed for determination of trace griseofulvin from milk. The PMIPS was prepared by surface imprinting technique using poly(styrene-co-methacrylic acid) (PS-co-PMMA) microspheres as the sacrificial substrate, griseofulvin as the template, a photoresponsive azobenzene derivative 4-((4-(methacryloyloxy)phenyl)diazenyl)-3,5-dimethyl benzenesulfonic acid as the functional monomer, and triethanolamine trimethacrylate as the cross-linker. The PMIPS was obtained after the removal of the sacrificial PS-co-PMMA core from the surface imprinted core-shell microspheres, PS-co-PMAA@PMIP. Compared with PS-co-PMAA@PMIP, PMIPS displayed better properties such as higher surface area and pore volume, rapid photo-isomerization rate, and higher adsorption capacities, specific binding constant and binding density. The PMIPS could efficiently detect griseofulvin in complex samples such as milk.


Assuntos
Griseofulvina/análise , Luz , Leite/química , Impressão Molecular , Polímeros/química , Adsorção , Animais , Isomerismo , Cinética , Nitrogênio/química , Polímeros/síntese química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente
7.
Mater Sci Eng C Mater Biol Appl ; 76: 568-578, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28482565

RESUMO

This paper reports a photoresponsive hollow molecularly imprinted polymer for the determination of trace triamterene in biological sample. The photoresponsive hollow molecularly imprinted polymer was prepared on sacrificial silica microspheres via surface imprinting technique through atom transfer radical polymerization using a novel water-soluble azobenzene derivative, 4-[(4-methacryloyloxy)phenylazo]-3,5-dimethyl benzenesulfonic acid, as the functional monomer, and the sacrificial silica core was subsequently removed using HF etching method with 1.25vol.% HF ethanolic solution. The morphologies and properties of the photoresponsive hollow molecularly imprinted polymer were further characterized and compared systematically with the corresponding photoresponsive surface molecularly imprinted polymer. Compared with surface imprinted polymer, the hollow material displayed higher binding capacity, better recognition ability, faster mass-transfer rate, and larger isomerization rate constants toward triamterene. The static binding properties of the imprinted materials were investigated under three irradiation conditions. The photoresponsive hollow molecularly imprinted polymer showed better specificity toward triamterene than its structural analogues (folic acid and caffeine) as examined by UV-vis and HPLC. The photoresponsive hollow molecularly imprinted polymer was utilized for the determination of trace triamterene in biological samples (human urine and serum) with advantages of simple sample pre-treatment, good recovery and good sensitivity.


Assuntos
Polímeros/química , Humanos , Microesferas , Impressão Molecular , Polimerização , Triantereno
8.
J Sep Sci ; 40(6): 1396-1402, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28106341

RESUMO

We aim to develop novel photoresponsive surface molecularly imprinted polymer (SIMP) microspheres, an SiO2 -SIMP, for the photocontrolled extraction of uric acid from biological samples. The SiO2 -SMIP was prepared on silica microspheres by surface polymerization and characterized by using scanning electron microscopy, transmission electron microscopy, FTIR spectroscopy, thermogravimetric analysis, nitrogen adsorption-desorption analysis, and UV-visible spectroscopy. The SiO2 -SMIP microspheres showed a photocontrolled uptake and release of uric acid in NaH2 PO4 buffer upon alternate irradiation at 365 and 440 nm. The SiO2 -SMIP microspheres were able to photocontrollably extract uric acid from complicated biological samples for concentration analysis with no significant interference encountered and it exhibited very good recognition ability and fast binding kinetics toward uric acid.


Assuntos
Microesferas , Impressão Molecular , Ácido Úrico/isolamento & purificação , Adsorção , Humanos , Polímeros , Dióxido de Silício , Ácido Úrico/urina
9.
Biochim Biophys Acta ; 1863(8): 1961-8, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27163878

RESUMO

Transplantation of mesenchymal stem cells (MSCs) into the degenerated intervertebral disc (IVD) has shown promise for decelerating or arresting IVD degeneration. Cellular mechanical properties play crucial roles in regulating cell-matrix interactions, potentially reflecting specific changes that occur based on cellular phenotype and behavior. However, the effect of co-culturing of MSCs with nucleus pulposus cells (NPCs) on the mechanical properties of NPCs remains unknown. In our study, we demonstrated that co-culture of degenerated NPCs with MSCs resulted in significantly decreased mechanical moduli (elastic modulus, relaxed modulus, and instantaneous modulus) and increased biological activity (proliferation and expression of matrix genes) in degenerated NPCs, but not normal NPCs. SDF-1, CXCR4 ligand, was highly expressed in MSCs when co-cultured with degenerated NPCs. Inhibition of SDF-1 using CXCR4 antagonist AMD3100 or knocking-down CXCR4 in degenerated NPCs abolished the MSCs-induced decrease in the mechanical moduli and increased biological activity of degenerated NPCs, suggesting a crucial role for SDF-1/CXCR4 signaling. AKT and FAK inhibition attenuated the MSCs- or SDF-1-induced decrease in the mechanical moduli of degenerated NPCs. In conclusion, it was demonstrated in vitro that MSCs regulate the mechanical properties of degenerated NPCs through SDF-1/CXCR4/AKT signaling. These findings highlight a possible mechanical mechanism for MSCs-induced modulation with degenerated NPCs, which may be applicable to MSCs-based therapy for disc degeneration.


Assuntos
Quimiocina CXCL12/fisiologia , Degeneração do Disco Intervertebral/patologia , Células-Tronco Mesenquimais/fisiologia , Núcleo Pulposo/patologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Receptores CXCR4/fisiologia , Transdução de Sinais/fisiologia , Agrecanas/biossíntese , Agrecanas/genética , Células Cultivadas , Quimiocina CXCL12/antagonistas & inibidores , Técnicas de Cocultura , Colágeno Tipo II/biossíntese , Colágeno Tipo II/genética , Módulo de Elasticidade , Compostos Heterocíclicos/farmacologia , Humanos , Técnicas In Vitro , Células-Tronco Mesenquimais/metabolismo , Microscopia de Força Atômica , Núcleo Pulposo/citologia , Núcleo Pulposo/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , Receptores CXCR4/antagonistas & inibidores
10.
Mater Sci Eng C Mater Biol Appl ; 66: 33-39, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27207036

RESUMO

A photoresponsive surface molecularly imprinted polymer for uric acid in physiological fluids was fabricated through a facile and effective method using bio-safe and biocompatible ZnO nanorods as a support. The strategy was carried out by introducing double bonds on the surface of the ZnO nanorods with 3-methacryloxypropyltrimethoxysilane. The surface molecularly imprinted polymer on ZnO nanorods was then prepared by surface polymerization using uric acid as template, water-soluble 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid as functional monomer, and triethanolamine trimethacryl ester as cross-linker. The surface molecularly imprinted polymer on ZnO nanorods showed good photoresponsive properties, high recognition ability, and fast binding kinetics toward uric acid, with a dissociation constant of 3.22×10(-5)M in aqueous NaH2PO4 buffer at pH=7.0 and a maximal adsorption capacity of 1.45µmolg(-1). Upon alternate irradiation at 365 and 440nm, the surface molecularly imprinted polymer on ZnO nanorods can quantitatively uptake and release uric acid.


Assuntos
Impressão Molecular , Nanotubos/química , Polímeros/química , Ácido Úrico/análise , Óxido de Zinco/química , Adsorção , Cinética , Metacrilatos/química , Silanos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química
11.
Tissue Eng Part A ; 20(5-6): 908-20, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24102374

RESUMO

In a general view of anatomy, intervertebral disc is composed of three parts: annulus fibrosus (AF), nucleus pulposus (NP), and cartilage endplate (CEP). Recently, several types of stem cells were successfully isolated from these corresponding regions, but up to now, no research was performed about which kind of stem cells is the most efficient candidate for NP tissue engineering or for stem cell-based disc regeneration therapy. In this study, we compared the regenerative potentials of the above-mentioned three kinds of disc-derived stem cells with that of the classic bone marrow (BM)-mesenchymal stem cells (MSCs) in a rabbit disc degeneration model. By magnetic resonance imaging (MRI), X-ray, histology, etc. evaluations, we found that cartilage endplate-derived stem cells (CESCs) showed superior capacity compared with the annulus fibrosus-derived stem cells (AFSCs), nucleus pulposus-derived stem cells (NPSCs), and BM-MSCs (p<0.05); additionally, when comparing the CESC group with the normal control group, there existed no statistical difference in X-ray (p>0.05). Those results demonstrated that the CESC-seeded alginate construct performed the most powerful ability for NP regeneration, while AFSCs showed the most inferior potency, NPSCs and BM-MSCs had similar regenerative capacity and located in the middle. All in all, our study showed that CESCs might act as an efficient seed cell source for NP tissue engineering, which paved a new way for the biological solution of disc degeneration diseases.


Assuntos
Alginatos/farmacologia , Disco Intervertebral/citologia , Células-Tronco/citologia , Engenharia Tecidual/métodos , Adulto , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Citometria de Fluxo , Fluoresceínas/metabolismo , Ácido Glucurônico/farmacologia , Ácidos Hexurônicos/farmacologia , Humanos , Imunofenotipagem , Disco Intervertebral/diagnóstico por imagem , Disco Intervertebral/cirurgia , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Coelhos , Radiografia , Coloração e Rotulagem , Transplante de Células-Tronco , Células-Tronco/efeitos dos fármacos , Succinimidas/metabolismo
12.
Mol Med Rep ; 7(6): 1850-4, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23625325

RESUMO

The aim of the present study was to investigate the composition, morphology, characteristics, distribution and function of distinct macrophage subpopulations in the mouse thymus. Apoptosis of mouse thymocytes was induced by glucocorticoids and three monoclonal antibodies against Mac-2, F4/80 and ED1 were used for immunofluorescence staining and immunohistochemical analysis. The morphology of thymic macrophages was examined by transmission electron microscopy. Four subpopulations of mouse thymic macrophages were identified. Dendritic macrophages were identified using anti-Mac-2 and anti-F4/80 antibodies, and were demonstrated to be distributed in the entire thymus. Phagocytes were also observed. In addition, plate-shaped macrophages, identified using the anti-F4/80 antibody, were distributed under the thymic cortex capsule. Small oval macrophages, identified using the anti-Mac-2 antibody, were distributed in the thymic medulla and corticomedullary region (CMR), while phagocytes were not observed in these types of cell. ED1+ thymic macrophages with irregular forms were distributed in the CMR. All of the four subpopulations of mouse thymic macrophages described above exhibited acid phosphate activity. This study indicated the existence of macrophage subpopulations with different shapes, distribution and functions in the mouse thymus.


Assuntos
Macrófagos/citologia , Timo/citologia , Animais , Antígenos de Diferenciação/imunologia , Antígenos de Diferenciação/metabolismo , Apoptose , Feminino , Imunofluorescência , Galectina 3/imunologia , Galectina 3/metabolismo , Imuno-Histoquímica , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Modelos Animais , Fagócitos/citologia , Fagócitos/patologia
13.
PLoS One ; 7(8): e43984, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22952837

RESUMO

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a multifunctional cytokine that regulates inflammatory reactions and the pathophysiology of many inflammatory diseases. Intervertebral disc (IVD) degeneration is characterized by an inflammatory reaction, but the potential role of MIF in IVD degeneration has not been determined. Recent studies have shown that MIF and its receptor, CD74, are involved in regulating the migration of human mesenchymal stem cells (MSCs); Thus, MIF might impair the ability of mesenchymal stem cells (MSCs) to home to injured tissues. Our previous studies indicated that cartilage endplate (CEP)-derived stem cells (CESCs) as a type of MSCs exist in human degenerate IVDs. Here, we investigate the role of MIF in regulating the migration of CESCs. METHODS AND FINDINGS: CESCs were isolated and identified. We have shown that MIF was distributed in human degenerate IVD tissues and was subject to regulation by the pro-inflammatory cytokine TNF-α. Furthermore, in vitro cell migration assays revealed that nucleus pulposus (NP) cells inhibited the migration of CESCs in a number-dependent manner, and ELISA assays revealed that the amount of MIF in conditioned medium (CM) was significantly increased as a function of increasing cell number. Additionally, recombinant human MIF (r-MIF) inhibited the migration of CESCs in a dose-dependent manner. CESCs migration was restored when an antagonist of MIF, (S, R)-3(4-hydroxyphenyl)-4, 5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1), was added. Finally, a CD74 activating antibody (CD74Ab) was used to examine the effect of CD74 on CESCs motility and inhibited the migration of CESCs in a dose-dependent manner. CONCLUSIONS: We have identified and characterized a novel regulatory mechanism governing cell migration during IVD degeneration. The results will benefit understanding of another possible mechanism for IVD degeneration, and might provide a new method to repair degenerate IVD by enhancing CESCs migration to degenerated NP tissues to exert their regenerative effects.


Assuntos
Antígenos de Diferenciação de Linfócitos B/metabolismo , Cartilagem/citologia , Movimento Celular , Antígenos de Histocompatibilidade Classe II/metabolismo , Fatores Inibidores da Migração de Macrófagos/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Idoso , Antígenos de Diferenciação de Linfócitos B/genética , Antígenos de Diferenciação de Linfócitos B/imunologia , Movimento Celular/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Disco Intervertebral/patologia , Degeneração do Disco Intervertebral/metabolismo , Isoxazóis/farmacologia , Ligação Proteica/efeitos dos fármacos , RNA Interferente Pequeno/genética , Células-Tronco/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima/efeitos dos fármacos
14.
Eur Spine J ; 21(4): 613-22, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22033570

RESUMO

INTRODUCTION: Cartilage endplate (CEP) degeneration is usually accompanied by loss of cellularity, and this loss may be a crucial key factor in initiation and development of degenerative disc disease. The study of cell types in degenerated CEP could help in understanding CEP etiopathogenesis, and may help in devising new treatments, especially if the presence of progenitor cells could be demonstrated. The aim of this study was to determine if progenitor cells existed in degenerated human CEP. MATERIALS AND METHODS: Cells isolated from CEP were cultured in a three-dimensional agarose suspension to screen for proliferative cell clusters. Cell clusters were then expanded in vitro and the populations were analyzed for colony forming unit, immunophenotype, multilineage induction, and expression of stem cell-related genes. RESULTS: The presence of progenitor cells in degenerated human CEP is indicated by the results of CFU, immunophenotype, multilineage induction, and expression of stem cell-related genes. CONCLUSIONS: We believe that this is the first study which has conclusively shown the presence of progenitor cells in degenerated CEP. The finding of this study may influence the clinical management of degenerative disc disorder.


Assuntos
Cartilagem/patologia , Degeneração do Disco Intervertebral/patologia , Vértebras Lombares/patologia , Células-Tronco/patologia , Adulto , Células Cultivadas , Discotomia , Feminino , Humanos , Técnicas In Vitro , Degeneração do Disco Intervertebral/etiologia , Degeneração do Disco Intervertebral/cirurgia , Masculino , Pessoa de Meia-Idade , Estenose Espinal/complicações , Estenose Espinal/patologia , Estenose Espinal/cirurgia , Espondilolistese/complicações , Espondilolistese/patologia , Espondilolistese/cirurgia
15.
PLoS One ; 6(10): e26285, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22028847

RESUMO

Mesenchymal stem cells (MSCs) derived from adult tissues are an important candidate for cell-based therapies and regenerative medicine due to their multipotential differentiation capability. MSCs have been identified in many adult tissues but have not reported in the human intervertebral disc cartilage endplate (CEP). The initial purpose of this study was to determine whether MSCs exist in the degenerated human CEP. Next, the morphology, proliferation capacity, cell cycle, cell surface epitope profile and differentiation capacity of these CEP-derived stem cells (CESCs) were compared with bone-marrow MSCs (BM-MSCs). Lastly, whether CESCs are a suitable candidate for BM-MSCs was evaluated. Isolated cells from degenerated human CEP were seeded in an agarose suspension culture system to screen the proliferative cell clusters. Cell clusters were chosen and expanded in vitro and were compared with BM-MSCs derived from the same patient. The morphology, proliferation rate, cell cycle, immunophenotype and stem cell gene expression of the CESCs were similar to BM-MSCs. In addition, the CESCs could be induced into osteoblasts, adipocytes, chondrocytes, and are superior to BM-MSCs in terms of osteogenesis and chondrogenesis. This study is first to demonstrate the presence of stem cells in the human degenerated CEP. These results may improve our understanding of intervertebral disc (IVD) pathophysiology and the degeneration process, and could provide cell candidates for cell-based regenerative medicine and tissue engineering.


Assuntos
Cartilagem/patologia , Degeneração do Disco Intervertebral/patologia , Disco Intervertebral/patologia , Células-Tronco Mesenquimais/citologia , Adipogenia , Adulto , Células da Medula Óssea/citologia , Ciclo Celular , Proliferação de Células , Condrogênese , Feminino , Regulação da Expressão Gênica , Humanos , Disco Intervertebral/cirurgia , Degeneração do Disco Intervertebral/cirurgia , Vértebras Lombares/patologia , Vértebras Lombares/cirurgia , Masculino , Células-Tronco Mesenquimais/metabolismo , Pessoa de Meia-Idade , Osteogênese
16.
Spine (Phila Pa 1976) ; 36(26): 2252-9, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-21358466

RESUMO

STUDY DESIGN: Advancement in tissue engineering provides a promising approach to recover the functionality of the degenerated intervertebral disc. In our study, a nucleus pulposus (NP) cell-seeded collagen II/hyaluronan/chondroitin-6-sulfate (CII/HyA/CS) tri-copolymer construct was implanted into the disc space directly after nucleotomy in a rabbit model. OBJECTIVE: The aim of this study was to investigate whether the NP cell-seeded CII/HyA/CS tri-copolymer constructs could regenerate the degenerated disc in vivo after implantation into the rabbit nucleotomy model. SUMMARY OF BACKGROUND DATA: Nucleotomy is one of the most prevalent surgical modalities to treat degenerative disc disease, which could achieve good short-term effects of pain relieve, whereas removal of the entire or partial NP changes the biomechanical characteristics of the remaining disc and the adjacent vertebral segments and a series of long-term complications such as accelerated annulus and the facet joints degeneration may ensue. Therefore, it is necessary to think about possible procedures immediately after the primary nucleotomy surgery to avoid these complications. METHODS: NP cells isolated from thoracic and lumbar spines of New Zealand White rabbits of approximately 3 weeks of age and 1 kg in weight were labeled with a 5- (and-6) -carboxyflurescein diacetate succinimidyl ester (CFDA-SE) fluorescent dye and seeded within the CII/HyA/CS scaffold by a centrifugation method. After in vitro culture for 1 week, NP cell-seeded CII/HyA/CS tri-copolymer constructs were allografted into the disc defects of recipient rabbit immediately after nucleotomy of the lumbar spine. The Bradner Disc Index and the T2-weighted signal intensity index were determined using lateral plane radiographs and magnetic resonance imaging at 4, 12, and 24 weeks after the operation. Finally, the operated discs were explanted for gross morphological observation, histological evaluation, and cell viability assessment. Animals with only nucleotomy and cell-free CII/HyA/CS scaffold implantation served as controls. RESULTS: In our study, we could demonstrate that the T2-weighted signal intensity index of the operated discs decreased in all three groups 1 month after surgery and the index of the cell-containing scaffold insertion group was significantly higher than that of the other two groups. After 24 weeks, the index of the cell-containing scaffold insertion group increased significantly. However, further decline was observed in both the noninsertion group and the scaffold insertion group. In radiographic analysis, the narrowing of the intervertebral disc space was significantly retarded by the cell-scaffold hybrids implantation up to 24 postoperative weeks. Furthermore, the gross morphology and histological evaluation indicated that the allografted NP cells were viable and showed extracellular matrix production. CONCLUSION: In our study, we had constructed rabbit NP cell-seeded CII/HyA/CS tri-copolymer implants in vitro. Immediately after nucleotomy of the recipient rabbit, we allografted the precultured cell-scaffold hybrids into the lacuna of the disc. Results documented survival of the allografted NP cells and extracellular matrix deposition, which finally resulted in maintenance of disc height and restoration of T2-weighted signal intensity on magnetic resonance imaging.


Assuntos
Degeneração do Disco Intervertebral/fisiopatologia , Disco Intervertebral/fisiologia , Polímeros/metabolismo , Regeneração , Animais , Técnicas de Cultura de Células/métodos , Sobrevivência Celular/fisiologia , Transplante de Células/métodos , Células Cultivadas , Sulfatos de Condroitina/metabolismo , Colágeno Tipo II/metabolismo , Modelos Animais de Doenças , Feminino , Sobrevivência de Enxerto/fisiologia , Ácido Hialurônico/metabolismo , Disco Intervertebral/citologia , Disco Intervertebral/cirurgia , Degeneração do Disco Intervertebral/diagnóstico por imagem , Degeneração do Disco Intervertebral/cirurgia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Imagem por Ressonância Magnética , Masculino , Coelhos , Radiografia , Engenharia Tecidual/métodos , Tecidos Suporte , Transplante Homólogo , Resultado do Tratamento
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