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1.
Environ Res ; 184: 109296, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32146214

RESUMO

Hexavalent chromium (Cr6+) is a commonly found heavy metal at polluted groundwater sites. In this study, the effectiveness of Cr6+ bioreduction by the chromium-reducing bacteria was evaluated to remediate Cr6+-contaminated groundwater. Microcosms were constructed using indigenous microbial consortia from a Cr6+-contaminated aquifer as the inocula, and slow-releasing emulsified polycolloid-substrate (ES), cane molasses (CM), and nutrient broth (NB) as the primary substrates. The genes responsible for the bioreduction of Cr6+ and variations in bacterial diversity were evaluated using metagenomics assay. Complete Cr6+ reduction via the biological mechanism was observed within 80 days using CM as the carbon source under anaerobic processes with the increased trivalent chromium (Cr3+) concentrations. Cr6+ removal efficiencies were 83% and 59% in microcosms using ES and NB as the substrates, respectively. Increased bacterial communities associated with Cr6+ bioreduction was observed in microcosms treated with CM and ES. Decreased bacterial communities were observed in NB microcosms. Compared to ES, CM was more applicable by indigenous Cr6+ reduction bacteria and resulted in effective Cr6+ bioreduction, which was possibly due to the growth of Cr6+-reduction related bacteria including Sporolactobacillus, Clostridium, and Ensifer. While NB was applied for specific bacterial selection, it might not be appropriate for electron donor application. These results revealed that substrate addition had significant impact on microbial diversities, which affected Cr6+ bioreduction processes. Results are useful for designing a green and sustainable bioreduction system for Cr6+-polluted groundwater remediation.

2.
Chemosphere ; 238: 124596, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524629

RESUMO

Deteriorated environmental conditions during the bioremediation of trichloroethene (TCE)-polluted groundwater cause decreased treatment efficiencies. This study assessed the effect of applying immobilized Clostridium butyricum (a hydrogen-producing bacterium) in silica gel on enhancing the reductive dechlorination efficiency of TCE with the slow polycolloid-releasing substrate (SPRS) supplement in groundwater. The responses of microbial communities with the immobilized system (immobilized Clostridium butyricum and SPRS amendments) were also characterized by the metagenomics assay. A complete TCE removal in microcosms was obtained within 30 days with the application of this immobilized system via reductive dechlorination processes. An increase in the population of Dehalococcoides spp. was observed using the quantitative polymerase chain reaction (qPCR) analysis. Results of metagenomics assay reveal that the microbial communities in the immobilized system were distinct from those in systems with SPRS only. Bacterial communities associated with TCE biodegradation also increased in microcosms treated with the immobilized system. The immobilized system shows a great potential to promote the TCE dechlorination efficiency, and the metagenomics-based approach provides detailed insights into dechlorinating microbial community dynamics. The results would be helpful in designing an in situ immobilized system to enhance the bioremediation efficiency of TCE-contaminated groundwater.


Assuntos
Chloroflexi/metabolismo , Clostridium butyricum/metabolismo , Água Subterrânea/química , Tricloroetileno/metabolismo , Biodegradação Ambiental , Chloroflexi/crescimento & desenvolvimento , Halogenação , Metagenômica , Microbiota/fisiologia , Sílica Gel
3.
Glycobiology ; 30(1): 49-57, 2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31553041

RESUMO

Galectins are ß-galactoside-binding animal lectins primarily found in the cytosol, while their carbohydrate ligands are mainly distributed in the extracellular space. Cytosolic galectins are anticipated to accumulate on damaged endocytic vesicles through binding to glycans initially displayed on the cell surface and subsequently located in the lumen of the vesicles, and this can be followed by cellular responses. To facilitate elucidation of the mechanism underlying this process, we adopted a model system involving induction of endocytic vesicle damage with light that targets the endocytosed amphiphilic photosensitizer disulfonated aluminum phthalocyanine. We demonstrate that the levels of galectins around damaged endosomes are dependent on the composition of carbohydrates recognized by the proteins. By super resolution imaging, galectin-3 and galectin-8 aggregates were found to be distributed in distinct microcompartments. Importantly, galectin accumulation is significantly affected when cell surface glycans are altered. Furthermore, accumulated galectins can direct autophagy adaptor proteins toward damaged endocytic vesicles, which are also significantly affected following alteration of cell surface glycans. We conclude that cytosolic galectins control cellular responses reflect dynamic modifications of cell surface glycans.

4.
Cells ; 8(7)2019 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-31262060

RESUMO

Diabetes-associated advanced glycation end-products (AGEs) can increase extracellular matrix (ECM) expression and induce renal fibrosis. Calbindin-D28k, which plays a role in calcium reabsorption in renal distal convoluted tubules, is increased in a diabetic kidney. The role of calbindin-D28k in diabetic nephropathy still remains unclear. Here, calbindin-D28k protein expression was unexpectedly induced in the renal tubules of db/db diabetic mice. AGEs induced the calbindin-D28k expression in human renal proximal tubule cells (HK2), but not in mesangial cells. AGEs induced the expression of fibrotic molecules, ECM proteins, epithelial-mesenchymal transition (EMT) markers, and endoplasmic reticulum (ER) stress-related molecules in HK2 cells, which could be inhibited by a receptor for AGE (RAGE) neutralizing antibody. Calbindin-D28k knockdown by siRNA transfection reduced the cell viability and obviously enhanced the protein expressions of fibrotic factors, EMT markers, and ER stress-related molecules in AGEs-treated HK2 cells. Chemical chaperone 4-Phenylbutyric acid counteracted the AGEs-induced ER stress and ECM and EMT markers expressions. Calbindin-D28k siRNA in vivo delivery could enhance renal fibrosis in db/db diabetic mice. These findings suggest that inducible calbindin-D28k protects against AGEs/RAGE axis-induced ER stress-activated ECM induction and cell injury in renal proximal tubule cells.


Assuntos
Calbindina 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Nefropatias Diabéticas/patologia , Produtos Finais de Glicação Avançada/metabolismo , Túbulos Renais Distais/patologia , Animais , Calbindina 1/genética , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/metabolismo , Modelos Animais de Doenças , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/patologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Fibrose , Técnicas de Silenciamento de Genes , Humanos , Túbulos Renais Distais/efeitos dos fármacos , Masculino , Células Mesangiais/metabolismo , Camundongos , Fenilbutiratos/farmacologia , RNA Interferente Pequeno/metabolismo , Receptor para Produtos Finais de Glicação Avançada/antagonistas & inibidores , Receptor para Produtos Finais de Glicação Avançada/metabolismo
5.
Environ Sci Pollut Res Int ; 26(33): 34027-34038, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30232775

RESUMO

The objectives of this study were to (1) conduct laboratory bench and column experiments to determine the oxidation kinetics and optimal operational parameters for trichloroethene (TCE)-contaminated groundwater remediation using potassium permanganate (KMnO4) as oxidant and (2) to conduct a pilot-scale study to assess the efficiency of TCE remediation by KMnO4 oxidation. The controlling factors in laboratory studies included soil oxidant demand (SOD), molar ratios of KMnO4 to TCE, KMnO4 decay rate, and molar ratios of Na2HPO4 to KMnO4 for manganese dioxide (MnO2) production control. Results show that a significant amount of KMnO4 was depleted when it was added in a soil/water system due to the existence of natural soil organic matters. The presence of natural organic material in soils can exert a significant oxidant demand thereby reducing the amount of KMnO4 available for the destruction of TCE as well as the overall oxidation rate of TCE. Supplement of higher concentrations of KMnO4 is required in the soil systems with high SOD values. Higher KMnO4 application resulted in more significant H+ and subsequent pH drop. The addition of Na2HPO4 could minimize the amount of produced MnO2 particles and prevent the clogging of soil pores, and TCE oxidation efficiency would not be affected by Na2HPO4. To obtain a complete TCE removal, the amount of KMnO4 used to oxidize TCE needs to be higher than the theoretical molar ratio of KMnO4 to TCE based on the stoichiometry equation. Relatively lower oxidation rates are obtained with lower initial TCE concentrations. The half-life of TCE decreased with increased KMnO4 concentrations. Results from the pilot-scale study indicate that a significant KMnO4 decay occurs after the injection due to the reaction of KMnO4 with soil organic matters, and thus, the amount of KMnO4, which could be transported from the injection point to the downgradient area, would be low. The effective influence zone of the KMnO4 oxidation was limited to the KMnO4 injection area (within a 3-m radius zone). Migration of KMnO4 to farther downgradient area was limited due to the reaction of KMnO4 to natural organic matters. To retain a higher TCE removal efficiency, continuous supplement of high concentrations of KMnO4 is required. The findings would be useful in designing an in situ field-scale ISCO system for TCE-contaminated groundwater remediation using KMnO4 as the oxidant.


Assuntos
Recuperação e Remediação Ambiental/métodos , Água Subterrânea/química , Permanganato de Potássio/química , Tricloroetileno/química , Poluentes Químicos da Água/química , Compostos de Manganês , Oxidantes , Oxirredução , Óxidos , Solo , Tricloroetileno/análise , Poluentes Químicos da Água/análise
6.
J Biomed Mater Res A ; 106(12): 3231-3238, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30208260

RESUMO

Recessive dystrophic Epidermolysis Bullosa (RDEB) is caused by mutations in collagen-type VII gene critical for the dermoepidermal junction (DEJ) formation. Neither tissues of animal models nor currently available in vitro models are amenable to the quantitative assessment of mechanical adhesion between dermal and epidermal layers. Here, we created a 3D in vitro DEJ model using extracellular matrix (ECM) proteins of the DEJ anchored to a poly(ethylene glycol)-based slab (termed ECM composites) and seeded with human keratinocytes and dermal fibroblasts. Keratinocytes and fibroblasts of healthy individuals were well maintained in the ECM composite and showed the expression of collagen type VII over a 2-week period. The ECM composites with healthy keratinocytes and fibroblasts exhibited yield stress associated with the separation of the model DEJ at 0.268 ± 0.057 kPa. When we benchmarked this measure of adhesive strength with that of the model DEJ fabricated with cells of individuals with RDEB, the yield stress was significantly lower (0.153 ± 0.064 kPa) consistent with our current mechanistic understanding of RDEB. In summary, a 3D in vitro model DEJ was developed for quantification of mechanical adhesion between epidermal- and dermal-mimicking layers, which can be utilized for assessment of mechanical adhesion of the model DEJ applicable for Epidermolysis Bullosa-associated therapeutics. © 2018 The Authors. Journal Of Biomedical Materials Research Part A Published By Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 3231-3238, 2018.


Assuntos
Epidermólise Bolhosa Distrófica/patologia , Proteínas da Matriz Extracelular/química , Fibroblastos/patologia , Queratinócitos/patologia , Polietilenoglicóis/química , Tecidos Suporte/química , Fenômenos Biomecânicos , Células Cultivadas , Técnicas de Cocultura , Colágeno Tipo VII/análise , Derme/patologia , Humanos , Proteínas Imobilizadas/química , Masculino , Estresse Mecânico
7.
Glycobiology ; 28(6): 392-405, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29800364

RESUMO

While glycans are generally displayed on the cell surface or confined within the lumen of organelles, they can become exposed to the cytosolic milieu upon disruption of organelle membrane by various stresses or pathogens. Galectins are a family of ß-galactoside-binding animal lectins synthesized and predominantly localized in the cytosol. Recent research indicates that some galectins may act as "danger signal sensors" by detecting unusual exposure of glycans to the cytosol. Galectin-8 was shown to promote antibacterial autophagy by recognizing host glycans on ruptured vacuolar membranes and interacting with the autophagy adaptor protein NDP52. Galectin-3 also accumulates at damaged phagosomes containing bacteria; however, its functional consequence remains obscure. By studying mouse macrophages infected with Listeria monocytogenes (LM), we showed that endogenous galectin-3 protects intracellular LM by suppressing the autophagic response through a host N-glycan-dependent mechanism. Knock out of the galectin-3 gene resulted in enhanced LC3 recruitment to LM and decreased bacterial replication, a phenotype recapitulated when Galectin-8-deficient macrophages were depleted of N-glycans. Moreover, we explored the concept that alterations in cell surface glycosylation by extracellular factors can be deciphered by cytosolic galectins during the process of phagocytosis/endocytosis, followed by rupture of phagosomal/endosomal membrane. Notably, treatment of cells with sialidase, which removes sialic acid from glycans, resulted in increased galectin-3 accumulation and decreased galectin-8 recruitment at damaged phagosomes, and led to a stronger anti-autophagic response. Our findings demonstrate that cytosolic galectins may sense changes in glycosylation at the cell surface and modulate cellular response through differential recognition of glycans on ruptured phagosomal membranes.


Assuntos
Autofagia , Galectina 3/metabolismo , Galectinas/metabolismo , Fagossomos/metabolismo , Polissacarídeos/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Citosol/metabolismo , Galectina 3/genética , Galectinas/genética , Listeria monocytogenes/patogenicidade , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/metabolismo , Ligação Proteica
8.
PLoS One ; 12(10): e0186214, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29016672

RESUMO

The bladder is an important organ for the storage of excreted water and metabolites. If metabolites with carcinogenic characteristics are present in urine, the urothelial lining of the bladder could be damaged and genetically altered. In this study, we analyzed the interaction of arsenic and N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) on mouse bladder carcinogenesis. Our previous study found that arsenic affects BBN-altered urothelial enzymatic activity, protein expression, DNA oxidation and global DNA CpG methylation levels. In this study, two mouse models were used. First, after administering a co-treatment of BBN and arsenic for 20 weeks, BBN alone led to a urothelial carcinoma formation of 20%, and arsenic promoted a BBN-induced urothelial carcinoma formation of 10%. The protein expression of GSTM1, GSTO1, NQO1, and p21 did not change by arsenic along with the BBN co-treatment, but the Sp1 expression increased. In the second mouse model, BBN was a pretreatment promoter; arsenic dose-dependently deteriorated BBN-promoted dysplasia by 10% and 40% at 10 ppm and 100 ppm, respectively. Conversely, BBN pretreatment also accelerated arsenic-induced dysplasia by 30%. The urothelial carcinogenic effect reversed after ceasing BBN for a period of 20 weeks. In summary, three conclusions were drawn from this study. The first is the mutual promotion of arsenic and BBN in bladder carcinogenesis. Second, arsenic dosages without bladder carcinogenicity (10 ppm) or with slight carcinogenicity (100 ppm) promote BBN-induced mice bladder cancer progression. Finally, the dysplastic urothelium had reverted to near-normal morphology after ceasing BBN intake for 20 weeks, providing a good suggestion for people who want to quit smoking.


Assuntos
Arsênico/toxicidade , Butilidroxibutilnitrosamina/toxicidade , Carcinogênese/induzido quimicamente , Carcinógenos/toxicidade , Carcinoma de Células de Transição/induzido quimicamente , Neoplasias da Bexiga Urinária/induzido quimicamente , Animais , Carcinogênese/genética , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma de Células de Transição/genética , Carcinoma de Células de Transição/metabolismo , Carcinoma de Células de Transição/patologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Interações de Medicamentos , Feminino , Regulação Neoplásica da Expressão Gênica , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , Fator de Transcrição Sp1/agonistas , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/metabolismo , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/metabolismo , Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/patologia , Urotélio/efeitos dos fármacos , Urotélio/metabolismo , Urotélio/patologia
9.
Colloids Surf B Biointerfaces ; 138: 26-31, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26642073

RESUMO

Biofunctional scaffolds that support the adhesion, proliferation, and osteo-differentiation of mesenchymal stem cells (MSCs) are critical for bone tissue engineering. In this study, a simple in situ UV-crosslinking strategy was utilized to fabricate gelatin electrospun fibrous (GEF) scaffolds with multiple biosignals, including cell adhesive Arg-Gly-Asp (RGD) peptide, osteo-conductive hydroxyapatite (HAp) nanoparticles, and osteo-inductive bone morphogenic protein-2 (BMP-2). The adhesion and proliferation of MSCs on the GEF scaffolds were improved by the incorporation of RGD. Meanwhile, the incorporation of HAp and BMP-2 enhanced osteo-differentiation of MSCs. The three incorporated bio-factors exert a synergistic effect on osteogenesis of MSCs in the GEF scaffolds. This strategy of incorporating multiple biomolecules could be used to fabricate crosslinked electrospun scaffolds of natural polymers for tissue-engineering applications.


Assuntos
Gelatina/química , Células-Tronco Mesenquimais/citologia , Osteogênese/fisiologia , Engenharia Tecidual/métodos , Tecidos Suporte/química , Fosfatase Alcalina/metabolismo , Animais , Proteína Morfogenética Óssea 2/química , Proteína Morfogenética Óssea 2/metabolismo , Proteína Morfogenética Óssea 2/farmacologia , Cálcio/metabolismo , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Linhagem Celular , Durapatita/química , Durapatita/metabolismo , Durapatita/farmacologia , Técnicas Eletroquímicas/métodos , Gelatina/metabolismo , Gelatina/efeitos da radiação , Humanos , Células-Tronco Mesenquimais/metabolismo , Nanopartículas/química , Nanopartículas/metabolismo , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Oligopeptídeos/farmacologia , Osteogênese/efeitos dos fármacos , Reprodutibilidade dos Testes , Raios Ultravioleta
10.
Toxicol Appl Pharmacol ; 279(3): 322-330, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-24998975

RESUMO

Bladder cancer is highly recurrent following specific transurethral resection and intravesical chemotherapy, which has prompted continuing efforts to develop novel therapeutic agents and early-stage diagnostic tools. Specific changes in protein expression can provide a diagnostic marker. In our present study, we investigated changes in protein expression during urothelial carcinogenesis. The carcinogen BBN was used to induce mouse bladder tumor formation. Mouse bladder mucosa proteins were collected and analyzed by 2D electrophoresis from 6 to 20 weeks after commencing continuous BBN treatment. By histological examination, the connective layer of the submucosa showed gradual thickening and the number of submucosal capillaries gradually increased after BBN treatment. At 12-weeks after the start of BBN treatment, the urothelia became moderately dysplastic and tumors arose after 20-weeks of treatment. These induced bladder lesions included carcinoma in situ and connective tissue invasive cancer. In protein 2D analysis, the sequentially downregulated proteins from 6 to 20 weeks included GSTM1, L-lactate dehydrogenase B chain, keratin 8, keratin 18 and major urinary proteins 2 and 11/8. In contrast, the sequentially upregulated proteins identified were GSTO1, keratin 15 and myosin light polypeptide 6. Western blotting confirmed that GSTM1 and NQO-1 were decreased, while GSTO1 and Sp1 were increased, after BBN treatment. In human bladder cancer cells, 5-aza-2'-deoxycytidine increased the GSTM1 mRNA and protein expression. These data suggest that the downregulation of GSTM1 in the urothelia is a biomarker of bladder carcinogenesis and that this may be mediated by DNA CpG methylation.


Assuntos
Butilidroxibutilnitrosamina/toxicidade , Carcinógenos/toxicidade , Glutationa Transferase/biossíntese , Neoplasias da Bexiga Urinária/induzido quimicamente , Neoplasias da Bexiga Urinária/genética , Animais , Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Western Blotting , Peso Corporal/efeitos dos fármacos , Linhagem Celular Tumoral , Corantes , Decitabina , Regulação para Baixo/efeitos dos fármacos , Eletroforese em Gel Bidimensional , Feminino , Glutationa Transferase/efeitos dos fármacos , Glutationa Transferase/genética , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Membrana Mucosa/efeitos dos fármacos , Membrana Mucosa/ultraestrutura , RNA Mensageiro/antagonistas & inibidores , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase em Tempo Real , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/patologia
11.
Tissue Eng Part A ; 20(13-14): 1896-907, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24471778

RESUMO

Structural similarity of electrospun fibers (ESFs) to the native extracellular matrix provides great potential for the application of biofunctional ESFs in tissue engineering. This study aimed to synthesize biofunctionalized poly (L-lactide-co-glycolide) (PLGA) ESFs for investigating the potential for cardiac tissue engineering application. We developed a simple but novel strategy to incorporate adhesive peptides in PLGA ESFs. Two adhesive peptides derived from laminin, YIGSR, and RGD, were covalently conjugated to poly-L-lysine, and then mingled with PLGA solution for electrospinning. Peptides were uniformly distributed on the surface and in the interior of ESFs. PLGA ESFs incorporated with YIGSR or RGD or adsorbed with laminin significantly enhanced the adhesion of cardiomyocytes isolated from neonatal rats. Furthermore, the cells were found to adhere better on ESFs compared with flat substrates after 7 days of culture. Immunofluorescent staining of F-actin, vinculin, a-actinin, and N-cadherin indicated that cardiomyocytes adhered and formed striated α-actinin better on the laminin-coated ESFs and the YIGSR-incorporated ESFs compared with the RGD-incorporated ESFs. The expression of α-myosin heavy chain and ß-tubulin on the YIGSR-incorporated ESFs was significantly higher compared with the expression level on PLGA and RGD-incorporated samples. Furthermore, the contraction of cardiomyocytes was faster and lasted longer on the laminin-coated ESFs and YIGSR-incorporated ESFs. The results suggest that aligned YIGSR-incorporated PLGA ESFs is a better candidate for the formation of cardiac patches. This study demonstrated the potential of using peptide-incorporated ESFs as designable-scaffold platform for tissue engineering.


Assuntos
Materiais Biocompatíveis/farmacologia , Coração/fisiologia , Ácido Láctico/farmacologia , Ácido Poliglicólico/farmacologia , Engenharia Tecidual/métodos , Animais , Animais Recém-Nascidos , Adesão Celular/efeitos dos fármacos , Adesão Celular/genética , Células Cultivadas , Imunofluorescência , Regulação da Expressão Gênica/efeitos dos fármacos , Coração/efeitos dos fármacos , Laminina/farmacologia , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/ultraestrutura , Oligopeptídeos/farmacologia , Especificidade de Órgãos/efeitos dos fármacos , Especificidade de Órgãos/genética , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos Wistar , Soluções
12.
Biofabrication ; 5(3): 035008, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23839910

RESUMO

Electrospun fibers of natural polymers are desirable for biomedical applications such as tissue engineering. Crosslinking of electrospun fibers of natural polymers is needed to prevent dissolution in water and to enhance mechanical strength. In this study, an in situ UV-crosslinking method was developed for crosslinking of gelatin electrospun fibers (GESFs) and water-soluble synthetic polymers. A mixture of gelatin and phenylazide-conjugated poly(acrylic acids) was electrospun under UV irradiation. The UV-crosslinked GESFs were not dissolved in water with improved mechanical strength. Compared to traditional crosslinking by glutaraldehyde vapor, the GESFs crosslinked by our method are superior in terms of retention of GESF morphology, uniform crosslinking throughout the fibers, low cytotoxic and retention of biofunctionality. L929 cells grew better on the UV-crosslinked GESF scaffolds compared to glutaraldehyde-crosslinked ones. Furthermore, bioactive nanoparticles, e.g. hydroxyapatite, could be incorporated into GESFs for enhancing osteoconductivity, which possess a great potential in bone tissue engineering.


Assuntos
Gelatina/química , Polímeros/química , Engenharia Tecidual/instrumentação , Tecidos Suporte/química , Acrilatos/química , Animais , Linhagem Celular , Proliferação de Células , Reagentes para Ligações Cruzadas/química , Camundongos , Fotoquímica , Polímeros/síntese química , Raios Ultravioleta
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