RESUMO
In this review, we focused on a few obstacles that hinder three-dimensional (3D) bioprinting process in tissue engineering. One of the obstacles is the bioinks used to deliver cells. Hydrogels are the most widely used bioink materials; however, they aremechanically weak in nature and cannot meet the requirements for supporting structures, especially when the tissues, such as cartilage, require extracellular matrix to be mechanically strong. Secondly and more importantly, tissue regeneration is not only about building all the components in a way that mimics the structures of living tissues, but also about how to make the constructs function normally in the long term. One of the key issues is sufficient nutrient and oxygen supply to the engineered living constructs. The other is to coordinate the interplays between cells, bioactive agents and extracellular matrix in a natural way. This article reviews the approaches to improve the mechanical strength of hydrogels and their suitability for 3D bioprinting; moreover, the key issues of multiple cell lines coprinting with multiple growth factors, vascularization within engineered living constructs etc. were also reviewed.
Assuntos
Bioimpressão , Engenharia Tecidual , Animais , Linhagem Celular , Humanos , Hidrogéis , NanopartículasRESUMO
AIM: To understand why autonomic failures, a common non-motor symptom of Parkinson's disease (PD), occur earlier than typical motor disorders. METHODS: Vagal application of DOPAL (3,4-dihydroxyphenylacetaldehyde) to simulate PD-like autonomic dysfunction and understand the connection between PD and cardiovascular dysfunction. Molecular and morphological approaches were employed to test the time-dependent alternation of α-synuclein aggregation and the ultrastructure changes in the heart and nodose (NG)/nucleus tractus solitarius (NTS). RESULTS: Blood pressure (BP) and baroreflex sensitivity of DOPAL-treated rats were significantly reduced accompanied with a time-dependent change in orthostatic BP, consistent with altered echocardiography and cardiomyocyte mitochondrial ultrastructure. Notably, time-dependent and collaborated changes in Mon-/Tri-α-synuclein were paralleled with morphological alternation in the NG and NTS. CONCLUSION: These all demonstrate that early autonomic dysfunction mediated by vagal application of DOPAL highly suggests the plausible etiology of PD initiated from peripheral, rather than central site. It will provide a scientific basis for the prevention and early diagnosis of PD.
Assuntos
Ácido 3,4-Di-Hidroxifenilacético/análogos & derivados , Doenças do Sistema Nervoso Autônomo/patologia , Doença de Parkinson Secundária/patologia , Nervo Vago , Ácido 3,4-Di-Hidroxifenilacético/farmacologia , Animais , Doenças do Sistema Nervoso Autônomo/etiologia , Barorreflexo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Eletrocardiografia , Hipotensão Ortostática/fisiopatologia , Masculino , Mitocôndrias Cardíacas/patologia , Miocárdio/patologia , Miócitos Cardíacos/patologia , Gânglio Nodoso/patologia , Doença de Parkinson Secundária/complicações , Ratos , Ratos Sprague-Dawley , alfa-Sinucleína/biossíntese , alfa-Sinucleína/genéticaRESUMO
OBJECTIVE: To investigate the role of oligodendrocyte apoptosis under the regulation of the bcl-2/bax protein expression in brain white matter in the pathogenesis of heroin-induced spongiform leucoencephalopathy (HSLE). METHODS: Samples of frontal lobe, cerebellum, and corpus callosum were obtained from the brains during autopsy of 4 HSLE cases and 5 normal controls and underwent light microscopy and electron microscopy. Immunocytochemistry was used to detect the expression of myelin basic protein (MBP), caspase-3, bcl-2 protein, and bax protein. RESULTS: Widespread demyelination was seen in the white matter of the frontal lobe, cerebellum and corpus callosum of the HSLE cases, most severely in the cerebellum. The levels of caspase-3 and bax expression of the HSLE group were significantly higher than those of the control group (both P <0.05) , however, the bcl-2 level of the HSLE group was no significantly different from that of the control group (P > 0.05). CONCLUSION: Widespread demyelination in the white matter is a prevailed pathological change of HSLE. Oligodendrocyte apoptosis under induced by the decrease of bcl-2/bax ratio may contribute to the pathogenesis.
Assuntos
Apoptose , Doença de Canavan/metabolismo , Oligodendroglia/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteína X Associada a bcl-2/biossíntese , Adulto , Idoso , Autopsia , Doença de Canavan/induzido quimicamente , Doença de Canavan/patologia , Feminino , Heroína , Dependência de Heroína/fisiopatologia , Humanos , Imuno-Histoquímica , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Proteína Básica da Mielina/biossíntese , Oligodendroglia/patologia , Oligodendroglia/ultraestruturaRESUMO
OBJECTIVE: To investigate the regulation of cyclooxygenase (Cox)-2/2', 3'-cyclic nucleotide3' phosphohydrolase (CNPase) on the oligodendrocyte apoptosis in the pathogenesis of the heroin-induced spongiform leucoencephalopathy (HSLE). METHODS: Samples of frontal lobe, cerebellum, and corpus callosum were obtained from the brains during autopsy of 4 HSLE patients and 5 patients who died of diseases other than cerebral diseases (controls) and underwent light microscopy and electron microscopy. Immunocytochemistry was carried out to detect the expression of myelin basic protein (MBP), caspase-3, COX-2, and CNPase protein. Apoptosis was examined by TUNEL staining. RESULTS: Widespread demyelination was seen in the white matter of the frontal lobe, cerebellum, and corpus callosum of the HSLE cases, most severely in cerebellum. In he HSLE group, the levels of caspase-3 and COX-2 expression were significantly higher, and the level of CNPase was significantly lower than those of the control group (all P < 0.05). CONCLUSION: Widespread demyelination in the white matter is a prevailing pathological change of HSLE. Oligodendrocyte apoptosis is one of the causes of HSLE. The upregulation of COX-2 and downregulation of CNPase may contribute to the pathogenesis.
Assuntos
2',3'-Nucleotídeo Cíclico Fosfodiesterases/metabolismo , Apoptose , Doença de Canavan/enzimologia , Ciclo-Oxigenase 2/metabolismo , Oligodendroglia/enzimologia , Adulto , Idoso , Doença de Canavan/induzido quimicamente , Doença de Canavan/patologia , Caspase 3/metabolismo , Feminino , Heroína , Humanos , Imuno-Histoquímica , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Oligodendroglia/patologia , Oligodendroglia/ultraestruturaRESUMO
OBJECTIVE: To investigate the characteristics of breakthrough bleeding in adult patients with severe hemophilia A (SHA) receiving low- and intermediate-dose FVIII for tertiary prophylaxis and explore the factors affecting the outcomes of the treatment. METHODS: Forty-nine patients (mean age 31.53∓7.33 years) with SHA receiving tertiary prophylaxis FVIII treatment were divided into low-dose group (n=15) and intermediate-dose group (n=34). The data including clinical bleeding phenotype (Pre?AJBR), 72 h FVIII trough activity, and Functional Independence Score in Hemophilia (FISH) were recorded in all the patients, and Hemophilia Steward APP was used to record the bleeding episode and the treatment data. All the patients were followed up for at least 6 months. RESULTS: In the low-dose and intermediate-dose groups, the number of joint bleeding (AJBR) episodes were 18.79∓13.03 and 9.28∓7.02 per year (P=0.016), and the proportions of spontaneous bleeding were 75.0% and 47.7%, respectively. The proportions of patients with target joint were 80% and 44%, target joint bleeding occurred in 59% and 41%, and cataract bleeding after 0-12 h of prophylactic injection occurred in 4.86% and 5.18% of the patients with a median breakthrough bleeding time of 40.08 h and 46.08 h (P=0.008), respectively. The proportions of patients with 72 h FVIII trough activity <1% were 44.4% and 34.8% in the two groups, respectively. AJBR was negatively correlated with the preventive dose consumed (r=-0.57, P=0.000, n=49) and FISH, but positively correlated with Pre-AJBR in the two groups (P<0.05). CONCLUSION: Tertiary prophylaxis with low- and intermediate-dose FVIII is not sufficient to achieve the goal of preventing progression of joint disease in Chinese adult patients with SHA. Although the prophylactic dose is the most important factor to affect the treatment efficacy, other non-factor approaches may also help to improve the efficacy of the treatment.
Assuntos
Fator VIII/uso terapêutico , Hemartrose/epidemiologia , Hemofilia A/tratamento farmacológico , Adulto , HumanosRESUMO
OBJECTIVE: To investigate the expressions of nestin and vascular endothehal growth factor (VEGF) mRNAs in rat brain tissue after cerebral ischemia-reperfusion injury and their changes in response to Tongxinluo (a traditional Chinese herbal preparation) treatment. METHODS: Cerebral ischemia was induced in rats by temporary middle cerebral artery occlusion (MCAO) followed by treatment with Tongxinluo at high and low doses. On days 3, 7, 14 and 21 after MCAO, nestin and VEGF mRNA expressions in the ependyma, subventricular zone (SVZ), and hippocampal subdentate gyrus zone (HDG) in the ischemic hemisphere were quantitatively analyzed using immunohistochemistry and RT-PCR. RESULTS: Compared with the sham-operated group, the rats with cerebral ischemia-reperfusion injury showed significantly increased nestin-positive neurons and VEGF mRNA expression in the SVZ and HDG 7, 14 and 21 days after MCAO (P<0.05). Treatment with Tongxinluo, especially at high doses, significantly increased the number of nestin-positive neurons and VEGF mRNA expression in the rats 7, 14 and 21 days after MCAO (P<0.05). CONCLUSION: Focal cerebral ischemia in rats results in rapid response and proliferation of neural stem cells in the SVZ and HDG in the ischemic hemisphere possibly by increasing VEGF mRNA expression in the adjacent tissues around the ischemic focus. Tongxinluo may enhance the differentiation and proliferation capacity of the neural stem cells after MCAO by inducing the expression of VEGF mRNA.
Assuntos
Isquemia Encefálica/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Proteínas de Filamentos Intermediários/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Traumatismo por Reperfusão/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Feminino , Proteínas de Filamentos Intermediários/genética , Masculino , Proteínas do Tecido Nervoso/genética , Nestina , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
OBJECTIVE: To investigate the effect of Tongxinluo in on the proliferation and differentiation of rat embryonic neural stem cells (NSCs). METHODS: NSCs were isolated from 12- to 14-day SD rat embryo and treated with Tongxinluo at different doses, and the proliferation and differentiation of the cells were observed by immunofluorescence staining at different time points. RESULTS: The ratio of embryonic NSCs labeled with nestin decreased soon after Tongxinluo treatment, but increased afterwards. Significant difference was noted in the number of cells labeled with beta-tubulin between Tongxinluo group and the control group 3 and 7 days after the treatment, and also between high-dose and low-dose Tongxinluo groups at 7 days. CONCLUSION: Tongxinluo can induce the proliferation and neuronal differentiation of rat embryonic NSCs, and the effect is related to the dose of Tongxinluo administered.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Células-Tronco Embrionárias/citologia , Neurônios/citologia , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Imunofluorescência , Masculino , Gravidez , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: To investigate nestin activation in rat brain subjected to ischemia-reperfusion injury and its changes in response to Tongxinluo treatment. METHODS: Cerebral ischemia was induced by temporary middle cerebral artery occlusion (MCAO) in rats. At 3, 7, 14 and 21 days after MCAO, nestin expression in the ependyma, subventricular zone (SVZ), hippocampal subdentate gyrus zone (HDG) of the rats treated with Tongxinluo were guantified by immunohistochemistry. RESULTS: Compared with the sham operation group, nestin was significantly increased 7, 14 and 21 days after MCAO (P<0.05), and immunofluorescence of BrdU+nestin-positive neurons significantly increased in the SVZ. After treatment with Tongxinluo, the number of BrdU-positive neurons and BrdU+nestin-positive neurons significantly increased as compared with MCAO group (P<0.05). CONCLUSION: Focal cerebral ischemia in the rat results in rapid response and proliferation of neural stem cells in the SVZ and HDG in the ischemic hemisphere, and Tongxinluo may enhance the differentiation and proliferation capacity of the neural stem cells after MCAO.