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This study focused on the synthesis, characterization and cytocompatibility of a biodegradable polymer by the cross-linking from poly(ethylene glycol-co-lactide) dimethacrylate (PLEGDMA), polyethylene glycol diacrylate (PEGDA) and N-isopropylacrylamide, where PLEGDMA was synthesized by ring-opening oligomerization of poly(ethylene glycol) with different molecular weights (Mn = 400, 600, 1000, 2000 Da) and L-lactide using low toxic iron(III) acetylacetonate (Fe(acac)3) as the catalyst and subsequently being terminated with dimethacrylate. The product, PLEGDMA, was analyzed to confirm its chemistry using FTIR spectroscopy, (1)H NMR spectra and gel permeation chromatography etc. The thermodynamic properties, mechanical behaviors, surface hydrophilicity, degradability and cytotoxicity of the cross-linked product were evaluated by differential scanning calorimetry, tensile tests, contact angle measurements and cell cultures. The effects of reaction variables such as PEGDA content and reactants ratio were optimized to achieve a material with low glass transition temperature (Tg), high wettability and preferable mechanical characteristics. Using a tubular mould which has been patented in our group, a tubular scaffold with predetermined dimension and pattern was fabricated, which aims at guiding the growth and phenotype regulation of esophageal primary cells like fibroblast and smooth muscle cell towards fabricating tissue engineered esophagus in future.
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Materiais Biocompatíveis , Esôfago , Compostos Férricos/química , Polímeros/química , Engenharia Tecidual , Células Cultivadas , Humanos , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
The present paper's main work is firstly preparing a single layer and a large area polystyrene microspheres mask, with 117, 350 and 500 nm in diameter, and then depositing a layer of zinc oxide thin film on the mask board by RF magnetron sputtering technique, using nanospheres lithography technique to remove the polystyrene spheres by soaking with tetrahydrofuran, and two-dimensional zinc oxide nano-array samples were obtained at last. The samples were characterized on the morphology and composition by scanning electron microscopy and energy dispersive X-ray spectrometer. The results showed that the samples are zinc oxide nanocluster formed by ordered cellular reticular structures. By measuring with absorption spectroscopy in the range from 300 to 800 nm at room temperature, the absorption peak turns up with broadening and red shift with the increase in the diameter of polystyrene colloidal spheres, namely the nano-particles diameters. As the sputtering time increases, that is, the increase in the zinc oxide film thickness, the light absorption rate increases. In addition, theoretical calculation based on the theory of discrete dipole approximation was performed to simulate the optical absorption properties of the zinc oxide nanocluster arrays between 300 and 800 nm. Dipole approximation theory can be used to calculate the absorption of the particles of any shape and size. Currently, the theoretical calculation results of various shapes of nanostructured metals such as gold and silver are consist ent with the experimental results. But the application of the theory of discrete dipole approximation calculation of ZnO nanoparticles was rarely reported. In this paper, this theory has been used to calculate the optical absorption properties of triangle-shaped ZnO nanoparticles array. Light absorption characteristics were simulated according to changes in the dielectric constant and thickness of zinc oxide films, and the results can be used to explain the experimental results.
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Electrical stimulation (ES) is proposed as a therapeutic solution for managing chronic wounds. However, its widespread clinical adoption is limited by the requirement of additional extracorporeal devices to power ES-based wound dressings. In this study, a novel sandwich-structured photovoltaic microcurrent hydrogel dressing (PMH dressing) is designed for treating diabetic wounds. This innovative dressing comprises flexible organic photovoltaic (OPV) cells, a flexible micro-electro-mechanical systems (MEMS) electrode, and a multifunctional hydrogel serving as an electrode-tissue interface. The PMH dressing is engineered to administer ES, mimicking the physiological injury current occurring naturally in wounds when exposed to light; thus, facilitating wound healing. In vitro experiments are performed to validate the PMH dressing's exceptional biocompatibility and robust antibacterial properties. In vivo experiments and proteomic analysis reveal that the proposed PMH dressing significantly accelerates the healing of infected diabetic wounds by enhancing extracellular matrix regeneration, eliminating bacteria, regulating inflammatory responses, and modulating vascular functions. Therefore, the PMH dressing is a potent, versatile, and effective solution for diabetic wound care, paving the way for advancements in wireless ES wound dressings.
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Diabetes Mellitus , Hidrogéis , Humanos , Biomimética , Proteômica , Cicatrização , BandagensRESUMO
OBJECTIVE: To study the effects of ketamine anesthesia and surgery on cognition and synaptic structure in hippocampus of senile rats. METHODS: Fifty-six rats aged 18 months were randomly divided into 3 groups: Groups C (control group), A (ketamine 40 mg/kg, i.p.) and O (ketamine anesthesia & splenectomy). Morris water maze test was used to observe cognition at Days 1, 3 & 7 after ketamine anesthesia or operation respectively. Accordingly Groups A and O were divided into 3 subgroup, i.e. A1, A3, A7 and O1, O3, O7. The time of Morris water maze test was recorded and the synaptic structure was measured in the polymorphic layer of the rat hippocampal field CA3. RESULTS: Compared to Group C, the latency period and swimming distance significantly increased in Groups A1, O1 and O3 (P < 0.05), and the numbers passing the original platform decreased significantly in Groups O1 and O3 (P < 0.01). The latency period was significantly longer in Group O1 than that in Group A1 (P < 0.05) while the swimming distance was unchanged. Compared to Group C, the width of synaptic cleft (P < 0.01) increased, the length and area of postsynaptic densities (P < 0.05 or P < 0.01) as well as synaptic curvature (P < 0.01) decreased in Groups O1 and O3. The percentage of perforated synapses also decreased in Groups O1 and O3. CONCLUSION: Surgical injury can impair cognition of senile rats and the synaptic plasticity might be involved in postoperative cognitive dysfunction.
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Cognição , Hipocampo/ultraestrutura , Ketamina/farmacologia , Plasticidade Neuronal , Esplenectomia/efeitos adversos , Animais , Comportamento Animal , Modelos Animais de Doenças , Feminino , Masculino , Aprendizagem em Labirinto , Ratos , Ratos Sprague-Dawley , Estresse Fisiológico , Sinapses/ultraestruturaRESUMO
OBJECTIVE: To evaluate the efficacy of α-lipoic acid (ALA) plus epalrestat combination therapy in the treatment of diabetic peripheral neuropathy (DPN). DATA SOURCES: The electronic databases of PubMed, Medline, Embase, the Cochrane Library, the Chinese National Knowledge Infrastructure, the Wanfang Database and the Chinese Biomedical Database were used to retrieve relevant studies without language restrictions. The search was conducted from the inception of each database to 7 October 2016. The key terms were (diabetic peripheral neuropathy or diabetic neuropathy or DPN) AND (α-lipoic acid or lipoic acid or thioctic acid) AND epalrestat. DATA SELECTION: All of the eligible studies met the following inclusion criteria: (1) Randomized controlled trials that compared efficacy and safety of epalrestat plus ALA combination therapy versus epalrestat or ALA monotherapy in patients with DPN. (2) The minimum duration of treatment was 2 weeks. (3) The DPN patients were diagnosed using the World Health Organization standardized type 2 diabetes mellitus and DPN criteria. (4) Studies contained at least one measure that could reflect the efficacy of the drug and nerve conduction velocities. Studies in which the control group used epalrestat or ALA combined with other drugs were excluded. Statistical analyses were performed using STATA software for meta-analysis. OUTCOME MEASURES: The primary outcomes were the therapeutic efficacy, median motor nerve conduction velocity (MNCV), median sensory nerve conduction velocity (SNCV), peroneal MNCV and peroneal SNCV. RESULTS: Twenty studies with 1894 DPN patients were included, including 864 patients in the ALA plus epalrestat group, 473 in the ALA group and 557 in the epalrestat group. The efficacy of ALA plus epalrestat combination therapy was superior to ALA and epalrestat monotherapies (RR = 1.29, 95% CI: 1.21-1.38; RR = 1.43, 95% CI: 1.34-1.54, respectively). ALA plus epalrestat combination therapy also significantly improved median MNCV (WMD = 5.41, 95% CI: 2.07-8.75), median SNCV (WMD = 5.87, 95% CI: 1.52-10.22), peroneal MNCV (WMD = 5.59, 95% CI: 2.70-8.47) and peroneal SNCV (WMD = 4.57, 95% CI: 2.46-6.68). CONCLUSION: : ALA plus epalrestat combination therapy was superior to ALA and epalrestat monotherapies for clinical efficacy and nerve conduction velocities in patients with DPN.
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OBJECTIVE: To evaluate the surgical clinical results of hypertrophic obstructive cardiomyopathy. METHODS: We retrospectively collected data on 24 patients who underwent surgical management in the past ten years in two hospitals in China and Madras Medical Mission in India. Myomectomy was carried out on all patients. Among them 3 patients underwent mitral valve replacement; 2 patients underwent mitral valve repair (anterior mitral leaflet plication); 2 patients underwent aortic valve replacement; 1 patient underwent aortic valve repair; 2 patients underwent aortic root replacement; 1 patient underwent Bentall's procedure and 1 patient underwent coronary artery bypass grafting because of a breached muscle bridge. RESULTS: One patient died of post-operative heart failure. The mean follow-up time was 4.3 years. There was significant improvement in the symptomatic status. Sixteen patients were asymptomatic with good effort tolerance and only four patients had New York heart association (NYHA) Classes I-II due to associated valvular lesions. CONCLUSION: Our experience proved that symptomatic hypertrophic obstructive cardiomyopathy or non-symptomatic hypertrophic obstructive cardiomyopathy with combined heart disease is indication for surgery as surgical intervention could get better clinical results in this kind of patients compared with other non-surgical method because it beneficially reduces the systolic anterior motion (SAM) of the mitral valve leaflet, which could not be avoided by other non-surgical treatment.
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Procedimentos Cirúrgicos Cardíacos , Cardiomiopatia Hipertrófica/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Adolescente , Adulto , Valva Aórtica/cirurgia , Valva Aórtica/transplante , China , Ponte de Artéria Coronária , Feminino , Próteses Valvulares Cardíacas , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Valva Mitral/patologia , Valva Mitral/cirurgia , Valva Mitral/transplante , Resultado do TratamentoRESUMO
OBJECTIVE: To investigate the effects of different subtypes IFN alpha (IFN alpha2b, IFN alpha2a, and IFN alpha1b) transduction molecular STAT1, STAT2, IFNAR, PKR, and RNase L, and to study the differences of their antiviral effects and to evaluate the key signaling transduction molecules. METHODS: (1) After HepG2 cells were treated with IFN alpha2b, IFN alpha2a, or IFN alpha1b, the mRNA levels of STAT1, STAT2, IFNAR, PKR, and RNase L were detected by RT-PCR. (2) After HepG2 cells were treated with 1000 U/ml IFN alpha2b, IFN alpha2a, or IFN alpha1b, the protein expression levels of STAT1 and IFNAR were examined by Western blot. RESULTS: RT-PCR results: (1) IFNAR, STAT1, and STAT2 mRNA expression levels were slightly higher in the IFN alpha1b group than those in the IFN alpha2b group (P > 0.05). The mRNA expression levels in IFN alpha1b or IFN alpha2b groups were significantly higher than in the IFN alpha2a group (P < 0.05). (2) The PKR mRNA expression showed no significant differences among IFN alpha1b, IFN alpha2b, and IFN alpha2a groups. (3) The RNase L mRNA expression was very weak. We could not compare the differences of the RNase L mRNA levels in different groups by RT-PCR. Western blot results: (1) The IFNAR, and STAT1 protein expressions were greatly up-regulated after IFN alpha induction compared with the untreated group (P < 0.05). (2) The IFNAR, and STAT1 protein expression levels in IFN alpha1b group were slightly higher than the IFN alpha2b group. IFNAR, and STAT1 protein levels of IFN alpha1b or IFN alpha2b group were significantly higher than IFN alpha2a group (P < 0.05). CONCLUSION: STAT1, STAT2, IFNAR mRNA and protein expressions could all be markedly up-regulated after IFN alpha treatment. Effects of IFN alpha1b or IFN alpha2b were greatly stronger than IFN alpha2a. The PKR mRNA expression also was greatly up-regulated after IFN alpha treatment. Expression levels of PKR in IFN alpha1b, IFN alpha2b, and IFN alpha2a groups were all similar. The mRNA level results were consistent with the protein level results. Our results showed that the antiviral activity of IFN alpha1b or IFN alpha2b were stronger than that of IFN alpha2a. The signal transduction molecules STAT1, STAT2, and IFNAR could be regarded as a key index to evaluate antiviral activity of IFN alpha. Further confirmation is still needed to see whether PKR could be regarded as a key index.
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Antivirais/farmacologia , Interferon-alfa/farmacologia , Fator de Transcrição STAT1/biossíntese , Fator de Transcrição STAT2/biossíntese , Carcinoma Hepatocelular/virologia , Humanos , Interferon alfa-2 , Neoplasias Hepáticas/virologia , Proteínas Recombinantes , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT2/genética , Transdução de Sinais , Células Tumorais CultivadasRESUMO
OBJECTIVE: To investigate the anti-HBV effect of fusion protein thymosin alpha1-interferon alpha (TA1-IFN) in vitro and to compare its effect with a combination of interferon alpha and thymosin alpha1. METHODS: After 2.2.15 cells were seeded for 24 hours, drugs of five serial concentrations (8000, 4000, 2000, 1000, 500 U/ml) were added to the wells, then the medium was changed every three days. After 2.2.15 cells were treated with drugs for 6 days, the medium was collected. The inhibitory rates on HBsAg and HBeAg were determined using Abbot kit, and the cytotoxicity of different drugs by means of MTT colorimetric assays was also observed. RESULTS: The inhibitory rate of fusion protein on HBsAg, HBeAg was dose-dependent and reached the maximum at 8000 U/ml concentration. In the meantime, the inhibitory rates of fusion protein on HBsAg and HBeAg were 72.2% +/- 0.8% and 60.4% +/- 1.1% respectively, and the cell survival rate was 85.2% +/- 2.0%; In the corresponding concentration, the inhibitory rates of combination thymosin alpha 1 and interferon alpha on HBsAg and HBeAg were 40.0% +/- 0.7%, 34.5% +/- 3.2% respectively. The results showed significant statistical differences between them; cell survival rate 70.0% +/- 1.9%, and the difference of the results was also significant. Cytotoxicity of fusion protein was weaker than a combination of thymosin alpha 1 and interferon alpha. CONCLUSION: Fusion protein TA1-IFN exerted stronger anti-HBV effects in vitro. Its anti-HBV effects in vitro were stronger than the combination of thymosin alpha and interferon alpha, and its cytotoxicity was weaker than the combination of thymosin alpha and interferon alpha. Our studies provided important evidence for clinical research on TA1-IFN, and also brought new hope for hepatitis B therapy.
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Antivirais/farmacologia , Vírus da Hepatite B/efeitos dos fármacos , Interferon-alfa/farmacologia , Proteínas Recombinantes de Fusão/farmacologia , Timosina/farmacologia , Humanos , Interferon-alfa/biossíntese , Interferon-alfa/genética , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Timosina/biossíntese , Timosina/genéticaRESUMO
Bovine pericardium has been extensively applied as the biomaterial for artificial heart valves and may potentially be used as a scaffold for tissue-engineered heart valves after decellularization. Although various methods of decellularization are currently available, it is unknown which method is the most ideal one for the decellularization for bovine pericardium. We compared three decellularization methods, namely, the detergent and enzyme extraction (DEE), the trypsin (TS), and the Triton X-100 and sodium-deoxycholate (TSD) method, to examine their efficacy on cell removal and their preservation of the mechanical function and the tissue matrix structure. Results indicated that decellularization was achieved by all the three methods as confirmed by hematoxylin-eosin staining, scanning electron microscopy, as well as quantitative DNA measurement. However, TS and TSD methods resulted in severe structural destruction of the bovine pericardium as shown by von Gieson staining and Gomori staining. Furthermore, both TS and TSD methods changed the mechanical property of the bovine pericardium, as evidenced by a lower elastic modulus, maximal-stress, maximal-disfiguration, maximal-load, and maximal-strain. In conclusion, the DEE method achieved both a complete decellularization and preservation of the mechanical function and tissue structure of the bovine pericardium. Thus, this method is superior to either the TS or the TSD method for preparing decellularized bovine pericardium scaffold for constructing tissue-engineered heart valves.