scholarly journals Engineering Biomimetic Gelatin Based Nanostructures as Synthetic Substrates for Cell Culture

2019 ◽  
Vol 9 (8) ◽  
pp. 1583
Author(s):  
Shaleena K. Pazhanimala ◽  
Driton Vllasaliu ◽  
Bahijja T. Raimi-Abraham
Keyword(s):  
Cell Proliferation ◽  
Fiber Diameter ◽  
Cost Effective ◽  
Solvent System ◽  
Attenuated Total Reflection ◽  
Force Microscopy ◽  
Membrane Topography ◽  
Nanofibrous Scaffolds ◽  
A Cell

There is a need for synthetic substrates that replicate the natural environment for in vitro intestinal models. Electrospinning is one of the most versatile and cost-effective techniques to produce nanofibrous scaffolds mimicking the basement membrane topography. In this study, three different novel electrospun nanofibrous scaffolds made of a polycaprolactone (PCL), gelatin, and poloxamer 188 (P188) blend were produced and compared with PCL and PCL/gelatin fibers produced using the same solvent system and electrospinning parameters. Each polymer solution used in this experiment was electrospun at four different voltages to study its influence on fiber diameter. The morphology and physical characteristics of the fibers were studied using scanning electron microscopy and atomic force microscopy. The average fiber diameter of all scaffolds was within 200–600 nm and no significant decrease in diameter with an increase in voltage was observed. Attenuated total reflection Fourier transform infrared spectroscopy was used to determine the chemical characteristics of the nanofibrous scaffold. The conductivity of the polymer solutions was also analyzed. Biocompatibility of the scaffolds was determined by a cell proliferation study performed using colorectal carcinoma (Caco-2) cells. PCL/gelatin/P188 scaffolds exhibited higher cell proliferation compared to PCL, PCL/gelatin scaffolds, and the control (tissue culture multi-well plate) with PCL/gelatin/P188 80:10:10 sample showing the highest cell proliferation.

scholarly journals In Vitro Assessment of Synthetic Nano Engineered Graft Designed for Further Clinical Study in Nerve Regeneration

2018 ◽  
Vol 5 (3) ◽  
pp. 86-91
Author(s):  
Ali Sadeghi ◽  
Fatholah Moztarzadeh ◽  
Jamshid Aghazadeh Mohandesi ◽  
Claudia Grothe ◽  
Kirsten Haastert Talini ◽  
...  
Keyword(s):  
Cell Attachment ◽  
Fiber Diameter ◽  
Solvent System ◽  
Neural Cell ◽  
Neural Regeneration ◽  
Nanofibrous Scaffolds ◽  
Composition Modification ◽  
Chitosan Fiber ◽  
Surface Modified

Background: Electrospun nanofibrous scaffolds are considered as promising candidates in neural tissue regeneration due to their ability to support neural cell attachment, spreading and proliferation. Methods: In this paper, various type of nanofibers scaffold based on polycaprolactone) (PCL) were fabricated using electrospinning. The main drawback of PCL scaffolds is their low bioactivity of scaffold surface. To overcome this surface and composition modification was used to enhanced hydrophilicity and bioactivity of scaffold. Results: The scanning electron microscopy (SEM) results indicate that fiber diameter entirely depends on the solvent system and added component of gelatin and chitosan which by adding gelatin and chitosan fiber diameter decreased. In vitro studies using PC12 cells revealed that the plasma surface modified and blended scaffold with chitosan and gelatin nanofibrous scaffold supports cell attachment, spreading and indicate a significant increase in proliferation of PC12 in the presence of chitosan. The results demonstrated that gelatin and chitosan caused a significant enhancement in the bioactivity of the scaffold, which confirmed by MTT assay and improved the cell spreading and proliferation of neural cell on the scaffolds. Conclusion: Based on the experimental results, the PCL/chitosan/PPy conductive substrate could be used as a potential scaffold for clinical research in the field of neural regeneration and healing.

scholarly journals Deficiency of G9a Inhibits Cell Proliferation and Activates Autophagy via Transcriptionally Regulating c-Myc Expression in Glioblastoma

2020 ◽  
Vol 8 ◽  
Author(s):  
Xiao Xue Ke ◽  
Rui Zhang ◽  
Xi Zhong ◽  
Lei Zhang ◽  
Hongjuan Cui
Keyword(s):  
Cell Proliferation ◽  
Cyclin B1 ◽  
Luciferase Reporter ◽  
Cycle Arrest ◽  
Histone Lysine Methyltransferase ◽  
Lysine Methyltransferase ◽  
A Cell ◽  
Cell Proliferation Control

Glioblastoma is an aggressive and difficult to treat cancer. Recent data have emerged implicating that histone modification level may play a crucial role in glioma genesis. The histone lysine methyltransferase G9a is mainly responsible for the mono- and di-methylation of histone H3 lysine 9 (H3K9), whose overexpression is associated with a more aggressive phenotype in cancer. However, the detailed correlations between G9a and glioblastoma genesis remain to be further elucidated. Here, we show that G9a is essential for glioblastoma carcinogenesis and reveal a probable mechanism of it in cell proliferation control. We found that G9a was highly expressed in glioblastoma cells, and knockdown or inhibition of G9a significantly repressed cell proliferation and tumorigenesis ability both in vitro and in vivo. Besides, knockdown or inhibition of G9a led to a cell cycle arrest in G2 phase, as well as decreased the expression of CDK1, CDK2, Cyclin A2, and Cyclin B1, while it induced the activation of autophagy. Further investigation showed that G9a deficiency induced cell proliferation suppression, and activation of autophagy was rescued by overexpression of the full-length c-Myc. Chromatin immunoprecipitation (ChIP) assay showed that G9a was enriched on the −2267 to −1949 region of the c-Myc promoter in LN-229 cells and the −1949 to −1630 region of the c-Myc promoter in U-87 MG cells. Dual-luciferase reporter assay showed that c-Myc promoter activity was significantly reduced after knockdown or inhibition of G9a. Our study shows that G9a controls glioblastoma cell proliferation by transcriptionally modulating oncogene c-Myc and provides insight into the capabilities of G9a working as a potential therapeutic target in glioblastoma.

scholarly journals PTP4A3, A Novel Target Gene of HIF-1alpha, Participates in Benzene-Induced Cell Proliferation Inhibition and Apoptosis through PI3K/AKT Pathway

2020 ◽  
Vol 17 (3) ◽  
pp. 910
Author(s):  
Yunqiu Pu ◽  
Fengxia Sun ◽  
Rongli Sun ◽  
Zhaodi Man ◽  
Shuangbin Ji ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Target Gene ◽  
Akt Pathway ◽  
Proliferation Inhibition ◽  
Cell Proliferation Inhibition ◽  
A Cell ◽  
Novel Target ◽  
In Cells

Benzene, a commonly used chemical, has been confirmed to specifically affect the hematopoietic system as well as overall human health. PTP4A3 is overexpressed in leukemia cells and is related to cell proliferation. We previously found that HIF-1alpha was involved in benzene toxicity and PTP4A3 may be the target gene of HIF-1alpha via ChIP-seq. The aim of this study is to confirm the relationship between HIF-1alpha and PTP4A3 in benzene toxicity, as well as the function of PTP4A3 on cell toxicity induced by 1,4-benzoquinone (1,4-BQ). Our results indicate that HIF-1alpha could regulate PTP4A3 with in vivo and in vitro experiments. A cell line with suppressed PTP4A3 was established to investigate the function of PTP4A3 in 1,4-BQ toxicity in vitro. The results revealed that cell proliferation inhibition was more aggravated in PTP4A3 low-expression cells than in the control cells after 1,4-BQ treatment. The relative oxygen species (ROS) significantly increased in cells with inhibited PTP4A3, while the rise was inferior to the control cells at the 20 μM 1,4-BQ group. An increase in DNA damage was seen in PTP4A3 down-regulated cells at the 10 μM 1,4-BQ group, whereas the results reversed at the concentration of 20 μM. Moreover, the apoptosis rate increased higher in down-regulated PTP4A3 cells after 1,4-BQ exposure. In addition, PI3K/AKT pathway was significantly restrained in cells with inhibited PTP4A3 after 1,4-BQ treatment. Our results indicate that HIF-1alpha may regulate PTP4A3 to be involved in benzene toxicity. Inhibition of PTP4A3 could aggravate cell proliferation suppression and apoptosis by regulating PI3K/AKT pathway after 1,4-BQ treatment.

scholarly journals Cortical Spheroid Model for Studying the Effects of Ischemic Brain Injury

2021 ◽  
Author(s):  
Rachel M McLaughlin ◽  
Amanda Laguna ◽  
Ilayda Top ◽  
Christien Hernadez ◽  
Liane L Livi ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Three Dimensional ◽  
Cost Effective ◽  
Glucose Deprivation ◽  
In Vitro Models ◽  
3D Architecture ◽  
A Cell ◽  
Antioxidant Agent

Stroke is a devastating neurological disorder and a leading cause of death and long-term disability. Despite many decades of research, there are still very few therapeutic options for patients suffering from stroke or its consequences. This is partially due to the limitations of current research models, including traditional in vitro models which lack the three-dimensional (3D) architecture and cellular make-up of the in vivo brain. 3D spheroids derived from primary postnatal rat cortex provide an in vivo-relevant model containing a similar cellular composition to the native cortex and a cell-synthesized extracellular matrix. These spheroids are cost-effective, highly reproducible, and can be produced in a high-throughput manner, making this model an ideal candidate for screening potential therapeutics. To study the cellular and molecular mechanisms of stroke in this model, spheroids were deprived of glucose, oxygen, or both oxygen and glucose for 24 hours. Both oxygen and oxygen-glucose deprived spheroids demonstrated many of the hallmarks of stroke, including a decrease in metabolism, an increase in neural dysfunction, and an increase in reactive astrocytes. Pretreatment of spheroids with the antioxidant agent N-acetylcysteine (NAC) mitigated the decrease in ATP seen after 24 hours of oxygen-glucose deprivation. Together, these results show the utility of our 3D cortical spheroid model for studying ischemic injury and its potential for screening stroke therapeutics.

scholarly journals Vinorelbine Augments Radiotherapy in Hepatocellular Carcinoma

Cancers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 872 ◽  
Author(s):  
Kheng Wei Yeoh ◽  
Aldo Prawira ◽  
Muhammad Zafrie Bin Saad ◽  
Kok Ming Lee ◽  
Eric Ming Hon Lee ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Dna Repair ◽  
Tumor Growth ◽  
Cost Effective ◽  
Survival Fraction ◽  
Conventional Radiotherapy ◽  
Early Phase Clinical Trials ◽  
Radio Sensitivity

There is a need to improve the effectiveness of radiotherapy (RT) in hepatocellular carcinoma (HCC). Therefore, the purpose of this study was to explore the efficacy and toxicity of the anti-microtubule agent Vinorelbine as a radiosensitizer in HCC. The radio sensitivity of 16 HCC patient-derived xenograft (PDX) models was determined by quantifying the survival fraction following irradiation in vitro, and Vinorelbine radio sensitization was determined by clonogenic assay. Ectopic HCC xenografts were treated with a single dose of 8 Gy irradiation and twice-weekly 3 mg/kg Vinorelbine. Tumor growth and changes in the proteins involved in DNA repair, angiogenesis, tumor cell proliferation, and survival were assessed, and the 3/16 (18.75%), 7/16 (43.75%), and 6/16 (37.5%) HCC lines were classified as sensitive, moderately sensitive, and resistant, respectively. The combination of RT and Vinorelbine significantly inhibited tumor growth, DNA repair proteins, angiogenesis, and cell proliferation, and promoted more apoptosis compared with RT or Vinorelbine treatment alone. Vinorelbine improved HCC tumor response to standard irradiation with no increase in toxicity. HCC is prevalent in less developed parts of the world and is mostly unresectable on presentation. Vinorelbine and conventional radiotherapy are cost-effective, well-established modalities of cancer treatment that are readily available. Therefore, this strategy can potentially address an unmet clinical need, warranting further investigation in early-phase clinical trials.

Tie2 Activation Promotes Protection and Reconstitution of the Endothelial Glycocalyx in Human Sepsis

2019 ◽  
Vol 119 (11) ◽  
pp. 1827-1838 ◽  
Author(s):  
Carolin Christina Drost ◽  
Alexandros Rovas ◽  
Kristina Kusche-Vihrog ◽  
Paul Van Slyke ◽  
Harold Kim ◽  
...  
Keyword(s):  
Heparan Sulfate ◽  
Boundary Region ◽  
Endothelial Glycocalyx ◽  
Human Sepsis ◽  
Force Microscopy ◽  
Control Serum ◽  
A Cell ◽  
Angiopoietin 2

AbstractThe endothelial glycocalyx (eGC), a carbohydrate-rich layer lining the luminal surface of the endothelium, provides a first vasoprotective barrier against vascular leakage in sepsis. We hypothesized that angiopoietin-2 (Angpt-2), antagonist of the endothelium-stabilizing receptor Tie2, induces a rapid loss of the eGC in human sepsis. Using intravital microscopy, we measured the perfused boundary region (PBR), an inverse parameter of eGC dimensions in sublingual microvessels, in patients with sepsis and age-matched nonseptic subjects. Median PBR values were significantly higher in patients compared with controls and correlated with serum Angpt-2 levels. To transfer and further explore these findings in a cell culture system, we exposed endothelial cells (ECs) to serum (5%) from a subgroup of septic patients and nonseptic controls. Confocal and atomic force microscopy revealed that sepsis serum, but not control serum, induced thinning of the eGC on human ECs in vitro, which correlated with paired PBR values obtained in vivo (r = 0.96, p < 0.01). Inhibition of Angpt-2 or Tie2 activation completely abolished eGC damage. Mechanistically, sepsis-induced eGC breakdown required the loss of its main constituent heparan sulfate; a result of heparan sulfate-specific enzyme heparanase, which was suppressed by Tie2 activation. Finally, Tie2 activation, but not Angpt-2 inhibition, initiated after septic or enzymatic damage provoked rapid refurbishment of the eGC. Our data indicate that eGC breakdown in human sepsis is mediated via Tie2 deactivation by Angpt-2. Activation of Tie2 seems to accelerate recovery of the eGC and might hold promise as a therapeutic target in human sepsis.

Electrospun hybrid nanofibrous meshes with adjustable performance for potential use in soft tissue engineering

2021 ◽  
pp. 004051752110639
Author(s):  
Ye Qi ◽  
Huiyuan Zhai ◽  
Yaning Sun ◽  
Hongxing Xu ◽  
Shaohua Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Soft Tissue ◽  
Fiber Diameter ◽  
Fiber Morphology ◽  
Surface Hydrophilicity ◽  
Nanofibrous Scaffolds ◽  
Soft Tissue Engineering ◽  
The Mean

Electrospun nanofibrous scaffolds have gained extensive attention in the fields of soft tissue engineering and regenerative medicine. In this study, a series of biodegradable nanofibrous meshes were fabricated by electrospinning poly(ε-caprolactone) (PCL) and poly( p-dioxanone) (PPDO) blends with various mass ratios. All the as-developed PCL/PPDO nanofibrous meshes possessed smooth and highly aligned fiber morphology. The mean fiber diameter was 521.5 ± 76.6 nm for PCL meshes and 485.8 ± 88.9 nm for PPDO meshes, and the mean fiber diameter seemed to present a decreasing tendency with the increasing of the PPDO component. For pure PCL meshes, the contact angle was about 117.5 ± 1.6°, the weight loss ratio was roughly 0.2% after 10 weeks of degradation, and the tensile strength was 41.2 ± 2.3 MPa in the longitudinal direction and 4.2 ± 0.1 MPa in the transverse direction. It was found that the surface hydrophilicity and in vitro degradation properties of PCL/PPDO meshes apparently increased, but the mechanical properties of PCL/PPDO meshes obviously decreased when more PPDO component was introduced. The biological tests showed that 4:1 PCL/PPDO nanofibrous meshes and 1:1 PCL/PPDO nanofibrous meshes could obviously promote the adhesion and proliferation of human adipose derived mesenchymal stem cells more than pure PCL and PPDO meshes and 1:4 PCL/PPDO meshes. The results demonstrated that it is feasible to adjust the surface hydrophilicity, degradation profile, and mechanical properties as well as biological properties of as-obtained nanofibrous meshes by blending PCL and PPDO components. This study provides meaningful reference and guidance for the design and development of PCL/PPDO hybrid nanofibrous scaffolds for soft tissue engineering research and application.

scholarly journals Effects of Chitosan Concentration on the Protein Release Behaviour of Electrospun Poly(ε-caprolactone)/Chitosan Nanofibers

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Fatemeh Roozbahani ◽  
Naznin Sultana ◽  
Davood Almasi ◽  
Farnaz Naghizadeh
Keyword(s):  
Fiber Diameter ◽  
Morphological Characteristics ◽  
Solvent System ◽  
Release Profile ◽  
Average Fiber Diameter ◽  
Blend Ratio ◽  
Chitosan Concentration ◽  
Nanofibrous Scaffolds ◽  
Model Protein ◽  
Scanning Electron

Poly(ε-caprolactone)/chitosan (PCL/chitosan) blend nanofibers with different ratios of chitosan were electrospun from a formic acid/acetic acid (FA/AA) solvent system. Bovine serum albumin (BSA) was used as a model protein to incorporate biochemical cues into the nanofibrous scaffolds. The morphological characteristics of PCL/chitosan and PCL/chitosan/BSA Nanofibers were investigated by scanning electron microscopy (SEM). Fourier transform infrared spectroscopy (FTIR) was used to detect the presence of polymeric ingredients and BSA in the Nanofibers. The effects of the polymer blend ratio and BSA concentration on the morphological characteristics and consequently on the BSA release pattern were evaluated. The average fiber diameter and pore size were greater in Nanofibers containing BSA. The chitosan ratio played a significant role in the BSA release profile from the PCL/chitosan/BSA blend. Nanofibrous scaffolds with higher chitosan ratios exhibited less intense bursts in the BSA release profile.

scholarly journals Towards a generic prototyping approach for therapeutically-relevant peptides and proteins in a cell-free translation system

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Yue Wu ◽  
Zhenling Cui ◽  
Yen-Hua Huang ◽  
Simon J. de Veer ◽  
Andrey V. Aralov ◽  
...  
Keyword(s):  
Interaction Analysis ◽  
Cost Effective ◽  
In Vitro Translation ◽  
Translation System ◽  
Activity Assessment ◽  
Free Translation ◽  
Macrocyclic Peptides ◽  
A Cell ◽  
Translation Systems

AbstractAdvances in peptide and protein therapeutics increased the need for rapid and cost-effective polypeptide prototyping. While in vitro translation systems are well suited for fast and multiplexed polypeptide prototyping, they suffer from misfolding, aggregation and disulfide-bond scrambling of the translated products. Here we propose that efficient folding of in vitro produced disulfide-rich peptides and proteins can be achieved if performed in an aggregation-free and thermodynamically controlled folding environment. To this end, we modify an E. coli-based in vitro translation system to allow co-translational capture of translated products by affinity matrix. This process reduces protein aggregation and enables productive oxidative folding and recycling of misfolded states under thermodynamic control. In this study we show that the developed approach is likely to be generally applicable for prototyping of a wide variety of disulfide-constrained peptides, macrocyclic peptides with non-native bonds and antibody fragments in amounts sufficient for interaction analysis and biological activity assessment.

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