scholarly journals Biocompatible and Enzymatically Degradable Gels for 3D Cellular Encapsulation under Extreme Compressive Strain

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 101
Author(s):  
Zain Clapacs ◽  
Sydney Neal ◽  
David Schuftan ◽  
Xiaohong Tan ◽  
Huanzhu Jiang ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Compressive Strain ◽  
Cell Encapsulation ◽  
Strain Resistance ◽  
Interpenetrating Network ◽  
Future Studies ◽  
Encapsulated Cells ◽  
High Toughness ◽  
Cellular Mechanosensing

Cell encapsulating scaffolds are necessary for the study of cellular mechanosensing of cultured cells. However, conventional scaffolds used for loading cells in bulk generally fail at low compressive strain, while hydrogels designed for high toughness and strain resistance are generally unsuitable for cell encapsulation. Here we describe an alginate/gelatin methacryloyl interpenetrating network with multiple crosslinking modes that is robust to compressive strains greater than 70%, highly biocompatible, enzymatically degradable and able to effectively transfer strain to encapsulated cells. In future studies, this gel formula may allow researchers to probe cellular mechanosensing in bulk at levels of compressive strain previously difficult to investigate.

scholarly journals Complementary techniques to analyse pericellular matrix formation by human MSC within hyaluronic acid hydrogels

2020 ◽  
Vol 1 (8) ◽  
pp. 2888-2896
Author(s):  
Christoph Salzlechner ◽  
Anders Runge Walther ◽  
Sophie Schell ◽  
Nicholas Groth Merrild ◽  
Tabasom Haghighi ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Amino Acid ◽  
Cell Encapsulation ◽  
Pericellular Matrix ◽  
Encapsulated Cells ◽  
The Matrix ◽  
Canonical Amino Acid ◽  
Confocal Raman ◽  
Complementary Techniques ◽  
Raman Spectral

Hydrogels are used widely for cell encapsulation to mimic the native ECM. Here, we characterise and visualise the matrix secreted by encapsulated cells by combining fluorescent non-canonical amino acid tagging with confocal Raman spectral imaging.

scholarly journals A Low-Cost Open Source Device for Cell Microencapsulation

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5090
Author(s):  
Miriam Salles Pereira ◽  
Liana Monteiro da Fonseca Cardoso ◽  
Tatiane Barreto da Silva ◽  
Ayla Josma Teixeira ◽  
Saul Eliahú Mizrahi ◽  
...  
Keyword(s):  
Immune System ◽  
Cell Therapy ◽  
Open Source ◽  
Low Cost ◽  
Cell Encapsulation ◽  
Host Cells ◽  
Host Immune System ◽  
Middle Income ◽  
Encapsulated Cells ◽  
Cell Microencapsulation

Microencapsulation is a widely studied cell therapy and tissue bioengineering technique, since it is capable of creating an immune-privileged site, protecting encapsulated cells from the host immune system. Several polymers have been tested, but sodium alginate is in widespread use for cell encapsulation applications, due to its low toxicity and easy manipulation. Different cell encapsulation methods have been described in the literature using pressure differences or electrostatic changes with high cost commercial devices (about 30,000 US dollars). Herein, a low-cost device (about 100 US dollars) that can be created by commercial syringes or 3D printer devices has been developed. The capsules, whose diameter is around 500 µm and can decrease or increase according to the pressure applied to the system, is able to maintain cells viable and functional. The hydrogel porosity of the capsule indicates that the immune system is not capable of destroying host cells, demonstrating that new studies can be developed for cell therapy at low cost with microencapsulation production. This device may aid pre-clinical and clinical projects in low- and middle-income countries and is lined up with open source equipment devices.

scholarly journals Particle-to-PFU Ratio of Ebola Virus Influences Disease Course and Survival in Cynomolgus Macaques

2015 ◽  
Vol 89 (13) ◽  
pp. 6773-6781 ◽  
Author(s):  
Kendra J. Alfson ◽  
Laura E. Avena ◽  
Michael W. Beadles ◽  
Hilary Staples ◽  
Jerritt W. Nunneley ◽  
...  
Keyword(s):  
Cell Culture ◽  
Ebola Virus ◽  
Disease Modeling ◽  
Cultured Cells ◽  
Plaque Assay ◽  
Cynomolgus Macaque ◽  
Case Fatality ◽  
Hemorrhagic Disease ◽  
Future Studies

ABSTRACTThis study addresses the role of Ebola virus (EBOV) specific infectivity in virulence. Filoviruses are highly lethal, enveloped, single-stranded negative-sense RNA viruses that can cause hemorrhagic fever. No approved vaccines or therapies exist for filovirus infections, and infectious virus must be handled in maximum containment. Efficacy testing of countermeasures, in addition to investigations of pathogenicity and immune response, often requires a well-characterized animal model. For EBOV, an obstacle in performing accurate disease modeling is a poor understanding of what constitutes an infectious dose in animal models. One well-recognized consequence of viral passage in cell culture is a change in specific infectivity, often measured as a particle-to-PFU ratio. Here, we report that serial passages of EBOV in cell culture resulted in a decrease in particle-to-PFU ratio. Notably, this correlated with decreased potency in a lethal cynomolgus macaque (Macaca fascicularis) model of infection; animals were infected with the same viral dose as determined by plaque assay, but animals that received more virus particles exhibited increased disease. This suggests that some particles are unable to form a plaque in a cell culture assay but are able to result in lethal diseasein vivo. These results have a significant impact on how future studies are designed to model EBOV disease and test countermeasures.IMPORTANCEEbola virus (EBOV) can cause severe hemorrhagic disease with a high case-fatality rate, and there are no approved vaccines or therapies. Specific infectivity can be considered the total number of viral particles per PFU, and its impact on disease is poorly understood. In stocks of most mammalian viruses, there are particles that are unable to complete an infectious cycle or unable to cause cell pathology in cultured cells. We asked if these particles cause disease in nonhuman primates by infecting monkeys with equal infectious doses of genetically identical stocks possessing either high or low specific infectivities. Interestingly, some particles that did not yield plaques in cell culture assays were able to result in lethal diseasein vivo. Furthermore, the number of PFU needed to induce lethal disease in animals was very low. Our results have a significant impact on how future studies are designed to model EBOV disease and test countermeasures.

Ultra-Light Photovoltaic Embedded Structures for Solar-Powered Aircrafts

2011 ◽  
Vol 311-313 ◽  
pp. 15-19
Author(s):  
Li Zhang ◽  
Lei Jiang Yao ◽  
Jing Shen Wang ◽  
Bin Li ◽  
Xiao Yan Tong
Keyword(s):  
Crystalline Silicon ◽  
Cell Model ◽  
Cell Encapsulation ◽  
Adhesively Bonded ◽  
Static Tests ◽  
Encapsulated Cells ◽  
Embedded Structure ◽  
Solar Powered ◽  
Stress And Deformation ◽  
Wing Skin

This work evaluated a new ultra-light photovoltaic embedded structure for solar-powered aircrafts, in which the mono-crystalline silicon (m-Si) solar cells encapsulated by epoxy were adhesively bonded to the upper wing skin made of rigid polyurethane foam (RPUF). To evaluate the effect on the cell encapsulation, static tests were carried out. The results showed that the encapsulated cells had better flexibility. The bonded-point and multi-cell models for the embedded structure were analyzed by FEA software. As the number of the bonded points increasing, the stress and deformation of the embedded structure decreased; once exceeded 16 points, the stress and deformation changed little. The deformation of the non-reinforced multi-cell model was very large; the stiffness improved greatly after reinforced by the glass fiber ribbons.

scholarly journals Bile Acids Enhance Invasiveness of Cryptosporidium spp. into Cultured Cells

2006 ◽  
Vol 74 (6) ◽  
pp. 3342-3346 ◽  
Author(s):  
Hanping Feng ◽  
Weijia Nie ◽  
Abhineet Sheoran ◽  
Quanshun Zhang ◽  
Saul Tzipori
Keyword(s):  
Protein Secretion ◽  
Cryptosporidium Parvum ◽  
Bile Salts ◽  
Cultured Cells ◽  
Sodium Taurocholate ◽  
Gliding Motility ◽  
Cryptosporidium Hominis ◽  
Future Studies ◽  
Cryptosporidium Spp ◽  
Host Parasite

ABSTRACT Bile salts such as sodium taurocholate (NaTC) are routinely used to induce the excystation of Cryptosporidium oocysts. Here we show that NaTC significantly enhanced the invasion of several cultured cell lines by freshly excysted Cryptosporidium parvum and Cryptosporidium hominis sporozoites. A variety of purified bile salts or total bile from bovine also enhanced the invasion of cultured cells by C. parvum. Further studies demonstrated that NaTC increased protein secretion and gliding motility of sporozoites, the key processes for successful invasion. These observations may lead to improved Cryptosporidium infectivity of cultured cells and help future studies on the host-parasite interaction.

scholarly journals An inverse-breathing encapsulation system for cell delivery

2021 ◽  
Vol 7 (20) ◽  
pp. eabd5835
Author(s):  
Long-Hai Wang ◽  
Alexander Ulrich Ernst ◽  
James Arthur Flanders ◽  
Wanjun Liu ◽  
Xi Wang ◽  
...  
Keyword(s):  
Cell Function ◽  
Waste Product ◽  
Cell Encapsulation ◽  
Permeable Membrane ◽  
Encapsulated Cells ◽  
Hypoxic Conditions ◽  
Cellular Environment ◽  
Lithium Peroxide ◽  
Potential System

Cell encapsulation represents a promising therapeutic strategy for many hormone-deficient diseases such as type 1 diabetes (T1D). However, adequate oxygenation of the encapsulated cells remains a challenge, especially in the poorly oxygenated subcutaneous site. Here, we present an encapsulation system that generates oxygen (O2) for the cells from their own waste product, carbon dioxide (CO2), in a self-regulated (i.e., “inverse breathing”) way. We leveraged a gas-solid (CO2–lithium peroxide) reaction that was completely separated from the aqueous cellular environment by a gas permeable membrane. O2 measurements and imaging validated CO2-responsive O2 release, which improved cell survival in hypoxic conditions. Simulation-guided optimization yielded a device that restored normoglycemia of immunocompetent diabetic mice for over 3 months. Furthermore, functional islets were observed in scaled-up device implants in minipigs retrieved after 2 months. This inverse breathing device provides a potential system to support long-term cell function in the clinically attractive subcutaneous site.

scholarly journals Genetic analyses in mouse fibroblast and melanoma cells demonstrate novel roles for PDGF-AB ligand and PDGF receptor alpha

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Julie L. Kadrmas ◽  
Mary C. Beckerle ◽  
Masaaki Yoshigi
Keyword(s):  
Gene Editing ◽  
Cultured Cells ◽  
Growth Factor Receptor ◽  
Mouse Fibroblast ◽  
Complete Understanding ◽  
Future Studies ◽  
Downstream Signaling ◽  
Receptor Interactions ◽  
Rapid Formation ◽  
Pdgfr Beta

Abstract Platelet Derived Growth Factor Receptor (PDGFR) signaling is a central mitogenic pathway in development, as well as tissue repair and homeostasis. The rules governing the binding of PDGF ligand to the receptor to produce activation and downstream signaling have been well defined over the last several decades. In cultured cells after a period of serum deprivation, treatment with PDGF leads to the rapid formation of dramatic, actin-rich Circular Dorsal Ruffles (CDRs). Using CDRs as a robust visual readout of early PDGFR signaling, we have identified several contradictory elements in the widely accepted model of PDGF activity. Employing CRISPR/Cas9 gene editing to disrupt the Pdgfra gene in two different murine cell lines, we show that in addition to the widely accepted function for PDGFR-beta in CDR formation, PDGFR-alpha is also clearly capable of eliciting CDRs. Moreover, we demonstrate activity for heterodimeric PDGF-AB ligand in the vigorous activation of PDGFR-beta homodimers to produce CDRs. These findings are key to a more complete understanding of PDGF ligand-receptor interactions and their downstream signaling consequences. This knowledge will allow for more rigorous experimental design in future studies of PDGFR signaling and its contributions to development and disease.

scholarly journals First Evaluation of Field Evolved Resistance to Commonly Used Insecticides in House Fly Populations from Saudi Arabian Dairy Farms

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1120
Author(s):  
Abdulwahab M. Hafez
Keyword(s):  
Public Health ◽  
Dairy Farms ◽  
House Fly ◽  
Susceptible Strain ◽  
Integrated Vector Management ◽  
Strain Resistance ◽  
Future Studies ◽  
Vector Management ◽  
Moderate Resistance ◽  
Fly Control

The house fly, Musca domestica L. (Diptera: Muscidae), is one of the major vectors of several pathogens that affect humans and animals. We evaluated the toxicity of eight insecticides commonly used for house fly control using five field populations collected from dairies in Riyadh, Saudi Arabia. Among the five tested pyrethroids, non to moderate resistance was found in adults of both sexes compared to a susceptible strain. Resistance ratios ranged from 0.5- to 7-fold for alpha-cypermethrin, 2- to 21-fold for deltamethrin, 4- to 19-fold for bifenthrin, 1- to 9-fold for cyfluthrin, and 1- to 8-fold for cypermethrin. Among the three tested organophosphates, low to moderate resistance was found among adult flies compared to the susceptible strain, and the resistance ratios ranged from 4- to 27-fold for fenitrothion, 2- to 14-fold for chlorpyrifos, and 3- to 12-fold for malathion. The median lethal times for the tested insecticides were 3–33 h for alpha-cypermethrin, 3–24 h for deltamethrin, 5–59 h for bifenthrin, 1–7 h for cypermethrin, 0.3–7 h for cyfluthrin, 6–36 h for fenitrothion, 2–21 h for chlorpyrifos, and 3–34 h for malathion. This study presents baseline data pertaining to registered public health insecticides, and the results will assist future studies monitoring insecticide resistance, and the planning of effective integrated vector management programs.

scholarly journals Assessment of viability of wharton's jelly mesenchymal stem cells encapsulated in alginate scaffold by WST-8 assay kit

2021 ◽  
Vol 9 (1) ◽  
pp. 42-47
Author(s):  
Zeinab Shafiei Seifabadi ◽  
Fatemeh Rezaei-Tazangi ◽  
Nastaran Azarbarz ◽  
Darioush Bijan Nejad ◽  
Javad Mohammadiasl ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Viability ◽  
Biomedical Applications ◽  
Cell Encapsulation ◽  
Fast Method ◽  
Encapsulated Cells ◽  
Long Time ◽  
Favorable Conditions ◽  
Alginate Scaffold

Abstract Cell encapsulation utilizing biodegradable material has promising outcomes for tissue engineering. From a long time ago, alginate has been generally utilized for drug delivery, cell transplantation and as a scaffold in biomedical applications. The aim of this study was the comparison of cell viability in the presence of two polymerizing ions: Ba2+ and Ca2+ to improvement the quality of alginate scaffold. For this purpose, WJMSCs after three passage were encapsulated in alginate scaffold in the presence of Ba2+ and ca2+. Cell viability was evaluated by WST-8 assay kit after 24, 48 and 72 hours. The results showed that encapsulated cells in the presence of Ca2+ had more viability than Ba2+. It was also found that using the WST-8 assay kit is a convenient and fast method for evaluation the viability of cells. It can be claimed that Calcl2 polymerizing solution provides more favorable conditions for cell viability compared to Bacl2 solution. Running title: Assessing the viability of stem cells by WST-8 assay kit

scholarly journals Self-healing, stretchable and robust interpenetrating network hydrogels

2018 ◽  
Vol 6 (11) ◽  
pp. 2932-2937 ◽  
Author(s):  
Laura J. Macdougall ◽  
Maria M. Pérez-Madrigal ◽  
Joshua E. Shaw ◽  
Maria Inam ◽  
Judith A. Hoyland ◽  
...  
Keyword(s):  
Cell Encapsulation ◽  
Self Healing ◽  
Network Approach ◽  
Natural Polymers ◽  
Interpenetrating Network ◽  
Hydrogel Network

A self-healable, mechanically strong and stretchable hydrogel network that supports cell encapsulation is reported to be achieved by creation of an interpenetrating network approach between PEG and natural polymers.

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