scholarly journals Gold-coated plant virus as computed tomography imaging contrast agent

2019 ◽  
Vol 10 ◽  
pp. 1983-1993 ◽  
Author(s):  
Alaa A A Aljabali ◽  
Mazhar S Al Zoubi ◽  
Khalid M Al-Batanyeh ◽  
Ali Al-Radaideh ◽  
Mohammad A Obeid ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Contrast Agent ◽  
Low Cost ◽  
Cell Types ◽  
Specific Cell ◽  
Scan Time ◽  
Ct Contrast Agent ◽  
Potential Applications ◽  
Resolution Imaging

Chemical modification of the surface of viruses, both the interior and the exterior, imparts new functionalities, that have potential applications in nanomedicine. In this study, we developed novel virus-based nanomaterials as a contrast agent for computed tomography (CT) imaging in vitro. The gold-coated cowpea mosaic virus (Au-CPMV) particles were generated by the electrostatic adsorption of positively charged electrolyte on the virus capsid with the subsequent incubation and reduction of anionic gold complexes. Au-CPMV particles as a CT contrast agent offer a fast scan time (less than 2 min), low cost, and biocompatibility and allow for high-resolution imaging with ca. 150 Hounsfield units (HU). The Au-CPMV surface was further modified allowing for the incorporation of targeting molecules of specific cell types.

scholarly journals The Stability of the Induced Epigenetic Programs

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Maria J. Barrero
Keyword(s):  
Stem Cells ◽  
Somatic Cells ◽  
Cell Types ◽  
Specific Cell ◽  
Cell Type ◽  
Pluripotent Cells ◽  
Potential Applications ◽  
The Stability

For many years scientists have been attracted to the possibility of changing cell identity. In the last decades seminal discoveries have shown that it is possible to reprogram somatic cells into pluripotent cells and even to transdifferentiate one cell type into another. In view of the potential applications that generating specific cell types in the laboratory can offer for cell-based therapies, the next important questions relate to the quality of the induced cell types. Importantly, epigenetic aberrations in reprogrammed cells have been correlated with defects in differentiation. Therefore, a look at the epigenome and understanding how different regulators can shape it appear fundamental to anticipate potential therapeutic pitfalls. This paper covers these epigenetic aspects in stem cells, differentiation, and reprogramming and discusses their importance for the safety of in vitro engineered cell types.

scholarly journals Synthesis, characterization, in vitro phantom imaging, and cytotoxicity of a novel graphene-based multimodal magnetic resonance imaging-X-ray computed tomography contrast agent

2014 ◽  
Vol 2 (22) ◽  
pp. 3519-3530 ◽  
Author(s):  
Gaurav Lalwani ◽  
Joe Livingston Sundararaj ◽  
Kenneth Schaefer ◽  
Terry Button ◽  
Balaji Sitharaman
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Contrast Agent ◽  
Resonance Imaging ◽  
X Ray ◽  
Ct Contrast Agent ◽  
X Ray Computed ◽  
Multimodal Mri ◽  
Ct Contrast

Development of a novel graphene-based multimodal MRI-CT contrast agent.

scholarly journals Gold Nanoparticles as X-Ray, CT, and Multimodal Imaging Contrast Agents: Formulation, Targeting, and Methodology

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Matthew M. Mahan ◽  
Amber L. Doiron
Keyword(s):  
Gold Nanoparticles ◽  
Contrast Agents ◽  
Soft Tissues ◽  
Low Cost ◽  
Cell Types ◽  
Surrounding Tissue ◽  
Specific Cell ◽  
Structure Property ◽  
X Ray ◽  
Scan Time

Computed tomography (CT) is among the most popular medical imaging modalities due to its high resolution images, fast scan time, low cost, and compatibility with all patients. CT scans of soft tissues require the localization of imaging contrast agents (CA) to create contrast, revealing anatomic information. Gold nanoparticles (AuNP) have attracted interest recently for their use as CT CA due to their high X-ray attenuation, simple surface chemistry, and biocompatibility. Targeting molecules may be attached to the particles to allow for the targeting of specific cell types and disease states. AuNP can also be readily designed to incorporate other imaging contrast agents such as rare earth metals and dyes. This review summarizes the current state-of-the-art knowledge in the field of AuNP used as X-ray and multimodal contrast agents. Primary research is analyzed through the lens of structure-property-function to best explain the design of a particle for a given application. Design specification of particles includes size, shape, surface functionalization, composition, circulation time, and component synergy. Key considerations include delivery of a CA payload to the site of interest, nontoxicity of particle components, and contrast enhancement compared to the surrounding tissue. Examples from literature are included to illustrate the strategies used to address design considerations.

Epithelial Organotypic Cultures: A Viable Model to Address Mechanisms of Carcinogenesis by Epitheliotropic Viruses

2018 ◽  
Vol 18 (4) ◽  
pp. 246-255 ◽  
Author(s):  
Lara Termini ◽  
Enrique Boccardo
Keyword(s):  
Three Dimensional ◽  
Cell Types ◽  
Experimental Models ◽  
Biological Research ◽  
Specific Gene ◽  
Specific Cell ◽  
Organotypic Cultures ◽  
Skin Physiology

In vitro culture of primary or established cell lines is one of the leading techniques in many areas of basic biological research. The use of pure or highly enriched cultures of specific cell types obtained from different tissues and genetics backgrounds has greatly contributed to our current understanding of normal and pathological cellular processes. Cells in culture are easily propagated generating an almost endless source of material for experimentation. Besides, they can be manipulated to achieve gene silencing, gene overexpression and genome editing turning possible the dissection of specific gene functions and signaling pathways. However, monolayer and suspension cultures of cells do not reproduce the cell type diversity, cell-cell contacts, cell-matrix interactions and differentiation pathways typical of the three-dimensional environment of tissues and organs from where they were originated. Therefore, different experimental animal models have been developed and applied to address these and other complex issues in vivo. However, these systems are costly and time consuming. Most importantly the use of animals in scientific research poses moral and ethical concerns facing a steadily increasing opposition from different sectors of the society. Therefore, there is an urgent need for the development of alternative in vitro experimental models that accurately reproduce the events observed in vivo to reduce the use of animals. Organotypic cultures combine the flexibility of traditional culture systems with the possibility of culturing different cell types in a 3D environment that reproduces both the structure and the physiology of the parental organ. Here we present a summarized description of the use of epithelial organotypic for the study of skin physiology, human papillomavirus biology and associated tumorigenesis.

scholarly journals Rho GTPases as Key Molecular Players within Intestinal Mucosa and GI Diseases

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 66
Author(s):  
Rashmita Pradhan ◽  
Phuong A. Ngo ◽  
Luz d. C. Martínez-Sánchez ◽  
Markus F. Neurath ◽  
Rocío López-Posadas
Keyword(s):  
Intestinal Mucosa ◽  
Rho Gtpases ◽  
Current Knowledge ◽  
Cell Types ◽  
Effector Proteins ◽  
Special Focus ◽  
Specific Cell ◽  
Rho Proteins

Rho proteins operate as key regulators of the cytoskeleton, cell morphology and trafficking. Acting as molecular switches, the function of Rho GTPases is determined by guanosine triphosphate (GTP)/guanosine diphosphate (GDP) exchange and their lipidation via prenylation, allowing their binding to cellular membranes and the interaction with downstream effector proteins in close proximity to the membrane. A plethora of in vitro studies demonstrate the indispensable function of Rho proteins for cytoskeleton dynamics within different cell types. However, only in the last decades we have got access to genetically modified mouse models to decipher the intricate regulation between members of the Rho family within specific cell types in the complex in vivo situation. Translationally, alterations of the expression and/or function of Rho GTPases have been associated with several pathological conditions, such as inflammation and cancer. In the context of the GI tract, the continuous crosstalk between the host and the intestinal microbiota requires a tight regulation of the complex interaction between cellular components within the intestinal tissue. Recent studies demonstrate that Rho GTPases play important roles for the maintenance of tissue homeostasis in the gut. We will summarize the current knowledge on Rho protein function within individual cell types in the intestinal mucosa in vivo, with special focus on intestinal epithelial cells and T cells.

scholarly journals Production of Human Pluripotent Stem Cell-Derived Hepatic Cell Lineages and Liver Organoids: Current Status and Potential Applications

2020 ◽  
Vol 7 (2) ◽  
pp. 36 ◽  
Author(s):  
João P. Cotovio ◽  
Tiago G. Fernandes
Keyword(s):  
Cell Types ◽  
In Vitro Models ◽  
Hepatic Cell ◽  
Current Status ◽  
Organ Shortage ◽  
Cell Lineages ◽  
Potential Applications ◽  
Liver Organoids

Liver disease is one of the leading causes of death worldwide, leading to the death of approximately 2 million people per year. Current therapies include orthotopic liver transplantation, however, donor organ shortage remains a great challenge. In addition, the development of novel therapeutics has been limited due to the lack of in vitro models that mimic in vivo liver physiology. Accordingly, hepatic cell lineages derived from human pluripotent stem cells (hPSCs) represent a promising cell source for liver cell therapy, disease modelling, and drug discovery. Moreover, the development of new culture systems bringing together the multiple liver-specific hepatic cell types triggered the development of hPSC-derived liver organoids. Therefore, these human liver-based platforms hold great potential for clinical applications. In this review, the production of the different hepatic cell lineages from hPSCs, including hepatocytes, as well as the emerging strategies to generate hPSC-derived liver organoids will be assessed, while current biomedical applications will be highlighted.

Differential susceptibilities of isolated hamster lung cell types to amiodarone toxicity

1998 ◽  
Vol 76 (7-8) ◽  
pp. 721-727 ◽  
Author(s):  
M W Bolt ◽  
W J Racz ◽  
J F Brien ◽  
T M Bray ◽  
T E Massey
Keyword(s):  
Alveolar Macrophages ◽  
Gradient Centrifugation ◽  
Cell Types ◽  
Clara Cell ◽  
Blue Dye ◽  
Alveolar Type ◽  
Specific Cell ◽  
Type Ii ◽  
Clara Cells

Treatment of cardiac dysrhythmias with the iodinated benzofuran derivative amiodarone (AM) is limited by pulmonary toxicity. The susceptibilities of different lung cell types of male Golden Syrian hamsters to AM-induced cytotoxicity were investigated in vitro. Bronchoalveolar lavage and protease digestion to release cells, followed by centrifugal elutriation and density gradient centrifugation, resulted in preparations enriched with alveolar macrophages (98%), alveolar type II cells (75-85%), and nonciliated bronchiolar epithelial (Clara) cells (35-50%). Alveolar type II cell and Clara cell preparations demonstrated decreased viability (by 0.5% trypan blue dye exclusion) when incubated with 50 µM AM for 36 h, and all AM-treated cell preparations demonstrated decreased viability when incubated with 100 or 200 µM AM. Based on a viability index ((viability of AM-treated cells ÷ viability of controls) × 100%), the Clara cell fraction was significantly (p < 0.05) more susceptible than all of the other cell types to 50 µM AM. However, AM cytotoxicity was greatest (p < 0.05) in alveolar macrophages following incubation with 100 or 200 µM AM. There was no difference between any of the enriched cell preparations in the amount of drug accumulated following 24 h of incubation with 50 µM AM, whereas alveolar macrophages accumulated the most drug during incubation with 100 µM AM. Thus, the most susceptible cell type was dependent on AM concentration. AM-induced cytotoxicity in specific cell types may initiate processes leading to inflammation and pulmonary fibrosis.Key words: amiodarone, susceptibility, alveolar macrophage, accumulation.

Abstract T P99: Development of Liposomes Loaded With Computed Tomogratphy Contrast Agent for Thrombus Imaging

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Stepan Koudelka ◽  
Petra Cimflova ◽  
Jaroslav Turanek ◽  
Robert Mikulik
Keyword(s):  
Contrast Agent ◽  
Size Distribution ◽  
Surrounding Tissue ◽  
Molar Ratio ◽  
Preparation Technology ◽  
Lipid Film ◽  
Thrombus Imaging ◽  
Novel Approach ◽  
Ct Contrast Agent

Introduction: Liposomes are the most established nanocarriers that can be loaded with contrast agents as well as tailored for targeting to the desired tissue. Targeted CT liposomes represent a novel approach for rapid thrombus imaging. They allow specific and selective accumulation in thrombus providing significant contrast enhancement (expressed as HU) over the surrounding tissue. Hypothesis: We hypothesize that preparation technology will produce homogenous liposomes with sufficient level of loaded CT contrast agent. Methods: Liposomes were composed of distearoyl phosphatidylcholine, cholesterol, and distearoyl phosphatidylethanolamine - polyethylene glycol 2000 (molar ratio, 55/45/5). CT liposomes were prepared by lipid film hydration with iohexol (Omnipaque 350, GE Healthcare) followed by freeze-thaw extrusion (100 nm). Subsequently, they were purified by dialysis (Slide-A-Lyzer, cut-off 10 kDa) to remove un-loaded ioxehol. After purification, liposome-associated iohexol was determined by UV/VIS spectrophotometry and CT. Size distribution of final CT liposomes was assessed by dynamic light scattering. Results: Preparation technology produced homogenous liposome population having appropriate size distribution (90-110 nm and PD index, 0.05-0.10). Iohexol that remains associated in final CT liposomes represented only 5% of its initial level entering the preparation process. Almost 95% of iohexol was released and its final content was found to be 5 mg iodine/ml. Conclusions: Liposomal CT formulation was prepared with satisfactory size distribution and homogenity. Although the significant portion of iohexol was released, these CT liposomes were still detectable in vitro by CT. This basic liposomal platform will be optimized to achieve higher iohexol loading and will be further developed for thrombus imaging such as targeted CT liposomes.

Temporal changes in the expression of the insulin-like growth factor II gene associated with tissue maturation in the human fetus

Development ◽  
1989 ◽  
Vol 106 (3) ◽  
pp. 543-554 ◽  
Author(s):  
A.L. Brice ◽  
J.E. Cheetham ◽  
V.N. Bolton ◽  
N.C. Hill ◽  
P.N. Schofield
Keyword(s):  
Growth Factor ◽  
Cell Types ◽  
Specific Cell ◽  
Insulin Like Growth Factor ◽  
Vitro Fertilization ◽  
Age Related ◽  
Factor Ii ◽  
Metanephric Blastema

The insulin-like growth factors are broadly distributed in the human conceptus and are thought to play a role in the growth and differentiation of tissues during development. Using in situ hybridization we have shown that a wide variety of specific cell types within tissues express the gene for insulin-like growth factor II at times of development from 18 days to 14 weeks of gestation. Examination of blastocysts produced by in vitro fertilization showed no expression, thus bracketing the time of first accumulation of IGF-II mRNA to between 5 and 18 days postfertilization. The pattern of IGF-II expression shows specific age-related differences in different tissues. In the kidney, for example, expression is found in the cells of the metanephric blastema which is dramatically reduced as the blastema differentiates. The reverse is also seen, and we have noted an increase in expression of IGF-II in the cytotrophoblast layer of the placenta with gestational age. The sites of expression do not correlate with areas of either high mitotic activity or specific types of differentiation, but the observed pattern of expression in the kidney, adrenal glands and liver suggests an explanation for the abnormally high IGF-II mRNA expression in developmental tumours such as Wilms' tumour.

Vertebrate retinal ganglion cells are selected from competent progenitors by the action of Notch

Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3637-3650 ◽  
Author(s):  
C.P. Austin ◽  
D.E. Feldman ◽  
J.A. Ida ◽  
C.L. Cepko
Keyword(s):  
Cell Fate ◽  
Ganglion Cells ◽  
Notch Pathway ◽  
Cell Types ◽  
Projection Neurons ◽  
Specific Cell ◽  
Vitro Assay ◽  
Notch Activity

The first cells generated during development of the vertebrate retina are the ganglion cells, the projection neurons of the retina. Although they are one of the most intensively studied cell types within the central nervous system, little is known of the mechanisms that determine ganglion cell fate. We demonstrate that ganglion cells are selected from a large group of competent progenitors that comprise the majority of the early embryonic retina and that differentiation within this group is regulated by Notch. Notch activity in vivo was diminished using antisense oligonucleotides or augmented using a retrovirally transduced constitutively active allele of Notch. The number of ganglion cells produced was inversely related to the level of Notch activity. In addition, the Notch ligand Delta inhibited retinal progenitors from differentiating as ganglion cells to the same degree as did activated Notch in an in vitro assay. These results suggest a conserved strategy for neurogenesis in the retina and describe a versatile in vitro and in vivo system with which to examine the action of the Notch pathway in a specific cell fate decision in a vertebrate.

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