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High Cell Viability (high + cell_viability)

Distribution by Scientific Domains

Polymers and Materials Science	60%
Medical Sciences	40%

Selected Abstracts

Cytotoxicity and Cell Cycle Effects of Bare and Poly(vinyl alcohol)-Coated Iron Oxide Nanoparticles in Mouse Fibroblasts

ADVANCED ENGINEERING MATERIALS, Issue 12 2009
Morteza Mahmoudi
Super-paramagnetic iron oxide nanoparticles (SPIONs) are recognized as powerful biocompatible materials for use in various biomedical applications, such as drug delivery, magnetic-resonance imaging, cell/protein separation, hyperthermia and transfection. This study investigates the impact of high concentrations of SPIONs on cytotoxicity and cell-cycle effects. The interactions of surface-saturated (via interactions with cell medium) bare SPIONs and those coated with poly(vinyl alcohol) (PVA) with adhesive mouse fibroblast cells (L929) are investigated using an MTT assay. The two SPION formulations are synthesized using a co-precipitation method. The bare and coated magnetic nanoparticles with passivated surfaces both result in changes in cell morphology, possibly due to clustering through their magnetostatic effect. At concentrations ranging up to 80,×,10,3,M, cells exposed to the PVA-coated nanoparticles demonstrate high cell viability without necrosis and apoptosis. In contrast, significant apoptosis is observed in cells exposed to bare SPIONs at a concentration of 80,×,10,3,M. Nanoparticle exposure (20,80,×,10,3,M) leads to variations in both apoptosis and cell cycle, possibly due to irreversible DNA damage and repair of oxidative DNA lesions, respectively. Additionally, the formation of vacuoles within the cells and granular cells indicates autophagy cell death rather than either apoptosis or necrosis. [source]

Highly Extensible Bio-Nanocomposite Films with Direction-Dependent Properties

ADVANCED FUNCTIONAL MATERIALS, Issue 3 2010
Akhilesh K. Gaharwar
Abstract The structure and mechanical properties of bio-nanocomposite films made from poly(ethylene oxide) (PEO) that is physically cross-linked with silicate nanoparticles, Laponite, are investigated. Direction-dependent mechanical properties of the films are presented, and the effect of shear orientation during sample preparation on tensile strength and elongation is assessed. Repeated mechanical deformation results in highly extensible materials with preferred orientation and structuring at the nano- and micrometer scales. Additionally, in vitro biocompatibility data are reported, and NIH 3T3 fibroblasts are observed to readily adhere and proliferate on silicate cross-linked PEO while maintaining high cell viability. [source]

Controlled size chitosan nanoparticles as an efficient, biocompatible oligonucleotides delivery system

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010
Romila Manchanda
Abstract Polymeric nanoparticles of chitosan crosslinked with glutaraldehyde have been prepared using reverse micellar system. An optically clear solution was obtained on redispersing these nanoparticles in aqueous buffer. The nanoparticles were characterized for their size and surface morphology employing dynamic laser scattering (DLS) and transmission electron microscopy (TEM). The TEM images showed spherical particles with smooth surface and narrow size distribution of about 90 nm, which was also supported by DLS data. Size and morphology of the particles remains the same on redispersing the lyophilized powder of these nanoparticles in aqueous buffer. Further, these nanoparticles were loaded with different synthetic oligonucleotides (ODNs). In vitro pH dependent release of the adsorbed oligonucleotides from these nanoparticles was also studied. At basic pH the release of oligonucleotides was found higher as compared with neutral and acidic medium. Cytotoxicity studies done on HEK 293 cells reveals that oligonucleotide loaded nanoparticles have high cell viability of nearly 76,88% whereas those of lipofectamine was about 35%. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Optimization of magnetosonoporation for stem cell labeling

NMR IN BIOMEDICINE, Issue 5 2010
Daohai Xie
Abstract Recent advances in magnetic cell labeling have taken place with the development of a magnetosonoporation (MSP) technique. The aim of this study was to optimize the MSP protocol in order to achieve high cell viability and intracellular uptake of MR contrast agents. First, we determined the sub-optimal MSP parameters by evaluating the viabilities of C17.2 neural stem cells without Feridex using various MSP intensities ranging from 0.1 to 1,w/cm2, duty cycles at 20%, 50% or 100%, and exposure times from 1,15,min. The sub-optimized MSP parameters with cell viabilities greater than 90% were further optimized by evaluating both cell viability and intracellular iron uptake when Feridex was used. We then used the optimized MSP parameters to determinate the optimal concentration of Feridex for magnetic cell labeling. Subsequently, we validated the feasibility of using MRI to track the migration of neural stem cells from the transplanted sites to glioma masses in four mouse brains when the cells had been labeled with Feridex using the optimized MSP protocol. The MRI findings were confirmed by histological correlations. Invitro experiments demonstrated that the optimal MSP protocol was achieved at 20% duty cycle, 0.3,w/cm2 ultrasound intensity, 5-min exposure time and 1mg/mL Feridex. This study demonstrated that the optimized MSP cell labeling technique can achieve both high cell viability and intracellular uptake of MR contrast agents, and has the potential to be a useful cell labeling technique to facilitate future clinical translation of MRI-integrated cell therapy. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Bone Marrow Mesenchymal Stem Cells Form Ectopic Woven Bone In Vivo Through Endochondral Bone Formation

ARTIFICIAL ORGANS, Issue 4 2009
Sophia Chia-Ning Chang
Abstract:, Autologous vascularized bone grafts, allografts, and biocompatible artificial bone substitutes each have their shortcomings. Bones regenerated using recombinant human bone morphogenetic proteins, demineralized bone powder, or combinations of these are generally small and do not meet the need. The current trend is to use tissue engineering approaches with bone marrow mesenchymal stem cells (MSCs) to generate bones of a desired size and shape. A suspension of osteogenically induced MSCs (CD11a,, CD29+, CD44+) was added to 2% alginate, gelled by mixing this combination with calcium sulfate (CaSO4 0.2 g/mL), and injected into the subcutaneous pocket in the dorsal aspect of nude mice. Cells of various concentrations (0, 10, 50, and 70 million/mL) were used. These implanted constructs were harvested at predetermined times up to 30 weeks for histology. The doubling time of bovine MSCs is 3.75 ± 1.96 days and the proliferation is rapid. Histological evaluation revealed signs of endochondrosis with woven bone deposition. The equilibrium modulus increased with time in vivo, though less than that of normal tissue. Implants seeded with 70 million cells/mL for 6 months resulted in the best formation of equilibrium modulus. This approach has several advantages: (i) obtaining MSCs is associated with low donor morbidity; (ii) MSCs proliferate rapidly in vitro, and a large number of viable cells can be obtained; and (iii) the MSC/alginate constructs can develop into bone-like nodules with high cell viability. Such a system may be useful in large-scale production of bony implants or in the repair of bony defects. The fact that endochondral bone formation led to woven bone suggests its potential feasibility in regional cell therapy. [source]