Search results for "Culture Techniques"
showing 10 items of 504 documents
Influence of polymer content in Ca-deficient hydroxyapatite–polycaprolactone nanocomposites on the formation of microvessel-like structures
2009
Calcium phosphate (CaP) ceramics are widely used in bone tissue engineering due to their good osteoconductivity. The mechanical properties of CaP can be modified by the addition of small volume fractions of biodegradable polymers such as polycaprolactone (PCL). Nevertheless, it is also important to evaluate how the polymer content influences cell-material or cell-cell interactions because of potential consequences for bone regeneration and vascularization. In this study we assessed the general biocompatibilty of Ca-deficient hydroxyapatite (CDHA)-PCL disks containing nominally 11 and 24% polycaprolactone using human umbilical vein endothelial cells and human primary osteoblasts. Confocal mi…
Vascularization and gene regulation of human endothelial cells growing on porous polyethersulfone (PES) hollow fiber membranes.
2004
Abstract Open-cell hollow fibers made of polyethersulfone (PES) manufactured in the absence of solvents with pore diameters smaller than 100 μm were examined for vascularization by human endothelial cells. The goal of this study was to determine whether the 3-D porous character of the PES surface affected human endothelial cell morphology and functions. Freshly isolated human endothelial cells from the skin (HDMEC), from the lung (HPMEC) and from umbilical cords (HUVEC) and two human endothelial cell lines, HPMEC-ST1.6R and ISO-HAS.c1 were added to PES fibers and cell adherence and growth was followed by confocal laser scanning microscopy. Prior coating of PES with gelatin or fibronectin wa…
Response of human endothelial cells to oxidative stress on Ti6Al4V alloy.
2007
Titanium and its alloys are amongst the most frequently used materials in bone and dental implantology. The good biocompatibility of titanium(-alloys) is attributed to the formation of a titanium oxide layer on the implant surface. However, implant failures do occur and this appears to be due to titanium corrosion. Thus, cells participating in the wound healing processes around an implanted material, among them endothelial cells, might be subjected to reactive oxygen species (ROS) formed by electrochemical processes during titanium corrosion. Therefore, we studied the response of endothelial cells grown on Ti6Al4V alloy to H(2)O(2) and compared this with the response of endothelial cells gr…
Fibrin-chitosan composite substrate for in vitro culture of chondrocytes
2013
The aim of this study was to develop a biocompatible monolayer substrate based on fibrin and chitosan for in vitro culture of chondrocytes. Fibrin-chitosan composite substrates combined the proved cell adhesion properties of fibrin with the hydrophilicity and poor adhesion capacity of chitosan. Chitosan microspheres were produced by coacervation method, agglomerated within a fibrin network and subsequently crosslinked with genipin. The composite substrate was stable for 28 days of culture due to the high crosslinking density. Human chondrocytes cultured on the composite substrate were viable during the culture period. At the end of culture time (28 days) the composite substrate showed low c…
Inflammatory and cytotoxic responses of an alveolar-capillary coculture model to silica nanoparticles: Comparison with conventional monocultures
2011
Abstract Background To date silica nanoparticles (SNPs) play an important role in modern technology and nanomedicine. SNPs are present in various materials (tyres, electrical and thermal insulation material, photovoltaic facilities). They are also used in products that are directly exposed to humans such as cosmetics or toothpaste. For that reason it is of great concern to evaluate the possible hazards of these engineered particles for human health. Attention should primarily be focussed on SNP effects on biological barriers. Accidentally released SNP could, for example, encounter the alveolar-capillary barrier by inhalation. In this study we examined the inflammatory and cytotoxic response…
Titanate nanotubes: towards a novel and safer nanovector for cardiomyocytes.
2012
Actively contractile cardiomyocyte (CM) monolayer represents an interesting tool to study both cardiac diseases and injuries. However, this model is poorly transfectable with conventional agents. Consequently, there is a need to develop new carriers that could overcome this problem. Titanate nanotubes (TiONts) could be a potential candidate due to possibly higher cell uptake as a direct consequence of their shape. On the basis of this rationale, TiONts were assessed for their cytotoxicity and internalization pathways. Cytotoxicity was assessed for TiONts either functionalized with PEI or unfunctionalized and its spherical counterpart P25 TiO2. No cytotoxic effect was observed under TiONts, …
Evaluation of mechanical and morphologic features of PLLA membranes as supports for perfusion cells culture systems
2015
Abstract Porous biodegradable PLLA membranes, which can be used as supports for perfusion cell culture systems were designed, developed and characterized. PLLA membranes were prepared via diffusion induced phase separation (DIPS). A glass slab was coated with a binary PLLA–dioxane solution (8 wt.% PLLA) via dip coating, then pool immersed in two subsequent coagulation baths, and finally dried in a humidity-controlled environment. Surface and mechanical properties were evaluated by measuring pore size, porosity via scanning electron microscopy, storage modulus, loss modulus and loss angle by using a dynamic mechanical analysis (DMA). Cell adhesion assays on different membrane surfaces were a…
The rapid anastomosis between prevascularized networks on silk fibroin scaffolds generated in vitro with cocultures of human microvascular endothelia…
2010
The survival and functioning of a bone biomaterial upon implantation requires a rapidly forming and stably functioning vascularization that connects the implant to the recipient. We have previously shown that human microcapillary endothelial cells (HDMEC) and primary human osteoblast cells (HOS) in coculture on various 3-D bone biomaterial scaffolds rapidly distribute and self-assemble into a morphological structure resembling bone tissue. Endothelial cells form microcapillary-like structures containing a lumen and these were intertwined between the osteoblast cells and the biomaterial. This tissue-like self-assembly occurred in the absence of exogenously added angiogenic stimuli or artific…
Attachement and spreading of fibroblasts on an RGD peptide-modified injectable hyaluronan hydrogel
2004
Hyaluronan (HA) hydrogels resist attachment and spreading of fibroblasts and most other mammalian cell types. A thiol-modified HA (3,3'-dithiobis(propanoic dihydrazide) [HA-DTPH]) was modified with peptides containing the Arg-Gly-Asp (RGD) sequence and then crosslinked with polyethylene glycol (PEG) diacrylate (PEGDA) to create a biomaterial that supported cell attachment, spreading, and proliferation. The hydrogels were evaluated in vitro and in vivo in three assay systems. First, the behavior of human and murine fibroblasts on the surface of the hydrogels was evaluated. The concentration and structure of the RGD peptides and the length of the PEG spacer influenced cell attachment and spre…
Manganese interferes with calcium, perturbs ERK signaling, and produces embryos with no skeleton.
2011
Manganese (Mn) has been associated with embryo toxicity as it impairs differentiation of neural and skeletogenic cells in vertebrates. Nevertheless, information on the mechanisms operating at the cellular level remains scant. We took advantage of an amenable embryonic model to investigate the effects of Mn in biomineral formation. Sea urchin (Paracentrotus lividus) embryos were exposed to Mn from fertilization, harvested at different developmental stages, and analyzed for their content in calcium (Ca), expression of skeletogenic genes, localization of germ layer markers, and activation of the extracellular signal-regulated kinase (ERK). By optical and immunofluorescence microscopy, we found…