Search results for "Biomaterials"
showing 10 items of 1265 documents
Design and physicochemical characterization of poly(amidoamine) nanoparticles and the toxicological evaluation in human endothelial cells: applicatio…
2013
In this study, we investigated nanoparticles formulated by self-assembly of a biodegradable poly(amidoamine) (PAA) and a fluorescently labeled peptide, in their capacity to internalize in endothelial cells and deliver the peptide, with possible applications for brain drug delivery. The nanoparticles were characterized in terms of size, surface charge, and loading efficiency, and were applied on human cerebral microvascular endothelial cells (hCMEC/D3) and human umbilical vein endothelial cells (Huvec) cells. Cell-internalization and cytotoxicity experiments showed that the PAA-based nanocomplexes were essentially nontoxic, and the peptide was successfully internalized into cells. The result…
Outgrowth endothelial cells isolated and expanded from human peripheral blood progenitor cells as a potential source of autologous cells for endothel…
2006
One challenge of particular importance in tissue engineering is to improve vascularization of larger size defects, which would then facilitate a sufficient supply with oxygen and nutrients to the central regions of a larger tissue-engineered construct or in highly vascularized tissues. In this study, we show that outgrowth endothelial cells (OECs) derived from human peripheral blood can serve as a source of human autologous endothelial cells and can be used in combination with fibroin silk fiber meshes for applications in tissue engineering. OEC reveal a highly differentiated endothelial phenotype as well as a high phenotypic stability during their expansion. Furthermore, OEC showed very pr…
Tissue-like self-assembly in cocultures of endothelial cells and osteoblasts and the formation of microcapillary-like structures on three-dimensional…
2007
The survival and functioning of a bone biomaterial requires a rapid and stable vascularization after implantation. However, the mechanisms involved in the context of the complex healing microenvironment are poorly understood. To evaluate the vascularization potential of bone biomaterials, angiogenic stimuli were added to human dermal microvascular endothelial cells (HDMEC) growing on three-dimensional (3-D) bone biomaterials consisting of porous hydroxyapatite, porous calcium phosphate, porous nickel-titanium, successfully being used in humans, and also silk fibroin nets. HDMEC did not migrate to form microcapillary-like structures as they did on cell culture plastic. In cocultures of HDMEC…
Endothelialization of a non-woven silk fibroin net for use in tissue engineering: growth and gene regulation of human endothelial cells
2004
Abstract We have previously shown that a biomaterial consisting of a non-woven fibroin net produced from silk (Bombyx mori) cocoons is an excellent scaffolding material for a wide variety of human cells of different tissue types. Endothelialization must take place for a biomaterial to be successful after implantation. Therefore, primary human endothelial cells and the human endothelial cell lines, HPMEC-ST1.6R and ISO-HAS-1, were examined for adherence and growth patterns on the fibroin nets by confocal laser scanning microscopy after vital staining of the cells and by electron microscopy. Endothelial cells adhered and spread along individual fibers of the nets and did not fill the gaps bet…
Fibronectin-mediated endothelialisation of chitosan porous matrices.
2009
Chitosan (Ch) porous matrices were investigated regarding their ability to be colonized by human microvascular endothelial cells (HPMEC-ST1.6R cell line) and macrovascular endothelial cells namely HUVECs. Specifically we assessed if previous incubation of Ch in a fibronectin (FN) solution was effective in promoting endothelial cell (EC) adhesion to Ch matrices with different degrees of acetylation (DAs). Upon FN physiadsorption, marked differences were found between the two DAs investigated, namely DA 4% and 15%. While cell adhesion was impaired on Ch with DA 15%, ECs were able to not only adhere to Ch with DA 4%, but also to spread and colonize the scaffolds, with retention of the EC pheno…
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…
Mesenchymal stem cell proliferation and differentiation on load-bearing trabecular Nitinol scaffolds.
2013
Bone tissue regeneration in load-bearing regions of the body requires high-strength porous scaffolds capable of supporting angiogenesis and osteogenesis. 70% porous Nitinol (NiTi) scaffolds with a regular 3-D architecture resembling trabecular bone were produced from Ni foams using an original reactive vapor infiltration technique. The "trabecular Nitinol" scaffolds possessed a high compressive strength of 79 MPa and high permeability of 6.9×10(-6) cm2. The scaffolds were further modified to produce a near Ni-free surface layer and evaluated in terms of Ni ion release and human mesenchymal stem cell (hMSC) proliferation (AlamarBlue), differentiation (alkaline phosphatase activity, ALP) and …
Red-Light-Controlled Release of Drug-Ru Complex Conjugates from Metallopolymer Micelles for Phototherapy in Hypoxic Tumor Environments
2018
Traditional photodynamic phototherapy is not efficient for anticancer treatment because solid tumors have a hypoxic microenvironment. The development of photoactivated chemotherapy based on photoresponsive polymers that can be activated by light in the “therapeutic window” would enable new approaches for basic research and allow for anticancer phototherapy in hypoxic conditions. This work synthesizes a novel Ru‐containing block copolymer for photoactivated chemotherapy in hypoxic tumor environment. The polymer has a hydrophilic poly(ethylene glycol) block and a hydrophobic Ru‐containing block, which contains red‐light‐cleavable (650–680 nm) drug–Ru complex conjugates. The block copolymer se…
Dynamic In Vivo Biocompatibility of Angiogenic Peptide Amphiphile Nanofibers
2009
Biomaterials that promote angiogenesis have great potential in regenerative medicine for rapid revascularization of damaged tissue, survival of transplanted cells, and healing of chronic wounds. Supramolecular nanofibers formed by self-assembly of a heparin-binding peptide amphiphile and heparan sulfate-like glycosaminoglycans were evaluated here using a dorsal skinfold chamber model to dynamically monitor the interaction between the nanofiber gel and the microcirculation, representing a novel application of this model. We paired this model with a conventional subcutaneous implantation model for static histological assessment of the interactions between the gel and host tissue. In the stati…