Human Vascular Endothelial Cells in Primary Cell Culture for the Evaluation of Nanoparticle Bioadhesion

2006 ◽  
Vol 6 (9) ◽  
pp. 3303-3309 ◽  
Author(s):  
Christoph Löhbach ◽  
Dirk Neumann ◽  
Claus-Michael Lehr ◽  
Alf Lamprecht
Keyword(s):  
Drug Delivery ◽  
Cell Culture ◽  
Endothelial Cells ◽  
Covalent Binding ◽  
Particle Diameter ◽  
Fluorescence Emission ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Human Endothelial Cells ◽  
Surface Modified

Nanoparticles (NP) are employed in various therapeutic approaches for innovative drug delivery strategies. Among them, there is drug delivery to the brain and sustained release forms for intravenous drug delivery. In order to optimize drug carriers and to elucidate involved mechanisms such as bioadhesion and cellular uptake, NP were surface modified and analyzed for their interaction with human endothelial cells in cell culture. Fluorescently labeled NP of different diameters (50 to 1000 nm) were surface modified either by simple adsorption of chitosan or by covalent binding to the lectin ulex europaeus agglutinin and thereafter applied to human endothelial cells for different incubation periods. After incubation with NP the binding of NP was quantified directly by the fluorescence emission signals from the cell layers. In order to visualize the binding behaviour, NP were localized three-dimensionally in the cell layer by confocal laser scanning microscopy. Cell binding experiments in phosphate buffer were observed to be particle size dependent with the 50 nm NP showing the highest binding percentage over all experiments. Binding decreased with increasing particle diameter and shorter incubation interval. The adhesion was further enhanced by NP surface modifications in the order blank < chitosan < lectin. The presence of plasma proteins enhanced the adhesiveness of chitosan coated NP, while the binding of lectin coated NP was inhibited. Experiments at 4 °C indicated the involvement of an active process in the binding of NP to endothelial cells.

scholarly journals Human endothelial cells express proteinase 3, the target antigen of anticytoplasmic antibodies in Wegener's granulomatosis

Blood ◽  
1993 ◽  
Vol 82 (4) ◽  
pp. 1221-1229
Author(s):  
WJ Mayet ◽  
E Csernok ◽  
C Szymkowiak ◽  
WL Gross ◽  
KH Meyer zum Buschenfelde
Keyword(s):  
Endothelial Cells ◽  
Wegener’S Granulomatosis ◽  
Laser Scanning ◽  
Interleukin 1 ◽  
Wegener's Granulomatosis ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Target Antigen ◽  
Proteinase 3 ◽  
Human Endothelial Cells

Autoantibodies directed against cytoplasmic antigens of neutrophils (ANCA), especially proteinase 3 (PR-3), have proved to be a useful clinical tool confirming the diagnosis or monitoring disease activity of Wegener's granulomatosis (WG). Although several concepts concerning the pathophysiologic potentials of ANCA have been discussed, only sparse data about ANCA-endothelium interactions have been available. In this study, we have investigated the expression of PR-3 in cytokine- treated human endothelial cells using purified anti-PR-3 antibodies of patients with WG, murine and human monoclonal anti-PR-3 antibodies as probes. We were able to show that tumor necrosis factor-alpha, interleukin-1 alpha/beta, and interferon-gamma led to an increased PR-3 expression in the cytoplasm of endothelial cells by performing polymerase chain reaction analysis, Western blot, cyto-enzyme-linked immunosorbent assays, and confocal laser scanning microscopy. Moreover, PR-3 was also translocated into the cell membrane, becoming accessible to ANCA. Our data suggest a possible direct pathogenic effect of anti- PR-3 antibodies in WG and other vasculitides. Anti-PR-3 antibodies represent an important missing link in ANCA-endothelial interactions.

scholarly journals Human endothelial cells express proteinase 3, the target antigen of anticytoplasmic antibodies in Wegener's granulomatosis

Blood ◽  
1993 ◽  
Vol 82 (4) ◽  
pp. 1221-1229 ◽  
Author(s):  
WJ Mayet ◽  
E Csernok ◽  
C Szymkowiak ◽  
WL Gross ◽  
KH Meyer zum Buschenfelde
Keyword(s):  
Endothelial Cells ◽  
Wegener’S Granulomatosis ◽  
Laser Scanning ◽  
Interleukin 1 ◽  
Wegener's Granulomatosis ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Target Antigen ◽  
Proteinase 3 ◽  
Human Endothelial Cells

Abstract Autoantibodies directed against cytoplasmic antigens of neutrophils (ANCA), especially proteinase 3 (PR-3), have proved to be a useful clinical tool confirming the diagnosis or monitoring disease activity of Wegener's granulomatosis (WG). Although several concepts concerning the pathophysiologic potentials of ANCA have been discussed, only sparse data about ANCA-endothelium interactions have been available. In this study, we have investigated the expression of PR-3 in cytokine- treated human endothelial cells using purified anti-PR-3 antibodies of patients with WG, murine and human monoclonal anti-PR-3 antibodies as probes. We were able to show that tumor necrosis factor-alpha, interleukin-1 alpha/beta, and interferon-gamma led to an increased PR-3 expression in the cytoplasm of endothelial cells by performing polymerase chain reaction analysis, Western blot, cyto-enzyme-linked immunosorbent assays, and confocal laser scanning microscopy. Moreover, PR-3 was also translocated into the cell membrane, becoming accessible to ANCA. Our data suggest a possible direct pathogenic effect of anti- PR-3 antibodies in WG and other vasculitides. Anti-PR-3 antibodies represent an important missing link in ANCA-endothelial interactions.

Observation and characterisation of the glycocalyx of viable human endothelial cells using confocal laser scanning microscopy

2004 ◽  
Vol 6 (5) ◽  
pp. 1006-1011 ◽  
Author(s):  
Anna L. Barker ◽  
Olga Konopatskaya ◽  
Christopher R. Neal ◽  
Julie V. Macpherson ◽  
Jacqueline L. Whatmore ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
Human Endothelial Cells

scholarly journals Degradation of Drug Delivery Nanocarriers and Payload Release: A Review of Physical Methods for Tracing Nanocarrier Biological Fate

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 770
Author(s):  
Patrick M. Perrigue ◽  
Richard A. Murray ◽  
Angelika Mielcarek ◽  
Agata Henschke ◽  
Sergio E. Moya
Keyword(s):  
Drug Delivery ◽  
Laser Scanning ◽  
Single Photon ◽  
Photon Emission ◽  
Correlation Spectroscopy ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Emission Computed Tomography ◽  
Systemic Delivery

Nanoformulations offer multiple advantages over conventional drug delivery, enhancing solubility, biocompatibility, and bioavailability of drugs. Nanocarriers can be engineered with targeting ligands for reaching specific tissue or cells, thus reducing the side effects of payloads. Following systemic delivery, nanocarriers must deliver encapsulated drugs, usually through nanocarrier degradation. A premature degradation, or the loss of the nanocarrier coating, may prevent the drug’s delivery to the targeted tissue. Despite their importance, stability and degradation of nanocarriers in biological environments are largely not studied in the literature. Here we review techniques for tracing the fate of nanocarriers, focusing on nanocarrier degradation and drug release both intracellularly and in vivo. Intracellularly, we will discuss different fluorescence techniques: confocal laser scanning microscopy, fluorescence correlation spectroscopy, lifetime imaging, flow cytometry, etc. We also consider confocal Raman microscopy as a label-free technique to trace colocalization of nanocarriers and drugs. In vivo we will consider fluorescence and nuclear imaging for tracing nanocarriers. Positron emission tomography and single-photon emission computed tomography are used for a quantitative assessment of nanocarrier and payload biodistribution. Strategies for dual radiolabelling of the nanocarriers and the payload for tracing carrier degradation, as well as the efficacy of the payload delivery in vivo, are also discussed.

Effect of glycocalyx on shear-dependent albumin uptake in endothelial cells

2004 ◽  
Vol 287 (5) ◽  
pp. H2287-H2294 ◽  
Author(s):  
Akinori Ueda ◽  
Manabu Shimomura ◽  
Mariko Ikeda ◽  
Ryuhei Yamaguchi ◽  
Kazuo Tanishita
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Laser Scanning ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Interface Barrier ◽  
Uptake Process ◽  
Static Conditions

The glycocalyx layer on the surface of an endothelial cell is an interface barrier for uptake of macromolecules, such as low-density lipoprotein and albumin, in the cell. The shear-dependent uptake of macromolecules thus might govern the function of the glycocalyx layer. We therefore studied the effect of glycocalyx on the shear-dependent uptake of macromolecules into endothelial cells. Bovine aorta endothelial cells were exposed to shear stress stimulus ranging from 0.5 to 3.0 Pa for 48 h. The albumin uptake into the cells was then measured using confocal laser scanning microscopy, and the microstructure of glycocalyx was observed using electron microscopy. Compared with the uptake into endothelial cells under static conditions (no shear stress stimulus), the albumin uptake at a shear stress of 1.0 Pa increased by 16% and at 3.0 Pa decreased by 27%. Compared with static conditions, the thickness of the glycocalyx layer increased by 70% and the glycocalyx charge increased by 80% at a shear stress of 3.0 Pa. The albumin uptake at a shear stress of 3.0 Pa for cells with a neutralized (no charge) glycocalyx layer was almost twice that of cells with charged layer. These findings indicate that glycocalyx influences the albumin uptake at higher shear stress and that glycocalyx properties (thickness and charge level) are involved with the shear-dependent albumin uptake process.

scholarly journals Cell Adherence and Drug Delivery from Particle Based Mesoporous Silica Films

2019 ◽  
Author(s):  
Emma Björk ◽  
Bernhard Baumann ◽  
Florian Hausladen ◽  
Rainer Wittig ◽  
mika lindén
Keyword(s):  
Drug Delivery ◽  
Laser Scanning ◽  
Single Cells ◽  
Silicon Wafers ◽  
Laser Scanning Microscopy ◽  
Drug Uptake ◽  
C2c12 Cells ◽  
Confocal Laser ◽  
Particle Sizes

Spatially and temporally controlled drug delivery is important for implant and tissue engineering applications, as the efficacy and bioavailability of the drug can be enhanced, and can also allow for drugging stem cells at different stages of development. Long-term drug delivery over weeks to months is however difficult to achieve, and coating of 3D surfaces or creating patterned surfaces is a challenge using coating techniques like spin- and dip-coating. In this study, mesoporous films consisting of SBA-15 particles grown onto silicon wafers using wet processing were evaluated as a scaffold for drug delivery. Films with various particle sizes (100 – 900 nm) and hence thicknesses were grown onto OTS-functionalized silicon wafers using a direct growth method. Precise patterning of the areas for film growth could be obtained by local removal of the OTS functionalization through laser ablation. The films were incubated with the model drug DiO, and murine myoblast cells (C2C12 cells) were seeded onto films with different particle sizes. Confocal laser scanning microscopy (CLSM) was used to study the cell growth, and a vinculin-mediated adherence of C2C12 cells on all films was verified. The successful loading of DiO into the films was confirmed by UV-vis and CLSM. It was observed that the drugs did not desorb from the particles during 24 hours in cell culture. During adherent growth on the films for 4 h, small amounts of DiO and separate particles were observed inside single cells. After 24 h, a larger number of particles and a strong DiO signal were recorded in the cells, indicating a particle mediated drug uptake. A substantial amount of DiO loaded particles were however attached on the substrate after 24 making the films attractive as a long-term reservoir for drugs on e.g. medical implants.<br>

Effect of shear stress on microvessel network formation of endothelial cells with in vitro three-dimensional model

2004 ◽  
Vol 287 (3) ◽  
pp. H994-H1002 ◽  
Author(s):  
Akinori Ueda ◽  
Masaki Koga ◽  
Mariko Ikeda ◽  
Susumu Kudo ◽  
Kazuo Tanishita
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Network Formation ◽  
Three Dimensional ◽  
Collagen Gel ◽  
Flow Chamber ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Collagen Gels

Shear stress stimulus is expected to enhance angiogenesis, the formation of microvessels. We determined the effect of shear stress stimulus on three-dimensional microvessel formation in vitro. Bovine pulmonary microvascular endothelial cells were seeded onto collagen gels with basic fibroblast growth factor to make a microvessel formation model. We observed this model in detail using phase-contrast microscopy, confocal laser scanning microscopy, and electron microscopy. The results show that cells invaded the collagen gel and reconstructed the tubular structures, containing a clearly defined lumen consisting of multiple cells. The model was placed in a parallel-plate flow chamber. A laminar shear stress of 0.3 Pa was applied to the surfaces of the cells for 48 h. Promotion of microvessel network formation was detectable after ∼10 h in the flow chamber. After 48 h, the length of networks exposed to shear stress was 6.17 (±0.59) times longer than at the initial state, whereas the length of networks not exposed to shear stress was only 3.30 (±0.41) times longer. The number of bifurcations and endpoints increased for networks exposed to shear stress, whereas the number of bifurcations alone increased for networks not exposed to shear stress. These results demonstrate that shear stress applied to the surfaces of endothelial cells on collagen gel promotes the growth of microvessel network formation in the gel and expands the network because of repeated bifurcation and elongation.

scholarly journals Preparation andIn VitroEvaluation of a Multifunctional Iron Silicate@Liposome Nanohybrid for pH-Sensitive Doxorubicin Delivery and Photoacoustic Imaging

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Zehua Liu ◽  
Shaoheng Tang ◽  
Zhiran Xu ◽  
Yingjun Wang ◽  
Xuan Zhu ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Laser Scanning ◽  
Imaging System ◽  
Photoacoustic Imaging ◽  
Drug Carrier ◽  
Ph Sensitive ◽  
Iron Silicate ◽  
Laser Scanning Microscopy ◽  
Confocal Laser

For preventing premature drug release in neutral environment and avoiding them being trapped into the endosomal/lysosomal system, we developed a novel iron silicate@liposome hybrid (ILH) formulation, which can be used as a carrier to transport doxorubicin (DOX) in a pH-sensitive manner and to escape from endosomal/lysosomal trapping through “proton-sponge” effect. The high intensity of photoacoustic signal fromin vitrophotoacoustic imaging (PAI) experiments suggests that it is a promising candidate for PAI agent, providing the potential for simultaneously bioimaging and cancer-targeting drug delivery. Cytotoxicity of our formulation toward tumor cells was remarkably higher than free DOX (48.4±7.7% and26.2±8.4%,P<0.001). Confocal laser scanning microscopy experiments showed the enhanced transportation and enrichment process of DOX in QSG-7703 cells. Taking together, we developed an easy approach to construct a multifunctional anticancer drug delivery/imaging system with a potency as a PAI agent. The strategy of combining drug carrier and imaging agent is an emerging platform for further construction of nanoparticle and may play a significant role in cancer therapy and diagnosis.

Skeletal-Targeted, Osteolytic-Responsive Drug Delivery System Improves Anti-Tumor Efficacy in Multiple Myeloma.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3155-3155
Author(s):  
Xuli Wang ◽  
Ye Yang ◽  
Scott Miller ◽  
Fenghuang Zhan
Keyword(s):  
Drug Delivery ◽  
Multiple Myeloma ◽  
Polymeric Micelles ◽  
Conflicts Of Interest ◽  
Drug Loading ◽  
Bone Matrix ◽  
Cathepsin K ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Tumor Inhibition

Abstract Abstract 3155 Background: Multiple myeloma (MM) cells often directly or indirectly induce the formation of osteoclasts, which enhance bone resorption by increasing secretion of a key protease (cathepsin K) to degrade bone matrix, leading to osteolytic lesions and serious skeletal complications. Hence, bone-targeted, osteolytic-responsive therapeutic modalities are greatly needed to improve clinical outcomes for MM. Methods and Results: A tri-block copolymer of peptide, poly(ethylene glycol) and poly(trimethylene carbonate) (Pep-b-PEG-b-PTMC) has been synthesized as a nanocarrier to improve treatment for MM. The functional peptide with the sequence of CKGHPGGPQAsp8 was designed to possess a bone tropism octapeptide (Asp8), a cathepsin K (CTSK)-cleavable substrate (HPGGPQ), multiple cationic residues and a terminal cysteine for site-specific conjugation. Maleimide-terminated diblock copolymer of PEG-b-PTMC was readily functionalized with the peptide to obtain Pep-b-PEG-b-PTMC that can spontaneously form micelles with the size of 75 nm in diameter. Sixty-six % of polymeric micelles were able to bind to hydroxyl apatite, showing high bone binding capability. The nanoparticles exhibited a negative-to-positive charge conversional profile upon exposure to cathepsin K, an overexpressed enzyme in osteolytic microenvironments. By using doxorubicin as a model drug, Pep-b-PEG-b-PTM showed 7.5 ± 0.5 % and 22.7 ± 1.5% for drug loading content and drug loading efficiency, respectively. More importantly, a unique characteristic of on-demand charge-conversional behaviour in a cathepsin K-rich condition led to enhanced cellular uptake of the nanotherapeutics, as demonstrated by confocal laser scanning microscopy. Enhanced tumor inhibition was observed in 5TGM1 MM cells when nanoparticles were pre-treated with 150 nM cathepsin K, demonstrating enzyme-triggered improved therapy. Efficacy of free DOX or DOX-loaded NPs in 5TGM1 mice bearing myeloma was further preliminarily tested. 5TGM1 mice bearing myeloma were established through injection of 5TGM1 cells (1 × 106 cells in 100 μL PBS) via tail vein, and tumor was allowed to grow for a week before initiating treatment study. Mice (n=3) were injected twice weekly with different therapeutic formulations at equivalent DOX dose (0.75 mg/Kg) or PBS. Tumor burden in the mice was monitored by ELISA measurements of serum IgG2b. Drug-loaded nanoparticles from Pep-b-PEG-b-PTMC were more efficacious in terms of mice survival rate and tumor inhibition when compared to the groups with non-targeted nanoparticles from mPEG-PTMC, free DOX or PBS controls. This improved drug efficacy may be attributed to more selective delivery of DOX to bone metastatic tissues and/or responsiveness of the nanoparticles to cathepsin K, thus improving tumor uptake of DOX, enhancing therapeutic efficacy in terms of tumor reduction as well as MM mouse survival. Conclusions: The promising results from this study may prompt the development of bone-targeted, enzyme-triggered drug delivery systems to improve their affinity to skeletal tissues, enhance selectivity for osteolytic regions and improve efficacy of anti-cancer agents, thus facilitating the development of effective nanotherapeutic modalities for multiple myeloma. Disclosures: No relevant conflicts of interest to declare.

Polymeric Micelles Modified by Folate-PEG-Lipid for Targeted Drug Delivery to Cancer Cells In Vitro

2008 ◽  
Vol 8 (6) ◽  
pp. 3085-3090 ◽  
Author(s):  
Akihiro Hayama ◽  
Tatsuhiro Yamamoto ◽  
Masayuki Yokoyama ◽  
Kumi Kawano ◽  
Yoshiyuki Hattori ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Cellular Uptake ◽  
Laser Scanning ◽  
Polymeric Micelles ◽  
Folate Receptor ◽  
Drug Carrier ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Kb Cells ◽  
Targeted Drug

A novel technique was developed for the formation of ligand-targeted polymeric micelles that can be applicable to various ligands. For tumor-specific drug delivery, camptothecin (CPT)-loaded polymeric micelles were modified by folate to produce a folate-receptor-targeted drug carrier. Folate-linked PEG5000-distearoylphosphatidylethanolamine (folate-PEG5000-DSPE) was added when preparations of drug-loaded polymeric micelles, resulting in folate ligands exposed to the surface. Folate-modified CPT-loaded polymeric micelles (F-micelle) were evaluated by measuring cellular uptake using a flow cytometer, fluorescence microscopy, and confocal laser scanning microscopy, and by cytotoxicity measurement. The results revealed that F-micelle showed higher cellular uptake in KB cells over-expressing folate receptor (FR) and higher cytotoxicity compared with non-folate modified CPT-loaded polymeric micelles (plain micelles) in KB cells, but not in FR-negative HepG2 cells. This result indicated that polymeric micelles were successfully modified by the folate-linked lipid.

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