Cytotoxic effects of basic FGF and heparin binding EGF conjugated with cytotoxin saporin on vascular cell cultures

Mammalian Cell-Growth Monitoring Based on an Impedimetric Sensor and Image Processing within a Microfluidic Platform

In recent years, advancements in microfluidic and sensor technologies have led to the development of new methods for monitoring cell growth both in macro- and micro-systems. In this paper, a microfluidic (MF) platform with a microbioreactor and integrated impedimetric sensor is proposed for cell growth monitoring during the cell cultivation process in a scaled-down simulator. The impedimetric sensor with an interdigitated electrode (IDE) design was realized with inkjet printing and integrated into the custom-made MF platform, i.e., the scaled-down simulator. The proposed method, which was integrated into a simple and rapid fabrication MF system, presents an excellent candidate for the scaled-down analyses of cell growths that can be of use in, e.g., optimization of the cultivated meat bioprocess. When applied to MRC-5 cells as a model of adherent mammalian cells, the proposed sensor was able to precisely detect all phases of cell growth (the lag, exponential, stationary, and dying phases) during a 96-h cultivation period with limited available nutrients. By combining the impedimetric approach with image processing, the platform enables the real-time monitoring of biomasses and advanced control of cell growth progress in microbioreactors and scaled-down simulator systems.

Recent Advances in Monitoring Cell Behavior Using Cell-Based Impedance Spectroscopy

Cell-based impedance spectroscopy (CBI) is a powerful tool that uses the principles of electrochemical impedance spectroscopy (EIS) by measuring changes in electrical impedance relative to a voltage applied to a cell layer. CBI provides a promising platform for the detection of several properties of cells including the adhesion, motility, proliferation, viability and metabolism of a cell culture. This review gives a brief overview of the theory, instrumentation, and detection principles of CBI. The recent applications of the technique are given in detail for research into cancer, neurodegenerative diseases, toxicology as well as its application to 2D and 3D in vitro cell cultures. CBI has been established as a biophysical marker to provide quantitative cellular information, which can readily be adapted for single-cell analysis to complement the existing biomarkers for clinical research on disease progression.

Immunotoxin Therapies for the Treatment of Epidermal Growth Factor Receptor-Dependent Cancers

Many epithelial cancers rely on enhanced expression of the epidermal growth factor receptor (EGFR) to drive proliferation and survival pathways. Development of therapeutics to target EGFR signaling has been of high importance, and multiple examples have been approved for human use. However, many of the current small molecule or antibody-based therapeutics are of limited effectiveness due to the inevitable development of resistance and toxicity to normal tissues. Recombinant immunotoxins are therapeutic molecules consisting of an antibody or receptor ligand joined to a protein cytotoxin, combining the specific targeting of a cancer-expressed receptor with the potent cell killing of cytotoxic enzymes. Over the decades, many bacterial- or plant-based immunotoxins have been developed with the goal of targeting the broad range of cancers reliant upon EGFR overexpression. Many examples demonstrate excellent anti-cancer properties in preclinical development, and several EGFR-targeted immunotoxins have progressed to human trials. This review summarizes much of the past and current work in the development of immunotoxins for targeting EGFR-driven cancers.

Effects of homocysteine on smooth muscle cell proliferation in both cell culture and artery perfusion culture models

BACKGROUND

Hyperhomocysteinemia is associated with increased risk for vascular disease. However, the pathogenic mechanisms of homocysteine are largely unknown. We evaluated the effects of homocysteine on smooth muscle cell (SMC) and endothelial cell proliferation in cell culture and on SMC proliferation of balloon angioplasty-injured arteries in a perfusion culture model.

METHODS

Human and pig SMCs and endothelial cells were cultured with variable amounts of homocysteine for 72 h and the total cells were counted using a hemocytometer. Fresh pig carotid arteries were harvested from a local slaughterhouse and cultured in a newly designed artery perfusion culture system. Five groups of arteries (six per group) were cultured for 48 h under different conditions: normal control, balloon angioplasty injury alone, and injury with three different doses of homocysteine. Vessel viability was evaluated. SMC proliferation was assayed by bromodeoxyuridine (BrdU) DNA labeling.

RESULTS

At concentrations equivalent to those in human hyperhomocysteinemia, homocysteine significantly stimulated both cultured human and pig SMC proliferation with a dose-dependent effect, while it inhibited cultured endothelial cell growth. Perfusion-cultured pig carotid arteries remained contractile in response to norepinephrine and relaxant to nitroglycerine, and viable cells were also isolated from the cultured arteries. SMC proliferation (BrdU index) showed significant differences among the groups. SMC proliferation was stimulated by vascular injury and further enhanced by homocysteine in a dose-dependent manner. The proliferative response occurred strongly on the luminal side of the vessel wall, with the effects tapering toward the adventitia.

CONCLUSIONS

Homocysteine had a mitogenic effect on vascular SMCs and a cytotoxic effect on endothelial cells. This differential effect of homocysteine on vascular cells may represent a pathogenic mechanism of vascular lesion formation in patients with hyperhomocysteinemia.