Cell Membrane Permeability Under the Influence of Terahertz (Submillimeter) Laser Radiation

2010 ◽  
Vol 5 (4) ◽  
pp. 177-181
Author(s):  
Yuliya S. Ol’shevskaya ◽  
Aleksandr S. Kozlov ◽  
Aleksandr K. Petrov ◽  
Tatyana A. Zapara ◽  
Aleksandr S. Ratushnyak
Keyword(s):  
Trypan Blue ◽  
Barrier Properties ◽  
Living Cells ◽  
Biologically Active ◽  
Cell Membrane Permeability ◽  
Transmembrane Transport ◽  
Cell Systems ◽  
Biological Objects ◽  
Viable Cells ◽  
Submillimeter Radiation

Within the framework of the task of revealing the mechanisms of the action of terahertz (submillimeter) radiation on biological objects, the influence of terahertz (submillimeter) radiation on the processes of transmembrane transport in cell systems was experimentally analyzed. Complex research using dyes which do not penetrate through intact membranes (Trypan Blue) and reveal viable cells (BCECF-AM) together with electrophysiological analysis has shown that radiation with a 130-micron wavelength creates conditions for penetration of compounds that usually do not go through the membrane of living cells. The penetration of dye may be conditioned by reversible disturbance in the barrier properties of neuron membranes under the action of 130-micron waves. Radiation with a wavelength of 150 microns does not show such properties. The received results may offer the challenge of developing methods of directed transport of biologically active compounds into cells

scholarly journals Nanodrug Transmembrane Transport Research Based on Fluorescence Correlation Spectroscopy

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 891
Author(s):  
Xinwei Gao ◽  
Yanfeng Liu ◽  
Jia Zhang ◽  
Luwei Wang ◽  
Yong Guo ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Fluorescence Correlation Spectroscopy ◽  
Drug Transport ◽  
Living Cells ◽  
Correlation Spectroscopy ◽  
Cell Membrane Permeability ◽  
Transmembrane Transport ◽  
Fluorescence Correlation ◽  
Imaging Results ◽  
And Diffusion

Although conventional fluorescence intensity imaging can be used to qualitatively study the drug toxicity of nanodrug carrier systems at the single-cell level, it has limitations for studying nanodrug transport across membranes. Fluorescence correlation spectroscopy (FCS) can provide quantitative information on nanodrug concentration and diffusion in a small area of the cell membrane; thus, it is an ideal tool for studying drug transport across the membrane. In this paper, the FCS method was used to measure the diffusion coefficients and concentrations of carbon dots (CDs), doxorubicin (DOX) and CDs-DOX composites in living cells (COS7 and U2OS) for the first time. The drug concentration and diffusion coefficient in living cells determined by FCS measurements indicated that the CDs-DOX composite distinctively improved the transmembrane efficiency and rate of drug molecules, in accordance with the conclusions drawn from the fluorescence imaging results. Furthermore, the effects of pH values and ATP concentrations on drug transport across the membrane were also studied. Compared with free DOX under acidic conditions, the CDs-DOX complex has higher cellular uptake and better transmembrane efficacy in U2OS cells. Additionally, high concentrations of ATP will cause negative changes in cell membrane permeability, which will hinder the transmembrane transport of CDs and DOX and delay the rapid diffusion of CDs-DOX. The results of this study show that the FCS method can be utilized as a powerful tool for studying the expansion and transport of nanodrugs in living cells, and might provide a new drug exploitation strategy for cancer treatment in vivo.

scholarly journals On the acoustic response of ultrasound and induced cell death

2021 ◽  
Author(s):  
Fatimah Alsaiari
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Cells ◽  
Cell Membrane Permeability ◽  
Repetition Period ◽  
Acoustic Response ◽  
Inertial Cavitation ◽  
Viable Cells ◽  
Passive Cavitation Detection ◽  
Negative Pressures ◽  
Cavitation Detection

Ultrasonically-stimulated microbubbles can enhance cell membrane permeability and decrease cell viability where the underlying acoustic mechanism has been associated with both non-inertial and inertial cavitation. In this study, breast cancer cells (MDA-MB-231) were exposed to 0.5MHz ultrasound pulses of 16μs duration at varying peak negative pressures (PNP: 218kPa, 335kPa and 908kPa) and pulse repetition period (PRP 10ms and 100ms) in the presence of Definity microbubbles (3.3% v/v). The acoustic response of microbubbles was measured using passive cavitation detection with 2.25MHz transducer, and characterized by their frequency a cavitation dose (CD). Results show that the number of non-viable cells and integrated cavitation dose (ICD) significantly increases with PNP, whereas no significant differences were found between 10ms and 100ms PRPs. In this study, no correlation was found between (ICD) and cell non-viability.

scholarly journals Antibody Mediated Transduction of Therapeutic Proteins into Living Cells

2005 ◽  
Vol 5 ◽  
pp. 782-788 ◽  
Author(s):  
James E. Hansen ◽  
Richard H. Weisbart ◽  
Robert N. Nishimura
Keyword(s):  
Therapeutic Proteins ◽  
Disease Process ◽  
Antibody Fragment ◽  
Living Cells ◽  
Cell Penetrating Peptides ◽  
Biologically Active ◽  
Protein Transduction ◽  
Protein Therapy ◽  
Single Chain ◽  
Protein Transduction Domains

Protein therapy refers to the direct delivery of therapeutic proteins to cells and tissues with the goal of ameliorating or modifying a disease process. Current techniques for delivering proteins across cell membranes include taking advantage of receptor-mediated endocytosis or using protein transduction domains that penetrate directly into cells. The most commonly used protein transduction domains are small cell-penetrating peptides derived from such proteins as the HIV-1 Tat protein. A novel protein transduction domain developed as the single chain fragment (Fv) of a murine anti-DNA autoantibody, mAb 3E10, has recently been developed and used to deliver biologically active proteins to living cellsin vitro. This review will provide a brief overview of the development of the Fv fragment and provide a summary of recent studies using Fv to deliver therapeutic peptides and proteins (such as a C-terminal p53 peptide, C-terminal p53 antibody fragment, full-length p53, and micro-dystrophin) to cells.

scholarly journals Fluorescence-activated sorting of rat hepatocytes based on their mixed function oxidase activities towards diethoxyfluorescein

1987 ◽  
Vol 247 (1) ◽  
pp. 23-28 ◽  
Author(s):  
I N H White ◽  
M L Green ◽  
R F Legg
Keyword(s):  
Dna Synthesis ◽  
Trypan Blue ◽  
Rat Hepatocytes ◽  
Fold Increase ◽  
Mixed Function Oxidase ◽  
Unscheduled Dna Synthesis ◽  
Rich Region ◽  
Trypan Blue Exclusion ◽  
Isolated Rat Hepatocytes ◽  
Viable Cells

The formation of ethoxyfluorescein and fluorescein from diethoxyfluorescein by isolated rat hepatocytes has been used as a basis for separating such cells dependent on their mixed function oxidase activities by fluorescence-activated flow cytometry. Five equal fractions defined by computer-generated regions were isolated. Non-viable cells with low fluorescence (region 1) represented 10-15% of the population, while the remainder with higher mixed function oxidase activities (regions 2-5), were greater than 95% viable by Trypan Blue exclusion. In region 1, 30% of the viable cells were binucleate, 67% diploid while in region 5, 13% were binucleate and 69% tetraploid. At 3 h after sorting, following attachment to glass coverslips, exposure of cells to methyl methanesulphonate, retrorsine or norethindrone resulted in unscheduled DNA synthesis which was 2-fold higher in the tetraploid-rich region 5, while aflatoxin B1, benzo[a]pyrene or 2-acetylaminofluorene caused a 5-fold increase in unscheduled DNA synthesis in these cells, relative to the diploid-rich hepatocytes in region 2.

Tumor Cells Resistant to Alemtuzumab Complement Mediated Cytotoxicity in Patients with High Risk Previously Untreated Early Stage CLL: A Possible Mechanism of Treatment Failure.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2973-2973
Author(s):  
Clive S. Zent ◽  
Nancy D. Bone ◽  
Susan M. Geyer ◽  
Neil E. Kay
Keyword(s):  
Flow Cytometry ◽  
B Cells ◽  
High Risk ◽  
B Cell ◽  
Cell Clone ◽  
Early Stage ◽  
Cell Membrane Permeability ◽  
Viable Cells ◽  
The Impact

Abstract The monoclonal antibodies (MoAb) alemtuzumab and rituximab have proven efficacy in the treatment of CLL. In addition, alemtuzumab is effective in patients with defective p53 function responding poorly to purine analogue therapy. The action of both MoAb is not completely understood. Proposed mechanisms include complement dependent cytotoxicity (CDC), antibody dependent cellular cytotoxicity (ADCC), and direct induction of apoptosis of CLL B cells. We have done correlative studies on CLL B cells from patients enrolled in a trial of alemtuzumab and rituximab in “high risk” early stage previously untreated CLL to determine: 1. Role of apoptosis induction and CDC in each MoAb and 2. If the addition of rituximab to alemtuzumab increases their in vitro cytotoxicity. Patients and Methods: Patients with early stage, previously untreated, high risk CLL are treated with subcutaneous alemtuzumab (dose escalation over 3 days then 30 mg Mon-Wed-Fri for 4 weeks) and rituximab (375 mg/m2/dose weekly from day 8 x 4 doses). High risk disease was defined as one or more of the following features of the CLL B cell clone: (1) 17p13−; (2) 11q22−; (3) unmutated IgVH (< 2%) and either CD38+ or ZAP-70+. Blood B lymphocytes collected prior to the start of therapy were tested for response to MoAb in vitro. Cells were cultured at 2 x 106/ml in AIM-V medium using standard conditions. Alemtuzumab and rituximab were used at 20 μg/ml and complement as 10% of 40 CH50 units/ml human serum. The impact of the MoAb was measured by counting viable cells (trypan blue negative) and measuring early apoptosis (annexin V) and cell death (cell membrane permeability to propidium iodide) using flow cytometry at 1 hour, and then daily for 3 days. Results: Treatment caused rapid resolution of lymphocytosis in all 7 patients and 3 patients were negative for circulating CLL cells using a highly sensitive 3 color flow cytometry (CD5+/CD19+/CD79b-) after therapy. All patients had a clinical response (2 CR, 5 PR). Alemtuzumab and complement were rapidly cytotoxic to most CLL cells. Mean cell viability was 39% (sd: 8%) after 1 hour of incubation. Cytotoxicity was similar in all samples irrespective of FISH defects, IgVH mutation status, and in vitro resistance to F-ara-A (n = 3). Alemtuzumab was inactive in the absence of complement for all samples. Rituximab alone and together with complement did not induce cytotoxicity or apoptosis. However, the addition of rituximab to alemtuzumab and complement did increase CDC where the number of viable cells was significantly lower at 1, 24, 48, and 72 hours incubation (p = 0.075, 0.047, 0.031, 0.027, respectively, for pairwise comparisons). CLL cells surviving alemtuzumab CDC subsequently had a lower level of apoptosis than control cells, implying a selection for resistant cells. Alemtuzumab CDC on this residual population was not increased at higher concentrations of alemtuzumab or complement. This mechanism of CDC resistance is currently under investigation. Conclusion: These data suggest that alemtuzumab CDC is an important mechanism of action in patients with CLL. However, alemtuzumab CDC kills only about 61% of CLL cells in vitro, and the surviving cells are more resistant to spontaneous apoptosis. This suggests that cells that survive alemtuzimab CDC contribute to disease progression or relapse. We intend to elucidate the mechanism of this resistance using our in vitro model with the hope that treatment strategies can be deployed to remove this residual CLL B cell clone.

scholarly journals THE REDUCTION OF FORMALDEHYDE BY BACTERIAL CELLS

1951 ◽  
Vol 34 (5) ◽  
pp. 573-582
Author(s):  
Paul H. Kopper ◽  
Keyword(s):  
Living Cells ◽  
Rapid Decrease ◽  
The Other ◽  
Nutritional Requirements ◽  
Bacterial Cells ◽  
Potential Significance ◽  
Viable Cells ◽  
Temperature Ranges ◽  
Number Of Bacteria ◽  
Reducing Capacity

Formaldehyde is reduced to methyl alcohol by living cells of a creatinine-decomposing strain of Pseudomonas aeruginosa. The amount of HCHO taken up in 30 minutes by 3 x 1010 cells of this organism is termed its reducing capacity. It was found to be 400 to 480 µg. The reaction takes place over wide pH and temperature ranges, is independent of the concentration of formaldehyde as long as the latter is not high enough to exert a toxic effect on the cell, but depends on the number of bacteria present. In cultures, 3 to 7 days old, there is a decline in reducing capacity without a proportionate decrease in the number of viable cells. On the other hand in cultures, 2 to 4 weeks old, the number of viable cells determines the amount of HCHO taken up. N/100 NaOH depresses the reducing capacity of the organism without affecting bacterial viability. Exposure of bacterial suspensions to temperatures of 46–52°C. for 10 minutes causes a far more rapid decrease in the number of viable cells than in reducing capacity. Incubation of cellular suspensions with nutrient substances, which are able to support adequately the growth of the organism, for 30 minutes prior to the addition of HCHO, induces increases in reducing capacity. The uptake of HCHO by different microorganisms seems to be related to their gaseous and nutritional requirements. Strains of P. aeruginosa and P. fluorescens are predominantly aerobic, least fastidious in their nutritional requirements, most active against HCHO, and least susceptible to the action of aureomycin and chloromycetin. The potential significance of cellular reducing capacity is discussed.

scholarly journals Temperature monitoring during light-induced release of cargo using polymer capsules modified with gold nanoparticles and nanodiamonds

2021 ◽  
Vol 2015 (1) ◽  
pp. 012045
Author(s):  
E N Gerasimova ◽  
V V Yaroshenko ◽  
P M Talianov ◽  
O O Peltek ◽  
L V Mikhailova ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Gold Nanoparticles ◽  
Side Effects ◽  
Temperature Measurement ◽  
Real Time ◽  
Au Nanoparticles ◽  
Living Cells ◽  
Temperature Monitoring ◽  
Biological Objects ◽  
Multifunctional Platform

Abstract Application of different light-sensitive drug delivery carriers is limited due to a risk of overheating of living cells. Therefore, a real-time temperature monitoring within biological objects that controls the photothermal release of different cargos from light-sensitive carriers is highly demanded. In this work, we develop a multifunctional platform comprised of polymer microcapsules modified with nitrogen vacancies (NV) centers as nanothermometers and gold (Au) nanoparticles (NPs) as heating elements for the realization of laser-induced cargo release with a simultaneous temperature measurement inside cells. Such platform allows to prevent unwanted side effects related with the overheating of living cells and tissues.

scholarly journals Selective cadmium fluorescence probe based on bis-heterocyclic molecule and its imaging in cells

2021 ◽  
Author(s):  
Masayori Hagimori ◽  
Yasushi Karimine ◽  
Naoko Mizuyama ◽  
Fumiko Hara ◽  
Takeshi Fujino ◽  
...  
Keyword(s):  
Fluorescence Probe ◽  
Living Cells ◽  
Cell Membrane Permeability ◽  
Fluorescence Probes ◽  
Low Molecular Weight ◽  
Biological Applications ◽  
Turn On ◽  
Heterocyclic Molecule ◽  
Heterocyclic Moiety ◽  
In Cells

Abstract Fluorescence probes that selectively image cadmium are useful for detecting and tracking the amount of Cd2+ in cells and tissues. In this study, we designed and synthesized a novel Cd2+ fluorescence probe based on the pyridine-pyrimidine structure, 4-(methylsulfanyl)-6-(pyridin-2-yl)pyrimidin-2-amine (3), as a low-molecular-weight fluorescence probe for Cd2+. Compound 3 could successfully discriminate between Cd2+ and Zn2+ and exhibited a highly selective turn-on response toward Cd2+ over biologically related metal ions. The dissociation constant and detection limit of 5.4 x 10− 6 mol L− 1 and 4.4 × 10− 7 mol L− 1, respectively, were calculated using fluorescence titration experiments. Studies with closely related analogs showed that the bis-heterocyclic moiety of 3 acted as both a coordination site for Cd2+ and a fluorophore. Further, the methylsulfanyl group of compound 3 is essential for achieving selective and sensitive Cd2+ detection. Fluorescence microscopy studies using living cells revealed that the cell membrane permeability of compound 3 is sufficient to detect intracellular Cd2+. These results indicate that novel bis-heterocyclic molecule 3 has considerable potential as a fluorescence probe for Cd2+ in biological applications.

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