2-Alkyl-Substituted-4-Amino-Thieno[2,3-d]Pyrimidines: Anti-Proliferative Properties to In Vitro Breast Cancer Models.

Thienopyrimidines are structural analogs of quinazolines, and the creation of new 2-alkyl derivatives of ethyl 4-aminothienopyrimidine-6-carboxylates for the study of their anti-proliferative properties is of great pharmacological interest. Some 2-alkyl-4-amino-thieno[2,3-d]pyrimidines 2-5 were synthesized, and their cyto- and phototoxicity against BALB 3T3 cells were established by an in vitro 3T3 NRU test. The obtained results indicate that the tested compounds are not cytotoxic or phototoxic, and that they are appropriate to be studied for their anti-proliferative and anti-tumor properties. The anti-proliferative potential of the compounds was investigated on MCF-7 and MDA-MB-231 cancer cells, as well as a MCF-10A cell line (normal human mammary epithelial cells). The most toxic to MCF-7 was thienopyrimidine 3 with IC50 13.42 µg/mL (IC50 0.045 µM), followed by compound 4 (IC50 28.89 µg/mL or IC50 0.11 µM). The thienopyrimidine 4 revealed higher selectivity to MCF-7 and lower activity (IC50 367 µg/mL i.e., 1.4 µM) than compound 3 with MCF-10A cells. With respect to MDA-MB-231 cells, ester 2 manifested the highest effect with IC50 52.56 µg/mL (IC50 0.16 µM), and 2-ethyl derivative 4 revealed IC50 62.86 µg/mL (IC50 0.24 µM). It was estimated that the effect of the substances on the cell cycle progression was due to cell cycle arrest in the G2 stage for MDA-MB-231, while arrest in G1 was detected for the estrogen (ER)-positive MCF-7 cell line. The tested compound's effects on the change of the zeta potential in the tumorigenic cells utilized in this study were determined. The calculation which we performed of the physicochemical properties and pharmacokinetic parameters influencing the biological activity suggested high intestinal absorption, as well as drug-likeness.

Antitumor Effect of Iscador on Breast Cancer Cell Lines with Different Metastatic Potential.

Studies were performed for the first time on the effect of Iscador Qu and Iscador M on phototoxicity, cytotoxicity, antiproliferative activity, changes in ξ-potential of cells, membrane lipid order, actin cytoskeleton organization and migration on three breast cancer lines with different metastatic potential: MCF10A (control), MCF-7 (low metastatic) and MDA-MB231 (high metastatic) cells. The tested Iscador Qu and M did not show any phototoxicity. The antiproliferative effect of Iscador species appeared to be dose-dependent and was related to the metastatic potential of the tested cell lines. A higher selectivity index was obtained for Iscador Qu and M towards the low metastatic MCF-7 cell line compared to the high metastatic MDA-MB-231. Iscador Qu demonstrated higher selectivity for both cancer cell lines compared to Iscador M. The malignant cell lines exhibited a decrease in fibril number and thickness regardless of the type of Iscador used. The strongest effect on migration potential was observed for the low metastatic cancer cell line MCF-7 after Iscador treatment. Both Iscador species induced a slight increase in the percentage of cells in early apoptosis for the low and high metastatic cell lines, MCF-7 and MDA-MB-231, unlike control cells. Changes in the zeta potential and membrane lipid order were observed for the low metastatic MCF-7 cell line in contrast to the high metastatic MDA-MB-231 cells. The presented results reveal a higher potential of Iscador as an antitumor agent for the low metastatic cancer cell line MCF-7 compared to the high metastatic one. Iscador Qu appears to be more potent compared to Iscador M, but at this point, the exact mechanism of action is still unclear and needs further investigations.

Redox-mediated Anticancer Activity of Anti-parasitic Drug Fenbendazole in Triple-negative Breast Cancer Cells.

BACKGROUND/AIM: An increasing number of studies are reporting anticancer activity of widely used antiparasitic drugs and particularly benzimidazoles. Fenbendazole is considered safe and tolerable in most animal species at the effective doses as an anthelmintic. Little is known about the redox-modulating properties of fenbendazole and the molecular mechanisms of its antiproliferative effects. Our study aimed to investigate the possibility of selective redox-mediated treatment of triple-negative breast cancer cells by fenbendazole without affecting the viability and redox status of normal breast epithelial cells. MATERIALS AND METHODS: The experiments were performed on three cell lines: normal breast epithelial cells (MCF-10A) and cancer breast epithelial cells (MCF7 - luminal adenocarcinoma, low metastatic; MDA-MB-231 - triple-negative adenocarcinoma, highly metastatic). Cells were treated with fenbendazole for 48-h and three parameters were analyzed using conventional assays: cell viability and proliferation, level of intracellular superoxide, and level of hydroperoxides. RESULTS: The data demonstrated that MDA-MB-231 cells were more vulnerable to fenbendazole-induced oxidative stress than MCF-7 cells. In normal breast epithelial cells MCF-10A, fenbendazole significantly suppressed oxidative stress compared to untreated controls. These data correlate with the effect of fenbendazole on cell viability and the IC50 values, which is indirect evidence of the potential targeting anticancer effect of the drug, especially in MDA-MB-231 cells. CONCLUSION: The difference in the levels of oxidative stress induced by fenbendazole in MDA-MB-231 and MCF-7 indicates that the two types of breast cancer respond to the drug through different redox-related mechanisms.

Design, Cytotoxicity and Antiproliferative Activity of 4-Amino-5-methyl-thieno[2,3-d]pyrimidine-6-carboxylates against MFC-7 and MDA-MB-231 Breast Cancer Cell Lines.

Novel 4-amino-thieno[2,3-d]pyrimidine-6-carboxylates substituted at the second position were prepared by cyclocondensation of 2-amino-3-cyano-thiophene and aryl nitriles in an acidic medium. The design of the target compounds was based on structural optimization. The derivatives thus obtained were tested in vitro against human and mouse cell lines. The examination of the compound effects on BLAB 3T3 and MFC-10A cells showed that they are safe, making them suitable for subsequent experiments to establish their antitumor activity. The photoirritancy factor of the compounds was calculated. Using the MTT test, the antiproliferative activity to MCF-10A, MCF-7 and MDA-MB-231 cell lines was estimated. The best antiproliferative effect in respect to the MCF-7 cell line revealed compound 2 with IC50 4.3 ± 0.11 µg/mL (0.013 µM). The highest selective index with respect to MCF-7 cells was shown by compound 3 (SI = 19.3), and to MDA-MB-231 cells by compound 2 (SI = 3.7). Based on energy analysis, the most stable conformers were selected and optimized by means of density functional theory (DFT). Ligand efficiency, ligand lipophilicity efficiency and the physicochemical parameters of the target 4-amino-thienopyrimidines were determined. The data obtained indicated that the lead compound among the tested substances is compound 2.

Electroporation, electrochemotherapy and electro-assisted drug delivery in cancer. A state-of-the-art review.

This review focuses on electrochemotherapy that consists in the delivery of anti-cancer drugs using high-voltage electrical pulses. Technical issues, choice of drugs, and protocol of drug delivery are still under investigation and no consensus has been achieved yet. The different aspects of electrochemotherapy are discussed in the present paper. It includes interrogations about the choice of the preferred anti-cancer drug and dose to be delivered on the solid tumors. Another promising area is related to the electro-assisted release of nanoparticles (quantum dots) in xenografted solid tumors. Molecular mechanisms of enhanced drug delivery are discussed in terms of high cholesterol level and large fraction of lipid rafts in cancer cells. Electrochemotherapy is a paradigmatic example of cooperation between physicists, biophysicists, chemists, technicians, manufacturers, biologists, clinicians, and patients to improve a very promising treatment delivery in line with the conception of personalized medicine.

Thieno[2,3-d]pyrimidin-4(3H)-one Derivatives of Benzimidazole as Potential Anti- Breast Cancer (MDA-MB-231, MCF-7) Agents.

AIMS: The purpose of this study was the synthesis of some new thienopyrimidine derivatives of 1,3-disubstituted benzimidazoles and the evaluation of their cytotoxicity against MDA-MB-231, MCF-7, and 3T3 cells lines. BACKGROUND: An overexpression or mutational activation of TK receptors EGFR and HER2/neu is characteristic of tumors. It has been found that some thieno[2,3-d]pyrimidines exhibited better inhibitory activity against Epidermal Growth Factor Receptor (EGFR/ErbB-2) tyrosine kinase in comparison to aminoquinazolines. Breast cancer activity towards MDA-MB-231 and MCF-7 cell lines by inhibiting EGFR was revealed by a novel 2-arylbenzimidazole. This motivated the synthesis of new thienopyrimidines possessing benzimidazole fragments in order to evaluate their cytotoxicity to the above-mentioned cell lines. OBJECTIVE: The objectives of the study were to design and synthesize a novel series of thieno[2,3-d]pyrimidines bearing biologically active moieties, such as 1,3-disubstituted-benzimidazole heterocycle, structurally similar to diaryl ureas in order to evaluate their cytotoxicity against MDA-MB-231, and MCF-7 breast cancer cell lines. METHODS: N,N-disubstituted benzimidazole-2-one carbonitriles were synthesized by Aza-Michael addition and used as precursors to generate some of the new thieno[2,3-d]pyrimidines in acidic medium The interaction of chloroethyl-2-thienopyrimidines, 2-amino-benzimidazole and benzimidazol-2-one nitriles under solid-liquid transfer catalysis conditions led to new thienopyrimidines. MTT assay for cell survival was performed in order to evaluate the cytotoxicity of the tested compounds. A fluorescence study was conducted to elucidate some aspects of the mechanism of action. RESULTS: The effects of nine synthesized compounds were investigated towards MDA-MB-231, MCF-7 and 3T3 cell lines. Thieno[2,3-d]pyirimidine-4-one 16 (IC50 - 0.058µM) and 21 (IC50 - 0.029µM) possess high cytotoxicity against MDA-MB-231 cells after 24h. The most cytotoxic compounds against breast cancer MCF-7 cells was compound 21 (IC50 - 0.074µM), revealing lower cytotoxicity against mouse fibroblast 3T3 cells with IC50 - 0.20µM. SAR analysis was performed. Fluorescence study of the treatment of MDA-MB cells with compound 21 was carried out in order to clarify some aspects of the mechanism of action. CONCLUSION: The relationship between cytotoxicity of compounds 14 and 20 against MCF-7 and 3T3 cells can suggest a similar mechanism of action. The antitumor potential of the tested compounds proves the necessity for further investigation to estimate the exact inhibition pathway in the cellular processes. The fluorescence study of the treatment of MDA-MB cells with compound 21 showed a rapid process of apoptosis.

Redox-related Molecular Mechanism of Sensitizing Colon Cancer Cells to Camptothecin Analog SN38.

BACKGROUND/AIM: The aim of this study was to elucidate the possibility of sensitizing colon cancer cells to the chemotherapeutic drug SN38 and investigate its mechanism of action after combined treatment with electroporation (EP). MATERIALS AND METHODS: Cells were treated with SN38, EP and their combination for 24/48 h. The cell viability, actin cytoskeleton integrity, mitochondrial superoxide, hydroperoxides, total glutathione, phosphatidyl serine expression, DNA damages and expression of membrane ABC transporters were analyzed using conventional analytical tests. RESULTS: The combination of EP and SN38 affected cell viability and cytoskeleton integrity. This effect was accompanied by: (i) high production of intracellular superoxide and hydroperoxides and depletion of glutathione; (ii) increased DNA damage and apoptotic/ferroptotic cell death; (iii) changes in the expression of membrane ABC transporters - up-regulation of SLCO1B1 and retention of SN38 in the cells. CONCLUSION: The anticancer effect of the combined treatment of SN38 and EP is related to changes in the redox-homeostasis of cancer cells, leading to cell death via apoptosis and/or ferroptosis. Thus, electroporation has a potential to increase the sensitivity of cancer cells to conventional anticancer therapy with SN38.

Bacterial Natural Disaccharide (Trehalose Tetraester): Molecular Modeling and in Vitro Study of Anticancer Activity on Breast Cancer Cells.

Isolation and characterization of new biologically active substances affecting cancer cells is an important issue of fundamental research in biomedicine. Trehalose lipid was isolated from Rhodococcus wratislaviensis strain and purified by liquid chromatography. The effect of trehalose lipid on cell viability and migration, together with colony forming assays, were performed on two breast cancer (MCF7-low metastatic; MDA-MB231-high metastatic) and one "normal" (MCF10A) cell lines. Molecular modeling that details the structure of the neutral and anionic form (more stable at physiological pH) of the tetraester was carried out. The tentative sizes of the hydrophilic (7.5 Å) and hydrophobic (12.5 Å) portions of the molecule were also determined. Thus, the used trehalose lipid is supposed to interact as a single molecule. The changes in morphology, adhesion, viability, migration, and the possibility of forming colonies in cancer cell lines induced after treatment with trehalose lipid were found to be dose and time dependent. Based on the theoretical calculations, a possible mechanism of action and membrane asymmetry between outer and inner monolayers of the bilayer resulting in endosome formation were suggested. Initial data suggest a mechanism of antitumor activity of the purified trehalose lipid and its potential for biomedical application.

Characterization and potential antitumor effect of a heteropolysaccharide produced by the red alga Porphyridium sordidum.

Taking into account the rising trend of the incidence of cancers of various organs, effective therapies are urgently needed to control human malignancies. However, almost all chemotherapy drugs currently on the market cause serious side effects. Fortunately, several studies have shown that some non-toxic biological macromolecules, including algal polysaccharides, possess anti-cancer activities or can increase the efficacy of conventional chemotherapy drugs. Polysaccharides are characteristic secondary metabolites of many algae. The efficacy of polysaccharides on the normal and cancer cells is not well investigated, but our investigations proved a cell specific effect of a newly isolated extracellular polysaccharide from the red microalga Porphyridium sordidum. The investigated substance was composed of xylose:glucose and galactose:manose:rhamnose in a molar ratio of 1:0.52:0.44:0.31. Reversible electroporation has been exploited to increase the transport through the plasma membrane into the tested breast cancer tumor cells MCF-7 and MDA-MB231. Application of 75 µg/mL polysaccharide in combination with 200 V/cm electroporation induced 40% decrease in viability of MDA-MB231 cells and changes in cell morphology while control cells (MCF10A) remained with normal morphology and kept vitality.

Loading Efficiency of Polymersomes with Contrast Agents and their Intracellular Delivery: Quantum Dots Versus Organic Dyes.

BACKGROUND/AIM: Contrast nanocarriers as drug-delivery systems, capable of selective delivery to cancer cells and solid tumors, are essential for the development of new diagnostic and therapeutic (theranostic) strategies. The present study aimed to investigate the loading efficiency of chitosan-based polymersomes with fluorescent contrast substances [quantum dots (QDs) and conventional organic dyes] and the possibility to control their release from the polymer matrix into cells by chemical modifications and electroporation. MATERIALS AND METHODS: All investigated fluorophores were retained within the polymer globule via electrostatic and hydrophilic-hydrophobic interactions, without conjugation with the polymer. The fluorophore-loaded polymersomes were characterized by dynamic light scattering, zeta-potential titration, and fluorescence spectroscopy. The release of fluorophore from the polymersomes, passively or after electroporation, was detected by 5-step spin-ultrafiltration, combined with fluorescence spectroscopy of the upper phase (supernatant) of the filter unit. Passive intracellular delivery of the nanoparticles to HeLa cells was detected by fluorescence confocal microscopy. RESULTS: The QDs were retained tightly and continuously in the polymer matrix, while the organic fluorophores [fluorescein isothiocyanate (FITC), FITC-dextran10,000 and FITC-dextran70,000] were released rapidly from the polymersomes. The detergent Brij significantly increased the retention of FITC-dextran10,000 in the polymer globule. Electroporation up to 1000 V/cm did not induce release of QDs from the polymersomes, but accelerated the release of Brij-treated FITC-dextran10,000 B from the polymer matrix. High-voltage pulses (over 750 V/cm) induced also fragmentation or aggregation of the nanoparticles. QD_labeled polymersomes penetrated passively in cancer cells after 24-hour incubation. CONCLUSION: The results suggest that QD-labeled polymersomes are appropriate fluorescent probes and a nano-drug delivery system with high tracing opportunities for in vitro and in vivo applications. Furthermore, loading polymersomes with organic dyes with different molecular weights (such as FITC-dextrans) is a simple model for visualizing and predicting the rate of release of small organic molecules (e.g. conventional drugs, other contrasts, stabilizers, and supplements) from the polymer matrix.

Electroinduced Delivery of Hydrogel Nanoparticles in Colon 26 Cells, Visualized by Confocal Fluorescence System.

BACKGROUND: Nano-scale drug delivery systems (nano-DDS) are under intense investigation. Nano-platforms are developed for specific administration of small molecules, drugs, genes, contrast agents [quantum dots (QDs)] both in vivo and in vitro. Electroporation is a biophysical phenomenon which consists of the application of external electrical pulses across the cell membrane. The aim of this study was to research electro-assisted Colon 26 cell line internalization of QDs and QD-loaded nano-hydrogels (polymersomes) visualized by confocal microscopy and their influence on cell viability. MATERIALS AND METHODS: The experiments were performed on the Colon 26 cancer cell line, using a confocal fluorescent imaging system and cell viability test. RESULTS: Electroporation facilitated the delivery of nanoparticles in vivo. We demonstrated increased voltage-dependent delivery of nanoparticles into cells after electrotreatment, without significant cell viability reduction. CONCLUSION: The delivery and retention of the polymersomes in vitro is a promising tool for future cancer treatment strategies and nanomedcine.

Passive and electro-assisted delivery of hydrogel nanoparticles in solid tumors, visualized by optical and magnetic resonance imaging in vivo.

The present study describes a development of nanohydrogel, loaded with QD(705) and manganese (QD(705)@Nanogel and QD(705)@Mn@Nanogel), and its passive and electro-assisted delivery in solid tumors, visualized by fluorescence imaging and magnetic resonance imaging (MRI) on colon cancer-grafted mice as a model. QD(705)@Nanogel was delivered passively predominantly into the tumor, which was visualized in vivo and ex vivo using fluorescent imaging. The fluorescence intensity increased gradually within 30 min after injection, reached a plateau between 30 min and 2 h, and decreased gradually to the baseline within 24 h. The fluorescence intensity in the tumor area was about 2.5 times higher than the background fluorescence. A very weak fluorescent signal was detected in the liver area, but not in the areas of the kidneys or bladder. This result was in contrast with our previous study, indicating that FITC@Mn@Nanogel did not enter into the tumor and was detected rapidly in the kidney and bladder after i.v. injection [J. Mater. Chem. B 2013, 1, 4932-4938]. We found that the embedding of a hard material (as QD) in nanohydrogel changes the physical properties of the soft material (decreases the size and negative charge and changes the shape) and alters its pharmacodynamics. Electroporation facilitated the delivery of the nanohydrogel in the tumor tissue, visualized by fluorescent imaging and MRI. Strong signal intensity was recorded in the tumor area shortly after the combined treatment (QD@Mn@Nanogel + electroporation), and it was observed even 48 h after the electroporation. The data demonstrate more effective penetration of the nanoparticles in the tumor due to the increased permeability of blood vessels at the electroporated area. There was no rupture of blood vessels after electroporation, and there were no artifacts in the images due to a bleeding.

Lymph node mapping using quantum dot-labeled polymersomes.

The present study was designed to investigate whether poly-ion complex hollow vesicles (polymersomes), based on chemically-modified chitosan, are appropriate for lymph node mapping in the context of their application in the development of theranostic nanosized drug delivery systems (nano-DDS). The experiments were performed on Balb/c nude mice (colon cancer-grafted). The mice were subjected to anesthesia and quantum dot (QD(705))-labeled polymersomes (d-120 nm) were injected intravenously via the tail vein. The optical imaging was carried out on Maestro EX Imaging System (excitation filter: 435-480 nm; emission filter: 700 nm). A strong fluorescent signal, corresponding to QD(705) fluorescence, was detected in the lymph nodes, as well as in the tumor. A very weak fluorescent signal was found in the liver area. The half-life of QD(705)-labelled polymersomes was 6 ± 2 hours in the bloodstream and 11 ± 3 hours in the lymph nodes. The data suggest that polymersomes are very promising carriers for lymph node mapping using QD as a contrast agent. They are useful matrix for development of nano-formulations with theranostic capabilities.

Fluorescent imaging for assessment of the effect of combined application of electroporation and rifampicin on HaCaT cells as a new therapeutic approach for psoriasis.

The study aimed to clarify the role of electric pulses in combination with chemotherapy on the viability of keratinocyte cell line HaCaT, in the context of its application as a new therapeutic approach for psoriasis. The data show that electroporation of HaCaT cells in combination with rifampicin induces cytoskeleton disruption and increases permeability of cell monolayer due to cell-cell junctions' interruption, visualized by fluorescent imaging of E-cadherin and actin integrity. This was accompanied with synergistic reduction of cell viability. The study proposes a new opportunity for more effective skin treatment than chemotherapy. The future application of this electrochemotherapeutic approach for combined local treatment of psoriasis may have serous benefits because of a high possibility to avoid side-effects of conventional chemotherapy.

New insights in the gene electrotransfer process: evidence for the involvement of the plasmid DNA topology.

Electropermeabilization is a non-viral method that can be used to transfer plasmid DNA (pDNA) into cells and tissues. According the applications and considered tissues, this safe method can be less efficient than the viral approaches. Biophysical mechanisms of gene electrotransfer are not entirely known. Contrary to small molecules that have direct and fast access to the cytoplasm, pDNA is electrophoretically pushed towards the permeabilized membrane where it forms a complex before being transferred into the cytoplasm. In order to understand the biophysical mechanisms of gene electrotransfer and in this way to improve it, we investigated the dependence of the topology of pDNA i.e. linear versus supercoiled on both pDNA/membrane interaction and gene expression. Our results revealed that: i) even if pDNA/membrane interactions are only slightly affected by the topology of pDNA, ii) gene transfer and expression are strongly influenced by it. Indeed, the linearization of pDNA leads to a decrease in the transfection level.

Multiple effects of electroporation on the adhesive behaviour of breast cancer cells and fibroblasts.

BACKGROUND: Recently electroporation using biphasic pulses was successfully applied in clinical developments for treating tumours in humans and animals. We evaluated the effects of electrical treatment on cell adhesion behaviour of breast cancer cells and fibroblasts. By applying bipolar electrical pulses we studied short- and long-lived effects on cell adhesion and survival, actin cytoskeleton and cell adhesion contacts in adherent cancer cells and fibroblasts. METHODS: Two cancer cell lines (MDA-MB-231 and MCF-7) and one fibroblast cell line 3T3 were used. Cells were exposed to high field intensity (200 - 1000 V/cm). Cell adhesion and survival after electrical exposure were studied by crystal violet assay and MTS assay. Cytoskeleton rearrangement and cell adhesion contacts were visualized by actin staining and fluorescent microscope. RESULTS: The degree of electropermeabilization of the adherent cells elevated steadily with the increasing of the field intensity. Adhesion behaviour of fibroblasts and MCF-7 was not significantly affected by electrotreatment. Interestingly, treating the loosely adhesive cancer cell line MDA-MB-231 with 200 V/cm and 500 V/cm resulted in increased cell adhesion. Cell replication of both studied cancer cell lines was disturbed after electropermeabilization. Electroporation influenced the actin cytoskeleton in cancer cells and fibroblasts in different ways. Since it disturbed temporarily the actin cytoskeleton in 3T3 cells, in cancer cells treated with lower and middle field intensity actin cytoskeleton was well presented in stress fibers, filopodia and lamellipodia. The electrotreatment for cancer cells provoked preferentially cell-cell adhesion contacts for MCF-7 and cell-ECM contacts for MDA-MB- 231. CONCLUSIONS: Cell adhesion and survival as well as the type of cell adhesion (cell-ECM or cell-cell adhesion) induced by the electroporation process is cell specific. The application of suitable electric pulses can provoke changes in the cytoskeleton organization and cell adhesiveness, which could contribute to the restriction of tumour invasion and thus leads to the amplification of anti-tumour effect of electroporation-based tumour therapy.

In vitro evaluation of elastic multiblock co-polymers as a scaffold material for reconstruction of blood vessels.

There is a need to create cell- and histocompatible implant materials, which might temporarily replace the mechanical function of a native tissue for regenerative therapies. To match the elastic behavior of the native tissue two different multiblock co-polymers were investigated: PDC, consisting of poly(p-dioxanone) (PPDO)/poly(ε-caprolactone) (PCL), and PDD, based on PPDO/poly((adipinate-alt-1,4-butanediol)-co-(adipinate-alt-ethylene glycol)-co-adipinate-alt-diethylene glycol) (Diorez). PDC is capable of a shapememory effect. Both multiblock co-polymers show an improved elasticity compared to materials applied in established vascular prosthesis. PDD is softer than PDC at 20°C, while PDC maintains its elasticity at 37°C. Thermodynamic characteristics indicate a more polar surface of PDD. Low cell adhesion was found on surfaces with low molar free energy of hysteresis (ΔG) derived from contact angle measurements in wetting and dewetting mode and high cell adhesion on high-ΔG surfaces. An increasing content of PCL in PDC improved cell adhesion and spreading of human umbilical vein endothelial cells. The prothrombotic potential of PDD is higher than PDC. Finally, it is concluded that PDC is a promising material for vascular tissue engineering because of its improved elastic properties, as well as balanced prothrombotic and anti-thrombotic properties with endothelial cells.

Electrodelivery of drugs into cancer cells in the presence of poloxamer 188.

In the present study it is shown that poloxamer 188, added before or immediately after an electrical pulse used for electroporation, decreases the number of dead cells and at the same time does not reduce the number of reversible electropores through which small molecules (cisplatin, bleomycin, or propidium iodide) can pass/diffuse. It was suggested that hydrophobic sections of poloxamer 188 molecules are incorporated into the edges of pores and that their hydrophilic parts act as brushy pore structures. The formation of brushy pores may reduce the expansion of pores and delay the irreversible electropermeability. Tumors were implanted subcutaneously in both flanks of nude mice using HeLa cells, transfected with genes for red fluorescent protein and luciferase. The volume of tumors stopped to grow after electrochemotherapy and the use of poloxamer 188 reduced the edema near the electrode and around the subcutaneously growing tumors.

Cytotoxic activity of platinum(II) and palladium(II) complexes of N-3-pyridinylmethanesulfonamide: the influence of electroporation.

The series of complexes: cis-[Pd(PMSA)2X2], cis-[Pt(PMSA)2X2], trans-[Pt(PMSA)2I2] and [Pt(PMSA)4]Cl2 (PMSA = N-3-pyridinylmethanesulfonamide; X = Cl, Br, I), previously synthesized and characterized by us, as well as the free ligand PMSA, were tested for their cytotoxic activity without electroporation -- against murine leukemia F4N and human SKW-3 and MDA-MB-231 tumour cell lines -- and with electroporation -- against the latter two cell lines. The majority of the complexes exhibited cytotoxic effects (IC50 < 100 micromol/l) under the conditions of electroporation. Both cis- and trans-[Pt(PMSA)2I2] had pronounced cytotoxic effects (29-61 micromol/l against MDA-MB-231 cells).

Induction of apoptosis by erucylphospho-N,N,N-trimethylammonium is associated with changes in signal molecule expressionand location.

At concentrations effecting apoptosis, the alkylphosphocholine ErPC3 induced increased expression of the Rb protein in breast cancer (MCF-7) and leukemia (SKW-3, AR-230) cell lines as well as hypophosphorylation (K-562, CMLT-1, DOHH-2) and fragmentation of Rb (BV-173, SKW-3) in leukemia cell lines. ErPC3 exerts at least part of its antineoplastic activity by apoptosis, and this chain of events comprises early changes in the lipid raft fraction of the cellular membrane as well as modulation of different signal molecules, such as Abl, Bcr-Abl (fusion protein), and Rb.