Induction of apoptosis and cell cycle arrest by polyvinylpyrrolidone K-30 and protective effect of alpha-tocopherol

Hyaluronic acid-based gels for oral application: Comparison of in vitro effects on gingival cells and bacteria

Purpose

This study aimed to evaluate the cytotoxic effects of different topical hyaluronic acid-based gels on human gingival fibroblasts and oral bacteria.

Methods

Four different hyaluronate gels - Bexident® Aftas (BA), GUM® AftaClear (AfC), Gengigel®(G), Aloclair® Plus (AlC) and a chlorhexidine gel - Bexident®Gums(BG) were selected. Human gingival fibroblasts (HGF) were seeded in 48-well plates with different gel/culture medium concentrations (v/v%) and cell viability was evaluated at 1 and 3 days of culture. Cell morphology was assessed, and alterations graded according to ISO 10993-5:2009(E). Streptococcus oralis CECT 907T colony was, seed on 48-well plate or spread onto the blood agar plates and exposed to the different gel's concentration. The optical density (OD) was assessed, and the diameter of the inhibition zone was measured (mm).

Results

BA and G elicited reduced HGF cytotoxicity, followed by AfC. AlC and BG were cytotoxic at concentrations up to 3% for all exposure times. PCM images of HGF showed moderate-to-severe alterations for AlC and BG and slight to mild changes, for BA, AfC and G. The highest antibacterial activity against S.oralis was observed on AlC and AfC, and no antibacterial activity was observed for BA and G. Inhibitory effect in sessile colonies was only observed in AlC and BG.

Conclusions

AlC demonstrated superior antibacterial activities against S.oralis but a higher cytotoxic potential in HGF. BA and G presented the lowest cytotoxicity with little to no antibacterial effect. AfC demonstrated bacteriostatic effects and low cytotoxicity on HGF.

Preclinical studies of a high drug-loaded meloxicam nanocrystals injection for analgesia

Meloxicam (MLX) is considered to have significant analgesic properties. However, the analgesic effects of MLX are compromised by its poor water solubility and thus the low drug loading. The purpose of this study was to develop a high drug-loaded MLX injection by formulating it into nanocrystals (NCs) for the treatment of analgesia. The developed MLXNCs exhibited satisfactory particle sizes and remarkably in vitro dissolution behaviors. In addition, the plasma concentrations of MLXNCs were comparable with the MLX solution (formulated with 1.0% polyoxyethylene castor oil 35) in rats. The acetic acid-induced writhing tests, hot plate tests and hind paw incision experiments demonstrated that the MLXNCs had significant analgesic effects. The findings provide insights into the developed high drug-loaded MLXNCs and provide new therapeutic options for acute and chronic pain management.

Evaluation and comparison of polysulfone TS-UL and PMMA NF-U dialyzers versus expanded hemodialysis and postdilution hemodiafiltration

Toray has created a new generation of dialyzers, the polysulphone (TS) UL series, and polymethylmethacrylate (PMMA) NF-U series, which offer enhanced efficacy over the previous TS-S series and NF-H series. The aim of this study was to evaluate the safety and efficacy of these dialyzer series versus contrasted expanded hemodialysis (HDx) and postdilution hemodiafiltration (HDF). We conducted a prospective study in 12 patients. Each patient underwent six dialysis sessions: FX80 Cordiax in HD, Toraysulfone TS-1.8 UL in HD, Theranova 400 in HDx, polymethylmethacrylate (PMMA) NF-2.1 U in HDF, Toraysulfone TS-2.1 UL in HDF, and FX80 Cordiax in HDF. The removal ratios (RRs) of urea, creatinine, ß₂ -microglobulin, myoglobin, prolactin, α₁ -microglobulin, α₁ -acid glycoprotein, and albumin were compared intraindividually. Dialysate albumin loss was also measured. The RRs for β₂ -microglobulin, myoglobin, prolactin, α₁ -microglobulin, and α₁ -acid glycoprotein were higher with the TS-2.1 UL and FX80 Cordiax dialyzers in HDF than those obtained with HD treatments and NF-2.1 U in HDF. The β₂ -microglobulin, myoglobin, and prolactin RRs were also higher with HDx than those obtained with HD treatments. The myoglobin and prolactin RRs were higher with TS-1.8 UL in HD than those obtained with helixone dialyzers in HD. Dialysate albumin loss was less than 3 g in all situations except in TS-2.1 UL in HDF. The highest global removal score values were obtained with the TS-2.1 UL and helixone dialyzers in HDF. Significant differences were found between all study situations. In conclusion, the new generation dialyzers, Toraysulfone TS Series UL and PMMA NF-U series, show excellent behaviour and tolerance in HD and HDF, representing an upgrade versus their predecessor series. The higher permeability of the TS UL series has been proven with higher efficiency in HD and maximum performance in HDF. The new PMMA NF-U series allows the use of HDF with good efficiency and complete safety.

Growth Inhibitory Effects of Dipotassium Glycyrrhizinate in Glioblastoma Cell Lines by Targeting MicroRNAs Through the NF-κB Signaling Pathway

It has been shown that nuclear factor kappa-B (NF-κB) is constitutively activated in glioblastoma (GBM), suggesting that the pathway could be a therapeutic target. Glycyrrhetic acid (GA), a compound isolated from licorice (Glycyrrhiza glabra), has been shown to decrease cell viability and increases apoptosis in human cancer cell lines by NF-κB signaling pathway suppression. Dipotassium glycyrrhizinate (DPG), a dipotassium salt of GA, has anti-inflammatory properties without toxicity. The current study examined the effectiveness of DPG as an anti-tumor in U87MG and T98G GBM cell lines. Additionally, we assessed DPG as a candidate for combinational therapy in GBM with temozolomide (TMZ). Our results demonstrated that the viability of U87MG and T98G cells significantly decreased in a time- and dose-dependent manner after DPG treatment, and the apoptotic ratio of DPG-treated groups was significantly higher than that of control groups. In addition, DPG in combination with TMZ revealed synergistic effects. Furthermore, the expression of NF-κB-luciferase-reporter in transfected GBM cell lines was remarkably reduced after DPG exposure by up-regulating miR16 and miR146a, which down-regulate its target genes, IRAK2 and TRAF6. A reduced neuro-sphere formation was also observed after DPG in both GBM cells. In conclusion, DPG presented anti-tumoral effect on GBM cell lines through a decrease on proliferation and an increase on apoptosis. In addition, our data also suggest that DPG anti-tumoral effect is related to NF-κB suppression, where IRAK2- and TRAF6-mediating miR16 and miR146a, respectively, might be a potential therapeutic target of DPG.

The Role of Biomembranes in Chromium (III)-induced Toxicity In Vitro

The role of biomembranes in the chronic toxicity of environmentally occurring chromium acetate hydroxide was investigated by using primary human fibroblasts. Transport of chromium acetate hydroxide across the plasma membrane of the cell, and the effects of chromium (III) ions on the plasma membrane as well as other intracellular membranes, were determined during six weeks of continuous exposure by using atomic absorption spectrometry, observation of cell morphology, membrane integrity assays (for lactate dehydrogenase leakage and lysosomal membrane disruption), and mitochondrial assays (for mitochondrial dehydrogenase activity and mitochondrial transmembrane potential analysis). The type of cell death induced by long-term exposure was determined in terms of phosphatidylserine externalisation, caspase-3 activation, and chromatin fragmentation. Chromium acetate hydroxide, at a concentration of 100μmol/l, accumulated in exposed cells, inflicting plasma membrane damage and suppressing mitochondrial function. Antioxidant co-enzyme Q, at a concentration of 10μmol/l, partially prevented plasma membrane damage and mitochondrial dysfunction. Exposure to chromium acetate hydroxide produced apoptosis, necrosis and an intermediate type of cell death in primary human fibroblasts. These results show that the plasma membrane and mitochondrial membrane are important targets for chronic chromium acetate hydroxide toxicity, and that this in vitro system holds promise for studying the toxicity resulting from long-term exposure to metal ions.

Toxicity and transfer of polyvinylpyrrolidone-coated silver nanowires in an aquatic food chain consisting of algae, water fleas, and zebrafish

Nanomaterials of various shapes and dimensions are widely used in the medical, chemical, and electronic industries. Multiple studies have reported the ecotoxicological effects of nanaoparticles when released in aquatic and terrestrial ecosystems; however, information on the toxicity of silver nanowires (AgNWs) to freshwater organisms and their transfer through the food webs is limited. In the present study, we aimed to evaluate the toxicity of 10- and 20-μm-long AgNWs to the alga Chlamydomonas reinhardtii, the water flea Daphnia magna, and the zebrafish and study their movement through this three-species food chain using a variety of qualitative and quantitative methods as well as optical techniques. We found that AgNWs directly inhibited the growth of algae and destroyed the digestive organs of water fleas. The results showed that longer AgNWs (20μm) were more toxic than shorter ones (10μm) to both algae and water fleas, but shorter AgNWs were accumulated more than longer ones in the body of the fish. Overall, this study suggests that AgNWs are transferred through food chains, and that they affect organisms at higher trophic levels, potentially including humans. Therefore, further studies that take into account environmental factors, food web complexity, and differences between nanomaterials are required to gain better understanding of the impact of nanomaterials on natural communities and human health.

The marine fungal metabolite, dicitrinone B, induces A375 cell apoptosis through the ROS-related caspase pathway

Dicitrinone B, a rare carbon-bridged citrinin dimer, was isolated from the marine-derived fungus, Penicillium citrinum. It was reported to have antitumor effects on tumor cells previously; however, the details of the mechanism remain unclear. In this study, we found that dicitrinone B inhibited the proliferation of multiple tumor types. Among them, the human malignant melanoma cell, A375, was confirmed to be the most sensitive. Morphologic evaluation, cell cycle arrest and apoptosis rate analysis results showed that dicitrinone B significantly induced A375 cell apoptosis. Subsequent observation of reactive oxygen species (ROS) accumulation and mitochondrial membrane potential (MMP) reduction revealed that the apoptosis induced by dicitrinone B may be triggered by over-producing ROS. Further studies indicated that the apoptosis was associated with both intrinsic and extrinsic apoptosis pathways under the regulation of Bcl-2 family proteins. Caspase-9, caspase-8 and caspase-3 were activated during the process, leading to PARP cleavage. The pan-caspase inhibitor, Z-VAD-FMK, could reverse dicitrinone B-induced apoptosis, suggesting that it is a caspase-dependent pathway. Our data for the first time showed that dicitrinone B inhibits the proliferation of tumor cells by inducing cell apoptosis. Moreover, compared with the first-line chemotherapy drug, 5-fluorouracil (5-Fu), dicitrinone B showed much more potent anticancer efficacy, suggesting that it might serve as a potential antitumor agent.

The effect of minimal concentration of ethylene glycol (EG) combined with polyvinylpyrrolidone (PVP) on mouse oocyte survival and subsequent embryonic development following vitrification

PURPOSE

Vitrification techniques employ a relatively high concentration of cryoprotectant in vitrification solutions. Exposure of oocytes to high concentrations of cryoprotectant is known to damage the oocytes via both cytotoxic and osmotic effects. Therefore, the key to successful vitrification of oocytes is to strike a balance between the usage of minimal concentration of cryoprotectant without compromising their cryoprotective actions.

METHODS

The minimal concentration of ethylene glycol (EG) on mouse oocyte survival and subsequent embryonic development was evaluated following vitrification-warming and parthenogenetic activation. Polyvinylpyrrolidone (PVP) combined with EG on mouse oocyte survival and subsequent embryonic development as well as morphology of the spindle and chromosome alignment were also evaluated. Vitrification system was adapted with JY Straw and the cooling rate was approximately 442-500 °C/min. In contrast, the warming rate was approximately 2,210-2,652 °C/min.

RESULTS

Survival rate of oocytes increased significantly when 15 % EG was combined with 2 % PVP in vitrification solution (VS). The effect of combination of EG and PVP was not significant when the concentration of EG was 20 % and higher. Although there were no significant differences in embryonic development, the percentage of abnormal spindle and chromosome alignment was significantly higher in the oocytes without 2 % PVP in VS.

CONCLUSIONS

Our data provide a proof of principle for oocyte vitrification that may not require a high concentration of cryoprotectant. There are synergic effects of EG combined with PVP for oocyte vitrification, which may provide important information to the field in developing less cytotoxic VS.

Polyvinyl pyrrolidone promotes DNA cleavage by a ROS-independent and depurination mechanism

Polyvinyl pyrrolidone polymer (PVP) has been widely applied in biological and medical fields. A few in vitro studies indicated that PVP might cause toxicity. However, the underlying mechanism is poorly understood. In this work, we found that PVP directly induced strand breakages of various DNA molecules, implicating a cleavage activity. Moreover, reactive oxygen species (ROS) scavenging analysis shows that DNA cleavage activity of PVP is not related to ROS-induced oxidation. As revealed by gel electrophoresis and liquid chromatography/mass spectrometry analysis, the major cleavage products of DNA were identified as two purine bases, guanine and adenine, suggesting that PVPs have a novel depurination activity. The selective depurination and DNA cleavage activity of PVPs were further confirmed by studying the interaction of PVP with four nucleosides and four well-designed oligodeoxynucleotides probes containing specific nucleotides. This study may provide insights into PVP-DNA interactions and resultant genotoxicity and may also open a new way for DNA study.

Polystyrene microsphere and 5-fluorouracil release from custom-designed wound dressing films

Custom-designed wound dressing films of chitosan and alginate have been prepared by a casting/solvent evaporation method for hydrophobic therapeutic agent encapsulation. In this parametric study, the propylene glycol (PG) and calcium chloride (CaCl2) concentrations were varied for chitosan and alginate films, respectively. Mechanical and chemical inter-related responses under observations included thickness (th), elasticity (E), tensile strength (TS), sorption ability (S%) and kinetics of in-vitro drug release, specifically in terms of membrane time to burst (t B ) and duration of release (t R ). As shown by results of a one tailed t-test significance testing at the 95% confidence interval (α = 0.05), alginate films were significantly more elastic (p = 0.003), thinner (p = 0.004) and more susceptible to osmotic burst (p = 0.011) and characterized by a longer duration of release (p = 0.03). Meanwhile chitosan films exhibited superior moisture permeability (p = 0.006) and sorption characteristics (p = 0.001), indicative of higher hydrophilicity. There were no significant differences in tensile strength (p = 0.324) for alginate and chitosan-based formulations. Preliminary testing was conducted using 0.71 μm in diameter microspheres for modeling film dissolution into Lactated Ringer's solution. Experimental release profiles were modeled for each film from which the average release from alginate films (M AGCa  = 81%) was estimated to be twice the percentage associated with chitosan films (M CD  = 42%). The film comprised of 2.5% (w/v) medium MW chitosan/dextran 70 kDa (5:1) was selected for studying the release of 5-Fluorouracil (5-FU) as a model hydrophobic drug. Diffusion coupled with film disintegration is immediate (t B  = 0) in case of encapsulated 5-FU as compared to the control film encapsulating microspheres characterized by t B  = 70 min ± 7 min. This shift in release profile and the ability to modulate the timing of membrane burst can be attributed to the approximate ratio (1: 505) in molecular size between drug and microsphere. This hypothesis has been validated by the film pore size measured to be 430 nm ± 88 nm using atomic force microscopy.

Yeast aging and apoptosis

A concerted balance between proliferation and apoptosis is essential to the survival of multicellular organisms. Thus, apoptosis per se, although it is a destructive process leading to the death of single cells, also serves as a pro-survival mechanism pro-survival mechanism that ensures healthy organismal development and acts as a life-prolonging or anti-aging anti-aging program. The discovery that yeast also possess a functional and, in many cases, highly conserved apoptotic machinery has made it possible to study the relationships between aging and apoptosis in depth using a well-established genetic system and the powerful tools available to yeast researchers for investigating complex physiological and cytological interactions. The aging process of yeast, be it replicative replicative or chronological chronological aging, is closely related to apoptosis, although it remains unclear whether apoptosis is a causal feature of the aging process or vice versa. Nevertheless, experimental results obtained during the past several years clearly demonstrate that yeast serve as a powerful and versatile experimental system for understanding the interconnections between these two fundamentally important cellular and physiological pathways.

In vitro evaluation of the safe margin, antithrombotic and antiproliferative actions for the treatment of restenosis: Nitric oxide donor and polymers

Drug-eluting stents (DES) were developed to combat the problem of in-stent restenosis, and evaluating the biological activity from DES systems is critical for its safety and efficacy. To test the cytotoxicity of nitric oxide (NO) donor-containing polymers for their potential use in DES applications, S-nitrosoglutathione (GSNO) or in combination with poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) in an aqueous polymeric solution (PVA/PVP/GSNO) was investigated using Balb/c 3T3 and Rabbit arterial smooth muscle (RASM) cells. The sensitivity of 3T3 cells to the cytotoxicity effects induced by GSNO was higher than that of RASM cells, while RASM cells were more susceptible to alterations in membrane permeability. Cell growth assays showed that GSNO and PVA/PVP/GSNO induced antiproliferative effects in RASM cells. Moreover, the presence of polymers can reduce the cytotoxicity and enhance the antiproliferative effects of GSNO. Dose-dependent inhibition of platelet aggregation was similar for both PVA/PVP/GSNO (EC50 of 3.4 ± 2.3 µM) and GSNO (EC50 of 2.8 ± 1.1 µM) solutions. Platelet adhesion assays showed that the inhibition caused by GSNO (EC50 of 5.0 mM) was dependent on the presence of plasma. These results demonstrate that the methodology adopted here is suitable to establish safety margins and evaluate the antithrombotic potential and antiproliferative effects of NO-eluting biomaterials and polymeric solutions for the new cardiovascular devices, and also to emphasize the importance of using more specific cell lines in these evaluations.

Effect of polyvinylpyrrolidone on bovine oocyte maturation in vitro and subsequent fertilization and embryonic development

The exact role of polyvinylpyrrolidone (PVP) in culture medium for oocyte maturation is still largely unknown. Bovine cumulus-oocyte complexes (COC) were cultured in in-vitro maturation (IVM) medium supplemented with 10% fetal bovine serum (FBS), 0.3% PVP (K-90) or 10% serum substitute supplement (SSS) respectively. The rates of oocyte maturation, fertilization and early embryonic development were evaluated. In addition, the status of DNA fragmentation in the oocytes was determined by comet assay, and the ratio of trophectoderm (TE) cells and inner cell mass (ICM) in blastocysts was determined by differential staining. Furthermore, the percentage of apoptotic cells in the blastocysts was examined by TUNEL assay. The results indicated that the effect of PVP in IVM medium was similar to FBS in terms of oocyte maturation and subsequent embryonic development. However, the addition of SSS in IVM medium retarded further embryonic development and resulted in more oocyte DNA fragmentation and a higher ratio of TE cells and ICM in the blastocysts. However, the number of apoptotic cells in blastocysts was similar among the three groups. These results suggest for the first time that the addition of PVP in oocyte maturation medium is not only a suitable substitute for serum but is also beneficial to in-vitro oocyte maturation.

Caspase 3, periodically expressed and activated at G2/M transition, is required for nocodazole-induced mitotic checkpoint

Caspases have been known for several years for their involvement in executing apoptosis, where unwanted or damaged cells are eliminated. Surprisingly, after analysis of the relevant data set from the Stanford microarray database, we noticed that the gene expression pattern for caspase 3, but not for caspase 1, 6, 7, 8, 9, or 10, undergoes periodic change in the HeLa cell cycle. In this study, we have demonstrated that caspase 3, but not other caspases, is upregulated and activated just prior to mitosis. Pretreatment of human hepatoma cells with a caspase 3 inhibitor z-DEVD-FMK, prior to the treatment with an antimicrotubule drug nocodazole, abrogates the mitotic arrest, suggesting that caspase 3 (or a caspase 3-like enzyme) might be involved in mitotic-spindle checkpoint. The studies not only characterize caspase 3 as a cell cycle-regulated protein, but also link the protein to nocodazole-dependent mitotic checkpoint, greatly expanding the understanding of caspase 3.

Sophorolipid produced from the new yeast strain Wickerhamiella domercqiae induces apoptosis in H7402 human liver cancer cells

The effects of sophorolipid on the growth and apoptosis of H7402 human liver cancer cells were investigated. By treatment with sophorolipid, a dose- and time-dependent inhibition of cell proliferation was observed. The cells developed many features of apoptosis, including condensation of chromatin, nuclear fragmentation, and appearance of apoptotic bodies, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling positive cells were stained dark brown. Sophorolipid treatment induced apoptosis in H7402 cells by blocking cell cycle at G1 phase and partly at S phase, activating caspase-3, and increasing Ca2+ concentration in cytoplasm. These findings may suggest a potential use of sophorolipid for liver cancer treatment.

Grifolin, a potential antitumor natural product from the mushroom Albatrellus confluens, inhibits tumor cell growth by inducing apoptosis in vitro

Grifolin is a natural biologically active substance isolated from the fresh fruiting bodies of the mushroom Albatrellus confluens. Here, for the first time, we describe a novel activity of grifolin, namely its ability to inhibit the growth of tumor cells by the induction of apoptosis. Grifolin strongly inhibited the growth of tumor cell lines: CNE1, HeLa, MCF7, SW480, K562, Raji and B95-8. Analysis of acridine orange (AO)/ethidium bromide (EB) staining and flow cytometry showed that grifolin possessed apoptosis induction activity to CNE1, HeLa, MCF7 and SW480. Furthermore, the cytochrome c release from mitochondria was detected by confocal microscopy in CNE1 cells after a 12h treatment with grifolin. The increase of caspase-8, 9, 3 activities revealed that caspase was a key mediator of the apoptotic pathway induced by grifolin, and the underexpression of Bcl-2 and up-regulation of Bax resulted in the increase of Bax: Bcl-2 ratio, suggesting that Bcl-2 family involved in the control of apoptosis. Owing to the combination of the significant antitumor activity by inducing apoptosis and natural abundance of the compound, grifolin holds the promise of being an interesting antitumor agent that deserves further laboratory and in vivo exploration.

Cytotoxicity of thermosensitive polymers poly(N-isopropylacrylamide), poly(N-vinylcaprolactam) and amphiphilically modified poly(N-vinylcaprolactam)

Thermosensitive polymers poly(N-isopropylacrylamide) (PNIPAM), poly(N-vinylcaprolactam) (PVCL) and PVCL grafted with amphiphilic poly(ethylene oxide) (PEO) chains (PVCL-graft-C11EO42) were prepared and characterized and their putative cytotoxicity was evaluated. The cytotoxicity of these thermosensitive polymers and their monomers was investigated as a function of polymer concentration, incubation time and incubation temperature by using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) cytotoxicity tests in Caco-2 and Calu-3 cell cultures. Also, the influence of the chain end functionality on toxicity was examined. Viability (MTT) and cellular damage (LDH) of the cells were shown to be dependent on the surface properties of the polymers, hydrophilicity or hydrophobicity. Hydrophilic PVCL and PVCL-graft-C11EO42 were well tolerated at all polymer concentrations (0.1-10.0 mg/ml) after 3 h of incubation at room temperature and at physiological temperature (37 degrees C). The more hydrophobic PNIPAM induced more clear cellular cytotoxicity at 37 degrees C. The monomers N-isopropylacrylamide and vinylcaprolactam and PEO-macromonomer showed dramatically higher cytotoxicity values with respect to the corresponding polymers. Cell damage was directly dependent on concentration, temperature and incubation time.