Destruction Of Cell Membrane Research Articles

Antibacterial properties and mechanism of graphene oxide-silver nanocomposites as bactericidal agents for water disinfection

Providing clean and affordable drinking water without harmful disinfection byproducts generated by conventional chemical disinfectants gives rise to the need for technological innovation. Nanotechnology has great potential in purifying water and wastewater treatment. A graphene oxide-silver (GO-Ag) nanocomposite with excellent antibacterial activity was prepared and characterized by transmission electron microscope and X-ray photoelectron spectroscopy. The tests were carried out using Escherichia coli and Staphylococcus aureus as model strains of Gram-negative and Gram-positive bacteria, respectively. The effect of bactericide dosage and pH on antibacterial activity of GO-Ag was examined. Morphological observation of bacterial cells by scanning electron microscope showed that GO-Ag was much more destructive to cell membrane of Escherichia coli than that of Staphylococcus aureus. Experiments were carried out using catalase, superoxide dismutase and sodium thioglycollate to investigate the formation of reactive oxygen species and free silver ions in the bactericidal process. The activity of intracellular antioxidant enzymes was measured to investigate the potential role of oxidative stress. According to the consequence, synergetic mechanism including destruction of cell membranes and oxidative stress accounted for the antibacterial activity of GO-Ag nanocomposites. All the results suggested that GO-Ag nanocomposites displayed a good potential for application in water disinfection.

Detoxification and function of immature tomato

α-Tomatine and chlorophyll (a and b) decreased, and β-carotene and lycopene increased with ripening of tomatoes. α-Tomatine was localised in peel of immature green tomatoes. The dose–response curve of α-tomatine determined by WST-1 (water soluble tetrazolium) assay was the same as that by LDH (lactate dehydrogenase) assay, suggesting that the cytotoxicity of α-tomatine depends on the destruction of plasma membrane. Immature green tomatoes had little cytotoxic effect after one month-incubation with 25% ethanol or 4.5% acetate at 7°C, and α-tomatine was decomposed by crude enzymes extracted from immature green tomatoes. Immature green tomatoes incubated with 4.5% acetic acid inhibited the accumulation of lipid in adipocytes. From the above facts the detoxification and the anti-obesity effect of immature green tomatoes are expected to be controlled by the removal of peel, the enzymatic decomposition or the incubation with 4.5% acetate or 25% ethanol.

Boron doped BiOBr nanosheets with enhanced photocatalytic inactivation of Escherichia coli

Boron (B) doped bismuth oxybromide (B-BiOBr) nanosheets were synthesized using a hydrothermal method and their photocatalytic activities were investigated through inactivating a typical bacterium, Escherichia coli K-12 using fluorescence tubes as visible light (VL) sources. B atoms are successfully doped into the crystal lattice of BiOBr. However, the morphology, crystal structure, and {001}-facet exposed feature of B-BiOBr nanosheets remains unchanged compared with pure BiOBr nanosheets. Significantly, the as-prepared B-BiOBr nanosheets show superior activity in the photocatalytic inactivation of E. coli K-12 over pure BiOBr nanosheets under VL irradiation. Photogenerated h+ is evidenced to be the major reactive species accounting for the inactivation process of B-BiOBr. With its electron-deficient characteristics, the B dopant is favorable to accept extra e− from VB of BiOBr, leading to improved charge carrier separation efficiency. The greatly enhanced bacterial inactivation efficiency was attributed to the synergic advantages of enhanced VL adsorption capability and more amount of photogenerated h+ with higher oxidative ability. In addition, the destruction process of bacterial cell was also observed from the destruction of cell membrane to the intracellular components.

Investigations of the effectiveness of nanoemulsions from sage oil as antibacterial agents on some food borne pathogens

There is growing interest in the development of natural antimicrobials to preserve foods. In this research, Sage (Salvia officinalis) essential oil was converted into a nanoemulsion using nonionic surfactants (Tween 80, Span 80) and high-intensity sonication. The antimicrobial activity of essential oil nanoemulsions (d ≈ 222 nm) was compared to that of pure essential oil against food-borne bacteria (Escherichia coli, Shigella dysentery, and Salmonella typhi) using minimum inhibitory and bactericidal concentration (MIC and MBC) methods. The antibacterial activity of the nanoemulsion was four-times higher than the bulk oil against E. coli and S. typhi. Kinetic studies showed that the nanoemulsions could destroy all the E. coli in about 10 min, whereas <50% of the bacteria were killed using pure oil. The potential mechanism of antibacterial activity of the pure and nanoemulsified oils was investigated using protein release, nucleic acid release, and potassium leakage studies, as well as infrared and electron microscopy analysis of the cell membranes. The results showed extensive bacterial cell membrane damage after nanoemulsion treatment. These results indicate that conversion of sage oil into a nanoemulsion improved its antibacterial activity by enhancing its ability to promote the destruction of bacterial cell membranes.

Efficient algal lipid extraction via photocatalysis and its conversion to biofuel

Microalgae play an important role in energy production to solve the major energy crisis. The present study demonstrates an efficient and environmental friendly route for bio-oil extraction from wet Nannochloropsis oculata algal biomass through photocatalysis. The method uses abundant solar energy and catalytic amount of titanium dioxide photocatalyst for the rupturing of wet algal cells and reduces most of the cost by avoiding dewatering and drying, for algal oil production. The various spectroscopy and microscopy techniques used show destruction of algal cell membrane by the photocatalyst, with a release of 52.2% lipid yield. The obtained lipid by photocatalysis on esterification yields biofuel which is in complete agreement with results obtained from conventional techniques. Algal oil is converted to biofuel through acid catalyzed transesterification. Bio-oil and biofuel samples were analyzed by ATR-IR, NMR and GCMS. The physicochemical characterization of photocatalyst was carried out by UV–Visible spectroscopy, XRD, EDS, BET and electron microscopy studies. The results suggest that the nanoparticles are efficient catalysts for rupturing the rigid micro algal cell membrane in an aqueous environment, using sunlight and hence prove to be a potential economic method for large scale bio-oil extraction.

Antibacterial/Antiviral Property and Mechanism of Dual-Functional Quaternized Pyridinium-type Copolymer

Due to the massive outbreaks of pathogen-caused diseases and the increase of drug-resistant pathogens, there is a particular interest in the development of novel disinfection agents with broad-spectrum antipathogenic activity. In the present study, water-soluble pyridinium-type polyvinylpyrrolidones with different counter anions were prepared. Structural characterization was conducted via 13C–1H heteronuclear single quantum coherence spectroscopy, static light scattering, UV spectrometry and apparent charge density. The influence of counter anion and polymer compositions on the antibacterial activity was studied against Staphylococcus aureus and Escherichia coli. Atomic force microscopy (AFM) was applied for tracking the morphological alterations in bacterial cells induced by prepared polycations. It was found that the exposure of bacteria to the polycations resulted in the destruction of cell membranes and the leakage of cytoplasm. The antiviral activity of pyridinium-type polycations against enveloped influenza virus was evaluated via a plaque assay. The action mode against enveloped virus was depicted to rationalize the antiviral mechanism.

Glycoalkaloid isolation fromSolanum linnaeanumberries

Introduction. Glycoalkaloids are plant secondary metabolites that can be both harmful and beneficial to human health. They cause gastroenteric symptoms, coma and even death at high concentrations. It is thought that glycoalkaloids are toxic to human health as a result of their effects on the nervous system and destruction of cell membranes. On the other hand, glycoalkaloids can be effective drugs. For example, solasodine is used to treat skin cancer and tomatidine is used in cancer chemotherapy. Solasodine is also used as a precursor of steroidal drugs. The goal of the work was to isolate and separate efficiently these similar compounds. Materials and methods. Glycoalkaloids from Solanum linnaeanum berries were isolated using column chromatography and confirmed via NMR spectroscopy and MS/MS spectrometry. Results and discussion. The chemical structures of glycoalkaloids are nearly identical. For example, solamargine differs from solasonine in having a methyl group instead of a hydroxyl group bound to the sugar residue of the compound. Thus, their molecular weight and polarity are quite similar. In this work, the process yielded 37.1 mg solasonine, 92.3 mg solasonine and solamargine mix and 56.2 mg solamargine from 81.67 g dried S. linnaeanum berries. Conclusion. Solanum linnaeanum berries are a good source of these glycoalkaloids and the developed protocol proved efficient for purification of solasonine and solamargine.

ВПЛИВ ІНФУЗІЙНИХ РОЗЧИНІВ ЛАКТОПРОТЕЇНУ З СОРБІТОЛОМ ТА HAESLX- 5% НА БІОХІМІЧНІ МАРКЕРИ ФІБРОГЕНЕЗУ ЛЕГЕНЕВОЇ ТКАНИНИ В ЩУРІВ З ОПІКОВОЮ ТРАВМОЮ ШКІРИ

&lt;p&gt;&lt;strong&gt;INFLUENCE &lt;/strong&gt;&lt;strong&gt;of&lt;/strong&gt;&lt;strong&gt; &lt;/strong&gt;&lt;strong&gt;laktoprotein&lt;/strong&gt;&lt;strong&gt;um&lt;/strong&gt;&lt;strong&gt; with sorbitol and HAES-LX-5% infusion&lt;/strong&gt;&lt;strong&gt;’S&lt;/strong&gt;&lt;strong&gt; solutions &lt;/strong&gt;&lt;strong&gt;on&lt;/strong&gt;&lt;strong&gt; biochemical markers of fibrogenesis lung tissue in rats with &lt;/strong&gt;&lt;strong&gt;skin&lt;/strong&gt;&lt;strong&gt; burn trauma &lt;/strong&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Ocheretnyuk&lt;/strong&gt;&lt;strong&gt; &lt;/strong&gt;&lt;strong&gt;A&lt;/strong&gt;&lt;strong&gt;.А. &lt;/strong&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;VinnytsiaNationalMedicalUniversityby M.I. Pyrogov &lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Summary. &lt;/strong&gt;It is shown that in a case of burn disease, especially on day 3, remodeling of connective tissue and oxidative damage phospholipid lungs takes place. Infusion of colloidal hyperosmolar solution - HAES-LX- 5% and lactoproteinum solution with sorbitol equally causes antifibrogenic effect and reduces the severity of oxidative degradation of membrane phospholipids in rats with skin burns. Their protective effect is the most expressive on day 7 of the experiment.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Keywords:&lt;/strong&gt; infusion therapy, fibrogenesis, phospholipids, HAES-LX-5%, lactoproteinum with sorbitol.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Introduction.&lt;/strong&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Trigger mechanisms for alteration of lung tissue under conditions of skin burn injuries is considered a development of oxidative stress accompanied by accumulation of oxidative modification of lipids and destruction of cell membranes. This process is characterized also by remodeling of connective tissue and activation of fibrogenesis processes in the lung tissues. It is quite clear that the efficacy of potential correctors of the lung functional condition is largely determined by their ability to contain the accumulation of reactive free radicals, reduce lesion of bi-lipidic layer of cell membranes, and to detect depressing effect on fibrogenesis in the lung tissue.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="-1"&gt;&lt;strong&gt;Methods.&lt;/strong&gt;&lt;/p&gt;&lt;p class="-1"&gt;The contents of biochemical studies: serum samples were tested for markers of degradation of connective tissue and fibrogenesis (free oxyproline, transforming growth factor-β1), lung homogenate was tested for contents of phosphatidylcholine and &lt;a href="http://www.multitran.ru/c/m.exe?t=5341349_1_2&amp;amp;s1=%EB%E8%E7%EE%F4%EE%F1%F4%E0%F2%E8%E4%E8%EB%F5%EE%EB%E8%ED"&gt;lysophosphatidylcholine&lt;/a&gt;.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results and discussion.&lt;/strong&gt;&lt;/p&gt;&lt;p class="-1"&gt;Skin burn injury causes diverse biochemical and pathophysiological changes in rats in whole and particularly in the lung tissue. Our research has shown that burn disease is accompanied by distortion of phospholipid spectrum of lung tissue, which manifested by decrease of phosphatidylcholine content and increase of its oxidation product - &lt;a href="http://www.multitran.ru/c/m.exe?t=5341349_1_2&amp;amp;s1=%EB%E8%E7%EE%F4%EE%F1%F4%E0%F2%E8%E4%E8%EB%F5%EE%EB%E8%ED"&gt;lysophosphatidylcholine&lt;/a&gt;. Covalent modification of phospholipid membranes in case of burn disease leads to disruption of the permeability of cell membranes and disorders in the cellular pumps required to transport materials and create ion concentration gradient on both sides of cell membrane. Along with these changes, the burn disease is characterized by connective tissue remodeling and fibrogenesis processes activation, as convincingly proved by growth in serum free oxyproline and transforming growth factor TGF-β1. Pharmacological correction of burn disease using HAES-LX-5% and lactoproteinum with sorbitol solutions somewhat normalized ratio of phosphatidylcholine/&lt;a href="http://www.multitran.ru/c/m.exe?t=5341349_1_2&amp;amp;s1=%EB%E8%E7%EE%F4%EE%F1%F4%E0%F2%E8%E4%E8%EB%F5%EE%EB%E8%ED"&gt;lysophosphatidylcholine&lt;/a&gt; in cell membranes of the lung tissue and prevented remodeling of connective tissue and fibrogenesis activation. HAES -LX-5% was proven at least not inferior versus a reference medicine - lactoproteinum with sorbitol- in terms of the above-said effects.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions.&lt;/strong&gt;&lt;/p&gt;&lt;p class="-1"&gt;Skin burn injury in rats accompanied by the development of lung imbalance of lung phospholipids (phosphatidylcholine content reduced by 35-47% and the &lt;a href="http://www.multitran.ru/c/m.exe?t=5341349_1_2&amp;amp;s1=%EB%E8%E7%EE%F4%EE%F1%F4%E0%F2%E8%E4%E8%EB%F5%EE%EB%E8%ED"&gt;lysophosphatidylcholine&lt;/a&gt; grew by 34-66%) and increasing content of connective tissue destruction (free oxyproline - by 60-97%) and fibrogenesis (TGF-β1 – by 58-137%) markers in serum.&lt;/p&gt;&lt;p class="-1"&gt;Administration of colloidal-osmotic solution HAES-LX-5% and lactoproteinum with sorbitol suppressed development of connective tissue remodeling processes of fibrogenesis and oxidative lesion of lungs phosphorlipidic bilayer.&lt;/p&gt;

Fabrication of Ag nanoparticles modified TiO2–CNT heterostructures for enhanced visible light photocatalytic degradation of organic pollutants and bacteria

TiO2 synthesized using polymeric template consisting of polyethylene glycol and polyvinyl alcohol (Tev) and loaded with different wt% of Ag (2%, 6%) was exploited to create covalent bonds with carboxylate functionalized SWCNT/MWCNT moieties. The synthesized Ag free Tev–SWCNTs as well as Ag containing Tev–SWCNTs/MWCNTs have been characterized by UV–visible diffuse reflectance, powder XRD, HRTEM, and selected area electron diffraction (SAED), photoluminescence, Raman, FTIR and N2 sorptiometry. The materials containing Ag displayed high photocatalytic activity towards degradation of rhodamine B dye under visible irradiation (λmax>450nm). Specifically TevAg6–SWCNT has shown the best performance (0.3g/l catalyst, 20ppm RhB conc. and 80min reaction time) due to the synergistic effects derived from TiO2/Ag°/SWCNT heteroarchitectures. The antibacterial activity of synthesized photocatalysts; under visible light irradiations, towards Escherichia coli and Staphylococcus aureus was tested by performing bacterial DNA and agar well diffusion method. The results revealed that TevAg6–SWCNT was able to effectively kill both gram-positive and gram-negative bacteria. Although TevAg6–SWCNT indicated higher Eg values (1.9eV) than TevAg2–MWCNT (1.75cV) and they both exposed not only Ag° nanoparticles but also Ag2O, the former sample confirmed more lethal action against bacterial growth as well as superior photodegradation activity. This was due to delaying the recombination of electrons and holes, increasing the SBET value as well as decreasing the spherical nanoparticles of Ag° to 3nm diameter. The mechanisms of the dye degradation and destruction of bacterial cell membranes indicate the efficacy of OH and O2− as reactive radical intermediates in both processes.

Bactericidal mechanism of BiOI–AgI under visible light irradiation

The BiOI–AgI nanocomposites were synthesized by a solvothermal process, followed by an in-situ ion exchange reaction. The disinfection activities of BiOI–AgI on model cell type, Gram-negative Escherichia coli (E. coli), were examined under visible light irradiation conditions. BiOI–AgI could completely inactivate 5×107CFUmL−1E. coli cells in 18min under visible light irradiation (λ⩾400nm). The bactericidal mechanisms involved in this photocatalytic disinfection process were systematically investigated. Ag+ ions released from the nanocomposites did not contribute to the bactericidal activity of BiOI–AgI. Active species including h+, O2−, e−, and H2O2 generated by BiOI–AgI played important roles in the inactivation of bacteria. Direct contact of bacterial cells and nanoparticles was found to be essential for the disinfection processes. The destruction of cell membrane and emission of cytoplasm directly inactivated the cells. The influence of solution chemistry (pH and ionic strength) on disinfection process was also estimated. Low pH condition was found to be favorable for the inactivation process. High disinfection efficiencies were achieved at a wide range of solution ionic strength (0–1000mM). The reusability of BiOI–AgI were also determined. BiOI–AgI exhibited strong antibacterial activity toward E. coli even in five consecutively reused cycles. This study indicated that the fabricated BiOI–AgI could be potentially utilized to disinfect bacteria in water (even with high salinity).

Glycolytic inhibitors 2-deoxyglucose and 3-bromopyruvate synergize with photodynamic therapy respectively to inhibit cell migration.

Most cancer cells have the specially increased glycolytic phenotype, which makes this pathway become an attractive therapeutic target. Although glycolytic inhibitor 2-deoxyglucose (2-DG) has been demonstrated to potentiate the cytotoxicity of photodynamic therapy (PDT), the impacts on cell migration after the combined treatment has never been reported yet. The present study aimed to analyze the influence of glycolytic inhibitors 2-DG and 3-bromopyruvate (3-BP) combined with Ce6-PDT on cell motility of Triple Negative Breast Cancer MDA-MB-231 cells. As determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltertrazolium-bromide-Tetraz-olium (MTT) assay, more decreased cell viability was observed in 2-DG + PDT and 3-BP + PDT groups when compared with either monotherapy. Under optimal conditions, synergistic potentiation on cell membrane destruction and the decline of cell adhesion and cells migratory ability were observed in both 2-DG + PDT and 3-BP + PDT by electron microscope observation (SEM), wound healing and trans-well assays. Besides, serious microfilament network collapses as well as impairment of matrix metalloproteinases-9 (MMP-9) were notably improved after the combined treatments by immunofluorescent staining. These results suggest that 2-DG and 3-BP can both significantly potentiated Ce6-PDT efficacy of cell migration inhibition.

Viral transduction of the HER2-extracellular domain expands trastuzumab-based photoimmunotherapy for HER2-negative breast cancer cells.

The prognosis of HER2-positive breast cancer has been improved by trastuzumab therapy, which features high specificity and limited side effects. However, trastuzumab-based therapy has shortcomings. Firstly, HER2-targeted therapy is only applicable to HER2-expressing tumors, which comprise only 20-25% of primary breast cancers. Secondly, many patients who initially respond to trastuzumab ultimately develop disease progression. To overcome these problems, we employed virus-mediated HER2 transduction and photoimmunotherapy (PIT) which involves trastuzumab conjugated with a photosensitizer, trastuzumab-IR700, and irradiation of near-infrared light. We hypothesized that the gene transduction technique together with PIT would expand the range of tumor entities suitable for trastuzumab-based therapy and improve its antitumor activity. The HER2-extracellular domain (ECD) was transduced by the adenoviral vector, Ad-HER2-ECD, and PIT with trastuzumab-IR700 was applied in the HER2-negative cancer cells. Ad-HER2-ECD can efficiently transduce HER2-ECD into HER2-negative human cancer cells. PIT with trastuzumab-IR700 induced direct cell membrane destruction of Ad-HER2-ECD-transduced HER2-negative cancer cells. Novel combination of viral transduction of a target antigen and an antibody-based PIT would expand and potentiate molecular-targeted therapy even for target-negative or attenuated cancer cells.

Mechanical/physical methods of cell distribution and tissue homogenization.

This chapter covers the various methods of Mechanical Cell Disruption and Tissue Homogenization that are currently commercially available for processing minute samples (<1 mL) to larger production quantities. These mechanical methods of lysing do not introduce chemicals or enzymes to the system. However, the energies needed when using these "harsh" methods can be high and destroy the very proteins being sought.The destruction of cell membranes and walls by these "harsh" methods is effected by subjecting the cells (1) to shearing by liquid flow, (2) to exploding by pressure differences between inside and outside of cell, (3) to collision forces by impact of beads or paddles, or (4) a combination of these forces. Practical suggestions to optimize each method, where to acquire such equipment, and links to reference sources are included.

Evaluation of the Protective Effects of Savliv Drops in CCL4- Induced Hepatic Fibrosis Albino Rats

Savliv® suspension, is an herbal drug for liver cirrhosis treatment developed by Indian scientists, used to prevent the liver fibrosis induced by carbon tetrachloride (CCL4) in male albino rats. This study provides further evidence on its role as a hepato-therapeutic agent in the experimental rats with CCL4 -induced liver fibrosis. Then Liver tissue and serum were collected. Oral administration of savliv®) drops (750 and 500µl /rat) after CCL4-fibrosis induction showed a significant decrease in the collagen fibre formation and cell membrane destruction. Histopathological examination revealed the regression of collagen fiber and connective tissues percentage between the liver lobules in the CCL4- induced liver fibrotic rats (G4&5) and reconstruction - regeneration of the damaged liver cells after treated rats (G4&5) with savliv drops (750 and 500µl /rat) at week 8, in a dose dependent manner. The serum levels of Glutamic-Oxaloacetic Transaminase (GOT), Glutamic Pyruvic Transaminase (GPT), and alkaline phosphatse (ALP) enzymes were significantly increased in the CCL4-model group in comparison with the control groups (oil: vehicle). Treatment with savliv® drops showed a marked reduction in the above condition. These results further support that the Savliv® drops has the potency of curative effects for liver fibrotic cells induced by toxic agent.

Research on the Development of Ultra High Pressure Fresh-Keeping Packaging Technology

&lt;b&gt; &lt;/b&gt;Ultra high pressure technology is a new type of non thermal processing technology; it is mainly through the structure of the cell wall and cell membrane and cell space destruction of microorganisms, the protein composition of degeneration, the enzyme activity decreased to achieve the purpose of sterilization. This article from the ultra high pressure technology in aquatic products industry, meat industry and fruit and vegetable and its products industry and other aspects of the application status and development direction of ultra high pressure sterilization technology, hope to be able to provide certain support theory in the study of ultra high pressure technology.

Synthesis, characterization, antimicrobial activity and mechanism of a novel hydroxyapatite whisker/nano zinc oxide biomaterial

Postoperative infections remain a risk factor that leads to failures in oral and maxillofacial artificial bone transplantation. This study aimed to synthesize and evaluate a novel hydroxyapatite whisker (HAPw) / nano zinc oxide (n-ZnO) antimicrobial bone restorative biomaterial. A scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD) were employed to characterize and analyze the material. Antibacterial capabilities against Staphylococcus aureus, Escherichia coli, Candida albicans and Streptococcus mutans were determined by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), and kinetic growth inhibition assays were performed under darkness and simulated solar irradiation. The mode of antibiotic action was observed by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). The MIC and MBC were 0.078–1.250 mg ml−1 and 0.156–2.500 mg ml−1, respectively. The inhibitory function on the growth of the microorganisms was achieved even under darkness, with gram-positive bacteria found to be more sensitive than gram-negative, and enhanced antimicrobial activity was exhibited under simulated solar excitation compared to darkness. TEM and CLSM images revealed a certain level of bacterial cell membrane destruction after treatment with 1 mg ml−1 of the material for 12 h, causing the leakage of intracellular contents and bacteria death. These results suggest favorable antibiotic properties and a probable mechanism of the biomaterial for the first time, and further studies are needed to determine its potential application as a postoperative anti-inflammation method in bone transplantation.

Comparative study of homogeneous and heterogeneous photo-oxidative treatment on bacterial cell via multianalytical techniques

• Heterogeneous photocatalyst, nano-titania is proved to be an effective antibacterial agent over the homogeneous neutral Photo-Fenton system. • The different mode of bactericidal activity was evaluated by cultivability, viability, cell permeability, extent of inner cell components release and morphological studies. • The heterogeneous photocatalyst causes disinfection through more of cell permeability unlike the homogeneous photocatalyst. The present article demonstrates the comparative efficiency of homogeneous and heterogeneous photocatalyst on cell membrane destruction using electron microscopy and spectroscopy techniques to understand the mechanism and evolve an effective water disinfection technique. The antibacterial activity of a heterogeneous photocatalyst nano-TiO 2 was compared with a homogeneous neutral Photo-Fenton reagent (Fe 2+/3+ , H 2 O 2 ) against Salmonella typhimurium , a gram negative water borne bacterium. To confirm the extent of both types of photooxidation treatment on bacterial cell, production of MDA, release of RNA, DNA and protein were carefully studied and analyzed. Based on the above experimental results, heterogeneous photocatalyst shows better performance than homogeneous neutral Photo-Fenton system and the difference is attributed to the mode of disinfection in the two systems. The damage of cell membrane and release of inner cell components is higher in heterogeneous system in contrast to the neutral Photo-Fenton system which causes disinfection through both cell membrane and internal cell damage. The entrapped RNA/DNA within the cell up to 80% in Fe 2+ treated bacteria substantiates destruction via internal cell damage.

CORRELATION OF ANTIOXIDANT LEVELS IN SYNOVIAL FLUID TO INTENSITY OF PAIN IN OSTEOARTHRITIS OF KNEE

Abstract Introduction: Osteoarthritis (OA) refers to progressive degeneration of articular cartilage with gradual painful disorganisation of the joint. Lipid peroxidation mediated by free radicals is the major mechanism of cell membrane destruction and cell damage. It is a known that there is an increased oxidative stress in OA and very little is known about the relation between the pain and decreased antioxidant levels. This study aimed at understanding the relation between the level of superoxide dismutase (SOD) and total antioxidant capacity (TAC) of synovial fluid in OA knee with the intensity of pain. Materials and Methods: 30 patients with clinicoradiologically evidence of knee OA were included in the study and pain was scored using Visual Analog Scale. 1ml synovial fluid was aspirated from the knee and superoxide dismutase (SOD) and total antioxidant capacity (TAC) was estimated. Statistical analysis between the pain score and the SOD and the TAC was done independently by Spearman's rank correlation method and correlation coefficient was obtained. Results: It was found that SOD and the TAC values were reduced in our subjects with mean value of 0.06477 ± 0.044814 and 122.51000 ± 50.764829 respectively. The mean value of pain was 6.70 ± 1.317. A significant correlation between SOD level and pain score (p&lt;0.05) was obtained. However, the correlation between TAC level and pain score was not significant (p&gt;0.05). Conclusion: The study concluded that there is a positive correlation between the intensity of pain and SOD levels in the synovial fluid in OA of knee which is due to the increased free radicals produced.

Irreversible electroporation: the evolution of a laboratory technique to be used in interventional oncology

Electroporation involves applying electric field pulses to cells, leading to the alteration or destruction of cell membranes. Irreversible electroporation (IRE) creates permanent defects in cell membranes and induces cell death. By directly targeting IRE to tumors, percutaneous nonthermal ablation is possible. The history of IRE, evolution of concepts, theory, biological applications, and clinical data regarding its safety and efficacy are discussed.

Microbubble-mediated ultrasound enhances the lethal effect of gentamicin on planktonic Escherichia coli.

Previous research has found that low-intensity ultrasound enhanced the lethal effect of gentamicin on planktonic E. coli. We aimed to further investigate whether microbubble-mediated low-intensity ultrasound could further enhance the antimicrobial efficacy of gentamicin. The planktonic E. coli (ATCC 25922) was distributed to four different interventions: control (GCON), microbubble only (GMB), ultrasound only (GUS), and microbubble-mediated ultrasound (GMUS). Ultrasound was applied with 100 mW/cm2 (average intensity) and 46.5 KHz, which presented no bactericidal activity. After 12 h, plate counting was used to estimate the number of bacteria, and bacterial micromorphology was observed with transmission electron microscope. The results showed that the viable counts of E. coli in GMUS were decreased by 1.01 to 1.42 log10 CFU/mL compared with GUS (P < 0.01). The minimal inhibitory concentration (MIC) of gentamicin against E. coli was 1 μg/mL in the GMUS and GUS groups, lower than that in the GCON and GMB groups (2 μg/mL). Transmission electron microscopy (TEM) images exhibited more destruction and higher thickness of bacterial cell membranes in the GMUS than those in other groups. The reason might be the increased permeability of cell membranes for gentamicin caused by acoustic cavitation.