In-Vitro Cytotoxicity and Clinical Correlates of MRSA Bacteremia

Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections are associated with significant morbidity and mortality. MRSA secretes a number of virulence factors and pore-forming toxins that enable tissue invasion. Prior studies have found associations between decreased toxin production and poor outcomes in invasive MRSA infection, particularly in pneumonia. In this retrospective observational cohort study of MRSA bacteremia in adult patients 2007-2015, we examined whether cytotoxicity was associated with 30-day mortality. Isolates were obtained from 776 patients and screened for cytotoxicity in a human HL-60 cell model, antimicrobial susceptibility and spa type, and clinical data were abstracted from charts. We did not find an association between low cytotoxic activity and 30-day mortality in univariate logistic regression analyses. There was a difference in distribution of the genotypes across cytotoxicity phenotypes, with spa -CC008 accounting for a larger proportion of isolates in the high cytotoxicity group. Isolates with a skin and soft tissue primary infective site had a higher median cytotoxicity. There was no association between cytotoxicity and host factors such as age or comorbidity burden. The isolates in our study came from heterogeneous primary sites of infection and were predominantly from spa -CC002 and spa -CC008 lineages, so it is possible that findings in prior studies reflect a different distribution in genotypes and clinical syndromes. Overall, in this large study of cytotoxicity of MRSA bloodstream isolates, we did not find the low cytotoxicity phenotype to be predictive of poor outcomes in MRSA bacteremia.

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Punicalagin Regulates Key Processes Associated with Atherosclerosis in THP-1 Cellular Model

Pharmaceuticals ◽

10.3390/ph13110372 ◽

2020 ◽

Vol 13 (11) ◽

pp. 372

Author(s):

Sanaa Almowallad ◽

Etimad Huwait ◽

Rehab Al-Massabi ◽

Salma Saddeek ◽

Kalamegam Gauthaman ◽

...

Keyword(s):

Cholesterol Efflux ◽

Cell Model ◽

In Vitro Cytotoxicity ◽

Intercellular Adhesion Molecule ◽

Potential Candidate ◽

Monocyte Chemoattractant Protein 1 ◽

Cytotoxicity Assays ◽

Monocyte Migration ◽

Ifn Γ

Atherosclerosis may lead to cardiovascular diseases (CVD), which are the primary cause of death globally. In addition to conventional therapeutics for CVD, use of nutraceuticals that prevents cholesterol deposition, reduce existing plaques and hence anti-atherosclerotic effects of nutraceuticals appeared to be promising. As such, in the present study we evaluated the beneficial effects of punicalagin, a phytochemical against an atherosclerotic cell model in vitro. Cytotoxicity assays were examined for 10 µM concentration of punicalagin on THP-1 macrophages. Real-time-polymerase chain reaction (RT-PCR) was used to analyze monocyte chemoattractant protein-1 (MCP-1) and Intercellular adhesion molecule (ICAM-1) expressions. Monocyte migration and cholesterol efflux assays were performed to investigate punicalagin’s further impact on the key steps of atherosclerosis. Cytotoxicity assays demonstrated no significant toxicity for punicalagin (10 µM) on THP-1 macrophages. Punicalagin inhibited the IFN-γ-induced overexpression of MCP-1 and ICAM-1 in macrophages by 10 fold and 3.49 fold, respectively, compared to the control. Punicalagin also reduced the MCP-1- mediated migration of monocytes by 28% compared to the control. Percentages of cellular cholesterol efflux were enhanced in presence or absence of IFN-γ by 88% and 84% compared to control with 58% and 62%, respectively. Punicalagin possesses anti-inflammatory and anti-atherosclerotic effects. Punicalagin also did not exhibit any cytotoxicity and therefore can be considered a safe and potential candidate for the treatment and prevention of atherosclerosis.

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Characterization of Cetacean Proline-Rich Antimicrobial Peptides Displaying Activity against ESKAPE Pathogens

International Journal of Molecular Sciences ◽

10.3390/ijms21197367 ◽

2020 ◽

Vol 21 (19) ◽

pp. 7367

Author(s):

Riccardo Sola ◽

Mario Mardirossian ◽

Bertrand Beckert ◽

Laura Sanghez De Luna ◽

Dennis Prickett ◽

...

Keyword(s):

Antimicrobial Peptides ◽

Mechanism Of Action ◽

In Vitro Cytotoxicity ◽

Peptide Transporter ◽

Cetacean Species ◽

Activity Spectrum ◽

Low Cytotoxicity ◽

Eskape Pathogens ◽

Bacterial Protein Synthesis

Proline-rich antimicrobial peptides (PrAMPs) may be a valuable weapon against multi-drug resistant pathogens, combining potent antimicrobial activity with low cytotoxicity. We have identified novel PrAMPs from five cetacean species (cePrAMPs), and characterized their potency, mechanism of action and in vitro cytotoxicity. Despite the homology between the N-terminal of cePrAMPs and the bovine PrAMP Bac7, some differences emerged in their sequence, activity spectrum and mode of action. CePrAMPs with the highest similarity with the Bac7(1-35) fragment inhibited bacterial protein synthesis without membrane permeabilization, while a second subgroup of cePrAMPs was more membrane-active but less efficient at inhibiting bacterial translation. Such differences may be ascribable to differences in presence and positioning of Trp residues and of a conserved motif seemingly required for translation inhibition. Unlike Bac7(1-35), which requires the peptide transporter SbmA for its uptake, the activity of cePrAMPs was mostly independent of SbmA, regardless of their mechanism of action. Two peptides displayed a promisingly broad spectrum of activity, with minimal inhibiting concentration MIC ≤ 4 µM against several bacteria of the ESKAPE group, including Pseudomonas aeruginosa and Enterococcus faecium. Our approach has led us to discover several new peptides; correlating their sequences and mechanism of action will provide useful insights for designing optimized future peptide-based antibiotics.

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In vitro cytotoxicity of co-exposure to superparamagnetic iron oxide and solid lipid nanoparticles

Toxicology and Industrial Health ◽

10.1177/0748233720977383 ◽

2020 ◽

pp. 074823372097738

Author(s):

Okunola A Alabi ◽

Adny H Silva ◽

Michele P Rode ◽

Carine dal Pizzol ◽

Angela Machado de Campos ◽

...

Keyword(s):

Iron Oxide ◽

Solid Lipid Nanoparticles ◽

Superparamagnetic Iron Oxide ◽

Lipid Nanoparticles ◽

In Vitro Cytotoxicity ◽

Ros Generation ◽

Solid Lipid ◽

Viability Assay ◽

Low Cytotoxicity

Increased production and use of different types of nanoparticles (NPs) in the last decades has led to increased environmental release of these NPs with potential detrimental effects on both the environment and public health. Information is scarce in the literature on the cytotoxic effect of co-exposure to many NPs as this concern is relatively recent. Thus, in this study, we hypothesized scenarios of cell’s co-exposure to two kinds of NPs, solid lipid nanoparticles (SLNs) and superparamagnetic iron oxide nanoparticles (SPIONs), to assess the potential cytotoxicity of exposure to NPs combination. Cytotoxicity of SPIONs, SLNs, and their 1:1 mixture (MIX) in six tumor and six non-tumor cell lines was investigated. The mechanisms underlining the induced cytotoxicity were studied through cell cycle analysis, detection of reactive oxygen species (ROS), and alterations in mitochondrial membrane potential (ΔΨM). Double staining with acridine orange and ethidium bromide was also used to confirm cell morphology alterations. The results showed that SPIONs induced low cytotoxicity compared to SLNs. However, the mixture of SPIONs and SLNs showed synergistic, antagonistic, and additive effects based on distinct tests such as viability assay, ROS generation, ΔΨM, and DNA damage, depending on the cell line. Apoptosis triggered by ROS and disturbances in ΔΨM are the most probable related mechanisms of action. As was postulated, there is possible cytotoxic interaction between the two kinds of NPs.

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Atom-Precise Fluorescent Copper Cluster for Tumor Microenvironment Targeting and Transient Chemodynamic Cancer Therapy

10.21203/rs.3.rs-853200/v1 ◽

2021 ◽

Author(s):

Zhenzhen Yang ◽

Anli Yang ◽

Wang Ma ◽

Kai Ma ◽

Ya-Kun Lv ◽

...

Keyword(s):

Tumor Microenvironment ◽

Cancer Therapy ◽

Dependent Manner ◽

Metal Nanoclusters ◽

Concentration Dependent Manner ◽

In Vivo Experiments ◽

Low Cytotoxicity ◽

High Cytotoxicity

Abstract Background: Reactive oxygen species (ROS) have been widely studied for cancer therapy. Nevertheless, instability and aspecific damages to cellular biomolecules limited the application effect. Recently, significant research efforts have been witnessed in the flourishing area of metal nanoclusters (NCs) with atomically precise structures for targeted release of ROS but few achieved success towards targeting tumor microenvironment.Results: In this work, we reported an atomically precise nanocluster Cu6(C4H3N2S)6 (Cu6NC), which could slowly break and generate ROS once encountered with acidic. The as-prepared Cu6NC demonstrated high biological safety and efficient chemodynamic anti-tumor properties. Moreover, Cu6NC enabled transient release of ROS and contained targeting behavior led by the tumor microenvironment. Both in vitro and in vivo experiments confirmed that Cu6NC demonstrated a low cytotoxicity for normal cells, while presented high cytotoxicity for tumor cells with a concentration-dependent manner.Conclusions: This work not only reported a promising candidate for chemodynamic cancer therapy, but also paved the route to address clinical issues at the atomic level.

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Role of the Agr-Like Quorum-Sensing System in Regulating Toxin Production by Clostridium perfringens Type B Strains CN1793 and CN1795

Infection and Immunity ◽

10.1128/iai.00438-12 ◽

2012 ◽

Vol 80 (9) ◽

pp. 3008-3017 ◽

Cited By ~ 35

Author(s):

Jianming Chen ◽

Bruce A. McClane

Keyword(s):

Quorum Sensing ◽

Clostridium Perfringens ◽

Cell Model ◽

Toxin Production ◽

Type B ◽

Wild Type ◽

Content Type ◽

Culture Supernatants ◽

Null Mutants

ABSTRACTClostridium perfringenstype B causes enteritis and enterotoxemia in domestic animals. By definition, these bacteria must produce alpha toxin (CPA), beta toxin (CPB) and epsilon toxin (ETX) although most type B strains also produce perfringolysin O (PFO) and beta2 toxin (CPB2). A recently identified Agr-like quorum-sensing (QS) system inC. perfringenscontrols all toxin production by surveyed type A, C, and D strains, but whether this QS is involved in regulating toxin production by type B strains has not been explored. Therefore, the current study introducedagrBnull mutations into type B strains CN1795 and CN1793. Both type BagrBnull mutants exhibited reduced levels of CPB, PFO, and CPA in their culture supernatants, and this effect was reversible by complementation. The reduced presence of CPB in culture supernatant involved decreasedcpbtranscription. In contrast, theagrBnull mutants of both type B strains retained wild-type production levels of ETX and CPB2. In a Caco-2 cell model of enteritis, culture supernatants of the type BagrBnull mutants were less cytotoxic than supernatants of their wild-type parents. However, in an MDCK cellin vitromodel for enterotoxemic effects, supernatants from theagrBnull mutants or wild-type parents were equally cytotoxic after trypsin activation. Coupling these and previous results, it is now evident that strain-dependent variations exist in Agr-like QS system regulation ofC. perfringenstoxin production. The cell culture results further support a role for trypsin in determining which toxins contribute to disease involving type B strains.

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Anticancer Conjugates and Cocktails Based on Methotrexate and Nucleoside Synergism

Clinical medicine Oncology ◽

10.4137/cmo.s2113 ◽

2009 ◽

Vol 3 ◽

pp. CMO.S2113 ◽

Cited By ~ 1

Author(s):

Anthony R. Vortherms ◽

Hester N. Dang ◽

Robert P. Doyle

Keyword(s):

Nucleoside Analogs ◽

In Vitro Cytotoxicity ◽

Drug Resistant ◽

Ovarian Cell ◽

Cytotoxicity Assays ◽

High Cytotoxicity ◽

Nanomolar Range ◽

Low Activity

Conjugates of methotrexate (MTX) and the nucleoside analogs 3-azidodeoxythymidine (AZT), iododeoxyuridine (IUdR) and dideoxycytidine (ddC) linked using poly(ethyleneglycol) are presented. In vitro cytotoxicity assays of the conjugates against drug resistant ovarian cell line A2780/AD are preformed and comparisons made to such assays performed for unconjugated (cocktail) systems. All systems tested were inactive, or had low activity, at 24 h. After 72 hr incubation however, the cocktails of MTX and AZT, IUdR or ddC showed high cytotoxicity in the low nanomolar range. The conjugates were only very moderately active with IC50 values in the [0.1 to 1.0 mM] range. Conjugation of the antifolate to the nucleoside analogs has it seems reduced the activity significantly when compared to a cocktail of the components, indicating a conjugate approach is unlikely to translate into success in vivo. The positive note comes from the observation that by combining two of the new conjugates, namely those based on MTX with IUdR or AZT, an IC50 at 24 hours of~ [180 μM] was produced.

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Development of an Acid-Labile Ketal Linked Amphiphilic Block Copolymer Nanoparticles for pH-Triggered Release of Paclitaxel

Polymers ◽

10.3390/polym13091465 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1465

Author(s):

Svetlana Lukáš Petrova ◽

Eliézer Jäger ◽

Alessandro Jäger ◽

Anita Höcherl ◽

Rafał Konefał ◽

...

Keyword(s):

Delivery System ◽

Cell Model ◽

Degradation Products ◽

Monomethyl Ether ◽

In Vitro Cytotoxicity ◽

Triggered Release ◽

Cytotoxicity Studies ◽

Endosomal Ph ◽

Acid Labile

Here, we report on the construction of biodegradable poly(ethylene oxide monomethyl ether) (MPEO)-b-poly(ε-caprolactone) (PCL) nanoparticles (NPs) having acid-labile (acyclic ketal group) linkage at the block junction. In the presence of acidic pH, the nanoassemblies were destabilized as a consequence of cleaving this linkage. The amphiphilic MPEO-b-PCL diblock copolymer self-assembled in PBS solution into regular spherical NPs. The structure of self-assemble and disassemble NPs were characterized in detail by dynamic (DLS), static (SLS) light scattering, small-angle X-ray scattering (SAXS), and transmission electron microscopy (TEM). The key of the obtained NPs is using them in a paclitaxel (PTX) delivery system and study their in vitro cytostatic activity in a cancer cell model. The acid-labile ketal linker enabled the disassembly of the NPs in a buffer simulating an acidic environment in endosomal (pH ~5.0 to ~6.0) and lysosomal (pH ~4.0 to ~5.0) cell compartments resulting in the release of paclitaxel (PTX) and formation of neutral degradation products. The in vitro cytotoxicity studies showed that the activity of the drug-loaded NPs was increased compared to the free PTX. The ability of the NPs to release the drug at the endosomal pH with concomitant high cytotoxicity makes them suitable candidates as a drug delivery system for cancer therapy.

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Synthesis and Comparative Characterization of Different Microparticles used as Biomaterials in Dentistry

Materiale Plastice ◽

10.37358/mp.21.2.5491 ◽

2021 ◽

Vol 58 (2) ◽

pp. 192-200

Author(s):

Sergiu Alexandru Tofan ◽

Cristian Olteanu ◽

Camelia Szuhanek ◽

ramona Amina Popovici ◽

Magda Mihaela Luca ◽

...

Keyword(s):

Living System ◽

In Vitro Cytotoxicity ◽

Functional Requirements ◽

Clinical Evaluations ◽

Polymeric Microparticles ◽

Great Availability ◽

Low Cytotoxicity ◽

Materials Used

A biomaterial must be biologically compatible, mechanical, functional, corrosion resistant and easily adapt to clinical and laboratory technologies. Dental biomaterials are materials used to replace a part of a living system or to work closely with living tissue. Many scientific articles present different polymeric biocomposites with possible application in dentistry and this is a proof of the opportunity of a research in a field in full ascent and with great availability in the promotion of materials destined to �work under biological constraint� and which must also meet the functional requirements of a dental implant. The objectives of this research were to obtain and to comparatively evaluate different polymeric microparticles that can be used in dentistry. The samples based on poly(lactic-co-glycolic acid) and respectively polyurethane microparticles were characterized by pH and Zetasizer measurements, and in vitro cytotoxicity assays. The results indicate the obtaining of particles with a neutral pH, medium homogeneity, and with different tendencies to form agglomerations. Their low cytotoxicity, tested on the primary human gingival fibroblasts by MTT and LDH techniques, indicates that these microparticles are safe to be tested in further clinical evaluations.

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Robust Copper Metal–Organic Framework-Embedded Polysiloxanes for Biomedical Applications: Its Antibacterial Effects on MRSA and In Vitro Cytotoxicity

Nanomaterials ◽

10.3390/nano11030719 ◽

2021 ◽

Vol 11 (3) ◽

pp. 719

Author(s):

Kihak Gwon ◽

Youngmee Kim ◽

Hyunjun Cho ◽

Seonhwa Lee ◽

So-Hyeon Yang ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Metal Organic Framework ◽

In Vitro Cytotoxicity ◽

Disease Treatment ◽

Metal Organic ◽

Bactericidal Activities ◽

Low Cytotoxicity ◽

Phosphate Buffered Saline ◽

Organic Framework

Polysiloxanes (PSs) have been widely utilized in the industry as lubricants, varnishes, paints, release agents, adhesives, and insulators. In addition, their applications have been expanded to include the development of new biomedical materials. To modify PS for application in therapeutic purposes, a flexible antibacterial Cu-MOF (metal–organic framework) consisting of glutarate and 1,2-bis(4-pyridyl)ethane ligands was embedded in PS via a hydrosilylation reaction of vinyl-terminated and H-terminated PSs at 25 °C. The bactericidal activities of the resulting Cu-MOF-embedded PS (PS@Cu-MOF) and the control polymer (PS) were tested against Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus. PS@Cu-MOF exhibited more than 80% bactericidal activity toward the tested bacteria at a concentration of 100 μg⋅mL−1 and exhibited a negligible cytotoxicity toward mouse embryonic fibroblasts at the same concentration. Release tests of the Cu(II) ion showed PS@Cu-MOF to be particularly stable in a phosphate-buffered saline solution. Furthermore, its physical and thermal properties, including the phase transition, rheological measurements, swelling ratio, and thermogravimetric profile loss, were similar to those of the control polymer. Moreover, the low cytotoxicity and bactericidal activities of PS@Cu-MOF render it a promising candidate for use in medicinal applications, such as in implants, skin-disease treatment, wound healing, and drug delivery.

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Atom-precise fluorescent copper cluster for tumor microenvironment targeting and transient chemodynamic cancer therapy

Journal of Nanobiotechnology ◽

10.1186/s12951-021-01207-6 ◽

2022 ◽

Vol 20 (1) ◽

Author(s):

Zhenzhen Yang ◽

Anli Yang ◽

Wang Ma ◽

Kai Ma ◽

Ya-Kun Lv ◽

...

Keyword(s):

Tumor Microenvironment ◽

Cancer Therapy ◽

Dependent Manner ◽

Metal Nanoclusters ◽

Concentration Dependent Manner ◽

In Vivo Experiments ◽

Low Cytotoxicity ◽

High Cytotoxicity

Abstract Background Reactive oxygen species (ROS) have been widely studied for cancer therapy. Nevertheless, instability and aspecific damages to cellular biomolecules limit the application effect. Recently, significant research efforts have been witnessed in the flourishing area of metal nanoclusters (NCs) with atomically precise structures for targeted release of ROS but few achieved success towards targeting tumor microenvironment. Results In this work, we reported an atomically precise nanocluster Cu6(C4H3N2S)6 (Cu6NC), which could slowly break and generate ROS once encountered with acidic. The as-prepared Cu6NC demonstrated high biological safety and efficient chemodynamic anti-tumor properties. Moreover, Cu6NC enabled transient release of ROS and contained targeting behavior led by the tumor microenvironment. Both in vitro and in vivo experiments confirmed that Cu6NC demonstrated a low cytotoxicity for normal cells, while presented high cytotoxicity for tumor cells with a concentration-dependent manner. Conclusions This work not only reported a promising candidate for chemodynamic cancer therapy, but also paved the route to address clinical issues at the atomic level. Graphical Abstract

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