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Yang, Aoran; Cardona, Delia; Barile, Frank A.

doi:10.1023/a:1015328100876

Cited by 30 publications

(12 citation statements)

References 11 publications

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“…58 The resulting IC 50 values (concentration of the nanoclays or byproducts that inhibit cell growth by 50%) were extrapolated from the dose response trend lines derived from raw data (Table S8). IC 50 is an acceptable mean for early measure and comparison of particle cytotoxicity, 59 and could help identify early deleterious mechanisms associated with nanoclays exposure to cellular systems.…”

Section: Resultsmentioning

confidence: 99%

Early Assessment and Correlations of Nanoclay’s Toxicity to Their Physical and Chemical Properties

Wagner

White

Stueckle

et al. 2017

ACS Appl. Mater. Interfaces

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Nanoclays' functionalization with organic modifiers increases their individual barrier properties, thermal stability, and mechanical properties and allows for ease of implementation in food packaging materials or medical devices. Previous reports have shown that, while organic modifiers integration between the layered mineral silicates leads to nanoclays with different degrees of hydrophobicity that become easily miscible in polymers, they could also pose possible effects at inhalation or ingestion routes of exposure. Through a systematic analysis of three organically modified and one pristine nanoclay, we aimed to relate for the first time the physical and chemical characteristics, determined via microscopical and spectroscopical techniques, with the potential of these nanoclays to induce deleterious effects in in vitro cellular systems, i.e. in immortalized and primary human lung epithelial cell lines. To derive information on how functionalization could lead to toxicological profiles throughout nanoclays' life cycle, both as-received and thermally degraded nanoclays were evaluated. Our analysis showed that the organic modifiers chemical composition influenced both the physical and chemical characteristics of the nanoclays as well as their toxicity. Overall, when cells were exposed to nanoclays with organic modifiers containing bioreactive groups, they displayed lower cellular numbers as well more elongated cellular morphologies relative to the pristine nanoclay and the nanoclay containing a modifier with long carbon chains. Additionally, thermal degradation caused loss of the organic modifiers as well as changes in size and shape of the nanoclays, which led to changes in toxicity upon exposure to our model cellular systems. Our study provides insight into the synergistic effects of chemical composition, size, and shape of the nanoclays and their toxicological profiles in conditions that mimic exposure in manufacturing and disposal environments, respectively, and can help aid in safe-by-design manufacturing of nanoclays with user-controlled functionalization and lower toxicity levels when food packaging applications are considered.

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Section: Resultsmentioning

confidence: 99%

Early Assessment and Correlations of Nanoclay’s Toxicity to Their Physical and Chemical Properties

Wagner

White

Stueckle

et al. 2017

ACS Appl. Mater. Interfaces

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“…have demonstrated oxidative stress-dependent toxicity associated with osteoblast exposure to fluoride and fluoride-containing bioactive glasses [40]. Nevertheless, fluoride-mediated toxicity appears to be cell line dependent [41–43] and could arise from differences in culture techniques (particulate versus monolith bioactive glass [40]). Furthermore, studies reporting the level at which fluoride produces a cytotoxic effect are conflicting [41].…”

Section: Discussionmentioning

confidence: 99%

Surface properties and ion release from fluoride-containing bioactive glasses promote osteoblast differentiation and mineralization in vitro

et al. 2013

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1 IntroductionBioactive glasses (BG) have the ability to bond directly with living tissue via the formation of a hydroxycarbonate apatite-like layer on their surface, and are therefore utilised in a variety of dental and orthopaedic applications [1,2]. However, this is not their only mechanism of action. BG can also be designed to release ions that stimulate specific cell behaviour. Indeed, we have recently reported on BG that release strontium ions, the active component of the osteoporosis drug strontium ranelate, which act to both promote osteoblast activity and inhibit osteoclast activity [3].Fluoride is widely recognised for its ability to prevent dental caries as it inhibits dentine and enamel demineralisation [4], however, it also affects the axial skeleton. That is, clinical examinations of osteoporotic patients have demonstrated that fluoride treatment stimulates bone formation [5]. Nevertheless, in placebocontrolled, double-blind clinical trials, sodium fluoride (NaF) was found not to be efficacious in preventing osteoporosis-related fractures [6,7]. In subsequent detailed analyses of these trials, fluoride's lack of efficacy was attributed to its substitution into bone apatite, creating structurally and mechanically inferior bone, as mineral crystal size and crystallinity increased [8]. Consequently, fluoride's use as an osteoporosis treatment was largely dismissed. Moreover, this seemed judicious as osteomalacia was reported in patients treated with NaF [9], and skeletal fluorosis, which is endemic in areas with high levels of fluoride in the ground water, is known to cause a range of skeletal abnormalities [10].As clinical trials with fluoride failed to demonstrate clear anti-fracture efficacy, other osteoporosis drugs have come into favour. Anti-catabolic agents such 2 as bisphosphonates, which block osteoclast-mediated bone resorption via inhibition of the mevalonate pathway [11] are widely prescribed. However, anti-catabolic agents only prevent further bone resorption and do not promote bone formation.Furthermore, long-term bisphosphonate use has been associated with osteonecrosis of the jaw [12] and atypical, low-energy femur fractures [13], which has created reluctance among some clinicians to prescribe them. Anabolic agents such as recombinant parathyroid hormone (PTH), which stimulate osteoblast-mediated bone matrix formation [14], are also often administered. However, PTH is expensive and requires daily subcutaneous injections. As a result, alternative treatments, such as inexpensive NaF, have recently been re-examined [15].In vitro studies point towards a small dosing range for NaF that will successfully promote osteoblast activity [16], and recent meta-analyses have shown that fluoride is efficacious in preventing osteoporosis-related fractures when administered at doses lower than those used in the widely reported clinical trials [17].Furthermore, in vitro studies have demonstrated that fluoride has an anabolic effect on bone, enhancing osteoblast proliferation [18, 19] and alkaline phosp...

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“…We tested the toxicity of BC against the human healthy cell line WS1 as described in Yang et al (2002). In brief, we plated WS1 cells (1 × 10 4 cells) onto a 96-well plate and incubated the plates for 18 h. After the incubation period, we treated the cells with 1.5 and 3 mg/L of BC and 0.82 mg/L of doxorubicin.…”

Section: Methodsmentioning

confidence: 99%

Balsacone C, a New Antibiotic Targeting Bacterial Cell Membranes, Inhibits Clinical Isolates of Methicillin-Resistant Staphylococcus aureus (MRSA) Without Inducing Resistance

et al. 2019

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New options are urgently needed for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. Balsacone C is a new dihydrochalcone extracted from Populus balsamifera that has been reported previously as being active against Staphylococcus aureus. Here, we evaluate the antibacterial activity of balsacone C against MRSA. Thirty-four (34) MRSA isolates were obtained from hospitalized patients; these isolates were then characterized for their resistance. Most of these MRSA (>85%) were resistant to penicillin, amoxicillin/clavulanic acid, ciprofloxacin, moxifloxacin, levofloxacin, clindamycin, erythromycin, and cefoxitin as well as being sensitive to linezolid, trimethoprim/sulfamethoxazole, rifampicin, and gentamicin. When tested against all MRSA isolates and various gram-positive bacteria, the antibacterial activity of balsacone C produced a MIC of 3–11.6 mg/mL. We observed no resistant isolates of MRSA (against balsacone C) even after 30 passages. Microscopy fluorescence showed that bacteria cell membrane integrity was compromised by low concentrations of balsacone C. Scanning electron microscope (SEM) confirmed balsacone C–provoked changes in the bacterial cell membrane and we find a dose-dependent release of DNA and proteins. This loss of cellular integrity leads to cell death and suggests a low potential for the development of spontaneous resistance.

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Untitled

Cited by 30 publications

References 11 publications

Early Assessment and Correlations of Nanoclay’s Toxicity to Their Physical and Chemical Properties

Early Assessment and Correlations of Nanoclay’s Toxicity to Their Physical and Chemical Properties

Surface properties and ion release from fluoride-containing bioactive glasses promote osteoblast differentiation and mineralization in vitro

Balsacone C, a New Antibiotic Targeting Bacterial Cell Membranes, Inhibits Clinical Isolates of Methicillin-Resistant Staphylococcus aureus (MRSA) Without Inducing Resistance

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