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Background Prolonged cytotoxic concentrations of cytarabine (CA) are required for maximum cytotoxicity. DepoCyt is a human liposomal cytarabine (LC) product that lasts longer in plasma and CSF compared with free CA (FC). The use of LC has not been evaluated in dogs. Objectives To perform a LC pharmacokinetic (PK) study when administered SC in dogs. Animals Five healthy female beagles. Methods Three-period, 3-treatment, nonblinded, randomized, and crossover design, including a pilot study. LC was administered at 50 mg/m2 SC and FC was administered at 25 and 50 mg/m2 SC and IV. Plasma CA concentrations were measured until 240, 72, and 8 hours after SC LC, SC FC, and IV FC administration, respectively. CA plasma concentrations were quantitated by ultra-high-performance liquid chromatography with mass spectrometry (MS/MS) detection and concentration-time profiles were evaluated by noncompartmental analysis. Results Subcutaneous LC administration resulted in a maximum plasma concentration of 26.3 to 59.78 ng/mL, time to reach maximum plasma concentration of 2 hours, area under the concentration-time curve to last measurable concentration of 669.3 to 1126 h × ng/mL, and plasma bioavailability (%F) of 19.6% to 31.3%. The PK profiles of FC after SC and IV administration differed when compared with LC. Conclusions and clinical importance In healthy dogs, SC LC administration at 50 mg/m2 results in measurable plasma CA concentrations, is apparently safe and well tolerated, but does not result in prolonged cytotoxic plasma concentrations. Poor absorption of LC prevented establishment of a complete LC PK profile.

Conventional treatment with taxanes (docetaxel-DTX or cabazitaxel-CBZ) increases the survival rates of patients with aggressive metastatic castration-resistant prostate cancer (mCRPC); however, most patients acquire resistance to taxanes. The andrographolide analog, 19

Doxorubicin (Dox) is a chemotherapeutic agent used widely to treat a variety of malignant cancers. However, Dox chemotherapy is associated with several adverse effects, including “chemobrain,” the observation that cancer patients exhibit through learning and memory difficulties extending even beyond treatment. This study investigated the effect of Dox treatment on learning and memory as well as hippocampal synaptic plasticity. Dox-treated mice (5 mg/kg weekly x 5) demonstrated impaired performance in the Y-maze spatial memory task and a significant reduction in hippocampal long-term potentiation. The deficit in synaptic plasticity was mirrored by deficits in the functionality of synaptic `α-amino-3- hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) channels, including reduced probability of opening, decreased dwell open time, and increased closed times. Furthermore, a reduction in the AMPAR subunit GluA1 level, its downstream signaling molecule Ca2+/calmodulin-dependent protein kinase (CaMKII), and brain-derived neurotrophic factor (BDNF) were observed. This was also accompanied by an increase in extracellular signal regulated kinase (ERK) and protein kinase B (AKT) activation. Together these data suggest that Dox-induced cognitive impairments are at least partially due to alterations in the expression and functionality of the glutamatergic AMPAR system., Highlights • Doxorubicin is associated with “chemobrain,” a long-term cancer related cognitive impairment. • Doxorubicin treatment results in hippocampus-dependent learning and memory deficits. • Impairment in hippocampal long-term potentiation is accompanied with reduced functionality of glutamate subtype AMPA receptor. • Dysregulation of CaMKII, BDNF, ERK, and AKT protein signaling leading to learning and memory impairment., Doxorubicin, chemobrain, long-term potentiation, AMPA, cognitive deficits, synaptic plasticity

Green leafy vegetables (GLV) may reduce the risk of red meat (RM)-induced colonic DNA damage and colorectal cancer (CRC). We previously reported the primary outcomes (feasibility) of a 12-week randomized controlled crossover trial in adults with habitual high RM and low GLV intake with body mass index (BMI) &gt, 30 kg/m2 (NCT03582306). Herein, our objective was to report a priori secondary outcomes. Participants were recruited and enrolled in 2018, stratified by gender, and randomized to two arms: immediate intervention group (IG, n = 26) or delayed intervention group (DG, n = 24). During the 4 week intervention period, participants were provided with frozen GLV and counseled to consume 1 cooked cup equivalent daily. Participants consumed their normal diet for the remaining 8 weeks. At each of four study visits, anthropometrics, stool, and blood were taken. Overall, plasma Vitamin K1 (0.50 ± 1.18 ng/mL, p &lt, 0.001) increased, while circulating 8OHdG (−8.52 ± 19.05 ng/mL, p &lt, 0.001), fecal 8OHdG (−6.78 ± 34.86 ng/mL, p &lt, 0.001), and TNFα (−16.95 ± 60.82 pg/mL, p &lt, 0.001) decreased during the GLV intervention compared to control periods. Alpha diversity of fecal microbiota and relative abundance of major taxa did not differ systematically across study periods. Further investigation of the effects of increased GLV intake on CRC risk is warranted.

Anecdotally, amikacin has been added to compounded topical preparations for the management of canine bacterial otitis externa. However, the stability of amikacin within these solutions is unknown.The purpose of this study was to determine the stability of amikacin at 10 and 30 mg/mL concentrations in four topical solutions over a 56 day period. We hypothesised that amikacin would maintain chemical stability within the various solutions.Amikacin was formulated to 10 and 30 mg/mL (1% and 3%) concentrations within four topical solutions: tris-EDTA (TrizEDTA Aqueous Flush) (TE); 0.15% chlorhexidine gluconate and tris-EDTA (TrizCHLOR Flush) (TC); 0.9% NaCl (NA); and 0.9% NaCl + 2 mg/mL dexamethasone (ND). Samples were made in duplicate and stored at room temperature (25°C) for 0, 7,14, 21, 28 and 56 days. Amikacin content was quantified, in triplicate, by ultrahigh-performance liquid chromatography tandem mass spectrometry.The recovered amikacin concentrations for the 10 mg/mL solutions ranged from 10 to 13.5 mg/mL (mean 11.5 mg/mL) with the exception of NA sample 2 at Day (D)0 (9.4 mg/mL) and D7 (9.2 mg/mL). The recovered amikacin concentrations for the 30 mg/mL solutions ranged from 30 to 40.2 mg/mL (mean 35.7 mg/mL). No significant difference was seen between the amikacin concentrations at D0 compared to D56 for all solutions except 10 mg/mL TE (P 0.001).Amikacin maintained stability within TE, TC, NA and ND over 56 days except when formulated at 10 mg/mL within TE.De façon anecdotique, l’amikacine a été ajoutée aux préparations topiques composées pour la gestion d’otite externe bactérienne canine. Cependant, la stabilité de l’amikacine dans ses solutions n’est pas connue. HYPOTHÈSES/OBJECTIFS: Le but de cette étude était de déterminer la stabilité de l’amikacine à 10 et 30 mg/mL dans quatre solutions topiques sur une période de 56 jours. Nous supposons que l’amikacine pourrait maintenir une stabilité chimique dans ces solutions. MATÉRIELS ET MÉTHODES: L’amikacine a été formulée à 10 et 30 mg/mL (1% et 3%) dans quatre solutions topiques: tris-EDTA (TrizEDTA Aqueous Flush) (TE); 0.15% chlorhexidine gluconate et tris-EDTA (TrizCHLOR Flush) (TC); 0.9% NaCl (NA); et 0.9% NaCl + 2 mg/mL déxaméthasone (ND). Les échantillons ont été fait en double et conservés à température ambiante (25°C) pendant 0, 7,14, 21, 28 et 56 jours. Le contenu en amikacine a été quantifié, en triple, par chromatographie en phase liquide à haute performance couplée à la spectrométrie de masse. RÉSULTATS: Les concentrations en amikacine pour les solutions de 10 mg/mL allaient de 10 à 13,5 mg/mL (moyenne 11,5 mg/mL) avec l’exception d’échantillon de NA 2 à jour (D)0 (9.4 mg/mL) et D7 (9.2 mg/mL). Les concentrations d’amikacine restantes pour les solutions à 30 mg/mL allaient de 30 à 40.2 mg/mL (moyenne 35.7 mg/mL). Aucune différence significative n’a été vue entre les concentrations d’amikacine à D0 comparé à D56 pur toute ses solutions à l’exception de 10 mg/mL TE (P0.001).L’amikacine était stable avec TE, TC, NA et ND pendant 56 jours sauf quand formulée à 10 mg/mL dans TE.INTRODUCCIÓN: de forma anecdótica, se ha añadido amikacina a preparaciones tópicas compuestas para el tratamiento de la otitis externa bacteriana canina. Sin embargo, se desconoce la estabilidad de la amikacina dentro de estas soluciones. HIPÓTESIS/OBJETIVOS: El propósito de este estudio fue determinar la estabilidad de la amikacina a concentraciones de 10 y 30 mg/ml en cuatro soluciones tópicas durante un período de 56 días. Presumimos que la amikacina mantendría la estabilidad química dentro de las diversas soluciones. MÉTODOS Y MATERIALES: La amikacina se formuló a concentraciones de 10 y 30 mg/ml (1% y 3%) en cuatro soluciones tópicas: tris-EDTA (TrizEDTA Aqueous Flush) (TE); Gluconato de clorhexidina al 0,15% y tris-EDTA (TrizCHLOR Flush) (TC); NaCl (NA) al 0,9%; y NaCl al 0,9% + 2 mg/ml de dexametasona (ND). Las muestras se realizaron por duplicado y se almacenaron a temperatura ambiente (25°C) durante 0, 7, 14, 21, 28 y 56 días. El contenido de amikacina se cuantificó, por triplicado, mediante cromatografía líquida de ultra alta resolución con espectrometría de masas en tándem. RESULTADOS: las concentraciones de amikacina recuperadas para las soluciones de 10 mg/ml variaron de 10 a 13,5 mg/ml (media de 11,5 mg/ml) con la excepción de la muestra 2 de NA en el día (D) 0 (9,4 mg/ml) y D7 ( 9,2 mg/ml). Las concentraciones de amikacina recuperadas para las soluciones de 30 mg/ml variaron de 30 a 40,2 mg/ml (media de 35,7 mg/ml). No se observaron diferencias significativas entre las concentraciones de amikacina en D0 en comparación con D56 para todas las soluciones excepto 10 mg/ml de TE (P0,001). CONCLUSIONES Y RELEVANCIA CLÍNICA: la amikacina mantuvo la estabilidad dentro de TE, TC, NA y ND durante 56 días, excepto cuando se formuló a 10 mg/ml dentro de TE.Anekdotenhaft wurde Amikacin zusammengesetzten topischen Formulierungen zum Management der caninen bakteriellen Otitis externa zugegeben. Die Stabilität von Amikacin in diesen Lösungen ist jedoch unbekannt.Das Ziel dieser Studie war eine Bestimmung der Stabilität von Amikacin bei einer Konzentration von 10 und 30 mg/mL in vier topischen Lösungen über eine Dauer von 56 Tagen. Wir stellten die Hypothese auf, dass Amicacin in den verschiedenen Lösungen chemisch stabil bleiben würde.Amikacin wurde in 10 und 30 mg/mL (1% und 3%) Konzentrationen in vier topischen Lösungen hergestellt: Tris-EDTA (TrizEDTA wässrige Spülung) (TE); 0,15% Chlorhexidinglukonat und Tris-EDTA (TrizCHLOR Spülung) (TC); 0,9% NaCl (NA); und 0,9% NaCl + 2 mg/mL Dexamethason (ND). Die Proben wurden im Duplikat genommen und bei Raumtemperatur (25°C) 0, 7, 14, 21, 28 und 56 Tage lang gelagert. Der Amikacingehalt wurde im Triplikat mittels Hochleistungsflüssigkeitschromatografie Tandem Massenspektrometrie quantifiziert.Die erzielten Amikacin Konzentrationen für die 10 mg/mL Lösungen reichten von 10 bis 13,5 mg/mL (Durchschnitt 11,5 mg/mL) mit Ausnahme der NA Probe 2 am Tag (D) 0 (9,4 mg/mL) und D7 (9,2 mg/mL). Die erzielten Amikacin Konzentrationen für die 30 mg/mL Lösungen reichten von 30 bis 40,2 mg/mL (Durchschnitt 35,7 mg/mL). Es konnte kein signifikanter Unterschied zwischen den Amikacin Konzentrationen am D0 im Vergleich zu D56 für alle Lösungen außer der 10 mg/mL TE (P0,001) gefunden werden.Amikacin behielt seine Stabilität in TE, TC, NA und ND über 56 Tage mit Ausnahme der Formulierung von Amikazin in 10 mg/mL in TE.背景: 犬の細菌性外耳道炎の治療にアミカシンが配合された外用剤が使用されているという逸話がある。しかし, これらの溶液中でのアミカシンの安定性は不明である。 仮説/目的: 本研究の目的は, 4種類の外用剤における10および30 mg/mL濃度のアミカシンの56日間の安定性を調べることである。我々は, アミカシンが様々な溶液中で化学的安定性を維持するという仮説を立てた。 材料と方法: アミカシンを10および30 mg/mL(1%および3%) の濃度で, トリスEDTA(TrizEDTA Aqueous Flush) (TE) , 0.15%クロルヘキシジングルコン酸塩およびトリスEDTA(TrizCHLOR Flush) (TC) , 0.9%NaCl(NA) , および0.9%NaCl+2 mg/mL dexamethasone(ND) の4種類の外用液に配合した。サンプルは二重に作成し, 室温 (25°C) で0,7,14,21,28,56日間保存した。アミカシン含有量は、超高速液体クロマトグラフィー・タンデム質量解析法により3回に分けて定量した。 結果: 10 mg/mL溶液の回収アミカシン濃度は、10~13.5 mg/mL (平均11.5 mg/mL) の範囲であったが、NAサンプル2のD0日目 (9.4 mg/mL) およびD7日目 (9.2 mg/mL) を除いては、10~13.5 mg/mLの範囲であった。30 mg/mL溶液の回収アミカシン濃度は, 30~40.2 mg/mL (平均35.7 mg/mL) であった。10 mg/mL TEを除くすべての溶液で, D0とD56のamikacin濃度に有意な差は認められなかった (P0.001) 。 結論および臨床的妥当性: アミカシンは, TE中に10 mg/mLで配合した場合を除き, 56日間にわたりTE,TC,NAおよびND中で安定性を維持した。.背景: 根据个人临床经验, 阿米卡星被添加到复方外用制剂中, 用于治疗犬细菌性外耳炎。然而, 阿米卡星在这些溶液中的稳定性尚不清楚。 假设/目的: 本研究的目的是确定4种外用溶液中10和30 mg/mL浓度的阿米卡星在56天内的稳定性。我们假设阿米卡星在各种溶液中可保持化学稳定性。 方法和材料: 将阿米卡星配制成10和30 mg/mL(1%和3%)浓度的4种外用溶液:tris-EDTA(TrizEDTA冲洗液)(TE);0.15%葡萄糖酸氯己定和tris-EDTA(TrizCHLOR冲洗液)(TC);0.9%NaCl(NA); 和0.9%NaCl + 2 mg/mL地塞米松(ND)。一式两份制备样本, 并在室温(25 ℃)下储存0、7、14、21、28和56天。通过超高效液相色谱串联质谱法一式三份定量阿米卡星含量。 结果: 除第0天(9.4 mg/mL)和第7天(9.2 mg/mL)的NA样本2外, 10 mg/mL溶液的阿米卡星重测浓度范围为10-13.5 mg/mL (平均值11.5 mg/mL) 。30 mg/mL溶液的阿米卡星重测浓度范围为30-40.2 mg/mL (平均值35.7 mg/mL) 。对于除10 mg/mL TE外的所有溶液, D0与D56时的阿米卡星浓度之间未观察到显著差异(P0.001)。 结论和临床相关性: 阿米卡星在TE、TC、NA和ND内可保持稳定56天, 但在TE内以10 mg/mL配制时除外。.Anedoticamente, a amicacina foi adicionada a formulações tópicas utilizadas no manejo da otite externa canina bacteriana. No entanto, a estabilidade da amicacina dentro dessas soluções é desconhecida. HIPÓTESE/OBJETIVOS: O objetivo deste estudo foi determinar a estabilidade da amicacina em concentrações de 10 e 30 mg/ml em quatro soluções tópicas ao longo de um período de 56 dias. Nossa hipótese foi a de que a amicacina manteria a estabilidade química dentro das várias soluções. MÉTODOS E MATERIAIS: A Amicacin foi formulada em concentrações de 10 e 30 mg/ml (1% e 3%) dentro de quatro soluções tópicas: tris-EDTA ((TrizEDTA Aqueous Flush) (TE); 0,15% de gluconato de clorexidina e Tris-EDTA (TrizCHLORr Flush) (TC); NaCl 0,9% (NA); e 0,9% NaCl + 2 mg/ml dexametasona (ND). As amostras foram feitas em duplicata e armazenadas à temperatura ambiente (25°C) por 0, 7,14, 21, 28 e 56 dias. O teor de amicacina foi quantificado, em triplicada, por cromatografia líquida de alto desempenho.As concentrações de amicacina recuperadas para as soluções de 10 mg/ml variaram de 10 a 13,5 mg/ml (média 11,5 mg/ml), com exceção da amostra 2 de NA no dia (D) 0 (9,4 mg/ml) e D7 (9,2 mg/ml). As concentrações de amicacina obtidas para as soluções de 30 mg/ml variaram de 30 a 40,2 mg/ml (média de 35,7 mg/ml). Nenhuma diferença significativa foi observada entre as concentrações de amicacina no D0 em comparação com D56 para todas as soluções, exceto 10 mg/ml TE (p0,001). CONCLUSÕES E RELEVÂNCIA CLÍNICA: A amicacina manteve sua estabilidade dentro do TE, TC, NA e ND por mais de 56 dias, exceto quando formuladas em 10 mg/ml dentro de TE.

Throughout the tumorigenic process, locational heterogeneities in tumor tissue microarchitecture develop as a result of aberrant angiogenesis and a subsequently induced oxygen and nutrient gradient within the three-dimensional (3D) mass. This phenomenon often results in differential tissue stiffness between the necrotic, quiescent, and proliferative tumor regions. In vitro, strong correlations have been found to exist between cell culture platform stiffness and acquired chemoresistance and varied drug response. Therefore, to accurately recapitulate the tumor microenvironment, biomimetic models must provide a mechanically similar scaffold. This study reports novel quantification of the in vivo prostate tumor stiffness and the ensuing development of tunable 3D bioengineered tumor tissue (BioTT) to successfully recapitulate in vivo mechanical cues in vitro. In vivo samples were generated by subcutaneously injecting Matrigel-suspended metastatic prostate cancer cells (PC-3) into the flank of athymic NCr nude mice. Resultant tumors (300 – 1,500 mm3) were excised from the murine host and geometrically dissected to provide samples from the tumor core, midpoint, and periphery. The Young’s modulus was quantified via parallel plate compression under physiological conditions. The 3D BioTT model is comprised of poly(ethylene glycol)-fibrinogen (PF) with varying amounts of excess poly(ethylene glycol) diacrylate (PEGDA) to modulate the mechanical properties of the scaffold. PC-3 cancer cells and BJ-5ta human fibroblasts were encapsulated within the covalently crosslinkable biomaterial and co-cultured for 29 days in vitro. Cell viability was assessed by LIVE/DEAD staining and cellular morphology was visualized with Hoechst 33342, Phalloidin, and the anti-fibroblast immunomarker, TE-7. Temporal variations in cell populations were quantified by flow cytometry and mechanical stiffness characterization was again performed by parallel plate compression. In vivo prostate cancer tumors presented a wide range of tissue stiffness heterogeneity (200 – 5,750 Pa), characterized by an increasing modulus with respect to locational progression from the core to the periphery (n = 48 per tumor region). The BioTT model successfully recapitulated the full tumor stiffness range through biomaterial composition modulation; the addition of excess PEGDA significantly stiffened the PF scaffold (p ≤ 0.05, n = 3). PC-3 and BJ-5ta cells survived the encapsulation process and remained viable throughout long-term co-culture. Visualization of the 3D cellular microenvironment revealed both cancer and stromal cells maintained characteristic morphology. In future studies, the BioTT will be extended to a microfluidic chip platform, thus augmenting the physiological relevancy of the model by incorporating dynamic shear conditions and the ability to monitor cancer cell metastasis. Citation Format: Nicole L. Habbit, Benjamin Anbiah, Luke S. Anderson, Joshita Suresh, Iman Hassani, Matthew Eggert, Shanese L. Jasper, Balabhaskar Prabhakarpandian, Robert D. Arnold, Elizabeth A. Lipke. In vivo prostate tumor tissue stiffness differs by tumor region and can be recapitulated in bioengineered prostate tumor tissues [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1915.

Triple negative breast cancer describes a subgroup of breast cancers which are negative for the estrogen and progesterone receptors as well as the HER2 protein. As such, triple negative breast cancers have seen little benefit from the targeted therapies developed for the treatment of breast cancer. To address this challenge, we examined an alternative target within the tumor as well as the tumor environment. Secretory phospholipase A2 (sPLA2) cleave phospholipids at sn-2 ester bonds, releasing lysophospholipids and fatty acids, and are over expressed in several pathologies including breast cancer. Herein, we evaluated the therapeutic activity of secretory phospholipase A2 responsive liposomes (SPRL) compared to the clinically used, sterically-stabilized, pegylated liposomes (SSL) for in vitro response in a triple-negative breast cancer (TNBC) model. In these studies, SSL and SPRL formulations were made according to previous studies and resulted in three formulations SSL, SPRL- E and SPRL-G. SPRL were made by the addition of either DSPE (SPRL-E) or DSPG (SPRL-G). Doxorubicin was used as the drug of choice and Dox-loaded liposomes were prepared by remote-loading using an ammonium sulfate gradient. Toxicity studies were performed by the use of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) or resazurin while uptake studies were performed by fluorescence microscopy and flow cytometry. Briefly, cells were seeded at a density of 10,000 cells per well and subjected to free doxorubicin or liposomal doxorubicin in concentrations from 0 - 100 µM. At the appropriate time points, 0-72 hours, cells were harvested for studies. Treatment of breast cancer cells with doxorubicin encapsulated in SSL and SPRL resulted in cytotoxicity in the MDA-MB-231 cells line comparable to free drug with an IC50 of approximately 3 µM at the 72 hour time point. In tracking of drug and liposome delivery, we demonstrated that drug uptake was liposome-dependent, as encapsulation of doxorubicin in SPRL resulted in greater intracellular drug levels compared to SSL. These data show the therapeutic activity of SPRL compared to SSL, and suggest that SPRL may be useful for the treatment of TNBC. Two-dimensional models do not fully recapitulate the complexity of barriers to drug delivery, nor the effect of multiple cell types. Therefore, ongoing studies are examining the utility of these liposome formulations in three-dimensional co-cultures that include macrophages and fibroblasts. In this model, we hope to assess the ability of the tumor microenvironment to alter drug release. Citation Format: Shanese L. Jasper, Elena B. Skarupa, Brian S. Cummings, Robert D. Arnold. Secretory phospholipase A2 as a trigger for drug release in the treatment of triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 991.

Three-dimensional N(22)C(2) cages are examined by theoretical calculations to determine relative stability among various isomers. Stability as a function of cage shape and stability as a function of carbon location are calculated and discussed. The results are compared to isomers of N(24) to determine the effects of carbon substitution into the cage structure. Further, since the various cage shapes in this study vary by degree of curvature, model calculations are carried out to determine the energetic consequences of curving the local structure around nitrogen and carbon. The model calculations are compared to the actual results on the larger cages to determine how well curvature effects explain the relative stability of N(22)C(2) isomer as compared to the corresponding N(24).

Background Resistance of food borne pathogens such as Salmonella to existing antibiotics is of grave concern. Silver coated single walled carbon nanotubes (SWCNTs-Ag) have broad-spectrum antibacterial activity and may be a good treatment alternative. However, toxicity to human cells due to their physico-chemical properties is a serious public health concern. Although pegylation is commonly used to reduce metal nanoparticle toxicity, SWCNTs-Ag have not been pegylated as yet, and the effect of pegylation of SWCNTs-Ag on their anti-bacterial activity and cell cytotoxicity remains to be studied. Further, there are no molecular studies on the anti-bacterial mechanism of SWCNTs-Ag or their functionalized nanocomposites. Materials and methods In this study we created novel pegylated SWCNTS-Ag (pSWCNTs-Ag), and employed 3 eukaryotic cell lines to evaluate their cytotoxicity as compared to plain SWCNTS-Ag. Simultaneously, we evaluated their antibacterial activity on Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) by the MIC and growth curve assays. In order to understand the possible mechanisms of action of both SWCNTs-Ag and pSWCNTs-Ag, we used electron microscopy (EM) and molecular studies (qRT-PCR). Results pSWCNTs-Ag inhibited Salmonella Typhimurium at 62.5 μg/mL, while remaining non-toxic to human cells. By comparison, plain SWCNTs-Ag were toxic to human cells at 62.5 μg/mL. EM analysis revealed that bacteria internalized either of these nanocomposites after the outer cell membranes were damaged, resulting in cell lysis or expulsion of cytoplasmic contents, leaving empty ghosts. The expression of genes regulating the membrane associated metabolic transporter system (artP, dppA, and livJ), amino acid biosynthesis (trp and argC) and outer membrane integrity (ompF) protiens, was significantly down regulated in Salmonella treated with both pSWCNTs-Ag and SWCNTs-Ag. Although EM analysis of bacteria treated with either SWCNTs-Ag or pSWCNTs-Ag revealed relatively similar morphological changes, the expression of genes regulating the normal physiological processes of bacteria (ybeF), quorum sensing (sdiA), outer membrane structure (safC), invasion (ychP) and virulence (safC, ychP, sseA and sseG) were exclusively down regulated several fold in pSWCNTs-Ag treated bacteria. Conclusions Altogether, the present data shows that our novel pSWCNTs-Ag are non-toxic to human cells at their bactericidal concentration, as compared to plain SWCNTS-Ag. Therefore, pSWCNTs-Ag may be safe alternative antimicrobials to treat foodborne pathogens. Electronic supplementary material The online version of this article (doi:10.1186/s12951-015-0085-5) contains supplementary material, which is available to authorized users.