642 research outputs found

    ENDOCANNABINOID-BASED NANOPARTICLES TARGETED TO THE SYNOVIUM FOR THE TREATMENT OF ARTHRITIS

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    Chronic inflammatory joint disease represents an emerging public health issue, occupying a sizeable proportion of the adult population in the industrialized world. Recently, there has been a resurgence of interest in marijuana and its natural and synthetic derivatives, cannabinoid receptor agonists and antagonists, as well as chemically related compounds, for their therapeutic potential as both an anti-inflammatory and analgesic. Whilst the benefits of endocannabinoid-based treatments appear promising, very few studies have investigated the use of the self-assembled nanoparticles (NPs) for targeted drug delivery. In this study, the nanostructure mesophase behaviour of a series of mixed monoethanolamide lipids of oleoylethanolamide (OEA) and linoylethanolamide (LEA) into higher order NP structures for the encapsulation and delivery of drugs was investigated. In addition to drug encapsulation, active targeting through the conjugation of a synovium-targeting peptide, HAP-1, to the surface of these NP’s was used to facilitate selective accumulation of therapeutic agents the inflamed joint. The inhibitory cytokine effects of these targeted NPs was demonstrated in vitro, and in vivo using an adjuvant induced arthritis model of inflammation. The ability to deliver endocannabinoid based NPs to specific sites of the body mediating pharmacological endocannabinoid-like effects to influence key physiological pathways, provides a novel drug delivery system and medicinal potential to treat many diseases in many fields of medicine in which inflammation is a key feature of the disease

    J Clin Toxicol

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    Single-walled carbon nanotubes (SWCNTs) are newly discovered material of crystalline carbon that forms single-carbon layer cylinders with nanometer diameters and varying lengths. Although SWCNTs are potentially suitable for a range of novel applications, their extremely small size, fiber-like shape, large surface area, and unique surface chemistry raise potential hazard to humans, including lung toxicity and fibrosis. The molecular mechanisms by which SWCNTs cause lung damage remain elusive. Here we show that SWCNTs dose and time-dependently caused toxicity in cultured human bronchial epithelial (BEAS-2B), alveolar epithelial (A549), and lung fibroblast (WI38) cells. At molecular levels, SWCNTs induced significant mitochondrial depolarization and ROS production at subtoxic doses. SWCNTs stimulated the secretion of proinflammatory cytokines and chemokines TNF\uce\ub1, IL-1\uce\ub2, IL-6, IL-10 and MCP1 from macrophages (Raw 264.7), which was attributed to the activation of the canonical signaling pathway of NF-\uce\ubaB by SWCNT. Finally, SWCNTs stimulated profibrogenic growth factors TGF\uce\ub21 production and fibroblast-to-myofibroblast-transformation. These results indicate that SWCNTs has a potential to induce human lung damage and fibrosis by damaging mitochondria, generating ROS, and stimulating production of proinflammatory and profibrogenic cytokines and growth factors.CC999999/Intramural CDC HHS/United States2015-12-21T00:00:00Z26702365PMC468614

    Effect of Polyethylene Glycol Modification of TiO2 Nanoparticles on Cytotoxicity and Gene Expressions in Human Cell Lines

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    Nanoparticles (NPs) are tiny materials used in a wide range of industrial and medical applications. Titanium dioxide (TiO2) is a type of nanoparticle that is widely used in paints, pigments, and cosmetics; however, little is known about the impact of TiO2 on human health and the environment. Therefore, considerable research has focused on characterizing the potential toxicity of nanoparticles such as TiO2 and on understanding the mechanism of TiO2 NP-induced nanotoxicity through the evaluation of biomarkers. Uncoated TiO2 NPs tend to aggregate in aqueous media, and these aggregates decrease cell viability and induce expression of stress-related genes, such as those encoding interleukin-6 (IL-6) and heat shock protein 70B’ (HSP70B’), indicating that TiO2 NPs induce inflammatory and heat shock responses. In order to reduce their toxicity, we conjugated TiO2 NPs with polyethylene glycol (PEG) to eliminate aggregation. Our findings indicate that modifying TiO2 NPs with PEG reduces their cytotoxicity and reduces the induction of stress-related genes. Our results also suggest that TiO2 NP-induced effects on cytotoxicity and gene expression vary depending upon the cell type and surface modification

    Induction of pyroptotic cell death as a potential tool for cancer treatment

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    Cancer is a complex pathological disease and the existing strategies for introducing chemotherapeutic agents have restricted potential due to a lack of cancer cell targeting specificity, cytotoxicity, bioavailability, and induction of multi-drug resistance. As a prospective strategy in tackling cancer, regulating the inflammatory pyroptosis cell death pathway has been shown to successfully inhibit the proliferation and metastasis of various cancer cell types. Activation of inflammasomes such as the NLRP3 results in pyroptosis through cleavage of gasdermins, which forms pores in the cell membranes, inducing membrane breakage, cell rupture, and death. Furthermore, pyroptotic cells release pro-inflammatory cytokines such as IL-1β and IL-18 along with various DAMPs that prime an auxiliary anti-tumor immune response. Thus, regulation of pyroptosis in cancer cells is a way to enhance their immunogenicity. However, immune escape involving myeloid-derived suppressor cells has limited the efficacy of most pyroptosis-based immunotherapy strategies. In this review, we comprehensively summarize the cellular and molecular mechanisms involved in the inflammasome-mediated pyroptosis pathways in cancer cells, exploring how it could modulate the tumor microenvironment and be beneficial in anti-cancer treatments. We discuss various existing therapeutic strategies against cancer, including immunotherapy, oncolytic virus therapy, and nanoparticle-based therapies that could be guided to trigger and regulate pyroptosis cell death in cancer cells, and reduce tumor growth and spread. These pyroptosis-based cancer therapies may open up fresh avenues for targeted cancer therapy approaches in the future and their translation into the clinic

    Human dermal fibroblast activation under pulsed electrical stimulation via conductive fabrics : signalling pathways and potential benefit for wound healing

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    Lors de la cicatrisation, plusieurs types cellulaires dont les kératinocytes et les fibroblastes ainsi que plusieurs facteurs de croissance jouent d’importants rôles. La cicatrisation cutanée peut aussi être activée par des facteurs exogènes, dont la stimulation électrique (SE). La SE peut moduler les fonctions fibroblastiques durant la cicatrisation. Le fibroblaste contribue de façon active à la cicatrisation en sécrétant différentes protéines (collagène, fibronectine, élastine) pour favoriser le comblement tissulaire. Les fibroblastes adoptent aussi un phénotype contractile en exprimant l’α-actine contribuant à la fermeture de la plaie. Notre hypothèse est que certaines de ces fonctions fibroblastiques pourraient être modulées par une stimulation électrique. Pour vérifier cette hypothèse nous avons utilisé une membrane biocompatible et conductrice à base de polyethylene terephthalate (PET) recouvert de polypyrrole (PPy). Les fibroblastes dermiques humains ont été cultivés sur ces membranes conducteurs, puis exposés ou non à un courant pulsé (PES) selon deux régimes : soit 10s PES suivi de 1200s de repos, ou 300s PES suivi de 600s de repos, durant 24 h. Deux intensités électriques ont été étudiées, 50 et 100 mV/mm. Nos travaux démontrent que la SE favorise l’adhésion, la prolifération et la migration des fibroblastes dermiques. Ces activités cellulaires sont consolidées par une sécrétion importante de FGF2 et d’α-SMA. Il est important de noter que l’effet de la SE favorise le changement phénotypique des fibroblastes en myo-fibroblastes grâce à la voie des Smad et de TGFβ/ERK. Nous avons aussi démontré que l’effet de la SE est maintenue à long terme et est transférable de la cellule mère vers les cellules filles. En effet après sous-culture les cellules expriment toujours de façon importante l’α-SMA. En conclusion, nous avons démontré que la stimulation électrique pulsée module positivement les fonctions cicatricielles des fibroblastes humains. Ces travaux démontrent pour la première fois les voies de signalisation (Smad et TGFβ/ERK) sollicitées par la SE pour activer les fibroblastes lors de la cicatrisation. Ces travaux suggèrent l’utilisation de la SE pour favoriser la guérison/cicatrisation des plaies.During skin wound healing, cutaneous cells particularly fibroblasts and keratinocytes as well as several growth factors play important roles. Wound healing can be activated by exogenous factors, including electrical stimulation (ES). ES can also modulate fibroblast functions. Fibroblasts contribute to healing by secreting structural proteins (collagen, fibronectin, elastin) to repair the wound area. Fibroblasts also adopt a contractile phenotype expressing α-actin contributing to wound closure. The hypothesis of the thesis is that fibroblasts proliferate and transdifferentiate into myofibroblasts by sensing pulsed electrical signals and adjusting relevant signalling pathways. To test this hypothesis we used biocompatible polyethylene terephthalate (PET) fabrics coated with electrically conductive polypyrrole (PPy). Human dermal fibroblasts were cultured on these conductive fabrics and exposed to the optimized pulsed ES: either 10s PES in a period of 1200s, or 300s PES in 600s period, for a total of 24 hours. Two electric intensities were studied, 50 and 100 mV/ mm. Our work showed that the PES promoted the adhesion, proliferation and migration of dermal fibroblasts. These cellular activities were consolidated by an elevated level of fibroblast growth factor 2 (FGF2) and the high expression of α-smooth muscle actin (α-SMA). Important findings were that PES promoted the phenotypic change of fibroblasts to myofibroblasts, and such change was coordinated through the Smad and TGFβ/ERK pathways. It also demonstrated that the effect of PES was able to maintain for a long period of time after the end of stimulation, and was transferable from the mother cells to the daughter cells. Following subculture, the electrically stimulated fibroblasts still expressed significant amount of α-SMA. In conclusion, this thesis demonstrates that PES through conductive fabrics can activate the wound healing functions in human dermal fibroblasts. This work revealed for the first time that Smad and TGFβ/ERK pathways are required by the PES-induced fibroblasts-to-myofibroblasts differentiation. This work also demonstrated that the PES activated cells can survive in vivo. These studies suggest the application of the PES in promoting tissue regeneration and wound healing
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