Browsing by Subject "Cancer therapy"
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Item Open Access The antiproliferative effect of celecoxib loaded pNIPAM nanoparticles(2012) Bayyurt, B.; Hasirci V.The aim of this study was to design a drug delivery system based on poly(N-isopropylacrylamide) (pNIPAM) nanoparticles (NPs). The model drug, Celecoxib, is a cyclooxygenase-2 inhibitor and has a great potential in chemoprevention and treatment of various cancer types, however, the clinical use is limited due to the side effects on the cardiovascular system which is most probably due to the high doses used in clinical applications. In this study, a novel nanoparticle preparation approach, nanoprecipitation, was used. The amount of crosslinker affected the size, encapsulation efficiency, loading and release rate of NPs. The antiproliferative effect of Celecoxib was tested on human osteosarcoma cells, Saos-2, and the nanoparticles were found to have cytotoxicity. Celecoxib loaded pNIPAM NPs had higher cytotoxicity and the cells treated with this formulation showed abnormal nuclear and cytoskeletal morphology indicating apoptosis. The nanoparticles were detected within the cytoplasm and their distribution differed depending on whether NP is loaded with Celecoxib or not. The drug delivery system developed in this study appears to have a potential as an antiproliferative tool in various applications such as prevention of restenosis or biofilm formation on biomaterials. © 2012 American Scientific Publishers. All rights reserved.Item Open Access Biosystems engineering of prokaryotes with tumor-killing capacities(Bentham Science Publishers Ltd., 2016) Kalyoncu, E.; Olmez, T. T.; Ozkan, A. D.; Sarioglu, O. F.Certain bacteria selectively attack tumor tissues and trigger tumor shrinkage by producing toxins and modulating the local immune system, but their clinical utility is limited because of the dangers posed by systemic infection. Genetic engineering can be used to minimize the risks associated with tumor-targeting pathogens, as well as to increase their efficiency in killing tumor cells. Advances in genetic circuit design have led to the development of bacterial strains with enhanced tumor-targeting capacities and the ability to secrete therapeutics, cytotoxic proteins and prodrug-cleaving enzymes, which allows their safe and effective use for cancer treatment. The present review details the recent advances in the design and application of these modified bacterial strains.Item Open Access Cucurbit[7]uril-capped hybrid conjugated oligomer-gold nanoparticles for combined photodynamic-photothermal therapy and cellular imaging(ACS, 2020) Özkan, Melis; Tunç, İ.; Midilli, Y.; Ortaç, Bülend; Tuncel, DönüşHerein, hybrid nanoparticles composed of a redemitting conjugated oligomer (COL) and gold nanoparticles (Au-NPs) were prepared through a one-pot synthetic method in which the oligomer acts as a reducing agent as well as a matrix to wrap the newly formed Au nanoparticles. These hybrid nanoparticles(COL-Au-NPs) exhibited photodynamic and photothermal activity against both Gram-positive and Gram-negative bacterial strains. They were also proven to possess high photostability and thermal reversibility. Dark cytotoxicity of COL-Au-NPs toward pathogens and mammalian breast cancer cells (MCF-7) reduced significantly upon complexation with cucurbit[7]uril while preserving their light-induced cytotoxic activity when irradiated with a 915 nm laser for photothermal therapy and white light for photodynamic therapy, respectively. Furthermore, these nanoparticles have cellular imaging capability because of their intrinsic fluorescence characteristics and can be used in image-guided therapy.Item Open Access Non-covalent functionalized SWNTs as delivery agents for novel Bodipy-based potential PDT sensitizers(2009) Erbas, S.; Gorgulu, A.; Kocakusakogullari, M.; Akkaya, E. U.Pyrenyl-functionalized distyryl-Bodipy sensitizer attached non-covalently to SWNTs was shown to generate singlet oxygen when excited at 660 nm with a red LED array; this work emphasizes the potential of SWNT as a viable alternative carrier of bioactive agents, including photodynamic therapy sensitizers. © 2009 The Royal Society of Chemistry.