Browsing by Subject "HYDROGELS"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    A New Generation Nanotherapeutic: pHEMA-Chitosan Nanocomposites in siRNA Delivery
    (BENTHAM SCIENCE PUBL LTD) Eroglu, E; Portakal, HS; Pamukçu, A
    Background: Despite great hopes for small interfering RNA (siRNA)-based gene therapies, restrictions, including the presence of nucleases, reticuloendothelial system and undesired electrostatic interactions between nucleic acids and the cell membrane, limit the success of these approaches. In the last few decades, non-viral nucleic acid delivery vectors in nanosize with high biocompatibility, low toxicity and proton sponge effect have emerged as magic bullets to overcome these drawbacks. Objective: This study aimed to develop poly(2-hydroxyethyl methacrylate) (pHEMA)-chitosan nanoparticles (PCNp), and to transfect green fluorescent protein (GFP)-silencing siRNA (GsiR) in vitro. Methods: Firstly, PCNp displaying core-shell structure were synthesized and thereafter GsiR was encapsulated into the core of PCNp. The synthesized PCNp with/without GsiR were characterized using ultraviolet-visible (UV-vis)-spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, thermal decomposition, atomic force microscopy (AFM), scanning electron microscopy (SEM), zeta potential and dynamic light scattering (DLS) measurements. Encapsulation of siRNA into the pHEMA core coated with chitosan shell was demonstrated using fluorescence and FTIR spectroscopy. Results: The surface charges of PCNp and PCNp-GsiR were found to be +39.5 and +40.2, respectively. In DLS analysis, an insignificant shift in the Z-average diameter of PCNp was observed from 109 nm to 133 nm using the encapsulation of GsiR. In comparison to other studied nanomaterials and a commercial transfection reagent, our findings suggest a promising GFP-silencing effect of 45%. Conclusion: To our knowledge, we have obtained comparable silencing activity with the other studied equivalents despite using the lowest concentration of siRNA in existing literature.
  • No Thumbnail Available
    Item
    Radiolabeling of new generation magnetic poly(HEMA-MAPA) nanoparticles with 131I and preliminary investigation of its radiopharmaceutical potential using albino Wistar rats
    (WILEY) Avcibasi, U; Demiroglu, H; Ediz, M; Akalin, HA; Özçaliskan, E; Senay, H; Türkcan, C; Özcan, Y; Akgöl, S; Avcibasi, N
    In this study, N-methacryloyl-l-phenylalanine (MAPA) containing poly(2-hydroxyethylmethacrylate) (HEMA)-based magnetic poly(HEMA-MAPA) nanobeads [mag-poly(HEMA-MAPA)] were radiolabeled with I-131 [I-131-mag-poly(HEMA-MAPA)], and the radiopharmaceutical potential of I-131-mag-poly(HEMA-MAPA) was investigated. Quality control studies were carried out by radiochromatographic method to be sure that I-131 binded to mag-poly(HEMA-MAPA) efficiently. In this sense, binding yield of I-131-mag-poly(HEMA-MAPA) was found to be about 95-100%. In addition to this, optimum radiodination conditions for I-131-mag-poly(HEMA-MAPA) were determined by thin-layer radiochromatography studies. In addition to thin-layer radiochromatography studies, lipophilicity (partition coefficient) and stability studies for I-131-mag-poly(HEMA-MAPA) were realized. It was determined that lipophilicities of mag-poly(HEMA-MAPA) and I-131-mag-poly(HEMA-MAPA) were 0.12 +/- 0.01 and 1.79 +/- 0.76 according to ACD/logP algorithm program, respectively. Stability of the radiolabeled compound was investigated in time intervals given as 0, 30, 60, 180, and 1440min. It was found that I-131-mag-poly(HEMA-MAPA) existed as a stable complex in rat serum within 60min. After that, biodistribution and scintigraphy studies were carried out by using albino Wistar rats. It was determined that the most important I-131 activity uptake was observed in the breast, the ovary, and the pancreas. Scintigraphy studies well supported biodistribution results. Copyright (c) 2013 John Wiley & Sons, Ltd.