National Repository of Grey Literature 3 records found  Search took 0.00 seconds. 
Preparation and characterization of nanodiamonds modified with biocompatible polymers
Kvaková, Klaudia ; Matoušková, Petra (referee) ; Cígler, Petr (advisor)
Nanodiamanty (250 nm) boli podrobené oxidácií, a tiež separované podľa veľkosti. Následne bola na povrch nanodiamantov adsorbovaná rozvetvená vrstva polyglycerolu. Táto vrstva vzniká kyslo katalyzovanou ,,ring opening“ polymeráciou glycidolu s hydroxylovými a karboxylovými skupinami povrchu nanodiamantov. Vzniknutá polyglycerolová vrstva zvyšuje stabilitu a biokompatibilitu nanodiamantov. Po vytvorení polyglycerolovej vrstvy bol do reakcie pridaný glycidyl propargyl éter, čím došlo k terminácií polymerácie, v dôsledku zavedenia propargylu do reakcie. Prítomná trojná väzba umožňuje nové modifikácie povrchu, napr. prostredníctvom CuAAC reakcie. S využitím CuAAC reakcie je možné na povrch fluorescenčných nanodiamantov pripojiť manózu (so spojkou obsahujúcou azidoskupinu). Pripravené nanočastice boli charakterizované použitím fyzikálno chemických metód. Distribúcia veľkosti častíc bola meraná pomocou dynamického rozptylu svetla (DLS), a taktiež bola potvrdená obrazovou analýzou mikrografov z elektrónového transmisného mikroskopu (TEM). Vyhodnotené bolo aj správanie sa nanodiamantov v biologických podmienkach (stabilitné testy v 1xPBS, 10xPBS a 100 % FBS) a bol meraný aj zeta potenciál. Nakoniec boli pripravené fluorescenčné diamanty (250 nm) s naviazanou manózou. Vzhľadom k výsledkom termogravimetrie, meraniam DLS a pozorovania pomocou TEM môžeme povedať, pripravené nanodiamanty sú pokryté tenkou vrstvou polyglycerolu. Prítomnosť manózy bola zistená na základe FTIR spektier. Nami pripravené fluorescenčné nanodiamanty obalené vrstvou polyglycerolu sú vhodné pre ďalšie testovanie in vitro a in vivo vďaka ich stabilite v médiách s vysokým obsahom solí ako napr. fosfátový pufor (PBS) a nízkemu viazaniu proteínov vo fetalnom bovinnom sere (FBS).
Nanofiber dressing consisting of antisense rna-functionalized nanodiamonds for therapy of non-healing wounds in diabetic individuals
Neuhoferová, Eva ; Petráková, V. ; Vocetková, K. ; Kindermann, Marek ; Křivohlavá, Romana ; Benson, Veronika
Non-healing wounds are serious complication in diabetic patients and represent an attractive challenge for development of suitable carrier system possessing constant and localized release of therapeutic biomolecule into the wound without any undesired side effects. Given the fact that these non-healing wounds are result of impaired balance in metalloproteinases synthesized by immune cells residing the wounds, gene therapy offering knock down of such enzymes is of great interest. \nHere we challenged a development of functional and biocompatible wound dressing enabling controlled release of trackable carrier loaded with therapeutic siRNA. Our dressing consists of scaffold from degradable polymer nanofibers enriched with fluorescent nanodiamond particles (FND). We have previously shown the nanodiamond particles are great carriers for antisense RNAs. Their advantages represent high biocompatibility, stable luminescence giving us the possibility to track the carrier system in the wound, and effective release of antisense RNA in the wound. Embedding of nanodiamond-siRNA systems into nanofiber scaffold enables continuous release of siRNA and maintaining the stable siRNA concentration in the wound site resulting in a promotion of wound healing. \nWe developed FND-siRNA complexes specific to MMP-9 that efficiently inhibit the expression of target MMP-9 mRNA. The complexes were embedded into core/shell nanofibers from PVA and PCL, visualized by confocal microscopy, and characterized by electron microscopy. Real-time PCR was used to assess the silencing effect of siRNA that has been delivered to target murine fibroblasts by FND released from nanofiber dressing. Nanofiber system with embedded FNDs was applied on wounds in diabetic animal models to evaluate its suitability regarding short and long term toxicity, efficacy, and handling in vivo. \n
Fluorescent nanodiamonds: The new platform for construction of chemo- and biosensors
Cígler, Petr ; Ledvina, Miroslav ; Tvrdoňová, Monika ; Řezáčová, V. ; Nesládek, M. ; Kratochvílová, Irena ; Fendrych, František ; Štursa, Jan ; Kučka, Jan ; Ráliš, Jan
Over the past few years, fluorescent nanodiamonds (FNDs) have been recognized as potential fluorophores for use in bioimaging, owing to their unique and attractive chemical and particularly spectral properties. The source material for their preparation, synthetic nanodiamond (ND), is non-expensive and commercially available. Notably, NDs have the highest biocompatibility of all carbon nanomaterials and their surface can be chemically modified by various techniques. FNDs are capable of fluorescing with almost quantitative quantum yields from point defects of crystall lattice - nitrogen-vacancy (NV) centers. In particular, the long-wavelength emission, high brightness, no photobleaching, no photoblinking, and an exceptional resistance to chemical degradation make them almost ideal core for development of fluorescent bioimaging probes.

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