Ondrej Holas

Dr. Ondrej Holas

Department of Pharmaceutical Technology, Faculty of Pharmacy in Hradec Kralove, Charles University, Heyrovskeho 1203, 50005 Hradec Kralove, Czech Republic
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Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 April 2010 in Talanta
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Journal Article
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MIroslav PohankaMIroslav Pohanka
MIroslav Pohanka
JKJana Zdarova Karasova
Jana Zdarova Karasova
Kamil KucaKamil Kuca
Kamil Kuca
JPJiri Pikula
Jiri Pikula
Ondrej HolasOndrej Holas
Ondrej Holas
JCJiri Cabal
Jiri Cabal

26 September 2012 in Expert Opinion on Drug Discovery
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Journal Article
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Ondrej HolasOndrej Holas
Ondrej Holas
KMKamil Musilek
Kamil Musilek
MIroslav PohankaMIroslav Pohanka
MIroslav Pohanka
Kamil KucaKamil Kuca
Kamil Kuca
Introduction: Determination of acetylcholinesterase and butyrylcholinesterase activity has become an important tool in drug design and discovery as well as in medicine and toxicology. There are a large number of compounds that are able to modulate cholinesterase activity. These compounds can be used for pharmacological management of various disorders (e.g., Alzheimer's disease, myasthenia Gravis). Moreover, organophosphate poisoning is frequently diagnosed via a cholinesterase activity assay. This broad variety of methods has been developed over the past decades for cholinesterase activity quantification. Areas covered: This review provides a summary of the methods that are based on specific properties of cholinesterases and their interactions with native or artificial substrates. The authors also aim to provide an overview of different techniques used for the determination of quantitative cholinesterase activity. Specifically, the authors describe and discuss the manometric, potentiometric, titrimetric, ...

1 September 2010 in Chemico-Biological Interactions
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Zrinka KovarikZrinka Kovarik
Zrinka Kovarik
MKMaja Katalinić
Maja Katalinić
Goran ŠinkoGoran Šinko
Goran Šinko
JBJiri Binder
Jiri Binder
Ondrej HolasOndrej Holas
Ondrej Holas
KKKamil Kuča
Kamil Kuča

1 October 2010 in Bioorganic & Medicinal Chemistry Letters
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Journal Article
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Jan KorabecnyJan Korabecny
Jan Korabecny
KMKamil Musilek
Kamil Musilek
Ondrej HolasOndrej Holas
Ondrej Holas
JBJiri Binder
Jiri Binder
FZFilip Zemek
Filip Zemek
KKKamil Kuca
Kamil Kuca

16 March 2021 in Nanomaterials
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Journal Article
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Barbora BoltnarováBarbora Boltnarová
Barbora Boltnarová
JKJana Kubackova
Jana Kubackova
JŠJosef Škoda
Josef Škoda
ASAlzbeta Stefela
Alzbeta Stefela
MSMonika Smekalova
Monika Smekalova
Ondrej HolasOndrej Holas
Ondrej Holas
Macrophages possess an innate ability to scavenge heterogenous objects from the systemic circulation and to regulate inflammatory diseases in various organs via cytokine production. That makes them attractive targets for nanomedicine-based therapeutic approaches to inflammatory diseases. In the present study, we have prepared several different poly(lactic-co-glycolic acid) (PLGA) polymer nanospheres for macrophage-targeted drug delivery using both nanoprecipitation and emulsification solvent evaporation methods. Two experimental linear PLGA polymers with relatively low molar weight, one experimental branched PLGA with unique star-like molecular architecture, and a commercially available PLGA, were used for nanosphere formulation and compared to their macrophage uptake capacity. The nanosphere formulations labelled with loaded fluorescent dye Rhodamine B were further tested in mouse bone marrow-derived macrophages and in hepatocyte cell lines AML-12, HepG2. We found that nanospheres larger than 100 nm prepared using nanoprecipitation significantly enhanced distribution of fluorescent dye selectively into macrophages. No effects of nanospheres on cellular viability were observed. Additionally, no significant proinflammatory effect after macrophage exposure to nanospheres was detected as assessed by a determination of proinflammatory cytokines Il-1β and Tnfα mRNA. All experimental PLGA nanoformulations surpassed the nanospheres obtained with the commercially available polymer taken as a control in their capacity as macrophage-specific carriers.

1 January 2008 in Journal of Enzyme Inhibition and Medicinal Chemistry
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Journal Article
Open access
KMKamil Musilek
Kamil Musilek
Ondrej HolasOndrej Holas
Ondrej Holas
Kamil KucaKamil Kuca
Kamil Kuca
DJDaniel Jun
Daniel Jun
VDVlastimil Dohnal
Vlastimil Dohnal
MDMartin Dolezal
Martin Dolezal
Six AChE monooxime-monocarbamoyl reactivators with an (E)-but-2-ene linker were synthesized using modification of currently known synthetic pathways. Their potency to reactivate AChE inhibited by the nerve agent tabun and insecticide paraoxon was tested in vitro. The reactivation efficacies of pralidoxime, HI-6, obidoxime, K048, K075 and the newly prepared reactivators were compared. According to the results obtained, one reactivator seems to be promising against tabun-inhibited AChE and two reactivators against paraoxon-inhibited AChE. The best results were obtained for bisquaternary substances with at least one oxime group in position four.