Ondřej Hovorka

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Rubropunctatin (1), monascorubrin (2), monascin (3) and ankaflavin (4) were purified from the mycelium of Monascus purpureus by flash chromatography on silica gel or reversed phase. Their embryotoxicity towards chicken embryos decreased in the order 2 > 1 > 3 > 4. The lower homologues 1 and 3 exhibited teratogenic effects on these organisms. Significant(More)
There is a wide range of techniques utilizing fluorescence of doxorubicin (Dox) commonly used for analysis of intracellular accumulation and destiny of various drug delivery systems containing this anthracycline antibiotic. Unfortunately, results of these studies can be significantly influenced by doxorubicin degradation product,(More)
We present data providing new evidence that poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA)-bound drugs, unlike free drugs, have both cytostatic and immunomobilizing activity (CIA). Immediately after injection, due to the high level of the drug, the main activity of the polymeric conjugate is cytotoxic and cytostatic. Later on, long-term circulating(More)
Giardia intestinalis is an ancient protist that causes the most commonly reported human diarrheal disease of parasitic origin worldwide. An intriguing feature of the Giardia cell is the presence of two morphologically similar nuclei, generally considered equivalent, in spite of the fact that their karyotypes are unknown. We found that within a single cell,(More)
We have synthesized conjugates containing doxorubicin (DOX) bound to oligopeptide side chains (GlyGly or GlyPheLeuGly) of a water-soluble copolymer carrier based on poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA) either through proteolytically (PK1 conjugates) [Synthetic polymeric drugs. U.S. Patent 5,037,883 (1991)] or hydrolytically cleavable bond (HC(More)
Conjugates based on N-(2-hydroxypropyl)methacrylamide (HPMA) represent a new generation of antibody-targeted polymeric anticancer drugs with both cytotoxic and immunoprotecting/immunomobilizing activity. 20-90% of mice that are cured of EL4 mouse T-cell lymphoma, BCL1 mouse B-cell leukaemia and 38C13 mouse B-cell lymphoma by injection of doxorubicin-HPMA(More)
Internalization and subcellular fate of free doxorubicin or its polymeric conjugates based on poly N-(2-hydroxypropyl)methacrylamide (pHPMA), either non-targeted or targeted with anti-Thy1.2 or anti-CD71 monoclonal antibody was tested on EL-4 mouse T-cell lymphoma, SW620 human colorectal carcinoma and OVCAR-3 human ovarian adenocarcinoma. Doxorubicin(More)
Doxorubicin is one of the most potent anti-tumor drugs with a broad spectrum of use. To reduce its toxic effect and improve its pharmacokinetics, we conjugated it to an HPMA copolymer carrier that enhances its passive accumulation within solid tumors via the EPR effect and decreases its cytotoxicity to normal, noncancer cells. In this study, we compared the(More)
We provide data on in vivo targeting of the Thy 1.2 (CDw90) cell surface receptor expressed on neoplastic T cells, mouse EL4 T cell lymphoma. The targeting antibody and the anticancer drug, doxorubicin (DOX) were conjugated to a water-soluble copolymer based on N-(2-hydroxypropyl)methacrylamide (HPMA) acting as a carrier responsible for controlled(More)
Polymeric conjugates based on N-(2-hydroxypropyl)methacrylamide (HPMA) have been tested as potential carrier for anticancer drug - doxorubicin (Dox). Two types of conjugates were synthesized: (a) conjugates containing Dox bound through an amidic bond to an oligopeptidic side-chain (usually GFLG) and (b) hydrolytically cleavable conjugates wherein Dox is(More)