Závěrečná zpráva o řešení grantu Interní grantové agentury MZ ČR
2 svazky : ilustrace, tabulky ; 30 cm
The objective of the project is to create and elaborate the general theory which would explain, on the base of deep anaysis particularly physical characteristics, the present differences between long-term success of biological substitutes under condidtions of low flow under 100ml/min and complete failure of arteficial vascular prostheses under the same conditions. On the base of results of these analyses and tests to find out the crucial key characteristics which optimization would prepare the field for the construction of vascular prostheses comparable to biological substitutes under the same conditions On the base of almost half century experience with the research of vascular substitutes we have certain hypotheses, but they can be prooved only on the base of laboratory and experimental results The positive outcome of the project would be the substantial contribution to cardiovascular surgery
Předmětem řešení je hlubokou analýzou především fysikálních charakteristik náhrad biologických a základních typů náhrad umělých vypracovat theorii, která by vysvětlovala stávající řádové rozdíly mezi jejich úspěšností za podmínek nízkého průtoku pod 100ml/min. Na základě takto vytvořené theorie pak optimalizovat a konkrétizovat zásadní charakeristiky, které by umožnily konstrukci umělé cévní náhrady, která by se svou úspěšností blížila náhradám biologikcým. Na základě vlastních dlouholetých zkušeností v této oblasti máme své odůvodněné představy o optimálním směru výzkumu, jehož kladný výsledek vy zásadně rozšířil možnosti kardiovaskulární rekonstrukční chirurgie
- MeSH
- Autografts MeSH
- Transplantation, Autologous MeSH
- Blood Vessel Prosthesis MeSH
- Blood Vessel Prosthesis Implantation MeSH
- Blood Vessels physiology MeSH
- Physiology MeSH
- Blood Flow Velocity MeSH
- Vascular Surgical Procedures MeSH
- Research MeSH
- Plastic Surgery Procedures MeSH
- Conspectus
- Patologie. Klinická medicína
- NML Fields
- angiologie
- cévní chirurgie
- NML Publication type
- závěrečné zprávy o řešení grantu IGA MZ ČR
BACKGROUND: Radiolabelled monoclonal antibodies with affinity towards tumour-associated antigens may enhance the efficacy of cancer treatment with targeted radiotherapy. The humanized antibody nimotuzumab represents a promising vector to deliver radioactivity to tumours overexpressing epidermal growth factor receptor type 1 (ErbB1). We analysed the effect of radiolabelling nimotuzumab on its uptake in cancer cells and its biodistribution profile in preclinical experiments. METHODS: Nimotuzumab was labelled with (131) I by oxidative iodination and with (177) Lu using nimotuzumab conjugates with two different chelators (DTPA and DOTA) and two different spacers (p-SCN-Bn and NHS). For the receptor studies, two cell lines (HaCaT and A431) were used. Biodistribution studies were performed in male Wistar rats. RESULTS: The choice of radiolabel and the manner of its attachment to nimotuzumab had little effect on the internalization of the antibody into ErbB1-expressing cell lines. However, the type of radiolabel, the way in which it was attached to nimotuzumab and the radiolabelling procedure, significantly affected the blood clearance, liver uptake and liver persistence of radiolabelled nimotuzumab. (131) I-nimotuzumab had the longest elimination half-life and the lowest radioactivity uptake in the liver. (177) Lu-labelled nimotuzumab exhibited a shorter elimination half-life, high radioactivity and long-term retention in the liver.
- MeSH
- Antibodies, Monoclonal, Humanized chemistry pharmacokinetics pharmacology MeSH
- Isotope Labeling MeSH
- Rats MeSH
- Humans MeSH
- Lutetium chemistry pharmacokinetics MeSH
- Cell Line, Tumor MeSH
- Drug Evaluation, Preclinical MeSH
- Radiopharmaceuticals chemical synthesis pharmacokinetics pharmacology MeSH
- Iodine Radioisotopes chemistry pharmacokinetics MeSH
- Tissue Distribution MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The epidermal growth factor receptor (EGFR) is a rational target of anticancer therapies due to its overexpression in a variety of malignant epithelial tumors. Nevertheless, this antigen is also present in normal tissues. Consequently, monoclonal antibodies which selectively bind to EGFR-overexpressing tumors will be choice drug candidates for development of radioimmunoconjugates (RIC). Nimotuzumab (h-R3) and trastuzumab are monoclonal antibodies (mAbs) which would preferentially target tissues with EGFR and HER2 overexpression, respectively. In this chapter, we describe preparation and evaluation of the targeting properties of RIC formed by (177)Lu/(90)Y and monoclonal antibodies which selectively target EGFR- and HER2/c-neu-overexpressing tissues. mAbs were labeled with n.c.a. (177)Lu/(90)Y using bifunctional chelating agents. RIC binding properties and toxicity were evaluated in vitro using cell lines with varying antigen expression. In vivo tumor targeting properties of RIC were evaluated in mice bearing colorectal (SNU-C2B) and A431 tumor xenografts. RICs were prepared with specific activities up to 2 GBq/mg without significant loss in biological activity. (90)Y-h-R3/trastuzumab increased cell growth inhibition compared with unmodified mAbs or (90)YCl(3) alone in cell lines with overexpression of the target antigen. (177)Lu-h-R3 showed significantly higher uptake in A431 (22.8 ± 3.1% ID/g) than in SNU-C2B (8.8 ± 4.1% ID/g) xenografts at 72 h post injection, indicating strong association between tumor uptake and EGFR expression levels.
- MeSH
- ErbB Receptors antagonists & inhibitors MeSH
- Immunoconjugates pharmacokinetics therapeutic use MeSH
- Isotope Labeling MeSH
- Rats MeSH
- Humans MeSH
- Lutetium therapeutic use MeSH
- Antibodies, Monoclonal therapeutic use MeSH
- Mice MeSH
- Cell Line, Tumor MeSH
- Rats, Wistar MeSH
- Radioimmunotherapy MeSH
- Yttrium Radioisotopes therapeutic use MeSH
- Radioisotopes therapeutic use MeSH
- Receptor, ErbB-2 antagonists & inhibitors MeSH
- Xenograft Model Antitumor Assays MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
OBJECTIVES: Nimotuzumab (h-R3) is a humanized monoclonal antibody (mAb) which recognizes the external domain of the epidermal growth factor receptor (EGFR) with high specificity. It was demonstrated that h-R3 has a unique clinical profile for immunotherapy of adult gliomas and pediatric pontine gliomas. The aim of this work was to evaluate the conjugate (177)Lu-h-R3 as a potential radioimmunoconjugate for radioimmunotherapy (RIT) of tumors overexpressing EGFR. METHODS: h-R3 was modified with the macrocylcic ligand S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane tetraacetic acid (p-SCN-Bn-DOTA) and the acyclic ligand S-2-(4-Isothiocyanatobenzyl)-diethylenetriamine pentaacetic acid (p-SCN-Bn-DTPA); the immunoconjugates were labeled with no-carried added (177)Lu. Specificity and affinity were tested using radioimmunoassays in a cell line overexpressing EGFR. Biodistribution in mice, healthy or bearing A431 epithelial carcinoma xenografts, was performed for 11 days. Tumor uptake, the influence of the nature of the chelate and the way of administration were studied. Absorbed dose in tumor and selected organs was calculated using the OLINDA/EXM software; the data from the animals was extrapolated to humans. RESULTS: (177)Lu-h-R3 conjugates were obtained with specific activity up to 915 MBq/mg without significant loss of immunoreactivity. The binding of (177)Lu-h-R3 conjugates to A431 cells showed to be EGFR specific, and the affinity was similar to native h-R3. Tumor uptake reached a maximum value of 22.4±3.1 %ID/g at 72 h and remained ~20% ID/g over 1 week. Locoregional application showed better tumor/nontumor ratios than intravenous application. CONCLUSIONS: (177)Lu-h-R3 should be considered for further evaluations as a potential radiopharmaceutical for RIT of tumors overexpressing EGFR.
- MeSH
- Radiation Dosage MeSH
- ErbB Receptors metabolism MeSH
- Neoplasms, Experimental radiotherapy MeSH
- Antibodies, Monoclonal, Humanized administration & dosage pharmacokinetics MeSH
- Immunoconjugates pharmacokinetics MeSH
- Immunologic Factors pharmacokinetics MeSH
- Humans MeSH
- Lutetium administration & dosage pharmacokinetics MeSH
- Mice, Inbred BALB C MeSH
- Mice MeSH
- Radioimmunotherapy methods MeSH
- Radioisotopes administration & dosage pharmacokinetics MeSH
- Carcinoma, Squamous Cell radiotherapy MeSH
- Tissue Distribution MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND: The humanized monoclonal antibody Nimotuzumab (h-R3) has demonstrated an exceptional and better clinical profile than other monoclonal antibodies for immunotherapy of epidermal growth factor receptor-overexpressing tumors. This work deals with the preparation and radiolabeling optimization of (177)Lu-Nimotuzumab and their preclinical evaluation. METHODS: Nimotuzumab was conjugated with S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane tetraacetic acid (p-SCN-Bn-DOTA), testing different molar ratios. The immunoconjugates were characterized. The radiolabeling with (177)Lu was optimized. Radioimmunoconjugates stability was tested in 2-[bis[2-[bis(carboxymethyl)amino]ethyl]amino]acetic acid (DTPA) excess and human serum. In vitro studies were performed in tumor model cell lines. Receptor-specific binding was tested by competitive inhibition. (177)Lu-Nimotuzumab in vivo studies were conducted in healthy and xenograft animals. RESULTS: Nimotuzumab conjugates were obtained with high purity. Radiolabeling yield and specific activities ranged from 63.6% to 94.5% and from 748 to 1142 MBq/mg, respectively. The stability in DTPA excess and human serum was 95.9% and 93.2% after 10 days, respectively. The radioimmunoconjugate showed specific receptor binding in tumor cell lines. Biodistribution in healthy animals showed the typical behavior of the immunoconjugates based on monoclonal antibodies. The study in xenografts mice demonstrated uptake of (177)Lu-Nimotuzumab in the tumor and reticuloendothelial organs. CONCLUSIONS: (177)Lu-Nimotuzumab was obtained with high purity and specific activities under optimal conditions without significant loss in immunoreactivity and might be a potential radioimmunoconjugate for radioimmunotherapy of tumors with epidermal growth factor receptor overexpression.
- MeSH
- Time Factors MeSH
- Chelating Agents pharmacology MeSH
- ErbB Receptors biosynthesis MeSH
- Heterocyclic Compounds pharmacology MeSH
- Antibodies, Monoclonal, Humanized therapeutic use MeSH
- Immunoconjugates therapeutic use MeSH
- Isothiocyanates pharmacology MeSH
- Rats MeSH
- Humans MeSH
- Lutetium therapeutic use MeSH
- Mice MeSH
- Cell Line, Tumor MeSH
- Neoplasms therapy MeSH
- Rats, Wistar MeSH
- Radioimmunotherapy methods MeSH
- Radioisotopes therapeutic use MeSH
- Gene Expression Regulation, Neoplastic MeSH
- Neoplasm Transplantation MeSH
- Chromatography, High Pressure Liquid methods MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Závěrečná zpráva o řešení grantu Interní grantové agentury MZ ČR
50 l. : il., tab., grafy ; 30 cm
Study of the 3´- deoxy-3´-(18F) fluorothymidine (FJFLT) preparation and finding a suitable synthesis precursor including the synthesis parameters optimization. Completion of the study of an irradiation target for sufficient production of fluorine. Development of methods of (18F) FLT quality control, above all of the radiochemical and chemical purity of the synthesized product. Performing the introductory biodistribution study including the distribution visualizing on a PET camera.
Studium přípravy 3´- deoxy ´- (18F) fluorothymidin (18F) FLT a nalezení vhodného prekuzoru pro syntézu ( 18F) FLT). Vývoj metod kontroly kvality (18F)FLT, především kontroly radiochemické čistoty a chemické čistoty syntetizovaného produktu. Provedení úvodní biodistribuční studie včetně zobrazení distribuce na PET kameře.
- MeSH
- Biopharmaceutics MeSH
- Chemistry, Pharmaceutical MeSH
- Drug Compounding MeSH
- Quality Control MeSH
- Thymidine analogs & derivatives MeSH
- Conspectus
- Farmacie. Farmakologie
- NML Fields
- farmacie a farmakologie
- chemie, klinická chemie
- farmacie a farmakologie
- NML Publication type
- závěrečné zprávy o řešení grantu IGA MZ ČR
