The delivery of nitric oxide (NO) specifically to solid tumours was explored in this study as a strategy to augment the passive accumulation of nanomedicines in tumours induced by the Enhanced Permeability and Retention (EPR) effect. An increase in accumulation was achieved by the binding of the chemical precursor of NO, based on an organic nitrate, to a water-soluble synthetic polymer drug carrier. Four structurally different N-(2-hydroxypropyl)methacrylamide (HPMA)-based polymer NO donors were synthesized. Depending on their chemical structure, two of these donors were hydrolytically stable, while two rapidly released the parent nitrate under acidic conditions, mimicking the intracellular environment. The polymer NO donors were shown to overcome the drawbacks related to low-molecular-weight NO releasing compounds, namely systemic toxicity, lack of site specificity, and fast blood clearance. The NO donors showed intracellular NO release upon incubation with tumour cells. In vivo, they potentiated the EPR effect, resulting in an increased accumulation of polymer-bound cytotoxic drug doxorubicin (Dox) in EL4 T-cell lymphoma inoculated in mice. This led to a better therapeutic outcome in the treatment of lymphoma with the high-molecular-weight polymer conjugates carrying Dox but not in the treatment with the free Dox. The localized augmentation of the EPR effect via the tumour-specific NO delivery system can be viewed as a promising strategy to potentiate polymer-based tumour therapy without increasing systemic toxicity.
- MeSH
- antibiotika antitumorózní aplikace a dávkování MeSH
- buněčné linie MeSH
- donory oxidu dusnatého aplikace a dávkování MeSH
- doxorubicin aplikace a dávkování MeSH
- lidé MeSH
- lymfom T-buněčný farmakoterapie MeSH
- myši inbrední C57BL MeSH
- nosiče léků aplikace a dávkování MeSH
- polymery aplikace a dávkování MeSH
- synergismus léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The effects of novel polymeric therapeutics based on water-soluble N-(2-hydroxypropyl)methacrylamide copolymers (P(HPMA)) bearing the anticancer drug doxorubicin (Dox), an inhibitor of ABC transporters, or both, on the viability and the proliferation of the murine monocytic leukemia cell line P388 (parental cell line) and its doxorubicin-resistant subline P388/MDR were studied in vitro. The inhibitor derivatives 5-methyl-4-oxohexanoyl reversin 121 (MeOHe-R121) and 5-methyl-4-oxohexanoyl ritonavir ester (MeOHe-RIT), showing the highest inhibitory activities, were conjugated to the P(HPMA) via the biodegradable pH-sensitive hydrazone bond, and the ability of these conjugates to block the ATP driven P-glycoprotein (P-gp) efflux pump was tested. The P(HPMA) conjugate P-Ahx-NH-N═MeOHe-R121 showed a dose-dependent increase in the ability to sensitize the P388/MDR cells to Dox from 1.5 to 24 μM, and achieved an approximately 50-fold increase in sensitization at 24 μM. The P(HPMA) conjugate P-Ahx-NH-N═MeOHe-RIT showed moderate activity at 6 μM (∼10 times higher sensitization) and increased sensitization by 50-fold at 12 μM. The cytostatic activity of the P(HPMA) conjugate P-Ahx-NH-N═MeOHe-R121(Dox) containing Dox and the P-gp inhibitor MeOHe-R121, both bound via hydrazone bonds to the P(HPMA) carrier, was almost 30 times higher than that of the conjugate P-Ahx-NH-N═Dox toward the P388/MDR cells in vitro. A similar result was observed for P-Ahx-NH-N═MeOHe-RIT(Dox), which exhibited almost 10 times higher cytostatic activity than P-Ahx-NH-N═Dox.
- MeSH
- ABC transportéry antagonisté a inhibitory MeSH
- akrylamidy chemická syntéza MeSH
- antibiotika antitumorózní farmakologie MeSH
- chemorezistence * MeSH
- doxorubicin farmakologie MeSH
- hydrazony chemie MeSH
- koncentrace vodíkových iontů MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- P-glykoprotein metabolismus MeSH
- systémy cílené aplikace léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Treatment of murine EL4 T cell lymphoma with N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer conjugates of doxorubicin (Dox) leads to complete tumor regression and to the development of therapy-dependent longlasting cancer resistance. This phenomenon occurs with two types of Dox conjugates tested, despite differences in the covalent linkage of Dox to the polymer carrier. Such a cancer resistance cannot fully express in conventional treatment with free Dox, due to substantial immunotoxicity of the treatment, which was not observed in the polymer conjugates. In this study, calreticulin (CRT) translocation and high mobility group box-1 protein (HMGB1) release was observed in EL4 cells treated with a conjugate releasing Dox by a pH-dependent manner. As a result, the treated tumor cells were engulfed by dendritic cells (DC) in vitro, and induced their expression of CD80, CD86, and MHC II maturation markers. Conjugates with Dox bound via an amide bond only increased translocation of HSPs to the membrane, which led to an elevated phagocytosis but was not sufficient to induce increase of the maturation markers on DCs in vitro. Both types of conjugates induced engulfment of the target tumor cells in vivo, that was more intense than that seen with free Dox. It means that the induction of anti-tumor immunity documented upon treatment of EL4 lymphoma with HPMA-bound Dox conjugates does not rely solely on CRT-mediated cell death, but involves multiple mechanisms.
- MeSH
- antigeny CD80 metabolismus MeSH
- antigeny CD86 metabolismus MeSH
- antitumorózní látky aplikace a dávkování chemie toxicita MeSH
- apoptóza účinky léků MeSH
- chemorezistence účinky léků MeSH
- dendritické buňky cytologie imunologie MeSH
- doxorubicin aplikace a dávkování analogy a deriváty chemie toxicita MeSH
- fagocytóza MeSH
- kalretikulin metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- kyseliny polymethakrylové aplikace a dávkování chemie toxicita MeSH
- lymfom T-buněčný farmakoterapie imunologie MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nosiče léků chemie MeSH
- protein HMGB1 metabolismus MeSH
- proteiny tepelného šoku metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Novel star polymer-doxorubicin conjugates designed for passive tumor targeting have been developed and their potential for treatment of cancer has been investigated. In the present study the synthesis, physico-chemical characterization, drug release, bio-distribution and preliminary data of in vivo efficacy of the conjugates are described. In the water-soluble conjugates the core of a molecule formed by poly(amido amine) (PAMAM) dendrimers was grafted with semitelechelic N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers bearing doxorubicin (Dox) attached by hydrazone bonds enabling intracellular pH-controlled hydrolytic drug release, or by GFLG sequence susceptible to enzymatic degradation. The controlled synthesis utilizing semitelechelic copolymer precursors facilitated preparation of polymer conjugates in a broad range of molecular weights (1.1-3.0·10(5) g/mol). In contrast to free drug or linear conjugates the star polymer-Dox conjugates exhibited prolonged blood circulation and enhanced tumor accumulation in tumor-bearing mice indicating important role of the EPR effect. The star polymer-Dox conjugates showed significantly higher anti-tumor activity in vivo than Dox?HCl or its linear or graft polymer conjugates, if treated with a single dose 15 or 5 mg Dox eq./kg. Method of tumor initialization (acute or chronic experimental tumor models) significantly influenced effectiveness of the treatment with much lower success in treatment of mice bearing chronic tumors.
- MeSH
- akrylamidy chemie MeSH
- antibiotika antitumorózní aplikace a dávkování chemie farmakokinetika MeSH
- dendrimery chemie MeSH
- doxorubicin aplikace a dávkování chemie farmakokinetika MeSH
- koncentrace vodíkových iontů MeSH
- léky s prodlouženým účinkem MeSH
- lymfom T-buněčný farmakoterapie patologie MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- nosiče léků chemie MeSH
- rozpustnost MeSH
- systémy cílené aplikace léků MeSH
- tkáňová distribuce MeSH
- voda chemie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
The cytostatic effects of polymeric conjugates based on N-(2-hydroxypropyl)methacrylamide copolymers (PHPMA) and containing doxorubicin bound through amide and hydrazone bonds (mixed conjugates) were compared with the cytostatic effects of monoconjugates containing drug bound through an amide or hydrazone bond. One group of mixed conjugates was formed from two comonomers containing doxorubicin bound to the methacryloyl group through a spacer and an amide (DOX(AM)) or hydrazone (DOX(HYD)) bond via copolymerization with HPMA. A second group of mixed conjugates was formed from two different interconnected HPMA copolymers, one containing DOX(AM) and the other DOX(HYD), forming a high-molecular-weight branched structure. The third mixed polymeric system was a simple mixture of monoconjugates DOX(AM)-PHPMA and DOX(HYD)-PHPMA. Simultaneous treatment with all mixed forms of the polymeric derivatives of doxorubicin significantly increased antitumor efficacy after application of monoconjugates, suggesting a synergizing effect that could be used in designing new doxorubicin-containing therapeutic systems.
- MeSH
- akrylamidy chemie MeSH
- amidy chemie MeSH
- antibiotika antitumorózní chemie farmakologie MeSH
- buněčné linie MeSH
- doxorubicin chemie farmakologie MeSH
- fluorescenční mikroskopie MeSH
- hydrazony chemie MeSH
- lidé MeSH
- lymfom T-buněčný farmakoterapie MeSH
- molekulární struktura MeSH
- myši inbrední C57BL MeSH
- myši nahé MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- polymery chemická syntéza chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
