One obstacle to the successful delivery of nanodrugs into solid tumors is the heterogeneity of an enhanced permeability and retention (EPR) effect as a result of occluded or embolized tumor blood vessels. Therefore, the augmentation of the EPR effect is critical for satisfactory anticancer nanomedicine. In this study, we focused on one vascular mediator involved in the EPR effect, carbon monoxide (CO), and utilized two CO generating agents, one is an extrinsic CO donor (SMA/CORM2 micelle) and another is an inducer of endogenous CO generation via heme oxygenase-1 (HO-1) induction that is carried out using pegylated hemin. Both agents generated CO selectively in solid tumors, which resulted in an enhanced EPR effect and a two- to three-folds increased tumor accumulation of nanodrugs. An increase in drug accumulation in the normal tissue did not occur with the treatment of CO generators. In vivo imaging also clearly indicated a more intensified fluorescence of macromolecular nanoprobe in solid tumors when combined with these CO generators. Consequently, the combination of CO generators with anticancer nanodrugs resulted in an increased anticancer effect in the different transplanted solid tumor models. These findings strongly warrant the potential application of these CO generators as EPR enhancers in order to enhance tumor detection and therapy using nanodrugs.
- Publikační typ
- časopisecké články MeSH
Small molecule Toll-like receptor-7 and -8 agonists (TLR-7/8a) can be used as vaccine adjuvants to induce CD8 T cell immunity but require formulations that prevent systemic toxicity and focus adjuvant activity in lymphoid tissues. Here, we covalently attached TLR-7/8a to polymers of varying composition, chain architecture and hydrodynamic behavior (∼300 nm submicrometer particles, ∼10 nm micelles and ∼4 nm flexible random coils) and evaluated how these parameters of polymer-TLR-7/8a conjugates impact adjuvant activity in vivo. Attachment of TLR-7/8a to any of the polymer compositions resulted in a nearly 10-fold reduction in systemic cytokines (toxicity). Moreover, both lymph node cytokine production and the magnitude of CD8 T cells induced against protein antigen increased with increasing polymer-TLR-7/8a hydrodynamic radius, with the submicrometer particle inducing the highest magnitude responses. Notably, CD8 T cell responses induced by polymer-TLR-7/8a were dependent on CCR2+ monocytes and IL-12, whereas responses by a small molecule TLR-7/8a that unexpectedly persisted in vaccine-site draining lymph nodes (T1/2 = 15 h) had less dependence on monocytes and IL-12 but required Type I IFNs. This study shows how modular properties of synthetic adjuvants can be chemically programmed to alter immunity in vivo through distinct immunological mechanisms.
- MeSH
- adjuvancia imunologická aplikace a dávkování chemie farmakologie MeSH
- aktivace lymfocytů * MeSH
- buněčné linie MeSH
- CD8-pozitivní T-lymfocyty účinky léků imunologie MeSH
- cytokiny metabolismus MeSH
- hydrodynamika MeSH
- kultivované buňky MeSH
- micely * MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- toll-like receptor 7 agonisté MeSH
- toll-like receptor 8 agonisté MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Intramural MeSH
We have developed a tumor environment-responsive polymeric anticancer prodrug containing pirarubicin (THP) conjugated to N-(2-hydroxypropyl) methacrylamide copolymer (PHPMA), [P-THP], through a spacer containing pH-sensitive hydrazone bond, that showed remarkable therapeutic effect against various tumor models and in a human pilot study. Toward clinical development, here we report THP release profile from its HPMA copolymer conjugate, the conjugate stability, protein and cell-binding and solubility of P-THP. Size exclusion chromatography of P-THP (molecular weight 38 kDa) showed similar hydrodynamic volume as bovine serum albumin (BSA) in aqueous solution, with no apparent interactions with BSA, nor aggregation by itself. pH-responsive release of free THP was reconfirmed at pHs 6.5 and lower. The drug release was significantly affected by a type of used buffer. Phosphate buffer seems to facilitate faster hydrazone bond cleavage at pH 7.4 whereas higher stability was achieved in L-arginine solution which yielded only little cleavage and THP release, approx. 15% within 2 weeks at the same pH at 25 °C. Furthermore, ex vivo study using sera of different animal species showed very high stability of P-THP. Incubation with blood showed high stability of P-THP during circulation, without binding to blood cells. These findings revealed that L-arginine solution provides appropriate media for formulation of P-THP infusion solution as tumor-targeted polymeric anticancer drug based on EPR effect.
- MeSH
- antitumorózní látky chemie MeSH
- arginin chemie MeSH
- doxorubicin analogy a deriváty chemie MeSH
- králíci MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- methakryláty chemie MeSH
- myši MeSH
- nosiče léků chemie MeSH
- pilotní projekty MeSH
- polymery chemie MeSH
- rozpustnost účinky léků MeSH
- sérový albumin hovězí chemie MeSH
- uvolňování léčiv účinky léků MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Enhanced permeability and retention (EPR) effect-based nanomedicine is a promising strategy for successful anticancer therapy. The EPR effect is based on tumor blood flow. Because advanced large tumors, as frequently seen in clinical settings, are heterogeneous, with regions of defective vasculature and blood flow, achieving the desired tumor drug delivery is difficult. Here, we utilized the EPR effect to increase drug delivery. To augment the EPR effect for improved therapeutic effects of nanomedicine, we exploited vascular mediators-the nitric oxide (NO) generators nitroglycerin (NG), hydroxyurea, and l-arginine. These compounds generate NO in tumors with relatively high selectivity. Using different nanosized drugs in our protocol significantly increased (1.5-2 times) delivery of nanomedicines to different solid tumor models, along with markedly improving (2-3-fold) the antitumor effects of these drugs. Also, in 7,12-dimethylbenz[a]anthracene-induced advanced end-stage breast cancer, often seen in clinical settings, 2 mg/kg polymer-conjugated pirarubicin (P-THP) with NG (0.2 mg/mouse) showed better effects than did 5 mg/kg P-THP, and 5 mg/kg P-THP used with NG resulted in cures or stable tumors (no tumor growth) for up to 120 days. Moreover, in a murine autochthonous azoxymethane/dextran sulfate sodium-induced colon cancer model, NO donors markedly improved the therapeutic effects of P-THP even after just one injection, results that were comparable with those achieved with three weekly P-THP treatments. These findings strongly suggest the potential usefulness of NO donors as EPR effect enhancers to improve the therapeutic efficacy of nanomedicines.
- MeSH
- antitumorózní látky farmakologie MeSH
- arginin farmakologie MeSH
- donory oxidu dusnatého farmakologie MeSH
- doxorubicin analogy a deriváty farmakologie MeSH
- hydroxymočovina farmakologie MeSH
- makromolekulární látky farmakologie MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- nádory krevní zásobení patologie MeSH
- nanočástice chemie MeSH
- nanomedicína * MeSH
- nitroglycerin farmakologie MeSH
- oxid dusnatý biosyntéza MeSH
- permeabilita MeSH
- potkani Sprague-Dawley MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Over the past few decades, numerous polymer drug carrier systems are designed and synthesized, and their properties are evaluated. Many of these systems are based on water-soluble polymer carriers of low-molecular-weight drugs and compounds, e.g., cytostatic agents, anti-inflammatory drugs, or multidrug resistance inhibitors, all covalently bound to a carrier by a biodegradable spacer that enables controlled release of the active molecule to achieve the desired pharmacological effect. Among others, the synthetic polymer carriers based on N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers are some of the most promising carriers for this purpose. This review focuses on advances in the development of HPMA copolymer carriers and their conjugates with anticancer drugs, with triggered drug activation in tumor tissue and especially in tumor cells. Specifically, this review highlights the improvements in polymer drug carrier design with respect to the structure of a spacer to influence controlled drug release and activation, and its impact on the drug pharmacokinetics, enhanced tumor uptake, cellular trafficking, and in vivo antitumor activity.
Tumor-targeted photodynamic therapy (PDT) using polymeric photosensitizers is a promising therapeutic strategy for cancer treatment. In this study, we synthesized a pHPMA conjugated pyropheophorbide-a (P-PyF) as a cancer theranostic agent for PDT and photodynamic diagnostics (PDD). Pyropheophorbide-a has one carboxyl group which was conjugated to pHPMA via amide bond yielding the intended product with high purity. In aqueous solutions, P-PyF showed a mean particle size of ∼200 nm as it forms micelle which exhibited fluorescence quenching and thus very little singlet oxygen (1O2) production. In contrast, upon disruption of micelle strong fluorescence and 1O2 production were observed. In vitro study clearly showed the PDT effect of P-PyF. More potent 1O2 production and PDT effect were observed during irradiation at ∼420 nm, the maximal absorbance of pyropheophorbide-a, than irradiation at longer wavelength (i.e., ∼680 nm), suggesting selection of proper absorption light is essential for successful PDT. In vivo study showed high tumor accumulation of P-PyF compared with most of normal tissues due to the enhanced permeability and retention (EPR) effect, which resulting in superior antitumor effect under irradiation using normal xenon light source of endoscope, and clear tumor imaging profiles even in the metastatic lung cancer at 28 days after administration of P-PyF. On the contrary irradiation using long wavelength (i.e., ∼680 nm), the lowest Q-Band, exhibited remarkable tumor imaging effect with little autofluorescence of background. These findings strongly suggested P-PyF may be a potential candidate-drug for PDT/PDD, particularly using two different wavelength for treatment and detection/imaging, respectively.
- MeSH
- časové faktory MeSH
- chlorofyl aplikace a dávkování analogy a deriváty farmakokinetika MeSH
- fluorescence MeSH
- fotochemoterapie metody MeSH
- fotosenzibilizující látky aplikace a dávkování MeSH
- kyseliny polymethakrylové chemie MeSH
- micely MeSH
- myši inbrední BALB C MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- nádory plic diagnóza farmakoterapie MeSH
- permeabilita MeSH
- polymery chemie MeSH
- teranostická nanomedicína metody MeSH
- tkáňová distribuce MeSH
- velikost částic MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Herein, the biodegradable micelle-forming amphiphilic N-(2-hydroxypropyl) methacrylamide (HPMA)-based polymer conjugates with the anticancer drug doxorubicin (Dox) designed for enhanced tumor accumulation were investigated, and the influence of their stability in the bloodstream on biodistribution, namely, tumor uptake, and in vivo antitumor efficacy were evaluated in detail. Dox was attached to the polymer carrier by a hydrazone bond enabling pH-controlled drug release. While the polymer-drug conjugates were stable in a buffer at pH 7.4 (mimicking bloodstream environment), Dox was released in a buffer under mild acidic conditions modeling the tumor microenvironment or cells. The amphiphilic polymer carriers differed in the structure of hydrophobic cholesterol derivative moieties bound to the HPMA copolymers via a hydrolyzable hydrazone bond, exhibiting different rates of micellar structure disintegration at various pH values. Considerable dependence of the studied polymer-drug conjugate biodistribution on the stability of the micellar structure was observed in neutral, bloodstream-mimicking, environment, showing that a faster rate of the micelle disintegration in pH 7.4 increased the conjugate blood clearance, decreased tumor accumulation, and significantly reduced the tumor:blood and tumor:muscle ratios. Similarly, the final therapeutic outcome was strongly affected by the stability of the micellar structure because the most stable micellar conjugate showed an almost similar therapeutic outcome as the water-soluble, nondegradable, high-molecular-weight starlike HPMA copolymer-Dox conjugate, which was highly efficient in the treatment of solid tumors in mice. Based on the results, we conclude that the bloodstream stability of micellar polymer-anticancer drug conjugates, in addition to their low side toxicity, is a crucial parameter for their efficient solid tumor accumulation and high in vivo antitumor activity.
- MeSH
- antitumorózní látky chemie farmakokinetika terapeutické užití MeSH
- doxorubicin chemie farmakokinetika terapeutické užití MeSH
- hydrofobní a hydrofilní interakce MeSH
- koncentrace vodíkových iontů MeSH
- lymfom krev farmakoterapie MeSH
- micely MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- nosiče léků chemie MeSH
- polymery chemie MeSH
- uvolňování léčiv MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Slavnostní přednášky Akademie věd České republiky : špičkový výzkum ve veřejném zájmu ; V.
Vydání první 55 stran : ilustrace ; 16 cm
Většina klinicky používaných chemoterapeutik je systémově toxická, to znamená, že ovlivňují celý organismus pacienta. Nerozeznávají, jedná-li se o buňku zdravou nebo nádorovou. Mají vedlejší účinky, a tak o nich říkáme, že jsou myelotoxická, hepatotoxická, nefrotoxická a imunotoxická. Cíleně směrovaná léčiva, která jsou tvořena syntetickým polymerním nosičem, na který je navázáno léčivo a směrující struktura, působí přímo na postižené buňky, a tak tyto nežádoucí vedlejší účinky nemají.
- MeSH
- biologická terapie MeSH
- glykoproteiny MeSH
- imunotoxiny MeSH
- toxikologie MeSH
- Publikační typ
- přednášky MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- onkologie
In this study, we compared the enhanced permeability and retention (EPR) effect, toxicity, and therapeutic effect of the conjugate of the linear polymer poly(N-(2-hydroxypropyl)methacrylamide) (HPMA) with pirarubicin with an Mw below the renal threshold (39g/mol) (named LINEAR) and the disulfide-linked tandem-polymeric dimer of the poly(HPMA)-pirarubicin conjugate with an Mw above the renal threshold (93g/mol) (named DIBLOCK). The DIBLOCK conjugate, which was susceptible to reductive degradation, showed both a better EPR effect (tumor delivery) (2.5 times greater at 24h) and a prolonged plasma half-life. In addition, DIBLOCK had a better antitumor effect, as judged by percent survival, than did LINEAR (80% vs 65% at 150days), without any apparent toxicity in an S180 tumor model. However, the LD50 value of LINEAR was slightly higher than that of DIBLOCK (50mg/kg vs 37.5mg/kg, respectively). DIBLOCK required a longer time than LINEAR to reach maximum accumulation in the tumor. DIBLOCK also showed a greater time-dependent increase in the concentration in the tumor compared with the plasma concentration.
- MeSH
- antitumorózní látky škodlivé účinky chemie farmakologie MeSH
- biologická dostupnost MeSH
- biologický transport MeSH
- doxorubicin škodlivé účinky analogy a deriváty chemie farmakologie MeSH
- kyseliny polymethakrylové chemická syntéza MeSH
- lidé MeSH
- molekulová hmotnost MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nosiče léků chemická syntéza MeSH
- poločas MeSH
- renální reabsorpce MeSH
- tkáňová distribuce MeSH
- uvolňování léčiv MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Publikační typ
- abstrakt z konference MeSH
