Intralipid, a clinically used lipid emulsion, was reportedly utilized as one strategy to suppress off-target delivery of anticancer nanomedicines; Intralipid also effectively improved drug delivery to tumors and produced better therapeutic effects. However, the mechanisms involved-the why and how-in Intralipid's facilitation of delivery of nanomedicines to tumors have not yet been reported in detail. In this study, we investigated Intralipid and discovered the beneficial effects of Intralipid pretreatment when using three anticancer nanomedicines, including the clinically approved drug doxorubicin (Doxil). Intralipid pretreatment induced a 40% reduction in liver uptake of a polymeric nanoprobe used in photodynamic therapy as well as a 1.5-fold-increased nanomedicine accumulation in tumors. This increased accumulation consequently led to significantly better therapeutic effects, and this finding was validated by using Doxil. As an interesting result, Intralipid pretreatment significantly prolonged the plasma half-life of nanomedicines in normal healthy mice but not in tumor-bearing mice, which suggests that tumors become an alternative route of nanomedicine delivery when liver delivery is suppressed. Also, we found markedly increased tumor blood flow, as measured by fluorescence angiography, and significantly lower blood viscosity after Intralipid pretreatment. All our results together indicate that Intralipid treatment not only suppressed off-target nanomedicine delivery by the reticuloendothelial system, but more important, it enhanced nanomedicine delivery to tumors by improving tumor blood flow, which is key to satisfactory drug delivery via the enhanced permeability and retention effect. Significantly better therapeutic outcomes were thus achieved by the strategy of combining utilization of nanomedicines and Intralipid pretreatment. STATEMENT OF SIGNIFICANCE: Off-target delivery to organs such as the liver and obstructed tumor blood flow as is often seen in advanced cancers are major barriers to the therapeutic efficacy of anticancer nanomedicines. Intralipid has been shown effective for suppressing nanomedicine accumulation in the liver, resulting in improved anticancer effects. Unraveling the mechanisms involved in this process will be greatly helpful for the clinical application of anticancer nanomedicines. We reported here that Intralipid could also significantly increase tumor delivery of nanomedicine, which is beneficial for improving tumor blood flow and lowering blood viscosity. To our knowledge, this is the first study to investigate the role of Intralipid in this regard. This knowledge provides a solid rationale for the use of Intralipid in combination with anticancer nanomedicines.

• MeSH
• antitumorózní látky * farmakologie   terapeutické užití   MeSH
• emulze MeSH
• fosfolipidy MeSH
• myši MeSH
• nádory * farmakoterapie   MeSH
• nanomedicína MeSH
• sójový olej MeSH
• systémy cílené aplikace léků MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

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

N-(2-Hydroxypropyl)methacrylamide copolymer conjugates of pirarubicin (THP), P-THP, accumulates selectively in solid tumor tissue by the enhanced permeability and retention (EPR) effect. Despite of high accumulation in solid tumors, some macromolecular antitumor agents show poor therapeutic outcome because of poor tissue diffusion into the tumor as well as obstructed tumor blood flow. Here, we confirmed that cellular uptake of P-THP was 25 times less than that of free THP at 1-4 h incubation time in vitro. The passage of P-THP through the confluent tight-monolayer cells junction was 12 times higher than free THP, and P-THP penetrated deeper into the tumor cell spheroid (1.3-1.7-fold) than free THP in 4 h. In addition, P-THP showed cytotoxicity comparable to that of free THP to tumor-cells in spheroid form, despite of 7 times lower cytotoxicity of P-THP to the monolayer cells to that of free THP in vitro. These results indicate that P-THP administration can exhibit deeper diffusion into the tumor cell spheroid than free THP. As a consequence, P-THP exhibits more efficient antitumor activity than free THP in vivo, which is also supported by better pharmacokinetics and tumor accumulation of P-THP than free THP.

• MeSH
• akrylamidy chemie   MeSH
• antitumorózní látky aplikace a dávkování   farmakokinetika   MeSH
• buněčné sféroidy MeSH
• doxorubicin aplikace a dávkování   analogy a deriváty   farmakokinetika   MeSH
• HCT116 buňky MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• nádory farmakoterapie   patologie   MeSH
• nosiče léků chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem 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

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

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

Many conjugates of water-soluble polymers with biologically active molecules were developed during the last two decades. Although, therapeutic effects of these conjugates are affected by the properties of carriers, the properties of the attached drugs appear more important than the same carrier polymer in this case. Pirarubicin (THP), a tetrahydropyranyl derivative of doxorubicin (DOX), demonstrated more rapid cellular internalization and potent cytotoxicity than DOX. Here, we conjugated the THP or DOX to N-(2-hydroxypropyl)methacrylamide copolymer via a hydrazone bond. The polymeric prodrug conjugates, P-THP and P-DOX, respectively, had comparable hydrodynamic sizes and drug loading. Compared with P-DOX, P-THP showed approximately 10 times greater cellular uptake during a 240 min incubation and a cytotoxicity that was more than 10 times higher during a 72-h incubation. A marginal difference was seen in P-THP and P-DOX accumulation in the liver and kidney at 6 h after drug administration, but no significant difference occurred in the tumor drug concentration during 6-24 h after drug administration. Antitumor activity against xenograft human pancreatic tumor (SUIT2) in mice was greater for P-THP than for P-DOX. To sum up, the present study compared the biological behavior of two different drugs, each attached to an N-(2-hydroxypropyl)methacrylamide copolymer carrier, with regard to their uptake by tumor cells, body distribution, accumulation in tumors, cytotoxicity, and antitumor activity in vitro and in vivo. No differences in the tumor cell uptake of the polymer-drug conjugates, P-THP and P-DOX, were observed. In contrast, the intracellular uptake of free THP liberated from the P-THP was 25-30 times higher than that of DOX liberated from P-DOX. This finding indicates that proper selection of the carrier, and especially conjugated active pharmaceutical ingredient (API) are most critical for anticancer activity of the polymer-drug conjugates. THP, in this respect, was found to be a more preferable API for polymer conjugation than DOX. Hence the treatment based on enhanced permeability and retention (EPR) effect that targets more selectively to solid tumors can be best achieved with THP, although both polymer conjugates of DOX and THP exhibited the EPR effects and drug release profiles in acidic pH similarly.

• MeSH
• akrylamidy chemie   MeSH
• antibiotika antitumorózní chemie   farmakologie   MeSH
• antitumorózní látky chemie   farmakologie   MeSH
• doxorubicin analogy a deriváty   chemie   farmakologie   MeSH
• experimentální sarkom farmakoterapie   metabolismus   patologie   MeSH
• lidé MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• nádorové buňky kultivované MeSH
• nosiče léků aplikace a dávkování   chemie   MeSH
• polymery aplikace a dávkování   chemie   MeSH
• proliferace buněk účinky léků   MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Nanomedicine allows achievement of tumor-selective drug delivery because of the enhanced permeability and retention (EPR) effect of solid tumors. We report here the first clinical application of a new agent-HPMA copolymer-conjugated pirarubicin (P-THP)-with a molecular size of about 8 nm, or 38.5 kDa. A patient had advanced prostate cancer with multiple metastases in the lung, pelvis, femur, and perhaps the sacrum. In April 2013, this 60-year-old patient started treatment with leuprorelin and estradiol, which continued until July 2014, but the patient became refractory to this treatment. So the patient underwent proton beam radiotherapy targeted to the primary prostate cancer, and P-THP was administered for numerous metastatic tumor nodules concomitantly with radiotherapy. This combination therapy had remarkable results, with complete remission of multiple metastases in the lung and bone. The prostate-specific antigen (PSA) value was decreased from about 1000 ng/mL on April 30, 2013, to about 100 ng/mL on June 24, 2013, with hormone therapy, but rose again to 964.2 ng/mL and then to 1472 ng/mL in July 2013, during leuprorelin administration. P-THP treatment administered concomitantly with proton beam irradiation was started in August 2013. The PSA value was decreased to 102 ng/mL on August 26, 2013, and then to 0.971 ng/mL on October 8, 2013, and 0.277 ng/mL on January 15, 2015. The P-THP doses ranged from 30 to 75 mg of free THP equivalent/patient every 2-3 weeks without signs of serious toxicity, such as cardiovascular side effects or a reduction in quality of life. No evidence of relapse was found more than 20 months after P-THP administration. This case demonstrates the value of hydrazone-bonded polymeric drugs in multimodal therapy.

• MeSH
• antitumorózní látky terapeutické užití   MeSH
• doxorubicin analogy a deriváty   terapeutické užití   MeSH
• kombinovaná terapie MeSH
• lidé středního věku MeSH
• lidé MeSH
• methakryláty chemie   MeSH
• nádory kostí sekundární   terapie   MeSH
• nádory plic sekundární   terapie   MeSH
• nádory prostaty patologie   terapie   MeSH
• prognóza MeSH
• staging nádorů MeSH
• systémy cílené aplikace léků * MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH

Previously we showed that linear poly(N-(2-hydroxypropyl)methacrylamide) conjugates of pirarubicin (THP), LP-THP, with MW about 39 kDa, exhibited far better tumor accumulation and therapeutic effect than that of parental free THP. To improve the pharmacokinetics of LP-THP further, high-MW conjugate of poly(amido amine) (PAMAM) dendrimer grafted with semitelechelic HPMA copolymer (PHPMA) was synthesized [star polymer (SP); 400 kDa] and conjugated with THP via hydrazone bond-containing spacer (SP-THP). THP was conjugated to SP to form SP-THP via acid cleavable hydrazone bonding, which responds to acidic milieu of tumor tissue. As a consequence, it would release free THP, by active therapeutic principle. SP-THP exhibits larger hydrodynamic diameter (25.9 nm) in aqueous solution than that of LP-THP (8.2 nm) as observed by light scattering and size exclusion chromatography. Because of the larger size, the tumor AUC5h-72 h of SP-THP was 3.3 times higher than that of LP-THP. More importantly, released free THP was retained selectively in the tumor tissue for at least up to 72 h after administration of SP-THP. We found that SP-THP exhibited superior antitumor effect to LP-THP against both S-180 tumor-bearing mice in vivo, and with chemically AOM/DSS-induced colon tumor-bearing mice, most probably due to their different molecular size. In our comparison study of in vitro and in vivo behavior of SP-THP and LP-THP we concluded that SP-THP exhibited enhanced therapeutic efficacy not only in implanted tumor but also in orthotopic/spontaneous tumor despite its higher toxicity compared to LP-THP. Upon these findings further investigation using various tumors including transgenic, and metastatic tumors is going to be conducted soon.

• MeSH
• antitumorózní látky chemie   farmakokinetika   farmakologie   MeSH
• berberinové alkaloidy chemie   farmakokinetika   MeSH
• dendrimery chemie   farmakokinetika   MeSH
• doxorubicin analogy a deriváty   chemie   farmakokinetika   farmakologie   MeSH
• HeLa buňky MeSH
• lidé MeSH
• melanom experimentální MeSH
• methakryláty chemie   farmakokinetika   MeSH
• myši inbrední ICR MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory farmakoterapie   MeSH
• nosiče léků chemie   farmakokinetika   MeSH
• polymery chemie   farmakokinetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH