Nejvíce citovaný článek - PubMed ID 30180562
Background: Efficient theranostic strategies concurrently bring and use both the therapeutic and diagnostic features, serving as a cutting-edge tool to combat advanced cancers. Goals of the Investigation: Here, we develop stimuli-sensitive theranostics consisting of tailored copolymers forming micellar conjugates carrying pyropheophorbide-a (PyF) attached by pH-sensitive hydrazone bonds, thus enabling the tumor microenvironment-sensitive activation of the photodynamic therapy (PDT) effect, fluorescence or phosphorescence. Results: The nanomedicines show superior anti-tumor PDT efficacy and huge tumor-imaging potential, while reducing their accumulation, and potentially side effects, in the liver and spleen. The developed theranostics exhibit clear selective tumor accumulation at high levels in the mouse sarcoma S180 tumor model with almost no PyF found in the healthy tissues after 48 h. Once in the tumor, illumination at λexc = 420 nm reaches the therapeutic effect due to the 1O2 generation. Indeed, an almost complete inhibition of tumor growth is observed up to 18 days after the treatment. Conclusion: The clear benefit of the specific PyF release and activation in the acidic tumor environment for the targeted delivery and tissue distribution dynamics was proved. Conjugates carrying pyropheophorbide-a (PyF) attached by pH-sensitive hydrazone bonds showed their excellent antitumor PDT effect and its applicability as advanced theranostics at very low dose of PyF.
- Klíčová slova
- HPMA polymers, fluorescence imaging, pH-responsive theranostics, photodynamic therapy, tumor-targeted nanomedicines,
- MeSH
- fotochemoterapie * metody MeSH
- fotosenzibilizující látky terapeutické užití MeSH
- hydrazony terapeutické užití MeSH
- individualizovaná medicína MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádorové mikroprostředí MeSH
- nádory * diagnostické zobrazování farmakoterapie patologie MeSH
- polymery chemie MeSH
- teranostická nanomedicína metody MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- fotosenzibilizující látky MeSH
- hydrazony MeSH
- polymery MeSH
Recently, we reported induced anoxia as a limiting factor for photodynamic tumor therapy (PDT). This effect occurs in vivo if the amount of generated singlet oxygen that undergoes chemical reactions with cellular components exceeds the local oxygen supply. The amount of generated singlet oxygen depends mainly on photosensitizer (PS) accumulation, efficiency, and illumination intensity. With illumination intensities above a certain threshold, singlet oxygen is limited to the blood vessel and the nearest vicinity; lower intensities allow singlet oxygen generation also in tissue which is a few cell layers away from the vessels. While all experiments so far were limited to light intensities above this threshold, we report experimental results for intensities at both sides of the threshold for the first time, giving proof for the described model. Using time-resolved optical detection in NIR, we demonstrate characteristic, illumination intensity-dependent changes in signal kinetics of singlet oxygen and photosensitizer phosphorescence in vivo. The described analysis allows for better optimization and coordination of PDT drugs and treatment, as well as new diagnostic methods based on gated PS phosphorescence, for which we report a first in vivo feasibility test.
- Klíčová slova
- illumination intensity, photodynamic therapy, singlet oxygen, time-resolved phosphorescence,
- Publikační typ
- časopisecké články MeSH
Nanomedicines are considered next generation therapeutics with advanced therapeutic properties and reduced side effects. Herein, we introduce tailored linear and star-like water-soluble nanosystems as stimuli-sensitive nanomedicines for the treatment of solid tumors or hematological malignancies. The polymer carrier and drug pharmacokinetics were independently evaluated to elucidate the relationship between the nanosystem structure and its distribution in the body. Positron emission tomography and optical imaging demonstrated enhanced tumor accumulation of the polymer carriers in 4T1-bearing mice with increased tumor-to-blood and tumor-to-muscle ratios. Additionally, there was a significant accumulation of doxorubicin bound to various polymer carriers in EL4 tumors, as well as excellent in vivo therapeutic activity in EL4 lymphoma and moderate efficacy in 4T1 breast carcinoma. The linear nanomedicine showed at least comparable pharmacologic properties to the star-like nanomedicines regarding doxorubicin transport. Therefore, if multiple parameters are considered such as its optimized structure and simple and reproducible synthesis, this polymer carrier system is the most promising for further preclinical and clinical investigations.
- Klíčová slova
- Biodistribution, Cancer, Drug delivery, HPMA, Polymeric carriers, Positron emission tomography,
- MeSH
- doxorubicin farmakokinetika MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nanomedicína MeSH
- nosiče léků * chemie MeSH
- polymery * chemie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- doxorubicin MeSH
- nosiče léků * MeSH
- polymery * MeSH
Recently, numerous polymer materials have been employed as drug carrier systems in medicinal research, and their detailed properties have been thoroughly evaluated. Water-soluble polymer carriers play a significant role between these studied polymer systems as they are advantageously applied as carriers of low-molecular-weight drugs and compounds, e.g., cytostatic agents, anti-inflammatory drugs, antimicrobial molecules, or multidrug resistance inhibitors. Covalent attachment of carried molecules using a biodegradable spacer is strongly preferred, as such design ensures the controlled release of the drug in the place of a desired pharmacological effect in a reasonable time-dependent manner. Importantly, the synthetic polymer biomaterials based on N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers are recognized drug carriers with unique properties that nominate them among the most serious nanomedicines candidates for human clinical trials. This review focuses on advances in the development of HPMA copolymer-based nanomedicines within the passive and active targeting into the place of desired pharmacological effect, tumors, inflammation or bacterial infection sites. Specifically, this review highlights the safety issues of HPMA polymer-based drug carriers concerning the structure of nanomedicines. The main impact consists of the improvement of targeting ability, especially concerning the enhanced and permeability retention (EPR) effect.
- Klíčová slova
- EPR effect, HPMA copolymers, controlled release, drug delivery, nanomedicines,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The study describes the synthesis, physicochemical properties, and biological evaluation of polymer therapeutics based on N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers intended for a tumor-targeted immuno-oncotherapy. Water-soluble linear and cholesterol-containing HPMA precursors were synthesized using controlled reversible addition-fragmentation chain transfer polymerization to reach molecular weight Mn about 2 × 104 g·mol-1 and low dispersity. These linear or self-assembled micellar conjugates, containing immunomodulatory agent cucurbitacin-D (CuD) or the anticancer drug doxorubicin (Dox) covalently bound by the hydrolytically degradable hydrazone bond, showed a hydrodynamic size of 10-30 nm in aqueous solutions. The CuD-containing conjugates were stable in conditions mimicking blood. Importantly, a massive release of active CuD in buffer mimicking the acidic tumor environment was observed. In vitro, both the linear (LP-CuD) and the micellar (MP-CuD) conjugates carrying CuD showed cytostatic/cytotoxic activity against several cancer cell lines. In a murine metastatic and difficult-to-treat 4T1 mammary carcinoma, only LP-CuD showed an anticancer effect. Indeed, the co-treatment with Dox-containing micellar polymer conjugate and LP-CuD showed potentiation of the anticancer effect. The results indicate that the binding of CuD, characterized by prominent hydrophobic nature and low bioavailability, to the polymer carrier allows a safe and effective delivery. Therefore, the conjugate could serve as a potential component of immuno-oncotherapy schemes within the next preclinical evaluation.
Nanomedicines are a novel class of therapeutics that benefit from the nano dimensions of the drug carrier. These nanosystems are highly advantageous mainly within cancer treatment due to their enhanced tumor accumulation. Monolayer tumor cells frequently used in routine preclinical assessment of nanotherapeutics do not have a spatial structural architecture that allows the investigation of the penetration of nanomedicines to predict their behavior in real tumor tissue. Therefore, tumor spheroids from colon carcinoma C26 cells and glioblastoma U87-MG cells were used as 3D in vitro models to analyze the effect of the inner structure, hydrodynamic size, dispersity, and biodegradability of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-based nanomedicines carrying anticancer drug pirarubicin (THP) on the penetration within spheroids. While almost identical penetration through spheroids of linear and star-like copolymers and also their conjugates with THP was observed, THP penetration after nanomedicines application was considerably deeper than for the free THP, thus proving the benefit of polymer carriers. The cytotoxicity of THP-polymer nanomedicines against tumor cell spheroids was almost identical as for the free THP, whereas the 2D cell cytotoxicity of these nanomedicines is usually lower. The nanomedicines thus proved the enhanced efficacy within the more realistic 3D tumor cell spheroid system.
- Klíčová slova
- HPMA polymers, cytotoxicity, penetration, pirarubicin, tumor spheroids,
- Publikační typ
- časopisecké články MeSH
Polymer-drug conjugates have several advantages in controlled drug delivery to inflammation as they can accumulate and release the drug in inflamed tissues or cells, which could circumvent the shortcomings of current therapy. To improve the therapeutic potential of polymer-drug conjugates in joint inflammation, we synthesized polymer conjugates based on N-(2-hydroxypropyl) methacrylamide) copolymers labeled with a near-infrared fluorescent dye and covalently linked to the anti-inflammatory drug dexamethasone (DEX). The drug was bound to the polymer via a spacer enabling pH-sensitive drug release in conditions mimicking the environment inside inflammation-related cells. An in vivo murine model of adjuvant-induced arthritis was used to confirm the accumulation of polymer conjugates in arthritic joints, which occurred rapidly after conjugate application and remained until the end of the experiment. Several tested dosage schemes of polymer DEX-OPB conjugate showed superior anti-inflammatory efficacy. The highest therapeutic effect was obtained by repeated i.p. application of polymer conjugate (3 × 1 mg/kg of DEX eq.), which led to a reduction in the severity of inflammation in the ankle by more than 90%, compared to 40% in mice treated with free DEX.
- Klíčová slova
- HPMA, adjuvant-induced arthritis, dexamethasone, drug delivery, inflammation, passive targeting, polymer conjugate,
- Publikační typ
- časopisecké články MeSH
Design, controlled synthesis, physico-chemical and biological characteristics of novel well-defined biodegradable star-shaped copolymers intended for advanced drug delivery is described. These new biocompatible star copolymers were synthesised by grafting monodispersed semitelechelic linear (sL) N-(2-hydroxypropyl)methacrylamide copolymers onto a 2,2-bis(hydroxymethyl)propionic acid (bisMPA)-based polyester dendritic core of various structures. The hydrodynamic diameter of the star copolymer biomaterials can be tuned from 13 to 31 nm and could be adjusted to a given purpose by proper selection of the bisMPA dendritic core type and generation and by considering the sL copolymer molecular weight and polymer-to-core molar ratio. The hydrolytic degradation was proved for both the star copolymers containing either dendron or dendrimer core, showing the spontaneous hydrolysis in duration of few weeks. Finally, it was shown that the therapy with the biodegradable star conjugate with attached doxorubicin strongly suppresses the tumour growth in mice and is fully curative in most of the treated animals at dose corresponding approximately to one fourth of maximum tolerated dose (MTD) value. Both new biodegradable systems show superior efficacy and tumour accumulation over the first generation of star copolymers containing non-degradable PAMAM core.
- Klíčová slova
- Cancer, Doxorubicin, Drug delivery, HPMA, Star-like polymers, bisMPA,
- MeSH
- akrylamidy MeSH
- biokompatibilní materiály * MeSH
- doxorubicin MeSH
- léčivé přípravky * MeSH
- methakryláty MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nosiče léků MeSH
- polymery MeSH
- systémy cílené aplikace léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- akrylamidy MeSH
- biokompatibilní materiály * MeSH
- doxorubicin MeSH
- hydroxypropyl methacrylate MeSH Prohlížeč
- léčivé přípravky * MeSH
- methakryláty MeSH
- N-(2-hydroxypropyl)methacrylamide MeSH Prohlížeč
- nosiče léků MeSH
- polymery MeSH
Multidrug resistance (MDR) is often caused by the overexpression of efflux pumps, such as ABC transporters, in particular, P-glycoprotein (P-gp). Here, we investigate the di- and tri- block amphiphilic polymer systems based on polypropylene glycol (PPO) and copolymers of (N-(2-hydroxypropyl)methacrylamide) (PHPMA) as potential macromolecular inhibitors of P-gp, and concurrently, carriers of drugs, passively targeting solid tumors by the enhanced permeability and retention (EPR) effect. Interestingly, there were significant differences between the effects of di- and tri- block polymer-based micelles, with the former being significantly more thermodynamically stable and showing much higher P-gp inhibition ability. The presence of Boc-protected hydrazide groups or the Boc-deprotection method did not affect the physico-chemical or biological properties of the block copolymers. Moreover, diblock polymer micelles could be loaded with free PPO containing 5-40 wt % of free PPO, which showed increased P-gp inhibition in comparison to the unloaded micelles. Loaded polymer micelles containing more than 20 wt % free PPO showed a significant increase in toxicity; thus, loaded diblock polymer micelles containing 5-15 wt % free PPO are potential candidates for in vitro and in vivo application as potent MDR inhibitors and drug carriers.
- Klíčová slova
- P-glycoprotein, block copolymers, micelles, multidrug resistance, polymer therapeutics, solid tumors,
- Publikační typ
- časopisecké články MeSH
