Biodegradable nanomedicines are widely studied as candidates for the effective treatment of various cancerous diseases. Here, we present the design, synthesis and evaluation of biodegradable polymer-based nanomedicines tailored for tumor-associated stimuli-sensitive drug release and polymer system degradation. Diblock polymer systems were developed, which enabled the release of the carrier drug, pirarubicin, via a pH-sensitive spacer allowing for the restoration of the drug cytotoxicity solely in the tumor tissue. Moreover, the tailored design enables the matrix-metalloproteinases- or reduction-driven degradation of the polymer system into the polymer chains excretable from the body by glomerular filtration. Diblock nanomedicines take advantage of an enhanced EPR effect during the initial phase of nanomedicine pharmacokinetics and should be easily removed from the body after tumor microenvironment-associated biodegradation after fulfilling their role as a drug carrier. In parallel with the similar release profiles of diblock nanomedicine to linear polymer conjugates, these diblock polymer conjugates showed a comparable in vitro cytotoxicity, intracellular uptake, and intratumor penetration properties. More importantly, the diblock nanomedicines showed a remarkable in vivo anti-tumor efficacy, which was far more superior than conventional linear polymer conjugates. These findings suggested the advanced potential of diblock polymer conjugates for anticancer polymer therapeutics.

• Klíčová slova
• HPMA conjugate, anticancer, diblock conjugate, drug delivery, pirarubicin,
• 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

Rationale: The blood-brain barrier (BBB) is a major obstacle for drug delivery to the brain. Sonopermeation, which relies on the combination of ultrasound and microbubbles, has emerged as a powerful tool to permeate the BBB, enabling the extravasation of drugs and drug delivery systems (DDS) to and into the central nervous system (CNS). When aiming to improve the treatment of high medical need brain disorders, it is important to systematically study nanomedicine translocation across the sonopermeated BBB. To this end, we here employed multimodal and multiscale optical imaging to investigate the impact of DDS size on brain accumulation, extravasation and penetration upon sonopermeation. Methods: Two prototypic DDS, i.e. 10 nm-sized pHPMA polymers and 100 nm-sized PEGylated liposomes, were labeled with fluorophores and intravenously injected in healthy CD-1 nude mice. Upon sonopermeation, computed tomography-fluorescence molecular tomography, fluorescence reflectance imaging, fluorescence microscopy, confocal microscopy and stimulated emission depletion nanoscopy were used to study the effect of DDS size on their translocation across the BBB. Results: Sonopermeation treatment enabled safe and efficient opening of the BBB, which was confirmed by staining extravasated endogenous IgG. No micro-hemorrhages, edema and necrosis were detected in H&E stainings. Multimodal and multiscale optical imaging showed that sonopermeation promoted the accumulation of nanocarriers in mouse brains, and that 10 nm-sized polymeric DDS accumulated more strongly and penetrated deeper into the brain than 100 nm-sized liposomes. Conclusions: BBB opening via sonopermeation enables safe and efficient delivery of nanomedicine formulations to and into the brain. When looking at accumulation and penetration (and when neglecting issues such as drug loading capacity and therapeutic efficacy) smaller-sized DDS are found to be more suitable for drug delivery across the BBB than larger-sized DDS. These findings are valuable for better understanding and further developing nanomedicine-based strategies for the treatment of CNS disorders.

• Klíčová slova
• Blood-brain barrier, Drug delivery, Microbubbles, Nanomedicine, Ultrasound,
• MeSH
• fluorescenční barviva aplikace a dávkování   MeSH
• hematoencefalická bariéra diagnostické zobrazování   metabolismus   MeSH
• liposomy aplikace a dávkování   MeSH
• mikrobubliny MeSH
• mozek diagnostické zobrazování   MeSH
• myši nahé MeSH
• myši MeSH
• nanomedicína metody   MeSH
• nemoci mozku farmakoterapie   MeSH
• optické zobrazování metody   MeSH
• systémy cílené aplikace léků metody   MeSH
• ultrasonografie metody   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fluorescenční barviva MeSH
• liposomy MeSH

Here we describe the synthesis and biological properties of two types of star-shaped polymer-doxorubicin conjugates: non-targeted conjugate prepared as long-circulating high-molecular-weight (HMW) polymer prodrugs with a dendrimer core and a targeted conjugate with the anti-CD20 monoclonal antibody (mAb) rituximab (RTX). The copolymers were linked to the dendrimer core or to the reduced mAb via one-point attachment forming a star-shaped structure with a central antibody or dendrimer surrounded by hydrophilic polymer chains. The anticancer drug doxorubicin (DOX) was attached to the N-(2-hydroxypropyl)methacrylamide (HPMA)-based copolymer chain in star polymer systems via a pH-labile hydrazone linkage. Such polymer-DOX conjugates were fairly stable in aqueous solutions at pH 7.4, and the drug was readily released in mildly acidic environments at pH 5-5.5 by hydrolysis of the hydrazone bonds. The cytotoxicity of the polymer conjugates was tested on several CD20-positive or negative human cell lines. Similar levels of in vitro cytotoxicity were observed for all tested polymer conjugates regardless of type or structure. In vivo experiments using primary cell-based murine xenograft models of human diffuse large B-cell lymphoma confirmed the superior anti-lymphoma efficacy of the polymer-bound DOX conjugate when compared with the original drug. Targeting with RTX did not further enhance the anti-lymphoma efficacy relative to the non-targeted star polymer conjugate. Two mechanisms could play roles in these findings: changes in the binding ability to the CD-20 receptor and a significant loss of the immunological properties of RTX in the polymer conjugates.

• Klíčová slova
• HPMA copolymers, doxorubicin, drug delivery systems, drug targeting, monoclonal antibody,
• MeSH
• antitumorózní látky chemie   farmakologie   MeSH
• apoptóza účinky léků   MeSH
• doxorubicin chemie   farmakologie   MeSH
• lidé MeSH
• lymfom farmakoterapie   mortalita   patologie   MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• polymery * chemie   MeSH
• prekurzory léčiv * chemie   farmakologie   MeSH
• rituximab chemie   farmakologie   MeSH
• systémy cílené aplikace léků MeSH
• uvolňování léčiv MeSH
• viabilita 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
• Názvy látek
• antitumorózní látky MeSH
• doxorubicin MeSH
• polymery * MeSH
• prekurzory léčiv * MeSH
• rituximab MeSH

The synthesis of a series of novel, water-soluble poly(organophosphazenes) prepared via living cationic polymerization is presented. The degradation profiles of the polyphosphazenes prepared are analyzed by GPC, 31P NMR spectroscopy, and UV-Vis spectroscopy in aqueous media and show tunable degradation rates ranging from days to months, adjusted by subtle changes to the chemical structure of the polyphosphazene. Furthermore, it is observed that these polymers demonstrate a pH-promoted hydrolytic degradation behavior, with a remarkably faster rate of degradation at lower pH values. These degradable, water soluble polymers with controlled molecular weights and structures could be of significant interest for use in aqueous biomedical applications, such as polymer therapeutics, in which biological clearance is a requirement and in this context cell viability tests are described which show the non-toxic nature of the polymers as well as their degradation intermediates and products.

• Klíčová slova
• biocompatible polymers, biodegradable polymers, polymer therapeutics, polyphosphazenes, water-soluble polymers,
• Publikační typ
• časopisecké články MeSH

To avoid the side effects of the anti-cancer drug doxorubicin (Dox), we conjugated this drug to a N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer backbone. Dox was conjugated via an amide bond (Dox-HPMA(AM), PK1) or a hydrazone pH-sensitive bond (Dox-HPMA(HYD)). In contrast to Dox and Dox-HPMA(HYD), Dox-HPMA(AM) accumulates within the cell's intracellular membranes, including those of the Golgi complex and endoplasmic reticulum, both involved in protein glycosylation. Flow cytometry was used to determine lectin binding and cell death, immunoblot to characterize the presence of CD7, CD43, CD44, and CD45, and high-performance anion exchange chromatography with pulsed amperometric detector analysis for characterization of plasma membrane saccharide composition. Incubation of EL4 cells with Dox-HPMA(AM) conjugate, in contrast to Dox or Dox-HPMA(HYD), increased the amounts of membrane surface-associated glycoproteins, as well as saccharide moieties recognized by peanut agglutinin, Erythrina cristagalli, or galectin-1 lectins. Only Dox-HPMA(AM) increased expression of the highly glycosylated membrane glycoprotein CD43, while expression of others (CD7, CD44, and CD45) was unaffected. The binding sites for galectin-1 are present on CD43 molecule. Furthermore, we present that EL4 treated with Dox-HPMA(AM) possesses increased sensitivity to galectin-1-induced apoptosis. In this study, we demonstrate that Dox-HPMA(AM) treatment changes glycosylation of the EL4 T cell lymphoma surface and sensitizes the cells to galectin-1-induced apoptosis.

• MeSH
• amidy chemie   MeSH
• antibiotika antitumorózní farmakologie   MeSH
• antigeny CD43 metabolismus   MeSH
• apoptóza MeSH
• doxorubicin analogy a deriváty   farmakologie   MeSH
• endoplazmatické retikulum metabolismus   MeSH
• galektin 1 metabolismus   MeSH
• glykosylace MeSH
• Golgiho aparát metabolismus   MeSH
• kyseliny polymethakrylové farmakologie   MeSH
• lymfom T-buněčný farmakoterapie   metabolismus   patologie   MeSH
• myši MeSH
• nádorové buněčné linie účinky léků   MeSH
• nosiče léků MeSH
• proliferace buněk MeSH
• průtoková cytometrie MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• amidy MeSH
• antibiotika antitumorózní MeSH
• antigeny CD43 MeSH
• doxorubicin-N-(2-hydroxypropyl)methacrylamide copolymer conjugate MeSH Prohlížeč
• doxorubicin MeSH
• galektin 1 MeSH
• kyseliny polymethakrylové MeSH
• nosiče léků MeSH

PURPOSE: In vivo efficacy and safety of HPMA-based copolymers armed with doxorubicin via a spacer containing pH-sensitive linkage that can be prepared within a broad range of attached drug contents (1) was tested in murine tumor models. METHODS: Mice bearing T cell lymphoma EL4 or B cell lymphoma 38C13 were treated with a single dose of the conjugate (15, 25, and 75 mg Dox eq./kg i.v.) in a therapeutic regime. Anti-tumor resistance of the cured animals was proved by a second challenge with a lethal dose of tumor cells without additional treatment. RESULTS: The content of drug bound to the polymer is an important parameter in relation to the conjugate therapeutic efficacy. The best anti-tumor effects were produced by conjugates with 10 - 13 wt% of bound doxorubicin. Free doxorubicin up to 4.6% relative to total drug content had no impact on the treatment efficacy and acute toxicity. The conjugates induced a complete cure of mice and regular treatment-dependent development of specific anti-tumor resistance. No myelosuppression or organ damage was observed. CONCLUSIONS: A well-defined HPMA copolymer-doxorubicin conjugate with pH-sensitive drug release is a good candidate for clinical trials as it has remarkable anti-tumor efficacy and a favorable safety profile.

• MeSH
• antibiotika antitumorózní farmakokinetika   farmakologie   MeSH
• doxorubicin analogy a deriváty   chemická syntéza   farmakokinetika   farmakologie   MeSH
• imunomodulace účinky léků   MeSH
• koncentrace vodíkových iontů MeSH
• kyseliny polymethakrylové chemická syntéza   farmakokinetika   farmakologie   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nosiče léků chemická syntéza   farmakokinetika   farmakologie   MeSH
• polymery * chemická syntéza   farmakokinetika   farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibiotika antitumorózní MeSH
• doxorubicin-N-(2-hydroxypropyl)methacrylamide copolymer conjugate MeSH Prohlížeč
• doxorubicin MeSH
• kyseliny polymethakrylové MeSH
• nosiče léků MeSH
• polymery * MeSH