The development of stimuli-responsive drug delivery systems enables targeted delivery and environment-controlled drug release, thereby minimizing off-target effects and systemic toxicity. We prepared and studied tailor-made dual-responsive systems (thermo- and pH-) based on synthetic diblock copolymers consisting of a fully hydrophilic block of poly[N-(1,3-dihydroxypropyl)methacrylamide] (poly(DHPMA)) and a thermoresponsive block of poly[N-(2,2-dimethyl-1,3-dioxan-5-yl)methacrylamide] (poly(DHPMA-acetal)) as drug delivery and smart stimuli-responsive materials. The copolymers were designed for eventual medical application to be fully soluble in aqueous solutions at 25 °C. However, they form well-defined nanoparticles with hydrodynamic diameters of 50-800 nm when heated above the transition temperature of 27-31 °C. This temperature range is carefully tailored to align with the human body's physiological conditions. The formation of the nanoparticles and their subsequent decomposition was studied using dynamic light scattering (DLS), transmission electron microscopy (TEM), isothermal titration calorimetry (ITC), and nuclear magnetic resonance (NMR). 1H NMR studies confirmed that after approximately 20 h of incubation at pH 5, which closely mimics tumor microenvironment, approximately 40% of the acetal groups were hydrolyzed, and the thermoresponsive behavior of the copolymers was lost. This smart polymer response led to disintegration of the supramolecular structures, possibly releasing the therapeutic cargo. By tuning the transition temperature to the values relevant for medical applications, we ensure precise and effective drug release. In addition, our systems did not exhibit any cytotoxicity against any of the three cell lines. Our findings underscore the immense potential of these nanoparticles as eventual advanced drug delivery systems, especially for cancer therapy.

• Klíčová slova
• RAFT polymerization, drug delivery systems, pH-sensitive polymers, self-assembling block copolymers, thermoresponsive polymers,
• MeSH
• antitumorózní látky chemie   farmakologie   chemická syntéza   aplikace a dávkování   MeSH
• biokompatibilní materiály chemie   farmakologie   chemická syntéza   MeSH
• doxorubicin chemie   farmakologie   MeSH
• koncentrace vodíkových iontů MeSH
• lidé MeSH
• molekulární struktura MeSH
• nanočástice * chemie   MeSH
• nosiče léků chemie   MeSH
• polymery * chemie   chemická syntéza   farmakologie   MeSH
• systémy cílené aplikace léků MeSH
• teplota * MeSH
• testování materiálů * MeSH
• uvolňování léčiv MeSH
• velikost částic * MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antitumorózní látky MeSH
• biokompatibilní materiály MeSH
• doxorubicin MeSH
• nosiče léků MeSH
• polymery * MeSH

The clinical prospects of cancer nanomedicines depend on effective patient stratification. Here we report the identification of predictive biomarkers of the accumulation of nanomedicines in tumour tissue. By using supervised machine learning on data of the accumulation of nanomedicines in tumour models in mice, we identified the densities of blood vessels and of tumour-associated macrophages as key predictive features. On the basis of these two features, we derived a biomarker score correlating with the concentration of liposomal doxorubicin in tumours and validated it in three syngeneic tumour models in immunocompetent mice and in four cell-line-derived and six patient-derived tumour xenografts in mice. The score effectively discriminated tumours according to the accumulation of nanomedicines (high versus low), with an area under the receiver operating characteristic curve of 0.91. Histopathological assessment of 30 tumour specimens from patients and of 28 corresponding primary tumour biopsies confirmed the score's effectiveness in predicting the tumour accumulation of liposomal doxorubicin. Biomarkers of the tumour accumulation of nanomedicines may aid the stratification of patients in clinical trials of cancer nanomedicines.

• MeSH
• biologické markery metabolismus   MeSH
• doxorubicin * terapeutické užití   analogy a deriváty   MeSH
• lidé MeSH
• makrofágy spojené s nádory metabolismus   MeSH
• myši MeSH
• nádorové biomarkery metabolismus   MeSH
• nádorové buněčné linie MeSH
• nádory * patologie   metabolismus   farmakoterapie   MeSH
• nanomedicína * metody   MeSH
• polyethylenglykoly MeSH
• strojové učení MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biologické markery MeSH
• doxorubicin * MeSH
• liposomal doxorubicin MeSH Prohlížeč
• nádorové biomarkery MeSH
• polyethylenglykoly MeSH

Drug delivery to central nervous pathologies is compromised by the blood-brain barrier (BBB). A clinically explored strategy to promote drug delivery across the BBB is sonopermeation, which relies on the combined use of ultrasound (US) and microbubbles (MB) to induce temporally and spatially controlled opening of the BBB. We developed an advanced in vitro BBB model to study the impact of sonopermeation on the delivery of the prototypic polymeric drug carrier pHPMA as a larger molecule and the small molecule antiviral drug ribavirin. This was done under standard and under inflammatory conditions, employing both untargeted and RGD peptide-coated MB. The BBB model is based on human cerebral capillary endothelial cells and human placental pericytes, which are co-cultivated in transwell inserts and which present with proper transendothelial electrical resistance (TEER). Sonopermeation induced a significant decrease in TEER values and facilitated the trans-BBB delivery of fluorescently labeled pHPMA (Atto488-pHPMA). To study drug delivery under inflamed endothelial conditions, which are typical for e.g. tumors, neurodegenerative diseases and CNS infections, tumor necrosis factor (TNF) was employed to induce inflammation in the BBB model. RGD-coated MB bound to and permeabilized the inflamed endothelium-pericyte co-culture model, and potently improved Atto488-pHPMA and ribavirin delivery. Taken together, our work combines in vitro BBB bioengineering with MB-mediated drug delivery enhancement, thereby providing a framework for future studies on optimization of US-mediated drug delivery to the brain.

• Klíčová slova
• Blood-brain barrier, Drug delivery, Microbubbles, Sonopermeation, Ultrasound,
• MeSH
• antivirové látky aplikace a dávkování   chemie   farmakologie   farmakokinetika   MeSH
• endoteliální buňky * účinky léků   metabolismus   MeSH
• hematoencefalická bariéra * metabolismus   MeSH
• kokultivační techniky * MeSH
• lidé MeSH
• mikrobubliny * MeSH
• oligopeptidy * chemie   aplikace a dávkování   farmakokinetika   MeSH
• pericyty * metabolismus   účinky léků   MeSH
• polymery chemie   aplikace a dávkování   MeSH
• ribavirin aplikace a dávkování   chemie   farmakokinetika   MeSH
• systémy cílené aplikace léků metody   MeSH
• ultrazvukové vlny MeSH
• zánět farmakoterapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antivirové látky MeSH
• arginyl-glycyl-aspartic acid MeSH Prohlížeč
• oligopeptidy * MeSH
• polymery MeSH
• ribavirin MeSH

Minimal immunogen vaccines are being developed to focus antibody responses against otherwise challenging targets, including human immunodeficiency virus (HIV), but multimerization of the minimal peptide immunogen on a carrier platform is required for activity. Star copolymers comprising multiple hydrophilic polymer chains ("arms") radiating from a central dendrimer unit ("core") were recently reported to be an effective platform for arraying minimal immunogens for inducing antibody responses in mice and primates. However, the impact of different parameters of the star copolymer (e.g., minimal immunogen density and hydrodynamic size) on antibody responses and the optimal synthetic route for controlling those parameters remains to be fully explored. We synthesized a library of star copolymers composed of poly[N-(2-hydroxypropyl)methacrylamide] hydrophilic arms extending from poly(amidoamine) dendrimer cores with the aim of identifying the optimal composition for use as minimal immunogen vaccines. Our results show that the length of the polymer arms has a crucial impact on the star copolymer hydrodynamic size and is precisely tunable over a range of 20-50 nm diameter, while the dendrimer generation affects the maximum number of arms (and therefore minimal immunogens) that can be attached to the surface of the dendrimer. In addition, high-resolution images of selected star copolymer taken by a custom-modified environmental scanning electron microscope enabled the acquisition of high-resolution images, providing new insights into the star copolymer structure. Finally, in vivo studies assessing a star copolymer vaccine comprising an HIV minimal immunogen showed the criticality of polymer arm length in promoting antibody responses and highlighting the importance of composition tunability to yield the desired biological effect.

• MeSH
• dendrimery * chemie   MeSH
• lidé MeSH
• myši MeSH
• nosiče léků chemie   MeSH
• polyaminy MeSH
• polymery chemie   MeSH
• vakcíny proti AIDS imunologie   chemie   aplikace a dávkování   MeSH
• vakcíny imunologie   chemie   aplikace a dávkování   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dendrimery * MeSH
• nosiče léků MeSH
• Poly(amidoamine) MeSH Prohlížeč
• polyaminy MeSH
• polymery MeSH
• vakcíny proti AIDS MeSH
• vakcíny MeSH

Blood vessel functionality is crucial for efficient tumor-targeted drug delivery. Heterogeneous distribution and perfusion of angiogenic blood vessels contribute to suboptimal accumulation of (nano-) therapeutics in tumors and metastases. To attenuate pathological angiogenesis, an L-RNA aptamer inhibiting the CC motif chemokine ligand 2 (CCL2) was administered to mice bearing orthotopic 4T1 triple-negative breast cancer tumors. The effect of CCL2 inhibition on tumor blood vessel functionality and tumor-targeted drug delivery was evaluated via multimodal and multiscale optical imaging, employing fluorophore-labeled polymeric (10 nm) and liposomal (100 nm) nanocarriers. Anti-CCL2 treatment induced a dose-dependent anti-angiogenic effect, reflected by a decreased relative blood volume, increased blood vessel maturity and functionality, and reduced macrophage infiltration, accompanied by a shift in the polarization of tumor-associated macrophages (TAM) towards a less M2-like and more M1-like phenotype. In line with this, CCL2 inhibitor treatment improved the delivery of polymers and liposomes to tumors, and enhanced the antitumor efficacy of free and liposomal doxorubicin. Together, these findings demonstrate that blocking the CCL2-CCR2 axis modulates TAM infiltration and polarization, resulting in vascular normalization and improved tumor-targeted drug delivery.

• Klíčová slova
• CCL2, Chemokine signaling, EPR, Imaging, Nanomedicine, Tumor targeting,
• MeSH
• chemokin CCL2 * farmakologie   MeSH
• ligandy MeSH
• makrofágy MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory * patologie   MeSH
• nanomedicína MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chemokin CCL2 * MeSH
• ligandy MeSH

Antibody-mediated targeting is an efficient strategy to enhance the specificity and selectivity of polymer nanomedicines towards the target site, typically a tumor. However, direct covalent coupling of an antibody with a polymer usually results in a partial damage of the antibody binding site accompanied with a compromised biological activity. Here, an original solution based on well-defined non-covalent interactions between tris-nitrilotriacetic acid (trisNTA) and hexahistidine (His-tag) groups, purposefully introduced to the structure of each macromolecule, is described. Specifically, trisNTA groups were attached along the chains of a hydrophilic statistical copolymer based on N-(2-hydroxypropyl)methacrylamide (HPMA), and at the end or along the chains of thermo-responsive di-block copolymers based on N-isopropylmethacrylamide (NIPMAM) and HPMA; His-tag was incorporated to the structure of a recombinant single chain fragment of an anti-GD2 monoclonal antibody (scFv-GD2). Static and dynamic light scattering analyses confirmed that mixing of polymer with scFv-GD2 led to the formation of polymer/scFv-GD2 complexes; those prepared from thermo-responsive polymers formed stable micelles at 37 °C. Flow cytometry and fluorescence microscopy clearly demonstrated antigen-specific binding of the prepared complexes to GD2 positive murine T-cell lymphoma cells EL-4 and human neuroblastoma cells UKF-NB3, while no interaction with GD2 negative murine fibroblast cells NIH-3T3 was observed. These non-covalent polymer protein complexes represent a new generation of highly specific actively targeted polymer therapeutics or diagnostics.

• Klíčová slova
• Hydrophilic polymers, Non-covalent attachment, Polymer drug delivery system, Recombinant proteins, Thermo-responsive polymers, Tris(nitrilotriacetic acid) ligation, Tumor-specific targeting,
• MeSH
• kyselina nitrilotrioctová MeSH
• lidé MeSH
• myši MeSH
• nádory * MeSH
• polymery * chemie   MeSH
• rekombinantní proteiny MeSH
• systémy cílené aplikace léků metody   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hydroxypropyl methacrylate MeSH Prohlížeč
• kyselina nitrilotrioctová MeSH
• polymery * MeSH
• rekombinantní proteiny MeSH

Nano-sized carriers are widely studied as suitable candidates for the advanced delivery of various bioactive molecules such as drugs and diagnostics. Herein, the development of long-circulating stimuli-responsive polymer nanoprobes tailored for the fluorescently-guided surgery of solid tumors is reported. Nanoprobes are designed as long-circulating nanosystems preferably accumulated in solid tumors due to the Enhanced permeability and retention effect, so they act as a tumor microenvironment-sensitive activatable diagnostic. This study designs polymer probes differing in the structure of the spacer between the polymer carrier and Cy7 by employing pH-sensitive spacers, oligopeptide spacers susceptible to cathepsin B-catalyzed enzymatic hydrolysis, and non-degradable control spacer. Increased accumulation of the nanoprobes in the tumor tissue coupled with stimuli-sensitive release behavior and subsequent activation of the fluorescent signal upon dye release facilitated favorable tumor-to-background ratio, a key feature for fluorescence-guided surgery. The probes show excellent diagnostic potential for the surgical removal of intraperitoneal metastasis and orthotopic head and neck tumors with very high efficacy and accuracy. In addition, the combination of macroscopic resection followed by fluorescence-guided surgery using developed probes enable the identification and resection of most of the CAL33 intraperitoneal metastases with total tumor burden reduced to 97.2%.

• Klíčová slova
• HPMA copolymers, fluorescence, guided surgery, polymer probes, stimuli-sensitiveness,
• MeSH
• chytré polymery * MeSH
• fluorescence MeSH
• fluorescenční barviva chemie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádorové mikroprostředí MeSH
• nádory hlavy a krku * diagnostické zobrazování   chirurgie   MeSH
• polymery MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chytré polymery * MeSH
• fluorescenční barviva MeSH
• polymery MeSH

Multidrug resistance (MDR) reduces the efficacy of chemotherapy. Besides inducing the expression of drug efflux pumps, chemotherapy treatment alters the composition of the tumor microenvironment (TME), thereby potentially limiting tumor-directed drug delivery. To study the impact of MDR signaling in cancer cells on TME remodeling and nanomedicine delivery, we generated multidrug-resistant 4T1 triple-negative breast cancer (TNBC) cells by exposing sensitive 4T1 cells to gradually increasing doxorubicin concentrations. In 2D and 3D cell cultures, resistant 4T1 cells are presented with a more mesenchymal phenotype and produced increased amounts of collagen. While sensitive and resistant 4T1 cells showed similar tumor growth kinetics in vivo, the TME of resistant tumors was enriched in collagen and fibronectin. Vascular perfusion was also significantly increased. Fluorophore-labeled polymeric (∼10 nm) and liposomal (∼100 nm) drug carriers were administered to mice with resistant and sensitive tumors. Their tumor accumulation and penetration were studied using multimodal and multiscale optical imaging. At the whole tumor level, polymers accumulate more efficiently in resistant than in sensitive tumors. For liposomes, the trend was similar, but the differences in tumor accumulation were insignificant. At the individual blood vessel level, both polymers and liposomes were less able to extravasate out of the vasculature and penetrate the interstitium in resistant tumors. In a final in vivo efficacy study, we observed a stronger inhibitory effect of cellular and microenvironmental MDR on liposomal doxorubicin performance than free doxorubicin. These results exemplify that besides classical cellular MDR, microenvironmental drug resistance features should be considered when aiming to target and treat multidrug-resistant tumors more efficiently.

• Klíčová slova
• Drug targeting, EPR effect, Multidrug resistance, Nanomedicine, Tumor microenvironment,
• MeSH
• chemorezistence MeSH
• doxorubicin MeSH
• lidé MeSH
• liposomy MeSH
• mnohočetná léková rezistence MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádorové mikroprostředí MeSH
• nádory prsu * MeSH
• polymery farmakologie   MeSH
• triple-negativní karcinom prsu * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• doxorubicin MeSH
• liposomy MeSH
• polymery MeSH

Microbial resistance is one of the main problems of modern medicine. Recently, antimicrobial peptides have been recognized as a novel approach to overcome the microbial resistance issue, nevertheless, their low stability, toxicity, and potential immunogenic response in biological systems have limited their clinical application. Herein, we present the design, synthesis, and preliminary biological evaluation of polymer-antibacterial peptide constructs. The antimicrobial GKWMKLLKKILK-NH2 oligopeptide (PEP) derived from halictine, honey bee venom, was bound to a polymer carrier via various biodegradable spacers employing the pH-sensitive or enzymatically-driven release and reactivation of the PEP's antimicrobial activity. The antibacterial properties of the polymer-PEP constructs were assessed by a determination of the minimum inhibitory concentrations, followed by fluorescence and transmission electron microscopy. The PEP exerted antibacterial activity against both, gram-positive and negative bacteria, via disruption of the bacterial cell wall mechanism. Importantly, PEP partly retained its antibacterial efficacy against Staphylococcus epidermidis, Escherichia coli, and Acinetobacter baumanii even though it was bound to the polymer carrier. Indeed, to observe antibacterial activity similar to the free PEP, the peptide has to be released from the polymer carrier in response to a pH decrease. Enzymatically-driven release and reactivation of the PEP antimicrobial activity were recognized as less effective when compared to the pH-sensitive release of PEP.

• Klíčová slova
• HPMA copolymers, antimicrobial peptides, bacteria, drug delivery,
• Publikační typ
• časopisecké články MeSH

Polymer nanomedicines with anti-tumor activity should exhibit sufficient stability during systemic circulation to the target tissue; however, they should release the active drug selectively in the tumor. Thus, choice of a tumor-specific stimuli-sensitive spacer between the drug and the carrier is critical. Here, a series of polymer conjugates of anti-cancer drugs doxorubicin and pirarubicin covalently bound to copolymers based on N-(2-hydroxypropyl)methacrylamide via various enzymatically cleavable oligopeptide spacers were prepared and characterized. The highest rate of the drug release from the polymer carriers in presence of the lysosomal protease cathepsin B was determined for the copolymers with Val-Cit-Aba spacer. Copolymers containing pirarubicin were more cytotoxic and showed higher internalization rate than the corresponding doxorubicin counterparts. The conjugates containing GFLG and Val-Cit-Aba spacers exhibited the highest anti-tumor efficacy in vivo against murine sarcoma S-180, the highest rate of the enzymatically catalyzed drug release, and the highest cytotoxicity in vitro.

• Klíčová slova
• Drug delivery, Enzymatic release, Polymer cancerostatics,
• MeSH
• antitumorózní látky * farmakologie   terapeutické užití   chemie   MeSH
• doxorubicin farmakologie   chemie   MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory * farmakoterapie   MeSH
• nanomedicína MeSH
• nosiče léků chemie   MeSH
• polymery chemie   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
• nosiče léků MeSH
• pirarubicin MeSH Prohlížeč
• polymery MeSH