Search

Polymer capsules fabricated via the layer-by-layer (LbL) approach have emerged as promising biomedical systems for the release of a wide variety of therapeutic agents, owing to their tunable and controllable structure and the possibility to include several functionalities in the polymeric membrane during the fabrication process. However, the limitation of the capsules with a single functionality to overcome the challenges involved in the treatment of complex pathologies denotes the need to develop multifunctional capsules capable of targeting several mediators and/or mechanisms. Oxidative stress is caused by the accumulation of reactive oxygen species [e.g., hydrogen peroxide (H2O2), hydroxyl radicals (•OH), and superoxide anion radicals (•O2-)] in the cellular microenvironment and is a key modulator in the pathology of a broad range of inflammatory diseases. The disease microenvironment is also characterized by the presence of proinflammatory cytokines, increased levels of matrix metalloproteinases, and acidic pH, all of which could be exploited to trigger the release of therapeutic agents. In the present work, multifunctional capsules were fabricated via the LbL approach. Capsules were loaded with an antioxidant enzyme (catalase) and functionalized with a model drug (doxorubicin), which was conjugated to an amine-containing dendritic polyglycerol through a pH-responsive linker. These capsules efficiently scavenge H2O2 from solution, protecting cells from oxidative stress, and release the model drug in acidic microenvironments. Accordingly, in this work, a polymeric microplatform is presented as an unexplored combinatorial approach applicable for multiple targets of inflammatory diseases, in order to perform controlled spatiotemporal enzymatic reactions and drug release in response to biologically relevant stimuli.

The use of penetration enhancers (chemical or physical) has been proven to dramatically improve the penetration of therapeutics. Nevertheless, their use poses great risks, as they can lead to permanent damage of the skin, reduce its barrier efficiency, and result in the intrusion of harmful substances. Among the most used skin penetration enhancers, water is greatly accepted because skin quickly recovers from its exposure. Nanocapsules (NCs) represent a promising combination of the carrier system and penetration enhancer because their water-containing void combined with their polymer-based shell can be used to induce high local skin hydration, while simultaneously aiding the transport of drugs across the skin barrier. In this study, NCs were synthesized with a void core of 100 nm in diameter, a thermoresponsive shell based on different ratios of poly(N-isopropylacrylamide) and poly(N-isopropylmethacrylamide) as thermoresponsive polymers, and dendritic polyglycerol as a macromolecular cross-linker. These NCs can shrink or swell upon a thermal trigger, which was used to induce the release of the entrapped water in a controlled fashion. The interactions and effects of thermoresponsive NCs on the stratum corneum of excised human skin were investigated using fluorescence microscopy, high-resolution optical microscopy, and stimulated Raman spectromicroscopy. It could be observed that the thermoresponsive NCs increase the amount of deuterated water that penetrated into the viable epidermis. Moreover, NCs increased the skin penetration of a high-molecular weight dye (Atto Oxa12 NHS ester, MW = 835 g/mol) with respect to formulations in water or 30% DMSO, emphasizing the features of the NCs as a skin penetration enhancer.

The mechanical properties of nanoparticles, especially those designed for biomedical purposes, have a large impact on their performance and have been scarcely studied. Thermoresponsive polymer-base...

The current limitations in the use of nanocarriers to treat constantly evolving diseases call for the design of novel and smarter drug delivery systems (DDS). Nanogels (NGs) are three-dimensional crosslinked polymers with dimensions on the nanoscale and with a great potential for use in the biomedical field. Particular interest focuses on their application as DDS to minimize severe toxic effects and increase the therapeutic index of drugs. They have recently gained attention, since they can include responsive modalities within their structure, which enable them to excerpt a therapeutic function on demand. Their bigger sizes and controlled architecture and functionality, when compared to non-crosslinked polymers, make them particularly interesting to explore novel modalities to cross biological barriers. The present review summarizes the most significant developments of NGs as smart carriers, with focus on smart modalities to cross biological barriers such as cellular membrane, tumor stroma, mucose, skin, and blood brain barrier. We discuss the properties of each barrier and highlight the importance that the NG design has on their capability to overcome them and deliver the cargo at the site of action.

Graphite electrodes were modified with triangular (AuNTrs) or spherical (AuNPs) nanoparticles and further modified with fructose dehydrogenase (FDH). The present study reports the effect of the shape of these nanoparticles (NPs) on the catalytic current of immobilized FDH pointing out the different contributions on the mass transfer–limited and kinetically limited currents. The influence of the shape of the NPs on the mass transfer–limited and the kinetically limited current has been proved by using two different methods: a rotating disk electrode (RDE) and an electrode mounted in a wall jet flow-through electrochemical cell attached to a flow system. The advantages of using the wall jet flow system compared with the RDE system for kinetic investigations are as follows: no need to account for substrate consumption, especially in the case of desorption of enzyme, and studies of product-inhibited enzymes. The comparison reveals that virtually identical results can be obtained using either of the two techniques. The heterogeneous electron transfer (ET) rate constants (kS) were found to be 3.8 ± 0.3 s−1 and 0.9 ± 0.1 s−1, for triangular and spherical NPs, respectively. The improvement observed for the electrode modified with AuNTrs suggests a more effective enzyme-NP interaction, which can allocate a higher number of enzyme molecules on the electrode surface. Graphical abstractThe shape of gold nanoparticles has a crucial effect on the catalytic current related to the oxidation of D-(-)-fructose to 5-keto-D-(-)-fructose occurring at the FDH-modified electrode surface. In particular, AuNTrs have a higher effect compared with the spherical one. Electronic supplementary material The online version of this article (10.1007/s00216-019-01944-6) contains supplementary material, which is available to authorized users.

Macromolecular bioactives, like proteins and peptides, emerged as highly efficient therapeutics. The main limitation for their clinical application is their instability and potential immunogenicity. Thus, controlled delivery systems able protect the proteins prior release are highly on demand. In the present study, we developed hydrophilic thermo-responsive nanogels with tunable volume phase transition temperatures (VPTTs) and suitable features for controlled protein delivery by the use of multifunctional, dendritic polyglycerol (dPG) as macromolecular cross-linker and temperature-sensitive polymers poly(N-isopropylacrylamide) (NIPAM) and poly(N-isopropylacrylmethacrylate) as linear counterpart. We comprehensively studied the impact of the initiator, monomers and cross-linker on the nanogel structure during the synthesis. Careful analysis of the polymerization process revealed importance of balanced reactions kinetics to form particles with diameters in the range 100–200 nm and low polydispersity. We can control the cross-linking density of the nanogels mainly by the dPG feed and its degree of acrylation. In addition, our screenings revealed that the hydrophilic character of dPG enables it to stabilize the growing particles during the polymerization and thereby reduces final particle size. Co-polymerization of NIPAM and NIPMAM allows precise tuning of the VPTT of the nanogels in the desired range of 34–47 °C. Our nanogels showed outstanding high protein encapsulation efficiency and triggered cargo release upon a temperature change. The delivery efficiency of these nanogels was investigated on excised human skin demonstrating efficient dermal penetration of encapsulated proteins dependent on a temperature triggered release mechanism.

A major drawback of chemotherapy is that cancer cells can develop multi-drug resistance, leading to failure of anticancer treatments. To overcome this limitation, we report the preparation of environment-sensitive polylactide (PLA)-based nanoparticles, assembled by multiple hydrogen bonds. These nanoparticles showed sizes in the 100–150 nm range, a spherical morphology, and low toxicity in cell culture. In addition, their 3D supramolecular polymer network was sensitive to both pH and temperature and yielded dynamically reversible networks that could recognize the intrinsic differences between cancer and normal tissues. Release studies of the encapsulated anticancer drug doxorubicin (DOX) demonstrated that the nanoparticles exhibited high stability at physiological conditions. However, when the pH was reduced from 7.4 to 5, an accelerated release was observed. Most importantly, by applying this supramolecular linked nanocarrier for the delivery of DOX, the drug-resistance of KB-V1 cells could be overcome. All these features demonstrate the versatility of the proposed modular approach and their great potential for anticancer therapy.

Mucosal surfaces pose a challenging environment for efficient drug delivery. Various delivery strategies such as nanoparticles have been employed so far; yet, still yielding limited success. To address the need of efficient transmucosal drug delivery, this report presents the synthesis of novel disulfide-containing dendritic polyglycerol (dPG)-based nanogels and their preclinical testing. A bifunctional disulfide-containing linker is coupled to dPG to act as a macromolecular crosslinker for poly-N-isopropylacrylamide (PNIPAM) and poly-N-isopropylmethacrylamide (PNIPMAM) in a precipitation polymerization process. A systematic analysis of the polymerization reveals the importance of a careful polymer choice to yield mucus-degradable nanogels with diameters between 100 and 200 nm, low polydispersity, and intact disulfide linkers. Absorption studies in porcine intestinal tissue and human bronchial epithelial models demonstrate that disulfide-containing nanogels are highly efficient in overcoming mucosal barriers. The nanogels efficiently degrade and deliver the anti-inflammatory biomacromolecule etanercept into epithelial tissues yielding local anti-inflammatory effects. Over the course of this work, several problems are encountered due to a limited availability of valid test systems for mucosal drug-delivery systems. Hence, this study also emphasizes how critical a combined and multifaceted approach is for the preclinical testing of mucosal drug-delivery systems, discusses potential pitfalls, and provides suggestions for solutions.

Liquid-phase transmission electron microscopy is a technique for simultaneous imaging of the structure and dynamics of specimens in a liquid environment. The conventional sample geometry consists of a liquid layer tightly sandwiched between two Si3N4 windows with a nominal spacing on the order of 0.5 μm. We describe a variation of the conventional approach, wherein the Si3N4 windows are separated by a 10-μm-thick spacer, thus providing room for gas flow inside the liquid specimen enclosure. Adjusting the pressure and flow speed of humid air inside this environmental liquid cell (ELC) creates a stable liquid layer of controllable thickness on the bottom window, thus facilitating high-resolution observations of low mass-thickness contrast objects at low electron doses. We demonstrate controllable liquid thicknesses in the range 160 ± 34 to 340 ± 71 nm resulting in corresponding edge resolutions of 0.8 ± 0.06 to 1.7 ± 0.8 nm as measured for immersed gold nanoparticles. Liquid layer thickness 40 ± 8 nm allowed imaging of low-contrast polystyrene particles. Hydration effects in the ELC have been studied using poly-N-isopropylacrylamide nanogels with a silica core. Therefore, ELC can be a suitable tool for in situ investigations of liquid specimens.

Advanced materials and chemo-specific designs at the nano/micrometer-scale have ensured revolutionary progress in next-generation clinically relevant technologies. For example, isolating a rare population of cells, like circulating tumor cells (CTCs) from the blood amongst billions of other blood cells, is one of the most complex scientific challenges in cancer diagnostics. The chemical tunability for achieving this degree of exceptional specificity for extra-cellular biomarker interactions demands the utility of advanced entities and multistep reactions both in solution and in the insoluble state. Thus, this review delineates the chemo-specific substrates, chemical methods, and structure–activity relationships (SARs) of chemical platforms used for isolation and enumeration of CTCs in advancing the relevance of liquid biopsy in cancer diagnostics and disease management. We highlight the synthesis of cell-specific, tumor biomarker-based, chemo-specific substrates utilizing functionalized linkers through chemistry-based conjugation strategies. The capacity of these nano/micro substrates to enhance the cell interaction specificity and efficiency with the targeted tumor cells is detailed. Furthermore, this review accounts for the importance of CTC capture and other downstream processes involving genotypic and phenotypic CTC analysis in real-time for the detection of the early onset of metastases progression and chemotherapy treatment response, and for monitoring progression free-survival (PFS), disease-free survival (DFS), and eventually overall survival (OS) in cancer patients.

Preprint Treatment of triple negative breast cancer (TNBC)-associated metastasis represents an unmet clinical need, and we lack effective therapeutics for a disease that exhibits high relapse rates and associates with poor patient outcomes. Advanced nanosized drug delivery systems may enhance the efficacy of first-line chemotherapeutics by altering drug pharmacokinetics and enhancing tumor/metastasis targeting to signif-icantly improve efficacy and safety. Herein, we propose the application of injectable poly-amino acid-based nanogels (NGs) as a versatile hydrophilic drug delivery platform for the treatment of TNBC lung metastasis. We prepared biocompatible and biodegradable cross-linked NGs from polyglutamic acid (PGA) loaded with the chemotherapeutic agent doxorubicin (DOX). Our optimized synthetic procedures generated NGs of ~100 nm in size and 25 wt% drug loading content that became rapidly internalized in TNBC cell lines and displayed IC50 values comparable to the free form of DOX. Importantly, PGA-DOX NGs significantly inhibited lung metastases and almost completely suppressed lymph node metastases in a spontaneously metastatic orthotopic mouse TNBC model. Overall, our newly developed PGA-DOX NGs represent a potentially effective therapeutic strategy for the treatment of TNBC metastases. A.S-H thanks MC IEF actions (Project 302717). We thank Dr. M. A. Molina for AFM experiments, Ser-vicio SEM Cordoba (Argentina), and Mario Soriano Navarro from the electron microscopy service for Cryo-TEM pictures at CIPF. The authors would also like to thank Dr. Stuart P. Atkinson for his collabo-ration in the revision of the manuscript. This work has been supported by the European Research Council (grant ERC-CoG-2014-648831 “MyNano”), by the Spanish Ministry of Science and Innovation (SAF2013-44848-R, SAF2016-80427-R, RTI2018-099227-B-I00), by a Marie Curie IEF (Project 302717), and the Bundesministerium für Bildung und Forschung (BMBF) through the NanoMatFutur award (13N12561). Part of the equipment employed in this work has been funded by Generalitat Valen-ciana and co-financed with FEDER funds (PO FEDER of Comunitat Valenciana 2014–2020)

Nanomedicine for cancer therapy is a successful tool to diminish the side effect of chemotherapeutics such as paclitaxel (PTX). In this regard, Abraxane®, a human serum albumin (HSA)-based nanomedicine system has shown lesser side effects than Taxol®. However, the large-scale production of HSA protein is limited and expensive, which is traduced in a high cost of the treatments in clinical applications. Thus, the use of easily-available alternative nanocarriers could increment the accessibility of patients to nanomedicine for cancer treatments. Casein is a low-cost protein able to self-assemble into micelles which could efficiently encapsulate PTX into their structure. In this work, the synthesis of chemically crosslinked casein micelles (CCM), used to prepare PTX-based nanoformulations, is presented. CCM@PTX nanoformulations showed promising results in vitro to be applied as nanomedicine for cancer therapy. Thus, the obtained nanoformulations are great candidates to be parenterally administered, accumulate in tumor by passive targeting without leakage of PTX in plasma, and release the drug within the tumor microenvironment, in response to overexpressed proteases such as trypsin. Fil: Cuggino, Julio César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Picchio, Matías Luis. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentina Fil: Gugliotta, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Bürgi Fissolo, María de Los Milagros. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ronco, Ludmila Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Calderón, Marcelo. Polymat; España Fil: Etcheverrigaray, Marina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina Fil: Alvarez Igarzabal, Cecilia Ines. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentina Fil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

Macrophages are hosts for intracellular pathogens involved in numerous diseases including leishmaniasis. They express surface receptors that may be exploited for specific drug-targeting. Recently, we developed a PEGylated dendritic polyglycerol-based conjugate (PG&ndash, PEG) that colocalizes with intracellular parasite. We hereby study the effect of surface decoration with mannose units on the conjugates&rsquo, targeting ability toward leishmania intracellular parasites. Murine and human macrophages were exposed to fluorescently labeled mannosylated PG&ndash, PEG and uptake was quantified by flow cytometry analysis. Nanocarriers bearing five mannose units showed the highest uptake, which varied between 30 and 88% in the population in human and murine macrophages, respectively. The uptake was found to be dependent on phagocytosis and pinocytosis (80%), as well as clathrin-mediated endocytosis (79%). Confocal microscopy showed that mannosylated PG&ndash, PEGs target acidic compartments in macrophages. In addition, when both murine and human macrophages were infected and treated, colocalization between parasites and mannosylated nanoconjugates was observed. Leishmania-infected bone marrow-derived macrophages (BMM) showed avidity by mannosylated PG&ndash, PEG whereas non-infected macrophages rarely accumulated conjugates. Moreover, the antileishmanial activity of Amphotericin B was kept upon conjugation to mannosylated PG&ndash, PEG through a pH-labile linker. This study demonstrates that leishmania infected macrophages are selectively targeted by mannosylated PEGylated dendritic conjugates.

In this work, we report the synthesis of graft copolymers based on casein and N-isopropylacrylamide, which can self-assemble into biodegradable micelles of approximately 80 nm at physiological conditions. The obtained copolymers were degraded by trypsin, an enzyme that is overexpressed in several malignant tumors. Moreover, graft copolymers were able to load doxorubicin (Dox) by ionic interaction with the casein component. In vitro release experiments showed that the in situ assembled micelles can maintain the cargo at plasma conditions but release Dox immediately after their exposition at pH 5.0 and trypsin. Cellular uptake and cytotoxicity assays revealed the efficient delivery to the nucleus and antiproliferative efficacy of Dox in the breast cancer cell line MDA231. Both delivery and therapeutic activity were enhanced in presence of trypsin. Overall, the prepared micelles hold a great potential for their utilization as dual responsive trypsin/pH drug delivery system. Fil: Cuggino, Julio César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Ambrosioni, Franco Exequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; Argentina Fil: Picchio, Matías Luis. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentina Fil: Nicola, Maribel. Fundación Para El Progreso de la Medicina; Argentina Fil: Jimenez Kairuz, Alvaro Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; Argentina Fil: Gatti, Gerardo Alberto. Fundación Para El Progreso de la Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Calderon, Marcelo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Alvarez Igarzabal, Cecilia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

Hair follicles can serve as an effective reservoir for dermal drug delivery upon the topical application of particulate substances. Here, the follicular penetration of an indodicarbocyanine-labelled thermoresponsive nanogel (189 nm) having a cloud point temperature of 34°C and linked via an acid-labile linker to the model drug indocarbocyanine was investigated. In total, 227 hair follicles of porcine ear skin were examined after topical application of the thermoresponsive nanogels at room temperature (21°C), physiological skin surface temperature (32°C) and core body temperature (37°C) for the follicular penetration depths of indodicarbocyanine and indocarbocyanine using confocal laser scanning microscopy. The results showed a significantly increased mean follicular penetration of the carrier to a depth of 298.8±85.8 μm after incubation at 37°C compared to samples incubated at 21°C and 32°C with mean follicular penetration depths of 202.7±81.7 μm and 219.4±52.9 μm, respectively (p

Despite exciting advances in gene editing, their clinical translation is still hampered by the lack of delivery systems that can encapsulate and deliver gene editing tools like CRISPR-Cas9 or prime editors to the target side. This is particularly challenging in human epithelia, such as the skin and the lung; the latter of which being a mucosal surface that is covered by a mucus layer. In this perspective, the design and biological assessment of delivery systems for gene editing tools like CRISPR in skin and mucosal surfaces are discussed. The current state-of-the-art, current knowledge, and translational gaps, and guide toward improved translation are highlighted.

The thermoresponsive behavior of an elastin-based polymer can be altered by the polymeric macromolecular conformation. Thus, when the elastin basic amino acid sequence VPGVG is used as a pendant group of a poly(phenylacetylene) (PPA) its thermoresponsive behavior in water can be remotely detected through conformational changes on the formed helix. Circular dichroism at different temperatures shows an inversion of the first Cotton effect (450 nm) at 25.8 °C that matches with the cloud point temperature. The elastin-based side-chain poly(phenylacetylene) shows an upper critical solution temperature with low pH and concentration dependency, not expected in elastin-based polymers. It was found that the polymer self-assembles in water into spherical nanoparticles with hydrodynamic diameters of 140 nm at the hydrophobic state. Fundación Segundo Gil Dávila Dahlem Research School, Freie Universität Berlin. Grant Number: Dahlem International PostDocs fellowship Ministerio de Ciencia e Innovación. Grant Number: CTQ2015-70519-P Xunta de Galicia. Grant Number: Centro Singular de Investigación de Galicia Acreditación 2016-2019 European Regional Development Fund. Grant Number: ERDF Bundesministerium für Bildung und Forschung. Grant Number: Nanomatfutur award, 13N12561, Thermonanogele SI

Nanoscaled soft particles, such as nanogels, can be designed to incorporate different types of compounds and release them in a controlled and triggered manner. Thermoresponsive nanogels (tNG), releasing their cargo above a defined temperature, are promising carrier systems for inflammatory skin diseases, where the temperature of diseased skin differs from that of healthy skin areas. In this study a polyglycerol-based tNG with diameter of 156nm was investigated for penetration and release properties upon topical application on ex vivo human skin with intact or disrupted barrier. Furthermore, temperature-triggered effects and the internalization of tNG by skin cells upon translocation to the viable skin layers were analyzed. The investigated tNG were tagged with indodicarbocyanine and loaded with fluorescein, so that fluorescent microscopy and flow cytometry could be used to evaluate simultaneously particle penetration and release of the fluorochrome. Topically applied tNG penetrated into the SC of both intact and disrupted skin explants. Only in barrier-disrupted skin significant amounts of released fluorochrome and tNG penetrated in the epidermis and dermis 2h after topical application. When a thermal trigger was applied by infrared radiation (30s, 3.9mJ/cm2), a significantly higher penetration of tNG in the SC and release of the dye in the epidermis were detected with respect to non-triggered samples. Penetrated tNG particles were internalized by skin cells in both epidermis and dermis. Only few CD1a-positive Langerhans cells associated with tNG were found in the epidermis. However, in the dermis a significant percentage of cells associated with tNG were identified to be antigen presenting cells, i.e. HLA-DR+and CD206+cells. Thus, tNG represent promising carrier systems for the treatment of inflammatory skin diseases, not only because of their improved penetration and controlled release properties, but also because of their ability to effectively reach dermal dendritic cells in barrier-disrupted skin.

Engineered nanogels are of high value for a targeted and controlled transport of compounds due to the ability to change their chemical properties by external stimuli. As it has been indicated that nanogels possess a high ability to penetrate the stratum corneum, it cannot be excluded that nanogels interact with dermal dendritic cells, especially in diseased skin. In this study the potential crosstalk of the thermore-sponsive nanogels (tNGs) with the dendritic cells of the skin was investigated with the aim to determine the immunotoxicological properties of the nanogels. The investigated tNGs were made of dendritic polyglycerol (dPG) and poly(glycidyl methyl ether-co-ethyl glycidyl ether) (p(GME-co-EGE)), as polymer conferring thermoresponsive properties. Although the tNGs were taken up, they displayed neither cytotoxic and genotoxic effects nor any induction of reactive oxygen species in the tested cells. Interestingly, specific uptake mechanisms of the tNGs by the dendritic cells were depending on the nanogels cloud point temperature (Tcp), which determines the phase transition of the nanoparticle. The study points to caveolae-mediated endocytosis as being the major tNGs uptake mechanism at 37 degrees C, which is above the Tcp of the tNGs. Remarkably, an additional uptake mechanism, beside caveolae-mediated endocytosis, was observed at 29 degrees C, which is the Tcp of the tNGs. At this temperature, which is characterized by two different states of the tNGs, macropinocytosis was involved as well. In summary, our study highlights the impact of thermoresponsivity on the cellular uptake mechanisms which has to be taken into account if the tNGs are used as a drug delivery system.

Organic macromolecules with dendrimeric architectures are polymeric materials potentially useful as nanocarriers for therapeutic drugs. In this work, we evaluate a series of Newkome-type dendrons in Langmuir and Langmuir-Blodgett films as platforms capable of interacting with a potential antitumoral agent. The nanocomposite is proposed as model for the development of surface mediated drug delivery systems. We were successful in the formation and characterization of pure (dendrons) and composite (drug-dendron) stable and reproducible monolayers, and their transfer to solid substrates. A detailed study of topographic characteristics of the generated surfaces by atomic force microscopy was conducted. Furthermore, we probed dendron monolayer films as anchorage surfaces for mammalian cells. Normal cell attachment and proliferation on the surfaces were observed. No evident cytotoxic effects were detected, demonstrating the adequate biocompatibility of the surfaces. Fil: Dib, Nahir. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Reviglio, Ana Lucía. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Fernández, Luciana. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Morales, Gustavo. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Santo, Marisa Rosana. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Otero, Luis Alberto. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química y Física; Argentina Fil: Alustiza, Fabrisio Eduardo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Liaudat, Ana Cecilia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Bosch, Pablo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina Fil: Calderon, Marcelo. Universität zu Berlin; Alemania. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina Fil: Martinelli, Marisa. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentina Fil: Strumia, Miriam Cristina. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentina

The adsorption of biomolecules to the surface of nanoparticles (NPs) following administration into biological environments is widely recognized. In particular, the "protein corona" is well understood in terms of formation kinetics and impact upon the biological interactions of NPs. Its presence is an essential consideration in the design of therapeutic NPs. In the present study, the protein coronas of six polymeric nanoparticles of prospective therapeutic use were investigated. These included three colloidal NPs-soft core-multishell (CMS) NPs, plus solid cationic Eudragit RS (EGRS), and anionic ethyl cellulose (EC) nanoparticles-and three nanogels (NGs)-thermoresponsive dendritic-polyglycerol (dPG) nanogels (NGs) and two amino-functionalized dPG-NGs. Following incubation with human plasma, protein coronas were characterized and their biological interactions compared with pristine NPs. All NPs demonstrated protein adsorption and increased hydrodynamic diameters, although the solid EGRS and EC NPs bound notably more protein than the other tested particles. Shifts toward moderately negative surface charges were also observed for all corona bearing NPs, despite varied zeta potentials in their pristine states. While the uptake and cellular adhesion of the colloidal NPs in primary human keratinocytes and human umbilical vein endothelial cells were significantly decreased when bearing the protein corona, no obvious impact was seen in the NGs. By contrast, corona bearing NGs induced marked increases in cytokine release from primary human macrophages not seen with corona bearing colloidal NPs. Despite this, no apparent enhancement to in vitro toxicity was noted. Finally, drug release from EGRS and EC NPs was assessed, where a decrease was seen in the EGRS NPs alone. Together these results provide a direct comparison of the physical and biological impact the protein corona has on NPs of widely varied character and in particular highlights a distinction between the corona's effects on NGs and colloidal NPs.

Nanoparticles (NPs) are widely explored for various biomedical applications to make more efficient therapeutics and to develop advanced diagnostic tools. The majority of NP-based systems that have been proven to successfully achieve therapeutic efficacy in vitro did not pass the in vivo conditions because of adverse effects, which have led to systemic toxicity and an unpredicted long-term outcome. Therefore, several NP-based therapeutic systems face challenges for their applicability in clinical trials. These discrepancies in the biological outcome could originate from the binding of proteins on the surface of NPs, thereby achieving a brand new biological identity. It is fundamentally important to understand the so-called "protein corona" around NPs for the development of successful products for therapeutics as well as in other biomedical applications. This review will focus on studies of protein corona formation onto the soft, organic-based NPs, upon incubation in biological media such as human plasma or serum and their physicochemical characteristics. These studies aim to describe these supramolecular structures in relationship with the resultant effects at the interface that might impact the therapeutic efficacy of the designed NPs.

Versatile, multifunctional nanomaterials for theranostic approaches in cancer treatment are highly on demand in order to increase therapeutic outcomes. Here, we developed thermo-responsive nanogels equipped with the efficient near-infrared (NIR) transducing polymer polypyrrole (PPY) for combinational photothermal and chemotherapeutic therapy along with photoacoustic imaging ability. Long-term stability and water-dispersibility of PPY was achieved using semi-interpenetration method for in situ polymerization of PPY into hydrophilic thermo-responsive nanogels. The semi-interpenetrated nanogels of spherical shape and with hydrodynamic sizes of around 200 nm retained the temperature response behaviour and exhibit excellent photothermal transducing abilities in the NIR region. The PPY nanogels served as photoacoustic contrast agents, which allowed determination of biodistribution profiles ex vivo. In addition, we developed a new method for biodistribution determination based on the photothermal response of the nanogels with an accuracy down to 12.5 μg/mL. We examined the ability of the nanogels as photothermal agents and drug delivery systems in vitro and in vivo. We showed that they efficiently inhibit tumor growth with combinational effects of chemotherapeutics and photothermal treatment. Our work encourages further exploration of nanogels as functional stabilizing matrix for photothermal transducers and their application as drug delivery devices in combination with photothermal therapy and imaging. Fil: Theune, Loryn E.. Freie Universität Berlin; Alemania Fil: Buchmann, Jens. Martin-universität Halle-wittenberg; Alemania Fil: Wedepohl, Stefanie. Freie Universität Berlin; Alemania Fil: Molina, María Alejandra. Freie Universität Berlin; Alemania. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina Fil: Laufer, Jan. Martin-universität Halle-wittenberg; Alemania Fil: Calderón, Marcelo. Freie Universität Berlin; Alemania

The development of polymers with low toxicity and efficient gene delivery remains a significant barrier of nonviral gene therapy. Modification and tuning of chemical structures of carriers is an attractive strategy for efficient nucleic acid delivery. Here, polyplexes consisting of plasmid DNA (pDNA) and dodecylated or non-dodecylated polysuccinimide (PSI)-based polycations are designed, and their transfection ability into HeLa cells is investigated by green fluorescent protein (GFP) expressing cells quantification. All cationic polymers show lower cytotoxicity than those of branched polyethyleneimine (bPEI). PSI and bPEI-based polyplexes have comparable physicochemical properties such as size and charge. Interestingly, a strong interaction between dodecylated polycations and pDNA caused by the hydrophobic moiety is observed in dodecylated PSI derivatives. Moreover, the decrease of GFP expression is associated with lower dissociation of pDNA from polyplexes according to the heparin displacement assay. Besides, a hydrophobization of PSI cationic derivatives with dodecyl side chains can modulate the integrity of polyplexes by hydrophobic interactions, increasing the binding between the polymer and the DNA. These results provide useful information for designing polyplexes with lower toxicity and greater stability and transfection performance. This work was developed within the framework of National Institute of Science and Technology of Pharmaceutical Nanotechnology (INCT-Nanofarma), which is supported by "Fundacao de Amparo a Pesquisa do Estado de Sao Paulo" (FAPESP, Brazil, Grant #14/14/50928-2) and "Conselho Nacional de Pesquisa" (CNPQ, Brazil, Grant #465687/2014-8). M.H.K. was the recipient of a CAPES and DAAD scholarship. Technical support by University of Sao Paulo and Freie Universitat Berlin is acknowledged.

Transdermal immunization is highly attractive because of the skin's accessibility and unique immunological characteristics. However, it remains a relatively unexplored route of administration because of the great difficulty of transporting antigens past the outermost layer of skin, the stratum corneum. In this article, the abilities of three poly(N-vinylcaprolactam) (PVCL)-based thermoresponsive assemblies - PVCL hydrogels and nanogels plus novel film forming PVCL/acrylic nanogels - to act as protein delivery systems were investigated. Similar thermal responses were observed in all systems, with transition temperatures close to 32 °C, close to that of the skin surface. The investigated dermal delivery systems showed no evidence of cytotoxicity in human fibroblasts and were able to load and release ovalbumin (OVA), a well-studied antigen, in a temperature-dependent manner in vitro. The penetration of OVA into ex vivo human skin following topical application was evaluated, where enhanced skin delivery was seen for the OVA-loaded PVCL systems relative to administration of the protein alone. The distinct protein release and skin penetration profiles observed for the different PVCL assemblies were here discussed on the basis of their structural differences. Fil: Sonzogni, Ana Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Yealland, Guy. Universidad Libre de Berlin; Alemania Fil: Kar, Mrityunjoy. Universidad Libre de Berlin; Alemania Fil: Wedepohl, Stefanie. Universidad Libre de Berlin; Alemania Fil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: González, Verónica Doris Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Hedtrich, Sarah. Universidad Libre de Berlin; Alemania Fil: Calderon, Marcelo. Universidad Libre de Berlin; Alemania Fil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

Semi-interpenetrated nanogels (NGs) able to release and sense diclofenac (DIC) have been designed to act as photothermal agents with the possibility to ablate cancer cells using mild-temperatures (45 °C). Combining mild heat treatments with simultaneous chemotherapy appears as a very promising therapeutic strategy to avoid heat resistance or damaging the surrounding tissues. Particularly, NGs consisted on a poly(N-isopropylacrylamide) (PNIPAM) and dendritic polyglycerol (dPG) mesh containing a semi-interpenetrating network (SIPN) of poly(hydroxymethyl 3,4-ethylenedioxythiophene) (PHMeEDOT). The PHMeEDOT acted as photothermal and conducting agent, while PNIPAM-dPG NG provided thermoresponsivity and acted as stabilizer. We studied how semi-interpenetration modified the physicochemical characteristics of the thermoresponsive SIPN NGs and selected the best condition to generate a multifunctional photothermal agent. The thermoswitchable conductiveness of the multifunctional NGs and the redox activity of DIC could be utilized for its electrochemical detection. Besides, as proof of the therapeutic concept, we investigated the combinatorial effect of photothermal therapy (PTT) and DIC treatment using the HeLa cancer cell line in vitro. Within 15 min NIR irradiation without surpassing 45 °C we were able to kill 95% of the cells, demonstrating the potential of SIPN NGs as drug carriers, sensors and agents for mild PTT.

Various specially designed poly(N-isopropylacrylamide-co-acrylic acid) (NIPA-co-AAc) nanogels (NGs) with different NIPA/AAc molar composition were synthesized by precipitation/dispersion polymerization and evaluated as carriers for drug delivery systems (DDSs) of doxorubicin hydrochloride (DOXOHCl) for cancer therapies. The NGs presented excellent dispersability in physiological environments (pH 7.4 and 5 at 37 C), as shown by dynamic light scattering (DLS). Moreover, the NGs exhibited high drug loading capacity and efficiency due to the ionic interaction of the cationic drug with the anionic NGs. NGDOXO HCl formulation presented excellent dispersability in water and minimal leakageof the cargo at plasma simulated medium (pH 7.4 and 0.14 M NaCl) at 37 C and a triggered release at lysosomal simulated medium (pH 5 and 0.14 M NaCl). This release behavior together with their size and the low cytotoxicity determined by the MTT assay converts these NGs in great candidates for their application as carriers in cancer therapies based on the enhanced permeability and retention effect (EPR) with drug pH-triggered release after endocytosis in tumor cells. Fil: Cuggino, Julio César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Molina, Maria. Freie Universität Berlin. Institut für Chemie und Biochemie; Alemania Fil: Wedepohl, Stefanie. Freie Universität Berlin. Institut für Chemie und Biochemie; Alemania Fil: Alvarez Igarzabal, Cecilia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Calderon, Marcelo. Freie Universität Berlin. Institut für Chemie und Biochemie; Alemania Fil: Gugliotta, Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

In this article, we describe the formation of functional honeycomb-like porous surfaces fabricated by the breath figures technique using blends of either amino-terminated poly(styrene) or a poly(styrene)-b-poly(acrylic acid) block copolymer with homopoly(styrene). Thus, the porous interfaces exhibited either amino or acid groups selectively located inside of the holes, which were subsequently employed to anchor stimuli-responsive nanogels by electrostatic interactions. These nanogels were prepared from poly(N-isopropylacrylamide) (PNIPAM) cross-linked with dendritic polyglycerol (dPG) and semi-interpenetrated with either 2-(dimethylamino)ethyl methacrylate (DMAEMA) or 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) to produce positively and negatively charged nanogel surfaces, respectively. The immobilization of these semi-interpenetrated networks onto the surfaces allowed us to have unique stimuli-responsive surfaces with both controlled topography and composition. More interestingly, the surfaces exhibited stimuli-responsive behavior by variations on the pH or temperature. Finally, the surfaces were evaluated regarding their capacity to induce a thermally triggered protein release at temperatures above the cloud point temperature (T(cp)) of the nanogels.

A rational design of magnetic capturing nanodevices, based on a specifi c interaction withcirculating tumor cells (CTCs), can advance the capturing effi ciency and initiate the developmentof modern smart nanoformulations for rapid isolation and detection of these CTCsfrom the bloodstream. Therefore, the development and evaluation of magnetic nanogels(MNGs) based on magnetic nanoparticles and linear thermoresponsive polyglycerol forthe capturing of CTCs with overexpressed transferrin (Tf + )receptors has been presented in this study. The MNGs aresynthesized using a strain-promoted ?click? approachwhich has allowed the in situ surface decoration withTf?polyethylene glycol (PEG) ligands of three different PEGchain lengths as targeting ligands. An optimal value ofaround 30% of cells captures is achieved with a linker ofeight ethylene glycol units. This study shows the potentialof MNGs for the capture of CTCs and the necessity of precisecontrol over the linkage of the targeting moiety to thecapturing device. Fil: Asadian Birjand, Mazdak. Universität zu Berlin; Alemania Fil: Biglione, Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Bergueiro, Julian. Universität zu Berlin; Alemania Fil: Cappelletti, Ariel Leonardo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Rahane, Chinmay. Maeers Maharashtra Institute Of Pharmacy; India Fil: Chate, Govind. Maeers Maharashtra Institute Of Pharmacy; India Fil: Khandare, Jayant. Maeers Maharashtra Institute Of Pharmacy; India Fil: Klemke, Bastian. Helmholtz-zentrum Berlin Für Materialien Und Energie Gm; Alemania Fil: Strumia, Miriam Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Calderon, Marcelo. Freie Universität Berlin; Alemania

Thermoresponsive nanogels emerged as a robust and efficient platform for the delivery of a number of therapeutic agents. The need to deliver a wide range of biomolecules from different sizes requires a structural system with the ability to be tuned according to the specific applications. In this study, we design a library of nanogels using dendritic polyglycerol (dPG) as a crosslinker and poly (N-isopropyl acrylamide) as connecting thermoresponsive chains. Nanogels with diameters in a range of 70–210 nm were obtained by precipitation polymerization with low polydispersity. We provide a detailed study on how the flexibility of the network and size of the nanogels can be tuned by the modification of functionalities of the dPG, monomer feed and the size of the crosslinker. Additionally, we use different molecular weight proteins (6–66 kDa) as an indicator of the density of the structure by encapsulation and release experiments. We prove that the versatility of the system relays on the correct design of the nanogels and the careful selection of the starting materials and its final proportion in the reaction. By controlling the network density, a wider range of application can be achieved from a system with a short-term release triggered by temperature to a long-term release that could serve as reservoir platform.

Aim: We analyzed the protein corona of thermoresponsive, poly(N-isopropylacrylamide)- or poly(N-isopropylmethacrylamide)-based nanogels. Materials & methods: Traces of protein corona detected after incubation in human serum were characterized by proteomics and dynamic light scattering in undiluted serum. Results: Apolipoprotein B-100 and albumin were the main components of the protein coronae. For dendritic polyglycerol-poly(N-isopropylacrylamide) nanogels at 37°C, an increase in adsorbed immunoglobulin light chains was detected, followed by partially reversible nanogel aggregation. All nanogels in their hydrophilic state are colloidally stable in serum and bear a dysopsonin-rich protein corona. Conclusion: We observed strong changes in NG stability upon slight alterations in the composition of the protein coronae according to nanogel solvation state. Nanogels in their hydrophilic state possess safe protein coronae.

The use of thermoresponsive nanogels (NGs) allows the controlled release of therapeutic molecules upon a thermal switch. Usually, this strategy involves the use of temperature increase to activate cargo expulsion from shrinking NGs. In this study, poly(N-isopropylacrylamide) (pNIPAM)-based NGs were involved in the release of a therapeutic protein corona by temperature decrease. NGs based on dendritic polyglycerol (dPG) and thermoresponsive pNIPAM were semi-interpenetrated with poly(4-acryloylamine-4-(carboxyethyl)heptanodioic acid) (pABC). The resulting semi-interpenetrated NGs retain the thermoresponsive properties of pNIPAM, together with pH-responsive, dendritic pABC as a secondary network, in one single nanoparticle. Semi-interpenetrated polymer network (SIPN) NGs are stable in physiological conditions, exhibit a reversible phase transition at 35 °C, together with tunable electrophoretic mobilities around the body temperature. The binding of cytochrome c (cyt c) was successful on SIPN NGs in their collapsed state at 37 °C. Upon cooling of the samples to room temperature, the swelling of the NG effectively boosted the release of cyt c, as compared with the same kept at constant 37 °C. These responsive SIPN NGs were able to deliver cyt c to cancer cells and specifically induce apoptosis at 30 °C, while the cells remained largely unaffected at 37 °C. In this way, we show therapeutic efficacy of thermoresponsive NGs as protein carriers and their efficacy triggered by temperature decrease. We envision the use of such thermal trigger as relevant for the treatment of superficial tumors, in which induction of apoptosis can be controlled by the application of local cooling agents. Fil: Miceli, Enrico. Freie Universität Berlin. Institute of Chemistry and Biochemistry; Alemania Fil: Wedepohl, Stefanie. Freie Universität Berlin. Institute of Chemistry and Biochemistry; Alemania Fil: Osorio Blanco, Ernesto Rafael. Freie Universität Berlin. Institute of Chemistry and Biochemistry; Alemania Fil: Rimondino, Guido Noé. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina Fil: Martinelli, Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina. Freie Universität Berlin. Institute of Chemistry and Biochemistry; Alemania Fil: Strumia, Miriam Cristina. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentina Fil: Molina, Maria. Freie Universität Berlin. Institute of Chemistry and Biochemistry; Alemania Fil: Kar, Mrityunjoy. Freie Universität Berlin. Institute of Chemistry and Biochemistry; Alemania Fil: Calderon, Marcelo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina

New types of biodegradable nanocarriers for drug delivery were prepared using casein (CAS) micelles as particle templates and glyceraldehyde (GAL) as a crosslinking agent. We found that highly crosslinked casein micelles (CCM) maintained their structural integrity at pH 7.4 (plasma conditions) but were easily degraded in the presence of proteases at pH 5 (lysosomal conditions). Nile red (NR) was chosen as a hydrophobic model drug inspired by the natural role of casein as lipophilic nutrient nanotransporter. The cumulative release of the NR-loaded micelles showed marginal dye leakage at pH 7.4 but was significantly accelerated by protease and pH-mediated degradation of the nanocarriers in a dual-responsive fashion. The prepared nanocarriers possess many favorable features for drug delivery: excellent biocompatibility and biodegradability, high stability in physiological conditions, remarkable capacity for the encapsulation of hydrophobic drugs, minimal drug leakage under extracellular conditions, and rapid drug release in response to the endo-lysosomal levels of pH and proteases. In this regard, the prepared CCM represent a promising candidate for the delivery and triggered release of anti-cancer drugs in lysosomal environments. Fil: Picchio, Matías Luis. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentina Fil: Cuggino, Julio César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Nagel, Gregor. Freie Universitat Berlin; Alemania Fil: Wedepohl, Stefanie. Freie Universitat Berlin; Alemania Fil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Alvarez Igarzabal, Cecilia Ines. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentina. Freie Universitat Berlin; Alemania Fil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Calderon, Marcelo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Freie Universitat Berlin; Alemania

A well-established strategy to treat drug resistance is the use of multiple therapeutics. Polymer-based drug delivery systems (DDS) can facilitate a simultaneous delivery of two or more drugs. In this study, we developed and synthesized a dendritic polyglycerol (PG) nanogel (NG) system that allows for free combination of different fixed ratios of active compound conjugates within a single NG particle. As a proof of concept, we synthesized NGs bearing the chemotherapeutic agent doxorubicin (DOX) and paclitaxel (PTX) in different ratios, as well as conjugated dye molecules. Our combination PG NGs were formed by simply mixing PG⁻drug/dye conjugates bearing free thiol groups with PG-acrylate in an inverse surfactant-free nanoprecipitation method. With this method we obtained PG-NGs in the size range of 110⁻165 nm with low polydispersity indices. Solubility of hydrophobic PTX was improved without the need for additional solubilizing agents such as polyethylene glycol (PEG). Interestingly, we found that our NGs made from PG-DOX conjugates have a high quenching efficiency for DOX, which could be interesting for theranostic purposes.

Thermoresponsive nanogels (NGs) with film-forming ability could have great potential in delivery system platforms with controlled and targeted release of drugs or proteins, such as in topical treatment. This platform offers the opportunity of combining both the high loading capacity of an NG dispersion and the delivery capability from a film, which could be previously obtained or directly formed onto the surface where the release is required. Therefore, this article investigates the synthesis of NGs based on poly(N-vinylcaprolactam), a thermoresponsive polymer, and poly(butyl acrylate), which promotes particle coalescence and cohesivity (i.e., film forming). The synthesized NGs have low cytotoxicity and are able to form flexible and smooth films, conserving the thermoresponsivity of the particulated system. The obtained films loaded with a model protein show delivery profiles responsive to temperature changes. Fil: Sonzogni, Ana Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Passeggi, Mario Cesar Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; Argentina Fil: Wedepohl, Stefanie. Freie Universität Berlin; Fil: Calderon, Marcelo. Universidad Nacional de Córdoba; Argentina Fil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: González, Verónica Doris Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

Aim: To develop an acid-sensitive lipidated, doxorubicin (Dox) prodrug (C16-Dox) to be entrapped in lipid nanoemulsion (NE-C16-Dox) as a nanocarrier to treat breast cancer models (in vitro and in vivo). Results: We report the efficacy of NE-C16-Dox in in vitro experiments, as well as the improved chemotherapeutic index and tumor-control efficacy compared with treatment with free Dox in an in vivo murine 4T1 breast cancer model. In addition, NE-C16-Dox allowed the use of a higher dose of Dox, acceptable biocompatibility and a significant reduction in lung metastasis. Conclusion: Taken together, these results indicate that NE-C16-Dox is promising for breast cancer treatment, thus creating possibilities to translate these nanotechnology concepts to clinical applications.

Exogenous factors can cause an imbalance in the redox state of biological systems, promoting the development of oxidative stress, especially reactive oxygen species (ROS). To monitor the intensity of ROS production in secondary keratinocytes (HaCaT) by diesel exhaust particles and thermoresponsive nanogels (tNG), electron paramagnetic resonance (EPR) spectroscopy after 1 and 24 h of incubation, respectively, was applied. Their cytotoxicity was analyzed by a cell viability assay (XTT). For tNG an increase in the cell viability and ROS production of 10% was visible after 24 h, whereas 1 h showed no effect. A ten times lower concentration of diesel exhaust particles exhibited no significant toxic effects on HaCaT cells for both incubation times, thus normal adult human keratinocytes (NHK) were additionally analyzed by XTT and EPR spectroscopy. Here, after 24 h a slight increase of 18% in metabolic activity was observed. However, this effect could not be explained by the ROS formation. A slight increase in the ROS production was only visible after 1 h of incubation time for HaCaT (9%) and NHK (14%).

In the last few decades, the synthesis of nanodevices has become a very active research field with many applications in biochemistry, biotechnology, and biomedicine. However, there is still a great need for smart nanomaterials that can sense and respond to environmental changes. Temperature- and pH-responsive nanogels (NGs), which are prepared in a one-pot synthesis from N-isopropylacrylamide (NiPAm) and a Newkome-type dendron (ABC) bearing carboxylic acid groups, are being investigated as multi-responsive drug carriers. As a result, NGs have been developed that are able to undergo a reversible volume phase transition triggered by acidic conditions, like the ones found in endolysosomal compartments of cancer cells. The NGs have been thoroughly characterized using dynamic light scattering and spectroscopies, such as infrared, nuclear magnetic resonance, UV-visible, and stimulated Raman. Strong hydrogen bonds have been detected when the ABC moieties are deprotonated, which has led to changes in the transition temperatures of the NGs and a reversible, pH-dependent aggregation. This pH-dependent phase change was exploited for the effective encapsulation and sustained release of the anticancer drug cisplatin and resulted in a faster release of the drug at endolysosomal pH values. The cisplatin-loaded NGs have exhibited high toxicities against A549 cells in vitro, while the unloaded NGs have been found to be not cytotoxic and hemocompatible. Fil: Rimondino, Guido Noé. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Miceli, E.. Freie Universität Berlin; Alemania Fil: Molina, M.. Freie Universität Berlin; Alemania Fil: Wedepohl, S.. Freie Universität Berlin; Alemania Fil: Thierbach, S.. Freie Universität Berlin; Alemania Fil: Rühl, E.. Freie Universität Berlin; Alemania Fil: Strumia, Miriam Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Martinelli, Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Calderón, M.. Freie Universität Berlin; Alemania

Novel nanogels that possess the capacity to change their physico-chemical properties in response to external stimuli are promising drug-delivery candidates for the treatment of severe skin diseases. As thermoresponsive nanogels (tNGs) are capable of enhancing penetration through biological barriers such as the stratum corneum and are taken up by keratinocytes of human skin, potential adverse consequences of their exposure must be elucidated. In this study, tNGs were synthesized from dendritic polyglycerol (dPG) and two thermoresponsive polymers. tNG_dPG_tPG are the combination of dPG with poly(glycidyl methyl ether-co-ethyl glycidyl ether) (p(GME-co-EGE)) and tNG_dPG_pNIPAM the one with poly(N-isopropylacrylamide) (pNIPAM). Both thermoresponsive nanogels are able to incorporate high amounts of dexamethasone and tacrolimus, drugs used in the treatment of severe skin diseases. Cellular uptake, intracellular localization and the toxicological properties of the tNGs were comprehensively characterized in primary normal human keratinocytes (NHK) and in spontaneously transformed aneuploid immortal keratinocyte cell line from adult human skin (HaCaT). Laser scanning confocal microscopy revealed fluorescently labeled tNGs entered into the cells and localized predominantly within lysosomal compartments. MTT assay, comet assay and carboxy-H2DCFDA assay, demonstrated neither cytotoxic or genotoxic effects, nor any induction of reactive oxygen species of the tNGs in keratinocytes. In addition, both tNGs were devoid of eye irritation potential as shown by bovine corneal opacity and permeability (BCOP) test and red blood cell (RBC) hemolysis assay. Therefore, our study provides evidence that tNGs are locally well tolerated and underlines their potential for cutaneous drug delivery.

Highly hydrophilic, responsive nanogels are attractive as potential systems for the topical delivery of bioactives encapsulated in their three-dimensional polymeric scaffold. Yet, these drug carrier systems suffer from drawbacks for efficient delivery of hydrophobic drugs. Addressing this, β-cyclodextrin (βCD) could be successfully introduced into the drug carrier systems by exploiting its unique affinity toward dexamethasone (DXM) as well as its role as topical penetration enhancer. The properties of βCD could be combined with those of thermoresponsive nanogels (tNGs) based on dendritic polyglycerol (dPG) as a crosslinker and linear thermoresponsive polyglycerol (tPG) inducing responsiveness to temperature changes. Electron paramagnetic resonance (EPR) studies localized the drug within the hydrophobic cavity of βCD by differences in its mobility and environmental polarity. In fact, the fabricated carriers combining a particulate delivery system with a conventional penetration enhancer, resulted in an efficient delivery of DXM to the epidermis and the dermis of human skin ex vivo (enhancement compared to commercial DXM cream: ∼2.5 fold in epidermis, ∼30 fold in dermis). Furthermore, DXM encapsulated in βCD tNGs applied to skin equivalents downregulated the expression of proinflammatory thymic stromal lymphopoietin (TSLP) and outperformed a commercially available DXM cream.

Control over morphology and porosity of supramolecular complexed polylactide (PLA) microparticles can be achieved by manipulation of the supramolecular interactions between their constituent polymeric building blocks. It is expected that such modular systems are ideal candidates to serve as degradable delivery carriers. In view of this goal, this study reports about a modular fabrication of biodegradable microparticles from terpyridine (TPy) and bisterpyridine (bisTPy) end-functionalized PLAs that can be transiently extended by chain association through differently strong complexation to three metal cations: Ni2+ , Co2+ , or Fe2+ . Further influence on the morphology of the particles can be exerted by hydrogen-bonding association of enantiomeric l- and d-PLA chains in the form of stereocomplexes. Both effects cause different stabilization of phase-separating TPy and bisTPy PLA micrograins in a process of droplet-based microfluidic particle templating, resulting in different forms of microparticle porosity. If the resulting particles are tailored such to be highly porous, they exhibit a faster release of a model drug, (S)-(+)-4-(3-amino-pyrrolidino)-7-nitrobenzo-furazan, than if they have smooth surfaces. As a result, control over the synthetic parameters, and hence, the particle porosity, can be used to tune the release profiles of drugs from the PLA microspheres.

Nanoparticles with a size of several hundred nanometers can effectively penetrate into the hair follicles and may serve as depots for controlled drug delivery. However, they can neither overcome the hair follicle barrier to reach the viable cells nor release the loaded drug adequately. On the other hand, small drug molecules cannot penetrate deep into the hair follicles. Thus, the most efficient way for drug delivery through the follicular route is to employ nanoparticles that can release the drug close to the target structure upon exposure to some external or internal stimuli. Accordingly, 100-700 nm sized thermoresponsive nanogels with a phase transition temperature of 32-37 °C were synthesized by the precipitation polymerization technique using N-isopropylacrylamide as a monomer, acrylated dendritic polyglycerol as a crosslinker, VA-044 as an initiator, and sodium dodecyl sulphate as a stabilizer. The follicular penetration of the indodicarbocyanine (IDCC) labeled nanogels into the hair follicles and the release of coumarin 6, which was loaded as a model drug, in the hair follicles were assessed ex vivo using porcine ear skin. Confocal laser scanning microscopy (CLSM) enabled independent tracking of the nanogels and the loaded dye, although it is not as precise and accurate as standard analytical methods. The results showed that, unlike smaller nanogels (

To develop nanogels (NG) able to modulate the encapsulation and release of drugs, in order to circumvent drug resistance mechanisms in cancer cells. Materials & methods: Poly-N-isopropylacrylamide-dendritic polyglycerol NG were semi-interpenetrated with 2-acrylamido-2-methylpropane sulfonic acid or (2- dimethylamino) ethyl methacrylate. Physico-chemical properties of the NGs as well as doxorubicin (DOXO) loading and release were characterized. Drug delivery performance was investigated in vitro and in vivo in a multidrug-resistant tumor model. Both the DOXO loaded semi-interpenetrating polymer network NGs were more efficient in multidrug resistant cancer cell proliferation inhibition studies. In vivo, the DOXO loaded NG semi-interpenetrated with 2-acrylamido-2-methylpropane sulfonic acid was able to overcome drug resistance and reduce the tumor volume to about 25%. The innovative semi-interpenetrating polymer network NGs appear to be promising drug carriers for drug resistant cancer therapy. Fil: Molina, María Alejandra. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Freie Universität Berlin; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Wedepohl, Stefanie. Freie Universität Berlin; Alemania Fil: Miceli, Enrico. Freie Universität Berlin; Alemania. Helmholtz Virtual Institute On Multifunctional Biomaterials For Medicine; Alemania Fil: Calderon, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Helmholtz Virtual Institute On Multifunctional Biomaterials For Medicine; Alemania. Freie Universität Berlin; Alemania

In this paper we present a comprehensive study for the ability of thermoresponsive nanogels (tNG) to act as cutaneous penetration enhancers. Given the unique properties of such molecular architectures with regard to their chemical composition and thermoresponsive properties, we propose a particular mode of penetration enhancement mechanism, i.e. hydration of the stratum corneum. Different tNG were fabricated using dendritic polyglycerol as a multifunctional crosslinker and three different kinds of thermoresponsive polymers as linear counterpart: poly(N-isopropylacrylamide) (pNIPAM), p(di(ethylene glycol) methyl ether methacrylate - co - oligo ethylene glycol methacrylate) (DEGMA-co-OEGMA475), and poly(glycidyl methyl ether - co - ethyl glycidyl ether) (tPG). Excised human skin was investigated by means of fluorescence microscopy, which enabled the detection of significant increment in the penetration of tNG as well as the encapsulated fluorescein. The morphology of the treated skin samples was thoroughly investigated by transmission electron microscopy and stimulated Raman spectromicroscopy. We found that tNG can perturbate the organization of both proteins and lipids in the skin barrier, which was attributed to tNG hydration effects. Interestingly, different drug delivery properties were detected and the ability of each investigated tNG to enhance skin penetration correlated well with the degree of induced stratum corneum hydration. The differences in the penetration enhancements could be attributed to the chemical structures of the nanogels used in this study. The most effective stratum corneum hydration was detected for nanogels having additional or more exposed polyether structure in their chemical composition.

Nowadays, combination therapy became a standard in oncology. In this study, we compare the activity of two polymeric carriers bearing a combination of the anticancer drugs paclitaxel (PTX) and doxorubicin (DOX), which differ mainly in their architecture and supramolecular assembly. Drugs were covalently bound to a linear polymer, polyglutamic acid (PGA) or to a dendritic scaffold, polyglycerol (PG) decorated with poly(ethylene glycol) (PEG), forming PGA-PTX-DOX and PG-PTX-bz-DOX-PEG, respectively. We explored the relationship between the polymeric architectures and their performance with the aim to augment the pharmacological benefits of releasing both drugs simultaneously at the tumor site at a synergistic ratio. We recently designed and characterized a PGA-PTX-DOX conjugate. Here, we describe the synthesis and characterization of PG dendritic scaffold bearing the combination of PTX and DOX. The performance of both conjugates was evaluated in a murine model of mammary adenocarcinoma in immunocompetent mice, to investigate whether the activity of the treatments is affected by the immune system. Drug conjugation to a nano-sized polymer enabled preferred tumor accumulation by extravasation-dependent targeting, making use of the enhanced permeability and retention (EPR) effect. Both PGA-PTX-DOX and PG-PTX-bz-DOX-PEG nano-sized conjugates exhibited superior anti-tumor efficacy and safety compared to the combination of the free drugs, at equivalent concentrations. However, while PGA-PTX-DOX was more efficient than a mixture of each drug conjugated to a separate PGA chain, as was previously shown, PG-PTX-bz-DOX-PEG had similar activity to the mixture of the PG-PTX-bz-PEG and PG-DOX-PEG conjugates. Our results show that both conjugates are potential candidates as precision combination nanomedicines for the treatment of breast cancer.

Herein we report the preparation of honeycomb porous films for selective immobilization of biomolecules via the breath figure technique, a water-assisted micropatterning method. In particular, porous films are obtained from polymeric blends composed of high molecular weight polystyrene as the major component and an oligoglycerol based dendron covalently bonded to a hydrophobic polystyrene chain as the minor constituent. The multivalent dendritic architecture presents a well-defined molecular structure with controlled glycine arrays on their surfaces. Due to the mechanism of the breath figure formation, the resulting films exhibit an especial chemical distribution at the surfaces, in which the dendritic functional polymer is located preferentially in the interior of the pores while the rest of the polymer surface is mainly formed by the high molecular weight polystyrene. The high amount of amine functional groups inside the pores allowed the specific immobilization of biomolecules into the cavities by electrostatic interactions. In particular, the protein bovine serum albumin (BSA) and a DNA sequence were attached onto the films as a proof of concept. Besides, it was demonstrated that the density of biomolecules immobilized can be easily tuned by varying the content of the dendritic functional polymer in the film. These unique characteristics open new alternatives for the use of these platforms in biorelated applications including bio-recognition processes, or the understanding of cell–protein and even cell–DNA interactions on biofunctional microstructured polymeric supports.

To study the mechanism of cellular internalization, hyperbranched polyether derivatives consisting of amino-bearing hyperbranched polyglycerols (HPGs) of varied molecular mass and size range are designed and synthesized. HPGs were further fluorescently labelled by conjugating maleimido indocarbocyanine dye (ICC-mal). The conjugates are characterized by UV-vis spectroscopy, fluorescence profile, zeta potential, and dynamic light scattering. The uptake mechanism is studied by fluorescence-activated cell sorting (FACS) analysis, fluorescence spectroscopy, and confocal microscopy with human lung cancer cells A549, human epidermoid carcinoma cells A431, and human umbilical vein endothelial cells (HUVEC) cells. For the first time, the results suggest that the higher-molecular-weight HPGs (40-870 kDa) predominantly accumulate in the cytoplasm much better than their low-molecular-weight counterparts (2-20 kDa). The HPG nanocarriers discussed here have many biomedical implications, particularly for delivering drugs to the targeted site.

Nanogels are water soluble cross-linked polymer networks with nanometer size dimensions that can be designed to incorporate different types of compounds and are promising carrier systems for drugs and biological molecules. In this study, the interactions of thermoresponsive nanogels (tNGs) with the human skin barrier and underlying epidermis cells were investigated with the aim of using such macromolecules to improve dermal and transdermal drug delivery. The investigated tNGs were made of acrylated dendritic polyglycerol, as water soluble cross-linker, and of oligo ethylene glycol methacrylate (OEGMA) as subunit conferring thermoresponsive properties. tNGs with different polymer transition temperatures were tagged with Rhodamine B (RhdB) and analyzed for their physicochemical properties. We found that tNGs with cloud point temperatures (Tcps) of 38 °C (tNG-RhdB-T38) lost softness (measured by PeakForce quantitative nanomechanics, QNM) and aggregated to bigger sized particles (measured as increase of particle average size by dynamic light scattering, DLS) when temperature changed from 15 to 37 °C. On the contrary, at the same conditions, tNGs with higher Tcps (tNG-RhdB-T55) did not show any significant changes of these characteristics. Applied on excised human skin, both tNGs penetrated deep in the stratum corneum (SC). Small amounts of tNGs were detected also in cells of the viable epidermis. Interestingly, whereas tNG softness correlated with higher penetration in SC, a better cellular uptake was observed for the thermoresponsive tNG-RhdB-T38. We conclude that soft nanocarriers possess a high SC penetration ability and that thermoresponsive nanogels are attractive carrier systems for the targeting of drugs to epidermis cells.