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Hierarchically structured surfaces including sensitive materials presents the advantage to exalt wettability variation due to the combination of micro structure effect directed by Cassie Baxter and/or Wenzel behaviour which is tuned by the surface energy variation of sensitive polymer films. Herein is reported the synthesis and the hierarchical structuration of a pH sensitive diblock copolymer P(S- stat -MMA)- b -P4VP with a pH-sensitive Poly 4-vinylpyridine P4VP block. Applying the Breath Figure method casting (minute time scale process), this diblock copolymer allows to obtain a micro porous honeycomb film while a wall nano-structuration due to self-assembly of diblock copolymer is observed. The pH-triggered wettability is studied and correlated with the morphology evolution of P4VP nano-domains investigated by AFM in a liquid cell. Indeed, a nano-dots to nano-rings/donuts transition is highlighted when decreasing the pH below the pK a of the P4VP. This nano "sea Anemone" shape transition induces the macroscopic changes of the wettability of a hierarchically self-organized honeycomb film, explained by the protonation of P4VP chains inducing electrostatic repulsion and then hydrophilic surface. [ABSTRACT FROM AUTHOR]

Abstract: The concomitant polymer embedding and surface patterning of micron-sized aluminum flakes by dispersion polymerization of styrene is reported. The aluminum pigments coated by a thin silica layer were modified by trimethoxysilylpropyl acrylate grafting (TMSPA-grafted Al@silica). Dispersion polymerization of styrene was further performed in alcoholic or hydro-alcoholic media in the presence of the organically modified TMSPA-grafted Al@silica pigments as a seed and poly(N-vinylpyrrolidone) (PVP) as a steric stabilizer to lead to hybrid aluminum flakes. The weight fraction of polymer onto the aluminum pigment surface was tuned from 14 to 29 wt.% by the hydro-alcoholic continuous phase composition and from 19 to 38 wt.% by the initiator content. The chemical nature of the initiator plays an important role in the surface patterning of the hybrid aluminum flakes as 2,2′-azobis(isobutyronitrile) initiator provided polymer nodules, i.e. due to a pattern of polymer protrusions with nodules shape at the surface of the inorganic substrate, while a flat and continuous polymer layer was obtained with 2,2′-azobis(2-amidinopropane) dihydrochloride initiator. Moreover, the introduction of ammonium groups at the surface of the polymer particles was possible by the delayed addition of a cationic acrylate co-monomer ([2-(acryloyloxy)ethyl]-trimethylammonium chloride) rendering the pigments dispersible in water. Finally, gold nanoparticles were successfully deposited onto the micro-patterned aluminum flakes to open the way towards new colored aluminum pigments. Both location of cationic ammonium function in the polymer nodule and nature of gold nanoparticles ligands were investigated with the aim to evaluate the amount of adsorbed gold nanoparticles. The final hierarchically patterned aluminum pigments dispersed in water exhibited an intense purple color. [Copyright &y& Elsevier]

Abstract: Crude wood fibers represent a wide class of renewable resources. The surface modification of such materials via covalent grafting of polymer offers new surface properties with non-leaching coating. The grafting of the polymer chains was achieved by surface-initiated controlled radical polymerization through a grafted xanthate chain transfer agent. Macromolecular design via interchange of xanthate (MADIX) technique was chosen to graft poly(vinyl acetate), polystyrene, poly(n-butyl acrylate) and poly(4-vinylbenzyl chloride)-polystyrene amphiphilic cationic copolymers. Water contact angle measurements highlighted the hydrophobization of the wood fiber surface with a nanoscaled polymer monolayer indicating the appropriate coverage of the fiber. X-ray photoelectron spectroscopy showed the successful grafting of the polymer after drastic washing procedure. The quaternization of the grafted polystyrene-co-poly(4-vinyl benzyl chloride) copolymers with tertiary amine allows the introduction of biocide quaternary ammonium functions while preserving the hydrophobic character of the modified wood fiber when introducing a long alkyl chain in the statistical copolymer. Finally, the cationic copolymer was subjected to Coniophora Puteana to evaluate its propensity to limit the fungi expansion. [Copyright &y& Elsevier]

The four‐step synthesis of amphiphilic glycopolymers associating dextran as backbone and poly(methyl methacrylate) (PMMA) as grafts is reported, using the "grafting from" strategy. In the first step, the dextran OH functions were partially acetylated. The second step consisted in linking initiator groups by reaction of 2‐bromoisobutyryl bromide (BiBB) with the unprotected OH functions. Third, the atom transfer radical polymerization (ATRP) of methyl methacrylate was carried out in DMSO from the resulting dextran derivative used as a macroinitiator. Finally, the cleavage of the acetate groups led to the expected glycopolymers. Careful attention was given both to the copolymer structure and the control of polymerization. PMMA grafts were analyzed by SEC‐MALLS after their deliberate cleavage from the backbone to evidence a controlled polymerization. Moreover, the mildness of the final deprotection conditions was proved to ensure acetate cleavage without either degrading dextran backbone and PMMA grafts or cleaving grafts from dextran backbone. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7606–7620, 2008 [ABSTRACT FROM AUTHOR]

Abstract: Poly(n-butyl methacrylate), PBMA, chains were grafted by atom transfer radical polymerization (ATRP) from the surface of iron plates using electrochemically attached initiators based on diazonium salts providing an iron/polyphenylene/PBMA structure. This surface-initiated ATRP procedure was controlled by the addition of a small proportion of Cu++ deactivator, but in the absence of any sacrificial initiator. Combined XPS, IR and AFM experiments provide a powerful means for the characterization of the obtained complex iron/polyphenylene/PBMA layered structure. It is possible to measure the thickness of the brominated aryl structure covalently attached to iron. Concerning the PBMA brushes, their presence on the surface was confirmed by IRRAS. The brominated chain end could be traced by XPS testifying for the ATRP character of the polymerization and the thickness of the polymer brushes was determined. The controlled living ATRP character of the polymerization is confirmed through a linear correlation between the thickness of the layer and the degree of polymerization. Measurement of the grafting density of PBMA chains indicates that they are compactly packed and that, approximately, one brominated aryl chain out of two efficiently initiates ATRP. [Copyright &y& Elsevier]

This study addresses the wetting and adhesion of a low molecular mass poly(n‐butyl acrylate) homopolymer melt, used as a weak acrylic adhesive, on two types of textured polymer films prepared by the breath figure templating method. The first film is a polystyrene homopolymer honeycomb‐like structure with well‐defined porous structure and long‐range ordering. The second is a disordered poly(n‐butyl acrylate)‐block‐polystyrene diblock copolymer film featuring a broad distribution of pore diameters. Static contact angle measurements show that porous films repel better the polymer melt than the corresponding nontextured films. Contact angles and spreading of polymer melt droplets on these textured surfaces reveals a Cassie‐Baxter state on the ordered porous film and a partial Wenzel state on the disordered porous films. In addition, probe tack results show that the textured surfaces tend to induce cavitation. The correlation between the wetting and adhesion highlights the major role of melt insertion into the pores, which is primarily controlled by the pores' dimensions. [ABSTRACT FROM AUTHOR]

The first nitroxide-mediated polymerization of butyl acrylate/methyl methacrylate and/ or styrene diblock copolymers-based nanoclay composites is reported. Polybutyl acrylate (PBA) macroinitiators synthesized in the presence of raw and modified clays are used for chain extension. All materials are characterized by proton nuclear magnetic resonance, size exclusion chromatography, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry techniques. The obtained proton nuclear magnetic resonance and size exclusion chromatography results show that all syntheses are carried out in controlled manner. X-ray diffraction analysis of hybrid materials reveals the formation of different structures varying between exfoliated and disordered ones. These structures depend on nanoclay distribution in different (co) polymer matrix and probable polymer/nanoclay interactions. All PBA composites and hybrid diblock materials register the enhanced thermal stability and show two glass transition temperature Tg values corresponding to the two diblock acrylic macromolecular features. [ABSTRACT FROM AUTHOR]

Abstract: In this article, we present new samples of lamellar magnetic nanocomposites based on the self-assembly of a polystyrene-b-poly(n-butyl methacrylate) diblock copolymer synthesized by atom transfer radical polymerization. The polymer films were loaded with magnetic iron oxide nanoparticles covered with polystyrene chains grown by surface initiated-ATRP. The nanostructuration of the pure and magnetically loaded copolymer films on silicon was studied by atomic force microscopy, ellipsometry, neutron reflectivity and contact angle measurement. The present study highlights the strong influence of the copolymer extremity – driven itself by the choice of the ATRP chemical route – on the order of the repetition sequences of the blocks in the multi-lamellar films. In addition, a narrower distribution of the nanoparticles’ sizes was examined as a control parameter of the SI-ATRP reaction. [ABSTRACT FROM AUTHOR]

Abstract: Size-exclusion chromatography (SEC) separates polymers by hydrodynamic volume (the universal calibration principle). Molecular weights can be determined using viscometry (relying on universal calibration) and light scattering (independent of universal calibration). In the case of complex branched polyacrylates with tetrahydrofuran as eluent, universal calibration is valid, although the separation in term of molecular weight is incomplete: a given elution slice contains a range of molecular weights, described in terms of a ‘local polydispersity’. The local polydispersity index decreases when the number of branches per chain increases and complete separation is reached for highly branched chains. [Copyright &y& Elsevier]

Abstract: A well-defined, amphiphilic poly(styrene-co-acrylic acid) copolymer was synthesized in a single step by nitroxide-mediated controlled free-radical copolymerization of styrene and acrylic acid, without protection of the acid groups: M n=6500gmol−1, M w/M n=1.5 and a composition of F AA=0.70±0.03 in acrylic acid. In addition to the good control over molar mass and molar mass distribution, the copolymer exhibited a narrow composition distribution with a slight gradient. Such copolymer was an efficient stabilizer for the emulsion polymerizations of styrene and of mixtures of methyl methacrylate and n-butyl acrylate, until 45wt% solids. A low amount (typically 3–4wt% based on the monomer(s)) was needed for a good stabilization. This is approximately a decade lower than the required amount of random, amphiphilic copolymers prepared via conventional free-radical polymerization. The performances were, however, below those of analogous diblock copolymers, but the great advantage is the very easy synthetic procedure. [Copyright &y& Elsevier]

Graphical abstract Abstract Since the last decade, there has been an increasing demand for the design of more advanced functional materials. The integration of inorganic nanoparticles to polymer matrices is a powerful tool to confer their fascinating and complementary properties to the polymer materials. Among the different polymer nanocomposites, transparent nanocomposites are of particular interest due to their significance in a wide range of applications. To achieve a high level of transparency in the nanocomposites, it is necessary to minimize the aggregation of the nanoparticles that induce significant light scattering and thus hamper the application for transparent materials. The basic concepts of light scattering, the refractive index modulation and the methods to characterize the transparency of nanocomposites are provided to introduce this review. The fabrication of the transparent nanocomposites has been the subject of many efforts to develop methods to limit aggregation. To address this challenge, several methods have been implemented to control the polymerization process, the nanoparticle synthesis, and the polymer-nanoparticle interface together with the polymer casting or processing. The main methodologies developed to fabricate transparent nanocomposites are discussed according to four main categories: the blending of nanoparticles and polymer; the in-situ polymerization in the presence of pre-formed nanoparticles; the in-situ nanoparticle synthesis in a pre-formed polymer matrix; and finally the simultaneous polymerization and in-situ nanoparticle synthesis. The few studies dealing with casting of polymer solution loaded with core-shell nanoparticles are also discussed. In light of the literature on polymer nanocomposites, this review focuses on transparent nanocomposites with special attention given to the level of transparency and how this transparency is assessed for each study claiming transparency of the nanocomposite. For each class of nanocomposites, it is of great importance to provide an overview of the different level of transparency according to the thickness of the polymer material. The second part of the review provides a thorough overview of the properties investigated in transparent nanocomposites with attention paid to the characterization of transparency. The transparent nanocomposites were described according to the targeted properties which are primarily the improvement of mechanical properties, thermal stability, barrier properties, magnetic properties and the optical properties. The optical properties have been the most thoroughly investigated due to the myriad inorganic nanoparticles exhibiting an excellent wide range of optical properties. Thus, the present review also describes the polymer/nanoparticle systems designed for the fabrication of transparent polymer nanocomposites with advanced optical properties: UV or IR-filtering properties, photoluminescence, ability to produce extreme refractive index, dichroism or non-linear optical properties. [ABSTRACT FROM AUTHOR]

A series of reactive poly([2-(acryloyloxy)ethyl]trimethylammonium chloride) (P(AETAC)) cationic polymers with varying degrees of polymerization were synthesized by RAFT/MADIX polymerization and investigated as stabilizers for the emulsion polymerization of N-vinylcaprolactam (PVCL) in the presence of a cross-linker. It was demonstrated that the xanthate chain end of the cationic P(AETAC-X) polymers played a crucial role to produce stable cationic PVCL-based microgels at higher initial solids content (5-10 wt %) than usually reported for the synthesis of PVCL microgels. The thermoresponsive PVCL microgels with cationic shell undergo a reversible volume shrinkage upon heating in the absence of any hysteresis in accordance with the narrow particle size distribution. The values of the volume phase transition temperature ranged between 28 and 30 °C for the microgels synthesized using 4 and 8 wt % of P(AETAC-X) based on VCL. The presence of a cationic outer shell onto the microgels was evidenced by the positive values of the electrophoretic mobility. The swelling behavior of the thermoresponsive microgel particles can be tuned by playing on two synthesis variables which are the initial solids content and the content of P(AETAC-X) macro-RAFT stabilizer. Furthermore, the inner structure of the synthesized microgels was probed by transverse relaxation nuclear magnetic resonance (T2 NMR) and small-angle neutron scattering (SANS) measurements. The fit of T2 NMR data confirmed a core-shell morphology with different cross-linking density in PVCL microgels. Through the determination of the network mesh size, SANS was suitable to explain the increase of the values of the PVCL microgel swelling ratios by increasing the initial solids content of their synthesis. [ABSTRACT FROM AUTHOR]

Amphiphilic copolymers based on renewable resources were involved as emulsifiers to prepare transparent terpene-in-water nanoemulsions. The amphiphilic copolymers are composed of hydrophobically modified poly(acrylic acid) (HMPAA) grafted with different fractions of hydrophobic bio-based tetrahydrogeraniol (THG) side chains. The well-defined PAA were synthesized by reversible addition fragmentation transfer (RAFT) polymerization in order to tune the number-average molar mass of the initial PAA. The self-assembly in aqueous solution of the HMPAA copolymers was investigated through the measurement of their critical aggregation concentration by viscometry, tensiometry, dynamic light scattering and the determination of their aggregation number by static light scattering. Series of oil-in-water nanoemulsions using dihydromyrcenol (DHM) terpene as dispersed phase and PAA-THG as emulsifier were prepared with different PAA-THG/DHM weight ratios and DHM/water weight ratios. The level of transparency of the emulsions was monitored though the transmittance value measured at 600 nm and the measurements of the hydrodynamic diameter of droplets by dynamic light scattering. This study highlights that the structure of the PAA x -THG y is a key parameter to prepare terpene-in-water nanoemulsions with the required high level of transparency. The optimised structure of the emulsifier consists in a moderate degree of polymerization of PAA backbone ( DP ‾ n ,PAA ≤ 180 ) along with an intermediate average degree of substitution in hydrophobic THG side chains (13 ≤ DS ‾ ≤ 32). [ABSTRACT FROM AUTHOR]

Well-defined thermoresponsive amphiphilic statistical copolymers based on N-vinylcaprolactam (VCL) and vinyl acetate (VAc) were successfully synthesized by RAFT/MADIX polymerization mediated by O-ethyl-S-(1-ethoxycarbonyl)ethyldithiocarbonate chain transfer agent at 65 °C. We achieved the synthesis of a series of copolymers with controlled molar masses and low dispersities over a wide range of monomer feed ratios (0 < fVAc,0 < 1). Both conventional linearization methods and a nonlinear least-squares methods (NLLS) were applied to estimate reliable values of reactivity ratios for VAc and VCL radical polymerization in regards to the disparate values previously reported in the literature. The highest measurement precision was observed for the NLLS method based on the integrated form of the copolymerization equation developed by Skeist. The calculated values of the reactivity ratios (rVAc = 0.33 ± 0.10 and rVCL = 0.29 ± 0.15) perfectly fitted the drift in monomer feed ratio versus conversion. The VCL and VAc monomer units are distributed homogeneously along the copolymer chains. Both the cloud point temperatures and glass transition temperatures evolve linearly with the copolymer composition. Analyses of the aqueous solutions of the amphiphilic copolymers by means of dynamic and static light scattering show that P(VAc-co-VCL) copolymers undergo a reversible temperature-induced conformational change between large aggregates (T > Tcloud point) and either unimers for FVAc inferior to 0.3 (Nagg = 1, Dh ∼ 7 nm) or small aggregates for FVAc = 0.53 (Nagg = 3, Dh ∼ 14 nm). [ABSTRACT FROM AUTHOR]

Light-responsive glycopolymer micelles were produced by the self-assembly of amphiphilic block copolymers containing azobenzene and β-galactose units. These well-defined block copolymers were synthesised firstly by the RAFT polymerisation of an azobenzene methacrylate monomer (AzoMA) to produce two short azobenzene macroRAFT agents containing 7 and 15 monomer units. Chain extension with a second block of ∼150 or ∼250 sugar units comprising of a protected β-galactose monomer (β-AcGalEtMA) generated four block copolymers, which were converted to amphiphilic structures by deprotection of the acetyl groups on the sugar units. Micelles with well-defined sizes of 26–50 nm were produced by self-assembly in water. The azobenzene units isomerised very rapidly to their more polar cis isomers under UV irradiation, reaching the photostationary state within 2 min, with reversion to the trans state taking several hours in the dark. This transition to the more polar cis state is an important criteria for aiding expulsion of a hydrophobic payload. In cell studies, unloaded micelles showed low cytotoxicity, and micelles loaded with the model hydrophobic compound Nile red demonstrated high cellular uptake in human melanoma A375 cells, demonstrating their suitability as a potential drug delivery system for melanoma. [ABSTRACT FROM AUTHOR]

This article reports a rational strategy for preparing smart oligo(ethylene glycol)-based hybrid microgels loaded with high content of homogeneously distributed preformed magnetic nanoparticles (NPs) (up to 33 wt%). The strategy is based on the synthesis of biocompatible multiresponsive microgels by precipitation copolymerization of di(ethylene glycol) methyl ether methacrylate, oligo(ethylene glycol) methyl ether methacrylate, methacrylic acid, and oligo(ethylene glycol)diac­rylate. An aqueous dispersion of preformed magnetic NPs is straightforwardly loaded into the microgels. Robust monodisperse thermoresponsive magnetic microgels are produced, exhibiting a constant value of the volume phase transition temperature whatever the NPs content. The homogeneous microstructure of the initial stimuli-responsive biocompatible microgels plays a crucial role for the design of unique well-defined ethylene glycol-based thermoresponsive hybrid microgels. [ABSTRACT FROM AUTHOR]

Abstract: To address the issue of the aggregation in second-order nonlinear optical (NLO) polymers we developed an approach based on the synthesis of a multifunctional macromolecular chain transfer agent. The controlled monomer insertion polymerization into the main chain by a ‘reversible addition-fragmentation chain transfer’ (RAFT) mechanism allows the spatial arrangement of the NLO chromophores along the polymeric chain in order to obtain sequence-ordered polymers. In a first step, a novel trithiocarbonate based macroinitiator containing the disperse red 19 (DR19) units in the main chain was synthesized by polycondensation; in a second step, this polymeric precursor was applied to the synthesis of a sequentially ordered polymer by controlled insertion radical polymerization of styrene. Size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) data revealed that, (i) for the first time, polystyrenes (PS) bearing DR19 dyes covalently bounded were obtained, and (ii) both the insertion reaction and the length of the polystyrene segments were accurately controlled. Whatever the incorporated dye amount, all the copolymers were soluble in common solvents. Second-order optical nonlinearity in corona-poled thin films was evaluated, and second harmonic coefficients up to 80 pm/V were determined for loading ratio lower than 10 wt-% (DR19/PS). This approach opens up opportunities for the incorporation of more efficient chromophores even in apolar matrices. [Copyright &y& Elsevier]

Honeycomb-structuredporous polymer films based on photosensitizer-graftedpolystyrene are prepared through the breath figure process. Rose Bengal(RB) photosensitizer is first attached to a well-defined poly(styrene-stat-4-vinylbenzyl chloride) statistical copolymer, synthesizedby nitroxide-mediated radical polymerization. The RB grafted poly(styrene-stat-4-vinylbenzyl chloride) (ca. 20 000 g mol–1molar mass, 1.2 dispersity) leads to porous polymerfilms, with a hexagonal pore pattern, while a simple mixture of poly(styrene-stat-4-vinylbenzyl chloride) and the insoluble RB photosensitizerproduced unstructured, nonporous films. The RB-grafted honeycomb films,compared with the corresponding nonporous flat films, are more efficientfor oxidation of organic molecules via singlet oxygen production ata liquid/solid interface. The oxidations of 1,5-dihydroxynaphthaleneto juglone and α-terpinene to ascaridole are followed in ethanolin the presence of both types of films. Oxidation of the organic moleculesis a factor 5 greater with honeycomb compared to the nonporous films.This gain is ascribed to two factors: the specific location of thepolar photosensitizer at the film interface and the greater exchangesurface, as revealed by fluorescence and scanning electron microscopies. [ABSTRACT FROM AUTHOR]

Branched and star-branched polymers were successfully synthesized by the combination of two successive controlled radical polymerization methods. A series of linear and star poly( n-butyl acrylate)- co-poly(2-(2-bromoisobutyryloxy) ethyl acrylate) statistical copolymers, P( nBA- co-BIEA) x, were first synthesized by nitroxide-mediated polymerization (NMP at T > 100 °C). The subsequent polymerization of n-butyl acrylate by single electron transfer-living radical polymerization (SET-LRP at T = 25 °C), initiated from the brominated sites of the P( nBA- co-BIEA) x copolymer, produced branched or star-branched poly( n-butyl acrylate) (P nBA). Both types of polymerizations (NMP and SET-LRP) exhibited features of a controlled polymerization with linear evolutions of logarithmic conversion versus time and number-average molar masses versus conversion for final Mn superior to 80,000 g mol−1. The branched and star-branched architectures with high molar mass and low number of branches were fully characterized by size exclusion chromatography. The Mark-Houwink Sakurada relationship and the analysis of the contraction factor ( g′ = ([η]branched/[η]linear)M) confirmed the elaboration of complex P nBA. The zero-shear viscosities of the linear, star-shaped, branched, and star-branched polymers were compared. The modeling of the rheological properties confirmed the synthesis of the branched architectures. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 [ABSTRACT FROM AUTHOR]

Abstract: Since its introduction in 1994, the preparation of ordered porous polymer films by the breath figure (BF) method has received a considerable interest. The so-called “honeycomb” (HC) films exhibit a hexagonal array of micrometric pores obtained by water droplet condensation during the fast solvent evaporation performed under a humid flow. The main focus of this feature article is to describe the recent advances in the design of honeycomb polymer films by the BF process. We first review the recent studies related to the honeycomb film formation through the exploration of different parameters such as the relative humidity, the polymer concentration, the drying rate, the substrate or the role of interfacial tension. The influence of the architecture and microstructure of the polymer is examined through examples. In this contribution, a special attention is given to the recent articles focused on the preparation of elaborate functional honeycomb-structured polymer films obtained via the simple BF method. In this context, we review the preparation of hierarchical HC films showing either sub- or super-structure, the formation of hybrid HC films by self-assembly of nanoparticles or in situ generation of the inorganic matter, the fluorescence in HC films introduced either by a fluorescent polymer or by fluorescent chemical groups, the elaboration of biomaterials from HC films decorated by glycopolymer and/or showing sensing ability and finally the design of functional polymeric surfaces with either stimuli-responsive or superhydrophobic properties. [Copyright &y& Elsevier]

The present work investigates the potentiality of poly(N -vinyl caprolactam) (PVCL)-based thermoresponsive microgels decorated with cationic polymer brushes as drug delivery carriers. The effect of physico-chemical features of the colloids on cell viability response have to be carefully investigated to establish the range of suitable hydrodynamic diameters, crosslinking densities, lengths and ratios of the cationic polyelectrolyte shell which allow their efficient and effective use for cargo loading, transport and delivery. The colloidal stability of all cationic thermoresponsive microgels is maintained over several days of incubation at 37 °C in biological mimicking medium (Dulbecco's Modified Eagle's Medium supplemented with fetal bovine serum). The thin cationic polymer shell covalently anchored does not hinder the all range of microgels to be biocompatible while the higher cytotoxicity of the doxorubicin-loaded microgels on HeLa cells proves their anti-tumor activity. The core-shell PVCL drug delivery nanocarriers allow a sustained release of doxorubicin with a slightly higher viability of HeLa cells incubated in the presence of DOXO-loaded microgels compared to the free DOXO. The nature of the endocytosis pathway is investigated through a quantification of the extent of the cellular survival rate in the presence of various cellular uptake inhibitors. A clathrin-dependent internalization was observed. Unlabelled Image • Core-shell cationic thermoresponsive microgels of different colloidal features. • Stability in different biological mimicking media. • Evaluation of biocompatibility of poly(N-vinylcaprolactam) microgels. • Investigation of the mechanism of cell internalization of microgels • Performances of DOXO-loaded microgels towards Hela cells. [ABSTRACT FROM AUTHOR]

The design of photoactive polymer substrates producing singlet oxygen under visible light irradiation has great technological potential. Aqueous dispersion of novel photoactive core–shell particles was synthesized by surfactant‐free reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization of n‐butyl acrylate. The surface of the nanoparticles is directly decorated thanks to the polymerization‐induced self‐assembly process using a hydrophilic macromolecular chain transfer agent (macro‐CTA) functionalized with the organic photosensitizer. The macro‐CTA was synthesized by statistical copolymerization of acrylic acid and 2‐Rose Bengal ethyl acrylate (RBEA) at 80 °C mediated with 4‐cyano‐4‐[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid. Monitoring polymerization kinetics of RAFT polymerization highlights that increasing amount of RBEA induces retardation, still more pronounced when using the vinylbenzyl Rose Bengal comonomer. The present work provides insight into the quantum yield of singlet oxygen production in water (ΦΔ = 0.2–0.6) for the three types of synthesized polymers (hydrophilic polymer, latex particles, and polymer film). The photoactive core–shell latex particles enabled the easy preparation of photoactive polymer film by simple casting. Monodisperse photoactive core–shell latex particles of 90 nm are synthesized by emulsion polymerization. The poly(n‐butyl acrylate) colloids obtained by polymerization‐induced self‐assembly are decorated with a hydrophilic stabilizing shell of poly(acrylic acid) containing covalently anchored organic photosensitizer. The photoactivity of the film‐forming waterborne latex is kept in the polymer coating producing singlet oxygen under visible light. [ABSTRACT FROM AUTHOR]