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Natural single‐chain nanoparticles (SCNPs) such as proteins have inspired research into the formation and application of synthetic SCNPs. Although the latter can mimic general aspects of the self‐assembly behavior of their biological counterparts, these systems remain relatively understudied. In this respect, a systematic series of amphiphilic statistical copolymers (ASC) of different molecular weights, with a hydrophilic comonomer (methacrylic acid) and varying hydrophobic comonomer to encompass methacrylates of different hydrophobicity, are synthesized. Small‐angle X‐ray scattering studies confirmed that SCNPs are achieved for each copolymer series when dispersed in basified water at 1% w/w. When the aggregation number of the ASC nanoparticles is close to unity the particle shape elongates resulting in a larger particle surface area to volume ratio, allowing more hydrophilic groups to locate on the particle surface tending to keep the particle surface charge density (PSC) constant. Thus, within a series, particle elongation increases with copolymer molecular weight. Structural parameters of SCNPs formed by ASCs composed of hydrophobic components with low partition coefficients are well consistent with predictions obtained from the PSC model. These results highlight the main parameters, namely molecular weight and acid content, responsible for the SCNP formation and provide insight into how specific particle morphology can be targeted. [ABSTRACT FROM AUTHOR]

A series of novel amphiphilic alternating CPEG copolymers were synthesized through an amine–epoxy click reaction comprising aliphatic amine and polyethylene glycol diglycidyl ether (PEGDE). These polymers were characterized in detail via nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) to confirm the successful synthesis. Due to their amphiphilic structure, these polymers display thermoresponsiveness, with tunable cloud points (Tcps) that are adjustable from 20.8 °C to 46.8 °C by altering the side-chain length of the aliphatic amine, varying the mixing ratios of copolymers, the solution's pH, and salt additions. This tunable thermoresponsive behavior positions CPEG copolymers as promising candidates for a range of functional material applications. [ABSTRACT FROM AUTHOR]

The aqueous solution of binary mixtures of amphiphilic copolymers is a potential platform for fabricating mixed polymeric micelles for pharmaceutical applications, particularly in developing drug delivery depots for a poorly water-soluble compound. This study fabricated and investigated binary mixtures of poloxamer 403 (P403) and poloxamer 407 (P407) at varying P403:P407 molar ratios to develop a vehicle for the poorly water-soluble compound, using ibuprofen as a model drug. The cooperative formation of mixed micelles was obtained, and the solubility of ibuprofen in the binary mixtures was enhanced compared to the solubility in pure water and an aqueous single P407 solution. The binary mixture with the P403:P407 molar ratio of 0.75:0.25 at a total polymer concentration of 19% w/v exhibited the temperature dependence of micellization and sol-to-gel characteristics of the thermosensitive mixed micellar gels. It possessed suitable micellization and gelation characteristics for in situ gelling systems. The release of ibuprofen from the thermosensitive mixed micellar depots was sustained through a diffusion-controlled mechanism. The findings can aid in formulating binary mixtures of P403 and P407 to achieve the desired properties of mixed micelles and micellar gels. [ABSTRACT FROM AUTHOR]

Luminescent Ag nanoclusters (Ag NCs) are a promising probe material for sensing and bioimaging applications. However, the intrinsic obstacle of poor water stability and photostability greatly restrict their practical application in biological systems. Herein, we report the intracellular hypochlorite (ClO−) detection with amphiphilic copolymer-modified luminescent Ag NCs with good biocompatibility and photostability. The Ag NCs were synthesized by using chemically inert hydrophobic ligands and then modified with an amphiphilic (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000]) (DSPE-PEG-2000) and sodium dodecyl sulfonate (SDS) for phase transfer. It was found that the approach of the removal of organic solvents during the phase transfer has remarkable influences on the properties of the Ag NCs, including their size, luminescence property, and aqueous stability. Furthermore, the silver core of Ag NCs could be oxidatively damaged by ClO−, thereby causing photoluminescence (PL) quenching. The ClO−-induced PL quenching was specific over the other common reactive oxygen species (ROS) as well as some common interferences. Finally, they have been successfully applied as a fluorescent nanoprobe for detecting exogenous and endogenous ClO− in living cells. [ABSTRACT FROM AUTHOR]

In this work, nine amphiphilic acrylamide copolymers were synthesized using three surface-active co-monomers based on polyethoxylated sorbitan monoesters. The prepared co-monomers and copolymers were characterized by FT-IR, 1H-NMR, and viscosity average molecular weight. Surface/interfacial activities, contact angles, and rheological properties for aqueous solutions of the prepared copolymers were determined. Also, the influence of salts' concentration and temperature variation was investigated. The results showed that incorporating the prepared co-monomers into the copolymers backbone enhanced their properties and capabilities. This improvement was enlarged by increasing the feed ratio and chain length of the attached co-monomers. The copolymers PT20S-3, PT40S-3, and PT60S-3 showed better results and the latter exhibited the best values. They were 37.6 mN.m−1, 6.4 mN.m−1, 15.678° and 338.48 mPa.s for γST, γIFT, CA, and ηapp respectively. The copolymer PT60S-3 was expected to have a prospective use as a chemical EOR agent. [ABSTRACT FROM AUTHOR]

This manuscript serves as the starting point for in-depth research of multicomponent, statistical, methacrylate-based copolymers that potentially mimic the behavior of proteins in aqueous solutions. These synthetic macromolecules are composed of specially chosen comonomers: methacrylic acid (MAA), oligoethylene glycol methyl ether methacrylate (OEGMA475), 2-(dimethylamino)ethyl methacrylate (DMAEMA) and benzyl methacrylate (BzMA). Monomer choice was based on factors such as the chemical nature of pendant functional groups, the polyelectrolyte/polyampholyte and amphiphilic character and the overall hydrophobic–hydrophilic balance (HLB) of the obtained quaterpolymers. Their synthesis was achieved via a one-pot reversible addition fragmentation chain transfer (RAFT) polymerization in two distinct compositions and molecular architectures, linear and hyperbranched, respectively, in order to explore the effects of macromolecular topology. The resulting statistical quaterpolymers were characterized via 1H-NMR and ATR-FTIR spectroscopies. Their behavior in aqueous solutions was studied by dynamic (DLS) and electrophoretic light scattering (ELS) and fluorescence spectroscopy (FS), producing vital information concerning their self-assembly and the structure of the formed aggregates. The physicochemical studies were extended by tuning parameters such as the solution pH and ionic strength. Finally, the quaterpolymer behavior in FBS/PBS solutions was investigated to test their colloid stability and biocompatibility in an in vivo-mimicking, biological fluid environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Henry's constant is obtained from the results of Self-Consistent field calculations to compare the surface affinity of amphiphilic copolymers of various architectures. • Spatial distribution of adsorbing segments along polymer chains has great influence on their adsorption and ultimately on colloidal stabilising properties, when used as dispersants. • For star-like polymers with identical chemical compositions, the surface affinity decreases with increasing number of arms. • For amphiphilic copolymers of the same chemical composition, dendritic polymers have the highest surface affinity. Polymer architecture is known to have significant impact on its adsorption behaviour. Most studies have been concerned with the more concentrated, "close to surface saturation" regime of the isotherm, where complications such as lateral interactions and crowding also additionally affect the adsorption. We compare a variety of amphiphilic polymer architectures by determining their Henry's adsorption constant (k H), which, as with other surface active molecules, is the proportionality constant between surface coverage and bulk polymer concentration in a sufficiently dilute regime. It is speculated that not only the number of arms or branches, but also the position of adsorbing hydrophobes influence the adsorption, and that by controlling the latter the two can counteract each other. The Self-consistent field calculation of Scheutjens and Fleer was implemented to calculate the adsorbed amount of polymer for many different polymer architectures including linear, star and dendritic. Using the adsorption isotherms at very low bulk concentrations, we determined the value of k H for these. It is found that the branched structures (star polymers and dendrimers) can be viewed as analogues of linear block polymers based on the location of their adsorbing units. Polymers containing consecutive trains of adsorbing hydrophobes in all cases showed higher level of adsorption compared to their counterparts, where the hydrophobes were more uniformly distributed on the chains. While increasing the number of branches (or arms for star polymers) also confirmed the known result that the adsorption decreased with the number of arms, this trend can be partially offset by the appropriate choice of the location of anchoring groups. [ABSTRACT FROM AUTHOR]

Mixed micelles from copolymers in aqueous media have emerged as a valuable tool for producing functional polymer nanostructures with applications in nanomedicine, including drug delivery and bioimaging. In this review, we discuss the basics of mixed copolymer micelles' design, structure, and physicochemical properties. We also focus on their utilization in biomedical applications using examples from recent literature. [ABSTRACT FROM AUTHOR]

Water-soluble forms of α-tocopherol (TP) as an effective antioxidant were obtained by encapsulating it into nanoparticles (NPs) of amphiphilic copolymers of N-vinylpyrrolidone with triethylene glycol dimethacrylate (CPL1-TP) and N-vinylpyrrolidone with hexyl methacrylate and triethylene glycol dimethacrylate (CPL2-TP) synthesized by radical copolymerization in toluene. The hydrodynamic radii of NPs loaded with TP (3.7 wt% per copolymers) were typically ca. 50 or 80 nm depending on copolymer composition, media, and temperature. Characterization of NPs was accomplished by transmission electron microscopy (TEM), IR-, and 1H NMR spectroscopy. Quantum chemical modeling showed that TP molecules are capable to form hydrogen bonds with donor groups of the copolymer units. High antioxidant activity of both obtained forms of TP has been found by the thiobarbituric acid reactive species and chemiluminescence assays. CPL1-TP and CPL2-TP effectively inhibited the process of spontaneous lipid peroxidation as well as α-tocopherol itself. The IC50 values of luminol chemiluminescence inhibition were determined. Antiglycation activity against vesperlysine and pentosidine-like AGEs of TP water-soluble forms was shown. The developed NPs of TP are promising as materials with antioxidant and antiglycation activity and can be used in various biomedical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel AEE monomer BDPPA with asymmetric D-A-D' structure was prepared, which has an obvious red-shift emission as compared with PHT and TPE. • The desirable PEG-BD copolymers exhibited excellent biocompatibility and easy cells endocytosis, making them be potential for bioimaging. • Moreover, the effect of D-A-D' structure and ICT effect on the fluorescence property of AEE molecules was revealed. Organic fluorescence dyes with long wavelength emission are attracting people's interests in bioimaging, cells tracing and medical diagnosis due to their many advantages. This contribution exhibited a novel red fluorescent monomer BDPPA with traditional tetraphenylethylene (TPE) and phenothiazine (PHT) as structural units, which showed aggregation-induced emission enhancement (AEE) effects together with the twisted intramolecular charges transfer (TICT) owing to its D-A-D' structure. The maximal emission wavelength of BDPPA located at 592 nm with a shoulder peak at 629 nm. Afterwards, the amphiphilic PEG-BD copolymers was acquired by RAFT polymerization of BDPPA and PEGMA. When the feeding ratio of BDPPA increased from 10.0 % to 20.0 %, the ratio of BDPPA in PEG-BD copolymers correspondingly increased from 9.6 % to 20.9 %. The obtained amphiphilic PEG-BD could self-assemble into fluorescence organic nanoparticles (FONs) with about 150 nm diameter in H 2 O solution. Owing to their TICT effect and D-A-D' structure, both BDPPA and PEG-BD copolymers showed obvious fluorescence in THF solvent, and their intensity firstly decreased and then grew with the increase of water concentration, indicative of the obvious aggregation-induced emission enhancement (AEE). From the calculations of energy quantum, the difference ΔE of BDPPA decreased to 3.09 eV from 3.53 eV of its substrate PHT, which was very favourable for the long wavelength emission and cell imaging. Moreover, due to the long wavelength emission, excellent water solubility and biocompatibility, and AEE effect, the obtained PEG-BD FONs revealed the promising application in biological imaging field. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel gradient-like copolymers were synthesized by RAFT polymerization. • Copolymerization of N -vinylsuccinimide with O-cholesteryl (meth)acrylate was studied. • Amphiphilic poly(vinylsuccinamic acid-co-cholesteryl (meth)acrylate)s were obtained. • Stable nanoparticles of 100–400 nm were produced by several techniques. • Irinotecan delivery systems with high loading and inhibitory activity were developed. Today, biocompatible and bioinspired well-defined copolymers with the ability to form nanoparticles are of great interest as potential drug delivery systems. In this study, we report the synthesis of novel biocompatible copolymers from monomers with different activity and capable of forming gradient copolymers by RAFT polymerization. In particular, the copolymerization of N -vinylsuccinimide (VSI) and O -cholesteryl (meth)acrylate (Ch(M)A) mediated by S,S' -dibenzyl trithiocarbonate (DBTTC) has been thoroughly studied by varying the monomer ratio and the ratio of monomer to RAFT agent. Important dependencies such as molecular weight and monomer conversion versus time, and molar fraction of monomer units as a function of monomer conversion were investigated. The obtained copolymers were thoroughly characterized using a number of physicochemical methods such as 1H NMR, 1H–13C HSQC and ATR-IR-spectroscopy, size-exclusion chromatography, static and dynamic light-scattering, as well as thermogravimetric analysis. In addition, the reactivity ratios of VSI and ChMA were determined and the dyad and triad compositions of the copolymers were calculated from the obtained values. The synthesized P(VSI- co -Ch(M)A) were subjected to selective hydrolysis of succinimide ring to convert it into succinamic acid. This approach yields a set of bioinspired amphiphilic copolymers based on N -vinylsuccinamic acid (VSAA) and Ch(M)A. The synthesized series of P(VSI- co- Ch(M)A) and P(VSAA- co -Ch(M)A) were used to obtain nanoparticles by nanoprecipitation or self-assembly via direct dissolution in aqueous medium. In addition, the method of surface hydrolysis of VSI units in pre-formed P(VSI- co- Ch(M)A) nanoparticles was applied to produce nanoparticles with hydrophilic negatively charged surface and enhanced stability. All techniques were optimized to prepare nanoparticles with characteristics suitable for systems considered for drug delivery. Successful loading of the antitumor drug irinotecan into nanoparticles was achieved with high encapsulation efficacies. The storage stability of empty and irinotecan loaded nanoparticles were studied in various media (water, saline solution, serum containing cell culture medium) under room and refrigerator conditions. The developed empty nanoparticles exhibited low rate of uptake by macrophages and low cytotoxicity to irinotecan-sensitive colon cancer cells (Caco-2). In turn, the irinotecan-loaded nanoparticles demonstrated inhibitory activity against Caco-2 cells comparable to the free drug. [ABSTRACT FROM AUTHOR]

In this study, reversible addition-fragmentation chain transfer (RAFT) polymerization is utilized in order to synthesize novel hyperbranched poly(oligoethylene glycol) methyl ether methacrylate-co-tert-butyl methacrylate-co-methacrylic acid) (H-[P(OEGMA-co-tBMA-co-MAA)]) copolymers in combination with selective hydrolysis reactions. The copolymers showing amphiphilicity induced by the polar OEGMA and hydrophobic tBMA monomeric units, and polyelectrolyte character due to MAA units, combined with unique macromolecular architecture were characterized by physicochemical techniques, such as size exclusion chromatography (SEC) and 1H-NMR spectroscopy. The hyperbranched copolymers were investigated in terms of their ability to self-assemble into nanostructures when dissolved in aqueous media. Dynamic light scattering and fluorescence spectroscopy revealed multimolecular aggregates of nanoscale dimensions with low critical aggregation concentration, the size and mass of which depend on copolymer composition and solution conditions, whereas zeta potential measurements indicated pH sensitive features. In addition, aiming to evaluate their potential use as nanocarriers, the copolymers were studied in terms of their drug encapsulation and protein complexation ability utilizing curcumin and lysozyme, as a model hydrophobic drug and a model cationic protein, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Symmetric 14-armed βCD-cored star amphiphilic block copolymers βCD-(PBO-PGL) 14 were obtained with tunable arm block lengths, high purity and low polydispersity. • Star copolymers βCD-(PBO-PGL) 14 have similar self-assembly behavior compared to linear analogues (PGL-PBO-PGL). • Polymersomes made from βCD-(PBO-PGL) 14 have different ion permeability behavior compared to linear analogues (PGL-PBO-PGL). For polymersome-based nanoreactor purposes, we herein present the synthesis and characterization of well-defined star amphiphilic copolymers composed of a beta -cyclodextrin (βCD) core and seven poly(butylene oxide)- block -polyglycidol (PBO-PGL) arms per side (βCD-(PBO-PGL) 14). The self-assembly behavior of 14-armed βCD-(PBO-PGL) 14 and PGL-PBO-PGL (linear analogues without the βCD segment) was investigated using scattering techniques for comparison. The morphologies, including vesicles and micelles, are governed by the hydrophobic-to-hydrophilic (weight) ratio, regardless of the polymer architecture (linear or star). Interestingly, despite notable differences in polymer conformation, the produced supramolecular structures were evidenced to be fairly similar on the structural point of view. We subsequently investigated the ion permeability of the membranes of the self-assemblies focusing on the impact of the presence of βCD. The results demonstrated that the βCD-containing vesicular membranes are less permeable to H+, compared with βCD-free vesicular membranes. The presence of βCD in planar membranes also influences the K+Cl− permeability to some extent. Thus, βCD-containing membranes can be considered as potential candidates in designing nano-containers towards applications where precise changes in environmental pH are required. [ABSTRACT FROM AUTHOR]

A series of nanoparticles (NPs) with a hydrodynamic radius from 20 to 100 nm in PBS was developed over the solubilization of hydrophobic dye methyl pheophorbide a (chlorin e6 derivative) by amphiphilic copolymers of N-vinylpyrrolidone with (di)methacrylates. Photophysical properties and biological activity of the NPs aqueous solution were studied. It was found that the dye encapsulated in the copolymers is in an aggregated state. However, its aggregation degree decreases sharply, and singlet oxygen quantum yield and the fluorescence signal increase upon the interaction of these NPs with model biological membranes—liposomes or components of a tissue homogenate. The phototoxic effect of NPs in HeLa cells exceeds by 1.5–2 times that of the reference dye chlorin e6 trisodium salt—one of the most effective photosensitizers used in clinical practice. It could be explained by the effective release of the hydrophobic photosensitizer from the NPs into biological structures. The demonstrated approach can be used not only for the encapsulation of hydrophobic photosensitizers for PDT but also for other drugs, and N-vinylpyrrolidone amphiphilic copolymers show promising potential as a modern platform for the design of targeted delivery vehicles. [ABSTRACT FROM AUTHOR]

This paper provides a review of the literature on the use of Pluronic® triblock copolymers for drug encapsulation over the last 10 years. A special focus is given to the progress of drug delivery systems (e.g. , micelles, liposomes, micro/nanoemulsions, hydrogels and nanogels, and polymersomes and niosomes); the beneficial aspects of Pluronic® triblock copolymers as biological response modifiers and as pharmaceutical additives, adjuvants, and stabilizers, are also discussed. The advantages and limitations encountered in developing site-specific targeting approaches based on Pluronic-based nanostructures in cancer treatment are highlighted, in addition to innovative examples for improving tumor cytotoxicity while reducing side effects. [Display omitted] [ABSTRACT FROM AUTHOR]

Nanosized systems of DOX with antitumor activity on the base of micelle-like particles of amphiphilic thermosensitive copolymers of N-vinylpyrrolidone (VP) with triethylene glycol dimethacrylate (TEGDM), and N-vinylpyrrolidone and methacrylic acid (MAA) with TEGDM were explored. They were investigated in aqueous solutions by electron absorption spectroscopy, dynamic light scattering and cyclic voltammetry. Experimental data and quantum-chemical modeling indicated the formation of a hydrogen bond between oxygen-containing groups of monomer units of the copolymers and H-atoms of OH and NH2 groups of DOX; the energies and H-bond lengths in the considered structures were calculated. A simulation of TDDFT spectra of DOX and its complexes with the VP and TEGDM units was carried out. Electrochemical studies in PBS have demonstrated that the oxidation of encapsulated DOX appeared to be easier than that of the free one, and its reduction was somewhat more difficult. The cytotoxicity of VP-TEGDM copolymer compositions containing 1, 5 and 15 wt% DOX was studied in vitro on HeLa cells, and the values of IC50 doses were determined at 24 and 72 h of exposure. The copolymer compositions containing 5 and 15 wt% DOX accumulated actively in cell nuclei and did not cause visual changes in cell morphology. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated that films of sequence‐controlled amphiphilic copolymers display contact angles that depend on microblock size. This suggests that microblock length may provide a means of tuning surface and interfacial properties. In this work, the interfacial rheology of a series of sequence‐controlled copolymers, prepared through the addition of bicyclo[4.2.0]oct‐1(8)‐ene‐8‐carboxamide (monomer A) and cyclohexene (monomer B) to generate sequences up to 24 monomeric units composed of (AmBn)i microblocks, where m, n, and i range from 1 to 6. Interfacial rheometry is used to measure the mechanical properties of an air–water interface with these copolymers. As the microblock size increases, the interfacial storage modulus, G′, increases, which may be due to an increase in the size of interfacial hydrophobic domains. Small‐angle X‐ray scattering shows that the copolymers have a similar conformation in solution, suggesting that any variations in the mechanics of the interface are due to assembly at the interface, and not on solution association or bulk rheological properties. This is the first study demonstrating that microblock size can be used to control interfacial rheology of amphiphilic copolymers. Thus, the results provide a new strategy for controlling the dynamics of fluid interfaces through precision sequence‐controlled polymers. [ABSTRACT FROM AUTHOR]

Co-delivery of chemotherapeutics in cancer treatment has been proven essential for overcoming multidrug resistance and improving the outcome of therapy. We report the synthesis of amphiphilic copolymers of N-vinyl-2-pyrrolidone and allyl glycidyl ether of various compositions and demonstrate that they can form nanoaggregates capable of simultaneous covalent immobilization of doxorubicin by the epoxy groups in the shell and hydrophobic-driven incorporation of paclitaxel into the core of nanoparticles. The structure of the obtained copolymers was characterized by 13C NMR, IR, and MALDI spectroscopy, as well as adsorption at the water/toluene interface. A linear increase in the number-average molecular weight of amphiphilic copolymers and a decrease in the number-average diameter of macromolecular aggregates with an increase in the ratio N-vinyl-2-pyrrolidone/allyl glycidyl ether were observed. The assembled nanocarriers were characterized by DLS. The reported novel nanocarriers can be of interest for delivery and co-delivery of a wide range of pharmacological preparations and combined therapy for cancer and other deceases. [ABSTRACT FROM AUTHOR]

In this research, the development and investigation of novel nanoobjects based on biodegradable random polypeptides and synthetic non-degradable glycopolymer poly(2-deoxy-2-methacrylamido-d-glucose) were proposed as drug delivery systems. Two different approaches have been applied for preparation of such nanomaterials. The first one includes the synthesis of block-random copolymers consisting of polypeptide and glycopolymer and capable of self-assembly into polymer particles. The synthesis of copolymers was performed using sequential reversible addition-fragmentation chain transfer (RAFT) and ring-opening polymerization (ROP) techniques. Amphiphilic poly(2-deoxy-2-methacrylamido-d-glucose)-b-poly(l-lysine-co-l-phenylalanine) (PMAG-b-P(Lys-co-Phe)) copolymers were then used for preparation of self-assembled nanoparticles. Another approach for the formation of polypeptide-glycopolymer particles was based on the post-modification of preformed polypeptide particles with an oxidized glycopolymer. The conjugation of the polysaccharide on the surface of the particles was achieved by the interaction of the aldehyde groups of the oxidized glycopolymer with the amino groups of the polymer on particle surface, followed by the reduction of the formed Schiff base with sodium borohydride. A comparative study of polymer nanoparticles developed with its cationic analogues based on random P(Lys-co-d-Phe), as well as an anionic one—P(Lys-co-d-Phe) covered with heparin––was carried out. In vitro antitumor activity of novel paclitaxel-loaded PMAG-b-P(Lys-co-Phe)-based particles towards A549 (human lung carcinoma) and MCF-7 (human breast adenocarcinoma) cells was comparable to the commercially available Paclitaxel-LANS. [ABSTRACT FROM AUTHOR]

Here, we report on the evaluation of critical packing parameters, PC, of l-tyrosine and ethylene glycol (PEG) amphiphilic block copolymers. The copolymers were synthesized via l-tyrosine-N-carboxyanhydride ring-opening polymerization using different amino-terminated PEGs as macroinitiators. The size and shape of their associates formed in water were investigated by transmission electron microscopy and dynamic and static light scatterings. The copolymers containing 20–30 wt. % of Tyr formed rod-like micelles. The copolymers with 30–50 wt. % of Tyr formed spherical vesicles, while those with 50–80 wt. % Tyr formed irregularly shaped polymeric nanoparticles. PC of the copolymers was estimated as the ratio of the van der Waals volume of the hydrophobic block (V) to its length (L) and the cross-sectional area of the polar block (SH). The values of SH for each copolymer were calculated according to the equation obtained from the correlation analysis of the published data. The hydrophobic block length L was calculated in three ways, i.e., assuming that polytyrosine adopts (1) stretched, (2) amyloid hairpin, or (3) Gaussian coil conformation. In the latter case, the best match of the calculated PC values with the morphology of the copolymer assemblies was observed. [ABSTRACT FROM AUTHOR]

We report the synthesis and the micellar self‐assembly in aqueous media of novel amphiphilic block copolymers. The copolymers consist of a poly[(methyl methacrylate)‐co‐(hydroxypropyl methacrylate)] statistical copolymer block and a poly[oligo(ethylene glycol) methyl ether methacrylate] block, and were synthesized by reversible addition–fragmentation chain transfer polymerization. The amphiphilic P(MMA‐co‐HPMA)‐b‐POEGMA block copolymers contain monomers of differing polarity and in varying ratios. Furthermore, HPMA segments are chosen in order to enhance hydrogen bonding interactions within the core of spherical micelles formed by the copolymers in aqueous media, as evidenced by light scattering and fluorescence spectroscopy studies. The amphiphilic copolymers are able to encapsulate the hydrophobic drugs curcumin and indomethacin as found using light scattering and spectroscopic methods. © 2021 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Polymer micelles obtained from amphiphilic copolymers have emerged as promising drug vehicles given their nanometric size, simple release, and encapsulation mechanisms. Nevertheless, their lack of functional groups that interact with the drugs causes low encapsulation capacities. In this paper, the synthesis of an amphiphilic copolymer composed of polyethylene glycol and a poly(ester-co-carbonate) segment containing alkyne groups, as well as its coupling in a post-synthesis stage with other azido-functionalized substances through click reaction, is reported. The modifiers can be intentionally selected to favor polymer–drug compatibility for the rational development of drug delivery systems. Herein, amphotericin B was taken as a model because it is a water-insoluble and highly toxic drug. Cholesterol and oleic acid were employed as modifiers of the copolymers and provided improvements on the drug loading capacity compared with an unmodified copolymer. While oleic acid modified structures presented the highest encapsulation when five units were grafted; a single cholesterol molecule gave the highest enhancement. [ABSTRACT FROM AUTHOR]

Poly(tert‐butyl acrylate) (PtBA) is a versatile hydrophobic macromolecule usually preferred in the development of new materials for a host of applications. PtBA homopolymers with well‐defined structure and controlled molecular weight in a wide range were successfully synthesized via radiation‐induced reversible addition–fragmentation chain transfer (RAFT) polymerization in the presence of a trithiocarbonate type RAFT agent. The polymerization of tBA was performed under 60Co γ‐irradiation in the presence of 2‐(dodecylthiocarbonothioylthio)‐2‐methylpropionic acid (DDMAT) as the RAFT agent in toluene at room temperature with three [tBA]/[DDMAT] ratios (400, 600 and 1000) and different irradiation times. Radiation‐induced polymerization of tBA displayed controlled free radical polymerization characteristics: a narrow molecular weight distribution (Mw/Mn ~ 1.1), pseudo first order kinetics and controlled molecular weights. The system followed the RAFT polymerization mechanism even at very low amounts of RAFT agent ([tBA]/[DDMAT] = 1000), and molecular weights up to 113 900 with narrow dispersity (Ð =1.06) were obtained. PtBA was further hydrolysed into different amphiphilic PtBA‐co‐poly(acrylic acid) (PAA) copolymers by low (27.5%) and high (77.3%) degrees of hydrolysis. The pH sensitivity of the two copolymers was investigated by dynamic light scattering at pH 2 and pH 9 (above and below the pKa value of PAA) and their hydrodynamic diameters and zeta potential values were determined. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Amphiphilic copolymers with poly (alkyl acrylate) as hydrophobic and poly (acrylic acid) (AA) as hydrophilic block have been synthesised. The alkyl chain was varied from butyl to dodecyl, thereby varying systematically the polarity of the hydrophobic block whose length was between 35 and 70, while the PAA block had ~ 100 units. Such relatively short amphiphiles should equilibrate quickly in aqueous solution, and their corresponding self-assembly properties were characterised by means of critical micelle concentration (cmc) determination. Detailed information regarding the aggregate structures was obtained by static light scattering (SLS) and small angle neutron scattering (SANS). This could be correlated with the molecular architecture of the copolymers and the degree of ionisation of the PAA block. Generally, it is found that the aggregation numbers become smaller upon fully charging the PAA head group and only for dodecyl acrylate really well-defined micellar aggregates are formed. This means that the extent of hydrophobicity of the alkyl acrylate block and its length determine in a clear fashion the propensity for micelle formation and the mass and aggregation number of the formed micelles. [ABSTRACT FROM AUTHOR]

ABA and BAB triblock amphiphilic copolymers based on sucrose methacrylate and methyl methacrylate are synthesized by sequential reversible addition–fragmentation chain transfer polymerization using S,S′‐bis(R,R′‐dimethyl‐R′′‐acetic acid)‐trithiocarbonate as a chain transfer agent. The copolymers present narrow molar mass dispersity, controlled molar mass and architecture as determined by gel permeation chromatography and 1H and 13C nuclear magnetic resonance. The copolymers with molar and mass fractions of poly(sucrose methacrylate) block ranging from 1 to 22 mol% and 3 to 52 wt%, respectively, and different molar masses present characteristics of a surfactant such as self‐assembly. The self‐assembly of the triblock copolymers in water, N,N‐dimethylformamide (DMF), dichloromethane, tetrahydrofuran, or benzene results mostly in vesicles as confirmed by scanning electron microscopy images and small‐angle X‐ray of the dispersions. Moreover, the copolymers present the capability to stabilize aromatic molecules (Nile Red dye) and nonpolar solvents in an aqueous phase and polar ionic molecules (methylene blue) and water in a nonpolar medium, suggesting the potential for application in drug encapsulation, environmental remediation systems, and molecular extraction in liquid–liquid immiscible systems, for example. Films prepared by casting from copolymer solutions in DMF present a lamellar structure with the lamellar thickness varying according to the copolymer molar mass. [ABSTRACT FROM AUTHOR]

Hydrophobically associating hydrogels based on copolymers of a watersoluble monomer with a fluoroacrylate or fluoromethacrylate possess microphaseseparated morphologies that provide unique properties. Physical crosslinks in these hydrogels involve hydrophobic bonds between fluoro(meth)acrylate groups that associate into 2-6-nm-diameter core-shell nanodomains that represent multifunctional crosslinks. These hydrogels exhibit exceptional mechanical properties and fracture toughness values approaching 104 J/m², are extrudable, and show self-healing behavior of the microstructure. This chapter reviews the characteristics of these microphase-separated, hydrophobically associating hydrogels and discusses potential applications of these materials as injectable in situ forming hydrogels, electrospun fiber mats suitable for tissue scaffolds, controlled drug release, antifreeze materials, and shape memory hydrogels. [ABSTRACT FROM AUTHOR]

• Controlled synthesis of amphiphilic copolymer based on LMA and PEGMA monomers. • Effect of compositional drift in thermal and emulsifier properties. • Interesting bulk rheological properties. • Incorporation of toluene in formed micelles. Evaluation of loading capacity using 2D NMR. In this work we study the synthesis and properties of copolymers constituted of lauryl methacrylate and poly(ethylene glycol) methyl ether methacrylate monomers, prepared by atom transfer radical copolymerization in the entire composition range (with low and high monomer conversion). We propose a description of the copolymer microstructure, and evaluate the composition drift effect in the thermal and solution properties of the obtained copolymers. Nuclear magnetic resonance (NMR) was used to determine the chemical composition of the copolymers, while differential scanning calorimetry and themogravimetric analysis was employed to understand the thermal chracteristics. Rheological studies were conducted to obtain the viscosity and viscoelastic properties that were correlated with thermal transitions at different temperatures. Finally, dynamic light scattering (DLS) and surface tension measurements were used to evaluate the copolymer solution properties. The incorporation of an oil phase in the self-assembled aggregates was evaluated by DLS and characterized by atomic force microscopy, diffusion-ordered spectroscopy NMR and nuclear Overhauser effect NMR spectroscopy. Our results suggest a longer sequence of LMA units in the copolymer chain and a drift effect in the case of high monomer conversions. A clear dependence on copolymer composition and microstructure to disperse an oil phase in water was observed. We believe that these results bring valuable knowledge that advances the field of macrosurfactants as well as their potential applications in oil recovery and other industrial processes. [ABSTRACT FROM AUTHOR]

The synthesis and aqueous solution properties of copolymers comprised of N - vinylpyrrolidone (NVP) and vinyl laurate (VL) with three different architectures is reported. By using reversible addition-fragmentation chain-transfer (RAFT) polymerization, statistical, forced gradient, and block copolymers were synthesized with varying compositions and molecular weights. Surface tension, critical micelle concentrations (CMCs) and micelle size were determined, and related to copolymer composition, molecular weight and architecture. It was observed that more block-like polymer architectures produced from the block copolymerizations and forced gradient copolymerizations were likely to self-assemble in solution, indicating that the degree and placement of the hydrophilic (NVP) and hydrophobic (VL) monomer units are important in predicting solution behavior of such copolymers. [ABSTRACT FROM AUTHOR]

Supramolecular self-assembly of polymeric molecules for sharp-pH-sensitive (SPS) nanoparticles is an especially important application in biology. Here, amphiphilic polypeptide copolymers are synthesized and spontaneously assembled to micelles in aqueous solution, and protonation of the tertiary amine groups in the side-chain of the copolymer under weak acid causes the micelle disassembly, which is sharp-pH-sensitive, and the responsive pHs can be adjusted by adding salts. Size and morphologic change of the polymeric micelles are characterized by means of dynamic lighting scattering, transmission electron microscope (TEM), and atomic force microscope (AFM) in sequential pH alterations. It is found that the Hofmeister ions play a key factor in controlling the subtle interaction of different noncovalent bonds among polypeptide molecules during their self-assembly or disassembly. The physical property exploration of the SPS micelles may provide a new chance for the development of dynamic, complex nanostructures in various pH-responsive applications. [ABSTRACT FROM AUTHOR]

Amphiphilic copolymers were obtained by grafting azide-terminated polyglycidol, poly(ethylene oxide), or poly(2-hydroxyethyl acrylate) chain segments onto alkyne-functionalized arborescent poly( -benzyl L-glutamate) (PBG) cores of generations G1--G3 via copper(I)-catalyzed azide--alkyne Huisgen cycloaddition (CuAAC) coupling. The alkyne functional groups on the arborescent PBG substrates were either distributed randomly or located exclusively at the end of the chains added in the last grafting cycle of the core synthesis. The location of these coupling sites influenced the ability of the arborescent copolymers to form unimolecular micelles in aqueous environments: The chain end grafting approach provided enhanced dispersibility in aqueous media and favored the formation of unimolecular micelles in comparison to random grafting. This is attributed to a better defined core-shell morphology for the copolymers with end-grafted shell segments. Aqueous solubility also depended on the type of material used for the shell chains. Coupling by CuAAC opens up possibilities for grafting a broad range of polymers on the arborescent substrates under mild conditions. [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]

Background Mimicking cell membranes by simple models based on the reconstitution of membrane proteins in lipid bilayers represents a straightforward approach to understand biological function of these proteins. This biomimetic strategy has been extended to synthetic membranes that have advantages in terms of chemical and mechanical stability, thus providing more robust hybrid membranes. Scope of the review We present here how membrane proteins and biopores have been inserted both in the membrane of nanosized and microsized compartments, and in planar membranes under various conditions. Such bio-hybrid membranes have new properties (as for example, permeability to ions/molecules), and functionality depending on the specificity of the inserted biomolecules. Interestingly, membrane proteins can be functionally inserted in synthetic membranes provided these have appropriate properties to overcome the high hydrophobic mismatch between the size of the biomolecule and the membrane thickness. Major conclusion Functional insertion of membrane proteins and biopores in synthetic membranes of compartments or in planar membranes is possible by an appropriate selection of the amphiphilic copolymers, and conditions of the self-assembly process. These hybrid membranes have new properties and functionality based on the specificity of the biomolecules and the nature of the synthetic membranes. General significance Bio-hybrid membranes represent new solutions for the development of nanoreactors, artificial organelles or active surfaces/membranes that, by further gaining in complexity and functionality, will promote translational applications. This article is part of a Special Issue entitled: Lipid order/lipid defects and lipid-control of protein activity edited by Dirk Schneider. [ABSTRACT FROM AUTHOR]

Copolymers of poly(ε-caprolactone) containing zwitterionic sulfobetaine may be used as biomedical materials. The interaction of these materials with proteins is rarely reported. In this study, amphiphilic copolymers PCL-PDEAS, PCL-PEG200-PDEAS, and PCL-PEG400-PDEAS, which contained poly{N-[2-(methacryloyloxy)ethyl]-N,N-diethyl-N-(3-sulfopropyl)-ammonium} (PDEAS), were designed and synthesized in order to explore interaction of these materials and their micelles with proteins. The structure of the copolymers was confirmed by H-NMR, Fourier transform infrared spectroscopy (FTIR), and element analysis (EA). The copolymers could form either films or micelles. The adsorption of bovine serum albumin (BSA) and fibrinogen (Fg) on the copolymer films and their micelles was studied. The results showed that BSA adsorbed on the films presented different tendencies from their micelle formulation. The protein adsorption may be related to the hydration in the shell of the micelles and the electrostatic interaction between the charges of zwitterion and the protein. The reason for the different amounts of protein adsorption between film and micelle formulation is the difference of molecular chain arrangement and charge distribution of PCLDEAS copolymer. [ABSTRACT FROM AUTHOR]

We described the fabrication of functional and microstructured surfaces from polymer blends by spray deposition. This simple technique offers the possibility to simultaneously finely tune the microstructure as well as the surface chemical composition. Whereas at lower polymer concentration, randomly distributed surface micropatterns were observed, an increase of the concentration leads to significant changes on these structures. On the one hand, using pure homopolystyrene fiber-like structures were observed when the polymer concentration exceeded 30 mg/mL. Interestingly, the incorporation of 2,3,4,5,6-pentafluorostyrene changed the morphology, and, instead of fibers, micrometer size particles were identified at the surface. These fluorinated microparticles provide superhydrophobic properties leading to surfaces with contact angles above 165|. Equally, in addition to the microstructures provided by the spray deposition, the use of thermoresponsive polymers to fabricate interfaces with responsive properties is also described. Contact angle measurements revealed variations on the surface wettability upon heating when blends of polystyrene and polystyrene-b-poly(dimethylaminoethyl methacrylate) are employed. Finally, the use of spraying techniques to fabricate gradient surfaces is proposed. Maintaining a constant orientation, the surface topography and thus the contact angle varies gradually from the center to the edge of the film depending on the spray angle. [ABSTRACT FROM AUTHOR]

Poly ((ethylene oxide)- b-(propylene oxide)- b-(ethylene oxide)) triblock copolymers commonly known as poloxamers or Pluronics constitute an important class of nonionic, biocompatible surfactants. Here, a method is reported to incorporate two acid-labile acetal moieties in the backbone of poloxamers to generate acid-cleavable nonionic surfactants. Poly(propylene oxide) is functionalized by means of an acetate-protected vinyl ether to introduce acetal units. Three cleavable PEO-PPO-PEO triblock copolymers ( Mn,total = 6600, 8000, 9150 g·mol−1; Mn,PEO = 2200, 3600, 4750 g·mol−1) have been synthesized using anionic ring-opening polymerization. The amphiphilic copolymers exhibit narrow molecular weight distributions ( Ð = 1.06-1.08). Surface tension measurements reveal surface-active behavior in aqueous solution comparable to established noncleavable poloxamers. Complete hydrolysis of the labile junctions after acidic treatment is verified by size exclusion chromatography. The block copolymers have been employed as surfactants in a miniemulsion polymerization to generate polystyrene (PS) nanoparticles with mean diameters of ≈200 nm and narrow size distribution, as determined by dynamic light scattering and scanning electron microscopy. Acid-triggered precipitation facilitates removal of surfactant fragments from the nanoparticles, which simplifies purification and enables nanoparticle precipitation 'on demand.' [ABSTRACT FROM AUTHOR]

The dispersion of carbon nanoparticles in water was investigated using dispersants based on block copolymers of poly(acrylic acid) (PAA) and poly(amideimide) (PAI) or a homopolymer of PAA. A diblock copolymer (PAA- block-PAI), triblock copolymer (PAA- block-PAI- block-PAA), and hetero-arm star block copolymer (PAAPAI) with similar molecular weights and PAA contents were used as dispersants. The dispersion of solutions with these polymers was investigated by ζ-potential measurements and transmission electron microscopy. The adsorption of PAI onto carbon nanoparticles was observed. The dispersion of carbon nanoparticles was measured using dynamic light scattering and UV-vis spectroscopy. The dispersibility of carbon nanoparticles increased through the series of copolymers (from most to least dispersed): PAAPAI, PAA- block-PAI, PAA- block-PAI- block-PAA, and homo-PAA. PAA-PAI copolymers behaved as effective dispersants for carbon nanoparticles in water. The presence of a hydrophobic block was essential for dispersion. The architecture of the block copolymers also influenced the dispersion of nanoparticles. Locally concentrated regions of PAA exhibited repulsive interactions, causing dispersion of nanoparticles. PAAPAI demonstrated the greatest potential as an anode binder in lithium-ion batteries because it functioned as a dispersant for the conductive additive. [ABSTRACT FROM AUTHOR]

Poly(ethylene oxide)- block -poly(methyl methacrylate) amphiphilic copolymers were prepared via electrochemically mediated atom transfer radical polymerization ( e ATRP) utilizing only 50 ppm of Cu II complex, rather than previously reported concentrations of catalyst of ca. 1,000–30,000 ppm. The copolymers were also prepared via a simplified electrochemically mediated ATRP ( se ATRP) procedure utilizing an aluminum wire sacrificial anode as a counter electrode, which was directly immersed into the reaction flask, without the need of its separation. This se ATRP system works under both potentiostatic and galvanostatic conditions. In each case the polymerization results showed similar molecular weight evolution while maintaining a narrow molecular weight distribution throughout the reactions. The successful chain extension and formation of block copolymers confirmed the living nature of the poly(alkyl methacrylates) prepared by e ATRP and se ATRP. [ABSTRACT FROM AUTHOR]

Poly (diethyl vinylphosphonate-co-2-chloroethyl methacrylate) (P(DEVP-co-CEMA)) copolymers are synthesized by free radical copolymerization initiated by benzoyl peroxide. The reactivity ratios for the free radical copolymerization of CEMA (M1) and DEVP (M2) arer1 = 19.45 andr2 = 0.11, respectively. The desired amphiphilic copolymers with relatively low polydispersity index (PDI) and different DEVP contents are isolated and purified from the reaction mixtures through precipitation fractionation. The structures and molecular characteristics of the obtained products are characterized by1H NMR, FTIR, and SEC analysis. All of these fractionated copolymers have a unimodal distribution and moderate PDI. The thermal properties of the P(DEVP-co-CEMA) copolymers are investigated by TGA and differential scanning calorimetry (DSC) measurements. Single glass transition temperature (Tg) appears in the DSC profiles differing from the existence of twoTgs in the blend of poly (diethyl vinylphosphonate) and poly (2-chloroethyl methacrylate), which indicates the random structure of the copolymers. The MALDI–ToF mass analysis further reveals that DEVP and CEMA units are randomly distributed in the copolymer chains. The self-assembly behavior of the P(DEVP-co-CEMA) copolymers in aqueous solution is preliminarily investigated. [ABSTRACT FROM AUTHOR]

Microbial biofilms are known to support a number of human infections, including those related to medical devices. This work is focused on the development of novel dual-function amphiphilic random copolymers to be employed as coatings for medical devices. Particularly, copolymers were obtained by polymerization of an antimicrobial cationic monomer (bearing tertiary amine) and an antioxidant and antimicrobial hydrophobic monomer (containing hydroxytyrosol, HTy). To obtain copolymers with various amphiphilic balance, different molar ratios of the two monomers were used. 1 H NMR and DSC analyses evidenced that HTy aromatic rings are able to interact with each other leading to a supra-macromolecular re-arrangement and decrease the copolymer size in water. All copolymers showed good antioxidant activity and Fe 2+ chelating ability. Cytotoxicity and hemolytic tests evidenced that the amphiphilic balance, cationic charge density and polymer size in solution are key determinants for polymer biocompatibility. As for the antimicrobial properties, the lowest minimal inhibitory concentration (MIC = 40 μg/mL) against Staphylococcus epidermidis was shown by the water-soluble copolymer having the highest HTy molar content (0.3). This copolymer layered onto catheter surfaces was also able to prevent staphylococcal adhesion. This approach permits not only prevention of biofilm infections but also reduction of the risk of emergence of drug-resistant bacteria. Indeed, the combination of two active compounds in the same polymer can provide a synergistic action against biofilms and suppress reactive species oxygen (ROS), known to promote the occurrence of antibiotic resistance. [ABSTRACT FROM AUTHOR]

ABSTRACT Four families of hyperbranched amphiphilic block copolymers of styrene (Sty, less polar monomer) and 2-vinylpyridine (2VPy, one of the two more polar monomers) or 4-vinylpyridine (4VPy, the other polar monomer) were prepared via self-condensing vinyl reversible addition-fragmentation chain transfer polymerization (SCVP-RAFT). Two families contained 4VPy as the more polar monomer, one of which possessing a Sty -b-4VPy architecture, and the other possessing the reverse block architecture. The other two families bore 2VPy as the more polar monomer and had either a 2VPy -b-Sty or a Sty -b-2VPy architecture. Characterization of the hyperbranched block copolymers in terms of their molecular weights and compositions indicated better control when the VPy monomers were polymerized first. Control over the molecular weights of the hyperbranched copolymers was also confirmed with the aminolysis of the dithioester moiety at the branching points to produce linear polymers with number-average molecular weights slightly greater than the theoretically expected ones, due to recombination of the resulting thiol-terminated linear polymers. The amphiphilicity of the hyperbranched copolymers led to their self-assembly in selective solvents, which was probed using atomic force microscopy and dynamic light scattering, which indicated the formation of large spherical micelles of uniform diameter. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1310-1319 [ABSTRACT FROM AUTHOR]

In previous works, poly(D,L-lactide-co-εCL-poly(ethylene glycol) (poly(D,L-La-co-αPEGεCL) amphiphilic graftcopolymers were successfully synthesized according to a copper azide-alkyne cycloaddition (CuAAC) strategy. This paper aims at reporting on the behavior of this amphiphilic copolymer in water, which was not studied in the previous paper. Moreover, the ability of the copolymer to stabilize a PLA nanoparticles aqueous suspension is presented. For this purpose, dynamic light scattering (DLS) and transmission electron microscopy (TEM) are proposed to characterize the nanoparticles in solution. Otherwise, the strategy developed for the synthesis of the amphiphilic copolymers was adapted and extended to the synthesis of PLA-based degradable hydrogel, potentially applicable as drug-loaded degradable polymer implant. [ABSTRACT FROM AUTHOR]

Casein-based emulsion for film former was innovatively prepared via emulsifier-free emulsion polymerization by employing self-made amphiphilic copolymers (A m B n C o ) as the stabilizer. Structure of A m B n C o was confirmed by 1 H NMR spectrometry. Stability of the as-prepared emulsion in different concentrations of A m B n C o was evaluated by measuring their droplet size, microstructure and viscosity. The results indicated that the obtained particles were 40–50 nm in size with uniform size distribution, and exhibited obvious core–shell structure. The emulsion containing 1.0 wt% of A m B n C o presented superior storage stability. [ABSTRACT FROM AUTHOR]

A simple 'green synthesis' of noble metal nanoparticles by direct reaction between Dextran-graft-lactone copolymers and metal salts without the need to separately add reducing and stabilizing agents was carried out. The effects of the composition, molecular weights of copolymers and solvents on the characteristics of the nanoparticles were considered. The amphiphilic character of the copolymers seems to be an important factor in the results of the synthesis. According to the results, general correlations between experimental parameters of synthesis and characteristics of the obtained nanoparticles were established. Techniques such as, transmission electron microscopy, scanning electron microscopy, UV-visible spectroscopy, Zeta Potential, dynamic light scattering and Fourier transform Infrared Spectroscopy, were used for the characterization of the products. The results indicate the possibility of control of the characteristics of the nanostructured material. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

[Display omitted] • RAFT polymerization of well-defined coumarin bearing amphiphilic copolymers. • Coumarin functionalized unique amphiphilic copolymers as repeating units on the chain. • Temperature responsive Pluronic F127 with light-responsive amphiphilic copolymers. • Designing mechanically strong injectable PF127 hydrogels. Temperature responsive Pluronic F127 micelles were combined with light-responsive coumarin bearing amphiphilic copolymers to obtain both mechanically strong and injectable gels. For this purpose two monomers, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin (CEMA) and 7-methacryloyloxy-4-methylcoumarin (CMA), were synthesized and further polymerized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Well-defined amphiphilic diblock terpolymers were obtained by using preliminarily synthesized polyethylene glycol (PEG) based macroRAFT agent. The structures of copolymers were confirmed with proton nuclear magnetic resonance spectroscopy (1H NMR), Fourier-transform infrared (FT-IR) spectroscopy and gel permeation chromatography (GPC) analyses. Amphiphilic diblock terpolymers self-assembled into micelles in aqueous solution spontaneously and crosslinking of the micelle cores through the photodimerization of coumarin groups under UV irradiation at 350 nm was examined by UV spectroscopy. Hydrogels were prepared using two different methods, PF127-Mx gels formed using polymer micelle solutions with PF127 solid and PF127-Px gels formed by mixing solid polymers with 20 % F127 solution. Upon characterization of hydrogels via dynamic light scattering (DLS) and transition electron microscope (TEM), rheological properties of the gels were evaluated as a function of temperature, composition, UV exposure time, strain and frequency. Injectability tests of hydrogel systems were performed on a texture analyzer and all the formulations were found in the injectable range. The study reveals that hydrogels based on combination of PF127 and coumarin functional terpolymer amphiphiles hold great potential as injectable biomaterials. [ABSTRACT FROM AUTHOR]

ABSTRACT Amphiphilic hyperbranched copolymer chains made of large hyperbranched poly(acrylic acid) cores grafted with short polystyrene stickers (HB-PAA n- g-PS n + 1) with different n values ( n = 1, 10, 47) were well prepared and confirmed by size exclusion chromatography, Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance. The study on the interchain association behavior of these amphiphilic chains indicates that larger HB-(PAA) n- g-(PS) n + 1 copolymer chains have a less tendency to undergo interchain association. Moreover, the simple vial-inversion and rheological experiments show that the apparent critical gel concentration ( Cg) decreases with n, but no sol-gel transition was observed for triblock PS-PAA-PS even when the concentration is up to 200 g L−1. Further transmission electron microscopy study of the latex particles prepared with HB-(PAA) n- g-(PS) n + 1 as surfactant reveals that the latex particles are spherical and narrowly dispersed; while the measured latex particle number ( Np) indicates the surfactant efficiency of HB-(PAA)47- g-(PS)48 is poorer than that of triblock PS-PAA-PS ( n = 1). Finally, pyrene solubilization measurement shows the solubilization efficiency of HB-(PAA) n- g-(PS) n + 1 copolymers decreases with n, consistent with the previous observed interchain association result. The present study demonstrates that both the chain topology and the styrene weight fraction dominates the final solution properties of amphiphilic HB-(PAA) n- g-(PS) n + 1 chains in aqueous solution. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 128-138 [ABSTRACT FROM AUTHOR]

ABSTRACT An approach to the synthesis of new regular graft-copolymers polyimide (PI)- graft-polymethacrylic acid is elaborated, including (1) synthesis of multicenter PI macroinitiators, (2) controlled ATRP of tert-butylmethacrylate on the prepared macroinitiators, and (3) protonolysis of tert-butyl ester groups of side chains of the resulting PI- graft-poly( tert-butylmethacrylate). Experimental conditions for attaining complete conversions of the first and the third stages of the process are determined by means of 1H NMR and FTIR-spectroscopy. Polymer products of the first and the second stages of the process, as well as poly( tert-butylmethacrylate) side chains cleaved from the PI- graft-poly( tert-butylmethacrylate) copolymers by complete decomposition of the PI backbone under alkaline hydrolysis conditions, are characterized by GPC. The kinetics of poly( tert-butylmethacrylate) chain growth on a PI macroinitiator under ATRP conditions are studied. The results obtained provide evidence for the controlled character of the ATRP process and the regular structure of the synthesized graft-copolymers. It is shown that PI- g-PMAA PI brushes are significantly more efficient intracellular delivery agents for the potential photosensitizer [tetra(4-fluorophenyl)tetracyanoporhyrazine free base] than are the commonly used PEG-micelles. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4267-4281 [ABSTRACT FROM AUTHOR]

Highlights: [•] Oligocaprolactone chains are grafted onto starch backbone via CuAAC click chemistry. [•] Azido-functionalized oligocaprolactones are synthesized by functional ROP. [•] Propargylated starch and PCL-g-starch are characterized by NMR and XPS spectroscopy. [•] Swelling behavior of amphiphilic copolymers in interpreted in terms of solubility parameters. [•] The amphiphilic copolymers present the capacity to organize in aggregates in aqueous solutions. [ABSTRACT FROM AUTHOR]

Abstract: One of the major industrial uses of lipases is as active agent in bio-based washing formulations. Current methods to improve lipase stability in detergent formulations usually entail a decrease in the enzymatic activity, thus lowering the general performance of the detergent. This work proposes an alternative approach for enzyme stabilization and activity enhancement based on the application of amphiphilic light-harvesting copolymers, called here photozymes. The biopolymer-based chitosan-Rose Bengal and the synthetic poly(SSS0.75–co-VBA0.24–co-VB/hematoporphyrin0.01) photozymes were used as boosting agents in washing formulations containing lipase. Organic stain removal from textiles was improved by 33% at 25°C. This cleaning enhancement was attributed to the increase of lipase activity due to interfacial activation in presence of photozymes, along with prevention of dirt re-deposition on the cleaned surfaces. Although both photozymes improved lipase activity, chitosan-Rose Bengal photozyme performed better at pHs above 9 while at pHs below this value SSS–VBA–VB/HP was the most effective. Dynamic light scattering, zeta-potential measurements, fluorescence spectroscopy and FRET experiments confirmed the pseudomicellar conformation and hosting capacity of the photozymes in aqueous media leading to improved dirt solubilization and emulsification. Moreover, the photocatalytic activity of the photozyme allowed for a de-coloration of the waste washing liquor upon UV irradiation. [Copyright &y& Elsevier]

Polymeric surfaces in contact with blood in vivo are foreign bodies and are quickly isolated from blood by the non-specific defense systems. Nanoparticles (NP) used as drug carriers are normally quickly taken up by phagocytes and sequestered in liver and spleen to which they can deliver drugs. Long-circulating and/or low complement activating core-shell NPs can be obtained from PEO/PEG amphiphilic copolymers forming brush or loops on the surface. Core-shell NPs can also be obtained from polysaccharidic graft or block amphiphilic copolymers. Complement activation by the NPs and protein adsorption both depend on the structure, nature and molecular weight of the polysaccharide chains composing the shell. NPs showing low complement activation can be obtained if the polysaccharide on the surface is long and in a brush configuration. Fragile molecules such as hemoglobin or siRNA can be loaded and protected by appropriate brush shells without modifying the low complement activation properties. [ABSTRACT FROM AUTHOR]

The research topics of our group are in general from the field of physical chemistry of colloidal systems. Within this rather wide layout a large variety of quite different questions and systems are tackled, where the common bridging factor is the aim of understanding the properties of colloidal systems based on their mesoscopic structure and dynamics, which in turn are controlled by their molecular composition. With such an enhanced understanding of the correlation between mesoscopic structure and the macroscopic properties the goal then is to employ this knowledge in order to formulate increasingly complex colloidal system with correspondingly more variable and interesting functionalities. From this general context of investigations, some representative systems and questions that have been studied in recent time by us are covered in this text They comprise the phase behaviour and the structures formed in solutions of surfactants and amphophilic copolymers. Once these static properties are known, we also have a high interest in the dynamic properties and the kinetics of morphological transitions as they are observed under non-equilibrium conditions, since they are frequently encountered in applications. A key property of amphiphilic molecules is their ability to solubilise sparingly soluble compounds thereby forming microemulsions or nanoemulsions, where the ability to form such systems depends strongly on the molecular architecture of the amphiphiles. By turning to polymeric amphiphiles the concept of surfactants and their architecture can be extended largely towards more versatile structures, more complex self-assembly and much larger length and time scales. Another direction is the surfactant assisted formation of nanoparticles or mesoporous inorganic materials. By combining copolymers with other polymers, copolymers, colloids, or surfactants - for instance via electrostatically driven co-assembly - one may then form increasingly complex colloidal aggregates. By doing so one is able to control rheological properties or develop complex delivery systems, whose properties can be tailor-made by appropriate choice of the molecular build-up. This striving towards well controlled complexity achieved by means of self- and co-assembly then leads to increasingly more functional systems and is the key direction for future research activities in our group. [ABSTRACT FROM AUTHOR]