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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., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Chimeric or mixed nanosystems belong to the class of advanced therapeutics. Their distinctive characteristic compared with other types of nanoparticles is that they combine two or more different classes of biomaterials. These platforms have created a promising and versatile field of nanomedicine, incorporating materials that are biocompatible, such as lipids, but also functional, such as stimuli-responsive polymers. In the present work, thermoresponsive chimeric nanocarriers composed of l-α-phosphatidylcholine (Egg, Chicken) (EPC) phospholipids and poly(N-isopropylacrylamide)-b-poly(lauryl acrylate) (PNIPAM-b-PLA) block copolymers were designed and developed. Initially, model lipid bilayers with incorporated polymers and drug molecule TRAM-34 were built and studied for their thermodynamics, in order to assess the stability and functionality of the systems. Chimeric nanoparticles of EPC and PNIPAM-b-PLA were then developed and evaluated for their physicochemical properties in different medium conditions, as well as for their morphology. Polymer incorporation led to alterations in the properties and morphology of the nanoparticles, while interactions with serum proteins were absent. TRAM-34 was also incorporated inside the developed nanocarriers, followed by incorporation and release studies, which revealed the functionality of the system in elevated temperature conditions. Finally, in vitro studies on normal cells suggest the biocompatibility of these nanosystems. The proposed platforms are promising for further studies and applications in vitro and in vivo., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Amphiphilic antimicrobial polymers display activity against the outer bacterial cell membrane, triggering various physiological effects. We investigated the regulation of ion transport across the lipid bilayer to understand differences in biological activity for a series of amphiphilic polymethyloxazoline - polyethyleneimine copolymers. The results confirmed that the tested structures were able to increase the permeability of the lipid bilayer (LB) membrane or its rupture. Black lipid membrane (BLM) experiments show that the triggered conductance profile and its character is strongly correlated with the polymer structure and zeta potential. The polymer exhibiting the highest antimicrobial activity promotes ion transport by using a unique mechanism and step-like characteristics with well-defined discreet openings and closings. The molecule was incorporated into the membrane in a reproducible way, and the observed channel-like activity could be responsible for the antibacterial activity of this molecule., (© 2020 Wiley-VCH GmbH.)

This article presents the evaluation of diblock and triblock poly(ethylene glycol)- b -poly(1,3-trimethylene carbonate) amphiphilic copolymers (PEG-PTMCs) as excipients for the formulation of long-acting injectables (LAIs). Copolymers were successfully synthesised through bulk ring-opening polymerisation. The concomitant formation of PTMC homopolymer could not be avoided irrespective of the catalyst amount, but the by-product could easily be removed by gel chromatography. Pure PEG-PTMCs undergo faster erosion in vivo than their corresponding homopolymer. Furthermore, these copolymers show outstanding stability compared to their polyester analogues when formulated with amine-containing reactive drugs, which makes them particularly suitable as LAIs for the sustained release of drugs susceptible to acylation.

Hydrated copolymers of N -vinylpyrrolidone (VP) with triethylene glycol dimethacrylate as a promising platform for biologically active compounds (BAC) were investigated by different physical chemical methods (dynamic light scattering, infrared spectroscopy, thermal gravimetric analysis, and differential scanning calorimetry) and the quantum chemical modeling of water coordination by the copolymers in a solution. According to the quantum chemical simulation, one to two water molecules can coordinate on one O-atom of the lactam ring of VP units in the copolymer. Besides the usual terminal coordination, the water molecule can form bridges to bind two adjacent C=O groups of the lactam rings of VP units. In addition to the first hydration shell, the formation of a second one is also possible due to the chain addition of water molecules, and its structure depends on a mutual orientation of C=O groups. We showed that N , N -dimethylbiguanidine hydrochloride (metformin) as a frontline drug for the treatment of type 2 diabetes mellitus can be associated in aqueous solutions with free and hydrated C=O groups of the lactam rings of VP units in studied copolymers. Based on the characteristics of the H-bonds, we believe that the level of the copolymer hydration does not affect the behavior and biological activity of this drug, but the binding of metformin with the amphiphilic copolymer will delight in the penetration of a hydrophilic drug across a cell membrane to increase its bioavailability.

Polymersomes, also called polymeric vesicles, are self-assembled by amphiphilic copolymers. Due to their unique characters, polymersomes are attracting more and more interest as an important class of vehicles for nanopharmaceuticals. In this chapter, various methods to prepare and characterize polymersomes are introduced systematically with several applicable examples. In addition, the advantages and disadvantages of each method were compared and analyzed with the aim to help readers choose the appropriate method in the process of experiments. Although some methods we introduced here are effective in preparing and characterizing polymersomes, the remaining challenge in this filed is to develop new tools. The reason is that polymersome is a kind of complex nanostructure, and some minor factors can affect the formation of polymersome. Meanwhile, more advanced technology should be developed to precisely determine the structure of some complex polymersomes such as multilayer polymersomes.

Amphiphilic block copolymers-based mixed micelles established as new drug-loading system showed superior characteristics in delivering drug such as improved solubility, enhanced stability, multifunctional carrier materials, targeting ability, and high bioavailability. Recently, there are increasing focuses on exploration and study of noninvasive routes, and the results present perfect feasibility, improved compliance and fewer aches and pains. The aim to apply mixed micelles to noninvasive alternative routes has driven massive pharmaceutical attention. Recently, various studies of micelles strategy for noninvasive routes have been conducted to overcome the inherent barriers for uptake across the gastrointestinal tract, mucosal membranes and other in vivo noninvasive barriers, and the result argues well. The objective of this article is to summary these studies and developments of mixed micelles used on noninvasive drug delivery and provide a reference for further research.

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., (Copyright © 2015. Published by Elsevier Ltd.)

Polymeric micelles functionalized with folate conjugated bovine serum albumin (FA-BSA) and loaded with superparamagnetic iron oxide nanoparticles (SPIONs) are investigated as a specific contrast agent for tumor targeting and magnetic resonance imaging (MRI) in vitro and in vivo. The SPIONs-loaded polymeric micelles are produced by self-assembly of amphiphilic poly(HFMA-co-MOTAC)-g-PEGMA copolymers and oleic acid modified Fe3O4 nanoparticles and functionalized with FA-BSA by electrostatic interaction. The FA-BSA modified magnetic micelles have a hydrodynamic diameter of 196.1 nm, saturation magnetization of 5.5 emu/g, and transverse relaxivity of 167.0 mM(-1) S(-1). In vitro MR imaging, Prussian blue staining, and intracellular iron determination studies demonstrate that the folate-functionalized magnetic micelles have larger cellular uptake against the folate-receptor positive hepatoma cells Bel-7402 than the unmodified magnetic micelles. In vivo MR imaging conducted on nude mice bearing the Bel-7402 xenografts after bolus intravenous administration reveals excellent tumor targeting and MR imaging capabilities, especially at 24h post-injection. These findings suggest the potential of FA-BSA modified magnetic micelles as targeting MRI probe in tumor detection., (Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Amphiphilic copolymers (ACs) are versatile systems with self-assembling and aggregating properties, enabling the formation of nanomaterials (NMs) such as micelles, vesicles, nanocapsules, and nanogels. These materials have been extensively explored for the delivery of various drugs and active compounds, enhancing the solubility and permeation of poorly water-soluble drugs into skin tissue. This improvement facilitates the treatment of skin diseases, including chronic conditions like cancer, as well as infections caused by bacteria, fungi, and viruses. This review summarizes recent applications of ACs in skin treatment, with a particular focus on their use in anti-cancer drug therapy. It covers the synthesis, classification, and characterization of ACs using various experimental techniques. Additionally, it discusses recent research on different drug delivery pathways using ACs, including encapsulation efficiency, release behavior, characteristics, applications, and responses to various chemical and physical stimuli (both in vivo and in vitro). Furthermore, this review provides a comprehensive analysis of the effects of ACs NMs on several skin diseases, highlighting their potential as alternative treatments. [ABSTRACT FROM AUTHOR]

Giant unilamellar vesicles (GUVs) are microcompartments serving to confine reactions, allow signaling pathways, or design synthetic cells. Polymer GUVs are composed of copolymer membranes mimicking cell membranes, and present advantages over lipid-based GUVs, such as higher mechanical stability and chemical versatility. Such microcompartments are essential for understanding reactions/signaling occurring in cells, which are difficult to study by in vivo approaches due to the cell's complexity. However, the lack of control over their production, stability, and membrane diffusion properties is still limiting their use for bio-related applications. Here, polymer GUVs produced by microfluidics and permeabilized with DNA-origami nanopores (DoNs) that present a high level of control over these essential properties are introduced. After systematic optimization of conditions, DoN-GUVs reveal a narrow size distribution, allow for high encapsulation efficiencies, and are stable for weeks, protecting encapsulated biomolecules. The kinetics of diffusion of molecules through the GUV's membrane is tuned by insertion of DoNs with a controlled 3D-structure. DNA polymerase I, encapsulated as model for bioreactions, successfully produced DNA duplex strands with spatiotemporal control. DoN-GUVs loaded with active molecules open new avenues in bioreactions, from the detection of biomolecules, over the tuning of molecular transport rates, to the investigation of cellular processes/signaling. [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]

The development of effective anti-cancer therapeutics remains one of the current pharmaceutical challenges. The joint delivery of chemotherapeutic agents and biopharmaceuticals is a cutting-edge approach to creating therapeutic agents of enhanced efficacy. In this study, amphiphilic polypeptide delivery systems capable of loading both hydrophobic drug and small interfering RNA (siRNA) were developed. The synthesis of amphiphilic polypeptides included two steps: (i) synthesis of poly-αl-lysine by ring-opening polymerization and (ii) its post-polymerization modification with hydrophobic l-amino acid and l-arginine/l-histidine. The obtained polymers were used for the preparation of single and dual delivery systems of PTX and short double-stranded nucleic acid. The obtained double component systems were quite compact and had a hydrodynamic diameter in the range of 90–200 nm depending on the polypeptide. The release of PTX from the formulations was studied, and the release profiles were approximated using a number of mathematical dissolution models to establish the most probable release mechanism. A determination of the cytotoxicity in normal (HEK 293T) and cancer (HeLa and A549) cells revealed the higher toxicity of the polypeptide particles to cancer cells. The separate evaluation of the biological activity of PTX and anti-GFP siRNA formulations testified the inhibitory efficiency of PTX formulations based on all polypeptides (IC50 4.5–6.2 ng/mL), while gene silencing was effective only for the Tyr-Arg-containing polypeptide (56–70% GFP knockdown). [ABSTRACT FROM AUTHOR]

Polymeric micelles are most popular and promising drug delivery systems in recent years. Polymeric micelles are self assembled nano sized colloidal particles and size is ranges from 10-100 nm. The aim of the present study is to formulate oregano polymeric micelles to improve its aqueous solubility. Oregano loaded polymeric micelles were prepared with different polymers like PVA, PEG4000, and Pluronic F127 using solvent diffusion technique. The drug and polymer ratio were taken by Box-Behnken design. Optimization of the micellar formulation was done by using response surface method (RSM). The active constituents of oregano were analyzed by HPLC at 274 nm. The retention time of oregano in HPLC was found at 11min. The prepared polymeric micelles have low CMC value, the particle size and zeta potential was found to be in between 53.9±6.4 to 255±7.2 and -11.7±2.2 to 42.9±0.9 respectively. In vitro drug release studies revealed that 70.1 ± 1.81 % of drug released from micelles after 24h. The entrapment efficiency was found different for all formulations due to different concentration of drug and PEG used. The optimized oregano polymeric micelle formulation was further evaluated by phase contrast microscopy, FTIR analysis and in-vitro drug release kinetics. Optimized micelle formulation displayed a spherical- shaped morphology, no drugexcipient interactions and follows first order so the formulations released in sustained manner, and it also follows Higuchi and Hixson crowell release mode. It is concluded that the prepared oregano polymeric micellar system has an excellent potential delivery with increased solubility to be used orally. [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]

The paper describes a comparative study on the effects of the composition of polymers of higher alkyl (meth)acrylates on their dispersion degree in petroleum oil I-20A. The dispersion degree parameter is evaluated in accordance with a modified spectrophotometric method proposed in the study. It was found that increasing the polymer amphiphilicity by introducing nitrogen-based units in an amount of 5–15% dramatically enhances the dispersion properties, and that amide groups have a stronger effect than amine ones. Increasing the polyalkyl methacrylate amphiphilicity by introducing (in an amount of 5–40%) alkoxy oligo(ethylene glycol) methacrylate (AOEGM) units containing 3–7 ethoxy groups does not enhance the polymer's dispersion ability. The only exception was a single case of a fairly high dispersion ability achieved for a copolymer containing 30% of AOEGM units with long hydrophilic chains consisting of ten ethoxy groups. [ABSTRACT FROM AUTHOR]

New cis -bis[ N -(2-nitroxyethyl)isonicotinamide- N ]platinum(iv) tetrachloride hybrid materials were obtained via its solubilization by nanoparticles of N -vinylpyrrolidone copolymer with dimethacrylates and characterized. The materials containing 2% of PtIV complex cause a cytotoxic effect on the tumor A-172 cells; IC50 values were ca. 106 μm after incubation for 48 h. [ABSTRACT FROM AUTHOR]

Nitroxide-containing amphiphilic polymers for therapeutic use were prepared in two-step procedure. Firstly, amphiphilic copolymers composed of hydrophobic poly(n -butyl acrylate) (P n BA) and hydrophilic poly[oligo(ethylene glycol) methyl ether acrylate] (POEGA) or poly(2-hydroxyethyl acrylate) (PHEA) were synthesized by simplified electrochemically mediated atom transfer radical polymerization (se ATRP). Due to the precisely-controlled structure of each polymer block proved by narrow dispersity (M w / M n < 1.19), chain-end halide functionality of macromolecules was preserved. Therefore, it was possible to efficiently convert the halide atom at the end of the chain to stable radicals via the amination of the polymer with 4-amino-2,2,6,6-tetrametylopiperydynyloksyl (4-amino-TEMPO, 4-AT). The prepared polymers are able to self-assemble in an aqueous solution into micelles with a hydrodynamic diameter of approximately 31 nm measured by dynamic light scattering (DLS) analysis. The susceptibility of the prepared micelles for biomedical applications was studied by evaluation of the effect on erythrocytes and fibroblasts and their antioxidant properties by testing of inhibition of oxidation reactions – oxidation of dihydrorhodamine 123 (DHR 123), induced by biologically relevant oxidants. The antioxidant effects of polymeric micelles were compared with those of free 4-AT. Prepared TEMPO-containing micelles exhibited biocompatibility in interaction with human erythrocytes and fibroblasts and exerted antioxidant effects. Therefore, the micelles are potentially good candidates for in vivo applications. [Display omitted] • Amphiphilic copolymers with highly preserved chain-end functionality were provided by se ATRP concept. • The precisely-controlled structure of each polymer block enables post-modification with 4-amino-TEMPO. • Polymeric micelles showed satisfactory biocompatibility and exerted antioxidant effects. • Nitroxide-containing polymer-based micelles have great potential for therapeutic use. [ABSTRACT FROM AUTHOR]

The oxidative coupling of 4- tert-butylphenol ( 1), 2,6-di- tert-butyl- p-cresol ( 11) and 4-cyanophenol ( 10) in the presence of iron salen catalysts (salen = N, N′-bis(salicylidine)ethylenediamine) and the influence of amine additives on the conversion of 1 were investigated. Furthermore, the activity of the iron complexes was correlated with the substituents at the 5,5′-positions of the salen ligands. Mechanistically conclusions based on dimer formation in the reaction between 10 and 11 are presented. In the second part of the study the obtained hydrophobic poly(4- tert-butylphenol) was modified with Jeffamine® M-600, M-1000 or M-2070 to give amphiphilic copolymers (18a-c). The amphiphilic copolymers were characterized via size-exclusion chromatography and dynamic light scattering. The concentration dependence of the cloud point appearance in water of amphiphilic copolymer 18c was analysed via turbidity measurements. © 2016 Society of Chemical Industry [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]

[Display omitted] • Brush copolymer analogues of PEG-PLA copolymers were produced via ATRP or ARGET ATRP. • Functionalization of either block was achieved via copolymerization. • Resulting nanoparticles have tunable stability and appropriate size/polydispersity. • High drug loading is achievable with hydrophobic drug payloads (>96% encapsulation) PL(G)A-PEG block polymers have been widely used in a variety of drug delivery applications but are inherently limited in terms of their capacity for functionalization and thus customization to specific delivery tasks. Herein, we report synthetically tunable and functionalizable brush co-polymer analogues of conventional PL(G)A-PEG polymers fabricated via atom transfer radical polymerization (ATRP) of methacrylate-based co-monomers with oligo(lactic acid) side chains in the hydrophobic block and oligo(ethylene glycol) side chains in the hydrophilic block. Block co-polymers prepared by varying the molecular weights of each block, the functionality of either block (via functional monomer copolymerization), as well as the number of lactic acid repeat units in the hydrophobic block were subsequently used to fabricate nanoparticles with sizes of 100–500 nm and tunable degradation rates via flash nanoprecipitation. The resulting nanoparticles exhibited high colloidal stability (consistent with the dense brush-like POEGMA interface), favorable in vitro cytocompatibility, and the capacity for effective drug loading (>96% encapsulation efficiency for paclitaxel and 41% even for the hydrophilic therapeutic doxorubicin hydrochloride). Furthermore, functionalization of the hydrophobic POLAMA block with methacrylic acid residues enabled controlled dissolution of the nanoparticle over time, offering potential to tune drug release via an alternative mechanism not readily accessible with conventional PLA-PEG-based block copolymers. Combining these properties with the flexible chemical compositions and the generally recognized as safe degradation properties of the brush polymer analogues, POLAMA- b- POEGMA polymers represent a highly versatile platform for nanoparticle-based drug delivery applications. [ABSTRACT FROM AUTHOR]

ABSTRACT Copper-catalyzed azide-alkyne cycloaddition (CuAAC) was used to prepare glycosylated polyethylene (PE)-poly(ethylene glycol) (PEG) amphiphilic block copolymers. The synthetic approach involves preparation of alkyne-terminated PE- b-PEG followed by CuAAC reaction with different azide functionalized sugars. The alkyne-terminated PE- b-PEG was prepared by etherification reaction between hydroxyl-terminated PE- b-PEG ( Mn ∼ 875 g mol−1) and propargyl bromide and azidoethyl glycosides were prepared by glycosylation of 2-azidoethanol. Atmospheric pressure solids analysis probe-mass spectrometry was used as a novel solid state characterization tool to determine the outcome of the CuAAC click reaction and end-capping of PE- b-PEG by the azidoethyl glycoside group. The aqueous solution self-assembly behavior of these amphiphilic glycosylated polymers was explored by TEM and dye solubilization studies. Carbohydrate-bearing spherical aggregates with the ability to solubilize a hydrophobic dye were observed. The potential of these amphiphilic glycosylated polymers to self-assemble via electro-formation into giant carbohydrate-bearing polymersomes was also investigated using confocal fluorescence microscopy. An initial bioactivity study of the carbohydrate-bearing aggregates is furthermore presented. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 5184-5193 [ABSTRACT FROM AUTHOR]

Abstract: Amphiphilic copolymers containing β-cyclodextrin (β-CD) core were synthesized successfully. Synthesis was initiated from tosylated cyclodextrin ((Tosyl)7-β-CD) which is containing two types of functional groups. Hydroxyl functional groups of (Tosyl)7-β-CD were used as initiator for ring opening polymerization of lactide. This step led to star polymers containing tosylated cyclodextrin core and polylactide arms (PLA–(Tosyl)7-β-CD). In the next step, tosyl groups of PLA–(Tosyl)7-β-CD were used as initiator for ring opening polymerization of 2-ethyl-2-oxazoline and amphiphilic copolymers containing cyclodextrin core, PLA and poly(2-ethyl-2-oxazoline) arms (PLA–β-CD–POX) were obtained. Loading of Congo red as guest molecule by amphiphilic copolymers was investigated. The release of guest molecule from chloroform solution of copolymers to water phase was also investigated. [Copyright &y& Elsevier]

Abstract: Novel amphiphilic graft polyphosphazenes (PNIPAm/EtGly-PPPs) bearing poly (N-isopropylacrylamide) (PNIPAm) as a hydrophilic segment and ethyl glycinate (EtGly) as a hydrophobic group were synthesized via ring-opening polymerization and subsequent substitution reaction. The lower critical solution temperature (LCST) of copolymers was investigated by turbidity method using UV–Vis spectroscopy. Copolymers show their LCSTs in the range of 18.5–33°C, depending on the mole ratio of the substituents. The self-assembly characteristics of copolymers in aqueous solution was studied by using fluorescence technique, dynamic light scattering (DLS), and TEM. The critical association concentration (CAC) of copolymers varied from 0.112 to 0.0309g/L, was related with the mole ratio of PNIPAm to EtGly. The TEM images showed self-assembled nanoparticles with a spherical shape at about 30°C, while network-like aggregates were observed for copolymer with high PNIPAm content at relatively low temperature. The particle size of nanoparticles, depending on copolymer compositions, was in the range of 80–900nm at 25°C. These copolymers may be used as injectable drug carriers for the delivery of hydrophobic compounds. [Copyright &y& Elsevier]

Amphiphilic poly (MePEG-co-alkyl cyanoacrylate) copolymers have been studied as carriers for stealth nanoparticles. A promising area is nanoparticles prepared using copolymers with both high ratio of PEG blocks and sufficient hydrophobicity. In this study, poly (MePEG cyanoacrylate-co-docosyl cyanoacrylate) copolymer with longer alkyl chains has been synthesized by condensing MePEG cyanoacetate and docosyl cyanoacetate with formaldehyde in the presence of pyrrolidine. The hydrophobicity of the copolymer can be modulated by adjusting the MePEG/docosyl ratio. Characterization of the copolymers has been performed by FTIR, 1H-NMR, and GPC analysis. PEGylated monodisperse nanoparticles were prepared by nanoprecipitation and characterized for particle size, morphology, and zeta potential. Preparation variables such as surfactant concentration in aqueous phase, copolymer concentration, and phase volume ratio influenced particle size. Negative surface zeta potential decreased with increased PEG content in the copolymer, which indicated that nanoparticles prepared with copolymer bearing larger number of PEG moieties provided better shield of the core surface. The newly synthesized copolymer is a potential material to be used to prepare stealth nanoparticles with high PEG density. [ABSTRACT FROM AUTHOR]

Abstract: Biodegradable polymers represent a class of extremely useful materials for many biomedical and pharmaceutical applications, as exemplified by drug delivery systems, which in recent years have taken advantage of (bio)degradable polymeric matrices. However, before being selected for any biomedical application, a biodegradable polymer requires careful investigation of its interactions and compatibility within the human body. To date, polyesters, both natural and synthetic, constitute the most fully developed class of degradable biomaterials. Poly(ε-caprolactone) (PCL) and polylactides (PLAs), recognized as biocompatible and biodegradable polyesters, are very promising for controlled drug delivery devices. Bacterial polyesters and malic acid-based polymers (poly(malic acid), PMLA and derivatives) are poly(β-hydroxyacid)-type polyesters that represent excellent alternatives for temporary therapeutic applications. Although these polyesters can be produced by polycondensation, high molecular weight structures have, until now, been produced almost exclusively by ring-opening polymerization (ROP) of the corresponding cyclic monomers. The ability of aluminum alkoxides (AlR x (OR′)3− x ) and tin(II) bis(2-ethylhexanoate) (Sn(Oct)2) to control the ROP of (di)lactones in terms of molecular parameters has opened the way to a wide range of molecular structures and topologies. Beyond the mechanistic and thermodynamic aspects of ROP of (di)lactones using organometallic compounds, this review is focused on new non-organometallic N-heterocyclic carbenes recently reported as catalysts for the controlled ROP of cyclic esters. Interestingly, the use of these simple organic molecules as catalysts or promoters in asymmetric polymer synthesis has provided organocatalytic alternatives to traditional organometallic reagents. [Copyright &y& Elsevier]

Abstract: Poly(ethylene oxide) monomethylether was functionalized by alkyl chains of various lengths (l=10–19 methylene groups) bearing a polymerizable methacrylate moiety. Each synthesis step on the polymer gives quantitative functionalization rates. The self-assembly of the amphiphilic polymers in water was studied by light scattering for various end-groups. Sterical and polar effects were shown to influence the micellization step. The cores of the micelles formed by PEO-Cl-methacrylate were irreversibly cross-linked by UV irradiation. Star polymers that are stable under dilution in good solvent are obtained after 1-min irradiation. The hydrodynamic radius and the molar mass of the nanoparticles depend on the amount of photoinitiator introduced in the cores. [Copyright &y& Elsevier]

The aim of this study is to design and develop novel hybrid pH-responsive hydrogels. For this purpose, new copolymers with different molecular weights and different content of the hydrophobic part are synthesized. The self-assembly behavior of PSMA-co-PDMAEMA copolymerswasstudiedin two different dispersion media (simulated gastric fluid-SGF, pH = 1.2 and simulated intestinal fluid-SIF, pH = 6.8) and in different concentrations. The physicochemical characteristics of the nano-assemblies were found to be dependent on the composition of the copolymer and the aqueous environment. Having a complete knowledge of the self-assembly behavior of the copolymers in aqueous media, the encapsulation of the PSMA-co-PDMAEMA 1/2 nano-assemblies into Alginate beads was achieved by following the protocol of the preparation of hydrogels. The Calcium:Alginate hydrogels were used as reference systems for comparison reasons. The size and the morphology of pure and mixed beads were found to be dependent on the composition of the block copolymer, as revealed from SEM images. The behavior of the mixed hydrogels was the same during the swelling studies, but the rate of the swelling and the amount of weight change were found to be additionally dependent on the composition of the polymeric guest. The hydration state of the polymeric chains plays a key role inthe swelling behavior of the mixed hydrogels. In conclusion, pH-responsive hybrid hydrogels were developed and their behavior and morphology are strongly dependent on the molecular characteristics of the polymeric guest. [ABSTRACT FROM AUTHOR]