Diabetes mellitus is a chronic, life-threatening illness that affects people of every age and ethnicity. It is a long-term pain for those who are affected and must regulate their blood glucose level by frequent subcutaneous injection of insulin every day. Herein, we propose a noninsulin and antidiabetic drug-free strategy for regulating blood glucose level by a nanosized “sugar sponge” which is a lectin-bound glycopolymersome capable of regulating glucose due to the dynamic recognition between the lectin and different carbohydrates. The glycopolymersome is self-assembled from poly(ethylene oxide)-block-poly[(7-(2-methacryloyloxyethoxy)-4-methylcoumarin)-stat-2-(diethylamino)ethyl methacrylate-stat-(α-d-glucopyranosyl)ethyl methacrylate] [PEO-b-P(CMA-stat-DEA-stat-GEMA)]. The lectin bound in the glycopolymersome has different affinity for the glucose in the blood and the glucosyl group in the glycopolymersome. Therefore, this sugar sponge functions as a glucose storage unit by dynamic sugar replacement: The lectin in the sugar sponge will bind and store the glucose from its surrounding solution when the glucose concentration is too high and will release the glucose when the glucose concentration is too low. In vitro, this sugar-breathing behavior is characterized by a remarkable size change of the sugar sponge due to the swelling/shrinkage at high/low glucose levels, which can be used for blood sugar monitoring. In vivo, this sugar sponge showed an excellent antidiabetic effect for type I diabetic mice within 2 days upon one dose, which is much longer than traditional long-acting insulin. Overall, this concept of “controlling sugar levels with sugar” opens new avenues for regulating the blood glucose level without the involvement of insulin or other antidiabetic drugs.

It is an important challenge for bone repair to effectively deliver growth factors and at the same time to prevent and cure inflammation without obvious pathogen resistance. We designed a kind of antibacterial peptide-mimetic alternating copolymers (PMACs) to effectively inhibit and kill both Gram-positive and Gram-negative bacteria. The minimum inhibition concentrations (MICs) of the PMACs against E. coli and S. aureus are 8.0 μg/mL, which are much lower than that of antibacterial peptides synthesized by other methods such as widely used ring-opening polymerization of N-carboxyanhydride. Furthermore, the PMACs can self-assemble into polymer vesicles (polymersomes) in pure water with low cytotoxicity (IC50 > 1000 μg/mL), which can encapsulate growth factors in aqueous solution and release them during long-term antibacterial process for facilitating bone repair. We also find that the alternating structure is essential for the excellent antibacterial activity. The in vivo tests in rabbits confirmed that the growth-factor-encapsulated antibacterial vesicles have better bone repair ability compared with control groups without antibacterial vesicles. Overall, we have provided a novel method for designing PMAC-based highly effective intrinsically antibacterial vesicles that may have promising biomedical applications in the future.

Natural extracellular matrices (ECMs) have been widely used as a support for the adhesion, migration, differentiation, and proliferation of adipose-derived stem cells (ADSCs). However, poor mechanical behavior and unpredictable biodegradation properties of natural ECMs considerably limit their potential for bioapplications and raise the need for different, synthetic scaffolds. Hydrogels are regarded as the most promising alternative materials as a consequence of their excellent swelling properties and their resemblance to soft tissues. A variety of strategies have been applied to create synthetic biomimetic hydrogels, and their biophysical and biochemical properties have been modulated to be suitable for cell differentiation. In this review, we first give an overview of common methods for hydrogel preparation with a focus on those strategies that provide potential advantages for ADSC encapsulation, before summarizing the physical properties of hydrogel scaffolds that can act as biological cues. Finally, the challenges in the preparation and application of hydrogels with ADSCs are explored and the perspectives are proposed for the next generation of scaffolds.

Presented in this article is the template-free fabrication of nitrogen-doped hollow carbon spheres (N-HCSs) as electrode materials for high-performance supercapacitors based on scalable homopolymer vesicles, which are self-assembled from an amphiphilic homopolymer, poly(amic acid) (PAA). This homopolymer can be massively produced by simple stepwise polymerization at room temperature with a fast polymerization rate. For the first time, PAA homopolymer vesicles are carbonized to form N-HCSs with tunable porous structures and nitrogen contents (from 1.3% to 7.4%) by controlling the content of the cross-linker (melamine). This template-free method for fabricating N-HCSs is more environmentally friendly and does not involve tedious synthetic procedures compared to traditional template-based methods. More importantly, the N-HCSs exhibit excellent electrochemical performance with a very high specific capacitance (266.9 F g−1) after more than 1000 cycles when used as the active electrode material for the supercapacitor. The N-HCSs presented in this paper retain its specific capacitance as high as 84% at a very high current density (20 A g−1). Given the potential massive production and excellent electrochemical properties, the N-HCSs based on the carbonization of scalable PAA homopolymer vesicles are promising candidate electrode materials for energy storage devices.

We report a compound polymer micelle with light-triggered “on–off” switching of fluorescence based on the self-assembly of two block copolymers. First, the naphthalimide fluorophore is incorporated into poly(styrene-stat-naphthalimide)-b-poly(N-isopropyl acrylamide) [P(St-stat-MANI)-b-PNIPAM]. Second, the naphthopyran unit is engineered in poly(styrene-stat-naphthopyran)-b-poly(N-isopropyl acrylamide) [P(St-stat-NP)-b-PNIPAM] to manipulate the fluorescence when self-assembled into compound micelles with fluorophore-containing P(St-stat-MANI)-b-PNIPAM. The fluorescence of naphthalimide (MANI) can be modulated between “on” and “off” states by the photochromic reaction of naphthopyran (NP) upon UV irradiation and thermal fading reaction. Furthermore, Nile red (NR) was encapsulated in the micelle and showed a controlled release behavior by light. Our strategy may be extended for designing a range of multifunctional smart fluorescent materials such as chemical sensors.

Multifunctional statistical copolymers can be simply synthesized in one step without tedious and time-consuming procedures. In addition, the fuzzy boundary between different functional groups in the statistical copolymers can facilitate the fabrication of new functional nanomaterials. Herein, we designed a novel multifunctional vesicle based on a statistical copolymer, poly[[2-hydroxy-3-(naphthalen-1-ylamino)propyl methacrylate]-stat-[2-(diethylamino)ethyl methacrylate]] [P(HNA21-stat-DEA35)] which can be synthesized by reversible addition–fragmentation transfer (RAFT) polymerization in one step. The HNA moiety is designed for capturing polycyclic aromatic hydrocarbons (PAHs) by π–π stacking, while the DEA moiety is engineered to immobilize gold nanoparticles for facilitating the reduction of 4-nitrophenol (4-NP) in aqueous solution. This vesicle showed excellent ability in water remediation by absorbing PAHs and accelerating the reduction of 4-nitrophenol (4-NP). Overall, this multifunctional statistical copolymer vesicle provides a new insight for designing multifunctional water remediation materials.

Traditional antibiotics usually sterilize in chemical ways, which may lead to serious drug resistance. By contrast, peptide-based antibacterial materials are less susceptible to drug resistance. Herein we report the preparation of an antibacterial peptide-based copolymer micelle and the investigation of its membrane-penetration antibacterial mechanism by transmission electron microscopy (TEM). The copolymer is poly(l-lactide)-block-poly(phenylalanine-stat-lysine) [PLLA31-b-poly(Phe24-stat-Lys36)], which is synthesized by ring-opening polymerization. The PLLA chains form the core, whereas the polypeptide chains form the coronas of the micelle in aqueous solution. This micelle boasts excellent antibacterial efficacy against both Gram-positive and Gram-negative bacteria. Furthermore, TEM studies clearly reveal that the micelles pierce and then destroy the cell membrane of the bacteria. We also compared the advantages and disadvantages of two general methods for measuring the Minimal Inhibitory Concentration (MIC) values of antibacterial micelles. Overall, this study provides us with direct evidence for the antibacterial mechanism of polypeptide-based micelles and a strategy for synthesizing biodegradable antibacterial nanomaterials without antibiotic resistance.

We report a facile strategy for incorporating persistent and effective antibacterial property into a widely used polymer, poly(methyl methacrylate) (PMMA), by copolymerizing methyl methacrylate (MMA) with 2-(tert-butylamino)ethyl methacrylate (TA) in one pot via atom transfer radical polymerization (ATRP). The subsequent self-assembly of the resultant poly(methyl methacrylate)-block-poly[(2-tert-butylamino)ethyl methacrylate] (PMMA20-b-PTA15) diblock copolymer affords well-defined water-dispersible vesicles, which can be facilely sprayed on the walls in hospitals for effective inhibition and killing of bacteria. 1H-NMR and gel permeation chromatography (GPC) studies confirmed the successful synthesis of welldefined copolymer. Transmission electron microscopy (TEM), atomic force microscopy (AFM) and dynamic light scattering (DLS) studies proved the formation of vesicles with narrow size distribution. DLS studies revealed the excellent stability of vesicles at various temperatures. Antibacterial tests showed effective antibacterial activities of polymer vesicles against both Gram-positive and Gram-negative bacteria. Moreover, this strategy may be extended for preparing a wide range of polymeric materials for facile antibacterial applications in many fields.

Antimicrobial resistance is an increasingly problematic issue in the world and there is a present and urgent need to develop new antimicrobial therapies without drug resistance. Antibacterial polymers are less susceptible to drug resistance but they are prone to inducing serious side effects due to high positive charge. Herein we report a peptide-grafted hyperbranched polymer which can self-assemble into unusual nanosheets with highly effective intrinsically antibacterial activity but weak positive charges (+ 6.1 mV). The hyperbranched polymer was synthesized by sequential Michael addition-based thiol–ene and free radical mediated thiol–ene reactions, and followed by ring-opening polymerization of N-carboxyanhydrides (NCAs). The nanosheet structure was confirmed by transmission electron microscopy (TEM) and atomic force microscopy (AFM) studies. Furthermore, a novel “wrapping and penetrating” antibacterial mechanism of the nanosheets was revealed by TEM and it is the key to significantly decrease the positive charges but have a very low minimum inhibitory concentration (MIC) of 16 μg mL–1 against typical Gram-positive and Gram-negative bacteria. Overall, our synthetic strategy demonstrates a new insight for synthesizing antibacterial nanomaterials with weak positive charges. Moreover, the unique antibacterial mechanism of our nanosheets may be extended for designing next-generation antibacterial agents without drug resistance.

The apparent size increase of poly(N-isopropyl acrylamide) (PNIPAM)-based polymeric micelles upon heating was usually ascribed to their volume growth or aggregation in aqueous solution. Herein we designed a photo-cross-linkable PNIPAM-based copolymer and proposed another thermo-responsive behaviour – fusion, which is disclosed by transmission electron microscopy (TEM) after in situ fixing morphologies at desired temperatures.

It is an important challenge to in situ grow ultrafine super-paramagnetic iron oxide nanoparticles (SPIONs) in drug carriers such as polymer vesicles (also called polymersomes) while keeping their biodegradability for enhanced T2-weighted magnetic resonance imaging (MRI) and drug delivery. Herein, we present a new strategy by rationally separating the corona and membrane functions of polymer vesicles to solve the above problem. We designed a poly(ethylene oxide)-block-poly(ε-caprolactone)-block-poly(acrylic acid) (PEO43-b-PCL98-b-PAA25) triblock copolymer and self-assembled it into polymer vesicle. The PAA chains in the vesicle coronas are responsible for the in situ nanoprecipitation of ultrafine SPIONs, while the vesicle membrane composed of PCL is biodegradable. The SPIONs-decorated vesicle is water-dispersible, biocompatible, and slightly cytotoxic to normal human cells. Dynamic light scattering, transmission electron microscopy, energy disperse spectroscopy, and vibrating sample magnetometer revealed the formation of ultrafine super-paramagnetic Fe3O4 nanoparticles (1.9 ± 0.3 nm) in the coronas of polymer vesicles. Furthermore, the CCK-8 assay revealed low cytotoxicity of vesicles against normal L02 liver cells without and with Fe3O4 nanoparticles. The in vitro and in vivo MRI experiments confirmed the enhanced T2-weighted MRI sensitivity and excellent metastasis in mice. The loading and release experiments of an anticancer drug, doxorubicin hydrochloride (DOX·HCl), indicated that the Fe3O4-decorated magnetic vesicles have potential applications as a nanocarrier for anticancer drug delivery. Moreover, the polymer vesicle is degradable in the presence of enzyme such as Pseudomonas lipases, and the ultrafine Fe3O4 nanoparticles in the vesicle coronas are confirmed to be degradable under weakly acidic conditions. Overall, this decoration-in-vesicle-coronas strategy provides us with a new insight for preparing water-dispersible ultrafine super-paramagnetic Fe3O4 nanoparticles with promising theranostic applications in biomedicine.Keywords: drug delivery; magnetic resonance imaging; self-assembly; super-paramagnetic iron oxide nanoparticles; vesicles;

We report a novel silkworm cocoon-like nanostructure based on the 3D hierarchical self-assembly of cylinders which are spontaneously formed by an H-shaped polymer brush comprising a disulfide-bridged spacer and two brushes with alternating PEG and PCL side chains. Crystalline of PCL between adjacent cylinders bridges cylinders.

Effective inhibition of bacteria and removal of carcinogenic organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) are important technical challenges in water purification because most of the traditional filter membranes are prone to being biologically contaminated by bacteria and difficult to filter off PAHs. Herein we present the synthesis and characterization of a novel multifunctional nanocapsule (vesicle) based on a statistical copolymer, poly[[2-hydroxy-3-(naphthalen-1-ylamino)propyl methacrylate]-stat-[2-(tert-butylamino)ethyl methacrylate]] [P(HNA23-stat-TA20)], which can be easily synthesized in one step. The TA moiety is engineered for effective bacterial inhibition, while the HNA moiety is in charge of the capturing of PAHs by π–π stacking. The nanocapsules can effectively inhibit bacteria and quickly reduce the pyrene content in water to an extremely low residual concentration of 5.6 (in 1 min) or 0.56 (in 60 min) parts per billion (ppb). Moreover, this rational engineering principle could be extended by statistically copolymerizing HNA with other functional monomers for designing a range of multifunctional nanomaterials.

Cancer patients after chemotherapy may also suffer bacterial attack due to badly decreased immunity. Although with high bacterial efficacy, conventional antibiotics are prone to inducement of drug resistance and may be not suitable for some cancer patients. In contrast, antibacterial peptides are highly effective in inhibiting bacteria without inducing resistance in pathogens. Presented in this article is a novel kind of highly effective antibacterial peptide-based biocompatible and biodegradable block copolymer vesicle. The copolymer is poly(ε-caprolactone)-block-poly[phenylalanine-stat-lysine-stat-(lysine-folic acid)] [PCL19-b-poly[Phe12-stat-Lys9-stat-(Lys-FA)6]], which can self-assemble into vesicles in aqueous solution. The biocompatible and biodegradable PCL forms the vesicle membrane, whereas the poly[Phe12-stat-Lys9-stat-(Lys-FA)6] block constitutes the vesicle coronas. Compared to the individual polymer chains, the vesicles showed enhanced antibacterial activities against both Gram-positive and Gram-negative bacteria (16 μg mL–1) due to the locally concentrated antibacterial poly[Phe12-stat-Lys9-stat-(Lys-FA)6] coronas, which may avoid the inducement of antibiotic-resistant bacteria and side effects of multidrug interactions. Furthermore, folic acid is introduced into the vesicle coronas for potential further applications such as cancer-targeted drug delivery. Moreover, the amino groups can be further functionalized when necessary. This low cytotoxic, biocompatible, biodegradable, and antibacterial vesicle (without antibiotic resistance) may benefit patients after tumor surgery because it is highly anti-inflammatory, and it is possible to deliver the anticancer drug to tumor cells simultaneously.

We report a facile strategy for preparing persistent and effective antibacterial polymersomes (polymer vesicles) based on triblock copolymers synthesized by sequential copolymerization of 2-diethylaminoethyl methacrylate (DEA) and 2-(tert-butylamino)ethyl methacrylate (TA) via atom transfer radical polymerization (ATRP). The poly(ethylene oxide)-block-poly(2-diethylaminoethyl methacrylate)-block-poly[(2-tert-butylamino)ethyl methacrylate] (PEO-b-PDEA-b-PTA) triblock copolymers can self-assemble into polymersomes in aqueous solution when directly dissolved in pure water without the aid of organic solvents. 1H NMR and gel permeation chromatography (GPC) studies confirmed the well-defined copolymers. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) studies proved the formation of polymersomes. Antibacterial tests showed good antibacterial activities of polymersomes against both Gram-positive and Gram-negative bacteria. Moreover, those polymersomes may be facilely sprayed in hospitals which are susceptible to bacterial attack for long-term effective antibacterial applications.

Traditional T1 magnetic resonance imaging (MRI) contrast agents such as diethylenetriaminepentacetatic acid (DTPA) chelated gadolinium [Gd(III)] have poor sensitivity, leading to a risk of accumulated toxicity in vivo. To significantly improve the sensitivity of a T1 MRI contrast agent and to enhance the efficacy of cancer chemotherapy, herein for the first time we report a noncytotoxic asymmetrical cancer targeting polymer vesicle based on R-poly(l-glutamic acid)-block-poly(ε-caprolactone) [R is folic acid (FA) or DTPA]. Such asymmetrical vesicles have a cancer-targeting outer corona and a Gd(III)-chelating and drug-loading-enhancing inner corona, exhibiting an extremely high T1 relaxivity (42.39 mM–1 s–1, 8-fold better than DTPA-Gd) and anticancer drug loading efficiency (52.6% for doxorubicin hydrochloride, DOX·HCl). Moreover, the DOX-loaded vesicles exhibited excellent antitumor activity (2-fold better than free DOX). This “chelating-just-inside” strategy for synthesizing asymmetrical polymer vesicles demonstrated promising potential theranostic applications in magnetic resonance imaging and cancer-targeted drug delivery.

Cancer stem cells (CSCs) have the capability to initiate tumor, to sustain tumor growth, to maintain the heterogeneity of tumor, and are closely linked to the failure of chemotherapy due to their self-renewal and multilineage differentiation capability with an innate resistance to cytotoxic agents. Herein, we designed and synthesized a novel anti-EpCAM (epithelial cell adhesion molecule)-monoclonal-antibody-labeled CSCs-targeting, noncytotoxic and pH-sensitive block copolymer vesicle as a nanocarrier of anticancer drug and siRNA (to overcome CSCs drug resistance by silencing the expression of oncogenes). This vesicle shows high delivery efficacy of both anticancer drug doxorubicin hydrochloride (DOX·HCl) and siRNA to the CSCs because it is labeled by the monoclonal antibodies to the CSCs-surface-specific marker. Compared to non-CSCs-targeting vesicles, the DOX·HCl or siRNA loaded CSCs-targeting vesicles exhibited much better CSCs killing and tumor growth inhibition capabilities with lower toxicity to normal cells (IC50,DOX decreased by 80%), demonstrating promising potential applications in nanomedicine.

Fabrication of membranes with excellent biocompatibility and bioactivity remains an important technical challenge in bone tissue engineering. In this paper, poly(l-lactic-co-glycolic acid) (PLGA)–SBA15 (Santa Barbara Amorphous 15) composite membranes were prepared by using an electrospinning technique; PLGA was used as a biocompatible and biodegradable polymer and SBA15 was used as a mesoporous silica. The PLGA–SBA15 composite membrane facilitates the cell attachment and the cell proliferation versus pure PLGA membrane where human bone marrow-derived mesenchymal stem cells (hMSCs) were seeded. Furthermore, the analysis of alkaline phosphatase (ALP) activity indicated that this PLGA–SBA15 composite membrane has better osteogenic induction compared with the pure PLGA membrane. Moreover, the presence of SBA15 increased the loading efficiency of the recombinant human bone morphogenetic protein-2 (rhBMP-2) to the membranes. Furthermore, the composite membrane had optimized sustained release of rhBMP-2. Overall, this PLGA–SBA15 composite is an excellent material for bone tissue engineering.Keywords: bioactivity; bone tissue engineering; electrospinning; PLGA; SBA15

The high incidence of bacterial infection and the growing resistance of bacteria to conventional antibiotics have resulted in the strong need for the development of new generation of antibiotics. Nano-sized particles have been considered as novel antibacterial agents with high surface area and high reactivity. The overall antibacterial properties of antimicrobial nanostructures can be significantly enhanced compared with conventional antibacterial agents not in a regular nanostructure, showing a better effect in inhibiting the growth and reproduction of microbials such as bacteria and fungi, etc. In this review, recent advances in the research and applications of antimicrobial polymeric nanostructures have been highlighted, including silver-decorated polymer micelles and vesicles, antimicrobial polymer micelles and vesicles, and antimicrobial peptide-based vesicles, etc. Furthermore, we proposed the current challenges and future research directions in the field of antibacterial polymeric nanostructures for the real-world biomedical applications.

Presented in this paper is a hybrid polymer/titanium dioxide (TiO2) vesicle that has excellent UV-screening efficacy and strong capacity to encapsulate antioxidant agents. Poly(ethylene oxide)-block-poly(2-(dimethylamino)ethyl methacrylate)-block-polystyrene (PEO-b-PDMAEMA-b-PS) triblock terpolymer was synthesized by atom transfer radical polymerization (ATRP) and then self-assembled into vesicles. Those vesicles showed excellent UV-screening property due to the scattering by vesicles and the absorption by PS vesicle membrane. The selective deposition of solvophobic tetrabutyl titanate in the PDMAEMA shell and the PS membrane of the vesicles led to the formation of polymer/TiO2 hybrid vesicles, resulting in an enhanced UV-screening property by further reflecting and scattering UV radiation. The vesicles can effectively encapsulate antioxidant agents such as ferulic acid (up to 57%), showing a rapid antioxidant capability (within 1 min) and a long-lasting antioxidant effect.Keywords: antioxidant agent; self-assembly; titanium dioxide; triblock terpolymer; UV screening; vesicle

We report the first enzymatically degradable polymer vesicle decorated with silver nanoparticles, which showed low cytotoxicity against human normal liver L02 cells near the minimum inhibitory concentrations (MICs) but excellent antibacterial efficacy against both Gram-negative and Gram-positive bacteria with quite low MICs of 3.56 μg mL−1 and 7.12 μg mL−1, respectively, exhibiting promising potential applications in nanomedicine.

It is a theoretical and technical challenge to construct well-defined nanostructures such as vesicles from fully hydrophilic homopolymers in pure water. In this paper, we incorporate one terminal alkynyl group into a fully hydrophilic linear or non-linear homopolymer to drive its unusual self-assembly in aqueous solution to form multicompartment vesicles, spherical compound micelles, flower-like complex particles, etc., which have been confirmed by transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic/static light scattering (DLS/SLS) and drug encapsulation experiments. The formation of poly(N-isopropyl acrylamide) (NIPAM) and poly[oligo(ethylene glycol) methacrylate] (POEGMA475) self-assemblies is mainly determined by the terminal alkynyl group itself (typically 1–3 wt%) while it is independent of other factors such as traditional hydrophobic–hydrophilic balance. Moreover, upon increasing the chain length of PNIPAM homopolymers, multicompartment vesicles, spherical micelles, and large flower-like complex particles can be obtained during the self-assembly process. In contrast, smaller micelles were formed when the kind of terminal alkynyl group attached to the PNIPAM chain was changed from a propargyl isobutyrate group to a (di)propargyl 2-methylpropionamide group. Particularly, a long chain hyperbranched structure with lots of terminal alkynyl groups induces the formation of vesicles. Also, the encapsulation experiment of doxorubicin hydrochloride was employed to further distinguish vesicular and micellar nanostructures. Additionally, the terminal alkynyl group-driven self-assembly has been applied to hydrophilic POEGMA475 homopolymers to afford similar nanostructures to PNIPAM homopolymers such as multicompartment vesicles and spherical compound micelles. Our study has opened up a new way to prepare hydrophilic homopolymer self-assemblies with tunable morphology.

Presented in this article is the proof of principle that silver nanoparticles can be decorated on homopolymer vesicles. The homopolymer vesicles are prepared by self-assembly of poly(2-(2-ethoxyethoxy)ethyl acrylate) (PEEA) in water/tetrahydrofuran (THF) solvent mixture. The –COOH end groups on the surface of the homopolymer vesicle facilitate the growth of ultrafine silver nanoparticles because of the electrostatic interactions between the negatively charged carboxyl group and positively charged Ag+ ions, which were in situ reduced by sodium borohydride (NaBH4). Those silver-decorated PEEA homopolymer vesicles exhibit good antibacterial activity against both Gram-positive and Gram-negative bacteria. This strategy may be extended to prepare more economic antibacterial agents and catalysts.

We report the reduction of 4-nitrophenol catalyzed by silver nanoparticles supported on polymer micelles and vesicles which can significantly improve the stability, dispersibility and catalytic activity of silver nanoparticles even at one ppm.

Copper nanoparticles are often susceptible to rapid oxidation in water. We report a water-dispersible and long-term stable copper nanoparticle protected by a block copolymer micelle that can effectively inhibit the access of oxygen to the copper inside its hydrophobic core, providing a sufficient diffusion barrier against oxidation in water.

The efficient intracellular drug delivery is an important challenge due to the slow endocytosis and inefficient drug release of traditional delivery vehicles such as symmetrical polymer vesicles, which have the same coronas on both sides of the membrane. Presented in this paper is a noncytotoxic poly(ethylene oxide)-block-poly(caprolactone)-block-poly(acrylic acid) (PEO113-b-PCL132-b-PAA15) triblock copolymer vesicle with an asymmetrical structure. The biocompatible exterior PEO coronas are designed for stealthy drug delivery; The pH-responsive interior PAA chains are designed for rapid endosomal escape and enhanced drug loading efficiency. The hydrophobic PCL vesicle membrane is for biodegradation. Such asymmetrical polymer vesicle showed high doxorubicin (DOX) loading efficiency and good biodegradability under extracellular enzymatic conditions. Compared with three traditional symmetrical vesicles prepared from PEO113-b-PCL110, PEO43-b-PCL98-b-PAA25, and PAA21-b-PCL75 copolymers, the DOX-loaded asymmetrical PEO113-b-PCL132-b-PAA15 polymer vesicles exhibited rapid endocytosis rate and much faster endosomal escape ability, demonstrating promising potential applications in nanomedicine.

The facile loading of sensitive and fragile biomacromolecules, such as glucose oxidase, hemoglobin, and ribonucleic acid (RNA), via synthetic vehicles directly in pure aqueous media is an important technical challenge. Inspired by the nucleus pore complex that connects the cell nucleus and the cytoplasm across the nuclear envelope, here we describe the development of a kind of polymeric nuclear envelope-like vesicle (NEV) to address this problem. The NEV is tailored to form the polymer pore complex (70 nm, similar to a nucleus pore complex) within the vesicle membrane based on nanophase segregation, which is confirmed via fluorescence spectrometry and dynamic light scattering (DLS) during self-assembly. This pH-triggered polymer pore complex can mediate the transportation of biomacromolecules across the vesicle membrane. Moreover, the NEVs facilitate the natural consecutive enzyme-catalyzed reactions via the H+ sponge effect. This simple strategy might also be extended for mimicking other synthetic cell organelles.Keywords: biocatalysis; biomacromolecule encapsulation; lateral segregation mechanism; nuclear envelope; polymer vesicles

Homopolymers have been considered as a nonideal building block for creating well-defined nanostructures due to their fuzzy boundary between hydrophobic and hydrophilic moieties. However, this unique fuzzy boundary may provide some opportunities for fabricating functional nanomaterials. Presented in this paper is a pH-responsive multifunctional homopolymer vesicle based on poly[2-hydroxy-3-(naphthalen-1-ylamino)propyl methacrylate] (PHNA). This vesicle is confirmed to be an excellent supporter for gold nanoparticles (AuNPs) to facilitate the reduction reaction of 4-nitrophenol (4-NP). The pH-responsive vesicle membrane favors the effective embedding and full immobilization of AuNPs because it is kinetically frozen under neutral and basic environments, preventing AuNPs from aggregation. Meanwhile, there is a synergistic effect between the AuNPs and the supporter (PHNA vesicle). Due to the π–π interaction between the naphthalene pendants in every repeat unit of PHNA and the extra aromatic compounds, a substrate-rich (high concentration of 4-NP) microenvironment can be created around AuNPs, which can dramatically accelerate the AuNPs-catalyzed reactions. In addition, we proposed a method for more accurately determining the membrane thickness of rigid polymer vesicles from TEM images based on “stack-up” vesicles, which may overturn the measuring method commonly used by far. Moreover, proof-of-concept studies showed that those homopolymer vesicles may be used as a powerful adsorbent for effective water remediation to remove trace carcinogenic organic pollutants such as polycyclic aromatic hydrocarbons to below parts per billion (ppb) level at a very fast rate based on the π–π interaction between the naphthalene pendants in PHNA vesicle and polycyclic aromatic hydrocarbons. Overall, this multifunctional homopolymer vesicle provides an alternative insight on preparing effective recyclable AuNPs-decorated nanoreactor and powerful water remediation adsorbent.Keywords: homopolymer vesicles; membrane thickness determination; pH-responsive; water remediation; π−π interaction

Presented in this article is the preparation of a new theranostic vesicle which exhibits excellent in vitro and in vivo T1 magnetic resonance (MR) imaging contrast effect and good anticancer drug delivery ability. The theranostic vesicle has been easily prepared based on an amphiphilic biocompatible and biodegradable dibock copolymer, poly(ethylene glycol)-block-poly(l-lactic-co-glycolic acid) (PEG-b-PLGA) and bovine serum albumin-gadolinium (BSA-Gd) complexes. Dynamic light scattering (DLS), transmission electron microscopy (TEM), UV–vis spectroscopy, and inductively coupled plasma atomic emission spectroscopy (ICP-AES) measurements confirmed the formation and physiological stability of BSA-Gd@PEG-b-PLGA vesicles. Furthermore, the in vitro and in vivo MR imaging experiments revealed their excellent T1-weighted MR imaging function. Red blood cell hemolysis and cytotoxicity experiments confirmed their good blood compatibility and low cytotoxicity. Doxorubicin (DOX) loading and release experiments indicated a more retarded release rate of DOX in those theranostic vesicles than sole PEG-b-PLGA nanoparticles without BSA. Overall, this new biocompatible and biodegradable vesicle shows promising potential in theranostic applications.

Presented in this paper is an “armed” high-genus block copolymer vesicle (g = 18) which has excellent blood compatibility and more internal barriers than simple polymer vesicles (g = 0) for controlled anti-cancer drug delivery. The high-genus vesicle also shows better antibacterial activity against both Gram-positive and Gram-negative bacteria without quaternary ammonium moieties or the loading of any external antibiotics compared to the non-self-assembled individual polymer chains, or a conventional simple vesicle. This high-genus polymer vesicle was prepared by the self-assembly of PMEO2MA20-b-PTA20 diblock copolymers in DMF–water, where PMEO2MA is thermo-responsive poly[2-(2-methoxyethoxy)ethyl methacrylate] and PTA is pH-responsive and antibacterial poly[2-(tert-butylaminoethyl) methacrylate]. Doxorubicin (DOX) loading/release experiments revealed a retarded release rate of DOX in high-genus block copolymer vesicles than conventional simple vesicles, which could be used as an efficient drug delivery carrier with more internal barriers for drug molecules than conventional simple vesicles. Moreover, this “armed” drug delivery vehicle makes antibacterial and anti-cancer therapeutic processes proceed spontaneously, representing a safer and more efficient drug delivery system in nanomedicine.

We report an unusual homopolymer vesicle, which has a soft bilayer membrane composed of oligo(ethyleneoxy) side chains (OEs) with a gradually decreased packing density from the centre of the membrane to both margins, exhibiting thermo-responsive zeta potential and dispersibility and showing potential applications for anti-cancer drug delivery.

A novel thermo- and pH-responsive antimicrobial diblock copolymer has been synthesized and directly dissolved in water to form polymer vesicles upon simply raising the temperature. Compared to individual polymer chains, polymer vesicles exhibit much better antimicrobial efficacy against both Gram-negative and Gram-positive bacteria under physiological conditions with neither quaternary ammonium moieties nor the loading of any external antibiotics as a result of their increased local concentration of cationic charge.

We report a role-switching method for preparing ultrafine water-dispersible silver nanoparticles with long-term stability based on a soft deformable block copolymer vesicle. Those ultrafine silver nanoparticles showed excellent antibacterial efficacy against both Gram-negative and Gram-positive bacteria with quite low minimum inhibitory concentrations (MICs) of 16.9 μg mL−1 and 8.45 μg mL−1, respectively.

Antibacterial polypeptides as ancient immune defense systems are effective against bacteria. Here we report a novel kind of “armed” carrier: an antibacterial polypeptide-grafted chitosan-based nanocapsule with an excellent antibacterial efficacy against both Gram-positive and Gram-negative bacteria. This nanocapsule also has excellent blood compatibility and low cytotoxicity. Patients after tumor surgery may benefit from this “armed” carrier because it is highly anti-inflammation and is able to deliver anticancer and antiepileptic drugs simultaneously.

TiO2 nanoparticle has been considered as a safe sunscreen agent to reduce the skin cancer risk when exposed to sunlight. However, recently it was found that TiO2 particles accelerate the photodamage of skin due to their photocatalytic degradation activity. To effectively eradicate this unwanted effect, we present a new strategy toward the preparation of organic/inorganic hybrid polymer/TiO2 nanoparticles with highly effective UV-screening property but eliminated photocatalytic activity. We prepared new polymer micelles with corona–shell–core structure based on self-assembly of poly(ethylene oxide)-block-poly(2-(dimethylamino)ethyl methacrylate)-block-poly(styrene) (PEO-b-PDMA-b-PS) triblock copolymer. Selective deposition of hydrophobic tetrabutyl titanate (TBT) in the PDMA shell in polar solvent leads to a thin PDMA/TiO2 hybrid layer (∼8 nm), which can not only effectively reflect UV rays but also eliminate its photocatalytic ability to protect skin. The sol–gel reactions of TBTs in the PS core domain lead to a PS/TiO2 hybrid core, which can also absorb/reflect UV lights by PS/TiO2. The biocompatible PEO coronas can prevent direct contact of TiO2 with skin. Moreover, sol–gel reactions in the PDMA and PS domains can stabilize the triblock copolymer micelles, which offer the promising potential for further formulations in aqueous solution. The ATRP kinetics confirmed that PEO-b-PDMA-b-PS triblock copolymer can be synthesized in one pot, which simplified the synthetic procedure of copolymers. TEM and DLS studies revealed the morphology and size of self-assembled polymer micelles and the subsequent polymer/TiO2 hybrid nanoparticles upon sol–gel reactions. UV experiments confirmed the highly efficient UV screening activity but eliminated photocatalytic property of polymer/TiO2 hybrid nanoparticles. For example, at extremely low TiO2 content in solution (10 ppm of polymer/TiO2 solid), ∼70% UV radiation can be blocked compared to pure organic polymer micelle, which is also much more efficient than commercially available TiO2 nanoparticles (P25). UV and DLS studies confirmed the ultrahigh stability of polymer/TiO2 hybrid nanoparticles upon strong UV radiation, which is suitable for long-term applications. Nitrogen adsorption/desorption experiment revealed that the ultralow surface area of TiO2 nanoparticles (1.6 m2 g–1) is consistent with their extremely poor photocatalytic performance.

Presented in this article is the synthesis of a new class of block copolymer, poly(ethylene oxide)-block-poly(tert-butyl acrylate-stat-acrylic acid) [PEO-b-P(AA-stat-tBA)], which can self-assemble into polymer vesicles with tuneable sizes at various conditions. The biocompatible and hydrophilic PEO chains form the vesicle coronas, while the PAA-stat-PtBA chains form the membrane. Superparamagnetic iron oxide nanoparticles (SPIONs) were generated in situ within the membrane of the polymer vesicles by nanoprecipitation. 1H NMR, GPC, DLS, TGA, VSM and TEM were employed to characterize the structure and properties of the block copolymer, polymer vesicles and Fe3O4-decorated magnetic polymer vesicles. The water-dispersible, biocompatible, drug deliverable and superparamagnetic polymer vesicles exhibited excellent colloidal stability at a range of pH conditions and very high T2 relaxivity, demonstrating ultra-sensitivity for magnetic resonance imaging and promising potential applications in nanomedicine.

New amphiphilic ABC triblock copolymers have been designed and self-assembled into water-dispersible and biodegradable polymer micelles, which exhibit good antibacterial activities without quaternary ammonium moieties or the loading of any external antibiotics due to the increased local concentration of cationic charge in the polymer micelles compared to the un-self-assembled individual polymer chains.

It is well known that silver nanoparticles have excellent antibacterial activities. However, to prepare well-defined, water-dispersible and long-term stable silver nanoparticles still remains insufficient. Presented in this paper are the design and preparation of new water-dispersible silver-decorated polymer vesicles and micelles based on a new kind of amphiphilic block-statistical copolymer, PEO-b-P(DMA-stat-tBA) (polymer 1) and its partially hydrolyzed derivative, PEO-b-P(DMA-stat-tBA-stat-AA) (polymer 2). Here PEO stands for poly(ethylene oxide), DMA for 2-(dimethylamino)ethyl methacrylate, tBA for t-butyl acrylate and AA for acrylic acid. PEO and poly(tBA) are designed to provide permanent hydrophilicity and hydrophobicity for macromolecular self-assembly in water, respectively. Poly(DMA) is introduced for the coordination of Ag+ ions to form silver nanoparticles in situ upon reduction. Poly(AA) is designed to serve the scaffold for the silver nanoparticle formation in the micelle core by electrostatic interactions with Ag+ ions. The silver-decorated polymer vesicles and micelles have been prepared in five steps: Firstly, polymer 1 was synthesized by Atom Transfer Radical Polymerization (ATRP) in the presence of CuBr/PMDETA in methanol at 60 °C. Secondly, a fraction of hydrophobic poly(tBA) in polymer 1 was hydrolyzed into hydrophilic and functional poly(acrylic acid) (PAA) to form polymer 2 in the presence of trifluoroacetic acid (TFA). Thirdly, polymer 1 was self-assembled into polymer vesicles with tuneable sizes ranged from 100–700 nm in basic water–DMF and polymer micelles with ∼50 nm diameter in neutral water–DMF, respectively. Polymer 2 was self-assembled into small micelles with ∼20 nm diameter by direct dissolution in water. Fourthly, the silver precursor AgNO3 was introduced into the polymer micelle or polymer vesicle solution where the Ag+ ion was absorbed in the core of the micelles or the membrane of the vesicles. Finally, the Ag nanoparticles were formed in the core of the micelles or the membrane of the vesicles when the reducing agent sodium borohydride was introduced. 1H NMR, GPC, DLS, UV and TEM were employed to characterize the structure and composition of the block copolymers, polymer micelles and vesicles, and silver-decorated polymer micelles and vesicles. Those water-dispersible silver-decorated polymer micelles and vesicles showed excellent antibacterial efficacy against Escherichia coli (E. coli) with quite low minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).

Polymer vesicles have been widely explored as drug delivery carriers. However, there are still several notable problems in the determination of the drug loading content (DLC) and the drug loading efficiency (DLE) of the drug delivery vehicles. Presented in this paper is the reconsideration of various important factors in the measurement of the DLC and DLE based on an ‘instant’ biocompatible and biodegradable polymer vesicle which can be directly dissolved in water, with a focus on the study on the time for removing the free drug. Firstly, an anti-cancer drug, doxorubicin (DOX), was successfully encapsulated into a highly biocompatible and biodegradable poly(ε-caprolactone)-block-poly[2-(methacryloyloxy)ethyl phosphorylcholine] (PCL-b-PMPC) diblock copolymer vesicle. Secondly, a specific methodology for removing the unencapsulated drug by dialysis method before the drug release experiment has been established to verify the DLC and the DLE of DOX. A number of important factors have been investigated, such as the period of time for removing the free drug, the temperature and the volume of water outside the dialysis tube, etc. Finally, the DOX release experiment was carried out at pH 5.0 and pH 7.4 with the cumulative release percentages of 55% and 35% after 24 h when the DOX feeding was 1.0 mg. As PCL-b-PMPC vesicles absorb UV light, the DOX encapsulated in polymer vesicles was calculated by subtracting the UV absorbance of vesicle solution from the UV absorbance of DOX-loaded vesicle solution at different DOX feedings of 1.0, 3.0 and 5.0 mg. We also found the appropriate calibration curves at different solution conditions were of great significance for the calculation of DLC and DLE.

We have previously reported the preparation of a novel pH-sensitive and biocompatible polymer vesicle in pure water based on the spontaneous self-assembly of a diblock copolymer, PMPC-b-PDPA, where PMPC is poly[2-(methacryloyloxy)ethyl phosphorylcholine] and PDPA is poly[2-(diisopropylamino)ethyl methacrylate] ( J. Am. Chem. Soc. 2005, 127, 17982). Herein, we intend to report the strategy for controlling the pH trigger points of association/dissociation of pH-responsive polymer vesicles for anticancer drug delivery. We introduced a reactive block, poly[2-(dimethylamino)ethyl methacrylate] (PDMA) into the above diblock copolymer to form reactive PMPC-b-PDMA-b-PDPA and PMPC-b-PDPA-b-PDMA triblock copolymers, as well as PMPC-b-P(DMA-stat-DPA) block-statistical copolymer by atom transfer radical polymerization (ATRP) in methanol at room temperature. As a result of different block length of PDPA, the introduction of PDMA chain at different positions, and different initial copolymer concentrations, those block copolymer vesicles showed tunable pH trigger points and various isoelectric points (IEPs) in aqueous solution. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) studies confirmed that the block copolymers with relatively long PDPA block form polymer vesicles by simply tuning the solution pH in pure water. Above pH 6.2, the PDPA block becomes hydrophobic so it forms the vesicle membrane. In all cases, the hydrophilic PMPC chains form the vesicle coronas. The PDMA chains are designed in three different positions. In PMPC-b-PDMA-b-PDPA vesicles, the PDMA chains form the middle shell between the PDPA vesicle membrane and the PMPC vesicle corona. In PMPC-b-PDPA-b-PDMA vesicles, the PDMA can mix with PMPC to serve as mixed coronas. In PMPC-b-P(DMA-stat-DPA) vesicles, the reactive PDMA chains can be incorporated into the vesicle membrane, which provides an effective strategy regarding the immobilization of vesicles by selective quaternization of PDMA with a bifunctional cross-linker, such as 1,2-bis(2-iodoethoxy)ethane (BIEE). The degree of cross-linking can be tuned by varying the molar ratio of PDMA to BIEE, which was further investigated by 1H NMR, DLS, and TEM, suggesting tunable permeability of vesicle membrane. The triblock copolymer vesicles were able to encapsulate anticancer drugs such as DOX, exhibiting obviously retarded release profile at physiological conditions.

Anisotropic particles, such as patchy, multicompartment and Janus particles, have attracted significant attention in recent years due to their novel morphologies and diverse potential applications. The non-centrosymmetric features of these particles make them a unique class of nano- or micro-colloidal materials. Patchy particles usually have different compositional patches in the corona, whereas multicompartment particles have a multi-phasic anisotropic architecture in the core domain. In contrast, Janus particles, named after the double-faced Roman god, have a strictly biphasic geometry of distinct compositions and properties in the core and/or corona. The term Janus particles, multicompartment particles and patchy particles frequently appears in the literature, however, they are sometimes misused due to their structural similarity. Therefore, in this critical review we classify the key features of these different anisotropic colloidal particles and compare structural properties as well as discuss their preparation and application. This review brings together and highlights the significant advances in the last 2 to 3 years in the fabrication and application of these novel patchy, multicompartment and Janus particles (98 references).

Improving the relaxivity of magnetic resonance imaging (MRI) contrast agents is an important challenge for cancer theranostics. Herein we report the design, synthesis, characterization, theoretical analysis and in vivo tests of a superparamagnetic polymersome as a new MRI contrast agent with extremely high T2 relaxivity (611.6 mM−1s−1). First, a noncytotoxic cancer-targeting polymersome is synthesized based on a biodegradable diblock copolymer, folic acid-poly(l-glutamic acid)-block-poly(ε-caprolactone) [FA-PGA-b-PCL]. Then, ultra-small superparamagnetic iron oxide nanoparticles (SPIONs) are in situ generated in the hydrophilic PGA coronas of polymersomes to afford magnetic polymersomes. The in vivo MRI assay revealed prominent negative contrast enhancement of magnetic polymersomes at a very low Fe dose of 0.011 mmol/kg. Moreover, this cancer-targeting magnetic polymersome can effectively encapsulate and deliver anticancer drug to inhibit the tumor growth, demonstrating promising theranostic applications in biomedicine.

The high incidence of bacterial infection and the growing resistance of bacteria to conventional antibiotics have resulted in the strong need for the development of new generation of antibiotics. Nano-sized particles have been considered as novel antibacterial agents with high surface area and high reactivity. The overall antibacterial properties of antimicrobial nanostructures can be significantly enhanced compared with conventional antibacterial agents not in a regular nanostructure, showing a better effect in inhibiting the growth and reproduction of microbials such as bacteria and fungi, etc. In this review, recent advances in the research and applications of antimicrobial polymeric nanostructures have been highlighted, including silver-decorated polymer micelles and vesicles, antimicrobial polymer micelles and vesicles, and antimicrobial peptide-based vesicles, etc. Furthermore, we proposed the current challenges and future research directions in the field of antibacterial polymeric nanostructures for the real-world biomedical applications.

The apparent size increase of poly(N-isopropyl acrylamide) (PNIPAM)-based polymeric micelles upon heating was usually ascribed to their volume growth or aggregation in aqueous solution. Herein we designed a photo-cross-linkable PNIPAM-based copolymer and proposed another thermo-responsive behaviour – fusion, which is disclosed by transmission electron microscopy (TEM) after in situ fixing morphologies at desired temperatures.

Anisotropic particles, such as patchy, multicompartment and Janus particles, have attracted significant attention in recent years due to their novel morphologies and diverse potential applications. The non-centrosymmetric features of these particles make them a unique class of nano- or micro-colloidal materials. Patchy particles usually have different compositional patches in the corona, whereas multicompartment particles have a multi-phasic anisotropic architecture in the core domain. In contrast, Janus particles, named after the double-faced Roman god, have a strictly biphasic geometry of distinct compositions and properties in the core and/or corona. The term Janus particles, multicompartment particles and patchy particles frequently appears in the literature, however, they are sometimes misused due to their structural similarity. Therefore, in this critical review we classify the key features of these different anisotropic colloidal particles and compare structural properties as well as discuss their preparation and application. This review brings together and highlights the significant advances in the last 2 to 3 years in the fabrication and application of these novel patchy, multicompartment and Janus particles (98 references).

Presented in this paper is an “armed” high-genus block copolymer vesicle (g = 18) which has excellent blood compatibility and more internal barriers than simple polymer vesicles (g = 0) for controlled anti-cancer drug delivery. The high-genus vesicle also shows better antibacterial activity against both Gram-positive and Gram-negative bacteria without quaternary ammonium moieties or the loading of any external antibiotics compared to the non-self-assembled individual polymer chains, or a conventional simple vesicle. This high-genus polymer vesicle was prepared by the self-assembly of PMEO2MA20-b-PTA20 diblock copolymers in DMF–water, where PMEO2MA is thermo-responsive poly[2-(2-methoxyethoxy)ethyl methacrylate] and PTA is pH-responsive and antibacterial poly[2-(tert-butylaminoethyl) methacrylate]. Doxorubicin (DOX) loading/release experiments revealed a retarded release rate of DOX in high-genus block copolymer vesicles than conventional simple vesicles, which could be used as an efficient drug delivery carrier with more internal barriers for drug molecules than conventional simple vesicles. Moreover, this “armed” drug delivery vehicle makes antibacterial and anti-cancer therapeutic processes proceed spontaneously, representing a safer and more efficient drug delivery system in nanomedicine.

Presented in this article is the synthesis of a new class of block copolymer, poly(ethylene oxide)-block-poly(tert-butyl acrylate-stat-acrylic acid) [PEO-b-P(AA-stat-tBA)], which can self-assemble into polymer vesicles with tuneable sizes at various conditions. The biocompatible and hydrophilic PEO chains form the vesicle coronas, while the PAA-stat-PtBA chains form the membrane. Superparamagnetic iron oxide nanoparticles (SPIONs) were generated in situ within the membrane of the polymer vesicles by nanoprecipitation. 1H NMR, GPC, DLS, TGA, VSM and TEM were employed to characterize the structure and properties of the block copolymer, polymer vesicles and Fe3O4-decorated magnetic polymer vesicles. The water-dispersible, biocompatible, drug deliverable and superparamagnetic polymer vesicles exhibited excellent colloidal stability at a range of pH conditions and very high T2 relaxivity, demonstrating ultra-sensitivity for magnetic resonance imaging and promising potential applications in nanomedicine.

New amphiphilic ABC triblock copolymers have been designed and self-assembled into water-dispersible and biodegradable polymer micelles, which exhibit good antibacterial activities without quaternary ammonium moieties or the loading of any external antibiotics due to the increased local concentration of cationic charge in the polymer micelles compared to the un-self-assembled individual polymer chains.

We report an unusual homopolymer vesicle, which has a soft bilayer membrane composed of oligo(ethyleneoxy) side chains (OEs) with a gradually decreased packing density from the centre of the membrane to both margins, exhibiting thermo-responsive zeta potential and dispersibility and showing potential applications for anti-cancer drug delivery.

Self-assembly of amphiphilic homopolymers composed of both hydrophilic and hydrophobic components in each repeating unit is burgeoning in recent years due to their facile synthesis compared to block copolymers. However, ordered homopolymer nanostructures are very limited, and solid TEM evidence for the formation of vesicles and other complex morphologies is necessary to address the mechanistic insights of homopolymer self-assembly. Presented in this article are the studies on the morphological transition, the structure analysis, and the formation mechanism of homopolymer self-assembly. First, a series of amphiphilic homopolymers, poly(2-hydroxy-3-phenoxypropyl acrylate) (PHPPA) with various molecular weights (MWs) have been designed and synthesized by the reversible addition–fragmentation chain transfer (RAFT) process. Second, upon simply changing the homopolymer’s chain length or cosolvents during self-assembly, a wide range of new homopolymer-based nanostructures can be obtained, such as large compound micelles (LCMs), simple vesicles, large compound vesicles (LCVs), and hydrated large compound micelles (HLCMs) as a result of different intensity of inter/intra-polymer hydrogen bonding in the homopolymer self-assemblies. Moreover, micrometer-sized branched cylinders are formed by premixing PHPPA36 and PHPPA103 homopolymers, which is not observed by self-assembly of PHPPA36 and PHPPA103 individually. Third, we claim that the structures of homopolymer self-assemblies are much different from their block copolymer analogues due to homopolymer’s fuzzy hydrophobic and hydrophilic domains compared to block copolymer’s distinct ones. We confirm that the structure of micelle core or vesicle membrane (alike to each other in nature) consists of both hydrophilic and hydrophobic moieties, which is different from block copolymer micelles or vesicles with hydrophobic cores or membranes. Also, a dye encapsulation experiment is employed to identify and distinguish a new nanostructure, HLCMs, from LCMs. Our study has provided a new perspective on homopolymer self-assembly.

Presented in this article is the template-free fabrication of nitrogen-doped hollow carbon spheres (N-HCSs) as electrode materials for high-performance supercapacitors based on scalable homopolymer vesicles, which are self-assembled from an amphiphilic homopolymer, poly(amic acid) (PAA). This homopolymer can be massively produced by simple stepwise polymerization at room temperature with a fast polymerization rate. For the first time, PAA homopolymer vesicles are carbonized to form N-HCSs with tunable porous structures and nitrogen contents (from 1.3% to 7.4%) by controlling the content of the cross-linker (melamine). This template-free method for fabricating N-HCSs is more environmentally friendly and does not involve tedious synthetic procedures compared to traditional template-based methods. More importantly, the N-HCSs exhibit excellent electrochemical performance with a very high specific capacitance (266.9 F g−1) after more than 1000 cycles when used as the active electrode material for the supercapacitor. The N-HCSs presented in this paper retain its specific capacitance as high as 84% at a very high current density (20 A g−1). Given the potential massive production and excellent electrochemical properties, the N-HCSs based on the carbonization of scalable PAA homopolymer vesicles are promising candidate electrode materials for energy storage devices.