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The clinical application of some natural molecules in therapy is usually limited due to the lack of feasible delivery systems. Core-shell nanocarriers (polymersomes and niosomes) are interesting stable nanocarriers that are biocompatible, biodegradable, and able to produce sustainable delivery. They can be modified and functionalized according to the application needed. In this report, we describe the synthesis of a smart and pH-responsive poly(ethylene oxide)-poly(lactide) polymersome (PEO-PL) and niosomes (NIO) loaded with GSH for efficient peptide delivery and potent application against advanced glycation end-products-related damages and toxicities. PEO-PL was constructed using the one-pot sequential anionic ring-opening polymerization method, while the niosomes were prepared via the thin film layer technique. The nanocarriers were characterized for their size and morphology by DLS and SEM. The formulations demonstrated a high encapsulation rate reaching 95% and showed increased sensitivity to release their content in acidic conditions (pH 5.5) compared with physiological media. PEO-PL showed a higher retention rate compared with the NIO. The nanocarriers showed no apparent toxicity even at high concentrations (400 mu g/mL). The MTT test demonstrated that HeLa cell lines were more sensitive to GSH than U87 cell lines starting from 100 and 400 mu g/mL, respectively. Testing the synthesized core-shell nanocarriers on altered proteins showed prolonged and high prevention rates of glycation, aggregation, and oxidation without hindering the effect of GSH. These bioresponsive nanocarriers appear as an interesting platform for biomedicine and therapy.

This manuscript describes fabrication of a cross-linked and nanoengineered three-dimensional matrix of polymersomes for encapsulation of macromolecular cargo such as enzymes. Our approach involves the integration of glucose oxidase (GOx) enzyme into networks of a polysaccharide-silica matrix. Direct chemical cross-linking occurs between the residual groups of alginate polymer and the alkoxysilane moieties in a palladium nanoparticle dispersion; a transformation in the chemical configuration of the alginate hydrogel along with precise control over the pore size distribution facilitate immobilization of enzyme. The activity of the polymersomes was evaluated by enzymatic oxidation of the glucose substrate in phosphate buffer through loading different concentrations of GOx. In situ generated H2O2 was decomposed by the as-synthesized Prussian blue nanoparticles, which serve as an excellent peroxidase mimetic. The functional enzyme polymersome system was utilized for in vitro detection of blood glucose values.

Amphiphilic diblock copolymers may assemble in aqueous solutions to form vesicles delimited by a polymeric double layer, also known as polymersomes, considered a more robust option to liposomes. Diblock copolymers may respond to pH, temperature, and other conditions. Because of such properties, polymersomes are currently being studied as drug delivery systems or as nanoreactors. pH-responsive polymersomes are potentially crucial because unusual pH gradients are present in cells under several physiological and pathological conditions. We synthesized two diblock copolymers of poly [2-(dimethylamino) ethyl methacrylate]-block-polystyrene (PDMAEMA-b-PS) via RAFT. We both developed new materials and better-understood polymersomes' properties with pH and temperature-responsive groups with these polymers. GPC, 1H-NMR, and FTIR characterized copolymers. The ionization equilibrium of the PDMAEMA amino groups on the polymersomes was analyzed by potentiometric titration and Zeta potential measurements. The hydrodynamic radius of the polymersomes in different pH and temperatures was analyzed by DLS. Entrapment of an electron paramagnetic resonance probe indicated the presence of a hydrophilic inner core. Negative staining transmission electron microscopy showed spherical aggregates and confirmed the diameter around 80 nm. These polymersomes with dual stimulus–response (i.e., pH and temperature) may be a platform for gene delivery and nanoreactors.

Self-assembly of amphiphilic block copolymers into polymersomes continues to be a hot topic in modern research on biomimetics. Their well-known and valued mechanical strength can be increased even further if they are cross-linked. These additional bonds prevent a collapse or disassembly of the polymersomes and open the way towards smart nanoreactors. A variety of chemistries have been applied to obtain the desired cross-linked polymersomes, and therefore, the chemical approaches performed over time will be highlighted in this mini-review. Due to the large number of studies, a selected set of photo-cross-linked and pH-sensitive polymersomes will be specifically highlighted. This system has proven to be a very potent candidate for the formation of nanoreactors and drug delivery systems, and even for the formation of functional multicompartment cell mimics.

Cancer cells have reductive and acidic environments as compared to the normal body cells. Development of reductive/acidic responsive polymersomes will play a major role in cancer therapy to trigger the release of the loaded drug. In our work, we synthesized three different reductive/acidic dual-responsive polymers, poly[(mPEG-SS-amino) (N,N-diisopropylethylenediamino)phosphazenes] (PPDPs) in different mole ratios of side groups. These PPDPs were characterized by 1H NMR, 31P NMR, FT-IR and GPC. After that, the PPDPs were allowed to self-assemble into drug-loaded polymersomes with high loading content and encapsulation efficiency of hydrophilic/hydrophobic anticancer drugs. The hydrophilic anticancer drug doxorubicin hydrochloride (DOX·HCl) and hydrophobic drug doxorubicin were used. These PPDPs-based polymersomes showed reductive/acidic stimuli-responsive release of anticancer drugs. Moreover, these polymersomes also exhibited suitable hydrodynamic diameters, which will facilitate the longtime circulation in bloodstream due to avoiding renal clearance and close contact to the tumor cells in vascular sections due to enhanced permeability and retention effect. Collectively, these developed polymersomes may provide an effective platform for anticancer drugs delivery.

Biocatalytic cascades guide complex, efficient and selective intracellular transformations. These unique features originate from the spatial organization of the biocatalysts in confined cellular environments that allow the directional channelling of reaction intermediates across the cells. Here we address efforts directed towards the development of synthetic cell analogues and supramolecular ensembles acting as nano/microenvironments for operating biocatalytic cascades. Multienzyme systems are integrated within metal–organic frameworks, polymersomes, lipid-stabilized microdroplets and hydrogel microparticles acting as cell-like containments. Also, multienzyme systems are spatially positioned on one-dimensional DNA wires, two-dimensional DNA strips or origami tiles, and three-dimensional DNA origami bundles or cages, and specific protein–protein interactions or peptide–protein complexes provide versatile scaffolds for engineering enzyme assemblies. Biocatalytic cascades operating on these scaffolds or in confined nano/microenvironments reveal substantially enhanced reaction yields compared with the analogous diffusional mixtures of the biocomponents. Mechanistic pathways accounting for the enhanced biocatalytic activities and future challenges in developing and applying biocatalytic cascades are presented. Spatial organization of biocatalytic cascades can improve their performance. In this Review Article, Itamar Willner and colleagues discuss technologies to artificially confine and localize enzyme cascades, the origin of observed rate enhancements and potential applications of such designed systems.

Vesicles constructed of either synthetic polymers alone (polymersomes) or a combination of polymers and lipids (lipo-polymersomes) demonstrate excellent long-term stability and ability to integrate membrane proteins. Applications using lipo-polymersomes with integrated membrane proteins require suitable supports to maintain protein functionality. Using lipo-polymersomes loaded with the light-driven proton pump bacteriorhodopsin (BR), we demonstrate here how the photocurrent is influenced by a chosen support. In our study, we deposited BR-loaded lipo-polymersomes in a cross-linked polyelectrolyte multilayer assembly either directly physisorbed on gold electrode microchips or cross-linked on an intermediary polyethersulfone (PES) membrane covalently grafted using a hydrogel cushion. In both cases, electrochemical impedance spectroscopic characterization demonstrated successful polyelectrolyte assembly with BR-loaded lipo-polymersomes. Light-induced proton pumping by BR-loaded lipo-polymersomes in the different support constructs was characterized by amperometric recording of the generated photocurrent. Application of the hydrogel/PES membrane support together with the polyelectrolyte assembly decreased the transient current response upon light activation of BR, while enhancing the generated stationary current to over 700 nA/cm2. On the other hand, the current response from BR-loaded lipo-polymersomes in a polyelectrolyte assembly without the hydrogel/PES membrane support was primarily a transient peak combined with a low-nanoampere-level stationary photocurrent. Hence, the obtained results demonstrated that by using a hydrogel/PES support it was feasible to monitor continuously light-induced proton flux in biomimetic applications of lipo-polymersomes.

In this paper, we report the polymersome-mediated intracellular delivery of pro-apoptotic BikDDA gene using two different peptide–copolymer covalent conjugation strategies specific for prostate cancer targeting. The BikDDA gene was used as a therapeutic agent on prostate cancer cells. The transfection efficiency of BikDDA-loaded poly[oligo(ethyleneglycol) methacrylate]-co-poly[2-(diisopropylamino) ethyl methacrylate] (P(OEG10MA)20-PDPA100) polymersomes revealed that they could serve as a suitable non-viral gene transfection tool. The targeted delivery of BikDDA into prostate cancer cells (LNCaP) using polymersomes was successfully carried out by conjugating the PSMA-targeting moiety (peptide 563) to P(OEG10MA)20-PDPA100 copolymer using either succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC) as a bifunctional linker between the thiol-bearing targeting peptide and amino-bearing P(OEG10MA)20-PDPA100 copolymer or attaching a maleimide-modified targeting peptide onto a thiol-terminated P(OEG10MA)20-PDPA100 copolymer. The pH-responsive and biocompatible polymersomes, conjugated with peptide 563, exhibited an enhanced cellular uptake by LNCaP cells in comparison to the healthy prostate epithelial cell line PNT1A, thus indicating the cell-specific delivery. The increased Bik mRNA expression and cell death in these LNCaP cells indicates high effectiveness of the targeting polymersomes. According to these results, we believe more efficient gene delivery systems via specifically targeted pH-sensitive polymersomes can be a promising approach and promote the development of novel therapies against prostate cancer.

Researchers have put significant efforts on developing versatile fluorescent polymeric systems due to their promising biological/biomedical labelling, tracking, monitoring, imaging, and diagnostic applications. However, complicated organic/polymeric synthesis or post-modification of these functionalized platforms is still a big obstacle for their further application and thereby provides clear motivation for exploring alternative strategies for the design and fabrication of easily available fluorescent systems. The marriage of supramolecular polymers and fluorescent imaging can provide a facile and dynamic manner instead of tedious and time-consuming synthesis due to the dynamic and reversible nature of noncovalent interactions. Herein, based on water-soluble pillararene/paraquat molecular recognition, we successfully prepare two amphiphilic polypseudorotaxanes which can self-assemble into supramolecular polymersomes in water. These polymersomes can be reversibly destroyed and reformed by tuning the solution pH. Attributed to the aggregation-induced emission of tetraphenylethylene groups, intense fluorescence can be introduced into the obtained supramolecular polymersomes. Furthermore, pH-triggered release of an encapsulated water-insoluble drug (doxorubicin) from the self-assembled fluorescent supramolecular polymersomes is also investigated.\ud \ud

Nature makes use of molecular machines to perform intricate functions in every significant biological process and to power macroscopic motion in organisms. Biomolecular motor proteins perform crucial tasks such as cell division, intracellular transport and mechanical actuation in biological cells. The rotary motor FoF1-ATPase is one of the most extensively studied biomolecular machines as a result of its vital physiological function. Research on the function of FoF1-ATPase can help to better understand the underlying biological processes and may also result in the development of biological molecular motor-based devices or even inspire the creative design and construction of artificial molecular machines. Recent advances in nanoscience and biotechnology have enabled engineering experiments with FoF1-ATPase that have achieved notable success. In this Review, we first outline the reconstitution of FoF1-ATPase into simple liposomes and polymersomes and then focus on recent progress in the reconstitution of FoF1-ATPase on layer-by-layer-assembled systems. The elaborate structural designs utilized in layer-by-layer-assembled systems to better mimic natural cell structures are introduced. The rational integration of functional components to achieve stimuli-responsive ATP syntheses from FoF1-ATPase-based biomimetic systems is highlighted. Finally, we address some remaining key challenges and speculate on future directions for the field. FoF1-ATPase is a vital molecular machine in organisms responsible for the catalytic synthesis of the basic energy unit ATP. In this Review, the development of FoF1-ATPase reconstitution into artificial architectures is discussed ultimately leading to the development of stimuli-responsive ATP synthesis.

Fluorescent vesicles have recently attracted increasing attention because of their potential applications in bioimaging, diagnostics, and theranostics, for example, in vivo study of the delivery and the distribution of active substances. However, fluorescent vesicles containing conventional organic dyes often suffer from the problem of aggregation-caused quenching (ACQ) of fluorescence. Fluorescent vesicles working with aggregation-induced emission (AIE) offer an extraordinary tool to tackle the ACQ issue, showing advantages such as high emission efficiency, superior photophysical stability, low background interference, and high sensitivity. AIE fluorescent vesicles represent a new type of fluorescent and functional nanomaterials. In this review, we summarize the recent advances in the development of AIE fluorescent vesicles. The review is organized according to the chemical structures and architectures of the amphiphilic molecules that constitute the AIE vesicles, i.e., small-molecule amphiphiles, amphiphilic polymers, and amphiphilic supramolecules and supramacromolecules. The studies on the applications of these AIE vesicles as stimuli-responsive vesicles, fluorescence-guided drug release carriers, cell imaging tools, and fluorescent materials based on fluorescence resonance energy transfer (FRET) are also discussed.

Co-delivery of anti-inflammatory siRNA and hydrophilic drug provides a promising approach for the treatment of ulcerative colitis (UC). However, lack of a suitable and efficient co-delivery carrier poses critical challenge against their utilization. We herein developed macrophage-targeting, reversibly crosslinked polymersomes (TKPR-RCP) based on the TKPR-modified, poly(ethylene glycol)-b-poly(trimethylene carbonate-co-dithiolane trimethylene carbonate)-b-polyethylenimine (PEG-P(TMC-DTC)-PEI) triblock copolymer, which could efficiently encapsulate TNF-α siRNA and dexamethasone sodium phosphate (DSP) in their hydrophilic core. The cationic PEI segments provided additional electrostatic interactions with cargo molecules to promote the encapsulation, and disulfide crosslinking of the polymersome membrane endowed the TKPR-RCP with high colloidal stability. Because the cationic PEI was embedded in the hydrophilic core, the polymersomes displayed neutral surface charge and thus possessed high serum stability. The TKPR-RCP co-encapsulating TNF-α siRNA and DSP could be efficiently internalized by macrophages (∼ 98%) and undergo redox-responsive membrane de-crosslinking to accelerate cargo release in the cytoplasm, thus inducing efficient gene silencing and anti-inflammatory effect. Intravenous injection of the co-delivery TKPR-RCP mediated potent and cooperative anti-inflammatory effect in inflamed colons of UC mice, and significantly prevented animals from colonic injury. This study therefore provides a promising approach for the co-delivery of hydrophilic drug/siRNA toward the treatment of inflammatory bowel diseases.

ObjectiveResearches proving methods for nano encapsulation of neonatal porcine islet-like cell clusters (NPCCs) using polymersomes (PSomes) formed using polymers of polyethylene glycol-block-poly lactide (PEG-b-PLA). Herein, our studies present efficient nano encapsulation procedure with minimal damage and loss of NPCCs. MethodsWe used N-hydroxysuccinimide (NHS) on the N-terminal of PSomes to induce binding of amine groups in the extracellular matrix surrounding NPCCs. F-10 culture medium with bovine serum albumin was used in the nano-encapsulation procedure to minimize damage and loss of NPCCs. Finally, we induced crosslinking between bi-functional PSomes (NHS-/NH2-PSomes). ResultsF-10 culture medium containing 0.25% BSA with pH of 7.3 minimized the damage and loss of NPCCs after nano-encapsulation as compared with using basic HBSS buffer (pH 8.0). Also, we induced the efficiency nano encapsulation through conjugation of PSomes using bi-functional PSomes (NHS-/NH2-PSomes).

Aggregation-induced quenching of porphyrin molecules as photosensitizer significantly reduces the quantum yield of the singlet oxygen generation, and it is able to decrease the efficacy of photodynamic therapy. We utilized amphiphilic copolymers in this work to precisely control porphyrin H-type and J-type aggregations in water. The amphiphilic copolymer bearing azobenzene, β-cyclodextrin, and porphyrin was successfully synthesized by the atom transfer radical polymerization technique. The azobenzene and β-cyclodextrin complex, as a host–guest supramolecular interaction, has great potential in the design of light-responsive nanocarriers. The amphiphilic block copolymer can be self-assembled into polymersomes, whose application in the generation of singlet oxygen has been also tested. We further demonstrate that, due to the stable H- and J-aggregates of porphyrin, which act as noncovalent cross-linking points, the structure of polymersomes can be reversible under light-stimulus. This formation method has the advantage of allowing for both the encapsulation of hydrophilic and hydrophobic molecules and release upon external light without any distinguishable changes in the structure. Furthermore, the morphology and particle size distribution of the polymersomes were also investigated by using transition electron microscopy, dynamic light scattering, and field emission scanning electron microscopy.

Over the past two decades, polymersomes have been widely investigated for the delivery of diagnostic and therapeutic agents in cancer therapy. Polymersomes are stable polymeric vesicles, which are prepared using amphiphilic block polymers of different molecular weights. The use of high molecular weight amphiphilic copolymers allows for possible manipulation of membrane characteristics, which in turn enhances the efficiency of drug delivery. Polymersomes are more stable in comparison with liposomes and show less toxicity in vivo. Furthermore, their ability to encapsulate both hydrophilic and hydrophobic drugs, significant biocompatibility, robustness, high colloidal stability, and simple methods for ligands conjugation make polymersomes a promising candidate for therapeutic drug delivery in cancer therapy. This review is focused on current development in the application of polymersomes for cancer therapy and diagnosis. Graphical abstract.

Extended-release local anesthetics (LAs) have drawn increasing attention with their promising role in improving analgesia and reducing adverse events of LAs. Nano-structured carriers such as liposomes and polymersomes optimally meet the demands of/for extended-release, and have been utilized in drug delivery over decades and showed satisfactory results with extended-release. Based on mature technology of liposomes, EXPAREL, the first approved liposomal LA loaded with bupivacaine, has seen its success in an extended-release form. At the same time, polymersomes has advances over liposomes with complementary profiles, which inspires the emergence of hybrid carriers. This article summarized the recent research successes on nano-structured extended-release LAs, of which liposomal and polymeric are mainstream systems. Furthermore, with continual optimization, drug delivery systems carry properties beyond simple transportation, such as specificity and responsiveness. In the near future, we may achieve targeted delivery and controlled-release properties to satisfy various analgesic requirements.

Triblock poly(e-caprolactone) – poly(ethylene glycol) – poly(e-caprolactone) (PCL-PEG-PCL) copolymers were synthesized and used to prepare polymersomes for controlled release of lovastatin (LOV) as hydrophobic drug. Biodegradable PCL-PEG-PCL copolymer nanoparticles were prepared and the drug loading, release, release kinetics, and anti-cancer activity of these drugs was investigated. The PCL-PEG-PCL copolymer was synthesized by ring-opening polymerization of e-caprolactone in the presence of mPEG as the initiator and Sn(Oct)2 as the catalyst. The synthesized copolymers and nanoparticles were characterized by FTIR, 1H NMR, DLS, and AFM techniques. The efficiency of drug loading and release from nanoparticles in vitro was studied by UV-Vis spectrophotometry. Additionally, MTT assays on HFF-2 cell lines were performed for determining the biocompatibility of polymersomes. Finally, the antiproliferative activity of polymersomes was examined on MCF-7 breast cancer cell line. The obtained results showed that the average diameter of nanoparticles was less than 57 nm. The loading capacity and encapsulation efficiency of LOV was 16.1 ± 0.36% and 59.01 ± 0.78%, respectively. In vitro release study showed that the release rate of polymersomes depended on pH and was higher at lower pH than under neutral condition. The result of cell viability assay on the MCF-7 line proved that bare nanoparticles showed little inherent cytotoxicity whereas the LOV-loaded nanoparticles were cytotoxic.

Although gas-filled microbubbles with high echogenicity are widely applied inclinical ultrasonography, the micron scale particle size impedes their use in the treatment of solid tumors,which are accessible to objects less than several hundred nanometers. We herein propose an unusual approach involving apH-induced core–shell micelle-to-vesicle transition to prepare ultrasound-sensitive polymeric nanospheres (polymersomes in structure) possessing multiple features, including nanosize, monodispersity, and incorporation of a phase-transitional imaging agent into the aqueous lumen. These features are not achievable via the conventional double-emulsion method for polymersome preparation. The nanospheres were constructed based on a novel triblock copolymer with dual pH sensitivity. The liquid-to-gas phase transition of the imaging agent induced by external low-frequency ultrasound may destroy the nanospheres for a rapid drug release, with simultaneous tissue-penetrating drug delivery inside a tumor. These effects may provide new opportunities for the development of an effective cancer therapy with few adverse effects.

Nature has engineered exquisitely responsive systems where molecular-scale information is transferred across an interface and propagated over long length scales. Such systems rely on multiple interacting, signalling and adaptable molecular and supramolecular networks that are built on dynamic, non-equilibrium structures. Comparable synthetic systems are still in their infancy. Here, we demonstrate that the light-induced actuation of a molecularly thin interfacial layer, assembled from a hydrophilic- azobenzene -hydrophobic diblock copolymer, can result in a reversible, long-lived perturbation of a robust glassy membrane across a range of over 500 chemical bonds. We show that the out-of-equilibrium actuation is caused by the photochemical trans-cis isomerization of the azo group, a single chemical functionality, in the middle of the interfacial layer. The principles proposed here are implemented in water-dispersed nanocapsules, and have implications for on-demand release of embedded cargo molecules.

Vesicular nanocarrier formulations confer the ability to deliver hydrophobic and hydrophilic cargos simultaneously to cells of interest in vivo. While liposomal formulations reached the clinic long ago, younger technologies such as polymeric vesicles (polymersomes) have yet to make the transition to clinical approval and use, in part due to difficulties in ensuring their safe and scalable production. In this work, we demonstrate the scalable production of poly(ethylene glycol)-block-poly(propylene sulfide) (PEG-bl-PPS) polymersomes via flash nanoprecipitation, and further show the safe administration of these nanocarriers to mice and non-human primates. In mice, PEG-bl-PPS polymersomes were found to be well tolerated at up to 200 mg/(kg·week). Following the administration of a more relevant 20 mg/(kg·week) dosage in non-human primates, polymersomes were found to associate with numerous phagocytic immune cell populations, including a remarkable 68% of plasmacytoid dendritic cells and > 95% of macrophages in the spleen, while showing no toxicity or abnormalities in the liver, kidney, spleen, or blood. Despite the presence of a dense PEG corona, neither anti-PEG antibodies nor complement activation were detected. This work provides evidence of the translatability of PEG-bl-PPS polymersomes into the clinic for therapeutic applications in humans.

Choline phosphate (CP) as a novel zwitterion possesses specific and excellent properties compared with phosphorylcholine (PC), as well as its polymer, such as poly(2-(methacryloyloxy)ethyl choline phosphate) (PMCP), has been studied extensively due to its unique characteristics of rapid cellular internalization via the sepcial quadrupole interactions with the cell membrane. Recently, we reported a novel PMCP-based drug delivery system to enhance the cellular internalization where the drug was conjugated to the polymer via reversible acylhydrazone bond. Herein, to make full use of this feature of PMCP, we synthesized the diblock copolymer poly(2-(methacryloyloxy)ethyl choline phosphate)-b-poly(2-(diisopropylamino)ethyl methacrylate) (PMCP-b-PDPA), which could self-assemble into polymersomes with hydrophilic PMCP corona and hydrophobic membrane wall in mild conditions when the pH value is ≥ 6.4. It has been found that these polymersomes can be successfully used to load anticancer drug Dox with the loading content of about 11.30 wt%. After the polymersome is rapidly internalized by the cell with the aid of PMCP, the loaded drug can be burst-released in endosomes since PDPA segment is protonated at low pH environment, which renders PDPA to transfer from hydrophobic to hydrophilic, and the subsequent polymersomes collapse thoroughly. Ultimately, the “proton sponge” effect of PDPA chain can further accelerate the Dox to escape from endosome to cytoplasm to exert cytostatic effects. Meanwhile, the cell viability assays showed that the Dox-loaded polymersomes exhibited significant inhibitory effect on tumor cells, indicating its great potential as a targeted intracellular delivery system with high efficiency.

CO2-responsive bowl-shaped polymersomes caused by osmotic pressure have been successfully designed and constructed. Upon CO2-stimulus, these polymersomes can transform from bowl-shape into wrinkled structure because of the restricted hydration effect. These promising polymersomes with special structure upon exposure to biological gas are expected to be useful in nanomedicine.

In the present study, we prepared a multi-drug delivery system based on reduction-sensitive paclitaxel (PTX) polymeric prodrug(PEG-b-PMPMC-g-PTX, PMP) polymersomes to co-deliver PTX, doxorubicin hydrochloride(DOX·HCl) and the P-glycoprotein(P-gp) inhibitor Tariquidar(TQR) to effectively reverse drug resistance by inhibiting the expression of P-gp and improving the accumulation of the encapsulated anticancer drugs. The PTX was linked to the backbone by reduction-sensitive disulphide, making the polymersomes prone to collapse in the reductive environment and to release the drugs. Transmission electron microscope(TEM) was used to confirm the morphology of polymeric assemblies. Moreover, the rupture process of polymersomes was verified by dynamic light scattering (DLS). The results of confocal laser scanning microscopy(CLSM) and flow cytometry indicate that the PMP/DOX·HCl/TQR three-drug-loaded polymersomes show the strongest fluorescence intensity for DOX·HCl compared with PMP/DOX·HCl polymersomes and free DOX·HCl in drug-resistant MCF-7/ADR cells. More importantly, the PMP/DOX·HCl/TQR multi-drug co-delivery system shows a greater growth-inhibitory effect on tumour cells than the other two samples, including PMP/DOX·HCl nanoparticles without the TQR component and free DOX·HCl, when co-incubated with either nonresistant HeLa cells or drug-resistant MCF-7/ADR cells. This growth-inhibitory effect was especially evident in drug-resistant cells. These results imply that the co-delivery of PTX, DOX·HCl and TQR based on reduction-sensitive polymeric prodrug may be promising for overcoming multi-drug resistance in tumour treatments.

Background Tamoxifen (Tam) is the most frequent treatment for estrogen receptor (ER) positive breast cancer. We recently showed that fibronectin (FN) leads to Tam resistance and selection of breast cancer stem cells. With the aim of developing a nanoformulation that would simultaneously tackle ER and FN/β1 integrin interactions, we designed polyethylene glycol-polycaprolactone polymersomes polymersomes (PS) that carry Tam and are functionalized with the tumor-penetrating iRGD peptide (iRGD-PS-Tam). Results Polyethylene glycol-polycaprolactone PS were assembled and loaded with Tam using the hydration film method. The loading of encapsulated Tam, measured by UPLC, was 2.4 ± 0.5 mol Tam/mol polymer. Physicochemical characterization of the PS demonstrated that iRGD functionalization had no effect on morphology, and a minimal effect on the PS size and polydispersity (176 nm and Pdi 0.37 for iRGD-TAM-PS and 171 nm and Pdi 0.36 for TAM-PS). iRGD-PS-Tam were taken up by ER+ breast carcinoma cells in 2D-culture and exhibited increased penetration of 3D-spheroids. Treatment with iRGD-PS-Tam inhibited proliferation and sensitized cells cultured on FN to Tam. Mechanistically, treatment with iRGD-PS-Tam resulted in inhibition ER transcriptional activity as evaluated by a luciferase reporter assay. iRGD-PS-Tam reduced the number of cells with self-renewing capacity, a characteristic of breast cancer stem cells. In vivo, systemic iRGD-PS-Tam showed selective accumulation at the tumor site. Conclusions Our study suggests iRGD-guided delivery of PS-Tam as a potential novel therapeutic strategy for the management of breast tumors that express high levels of FN. Future studies in pre-clinical in vivo models are warranted.

Polymersomes are versatile nanostructures for protein delivery with hydrophilic core suitable for large biomolecule encapsulation and protective stable corona. Nonetheless, pharmaceutical products based on polymersomes are not available in the market, yet. Here, using commercially available copolymers, we investigated the encapsulation of the active pharmaceutical ingredient (API) L-asparaginase, an enzyme used to treat acute lymphoblastic leukemia, in polymersomes through a quality-by-design (QbD) approach. This allows for streamlining of processes required for improved bioavailability and pharmaceutical activity. Polymersomes were prepared by bottom-up (temperature switch) and top-down (film hydration) methods employing the diblock copolymers poly(ethylene oxide)–poly(lactic acid) (PEG45-PLA69, PEG114-PLA153, and PEG114-PLA180) and the triblock Pluronic® L-121 (poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide), PEG5-PPO68-PEG5). Quality Target Product Profile (QTPP), Critical Quality Attributes (CQAs), Critical Process Parameters (CPPs), and the risk assessment were discussed for the early phase of polymersome development. An Ishikawa diagram was elaborated focusing on analytical methods, raw materials, and processes for polymersome preparation and L-asparaginase encapsulation. PEG-PLA resulted in diluted polymersomes systems. Nonetheless, a much higher yield of Pluronic® L-121 polymersomes of 200 nm were produced by temperature switch, reaching 5% encapsulation efficiency. Based on these results, a risk estimation matrix was created for an initial risk assessment, which can help in the future development of other polymersome systems with biological APIs nanoencapsulated.

Encapsulating bacteria within constrained microenvironments can promote the manifestation of specialized behaviors. Using double-emulsion droplet-generating microfluidic synthesis, live Bacillus subtilis bacteria were encapsulated in a semi-permeable membrane composed of poly(ethylene glycol)-b-poly(D,L-lactic acid) (mPEG-PDLLA). This polymer membrane was sufficiently permeable to permit exponential bacterial growth, metabolite-induced gene expression, and rapid biofilm growth. The biodegradable microparticles retained structural integrity for several days and could be successfully degraded with time or sustained bacterial activity. Microencapsulated B. subtilis successfully captured and contained sodium selenite added outside the polymersomes, converting the selenite into elemental selenium nanoparticles that were selectively retained inside the polymer membrane. This remediation of selenium using polymersomes has high potential for reducing the toxicity of environmental selenium contamination, as well as allowing selenium to be harvested from areas not amenable to conventional waste or water treatment.

Nano-sized systems have been used extensively for the delivery of various therapeutics, such as pharmaceuticals, proteins, and nucleic acids. Exosomes are small extracellular vesicles secreted from parent cells by fusion of multivesicular late endosomes with the plasma membrane, which act as an intercellular communication mediator and contain bioactive molecules. Thus, exosomes may possess potential as a natural delivery system. Polymersomes are synthetic vesicles composed of external bilayers, typically generated from amphiphilic block copolymers, which resemble many aspects of exosomes and have been utilized widely in many drug delivery applications. In this review, general properties of exosomes and polymersomes and their recent applications in the drug delivery areas and potential in theranostic approaches are discussed.

In this work, monodisperse giant polymersomes are fabricated by dewetting of water-in-oil-in-water double emulsion droplets which are assembled by amphiphilic block copolymer molecules in a microfluidic device. The dewetting process can be tuned by solvation between solvent and amphiphilic block copolymer to get polymersomes with controllable morphology. Good solvent (chloroform and toluene) hinders dewetting process of double emulsion droplets and gets acornlike polymersomes or patched polymersomes. On the other hand, poor solvent (hexane) accelerates the dewetting process and achieves complete separation of inner water phase from oil phase to form complete bilayer polymersomes. In addition, twin polymersomes with bilayer membrane structure are formed by this facile method. The formation mechanism for different polymersomes is discussed in detail.

Polymersomes are polymer-based vesicles that form upon hydration of amphiphilic block copolymers and display high stability and durability, due to their mechanical and physical properties. They have hydrophilic reservoirs as well as thick hydrophobic membranes; allowing to encapsulate both water-soluble bioactive agent and hydrophobic drugs. In this study, poly ethylene glycol (PEG3350 and PEG6000) were used as hydrophilic part and poly(vinyl benzoate) (PVBz) as hydrophobic block to synthesize amphiphilic triblock copolymers (PVBz-b-PEG-b-PVBz). Different proportions of hydrophilic/hydrophobic part were assayed in order to obtain polymersomes by solvent injection method. For the synthesis of the copolymers, the initial block of PEG was derived to obtain a macroinitiator through a xanthate functional group (PEGX3 or PEGX6) and the polymerization of vinyl benzoate was carried out through reversible addition-fragmentation chain transfer polymerization (RAFT). The structure of PEGX and copolymers was confirmed by Infrared, ¹H-NMR and UV-Vis spectrometry, while the average molecular weight (Mw) and polydispersity index (PI) were determined by size exclusion chromatography (SEC). The structures adopted by the copolymers in aqueous solution by self-assembly were investigated using transmission electron microscopy (TEM), dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS). Both techniques confirm that polymersomes were obtained for a fraction of hydrophilic block (f) ≈ 35 ± 10%, with a diameter of 38.3 ± 0.3 nm or 22.5 ± 0.7 nm, as determined by TEM and according to the M; w; of the precursor block copolymer. In addition, we analyzed the possible cytotoxicity in view of its potential application as biomedical nanocarrier. The results suggest that polymersomes seem not induce cytotoxicity during the periods of time tested., Laboratorio de Investigación en Osteopatías y Metabolismo Mineral, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas

Responsive polymersomes enhance the action of STING-targeting cyclic dinucleotides in cancer therapy.

To develop a technique that maximizes the encapsulation of functional proteins within neutrally charged, fully PEGylated and nanoscale polymer vesicles (i.e., polymersomes).Three conventional vesicle formation methods were utilized for encapsulation of myoglobin (Mb) in polymersomes of varying size, PEG length, and membrane thickness. Mb concentrations were monitored by UV-Vis spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES) and by the bicinchoninic acid (BCA) assay. Suspensions were subject to protease treatment to differentiate the amounts of surface-associated vs. encapsulated Mb. Polymersome sizes and morphologies were monitored by dynamic light scattering (DLS) and by cryogenic transmission electron microscopy (cryo-TEM), respectively. Binding and release of oxygen were measured using a Hemeox analyzer.Using the established "thin-film rehydration" and "direct hydration" methods, Mb was found to be largely surface-associated with negligible aqueous encapsulation within polymersome suspensions. Through iterative optimization, a novel "progressive saturation" technique was developed that greatly increased the final concentrations of Mb (from 0.5 to 2.0 mg/mL in solution), the final weight ratio of Mb-to-polymer that could be reproducibly obtained (from 1 to 4 w/w% Mb/polymer), as well as the overall efficiency of Mb encapsulation (from 5 to 90%). Stable vesicle morphologies were verified by cryo-TEM; the suspensions also displayed no signs of aggregate formation for 2 weeks as assessed by DLS. "Progressive saturation" was further utilized for the encapsulation of a variety of other proteins, ranging in size from 17 to 450 kDa.Compared to established vesicle formation methods, "progressive saturation" increases the quantities of functional proteins that may be encapsulated in nanoscale polymersomes.

The reconstitution of the integral membrane protein photosynthetic reaction center (RC) in polymersomes, i.e. artificial closed vesicles, was achieved by the micelle-to-vesicle transition technique, a very mild protocol based on size exclusion chromatography often used to drive the incorporation of proteins contemporarily to liposome formation. An optimized protocol was used to successfully reconstitute the protein in a fully active state in polymersomes formed by the tri-block copolymers PMOXA22-PDMS61-PMOXA22. The RC is very sensitive to its solubilizing environment and was used to probe the positioning of the protein in the vesicles. According to charge-recombination experiments and to the enzymatic activity assay, the RC is found to accommodate in the PMOXA22 region of the polymersome, facing the water bulk solution, rather than in the PDMS61 transmembrane-like region. Furthermore, polymersomes were found to preserve protein integrity efficiently as the biomimetic lipid bilayers but show a much longer temporal stability than lipid based vesicles.

The asymmetric amphiphilic block copolymer polystyrene962-block-poly(ethylene oxide)227 (PS962-b-PEO227) canforms micelles with N, N-dimethylformamide (DMF) as co-solvent and water as selected solvent, and when the water content of the mixed solvent is higher than 4.5 wt%, the vesicle will be dominated. This work finds that once vesicles are formed in the DMF-water mixed solvent, the vesicle size and membrane thickness can be tuned by further increasing water content. As the water fraction elevated from 4.8 wt% to 13.0 wt%, the vesicle size dercreases from 246 nm to 150 nm, while the membrane thickness increases from 28 nm to 42 nm. In addition, the block copolymer packing and the free energy are analyzed as the vesicle size becomes small and the membrane becomes thick.

Simvastatin (Sim), a lipid-lowering drug has been studied in chronic neuroinflammation associated with degenerative brain disorders due to its potential protective properties against inflammatory reaction, oxidative damage, neuronal dysfunction, and death. Meanwhile, potential application of Sim in neuroinflammation will require a suitable delivery system that can overcome notable challenges pertaining to poor blood-brain barrier (BBB) permeability and side/off-target effects. Herein, we engineered and characterized nano-sized polymersomes loaded with Sim (Sim-Ps) using PEG-PdLLA (methoxy polyethylene glycol-poly(D,L) lactic acid) diblock co-polymers. Studies in BV2 microglia indicated that Sim-Ps was superior to Sim alone in suppressing nitric oxide (NO) and proinflammatory cytokines (interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) secretion against LPS activation. The effectiveness of Sim-Ps as compared with Sim alone, in attenuating NO and cytokine production by activated BV2 cells can be attributed to (a) colloidal stability of the delivery platform, (b) protracted release of biologically active Sim, and (c) particulate internalization coupled with enhanced Sim exposure to BV2 cells. Intranasal delivery in BALB/c mice demonstrated enhanced brain distribution with increasing time after administration. Overall data demonstrated suitability of PEG-PdLLA polymersomes in Sim delivery for potential application in treating neuroinflammation.

A microfluidic device incorporating three coaxial capillaries set in a single block of ultra-high molecular weight polyethylene (UHMWPE) for the rapid formation of monodisperse double emulsions and polymersomes is described. The device utilizes easily interchangeable, coaxial capillaries whose geometry is maintained by a single UHMWPE block. Water-in-oil droplet formation using the device is characterized by measuring the diameter of the drops produced as a function of varying Reynolds, Weber, and capillary numbers. These parameters are used to characterize the dripping to jetting transition across a range of channel sizes. Double emulsions incorporating solutions of amphiphilic block copolymers are then processed to form large numbers of monodisperse polymersomes in an effective and controlled manner.

Scientific Reports 6: Article number: 33491; published online: 26 September 2016; updated: 19 December 2016

We have mimicked the biofilm formation with highly stable biocompatible poly(2-methyl-2-oxazoline)-based polymersomes by simple spreading-drying of a droplet of the sample solution onto a glass support. The diffusion-limited aggregation process of polymersomes onto the surface was analyzed within a fractal framework. The different examples analyzed and presented together indicate one means by which the aggregation process can be controlled and predicted. The anti-bacterial adhesion properties of poly(2-methyl-2-oxazoline) allow potential uses in surface modification for biofouling prevention improving stability and response time.

Lipids and amphiphilic block copolymers spontaneously self-assemble in water to form a plethora of micelles and vesicles. They are typically fluidic in nature and often mechanically weak for applications such as drug delivery and gene therapeutics. Mechanical properties of polymeric materials could be improved by forming crystalline structures. However, most of the self-assembled micelles and vesicles have curved surfaces and precisely tuning crystallization within a nanoscale curved space is challenging, as the curved geometry is incommensurate with crystals having three-dimensional translational symmetry. Herein, we report using a miniemulsion crystallization method to grow nanosized, polymer single-crystal-like capsules. We coin the name crystalsome to describe this unique structure, because they are formed by polymer lamellar crystals and their structure mimics liposomes and polymersomes. Using poly(L-lactic acid) (PLLA) as the model polymer, we show that curved water/p-xylene interface formed by the miniemulsion process can guide the growth of PLLA single crystals. Crystalsomes with the size ranging from ∼148 nm to over 1 μm have been formed. Atomic force microscopy measurement demonstrate a two to three orders of magnitude increase in bending modulus compared with conventional polymersomes. We envisage that this novel structure could shed light on investigating spherical crystallography and drug delivery., Self-assemblies of polymers to form polymersomes in solution can be used as carriers for drug delivery, but it is challenging to control polymer crystallization to improve their mechanical stability. Here, Wang et al. show the formation of nanosized crystalsomes composed of polymer lamellar single crystals.

We report a parallelized capillary microfluidic device for enhanced production rate of monodisperse polymersomes. This device consists of four independent capillary microfluidic devices, operated in parallel; each device produces monodisperse water-in-oil-in-water (W/O/W) double-emulsion drops through a single-step emulsification. During generation of the double-emulsion drops, the innermost water drop is formed first and it triggers a breakup of the middle oil phase over wide range of flow rates; this enables robust and stable formation of the double-emulsion drops in all drop makers of the parallelized device. Double-emulsion drops are transformed to polymersomes through a dewetting of the amphiphile-laden middle oil phase on the surface of the innermost water drop, followed by the subsequent separation of the oil drop. Therefore, we can make polymersomes with a production rate enhanced by a factor given by the number of drop makers in the parallelized device.

In order to increase the bioavailability of hydrophilic unstable drugs, polymersomes from AB3 type tetra block copolymers composing of poly(ethylene glycol)-b-(3) poly(lactic acid) (EO-3LA) as a water-soluble drug delivery carrier have been investigated due to its unique properties such as high stability and high water soluble drug loading efficiency. The sizes of EO-3LA polymersomes determined by dynamic light scattering were ranged in 190–220 nm with monodispersion. Its polymeric layer with 10–20 nm at the outershell was observed by field emission scanning electron microscopy. The polymersomes showed low critical aggregation concentrations (9.2–14.9 ug/ml). Anthocyanin was employed as a model drug for unstable drug in this study. The anthocyanin loading contents of EO-3LA polymersomes are depending on PLLA content in the polymers. The high loading contents (6.6–7.0 wt%) of the polymersomes are due to their tight and rigid polymeric membranes. The polymeric membrane in EO-3LA polymersomes contributed to improve drug stability on various pHs. Moreover, this property induced sustained anthocyanin release pattern from the polymersome. Therefore, the polymersome has potential as a drug carrier for water-soluble and unstable drugs.

This is a post-peer-review, pre-copyedit version of an article published in Pharmaceutical Research. The final authenticated version is available online at: https://doi.org/10.1007/s11095-011-0568-5 The purpose of this Expert Review is to discuss the impact of click chemistry in nanosized drug delivery systems. Since the introduction of the click concept by Sharpless and coworkers in 2001, numerous examples of click reactions have been reported for the preparation and functionalization of polymeric micelles and nanoparticles, liposomes and polymersomes, capsules, microspheres, metal and silica nanoparticles, carbon nanotubes and fullerenes, or bionanoparticles. Among these click processes, Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) has attracted most attention based on its high orthogonality, reliability, and experimental simplicity for non-specialists. A renewed interest in the use of efficient classical transformations has been also observed (e.g., thiol-ene coupling, Michael addition, Diels-Alder). Special emphasis is also devoted to critically discuss the click concept, as well as practical aspects of application of CuAAC to ensure efficient and harmless bioconjugation This work was financially supported by the Spanish Ministry of Science and Innovation (CTQ2009-10963 and CTQ2009-14146-C02-02) and the Xunta de Galicia (10CSA209021PR) SI

According to Wachtershauser’s “Iron-Sulfur-World” one major requirement for the development of life on the prebiotic Earth is compartmentalization. Vesicles spontaneously formed from amphiphilic components containing a specific set of molecules including sulfide minerals may have lead to the first autotrophic prebiotic units. The iron sulfide minerals may have been formed by geological conversions in the environment of deep-sea volcanos (black smokers), which can be observed even today. Wachtershauser postulated the evolution of chemical pathways as fundamentals of the origin of life on earth. In contrast to the classical Miller-Urey experiment, depending on external energy sources, the “Iron-Sulfur-World” is based on the catalytic and energy reproducing redox system $$ FeS + {H_2}S \to FeS{}_2 + {H_2} $$ . The energy release out of this redox reaction (∆RG° = −38 kJ/mol, pH 0) could be the cause for the subsequent synthesis of complex organic molecules and the precondition for the development of more complex units similar to cells known today. Here we show the possibility for precipitating iron sulfide inside vesicles composed of amphiphilic block-copolymers as a model system for a first prebiotic unit. Our findings could be an indication for a chemoautotrophic FeS based origin of life.

Block copolymers are made up of blocks of different polymerized monomers. Among the block copolymers, amphiphilic block copolymers can self-assemble to form nano-sized vehicles, such as micelles, nanoparticles, polymersomes, in aqueous or non-aqueous media. This review describes the synthesis, formation, and major applications of amphiphilic block copolymer and corresponding vehicles in order to provide an overview of the current features of functionalized block copolymers for drug delivery applications.

To evaluate the effect of lactoferrin (Lf) and transferrin (Tf) in brain targeting.Polymersomes (PSs), employed as vectors, were conjugated with Lf or Tf and were characterized by morphology, particle size, zeta potential, and surface densities of the Lf or Tf molecules. In vitro uptake of Lf-PS and Tf-PS by bEnd.3 cells was investigated using coumarin-6 as a fluorescent probe. In vivo tissue distribution and pharmacokinetics of (125)I-Lf-PS and (125)I-Tf-PS were also examined.The mean particle size of PS, Lf-PS, and Tf-PS was around 150 nm and the zeta potential of the PSs was about -20 mV. Less than 0.12% of the coumarin was released from coumarin-6-loaded PS in 84 h indicating that coumarin-6 was an accurate probe for the PSs' behavior in vitro. It was shown that the uptake of Lf-PS and Tf-PS by bEnd.3 cells was time-, temperature-, and concentration-dependent. Both Lf and Tf could increase the cell uptake of PSs at 37 degrees C, but the uptake of Tf-PS was significantly greater than that of Lf-PS. In vivo tissue distribution and pharmacokinetics in mice revealed higher brain uptake and distribution of Tf-PS than Lf-PS, which was in accordance with in vitro uptake results. The drug targeting index (DTI) of Tf-PS with regard to Lf-PS was 1.51.Using a PS as the delivery vector and bEnd.3 cells as the model of the blood-brain barrier (BBB), Tf was more effective than Lf in brain targeting.

In order to realize long-term carrying/delivering oxygen and minimize the adverse effects of free hemoglobin (Hb) in vivo, Hb is desired to be confined in Hb-loaded nanoparticles (HbP), a novel blood substitute with potential clinical applications, and thus functions as the native red blood cells (RBCs). However, the initial burst release of Hb ("leaky effect") greatly underscores the significance of this work. The study described here wants to disclose the key preparative parameters, including polymer, excipients in the inner aqueous phase and solvent profile, affecting the Hb release behavior (the initial 24 h) from HbP fabricated by commonly used solvent diffusion/evaporation double emulsion technique. The results demonstrate that PEGlytated polymers, regardless of two- or tri-block copolymers show slower release compared with the corresponding non-PEGlytated ones. The higher polymer concentration yields lower initial release. PEG200, added as excipient facilitates Hb burst effect to about 38.4%, almost 17% increase compared to the control ( approximately 21%), whereas, PVA and Poloxamer188, due to amphiphilic nature, can effectively attenuate this leakage to about 13.0 and 5.1%, respectively. The diffusion/extraction rate from oil phase and the subsequent evaporation rate from the aqueous continuous phase of solvents impose different influences on Hb release. To reduce the burst effect, the initial diffusion/extraction rate should be slow, whereas, the concomitant evaporation rate should be as fast as possible. The results obtained here will be guidance's for the future tailored design of more desirable polymersome nanoparticle blood substitutes.

Di-block copolymers composed of two biocompatible polymers, poly(ethylene glycol) and poly(d,l-lactide), were synthesized by ring-opening polymerization for the preparation of doxorubicin-loaded self-assembled nanostructures, including polymeric vesicles (polymersomes) and micelles. The capability and stability of the nanostructures prepared for the controlled release of DOX are discussed in this paper. The in vitro drug release at 37 °C was evaluated up to 6 days at pH 7.4 and 5.5 and in the presence of 50 % FBS. The cellular uptake and cytotoxicity effect of both formulations were also evaluated in the MCF-7 cell line. The SEM and AFM images confirmed the hollow spherical structure of the polymersomes and the solid round structures of the micelles. The TEM results also revealed the uniformity in size and shape of the drug-loaded micelle and polymersome nanostructures. The DOX-loaded micelles and polymersomes presented efficient anticancer performance, as verified by flow cytometry and MTT assay tests. The most important finding of this study is that the prepared nanopolymersomes presented significant increases in the doxorubicin encapsulation efficiency and the stability of the formulation in comparison with the micelle formulation. In vitro studies revealed that polymersomes may be stable in the blood circulation and meet the requirements for an effective drug delivery system.

Giant vesicles prepared from the diblock copolymer polybutadien-b-polyethyleneoxide (PB-PEO) exhibit a shear surface viscosity, which is about 500 times higher than those found in common phospholipid bilayers. Our result constitutes the first direct measurement of the shear surface viscosity of such polymersomes. At the same time, we measure bending and stretching elastic constants, which fall in the range of values typical for lipid membranes. Pulling out a tether from an immobilized polymersome and following its relaxation back to the vesicle body provides an estimate of the viscous coupling between the two monolayers composing the polymer membrane. The detected intermonolayer friction is about an order of magnitude higher than the characteristic one for phospholipid membranes. Polymersomes are tough vesicles with a high lysis tension. This, together with their robust rheological properties, makes them interesting candidates for a number of technological applications.

It is already more than a century since the pioneering work of the Nobel Laureate Ehrlich gave birth to the side chain theory1, which helped to define antibodies and their ability to target specific biological sites. However, the use of antibodies is still restricted to the extracellular space due to the lack of a suitable delivery vehicle for the efficient transport of antibodies into live cells without inducing toxicity. In this work, we report the efficient encapsulation and delivery of antibodies into live cells with no significant loss of cell viability or any deleterious affect on the cell metabolic activity. This delivery system is based on poly(2-(methacryloyloxy)ethyl phosphorylcholine)-block-(2-(diisopropylamino)ethyl methacrylate), (PMPC-PDPA), a pH sensitive diblock copolymer that self-assembles to form nanometer-sized vesicles, also known as polymersomes, at physiological pH. These polymersomes can successfully deliver relatively high antibody payloads within live cells. Once inside the cells, we demonstrate that these antibodies can target their epitope by immune-labelling of cytoskeleton, Golgi, and transcription factor proteins in live cells. We also demonstrate that this effective antibody delivery mechanism can be used to control specific subcellular events, as well as modulate cell activity and pro-inflammatory process.