Glycol Methyl Ether Methacrylate Research Articles

Selective Protein Conjugation of Poly(glycerol monomethacrylate) and Poly(polyethylene glycol methacrylate) with Tunable Topology via Reductive Amination with Multifunctional ATRP Initiators for Activity Preservation

In this study, we compare poly(glycerol monomethacrylate) (PGMA) of different chain lengths and architectures (linear and two-arm) with poly(poly(ethylene glycol) methyl ether methacrylate) (PPEGMA) as an alternative polymer platform for the synthesis of a new generation of protein–polymer conjugates. Mono- and two-arm functional atom-transfer radical polymerization (ATRP) initiators were designed and selectively attached to lysozyme at the N-terminus via reductive amination. Site-specific, grafting from activator regenerated by electron transfer (ARGET) ATRP was carried out in phosphate buffer, and the reaction parameters were optimized to obtain polymer conjugates with predetermined molar mass and topology. The activity preservation under proteolytic and high-temperature conditions showed a clear dependence on the structure of the repeating unit and on the macromolecular architecture. These results highlighted the potential of PGMA as a poly(ethylene glycol) (PEG) alternative for the half-life extension of biotherapeutics. Moreover, this synthetic approach may inspire the design of a new class of protein–polymer conjugates through an optimal combination of macromolecular composition and topology.

On-Demand Chemomagnetic Modulation of Striatal Neurons Facilitated by Hybrid Magnetic Nanoparticles.

Minimally invasive manipulation of cell signaling is critical in basic neuroscience research and in developing therapies for neurological disorders. Here, we describe a wireless chemomagnetic neuromodulation platform for the on-demand control of primary striatal neurons that relies on nanoscale heating events. Iron oxide magnetic nanoparticles (MNPs) are functionally coated with thermoresponsive poly (oligo (ethylene glycol) methyl ether methacrylate) (POEGMA) brushes loaded with dopamine. Dopamine loaded MNPs-POEGMA are co-cultured with primary striatal neurons. When alternating magnetinec fields (AMF) are applied, MNPs undergo hysteresis power loss and dissipate heat. The local heat produced by MNPs initiates a thermodynamic phase transition on POEGMA brushes resulting in polymer collapse and dopamine release. AMF-triggered dopamine release enhances the response of dopamine ion channels expressed on the cell membranes enhancing the activity of ~50% of striatal neurons subjected to the treatment. Chemomagnetic actuation on dopamine receptors is confirmed by blocking D1 and D2 receptors. The reversible thermodynamic phase transition of POEGMA brushes allow the on-demand release of dopamine in multiple microdoses. AMF-triggered dopamine release from MNPs-POEGMA causes no cell cytotoxicity nor promotes cell ROS production. This research represents a fundamental step forward for the chemomagnetic control of neural activity using hybrid magnetic nanomaterials with tailored physical properties.

Feasibility of Using Poly[oligo(ethylene glycol) Methyl Ether Methacrylate] as Tumor-Targeted Carriers of Diagnostic Drugs

Feasibility of Using Poly[oligo(ethylene glycol) Methyl Ether Methacrylate] as Tumor-Targeted Carriers of Diagnostic Drugs

Effect of Thermal Stimulus on Kinetic Rehydration of Thermoresponsive Poly(diethylene glycol monomethyl ether methacrylate)-block-poly(poly(ethylene glycol) methyl ether methacrylate) Thin Films Probed by In Situ Neutron Reflectivity.

The kinetic rehydration of thin di-block copolymer poly(diethylene glycol monomethyl ether methacrylate)-block-poly(poly(ethylene glycol) methyl ether methacrylate) (PO2-b-PO300) films containing two thermoresponsive components is probed by in situ neutron reflectivity (NR) with different thermal stimuli in the D2O vapor atmosphere. The transition temperatures (TTs) of PO2 and PO300 blocks are 25 and 60 °C, respectively. After the one-step stimulus (rapid decrease in temperature from 60 to 20 °C), the film directly switches from a collapsed to a fully swollen state. The rehydration process is divided into four steps: (a) D2O condensation, (b) D2O absorption, (c) D2O evaporation, and (d) film reswelling. However, the film presents a different rehydration behavior when the thermal stimulus is separated into two smaller steps (first decrease from 60 to 40 °C and then to 20 °C). The film first switches from a collapsed to a semiswollen state caused by the rehydrated PO300 blocks after the first step of thermal stimulus (60 to 40 °C) and then to a swollen state induced by the rehydrated PO2 blocks after the second step (40 to 20 °C). Thus, the kinetic responses are distinct from that after the one-step thermal stimulus. Both the time and extent of condensation as well as evaporation processes are significantly reduced in these two smaller steps. However, the final states of the rehydrated PO2-b-PO300 films are basically identical irrespective of the applied thermal stimulus. Thus, the final state of thermoresponsive di-block copolymer films is not affected by the external thermal stimuli, which is beneficial for the design and preparation of sensors or switches based on thermoresponsive polymer films.

Engineering sterilization-resistant and fouling-resistant porous membranes by the vapor-induced phase separation process using a sulfobetaine methacrylamide amphiphilic derivative

The in-situ modification of polyvinylidene fluoride (PVDF)-based membranes with zwitterionic copolymers for environmental applications remains challenging because of the large polarity difference between PVDF and zwitterionic materials. Besides, common zwitterionic units such as sulfobetaine methacrylate fail when exposed to elevated temperatures, limiting their range of applications in biomedical engineering. We designed an amphiphilic copolymer containing sulfobetaine methacrylamide (SBAA), styrene and ethylene glycol methyl ether methacrylate (EGMA) groups. Once the appropriate composition determined, membranes were prepared by vapor-induced phase separation (VIPS), a process permitting fine control over formation mechanisms, hence over the matrix structure. Sorption, mapping FT-IR and DSC tests indicated that even a low proportion of SBAA (< 10 mol%) in the P(S-r-EGMA-r-SBAA) copolymer significantly increases the proportion of non-freezable water and enhances the strength of the hydration layer, compared to a system containing styrene and EGMA groups only, P(S-r-EGMA). The modification also resulted in a large increase in membrane hydration capacity (> 550 mg/cm3 vs. < 25 mg/cm3 for the virgin membrane). Consequently, the zwitterionic copolymer could efficiently mitigate biofouling by fibrinogen (76% drop), Escherichia coli (99% decrease) or whole blood (82% reduction), even after a steam sterilization process, while the control zwitterionic sulfobetaine methacrylate material failed at maintaining its performances. Separation tests carried out with bacterial solutions revealed the ability of the zwitterionic copolymer to significantly decrease irreversible fouling (27%), compared to a commercial membrane (47%). All in all, their porous structure, hydration capacity and their ability to withstand steam sterilization make these novel porous zwitterionic membranes ideal candidates for biomedical (blood filtration) or environmental applications (water treatment).

Temperature-Responsive Aldehyde Hydrogels with Injectable, Self-Healing, and Tunable Mechanical Properties.

Injectable and self-healing hydrogels with exemplary biocompatibility and tunable mechanical properties are urgently needed due to their significant advantages for tissue engineering applications. Here, we report a new temperature-responsive aldehyde hydrogel with dual physical-cross-linked networks and injectable and self-healing properties prepared from an ABA-type triblock copolymer, poly{[FPMA(4-formylphenyl methacrylate)-co-DEGMA[di(ethylene glycol) methyl ether methacrylate]-b-MPC(2-methacryloyloxyethyl phosphorylcholine)-b-(FPMA-co-DEGMA)}. The thermoresponsive poly(DEGMA) segments drive the dehydration and hydrophobic interaction, enabling polymer chain winding as the first cross-linking network, when the temperature is raised above the critical gelation temperature. Meanwhile, the benzaldehyde groups offer physical interactions, including hydrogen bonding and hydrophobic and π-π stacking interactions as the second cross-linking network. When increasing the benzaldehyde content in the triblock copolymers from 0 to 8.2 mol %, the critical gelation temperature of the resulted hydrogels dropped from 35.5 to 19.9 °C and the mechanical modulus increased from 21 to 1411 Pa. Owing to the physical-cross-linked networks, the hydrogel demonstrated excellent injectability and self-healing properties. The cell viabilities tested from MTT assays toward both normal lung fibroblast cells (MRC-5) and cancerous cervical (HeLa) cells were found to be 100 and 101%, respectively, for varying polymer concentrations up to 1 mg/mL. The 3D cell encapsulation of the hydrogels was evaluated by a cytotoxicity Live/Dead assay, showing 92% cell viability. With these attractive physiochemical and biological properties, this temperature-responsive aldehyde hydrogel can be a promising candidate as a cell scaffold for tissue engineering.

The Preparation of Novel P(OEGMA-co-MEO2MA) Microgels-Based Thermosensitive Hydrogel and Its Application in Three-Dimensional Cell Scaffold.

Thermosensitive hydrogel scaffolds have attracted particular attention in three-dimensional (3D) cell culture. It is very necessary to develop a type of thermosensitive hydrogel material with low shrinkage, and excellent biocompatibility and biodegradability. Here, five types of thermosensitive microgels with different volume phase transition temperature (VPTT) or particle sizes were first synthesized using 2-methyl-2-propenoic acid-2-(2-methoxyethoxy) ethyl ester (MEO2MA) and oligoethylene glycol methyl ether methacrylate (OEGMA) as thermosensitive monomers by free radical polymerization. Their VPTT and particle sizes were investigated by a nanometer particle size meter and an ultraviolet spectrophotometer. The feasibility of using these P(OEGMA-co-MEO2MA) microgels to construct thermosensitive hydrogel by means of the thermal induction method is discussed for the first time. The prepared thermosensitive hydrogel with the optimum performance was screened for in situ embedding and three-dimensional (3D) culture of MCF-7 breast cancer cells. The experimental results of AO/EB and MTT methods indicate that the pioneering scaffold material has prominent biocompatibility, and cells grow rapidly in the 3D scaffold and maintain high proliferative capacity. At the same time, there is also a tendency to aggregate to form multicellular spheres. Therefore, this original P(OEGMA-co-MEO2MA) thermosensitive hydrogel can serve as a highly biocompatible and easily functionalized 3D cell culture platform with great potential in the biomedical area.

Controlling the Biological Behaviors of Polymer-Coated Upconverting Nanoparticles by Adjusting the Linker Length of Estrone Ligands.

The estrone ligand is used for modifying nanoparticle surfaces to improve their targeting effect on cancer cell lines. However, to date, there is no common agreement on the ideal linker length to be used for the optimum targeting performance. In this study, we aimed to investigate the impact of poly(poly ethylene glycol methyl ether methacrylate) (PPEGMEMA) linker length on the cellular uptake behavior of polymer-coated upconverting nanoparticles (UCNPs). Different triblock terpolymers, poly(poly (ethylene glycol) methyl ether methacrylate)-block-polymethacrylic acid-block-polyethylene glycol methacrylate phosphate (PPEGMEMAx-b-PMAAy-b-PEGMP3: x = 7, 15, 33, and 80; y = 16, 20, 18, and 18), were synthesized with different polymer linker chain lengths between the surface and the targeting ligand by reversible addition-fragmentation chain transfer polymerization. The estrone ligand was attached to the polymer via specific terminal conjugation. The cellular association of polymer-coated UCNPs with linker chain lengths was evaluated in MCF-7 cells by flow cytometry. Our results showed that the bioactivity of ligand modification is dependent on the length of the polymer linker. The shortest polymer PPEGMEMA7-b-PMAA16-b-PEGMP3 with estrone at the end of the polymer chain was found to have the best cellular association behavior in the estrogen receptor (ER)α-positive expression cell line MCF-7. Additionally, the anticancer drug doxorubicin•HCl was encapsulated in the nanocarrier to evaluate the 2D and 3D cytotoxicity. The results showed that estrone modification could efficiently improve the cellular uptake in ERα-positive expression cell lines and in 3D spheroid models.

Preparation of highly adhesive urethane–acrylate-based gel-polymer electrolytes and their optimization in flexible electrochromic devices

Gel-polymer electrolytes are attractive for applications in flexible electrochromic devices (ECDs). Among such electrolytes, UV-curable gel-polymer electrolytes are particularly advantageous because they can be cured in a short time and suffer less deformation from heating due to low-temperature treatment. In this study, we developed a polyurethane-acrylate-based UV-curable gel-polymer electrolyte with excellent adhesion, optical transparency, and high ion conductivity by optimizing the urethane acrylate mixing ratio. The use of urethane acrylate conferred high adhesion to these gel-polymer electrolytes, and an electrolyte with high ion conductivity was developed by optimizing the ratio of urethane acrylate (oligomer) and poly(ethylene glycol) methyl ether methacrylate (monomer). The optical properties of the ECDs fabricated using the optimized electrolytes were compared. In the case of the glass-type ECDs, upon adding 33.2 wt% urethane acrylate, the coloring transmittance was observed to be 8.54%; the bleaching transmittance was 62.96%; and the change in transmittance reached 54.42%. By conducting a switching cycle test for approximately 45 times on a flexible electrochromic device made of indium tin oxide on a polyethylene terephthalate (ITO-PET) film, 43% change in transmittance was confirmed. These gel-polymer electrolytes are expected to be useful for the commercialization of flexible ECDs.

Polymeric dual-modal imaging nanoprobe with two-photon aggregation-induced emission for fluorescence imaging and gadolinium-chelation for magnetic resonance imaging.

Nanoprobes that offer both fluorescence imaging (FI) and magnetic resonance imaging (MRI) can provide supplementary information and hold synergistic advantages. However, synthesis of such dual-modality imaging probes that simultaneously exhibit tunability of functional groups, high stability, great biocompatibility and desired dual-modality imaging results remains challenging. In this study, we used an amphiphilic block polymer from (ethylene glycol) methyl ether methacrylate (OEGMA) and N-(2-hydroxypropyl) methacrylamide (HPMA) derivatives as a carrier to conjugate a MR contrast agent, Gd-DOTA, and a two-photon fluorophore with an aggregation-induced emission (AIE) effect, TPBP, to construct a MR/two-photon fluorescence dual-modality contrast agent, Gd-DOTA-TPBP. Incorporation of gadolinium in the hydrophilic chain segment of the OEGMA-based carrier resulted in a high r1 value for Gd-DOTA-TPBP, revealing a great MR imaging resolution. The contrast agent specifically accumulated in the tumor region, allowing a long enhancement duration for vascular and tumor contrast-enhanced MR imaging. Meanwhile, coupling TPBP with AIE properties to the hydrophobic chain segment of the carrier not only improved its water solubility and reduced its cytotoxicity, but also significantly enhanced its imaging performance in an aqueous phase. Gd-DOTA-TPBP was also demonstrated to act as an excellent fluorescence probe for two-photon-excited bioimaging with higher resolution and greater sensitivity than MRI. Since high-resolution, complementary MRI/FI dual-modal images were acquired at both cellular and tissue levels in tumor-bearing mice after application of Gd-DOTA-TPBP, it has great potential in the early phase of disease diagnosis.

Impact of Zwitterionic Polymers on the Tumor Permeability of Molecular Bottlebrush-Based Nanoparticles.

Biocompatible polymers possessing antifouling properties for biomolecules are necessary to be combined with nanoparticles for cancer chemotherapy to improve their retention in blood and subsequent tumor accumulation. However, these properties simultaneously lead to poor affinity to cells, and low tumor tissue permeability subsequently, which is one of the major barriers in achieving efficient anticancer efficacy. To address this, we try to elucidate the tumor permeability of nanoparticles using molecular bottlebrushes (MBs) as model polymeric nanoparticles composed of various biocompatible polymers. An MB comprising nonionic poly[(ethylene glycol) methyl ether methacrylate] (PEGMA) shows no tumor permeability at all, whereas zwitterionic MBs composed of poly(phosphobetaine methacrylate), poly(sulfobetaine methacrylate), or poly(carboxybetaine methacrylate) penetrate deeply into tumor tissues. The carboxybetaine-based MBs showed an efficient cellular uptake into cancer cells while the other MBs did not, which enable them to penetrate into tumor tissues via the transcytosis pathway. Additionally, their permeability is based on intercellular or intracellular pathways, which might be related to the zwitterionic betaine properties that recognize protein transporters on cancer cells. Surprisingly, incorporating only 10 mol % of the zwitterionic betaine polymers into PEGMA-based MBs significantly enhances their tissue permeability. This platform technology enables us to redesign the PEG-based nanoparticles developed for cancer chemotherapy in clinical applications.

A robust all-organic protective layer towards ultrahigh-rate and large-capacity Li metal anodes.

The low cycling efficiency and uncontrolled dendrite growth resulting from an unstable and heterogeneous lithium-electrolyte interface have largely hindered the practical application of lithium metal batteries. In this study, a robust all-organic interfacial protective layer has been developed to achieve a highly efficient and dendrite-free lithium metal anode by the rational integration of porous polymer-based molecular brushes (poly(oligo(ethylene glycol) methyl ether methacrylate)-grafted, hypercrosslinked poly(4-chloromethylstyrene) nanospheres, denoted as xPCMS-g-PEGMA) with single-ion-conductive lithiated Nafion. The porous xPCMS inner cores with rigid hypercrosslinked skeletons substantially increase mechanical robustness and provide adequate channels for rapid ionic conduction, while the flexible PEGMA and lithiated Nafion polymers enable the formation of a structurally stable artificial protective layer with uniform Li+ diffusion and high Li+ transference number. With such artificial solid electrolyte interphases, ultralong-term stable cycling at an ultrahigh current density of 10 mA cm-2 for over 9,100 h (>1 year) and unprecedented reversible lithium plating/stripping (over 2,800 h) at a large areal capacity (10 mAh cm-2) have been achieved for lithium metal anodes. Moreover, the protected anodes also show excellent cell stability when paired with high-loading cathodes (~4 mAh cm-2), demonstrating great prospects for the practical application of lithium metal batteries.

Synthesis of a Degradable Hydrogel Based on a Graft Copolymer with Unexpected Thermoresponsiveness

AbstractIncorporating multiple pyridyl disulfide (PDS) moieties into polymer chains allows the fabrication of a chemically cross‐linked hydrogel through the rapid thiol–disulfide exchange reaction. By aminolysis in the presence of 2,2′‐dithiodipyridine (DTP), the end groups of polymers synthesized via reversible addition−fragmentation chain transfer (RAFT) polymerization can readily be converted into PDS‐groups. In this contribution, a RAFT‐synthesized graft copolymer with thermoresponsive poly[di(ethylene glycol) methyl ether methacrylate] forming the backbone and hydrophilic poly(N,N‐dimethylacrylamide) as the side chains is presented. The copolymer chains exhibit surprisingly a two‐step lower critical solution temperature transition in aqueous solutions. After modification of the end groups of the backbone and side chains, the PDS‐terminated chains can react with a dithiol cross‐linker to form a thermoresponsive hydrogel. In a reducing environment, the cleavable disulfide linkages lead to on‐demand dissolution of the hydrogel. The resulting thiol‐terminated chains undergo a reversible sol–gel transition in response to redox variations, expanding the potential application areas of such a polymer system.

Simultaneous and Efficient Removal of Oleophilic and Hydrophilic Stains from Polyurethane by the Combination of Easy-Cleaning and Self-Cleaning.

The simultaneous and efficient removal of oleophilic and hydrophilic stains from polyurethane (PU) is realized by combining the easy-cleaning from the hydrophilic thermoresponsive hydrogel coating containing acrylamide (AAm), gum arabic (GA), and (ethylene glycol) methyl ether methacrylate (OEGMA300) P(GA/AAm/OEGMA300) and the self-cleaning from the embedded nonmetallic photocatalyst g-C3N4. Due to the existence of strong hydrogen bonds between the hydroxyl groups in the hybrid hydrogel coating and the hydroxyl/carboxyl groups in the plasma-treated PU, the hybrid hydrogel coating is very stable on PU. Simultaneously, the acrylamide network in the hybrid hydrogel coating enhances its mechanical strength. Because the transition temperature of OEGMA300 is well above the room temperature, the cross-linked coating remains hydrophilic in ambient conditions. Thus, oleophilic stains, such as oil and grease, can be easily removed from the coating surface. In addition, the embedded photocatalyst g-C3N4 in the hybrid hydrogel coating introduces the extra capability of decomposing organic compounds under sunshine, which favors the removal of hydrophilic stains such as dyes and wines. After sunlight illumination and simply rinsing with water, both hydrophilic and oleophilic stains can be easily removed. Moreover, this joint cleaning performance can work for a long time. Even after four consecutive cycles, both the easy-cleaning to oleophilic stains by the hydrophilic hydrogel surface and self-cleaning to the hydrophilic stains by the embedded g-C3N4 remain unchanged.

Elucidating the mechanisms of the molecular sieving phenomenon created by comb-shaped polymers grafted to a protein – a simulation study

Advances in polymer chemistry now allow the creation of protein–polymer conjugates of great complexity. These advances equally enable the fine-tuning of their structure (and hence properties) to address specific challenges they face as therapeutics. Some of these challenges faced by non-human proteins include their rapid degradation, elimination or immunogenicity in vivo, and one of the most recognized solutions for this is to mask their surface with chains of linear poly(ethylene glycol). This, however, generally reduces bioactivity. Several experimental studies have shown that switching from linear to architecturally complex polymers (comb-shaped, branched, dendronized) partially resolves this issue for a subset of proteins whose bioactivity involves small molecules, by creating a “molecular sieving” effect. The mechanisms underlying molecular sieving, however, have never been entirely elucidated. This study presents a coarse-grained model of α-chymotrypsin modified with multiple chains of the comb-shaped polymer poly(oligo(ethylene glycol) methyl ether methacrylate) to study molecular sieving. Results demonstrate the steric nature of the phenomenon (i.e., creation of gaps in the polymer coating), though steric considerations alone could not reconcile all of the experimental trends. The simulations rather suggest that these gaps enable the selective accumulation of small (substrate) molecules near the surface of the protein (in a favourable microenvironment created by the polymer), which exacerbates the “molecular sieving” phenomenon (i.e., difference in the ability of small vs. large substrates to reach the protein).

Hydrophilic Random Cationic Copolymers as Polyplex-Formation Vectors for DNA

Research on the improvement and fabrication of polymeric systems as non-viral gene delivery carriers is required for their implementation in gene therapy. Random copolymers have not been extensively utilized for these purposes. In this regard, double hydrophilic poly[(2-(dimethylamino) ethyl methacrylate)-co-(oligo(ethylene glycol) methyl ether methacrylate] [P(DMAEMA-co-OEGMA)] random copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The copolymers were further modified by quaternization of DMAEMA tertiary amine, producing the cationic P(QDMAEMA-co-OEGMA) derivatives. Fluorescence and ultraviolet–visible (UV–vis) spectroscopy revealed the efficient interaction of copolymers aggregates with linear DNAs of different lengths, forming polyplexes, with the quaternized copolymer aggregates exhibiting stronger binding affinity. Light scattering techniques evidenced the formation of polyplexes whose size, molar mass, and surface charge strongly depend on the N/P ratio (nitrogen (N) of the amine group of DMAEMA/QDMAEMA over phosphate (P) groups of DNA), DNA length, and length of the OEGMA chain. Polyplexes presented colloidal stability under physiological ionic strength as shown by dynamic light scattering. In vitro cytotoxicity of the empty nanocarriers was evaluated on HEK293 as a control cell line. P(DMAEMA-co-OEGMA) copolymer aggregates were further assessed for their biocompatibility on 4T1, MDA-MB-231, MCF-7, and T47D breast cancer cell lines presenting high cell viability rates.

Targeted delivery of quercetin by biotinylated mixed micelles for non-small cell lung cancer treatment

Lung cancer is the leading cause of cancer death world-wide and its treatment remains a challenge in clinic, especially for non-small cell lung cancer (NSCLC). Thus, more effective therapeutic strategies are required for NSCLC treatment. Quercetin (Que) as a natural flavonoid compound has gained increasing interests due to its anticancer activity. However, poor water solubility, low bioavailability, short half-life, and weak tumor accumulation hinder in vivo applications and antitumor effects of Que. In this study, we developed Que-loaded mixed micelles (Que-MMICs) assembled from 1,2-distearoyl-sn-glycero-3-phosphoethanolamine–poly(ethylene glycol)–biotin (DSPE–PEG–biotin) and poly(ethylene glycol) methyl ether methacrylate–poly[2-(dimethylamino) ethyl acrylate]–polycaprolactone (PEGMA–PDMAEA–PCL) for NSCLC treatment. The results showed that Que was efficiently encapsulated into the mixed micelles and the encapsulation efficiency (EE) was up to 85.7%. Cellular uptake results showed that biotin conjugation significantly improved 1.2-fold internalization of the carrier compared to that of non-targeted mixed micelles. In vitro results demonstrated that Que-MMICs could improve cytotoxicity (IC50 = 7.83 μg/mL) than Que-MICs (16.15 μg/mL) and free Que (44.22 μg/mL) to A549 cells, which efficiently induced apoptosis and arrested cell cycle. Furthermore, Que-MMICs showed satisfactory tumor targeting capability and antitumor efficacy possibly due to the combination of enhanced permeability and retention (EPR) and active targeting effect. Collectively, Que-MMICs demonstrated high accumulation at tumor site and exhibited superior anticancer activity in NSCLC bearing mice model.

Synthesis of Glucose/Fructose Sensitive Poly(ethylene glycol) Methyl Ether Methacrylate Particles with Novel Boronate Ester Bridge Crosslinker and their Dye Release Applications.

In this study, it is aimed to develop glucose/fructose sensitive poly(ethylene glycol) methyl ether methacrylate (PEGMA) particles which can be employed in controlled drug delivery applications. For this purpose, a boric acid based crosslinker was synthesized using 4-vinylphenylboronic acid and its formation was confirmed by 1H-NMR and FT-IR analyses. Sugar-sensitive polymeric particles were then achieved using this crosslinker and PEGMA monomer in single step and surfactant free emulsion polymerization technique. Polymeric particles were characterized by DLS, SEM, and TEM in terms of size and morphology. In order to determine the sensitivity of the particles to sugar molecules, first Rhodamine B dye (as a model drug) loading experiments were performed. Then, the particles were subjected to glucose/fructose rich media and dye release was monitored as a function of time using UV-Vis spectrophotometry. The results of the current study revealed that the PEGMA particles were more sensitive to fructose (~39% release) compared to glucose (~25% release) at pH 7.4 and 310 K.

Self-assembly of Li single-ion-conducting block copolymers for improved conductivity and viscoelastic properties

Single-ion conducting polyelectrolytes (SICPs) with mobile Li cation have recently gathered significant attention as an “ideal” electrolyte for safe solid-state rechargeable lithium batteries, because they eliminate salt concentration gradients and concentration overpotentials, allowing transference number (tLi+) values close to unity. In this work, a series of single ion conducting block copolymers, namely [(LiM)n-r-(PEGM)m]-b-(PhEtM)k (A-b-B), is synthesized via reversible addition-fragmentation chain transfer (RAFT) copolymerization of 1-[3-(methacryloyloxy)propylsulfonyl]-(trifluoromethanesulfonyl)imide (LiM), poly(ethylene glycol)methyl ether methacrylate (PEGM) and 2-phenylethyl methacrylate (PhEtM) with controlled PEGM:LiM ratio, molecular weights (Mn = 25.8 ÷ 85.9 kDa) and narrow polydispersity (Mw/Mn = 1.12 ÷ 1.21). The bulk ionic conductivity, solid-state morphology and thermal properties of block copolymers are studied as a function of their composition. Block copolymers having molecular weights in the range of 46 ÷ 63 kDa and any ratio of PEGM:LiM (from 3:1 to 7:1) tend to evolve in quasi-hexagonally-packed cylinders, while copolymers with higher molecular weights (Mn > 74 kDa) and the ratio of PEGM:LiM = 5:1 and MA/MB ≤ 2.0 show lamellar phase separation. The lamellar long-range ordering in poly[(LiM17-r-PEGM86)-b-PhEtM131] and poly[(LiM17-r-PEGM86)-b-PhEtM194] results not only in the improved viscoelastic (mechanical) performance compared to parent copolymer poly[LiM17-r-PEGM86] (complex viscosity = 2.5 × 108 mPa s and 8.7 × 104 mPa s at 25 °C, respectively), but also in the demonstration of sufficiently high ionic conductivity despite the decrease in Li+ amount (σ = 3.8 × 10−7 and 4.1 × 10−7 S/cm at 25 °C, correspondingly). The selected poly[(LiM17-r-PEGM86)-b-PhEtM131] further shows high tLi+ (0.96 at 70 °C) and wide electrochemical stability (4.4 V vs. Li+/Li at 70 °C), which results in reversible and stable cycling at high specific capacities (up to 150 and 118 mAh g−1 at C/20 and C/5 rates, respectively) when assembled in lab-scale truly-solid-state Li metal cells with Li/copolymer/LiFePO4 configuration.

Reversing RAFT Polymerization: Near-Quantitative Monomer Generation Via a Catalyst-Free Depolymerization Approach.

The ability to reverse controlled radical polymerization and regenerate the monomer would be highly beneficial for both fundamental research and applications, yet this has remained very challenging to achieve. Herein, we report a near-quantitative (up to 92%) and catalyst-free depolymerization of various linear, bulky, cross-linked, and functional polymethacrylates made by reversible addition–fragmentation chain-transfer (RAFT) polymerization. Key to our approach is to exploit the high end-group fidelity of RAFT polymers to generate chain-end radicals at 120 °C. These radicals trigger a rapid unzipping of both conventional (e.g., poly(methyl methacrylate)) and bulky (e.g., poly(oligo(ethylene glycol) methyl ether methacrylate)) polymers. Importantly, the depolymerization product can be utilized to either reconstruct the linear polymer or create an entirely new insoluble gel that can also be subjected to depolymerization. This work expands the potential of polymers made by controlled radical polymerization, pushes the boundaries of depolymerization, offers intriguing mechanistic aspects, and enables new applications.