Glycol Methyl Ether Methacrylate Research Articles

Carboxylic Acid End-Capped Brushes on Titanium via Interface-Mediated RAFT Polymerization and Cell–Surface Interactions

Polymer brushes with tailored surface functionalities are important materials to manipulate the interactions between cells and surfaces in a biomedical context. To enhance the control of the conjugation of cell-adhesive peptides to the polymer brush terminus, poly(di(ethylene glycol)methyl ether methacrylate) (PDEGMA) brushes were fabricated via interface-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization on titanium substrates. Due to the immobilization of 4-((((2-carboxyethyl)thio)carbonothioyl)thio)-4-cyanopentanoic acid as a chain transfer agent (CTA) on the titanium substrates before the subsequent RAFT polymerization, terminal carboxylic acid groups were introduced in the brushes. The brushes obtained were characterized by ellipsometry, static water contact angle measurements, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT-IR) spectroscopy. PDEGMA brushes allow the facile conjugation of peptides containing the arginine-glycine-aspartic acid (GRGDS) sequence, which afforded the peptide-specific attachment of NIH 3T3 fibroblasts. By contrast, the inhibition of cell attachment was observed on PDEGMA brushes with 7 nm dry thickness conjugated with arginine-alanine-aspartic acid (GRADS). The strategy of surface functional group modification with controllable antifouling or cell-adhesive properties will allow a versatile bio-functionalization approach independent of the underlying surface condition as polymeric biomaterials, among others, in titanium-based medical implant devices.

Li6.4La3Zr1.4Ta0.6O12/Star-Shaped Hybrid Polyhedral Oligomeric Cage Silsesquioxane Polymer Composite Electrolytes for All-Solid-State Lithium Metal Batteries

The low ionic conductivity and mechanical strength are important factors impeding the application of solid polymer electrolytes. Herein, we design synthesize an organic/inorganic hybrid star-shaped polymer of octa(poly(methyl methacrylate)–poly(poly(ethylene glycol) methyl ether methacrylate) cage oligomeric silsesquioxanes (POSS–(PMMA–PPEGMEM)8) by one-step free atom transfer radical polymerization (ATRP), and compound with Li6.4La3Zr1.4Ta0.6O12 (LLZTO) to prepare a composite polymer electrolyte membrane (LP-CPEM). The star-shaped structure of the POSS–(PMMA–PPEGMEM)8 induced by octachloropropyl polyhedral cage oligomeric silsesquioxane (OCP-POSS) is beneficial to reduce the crystallinity of polymer and increase the movement of the polymer chain to form a continuous interconnected ion migration channel. The LLZTO fillers in the LP-CPEM could simultaneously hinder the orderly arrangement of polymer chains and provide other ion transport paths to increase the ion conductivity of LP-CPEM. The LP-CPEM with 7.5 wt % LLZTO has higher ionic conductivity of 3.8 × 10–4 S cm–1 at 30 °C and high mechanical strength (5.2 MPa). Additionally, Li/Li symmetric cells demonstrate stable constant current charging/discharging during 1000 h at 0.1 mA cm–2, and the all-solid-state batteries fabricated by the LP-CPEM exhibit good cyclic stability. It is promising for the development of next-generation high-safety all-solid-state lithium metal batteries.

Preparation and characterization of self‐emulsifying poly(ethylene glycol) methyl ether methacrylate grafted polyacrylate copolymers modified by waterborne polyester

AbstractThe high molecular weight polyacrylate self‐emulsifying emulsion with 20% hydroxyl monomer and 50% solid content was prepared. Waterborne polyester was used to modify the acrylate resin. Besides acrylic acid (AA) and methacrylic acid (MAA), poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) was also used as functional monomer to stabilize the polymerization process and improve the properties of the emulsion. The effects of the amount of waterborne polyester (WP), ammonium persulfate (APS), poly(ethylene glycol) methyl ether methacrylate (PEGMEMA), methacrylic acid (MAA)/acrylic acid (AA) monomer ratio, butyl acrylate (BA)/styrene (St) monomer ratio on the molecular weight, particle size, viscosity, storage stability, and cured film properties of the polyacrylate emulsion were investigated. The average molecular weight of the modified polyacrylate was up to about 2.5 × 104 g mol−1. The emulsion remained stable after 6 months at room temperature. Transmission electron microscope (TEM) images showed that the latex particles had core‐shell structure. The films cured with melamine formaldehyde (MF) resin showed excellent water resistance, adhesion, and hardness.

Hollow polypyrrole coated with mesoporous silica nanoparticles graft copolymer multifunctional nanocomposites for intracellular cancer therapy

A novel hollow polypyrrole coated by mesoporous silica nanoparticles graft poly(2-(4-formylbenzoyloxy)ethyl methacrylate- co -2-(dimethylamino)ethyl methacrylate)- block -poly(triethylene glycol methyl ether methacrylate) multifunctional nanocomposite (HPPy@MSN-SS-NH- g -P(FBEMA- co -DMAEMA)- b -PTEGMA) was designed and prepared via disulfide bond linkages. This material as a gatekeeper integrated multifunctionality such as pore capping, and pH and potothermal multistimuli response abilities, and possessed good photothermal stability, near-infrared (NIR) photothermal conversion capacity and dispersion stability in aqueous solution. It could entrap anticancer doxorubicin (DOX) by pore channels of HPPy@MSN, the core of amphiphilic copolymer micelles and Schiff base linkages, offering a load capacity and load efficiency of up to about 41.5 and 83.1%, respectively. Dynamic light scattering analysis showed that the DOX-loaded preparations had particle size of less than 300 nm, and could achieve intracellular chemo–photothermal combination therapy by controlling the mesopore on-off based on the gatekeepers, tumor environments including pH and reductant stimuli. The drug-loaded nanoparticles exhibited optimal drug release dynamics in cancer tissues upon triggered by pH and glutathione (GSH) under the NIR irradiation. Cell counting Kit-8 assay manifested that the nanocarriers are non-toxic and safe, whereas the drug-loaded preparations exhibited robust anticancer efficacy. Cellular uptake and TUNEL assay revealed high concentrations of DOX accumulating around and inside Hela cells, accordingly producing significant tumor cell apoptosis. Therefore, the newly-developed materials can be used for comprehensive therapy of cancer as a promising candidate of drug delivered carriers. • We prepared hollow PPy coated with MSNs graft copolymer multifunctional composites. • The nanocomposites exhibited pH, reductant and potothermal multi-responsivities. • This material entrapped DOX by pores, hydrophobic actions and Schiff base linkages. • The drug release was triggered by synergism of pore capping, pH, reductant and NIR. • A chemo–photothermal combination therapy could be achieved by the mesopore on-off.

Thermoresponsive polymer assemblies via variable temperature liquid-phase transmission electron microscopy and small angle X-ray scattering

Herein, phase transitions of a class of thermally-responsive polymers, namely a homopolymer, diblock, and triblock copolymer, were studied to gain mechanistic insight into nanoscale assembly dynamics via variable temperature liquid-cell transmission electron microscopy (VT-LCTEM) correlated with variable temperature small angle X-ray scattering (VT-SAXS). We study thermoresponsive poly(diethylene glycol methyl ether methacrylate) (PDEGMA)-based block copolymers and mitigate sample damage by screening electron flux and solvent conditions during LCTEM and by evaluating polymer survival via post-mortem matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS). Our multimodal approach, utilizing VT-LCTEM with MS validation and VT-SAXS, is generalizable across polymeric systems and can be used to directly image solvated nanoscale structures and thermally-induced transitions. Our strategy of correlating VT-SAXS with VT-LCTEM provided direct insight into transient nanoscale intermediates formed during the thermally-triggered morphological transformation of a PDEGMA-based triblock. Notably, we observed the temperature-triggered formation and slow relaxation of core-shell particles with complex microphase separation in the core by both VT-SAXS and VT-LCTEM.

Oxygen-Tolerant RAFT Polymerization Catalyzed by a Recyclable Biomimetic Mineralization Enhanced Biological Cascade System.

An enzyme cascade system including glucose oxidase (GOx) and iron porphyrin (DhHP-6) is encapsulated in a metal-organic framework called zeolitic imidazolate framework-8 (ZIF-8) through one-step facile synthesis. The composite (GOx&DhHP-6@ZIF-8) is then used to initiate oxygen-tolerant reversible addition-fragmentation chain-transfer polymerization for different methacrylate monomers, such as 2-diethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, and poly(ethylene glycol) methyl ether methacrylate (Mn = 500g mol-1 ). The composite shows the robustness toward solvent and temperatures, all polymerizations using above monomers and catalyzing by GOx&DhHP-6@ZIF-8 exhibits high monomer conversion (>85%) and narrow molar mass dispersity (<1.3). Besides, acrylic and acrylamide monomers such as 2-hydroxyethyl acrylate and N,N-dimethylacrylamide are also carried to demonstrate the broad applicability. Proton nuclear magnetic resonance characterization and chain extension experiments confirm the retaining end groups of the resultant polymers, which is a significant feature of living polymerization. More importantly, the process of recycling the composite through a centrifuge is simplistic, and the composite still maintains similar activity compared to the original composites after five times. This low-cost and easily separated composite catalyst represents a versatile strategy to synthesize well-defined functional polymers suitable for industrial-scale production.

Enzyme-catalyzed cascade reactions on multienzyme proteinosomes

In this research, to mimic the structures and the functionalities of the organelles in living cells multienzyme proteinosomes with β-galactosidase (β-gal), glucose oxidase (GOx) and horseradish peroxidase (HRP) on the surfaces are fabricated by hydrophobic-interaction induced self-assembly approach. To investigate the mechanism of the formation of proteinosomes, poly(di(ethylene glycol) methyl ether methacrylate) (PDEGMA) and bovine serum albumin are employed in a model system and the study demonstrates that the hydrophobic interaction between the dehydrated polymer chains and the hydrophobic patches on the proteins plays a key role in the fabrication of the proteinosomes. Based on the model system, multienzyme proteinosomes with β-gal, GOx and HRP on the surfaces are fabricated through hydrophobic interaction between PDEGMA and enzyme molecules. Enzyme-catalyzed cascade reactions are performed on the surfaces of the proteinosomes, and the immobilized enzymes show higher bioactivities than the “free” enzymes, due to the direct transfer of the product as a substrate from one enzyme molecule to another. This research provides a unique method for the synthesis of multienzyme proteinosomes with improved bioactivities, and the biofunctional structures will find promising applications in medical and biological science.

Synthesis and characterization of thermo-responsive polymer based on carboxymethyl chitosan and its potential application in water-based drilling fluid

Novel graft copolymer (CSGO) based on carboxymethyl chitosan (CMCS) with thermosensitive poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) side chain was synthesized through free radical polymerization. The highly grafted POEGMA chains on the amino groups of CMCS brought CSGO with thermo-responsive behavior with lower critical solution temperature (LCST) confirmed by turbidimetric, temperature sweep rheology and DSC tests. The potential application of CSGO in sodium bentonite (Na-Bent) dispersion was investigated through rheological, filtration and inhibition measurements, and the interaction mechanism between CSGO and Na-Bent was evaluated. The results showed that CSGO improved the rheological and filtration properties of Na-Bent dispersion before and after aging within 120 ℃, ascribing to combined results of aggregation and film-forming effects on bentonite particles. More interestingly, the thermal-induced hydrophilic-to-hydrophobic transition caused the association of Na-Bent/CSGO flocs and the formation of partially desorbed polymer aggregates, contributing to the thermo-thickening rheology, lower fluid loss and better shale dispersion inhibition ability at elevated temperature. Additionally, CSGO could effectively inhibit clay hydration swelling, following a Fick diffusion mechanism of water through the formed CSGO film on the clay core. Besides forming a film to minimize osmotic swelling, the mixed intercalation of CSGO into clay interlayer with a monolayer CMCS backbone and/or a monolayer POEGMA side chain could inhibit crystalline swelling to a certain extent. Therefore, the superior properties and the attractive high-temperature behaviors of CSGO highlighted its potential application in water-based drilling fluid with recycling values during circulation.

Polymer/C.I. Pigment Red 170 hybrid latexes prepared by RAFT-mediated surfactant-free emulsion polymerization

By using organic pigment-based ink-jet inks, the digital ink-jet printing of textiles is one kind of environmentally friendly technology for cleaner dyeing. Due to the shortcomings of easy agglomeration and poor water dispersion stability of organic nanoparticles, however, the encapsulation and dispersion of organic pigment nanoparticles are also hot and difficult research problems. In this work, we report the reversible addition-fragmentation chain transfer (RAFT) polymerization technology was used to synthesize random copolymer of 2-(dimethylamino) ethyl methacrylate (DMAEMA), poly(ethylene glycol) methyl ether methacrylate (PEGA), and methyl methacrylate (MMA) or butyl acrylate (BA) with a trithiocarbonate reactive end-group. These cationic macromolecular RAFT agents (macro-RAFT) with a pH of 5 were subsequently adsorbed at the surface of size-monodisperse colloidal Pigment Red 170 particles. The absorbed macro-RAFT agents were considered to be the living points to mediate the RAFT polymerization of monomers (MMA and BA) by starved feed emulsion polymerization. TEM results shown that the resulting hybrid latexes synthesized in presence of the tri-copolymer macro-RAFT agents resulted in the formation of individually encapsulated pigment particles. In addition, the dynamic light scattering (DLS), zeta potential and stability tests found that the macro-RAFT agent participated in the growing latex stabilization which is the key to obtaining the stable and uniform core-shell hybrid latex. More importantly, the preparation of film-forming copolymer/pigment hybrid latex in this study shown that the high potential of the P(DMAEMA- co -PEGA- co -MMA or BA) macro-RAFT agent for the development of polymer-pigment hybrid latexes which has good application properties. • Cationic and brush-type macro-RAFT agents were synthesized through RAFT polymerization. • Amphiphilic macro-RAFT agent has good adsorption and dispersion properties for the C.I. Pigment Red 170. • The film-forming polymers with lower T g are successfully encapsulated on the surface of pigment. • The encapsulated polymer/pigment hybrid latexes exhibit excellent dispersion stability with freeze-thaw, storage and pH.

Thermoresponsive poly(di(ethylene glycol) methyl ether methacrylate)-ran-(polyethylene glycol methacrylate) graft copolymers exhibiting temperature-dependent rheology and self-assembly

Graft copolymers with brush-type architectures are explored containing poly(ethylene glycol) methacrylates copolymerized with “thermoresponsive” monomers which impart lower critical solution temperatures to the polymer. Initially, the chemical structure of the thermoresponsive polymer is explored, synthesizing materials containing N-isopropyl acrylamide, N,N-diethyl acrylamide and diethylene glycol methyl ether methacrylate. Thermoresponsive graft-copolymers containing di(ethylene glycol) methyl ether methacrylate (DEGMA) exhibited phase transition temperature close to physiological conditions (ca 30 °C). The effect of polymer composition was explored, including molecular weight, PEG-methacrylate (PEGMA) terminal functionality and PEGMA/DEGMA ratios. Molecular weight exhibited complex relationships with phase behavior, where lower molecular weight systems appeared more stable above lower critical solution temperatures (LCST), but a lower limit was identified. PEGMA/DEGMA feed was able to control transition temperature, with higher PEGMA ratios elevating thermal transition. It was found that PEGMA terminated with methoxy functionality formed stable colloidal structures above LCST, whereas those the hydroxy termini generally formed two-phase sedimented systems when heated. Two thermoresponsive DEGMA-based graft polymers, poly(PEGMA7-ran-DEGMA170) and poly(PEGMA1-ran-DEGMA38), gave interesting temperature-dependent rheology, transitioning to a viscous state upon heating. These materials may find application in forming thermothickening systems which modify rheology upon exposure to the body’s heat.

Ionic Liquid-Decorated Copolymer Binders for Silicon/Graphite Anodes with Enhanced Rate Capability and Excellent Cycle Stability

Ionic liquid (IL)-decorated copolymers based on poly((ethylene glycol) methyl ether methacrylate)-co-(acrylic acid)-co-(1-vinyl-3-ethylimidazolium hexafluorophosphate) were prepared and used as binders for Si/Gr anodes in lithium-ion batteries. The IL-decorated copolymer-bonded Si/Gr anodes showed a higher rate capability and better cycle stability than poly(vinylidene fluoride) (PVDF)-bonded and poly(acrylic acid) (PAA)-bonded Si/Gr anodes. In particular, the Si/Gr@CP1 anode exhibited an initial charge/discharge capacity of 1053/1286 mAh g–1 during the first formation cycle and retained 93.1% of its specific capacity after 100 cycles at a current density of 0.6 A g–1. Measurements from electrochemical impedance spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy demonstrated the quick formation of a well-structured solid–electrolyte interphase (SEI) layer on the IL-decorated copolymer-bonded Si/Gr anodes, which led to the excellent electrochemical performance of Si/Gr@CP1. The quick formation of this SEI layer was attributed to the introduction of IL into the polymer binder, which accumulated a large number of PF6– anions on the anode surface and facilitated SEI formation through in situ decomposition. The success of this work provides a promising avenue for pursuing high-capacity lithium-ion batteries (LIBs) with an extended cycle life.

New amphiphilic terpolymers of N-vinylpyrrolidone with poly(ethylene glycol) methyl ether methacrylate and triethylene glycol dimethacrylate as carriers of the hydrophobic fluorescent dye

New amphiphilic terpolymers of N-vinylpyrrolidone with poly(ethylene glycol) methyl ether methacrylate and triethylene glycol dimethacrylate as carriers of the hydrophobic fluorescent dye

Comestible curcumin: From kitchen to polymer chemistry as a photocatalyst in metal-free ATRP of (meth)acrylates

The article presents an application of curcumin, a widely available and cost-effective organic dye, to control visible-light mediated ATRP. A two-component photocatalytic system composed of curcumin and an amine-based electron donor activates alkyl bromide and controls radical polymerizations by a reductive quenching pathway. The polymerizations of various types of (meth)acrylates were performed under blue LED irradiation (λmax = 460 nm, 5 mW cm−2). The effect of electron donor type, solvent, photocatalyst and electron donor concentration, target degree of polymerization (DPtarget) etc. on the metal-free ATRP of methyl methacrylate (MMA) and poly(ethylene glycol) methyl ether methacrylate (OEGMA500) was systematically investigated to optimize the polymerization conditions. Moreover, comestible curcumin of four different brands available in the market as kitchen spices was used, which makes this approach economical (∼0.04 € for 15 g of turmeric). In order to increase the applicability of the curcumin-based polymerization strategy, the concept was extended to the polymerization of other methacrylates – butyl methacrylate (nBMA), di(ethylene glycol) methyl ether methacrylate (DEGMA), 2-(dimethylamino)ethyl methacrylate (DMAEMA), and acrylates i.e. poly(ethylene glycol) methyl ether acrylate (OEGA480), n-butyl acrylate (nBA) and 2-hydoxyethyl acrylate (HEA). In situ chain extension experiment demonstrated the preservation of chain-end functionality, enabling the facile synthesis of well-controlled copolymers.

Pickering Emulsions Stabilized by Diblock Copolymer Worms Prepared via Reversible Addition–Fragmentation Chain Transfer Aqueous Dispersion Polymerization: How Does the Stimulus Sensitivity Affect the Rate of Demulsification?

Responsive Pickering emulsions exhibit promising application in industry owing to the integration of the high storage stability with on-demand demulsification. In this study, stimuli-responsive Pickering emulsions stabilized by poly[oligo(ethylene glycol) methyl ether methacrylate]15-b-poly(diacetone acrylamide)120 (E15D120) worms were indicated, in which E15D120 worms were prepared via reversible addition-fragmentation chain transfer-based aqueous dispersion polymerization using thermo-sensitive POEGMA15 as both the stabilizer block and macro-chain transfer agent. The factors influencing the morphologies of copolymers during polymerization-induced self assembly have been investigated. A series of different morphological polymer nanoparticles including spheres, worms, and vesicles could be produced through rational synthesis. E15D120 worms demonstrated excellent emulsifying performances and could be used as emulsifiers to form n-dodecane-in-water Pickering emulsions at a low content. The formed n-dodecane-in-water Pickering emulsions revealed a slow demulsification at pH 10 or 70 °C or pH 10/70 °C combinations, and several hours were needed for the demulsification of Pickering emulsions. However, n-dodecane-in-water Pickering emulsions displayed a rapid demulsification (∼10 min) at an elevated temperature, such as 90 °C. The different demulsification rates were attributed to different sensitivities of E15D120 worms to external stimuli. Pickering emulsions integrating a rapid responsive demulsification with a slow one would be well satisfactory on different occasions.

Epoxy-Based Interlocking Membranes for All Solid-State Lithium Ion Batteries: The Effects of Amine Curing Agents on Electrochemical Properties.

In this study, a series of crosslinked membranes were prepared as solid polymer electrolytes (SPEs) for all-solid-state lithium ion batteries (ASSLIBs). An epoxy-containing copolymer (glycidyl methacrylate-co-poly(ethylene glycol) methyl ether methacrylate, PGA) and two amine curing agents, linear Jeffamine ED2003 and hyperbranched polyethyleneimine (PEI), were utilized to prepare SPEs with various crosslinking degrees. The PGA/polyethylene oxide (PEO) blends were cured by ED2003 and PEI to obtain slightly and heavily crosslinked structures, respectively. For further optimizing the interfacial and the electrochemical properties, an interlocking bilayer membrane based on overlapping and subsequent curing of PGA/PEO/ED2003 and PEO/PEI layers was developed. The presence of this amino/epoxy network can inhibit PEO crystallinity and maintain the dimensional stability of membranes. For the slightly crosslinked PGA/PEO/ED2003 membrane, an ionic conductivity of 5.61 × 10−4 S cm−1 and a lithium ion transference number (tLi+) of 0.43 were obtained, along with a specific capacity of 156 mAh g−1 (0.05 C) acquired from an assembled half-cell battery. However, the capacity retention retained only 54% after 100 cycles (0.2 C, 80 °C), possibly because the PEO-based electrolyte was inclined to recrystallize after long term thermal treatment. On the other hand, the highly crosslinked PGA/PEO/PEI membrane exhibited a similar ionic conductivity of 3.44 × 10−4 S cm−1 and a tLi+ of 0.52. Yet, poor interfacial adhesion between the membrane and the cathode brought about a low specific capacity of 48 mAh g−1. For the reinforced interlocking bilayer membrane, an ionic conductivity of 3.24 × 10−4 S cm−1 and a tLi+ of 0.42 could be achieved. Moreover, the capacity retention reached as high as 80% after 100 cycles (0.2 C, 80 °C). This is because the presence of the epoxy-based interlocking bilayer structure can block the pathway of lithium dendrite puncture effectively. We demonstrate that the unique interlocking bilayer structure is capable of offering a new approach to fabricate a robust SPE for ASSLIBs.

Synthesis of ultra‐high molecular weight core cross‐linked star (CCS) polymer using high molecular weight spherical nanoparticles and arm‐first method

AbstractP (N,N‐Dimethylacrylamide) ‐b‐P (2‐methoxyethyl acrylate) (PDMA‐b‐PMEA) and Poly (poly (ethylene glycol) methyl ether methacrylate) ‐b‐P (2‐methoxyethyl acrylate) (PPEGMA‐b‐PMEA) di‐block copolymer nanoparticles are prepared by RAFT dispersion polymerization in water at 35°C. By changing the degree of polymerization (DP) of PMEA and the solid content of the reaction solution, only spherical nanoparticles are obtained. Using PDMA and PPEGMA as macromolecular chain transfer agents (Macro‐CTA), the actual DP of PMEA block can be up to 11,520 and 17,000, respectively, the size of the obtained spherical nanoparticles can be close to 600 nm, and the molecular weight of the block copolymer can reach 106. Such large spheres may serve as model sterically stabilized particles for analytical centrifugation studies. In the mixed solvent of ethanol and water (1:1, v/v), we synthesize ultra‐high molecular weight CCS polymer by the arm‐first method. Star polymer with such high molecular weight and small particle size can be used for emulsification.

Post-functionalization of drug-loaded nanoparticles prepared by polymerization-induced self-assembly (PISA) with mitochondria targeting ligands.

Herein, the postfunctionalization of different non-fouling PISA particles, prepared from either poly(oligo ethylene glycol methyl ether methacrylate) (pPEGMA) and the anticancer drug PENAO (4-(N-(S-penicillaminylacetyl)amino)phenylarsenonous acid) or zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC) and PENAO were reported. Both PISA particles were reacted with triphenylphosphonium (TPP) as mitochondria targeting units in order to evaluate the changes in cellular uptake or the toxicity of the conjugated arsenic drug. Attachment of TPP onto the PISA particles however was found not to enhance the mitochondrial accumulation, but it did influence overall the biological activity of pMPC-based particles in 2D and 3D cultured sarcoma SW982 cells. When TPP was conjugated to the pMPC PISA particles more cellular uptake as well as better spheroid penetration were observed, while TPP on PEG-based PISA had only little effect. It was hypothesized that TPP on the micelle surface may not be accessible enough to allow mitochondria targeting, but more structural investigations are required to elucidate this.

Modulating the Thermoresponse of Polymer-Protein Conjugates with Hydrogels for Controlled Release.

Sustained release is being explored to increase plasma and tissue residence times of polymer-protein therapeutics for improved efficacy. Recently, poly(oligo(ethylene glycol) methyl ether methacrylate) (PEGMA) polymers have been established as potential PEG alternatives to further decrease immunogenicity and introduce responsive or sieving properties. We developed a drug delivery system that locally depresses the lower critical solution temperature (LCST) of PEGMA-protein conjugates within zwitterionic hydrogels for controlled release. Inside the hydrogel the conjugates partially aggregate through PEGMA-PEGMA chain interactions to limit their release rates, whereas conjugates outside of the hydrogel are completely solubilized. Release can therefore be tuned by altering hydrogel components and the PEGMA’s temperature sensitivity without the need for traditional controlled release mechanisms such as particle encapsulation or affinity interactions. Combining local LCST depression technology and degradable zwitterionic hydrogels, complete release of the conjugate was achieved over 13 days.

Stimuli‐Responsive Hydrogels Based on Random Copolymers of the Sucrose Methacrylate

AbstractPoly(sucrose methacrylate‐co‐acrylic acid), P(SMA‐co‐AA), and poly(sucrose methacrylate‐co‐diethylene glycol methyl ether methacrylate), P(SMA‐co‐EG2MA), are synthesized by free radical polymerization using sucrose dimethacrylate as a crosslinker. The copolymers present one glass transition suggesting a random distribution of the comonomers. The copolymers–water interaction parameter χ is around 0.5, while Mc increases with SMA molar fraction. The kinetics of water swelling show a Fickian behavior for P(SMA‐co‐AA) richer in acrylic acid. The swelling is driven by the ionic character of the P(SMA‐co‐AA), except at pH = 2, and by the hydrophilicity of the SMA for the P(SMA‐co‐EG2MA). The temperature influences the swelling behavior of the P(SMA‐co‐EG2MA) due to the lower critical solution temperature (LCST) behavior. The pH‐ and thermoresponsiveness of the P(SMA‐co‐AA) and P(SMA‐co‐EG2MA) hydrogels are maintained by replacing the sensitive comonomers with SMA up to mass fractions of 85 and 20 wt%, respectively, ≈71 and 17 wt% of sucrose, a product from a renewable resource. The hydrolytic degradation of the hydrogels is more pronounced for copolymers richer in SMA and resulted in sucrose release. Hydrogels present viscoelastic behavior, and the P(SMA‐co‐AA) series is more resistant to compression. The xerogels of the copolymers richer in SMA show a foam‐like morphology with open cells.

Homopolymer and ABC Triblock Copolymer Mixtures for Thermoresponsive Gel Formulations.

Our group has recently invented a novel series of thermoresponsive ABC triblock terpolymers based on oligo(ethylene glycol) methyl ether methacrylate with average Mn 300 g mol−1 (OEGMA300, A unit), n-butyl methacrylate (BuMA, B unit) and di(ethylene glycol) methyl ether methacrylate (DEGMA, C unit) with excellent thermogelling properties. In this study, we investigate how the addition of OEGMA300x homopolymers of varying molar mass (MM) affects the gelation characteristics of the best performing ABC triblock terpolymer. Interestingly, the gelation is not disrupted by the addition of the homopolymers, with the gelation temperature (Tgel) remaining stable at around 30 °C, depending on the MM and content in OEGMA300x homopolymer. Moreover, stronger gels are formed when higher MM OEGMA300x homopolymers are added, presumably due to the homopolymer chains acting as bridges between the micelles formed by the triblock terpolymer, thus, favouring gelation. In summary, novel formulations based on mixtures of triblock copolymer and homopolymers are presented, which can provide a cost-effective alternative for use in biomedical applications, compared to the use of the triblock copolymer only.