Tunable Thermoresponsive Mesoporous Block Copolymer Membranes

Tang, Yanchun; Ito, Kohzo; Hong, Ling; Ishizone, Takashi; Yokoyama, Haruki

doi:10.1021/acs.macromol.6b01665

Cited by 18 publications

(20 citation statements)

References 42 publications

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“…A key test of pore formation is whether leakage of liposome contents can be prevented by plugging the pore using a molecule of the correct Stoke’s radius (Saito et al, 2000). We examined the CelTOS-dependent release of carboxyfluorescein from liposomes in the presence of 20 μM dextran molecules of various molecular weights: 66.9 kDa (Stoke’s radius:~5.8 nm), 148 kDa (Stoke’s radius:~8 nm), 500 kDa (Stoke’s radius: 14.7 nm), 1500–2800 kDa (Stoke’s radius ranging from ~25 to ~60 nm (Tang et al, 2016); Stoke’s radius of 2000 kDa Dextran: 27 nm [Armstrong et al, 2004]). Remarkably, only the 500 kDa dextran blocked carboxyfluorescein release from liposomes disrupted with PfCelTOS and PvCelTOS, respectively (Figure 5A and B).…”

Section: Resultsmentioning

confidence: 99%

Malaria parasite CelTOS targets the inner leaflet of cell membranes for pore-dependent disruption

Jimah

Salinas

Sala-Rabanal

et al. 2016

eLife

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Apicomplexan parasites contain a conserved protein CelTOS that, in malaria parasites, is essential for traversal of cells within the mammalian host and arthropod vector. However, the molecular role of CelTOS is unknown because it lacks sequence similarity to proteins of known function. Here, we determined the crystal structure of CelTOS and discovered CelTOS resembles proteins that bind to and disrupt membranes. In contrast to known membrane disruptors, CelTOS has a distinct architecture, specifically binds phosphatidic acid commonly present within the inner leaflet of plasma membranes, and potently disrupts liposomes composed of phosphatidic acid by forming pores. Microinjection of CelTOS into cells resulted in observable membrane damage. Therefore, CelTOS is unique as it achieves nearly universal inner leaflet cellular activity to enable the exit of parasites from cells during traversal. By providing novel molecular insight into cell traversal by apicomplexan parasites, our work facilitates the design of therapeutics against global pathogens.DOI: http://dx.doi.org/10.7554/eLife.20621.001

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Section: Resultsmentioning

confidence: 99%

Malaria parasite CelTOS targets the inner leaflet of cell membranes for pore-dependent disruption

Jimah

Salinas

Sala-Rabanal

et al. 2016

eLife

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“…The thermo-and pH-depended hydraulic permeabilities of PDS_m, PMS_m, PDMS_m, and PMDS_m membranes were investigated by filtrating water, acetate buffer (pH=4.6) and carbonate buffer (pH=10.1) at 15, 35 and 65 ᴼC with a home-made dead-end filtration setup which have used in our previous work. [4] The transmembrane pressure was set at 0.02 MPa. Permeate was collected in a beaker for 15 min and the amount was determined gravimetrically every 1 min.…”

Section: Characterization Of Membranesmentioning

confidence: 99%

“…Different types of stimuli were applied to induce responses, including temperature, pH, specific ions, light and electric and magnetic fields. [1][2][3][4][5][6][7] Although the interest in the stimuli-responsive membranes has increased dramatically in the last two to three decades, the researches almost focused on the membranes with single responsivity. Only a few studies have been done for developing dual-or multi-responsive membranes.…”

Section: Introductionmentioning

confidence: 99%

Multi-Stimuli-Responsive Mesoporous Membranes and Effect of Molecular Architecture on Thermo- and pH-Responsive Behavior of the grafted Block Copolymer brushes

Tang

Ito²,

Yokoyama³

2019

Preprint

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In this study, we prepared ultrafiltration membranes with a decoupled responses of filtration property to temperature and pH. The membrane preparation method was developed based on our previous work. We utilized methanol-supercritical carbon dioxide (methanol-scCO2) selective swelling method to introduce nanopores to block copolymers containing poly(diethylene glycol) methyl ether methacrylate (PMEO2MA), poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) and polystyrene (PS) blocks. Formation of the mesoporous barrier layer with PS being the mechanically stable part of the matrix was driven by selective swelling of the PMEO2MA-b-PDMAEMA domains. Due to the selective swelling of PMEO2MA or PDMAEMA domains to introduce pores, the interior of the pores are covered with PMEO2MA or PDMAEMA blocks after pore formation. The PMEO2MA-b-PDMAEMA polymer brushes are naturally attached on the pore walls and worked as functional gates. PMEO2MA is a non-toxic, neutral thermo-responsive polymer with LCST at 26 ᴼC. PDMAEMA is a typical weak polyelectrolyte with pKa value at 7.0-7.5 and also a thermo-responsive polymer revealed a LCST of 20-80 °C in aqueous solution. Therefore, these membranes were expected to have multi dimensions as function of the combination of temperature and pH. Moreover, to understand the detail of the temperature and pH depended conformation transitions of PMEO2MA-b-PDMAEMA brushes, those diblock copolymers were end-tethered on flat substrates and analyzed via neutron reflectivity (NR).

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“…This type of polymers feature certain chemical functionalities, which can be addressed by external triggers such as the presence of solvent, change of temperature, variation of pH, by light, redox reagents, or electrical or magnetic fields [ 8 , 9 , 10 , 11 ]. Especially thermo-responsive membranes were shown to reversibly switch their pore diameter and surface properties, and therefore, controlling the selectivity of the membrane [ 4 , 12 , 13 , 14 , 15 , 16 ]. In general, among the broad variety of stimuli-responsive mechanisms, redox reactions induced by the addition of oxidation or reducing agents or by applying electrical potentials are much less investigated.…”

Section: Introductionmentioning

confidence: 99%

Ferrocene-Modified Block Copolymers for the Preparation of Smart Porous Membranes

et al. 2017

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Abstract:The design of artificially generated channels featuring distinct remote-switchable functionalities is of critical importance for separation, transport control, and water filtration applications. Here, we focus on the preparation of block copolymers (BCPs) consisting of polystyrene-block-poly(2-hydroxyethyl methacrylate) (PS-b-PHEMA) having molar masses in the range of 91 to 124 kg mol −1 with a PHEMA content of 13 to 21 mol %. The BCPs can be conveniently functionalized with redox-active ferrocene moieties by a postmodification protocol for the hydrophilic PHEMA segments. Up to 66 mol % of the hydroxyl functionalities can be efficiently modified with the reversibly redox-responsive units. For the first time, the ferrocene-containing BCPs are shown to form nanoporous integral asymmetric membranes by self-assembly and application of the non-solvent-induced phase separation (SNIPS) process. Open porous structures are evidenced by scanning electron microscopy (SEM) and water flux measurements, while efficient redox-switching capabilities are investigated after chemical oxidation of the ferrocene moieties. As a result, the porous membranes reveal a tremendously increased polarity after oxidation as reflected by contact angle measurements. Additionally, the initial water flux of the ferrocene-containing membranes decreased after oxidizing the ferrocene moieties because of oxidation-induced pore swelling of the membrane.

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Tunable Thermoresponsive Mesoporous Block Copolymer Membranes

Cited by 18 publications

References 42 publications

Malaria parasite CelTOS targets the inner leaflet of cell membranes for pore-dependent disruption

Malaria parasite CelTOS targets the inner leaflet of cell membranes for pore-dependent disruption

Multi-Stimuli-Responsive Mesoporous Membranes and Effect of Molecular Architecture on Thermo- and pH-Responsive Behavior of the grafted Block Copolymer brushes

Ferrocene-Modified Block Copolymers for the Preparation of Smart Porous Membranes

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