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Biophysical Journal Jan 2022Hybrid polymer/lipid vesicles are self-assembled structures that have been the subject of an increasing number of studies in recent years. They are particularly...
Hybrid polymer/lipid vesicles are self-assembled structures that have been the subject of an increasing number of studies in recent years. They are particularly promising tools in the development of cell membrane models because they offer the possibility to fine-tune their membrane structure by adjusting the distribution of components (presence or absence of "raft-like" lipid domains), which is of prime importance to control their membrane properties. Line tension in multiphase membranes is known to be a key parameter on membrane structuration, but remains unexplored, either experimentally or by computer modeling for hybrid polymer/lipid vesicles. In this study, we were able to measure the line tension on different budded hybrid vesicles, using a micropipette aspiration technique, and show the influence of the molar mass and the architecture of block copolymers on line tension and its consequences for membrane structuration.
Topics: Cell Membrane; Lipids; Molecular Weight; Polymers
PubMed: 34890579
DOI: 10.1016/j.bpj.2021.12.005 -
Medecine Sciences : M/S Jan 2017Nanocarriers based on polymers are currently attracting much attention to perform efficient drug delivery, especially in cancer therapy. Over the last decades, different... (Review)
Review
Nanocarriers based on polymers are currently attracting much attention to perform efficient drug delivery, especially in cancer therapy. Over the last decades, different kinds of polymer nanoparticulate systems have been developed (e.g., simple, stealth, targeted, stimuli-responsive and prodrug) to propose novel, better and safer cancer therapies. This article will give a brief overview of the different classes of polymer nanoparticles that have been reported and discuss some key achievements deriving from their use in the field of cancer therapy.
Topics: Antineoplastic Agents; Drug Carriers; Drug Delivery Systems; Humans; Molecular Targeted Therapy; Nanoparticles; Polymers
PubMed: 28120750
DOI: 10.1051/medsci/20173301003 -
Proceedings of the Japan Academy.... Dec 2023This review mainly highlights our studies on the synthesis of one-handed helical polymers with a static memory of helicity based on the noncovalent helicity induction... (Review)
Review
This review mainly highlights our studies on the synthesis of one-handed helical polymers with a static memory of helicity based on the noncovalent helicity induction with a helical-sense bias and subsequent memory of the helicity approach that we developed during the past decade. Apart from the previous approaches, an excess one-handed helical conformation, once induced by nonracemic molecules, is immediately retained ("memorized") after the complete removal of the nonracemic molecules, accompanied by a significant amplification of the asymmetry, providing novel switchable chiral materials for chromatographic enantioseparation and asymmetric catalysis as well as a highly sensitive colorimetric and fluorescence chiral sensor. A conceptually new one-handed helix formation in a racemic helical polymer composed of racemic repeating units through the deracemization of the pendants is described.
Topics: Polymers; Molecular Conformation
PubMed: 37853628
DOI: 10.2183/pjab.99.025 -
Biophysical Journal Oct 2022The plasma membrane hosts a wide range of biomolecules, mainly proteins and carbohydrates, that mediate cellular interactions with its environment. The crowding of such...
The plasma membrane hosts a wide range of biomolecules, mainly proteins and carbohydrates, that mediate cellular interactions with its environment. The crowding of such biomolecules regulates cellular morphologies and cellular trafficking. Recent discoveries have shown that the structure and density of cell surface polymers and hence the signaling machinery change with the state of the cell, especially in cancer progression. The alterations in membrane-attached glycocalyx and glycosylation of proteins and lipids are common features of cancer cells. The overexpression of glycocalyx polymers, such as mucin and hyaluronan, strongly correlates with cancer metastasis. Here, we present a mesoscale biophysics-based model that accounts for the shape regulation of membranes by crowding of membrane-attached biopolymer-glycocalyx and actin networks. Our computational model is based on the dynamically triangulated Monte Carlo model for membranes and coarse-grained representations of polymer chains. The model allows us to investigate the crowding-induced shape transformations in cell membranes in a tension- and graft polymer density-dependent manner. Our results show that the number of membrane protrusions and their shape depend on membrane tension, with higher membrane tension inducing more tubular protrusions than the vesicular shapes formed at low tension at high surface coverage of polymers. The shape transformations occur above the threshold density predicted by the polymer brush theory, but this threshold also depends on the membrane tension. Increasing the size of the polymer, either by changing the length or by adding side chains, is shown to increase the crowding-induced curvature. The effect of crowding is more prominent for flexible polymers than for semiflexible rigid polymers. We also present an extension of the model that incorporates properties of the actin-like filament networks and demonstrate how tubular structures can be generated by biopolymer crowding on the cytosolic side of cell membranes.
Topics: Actins; Cell Membrane; Hyaluronic Acid; Lipids; Mucins; Polymers
PubMed: 35619564
DOI: 10.1016/j.bpj.2022.05.031 -
Biomacromolecules Nov 2023This study aims to design an anionic, thiolated cellulose derivative and to evaluate its mucoadhesive and permeation-enhancing properties utilizing enoxaparin as a model...
This study aims to design an anionic, thiolated cellulose derivative and to evaluate its mucoadhesive and permeation-enhancing properties utilizing enoxaparin as a model drug. 2-Mercaptosuccinic acid-modified cellulose (cellulose-mercaptosuccinate) was synthesized by the reaction of cellulose with -acetylmercaptosuccinic anhydride. The chemical structure of the target compound was confirmed by FTIR and H NMR spectroscopy. The thiol content was determined by Ellman's test. The conjugate exhibited 215.5 ± 25 μmol/g of thiol groups and 84 ± 16 μmol/g of disulfide bonds. Because of thiolation, mucoadhesion on porcine intestinal mucosa was 9.6-fold enhanced. The apparent permeability () of the model dye Lucifer yellow was up to 2.2-fold improved by 0.5% cellulose-mercaptosuccinate on a Caco-2 cell monolayer. Enoxaparin permeation through rat intestinal mucosa increased 2.4-fold in the presence of 0.5% cellulose-mercaptosuccinate compared with the drug in buffer only. studies in rats showed an oral bioavailability of 8.98% using cellulose-mercaptosuccinate, which was 12.5-fold higher than that of the aqueous solution of the drug. Results of this study show that the modification of cellulose with 2-mercaptosuccinic acid provides mucoadhesive and permeation-enhancing properties, making this thiolated polymer an attractive excipient for oral drug delivery.
Topics: Humans; Rats; Animals; Swine; Polymers; Caco-2 Cells; Enoxaparin; Cellulose; Drug Delivery Systems; Sulfhydryl Compounds; Pharmaceutical Preparations; Intestinal Mucosa
PubMed: 37796043
DOI: 10.1021/acs.biomac.3c00577 -
International Journal of Molecular... Dec 2022Novel poly(dithiophosphate)s (PDTPs) were successfully synthesized under mild conditions without any additive in the presence of THF or toluene diluents at 60 °C by a...
Novel poly(dithiophosphate)s (PDTPs) were successfully synthesized under mild conditions without any additive in the presence of THF or toluene diluents at 60 °C by a direct, catalyst-free reaction between the abundant phosphorus pentasulfide (PS) and glycols such as ethylene glycol (EG), 1,6-hexanediol (HD) and poly(ethylene glycol) (PEG). GPC, FTIR, H and P NMR analyses proved the formation of macromolecules with dithiophosphate coupling groups having P=S and P-SH pendant functionalities. Surprisingly, the ring-opening of THF by the P-SH group and its pendant incorporation as a branching point occur during polymerization. This process is absent with toluene, providing conditions to obtain linear chains. P NMR measurements indicate long-time partial hydrolysis and esterification, resulting in the formation of a thiophosphoric acid moiety and branching points. Copolymerization, i.e., using mixtures of EG or HD with PEG, results in polymers with broadly varying viscoelastic properties. TGA shows the lower thermal stability of PDTPs than that of PEG due to the relatively low thermal stability of the P-O-C moieties. The low s of these polymers, from -4 to -50 °C, and a lack of PEG crystallites were found by DSC. This polymerization process and the resulting novel PDTPs enable various new routes for polymer synthesis and application possibilities.
Topics: Polymers; Phosphorus; Polyethylene Glycols; Sulfur
PubMed: 36555604
DOI: 10.3390/ijms232415963 -
Pharmaceutical Research Jul 2023This paper investigates drug release from a novel series of mPEG-functionalised PLLA polymers whose individual components (PEG and PLLA) have regulatory FDA approval....
This paper investigates drug release from a novel series of mPEG-functionalised PLLA polymers whose individual components (PEG and PLLA) have regulatory FDA approval. Two processing methods were explored to understand their effect on the morphology and drug release profiles of the polymers, with and without mPEG functionalisation. In the first method the polymer and Propranolol.HCl drug powders were mixed together before injection moulding. In the second method, supercritical CO was used to mix the polymer and drug before injection moulding. When non-functionalised PLLA was processed through injection moulding alone, there were no signs of polymer-drug interaction, and the drug was confined to crystals on the surface. This resulted in up to 85 wt% burst release of propranolol.HCl after one day of incubation. By contrast, injection moulding of mPEG-functionalised polymers resulted in the partial dissolution of drug in the polymer matrix and a smaller burst (50 wt% drug) followed by sustained release. This initial burst release was completely eliminated from the profile of mPEG-functionalised polymers processed via supercritical CO. The addition of mPEG facilitated the distribution of the drug into the bulk matrix of the polymer. Paired with supercritical CO processing, the drug release profile showed a slow, sustained release throughout the 4 months of the study.
Topics: Delayed-Action Preparations; Drug Liberation; Carbon Dioxide; Propranolol; Polymers; Polyethylene Glycols; Polyesters; Drug Carriers
PubMed: 35474159
DOI: 10.1007/s11095-022-03228-8 -
Molecules (Basel, Switzerland) Nov 2019The reaction between [Cu(μ-OAc)(μ-Pip)(MeOH)] () (OAc = acetate; Pip = 1,3-benzodioxole-5-carboxylate) and isonicotinamide (Isn) in MeOH as solvent yielded two mixture...
The reaction between [Cu(μ-OAc)(μ-Pip)(MeOH)] () (OAc = acetate; Pip = 1,3-benzodioxole-5-carboxylate) and isonicotinamide (Isn) in MeOH as solvent yielded two mixture pairs of three compounds: {(HPip)(Isn) (), [Cu(Pip)(Isn)] ()} and {(), {[Cu(Pip)(OAc)(μ-Isn)(Isn)(μ-OCH)(MeOH)]·2MeOH} ()}. Modifying the reaction conditions (t, T, molar ratio), and have been successfully isolated, whereas and had to be mechanically separated. The recrystallization of in pentanol yielded single crystals of compound [Cu(Pip)(Isn)]·CHOH (). The X-ray crystal structure of , , and has been elucidated showing a cocrystal, a monomer, and an unusual coordination polymer, respectively. The Pip ligand exhibited a chelate () or a monodentate () coordination mode, but the Isonicotinamide (Isn) ligand is the one that promoted the arrangement of different structures and also mainly directs the formation of the 2D and 3D supramolecular assemblies. All the structures have been analyzed by Hirshfeld surface. In addition, the energy frameworks and lattice energy values of and have been calculated.
Topics: Coordination Complexes; Crystallography, X-Ray; Models, Molecular; Molecular Structure; Niacinamide; Polymers
PubMed: 31744252
DOI: 10.3390/molecules24224169 -
Advanced Science (Weinheim,... Jan 2023Imaging and measuring compression stresses secure a safe and healthy life. Compression stresses in kPa range are not easily detected by conventional mechanoresponsive...
Imaging and measuring compression stresses secure a safe and healthy life. Compression stresses in kPa range are not easily detected by conventional mechanoresponsive materials because microscopic molecular motion of the chromophores is not induced by such weak stresses. Moreover, imaging of the stress distribution is not achieved so far. The present study shows a sponge device combining two stimuli-responsive materials, a capsule releasing interior liquid and color-changing polymer in responses to compression stress and chemical stimulus, respectively. The stimuli-responsive capsule is dispersed on a melamine sponge comprised of the fibers with coating the layered polydiacetylene (PDA). The application of weak compression stresses induces collapse of the capsules, outflow of the interior liquid, and subsequent irreversible color change of PDA. The cascading response in the sponge device colorimetrically enables imaging of the distribution and measuring the strength of the compression stresses in kPa range. Furthermore, the device demonstrates imaging and measuring unknown weak compression stresses applied by the irregular-shaped objects. A couple of clinical issues in surgical operation of intestine are studied using the stress-imaging sponge device. The device and its design strategy can be applied to stress imaging in a variety of fields.
Topics: Polyacetylene Polymer; Polymers; Diagnostic Imaging; Physical Phenomena
PubMed: 36507554
DOI: 10.1002/advs.202206097 -
Biomolecules Jun 2019I summarize work conducted in our laboratories over the past 30 years using small host molecules to restructure polymer materials at the nanometer level. Certain small...
I summarize work conducted in our laboratories over the past 30 years using small host molecules to restructure polymer materials at the nanometer level. Certain small molecules, such as the cyclic starches cyclodextrins (CDs) and urea (U) can form non-covalent crystalline inclusion compounds (ICs) with a range of guest molecules, including many polymers. In polymer-CD- and -U-ICs, guest polymer chains reside in narrow channels created by the host molecule crystals, where they are separated and highly extended. When the host crystalline lattice is carefully removed, the guest polymer chains coalesce into a bulk sample with an organization that is distinct from that normally produced from its melt or from solution. Amorphous regions of such coalesced polymer samples have a greater density, likely with less chain entanglement and more chain alignment. As a consequence, after cooling from their melts, coalesced amorphous polymers show glass-transition temperatures (Ts) that are elevated above those of samples prepared from their solutions or melts. Upon cooling from their melts, coalesced samples of crystallizable polymers show dramatically-increased abilities to crystallize more rapidly and much closer to their melting temperatures (Ts). These unique behaviors of polymers coalesced from their CD- and U-ICs are unexpectedly resistant to extended annealing above their Ts and Ts. Taking advantage of this behavior permits us to create polymer materials with unique and improved properties. Among these are amorphous polymers with elevated Ts and semi-crystalline polymers with finer more uniform morphologies. Improved mechanical properties can be achieved through self-nucleation with small amounts of the same polymer made rapidly crystallizable through coalescence from its CD- or U-IC. This can lead to single polymer composites with as-received polymer matrices and self-nucleated reinforcements. Through simultaneous formation and subsequent coalescence from their common CD-ICs, stable well-mixed blends can be achieved between any two or more polymers, despite their inherent immiscibilities. Such coalesced and well-mixed blends are also resistant to phase segregation when heated for extensive periods well above their Ts and Ts.
Topics: Chemical Phenomena; Models, Molecular; Molecular Conformation; Nanotechnology; Polymers
PubMed: 31248211
DOI: 10.3390/biom9060240