Two Independent Ways of Preparing Hypercharged Hydrolyzable Polyaminorotaxane (original) (raw)
Related papers
International Journal of Molecular Sciences
Pseudopolyrotaxanes (PPRs) are supramolecular structures consisting of macrocycles able to thread on a linear polymer chain in a reversible, non-covalent way, often referred to in the literature as “molecular necklaces”. While the synthesis and reaction mechanisms of these structures in solution have been widely described, their solvent-free production has received little attention, despite the advantages that this route may offer. We propose in this work a kinetic mechanism that describes the PPR formation in the solid phase as a process occurring in two consecutive stages. This mechanism has been used to investigate the spontaneous formation of a PPR that occurs when grinding α-Cyclodextrin (α-CD) with polyethylene glycol (PEG). In the threading stage, the inclusion of the polymer and subsequent release of the water molecules lodged in the cavity of the macrocycle cause vibrational changes that are reflected in the time-dependence of the FTIR-ATR spectra, while the further assembl...
Recent developments in polypseudorotaxanes and polyrotaxanes
Progress in Polymer Science, 2014
This review highlights developments since 2008 in the field of polypseudorotaxanes and polyrotaxanes. Progress in synthetic polyrotaxane chemistry has resulted in the preparation of numerous functionalized polymers for various applications in areas such as molecular machines, stimuli responsive materials, supramolecular gels and molecular sensors. This new genre of supramolecular polymers is advancing rapidly with several groups developing novel materials with unique characteristics.
Synthesis and characterization of new polyamino-cyclodextrin materials
Carbohydrate Research, 2012
With the aim of the synthesis of chemically modified cyclodextrins bearing polyamine pendant groups, potentially useful as capping agents for the preparation of nanosized metal systems or as auxiliaries for gene transfection, the reaction between the heptakis-(6-iodo)-(6-deoxy)-b-cyclodextrin and various polyamines has been explored. This synthetic approach allows obtaining materials constituted by mixtures of cyclodextrins, having different degrees of substitution, which were satisfactorily characterized by means of various complementary techniques (ESI-MS, NMR, potentiometric titration). The products obtained were successfully subjected to preliminary tests for their binding abilities towards suitable organic guests and as capping agents for the preparation of stable silver nanoparticles.
Polyrotaxanes: Past, present and future
Macromolecular Symposia, 1996
This review highlights developments since 2008 in the field of polypseudorotaxanes and polyrotaxanes. Progress in synthetic polyrotaxane chemistry has resulted in the preparation of numerous functionalized polymers for various applications in areas such as molecular machines, stimuli responsive materials, supramolecular gels and molecular sensors. This new genre of supramolecular polymers is advancing rapidly with several groups developing novel materials with unique characteristics.
Polyrotaxanes for applications in life science and biotechnology
Applied Microbiology and Biotechnology, 2011
Due to their low cytotoxicity, controllable size, and unique architecture, cyclodextrin (CD)-based polyrotaxanes and polypseudorotaxanes have inspired interesting exploitation as novel biomaterials. This review will update the recent progress in the studies on the structures of polyrotaxanes and polypseudorotaxanes based on different CDs and polymers, followed by summarizing their potential applications in life science and biotechnology, such as drug delivery, gene delivery, and tissue engineering. CD-based biodegradable polypseudorotaxane hydrogels could be used as promising injectable drug delivery systems for sustained and controlled drug release. Polyrotaxanes with drug or ligand-conjugated CDs threaded on polymer chain with biodegradable end group could be useful for controlled and multivalent targeting delivery. Cationic polyrotaxanes consisting of multiple oligoethylenimine-grafted CDs threaded on a block copolymer chain were attractive non-viral gene carries due to the strong DNA-binding ability, low cytotoxicity, and high gene transfection efficiency. Cytocleavable end caps were also introduced in the polyrotaxane systems in order to ensure efficient endosomal escape for intracellular trafficking of DNA. Finally, hydrolyzable polyrotaxane hydrogels with cross-linked α-CDs could be a desirable scaffold for cartilage and bone tissue engineering.
Biomacromolecules, 2006
The synthesis, characterization, and degradation kinetics of three R-cyclodextrin (R-CD)-poly(ethylene glycol) (PEG) polyrotaxanes with endcaps that were installed using Cu(I)-catalyzed Huisgen cyclization is reported. PEG1500, azidated with azidoacetic acid, was threaded with R-CD to form a pseudopolyrotaxane that was then capped in up to 82% yield with three different substituents to provide polyrotaxanes that were either acid-, base-, or fluoride-sensitive. NMR, GPC, XRD, and AFM methods were used to characterize the polyrotaxanes. Dethreading rates upon exposure to mild deprotection conditions were monitored by turbidity analysis. The vinyl ether-endcapped polyrotaxane is stable at pH 7 for 16 h but is solubilized at approximately 0.0211 min-1 at pH 4. The ester-endcapped polyrotaxane is solubilized at 0.0122 min-1 at pH 12.1. Our results show that pH-triggerable polyrotaxanes can be readily and efficiently prepared from pseudopolyrotaxanes in high yield by Huisgen cyclization of azido-and alkynyl-modified precursors in the presence of Cu(I).
Polypseudorotaxanes and polyrotaxanes
Progress in Polymer Science, 2005
This review highlights developments since 2008 in the field of polypseudorotaxanes and polyrotaxanes. Progress in synthetic polyrotaxane chemistry has resulted in the preparation of numerous functionalized polymers for various applications in areas such as molecular machines, stimuli responsive materials, supramolecular gels and molecular sensors. This new genre of supramolecular polymers is advancing rapidly with several groups developing novel materials with unique characteristics.