Antimicrobial cationic polymers mainly contain two functional components: the cationic groups and the hydrophobic groups. The antimicrobial activity is influenced by the type, amount, location and distribution of these two components. This review summarizes the designs and syntheses of antimicrobial cationic polymers by controlling the above two factors. It involves the structural designs from primary to secondary structures, from covalent to noncovalent syntheses and from bulk to surface. Furthermore, it will discuss how to advance structural designs toward functional controls for optimizing the antimicrobial performances and biocompatibility of antimicrobial cationic polymers. It is anticipated that this review will provide some guidelines for developing molecular engineering of antimicrobial cationic polymers with tailor-made structures and functions.
7 April 2014 in Angewandte Chemie International Edition
Supramolecular chemotherapy is aimed to employ supramolecular approach for regulating the cytotoxicity and improving the efficiency of antitumor drugs. In this paper, we demonstrated a new example of supramolecular chemotherapy by utilizing the clinical antitumor drug, oxaliplatin, which is the specific drug for colorectal cancer treatment. Cytotoxicity of oxaliplatin to the colorectal normal cell could be significantly decreased by host–guest complexation between oxaliplatin and cucurbit[7]uril (CB[7]). More importantly, oxaliplatin-CB[7] exhibited cooperatively enhanced antitumor activity than oxaliplatin itself. On the one hand, the antitumor activity of oxaliplatin can reappear by competitive replacement of spermine from oxaliplatin-CB[7]; on the other hand, CB[7] can consume the overexpressed spermine in tumor environments, which is essential for tumor cell growth. These two events can lead to the cooperatively enhanced antitumor performance. Supramolecular chemotherapy can be applied to treat with spermine-overexpressed tumors. It is highly anticipated that this strategy may be employed in many other clinical antitumor drugs, which opens a new horizon of supramolecular chemotherapy for potential applications in clinical antitumor treatments.
Closed-loop chemical recycling provides a solution to the end-of-use problem of synthetic polymers. However, it remains a major challenge to design dynamic bonds, capable of effective bonding and reversible cleaving, for preparing chemically recyclable cross-linked polymers. Herein, we report a dynamic maleic acid tertiary amide bond based upon reversible amidation reaction between maleic anhydrides and secondary amines. This dynamic bond allows for the construction of polymer networks with tailorable and robust mechanical properties, covering strong elastomers with a tensile strength of 22.3 MPa and rigid plastics with a yield strength of 38.3 MPa. Impressively, these robust polymeric materials can be completely depolymerized in an acidic aqueous solution at ambient temperature, leading to efficient monomer recovery with >94% separation yields. Meanwhile, the recovered monomers can be used to remanufacture cross-linked polymeric materials without losing their original mechanical performance. This work unveils a general approach to design polymer networks with tunable mechanical performance and closed-loop recyclability, which will open a new avenue for sustainable polymeric materials.
8 May 2017 in Angewandte Chemie International Edition
A new method of supramolecular polymerization at the water–oil interface is developed. As a demonstration, an oil‐soluble supramonomer containing two thiol end groups linked by two ureidopyrimidinone units and a water‐soluble monomer bearing two maleimide end groups are employed. Supramolecular interfacial polymerization can be implemented by a thiol–maleimide click reaction at the water–chloroform interface to obtain supramolecular polymeric films. The glass transition temperature of such supramolecular polymers can be well‐tuned by simply changing the polymerization time and temperature. It is highly anticipated that this work will provide a facile and general approach to realize control over supramolecular polymerization by transferring the preparation of supramolecular polymers from solutions to water–oil interfaces and construct supramolecular materials with well‐defined properties.