Fabrication and aggregation of thermoresponsive glucose-functionalized double hydrophilic copolymers

Stimuli-responsive nanoscale drug delivery systems for cancer therapy

Currently, with the rapid development of nanotechnology, novel drug delivery systems (DDSs) have made rapid progress, in which nanocarriers play an important role in the tumour treatment. In view of the conventional chemotherapeutic drugs with many restrictions such as nonspecific systemic toxicity, short half-life and low concentration in the tumour sites, stimuli-responsive DDSs can deliver anti-tumour drugs targeting to the specific sites of tumours. Owing to precise stimuli response, stimuli-responsive DDSs can control drug release, so as to improve the curative effects, reduce the damage of normal tissues and organs, and decrease the side effects of traditional anticancer drugs. At present, according to the physicochemical properties and structures of nanomaterials, they can be divided into three categories: (1) endogenous stimuli-responsive materials, including pH, enzyme and redox responsive materials; (2) exogenous stimuli-responsive materials, such as temperature, light, ultrasound and magnetic field responsive materials; (3) multi-stimuli responsive materials. This review mainly focuses on the researches and developments of these novel stimuli-responsive DDSs based on above-mentioned nanomaterials and their clinical applications.

Galactose-Functionalized Double-Hydrophilic Block Glycopolymers and Their Thermoresponsive Self-Assembly Dynamics

Glycopolymers with large galactose units are attractive in biological processes because of their ability to selectively recognize lectin proteins. Recently, thermoresponsive double-hydrophilic block glycopolymers (TDHBGs) have been designed, which allow sugar residues to expose or hide via the lower critical solution temperature (LCST)-type phase transition. In this work, we first synthesize a new type of TDHBGs, composed of a thermoresponsive poly(di(ethylene glycol)methyl ether methacrylate) block and a galactose-functionalized, poly(6- O-vinyladipoyl-d-galactose) (POVNG) block. The LCST can be tuned by varying the size of the POVNG block. Then, we have systematically investigated their thermoresponsive self-assembly behavior, using static and dynamic light scattering techniques, combined with transmission electron microscopy (TEM) imaging. It is found that the TDHBGs possess both micellization and LCST-type transition, and there exist strong interactions between them, depending on the concentration and structure of the TDHBGs. It is particularly interesting that for the same type of TDHBGs under different conditions, such interactions result in rich morphologies of the formed micelles (or nanoparticles) such as spheres, hollow spheres, prolate ellipsoids, crystal-like, and so on, thus potentially enriching their biological applications by noting that they are hepatoma-targeting glycopolymers.

Thermoresponsive diblock glycopolymer by RAFT polymerization for lectin recognition

A thermoresponsive double-hydrophilic diblock glycopolymer, poly(diethyl- eneglycol methacrylate)-block-poly(6-O-vinyladipoyl-d-glucose) (PDEGMA-b-POVAG), was successfully prepared by a combination of enzymatic synthesis and reversible addition-fragment chain transfer (RAFT) polymerization protocols using poly(diethyl- eneglycol methacrylate) (PDEGMA) as macro-RAFT agent. The block glycopolymer was characterized by (1)H NMR and GPC. UV-vis, DLS and TEM studies revealed that the glycopolymer PDEGMA-b-POVAG was thermoresponsive with LCST at 31.0°C, and was able to self-assemble into spherical micelles of various sizes in aqueous solution. The glucose pendants in the glycopolymer could interact with the lectin Concanavalin A (Con A), the average hydrodynamic diameters of glycopolymer micelles increased to 170nm from 110nm after recognizing Con A. The diblock glycopolymer micelles have excellent biocompatibility with pig iliac endothelial cells, as measured using the MTT assay, but micelles loaded with Con A could be used to induce apoptosis in human hepatoma SMMC-7721 cells.

Synthesis and Aggregation of Double Hydrophilic Diblock Glycopolymers via Aqueous SET-LRP

A chemically unprotected mannose-containing acrylate (ManA) monomer was synthesized and polymerized by Cu(0)-mediated radical polymerization in water (SET-LRP). One-pot block copolymerization was achieved upon addition of a solution of N-isopropylacrylamide (NIPAm) or diethylene glycol ethyl ether acrylate (DEGEEA) forming thermoresponsive double hydrophilic diblock glycopolymers which revealed self-assembly properties in aqueous solution forming well-defined, sugar-decorated nanoparticles.

Electrospun glycopolymer fibers for lectin recognition

Thermoresponsive glycopolymers have been prepared by a free radical polymerisation process, and subsequently processed into blended fibers with poly-l-lactide-co-ε-caprolactone (PLCL) using electrospinning.

Lectin recognizing thermoresponsive double hydrophilic glycopolymer micelles by RAFT polymerization

Thermoresponsive double hydrophilic block glycopolymer micelles can recognize lectin on the different temperature.