Synthesis and properties of novel biomimetic and thermo-responsive dextran-based biohybrids

Cisplatin encapsulated nanoparticles from polymer blends for anti-cancer drug delivery

Synthesis of cubic nanostructure for cisplatin encapsulation.

Glycopolymer Brushes by Reversible Deactivation Radical Polymerization: Preparation, Applications, and Future Challenges

The cellular surface contains specific proteins, also known as lectins, that are carbohydrates receptors involved in different biological events, such as cell-cell adhesion, cell recognition and cell differentiation. The synthesis of well-defined polymers containing carbohydrate units, known as glycopolymers, by reversible deactivation radical polymerization (RDRP) methods allows the development of tailor-made materials with high affinity for lectins because of their multivalent interaction. These polymers are promising candidates for the biomedical field, namely as novel diagnostic disease markers, biosensors, or carriers for tumor-targeted therapy. Although linear glycopolymers are extensively studied for lectin recognition, branched glycopolymeric structures, such as polymer brushes can establish stronger interactions with lectins. This specific glycopolymer topology can be synthesized in a bottlebrush form or grafted to/from surfaces by using RDRP methods, allowing a precise control over molecular weight, grafting density, and brush thickness. Here, the preparation and application of glycopolymer brushes is critically discussed and future research directions on this topic are suggested.

A bio-inspired injectable hydrogel as a cell platform for real-time glycaemic regulation

Frequent subcutaneous insulin injection and islet transplantation are promising therapeutic options for type 1 diabetes mellitus. However, poor patient compliance, insufficient appropriate islet β cell donors and body immune rejection limit their clinical applications. The design of a platform capable of encapsulating insulin-secreting cells and achieving real-time blood glucose regulation, is a so far unmet need. Herein, inspired by the natural processes of regulating blood glucose in pancreatic islet β cells, we developed a poly(N-isopropylacrylamide-co-dextran-maleic acid-co-3-acrylamidophenylboronic acid) (P(AAPBA-Dex-NIPAM)) hydrogel as a cell platform with glucose responsiveness and thermo-responsiveness for the therapy of diabetes. This platform showed good biocompatibility against insulin-secreting cells and presented glucose-dependent insulin release behaviour. The bioinspired P(AAPBA₆-Dex-NIPAM₆₄) hydrogel had a positive effect on real-time glycaemic regulation, as observed by intraperitoneal glucose tolerance tests. The non-fasting blood glucose of diabetic rats was restored to a normal level during the period of treatment. Additionally, the inflammatory response did not occur after administration of the platform. Collectively, we expected that the bio-mimetic platform combined with an insulin-secreting capability could be a new diabetic treatment strategy.

Glycopolymers/PEI complexes as serum-tolerant vectors for enhanced gene delivery to hepatocytes

Serum stability is a crucial factor for ideal polymeric gene vectors. In this work, a series of serum-tolerant and low-toxicity glycopolymers/poly(ethyleneimine) (PEI) complexes were designed for gene delivery. Atomic transfer radical polymerization (ATRP) was used to synthesize the comb-shaped random copolymers dextran-g-poly(2-dimethylaminoethyl methacrylate-co-2-lactobionamidoethyl methacrylate) (DDrL). Then DDrLs/PEI were investigated for their use as plasmid DNA (pDNA) vectors, which can completely condense the pDNA into nanoparticles. The DDrLs/PEI/pDNA complexes in serum-containing media showed better stability than PEI/pDNA complexes. in vitro gene transfection studies showed that DDrLs/PEI exhibited a remarkable transfection efficiency enhancement in the presence of serum compared to that in serum-free conditions. Moreover, the transfection level of DDrLs/PEI were two orders of magnitude higher than that of PEI alone in the presence of 30% serum. DDrLs/PEI complexes with galactose enhanced pDNA delivery to hepatocytes, with higher protein expression in ASGPr-presenting HepG2 than in HeLa cells, which lack the receptor. All of the DDrLs/PEI/pDNA complexes had lower cytotoxicity than PEI/pDNA.

Dually sensitive dextran-based micelles for methotrexate delivery

Temperature and pH-sensitive micelles prepared from dextran grafted with poly(N-isopropylacrylamide) (PNIPAAm)/polyethylene glycol methyl ether (PEGMA) with/without 2-aminoethylmethacrylate (2-AEM) were evaluated as methotrexate delivery systems.

Synthesis of star-glycopolymers by Cu(0)-mediated radical polymerisation in the absence and presence of oxygen

Star glycopolymers were synthesized in the absence and presence of oxygen, and show strong binding to specific lectins.

Synthesis and evaluation of glyco-coated liposomes as drug carriers for active targeting in drug delivery systems

Novel sugar-conjugated cholesterols, β-Gal-, α-Man-, β-Man-, α-Fuc-, and β-Man-6P-S-β-Ala-Chol, were synthesized and incorporated into liposomes. In vitro experiments using the glyco-coated liposomes showed that the glyco-coated liposomes are efficiently taken up by cells expressing carbohydrate-binding receptors selectively. Glyco-coated liposomes are promising candidates for drug delivery vehicles.