Gram Scale Synthesis of Dual-Responsive Dendritic Polyglycerol Sulfate as Drug Delivery System

Power of the Disulfide Bond: An Ideal Random Copolymerization of Biodegradable Redox-Responsive Hyperbranched Polyglycerols

The development of copolymerization techniques that can randomly incorporate biodegradable moieties into the hyperbranched polyglycerol backbone is an option to prevent its bioaccumulation in vivo. In this study, redox-responsive and biocompatible hyperbranched polyglycerol copolymers of glycidol and 1,4,5-oxadithiepan-2-one were synthesized with an adjustable molecular weight and a defined disulfide bond content through anionic and coordination-insertion ring-opening polymerization. A truly random incorporation of the monomers was achieved under both copolymerization mechanisms. The copolymers were further characterized in terms of their aggregation behavior in solution, degradability, in vitro cell viability, and blood compatibility for potential future biomedical applications. Transmission electron microscopy revealed that the copolymer assembled into nanoparticles with a size range of 20 nm. The copolymers underwent degradation when incubated with two different reducing agents, resulting in smaller fragments of the polymer with thiol end groups. The copolymers demonstrated good biocompatibility, making them suitable for further investigation in biomedical applications.

Polyglycerols as Multi-Functional Platforms: Synthesis and Biomedical Applications

The remarkable and unique characteristics of polyglycerols (PG) have made them an attractive candidate for many applications in the biomedical and pharmaceutical fields. The presence of multiple hydroxy groups on the flexible polyether backbone not only enables the further modification of the PG structure but also makes the polymer highly water-soluble and results in excellent biocompatibility. In this review, the polymerization routes leading to PG with different architectures are discussed. Moreover, we discuss the role of these polymers in different biomedical applications such as drug delivery systems, protein conjugation, and surface modification.

Hyaluronic Acid-Zein Core-Shell Nanoparticles Improve the Anticancer Effect of Curcumin Alone or in Combination with Oxaliplatin against Colorectal Cancer via CD44-Mediated Cellular Uptake

Curcumin (CUR) has been reported to enhance the chemotherapeutic efficacy of oxaliplatin (OXA) in colorectal cancer (CRC) and inhibit OXA-induced side effects. However, shortcomings, including poor solubility and sensitivity to metabolic transformation, have greatly undermined its value in clinical applications. In this study, the potential of CUR-encapsulated hyaluronic acid (HA)–zein composite nanoparticles (HZ-CUR) as an oral adjuvant for OXA-based chemotherapy was assessed in representative CRC models in mice. Cell viability and colony formation assays in three human CRC cell lines showed that HZ-CUR had a stronger anti-CRC effect than free CUR when given alone and a stronger synergistic effect when combined with OXA, especially in HCT116 and HT29 cell lines. Western blotting, cellular uptake, and RNA interference assays revealed that OXA-induced upregulation of CD44 likely contributed to enhanced cellular uptake of HZ-CUR and thus the enhanced anticancer effect. The significantly improved anti-CRC effects and potential underlying mechanism of HZ-CUR alone and in combination with OXA were further validated in a subcutaneous xenograft and an in situ CRC model in mice. These findings support that HZ-CUR may be an effective oral adjuvant for OXA-based CRC chemotherapy that would not only improve its efficacy but also help reduce the associated side effects.