Novel oligonucleotide carrier as scavenger for reactive oxygen species

A novel oligonucleotide carrier which can scavenge ROS is described. The synthesized graft polymer is composed of a PEG segment and a TEMPO-containing hydrophobic segment for scavenging ROS. This graft polymer can form a PIC through electrostatic interaction with oligonucleotides such as siRNA. The amount of ROS was monitored by fluorescence measurements using H₂ DCFDA as a probe, and it was confirmed that the ROS level was effectively suppressed. The cellular uptake of PIC containing the fluorescence-labeled oligonucleotide was evaluated by fluorescence microscopy. Delivered siRNA suppressed the expression of the mRNA. The prepared graft copolymer is thus a promising candidate as a novel oligonucleotide carrier which also reduces ROS damage generated by cationic polymer carriers.

Nanogel engineering for new nanobiomaterials: from chaperoning engineering to biomedical applications

Nanosize hydrogels (nanogels) are polymer nanoparticles with three-dimensional networks, formed by chemical and/or physical cross-linking of polymer chains. Recently, various nanogels have been designed, with a particular focus on biomedical applications. In this review, we describe recent progress in the synthesis of nanogels and nanogel-integrated hydrogels (nanogel cross-linked gels) for drug-delivery systems (DDS), regenerative medicine, and bioimaging. We also discuss chaperone-like functions of physical cross-linking nanogel (chaperoning engineering) and organic-inorganic hybrid nanogels.