Reversible addition-fragmentation chain transfer (RAFT) is considered to be one of most famous reversible deactivation radical polymerization protocols. Benefiting from its living or controlled polymerization process, complex polymeric architectures with controlled molecular weight, low dispersity, as well as various functionality have been constructed, which could be applied in wide fields, including materials, biology, and electrology. Under the continuous research improvement, main achievements have focused on the development of new RAFT techniques, containing fancy initiation methods (e.g., photo, metal, enzyme, redox and acid), sulfur-free RAFT system and their applications in many fields. This review summarizes the current advances in major bright spot of novel RAFT techniques as well as their potential applications in the optoelectronic field, especially in the past a few years.

Chemotherapy is one of the major systemic treatments for cancer, in which the drug release kinetics is a key factor for drug delivery. In the present work, a versatile fluorescence-based real-time monitoring system for intracellular drug release has been developed. First, two kinds of star-conjugated copolymers with different connections (e.g., pH-responsive acylhydrazone and stable ether) between a hyperbranched conjugated polymer (HCP) core and many linear poly(ethylene glycol) (PEG) arms were synthesized. Owing to the amphiphilic three-dimensional architecture, the star-conjugated copolymers could self-assemble into multimicelle aggregates from unimolecular micelles with excellent emission performance in the aqueous medium. When doxorubicin (DOX) as a model drug was encapsulated into copolymer micelles, the emission of star-conjugated copolymer and DOX was quenched. In vitro biological studies revealed that fluorescent intensities of both star-conjugated copolymer and DOX were activated when the drug was released from copolymeric micelles, resulting in the enhanced cellular proliferation inhibition against cancer cells. Importantly, pH-responsive feature of the star-conjugated copolymer with acylhydrazone linkage exhibited accelerated DOX release at a mildly acidic environment, because of the fast breakage of acylhydrazone in endosome or lysosome of tumor cells. Such fluorescent star-conjugated copolymers may open up new perspectives to real-time study of drug release kinetics of polymeric drug delivery systems for cancer therapy.

Photodynamic therapy (PDT) has received increasing attention in disease treatment due to its minimally-invasive, selective destruction with a combination of a photosensitizer (PS), light, and oxygen. However, the limited cytotoxic singlet oxygen (¹O₂) generation and thin tissue penetrability have been two major barriers in conventional PDT, hindering its further development and clinical use. Recently, fluorescence resonance energy transfer-based drug delivery systems (FRET-DDSs), indirectly activating PS drugs by a donor fluorophore, have been successfully applied to alleviate these issues. The transfer of excitation energy from donors to PS drugs can significantly boost its light harvesting and extend the field of the light source, which dramatically improves its production efficiency of ¹O₂, thus leading to highly efficient and deep-tissue-penetrable PDT for the treatment of bacteria, cancer and other diseases. In this Review, we give the first-known overview of recent advances in FRET-DDSs for enhanced PDT. In particular, dependent on the excitation energy mechanism in the FRET process, six major types of FRET-DDSs, including one-photon, two-photon, upconversion, auto-fluorescence, X-ray, and Cerenkov excited FRET-DDSs, in PDT applications are summarized in detail. Furthermore, future research directions and perspectives in this emerging field are also discussed.

The phase behavior of ABC star triblock copolymers is examined using real-space self-consistent mean-field theory. The central part of the triangular phase diagram for ABC triblock copolymers with equal A/B, B/C, and C/A interactions is determined by comparing the free energy of a number of candidate ordered phases. In this region of the phase diagram, the dominant microstructures are cylinders with polygonal cross sections or two-dimensional polygon-tiling patterns. Most of the known polygon-tiling patterns observed in experiments and simulations, plus some neighboring morphologies, are considered in the construction of the phase diagram. The resulting phase behavior is consistent with experiments and computer simulations.