Tellurium-containing polymers have become increasingly attractive owing to their unique properties as biomaterials and optoelectronic materials. The relatively large atomic size and low electronegativity of tellurium give it with many unique properties, such as coordination ability and redox sensitivity. The introduction of tellurium can endow materials with different responsiveness, which makes it possible for them to be employed as biomaterials. The narrow band gap of polytellurophene also allows its use in optoelectronic materials. In this focus review, we highlight a series of recent advances in tellurium-containing polymers. First, tellurium-containing amphiphilic block copolymers are summarized; these species can self-assemble to form aggregates with coordination-responsive and reactive oxygen species-responsive properties. Then, we describe both tellurophene-containing homopolymers and copolymers, including their synthesis, chemical properties, and applications in different optoelectronic devices. It is anticipated that tellurium-containing polymers will have more applications in material science.

Research on anticancer therapies has advanced significantly in recent years. New therapeutic platforms that can further improve the health of patients are still highly demanded. We propose the idea of combining regular chemotherapy with radiation therapy to minimize side effects as well as increase drug-delivery efficiency. In this Focus Review, we seek to provide an overview of recent advances that can combine chemotherapy and radiotherapy. We begin by reviewing the current state of systems that can combine chemotherapy and gamma radiation. Among them, diselenide-containing polymers are highlighted as sensitive drug-delivery vehicles that can disassemble under gamma radiation. Then X-ray responsive materials as promising alternative systems are summarized, including X-ray responsive drug-delivery vehicles, prodrugs that can be activated by X-rays, and radiation-site-targeting systems. Finally, we describe strategies that involve phototherapies.

Dynamic covalent bonds are extensively employed in dynamic combinatorial chemistry. The metathesis reaction of disulfide bonds is widely used, but requires catalysis or irradiation with ultraviolet (UV) light. It was found that diselenide bonds are dynamic covalent bonds and undergo dynamic exchange reactions under mild conditions for diselenide metathesis. This reaction is induced by irradiation with visible light and stops in the dark. The exchange is assumed to proceed through a radical mechanism, and experiments with 2,2,6,6-tetramethylpiperidin-1-yloxyl (TEMPO) support this assumption. Furthermore, the reaction can be conducted in different solvents, including protic solvents. Diselenide metathesis can also be used to synthesize diselenide-containing asymmetric block copolymers. This work thus entails the use of diselenide bonds as dynamic covalent bonds, the development of a dynamic exchange reaction under mild conditions, and an extension of selenium-related dynamic chemistry.

Dynamic covalent bonds are extensively employed in dynamic combinatorial chemistry. The metathesis reaction of disulfide bonds is widely used, but requires catalysis or irradiation with ultraviolet (UV) light. It was found that diselenide bonds are dynamic covalent bonds and undergo dynamic exchange reactions under mild conditions for diselenide metathesis. This reaction is induced by irradiation with visible light and stops in the dark. The exchange is assumed to proceed through a radical mechanism, and experiments with 2,2,6,6-tetramethylpiperidin-1-yloxyl (TEMPO) support this assumption. Furthermore, the reaction can be conducted in different solvents, including protic solvents. Diselenide metathesis can also be used to synthesize diselenide-containing asymmetric block copolymers. This work thus entails the use of diselenide bonds as dynamic covalent bonds, the development of a dynamic exchange reaction under mild conditions, and an extension of selenium-related dynamic chemistry.

A new kind of SeN dynamic covalent bond has been found that can form between the Se atom of a phenylselenyl halogen species and the N atom of a pyridine derivative, such as polystyrene-b-poly(4-vinylpyridine). This SeN dynamic covalent bond can be reversibly and rapidly formed or cleaved under acidic or basic conditions, respectively. Furthermore, the bond can be dynamically cleaved by heating or treatment with stronger electron-donating pyridine derivatives. The multiple responses of SeN bond to external stimuli has enriched the existing family of dynamic covalent bonds. It can be used for controlled and reversible self-assembly and disassembly, which may find potential applications in a number of areas, including self-healing materials and responsive assemblies.

A novel glutathione peroxidase (GPx) mimic has been prepared by incorporation of a selenium-based catalytic unit into the focal point of a fully-branched hyperbranched polymer. First, an AB₂ monomer consisting of isatin and an electron rich aromatic moiety was polycondensed in the presence of 5-nitroisatin as a core reagent, resulting in a polymer with 100% degree of branching. The latter was coupled to the catalytically active moiety, Br(CH₂)₅SeSe(CH₂)₅Br, by nucleophilic substitution of the bromides by the residual amide groups of the incorporated nitroisatin core. The obtained polymer has demonstrated prominent GPx activity as desired, which could be attributed to the hydrophobic, densely branched and core-shell structure of the polymer surrounding the catalytic center.

Microcontact printing is a heavily used surface modification method in materials and life science applications. This concept article focuses on the development of versatile stamps for microcontact printing that can be used to bind and release inks through molecular recognition or through an ink reservoir, the latter being used for the transfer of heavy inks, such as biomolecules and particles. Conceptually, such stamp properties can be introduced at the stamp surface or by changing the bulk stamp material; both lines of research will be reviewed here. Examples include supramolecular stamps with affinity properties, polymer-layer-grafted PDMS stamps, and porous multilayer-grafted PDMS stamps for the first case, and hydrogel stamps and porous stamps made by phase-separation micromolding for the second. Potential directions for future advancement of this field are also discussed.