Polyurethane with β-Selenocarbonyl Structure Enabling the Combination of Plastic Degradation and Waste Upcycling.

Degradable polymers offer a promising solution to mitigate global plastic pollution, but the degraded products often suffer from diminished value. Upcycling is a more sustainable approach to upgrade polymer waste into value-added products. Herein, we report a β-selenocarbonyl-containing polyurethane (SePU), which can be directly degraded under mild conditions into valuable selenium fertilizers for selenium-rich vegetable cultivation globally, enabling both plastic degradation and waste upcycling.

Selenium-Containing Nanocomplexes Achieve Dual Immune Checkpoint Blockade for NK Cell Reinvigoration.

The blockade of immune checkpoints has emerged as a promising strategy for cancer immunotherapy. However, most of the current approaches focus on T cells, leaving natural killer (NK) cell-mediated therapeutic strategies rarely explored. Here, a selenium-containing nanocomplex is developed that acts as a dual immune checkpoint inhibitor to reinvigorate NK cell-based cancer immunotherapy.

Intracellular Hyperbranched Polymerization for Circumventing Cancer Drug Resistance.

Polymerization inside living cells provides chemists with a multitude of possibilities to modulate cell activities. Considering the advantages of hyperbranched polymers, such as a large surface area for target sites and multilevel branched structures for resistance to the efflux effect, we reported a hyperbranched polymerization in living cells based on the oxidative polymerization of organotellurides and intracellular redox environment. The intracellular hyperbranched polymerization was triggered by reactive oxygen species (ROS) in the intracellular redox microenvironment, effectively disrupting antioxidant systems in cells by an interaction between Te (+4) and selenoproteins, thus inducing selective apoptosis of cancer cells.

A Nanotherapeutic Strategy to Reverse NK Cell Exhaustion.

As a specialized immune effector cell, natural killer (NK) cells play a very important role in immunotherapy, but tumor immunosuppression caused by abnormal expression of cancer cells seriously weakens its therapeutic effect and leads to exhaustion. Here, self-assembled selenium-containing nanoparticles (NPs) composed of cetuximab, C5SeSeC5, and inhibitor LY345899 are developed to reverse NK cell exhaustion. The obtained NPs can target epidermal growth factor receptor on the surface of cancer cells and locate it in mitochondria.

Copper-Selenocysteine Quantum Dots for NIR-II Photothermally Enhanced Chemodynamic Therapy.

Chemodynamic therapy has been appealing for effective cancer treatment. Particularly, Fenton-like reactions catalyzed by Cu-based nanoparticles showed promising prospects. Herein, we fabricated copper-selenocysteine quantum dots (Cu-Sec QDs) with the majority of Cu by a facile and robust thermal titration process.

Selenium-containing nanoparticles synergistically enhance Pemetrexed&NK cell-based chemoimmunotherapy.

NK cell-based immunotherapy and pemetrexed (Pem)-based chemotherapy have broad application prospects in cancer treatment. However, the over-expressed NK cell inhibitory receptor on the surface of cancer cells and the low cell internalization efficiency of Pem greatly limit their clinical application. Herein, we construct a series of selenium-containing nanoparticles to synergistically enhance Pem-based chemotherapy and NK cell-based immunotherapy.

Oxidative Polymerization in Living Cells.

Intracellular polymerization is an emerging technique that can potentially modulate cell behavior, but remains challenging because of the complexity of the cellular environment. Herein, taking advantage of the chemical properties of organotellurides and the intracellular redox environment, we develop a novel oxidative polymerization reaction that can be conducted in cells without external stimuli. We demonstrate that this polymerization reaction is triggered by the intracellular reactive oxygen species (ROS), thus selectively proceeding in cancer cells and inducing apoptosis via a unique self-amplification mechanism.

CO/chemosensitization/antiangiogenesis synergistic therapy with HO-responsive diselenide-containing polymer.

Carbon monoxide (CO) therapy and antiangiogenesis therapy (AAT) are regarded as promising approaches for cancer treatment. However, the poor tumor targeting ability and inevitable side effects prevent their clinical application. In this study, we developed HO-responsive diselenide-containing micelles that combined CO therapy with chemosensitization therapy and AAT in a single system.

Anti-recurrence/metastasis and chemosensitization therapy with thioredoxin reductase-interfering drug delivery system.

Thioredoxin reductase (TrxR) is an essential mammalian enzyme that possesses a selenocysteine active site. TrxR is overexpressed in many malignant tumors and has a close relationship with apoptosis, drug resistance, recurrence and metastasis of tumors. Recently, TrxR has emerged as a promising target for anticancer therapy.

Selenium-Containing Carrier-Free Assemblies with Aggregation-Induced Emission Property Combine Cancer Radiotherapy with Chemotherapy.

Developing multifunctional carrier-free nanomedicine with high efficacy attracts tremendous attention in cancer treatment. Here, we develop selenium-containing carrier-free assemblies with aggregation-induced emission (AIE) property, which achieve the combination of cancer radiotherapy with chemotherapy. Under γ-radiation, diselenide bonds in the assemblies can be cleaved to form seleninic acid, which exhibits anticancer activity by upregulating the reactive oxygen species (ROS) levels in cancer cells.

Diselenide-Pemetrexed Assemblies for Combined Cancer Immuno-, Radio-, and Chemotherapies.

Immunotherapy has emerged as a promising new approach for cancer treatment. However, clinically available drugs have been limited until recently, and the antitumor efficacy of most cancer immunotherapies still needs to be improved. Herein, we develop diselenide-pemetrexed assemblies that combine natural killer (NK) cell-based cancer immunotherapy with radiotherapy and chemotherapy in a single system.

Diselenide-Containing Polymeric Vesicles with Osmotic Pressure Response.

Mechanophore is a kind of functional group that can undergo chemical reactions when given mechanical force stimuli. In this paper, osmotic pressure was used as an external force to trigger a diselenide exchange reaction. A diselenide bond containing block polymer capable of self-assembling to a vesicle structure and an ester bond containing a counterpart were synthesized in this study.