Unconstrained 3D Shape Programming with Light-Induced Stress Gradient

Cheng Liu, Yizheng Tan, Chaowei He, Shaobo Ji, and Huaping Xu Adv. Mater., 2021, 33, 2105194. Programming 2D sheets to form 3D shapes is significant for flexible electronics, soft robots, and biomedical devices. Stress regulation is one of the most used methods, during which external force is usually needed to keep the stress, leading to complex processing setups. Here, by introducing dynamic diselenide bonds into shape-memory materials, unconstrained shape programming with light is achieved. The material could hold and release internal stress by themselves through the shape-memory effect,...
More

Selenium-Sulfur-Doped Carbon Dots with Thioredoxin Reductase Activity

Luo Zhang, Chenxing Sun, Yizheng Tan and Huaping Xu CCS Chem., 2022, 4, 2249. Thioredoxin reductase (TrxR) is an essential enzyme for regulating the redox balance in cells, promoting cell proliferation, and inhibiting cell apoptosis. The biochemical pathway of TrxR metabolism involves a series of selenium-sulfur (Se-S) dynamic chemistry.  Theoretically, nanomaterials with Se-S dynamic bonds could exhibit TrxR-mimetic activities to tune TrxR activity and thus affect the cell activities. Herein, we report the selenium-sulfur-doped carbon dots (Se-S-CDs) synthesized by a facile hydrothermal m...
More

Measuring the Strength of S/Se Based Dynamic Covalent Bonds

Jiahao Xia, Hongbin Li, Huaping Xu Acta Polym. Sin., 2020, 51, 205.   Sulfur, selenium-containing bonds, including disufide bond (SS), diselenide bond (SeSe), and selenide-sulfide bond (SeS), are an important type of light responsive dynamic covalent bonds. Among them, SS and SeS bonds can undergo exchange reaction with the irridiation of UV light, while SeSe bond only requires visible light due to its weaker bond energy. The purpose of this research is to use atomic force microscope-based single molecule force spectroscopy (AFM-SMFS) measurement to reveal the reasons behind the re...
More

Oxidative Polymerization in Living Cells

Yiheng Dai, Tianyu Li, Zhiheng Zhang, Yizheng Tan, Shuojiong Pan, Luo Zhang, and Huaping Xu J. Am. Chem. Soc., 2021, 143, 10709. 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 t...
More

ROS-Responsive Tellurium-Containing Polymers

Shuojiong Pan, huaping Xu Acta Polymerica Sinica, 2021, 52, 857. Stimuli-responsive polymers are defined as polymers whose structure and properties can be changed in response to minor changes in the surrounding physical or chemical environment. In recent years, our research group pioneered in the research of ROS-responsive tellurium-containing polymers and their application in drug delivery. The work presented in this feature article, starting from the difference of oxidation responsiveness of tellurium and selenium, explored the ultra-sensitive ROS-response of tellurides. Then we studied ...
More

Side-Chain Selenium-Grafted Polymers Combining Antiangiogenesis Treatment with Photodynamic Therapy and Chemotherapy

Chenxing Sun, Shiqian Gao, Yizheng Tan, Zhiheng Zhang, and Huaping Xu ACS Biomater. Sci. Eng., 2021, 7, 3201. The abnormal tumor vasculature in solid tumors creates hypoxia and leads to compromising the delivery and anticancer efficiency of nanomedicine. Nanomaterials with intrinsic antiangiogenesis ability might normalize tumor vessels and improve the therapeutic effect of O2-related treatment like PDT. Herein, we designed and prepared ROS-responsive side-chain selenium-grafted polymers, which had potential antiangiogenic activity, as vehicles to load photodynamic therapeutic agent Ce6 an...
More

“Reprocessable Thermosets”: Synthesis and Characterization of Vitrimer in the Undergraduate Lab Course

Qiaomei Chen, Yang Yang, Ying Yu, and Huaping Xu J. Chem. Educ.; 2021, 98, 1429. This article introduces a novel experiment that involves vitrimers, a new type of polymer, in polymer chemistry and physics lab courses for undergraduate students. Vitrimers are permanently cross-linked networks that can be reprocessed under certain external stimuli. Therefore, they combine the advantages of traditional thermoplastics (excellent reprocessability) with thermosets (outstanding mechanical properties and environmental stability). They can be regarded as a kind of “special thermoset”, which moves t...
More

CO/chemosensitization/antiangiogenesis synergistic therapy with H2O2-responsive diselenide-containing polymer

Jichun Yang, Shuojiong Pan, Shiqian Gao, Tianyu Li, Huaping Xu Biomaterials, 271, 120721. 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 H2O2-responsive diselenide-containing micelles that combined CO therapy with chemosensitization therapy and AAT in a single system. Under the interaction of intratumoral H2O2, CO and gemcitabine (GEM) were released in situ from the micelles to redu...
More

Adaptive Se-Te Metathesis Controlled by Cucurbituril-Based Host-Guest Interaction

Cheng Liu, Zhiheng Zhang, Zhiyuan Fan, Chaowei He, Yizheng Tan, Huaping Xu Chem. Asian J.; 2020, 15, 4321. Regulating the reactivity and equilibrium of dynamic reaction is essential for adaptive chemistry and functional materials. Herein, cucurbituril-based host-guest interaction was embedded into the dynamic metathesis between diselenide and ditelluride to establish an equilibrium-adaptive system. In this system, cucurbit[6]uril (CB[6]) selectively bound with diselenide while cucurbit[7]uril (CB[7]) bound with not only diselenide but also ditelluride and exchange product. The dynamic natu...
More

Exploring the Difference of Bonding Strength Between Silver(I) and Chalcogenides in Block Copolymer Systems

Peng Zhao, Cong-Qiao Xu, Chenxing Sun, Jiahao Xia, Lin Sun, Jun Li and Huaping Xu Polym. Chem.; 2020, 11, 7087. Silver(I)–chalcogenide interactions have been widely found in the mineral paragenesis and are of great significance in medicinal systems. An accurate understanding of the intrinsic nature of these interactions would provide the basis for comprehending the involved natural and biological behaviors. However, few systematic works exploring the relative strength of silver(I)–chalcogenide bonds had been reported before. Thus, by combining single-molecule force spectroscopy (SMFS) from...
More