RNA‐Targeting Carbon Dots for Live‐Cell Imaging of Granule DynamicsJiang, Lei; Cai, Hao; Zhou, Wanwan; Li, Zijian; Zhang, Liang; Bi, Hong
doi: 10.1002/adma.202210776pmid: 36645339
It is significant to monitor the different RNA granules dynamics and phase separation process inside cells under various stresses, for example, oxidative stress. The current small‐molecule RNA probes work well only in fixed cells and usually encounter problems such as insufficient stability and biocompatibility, and thus a specific RNA‐targeting fluorescent nanoprobe that can be used in the living cells is urgently desired. Here, the de novo design and microwave‐assisted synthesis of a novel RNA‐targeting, red‐emissive carbon dots (named as M‐CDs) are reported by choosing neutral red and levofloxacin as precursors. The as‐synthesized M‐CDs is water‐soluble with a high fluorescence quantum yield of 22.83% and can selectively bind to RNA resulting in an enhanced red fluorescence. More interestingly, such an RNA‐targeting, red‐emissive M‐CDs can be fast internalized into cells within 5 s and thus used for real‐time imaging the dynamic process of intracellular stress granules under oxidative stress, revealing some characteristics of granules that have not been identified by previously reported RNA and protein biomarkers. This research paves a new pathway for visualizing bulk RNA dynamics and studying phase‐separation behaviors in living cells by rational design of the fluorescent carbon dots in terms of structure and functionality.
Dihydroxyterephthalate—A Trojan Horse PET Counit for Facile Chemical RecyclingLee, Ting‐Han; Forrester, Michael; Wang, Tung‐ping; Shen, Liyang; Liu, Hengzhou; Dileep, Dhananjay; Kuehl, Baker; Li, Wenzhen; Kraus, George; Cochran, Eric
doi: 10.1002/adma.202210154pmid: 36857624
Here, low‐energy poly(ethylene terephthalate) (PET) chemical recycling in water: PET copolymers with diethyl 2,5‐dihydroxyterephthalate (DHTE) undergo selective hydrolysis at DHTE sites, autocatalyzed by neighboring group participation, is demonstrated. Liberated oligomeric subchains further hydrolyze until only small molecules remain. Poly(ethylene terephthalate‐stat‐2,5‐dihydroxyterephthalate) copolymers were synthesized via melt polycondensation and then hydrolyzed in 150–200 °C water with 0–1 wt% ZnCl2, or alternatively in simulated sea water. Degradation progress follows pseudo‐first order kinetics. With increasing DHTE loading, the rate constant increases monotonically while the thermal activation barrier decreases. The depolymerization products are ethylene glycol, terephthalic acid, 2,5‐dihydroxyterephthalic acid, and bis(2‐hydroxyethyl) terephthalate dimer, which could be used to regenerate virgin polymer. Composition‐optimized copolymers show a decrease of nearly 50% in the Arrhenius activation energy, suggesting a 6‐order reduction in depolymerization time under ambient conditions compared to that of PET homopolymer. This study provides new insight to the design of polymers for end‐of‐life while maintaining key properties like service temperature and mechanical properties. Moreover, this chemical recycling procedure is more environmentally friendly compared to traditional approaches since water is the only needed material, which is green, sustainable, and cheap.
Benzo[d]thiazole Based Wide Bandgap Donor Polymers Enable 19.54% Efficiency Organic Solar Cells Along with Desirable Batch‐to‐Batch Reproducibility and General ApplicabilityPang, Bo; Liao, Chentong; Xu, Xiaopeng; Yu, Liyang; Li, Ruipeng; Peng, Qiang
doi: 10.1002/adma.202300631pmid: 36870079
The limited selection pool of high‐performance wide bandgap (WBG) polymer donors is a bottleneck problem of the nonfullerene acceptor (NFA) based organic solar cells (OSCs) that impedes the further improvement of their photovoltaic performances. Herein, a series of new WBG polymers, namely PH‐BTz, PS‐BTz, PF‐BTz, and PCl‐BTz, are developed by using the bicyclic difluoro‐benzo[d]thiazole (BTz) as the acceptor block and benzo[1,2‐b:4,5‐b′]dithiophene (BDT) derivatives as the donor units. By introducing S, F, and Cl atoms to the alkylthienyl sidechains on BDT, the resulting polymers exhibit lowered energy levels and enhanced aggregation properties. The fluorinated PBTz‐F not only exhibits a low‐lying HOMO level, but also has stronger face‐on packing order and results in more uniform fibril‐like interpenetrating networks in the related PF‐BTz:L8‐BO blend. A high‐power conversion efficiency (PCE) of 18.57% is achieved. Moreover, PBTz‐F also exhibits a good batch‐to‐batch reproducibility and general applicability. In addition, ternary blend OSCs based on the host PBTz‐F:L8‐BO blend and PM6 guest donor exhibits a further enhanced PCE of 19.54%, which is among the highest values of OSCs.
Nonepitaxial Electrodeposition of (002)‐Textured Zn Anode on Textureless Substrates for Dendrite‐Free and Hydrogen Evolution‐Suppressed Zn BatteriesZhang, Jingmin; Huang, Weiwei; Li, Longwei; Chang, Caiyun; Yang, Kai; Gao, Lei; Pu, Xiong
doi: 10.1002/adma.202300073pmid: 36861496
Nontoxic and safe aqueous Zn batteries are largely restricted by the detrimental dendrite growth and hydrogen evolution of Zn metal anode. The (002)‐textured Zn electrodeposition, demonstrated as an effective approach for solving these issues, is nevertheless achieved mainly by epitaxial or hetero‐epitaxial deposition of Zn on pre‐textured substrates. Herein, the electrodeposition of (002)‐textured and compact Zn on textureless substrates (commercial Zn, Cu, and Ti foils) at a medium‐high galvanostatic current density is reported. According to the systematic investigations on Zn nucleation and growth behaviors, this is ascribed to two reasons: i) the promoted nonepitaxial nucleation of fine horizontal (002) nuclei at increased overpotential and ii) the competitive growth advantages of (002)‐orientated nuclei. The resulting freestanding (002)‐textured Zn film exhibits significantly suppressed hydrogen evolution and prolonged Zn plating–stripping cycling life, achieving over 2100 mAh cm−2 cumulative capacity under a current density of 10 mA cm−2 and a high depth of discharge (DOD) of 45.5%. Therefore, this study provides both fundamental and practical insights into long‐life Zn metal batteries.
Complex Structures Made Simple – Continuous Flow Production of Core Cross‐Linked Polymeric Micelles for Paclitaxel Pro‐Drug‐DeliveryBauer, Tobias A.; Schramm, Jonas; Fenaroli, Federico; Siemer, Svenja; Seidl, Christine I.; Rosenauer, Christine; Bleul, Regina; Stauber, Roland H.; Koynov, Kaloian; Maskos, Michael; Barz, Matthias
doi: 10.1002/adma.202210704pmid: 36934295
Translating innovative nanomaterials to medical products requires efficient manufacturing techniques that enable large‐scale high‐throughput synthesis with high reproducibility. Drug carriers in medicine embrace a complex subset of tasks calling for multifunctionality. Here, the synthesisof pro‐drug‐loaded core cross‐linked polymeric micelles (CCPMs) in a continuous flow processis reported, which combines the commonly separated steps of micelle formation, core cross‐linking, functionalization, and purification into a single process. Redox‐responsive CCPMs are formed from thiol‐reactive polypept(o)ides of polysarcosine‐block‐poly(S‐ethylsulfonyl‐l‐cysteine) and functional cross‐linkers based on dihydrolipoic acid hydrazide for pH‐dependent release of paclitaxel. The precisely controlled microfluidic process allows the production of spherical micelles (Dh = 35 nm) with low polydispersity values (PDI < 0.1) while avoiding toxic organic solvents and additives with unfavorable safety profiles. Self‐assembly and cross‐linking via slit interdigital micromixers produces 350–700 mg of CCPMs/h per single system, while purification by online tangential flow filtration successfully removes impurities (unimer ≤ 0.5%). The formed paclitaxel‐loaded CCPMs possess the desired pH‐responsive release profile, display stable drug encapsulation, an improved toxicity profile compared to Abraxane (a trademark of Bristol‐Myers Squibb), and therapeutic efficiency in the B16F1‐xenotransplanted zebrafish model. The combination of reactive polymers, functional cross‐linkers, and microfluidics enables the continuous‐flow synthesis of therapeutically active CCPMs in a single process.
Engineering of Chain Rigidity and Hydrogen Bond Cross‐Linking toward Ultra‐Strong, Healable, Recyclable, and Water‐Resistant ElastomersGuo, Zhiwei; Lu, Xingyuan; Wang, Xiaohan; Li, Xiang; Li, Jian; Sun, Junqi
doi: 10.1002/adma.202300286pmid: 36854256
High‐performance elastomers have gained significant interest because of their wide applications in industry and our daily life. However, it remains a great challenge to fabricate elastomers simultaneously integrating ultra‐high mechanical strength, toughness, and excellent healing and recycling capacities. In this study, ultra‐strong, healable, and recyclable elastomers are fabricated by dynamically cross‐linking copolymers composed of rigid polyimide (PI) segments and soft poly(urea–urethane) (PUU) segments with hydrogen bonds. The elastomers, which are denoted as PIPUU, have a record‐high tensile strength of ≈142 MPa and an extremely high toughness of ≈527 MJ m−3. The structure of the PIPUU elastomer contains hydrogen‐bond‐cross‐linked elastic matrix and homogenously dispersed rigid nanostructures. The rigid PI segments self‐assemble to generate phase‐separated nanostructures that serve as nanofillers to significantly strengthen the elastomers. Meanwhile, the elastic matrix is composed of soft PUU segments cross‐linked with reversible hydrogen bonds, which largely enhance the strength and toughness of the elastomer. The dynamically cross‐linked PIPUU elastomers can be healed and recycled to restore their original mechanical strength. Moreover, because of the excellent mechanical performance and the hydrophobic PI segments, the PIPUU elastomers are scratch‐, puncture‐, and water‐resistant.