Formation of Zn–Zn and Zn–Pd Bonded Complexes by Reactions of Terminal Zinc Hydrides with Pd(II) Species

Divalent palladium-induced homocoupling of terminal zinc hydrides to zinc–zinc bonded complexes was achieved herein. Reactions of zinc hydrides [LZnH] (L = CH3C­(2,6-iPr2C6H3N)­CHC­(CH3)­(N­(CH2)n­CH2PPh2); 1a: n = 1; 1b: n = 2) with 0.5 equiv of allyl­(cyclopentadienyl)­palladium­(II) afforded heterotrinuclear [Zn2Pd] complexes 3 containing direct Zn–Zn and Zn–Pd bonds, with concomitant elimination of propylene and cyclopentadiene. Complexes 3 were also accessed by the reactions of zinc hydrides 1 with allylpalladium­(II) chloride with release of propylene and hydrogen chloride. Treatment of zinc hydrides 1 with 1 equiv of allyl­(cyclopentadienyl)­palladium­(II) gave Zn–Pd bonded complex 5 by elimination of propylene, which can be transformed into heterotrinuclear complex 3 by further reaction with one additional molar equivalent of zinc hydrides. Heterobimetallic Zn–Pd complex 5b was found to be an effective catalyst in the hydrosilylation of benzaldehyde and its derivatives. Reaction of 5b with silane reagent Ph2SiH2 produced [Pd2Si2H2] complex 8 with cleavage of the Pd–Zn bond, which served as an initiating species in the catalytic reaction. Complexes 4b, 5, and 8 in this study were characterized by X-ray diffraction

Catalytic Assembly of DNAzyme Integrates with Primer Exchange Reaction (CDiPER) for Highly Sensitive Detection of MicroRNA

MicroRNAs (miRNAs) have significant regulatory functions in the modulation of gene expression, making them essential biomarkers for the diagnosis and prognosis of diseases. Nevertheless, the identification of miRNA poses significant difficulty in terms of its low abundance, necessitating sensitive and reliable approaches. Herein, we develop a simple approach, termed Catalytic assembly of DNAzyme integrates with Primer Exchange Reaction (CDiPER), for reliable and sensitive miRNA detection through the target recognition-triggered DNAzyme assembly and primer exchange reaction (PER) strategy. In this method, target miRNA can precisely bind with a specifically designed hairpin probe (H probe) to induce the conformation changes of the H probe, releasing DNAzyme sections to activate the PER process for signal amplification and fluorescence signal production. The established method displays a high dynamic range of over 6 orders of magnitude and a low detection limit of 312 aM. The created method has a number of unique advantages, such as (i) a better sensitivity than existing systems using PER for signal amplification as a result of its integration with the target recognition-triggered DNAzyme assembly and (ii) streamlined operating procedures. Further, the technology was used to detect the expression of miRNA in collected clinical samples from diabetes mellitus patients, revealing that miRNA was decreased in patients and demonstrating the significant clinical promise of the method

Controlled Electric and Magnetic Hot Spots in All-Dielectric Metasurfaces with High‑<i>Q</i> Resonances

The precise control over the locations of hot spots in a nanostructured ensemble is of great importance in enhanced spectroscopy, super-resolution optical imaging, sensors, slow light, and beam-steering devices. However, for all-dielectric multiparticle configurations, the locations of hot spots are difficult to predict due to the complex coupling of optical resonance modes. In this work, theoretical simulations based on all-dielectric metasurfaces with high-Q resonances predict that the locations of hot spots can be efficiently controlled in the nanorod–nanorod gaps or in the nanorod interior by suppressing or promoting specific-mode coupling effects in a specific polarization state of incident light. These findings offer an avenue to realize high-performance filters, sensors, and modulators for prompting applications

Synthesis and Reactivity of Triangular Heterometallic Complexes Containing Zn–Zn Bond

This work provides a facile access to a series of triangular [Zn2M] (M = group 10 and 11 metals) clusters. Treatment of Zn–Zn-bonded compounds [LZn–ZnL] (L = CH3C­(2,6-iPr2C6H3N)­CHC­(CH3)­(NCH2CH2PR2); R = Ph, iPr) with zero-valent transition-metal reagents selectively afforded the corresponding triangular clusters [Zn2M], where M = Ni(0), Pd(0), and Pt(0). Notably, the isoelectronic triangular clusters [Zn2M]+, where M = Ag­(I) and Cu­(I), could also be obtained by reactions of [LZn–ZnL] with AgOTf and CuOTf, respectively. The [Zn2Ag]+ complex containing elusive Zn–Ag bonds was investigated by density functional theory analysis, showing a 3c–2e bonding feature in the metallic ring. The electrochemical behaviors of [Zn2M] complexes were examined and revealed the donation of electron density from the Zn–Zn σ-bond to the metal centers. Reaction of the [Zn2Ni] complex with isocyanide gave heterometallic species by coordination of isocyanide to the nickel center, keeping the trimetallic ring core structure intact. In contrast, the Zn–Zn bond was rapidly cleaved upon treatment of the [Zn2Ni] complex with dihydrogen or phenyl acetylene, generating the hydride- or acetylide-bridged heterotrimetallic complex

Image1_A three-dimensional actively spreading bone repair material based on cell spheroids can facilitate the preservation of tooth extraction sockets.TIF

Introduction: Achieving a successful reconstruction of alveolar bone morphology still remains a challenge because of the irregularity and complex microenvironment of tooth sockets. Biological materials including hydroxyapatite and collagen, are used for alveolar ridge preservation. However, the healing effect is often unsatisfactory.Methods: Inspired by superwetting biomimetic materials, we constructed a 3D actively-spreading bone repair material. It consisted of photocurable polyether F127 diacrylate hydrogel loaded with mixed spheroids of mesenchymal stem cells (MSCs) and vascular endothelial cells (ECs).Results: Biologically, cells in the spheroids were able to spread and migrate outwards, and possessed both osteogenic and angiogenic potential. Meanwhile, ECs also enhanced osteogenic differentiation of MSCs. Mechanically, the excellent physical properties of F127DA hydrogel ensured that it was able to be injected directly into the tooth socket and stabilized after light curing. In vivo experiments showed that MSC-EC-F127DA system promoted bone repair and preserved the shape of alveolar ridge within a short time duration.Discussion: In conclusion, the novel photocurable injectable MSC-EC-F127DA hydrogel system was able to achieve three-dimensional tissue infiltration, and exhibited much therapeutic potential for complex oral bone defects in the future.</p

DataSheet1_Chirality-biased protein expression profile during early stages of bone regeneration.docx

Introduction: Chirality is a crucial mechanical cue within the extracellular matrix during tissue repair and regeneration. Despite its key roles in cell behavior and regeneration efficacy, our understanding of chirality-biased protein profile in vivo remains unclear.Methods: In this study, we characterized the proteomic profile of proteins extracted from bone defect areas implanted with left-handed and right-handed scaffold matrices during the early healing stage. We identified differentially-expressed proteins between the two groups and detected heterogenic characteristic signatures on day 3 and day 7 time points.Results: Proteomic analysis showed that left-handed chirality could upregulate cell adhesion-related and GTPase-related proteins on day 3 and day 7. Besides, interaction analysis and in vitro verification results indicated that the left-handed chiral scaffold material activated Rho GTPase and Akt1, ultimately leading to M2 polarization of macrophages.Discussion: In summary, our study thus improved understanding of the regenerative processes facilitated by chiral materials by characterizing the protein atlas in the context of bone defect repair and exploring the underlying molecular mechanisms of chirality-mediated polarization differences in macrophages.</p

Image2_A three-dimensional actively spreading bone repair material based on cell spheroids can facilitate the preservation of tooth extraction sockets.TIF

Introduction: Achieving a successful reconstruction of alveolar bone morphology still remains a challenge because of the irregularity and complex microenvironment of tooth sockets. Biological materials including hydroxyapatite and collagen, are used for alveolar ridge preservation. However, the healing effect is often unsatisfactory.Methods: Inspired by superwetting biomimetic materials, we constructed a 3D actively-spreading bone repair material. It consisted of photocurable polyether F127 diacrylate hydrogel loaded with mixed spheroids of mesenchymal stem cells (MSCs) and vascular endothelial cells (ECs).Results: Biologically, cells in the spheroids were able to spread and migrate outwards, and possessed both osteogenic and angiogenic potential. Meanwhile, ECs also enhanced osteogenic differentiation of MSCs. Mechanically, the excellent physical properties of F127DA hydrogel ensured that it was able to be injected directly into the tooth socket and stabilized after light curing. In vivo experiments showed that MSC-EC-F127DA system promoted bone repair and preserved the shape of alveolar ridge within a short time duration.Discussion: In conclusion, the novel photocurable injectable MSC-EC-F127DA hydrogel system was able to achieve three-dimensional tissue infiltration, and exhibited much therapeutic potential for complex oral bone defects in the future.</p

DataSheet1_Superwettable and injectable GelMA-MSC microspheres promote cartilage repair in temporomandibular joints.docx

Temporomandibular disorders (TMD) can be treated by promoting cartilage regeneration with biomaterials. However, there are deficiencies in the infiltration function of bone filler biological materials. In this study, stems cells were loaded onto gelatin methacryloyl (GelMA) hydrogel microspheres endowed with superwettable properties and TGF-β sustained-release function, which can quickly infiltrate the irregular surface of the temporomandibular joint (TMJ) bone defect area and accelerate cartilage healing. First, to improve cell adhesion and spreading function, the BMSCs-coated GelMA microspheres were endowed with superwetting property. At the same time, the swelling adsorption characteristics of gelatin microspheres could be used to load recombinant TGF-β within the microspheres, which could in turn promote the chondrogenic differentiation of multi-potent bone marrow mesenchymal stem cells. The SEM imaging demonstrated that BMSCs-coated GelMA microsphere has superwettable and superhydrophilic property, which enabled rapid adaptation to the bone defect surface morphology, which is conducive to tissue repair. Furthermore, the cartilage defect model showed that rBMSCs-coated GelMA microspheres promote temporomandibular joint arthritis repair. In conclusion, our study established that BMSC-coated GelMA microspheres endowed with superwetting properties, can colonize the bone defect repair site better with sustained release of growth factors, thus providing an innovative strategy for promoting cartilage regeneration.</p