Inherent Stretching Elasticity of a Single Polymer Chain with a Carbon–Carbon Backbone

We study the single-chain elasticities of three kinds of neutral polymers with a carbon–carbon (C–C) backbone by atomic force microscopy-based single-molecule force spectroscopy in a nonpolar solvent (octane), aiming at measuring the inherent chain elasticity of this very important class of polymers. The finding that the single-chain elasticities of all three polymers in octane are virtually identical in the entire force region implies that the side chains of the polymers have no detectable effects on the single-chain elasticity. By utilizing the single-chain elasticity from quantum mechanics calculations, the freely rotating chain model can provide the best fitting curve when each C–C bond is set to be the rotating unit. Although there are some exceptions when the side chain is very huge, our work provides a general result for the inherent elasticity of single neutral flexible polymer chains with C–C backbones

Additional file 2: Figure S2. of LncRNA RP11-436H11.5, functioning as a competitive endogenous RNA, upregulates BCL-W expression by sponging miR-335-5p and promotes proliferation and invasion in renal cell carcinoma

A human miRNA target prediction tool (DIANA TOOLS) was used to find the predicted binding sites of miR-335-5p to lncRNA RP11-436H11.5 (PNG 6870 kb

Additional file 1: Figure S1. of LncRNA RP11-436H11.5, functioning as a competitive endogenous RNA, upregulates BCL-W expression by sponging miR-335-5p and promotes proliferation and invasion in renal cell carcinoma

A human lncRNA target prediction tool (DIANA TOOLS) was used to predict potential lncRNAs that could interact with miR-335-5p (PNG 8684 kb

New Layered Fluorosulfide SrFBiS₂

We have synthesized a new layered BiS₂-based compound, SrFBiS₂. This compound has a similar structure to LaOBiS₂. It is built up by stacking up SrF layers and NaCl-type BiS₂ layers alternatively along the <i>c</i> axis. Electric transport measurement indicates that SrFBiS₂ is a semiconductor. Thermal transport measurement shows that SrFBiS₂ has a small thermal conductivity and large Seebeck coefficient. First principle calculations are in agreement with experimental results and show that SrFBiS₂ is very similar to LaOBiS₂, which becomes a superconductor with F doping. Therefore, SrFBiS₂ may be a parent compound of new superconductors

Polydopamine Nanoparticles Modulating Stimuli-Responsive PNIPAM Hydrogels with Cell/Tissue Adhesiveness

Stimuli-responsive hydrogels can respond to stimuli by phase transformation or volume change and exhibit specific functions. Near-infrared (NIR)-responsive hydrogel is a type of stimuli-responsive hydrogel, which can be precisely controlled by altering the radiation intensity, exposure time of the light source, and irradiation sites. Here, polydopamine nanoparticles (PDA-NPs) were introduced into a poly­(<i>N</i>-isopropylacrylamide) (PNIPAM) network to fabricate a PDA-NPs/PNIPAM hydrogel with NIR responsibility, self-healing ability, and cell/tissue adhesiveness. After incorporation of PDA-NPs into the hydrogel, the PDA-NPs/PNIPAM hydrogel showed phase transitions and volume changes in response to NIR. Thus, the hydrogel can achieve triple response effects, including pulsatile drug release, NIR-driven actuation, and NIR-assisted healing. After coating PDA-NPs onto hydrogel surfaces, the hydrogel showed improved cell affinity, good tissue adhesiveness, and growth factor/protein immobilization ability because of reactive catechol groups on PDA-NPs. The tissue adhesion strength to porcine skin was as high as 90 KPa. <i>In vivo</i> full-skin defect experiments demonstrated that PDA-NPs coating on the hydrogel and an immobilized growth factor had a synergistic effect on accelerating wound healing. In summary, we combined thermosensitive PNIPAM and mussel-inspired PDA-NPs to form a NIR-responsive hydrogel, which may have potential applications for chemical and physical therapies

Table_1_Comprehensive Analysis of the Transcriptome-wide m6A Methylome in Lung Adenocarcinoma by MeRIP Sequencing.xlsx

N6-methyladenosine (m6A) is the most abundant internal modification on eukaryotic mRNAs. There is increasing evidence that m6A plays a key role in tumor progression, so it is important to analyze m6A modifications within the transcriptome-wide in lung adenocarcinoma (LUAD). Three pairs of LUAD samples and tumor-adjacent normal tissues were obtained from the South University of Science and Technology Hospital. And then methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) were used to identify differential m6A modifications between tumor and tumor-adjacent normal tissues. We identified 4041 aberrant m6A peaks, of which 1192 m6A peaks were upregulated and 2849 m6A peaks downregulated. It was found that genes with the dysregulated m6A peaks were enriched in the pathways in cancer, Rap1 signaling pathway, and insulin resistance. Additionally, 612 genes with abnormal regulation of m6A peaks and RNA expression were identified by combining MeRIP-seq and RNA-seq data. Through KEGG analysis, the 612 genes were enriched in cancer-related signaling pathways, such as the cGMP-PKG signaling pathway, and the Rap1 signaling pathway. What’s more, GSEA enrichment analysis showed these genes were enriched in cell cycle phase transition, cell division, cellular response to DNA damage stimulus, and chromosome organization. To further explore the relationship between differential m6A modified genes and clinical parameters of LUAD patients, we searched The Cancer Genome Atlas (TCGA) and identified 2 genes (FCRL5 and GPRIN1) that were associated with the prognosis and diagnosis of LUAD patients. Furthermore, we found a positive correlation between GPRIN1 and m6A reader YTHDF1 in the GEPIA2 database. It was verified that YTHDF1 binds to GPRIN1 mRNA and regulates its expression. Our study results suggest that m6A modification plays important role in the progression and prognosis of LUAD and maybe a potential new therapeutic target for LUAD patients in the future.</p

Transparent, Adhesive, and Conductive Hydrogel for Soft Bioelectronics Based on Light-Transmitting Polydopamine-Doped Polypyrrole Nanofibrils

Conductive hydrogels are promising materials for soft electronic devices. To satisfy the diverse requirement of bioelectronic devices, especially those for human–machine interfaces, hydrogels are required to be transparent, conductive, highly stretchable, and skin-adhesive. However, fabrication of a conductive-polymer-incorporated hydrogel with high performance is a challenge because of the hydrophobic nature of conductive polymers making processing difficult. Here, we report a transparent, conductive, stretchable, and self-adhesive hydrogel by in situ formation of polydopamine (PDA)-doped polypyrrole (PPy) nanofibrils in the polymer network. The in situ formed nanofibrils with good hydrophilicity were well-integrated with the hydrophilic polymer phase and interwoven into a nanomesh, which created a complete conductive path and allowed visible light to pass through for transparency. Catechol groups from the PDA–PPy nanofibrils imparted the hydrogel with self-adhesiveness. Reinforcement by the nanofibrils made the hydrogel tough and stretchable. The proposed simple and smart strategy of in situ formation of conductive nanofillers opens a new route to incorporate hydrophobic and undissolvable conductive polymers into hydrogels. The fabricated multifunctional hydrogel shows promise in a range of applications, such as transparent electronic skins, wound dressings, and bioelectrodes for see-through body-adhered signal detection

Transparent, Adhesive, and Conductive Hydrogel for Soft Bioelectronics Based on Light-Transmitting Polydopamine-Doped Polypyrrole Nanofibrils

Conductive hydrogels are promising materials for soft electronic devices. To satisfy the diverse requirement of bioelectronic devices, especially those for human–machine interfaces, hydrogels are required to be transparent, conductive, highly stretchable, and skin-adhesive. However, fabrication of a conductive-polymer-incorporated hydrogel with high performance is a challenge because of the hydrophobic nature of conductive polymers making processing difficult. Here, we report a transparent, conductive, stretchable, and self-adhesive hydrogel by in situ formation of polydopamine (PDA)-doped polypyrrole (PPy) nanofibrils in the polymer network. The in situ formed nanofibrils with good hydrophilicity were well-integrated with the hydrophilic polymer phase and interwoven into a nanomesh, which created a complete conductive path and allowed visible light to pass through for transparency. Catechol groups from the PDA–PPy nanofibrils imparted the hydrogel with self-adhesiveness. Reinforcement by the nanofibrils made the hydrogel tough and stretchable. The proposed simple and smart strategy of in situ formation of conductive nanofillers opens a new route to incorporate hydrophobic and undissolvable conductive polymers into hydrogels. The fabricated multifunctional hydrogel shows promise in a range of applications, such as transparent electronic skins, wound dressings, and bioelectrodes for see-through body-adhered signal detection

Bioadhesive Microporous Architectures by Self-Assembling Polydopamine Microcapsules for Biomedical Applications

Bioadhesive microporous architectures that mimic the functions of a natural extracellular matrix (ECM) were prepared by self-assembling polydopamine (PDA) microcapsules, which not only favor cell adhesion and growth, but also facilitate growth factor immobilization and release. PDA-coated polystyrene (PS) microspheres are synthesized by polymerization of dopamine on sulfonated PS microspheres and then assembled using positively charged chitosan (CHI) layers as link agents. After the PS core templates were removed, microporous architectures composed of PDA microcapsules were obtained. The produced microporous PDA architectures have a high capability of adsorbing BMP-2 and realize the sustained release of BMP-2. More importantly, the bioadhesive micro architecture and its immobilized BMP-2 synergistically enhance the activity and osteogenetic differentiation of bone marrow mesenchymal stem cells (BMSCs). Both supercell adhesion and BMP-2 immobilization ability of these architectures are attributed to the intrinsic adhesive nature of PDA and the porous architectures via the assembly of PDA microcapsules. The bioadhesive microporous PDA architectures with both cell affinitive and GF release features have a great potential to mimic natural ECM for modifying various medical devices in the fields of tissue engineering and regenerative medicine

Pulse Electrochemical Driven Rapid Layer-by-Layer Assembly of Polydopamine and Hydroxyapatite Nanofilms via Alternative Redox <i>in Situ</i> Synthesis for Bone Regeneration

Polydopamine (PDA) is an important candidate material for the surface modification of biomedical devices because of its good adhesiveness and biocompatibility. However, PDA nanofilms lack osteoinductivity, limiting their applications in bone tissue engineering. Hydroxyapatite nanoparticles (HA-NPs) are the major component of natural bone, which can be used to effectively enhance the osteoinductivity of PDA nanofilms. Herein, we developed a pulse electrochemical driven layer-by-layer (PED-LbL) assembly process to rapidly deposit HA-NPs and PDA (HA-PDA) multilayer nanofilms. In this process, PDA and HA-NPs are <i>in situ</i> synthesized in two sequential oxidative and reductive pulses in each electrochemical deposition cycle and alternately deposited on the substrate surfaces. PDA assists the <i>in situ</i> synthesis of HA-NPs by working as a template, which avoids the noncontrollable HA nucleation and aggregation. The HA-PDA multilayer nanofilms serve as a tunable reservoir to deliver bone morphogenetic protein-2 and exhibit high osteoinductivity both <i>in vitro</i> and <i>in vivo</i>. This PED-LbL assembly process breaks the limitation of traditional LbL assembly, allowing not only the rapid assembly of oppositely charged polyelectrolytes but also the <i>in situ</i> synthesis of organic/inorganic NPs that are uniformly incorporated in the nanofilm. It has broad applications in the preparation of versatile surface coatings on various biomedical devices