Synergistic Drug-Loaded Shear-Thinning Star Polymer Hydrogel Facilitates Gastrointestinal Lesion Resection and Promotes Wound Healing.

Easy injection, long-lasting barrier, and drug loading are the critical properties of submucosal injection materials for endoscopic surgery. However, conventional injectable polymers face challenges in simultaneously attaining these properties due to the inherent conflict between injectability and in situ stability. Here, a multi-arm star polymer hydrogel (denoted as ßCP hydrogel) with long-lasting submucosal barrier (exceeding 120 min), rapid hemostasis, and sustained antibacterial properties is successfully developed by grafting poly(oligo(ethylene glycol) methyl ether methacrylate) (PEGMA) side-chains from ß-CD via atom transfer radical polymerization (ATRP). During the onset of shearing, ßCP hydrogel experiences the unwinding of polymer side-chains between neighboring star polymers, which facilitates the process of endoscopic injectability. After submucosal injection, ßCP hydrogel undergoes the winding of polymer side-chains, thereby establishing a long-lasting barrier cushion. Meanwhile, owing to its distinctive structures with a hydrophobic inner cavity and an outer layer of hydrophilic polymer side-chains, ßCP hydrogel enables simultaneous loading and on-demand release of diverse categories of drugs. This unique performance can adapt to the diverse demands during different stages of wound healing in a porcine endoscopic surgery model. These results indicate an appealing prospect for new application of star polymers as a good submucosal injection material in endoscopic treatments.

All-in-one porous membrane enables full protection in guided bone regeneration.

The sophisticated hierarchical structure that precisely combines contradictory mechanical and biological characteristics is ideal for biomaterials, but it is challenging to achieve. Herein, we engineer a spatiotemporally hierarchical guided bone regeneration (GBR) membrane by rational bilayer integration of densely porous N-halamine functionalized bacterial cellulose nanonetwork facing the gingiva and loosely porous chitosan-hydroxyapatite composite micronetwork facing the alveolar bone. Our GBR membrane asymmetrically combine stiffness and flexibility, ingrowth barrier and ingrowth guiding, as well as anti-bacteria and cell-activation. The dense layer has a mechanically matched space maintenance capacity toward gingiva, continuously blocks fibroblasts, and prevents bacterial invasion with multiple mechanisms including release-killing, contact-killing, anti-adhesion, and nanopore-blocking; the loose layer is ultra-soft to conformally cover bone surfaces and defect cavity edges, enables ingrowth of osteogenesis-associated cells, and creates a favorable osteogenic microenvironment. As a result, our all-in-one porous membrane possesses full protective abilities in GBR.

Band-Aid-Like Self-Fixed Barrier Membranes Enable Superior Bone Augmentation.

In guided bone regeneration surgery, a barrier membrane is usually used to inhibit soft tissue from interfering with osteogenesis. However, current barrier membranes usually fail to resist the impact of external forces on bone-augmented region, thus causing severe displacement of membranes and their underlying bone graft materials, eventually leading to unsatisfied bone augmentation. Herein, a new class of local double-layered adhesive barrier membranes (ABMs) is developed to successfully immobilize bone graft materials. The air-dried adhesive hydrogel layers with suction-adhesion properties enable ABMs to firmly adhere to the wet bone surface through a "stick-and-use" band-aid-like strategy and effectively prevent the displacement of membranes and the leakage of bone grafts in uncontained bone defect treatment. Furthermore, the strategy is versatile for preparing diverse adhesive barrier membranes and immobilizing different bone graft materials for various surgical regions. By establishing such a continuous barrier for the bone graft material, this strategy may open a novel avenue for designing the next-generation barrier membranes.

A framework for computing angle of progression from transperineal ultrasound images for evaluating fetal head descent using a novel double branch network.

Background: Accurate assessment of fetal descent by monitoring the fetal head (FH) station remains a clinical challenge in guiding obstetric management. Angle of progression (AoP) has been suggested to be a reliable and reproducible parameter for the assessment of FH descent. Methods: A novel framework, including image segmentation, target fitting and AoP calculation, is proposed for evaluating fetal descent. For image segmentation, this study presents a novel double branch segmentation network (DBSN), which consists of two parts: an encoding part receives image input, and a decoding part composed of deformable convolutional blocks and ordinary convolutional blocks. The decoding part includes the lower and upper branches, and the feature map of the lower branch is used as the input of the upper branch to assist the upper branch in decoding after being constrained by the attention gate (AG). Given an original transperineal ultrasound (TPU) image, areas of the pubic symphysis (PS) and FH are firstly segmented using the proposed DBSN, the ellipse contours of segmented regions are secondly fitted with the least square method, and three endpoints are finally determined for calculating AoP. Results: Our private dataset with 313 transperineal ultrasound (TPU) images was used for model evaluation with 5-fold cross-validation. The proposed method achieves the highest Dice coefficient (93.4%), the smallest Average Surface Distance (6.268 pixels) and the lowest AoP difference (5.993°) by comparing four state-of-the-art methods. Similar results (Dice coefficient: 91.7%, Average Surface Distance: 7.729 pixels: AoP difference: 5.110°) were obtained on a public dataset with >3,700 TPU images for evaluating its generalization performance. Conclusion: The proposed framework may be used for the automatic measurement of AoP with high accuracy and generalization performance. However, its clinical availability needs to be further evaluated.

Multitask Deep Neural Network for the Fully Automatic Measurement of the Angle of Progression.

The angle of progression (AoP) for assessing fetal head (FH) descent during labor is measured from the standard plane of transperineal ultrasound images as the angle between a line through the long axis of pubic symphysis (PS) and a second line from the right end of PS tangentially to the contour of the FH. This paper presents a multitask network with a shared feature encoder and three task-special decoders for standard plane recognition (Task1), image segmentation (Task2) of PS and FH, and endpoint detection (Task3) of PS. Based on the segmented FH and two endpoints of PS from standard plane images, we determined the right FH tangent point that passes through the right endpoint of PS and then computed the AoP using the above three points. In this paper, the efficient channel attention unit is introduced into the shared feature encoder for improving the robustness of layer region encoding, while an attention fusion module is used to promote cross-branch interaction between the encoder for Task2 and that for Task3, and a shape-constrained loss function is designed for enhancing the robustness to noise based on the convex shape-prior. We use Pearson's correlation coefficient and the Bland-Altman graph to assess the degree of agreement. The dataset includes 1964 images, where 919 images are nonstandard planes, and the other 1045 images are standard planes including PS and FH. We achieve a classification accuracy of 92.26%, and for the AoP calculation, an absolute mean (STD) value of the difference in AoP (∆AoP) is 3.898° (3.192°), the Pearson's correlation coefficient between manual and automated AoP was 0.964 and the Bland-Altman plot demonstrates they were statistically significant (P < 0.05). In conclusion, our approach can achieve a fully automatic measurement of AoP with good efficiency and may help labor progress in the future.

Dendrite-Free and Long-Cycling Lithium Metal Battery Enabled by Ultrathin, 2D Shield-Defensive, and Single Lithium-Ion Conducting Polymeric Membrane.

Polymeric membranes are considered as promising materials to realize safe and long-life lithium metal batteries (LMBs). However, they are usually based on soft 1D linear polymers and thus cannot effectively inhibit piercing of lithium dendrites at high current density. Herein, single lithium-ion conducting molecular brushes (GO-g-PSSLi) are successfully designed and fabricated with a new 2D "soft-hard-soft" hierarchical structure by grafting hairy lithium polystyrenesulfonate (PSSLi) chains on both sides of graphene oxide (GO) sheets. The ultrathin GO-g-PSSLi membrane is further constructed by evaporation-induced layer-by-layer self-assembly of GO-g-PSSLi molecular brushes. Unlike conventional soft 1D linear polymeric structure, the rigid 2D extended aromatic structure of intralayer GO backbones can bear the shield effect of preventing the dendrites possibly generated at high current density from piercing. More importantly, such a shield effect can be significantly strengthened by layer-by-layer stacking of 2D molecular brushes. On the other hand, the 3D interconnected interlayer channels and the soft single lithium-ion conducting PSSLi side-chains on the surface of channels provide rapid lithium-ion transportation pathways and homogenize lithium-ion flux. As a result, LMBs with GO-g-PSSLi membrane possess long-term reversible lithium plating/striping (6 months) at high current density.

Corrigendum to "The JNU-IFM dataset for segmenting pubic symphysis-fetal head" data in brief. 41 (2022) 107904.

[This corrects the article DOI: 10.1016/j.dib.2022.107904.].

The JNU-IFM dataset for segmenting pubic symphysis-fetal head.

The use of transperineal ultrasound techniques for the assessment of fetal head descent and progression is an adjunct to clinical examination. Automatic identification of parameters based on ultrasound images will greatly reduce the subjectivity and non-repeatability of the clinician's judgment. However, the lack of a pubic symphysis-fetal head dataset hinders the development of algorithms. Here, we present an intrapartum transperineal ultrasound dataset of the Intelligent Fetal Monitoring Lab of Jinan University (named the JNU-IFM dataset), in which intrapartum transperineal ultrasound videos of 78 were recorded from 51 patients. These data were obtained with the Youkey D8 wireless 2D ultrasound probe with its corresponding supporting software by Wuhan Youkey Bio-Medical Electronics Co., Ltd., Wuhan, China. In these videos, 6224 high-quality images with four categories were selected to form the JNU- IFM dataset. These images were labelled using the Pair software and then validated by two experienced radiologists. We hope that this data set can be used in the segmentation of the pubic symphysis-fetal head.

Ultrathin Yet Robust Single Lithium-Ion Conducting Quasi-Solid-State Polymer-Brush Electrolytes Enable Ultralong-Life and Dendrite-Free Lithium-Metal Batteries.

Quasi-solid-state polymer electrolytes are one of the most promising candidates for long-life lithium-metal batteries. However, introduction of plasticizers for high ion conductivity at room temperature inevitably gives rise to poor mechanical strength and requires a very thick electrolyte membrane, which is detrimental to safety and energy density of the batteries. Herein, inspired by tube brushes coupling hardness with softness, a novel superstructured polymer bottlebrush BC-g-PLiSTFSI-b-PEGM (BC = bacterial cellulose; PLiSTFSI = poly(lithium 4-styrenesulfonyl-(trifluoromethylsulfonyl) imide); PEGM = poly(diethylene glycol monomethyl ether methacrylate)) with a hard nanofibril backbone and soft functional polymer side-chains is reported as an effective strategy to well balance the mechanical strength and ion conductivity of quasi-solid-state polymer electrolytes. The resulting single lithium-ion conducting quasi-solid-state polymer-brush electrolytes (SLIC-QSPBEs) integrate the features of the ultrathin membrane thickness (10 µm), the nanofibril backbone-strengthened porous nanonetwork (Young's modulus = 1.9 GPa), and the high-rate single lithium-ion conducting diblock copolymer brushes. As a result, the ultrathin yet robust SLIC-QSPBEs enable ultralong-term (over 3300 h) reversible and stable lithium plating/stripping in Li/Li symmetrical cell at a current density of 1 mA cm-2 for lithium anode. This work affords a promising strategy to develop advanced electrolytes for solid-state lithium-metal batteries.

A Polymerization-Cutting Strategy: Self-Protection Synthesis of Thiol-Based Nanoporous Adsorbents for Efficient Mercury Removal.

Highly toxic heavy metal ions such as mercury ions (Hg2+ ) are a great threat to human life and the environment. Developing new strategies and materials to remove the toxic heavy metal ions has attracted more and more attentions. Herein a facile self-protection synthesis of thiol-based nanoporous adsorbents for efficient mercury removal via a polymerization-cutting strategy is reported. The direct free-radical polymerization of divinyl disulfide derivative and subsequently cutting off the disulfide linkage, without post-synthesis or modification, can give rise to an exceptionally high density of thiol chelating sites. Moreover, the resultant thiol-based nanoporous adsorbents (NAs-SH) exhibit a high saturation uptake capacity (1240 mg g-1 ) and reused ability for mercury removal from water solution. The proposed polymerization-cutting strategy may provide an alternative and cost-effective method for the design and synthesis of various efficient nanoporous adsorbents at large scale in the future.

"Click Chemistry" Mediated Functional Microporous Organic Nanotube Networks for Heterogeneous Catalysis.

The synthesis of azide functional microporous organic nanotube networks (N3-MONNs) via a Friedel-Crafts hyper-cross-linking reaction is reported. Subsequently, a general method for obtaining heterogeneous catalysts through a Cu-catalyzed alkyne-azide reaction is presented. The small-molecule catalysts such as 2,2,6,6,-tetramethylpiperidine-1-oyl and 4-(N,N-dimethylamino)pyridine can be anchored into the MONNs. Owing to the hierarchically porous structure and high surface area, these catalysts show high activity in selective oxidation of alcohols and acylation reaction, respectively.

Hyper-Cross-Linking Mediated Self-Assembly Strategy To Synthesize Hollow Microporous Organic Nanospheres.

Hollow microporous organic nanospheres (H-MONs) are prepared by using polylactide-b-polystyrene diblock copolymers (PLA-b-PS) as the precursor via a hyper-cross-linking mediated self-assembly strategy, in which the hyper-cross-linking PS block forms the microporous organic shell framework, and the degradable PLA block produces the hollow mesoporous core structure. The formation mechanism, morphology, and porosity parameters of the resulting H-MONs are systematically investigated. Moreover, based on the hyper-cross-linking generated rigid microporous organic frameworks, hollow microporous carbon nanospheres (H-MCNs) can be achieved by further pyrolysis progress. The obtained H-MCNs as electrode materials of a supercapacitor exhibit excellent electrochemical performance with specific capacitances of up to 145 F g-1 at 0.2 A g-1, with almost no capacitance loss even after 5000 cycles at 10 A g-1. More especially, H-MONs can be further act as "nanoreactors" for the synthesis of Fe3O4 nanoparticles within hollow cores to construct magnetic core-shell Fe3O4@H-MONs nanocomposite materials. Our strategy represents a new avenue for the preparation of hollow morphology-controlled microporous organic polymers with various potential applications.

Three-Arm Branched Microporous Organic Nanotube Networks.

Here, a novel method is demonstrated for the preparation of three-arm branched microporous organic nanotube networks (TAB-MONNs) based on molecular templating of three-arm branched core-shell bottlebrush copolymers and Friedel-Crafts alkylation reaction. The unique three-arm branched bottlebrush copolymers are synthesized by a combination of atom transfer radical polymerization, reversible addition-fragmentation chain transfer polymerization, and ring-opening polymerization techniques. In this approach, the length and diameter of branched tube units can be well-controlled by rational molecular design. Moreover, the as-prepared TAB-MONNs possess a high surface area and exhibit a superior adsorption capacity for Rhodamine 6G (R6G) and p-cresol.

In Situ Formation of Dual-Phase Thermosensitive Ultrasmall Gold Nanoparticles.

A novel method for the in situ synthesis of dual-phase thermosensitive ultrasmall gold nanoparticles (USGNPs) with diameters in the range of 1-3 nm was developed by using poly(N-isopropylacrylamide)-block-poly(N-phenylethylenediamine methacrylamide) (PNIPAM-b-PNPEDMA) amphiphilic diblock copolymers as ligands. The PNPEDMA block promotes the in situ reduction of gold precursors to zero-valent gold and subsequently binds to the surface of gold nanoparticles, while PNIPAM acts as a stabilizing and thermosensitive block. The as-synthesized USGNPs stabilized by a thermosensitive PNIPAM layer exhibit a sharp, reversible, clear-opaque transition in aqueous solution between 30 and 38 °C. An unprecedented finding is that these USGNPs also show a reversible soluble-precipitate transition in nonpolar organic solvents such as chloroform at around 0 °C under acidic conditions.