Masking Strategy Constructed Metal Coordination Hydrogels with Improved Mechanical Properties for Flexible Electronic Sensors.

Metal coordination hydrogels (MC-HGs) that introduce dynamically coordinate bonds together with metal ionic conduction have attracted considerable attention in flexible electronics. However, the traditional soaking method alleged to have technical scalability faces the challenge of forming MC-HGs with a "core-shell" structure, which undoubtedly reduces the whole mechanical properties and ionic stimulation responsiveness required for flexible electronics materials. Herein, a novel strategy referred to as "masking" has been proposed based on the theory of the valence bond and coordination chemistry. By regulating the masking agents and their concentrations as well as pairing mode with the metal ions, the whole mechanical properties of the resulting composites (MC-HGsMasking) show nearly double the values of their traditional soaking samples (MC-HGsSoaking). For example, the fracture stress and toughness of Fe-HGsMasking(SA, 5.0 g/L) are 1.55 MPa and 2.14 MJ/m3, almost twice those of Fe-HGsSoaking (0.83 MPa and 0.93 MJ/m3, respectively). Microstructure characterization combined with finite element analysis, molecular dynamics, and first-principles simulations demonstrates that the masking strategy first facilitating interfacial permeation of metal complexes and then effective coordination with functional ligands (carboxylates) of the hydrogels is the mechanism to strengthen the mechanical properties of composites MC-HGsMasking, which has the potential to break through the limitations of current MC-HGs in flexible electronic sensor applications.

SSR molecular marker developments and genetic diversity analysis of Zanthoxylum nitidum (Roxb.) DC.

Zanthoxylum nitidum (Roxb.) is a commonly used traditional Chinese medicine. However, the collection and protection of wild germplasm resources of Z. nitidum are still insufficient, and there is limited research on its genetic diversity and fingerprint. In the present study, 15 simple sequence repeat (SSR) markers were developed by genotyping based on multiplexed shotgun sequencing. The genetic diversity of 51 populations (142 individuals) of Z. nitidum was evaluated using these 15 SSRs. A total of 245 alleles (Na) were detected, with an average value of 16.333, and the average polymorphism information content was 0.756. The genetic distance among 51 populations was 0.164~1.000, with an average of 0.659. Analysis of molecular variance showed low genetic differentiation (40%) and high genetic differentiation (60%) between populations and individuals, respectively. The genetic differentiation coefficient (Fst) of the population was 0.338, indicating that 66.2% of the genetic variation occurred within the population, and the gene flow (Nm) was 0.636, demonstrating that the gene exchange between populations was low. Clustering analysis revealed that the genetic similarity coefficient was 0.30, dividing the 51 populations into 4 groups of 2, 17, 3, and 29 populations. There was no specific relationship between geographical location differences and genetic distance. The genetic diversity level of Z. nitidum is relatively high, and our results provide a theoretical basis for the rapid identification of Z. nitidum germplasm resources and variety selection.

Dynamic changes in the levels of metabolites and endogenous hormones during the germination of Zanthoxylum nitidum (Roxb.) DC. Seeds.

Accumulating experimental data have shown that endogenous hormones play important roles in regulating seed dormancy and germination. Zanthoxylum nitidum is a medicinal plant that propagates via seeds, which require a long dormancy period for normal germination, and complex changes in metabolites occur during the germination process. However, the regulatory network of endogenous hormones and metabolites during the germination of Z. nitidum seeds remains unclear. This study investigated the dynamic changes in the levels of metabolites and endogenous hormones during the germination of Z. nitidum seeds. The results revealed an increase in the levels of gibberellin 3 (GA3), 12-oxophytodienoic acid (OPDA), 1-aminocyclopropane-1-carboxylic acid (ACC) and trans-zeatin (TZ) and decrease in the levels of abscisic acid (ABA), jasmonic acid (JA), N-[(-)-jasmonoyl]-(S)-isoleucine (JA-Ile) and trans-zeatin riboside (TZR). Overall, 112 differential metabolites (DAMs) were screened from 3 seed samples (Sa, Sb and Sc), most of which are related to primary metabolism. A total of 16 DAMs (including 3 monosaccharides, 3 phosphate lipids, 3 carboxylic acids, 1 amino acid, 2 pyrimidines, and 4 nucleotides) were identified in the three sample comparison pairs (Sa vs Sb, Sa vs Sc, and Sb vs Sc); these DAMs were significantly enriched in purine metabolism; glycerophospholipid metabolism, citrate cycle (TCA cycle), alanine, aspartate and glutamate metabolism and pyruvate metabolism. OPDA, ACC and GAs were significantly positively correlated with upregulated metabolites, whereas ABA and JA were significantly positively correlated with downregulated metabolites. Finally, a hypothetical metabolic network of endogenous hormones that regulate seed germination was constructed. This study deepens our understanding of the importance of endogenous hormonal profiles that mediate seed germination.

Fascinating Pathway to Facilitate the Photoisomerization of Spiropyran-Based Nanocomposites.

Recently, spiropyran-based composites have gained more attention on account of their stimuli-responsive essence, especially of the fascinating and green photo stimulus. However, the great dipole moment change between the ring-opened merocyanine and ring-closed spiropyran requires a large free volume available for isomerization, which significantly restrains the photoisomerization of spiropyran-based nanocomposites. Herein, a fascinating pathway by regulating the states both of spiropyran and the immobilized nanoparticle supports was put forward to facilitate the photoisomerization. The results demonstrated that the spiropyran grafting percentage of 5.18% and immobilized supports with less aggregation, high specific surface area, large pore size, and noncrystalline structure were suitable to fabricate spiropyran-based nanocomposites, which showed a significant improvement for Pb2+ and Cr3+ removal from aqueous solution on account of free photoisomerization of spiropyran on the support's surface. This work will pave the pathway to extend the exploitation of spiropyran-based nanocomposites in various fields such as biotechnology, physiology, and electronics to photonics and environmental-friendly fields.

Full-length transcriptome analysis of Zanthoxylum nitidum (Roxb.) DC.

Zanthoxylum nitidum (Roxb.) DC. (Z. nitidum) is a type of Chinese Dao-di herb, also called Liangmianzhen, which is widely used to treat arthralgia, rheumatic arthralgia, and stomach pain. However, genomic resources for Z. nitidum are still scarce. This study provides transcriptomic resources for Z. nitidum by applying single-molecule real-time (SMRT) sequencing technology. In total, 456,109 circular consensus sequencing (CCS) reads were generated with a mean length of 2,216 bp from Z. nitidum roots, old stems, young branches, leaves, flowers, and fruits. Of these total reads, 353,932 were full-length nonchimeric (FLNC) reads with an average length of 1,996 bp. A total of 16,163 transcripts with a mean length of 1,171 bp were acquired. Of these transcripts, 14,231 (88%) were successfully annotated using public databases. Across all the 16,163 transcripts, we identified 6,255 long non-coding RNAs (lncRNAs) and 22,780 simple sequence repeats (SSRs). Furthermore, 3,482 transcription factors were identified. Among the SSR loci, 1-3 nucleotide repeats were dominant, occupying 99.36% of the total SSR loci, with mono-, di-, and tri-nucleotide repeats accounting for 61.80%, 19.89%, and 5.02% of the total SSR loci, respectively. A total of 36 out of 100 randomly selected primer pairs were verified to be positive, 20 of which showed polymorphism. These findings enrich the genetic resources available for facilitating future studies and research on relevant topics such as population genetics in Z. nitidum.

X-ray Study of Cembranoids with Flexible Rings from Boswellia papyrifera Resins Allowing Structural Revision of Misleading Structures from the Past 70 Years.

Thirty new, highly oxygenated and stereogenic 14-membered macrocyclic diterpenoids, papyrifuranols A-Z (1-26) and AA-AD (27-30), and eight known analogs have been isolated from Boswellia papyrifera resins. All the structures were characterized by detailed spectral analyses, quantum calculations, X-ray diffraction, and modified Mosher's methods. Notably, six previously reported structures were revised. Our study points out misleading factors of macrocyclic cembranoid (CB) representation in the past seven decades by analyzing of 25 X-ray structures, lending a hand for the innately challenging structure identification of such flexible macrocyclic CBs and avoiding following the tracks of an overturned cart during future structure characterization and total synthesis. Biosynthetic conversions of all the isolates are proposed, and wound healing bioassays reveal that papyrifuranols N-P could significantly stimulate the proliferation and differentiation of umbilical cord mesenchymal stem cells.

Development and Characterization of Multifunctional Wound Dressing with the Property of Anti-bacteria and Angiogenesis.

Overcoming the bacterial infection and promoting angiogenesis are challenge and imperious demands in wound healing and skin regeneration. Hereby, we developed a multifunctional AMP/S1P@PLA/gelatin wound dressing fabricated by electrospinning poly (L-lactic acid) (PLA)/gelatin with antimicrobial polypeptides (AMPs) and sphingosine-1-phosphate (S1P) in order to inhibit the bacteria growth and induce angiogenesis. In our work, AMP/S1P@PLA/gelatin wound dressing was obtained by two-step method of electrospinning and dopamine adsorption. Our results showed that incorporating AMP into PLA/gelatin nanofibrous membranes significantly improved antibacterial properties against both Escherichia coli and Staphylococcus aureus. S1P releasing from AMP/S1P@PLA/gelatin nanofibrous membranes could significantly enhance tube formation. Simultaneously, we found that the AMP/S1P@PLA/gelatin nanofibrous membranes facilitated the adhesion, proliferation, and migration of human umbilical vein endothelial cells (HUVECs) and murine fibroblast (L929). AMP/S1P@PLA/gelatin membranes could also accelerate infected wound healing and skin regeneration by antibacterial and pro-angiogenesis effects. In summary, our developed AMP/S1P@PLA/gelatin nanofibrous membranes could be multifunctional dressing for infected wound healing and skin regeneration. Schematic figure to describe the characterizations and preparation of AMP/S1P@PLA/gelatin nanofibrous membranes.

Impaired regulation of MMP2/16-MLCK3 by miR-146a-5p increased susceptibility to myocardial ischaemic injury in aging mice.

AIMS: Aging impairs cardiac function and increases susceptibility to myocardial ischaemic injury. Cardiac myosin light chain kinase (MLCK3) phosphorylates cardiac myosin regulatory light chain (MLC2), controlling sarcomere organization and cardiomyocyte contraction. Dysregulation of MLCK3 and phosphorylated MLC2 (p-MLC2) contributes to heart failure after myocardial infarction (MI). We aimed at exploring how the MLCK3-p-MLC2 axis changes in aging hearts post MI and at investigating the underlying regulatory mechanisms. METHODS AND RESULTS: We generated adult (3 months) and aged (30 months) MI mouse models to compare their cardiac performance, and then detected MLCK3 expression and MLC2 activity. Aging increased the size of MI-induced infarctions and promoted cardiac contractile dysfunction. Furthermore, MLCK3 expression and MLC2 activity increased in adult hearts after MI, but not in aged hearts. miR-146a was found consistently increased in adult and aged hearts post MI. Mechanistic analyses performed in vitro demonstrated that miR-146a-5p down-regulated matrix metalloprotease (MMP)2/16 expression in cardiomyocytes. This down-regulation in turn increased MLCK3 expression and MLC2 activity. However, miR-146a-5p failed to regulate the MMP2/16-MLCK3-p-MLC2 axis in senescent cardiomyocytes or in cardiac miR-146a conditional knockout mice, with the latter experiencing an exacerbated deterioration of cardiac function post MI. CONCLUSION: These results suggest that an increase of MLCK3 and p-MLC2 contents through decreasing MMP2/16 by miR-146a-5p represents a compensatory mechanism that can protect cardiac contractile function after MI. Aging impairs this miR-146a-5p-regulated MMP2/16-MLCK3-p-MLC2 contractile axis, leading to compromised contractile function and increased susceptibility to heart failure.

Two-Dimensional Mg2 Si Nanosheet-Enabled Sustained Hydrogen Generation for Improved Repair and Regeneration of Deeply Burned Skin.

Molecular hydrogen holds a high potential for wound healing owing to its anti-inflammatory effect and high biosafety, but commonly used hydrogen administration routes hardly achieve the sustained supply of high-dosage hydrogen, limiting hydrogen therapy efficacy. Here, two-dimensional Mg2 Si nanosheet (MSN) is exploited as a super-persistent hydrogen-releasing nanomaterial with high biocompatibility, and the incorporation of MSN into the chitosan/hyaluronic acid hydrogel (MSN@CS/HA) is developed as a dressing to repair deeply burned skin. The MSN@CS/HA hydrogel dressing can continuously generate hydrogen molecules for about 1 week in the physiological conditions in support of local, long-term, and plentiful hydrogen supply and remarkably promotes the healing and regeneration of deep second-degree and third-degree burn wounds without visible scar and toxic side effect. Mechanistically, a sustained supply of hydrogen molecules induces anti-inflammatory M2 macrophage polarization in time by enhancing CCL2 (chemokine C-C motif ligand 2) expression to promote angiogenesis and reduce fibrosis and also enhances the proliferation and migration capability of skin cells directly and indirectly by locally scavenging overexpressed reactive oxygen species, synergistically favoring wound repair. The proposed synthesis method, therapeutic strategy, and mechanisms will open a window for synthesizing a variety of MSene nanomaterials and developing their various proangiogenesis applications besides wound healing.

Photocatalytic glucose depletion and hydrogen generation for diabetic wound healing.

High-glucose microenvironment in the diabetic foot ulcer (DFU) causes excessive glycation and induces chronic inflammation, leading to the difficulty of DFU healing. Hydrogen-rich water bath can promote the healing of DFU in clinic by virtue of the anti-inflammatory effect of hydrogen molecules, but the long-term daily soaking counts against the formation of a scab and cannot change the high-glucose microenvironment, limiting the outcome of DFU therapy. In this work, photocatalytic therapy of diabetic wound is proposed for sustainable hydrogen generation and local glucose depletion by utilizing glucose in the high-glucose microenvironment as a sacrificial agent. Hydrogen-incorporated titanium oxide nanorods are developed to realize efficient visible light (VIS)-responsive photocatalysis for glucose depletion and hydrogen generation, achieving a high efficacy of diabetic wound healing. Mechanistically, local glucose depletion and hydrogen generation jointly attenuate the apoptosis of skin cells and promote their proliferation and migration by inhibiting the synthesis of advanced glycation end products and the expression of their receptors, respectively. The proposed VIS-photocatalytic strategy provides a solution for facile, safe and efficient treatment of DFU.

Clinical Comparative Study of Intravitreal Injection of Triamcinolone Acetonide and Aflibercept in the Treatment of Diabetic Retinopathy Cystoid Macular Edema.

Objective To compare the curative effect of intravitreal injection of triamcinolone acetonide and aflibercept on diabetic retinopathy (DR) cystoid macular edema. Methods A total of 102 patients with DR cystoid macular edema admitted to the hospital were enrolled between July 2018 and July 2021. According to random number table method, they were divided into the control group (intravitreal injection of triamcinolone acetonide) and the observation group (intravitreal injection of aflibercept), 51 cases in each group. All were followed up for half a year. The clinical curative effect, visual acuity, central subfield macular thickness (CSMT), macular volume, scores of quality of life, and levels of cytokines in aqueous humor (vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1), human angiopoietin-like protein 4 (ANGPTL4)] at different time points (before and at 6 months after surgery) were compared between the two groups. The times of drugs injection and occurrence of adverse reactions in both groups were statistically analyzed. Results The total effective rate in observation group was higher than that in the control group (96.08% vs 82.35%) (P < 0.05). After 6 months of treatment, visual acuity was improved, and CSMT and macular volume were decreased in both groups. Also, the above changes were more significant in the observation group than those in the control group (P < 0.05). After 6 months of treatment, levels of cytokines in aqueous humor were decreased in both groups. The levels of VEGF, MCP-1, and ANGPTL4 in observation group were lower than those in the control group (P < 0.05). After 6 months of treatment, quality of life scores in observation group were higher than those in the control group (P < 0.05). In the follow-up period, average times of drugs injection in the observation group were more than those in the control group, and the incidence of adverse reactions was lower than that in control group (5.88% vs 21.57%) (P < 0.05). Conclusion The curative effect of intravitreal injection of both triamcinolone acetonide and aflibercept is good on DR cystoid macular edema. The curative effect of aflibercept is better, which can improve visual acuity and quality of life, and regulate cytokines in aqueous humor, with high safety. However, aflibercept has a high price, and further research is needed to determine whether its price can be matched with clinical benefits. In clinic, medication plan should be selected according to the actual situation.

The promising role and prognostic value of miR-198 in human diseases.

The importance of microRNAs (miRNAs or miRs) has attracted more and more attention. MiRNA is an approximately 22-nucleotide, single-stranded, non-coding RNA molecule that affects the expression of downstream target genes. MiRNAs regulate the occurrence and development of human diseases. The objective of this article is to explore the abnormal expression of miR-198 in a variety of human diseases. The relationships between abnormally expressed miR-198 and clinicopathological characteristics are also summarized. Its roles in various diseases and potential molecular mechanisms include involvement in many biological processes, such as cell cycle regulation, proliferation, invasion, migration, apoptosis, and drug resistance. The potential value of miR-198 for disease diagnosis, treatment, and especially, prognosis, are discussed. More in-depth research on miRNA will support the conversion from basic research to clinical applications of this molecule.

A nanoconcrete welding strategy for constructing high-performance wound dressing.

Engineering biomaterials to meet specific biomedical applications raises high requirements of mechanical performances, and simultaneous strengthening and toughening of polymer are frequently necessary but very challenging in many cases. In this work, we propose a new concept of nanoconcrete welding polymer chains, where mesoporous CaCO3 (mCaCO3) nanoconcretes which are composed of amorphous and nanocrystalline phases are developed to powerfully weld polymer chains through siphoning-induced occlusion, hydration-driven crystallization and dehydration-driven compression of nanoconcretes. The mCaCO3 nanoconcrete welding technology is verified to be able to remarkably augment strength, toughness and anti-fatigue performances of a model polymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-based porous membrane. Mechanistically, we have revealed polymer-occluded nanocrystal structure and welding-derived microstress which is much stronger than interfacial Van der Waals force, thus efficiently preventing the generation of microcracks and repairing initial microcracks by microcracks-induced hydration, crystallization and polymer welding of mCaCO3 nanoconcretes. Constructed porous membrane is used as wound dressing, exhibiting a special nanoplates-constructed surface topography as well as a porous structure with plentiful oriented, aligned and opened pore channels, improved hydrophilicity, water vapor permeability, anti-bacterial and cell adherence, in support of wound healing and skin structural/functional repairing. The proposed nanoconcrete-welding-polymer strategy breaks a new pathway for improving the mechanical performances of polymers.

Novel nanofibrous membrane-supporting stem cell sheets for plasmid delivery and cell activation to accelerate wound healing.

The integration of biomaterials with cells for high overall performances is vitally important in tissue engineering, as scaffold-free cell sheet lacks enough mechanical performance and cell viability while cell-free scaffold possesses limited biological functions. In this study, we propose a new strategy to strengthen cell sheets and enhance cell activity for accelerating wound healing based on a novel sandwich structure of cell sheet-plasmid@membrane-cell sheet (CpMC). Specifically, the CpMC contains two adipose-derived stem cell (ADSC) sheets on outer surfaces and an electrospun gelatin/chitosan nanofibrous membrane (NFM) encapsulating vascular endothelial growth factor (VEGF) plasmids in between. The physicochemical properties of NFM including swelling, stiffness, strength, elasticity, and biodegradation can be tailored by simply adjusting the ratio between gelatin and chitosan to be 7:3 which is optimal for most effectively supporting ADSCs adhesion and proliferation. The swelling/biodegradation of NFM mediates the sustained release of encapsulated VEGF plasmids into adjacent ADSCs, and NFM assists VEGF plasmids to promote the differentiation of ADSCs into endothelial, epidermal, and fibroblast cells, in support of the neoangiogenesis and regeneration of cutaneous tissues within 2 weeks. The proposed membrane-supporting cell sheet strategy provides a new route to tissue engineering, and the developed CpMC demonstrates a high potential for clinical translation.

An Activity-Based Ratiometric Fluorescent Probe for In†Vivo Real-Time Imaging of Hydrogen Molecules.

To reveal the biomedical effects and mechanisms of hydrogen molecules urgently needs hydrogen molecular imaging probes as an imperative tool, but the development of these probes is extremely challenging. A catalytic hydrogenation strategy is proposed to design and synthesize a ratiometric fluorescent probe by encapsulating Pd nanoparticles and conjugating azido-/coumarin-modified fluorophore into mesoporous silica nanoparticles, realizing in vitro and in vivo fluorescence imaging of hydrogen molecules. The developed hydrogen probe exhibits high sensitivity, rapid responsivity, high selectivity and low detection limit, enabling rapid and real-time detection of hydrogen molecules both in cells and in the body of animal and plant. By application of the developed fluorescent probe, we have directly observed the super-high transmembrane and ultrafast transport abilities of hydrogen molecules in cells, animals and plants, and discovered in vivo high diffusion of hydrogen molecules.

Euglena gracilis and Its Aqueous Extract Constructed With Chitosan-Hyaluronic Acid Hydrogel Facilitate Cutaneous Wound Healing in Mice Without Inducing Excessive Inflammatory Response.

Naturally occurring compounds isolated from the microalga Euglena gracilis, such as polysaccharide paramylon, exhibit antimicrobial, anti-viral, antitumor, and anti-inflammatory activities. Whether live E. gracilis cells and its aqueous extract accelerate burn wound healing remains to be investigated. In this study, live E. gracilis cells and its aqueous extract were mixed with chitosan-hyaluronic acid hydrogel (CS/HA) to form cell + CS/HA and extract + CS/HA, which were then smeared onto the deeply burned skin of mice. The efficacy of these mixtures in accelerating wound healing was assessed through wound size reduction measurement, histological and immunofluorescence analyses, and serum pro-inflammatory cytokine level (INF-γ, IL-1ß, and IL-6) determination. The live E. gracilis cells and its aqueous extract were found to facilitate wound healing by enhancing re-epithelization and reducing fibroplasia without stimulating excessive inflammatory response. In conclusion, live E. gracilis cells and its aqueous extract can be potentially used to treat cutaneous wounds.

LncRNA LINC00673 is Downregulated in Diabetic Retinopathy and Regulates the Apoptosis of Retinal Pigment Epithelial Cells via Negatively Regulating p53.

BACKGROUND: Long noncoding RNA (LncRNA) LINC00673 has been proven to play critical roles in cancer biology, while its role in other diseases is unknown. It has been reported that LINC00673 could interact with p53, a critical player in diabetes and diabetic complications, suggesting that LINC00673 may also participate in diabetic retinopathy (DR). This study aimed to investigate the role of LINC00673 in DR. METHODS: The present study included 3 groups of participants, including DR group, diabetes (DB) group, and healthy control (Control) group. Flow cytometry was utilized to determine cell apoptosis. Proteins and messenger RNAs (mRNAs) were estimated by Western blot and quantitative reverse transcription PCR (qRT-PCR), respectively. RESULTS: LINC00673 was downregulated in plasma samples of DR patients (n=60) in comparison with the healthy controls (n=60) and negatively correlated with p53 only across DR patients but not across the healthy controls. In retinal pigment epithelial cells (RPECs), high glucose treatment downregulated LINC00673. Moreover, LINC00673 overexpression downregulated p53 and decreased RPEC apoptosis, while LINC00673 silencing upregulated p53 and increased RPEC apoptosis. In addition, p53 overexpression reduced the effects of LINC00673 overexpression. CONCLUSION: LINC00673 is downregulated in DR patients and regulates RPEC apoptosis via negatively regulating p53.

Simultaneous promotion of photosynthesis and astaxanthin accumulation during two stages of Haematococcus pluvialis with ammonium ferric citrate.

To simultaneously promote biomass yield and astaxanthin content of Haematococcus pluvialis, ammonium ferric citrate (AFC) was employed to stimulate light harvest in photosynthesis during the green stage and oxidation induction in astaxanthin accumulation during the red stage. AFC not only improved chlorophyll synthesis by 22.5% to provide more electrochemical potential energy in the green stage, but also alleviated photosystem II damage to maintain a high level of effective quantum yield by enhancing carotenoid production. The citrate derived from AFC stimulated acetyl-CoA and NADPH production through citric acid cycle and transaminase cycle during the red stage, resulting in an increased lipid content by 1.77-fold. The astaxanthin content in H. pluvialis cells cultivated with 5 µM AFC was 12.5% higher than that without AFC, which was attributed to severe oxidative stress caused by AFC through Haber-Weiss reaction. These results provided a new approach to reduce emission of greenhouse gasses with producing high-value products.

In-situ crosslinked hydrogel based on amidated pectin/oxidized chitosan as potential wound dressing for skin repairing.

Hydrogel can provide a favorable moisture environment for skin wound healing. In this study, a novel in-situ crosslinked injectable hydrogel was prepared using the water-soluble amidated pectin (AP) and oxidized chitosan (OC) through Schiff-base reaction without any chemical crosslinker. The influence of AP content on the properties of the hydrogel was systemically investigated. It showed that gelation time, pore structure, swelling capability and degradability of the hydrogel can be tuned by varying the content of amine and aldehyde groups from AP and OC. All the porous hydrogels with various AP contents (65%, 70%, and 80%) presented desirable gelation time, swelling property, high hemocompatibility and biocompatibility. Particularly, AP-OC-65 hydrogel presented superior swelling capability and better hemo- and bio-compatibility, owing to more residual amine sites in the hydrogel. Therefore, the injectable AP-OC-65 hydrogel has a greater potential for application to wound dressing or skin substitute.

The complete chloroplast genome sequence of the medicinal plant Sophora tonkinensis.

Sophora tonkinensis belongs to genus Sophora of the Fabaceae family. It is mainly distributed in the ridge and peak regions of limestone areas in western China and has high medicinal value and important ecological functions. Wild populations of S. tonkinensis are in danger and need urgent conservation. Furthermore, wild S. tonkinensis resources are very limited relative to the needs of the market, and many adulterants are present on the market. Therefore, a method for authenticating S. tonkinensis and its adulterants at the molecular level is needed. Chloroplast genomes are valuable sources of genetic markers for phylogenetic analyses, genetic diversity evaluation, and plant molecular identification. In this study, we report the complete chloroplast genome of S. tonkinensis. The circular complete chloroplast genome was 154,644 bp in length, containing an 85,810 bp long single-copy (LSC) region, an 18,321 bp short single-copy (SSC) region and two inverted repeat (IR) regions of 50,513 bp. The S. tonkinensis chloroplast genome comprised 129 genes, including 83 protein-coding genes, 38 transfer RNA (tRNA) genes, and 8 ribosomal RNA (rRNA) genes. The structure, gene order and guanine and cytosine (GC) content of the S. tonkinensis chloroplast genome were similar to those of the Sophora alopecuroides and Sophora flavescens chloroplast genomes. A total of 1,760 simple sequence repeats (SSRs) were identified in the chloroplast genome of S. tonkinensis, and most of them (93.1%) were mononucleotides. Moreover, the identified SSRs were mainly distributed in the LSC region, accounting for 60% of the total number of SSRs, while 316 (18%) and 383 (22%) were located in the SSC and IR regions, respectively. Only one complete copy of the rpl2 gene was present at the LSC/IRB boundary, while another copy was absent from the IRA region because of the incomplete structure caused by IR region expansion and contraction. The phylogenetic analysis placed S. tonkinensis in Papilionoideae, sister to S. flavescens, and the genera Sophora and Ammopiptanthus were closely related. The complete genome sequencing and chloroplast genome comparative analysis of S. tonkinensis and its closely related species presented in this paper will help formulate effective conservation and management strategies as well as molecular identification approaches for this important medicinal plant.