AdNAC20 Regulates Lignin and Coumarin Biosynthesis in the Roots of Angelica dahurica var. Formosana.

Angelica dahurica var. formosana (ADF), which belongs to the Umbelliferae family, is one of the original plants of herbal raw material Angelicae Dahuricae Radix. ADF roots represent an enormous biomass resource convertible for disease treatment and bioproducts. But, early bolting of ADF resulted in lignification and a decrease in the coumarin content in the root, and roots lignification restricts its coumarin for commercial utility. Although there have been attempts to regulate the synthesis ratio of lignin and coumarin through biotechnology to increase the coumarin content in ADF and further enhance its commercial value, optimizing the biosynthesis of lignin and coumarin remains challenging. Based on gene expression analysis and phylogenetic tree profiling, AdNAC20 as the target for genetic engineering of lignin and coumarin biosynthesis in ADF was selected in this study. Early-bolting ADF had significantly greater degrees of root lignification and lower coumarin contents than that of the normal plants. In this study, overexpression of AdNAC20 gene plants were created using transgenic technology, while independent homozygous transgenic lines with precise site mutation of AdNAC20 were created using CRISPR/Cas9 technology. The overexpressing transgenic ADF plants showed a 9.28% decrease in total coumarin content and a significant 12.28% increase in lignin content, while knockout mutant plants showed a 16.3% increase in total coumarin content and a 33.48% decrease in lignin content. Furthermore, 29,671 differentially expressed genes (DEGs) were obtained by comparative transcriptomics of OE-NAC20, KO-NAC20, and WT of ADF. A schematic diagram of the gene network interacting with AdNAC20 during the early-bolting process of ADF was constructed by DEG analysis. AdNAC20 was predicted to directly regulate the transcription of several genes with SNBE-like motifs in their promoter, such as MYB46, C3H, and CCoAOMT. In this study, AdNAC20 was shown to play a dual pathway function that positively enhanced lignin formation but negatively controlled coumarin formation. And the heterologous expression of the AdNAC20 gene at Arabidopsis thaliana proved that the AdNAC20 gene also plays an important role in the process of bolting and flowering.

Nanoparticle-Polymer Synergies in Nanocomposite Hydrogels: From Design to Application.

Hydrogels are an important class of soft materials with high water retention that exhibit intelligent and elastic properties and have promising applications in the fields of biomaterials, soft machines, and artificial tissue. However, the low mechanical strength and limited functions of traditional chemically cross-linked hydrogels restrict their further applications. Natural materials that consist of stiff and soft components exhibit high mechanical strength and functionality. Among artificial soft materials, nanocomposite hydrogels are analogous to these natural materials because of the synergistic effects of nanoparticle (NP) polymers in hydrogels construction. In this article, the structural design and properties of nanocomposite hydrogels are summarized. Furthermore, along with the development of nanocomposite hydrogel-based devices, the shaping and potential applications of hydrogel devices in recent years are highlighted. The influence of the interactions between NPs and polymers on the dispersion as well as the structural stability of nanocomposite hydrogels is discussed, and the novel stimuli-responsive properties induced by the synergies between functional NPs and polymeric networks are reviewed. Finally, recent progress in the preparation and applications of nanocomposite hydrogels is highlighted. Interest in this field is growing, and the future and prospects of nanocomposite hydrogels are also reviewed.

[Endovascular exclusion of peripheral aneurysms with polytetrafluoroethene stent graft].

OBJECTIVE: To evaluate the value and clinical effect of peripheral aneurysms with polytetrafluoroethene (PTFE) stent graft after peripheral endovascular procedures. METHODS: From May 2012 to November 2013, 13 patients of peripheral aneurysms were treated with PTFE stent graft. There were 9 male and 4 female patients, aged from 24 to 74 years with a mean of 52 years. There were 7 aneurysms and 6 pseudoaneurysms. This stent graft was a self-expanding nitinol stent, internally covered by an ultra-thin polytetrafluoroethene (PTFE) graft. All peripheral aneurysms were repaired with the PTFE stent graft, using an entirely percutaneous approach. All patients were given clopidogrel and (or) aspirin postoperatively. Complications and reintervention rates were also examined. RESULTS: PTFE stent graft placement was successfully performed in all the 13 cases, and the instant isolation effect was quite satisfactory. During the follow-up period of 3 to 18 months, no stent graft related complications occurred in all patients except one patient with iliac arterial pseudoaneurysm, who developed pseudoaneurysms presented as a complication at puncture site. There were no other symptomatic complications with graft patience. CONCLUSION: Endovascular repair can be considered as an effective treatment strategy for peripheral aneurysms by PTFE stent graft.

Multifunctional Porous Bilayer Artificial Skin for Enhanced Wound Healing.

Meeting the exacting demands of wound healing encompasses rapid coagulation, superior exudate absorption, high antibacterial efficacy, and imperative support for cell growth. In this study, by emulating the intricate structure of natural skin, we prepare a multifunctional porous bilayer artificial skin to address these critical requirements. The bottom layer, mimicking the dermis, is crafted through freeze-drying a gel network comprising carboxymethyl chitosan (CMCs) and gelatin (GL), while the top layer, emulating the epidermis, is prepared via electrospinning poly(l-lactic acid) (PLLA) nanofibers. With protocatechuic aldehyde and gallium ion complexation (PA@Ga) as cross-linking agents, the bottom PA@Ga-CMCs/GL layer featured an adjustable pore size (78-138 µm), high hemostatic performance (67s), and excellent bacterial inhibition rate (99.9%), complemented by an impressive liquid-absorbing capacity (2000% swelling rate). The top PLLA layer, with dense micronanostructure and hydrophobic properties, worked as a shield to effectively thwarted liquid or bacterial penetration. Furthermore, accelerated wound closure, reduced inflammatory responses, and enhanced formation of hair follicles and blood vessels are achieved by the porous artificial skin covered on the surface of wound. Bilayer artificial skin integrates the advantages of nanofibers and freeze-drying porous materials to effectively replicate the protective properties of the epidermal layer of the skin, as well as the cell migration and tissue regeneration of the dermis. This bioabsorbable artificial skin demonstrates structural and functional comparability to real skin, which would advance the field of wound care through its multifaceted capabilities.

High-strength fibrous sensors with an enhanced aggregate state for biomechanical monitoring of the Achilles tendon.

Continuous monitoring of biomechanical signals generated from the injured Achilles tendon is essential for the deep understanding of the recovery or rehabilitation process, thus decreasing the risk of secondary injuries. With tissue-like components and adjustable properties, hydrogel-based biomechanical sensors are considered promising materials for human motion detection. However, existing hydrogels are characterized by inferior mechanical properties with strength and modulus typically lower than 1 MPa, as well as poor stability under physiological conditions, which hampers their applications in implantable devices. Moreover, acquiring the stress signal from collected electrical signals remains challenging. Herein, based on the regulation of polymer aggregation, a high-strength fibrous sensor composed of polyvinyl alcohol (PVA) and reduced graphene oxide (rGO) for in vivo monitoring is prepared through a two-step procedure, including freeze-thaw and freeze-soak. Benefiting from the synergy of crystallization, Hofmeister effect and nanocomposite, the hydrogel fibers feature high tensile strength (8.34 ± 0.66 MPa) and elastic modulus (1.15 ± 0.10 MPa). Meanwhile, the removal of salt ions during fabrication improves the water content (69.18 ± 1.47%) and anti-swelling performance of such fibers and minimizes side effects after implantation. It is demonstrated that the fibrous sensor could record the relative resistance changes upon stretching with ideal sensitivity (GF = 1.57) and convert them into bearing stress through formula derivation and calculations. In vitro and in vivo assays further confirm its feasibility for real-time monitoring of joint motion, providing important references for medical diagnosis and treatment.

[Drought resistance of Angelica dahurica during seedling stage under polyethylene glycol (PEG-6000)-simulated drought stress].

OBJECTIVE: To study the optimum conditions of simulated drought stress, and screen the indexes of drought resistance and comprehensively assess the drought resistance of the Angelica dahurica resources during seedling stage. METHOD: Investigations were carried out on the changes of height, root length, root-shoot ration, contents of soluble sugar, proline and malondialdehyde under polyethylene glycol (PEG-6000)-simulated drought stress. A comprehensive evaluation on the drought resistance of different (varietal) species of A. dahurica during seedling stage was applied by using the method of subordinate function. And the drought resistance indexes were selected out by applying the method of grey correlative degree analysis. RESULT: Drought stress of 9 days with 20% PEG was the optimum condition for the simulation of drought stress. The results showed that the drought resistant capability decreased in the order as follows, A. dahurica from Sichuan province, A. dahurica from Henan province, A. dahurica from Hebei province and A. dahurica from Zhejiang province. And the order of correlative degree of drought resistance and indexes was: soluble sugar > root length > proline > root-shoot ration > total content of chlorophyll > chlorophyll b > chlorophyll a > height > malondialdehyde. CONCLUSION: Osmotic adjustment substance and the indexes related to the root have more influence on the drought resistance of A. dahurica during seedling stage. A. dahurica from Sichuan province shows the highest drought resistance during seedling stage.

Transgenic PDGF-BB/sericin hydrogel supports for cell proliferation and osteogenic differentiation.

Sericin has been exploited as a biomaterial due to its biocompatibility, biodegradability, and low-immunogenicity as an isolated polymer and support for cell adhesion. In the present study, human platelet-derived growth factor (PDGF-BB)-functionalized sericin hydrogels were generated using transgenic silkworms, where the as-spun silk incorporated engineered PDGF-BB (termed PDGFM) in the sericin layers of the cocoons. Sericin and PDGFM were simultaneously extracted from the silk fibroin cocoon fibers, and the soluble extract was then formed into a hydrogel via thermal exposure. The PDGFM sericin hydrogels exhibited increased ß-sheet content and a compressive modulus of 74.91 ± 2.9 kPa comparable to chemically crosslinked sericin hydrogels (1.68-55.53 kPa) and a porous microstructure, which contributed to cell adhesion and growth. A 13.1% of total extracted PDGFM from the initial silk fibers was incorporated and immobilized in the sericin hydrogels during material processing, and 1.33% of PDGFM was released over 30 days from the hydrogels in vitro. The remaining PDGFM achieved long-term storage/stability in the sericin hydrogels for more than 42 days at 37 °C. In addition, the PDGFM sericin hydrogels were not immunogenic, were biocompatible and bioactive in promoting the support of cell proliferation. When combined with BMP-9, the PDGFM sericin hydrogels provided synergy to support the osteoblastic differentiation of mesenchymal stem cells (hMSCs) in vitro and in vivo. This study demonstrates that genetically functionalized PDGFM sericin hydrogels can provide useful biomaterials to support cell and tissue outcomes, here with a focus on osteogenesis.

Genetically engineered bi-functional silk material with improved cell proliferation and anti-inflammatory activity for medical application.

Functional silk is a promising material for future medical applications. These include fabrication of diverse silk fiber and silk protein-regenerated biomaterials such as silk sutures, hydrogel, films, and 3D scaffolds for wound healing and tissue regeneration and reconstruction. Here, a novel bi-functional silk with improved cell proliferation and anti-inflammatory activities was created by co-expressing the human basic fibroblast growth factor (FGF2) and transforming growth factor-ß1 (TGF_ß1) genes in silkworm. First, both FGF2 and TGF_ß1 genes were confirmed to be successfully expressed in silk thread. The characterization of silk properties by SEM, FTIR, and mechanical tests showed that this new silk (FT silk) had a similar diameter, inner molecular composition, and mechanical properties as those of normal silk. Additionally, expressed FGF2 and TGF_ß1 proteins were continuously and slowly released from FT silk for one week. Most importantly, the FGF2 and TGF_ß1 contained in FT silk not only promoted cell proliferation by activating the ERK pathway but also significantly reduced LPS-induced inflammation responses in macrophages by mediating the Smad pathway. Moreover, this FT silk had no apparent toxicity for cell growth and caused no cell inflammation. These properties suggest that it has a potential for medical applications. STATEMENT OF SIGNIFICANCE: Silk spun by domestic silkworm is a promising material for fabricating various silk protein regenerated biomaterials in medical area, since it owes good biocompatibility, biodegradability and low immunogenicity. Recently, fabricating various functional silk fibers and regenerated silk protein biomaterials which has ability of releasing functional protein factor is the hot point field. This study is a first time to create a novel bi-functional silk material with the improved cell proliferation and anti-inflammatory activity by genetic engineered technology. This novel silk has a great application potential as new and novel medical material, and this study also provides a new strategy to create various functional or multifunctional silk fiber materials in future.