Research on Field Source Characteristics of Leakage Current of Arrester Based on TMR Sensor.

The status of zinc oxide (ZnO) arresters is directly related to the safety of power grids. However, as the service life of ZnO arresters increases, their insulation performance may decrease due to factors such as operating voltage and humidity, which can be identified through the measurement of leakage current. Tunnel magnetoresistance (TMR) sensors with high sensitivity, good temperature stability, and small size are excellent for measuring leakage current. This paper constructs a simulation model of the arrester and investigates the deployment of the TMR current sensor and the size of the magnetic concentrating ring. The arrester's leakage current magnetic field distribution under different operating conditions is simulated. The simulation model can aid in optimizing the detection of leakage current in arresters using TMR current sensors, and the findings serve as a basis for monitoring the condition of arresters and improving the installation of current sensors. The TMR current sensor design offers potential advantages such as high accuracy, miniaturization, and ease of distributed application measurement, making it suitable for large-scale use. Finally, the validity of the simulations and conclusions is verified through experiments.

The effects of maturation and aging on the rotator cuff tendon-to-bone interface.

Rotator cuff tendon injuries often occur at the tendon-to-bone interface (i.e., enthesis) area, with a high prevalence for the elderly population, but the underlying reason for this phenomenon is still unknown. The objective of this study is to identify the histological, molecular, and biomechanical alterations of the rotator cuff enthesis with maturation and aging in a mouse model. Four different age groups of mice (newborn, young, adult, and old) were studied. Striking variations of the entheses were observed between the newborn and other matured groups, with collagen content, proteoglycan deposition, collagen fiber dispersion was significantly higher in the newborn group. The compositional and histological features of young, adult, and old groups did not show significant differences, except having increased proteoglycan deposition and thinner collagen fibers at the insertion sites in the old group. Nanoindentation testing showed that the old group had a smaller compressive modulus at the insertion site when compared with other groups. However, tensile mechanical testing reported that the old group demonstrated a significantly higher failure stress when compared with the young and adult groups. The proteomics analysis detected dramatic differences in protein content between newborn and young groups but minor changes among young, adult, and old groups. These results demonstrated: (1) the significant alterations of the enthesis composition and structure occur from the newborn to the young time period; (2) the increased risk of rotator cuff tendon injuries in the elderly population is not solely because of old age alone in the rodent model.

Irigenin alleviates angiotensin II-induced oxidative stress and apoptosis in HUVEC cells by activating Nrf2 pathway.

Endothelial dysfunction is closely related to various cardiovascular diseases. Oxidative stress and apoptosis are involved in the progress of endothelial dysfunction. Irigenin (IR) has antioxidative properties. We investigated IR as a novel therapy for angiotensin II (Ang II)-induced endothelial dysfunction and explored the potential mechanisms of IR. After human umbilical vein endothelial cell lines (HUVECs) were treated with Ang II (100, 200, 300 and 400 nmol/L) alone, IR (2.5, 5, 10, 20 and 40 µmol/L) alone or Ang II plus IR for 24 h, HUVECs viability, lactate dehydrogenase (LDH), apoptosis, oxidative stress, apoptosis-related protein and nuclear factor E2-related factor 2 (Nrf2) levels were detected by Cell Counting Kit (CCK)-8 assay, enzyme-linked immunosorbent assay, flow cytometry and western blot. Transfection rate of Nrf2 was detected by western blot. In the next rescue experiment, we used silent Nrf2 (siNrf2) to verify the previous experimental results. Different concentrations' Ang II repressed HUVECs viability and increased LDH release, and different concentrations' IR did not affect HUVECs viability or LDH release. Furthermore, IR elevated cell viability and Nrf2 level, inhibited LDH release, apoptosis, oxidative stress and apoptosis-related protein levels in Ang II-induced HUVECs. More important, siNrf2 suppressed the expression of Nrf2, and siNrf2 abrogated the protective effect of IR on Ang II-induced Nrf2 expression, cell viability, LDH activity, oxidative stress generation and apoptosis-related protein in HUVECs. IR protected HUVECs from Ang II-induced oxidative stress and apoptosis injury by activating Nrf2 pathway.

lncRNA DLG1-AS1 Promotes Cell Proliferation by Competitively Binding with miR-107 and Up-Regulating ZHX1 Expression in Cervical Cancer.

BACKGROUND/AIMS: Recent studies have revealed that long non-coding RNAs (lncRNAs) are involved in the occurrence and development of various tumors, thereby attracting increasing attention from researchers. The important biological functions of lncRNAs have been recognized gradually, but their mechanism in cervical cancer remains unclear. METHODS: Differentially expressed lncRNAs in cervical cancer and para-carcinoma tissues were identified by screening using an lncRNA array, and candidate lncRNAs were verified by quantitative real-time PCR. A series of bioinformatics and molecular biological methods were adopted to investigate the interactions among lncRNAs, microRNAs (miRNAs), and miRNA target genes in cervical cancer. Cell viability was measured using a Cell Counting Kit-8 assay. RESULTS: DLG1-AS1 was the most significantly up-regulated lncRNA in cervical cancer tissues, and it was confirmed that cervical cancer patients with high DLG1-AS1 expression had a poor prognosis. Down-regulation of DLG1-AS1 expression suppressed the proliferation of cervical cancer cells. Further investigation revealed that DLG1-AS1 eliminated the inhibition of miR-107 on the expression of its target gene ZHX1 by competitively binding to miR-107. Moreover, rescue assays proved that the effect of DLG1-AS1 on the proliferation of cervical cancer cells was dependent on miR-107. CONCLUSION: DLG1-AS1/miR-107/ZHX1 can form a competitive endogenous RNA network that regulates the proliferation of cervical cancer cells, resulting in tumor progression.

Application of Empirical Mode Decomposition and Independent Component Analysis for the Interpretation of Rock-Mineral Spectrum.

Rock-mineral spectrum is a mixture of varied mineral spectra, through which we can obtain information about its components quickly and conveniently without any damage to the sample. Empirical mode decomposition (EMD) cannot directly decompose source signals from information of the mixture, and independent component analysis (ICA) requires the number of mixed signals to be no less than the number of source signals. Combining these two methods, mixed signals can be decomposed using EMD method to obtain intrinsic mode function (IMF), while certain IMFs together with mixed signals can be used as input data matrix of ICA to obtain the source signals. This method overcomes the shortcomings of IMF and ICA. Studies have shown that, the higher content of source signals contained in the mixed signal, the better estimation can be obtained through EMD and ICA. The number of IMFs that participate in ICA decomposition determines the number of approximation of source signals. The accuracy of source signal estimation increases with the correlation coefficient between IMF and mixed signals. By applying this method to quantitative analysis of rock-mineral spectrum, information of the component minerals in rock-mineral can be obtained, which improves the efficiency of component analysis in detecting rock-minerals outside.

Adipose-derived stem cell-based optimization strategies for musculoskeletal regeneration: recent advances and perspectives.

Musculoskeletal disorders are the leading causes of physical disabilities worldwide. The poor self-repair capacity of musculoskeletal tissues and the absence of effective therapies have driven the development of novel bioengineering-based therapeutic approaches. Adipose-derived stem cell (ADSC)-based therapies are being explored as new regenerative strategies for the repair and regeneration of bone, cartilage, and tendon owing to the accessibility, multipotency, and active paracrine activity of ADSCs. In this review, recent advances in ADSCs and their optimization strategies, including ADSC-derived exosomes (ADSC-Exos), biomaterials, and genetic modifications, are summarized. Furthermore, the preclinical and clinical applications of ADSCs and ADSC-Exos, either alone or in combination with growth factors or biomaterials or in genetically modified forms, for bone, cartilage, and tendon regeneration are reviewed. ADSC-based optimization strategies hold promise for the management of multiple types of musculoskeletal injuries. The timely summary and highlights provided here could offer guidance for further investigations to accelerate the development and clinical application of ADSC-based therapies in musculoskeletal regeneration.

A Cross-Process Signal Integrity Analysis (CPSIA) Method and Design Optimization for Wafer-on-Wafer Stacked DRAM.

A multi-layer stacked Dynamic Random Access Memory (DRAM) platform is introduced to address the memory wall issue. This platform features high-density vertical interconnects established between DRAM units for high-capacity memory and logic units for computation, utilizing Wafer-on-Wafer (WoW) hybrid bonding and mini Through-Silicon Via (TSV) technologies. This 3DIC architecture includes commercial DRAM, logic, and 3DIC manufacturing processes. Their design documents typically come from different foundries, presenting challenges for signal integrity design and analysis. This paper establishes a lumped circuit based on 3DIC physical structure and calculates all values of the lumped elements in the circuit model with the transmission line model. A Cross-Process Signal Integrity Analysis (CPSIA) method is introduced, which integrates three different manufacturing processes by modeling vertical stacking cells and connecting DRAM and logic netlists in one simulation environment. In combination with the dedicated buffer driving method, the CPSIA method is used to analyze 3DIC impacts. Simulation results show that the timing uncertainty introduced by 3DIC crosstalk ranges from 31 ps to 62 ps. This analysis result explains the stable slight variation in the maximum frequency observed in vertically stacked memory arrays from different DRAM layers in the physical testing results, demonstrating the effectiveness of this CPSIA method.

Minor Spliceosomal 65K/RNPC3 Interacts with ANKRD11 and Mediates HDAC3-Regulated Histone Deacetylation and Transcription.

RNA splicing is crucial in the multilayer regulatory networks for gene expression, making functional interactions with DNA- and other RNA-processing machineries in the nucleus. However, these established couplings are all major spliceosome-related; whether the minor spliceosome is involved remains unclear. Here, through affinity purification using Drosophila lysates, an interaction is identified between the minor spliceosomal 65K/RNPC3 and ANKRD11, a cofactor of histone deacetylase 3 (HDAC3). Using a CRISPR/Cas9 system, Deletion strains are constructed and found that both Dm65KΔ/Δ and Dmankrd11Δ/Δ mutants have reduced histone deacetylation at Lys9 of histone H3 (H3K9) and Lys5 of histone H4 (H4K5) in their heads, exhibiting various neural-related defects. The 65K-ANKRD11 interaction is also conserved in human cells, and the HsANKRD11 middle-uncharacterized domain mediates Hs65K association with HDAC3. Cleavage under targets and tagmentation (CUT&Tag) assays revealed that HsANKRD11 is a bridging factor, which facilitates the synergistic common chromatin-binding of HDAC3 and Hs65K. Knockdown (KD) of HsANKRD11 simultaneously decreased their common binding, resulting in reduced deacetylation of nearby H3K9. Ultimately, this study demonstrates that expression changes of many genes caused by HsANKRD11-KD are due to the decreased common chromatin-binding of HDAC3 and Hs65K and subsequently reduced deacetylation of H3K9, illustrating a novel and conserved coupling mechanism that links the histone deacetylation with minor spliceosome for the regulation of gene expression.

circRNF13, a novel N6-methyladenosine-modified circular RNA, enhances radioresistance in cervical cancer by increasing CXCL1 mRNA stability.

BACKGROUND: Circular RNAs (circRNAs) and N6-methyladenosine (m6A) have been shown to play an increasingly critical role in the development of different cancers. However, there is limited evidence on how circRNAs and m6A interact to affect the radiosensitivity of cervical cancer (CC). This study provides a mechanistic understanding of the novel m6A-regulated circRNF13 in enhancing radioresistance in CC. METHODS: Differentially expressed circRNAs were identified from radiosensitive and radioresistant CC tissues. Meanwhile, these circRNAs were subjected to methylated RNA immunoprecipitation (Me-RIP). Finally, the effects of these circRNAs on radiosensitivity were characterized. RESULTS: CircRNF13 was poorly expressed in CC patients that were sensitive to concurrent radiochemotherapy. Experiments conducted both in vitro and in vivo confirmed that the knockdown of circRNF13 potentiated the radiosensitivity of CC cells. Further mechanistic studies revealed that METTL3/YTHDF2 promoted the degradation of circRNF13 and subsequently affected the stability of CXC motif chemokine ligand 1 (CXCL1), ultimately enhancing the radiosensitivity of CC cells. CONCLUSION: This study identified circRNF13 as a novel m6A-modified circRNA and validated the METTL3/YTHDF2/circRNF13/CXCL1 axis as a potential target for CC radiotherapy.

In situ delivery of a curcumin-loaded dynamic hydrogel for the treatment of chronic peripheral neuropathy.

Patients with peripheral nerve injuries would highly likely suffer from chronic neuropathic pain even after surgical intervention. The primary reasons for this involve sustained neuroinflammatory and dysfunctional changes in the nervous system after the nerve injury. We previously reported an injectable boronic ester-based hydrogel with inherent antioxidative and nerve protective properties. Herein, we first explored the anti-neuroinflammatory effects of Curcumin on primary sensory neurons and activated macrophages in vitro. Next, we incorporated thiolated Curcumin-Pluronic F-127 micelles (Cur-M) into our boronic ester-based hydrogel to develop an injectable hydrogel that serves as sustained curcumin release system (Gel-Cur-M). By orthotopically injecting the Gel-Cur-M to sciatic nerves of mice with chronic constriction injuries, we found that the bioactive components could remain on the nerves for at least 21 days. In addition, the Gel-Cur-M exhibited superior functions compared to Gel and Cur-M alone, which includes ameliorating hyperalgesia while simultaneously improving locomotor and muscular functions after the nerve injury. This could stem from in situ anti-inflammation, antioxidation, and nerve protection. Furthermore, the Gel-Cur-M also showed extended beneficial effects for preventing the overexpression of TRPV1 as well as microglial activation in the lumbar dorsal root ganglion and spinal cord, respectively, which also contributed to its analgesic effects. The underlying mechanism may involve the suppression of CC chemokine ligand-2 and colony-stimulating factor-1 in the injured sensory neurons. Overall, this study suggests that orthotopic injection of the Gel-Cur-M is a promising therapeutic strategy that especially benefits patients with peripheral neuropathy who require surgical interventions.

Controllable fabrication of alginate/poly-L-ornithine polyelectrolyte complex hydrogel networks as therapeutic drug and cell carriers.

Polyelectrolyte complex (PEC) hydrogels are advantageous as therapeutic agent and cell carriers. However, due to the weak nature of physical crosslinking, PEC swelling and cargo burst release are easily initiated. Also, most current cell-laden PEC hydrogels are limited to fibers and microcapsules with unfavorable dimensions and structures for practical implantations. To overcome these drawbacks, alginate (Alg)/poly-L-ornithine (PLO) PEC hydrogels are fabricated into microcapsules, fibers, and bulk scaffolds to explore their feasibility as drug and cell carriers. Stable Alg/PLO microcapsules with controllable shapes are obtained through aqueous electrospraying technique, which avoids osmotic shock and prolongs the release time. Model enzyme and nanosized cargos are successfully encapsulated and continuously released for more than 21 days. Alg/PLO PEC fibers are then prepared to encapsulate brown adipose progenitors (BAPs) and Jurkat T cells. The electrostatic interactions between Alg and PLO are found to facilitate the printability and self-support ability of Alg/PLO bioinks. Alg/PLO PEC fibers and scaffolds support cell proliferation, differentiation, and functionalization. These results demonstrate new options for biocompatible PEC hydrogel preparation and improve the understanding of PEC hydrogels as drug and cell carriers. STATEMENT OF SIGNIFICANCE: In this study, the concept of polyelectrolyte complex hydrogel networks as drug and cell carriers has been demonstrated. Their feasibility to achieve sustained drug release and cell functionality was explored, from microcapsules to fibers to three-dimension printed scaffolds. PEC microcapsules with controllable shapes were obtained. Therapeutic drugs can be encapsulated and continuously release for more than 21 days. Benefiting from the dynamic interactions of physically crosslinked PEC, self-healing fibers were achieved. Besides, the electrostatic interactions between polyelectrolytes were found to facilitate the printability and self-support ability of PEC bioinks. The PEC fibers and scaffolds with controllable structure supported cell proliferation, differentiation, and function. The outcome of current research promotes design of new biocompatible PEC hydrogels and potential drug and cell carriers.

Insight into the mechanism of myofibrillar protein gel influenced by konjac glucomannan: Moisture stability and phase separation behavior.

The effect and mechanism of myofibrillar protein (MP) gelation influenced by konjac glucomannan (KG) addition were studied. The KG addition significantly improved gel strength and water holding capability (WHC) of MP-KG composite gel, but it had additive limitation at 1.0%. The SEM showed that KG (<1.0%) reduced the appearance of moisture channels and promoted the formation of an integral MP gel network. Raman spectroscopy showed that KG addition (<1.0%) promoted the protein unfolding and the interaction of hydrophobic groups during thermal processing. However, the KG (>1.0%) would form continuous viscous hydrogel and interpenetrate with the MP solution, which hindered the interaction of hydrophobic groups during thermal process, and the MP formed a loose and degraded final structure. Hence, MP gels produced with the addition of KG underwent a transformation from a loose structure to a compact structure to an unaggregated structure, which was influenced by moisture stability and phase separation behavior.

Tannic acid-inspired, self-healing, and dual stimuli responsive dynamic hydrogel with potent antibacterial and anti-oxidative properties.

Due to their intrinsic injectable and self-healing characteristics, dynamic hydrogels, based on dynamic covalent bonds, have gained a great attention. In this study, a novel dynamic hydrogel based on the boronic ester dynamic covalent bond is facilely developed using phenylboronic acid-modified hyaluronic acid (HA-PBA) and plant-derived polyphenol-tannic acid (TA). The dynamic hydrogel gelated quickly under mild conditions and had favorable viscoelastic properties with good self-healing and shear-thinning capabilities. Moreover, the simultaneous utilization of TA as a reductant for the green synthesis of silver nanoparticles (AgNP) inspired the preparation of a TA-reduced AgNP hybrid dynamic hydrogel with potent and broad-spectrum antibacterial activities. The dynamic hydrogels could also be applied for pH- and reactive oxygen species (ROS)-responsive release of loaded protein molecules without showing evident cytotoxicity and hemolysis in vitro. In addition, the dynamic hydrogels showed the anti-oxidative properties of high free radical and ROS scavenging capacity, which was verified by the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical assay and ROS fluorescence staining. Overall, this novel class of cytocompatible, self-healing, dual stimuli responsive, antibacterial, anti-oxidative, and injectable hydrogels could be promising as a wound dressing for chronic wound healing.

Dynamic hyaluronic acid hydrogel with covalent linked gelatin as an anti-oxidative bioink for cartilage tissue engineering.

In the past decade, cartilage tissue engineering has arisen as a promising therapeutic option for degenerative joint diseases, such as osteoarthritis, in the hope of restoring the structure and physiological functions. Hydrogels are promising biomaterials for developing engineered scaffolds for cartilage regeneration. However, hydrogel-delivered mesenchymal stem cells or chondrocytes could be exposed to elevated levels of reactive oxygen species (ROS) in the inflammatory microenvironment after being implanted into injured joints, which may affect their phenotype and normal functions and thereby hinder the regeneration efficacy. To attenuate ROS induced side effects, a multifunctional hydrogel with an innate anti-oxidative ability was produced in this study. The hydrogel was rapidly formed through a dynamic covalent bond between phenylboronic acid grafted hyaluronic acid (HA-PBA) and poly(vinyl alcohol) and was further stabilized through a secondary crosslinking between the acrylate moiety on HA-PBA and the free thiol group from thiolated gelatin. The hydrogel is cyto-compatible and injectable and can be used as a bioink for 3D bioprinting. The viscoelastic properties of the hydrogels could be modulated through the hydrogel precursor concentration. The presence of dynamic covalent linkages contributed to its shear-thinning property and thus good printability of the hydrogel, resulting in the fabrication of a porous grid construct and a meniscus like scaffold at high structural fidelity. The bioprinted hydrogel promoted cell adhesion and chondrogenic differentiation of encapsulated rabbit adipose derived mesenchymal stem cells. Meanwhile, the hydrogel supported robust deposition of extracellular matrix components, including glycosaminoglycans and type II collagen, by embedded mouse chondrocytesin vitro. Most importantly, the hydrogel could protect encapsulated chondrocytes from ROS induced downregulation of cartilage-specific anabolic genes (ACAN and COL2) and upregulation of a catabolic gene (MMP13) after incubation with H2O2. Furthermore, intra-articular injection of the hydrogel in mice revealed adequate stability and good biocompatibilityin vivo. These results demonstrate that this hydrogel can be used as a novel bioink for the generation of 3D bioprinted constructs with anti-ROS ability to potentially enhance cartilage tissue regeneration in a chronic inflammatory and elevated ROS microenvironment.

The effects of three polysaccharides on the gelation properties of myofibrillar protein: Phase behaviour and moisture stability.

The effects of three polysaccharides on the textural properties and microstructure of myofibrillar protein (MP) gels were studied. The gel strength and rheological properties of composite MP gels were significantly improved with insoluble dietary fibre (DF) and modified starch (MS) addition, while konjac glucomannan (KG) had limited effects at 1% addition. The SEM images indicated that moisture extrusion formed moisture channels and deteriorated the aggregation of MP gel networks during the thermal process. The polysaccharides stabilized moisture and reduced the appearance of moisture channels in the gel network, thereby promoting the formation of compact and integral gel networks. The MP-polysaccharide mixture is a thermally incompatible system and presented two main forms after the thermal process: 1) the "trapped" structure and 2) the "interpenetrated" structure. In the "trapped" structure, the MP was the dominant structure of the composite gel network. In the "interpenetrated" structure, the continuous polysaccharide hydrogel substantially hindered the aggregation of MP gel networks. Principal component analysis showed that the phase behaviour and moisture stability of polysaccharides significantly influenced the textural quality and microstructure of composite MP gelation. The study indicated that polysaccharides that contribute to moisture stability and form a "trapped structure" (phase behaviour) are ideal fat replacements for improving composite gel properties, especially DF.

Insight into the mechanism of physicochemical influence by three polysaccharides on myofibrillar protein gelation.

In this study, the effect and mechanism of myofibrillar protein (MP) gelation influenced by the hydration characteristic of three polysaccharides were studied through puncture test, paraffin section, SEM and Raman spectroscopy. The gel strength and water holding capability reflect that MP gelation only significantly improves until modified starch (MS) addition beyond 1.0%. The MS granule improves MP gel property through simply physical swelling effect. At gelatinization temperature, MS absorbs the moisture nearby to compress the MP three-dimensional networks, but the swelling effect is limited. The insoluble dietary fiber (IDF) improves MP gelation property through moisture stability. The IDF addition could lessen the appearance of moisture channel in MP gel networks and promote the interaction of hydrophobic groups. The MP gelation with 2.0% IDF addition has the highest gel strength (279 g) and water holding capability (91.87%). The konjac glucomannan (KG) (>1.0%) could degrade gel property of MP gelation through interpenetrate structure, because the KG hydrogel hinders the aggregation of the MP gel networks. In conclusion, the IDF, which has strong water-holding capability at room temperature and distribute individually, is the best polysaccharides-based fat replacement in low-fat restructured products.

3D printing of multilayered scaffolds for rotator cuff tendon regeneration.

Repairing massive rotator cuff tendon defects remains a challenge due to the high retear rate after surgical intervention. 3D printing has emerged as a promising technique that enables the fabrication of engineered tissues with heterogeneous structures and mechanical properties, as well as controllable microenvironments for tendon regeneration. In this study, we developed a new strategy for rotator cuff tendon repair by combining a 3D printed scaffold of polylactic-co-glycolic acid (PLGA) with cell-laden collagen-fibrin hydrogels. We designed and fabricated two types of scaffolds: one featuring a separate layer-by-layer structure and another with a tri-layered structure as a whole. Uniaxial tensile tests showed that both types of scaffolds had improved mechanical properties compared to single-layered PLGA scaffolds. The printed scaffold with collagen-fibrin hydrogels effectively supported the growth, proliferation, and tenogenic differentiation of human adipose-derived mesenchymal stem cells. Subcutaneous implantation of the multilayered scaffolds demonstrated their excellent in vivo biocompatibility. This study demonstrates the feasibility of 3D printing multilayered scaffolds for application in rotator cuff tendon regeneration.

3D printed composite scaffolds with dual small molecule delivery for mandibular bone regeneration.

Functional reconstruction of craniomaxillofacial defects is challenging, especially for the patients who suffer from traumatic injury, cranioplasty, and oncologic surgery. Three-dimensional (3D) printing/bioprinting technologies provide a promising tool to fabricate bone tissue engineering constructs with complex architectures and bioactive components. In this study, we implemented multi-material 3D printing to fabricate 3D printed PCL/hydrogel composite scaffolds loaded with dual bioactive small molecules (i.e. resveratrol and strontium ranelate). The incorporated small molecules are expected to target several types of bone cells. We systematically studied the scaffold morphologies and small molecule release profiles. We then investigated the effects of the released small molecules from the drug loaded scaffolds on the behavior and differentiation of mesenchymal stem cells (MSCs), monocyte-derived osteoclasts, and endothelial cells. The 3D printed scaffolds, with and without small molecules, were further implanted into a rat model with a critical-sized mandibular bone defect. We found that the bone scaffolds containing the dual small molecules had combinational advantages in enhancing angiogenesis and inhibiting osteoclast activities, and they synergistically promoted MSC osteogenic differentiation. The dual drug loaded scaffolds also significantly promoted in vivo mandibular bone formation after 8 week implantation. This work presents a 3D printing strategy to fabricate engineered bone constructs, which can likely be used as off-the-shelf products to promote craniomaxillofacial regeneration.

Guiding Mesenchymal Stem Cells into Myelinating Schwann Cell-Like Phenotypes by Using Electrospun Core-Sheath Nanoyarns.

Nerve guidance conduit (NGC)-infilling substrates have been reported to facilitate the regeneration of injured peripheral nerves (PNs), especially for large nerve gaps. In this study, longitudinally oriented electrospun core-sheath nanoyarns (csNYs), consisting of a polylactic acid microfiber core and an electrospun nanofiber sheath, were fabricated for potential PN tissue engineering applications. Our novel csNY displayed a well-aligned nanofibrous surface topography, resembling the ultrastructure of axons and fascicles of a native PN system, and it also provided a mechanically stable structure. The biological results showed that the csNY significantly enhanced the attachment, growth, and proliferation of human adipose derived mesenchymal stem cells (hADMSC) and also promoted the migration, proliferation, and phenotype maintenance of rabbit Schwann cells (rSCs). Our csNY notably increased the differentiation capability of hADMSC into SC-like cells (hADMSC-SC), in comparison with a 2D tissue culture polystyrene plate. More importantly, when combined with the appropriate induction medium, our csNY promoted hADMSC-SC to express high levels of myelination-associated markers. Overall, this study demonstrates that our csNYs have great potential to serve as not only ideal in vitro culture models for understanding SC-axon interaction and SC myelination but also as promising NGC-infilling substrates for PN regeneration applications.

3D printing of silk fibroin-based hybrid scaffold treated with platelet rich plasma for bone tissue engineering.

3D printing/bioprinting are promising techniques to fabricate scaffolds with well controlled and patient-specific structures and architectures for bone tissue engineering. In this study, we developed a composite bioink consisting of silk fibroin (SF), gelatin (GEL), hyaluronic acid (HA), and tricalcium phosphate (TCP) and 3D bioprinted the silk fibroin-based hybrid scaffolds. The 3D bioprinted scaffolds with dual crosslinking were further treated with human platelet-rich plasma (PRP) to generate PRP coated scaffolds. Live/Dead and MTT assays demonstrated that PRP treatment could obviously promote the cell growth and proliferation of human adipose derived mesenchymal stem cells (HADMSC). In addition, the treatment of PRP did not significantly affect alkaline phosphatase (ALP) activity and expression, but significantly upregulated the gene expression levels of late osteogenic markers. This study demonstrated that the 3D printing of silk fibroin-based hybrid scaffolds, in combination with PRP post-treatment, might be a more efficient strategy to promote osteogenic differentiation of adult stem cells and has significant potential to be used for bone tissue engineering.