Hypoxia preconditioning of adipose stem cell-derived exosomes loaded in gelatin methacryloyl (GelMA) promote type H angiogenesis and osteoporotic fracture repair.

The challenges posed by delayed atrophic healing and nonunion stand as formidable obstacles in osteoporotic fracture treatment. The processes of type H angiogenesis and osteogenesis emerge as pivotal mechanisms during bone regeneration. Notably, the preconditioning of adipose-derived stem cell (ADSC) exosomes under hypoxic conditions has garnered attention for its potential to augment the secretion and functionality of these exosomes. In the present investigation, we embarked upon a comprehensive elucidation of the underlying mechanisms of hypo-ADSC-Exos within the milieu of osteoporotic bone regeneration. Our findings revealed that hypo-ADSC-Exos harboured a preeminent miRNA, namely, miR-21-5p, which emerged as the principal orchestrator of angiogenic effects. Through in vitro experiments, we demonstrated the capacity of hypo-ADSC-Exos to stimulate the proliferation, migration, and angiogenic potential of human umbilical vein endothelial cells (HUVECs) via the mediation of miR-21-5p. The inhibition of miR-21-5p effectively attenuated the proangiogenic effects mediated by hypo-ADSC-Exos. Mechanistically, our investigation revealed that exosomal miR-21-5p emanating from hypo-ADSCs exerts its regulatory influence by targeting sprouly1 (SPRY1) within HUVECs, thereby facilitating the activation of the PI3K/AKT signalling pathway. Notably, knockdown of SPRY1 in HUVECs was found to potentiate PI3K/AKT activation and, concomitantly, HUVEC proliferation, migration, and angiogenesis. The culminating stage of our study involved a compelling in vivo demonstration wherein GelMA loaded with hypo-ADSC-Exos was validated to substantially enhance local type H angiogenesis and concomitant bone regeneration. This enhancement was unequivocally attributed to the exosomal modulation of SPRY1. In summary, our investigation offers a pioneering perspective on the potential utility of hypo-ADSC-Exos as readily available for osteoporotic fracture treatment.

Icariin promotes osteogenic differentiation of human bone marrow mesenchymal stem cells by regulating USP47/SIRT1/Wnt/ß-catenin.

Icariin has been shown to promote osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). However, the underlying molecular mechanism by which Icariin regulates osteogenic differentiation needs to be further revealed. The viability of BMSCs was assessed by cell counting kit 8 assay. BMSC osteogenic differentiation ability was evaluated by detecting alkaline phosphatase activity and performing alizarin red S staining. The protein levels of osteogenic differentiation-related markers, sirtuin 1 (SIRT1), ubiquitin-specific protease 47 (USP47), and Wnt/ß-catenin-related markers were determined using western blot. SIRT1 mRNA level was measured using quantitative real-time PCR. The regulation of USP47 on SIRT1 was confirmed by ubiquitination detection and co-immunoprecipitation analysis. Icariin could promote BMSC osteogenic differentiation. SIRT1 expression was enhanced by Icariin, and its knockdown suppressed Icariin-induced BMSC osteogenic differentiation. Moreover, deubiquitinating enzyme USP47 could stabilize SIRT1 protein expression. Besides, SIRT1 overexpression reversed the inhibiting effect of USP47 knockdown on BMSC osteogenic differentiation, and USP47 knockdown also restrained Icariin-induced BMSC osteogenic differentiation. Additionally, Icariin enhanced the activity of the Wnt/ß-catenin pathway by upregulating SIRT1. Icariin facilitated BMSC osteogenic differentiation via the USP47/SIRT1/Wnt/ß-catenin pathway.

Comparative Proteomic Analysis of Two Wild Soybean (Glycine soja) Genotypes Reveals Positive Regulation of Saline-Alkaline Stress Tolerance by Tonoplast Transporters.

Soil saline-alkalization is a significant constraint for soybean production. Owing to higher genetic diversity of wild soybean, we compared the proteomic landscape of saline-alkaline stress-tolerant (SWBY032) and stress-sensitive (SWLJ092) wild soybean (Glycine soja) strains under saline and saline-alkaline stress. Out of 346 differentially expressed proteins (DEPs) specifically involved in saline-alkaline stress, 159 and 133 DEPs were identified in only SWLJ092 and SWBY032, respectively. Functional annotations revealed that more ribosome proteins were downregulated in SWLJ092, whereas more membrane transporters were upregulated in SWBY032. Moreover, protein-protein interaction analysis of 133 DEPs revealed that 14 protein-synthesis- and 2 TCA-cycle-related DEPs might alter saline-alkaline tolerance by affecting protein synthesis and amino acid metabolism. Furthermore, we confirmed G. soja tonoplast intrinsic protein (GsTIP2-1 and GsTIP2-2), inositol transporter (GsINT1), sucrose transport protein (GsSUC4), and autoinhibited Ca2+-ATPase (GsACA11) as tonoplast transporters can synergistically improve saline-alkaline tolerance in soybean, possibly by relieving the inhibition of protein synthesis and amino acid metabolism. Overall, our findings provided a foundation for molecular breeding of a saline-alkaline stress-tolerant soybean.

GmGAMYB-BINDING PROTEIN 1 promotes small auxin-up RNA gene transcription to modulate soybean maturity and height.

Flowering time, maturity, and plant height are crucial agronomic traits controlled by photoperiod that affect soybean (Glycine max [L.] Merr.) yield and regional adaptability. It is important to cultivate soybean cultivars of earlier maturity that adapt to high latitudes. GAMYB-binding protein 1 (GmGBP1), a member of the SNW/SKIP family of transcriptional coregulators in soybean, is induced by short days and interacts with transcription factor GAMYB (GmGAMYB) during photoperiod control of flowering time and maturity. In the present study, GmGBP1:GmGBP1 soybean showed the phenotypes of earlier maturity and higher plant height. Chromatin immunoprecipitation sequencing (ChIP-seq) assays of GmGBP1-binding sites and RNA sequencing (RNA-seq) of differentially expressed transcripts in GmGBP1:GmGBP1 further identified potential targets of GmGBP1, including small auxin-up RNA (GmSAUR). GmSAUR:GmSAUR soybean also showed earlier maturity and higher plant height. GmGBP1 interacted with GmGAMYB, bound to the promoter of GmSAUR and promoted the expression of FLOWER LOCUS T homologs 2a (GmFT2a) and FLOWERING LOCUS D LIKE 19 (GmFDL19). Flowering repressors such as GmFT4 were negatively regulated, resulting in earlier flowering and maturity. Furthermore, the interaction of GmGBP1 with GmGAMYB increased the gibberellin (GA) signal to promote height and hypocotyl elongation by activating GmSAUR and GmSAUR bound to the promoter of the GA-positive activating regulator gibberellic acid-stimulated Arabidopsis 32 (GmGASA32). These results suggested a photoperiod regulatory pathway in which the interaction of GmGBP1 with GmGAMYB directly activated GmSAUR to promote earlier maturity and plant height in soybean.

Network pharmacology and in vivo studies reveal the pharmacological effects and molecular mechanisms of Celastrol against acute hepatic injury induced by LPS.

Sepsis is currently the main factor of death in the ICU, and the liver, as an important organ of immunity and stable metabolism, can be acutely damaged during sepsis, and the mortality rate of patients with sepsis complicated by acute liver injury is greatly increased. Celastrol (CEL) is derived from the root bark of Tripterygium wilfordii Hook.f.. As a traditional Chinese medicine, CEL has anti-inflammatory, anti-cancer, anti-oxidant, and other biological activities. Obtain CEL and AHI intersection targets via database and construct protein-protein interaction (PPI) network by STRING. GO functional enrichment and KEGG pathway analyses were performed by R studio. Targets were finally selected to perform molecular docking simulations with CEL. In vivo experiments based on the model of AHI were established by intraperitoneal injection of Lipopolysaccharide (LPS) 4 h, and pre-treated with CEL (0.5 mg/kg, 1 mg/kg, 1.5 mg/kg). The results are as follows: 273 genes with the intersection of CEL and AHI were obtained, and GO and KEGG enrichment analysis were used to design the mechanism of inflammation, apoptosis, and oxidative stress-related injury. By constructing the PPI network selected top 10 targets are: STAT3, RELA, MAPK1, MAPK3, TP53, AKT1, HSP90AA1, JUN, TNF, MAPK14, predicted CEL protection AHI design related pathways of MAPK and PI3K/AKT-related signal pathways. In vivo experiments, CEL inhibited the activation of MAPK and PI3K/AKT related pathways, reduced inflammatory response, apoptosis, and oxidative stress, and significantly improved LPS-induced AHI. In summary, this study predicted the mechanisms involved in the protective effect of CEL on AHI through network pharmacology. In vivo, CEL inhibited MAPK and PI3K/AKT-related signaling pathways, and reduced inflammatory response, apoptosis, and oxidative stress to protect LPS-induced AHI.

CONSTANS-LIKE 1a positively regulates salt and drought tolerance in soybean.

Salt and drought stresses are major factors limiting soybean (Glycine max [L.] Merr.) growth and development; thus, improving soybean stress tolerance is critical. In this study, both salt stress and drought stress induced mRNA levels of CONSTANS-like 1a (GmCOL1a) and stabilized the GmCOL1a protein. Transgenic 35S:GmCOL1a soybean plants exhibited enhanced salt and drought tolerance, with higher relative water content in leaves, greater proline content, lower malondialdehyde (MDA) content, and less reactive oxygen species (ROS) production compared with wild-type plants; the GmCOL1a knockout co-9 mutant showed opposite phenotypes. In addition, GmCOL1a promoted the expression of genes related to salt tolerance, effectively reducing the Na+/K+ ratio in soybean plants, especially in stems and leaves of 35S:GmCOL1a soybean. Chromatin immunoprecipitation sequencing (ChIP-seq) analysis identified two potential direct targets of GmCOL1a, late embryogenesis abundant (GmLEA) and Δ1-pyrroline-5-carboxylate synthetase (GmP5CS) genes, which were verified by chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR), electrophoretic mobility shift assay (EMSA), and transient transcriptional activation assays. GmCOL1a bound directly to the Myc(bHLH)-binding and Che-binding motifs of GmLEA and GmP5CS promoters to stimulate mRNA expression. Analysis of transgenic hairy-root GmP5CS:GmP5CS soybean plants in wild type, co-9, and 35S:GmCOL1a backgrounds further revealed that GmCOL1a enhances salt and drought tolerance by promoting GmP5CS protein accumulation in transgenic soybean hairy roots. Therefore, we demonstrate that GmCOL1a plays an important role in tolerance to abiotic stress in soybean.

Effect of Chlorogenic Acid via Upregulating Resolvin D1 Inhibiting the NF-κB Pathway on Chronic Restraint Stress-Induced Liver Inflammation.

Chronic stress can cause chronic inflammatory injury to the liver. Chlorogenic acid (CGA) is known to have a wide range of biological activities and anti-inflammatory effects. Resolvin D1 (RvD1) is a polyunsaturated fatty acid derivative that has inhibitory effects on a variety of inflammatory diseases. However, whether CGA can inhibit liver inflammation in chronic stress through RvD1 remains unclear. In this work, male rats were subjected to restraint stress for 6 h every day and built a chronic stress model for 21 days. CGA (100 mg/kg) was administered intragastrically 1 h before restraint, with intraperitoneal injection of RvD1 inhibitor WRW4 (antagonist of FPR2, 0.1 mg/kg) or WRW4 solution every 2 days for 30 min before CGA administration. CGA reduced hepatic hemorrhage and inflammatory cell infiltration, alleviated hepatic injury, decreased the activation of the NF-κB pathway and the expression of interleukin 1ß, interleukin 6, and tumor necrosis factor α in the liver, and increased RvD1 in the serum and liver. The therapeutic effect of CGA was blocked after WRW4 intervention. These results suggest that the protective effects of CGA mediate the NF-κB pathway by upregulating the generation of RvD1. Above all, this research demonstrates the liver protective effect of CGA and provides a potential treatment strategy for chronic inflammatory disease.

Preparation and characterization of two novel osteoinductive fishbone-derived biphasic calcium phosphate bone graft substitutes.

Many studies have reported on the conversion of natural resources into xenografts with hydroxyapatite (HA) as major component, but the extraction of biphasic calcium phosphate (HA/ß-TCP) from animal bones and transformation into bone graft substitutes are rarely reported. In this research, two kinds of fish bones were made into granular porous biphasic calcium phosphate bone graft substitutes with particle sizes between 500 to 1000 µm through a series of preparation procedures (Salmo salar calcined at 900°C named Sa900 and Anoplopoma fimbria calcined at 800°C named An800). The chemical composition was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The morphology and porous structure of the scaffolds were comparatively analyzed by scanning electron microscopy (SEM) and mercury porosimeter. The specific surface area of materials was measured by the nitrogen adsorption technique based on BET theory. Cytotoxicity and ectopic osteogenesis were also carried out to investigate the biocompatibility and osteoinductive potential of these materials. The results showed that both fishbone-derived scaffolds were composed of HA and ß-TCP with different proportions, and numerous interconnected pores with different sizes were observed at the surface of materials. An800 had higher total porosity reaching 74.8% with higher interconnectivity and micropores mostly distributed at 0.27 µm and 0.12 µm, while Sa900 had a higher specific surface area and higher intraparticle porosity with nanopores mostly distributed at 0.07 µm. CCK-8 assays and Live/dead staining demonstrated excellent biocompatibility. Material-induced osteoid formation were observed on the interface of both internal pores and periphery of materials after implantation in muscle pouch of Wistar rats for 8 weeks which indicated some extent of osteoinductive potential of materials. The possible mechanism of material-induced osteogenesis and the effects of chemical composition, surface topography, and spatial structure on osteogenesis were also discussed in this paper.

Application of an arched, Ni-Ti shape-memory connector in repairing distal tibiofibular syndesmosis ligament injury.

OBJECTIVE: To investigate the clinical effect of internal fixation of a Ni-Ti arched shape-memory connector in the treatment of distal tibiofibular syndesmosis ligament injury. METHODS: From January 2013 to January 2016, 108 cases of ankle fracture with distal tibiofibular syndesmosis ligament injury in our hospital were selected, and all of them were fixed with ASCs or screw fixation. The functional evaluation and efficacy evaluation were performed according to the Olerud Molander Ankle Score (Omas) and SF-36. At the same time, follow-ups recorded the incidence of postoperative complications: osteoarthritis, superficial infection, symptomatic hard and soft tissue irritation, early removal and poor reduction of internal fixation, and later loss of reduction. RESULTS: In the ASC(Ni-Ti Arched shape-memory Connector) group, the incidence of symptomatic hardware, soft tissue or superficial infection decreased to 2.77%(from 13.8% or 11.1% in SCREW group). The early removal rate(2.77%) of internal fixation was also lower than that of the screw group. While the incidence of osteoarthritis is 13.8% in SCREW group, the incidence of osteoarthritis in the later follow-up was also as low as 1.38% in ASC group. Loss of fracture reduction due to removal of the fixation device for the distal tibiofibular syndesmosis ligament was not observed in the ASC group. With two postoperative scoring systems (OMAS and SF-36), patients in the ASC group significantly get higher score than that in SCREW group. CONCLUSION: The design of the Ni-Ti arched shape-memory connector can be adapted to the irregular anatomical structure of the malleolus and the ability to continue to contract by body temperature. The use of ASCs in fixation of articular ligaments can preserve a slight range of motion, and the results suggest that ASCs can effectively reduce the incidence of fixation looseness, fracture, infection and other complications.

Growth Repressor GmRAV Binds to the GmGA3ox Promoter to Negatively Regulate Plant Height Development in Soybean.

Plant height is an important component of plant architecture, and significantly affects crop quality and yield. A soybean GmRAV (Related to ABI3/VP1) transcription factor containing both AP2 and B3 domains is a growth repressor. Three GmRAV-overexpressing (GmRAV-ox) transgenic lines displayed extremely shorter height and shortened internodes compared with control plants, whereas transgenic inhibition of GmRAV expression resulted in increased plant height. GmRAV-ox soybean plants showed a low active gibberellin level and the dwarf phenotype could be rescued by treatment with exogenous GA3 treatment. ChIP (Chromatin immunoprecipitation)-qPCR assay showed that GmRAV could directly regulate the expression of the GA4 biosynthetic genes GA3-oxidase (GmGA3ox) by binding two CAACA motifs in the GmGA3ox promoter. The GmGA3ox promoter was bound by GmRAV, whose expression levels in leaves were both elevated in GmRAV-i-3 and decreased in GmRAV-ox-7 soybean plants. Transient expression assay in N. benthamiana also showed that the proGmRAV:GmRAV-3F6H effector strongly repressed the expression of LUC reporter gene driven by GmGA3ox promoter containing two CAACA motifs. Together, our results suggested that GmRAV protein repressed the expression of GmGA3ox by directly binding to the two CAACA motifs in the promoter to limit soybean plant height.

[A case-control study of two internal fixation methods in the treatment of comminuted fracture of inferior pole of patella].

OBJECTIVE: To compare the effects of tension band combined with patellar cerclage and memory alloy patellar concentrator fixation in the treatment of comminuted fracture of the lower pole of patella. METHODS: From July 2015 to July 2019, 60 patients with distal patellar fracture were treated and were divided into two groups according to different operation methods. In group A, 30 patients were fixed with memory alloy patellar concentrator (NiTi PC), 17 males and 13 females, aged 20 to 71 (39.4±9.9) years, including 19 cases of falling injury, 9 cases of traffic injury and 2 cases of sports injury. The time from injury to operation was 10 to 75 (33.1±7.8) hours; 30 cases in group B were fixed with tension band andcerclage, 15 males and 15 females, aged 21 to 76 (38.6±10.2) years, including 17 cases of falling injury, 12 cases of traffic injury and 1 case of smashing injury. The time from injury to operation was 10 to 91 (34.5±9.1) hours. The curative effects of two groups were observed and compared. RESULTS: All 60 patients were followed up for 9 to 30 months. There was no significant difference in intraoperative bleeding, operation time, follow-up time and fracture healing time between the two groups. Six months after operation, according to the Bostman function score of knee joint:30 cases in group A, the total score was 28.6±4.7, of which 26 cases were excellent and 4 cases were good. The total score of 30 cases in group B was 25.5±4.4, of which 20 cases were excellent, 8 cases were good and 2 cases were poor. There were significant differences in Bostman total score and curative effect evaluation between two groups (P<0.05). The score of group A was significantly better than that of group B. In group B, 1 case had Kirschner wire withdrawal, 2 cases had joint stiffness and 3 cases had internal fixation irritation. CONCLUSION: Memory alloy patellar concentrator is strong and reliable in the treatment of inferior patellar fracture. It can take early rehabilitation exercise after operation, with good recovery of joint function and range of motion and less complications.

GmRAV confers ecological adaptation through photoperiod control of flowering time and maturity in soybean.

Photoperiod strictly controls vegetative and reproductive growth stages in soybean (Glycine max). A soybean GmRAV (Related to ABI3/VP1) transcription factor containing both AP2 and B3 domains was shown to be a key component of this process. We identified six polymorphisms in the GmRAV promoter that showed significant association with flowering time and maturity of soybean in one or multiple environments. Soybean varieties with minor polymorphism exhibited a longer growth period contributing to soybean adaptation to lower latitudes. The cis-acting element GT1CONSENSUS motif of the GmRAV promoter controlled the growth period, and the major allele in this motif shortened duration of late reproductive stages by reducing GmRAV expression levels. Three GmRAV-overexpressing (GmRAV-ox) transgenic lines displayed later flowering time and maturity, shorter height and fewer numbers of leaves compared with control plants, whereas transgenic inhibition of GmRAV expression resulted in earlier flowering time and maturity and increased plant height. Combining DNA affinity purification sequencing and RNA sequencing analyses revealed 154 putative target genes directly bound and transcriptionally regulated by GmRAV. Two GmRAV binding motifs [C(A/G)AACAA(G/T)A(C/T)A(G/T)] and [C(T/A)A(C)C(T/G)CTG] were identified, and acting downstream of E3E4, GmRAV repressed GmFT5a transcriptional activity through binding a CAACA motif, thereby delaying soybean growth and extending both vegetative and reproductive phases.

Overexpression of GmGAMYB Accelerates the Transition to Flowering and Increases Plant Height in Soybean.

The flowering time and plant height of soybean are important agronomic characters, which control the adaptability and yield of soybean. R2R3 MYB transcription factor plays an important regulatory role in plant growth and development. In this study, soybean GmGAMYB gene of R2R3-MYB type was induced by long-days (LDs). GmGAMYB showed higher transcriptional levels in the flowers, leaves and pods of soybean. Overexpression of GmGAMYB in transgenic soybean showed earlier flowering time and maturity in LDs and short-days (SDs). GmGAMYB interacted with GmGBP1 and might promote flowering time by up-regulating the expression of GmFULc gene in soybean. Moreover, the expression level of GmGAMYB was also induced by gibberellins (GAs) and the plant height of GmGAMYB-ox plants was significantly increased, which was caused by the enlargement of internode cell in stem. Furthermore, GmGAMYB overexpression led to increased GA sensitivity in the hypocotyl of soybean seedlings compared with WT. GmGAMYB may be a positive regulator of GA response of promoting plant height by up-regulating the expression of GmGA20ox gene in soybean. Together, our studies preliminarily showed that the partial functions of GmGAMYB in regulating flowering time and GA pathway.

GmIDD Is Induced by Short Days in Soybean and May Accelerate Flowering When Overexpressed in Arabidopsis via Inhibiting AGAMOUS-LIKE 18.

Photoperiod is one of the main climatic factors that determine flowering time and yield. Some members of the INDETERMINATE DOMAIN (IDD) transcription factor family have been reported to be involved in regulation of flowering time in Arabidopsis, maize, and rice. In this study, the domain analysis showed that GmIDD had a typical ID domain and was a member of the soybean IDD transcription factor family. Quantitative real-time PCR analysis showed that GmIDD was induced by short day conditions in leaves and regulated by circadian clock. Under long day conditions, transgenic Arabidopsis overexpressing GmIDD flowered earlier than wild-type, and idd mutants flowered later, while the overexpression of GmIDD rescued the late-flowering phenotype of idd mutants. Chromatin immunoprecipitation sequencing assays of GmIDD binding sites in GmIDD-overexpression (GmIDD-ox) Arabidopsis further identified potential direct targets, including a transcription factor, AGAMOUS-like 18 (AGL18). GmIDD might inhibit the transcriptional activity of flower repressor AGL18 by binding to the TTTTGGTCC motif of AGL18 promoter. Furthermore, the results also showed that GmIDD overexpression increased the transcription levels of flowering time-related genes FLOWERING LOCUS T (FT), SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1), LEAFY (LFY) and APETALA1 (AP1) in Arabidopsis. Taken together, GmIDD appeared to inhibit the transcriptional activity of AGL18 and induced the expression of FT gene to promote Arabidopsis flowering.

Umbilical Mesenchymal Stem Cell-Derived Exosome-Encapsulated Hydrogels Accelerate Bone Repair by Enhancing Angiogenesis.

Repair of large bone defects represents a major challenge for orthopedic surgeons. The newly formed microvessels inside grafts play a crucial role in successful bone tissue engineering. Previously, an active role for mesenchymal stem cell (MSC)-derived exosomes in blood vessel development and progression was suggested in the repair of multiple tissues. However, the reports on the application of MSC-derived exosomes in the repair of large bone defects are sparse. In this study, we encapsulated umbilical MSC-derived exosomes (uMSCEXOs) in hyaluronic acid hydrogel (HA-Gel) and combined them with customized nanohydroxyapatite/poly-ε-caprolactone (nHP) scaffolds to repair cranial defects in rats. Imaging and histological evaluation indicated that the uMSCEXOs/Gel/nHP composites markedly enhanced bone regeneration in vivo, and the uMSCEXOs might play a key role in this process. Moreover, the in vitro results demonstrated that uMSCEXOs promoted the proliferation, migration, and angiogenic differentiation of endothelial progenitor cells (EPCs) but did not significantly affect the osteogenic differentiation of BMSCs. Importantly, mechanistic studies revealed that exosomal miR-21 was the potential intercellular messenger that promoted angiogenesis by upregulating the NOTCH1/DLL4 pathway. In conclusion, our findings exhibit a promising exosome-based strategy in repairing large bone defects through enhanced angiogenesis, which potentially regulated by the miR-21/NOTCH1/DLL4 signaling axis.

A new technology using a customized 3D printed fixator to assist fracture reduction and fixation: Technical note.

BACKGROUND: Poor reduction can lead to complications such as deformity and delayed fracture healing. We introduce a 3D printed external fixator technology that can assist in fracture reduction and fixation. METHODS: A fractured long bone was first fixed by a temporary external fixator and then scanned with computed tomography. Three-dimensional reconstruction of the contour and bone fragments of the affected limb was performed using Mimics software, and the fracture reduction was simulated. Subsequently, data were imported into SolidWorks software for customized external fixator design and 3D printing. Through the precise assembly of the 3D printed external fixator and external fixation pins, automatic fracture reduction. RESULTS: The patient's fractures were well reduced, firmly fixed, and the postoperative fractures healed well with no complications. CONCLUSION: The technique we introduce not only assists in fracture reduction for temporary external fixation but can also be used as a definitive treatment for long bone fractures.

MicroRNA-139-5p Promotes Functional Recovery and Reduces Pain Hypersensitivity in Mice with Spinal Cord Injury by Targeting Mammalian Sterile 20-like Kinase 1.

Currently, there is no cure for spinal cord injury (SCI), a heavy burden on patients physiology and psychology. We found that microRNA-139-5p (miR-139-5p) expression was significantly downregulated in damaged spinal cords in mice. So, we aimed to test the effect of treatment with miR-139-5p on functional recovery and neuropathic pain in mice with SCI and investigate the underlying mechanism. The luciferase reporter assay revealed that miR-139-5p directly targeted mammalian sterile 20-like kinase 1 (Mst1), and miR-139-5p treatment suppressed Mst1 protein expression in damaged spinal cords of mice. Wild-type mice and Mst1(-/-) mice were exposed to SCI and treated with miR-139-5p agomir via intrathecal infusion. Treatment of SCI mice with miR-139-5p accelerated locomotor functional recovery, reduced hypersensitivities to mechanical and thermal stimulations, and promoted neuronal survival in damaged spinal cords. Treatment with miR-139-5p enhanced phosphorylation of adenosine monophosphate-activated protein kinase alpha (AMPKα), improved mitochondrial function, and suppressed NF-κB-related inflammation in damaged spinal cords. Deficiency of Mst1 had similar benefits in mice with SCI. Furthermore, miR-139-5p treatment did not provide further protection in Mst1(-/-) mice against SCI. In conclusion, miR-139-5p treatment enhanced functional recovery and reduced pain hypersensitivity in mice with SCI, possibly through targeting Mst1.

Application of a novel shape-memory alloy concentrator in displaced olecranon fractures: a report of the technique and mid-term clinical results.

PURPOSE: Olecranon fracture is a common upper limb fracture, and several surgical approaches have been advocated for its fixation. To overcome the complications associated with common techniques, we present a novel shape-memory alloy concentrator, an alternative for tension band compression, to fix olecranon fracture. METHODS: Fifty-seven patients (26 men and 31 women) with olecranon fracture, with a mean age of 45 years, were included in this study. Each patient had undergone open reduction and internal fixation using the Nitinol (Ni-Ti) arched shape-memory connector (ASC). The clinical assessments were performed using the Disability of the Arm, Shoulder, and Hand (DASH) questionnaire and the Mayo Elbow Performance (MEP) score, which were both recorded at the final follow-up visit. RESULTS: The patients were followed up for 44 months on average (range, 31 to 56 months). No patients were lost to follow-up, and all of the olecranon fractures healed in an average of 15 weeks (range, 10 to 34 weeks). The mean DASH score was 8.6 (range, 0 to 32.4), and the mean MEP score was 92.5 (range, 74 to 100). Nine patients showed postoperative complications: prominent hardware (2), infection (1), loss of the range of functional motion (5), and heterotopic ossification (1). CONCLUSION: The ASC may serve as a favorable device for multi-fragmented and comminuted fractures with rare hardware irritation and may also provide continuous concentrative compression to accelerate osseous healing, thereby aiding the restoration and permitting an early rehabilitation with a low incidence of postoperative complications.

Combination of mini locking plate and nitinol arched shape-memory connector for purely lateral malleolus fractures: technique and clinical results.

BACKGROUND: Lateral malleolus fractures occur frequently. The common techniques for fixing purely lateral malleolus fractures are often challenging, owing to the extent of soft tissue damage and fracture non-union. Herein, we report a new treatment that entails minimally invasive insertion and continuous compression of the broken ends as a novel technique, and evaluate its clinical results. METHODS: This study enrolled 21 patients (13 males and 8 females; mean age 32.06±3.45 years, range 23-69 years) with purely lateral malleolus fractures. Each patient underwent open reduction treatment with a mini locking plate for internal fixation and compression of the fracture end with an Arched Shape-Memory Connector (ASC). The clinical assessments were made using the American Orthopedic Foot and Ankle Society (AOFAS) scores, which were recorded at the final follow-up visit. RESULTS: The patients were followed for an average of 14.7±1.2 months (range, 12-18 months). None of the patients showed surgical failure, and all of the purely lateral malleolus fractures healed in an average of 12.6±1.5 weeks (range, 10-16 weeks). The mean AOFAS score was 88.94 (range, 83-90). CONCLUSIONS: The new treatment had beneficial outcomes for purely lateral malleolus fractures. Mini locking plates are minimally invasive for surgical intervention, and combined with continuous concentrated compression with an ASC to accelerate osseous healing, they aid in restoration of function and enable early rehabilitation with a low incidence of postoperative complications.