BACKGROUND:Gradient artificial bone repair scaffolds can mimic unique anatomical features in musculoskeletal tissues,showing great potential for repairing injured musculoskeletal tissues. OBJECTIVE:To review the latest research advances in gradient artificial bone repair scaffolds for tissue engineering in the musculoskeletal system and describe their advantages and fabrication strategies. METHODS:The first author of the article searched the Web of Science and PubMed databases for articles published from 2000 to 2023 with search terms"gradient,bone regeneration,scaffold".Finally,76 papers were analyzed and summarized after the screening. RESULTS AND CONCLUSION:(1)As an important means of efficient and high-quality repair of skeletal system tissues,gradient artificial bone repair scaffolds are currently designed bionically for the natural gradient characteristics of bone tissue,bone-cartilage,and tendon-bone tissue.These scaffolds can mimic the extracellular matrix of native tissues to a certain extent in terms of structure and composition,thus promoting cell adhesion,migration,proliferation,differentiation,and regenerative recovery of damaged tissues to their native state.(2)Advanced manufacturing technology provides more possibilities for gradient artificial bone repair scaffold preparation:Gradient electrospun fiber scaffolds constructed by spatially differentiated fiber arrangement and loading of biologically active substances have been developed;gradient 3D printed scaffolds fabricated by layered stacking,graded porosity,and bio-3D printing technology;gradient hydrogel scaffolds fabricated by in-situ layered injections,simple layer-by-layer stacking,and freeze-drying method;and in addition,there are also scaffolds made by other modalities or multi-method coupling.These scaffolds have demonstrated good biocompatibility in vitro experiments,were able to accelerate tissue regeneration in small animal tests,and were observed to have significantly improved histological structure.(3)The currently developed gradient artificial bone repair scaffolds have problems such as mismatch of gradient scales,unclear material-tissue interactions,and side effects caused by degradation products,which need to be further optimized by combining the strengths of related disciplines and clinical needs in the future.

ObjectiveTo explore the possible mechanism of action of Lifei Xiaoji Pill （理肺消积丸， LXP） in the treatment of non small cell lung cancer based on the Warburg effect and the USP47/BACH1 pathway. MethodsFifty C57BL/6 mice were randomly divided into five groups， model group， LXP group， inhibitor group， LXP + inhibitor group， and cisplatin group， with 10 mice in each group. A lung cancer mouse model was established by subcutaneously injecting Lewis cells. On the next day， the model group mice were given 0.2 ml of saline by gavage daily， the LXP group given 240 mg/（kg·d） of LXP solution once a day by gavage， the inhibitor group intraperitoneally injected with P22077 at a dose of 10 mg/（kg·d） every day， the LXP + inhibitor group given both LXP by gavage and P22077 by intraperitoneal injection once a day， and the cisplatin group received 0.5 mg/（kg·d） cisplatin intraperitoneally every other day. All treatments lasted for 14 days. On the day after the last dose， tumor weight and volume were measured， tumor histopathology was examined by HE staining， apoptosis in tumor tissues was detected by TUNEL staining， and proliferation cell nuclear antigen （PCNA） protein levels were detected by immunohistochemistry. Warburg effect indicators， including glucose concentration， lactate content， and adenosine triphosphate （ATP） production in tumor tissues， were measured. Western Blot and qRT-PCR were used to detect the protein and mRNA expression levels of USP47， BACH1， hexokinase 2 （HK2）， and glyceraldehyde 3-phosphate dehydrogenase （GAPDH）. ResultsCompared with the model group， all drug intervention groups showed reduced tumor weight and volume， improved tumor pathology， decreased PCNA positive rate， increased apoptosis rate， and reduced expression levels of USP47， BACH1， and HK2 proteins and mRNA （P＜0.05 or P＜0.01）. Except for lactate content in the cisplatin group， the glucose concentration in tumor tissues of other drug intervention groups increased， while lactate content and ATP production decreased （P＜0.05 or P＜0.01）. Compared with the LXP group， the LXP + inhibitor group showed more significant improvements in these indicators （P＜0.05 or P＜0.01）. Compared with the cisplatin group， the LXP + inhibitor group had lower mRNA expression of HK2 and GAPDH， and lower protein levels of USP47 and HK2 （P＜0.05 or P＜0.01）. Compared with the inhibitor group， the cisplatin group had higher HK2 protein levels， while the LXP + inhibitor group showed lower mRNA expression of BACH1， HK2， and GAPDH （P＜0.05 or P＜0.01）. ConclusionLXP significantly inhibits tumor growth in lung cancer mice， and its mechanism of action may be related to inhibiting the Warburg effect via the USP47/BACH1 pathway.

OBJECTIVE: To explore decompression strategies for lateral lumbar spinal stenosis under unilateral biportal endoscopy (UBE) assistance. METHODS: A clinical data of 86 patients with lateral lumbar stenosis treated with UBE-assisted intervertebral decompression between September 2022 and December 2023 was retrospectively analyzed. There were 42 males and 44 females with an average age of 63.6 years (range, 45-79 years). The disease duration ranged from 6 to 14 months (mean, 8.5 months). Surgical levels included L _{2, 3} in 3 cases, L _{3, 4} in 26 cases, L _{4, 5} in 42 cases, and L ₅, S ₁ in 15 cases. According to Lee's grading system, there were 21 cases of grade 1, 37 cases of grade 2, and 28 cases of grade 3 for lumbar spinal stenosis. Based on the location of stenosis and clinical symptoms, the 33 cases underwent interlaminar approach, 7 cases underwent interlaminar approach with auxiliary third incision, 26 cases underwent contralateral inclinatory approach, and 20 cases underwent paraspinal approach; then, the corresponding decompression procedures were performed. Visual analogue scale (VAS) score was used to evaluate lower back/leg pain before operation and at 1 and 3 months after operation, while Oswestry disability index (ODI) was used to evaluate spinal function. At 3 months after operation, the effectiveness was evaluated using the modified MacNab evaluation criteria. The spinal stenosis and decompression were evaluated based on Lee's grading system using lumbar MRI before operation and at 3 months after operation. RESULTS: All procedures were successfully completed with mean operation time of 95.1 minutes (range, 57-166 minutes). Dural tears occurred in 2 cases treated with interlaminar approach with auxiliary third incision. All incisions healed by first intention. All patients were followed up 3-10 months (mean, 5.9 months). The clinical symptoms of the patients relieved to varying degrees. The VAS scores and ODI of lower back and leg pain at 1 and 3 months after operation significantly improved compared to preoperative levels ( P<0.05), and the indicators at 3 months significantly improved than that at 1 month ( P<0.05). According to the modified MacNab evaluation criteria, the effectiveness at 3 months after operation was rated as excellent in 52 cases, good in 21 cases, and poor in 13 cases, with an excellent and good rate of 84.9%. No lumbar instability was detected on flexion-extension X-ray films during follow-up. The Lee's grading of lateral lumbar stenosis at 2 days after operation showed significant improvement compared to preoperative grading ( P<0.05). CONCLUSION For lateral lumbar spinal stenosis, UBE-assisted decompression of the spinal canal requires the selection of interlaminar approach, interlaminar approach with auxiliary third incision, contralateral inclinatory approach, and paraspinal approach based on preoperative imaging findings and clinical symptoms to achieve better effectiveness.
Humans ; Spinal Stenosis/diagnostic imaging* ; Female ; Male ; Middle Aged ; Decompression, Surgical/methods* ; Aged ; Lumbar Vertebrae/surgery* ; Endoscopy/methods* ; Retrospective Studies ; Treatment Outcome

OBJECTIVE: To investigate the effects and underlying mechanism of ionizing radiation on the adipogenic of mesenchymal stem cells (MSCs). METHODS: Mouse MSCs were cultured in vitro and treated with 2 Gy and 6 Gy radiation with ⁶⁰Co, and the radiation dose rate was 0.98 Gy/min. Bulk RNA-seq was performed on control and irradiated MSCs. The changes of adipogenic differentiation and oxidative stress pathways of MSC were revealed by bioinformatics analysis. Oil Red O staining was used to detect the adipogenic differentiation ability of MSCs in vitro, and real-time fluorescence quantitative PCR (qPCR) was used to detect the expression differences of key regulatory factors Cebpa, Lpl and Pparg after radiation treatment. At the same time, qPCR and Western blot were used to detect the effect of inhibition of Nrf2, a key factor of antioxidant stress pathway, on the expression of key regulatory factors of adipogenesis. Moreover, the species conservation of the irradiation response of human bone marrow MSCs and mouse MSC was determined by qPCR. RESULTS: Bulk RNA-seq suggested that ionizing radiation promotes adipogenic differentiation of MSCs and up-regulation of oxidative stress-related genes and pathways. The results of Oil Red O staining and qPCR showed that ionizing radiation promoted the adipogenesis of MSCs, with high expression of Cebpa, Lpl and Pparg, as well as oxidative stress-related gene Nrf2. Nrf2 pathway inhibitors could further enhance the adipogenesis of MSCs in bone marrow after radiation. Notably, the similar regulation of oxidative pathways and enhanced adipogenesis post irradiation were observed in human bone marrow MSCs. In addition, irradiation exposure led to up-regulated mRNA expression of interleukin-6 and down-regulated mRNA expression of colony stimulating factor 2 in human bone marrow MSCs. CONCLUSION Ionizing radiation promotes adipogenesis of MSCs in mice, and oxidative stress pathway participates in this effect, blocking Nrf2 further promotes the adipogenesis of MSCs. Additionally, irradiation activates oxidative pathways and promotes adipogenic differentiation of human bone marrow MSCs.
Mesenchymal Stem Cells/cytology* ; Oxidative Stress/radiation effects* ; Animals ; Adipogenesis/radiation effects* ; Mice ; Radiation, Ionizing ; Cell Differentiation/radiation effects* ; Humans ; NF-E2-Related Factor 2/metabolism* ; PPAR gamma ; Cells, Cultured

OBJECTIVE: To establish an in vitro cell model simulating acute graft-versus-host disease (aGVHD) bone marrow microenvironment injury with the advantage of mouse serum of aGVHD model and explore the effect of serum of aGVHD mouse on the adipogenic differentiation ability of mesenchymal stem cells (MSCs). METHODS: The 6-8-week-old C57BL/6N female mice and BALB/c female mice were used as the donor and recipient mice of the aGVHD model, respectively. Bone marrow transplantation (BMT) mouse model (n=20) was established by being injected with bone marrow cells (1×10⁷ per mouse) from donor mice within 4-6 hours after receiving a lethal dose (8.0 Gy, 72.76 cGy/min) of γ ray general irradiation. A mouse model of aGVHD (n=20) was established by infusing a total of 0.4 ml of a mixture of donor mouse-derived bone marrow cells (1×10⁷ per mouse) and spleen lymphocytes (2×10⁶ per mouse). The blood was removed from the eyeballs and the mouse serum was aspirated on the 7^th day after modeling. Bone marrow-derived MSCs were isolated from 1-week-old C57BL/6N male mice and incubated with 2%, 5% and 10% BMT mouse serum and aGVHD mouse serum in the medium, respectively. The effect of serum in the two groups on the in vitro adipogenic differentiation ability of mouse MSCs was detected by Oil Red O staining. The expression levels of related proteins PPARγ and CEBPα were detected by Western blot. The expression differences of key adipogenic transcription factors including PPARγ, CEBPα, FABP4 and LPL were determined by real-time quantitative PCR (RT-qPCR). RESULTS: An in vitro cell model simulating the damage of bone marrow microenvironment in mice with aGVHD was successfully established. Oil Red O staining showed that the number of orange-red fatty droplets was significantly reduced and the adipogenic differentiation ability of MSC was impaired at aGVHD serum concentration of 10% compared with BMT serum. Western blot experiments showed that adipogenesis-related proteins PPARγ and CEBPα expressed in MSCs were down-regulated. Further RT-qPCR assay showed that the production of PPARγ, CEBPα, FABP4 and LPL, the key transcription factors for adipogenic differentiation of MSC, were significantly reduced. CONCLUSION The adipogenic differentiation capacity of MSCs is inhibited by aGVHD mouse serum.
Animals ; Mesenchymal Stem Cells/cytology* ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Adipogenesis ; Female ; Cell Differentiation ; Graft vs Host Disease/blood* ; Bone Marrow Cells/cytology* ; PPAR gamma/metabolism* ; Disease Models, Animal ; CCAAT-Enhancer-Binding Protein-alpha/metabolism*

OBJECTIVE: To prepare clinical-grade human umbilical cord-derived mesenchymal stem cells (hUC-MSC) with high expression of hematopoietic supporting factors and evaluate their stem cell characteristics. METHODS: Fetal umbilical cord tissues were collected from healthy postpartum women during full-term cesarean section. Wharton's jelly was mechanically separated and hUC-MSCs were obtained by explant culture method and enzyme digestion method in an animal serum-free culture system with addition of human platelet lysate. The phenotypic characteristics of hUC-MSCs obtained by two methods were detected by flow cytometry. The differences in proliferation ability between the two groups of hUC-MSCs were identified through CCK-8 assay and colony forming unit-fibroblast (CFU-F) assay. The differences in multilineage differentiation potential between the two groups of hUC-MSCs were identified through induction of adipogenic, osteogenic, and chondrogenic differentiation. The mRNA expression levels of hematopoietic supporting factors such as SCF, IL-3, CXCL12, VCAM1 and ANGPT1 in the two groups of hUC-MSCs were identified by real-time fluorescence quantiative PCR(RT-qPCR). RESULTS: The results of flow cytometry showed that hUC-MSCs obtained by the two methods both expressed high levels of CD73, CD90 and CD105, while lowly expressed CD31, CD45 and HLA-DR. The results of CCK-8 and CFU-F assay showed that the proliferation ability of hUC-MSCs obtained by explant culture method was better than those obtained by enzyme digestion method. The results of the triple lineage differentiation experiment showed that there was no significant difference in multilineage differentiation potential between the two grous of hUC-MSCs. The results of RT-qPCR showed that the mRNA expression levels of hematopoietic supporting factors SCF, IL-3, CXCL12, VCAM1 and ANGPT1 in hUC-MSCs obtained by explant cultrue method were higher than those obtained by enzyme digestion method. CONCLUSION Clinical-grade hUC-MSCs with high expression levels of hematopoietic supporting factors were successfully cultured in an animal serum-free culture system.
Humans ; Mesenchymal Stem Cells/metabolism* ; Umbilical Cord/cytology* ; Cell Differentiation ; Female ; Cell Proliferation ; Cells, Cultured ; Chemokine CXCL12/metabolism* ; Angiopoietin-1/metabolism* ; Vascular Cell Adhesion Molecule-1/metabolism* ; Stem Cell Factor/metabolism* ; Flow Cytometry ; Pregnancy

Objective To design a custom 3D printed monoblock acetabular implant for reconstructing PaproskyⅢA acetabular bone defects and to analyze the stress distribution,displacement,and clinical reliability of the implant and surrounding bone using finite element analysis(FEA).Methods Bilateral hip computed tomography(CT)data of a patient with PaproskyⅢA acetabular bone defects were collected.Models were developed and analyzed using Mimics Medical 21.0,Geomagic Wrap 2021,Solidworks 2023,and ANSYS Workbench 2022 R1 softwares.The biomechanical performance of the custom 3D printed monoblock acetabular implant was simulated under a single-leg stance condition.Results The peak von Mises stress of the hip components was observed at the femoral stem,measuring 67.318 MPa.For the custom 3D printeded monoblock acetabular implant,the peak stress was located at the anterosuperior contact area between the implant and acetabular bone,measuring 6.935 MPa.The femoral stem exhibited a peak stress of 67.318 MPa at its junction with the femoral head.The liner's peak stress was 1.333 MPa near the fixation of screw 9 at the superior part of the acetabular cup.The screws showed a peak stress of 2.215 MPa at the junction with the implant.For the cortical bone,the peak stress was 9.844 MPa at the distal femur,while the cancellous bone exhibited a peak stress of 0.701 MPa at its distal connection with the femoral stem.The pelvic bone's peak stress was 8.002 MPa at the anterior transition zone between the normal acetabulum and the defect.The peak micromotion of the custom 3D printed monoblock acetabular implant at its posterosuperior area,measuring 0.114 mm.The femoral stem and head exhibited a peak micromotion of 0.132 mm at the contact interface with the acetabular liner.The micromotion range at the implant-acetabular bone interface was 0.098 mm to 0.131 mm.Conclusion Under a simulated single-leg stance condition,the stress distribution in all components and the acetabular bone surface remains below their respective yield strengths.The micromotion threshold between the acetabular cup and acetabular bone is within acceptable limits.Biomechanical analysis indicates that the patient can perform early weight-bearing rehabilitation postoperatively.However,walking or jogging rehabilitation should be approached with caution.

Objective To investigate the diagnostic value of our regression model based on quantitative parameters of dual-energy CT and clinical features for stages T2 and T3 colorectal cancer.Methods A cross-section study was performed on 91 patients with colorectal cancer confirmed by postoperative pathology in our hospital from January 2022 to November 2023.All of them underwent dual-energy CT examination.According to the pathological T staging criteria of Chinese Colorectal Cancer Diagnosis and Treatment Standard(2020 Edition),they were divided into T2 group(n=43)and T3 group(n=48).Univariate analysis was used to compare the differences in quantitative CT parameters and clinical features between the 2 groups,and the obtained significant variables were employed to construct diagnosis models by univariate or multivariate logistic regression analysis.The area under receiver operating characteristic curve(AUC)of the CT parametric model and the model combined with clinical features was compared to evaluate the efficacy of diagnosing T2 and T3 stages.Results Univariate analysis showed that carcinoembryonic antigen(CEA),N stage,tumor location,tumor longest diameter(LD),CT value of virtual noncontrast(CT-VNC),fat fraction,electron density(Rho)and dual energy index(DEI)were significantly different between the T2 and T3 groups(P＜0.05).Multivariate logistic regression analysis found that N stage,tumor location,LD,fat fraction and DEI were independent risk factors for the diagnosis of stage T3.The AUC value of the model of above CT parameters in diagnosing stage T3 colorectal cancer was 0.671(95％CI:0.558～0.783),and the AUC value of the combined model of above CT parameters and clinical features was 0.886(95％CI:0.815～0.957),and statistical difference was observed in the AUC value between the combined model and the CT parametric model(P＜0.01).Conclusion The regression model constructed with dual-energy CT quantitative parameters combined with clinical features has high value in the preoperative diagnosis of stages T2 and T3 colorectal cancer before surgery.