Study on the diffusion and deposition law of pore slurry in gangue filling zone based on CFD-DEM coupling.

In this study, the slurry diffusion in a cavity filled with coal gangue was studied by combining experimental and numerical simulation methods. By calibrating slurry and particle materials, the grouting process in coal gangue filling area is simulated successfully, and the change of slurry diffusion flow field and particle movement and settling process in different dimensions are deeply analyzed. Both experimental and numerical simulation results show that the particle settlement presents a bell-shaped curve, which is of great significance for understanding the particle movement and settlement behavior in the filling cavity. In addition, it is found that the grouting speed has a significant effect on the particle settlement during the slurry diffusion process. When the grouting speed increases from 0.1m /s to 0.2m /s, the particle settlement and diffusion range increases about twice. In the plane flow field, it is observed that the outward diffusion trend and speed of grouting are more obvious. It is worth noting that in the whole process of grouting, it is observed that with the increase of grouting distance and depth, both the velocity of slurry and particles show a trend of rapid initial decline and gradually slow down, and the flow velocity of slurry near the grouting outlet at a flow rate of 0.2m/s is 2-4 times that of 0.1m/s. This provides important enlightenment for the porous seepage effect at different grouting speeds.

A new classification for quadrilateral plate fracture of acetabulum.

BACKGROUND: Recently, quadrilateral plate (QLP) fractures of acetabulum have attracted increasing attention. However, evidence for the appropriate classification of QLP fractures is still lacking, making it difficult to understand and manage these fractures. This study aimed to introduce a new classification for QLP fractures and evaluate its reproducibility. METHODS: A series of 1101 consecutive patients with acetabular fractures from 8 level-I trauma centers were enrolled in this study. All patients underwent preoperative radiograph and computed tomography imaging. QLP fractures were identified and classified using the new and Judet-Letournel classification system. The inter- and intra-observer reliabilities (kappa coefficients, κ) of these two systems were investigated by 4 observers. Furthermore, surgical approaches and fixation methods for each fracture type are described. RESULTS: In total, 243 (243/1101, 22%) patients with QLP fractures were identified and included in this analysis. The mean κ value of the intra-observer reliability was 0.84 (range, 0.763-0.919) for the new classification, indicating excellent agreement, and the inter-observer reliability was 0.762 (range, 0.625-0.876), indicating substantial agreement. The values were 0.649 (range, 0.523-0.708) and 0.584 (0.497-0.646), respectively, according to the Judet-Letournel classification. Six cases (6/243, 2.5%) could not be classified using the Judet-Letournel classification. The selection of surgical approaches and fixation methods depends on the fracture type; however, an anterior intra-pelvic approach and buttressing fixation using the plate or screw are preferred for QLP fractures. CONCLUSION: This study presents a new classification for QLP fractures, showing higher intra- and inter-observer reliabilities than those obtained using the Judet-Letournel classification. This allowed us to obtain an in-depth and comprehensive understanding of QLP fractures. Additionally, the new classification might guide further studies on surgical strategies for QLP fractures. LEVEL OF EVIDENCE: Level II.

[A multicenter retrospective study assessing pelvic unlocking closed reduction device for reducing unstable pelvic posterior ring disruption].

Objective: To explore the application value and effectiveness of pelvic unlocking closed reduction device for the treatment of unstable pelvic posterior ring disruption. Methods: A retrospective analysis of clinical data of 243 cases of unstable pelvic posterior ring disruption treated with pelvic unlocking closed reduction device in 13 orthopaedic trauma centers across the country between December 2018 and June 2020 was performed. There were 139 males and 104 females; the age ranged from 18 to 92 years, with an average age of 48.5 years. The cause of injury included 132 cases of traffic accident injuries, 102 cases of falling from height, and 9 cases of crushing injuries. According to AO/Orthopaedic Trauma Association (AO/OTA) classification, there were 5 cases of type 61-B1, 13 cases of type 61-B2, 32 cases of type 61-C1.1, 47 cases of type 61-C1.2, 89 cases of type 61-C1.3, 35 cases of type 61-C2, and 22 cases of type 61-C3. The time from injury to operation was 2-121 days, with a median of 10 days. Preoperative preparation time, installation time of unlocking closed reduction device, fracture reduction time, intraoperative fluoroscopy times, intraoperative blood loss, and surgical complications were recorded, and Matta scoring standard was used to evaluate the quality of fracture reduction. According to Matta evaluation results, the patients were divided into two subgroups: excellent-good group and fair-poor group. The differences in gender, age, time from injury to operation, AO/OTA classification, and perioperative clinical indicators were compared between the two groups, and the effects of baseline data and perioperative indicators on the quality of fracture reduction were studied. Results: Pelvic unlocking closed reduction device did not interfere with the display of the pelvic structure and fracture displacement direction during the intraoperative fluoroscopy, effectively correcting the displacement of the pelvic ring. The preoperative preparation time was 17-60 minutes, with an average of 30 minutes; installation time of unlocking closed reduction device was 10-32 minutes, with an average of 21 minutes; intraoperative fracture reduction time was 15-205 minutes, with an average of 49.2 minutes; intraoperative fluoroscopy times were 41-420 times, with an average of 132 times; intraoperative blood loss was 40-1 500 mL, with an average of 71.5 mL. The reduction quality of pelvic fracture was evaluated according to Matta score immediately after operation. The results were excellent in 153 cases, good in 61 cases, fair in 24 cases, and poor in 5 cases. The excellent and good rate was 88.1%. Further subgroup analysis showed that there was no significant difference in other indexes ( P>0.05) between the excellent-good group and the fair-poor group except for the time from injury to operation and AO/OTA classification ( P<0.05). Among them, the excellent-good reduction rate was 92.2% (119/129) in patients with injury-to-operation time less than 10 days, and the fair-poor reduction rate was 25.7% (9/35) and 40.9% (9/22) in patients with AO/OTA 61-C2 and 61-C3 types, respectively. There was no surgery-related complication due to the application of the pelvic unlocked reduction device, no secondary iliac fractures, vascular, or nerve injuries, and postoperative CT showed that all channel screws were located in the osseous channel. Conclusion: The pelvic unlocking reduction device can effectively help to reduce the unstable pelvic posterior ring and maintain reduction, meet the needs of different projection angles of pelvic fracture with intraoperative C-arm fluoroscopy. The system facilitate the operation of pelvic reduction and precise fixation.

Antiparasitical efficacy of sophoraflavanone G isolated from Sophora flavescens against parasitic protozoa Ichthyophthirius multifiliis.

Ichthyophthirius multifiliis, a global distributed protozoan parasite, causes "White spot disease" and leads to serious mortality of freshwater fish in aquaculture. The present study was conducted to assess the anti-I. multifiliis efficacy of active compound isolated from Sophora flavescens. The isolated active compound was identified as sophoraflavanone G (SG) with ESI-MS and NMR. In vitro tests, SG at concentrations of 0.5 mg/L and 2 mg/L resulted in death of all theronts and tomonts, respectively; SG at concentrations of 0.125 mg/L and 0.25 mg/L notably decreased theronts infectivity (p < 0.05). Additionally, the in vivo test results showed that a cumulative delivery of SG at concentration of 2 mg/L for 7 days protected fish from I. multifiliis infection. The 96-h LC50 (median lethal concentration) and safety concentration of SG to grass carp were 46.6 mg/L and 11.3 mg/L, respectively. The present work indicated that SG was a potential safe and effectively therapeutic agent in treating I. multifiliis.

Establishment and application of a TaqMan probe-based qPCR for the detection of Enterocytozoon hepatopenaei in shrimp Litopenaeus vannamei.

Enterocytozoon hepatopenaei (EHP) is a common parasite that invades the epithelial cytoplasm in the hepatopancreas of shrimp Litopenaeus vannamei and results in slow growth of the host shrimps to cause significant economic loss in shrimp aquaculture. In this study, a TaqMan probe-based qPCR for quantitative detection of EHP was established. A pair of specific primers and a TaqMan probe were designed based on the sequence of cysteine desulfurase gene (NFS1) of EHP. The standard curve between cycle threshold (Ct) and the logarithmic starting quantity (SQ) of the template was determined as Ct = - 3.231 lg (SQ) + 40.638, with a correlation coefficient (R2) of 0.998 and an amplification efficiency of 103.9%. The lower limit of quantification was 1.67 × 101 copies/µL for this TaqMan probe-based qPCR and 1.67 × 103 copies/µL for the conventional PCR. The TaqMan probe-based qPCR established in the research was 100 times more sensitive than the conventional PCR method. In addition, the results of clinical sample detection indicated that the present technique was efficient in detecting EHP in the hepatopancreas, feces, water, and pond bottom mud samples. Therefore, the established TaqMan probe-based qPCR is a suitable technique for detecting EHP in both shrimp and aquatic environment samples.

An integrin alpha 4 (ChIntα 4) from oyster Crassostrea hongkongensis mediates the hemocytes phagocytosis towards Vibrio alginolyticus.

Integrins, a family of cell adhesion transmembrane receptors, mediate cell adhesion, migration, proliferation, apoptosis, and phagocytosis. In the present study, an integrin ChIntα 4 from Crassostrea hongkongensis was characterized to investigate its role in defensing against pathogenic bacterium Vibrio alginolyticus. The full-length cDNA sequence of ChIntα 4 was 3572 bp with an open reading frame (ORF) of 3168 bp, which encoded a polypeptide with 1055 amino acids. The mRNA expression of ChIntα 4 in the hemocytes was significantly up-regulated at 6 h and 24 h post V. alginolyticus stimulation (p < 0.01). The recombinant ChIntα 4 protein could agglutinate the rabbit red blood cells and Gram-negative bacteria V. alginolyticus and Escherichia coli. Moreover, the phagocytic activity of the hemocytes was significantly down-regulated from 46.9% to 32.7% when blocked with anti-ChIntα 4 antibody, and it was significantly up-regulated from 42.7% to 59.5% post transfection with pCI-neo-ChIntα 4 plasmid (p < 0.05). In conclusion, these findings demonstrated that ChIntα 4 might be involved in resisting V. alginolyticus infection and regulating phagocytosis as a cell adhesion receptor in C. hongkongensis.

Unilateral lumbopelvic fixation for AO/OTA Type C1 and C2 pelvic fractures: Clinical efficacy and preliminary experiences in 23 patients.

PURPOSE: To report the clinical outcomes and preliminary experiences of unilateral lumbopelvic fixation for patients with AO/OTA Type C1 and C2 pelvic fractures. MATERIALS AND METHODS: Between May 2014 and Dec 2017, 23 consecutive patients with AO/OTA Type C1 and C2 pelvic factures were treated by unilateral lumbopelvic fixation. Estimated blood loss, operation duration, reduction quality, functional outcomes using Majeed scores and complications were evaluated. Subgroup analysis was used to assess the influence of unilateral lumbopelvic fixation on different type of pelvic fractures. RESULTS: Fifteen patients with Type C1 pelvic fractures and eight patients with Type C2 fractures underwent unilateral lumbopelvic fixation respectively. The mean follow-up time till May 2019 was 34.3 ± 9.9 months (range 17-60 months). Mean estimated blood loss was 473 ml and mean operation duration was 156 min during unilateral lumbopelvic fixation. The mean vertical displacement of pelvis decreased from 10.1 ± 4.9 mm to 3.1 ± 1.9 mm after unilateral lumbopelvic fixation. Majeed score assessments were available for 22 patients. Of these, 13 patients were graded as excellent, 8 were good and one was fair. The results of subgroup analysis showed that there was no difference of estimated blood loss, operation duration, postoperative displacements of pelvis and Majeed scores between the patients with Type C1 and C2 fractures. CONCLUSION: Unilateral lumbopelvic fixation could provide a well reduction quality and was an effective treatment for AO/OTA Type C1 and C2 pelvic fractures. STUDY DESIGN: Retrospective evaluation of 23 consecutive patients with AO/OTA Type C1 and C2 pelvic fractures treated by unilateral lumbopelvic fixation.

A novel closed reduction technique for treating femoral shaft fractures with intramedullary nails, haemostatic forceps and the lever principle.

BACKGROUND: Faster, easier, more economical and more effective versions of the minimally invasive reduction procedure for femoral shaft fractures need to be developed for use by orthopaedic surgeons. In this study, a fracture table was used to restore limb length, and long, curved haemostatic forceps and the lever principle were utilized to achieve minimally invasive reduction and intramedullary nail fixation of femoral shaft fractures. METHODS: A retrospective analysis involving 20 patients with femoral shaft fractures reduced with a fracture table; long, curved haemostatic forceps; and the lever principle was conducted. The operative effect was evaluated on the basis of the operative time, reduction time, fluoroscopy time, and intraoperative blood loss. RESULTS: All 20 cases were reduced in a closed fashion, and no conversions to open reduction were needed. The average operative time and fracture reduction time for all patients were 69.1 ± 13.5 min (range, 50-100 min) and 6.7 ± 1.9 min (range, 3-10 min), respectively. The fluoroscopy exposure time during the reduction process was 5-15 s, with an average time of 8.7 ± 2.7 s. The average intraoperative blood loss was 73.5 ± 22.5 mL (range, 50-150 mL). The patients exhibited excellent alignment in the injured limb after intramedullary nailing. Seventeen patients successfully completed a follow-up after fracture healing. The healing time ranged from 4 to 6 months. CONCLUSIONS: Displaced femoral shaft fractures in adults can be treated by a labour-saving lever technique involving fragments, 2 haemostatic forceps and soft tissue envelope-assisted closed reduction and intramedullary nail fixation. This technique is easy to perform; reduces blood loss, the fluoroscopy time and the surgical time for intraoperative reduction; and leads to excellent fracture healing.

[Effectiveness of repairing the deep layer of deltoid ligament by suture anchor repair method in treatment of mixed medial injury associated with ankle fractures].

OBJECTIVE: To explore the necessity of repairing the deep layer of deltoid ligament in the treatment of mixed medial injury associated with ankle fractures. METHODS: Between January 2016 and December 2018, 12 patients with mixed medial injury associated with ankle fractures were treated with the fixation of the lateral malleolus by bone plates, the fixation of the anterior colliculus of medial malleolus by cannulated screws, and the repair of the deltoid ligament by suture anchors. There were 8 males and 4 females, with an average age of 42 years (range, 18-56 years). According to the Lauge-Hansen classification criteria, there were 11 cases of supination-external rotation type and 1 case of pronation-external rotation type. According to the Weber classification criteria, all cases were type B. The time from injury to operation was 3-6 days, with an average of 4.7 days. In each patient, X-ray films of anteroposterior and lateral views and mortise view of ankle were taken postoperatively. The motion range of ankle joints was observed. The function of the ankle and the outcome of the treatment were evaluated according to the American Orthopaedic Foot and Ankle Society (AOFAS) scoring system, Olerud-Molander scoring system, and the visual analogue scale (VAS) score. RESULTS: All cases were followed up 12-42 months (mean, 28 months). The 12 patients returned to their pre-injury jobs. Five patients with sports injury completely recovered to their pre-injury motor function. No patient experienced persistent medial ankle pain or ankle instability. At last follow-up, the ankle range of motion in dorsiflexion was 9°-25° (mean, 17.96°), which was 0°-11° (mean, 4.02°) less than that in normal side; the range of motion in plantar flexion was 38°-50° (mean, 43.90°), which was 0°-7° (mean, 2.53°) less than that in normal side. The AOFAS score was 88-100 (mean, 96.7); the Olerud-Molander score was 90-100 (mean, 96.5); the VAS score was 0-3 (mean, 1.1). CONCLUSION: It is necessary to repair the deep layer of deltoid ligament in the mixed medial injuries associated with ankle fracture, which include anterior colliculus fracture and deep deltoid ligament injury. A better outcome can be achieved by employing the suture anchor repair method.

Minimally invasive treatment of old femoral fractures in adults.

OBJECTIVE: Extensive incision associated with large-scale callus exfoliation and internal fixation is the common therapeutic approach employed by the majority of orthopaedists in the treatment of old femoral fractures. Inspired by the surgical techniques of intramedullary fixation and reduction by traction, the present study attempted to treat old femoral fractures with minimally invasive methods utilising the principles of biological osteosynthesis (BO). METHODS: A retrospective analysis involving 16 patients with old femoral fractures treated with combined traction, small incision, limited callus treatment, reduction by leverage and intramedullary fixation was conducted. The operative effect was evaluated by the operation time, intraoperative blood loss, bone grafting, healing time of fractures during follow-up, VAS score, and Harris hip score. RESULTS: Intraoperative observation revealed an average operation time of 1.53 ± 0.34 h and average blood loss of 268.13 ± 97.29 ml without bone grafting in all patients. All enrolled patients had outcomes resulting in effective fixation restoration of limb alignment. Of the 16 enrolled patients, 13 patients completed follow-up with an average follow-up time of 7.42 ± 3.29 months. The average healing time for proximal femoral fractures was 3 months. The average healing time of femoral shaft fractures was 4 ± 1.09 months; two of these cases took 4 months to heal, whereas 1 case demonstrated a delayed healing time of 6 months. The VAS score was 1.15 ± 1.70, 1 patient experienced sciatica, and the Harris hip score was 92.92 ± 5.42. There were no complications of malunion, nonunion or infection among any of the patients who completed follow-up. CONCLUSIONS: Minimally invasive treatment is feasible for most patients with old femoral fractures of the trochanter and femoral shaft. This finding is consistent with BO principles, thereby providing a possible new method for the treatment of old femoral fractures.

BMP9 Promotes the Extracellular Matrix of Nucleus Pulposus Cells via Inhibition of the Notch Signaling Pathway.

Intervertebral disk degeneration (IDD) is a common disease that is caused by degeneration of the nucleus pulposus (NP). One goal in the treatment of IDD is delaying or reversing the degeneration of NP via the transformation of exogenous genes. This study first investigated the role of BMP9 in the extracellular matrix (ECM) of nucleus pulposus cells (NPCs) and its mechanism. We found that BMP9 promotes the expression of ECM in NPCs, and the key molecules of Notch signaling, namely, NICD-1, hes and hey, and it was significantly altered in BMP9-transfected NPCs, which suggests that BMP9 may regulate the ECM via the Notch signaling pathway. We verified the expression of Notch ligands and receptors in NPCs infected with Ad-BMP9 and demonstrated a significant decrease in DLL1 and Notch1; then, NPCs were transfected with Ad-dnNotch1, Ad-Jagged1, and Ad-DLL1, and different multiple groups were established to further identify the ligands or receptors that affected ECM expression. The results demonstrated that Ad-dnNotch1, Jagged1 and DLL1 inhibited ECM expression, and dnNotch1 promoted expression. Therefore, we demonstrated that BMP9 promoted the expression of ECM in NPCs via inhibition of Notch1 and DLL1. This study provides a possible method for IDD treatment.

Efficacy and antiparasitic mechanism of 10-gingerol isolated from ginger Zingiber officinale against Ichthyophthirius multifiliis in grass carp.

Ichthyophthirius multifiliis is a ciliate parasite of freshwater fish with a global distribution and results in severe economic losses in aquaculture. The present study aimed to investigate the efficacy and antiparasitic mechanism of active compounds isolated from Zingiber officinale against I. multifiliis. Three compounds were isolated from the Z. officinale extract and identified as 10-gingerol, 6-dehydroshogaol, and 6-dehydro-10-gingerol. 10-gingerol demonstrated the greatest antiparasitic efficacy in vitro. 10-gingerol resulted in 100% mortalities of theronts, nonencysted tomonts, and encysted tomonts at concentrations of 2, 8, and 16 mg/L, respectively. 10-gingerol significantly reduced theronts infectivity (p < 0.05) at a concentration of 1 mg/L, and it was effective in treating infected grass carp and protecting naïve fish from I. multifiliis infestation at a concentration of 4 mg/L. The antiparasitic mechanism might be attributed to the increase of intracellular osmotic pressure, accumulation of free radicals, and membrane damage of I. multifiliis post 10-gingerol treatment. The study demonstrated that 10-gingerol had the potential as a therapeutic agent against I. multifiliis.

Quantification of Paclitaxel and Polyaspartate Paclitaxel Conjugate in Beagle Plasma: Application to a Pharmacokinetic Study.

An LC-MS/MS method for the determination of polyaspartate paclitaxel conjugate (PASP-PTX) and paclitaxel (PTX) in dog plasma with cephalomannine (Internal Standard for PASP-PTX, IS-I) and clopidogrel bisulfate (Internal Standard for PTX, IS-II) as the internal standards was developed and validated. Plasma samples of PASP-PTX were extracted by ethyl acetate following the hydrolysis reaction, while protein precipitation was used for the extraction of PTX using acetonitrile. Analytes were separated by a CAPCELL PAK C18 MG II column using a gradient elution with the mobile phase (A) 5 mM ammonium containing 0.1% formic acid, and (B) acetonitrile. Quantification was performed by monitoring the m/z transitions of 286.2/105.0 for PASP-PTX, 264.2/83.0 for IS-I, 854.4/286.0 for PTX, and 322.1/184.1 for IS-II in the ESI positive mode. This method was validated in terms of specificity, linearity, precision, accuracy, and stability. The lower limit of quantification was 0.15 µg/mL for PASP-PTX and 0.01 µg/mL for PTX, and the calibration curves were linear over 0.15-300 µg/mL for PASP-PTX and over 0.01-10 µg/mL for PTX. The samples were stable under all the tested conditions. The method was successfully applied to study the pharmacokinetic profiles of PASP-PTX and PTX in beagles following intravenous administration of PASP-PTX.

Human mesenchymal stem cells as delivery of osteoprotegerin gene: homing and therapeutic effect for osteosarcoma.

Biological treatments have been studied extensively and previous studies have proved that osteoprotegerin (OPG) can inhibit the development and progress of human osteosarcoma. However, the utility of biologic agents for cancer therapy has a short half-life, which can hardly deliver to and function in tumor sites efficiently. Mesenchymal stem cells (MSCs) have the potential to migrate to tumor sites. In this study, MSCs transfected with adenoviruses carrying the OPG gene (MSCs-OPG) were used via the tail vein to treat athymic nude mice (nu/nu) bearing osteosarcoma. In vivo and ex vivo images were used to validate the MSCs homing to tumors. The therapeutic effect for osteosarcoma was evaluated by observations on growth of tumors and bone destruction. The results showed that infected MSCs-OPG labeled with red fluorescent protein (RFP) can migrate to tumor sites and express OPG protein. The treatment by MSCs-OPG reduced the tumor growth and inhibited bone destruction in vivo. All these indicated that MSCs can deliver OPG to tumor sites, which could be a new direction of biological treatment for human osteosarcoma.

Bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber composite: biomechanical properties and biocompatibility.

An ideal bone plate for internal fixation of bone fractures should have good biomechanical properties and biocompatibility. In this study, we prepared a new nondegradable bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber (n-HA/PA66/GF) composite. A breakage area on the n-HA/PA66/GF plate surface was characterized by scanning electron microscopy. Its mechanical properties were investigated using bone-plate constructs and biocompatibility was evaluated in vitro using bone marrow-derived mesenchymal stem cells. The results confirmed that adhesion between the n-HA/PA66 matrix and the glass fibers was strong, with only a few fibers pulled out at the site of breakage. Fractures fixed by the n-HA/PA66/GF plate showed lower stiffness and had satisfactory strength compared with rigid fixation using a titanium plate. Moreover, the results with regard to mesenchymal stem cell morphology, MTT assay, Alizarin Red S staining, enzyme-linked immunosorbent assay, and reverse transcription polymerase chain reaction for alkaline phosphatase and osteocalcin showed that the n-HA/PA66/GF composite was suitable for attachment and proliferation of mesenchymal stem cells, and did not have a negative influence on matrix mineralization or osteogenic differentiation of mesenchymal stem cells. These observations indicate that the n-HA/PA66/GF plate has good biomechanical properties and biocompatibility, and may be considered a new option for internal fixation in orthopedic surgery.

The immunomodulatory activity of human umbilical cord blood-derived mesenchymal stem cells in vitro.

Bone marrow-derived mesenchymal stem cells (BM-MSC) are currently being investigated in preclinical and clinical settings because of their self-renewal and multipotent differentiative capacity or their immunosuppressive function. However, BM may be detrimental because of the highly invasive donation procedure and BM-MSC decline with age. Therefore, MSC derived from other sources have been considered as an alternative. However, there is only limited knowledge on their immunomodulatory properties. Human umbilical cord blood (UCB) cells are good substitutes for BM-MSC because of the immaturity of newborn cells. In this study, we successfully isolated MSC from UCB. The morphological phenotypes, cell cycle status, surface markers and differentiation potential of these clonally expanded cells are consistent with BM-MSC. Furthermore, UCB-MSC expanded in vitro retain low immunogenicity and an immunomodulatory effect. Flow cytometry analysis showed that UCB-MSC did not express CD40, CD40 ligand, CD80, CD86 and major histocompatibility complex class II molecules. We have demonstrated that UCB-MSC are incapable of inducing allogeneic peripheral blood mononuclear cell (PBMC) proliferation and have a dose-dependent inhibition of PBMC immune responses in mixed lymphocyte reactions (MLR) and phytohaemagglutinin activation assays, even after interferon-gamma treatment. Additionally, we have found that UCB-MSC can suppress the function of mature dendritic cells. Using transwell systems, we have demonstrated an inhibition mechanism that depends on both cell contact and soluble factors. Based on the findings we conclude that banked UCB could serve as a potential alternative source of MSC for allogeneic application in the future.