Intraarticular injection of autologous chondrogenic induced bone marrow stem cells promotes regenesis of traumatic osteoarthritis and promotes repair of meniscus injury in a sheep model

Objective. The aim of this study was to determine if autologous bone marrow mesenchymal stem cells (AMSCs) cultured in chondrogenic medium containing growth factors could repair meniscus tissue and retard surgically induced osteoarthritis in the knee joint. Methods. Autologous Sheep bone marrow stem cells (AMSCs) were aspirated from sheep iliac crest and cultured in medium containing 5ng/ml TGFβ3 + 50ng/ml IGF-1 for 3 weeks. Six weeks after surgically induced osteoarthritis; a single dose of chondrogenic inducted AMSCs suspended in 5 ml Dulbecco’s Modified Eagle Medium (DMEM) at density of 10 million cells was injected intra-articularly into the osteoarthritic knee joint. After addition of another 6 weeks, the sheep were scarified and the femoral condyle and the proximal tibia were removed, fixed and photographed. The gross of the removed knee joint were graded by a blinded assessor based on ICRS grading system. Part of the tissue was imbedded in paraffin and sectioned into 5µm and stained with H&E and Safranin O. Result. The results indicated that surgically induced osteoarthritic knee joint treated with chondrogenic inducted AMSCs showed clear evidence of minimum articular cartilage destruction with meniscus repaired when compared with other control knee joints. Conclusion Our findings demonstrated that intra-articular injection of chondrogenic inducted AMSCs could stimulate regeneration of meniscal tissue and retards the progressive of osteoarthritis in sheep model

Anterior cruciate ligament resection and medial meniscectomy result in multifocal cartilage degenerations

Abstract: Damage to the meniscus and the anterior cruciate ligament alters the pattern of loading in the knee joint and frequently leads to cartilage degeneration and osteoarthritis. This study aimed to evaluate the area of greatest impact after traumatic osteoarthritic induction at the knee joint in sheep model. Osteoarthritis was induced unilaterally at the right hind knee of six sheep by surgical resection of the anterior cruciate ligament and medial meniscus. After 3 weeks recovery period, sheep were exercised once daily by running a 100 meters distance on a hard surface for 3 weeks. Gross and histological assessments were done. Six regions examined were; the patella, patella femoral groove, medial femoral condyle, lateral femoral condyle, medial tibia plateau and lateral tibia plateau. Their mean International Cartilage Repair Society grading was: 2.5±0.42, 3.3±0.17, 2.25±0.38, 1.33±0.25, 2±0.37 and 1.5±0.22 respectively. The control from all samples scored zero at the above regions. The lesions at various regions were significantly higher compared to the control (p < 0.05). Patella femoral groove was significantly higher compare to all other regions except for Patella. Lateral femoral condyle was the least (p < 0.05). Histological staining revealed defined osteoarthritic changes. Total excision of medial meniscus and anterior cruciate ligament followed by exercise regime induced osteoarthritis in the affected knee joint. The changes in pattern of degeneration, affected patella femoral groove the most; followed by the patella and medial femoral condyle, then medial tibia plateau, lateral tibia plateau and lastly the lateral femoral condyle

Dielectrophoretically assembled particles : feasibility for optofluidic systems

This work presents the dielectrophoretic manipulation of sub-micron particles suspended in water and the investigation of their optical responses using a microfluidic system. The particles are made of silica and have different diameters of 600, 450, and 250 nm. Experiments show a very interesting feature of the curved microelectrodes, in which the particles are pushed toward or away from the microchannel centerline depending on their levitation heights, which is further analyzed by numerical simulations. In doing so, applying an AC signal of 12 Vp-p and 5 MHz across the microelectrodes along with a flow rate of 1 &mu;l/min within the microchannel leads to the formation of a tunable band of particles along the centerline. Experiments show that the 250 nm particles guide the longitudinal light along the microchannel due to their small scattering. This arrangement is employed to study the feasibility of developing an optofluidic system, which can be potentially used for the formation of particles-core/liquid-cladding optical waveguides