BACKGROUND: In order to enhance the rate and degree of osseointegration of cementless implants, hydroxyapatile(HA) was applied on the different prosthesissurfaces. Themajoritiesofthesestudieshaveutilized non-weight-bearing in vivo dog models and have focused on the fixation of the femoral component. What is the osseointegration of macrotextured acetabular components in a weight-bearing model(dog) like?OBJECTIVE:To evaluate the various macrotextured surface coatings applied to acetabular components of the same design in aweight-bearing canine total hip replacement model.DESIGN: Randomized conparative study using theexperimentalanimals as subjectsSETTING: Department of Ortopaedics, Beijing Tongren Hospital;PathologyDepartment, Bone and Joint Laboratory,St. Michael' s Hospital, U of T,Toronto,CanadaMATERIALS: The experiment was completed in the Pathology Department,Bone and Joint laboratory, St. Michael' s Hospital, U of T, Toronto, Canada from October 2001 to December 2001. Acetabular components with the selected surface characteristics were implanted into forty dogs with the body mass of 29 - 44 kg of either gender and divided into seven groups, including group 1 (AD/HA), Group 2 (CoCr beads/PA), Group 3 (CPTi bead surface),Group 4(CPTi 30 PPI foam),Group 5(CPTi 30 PPI/PA foam),Group 6(CPTi 40 PPI foam), Group 7(CPTi 40 PPI/PA foam).METHODS: Exercise was restricted to leash walks for the first fourteen days post-operatively. After this, dogs were allowed unrestricted activity. The dogs were euthanized at either three or sixmonths after surgery as the project' s protocol. The whole acetabulum,divided into weight-bearing and non weightbearing areas, containing the component was harvested and submitted for histological and histomorphological assessment. MAIN OUTCOME MEASURES:The bone ongrowth and ingrowth with weight bearing and without weight bearing areas in each group.RESULTS:There was significantly greater bone apposition and bone ingrowth for implants withHAcoatingsascompared to uncoated implants. There was also significantly greater bone ingrowth in weight-bearing areas as compared tonon weight-bearing areas at both time periods. The bone growth into AD/HA was 17％ at 3 months and descended to 14％ at 6 months. The bone growth into CPTi beads surface was 21％ at 3 months,30％ at 6months in weight-bearing areas. All four foam-coating surfaces there were 15％ to 21％ ongrowth at 3 months,15％ to 32％ at 6 months and 21％to 32％ingrowth at 3 months,29％to 45％at 6 months in weight-bearing areas( P ＜ 0.05).CONCLUSION: Hydroxyapatite coating produces significantly greater boneingrowth andappositionin all thesurfacetreatmentstestedinthis study. Weightbearingproducesagreater boneingrowththannon weight-bearing areas and obviously increases with the time prolonging, especially the foam coating

Recent studies of exosomes derived from mesenchymal stem cells (MSCs) have indicated high potential clinical applications in many diseases. However, the limited source of MSCs impedes their clinical research and application. Most recently, induced pluripotent stem cells (iPSCs) have become a promising source of MSCs. Exosome therapy based on iPSC-derived MSCs (iMSCs) is a novel technique with much of its therapeutic potential untapped. Compared to MSCs, iMSCs have proved superior in cell proliferation, immunomodulation, generation of exosomes capable of controlling the microenvironment, and bioactive paracrine factor secretion, while also theoretically eliminating the dependence on immunosuppression drugs. The therapeutic effects of iMSC-derived exosomes are explored in many diseases and are best studied in wound healing, cardiovascular disease, and musculoskeletal pathology. It is pertinent clinicians have a strong understanding of stem cell therapy and the latest advances that will eventually translate into clinical practice. In this review, we discuss the various applications of exosomes derived from iMSCs in clinical medicine.

In this paper, we prepared a dual functional system based on dextrin-coated silver nanoparticles which were further attached with iron oxide nanoparticles and cell penetrating peptide (Tat), producing Tat-modified Ag-FeO nanocomposites (Tat-FeAgNPs). To load drugs, an -SH containing linker, 3-mercaptopropanohydrazide, was designed and synthesized. It enabled the silver carriers to load and release doxorubicin (Dox) in a pH-sensitive pattern. The delivery efficiency of this system was assessed using MCF-7 cells, and using null BalB/c mice bearing MCF-7 xenograft tumors. Our results demonstrated that both Tat and externally applied magnetic field could promote cellular uptake and consequently the cytotoxicity of doxorubicin-loaded nanoparticles, with the IC of Tat-FeAgNP-Dox to be 0.63 µmol/L. The delivery efficiency of Tat-FeAgNP carrying Cy5 to the mouse tumor was analyzed using the optical imaging tests, in which Tat-FeAgNP-Cy5 yielded the most efficient accumulation in the tumor (6.7±2.4% ID of Tat-FeAgNPs). Anti-tumor assessment also demonstrated that Tat-FeAgNP-Dox displayed the most significant tumor-inhibiting effects and reduced the specific growth rate of tumor by 29.6% ( = 0.009), which could be attributed to its superior performance in tumor drug delivery in comparison with the control nanovehicles.