Mesenchymal stem/stromal cells (MSCs)‐based therapy brings the reassuring capability to regenerative medicine through their self‐renewal and multilineage potency. Also, they secret a diversity of mediators, which are complicated in moderation of deregulated immune responses, and yielding angiogenesis in vivo. Nonetheless, MSCs may lose biological performance after procurement and prolonged expansion in vitro. Also, following transplantation and migration to target tissue, they encounter a harsh milieu accompanied by death signals because of the lack of proper tensegrity structure between the cells and matrix. Accordingly, pre-conditioning of MSCs is strongly suggested to upgrade their performances in vivo, leading to more favored transplantation efficacy in regenerative medicine. Indeed, MSCs ex vivo pre-conditioning by hypoxia, inflammatory stimulus, or other factors/conditions may stimulate their survival, proliferation, migration, exosome secretion, and pro-angiogenic and anti-inflammatory characteristics in vivo. In this review, we deliver an overview of the pre-conditioning methods that are considered a strategy for improving the therapeutic efficacy of MSCs in organ failures, in particular, renal, heart, lung, and liver.

Platform-switching reduces peri-implant marginal bone loss (MBL), and the aim of this study was to compare the effect of platform-switching on stress within crestal bone using different implant-abutment mis-matches (0.65 and 1mm) under two different vertical loads (30 N vs 200 N) for implants placed in posterior jaw sites. 3-D modeling software was used for an implant of 4.5mm diameter and 13mm length. Molars were modeled using CT images of bone density in human maxilla (D3 bone) and mandible (D2 bone). Collected data were analyzed using CATIA software. In posterior mandible, stress of 30 N force with platform mis-matches of 0.65 or 1mm were 2.920 and 2.440 MPa respectively. Using 200 N force, values increased to 19.44 and 16.30 MPa. In posterior maxilla and 30 N force, stresses with mis-matches of 0.65 and 1mm were 3.77 and 3.18 MPa respectively increasing to 25.14 & 20.17 with 200 N force. The effect can be predicted to be greatest as the mis-match increases with implants placed into lower quality bone (posterior maxilla with D3 quality).

No abstract