The use of mesenchymal stem cells for cartilage repair and regeneration: a systematic review.

BACKGROUND: The management of articular cartilage defects presents many clinical challenges due to its avascular, aneural and alymphatic nature. Bone marrow stimulation techniques, such as microfracture, are the most frequently used method in clinical practice however the resulting mixed fibrocartilage tissue which is inferior to native hyaline cartilage. Other methods have shown promise but are far from perfect. There is an unmet need and growing interest in regenerative medicine and tissue engineering to improve the outcome for patients requiring cartilage repair. Many published reviews on cartilage repair only list human clinical trials, underestimating the wealth of basic sciences and animal studies that are precursors to future research. We therefore set out to perform a systematic review of the literature to assess the translation of stem cell therapy to explore what research had been carried out at each of the stages of translation from bench-top (in vitro), animal (pre-clinical) and human studies (clinical) and assemble an evidence-based cascade for the responsible introduction of stem cell therapy for cartilage defects. This review was conducted in accordance to PRISMA guidelines using CINHAL, MEDLINE, EMBASE, Scopus and Web of Knowledge databases from 1st January 1900 to 30th June 2015. In total, there were 2880 studies identified of which 252 studies were included for analysis (100 articles for in vitro studies, 111 studies for animal studies; and 31 studies for human studies). There was a huge variance in cell source in pre-clinical studies both of terms of animal used, location of harvest (fat, marrow, blood or synovium) and allogeneicity. The use of scaffolds, growth factors, number of cell passages and number of cells used was hugely heterogeneous. SHORT CONCLUSIONS: This review offers a comprehensive assessment of the evidence behind the translation of basic science to the clinical practice of cartilage repair. It has revealed a lack of connectivity between the in vitro, pre-clinical and human data and a patchwork quilt of synergistic evidence. Drivers for progress in this space are largely driven by patient demand, surgeon inquisition and a regulatory framework that is learning at the same pace as new developments take place

Risk of subsequent primary oral cancer in a cohort of 69,460 5-year survivors of childhood and adolescent cancer in Europe: the PanCareSurFup study

Background Survivors of childhood cancer are at risk of subsequent primary malignant neoplasms (SPNs), but the risk for rarer types of SPNs, such as oral cancer, is uncertain. Previous studies included few oral SPNs, hence large-scale cohorts are required to identify groups at risks. Methods The PanCareSurFup cohort includes 69,460 5-year survivors of childhood cancer across Europe. Risks of oral SPNs were defined by standardised incidence ratios (SIRs), absolute excess risks and cumulative incidence. Results One hundred and forty-five oral SPNs (64 salivary gland, 38 tongue, 20 pharynx, 2 lip, and 21 other) were ascertained among 143 survivors. Survivors were at 5-fold risk of an oral SPN (95% CI: 4.4-5.6). Survivors of leukaemia were at greatest risk (SIR = 19.2; 95% CI: 14.6-25.2) followed by bone sarcoma (SIR = 6.4, 95% CI: 3.7-11.0), Hodgkin lymphoma (SIR = 6.2, 95% CI: 3.9-9.9) and soft-tissue sarcoma (SIR = 5.0, 95% CI: 3.0-8.5). Survivors treated with radiotherapy were at 33-fold risk of salivary gland SPNs (95% CI: 25.3-44.5), particularly Hodgkin lymphoma (SIR = 66.2, 95% CI: 43.6-100.5) and leukaemia (SIR = 50.5, 95% CI: 36.1-70.7) survivors. Survivors treated with chemotherapy had a substantially increased risk of a tongue SPN (SIR = 15.9, 95% CI: 10.6-23.7). Conclusions Previous radiotherapy increases the risk of salivary gland SPNs considerably, while chemotherapy increases the risk of tongue SPNs substantially. Awareness of these risks among both health-care professionals and survivors could play a crucial role in detecting oral SPNs early.</p

Methods to monitor distribution and metabolic activity of mesenchymal stem cells following in vivo injection into nucleotomized porcine intervertebral discs

Intervertebral disc (IVD) degeneration involves a series of biochemical and morphological changes leading to loss of spinal stability and flexibility. Cell therapy is promising to reconstitute IVDs with new cells, however, sustained metabolic activity seems crucial for an active contribution to regeneration. The aim of the present study was to establish methods for separate follow up of persistence and activity of autologous porcine mesenchymal stem cells (pMSC) after implantation into IVDs of Goettingen minipigs in vivo in order to conclude about the potential of such an intervention strategy. For quantitative follow up, the transfer matrix was supplemented with Al2O3 particles and pMSC which were retrovirally labeled with firefly luciferase (pMSC-Luc). Six mature Goettingen minipigs underwent matrix based cell transfer after partial nucleotomy of lumbar IVDs (n = 24). Day 0 and day 3 segments were analyzed for retained volume of Al2O3 particles by micro-computed-tomography (μCT) and for cell activity by luciferase enzyme assessment. Three days after injection a reduction of Al2O3 particles (P = 0.028) to about 9% and of pMSC-Luc activity to about 7% of initial values (P = 0.003) was detected, which suggests loss of 90% of the implant material under in vivo conditions without evidence for reduced pMSC-Luc metabolic activity (P = 0.887). In conclusion, separate follow up of implant material and cell activity was possible and unravels problems with in vivo implant persistence after annular puncture rather than quick loss of cell activity. Therefore, IVD-regeneration-strategies should increasingly focus on annulus reconstruction in order to reduce implant loss due to annular failure