In vitro chondral culture under compression and shear stimuli. From mesenchymal stem cells to hyaline cartilage. / Cultivo condral in vitro bajo estímulos de compresión y cizallamiento. De las células troncales mesenquimales al cartílago hialino.

INTRODUCTION: The in vitro creation of hyaline joint cartilage is a challenge since, to date, the ex vivo synthesis of a structured tissue with the same biomechanical and histological properties of the joint cartilage has not been achieved. To simulate the physiological conditions we have designed an in vitro culture system that reproduces joint movement. MATERIAL AND METHOD: We have developed a cell culture bioreactor that prints a mechanical stimulus on an elastin matrix, in which mesenchymal stem cells (MSC) are embedded. The first phase of study corresponds to the development of a bioreactor for hyaline cartilage culture and the verification of cell viability in the elastin matrix in the absence of stimulus. The second phase of the study includes the MSC culture under mechanical stimulus and the analysis of the resulting tissue. RESULTS: After culture under mechanical stimulation we did not obtain hyaline tissue due to lack of cellularity and matrix destructuring. CONCLUSION: The stimulus pattern used has not been effective in generating hyaline cartilage, so other combinations should be explored in future research.

Xenotransplantation of human adipose-derived stem cells in the regeneration of a rabbit peripheral nerve.

Adipose tissue-derived mesenchymal stem cells (AdMSCs) are useful in the regeneration of neural tissues. Furthermore, xenotransplantation of human adipose tissue-derived mesenchymal stem cells (hAdMSCs) into animal models has already been tested and the results encouraged us to study peripheral nerve regeneration in rabbits, in order to test the feasibility of a xenotransplantation of hAdMSCs. ANIMALS AND METHOD: To promote end-to-end nerve fiber contacts of a 4-cm gap in the peroneal nerve of white New Zealand rabbits, an autologous vein conduit was used and three groups of animals were evaluated. In Group I, the gap was repaired with a vein conduit refilled with fibrin. Group II was similar, but the animals were treated with cyclosporine A. In Group III, a fibrin scaffold with hAdMSCs was placed inside the autologous vein conduit, and animals were treated with cyclosporine A. Neurofilament immunohistochemistry results showed 100% nerve regeneration at the vein guidance channel 90 days after the surgery in the hAdMSC-transplanted group but lesser neural regeneration in the neurofilaments of groups I and II. The analysis of variance (ANOVA) test showed statistically significant differences among all groups (p < 0.04). Group III exclusively tested positive for human monoclonal anti-mitochondrial antibody. Electron microscopy images showed tiny bundles, with a predominance of nonmyelinated axons. Myelinated axons caused irregular thickness of the myelin sheath, which was especially observed in group III. CONCLUSIONS: Xenotransplantation of hAdMSCs into a fibrin scaffold promoted nerve regeneration through a vein conduit that connected a 4-cm gap created at the peroneal nerve of rabbits. Animals treated with hAdMSCs presented negative inflammatory response at the regenerated nerve gaps, but it was demonstrated that hAdMSCs were incorporated to the new nerve creating neural tissue and endothelial cells. However, hAdMSCs required immunosuppression with cyclosporine A to achieve axonal regeneration.

Platelet-rich plasma: applications in dermatology.

In recent years, the use of platelet-rich plasma has increased notably in a range of diseases and settings. Uses of these products now go beyond skin rejuvenation therapy in patients with facial ageing. Good outcomes for other dermatological indications such as skin ulcers and, more recently, alopecia have been reported in case series and controlled studies. However, these indications are not currently included in the labeling given that stronger scientific evidence is required to support their real benefits. With the increased use of these products, dermatologists need to become familiar with the underlying biological principles and able to critically assess the quality and outcomes of the studies of these products in different skin diseases.

¿Puedo seguir aplicando plasma rico en plaquetas a mis pacientes?, ¿cómo hacerlo legalmente? / Can I continue to use platelet-rich-plasma on my patients?, How do I use it legally?

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