BACKGROUND: Tissue engineering is a multidisciplinary area of research which aims to regenerate damaged tissues and organs in the human body, starting from the assumption that almost all animal tissues in the human body can be cultivated in a laboratory. The general principle is to isolate stem cells from a patient who requires a transplant and then the cells are cultured to grow and differentiate on a suitable support to produce the replacement tissue. On the one hand, it is necessary to find a suitable support (matrix or scaffold) on which cells can adhere and form stratified structures. On the other hand, the conditions allowing cells to proliferate and differentiate into the various types of tissues must be understood and reproduced. At present, the materials used as support in the treatment of ulcers and bums are manifold, such as collagen, hyaluronic acid, fibrin and PLGA. OBJECTIVE: To discuss the effectiveness of a new kind of biomaterial, autologous plasma, as scaffold for the growth, expansion and differentiation of autologous fibroblasts and keratinocytes.DESIGN: We have devised a method for dermal regeneration using autologous fibroblasts immersed in a matrix of human plasma so as to eliminate any problem linked to the safety of the sample and rejection from a patient. On this new dermis, keratinocytes have then been seeded.TIME AND SETTING: This work was performed at Cell Factory of C. Poma Hospital in Mantova in 2008. PARTICIPANT/MATERIALS: The human keratinocytes and fibroblasts used for this research were taken from a skin fragment after mastectomy in a 58-year-old patient. The experiment was approved by the independent ethics committee of C. Poma Hospital and the patient was requested to give informed consent.INTERVENTIONS/METHODS: Our studies were focussed on the isolation of human basal keratinocytes and fibroblasts from autologous biopsied skin samples and on their proliferation in culture flasks. Autologous plasma was subsequently used as scaffold for the formation of skin grafts whose morphofunctional and immunohistochemical characteristics are similar to those of normal skin.MAIN OUTCOME MEASURES: In order to evaluate the results, the samples of plasma were fixed in formalin, embedded in paraffin, stained with haematoxilyn-eosin and viewed through a microscope to count the number of cells in 40-fold 5 fields. Furthermore, all specimens underwent immunohistochemical examination for vimentin, keratin AE1 and AE3, collagen IV, P63 and Mib 1. RESULTS: The skin grafts obtained in the present study consist of few layers of normally-shaped keratinocytes on a plasma matrix with fibroblasts embedded inside. The formation of basement membrane shows that autologous plasma is a good scaffold for the growth, differentiation and proliferation of keratinocytes and fibroblasts and it also demonstrates that dermal and epidermal cells can be interlocked to reconstruct artificial grafts identical to normal skin.CONCLUSION: Plasma has given a remarkable performance as scaffold for the proliferation and differentiation of keratinocytes and fibroblasts. In particular, we have observed that fibroblast-enriched plasma can replace dermis temporarily, besides being a robust scaffold for the growth of keratinocytes. In addition, plasma is relatively cheap and easy to prepare. The use of autologous keratinocytes and fibroblasts, as well as that of autologous plasma, is essential to avoid any type of rejection. This kind of therapy is ideal for patients with chronic defects requiring continuous grafts.

The spatial distribution, innervation, and functional role of the bone-associated skeletal nerves have been previously reported in detail. However, studies examining exercise-induced associations between skeletal nerves and bone metabolism are limited. This review introduces a potential relationship between exercise and the skeletal nerves and discusses how it can contribute to exercise-induced bone anabolism. First, the background and current understanding of nerve fiber types and their functions in the skeleton are provided. Next, the influence of exercise and mechanical loading on the skeletal nervous system is elaborated. Effective synthesis of recent studies could serve as an established baseline for the novel discovery of the effects of exercise on skeletal nerve density and bone anabolic activity in the future. Therefore, this review overviews the existing evidence for the neural control of bone metabolism and the potential positive effects of exercise on the peripheral skeletal nervous system. The influence of exercise training models on the relationships of sensory nerve signals with osteoblast-mediated bone formation and the increased bone volume provides the first insight on the potential importance of exercise training in stimulating positive adaptations in the skeletal nerve-bone interaction and its downstream effect on bone metabolism, thereby highlighting its therapeutic potential in a variety of clinical populations.