The clinical use of platelet-rich plasma (PRP) is based on the increase in the concentration of growth factors and in the secretion of proteins which are able to maximize the healing process at the cellular level. Since PRP is an autologous biologic material, it involves a minimum risk of immune reactions and transmission of infectious and contagious diseases, and it has been widely used for the recovery of musculoskeletal lesions. Despite the great potential for applicability, the implementation of the therapeutic employment of PRP as a clinical alternative has become difficult, due to the lack of studies related to the standardization of the techniques and/or insufficient description of the adopted procedures. Therefore, it is required establish standard criteria to be followed for obtaining a PRP of high quality, as well as a larger number of studies which should establish the proper concentration of platelets for the different clinical conditions. In this context, the purpose of this review is to discuss some methodological aspects used for achieving the PRP, as well as to discuss the bioactive properties of PRP, and to point out its therapeutic use in different fields of regenerative medicine.

Within the chronic obstructive pulmonary disease (COPD) spectrum, lung emphysema presents, as a primarily histopathologic feature, the destruction of pulmonary parenchyma and, accordingly, an increase in the airflow obstruction distal to the terminal bronchiole. Notwithstanding the significant advances in prevention and treatment of symptoms, no effective or curative therapy has been accomplished. In this context, cellular therapy with stem cells (SCs) arises as a new therapeutic approach, with a wide application potential. The purpose of this study is to evaluate the safety of SCs infusion procedure in patients with advanced COPD (stage IV dyspnea). After selection, patients underwent clinical examination and received granulocyte colony-stimulating factor, immediately prior to the bone marrow harvest. The bone marrow mononuclear cells (BMMC) were isolated and infused into a peripheral vein. The 12-month follow-up showed a significant improvement in the quality of life, as well as a clinical stable condition, which suggest a change in the natural process of the disease. Therefore, the proposed methodology in this study for BMMC cell therapy in sufferers of advanced COPD was demonstrated to be free of significant adverse effects. Although a larger sample and a greater follow-up period are needed, it is possible to infer that BMMC cell therapy introduces an unprecedented change in the course or in the natural history of emphysema, inhibiting or slowing the progression of disease. This clinical trial was registered with ClinicalTrials.gov (NCT01110252) and was approved by the Brazilian National Committee of Ethics in Research (registration no. 14764, CONEP report 233/2009).

The clinical use of tissue engineering associated with cell therapy is considered a new alternative therapy for the repair of chronic lesions with potential application in different medical areas, mostly in orthopedic and dermatological diseases. Platelet-rich plasma (PRP) is a rich source of growth factors and cytokines important for wound healing. Adipose-derived mesenchymal stem cells (ADSCs) have shown potential to accelerate the resolution of ulcers, to stimulate cell proliferation, and to benefit the quality of skin repair. This study aims to determine the effect of PRP and conditioned medium (CM) from ADSC on fibroblast and keratinocyte proliferation in vitro. Migration and proliferation assays were performed to evaluate the growth of fibroblasts and keratinocytes in the presence of PRP, CM, and CM + PRP. Significant proliferative stimulation was observed after 48 h of culture (p < 0.05) on mean absorbance of fibroblasts cultured with 10 and 25 % PRP, 100 % CM, and 25 % PRP + 25 % CM, if compared with control. Keratinocyte proliferation was stimulated after 48 h in cultures with 25, 50, and 100 % CM, and growth was compared with controls. The migration assay detected a significant migratory stimulus in fibroblasts cultured with 10 % PRP + 10 % CM after 48 h. These in vitro results suggest that PRP and ADSC have therapeutic potential for healing and re-epithelialization of chronic wounds in vivo.

Emphysema is characterized by destruction of alveolar walls with loss of gas exchange surface and consequent progressive dyspnea. This study aimed to evaluate the efficiency of cell therapy with bone marrow mononuclear cells (BMMC) in an animal model of elastase-induced pulmonary emphysema. Emphysema was induced in C57Bl/J6 female mice by intranasal instillation of elastase. After 21 days, the mice received bone marrow mononuclear cells from EGFP male mice with C57Bl/J6 background. The groups were assessed by comparison and statistically significant differences (p < 0.05) were observed among the groups treated with BMMC and evaluated after 7, 14 and 21 days. Analysis of the mean linear intercept (Lm) values for the different groups allowed to observe that the group treated with BMMC and evaluated after 21 days showed the most significant result. The group that received no treatment showed a statistically significant difference when compared to other groups, except the group treated and evaluated after 21 days, evidencing the efficacy of cell therapy with BMMC in pulmonary emphysema.