Platelet derived bio-products in the form of platelet rich plasma, plasma rich in growth factors, or plasma-free platelet releasates, are being studied worldwide with the aim of proving their efficacy in tissue regeneration within many different clinical areas, such as traumatology, maxillofacial surgery, ophthalmology, dermatology and otorhinolaryngology, amongst others. The current lack of consensus in the preparation method and application form, or in the quality assessment of each bio-product, precludes adequate interpretation of the relevance of reported clinical outcomes, and while many clinicians are very positive about them, as many are sceptic. Relevant aspects of these products are considered to propose a classification nomenclature, which would aid at the comprehensive comparison of clinical outcomes of bio-products of the same characteristics. Finally, the uses of platelet-derived bio-products in in vitro culture (for cell therapy purposes) as a substitute of animal-origin sera, and other future perspectives of applications of platelet-derived bio-products are discussed.

Platelet-rich plasma (PRP) is used with increasing demand as autologous adjuvant therapy in many areas of regenerative medicine, thanks to the platelet rich content of growth factors and bio-active molecules. However, to date there is a lack of consensus on PRP preparation methods, on processing and application forms, on clinical application guidelines and on knowledge-based composition at the cellular and molecular level, making difficult the assessment of clinical results from different groups in different clinical areas. Here we describe the implementation of PRP production on a closed-system using the infrastructure of a certified blood bank, detailing methodology, and validation and production results 1 year after its implementation. Our methodology provides a reproducible, safe, practical and yet affordable PRP bio-product that will allow further studies to better define PRP applications in regenerative medicine and personalized therapeutic regimes.

Background: Intra-articular infiltration of platelet-rich plasma (PRP) is an alternative therapeutic option to classic hyaluronic acid for the treatment of symptomatic knee osteoarthritis (KOA). However, variation in preparation methods and quality assessment of PRP makes the study of its real clinical efficacy difficult. Purpose: To (1) evaluate the clinical efficacy of a characterized PRP product prepared in a standardized manner and in a closed-system for the treatment of KOA and to (2) evaluate the association of the clinical response to PRP-related variables. Study Design: Case series; Level of evidence, 4. Methods: We recruited 130 patients with nonoperative KOA and evaluated them for 1 year. PRP was prepared from a donation of autologous blood, obtaining 3 aliquots of approximately 10mL of product, which were frozen, allowing platelet disruption, platelet factor release, and long-term storage, until administration. Patients were treated 3 consecutive times every 4 weeks with an intra-articular PRP knee injection under sterile conditions. Complete blood count was performed on the whole-blood sample and the processed PRP before freezing it, for product quality assessment. Patients were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and basic satisfaction scale at 3 months, 6 months, and 1 year after intervention. Results: Quality assessment confirmed a leukocyte-poor PRP product (white blood cell count, 0.09 ± 0.09 × 109/L) with a high platelet purity (platelet count, 630.86 ± 191.75 × 109/L). WOMAC scores improved, and basic satisfaction was achieved in 70% of patients. No adverse events were reported. No correlations were observed between PRP quality parameters and clinical results. PRP complete treatment production costs were €108/US$125 (€36/US$41.6 per injection). Conclusion: This standardized PRP production method resulted in improved WOMAC scores at 1 year postoperatively in 70% of patients with KOA. This technique was safe and affordable and ensured consecutive infiltrations with the same product to each patient.