Platelet-Rich Preparations to Improve Healing. Part II: Platelet Activation and Enrichment, Leukocyte Inclusion, and Other Selection Criteria

Abstract

Multiple platelet-rich preparations have been reported to improve wound and bone healing, such as platelet-rich plasma (PRP) and platelet rich fibrin (PRF). The different methods employed during their preparation are important, as they influence the quality of the product applied to a wound or surgical site. Besides the general protocol for preparing the platelet-rich product (discussed in Part 1 of this review), multiple choices need to be considered during its preparation. For example, activation of the platelets is required for the release and enmeshment of growth factors, but the method of activation may influence the resulting matrix, growth factor availability, and healing. Additionally, some methods enrich leukocytes as well as platelets, but others are designed to be leukocyte-poor. Leukocytes have many important roles in healing and their inclusion in PRP results in increased platelet concentrations. Platelet and growth factor enrichment reported for the different types of platelet-rich preparations are also compared. Generally, TGF-β1 and PDGF levels were higher in preparations that contain leukocytes compared to leukocyte-poor PRP. However, platelet concentration may be the most reliable criterion for comparing different preparations. These and other criteria are described to help guide dental and medical professionals, in large and small practices, in selecting the best procedures for their patients. The healing benefits of platelet-rich preparations along with the low risk and availability of simple preparation procedures should encourage more clinicians to incorporate platelet-rich products in their practice to accelerate healing, reduce adverse events, and improve patient outcomes.

Therapeutic efficacy of autologous platelet‐rich plasma and polydeoxyribonucleotide on female pattern hair loss

“…In the early phases of PRP treatment, before angiogenesis, hair follicles obtain growth factors and nutritional elements from the injected PRP . Previous studies showed that slower and more efficient release of growth factors from concentrated platelets and leukocytes was obtained by using endogenous activation, rather than prior activation, of PRP preparation . Additionally, leukocyte‐rich PRP preparations without prior activation showed steady increases in PDGF‐AB over storage times of 120 hours .…”

Evaluation of L‐PRF combined with deproteinized bovine bone mineral for early implant placement after maxillary sinus augmentation: A randomized clinical trial

“…Leukocyte and platelet‐rich fibrin (L‐PRF), first described by Dohan and colleagues is an autogenous biomaterial containing several growth factors . L‐PRF, a second‐generation of platelet concentrates, is basically made of concentrated autologous platelets as well as leukocytes and cytokines .…”

Platelet‐Poor and Platelet‐Rich Plasma Stimulate Bone Lineage Differentiation in Periodontal Ligament Stem Cells

“…These include platelet‐rich plasma (PRP), platelet‐poor plasma (PPP), and platelet‐rich fibrin, among others 16 , 17 . At the clinical level, they may be applied in the form of a gel on surgical wounds as an autologous source of biomolecules for the treatment of a wide range of tissue injuries 13,17‐19 . However, conflicting results regarding the clinical effectiveness of PRP in periodontal regeneration have been reported in the literature, probably because of wide variations in the protocols used to generate PRP, heterogeneity among clinical studies that evaluate different types of defects, and the absence of a biologic rationale to define the adequate concentrations of growth factors and other components present in platelet‐derived fractions 18–23 .…”