Background and rationale of platelet gel in orthopaedic surgery

Abstract

Autologous platelet gel, which is usually prepared by adding thrombin and calcium to a platelet concentrate, is used to accelerate bone repair as a possible alternative to recombinant growth factors (GF), through the osteogenic GF released from alpha-granules. The advantages of platelet gel lie in its mimicking the GF effects of the physiological bone healing and regenerative processes, in addition to a relatively simple and low cost technique. Moreover, if autologous platelet gel is used, immunological reactions are avoided. In in vitro systems, platelet gel stimulated osteogenic differentiation of bone marrow stromal cells, while it inhibited complete osteoclast differentiation and activation. Moreover, platelet gel favoured endothelial cell proliferation and expression of pro-osteogenic functions. In experimental animals and in clinical application, the efficacy of platelet gel was increased by the combination with bone allografts, acting as scaffolds, and with bone marrow stromal cells.

Mesenchymal stem cell response to growth factor treatment and low oxygen tension in 3-dimensional construct environment

“…PRP contains pro-osteogenic factors including PDGF, TGF-β, EGF, VEGF, and bFGF that may play a critical role in the process of bone regeneration 15,17 . These factors make PRP a potential therapeutic agent to be used either alone or in combination with MSCs to regenerate bone 15,[18][19][20][21] . For muscular injuries, specific growth factors involved in repair are not completely understood at the present time; however the effects of growth factors present in PRP are believed to have the potential to improve healing and clinical outcomes 14 .…”

Platelet concentrate as an additive to bone allografts: a laboratory study using an uniaxial compression test

“…There is large evidence that by adding blood, autologous PRP or PLC the bone in-growth is enhanced, although antigenity is getting reduced in some cases (Khan et al 2005; Anitua et al 2004; Hannink et al 2009; Baylink et al 1993; Canalis et al 1989; Canalis 1985; Lozada et al 2001; Cenni et al 2010; Blair and Flaumenhaft 2009). The aim of the study was to investigate the mechanical differences of chemical cleaned allografts with known grain size distribution mixed with blood (BL), clotted blood (CB), platelet concentrate (PC) and platelet concentrated gel (PG) using an uniaxial compression test.…”

Influence of calcium salts and bovine thrombin on growth factor release from equine platelet-rich gel supernatants

“…When PRP is activated by adding either a calcium salt or thrombin, or by direct contact with the constitutive collagen of the treated tissues, it forms a fibrin polymer that is known as platelet-rich gel (PRG) (8). This biological scaffold acts as biomaterial that simultaneously sequesters and releases growth factors and permits cellular migration and differentiation, which consequently, induces tissue healing (20). Growth factor release from PRG depends on the platelet and leukocyte concentrations in its precursor PRP and on the activating substance used for inducing its gelation (8,21).…”