In vitro and in vivo effects of PDGF-BB delivery strategies on tendon healing: a review

To promote and support tendon healing, one viable strategy is the use or administration of growth factors at the wound/rupture site.Platelet derived growth factor-BB (PDGF-BB), together with other growth factors, is secreted by platelets after injury.PDGF-BB promotes mitogenesis and angiogenesis, which could accelerate tendon healing.Therefore, in vitro studies with PDGF-BB have been performed to determine its effect on tenocytes and tenoblasts.Moreover, accurate and sophisticated drug delivery devices, aiming for a sustained release of PDGF-BB, have been developed, either by using heparin-binding and fibrin-based matrices or different electrospinning techniques.In this review, the structure and composition, as well as the healing process of tendons, are described.Part A deals with in vitro studies.They focus on the multiple effects evoked by PDGF-BB on the cellular level.Moreover, they address strategies for the sustained delivery of PDGF-BB.Part B focuses on animal models used to test different delivery strategies for PDGF-BB, in the context of tendon reconstruction.These studies showed that dosage and timing of PDGF-BB application are the most important factors for deciding which delivery device should be applied for a specific tendon laceration.