Platelet-rich plasma, a source of autologous growth factors and biomimetic scaffold for peripheral nerve regeneration

ABSTRACT

Introduction: In mammals, axons of injured peripheral nerves (PNI) can and do regenerate, but often the functional recovery is incomplete or suboptimal. In recent years, in vivo tissue engineering approaches through molecular intervention and scaffolding are offering promising outcomes. Evidence is accumulating in both preclinical and clinical settings indicating that Platelet-rich plasma (PRP) and fibrin scaffolds obtained from this technology hold an important adjuvant therapeutic potential.

Areas covered: This review addresses current molecular and cellular data in intrinsic nerve repair processes and describes different strategies to harness and enhance these processes by using biochemical and biomechanical cues. It focuses on autologous fibrin, plasma and platelet-derived growth factors as filler or scaffolds that can synergize with the gold standard therapy and other nerve guidance conduits.

Expert opinion: PRP is applied as a filler of nerve conduits or vein-muscle grafts across nerve gaps post trauma by infiltrating the nerve stumps perineurally and intraneurally in neuropathies, or as scaffolds to bridge or wrap nerve stumps, with significant neurological recovery and pain reduction. The application of PRP at the injured nerve site might be considered as an ‘off the shelf’ alternative.

KEYWORDS:

• Injured peripheral nerves
• Platelet-rich plasma
• regeneration
• growth factors
• scaffold

Article highlights

• Peripheral nervous system possesses a remarkable ability to regenerate, however it might lead to overestimate the fully functional recovery after PNI since even when the gold standard nerve autograft is used to bridge an injured nerve gap, the complete functional recovery is seldom achieved.

• Three key events significantly contribute to axonal outgrowth, namely, angiogenesis, axon-SC partnership, and a permissive and inductive microenvironment where as important as the absence of inhibitory molecules is the presence of nerve guidance, and neurotropic and neurotrophic factors.

• The potential therapeutic effects of PRPs are tightly linked to a supportive fibrin matrix containing several neurotrophic and neurotropic factors whose sustained and gradual release appear to be instrumental agents that govern inflammation, angiogenesis, and macrophage polarization.

• PRP speeds up axonal functional recovery which may minimize muscle atrophy and fibrosis, leading to functional recovery of the nerve-muscle unit.

• PRP applied on nerve repair and neuropathies in a combinatorial strategy as a filler and as a perineural and intraneural ultrasound-guided injections, suturable membrane, and scaffold, is a candidate for an adjuvant approach to be harnessed by surgeons in the operating room and in the clinical setting.

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Acknowledgments

The authors thank Fernando Yanguela for assistance with Ultrasound guidance, and Sara Rivas for the elaboration of drawings.

Declaration of interest

E Anitua is a Scientific Director of BTI Biotechnology Institute, a dental company that investigates the fields of implantology and PRGF-Endoret technology. S Padilla, G Orive and R Prado are also scientists at the BTI Biotechnology Institute. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This manuscript has not been funded.