Autologous liquid platelet rich fibrin: A novel drug delivery system.

There is currently widespread interest within the biomaterial field to locally deliver biomolecules for bone and cartilage regeneration. Substantial work to date has focused on the potential role of these biomolecules during the healing process, and the carrier system utilized is a key factor in their effectiveness. Platelet rich fibrin (PRF) is a naturally derived fibrin scaffold that is easily obtained from peripheral blood following centrifugation. Slower centrifugation speeds have led to the commercialization of a liquid formulation (liquid-PRF) resulting in an upper plasma layer composed of liquid fibrinogen/thrombin prior to clot formation that remains in its liquid phase for approximately 15 min until injected into bodily tissues. Herein, we introduce the use of liquid PRF as an advanced local delivery system for small and large biomolecules. Potential target molecules including large (growth factors/cytokines and morphogenetic/angiogenic factors), as well as small (antibiotics, peptides, gene therapy and anti-osteoporotic) molecules are considered potential candidates for enhanced bone/cartilage tissue regeneration. Furthermore, liquid-PRF is introduced as a potential carrier system for various cell types and nano-sized particles that are capable of limiting/by-passing the immune system and minimizing potential foreign body reactions within host tissues following injection. STATEMENT OF SIGNIFICANCE There is currently widespread interest within the biomaterial field to locally deliver biomolecules for bone and cartilage regeneration. This review article focuses on the use of a liquid version of platelet rich fibrin (PRF) composed of liquid fibrinogen/thrombin as a drug delivery system. Herein, we introduce the use of liquid PRF as an advanced local delivery system for small and large biomolecules including growth factors, cytokines and morphogenetic/angiogenic factors, as well as antibiotics, peptides, gene therapy and anti-osteoporotic molecules as potential candidates for enhanced bone/cartilage tissue regeneration