Does Platelet-Rich Fibrin Enhance the Early Angiogenetic Potential of Different Bone Substitute Materials? An In Vitro and In Vivo Analysis

Abstract

The impaired angiogenic potential of bone substitute materials (BSMs) may limit regenerative processes. Therefore, changes in the angiogenetic properties of different BSMs in combination with platelet-rich fibrin (PRF) in comparison to PRF alone, as well as to native BSMs, were analyzed in vitro and in vivo to evaluate possible clinical application. In vitro, four BSMs of different origins (allogeneic, alloplastic, and xenogeneic) were biofunctionalized with PRF and compared to PRF in terms of platelet interaction and growth factor release (vascular endothelial growth factor (VEGF), tissue growth factor ß (TGFß) and platelet-derived growth factor (PDGF)) after 15 min. To visualize initial cell–cell interactions, SEM was performed. In vivo, all BSMs (±PRF) were analyzed after 24 h for new-formed vessels using a chorioallantoic membrane (CAM) assay. Especially for alloplastic BSMs, the addition of PRF led to a significant consumption of platelets (p = 0.05). PDGF expression significantly decreased in comparison to PRF alone (all BSMs: p < 0.013). SEM showed the close spatial relation of each BSM and PRF. In vivo, PRF had a significant positive pro-angiogenic influence in combination with alloplastic (p = 0.007) and xenogeneic materials (p = 0.015) in comparison to the native BSMs. For bio-activated xenogeneic BSMs, the branching points were also significantly increased (p = 0.005). Finally, vessel formation was increased for BSMs and PRF in comparison to the native control (allogeneic: p = 0.046; alloplastic: p = 0.046; and xenogeneic: p = 0.050). An early enhancement of angiogenetic properties was demonstrated when combining BSMs with PRF in vitro and led to upregulated vessel formation in vivo. Thus, the use of BSMs in combination with PRF may trigger bony regeneration in clinical approaches.

Possible Implications for Improved Osteogenesis? The Combination of Platelet-Rich Fibrin With Different Bone Substitute Materials

“…The possible underlying intercellular mechanism and early angiogenic interactions of the PRF with the respective BSM were evaluated in another study by our working group (Blatt et al, 2021). Here, it was demonstrated that PRF initially interacts with its respective BSM via platelet activation in vitro.…”

“…Furthermore, PRF had a significant positive proangiogenic effect, especially in combination with alloplastic and xenogeneic materials in vivo. Here, validated by scanning electron microscopy, a "storage" of the respective growth factors of the PRF via the close spatial relationship between the fibrin network and the BSM and a consecutive slow release that triggers vasoformative responses was hypothesized (Blatt et al, 2021). This assumption may be transferred to the implications of bony regeneration and could explain the release kinetics and expression of the above investigated markers found in this study: initially, PRF boosts primary viability of HOBs and subsequently releases differentiation and migration marker.…”

The Influence of Hyaluronic Acid Biofunctionalization of a Bovine Bone Substitute on Osteoblast Activity In Vitro

“…Recent studies analyzed combinations of BSMs with growth factors (e.g., BMP-2, VEGF) and PRF (platelet-rich fibrin). The findings of these studies illustrated that such biofunctionalized BSMs have the potency to accelerate and increase bone formation and vascularization as characteristic hallmarks of fast and sufficient bone regeneration [28][29][30][31][32][33]. As BSM modification with growth factors is technically challenging and restricted by legal requirements in most countries, further substances might be of interest for BSM biofunctionalization.…”

Non-Interventional Prospective Observational Study of Platelet Rich Fibrin as a Therapy Adjunctive in Patients with Medication-Related Osteonecrosis of the Jaw

“…The full understanding of immunological reactions leading to MRONJ and its involvement in osteogenesis and angiogenesis may represent the missing link to the comprehensive understatement of the disease. These considerations may partly explain the results obtained in this study, where the proven strong pro-angiogenic properties of the PRF, which are known to be strong [38][39][40][41][42], were demonstratively insufficient to significantly optimize soft tissue healing in MRONJ.…”