Methodological variations affect the release of VEGF in vitro and fibrinolysis’ time from platelet concentrates

Abstract

Blood Concentrates (BCs) are autologous non-transfusional therapeutical preparations with biological properties applied in tissue regeneration. These BCs differ in the preparation method, in fibrin network architecture, growth factors release as well as in platelet/cell content. Methodological changes result in distinct matrices that can compromise their clinical effectiveness. The present study evaluated the influence of different g-forces and types of tubes in the release of vascular endothelial growth factor (VEGF) from platelet-rich fibrin (PRF) as a function of time. The PRF-like samples were obtained with three g-forces (200, 400, and 800 x g) for 10 minutes in pure glass tubes or in polystyrene-clot activator tubes. Scanning and Transmission electron microscopy was used to morphometric analyzes of PRF's specimens and flow cytometry was used to quantify VEGF slow release until 7 days. Our results showed that platelets were intact and adhered to the fibrin network, emitting pseudopods and in degranulation. The fibrin network was rough and twisted with exosomic granulations impregnated on its surface. An increase in the concentration of VEGF in the PRF supernatant was observed until 7 days for all g forces (200, 400 or 800 xg), with the highest concentrations observed with 200 x g, in both tubes, glass or plastic. Morphological analyzes showed a reduction in the diameter of the PRF fibers after 7 days. Our results showed that g-force interferes with the shape of the fibrin network in the PRF, as well as affect the release of VEGF stored into platelets. This finding may be useful in applying PRF to skin lesions, in which the rapid release of growth factors can favor the tissue repair process. Our observations point to a greater clarification on the methodological variations related to obtaining PRF matrices, as they can generate products with different characteristics and degrees of effectiveness in specific applications.

Peri-Implantitis - Decontaminating and Regenerative Treatment Protocol

“…The three-dimensional arrangement of the fibrin matrix favors cell transit allowing the progenitor cells from the bone marrow to be integrated into the graft set, constituting the tripod of tissue engineering. (20,21) In the clinical case presented, there was a 4mm reduction in the probing depth and no bleeding after probing.…”

“…Studies have not shown the effectiveness of any of these regeneration materials over others. (18) In the present clinical case, the granules of the synthetic hydroxyapatite (Cerasorb M®) hydrated with a solution of piperacillin / tazobactam was mixed with liquid phase platelet-rich fibrin (20) . The objective was to promote the initial stability and the continuous release of antibiotics for the biomaterial and the environment.…”

“…Peri-implant mucositis affects 80% of patients and 50% of implants, while peri-implantitis affects between 28-56% of patients and 12-43% of implants (20) . Both pathologies have an infectious nature as a result of the accumulation of a biofilm.…”

“…The platelet-rich fibrin are therapeutic blood matrices obtained by selective centrifugation acting as an adjuvant in tissue repair. For fibrin matrices obtention six samples of autologous blood were collected in 10 mL pure glass dry tube (Montserrat, Brazil) and two blood samples in polystirene dry tube (Greiner Bio-One, Austria), both centrifuged in the Fibrin System® centrifuge (Ortoalresa, Spain) according to the methodological proposal of Oliveira et al, 2020 (20,21) that uses the relative centrifugal force (RCF) of 200 xg for 10 minutes, for obtained two physical forms of fibrin, polymeric or solid gel form and monomeric or temporary liquid phase form in only step of spin. The liquid phase was used to obtain sticky bone with Cerasorb M®.…”

Evaluation of mechanical properties of platelet-rich fibrin membrane for implant surgery: An analysis in vitro

“…[ 18 ] Otherwise, is known that the time and force performed in the centrifugation can influence the characteristics of the membrane that will be applied in the surgical receptor area. [ 8 19 ]…”