Biological Characterization and In Vitro Effects of Human Concentrated Growth Factor Preparation: An Innovative Approach to Tissue Regeneration

Abstract

SummaryScientific background: Platelet concentrates are nowadays widely applied in different clinical fields to improve soft tissue and bone regeneration. "Concentrated Growth Factors" (CGF) is a new generation of platelet concentrate products, which exhibits an interesting clinical and biotechnological application potential. Aim of the study:The aim of this study is to assess the biological rationale for the use of CGF, by evaluating blood cell localization, the in vitro cumulative release of seven growth factors (PDGF-AB, VEGF, TNF-α, TGF-β1, BDNF, BMP-2 and IGF-1), its in vitro effects on cell proliferation and its mechanical behavior.Methods: CGFs were obtained from volunteer donors. Blood cell localization was evaluated after properly morphological staining and immunohistochemistry. The amount of growth factors release was measured at 5 hours, 1, 3, 6, 7 and 8 days, using ELISA assay. Cells were cultured with and without CGF and their proliferation was evaluated after 72 hours, performing the quantification of Ki-67, using flow cytometry (FACS). The mechanical response of CGF under compression was also attempted. Results:The results showed that platelets and leukocytes were found in a very thin space called "buffy coat", localized between the white and red part of CGF. Each growth factor evaluated, had a specific kinetic release with a great variability among subjects. The in vitro cell proliferation was stimulated. CGF showed an "apparent plasticity" and its mechanical response was influenced by fibrin network structure. Conclusion:These findings support the CGF's clinical use and will allow us to better understand and improve the clinical outcomes. B io lo g y and M e d ic in e

In vitro and in vivo effects of concentrated growth factor on cells and tissues

“…The release dynamics of growth factors should be considered before obtaining the extract. Although Borsani et al assumed that release of growth factors from CGF continue for almost 8 days (Borsani et al, ), more sophistical research showed that some of the growth factors are released during 8 hr, while the release of some others continues throughout 13 days (Dohan Ehrenfest, de Peppo, Doglioli, & Sammartino, ; Honda et al, ; Zumstein et al, ). Based on these differences, the optimum concentration of CGF could vary in studies.…”

“…Another agent is the test tube used for blood collection, which its material may interfere with the properties of CGF (Bonazza et al, 2016;Tsujino et al, 2019 (Borsani et al, 2015), more sophistical research showed that some of the growth factors are released during 8 hr, while the release of some others continues throughout 13 days (Dohan Ehrenfest, de Peppo, Doglioli, & Sammartino, 2009;Honda et al, 2013;Zumstein et al, 2012). Based on these differences, the optimum concentration of CGF could vary in studies.…”

“…CCM should be supplemented with fetal bovine serum and antibiotics (Hong, Li, Cai, & Jiang, 2019;Jin et al, 2018). Another way to produce CGF extract is placing the CGF membrane into a sterile insert above the seeded cells in the sixwell plates (an insert in each well), which are immersed in culture medium (for 72 hr) (Borsani et al, 2015). Figure 1 shows different steps in preparing the various types of CGF.…”

In vitro treatment with concentrated growth factors (CGF) and sodium orthosilicate positively affects cell renewal in three different human cell lines

“…At the end of the centrifugation process, three blood fractions were identified (Borsani et al, 2015;Bonazza et al, 2016): the upper platelet poor plasma layer (PPP), representing the liquid phase of plasma; the lower red blood cells layer (RBC), containing erythrocytes and the middle CGF layer, consisting into three parts: the upper white part (WP), the downer red part (RP), and the middle "buffy coat" part (BC), representing the interface between WP and RP and containing leukocytes and platelets. Exclusion criteria were a systemic disorder, smoking, infection, non-steroidal anti-inflammatory drug use, and a hemoglobin level of <11 g/dL or a platelet concentration of <150,000 mm 3 .…”

“…It functions throughout the life cycle to maintain or restore the normal form and function of cells, tissues and, in some cases, organs, appendages, and whole organisms. These concentrates are obtained from the patient's own blood and contain autologous platelets, growth factors, and cytokines involved in the key processes of tissue regeneration, including cell proliferation and differentiation, extracellular matrix synthesis, chemotaxis, and angiogenesis (Borsani et al, 2015;Fioravanti et al, 2016). Recently, the use of platelet-rich preparations such as platelet-rich plasma (PRP), platelet-rich fibrin (PRF), platelet rich in growth factors (PRGF), and concentrated growth factors (CGF) has been shown to be effective in promoting the natural processes of wound healing and tissue regeneration (Ramos-Torrecillas et al, 2014;Sermer et al, 2015;Badran et al, 2017).…”