Mechanical, chemical, structural analysis and comparative release of PDGF-AA from L-PRF, A-PRF and T-PRF - an in vitro study

Abstract

Background Platelet concentrates have been popularly used in regenerative periodontal therapy as they are autologous in origin and they provide a supernatural concentration of platelets, growth factors and leukocytes. The release profile of various growth factors is considered important during the various phases of wound healing with the most important being the inflammatory phase where the release of the growth factors help in recruitment of cells and in collagen production. With the more recent modifications of PRF namely A-PRF and T-PRF, the mechanical and chemical degradation properties have also improved. The aim of the present study was to correlate the release profile of PDGF-AA from various forms of platelet concentrates (L-PRF, A-PRF, T-PRF) based on their mechanical and chemical properties. Methods Blood samples were drawn from 2 male and 3 female systemically healthy patients between 20 and 25 years of age who were about to undergo periodontal regeneration for PRF preparation. The blood sample was immediately centrifuged using a table top centrifuge (Remi R4C) at 1060 rpm (208 x g) for 14 min for A-PRF preparation, 1960 rpm (708 x g) for 12 min for L-PRF preparation and 1960 rpm (708 x g) for 12 min in titanium tubes for T-PRF preparation. Tensile test was performed using universal testing machine. The in vitro degradation test of the prepared PRF membranes were conducted by placing the PRF membrane in 10 ml of pH 7.4 PBS on an orbital shaker set at 50 rpm. SEM evaluation of the PRF membrane was done under both low and high magnification. In order to determine the amount of released growth factor PDGF-AA at 15 min, 60 min, 8 h, 1 day, 3 days, and 10 days, samples were placed into a shaking incubator at 37 °C to allow for growth factor release into the culture media. Results On comparing the three PRF membranes, it was found that T-PRF contained the maximum tensile strength (404.61 ± 5.92 MPa) and modulus of elasticity (151.9 ± 6.92 MPa). Statistically significant differences between the three groups were found on comparing the groups for their mechanical properties. In the degradation test, it was found that the maximum amount of degradation was found in L-PRF (85.75%), followed by A-PRF (84.18%) and the least was found in T-PRF (82.27%). T-PRF released the highest amount of PDGF-AA (6060.4 pg/ml) at early time points when compared to A-PRF (5935.3 pg/ml). While T-PRF had rapid release of PDGF-AA, A-PRF had a sustained release of growth factors released at later time points. Conclusion Results from the present study indicate that A-PRF is the most favourable form of platelet concentrate in regenerative periodontal therapy as it has a sustained release of growth factors over time.

Tensile strength assay comparing the resistance between two different autologous platelet concentrates (leucocyte-platelet rich fibrin versus advanced-platelet rich fibrin): a pilot study

“…Controversially, although other techniques [ 28 , 32 ] exist, the simplest way is to follow the protocols strictly using the correct centrifugation settings to obtain the correct membrane. Thus, the results obtained for L-PRF in this study (average of 0.02260 MPa) is in perfect agreement with the resistance of L-PRF published by Khorshidi et al [ 22 ] (0.20 ± 0.06 MPa), but strangely, Ravi and Santhanakrishnan (2020) [ 26 ] found an extremely higher value for L-PRF (290.076 ± 5.68 MPa). Nonetheless, the same authors also found extremely high values for A-PRF (362.565 ± 5.15 MPa), differently than obtained in this study (average of 0.04130 MPa).…”

“…Nonetheless, the same authors also found extremely high values for A-PRF (362.565 ± 5.15 MPa), differently than obtained in this study (average of 0.04130 MPa). However, this study may state that A-PRF had a higher resistance to traction than L-PRF similar to published by Ravi and Santhanakrishnan (2020) [ 26 ]; therefore, in this study, it was observed almost twice more in the average of resistance, with an extremely significant statistical difference. Concerning average traction, A-PRF also achieved a significant statistical difference compared to L-PRF.…”

“…Before the traction test, the membranes were standardized and measured using a WHO Periodontal probe and cut in a rectangular shape in which the short ends measured 5 mm of length and 1 mm of height each, only one per membrane. The tensile test was performed using a universal testing machine (Shimadzu MMT-101 N equipment, Shimadzu Corporation, Japan) [ 22 , 26 ] (Fig. 2 a), where the PRF membranes were conducted through a surgical tweezer, to put both extremities of the membranes fixed in the tensile force apparatus.…”

Autologous Platelet Gel (APG): A Preliminary Evaluation of the Mechanical Properties after Activation with Autologous Thrombin and Calcium Chloride

“…The authors recorded the tensile strength of leukocyte platelets (L-PRF) (mean value of 0.20 ± 0.06MPa), which was significantly increased compared to the platelet rich growth factor (PRGF) group (value of 0.14 ± 0.07MPa). Ravi and Santhanakrishnan [ 47 ] investigated the mechanical properties of three different types of PRF membranes through a PRF box under the compressor and lid for 10 min. The authors recorded the tensile strength of T-PRF (titanium prepared platelet-rich fibrin), obtaining a mean value of 404.61 ± 5.92MPa which was significantly higher than that of A-PRF (362.565 ± 5.15 MPa) and L-PRF, which contained the least tensile strength (290.076 ± 5.68MPa).…”

From Blood to Regenerative Tissue: How Autologous Platelet-Rich Fibrin Can Be Combined with Other Materials to Ensure Controlled Drug and Growth Factor Release

“…The second type of platelets, platelet-rich fibrin (PRF), plays an important role in modern medicine and is used as one of the components in the production of biomaterials. As mentioned in several sources, PRF is a second-generation platelet concentrate derived from centrifuged blood [5] and, in addition to platelets, also contains white blood cells, serum and concentrated growth factors [9], such as platelet-derived growth factor (PDGF), transforming growth factor-β (TGF-β) and insulin-like growth factor 1 (IGF-I) [10]. The properties of growth factors and cytokines within the PRF are shown in Table 2.…”