Tensile Strength Essay Comparing Three Different Platelet-Rich Fibrin Membranes (L-PRF, A-PRF, and A-PRF+): A Mechanical and Structural In Vitro Evaluation

Advanced platelet rich fibrin demonstrates improved osteogenic induction potential in human periodontal ligament cells, growth factor production and mechanical properties as compared to leukocyte and platelet fibrin and injectable platelet rich fibrin

OBJECTIVES

This cross-sectional invitro research aimed to compare and contrast the macroscopic and microscopic, mechanical and biochemical features of leukocyte-rich platelet-rich fibrin, advanced platelet-rich fibrin, and injectable platelet-rich fibrin.

MATERIALS AND METHODS

In all, 150 samples were taken from males aged 18 to 25 with good systemic health (n = 50 each for i-PRF, A-PRF, and L-PRF). The samples were assessed for clot length, clot width, membrane length and width. Microscopic parameters assessed were the distribution of cells and fibrin structure. Mechanical tests were performed for tensile strength using a universal testing machine and growth factor analysis was performed for platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)- β on Days 1, 3 and 7 using commercially available ELISA kits. The osteogenic potential was analyzed in a culture of human periodontal ligament cells for 21 days using cell viability assay, alkaline phosphatase formation and alizarin red staining for mineralization.

RESULTS

L-PRF demonstrates statistically superior clot length, width, weight, membrane length, width and weight in comparison to A-PRF (p < 0.05). L-PRF demonstrates a denser fibrin structure in comparison to A-PRF and i-PRF (p < 0.05). The cells in L-PRF are most commonly situated in the proximal of the clot where as they are distributed in the proximal and middle aspect for A-PRF(p < 0.05). A-PRF demonstrates the highest tensile strength followed by L-PRF (p < 0.05). When growth factor release was evaluated, A-PRF showed noticeably increased release of all growth factors, namely PDGF-BB, TGF-ß, and VEGF, in comparison to i-PRF and L-PRF (p < 0.05). On days 7 and 14, the cell viability of human periodontal ligament cells in co-culture with A-PRF was statistically substantially greater than that of L-PRF and i-PRF (p < 0.05). Alkaline phosphatase levels were statistically substantially higher in A-PRF, followed by i-PRF and L-PRF on days 14 and 21 (p < 0.05). After 21 days of culture, A-PRF treated cultures had much more Alizarin Red staining than L-PRF and i-PRF cultures did (p < 0.05).

CONCLUSION

It was determined that although L-PRF exhibits greater size and weight in comparison to A-PRF and i-PRF, A-PRF has superior mechanical properties, increased growth factor releases of TGF-b, PDGF-BB, and VEGF as well as superior cell viability, alkaline phosphatase production, and mineralization on human periodontal ligament cells.

CLINICAL RELEVANCE

Based on these findings, A-PRF can be recommended for improved delivery of growth factors and osteogenesis whereas L-PRF is better-suited for applications relying on the size of membrane.

The Association of Nanostructured Carbonated Hydroxyapatite with Denatured Albumin and Platelet-Rich Fibrin: Impacts on Growth Factors Release and Osteoblast Behavior

Platelet-rich Fibrin (PRF), a second-generation blood concentrate, offers a versatile structure for bone regeneration due to its composition of fibrin, growth factors, and cytokines, with adaptations like denatured albumin-enriched with liquid PRF (Alb-PRF), showing potential for enhanced stability and growth factor dynamics. Researchers have also explored the combination of PRF with other biomaterials, aiming to create a three-dimensional framework for enhanced cell recruitment, proliferation, and differentiation in bone repair studies. This study aimed to evaluate a combination of Alb-PRF with nanostructured carbonated hydroxyapatite microspheres (Alb-ncHA-PRF), and how this association affects the release capacity of growth factors and immunomodulatory molecules, and its impact on the behavior of MG63 human osteoblast-like cells. Alb-PRF membranes were prepared and associated with nanocarboapatite (ncHA) microspheres during polymerization. MG63 cells were exposed to eluates of both membranes to assess cell viability, proliferation, mineralization, and alkaline phosphatase (ALP) activity. The ultrastructural analysis has shown that the spheres were shattered, and fragments were incorporated into both the fibrin mesh and the albumin gel of Alb-PRF. Alb-ncHA-PRF presented a reduced release of growth factors and cytokines when compared to Alb-PRF (p < 0.05). Alb-ncHA-PRF was able to stimulate osteoblast proliferation and ALP activity at lower levels than those observed by Alb-PRF and was unable to positively affect in vitro mineralization by MG63 cells. These findings indicate that the addition of ncHA spheres reduces the biological activity of Alb-PRF, impairing its initial effects on osteoblast behavior.

Leukocyte- and Platelet-Rich Fibrin (L-PRF) Obtained from Smokers and Nonsmokers Shows a Similar Uniaxial Tensile Response In Vitro

We evaluated and compared the biomechanical properties of Leukocyte-and Platelet Rich Fibrin L-PRF clots and membranes derived from smoker and nonsmoker donors. Twenty venous-blood donors (aged 18 to 50 years) were included after signing informed consent forms. L-PRF clots were analyzed and then compressed to obtain L-PRF membranes. L-PRF clot and membrane samples were tested in quasi-static uniaxial tension and the stress-stretch response was registered and characterized. Furthermore, scanning electron microscope representative images were taken to see the fibrin structure from both groups. The analysis of stress-stretch curves allowed us to evaluate the statistical significance in differences between smoker and nonsmoker groups. L-PRF membranes showed a stiffer response and higher tensile strength when compared to L-PRF clots. However, no statistically significant differences were found between samples from smokers and nonsmokers. With the limitations of our in vitro study, we can suggest that the tensile properties of L-PRF clots and membranes from the blood of smokers and nonsmokers are similar. More studies are necessary to fully characterize the effect of smoking on the biomechanical behavior of this platelet concentrate, to further encourage its use as an alternative to promote wound healing in smokers.

Investigation of three common centrifugation protocols for platelet-rich fibrin (PRF) as a bio-carrier for ampicillin/sulbactam: a prospective trial

OBJECTIVES

Different platelet-rich fibrin (PRF) protocols exist and are known to differ in resulting mechanical and bioactive properties. Centrifugation parameters may also influence drug release, in particular antibiotics, when using PRF as a bio-carrier. We thus evaluated three common protocols regarding effects on the bio-carrier properties.

MATERIALS AND METHODS

In a prospective trial comprising 33 patients, we compared different protocols for PRF as a bio-carrier for ampicillin/sulbactam (SAM). Blood samples were taken shortly after a single dose of ampicillin/sulbactam (2 g/1 g) was administered to patients intravenously. PRF was obtained by centrifugation and three protocols were used: protocol A (1300 rpm, 8 min, RCF-max = 208 g), B (2300 rpm, 12 min, RCF-max = 652 g), and C (1500 rpm, 14 min, RCF-max = 276 g). The antibacterial activity of PRF was investigated against five oral species in vitro, based on agar diffusion methodology.

RESULTS

The study demonstrates that a single dose of SAM is sufficient to reach high concentrations in PRF in all protocols (150 µg/ml), which is comparable to the plasma SAM concentration. Antibacterial activity was inferred from the diameter of inhibition zones seen in agar diffusion tests using PRF discs. Protocol B resulted in the largest inhibition zones. One-way ANOVA revealed statistically improved results for protocol B for some bacteria.

CONCLUSIONS

The study provides valuable data on PRF antibiotic enrichment, notably SAM. A single dose of SAM is sufficient to reach clinically relevant concentrations in PRF.

CLINICAL RELEVANCE

These findings potentially extend the application of PRF, for example in patients with osteonecrosis of the jaw or in oral surgery (e.g., stick bone).

The effect of recurrent application of concentrated platelet-rich fibrin inside the extraction socket on the hard and soft tissues. a randomized controlled trial

Background

Platelet-rich fibrin (PRF) is commonly used for ridge preservation following tooth extraction. However, its effectiveness diminishes over a period of two weeks as it is resorbed and loses its biological activities. Therefore, this clinical study aims to evaluate the effect of recurrent application of concentrated PRF (C-PRF) inside the extraction socket on the hard and soft tissue alterations.

Methods

Twenty patients requiring single tooth extraction and replacement with a dental implant were randomized into one of two ridge preservation approaches: Advanced PRF plus alone (Control group) or advanced PRF plus with the recurrent application of a C-PRF inside the socket every two weeks for 2 months (four times). The ridge width, the ridge height, and the soft tissue thickness were assessed clinically at the baseline and reassessed after 3 months from tooth extraction during implant surgery. Then the amount of hard tissue loss and soft tissue alterations were calculated.

Results

There was a statistically significant difference in the amount of hard tissue loss between groups in the third month. The amount of horizontal ridge loss for the control and test groups were 2.9 ± 0.7 mm and 1.9 ± 0.5 mm, respectively (p-value < 0.05). The vertical bone loss for control and test groups were 1.8 ± 0.5 mm and 1.0 ± 0.3 mm, respectively (p-value < 0.05). Additionally, for the soft tissue thickness, there was no statistical difference between the groups (p-value > 0.05).

Conclusion

Within the limitations of this study, the recurrent application of C-PRF in the extraction socket could decrease the amount of ridge alteration following tooth extraction and may play a role in the bone regeneration procedures.

Trial registration

Registered on ClinicalTrials.gov (ID: NCT05492357, on 08/08/2022).

The effect of recurrent application of concentrated platelet-rich fibrin inside the extraction socket on the hard and soft tissues. a randomized controlled trial

BACKGROUND

Platelet-rich fibrin (PRF) is commonly used for ridge preservation following tooth extraction. However, its effectiveness diminishes over a period of two weeks as it is resorbed and loses its biological activities. Therefore, this clinical study aims to evaluate the effect of recurrent application of concentrated PRF (C-PRF) inside the extraction socket on the hard and soft tissue alterations.

METHODS

Twenty patients requiring single tooth extraction and replacement with a dental implant were randomized into one of two ridge preservation approaches: Advanced PRF plus alone (Control group) or advanced PRF plus with the recurrent application of a C-PRF inside the socket every two weeks for 2 months (four times). The ridge width, the ridge height, and the soft tissue thickness were assessed clinically at the baseline and reassessed after 3 months from tooth extraction during implant surgery. Then the amount of hard tissue loss and soft tissue alterations were calculated.

RESULTS

There was a statistically significant difference in the amount of hard tissue loss between groups in the third month. The amount of horizontal ridge loss for the control and test groups were 2.9 ± 0.7 mm and 1.9 ± 0.5 mm, respectively (p-value < 0.05). The vertical bone loss for control and test groups were 1.8 ± 0.5 mm and 1.0 ± 0.3 mm, respectively (p-value < 0.05). Additionally, for the soft tissue thickness, there was no statistical difference between the groups (p-value > 0.05).

CONCLUSION

Within the limitations of this study, the recurrent application of C-PRF in the extraction socket could decrease the amount of ridge alteration following tooth extraction and may play a role in the bone regeneration procedures.

TRIAL REGISTRATION

Registered on ClinicalTrials.gov (ID: NCT05492357, on 08/08/2022).

Evolution and Clinical Advances of Platelet-Rich Fibrin in Musculoskeletal Regeneration

Over the past few decades, various forms of platelet concentrates have evolved with significant clinical utility. The newer generation products, including leukocyte-platelet-rich fibrin (L-PRF) and advanced platelet-rich fibrin (A-PRF), have shown superior biological properties in musculoskeletal regeneration than the first-generation concentrates, such as platelet-rich plasma (PRP) and plasma rich in growth factors. These newer platelet concentrates have a complete matrix of physiological fibrin that acts as a scaffold with a three-dimensional (3D) architecture. Further, it facilitates intercellular signaling and migration, thereby promoting angiogenic, chondrogenic, and osteogenic activities. A-PRF with higher leukocyte inclusion possesses antimicrobial activity than the first generations. Due to the presence of enormous amounts of growth factors and anti-inflammatory cytokines that are released, A-PRF has the potential to replicate the various physiological and immunological factors of wound healing. In addition, there are more neutrophils, monocytes, and macrophages, all of which secrete essential chemotactic molecules. As a result, both L-PRF and A-PRF are used in the management of musculoskeletal conditions, such as chondral injuries, tendinopathies, tissue regeneration, and other sports-related injuries. In addition to this, its applications have been expanded to include the fields of reconstructive cosmetic surgery, wound healing in diabetic patients, and maxillofacial surgeries.

Third-Generation Platelet Concentrates in Periodontal Regeneration: Gaining Ground in the Field of Regeneration

Platelets are important for hemostasis and the healing of wounds. In clinical settings, healing cytokines including insulin-like growth factors (IGF), platelet-derived growth factors (PDGF), and transforming growth factors (TGF) are commonly implemented. The regenerative approach in dentistry frequently employs platelet concentrates (PCs) that are “autologous in origin” and have a high concentration of platelets, growth factors, and leukocytes. First-generation PCs is made of platelet-rich plasma (PRP), while second-generation PC is made of platelet-rich fibrin (PRF). Both have limitations, so modification protocols and development in PRP and PRF derivatives are required for advancement mechanisms, strength, biodegradability, retention ability in the field of regenerative dentistry, and so on. As third-generation PC, newer genera kinds of PRF, such as advanced-PRF (A-PRF), advanced-PRF+ (A-PRF+), injectable-PRF (i-PRF), and titanium-PRF (T-PRF), were introduced. A-PRF matrices in their solid form were introduced using the low-speed centrifugation concept (LSCC). The applied relative centrifugal force (RCF) for A-PRF is reduced to 208 g as a result of this improved preparation process. A-PRF features a greater number of neutrophil granules in the distal region, especially at the red blood cells-buffer coat (RBC-BC) interface, and the A-PRF clot has a more porosity-like structure with a bigger interfibrous space than PRF. Since the PRF is in a gel form and is difficult to inject, i-PRF was formulated to address this problem. Compared to the other two protocols, the i-PRF protocol requires far less time, and this is the advantage of this PC. This is because i-PRF just needs the blood components to be separated, which happens within the first two to four minutes. Compared to normal L-PRF, T-PRF creates fibrin that is thicker and more densely woven. Titanium has a higher hemocompatibility than glass, which could lead to greater polymerized fibrin formation. In periodontal regenerative operations, oral surgery, and implant dentistry, PRF and its newer advanced modifications have demonstrated promising results and desirable results in both soft and hard tissue regenerative techniques.