The effect of titanium-platelet rich fibrin on periodontal intrabony defects: A randomized controlled split-mouth clinical study.

This study aimed to determine the contribution of titanium prepared platelet-rich fibrin (T-PRF) with open flap debridement (OFD) on clinical, biochemical and radiographic measurements of periodontal regeneration. Twenty periodontitis patients with bilateral intrabony defects and stage III grade A periodontitis were included in the study. A total of 40 defects were randomly selected for OFD alone (control group, n = 20) or combined OFD+ T-PRF (test group, n = 20). Clinical and radiographic parameters (at baseline and nine months after surgery), and growth factor levels in gingival crevicular fluid (at baseline and at two, four, six, and twelve weeks after surgical treatment) were also evaluated. Considering the clinical parameters, alterations in probing pocket depth, gingival marginal level and clinical endpoint in the test regions treated with T-PRF significantly improved (P<0.05). Fibroblast growth factor-2 and platelet-derived growth factor-BB levels between the two groups in the second and fourth weeks were also significantly different (P<0.05). Furthermore, the receptor activator of nuclear factor κB ligand/osteoprotegerin ratio between the groups was significantly different in the second, fourth, sixth, and twelfth weeks (P<0.05). The bone-filling rate was also significantly greater in the test group than in the control group (P <0.001). Compared with OFD alone, combining T-PRF with the procedure was more successful with regards to clinical, radiographic, and biochemical measurements of periodontal regeneration.

Platelet-rich fibrin as an apical barrier for MTA placement in the treatment of teeth with open apices: a pilot study.

OBJECTIVE: The aim of the present pilot study was to assess the effectiveness of the platelet-rich fibrin (PRF) apical barrier for the placement of MTA for the treatment of teeth with periapical lesions and open apices. METHODS: A total of thirty teeth on twenty-eight patients with open apices and periapical periodontitis were enrolled and divided into two groups in the present pilot study. In the PRF group (fourteen teeth in thirteen patients), nonsurgical endodontic treatment was performed using PRF as an apical matrix, after which the apical plug of the MTA was created. For the non-PRF group (fourteen teeth in fourteen patients), nonsurgical endodontic therapy was performed using only the MTA for an apical plug with no further periapical intervention. Clinical findings and periapical digital radiographs were used for evaluating the healing progress after periodic follow-ups of 1, 3, 6, and 9 months. The horizontal dimension of the periapical lesion was gauged, and the changes in the dimensions were recorded each time. The Friedman test, Dunn-Bonferroni post hoc correction, and Mann-Whitney U test were used for statistical analysis, with P < 0.05 serving as the threshold for determining statistical significance. RESULTS: All patients in both groups in the present pilot study had no clinical symptoms after 1 month, with a significant reduction in the periapical lesion after periodic appointments. The lesion width of the PRF group was significantly smaller than that of the non-PRF group in the sixth and ninth month after treatment. CONCLUSIONS: PRF is a promising apical barrier matrix when combined with MTA for the treatment of teeth with open apices and periapical periodontitis. Small number of study subjects and the short time of follow-up period limit the generalizability of these results. TRIAL REGISTRATION: TCTR, TCTR20221109006. Registered 09 November 2022 - Retrospectively registered, https://www.thaiclinicaltrials.org/show/TCTR20221109006 .

Injectable platelet-rich fibrin promotes proliferation and trichogenic inductivity of dermal papilla cells through activating TGF-ß/Smad signaling pathway.

Dermal papilla cell (DPC) belongs to a specialized mesenchymal stem cell for hair follicle regeneration. Maintaining the ability of DPCs to stimulate hair in vitro culture is important for hair follicle morphogenesis and regeneration. As the third generation of platelet concentrate, injectable platelet-rich fibrin (i-PRF) is a novel biomaterial containing many growth factors and showing promising effects on tissue reconstruction. We aimed to explore the influences of i-PRF on the proliferative, migratory, as well as trichogenic ability of DPCs and compared the effects of i-PRF and platelet-rich plasma (PRP), the first generation of platelet concentrate. Both PRP and i-PRF facilitated DPCs proliferation, and migration, along with trichogenic inductivity as well as stimulated the TGF-ß/Smad pathway, while the impacts of i-PRF were more significant than PRP. A small molecule inhibitor of TGF-beta receptor I, Galunisertib, was also applied to treat DPCs, and it rescued the impacts of i-PRF on the proliferative, migratory, trichogenic inductivity, and proteins-associated with TGF-ß/Smad pathway in DPCs. These findings revealed that i-PRF had better effects than PRP in enhancing the proliferative, migratory, and hair-inducing abilities of DPCs by the TGF-ß/Smad pathway, which indicated the beneficial role of i-PRF in hair follicle regeneration.

Treatment of Odontogenic Maxillary Sinusitis with the Use of Growth Factors in Advanced Platelet-Rich Fibrin for Immediate Closure of Oro-Antral Communication: A Case Report.

Chronic odontogenic maxillary sinusitis (COMS), a prolonged inflammation of the maxillary sinus lasting over 12 weeks, is often a result of periapical lesions, marginal periodontitis, and complications like oro-antral communication (OAC) and fistula (OAF). OAC, commonly emerging post-teeth extraction in the lateral maxilla, lacks documented treatments using advanced platelet-rich fibrin (A-PRF). This study evaluates A-PRF's efficacy in treating COMS and immediately sealing extensive OAC. A case of a 28-year-old male with COMS linked to a periapical lesion and supernumerary molars is presented. Treatment involved extracting specific teeth while preserving adjacent ones and using A-PRF for immediate OAC closure. A-PRF, enriched with growth factors, was pivotal in healing, showcasing enhanced tissue regeneration, pain reduction, and faster recovery. The findings suggest A-PRF as an effective adjunct in treating extensive OAC and COMS, proposing its inclusion in standard treatment protocols. This study underscores A-PRF's potential in improving outcomes for patients with COMS and related complications.

Leukocytes within Autologous Blood Concentrates Have No Impact on the Growth and Proliferation of Human Primary Osteoblasts: An In Vitro Study.

Platelet-rich fibrin (PRF) is a widely used autologous blood concentrate in regenerative medicine. This study aimed to characterize the cellular composition and distribution of different PRF matrices generated by high (710 g) and low (44 g) relative centrifugal forces (RCFs) and to analyze their bioactivity on human primary osteoblasts (pOBs). PRF was separated into upper layer (UL) and buffy coat (BC) fractions, and their cellular contents were assessed using histological and immunohistochemical staining. The release of platelet-derived growth factor (PDGF) and transforming growth factor (TGF-ß) was quantified using an ELISA. Indirect PRF treatment on pOBs was performed to evaluate cell viability and morphology. A histological analysis revealed higher quantities of leukocytes and platelets in the low-RCF PRF. TGF-ß release was significantly higher in the low-RCF PRF compared to the high-RCF PRF. All PRF fractions promoted pOB proliferation regardless of the centrifugation protocol used. The low-RCF PRF showed higher TGF-ß levels than the high-RCF PRF. These findings contribute to understanding the cellular mechanisms of PRF and provide insights into optimizing PRF protocols for bone regeneration, advancing regenerative medicine, and improving patient outcomes.

Platelet rich fibrin as a bioactive matrix with proosteogenic and proangiogenic properties on human healthy primary cells in vitro.

Blood concentrates like platelet rich fibrin (PRF) have been established as a potential autologous source of cells and growth factors with regenerative properties in the field of dentistry and regenerative medicine. To further analyze the effect of PRF on bone tissue regeneration, this study investigated the influence of liquid PRF matrices on human healthy primary osteoblasts (pOB) and co-cultures composed of pOB and human dermal vascular endothelial cells (HDMEC) as in vitro model for bone tissue regeneration. Special attention was paid to the PRF mediated influence on osteoblastic differentiation and angiogenesis. Based on the low-speed centrifugation concept, cells were treated indirectly with PRF prepared with a low (44 g) and high relative centrifugal force (710 g) before the PRF mediated effect on osteoblast proliferation and differentiation was assessed via gene and protein expression analyses and immunofluorescence. The results revealed a PRF-mediated positive effect on osteogenic proliferation and differentiation accompanied by increased concentration of osteogenic growth factors and upregulated expression of osteogenic differentiation factors. Furthermore, it could be shown that PRF treatment resulted in an increased formation of angiogenic structures in a bone tissue mimic co-culture of endothelial cells and osteoblasts induced by the PRF mediated increased release of proangiogenic growth factors. The effects on osteogenic proliferation, differentiation and vascularization were more evident when low RCF PRF was applied to the cells. In conclusion, PRF possess proosteogenic, potentially osteoconductive as well as proangiogenic properties, making it a beneficial tool for bone tissue regeneration.

What is the context?The treatment of bone defects is still a challenge in the field of regenerative medicine. In this context, researchers and clinicians are continuously focusing on developing new therapeutic strategies like the use of autologous blood concentrates like Platelet rich fibrin (PRF) to improve regeneration by directly delivering wound healing promoting cells and growth factors to the defect side in order to restore the structure and functional integrity of damaged hard tissue in combination with adequate tissue regeneration.What is new?Focus of the present in vitro study was to further evaluate the potential of PRF paying particular attention to the PRF-mediated effect on osteogenic differentiation and angiogenesis of human primary osteoblasts as well as on a more complex tissue like co-culture consisting of osteoblasts and microvascular endothelial cells. We could demonstrate that PRF is able to support and affect a variety of processes involved in bone tissue regeneration including osteogenic proliferation, osteogenic differentiation as well as angiogenic structure formation.Treatment of PRF resulted in:- increased cell viability*- higher expression of osteogenic differentiation factors*- higher release of osteogenic growth factors*- increased formation of microvessel-like structures*(*compared to untreated control)What is the impact?PRF represents a beneficial autologous tool for regenerative purposes combining proosteogenic and proangiogenic properties. Therefore, PRF might be used for applications in versatile fields of medicine in the context of improving bone tissue regeneration.

Mesenchymal stem cells in PRP and PRF containing poly(3-caprolactone)/gelatin Scaffold: a comparative in-vitro study.

Scaffold design is one of the three most essential parts of tissue engineering. Platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) have been used in clinics and regenerative medicine for years. However, the temporal release of their growth factors limits their efficacy in tissue engineering. In the present study, we planned to synthesize nanofibrous scaffolds with the incorporation of PRP and PRF by electrospinning method to evaluate the effect of the release of PRP and PRF growth factors on osteogenic gene expression, calcification, proliferation, and cell adhesion of human bone marrow mesenchymal stem cell (h-BMSC) as they are part of scaffold structures. Therefore, we combined PRP/PRF, derived from the centrifugation of whole blood, with gelatin and Polycaprolactone (PCL) and produced nanofibrous electrospun PCL/Gel/PRP and PCL/Gel/PRF scaffolds. Three groups of scaffolds were fabricated, and h-BMSCs were seeded on them: (1) PCL/Gel; (2) PCL/Gel/PRP; (3) PCL/Gel/PRF. MTS assay was performed to assess cell proliferation and adhesion, and alizarin red staining confirmed the formation of bone minerals during the experiment. The result indicated that PCL/Gel did not have any better outcomes than the PRP and PRF group in any study variants after the first day of the experiment. PCL/gelatin/PRF was more successful regarding cell proliferation and adhesion. Although PCL/gelatin/PRP showed more promising results on the last day of the experiment in mineralization and osteogenic gene expression, except RUNX2, in which the difference with PCL/gelatin/PRF group was not significant.

Fucoidan/chitosan hydrogels as carrier for sustained delivery of platelet-rich fibrin containing bioactive molecules.

Platelet-rich fibrin (PRF), derived from human blood, rich in wound healing components, has drawbacks in direct injections, such as rapid matrix degradation and growth factor release. Marine polysaccharides, mimicking the human extracellular matrix, show promising potential in tissue engineering. In this study, we impregnated the self-assembled fucoidan/chitosan (FU_CS) hydrogels with PRF obtaining PRF/FU_CS hydrogels. Our objective was to analyze the properties of a hydrogel and the sustained release of growth factors from the hydrogel that incorporates PRF. The results of SEM and BET-BJH demonstrated the relatively porous nature of the FU_CS hydrogels. ELISA data showed that combining FU_CS hydrogel with PRF led to a gradual 7-day sustained release of growth factors (VEGF, EGF, IL-8, PDGF-BB, TGF-ß1), compared to pure PRF. Histology confirmed ELISA data, demonstrating uniform PRF fibrin network distribution within the FU_CS hydrogel matrix. Furthermore, the FU_CS hydrogels revealed excellent cell viability. The results revealed that the PRF/FU_CS hydrogel has the potential to promote wound healing and tissue regeneration. This would be the first step in the search for improved growth factor release.

Review of Dohan Eherenfest et al. (2009) on "Classification of platelet concentrates: From pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF)".

This classic discusses the original publication of Dohan Eherenfest et al. on "Classification of platelet concentrates: from pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF)", in which the authors propose four categories of platelet concentrates depending on their leucocyte and fibrin content (P-PRP, leucocyte- and platelet-rich plasma (L-PRP), pure platelet-rich fibrin (P-PRF), and L-PRF) to group a "jungle" of products in which the term platelet-rich plasma (PRP) was used indistinctly. They were able to identify common factors such as: (1) the use of anticoagulants and immediate centrifugation of the blood after its collection; (2) most preparation techniques allowed platelet concentrate preparation within an hour; (3) the centrifugation aimed to separate the blood in layers that would allow the extraction of specific fractions; and (4) the product was activated with thrombin or calcium chloride. The reviewed manuscript has been listed among the most cited PRP articles in regenerative medicine, with more than 800 citations, driving current scientific research and clinical practise by categorising L-PRP and P-PRP (now, leucocyte-poor PRP). The classification has also opened the door to understanding intrinsic biological mechanisms between platelets, leukocytes, fibrin, and growth factors, which will later be considered for studying the proliferation and differentiation of cells in different tissues affected by PRP. Since the initial classification of platelet concentrates, several other classification systems have been proposed and published in the current literature such as platelet, activation, white blood cell (PAW), Mishra, platelet, leucocyte, red blood cells, and activation (PLRA), dose of platelet, efficiency, purity, and activation (DEPA), method, activation, red blood cells, spin, platelets, image guidance, leukocytes, and light activation (MARSPILL), etc. These classifications have identified important aspects of PRP that affect the biological composition and, ultimately, the indications and outcomes. To date, there is still a lack of standardisation in sample preparation, cohort heterogeneity, and incomplete reporting of sample preparation utilised, leading to a lack of clarity and challenging researchers and clinicians.

Evaluation of the effect of injectable platelet-rich fibrin (i-PRF) in wound healing and growth factor release in rats: a split-mouth study.

This experimental study aimed to evaluate the effects of injectable platelet-rich fibrin (i-PRF) on mucosal healing and the release of growth factors in rats. 40 rats were used; i-PRF was administered in the right buccal area while saline was injected in the left. Cytokeratin, FGF, PDGF, TGF, and VEGF expressions were determined with immunohistochemistry. Gene expressions of EGF, TGF-ß, and VEGF were analysed. Epithelialization started on the 3rd day, and connective tissue maturation was more prominent in the i-PRF-applied group. Also, the releases of VEGF, EGF, TGF-ß, PDGF, and FGF were higher in the i-PRF group during the 14 days. Gene expression analysis showed that changes in TGF-ß at 14 days after i-PRF injection and VEGF after 21 days were statistically significant. The results of this study suggested that autologous i-PRF application enhanced the healing of oral mucosal wounds by increasing the release of growth factors for 21 days.

Osteogenic potential of apical papilla stem cells mediated by platelet-rich fibrin and low-level laser.

To evaluate the osteogenic potential of platelet-rich fibrin (PRF) and low-level laser therapy (LLLT) on human stem cells from the apical papilla (SCAP) we isolated, characterized, and then cultured in an osteogenic medium cells with PRF and/or LLLT (660 nm, 6 J/m2-irradiation). Osteogenic differentiation was assessed by bone nodule formation and expression of bone morphogenetic proteins (BMP-2 and BMP-4), whereas the molecular mechanisms were achieved by qRT-PCR and RNA-seq analysis. Statistical analysis was performed by ANOVA and Tukey's post hoc tests (p < 0.05* and p < 0.01**). Although PRF and LLLT increased bone nodule formation after 7 days and peaked at 21 days, the combination of PRF + LLLT led to the uppermost nodule formation. This was supported by increased levels of BMP-2 and -4 osteogenic proteins (p < 0.005). Furthermore, the PRF + LLLT relative expression of specific genes involved in osteogenesis, such as osteocalcin, was 2.4- (p = 0.03) and 28.3- (p = 0.001) fold higher compared to the PRF and LLLT groups, and osteopontin was 22.9- and 1.23-fold higher, respectively (p < 0.05), after 7 days of interaction. The transcriptomic profile revealed that the combination of PRF + LLLT induces MSX1, TGFB1, and SMAD1 expression, after 21 days of osteogenic differentiation conditions exposition. More studies are required to understand the complete cellular and molecular mechanisms of PRF plus LLLT on stem cells. Overall, we demonstrated for the first time that the combination of PRF and LLLT would be an excellent therapeutic tool that can be employed for dental, oral, and craniofacial repair and other tissue engineering applications.

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)- ß 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.

Lyophilized platelet rich fibrin and gelatin incorporated bioadhesive bone cement composite for repair of mandibular continuity defects.

Mandibular continuity defects stem from conditions such as malignancies, trauma, cysts, osteomyelitis and osteoradionecrosis, presenting significant challenges. If mandibular reconstruction fails, it can result in facial collapse, causing significant aesthetic and functional concerns for the patient. In the present study we developed a bio-adhesive Bone Cement (BC) enriched with lyophilised PRF and gelatin to enhance bone repair and induce regeneration. The developed BC consisted of a mixture of Tetracalcium Phosphate (TTCP) and O-Phospho-l-serine (OPLS) in addition to lyophilised Platelet Rich Fibrin (PRF) for sustained growth factor release and gelatin (GE) for improved cement resorption. It is primarily designed for in-situ application, conforming to the shape and size of the defect for effective bone repair and regeneration. The study evaluated four groups: (i) BC (control), (ii) BC-GE (control), (iii) BC-PRF, and (iv) BC-GE-PRF. All the four groups were characterised using FTIR, SEM and XRD. The mechanical studies of the prepared beads exhibited a significant increase in the compressive strength of the PRF loaded bone cement composites. In vitro degradation study of the beads over a 60-day period revealed a significantly higher percentage of bone cement resorption in the gelatin-incorporated groups, BC-GE (44 ± 0.5 %), and BC-GE-PRF (45 ± 2 %). The assessment of growth factor release (TGF-ß and VEGF) using ELISA revealed a prolonged and sustained release of both growth factors over a 28-day period. In vitro studies were performed on human Dental Follicle Stem Cells (DFSCs) to assess cell attachment, proliferation, mineralisation and osteogenic differentiation. These studies clearly depicted that BC-PRF and BC-GE-PRF showed significantly greater proliferation of DFSCs. Furthermore, BC-PRF and BC-GE-PRF samples exhibited notably elevated expression of Runx2 and OPN (osteogenic markers), as well as a higher intensity of alizarin red stain (mineralisation). Therefore, it was concluded that PRF incorporated bioadhesive bone cement composites greatly enhance the cell attachment, proliferation, mineralisation and osteogenic differentiation of the DFSCs. Thus, the PRF and gelatin incorporated bone cement composites is expected to facilitate effective and faster bone regeneration and healing in a wide range of dental and maxillofacial defects.

Improving properties of platelet-rich fibrin scaffold with tannic acid for wound healing.

Platelet-rich fibrin (PRF), which is the rich source of growth factors, has been used as an efficient scaffold in tissue engineering and wound healing. In this study, tannic acid as a green cross-linker with different concentrations (0.5%, 1%, 5% and 10%) was used to improve the properties of PRF. The cross-linked gel scaffolds were evaluated by analyses such as scanning electron microscopy, Fourier transform infrared spectroscopy, swelling and degradation, mechanical strength, cell toxicity, cell adhesion and antibacterial test. The results showed that the scaffold structure changes by increasing cross-linker concentration. The swelling rate decreased from 49% to 5% for the samples without the cross-linker and with tannic acid (10%), respectively. The degradation percentage for the cross-linked samples was 8%, which showed a lower degradation rate than the non-cross-linked samples (63%). The mechanical strength of the scaffold with the cross-linker increased up to three times (Young's modulus for the non-cross linked and the cross-linked samples: 0.01 and 0.6 MPa, respectively). Cytotoxicity was not observed up to 10% cross-linker concentration. The cells proliferated well on the cross-linked scaffolds and also showed a good antibacterial effect. In general, tannic acid can improve the physical and mechanical properties of PRF without negatively affecting its biological properties.

Effect of thermal manipulation on the biological and mechanical characteristics of horizontal platelet rich fibrin membranes.

BACKGROUD: Regardless of application scenarios, proper mechanical characteristics and degradation properties are prerequisites for horizontal platelet rich fibrin (H-PRF) to manifest its ability. Among the methods used to modify PRF, thermal manipulation is promising as it is easy to handle without adding extra additives. Yet there is no consensus on optimal temperature treatment. This study aimed to investigate the effects of heating on the biological and mechanical characteristics of H-PRF and explore the optimum heating temperature for H-PRF thermal treatment. METHODS: We employed a series of temperature gradients, room temperature, 50℃, 75℃, 90℃, 105℃. The microstructure and the mechanical properties were recorded by Scanning Electron Microscope (SEM) and tensile strength tests respectively. The degradation rate of H-PRF membranes was examined by digestion assay with plasmin and trypsin. The viability of cells within H-PRF membranes and the proliferation of osteoblasts cultured with extracts from different H-PRF groups was evaluated using CCK-8 assays. RESULTS: Compared with the nonheated group, overheated manipulation beyond 90℃ can significantly prolong the degradation properties for up to 3 to 4 weeks and enhance the mass stress of H-PRF membranes. A high-temperature treatment of 105℃ accompanied by the cell activity beneath H-PRF reduced more than half, and thus, the biological effect on human osteoblasts (hFOBs) also reduced dramatically. CONCLUSIONS: High thermal manipulation can prolong the degradation properties and enhance the mechanical properties of PRF membranes accompanied by the loss of biological effect.

Volumetric evaluation of effects of platelet-rich fibrin and concentrated growth factor on early bone healing after endodontic microsurgery: a randomized controlled trial.

BACKGROUND: This randomized controlled clinical trial compared the effects of platelet-rich fibrin (PRF) and concentrated growth factor (CGF) on early bone healing after endodontic microsurgery. METHODS: Eighteen patients with an isolated periapical lesion < 10 mm in the maxillary anterior region were randomly assigned to three groups: control, PRF, or CGF. Endodontic microsurgery was performed and PRF or CGF membranes were placed over the bone defects in the experimental groups. The volume of the bone defect at postoperative one week, three months, and six months was evaluated using cone-beam computed tomography and Mimics software. The results were statistically analyzed using the Kruskal-Wallis test and post-hoc Mann-Whitney U test with Bonferroni correction. RESULTS: At the three-month follow-up, the PRF and CGF groups showed significantly greater bone healing compared with the control group (p > 0.05). However, no significant difference was observed between the PRF and CGF groups. At the six-month follow-up, no significant differences were observed between the groups. CONCLUSIONS: These results suggested that PRF and CGF promote early bone healing after endodontic microsurgery.

The Effects of Injectable Platelet-Rich Fibrin and Advanced-Platelet Rich Fibrin on Gingival Fibroblast Cell Vitality, Proliferation, Differentiation.

BACKGROUND: Injectable Platelet Rich Fibrin (I-PRF) and Advanced-Platelet Rich Fibrin (A-PRF) are autologous materials derived from patients' blood and employed in periodontal regenerative surgery. Although I-PRF and A-PRF have different characteristics, their biological effects on gingival tissue fibroblasts remain unclear. This research aims to compare the in vitro capacity in inducing gene expression and proliferation of human gingival fibroblasts between A-PRF and I-PRF. METHODS: Human donors undergoing dental implant surgery were sampled for normal human gingival fibroblasts (NHGFCs), followed by preparing A-PRF and I-PRF membranes. Enzyme-linked immunosorbent assay (ELISA) kit was used to assess the release of platelet-derived growth factor-AA (PDGF-AA), transforming growth factor-beta1 (TGF- ß1), and insulin growth factor-1 (IGF-1) at different periods. Cell viability and proliferation of A-PRF and I-PRF were compared using CCK-8 assay. The impacts of platelet concentration on human gingival fibroblast cells (HGFCs) were evaluated by quantifying the level or amount of phosphorylated extracellular signal-regulated protein kinase (p-ERK), and Matrix metalloproteinases (MMPs), MMP-1 and MMP-3. The effects of PRF on aged human gingival fibroblast cells were examined retrospectively. RESULTS: Overall, A-PRF demonstrated a higher release of TGF-B1 and PDGF-AA, while I-PRF reflected higher levels of IGF-1. A significantly higher level of cell proliferation was induced by higher cell proliferation by A-PRF and I-PRF. Additionally, in comparison to I-PRF, the expression of ERK phosphorylation and MMP-1 &MMP-3 in HGFCs was demonstrated by I-PRF and A-PRF. The increase in A-PRF was time-dependent (p < 0.05). CONCLUSION: Both I-PRF and A-PRF induced a stimulatory biological impact on the proliferation of human gingiva fibroblasts, with the latter demonstrating better capacity in facilitating the release of different growth factors. A-PRF also induced higher gene expression of p-ERK, MMP-1 &MMP-3, and the proliferation of fibroblasts.

Reinforcement of colon anastomosis healing with leukocyte platelet-rich fibrin in rabbit model.

AIM: This study investigated the regenerative efficacy of leukocyte platelet-rich fibrin (L-PRF) on colon anastomotic healing in rabbits. MAIN METHODS: Thirty-six healthy male white New Zealand rabbits were subjected to complete transactions of the ascending colon. The rabbits were equally divided into two groups: the control group, where the transected colon ends were anastomosed by a simple interrupted suture pattern, and the L-PRF-treated group, in which L-PRF was wrapped entirely around the anastomotic line. The postoperative acute pain scale was assessed using the Bristol Rabbit Pain Scale before surgery and at each four-hour interval post-operatively. After euthanizing the rabbits, the adhesion degree score, anastomotic bursting pressure, and stenosis degree of the anastomotic colon were assessed, and histopathological examination at the 7th, 14th, and 28th days postoperatively. KEY FINDINGS: Rabbits in both groups showed a significant increase in pain scores compared to baseline. Postoperatively, the L-PRF group exhibited significantly lower pain scores, adhesion scores, and stenosis degrees than the control group. However, the anastomotic bursting pressure was significantly higher in the L-PRF group. Re-epithelialization, polymorphonuclear neutrophil infiltration, granulation tissue formation, and collagen deposition scores were improved considerably in the L-PRF group compared to the control group. Immunostaining of growth factor expression was significantly lower in the control than in the L-PRF group. SIGNIFICANCE: The L-PRF can augment collagen deposition, re-epithelialize the mucosa, promote angiogenesis, reduce adhesions, and diminish the stenosis degree scores. Therefore, it can be considered a promising aid in healing bowel anastomoses.

[Effects of advanced platelet-rich fibrin on deep partial-thickness burn wounds in nude mice].

Objective: To explore the effects of advanced platelet-rich fibrin (A-PRF) on deep partial-thickness burn wounds in nude mice and its mechanism. Methods: The experimental study method was adopted. Forty healthy volunteers in Subei People's Hospital were recruited, including 32 females and 8 males, aged 60 to 72 years. Leukocyte platelet-rich fibrin (L-PRF) and A-PRF membranes were prepared after venous blood was extracted from them. The microstructure of two kinds of platelet-rich fibrin (PRF) membranes was observed by field emission scanning electron microscope. The number of samples was 3 in the following experiments. The L-PRF and A-PRF membranes were divided into L-PRF group and A-PRF group and cultured, and then the release concentrations of platelet-derived growth factor-AB (PDGF-AB) and vascular endothelial growth factor (VEGF) in culture supernatant were determined by enzyme-linked immunosorbent assay on culture day 1, 3, 7, and 14. Mice L929 fibroblasts (Fbs) were divided into L-PRF group and A-PRF group, and cultured with L-PRF or A-PRF conditioned medium, respectively. On culture day 1, 3, and 7, the cell proliferation activity was detected by thiazole blue method. The cell migration rate was detected and calculated at 24 h after scratching by scratch test. Thirty-six male BALB/c nude mice aged 6-8 weeks were selected to make a deep partial-thickness burn wound on one hind leg, and then divided into normal saline group, L-PRF group, and A-PRF group, according to the random number table, with 12 mice in each group. The wounds of nude mice in normal saline group were only washed by normal saline, while the wounds of nude mice in L-PRF group and A-PRF group were covered with the corresponding membranes in addition. The wounds of nude mice in the 3 groups were all bandaged and fixed with dressings. On treatment day 4, 7, and 14, the wound healing was observed and the wound healing rate was calculated. Masson staining was used to observe the new collagen in wound tissue, and immunohistochemical staining was used to detect the percentage of CD31 positive cells in the wound. Data were statistically analyzed with independent sample t test, analysis of variance for repeated measurement, analysis of variance for factorial design, one-way analysis of variance, and least significant difference test. Results: L-PRF membrane's dense network structure was composed of coarse fibrin bundles, with scattered white blood cells and platelets with complete morphology. A-PRF membrane's loose network structure was composed of fine fibrin bundles, with scattered small amount of deformed white blood cells and platelets. On culture day 1, the release concentration of PDGF-AB in PRF culture supernatant in A-PRF group was significantly higher than that in L-PRF group (t=5.73, P<0.05), while the release concentrations of VEGF in PRF culture supernatant in the two groups were similar (P>0.05). On culture day 3, 7, and 14, the release concentrations of PDGF-AB and VEGF in PRF culture supernatant in A-PRF group were significantly higher than those in L-PRF group (with t values of 6.93, 7.45, 5.49, 6.97, 8.97, and 13.64, respectively, P<0.05). On culture day 3, 7, and 14, the release concentrations of PDGF-AB and VEGF in PRF culture supernatant in the two groups were all significantly higher than those in the previous time points within the group (P<0.05). On culture day 1, 3, and 7, the proliferation activity of mice Fbs in A-PRF group was 0.293±0.034, 0.582±0.054, and 0.775±0.040, respectively, which were significantly stronger than 0.117±0.013, 0.390±0.036, and 0.581±0.037 in L-PRF group (with t values of 8.38, 5.14, and 6.16, respectively, P<0.05). At 24 h after scratching, the migration rate of mice Fbs in A-PRF group was (60.9±2.2)%, which was significantly higher than (39.1±2.3)% in L-PRF group (t=11.74, P<0.05). On treatment day 4, the wound exudates of nude mice in L-PRF group and A-PRF group were less with no obvious signs of infection, while the wounds of nude mice in normal saline group showed more exudation. On treatment day 7, the wounds of nude mice in L-PRF group and A-PRF group were dry and crusted, while there was still a small amount of exudate in the wounds of nude mice in normal saline group. On treatment day 14, the wounds of nude mice in A-PRF group tended to heal; a small portion of wounds remained in nude mice in L-PRF group; the wound of nude mice was still covered with eschar in normal saline group. On treatment day 4, 7, and 14, the wound healing rate and percentage of CD31 positive cells of nude mice in L-PRF group were all significantly higher than those in normal saline group (P<0.05); compared with those in normal saline group and L-PRF group, the wound healing rate of nude mice in A-PRF group was significantly increased (P<0.05), the newborn collagen was orderly and evenly distributed, with no excessive deposition, and the percentage of CD31 positive cells was significantly increased (P<0.05). Conclusions: The stable fibrin network structure of A-PRF can maintain the sustained release of growth factors, accelerate cell proliferation, and promote cell migration, so as to shorten the healing time and improve the healing quality of deep partial-thickness burn wounds in nude mice.

Sema4D is diminished in leukocyte platelet-rich fibrin and impairs pre-osteoblastic MC3T3-E1 cells' functionality.

OBJECTIVE: Semaphorin 4D (Sema4D) is a coupling factor expressed on osteoclasts that may hinder osteoblast differentiation. Since the leukocyte platelet-rich fibrin (L-PRF) membrane promotes growth factor concentration, this study aims to quantify the amount of Sema4D in L-PRF membranes, and analyze the impact of Sema4D on osteoblast cell function in vitro. DESIGN: Enzyme-linked immunosorbent assay (ELISA) was used to quantify the levels of Sema4D in both L-PRF and whole blood (serum). To analyze the impairment of Sema4D on osteoblasts, MC3T3-E1 cells were induced to osteogenic differentiation and exposed to Sema4D ranging from 10 to 500 ng/ml concentrations. The following parameters were assayed: 1) cell viability by MTT assay after 24, 48, and 72 h; 2) matrix mineralization by Alizarin Red staining after 14 days, 3) Runt-related transcription factor 2 (RUNX-2), osteocalcin (OCN), osteonectin (ONC), bone sialoprotein (BSP) and alkaline phosphatase (ALP) gene expression by qPCR. For all data, the significance level was set at 5%. RESULTS: The amount of Sema4D in the whole blood (serum) was higher than in L-PRF. Osteoblasts exposed to Sema4D at all tested concentrations exhibited a decrease in matrix mineralization formation as well in RUNX-2, OCN, ONC, BSP, and ALP gene expression (p < 0.05). CONCLUSION: The presence of Sema4D, a molecule known for suppressing osteoblast activity, diminishes within L-PRF, enhancing its ability to facilitate bone regeneration.