The effect of platelet-rich fibrin on the biological properties of urothelial cells.

Urethral reconstruction presents a challenging issue in urology, primarily due to the limited availability of alternative materials for repair. The advancement of bioengineering technology has brought new hope to researchers, with a focus on the selection of appropriate biological scaffolds and seed cells. In order to find an ideal alternative material, we used platelet-rich fibrin as the bioscaffold and urothelial cells as the seed cells, meanwhile, we intended to investigate the effect of platelet-rich fibrin on the biological properties of urothelial cells. We transformed and characterised induced pluripotent stem cells into urothelial cells and prepared platelet-rich fibrin. Platelet-rich fibrin was cultured in a complex with urothelial cells to observe the effect of platelet-rich fibrin on the proliferation and migration ability of urothelial cells. The results showed that the induced pluripotent stem cells were successfully transformed into urothelial cells, platelet-rich fibrin was regularly arranged in cords, with platelets and other structures distributed between them, and the proliferation and migration of urothelial cells were significantly increased. These results suggested that platelet-rich fibrin is biocompatible with urothelial cells and it promotes the proliferation and migration of urothelial cells, which lays a good foundation for its use as an alternative material for urethral repair.

Leukocyte-and Platelet-Rich Fibrin for enhanced tissue repair: an in vitro study characterizing cellular composition, growth factor kinetics and transcriptomic insights.

BACKGROUND: Leukocyte- and platelet-rich fibrin (L-PRF) is an autologous platelet concentrate, prepared by centrifugation of blood and consisting of a dense fibrin network with incorporated leukocytes and platelets. This study aims to perform an in-depth analysis of the cells, growth factors, and transcriptome of L-PRF. METHODS AND RESULTS: Fresh, 1 week and 2 weeks cultured human L-PRF membranes and liquid L-PRF glue were characterized on cellular and transcriptional level using flow cytometry (n = 4), single-cell RNA sequencing (n = 5) and RT-qPCR. Growth factor kinetics were investigated using ELISA (EGF, VEGF, PDGF-AB, TGF-ß1, bFGF). L-PRF contained a large number of viable cells (fresh 97.14 ± 1.09%, 1 week cultured 93.57 ± 1.68%), mainly granulocytes in fresh samples (53.9 ± 19.86%) and T cells in cultured samples (84.7 ± 6.1%), confirmed with scRNA-seq. Monocytes differentiate to macrophages during 1 week incubation. Specifically arterial L-PRF membranes were found to release significant amounts of VEGF, EGF, PDGF-AB and TGF-ß1. CONCLUSION: We characterized L-PRF using in vitro experiments, to obtain an insight in the composition of the material including a possible mechanistic role for tissue healing. This was the first study characterizing L-PRF at a combined cellular, proteomic, and transcriptional level.

The Use of Platelet-Rich Fibrin (PRF) in the Management of Dry Socket: A Systematic Review.

Dry socket or alveolar osteitis is a common postoperative complication following tooth extraction, characterized by severe pain due to the disintegration of the blood clot within the socket. Various factors contribute to its development, such as traumatic extraction, patient age and sex, smoking, and anesthetic use. To mitigate this condition, socket preservation techniques, including the use of bone substitute materials, have been employed. Platelet-rich fibrin (PRF) has emerged as a promising biomaterial, enhancing healing and reducing the incidence of dry socket. Materials and Methods: This systematic review, adhering to the PRISMA guidelines and registered with PROSPERO (ID: CRD 578018), examines the efficacy of PRF in managing dry socket by analyzing studies from PubMed, Scopus, and Web of Science published between January 2013 and May 2024. Boolean keywords have been used in the search strategy: ("Treatment") AND ("Dry Socket") AND ("Platelet Rich Fibrin" OR "PRF"). A total of 738 publications were found using the electronic database search. After the screening phase, 13 records were chosen for qualitative analysis. The results from multiple clinical trials and comparative studies indicate that PRF significantly reduces postoperative pain, expedites healing, and lowers the incidence of Alveolar Osteitis. Despite promising results, further large-scale, randomized studies are needed to validate PRF as a standard treatment for dry socket.

Comparison of the therapeutic effect of platelet-rich plasma and injectable platelet-rich fibrin on testicular torsion/detorsion injury in rats.

Testicular torsion is a common disorder in males and results in blockage of testicular circulation with subsequent damage of testicular germ cells. The current work aimed to compare the therapeutic effect of platelet-rich plasma (PRP) and injectable platelet-rich fibrin (i-PRF) on torsion/detorsion (T/D) injury in rats. Forty mature male Wister rats were arranged into 4 groups; (1) Control, (2) T/D, (3) T/D + PRP, and (4) T/D+ i-PRF. The right testis was twisting 1080° clockwise for 3 h in groups 2, 3 and 4, then 10 µl of PRP or i-PRF was injected intra-testicular 3 h after detorsion in groups 3 and 4, respectively. After 30 days postoperatively, the semen quality and hormonal assay were improved in PRP and i-PRF-treated groups with superiority of i-PRF (P < 0.001). High significance of Catalase, Glutathione Peroxidase (GPx), Superoxide Dismutase, Interleukin-1ß (IL-1ß), Caspase-3 and Tumor necrosis factor-α (TNF-α) was reported in treated rats with PRP and i-PRF (P < 0.001) with superiority to i-PRF-treated rats (P < 0.001). Testicular histoarchitectures were improved in PRP and i-PRF-treated rats with superiority of i-PRF-treated rats. It was concluded that PRP and i-PRF have regenerative efficacy on testicular damage after induced T/D injury with a superior efficacy of i-PRF.

RNAseq of Gingival Fibroblasts Exposed to PRF Membrane Lysates and PRF Serum.

Platelet-rich fibrin (PRF) is prepared by spontaneous coagulation of fractionated blood. When squeezed between two plates, PRF is separated into solid PRF membranes and a liquid exudate, the PRF serum. The question arises regarding how much the overall activity remains in the PRF membranes and what is discarded into the PRF serum. To this end, we have exposed gingival fibroblasts to lysates prepared from PRF membranes and PRF serum, followed by bulk RNA sequencing. A total of 268 up- and 136 down-regulated genes in gingival fibroblasts exposed to PRF membrane lysates were significantly regulated under the premise of a minimum log2 with 2.5-fold change and a minus log10 significance level of two, respectively. PRF serum only caused 62 up- and 32 down-regulated genes under these conditions. Among the 46 commonly up-regulated genes were CXCL1, CXCL5, CXCL6, CXCL8, IL33, IL6, and PTGS2/COX2, stanniocalcin-1-all linked to an inflammatory response. PRF membrane lysates further increased chemokines CCL2, CCL7, CXCL2, CXCL3, and IL1R1, IL1RL1, and IL1RN, as well as the paracrine factors IL11, LIF, IGF1, BMP2, BMP6, FGF2, and CCN2/CTGF, and all hyaluronan synthases. On the other hand, PRF serum increased DKK1. The genes commonly down-regulated by PRF membrane lysates and PRF serum included interferon-induced protein with tetratricopeptide repeats (IFIT1, IFIT2, IFIT3) and odd-skipped-related transcription factors (OSR1 and OSR2), as well as FGF18 and GDF15, respectively. Taken together, PRF membrane lysates, compared to PRF serum, cause a more complex response in gingival fibroblasts, but each increased chemokine expression in gingival fibroblasts.

Platelet-rich fibrin as an adjunct to scaling and root planing in treatment of shallow periodontal pockets: A randomized clinical trial.

OBJECTIVES: To evaluate the efficacy of platelet-rich fibrin (PRF) as an adjunct to scaling and root planing (ScRp) for healing shallow periodontal pockets. METHODS: Twelve patients with periodontitis were enrolled in this split-mouth, randomized clinical trial. A total of 24 shallow periodontal pockets (4-6 mm) were treated by either ScRp alone (control) or PRF (test). Clinical attachment loss (CAL), probing pocket depth (PPD), bleeding on probing (BOP), and plaque index (PLI), as well as platelet-derived growth factor-BB (PDGF-BB) by enzyme-linked immunosorbent assay (ELISA) in gingival crevicular fluid (GCF) were measured at baseline and at 1- and 3-month follow-up visits. RESULTS: At 1- and 3-month follow-up visits, greater CAL gains (2.6 ± 0.25 mm and 3.26 ± 0.31 mm, respectively) and PPD reductions (2.58 ± 0.38 and 3.31 ± 0.39 mm, respectively) were observed in the test group compared to those in controls (CAL gain of 1.01 ± 0.49 mm and 1.43 ± 0.48 mm; PPD reduction of 1.1 ± 0.55 and 1.37 ± 0.49 mm, respectively). In addition, the increase in PDGF-BB in GCF in the test group (724.5 ± 186.09 pg/µl and 1957.5 ± 472.9 pg/µl) was significantly greater than that in controls (109.3 ± 24.07 and 614.64 ± 209.3 pg/µl) at 1- and 3-month follow-up visits, respectively. CONCLUSIONS: The noninvasive use of PRF as an adjunct to ScRp successfully improved clinical periodontal parameters and might contribute to increased PDGF-BB in GCF.

The Biological Role of Platelet Derivatives in Regenerative Aesthetics.

Bioproducts derived from platelets have been extensively used across various medical fields, with a recent notable surge in their application in dermatology and aesthetic procedures. These products, such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), play crucial roles in inducing blood vessel proliferation through growth factors derived from peripheral blood. PRP and PRF, in particular, facilitate fibrin polymerization, creating a robust structure that serves as a reservoir for numerous growth factors. These factors contribute to tissue regeneration by promoting cell proliferation, differentiation, and migration and collagen/elastin production. Aesthetic medicine harnesses these effects for diverse purposes, including hair restoration, scar treatment, striae management, and wound healing. Furthermore, these biological products can act as adjuvants with other treatment modalities, such as laser therapy, radiofrequency, and microneedling. This review synthesizes the existing evidence, offering insights into the applications and benefits of biological products in aesthetic medicine.

Platelet-Rich Plasma (PRP) and Injectable Platelet-Rich Fibrin (i-PRF) in the Non-Surgical Treatment of Periodontitis-A Systematic Review.

The gold standard in the non-surgical treatment of periodontitis is scaling and root planing (SRP). In recent years, the use of autogenous platelet concentrates has spread over many specialties in dentistry and, thus, has also been gaining popularity in periodontal treatment. Its two main fractions are platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), which, since 2014, can also be used via injection as injectable platelet-rich fibrin (i-PRF). The authors conducted a comprehensive systematic review in accordance with the PRISMA 2020 guidelines. It involved searching PubMed, Embase, Scopus, and Google Scholar databases using the phrases ("Root Planing" OR "Subgingival Curettage" OR "Periodontal Debridement") AND ("Platelet-Rich Plasma"). Based on the authors' inclusion and exclusion criteria, 12 results were included in the review, out of 1170 total results. The objective of this review was to ascertain the impact of utilizing PRP and i-PRF in SRP. The results revealed that both the incorporation of PRP and i-PRF were found to be significantly associated with are duction in gingival pocket depth and again in clinical attachment level; however, i-PRF demonstrated superiority in improving clinical parameters. Furthermore, i-PRF demonstrated notable bactericidal efficacy against Porphyromonas gingivalis. On the other hand, PRP proved inferior to an Nd:YAG laser in clinical parameter improvement; however, it demonstrated significant efficiency as well. This literature review led the authors to the conclusion that autologous platelet concentrates might be competent agents for improving the therapeutic outcomes of SRP.

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.

A Simplified GBR Treatment and Evaluation of Posterior Seibert Class I Ridge Defects via Bio-collagen and Platelet-Rich Fibrin: A Retrospective Study.

BACKGROUND: Classical guided bone regeneration (GBR) treatments can achieve favorable clinical results for ridge defects. However, extensive bone augmentation in the non-esthetic area in the posterior region for minor ridge defects is unnecessary. Therefore, this study used a collagen and Platelet-rich fibrin (PRF) mixture for bone augmentation on minor posterior ridge defects and evaluated the effects. METHODS: 22 Seibert Class I ridge defects were treated with BC and covered with a PRF membrane (simplified guided bone regeneration, simplified GBR) and other 22 were treated with Bio-Oss and covered with Bio-Gide (classical GBR). Cone-beam computed tomography imaging was conducted 6 months post-surgery to compare the ridge's horizontal width (HW) and buccal ridge's horizontal width to assess the osteogenic effect. In addition, the buccal ridge contour morphology was studied and classified. RESULTS: The buccal ridge contour of simplified GBR was Type A in 14 cases, Type B in 7 cases, and Type C in 1 case and it of classical GBR was Type A in 11 cases, Type B in 8 cases, and Type C in 3 cases. The mean HW significantly increased by 1.50 mm of simplified GBR treatment, while it increased by 1.83 mm in classical GBR treatment. CONCLUSION: The combined use of BC and PRF had a significant effect on bone augmentation and this treatment exhibited promising clinical results for correcting posterior Seibert Class I ridge defects. The morphological classification of the reconstructive effect in this study can be utilized in future clinical work.

Platelet-rich fibrin (PRF) modified nano-hydroxyapatite/chitosan/gelatin/alginate scaffolds increase adhesion and viability of human dental pulp stem cells (DPSC) and osteoblasts derived from DPSC.

Bone tissue regeneration strategies have incorporated the use of natural polymers, such as hydroxyapatite (nHA), chitosan (CH), gelatin (GEL), or alginate (ALG). Additionally, platelet concentrates, such as platelet-rich fibrin (PRF) have been suggested to improve scaffold biocompatibility. This study aimed to develop scaffolds composed of nHA, GEL, and CH, with or without ALG and lyophilized PRF, to evaluate the scaffold's properties, growth factor release, and dental pulp stem cells (DPSC), and osteoblast (OB) derived from DPSC viability. Four scaffold variations were synthesized and lyophilized. Then, degradation, swelling profiles, and morphological analysis were performed. Furthermore, PDGF-BB and FGF-B growth factors release were quantified by ELISA, and cytotoxicity and cell viability were evaluated. The swelling and degradation profiles were similar in all scaffolds, with pore sizes ranging between 100 and 250 µm. FGF-B and PDGF-BB release was evidenced after 24 h of scaffold immersion in cell culture medium. DPSC and OB-DPSC viability was notably increased in PRF-supplemented scaffolds. The nHA-CH-GEL-PRF scaffold demonstrated optimal physical-biological characteristics for stimulating DPSC and OB-DPSC cell viability. These results suggest lyophilized PRF improves scaffold biocompatibility for bone tissue regeneration purposes.

Comprehensive clinical and histological evaluation of bovine hydroxyapatite bone graft with polypropylene membrane versus leukocyte- and platelet-rich fibrin for alveolar preservation after tooth extraction.

BACKGROUND: Osseointegrated implant placement in the ideal prosthetic position necessitates a sufficient residual alveolar ridge. Tooth extraction and the subsequent healing process often lead to bony deformities, characterized by a reduction in alveolar ridge height and width, resulting in unfavorable ridge architecture for dental implant placement. Several materials, including allografts, alloplastics, xenografts, and autogenous bone, are commonly used to address these concerns. In this context, leucocyte- and platelet-rich fibrin (L-PRF) emerges as a promising solution. METHODS: This case report aims to compare the clinical and histological efficacy of bovine hydroxyapatite bone graft covered with polypropylene membrane (BHAG-PM) and leucocyte- and platelet-rich fibrin (L-PRF) in preserving dental alveoli following tooth extraction. Extraction, graft placement in the alveoli, and the anterior border between extracted elements were performed for both treatment groups. RESULTS: Up to 24 months of follow-up revealed satisfactory and comparable clinical and histological outcomes. These results suggest that both BHAG-PM and L-PRF effectively promote alveolar preservation, paving the way for ideal implant placement. CONCLUSIONS: In general, bone-substitute materials are effective in reducing alveolar changes after tooth extraction. Xenograft materials should be considered as among the best of the available grafting materials for alveolar preservation after tooth extraction. Both techniques effectively preserve the alveolar bone and facilitate the placement of osseointegrated implants in ideal positions, paving the way for successful oral rehabilitation.

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.

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.

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.

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.

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.

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.

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.