Effect of platelet-rich fibrin on cell proliferation, migration, differentiation, inflammation, and osteoclastogenesis: a systematic review of in vitro studies

Using Platelet-Rich Fibrin to Remove Graphite Tattoos May Yield Excellent Long-Term Result

Graphite tattoos are rarely reported because they are mainly caused by an accidental injury or habits during childhood that cause a pencil to penetrate the oral mucosa. Unlike other pigmentations, it stains layers that are deeper than the subepithelial and mucosal layers, and in most cases, it takes the form of a grayish black macule. This case report describes depigmentation with the denudation technique that was followed by a novel approach of using platelet-rich fibrin to cover exposed bone. A 41-year-old male patient presented with an aesthetic complaint from a grayish black staining on the labial gingiva near the maxillary central and lateral incisors. The lesion was diagnosed as a graphite tattoo due to the patient's history of sticking his gum with pencils when he was young. The entire pigmented gingiva was surgically removed and covered with two layers of PRF membrane to protect the exposed bone surface and provide an extracellular matrix for migration of gingival fibroblasts. Healing patterns were observed at 1, 2, 4, and 8 weeks, and satisfactory clinical and aesthetic results were obtained. Creeping attachment was observed at 8 years postop, and there was no recurrence for a long-term period of 13 years.

How to explain the beneficial effects of leukocyte- and platelet-rich fibrin

The survival of an organism relies on its ability to repair the damage caused by trauma, toxic agents, and inflammation. This process involving cell proliferation and differentiation is driven by several growth factors and is critically dependent on the organization of the extracellular matrix. Since autologous platelet concentrates (APCs) are fibrin matrices in which cells, growth factors, and cytokines are trapped and delivered over time, they are able to influence that response at different levels. The present review thoroughly describes the molecular components present in one of these APCs, leukocyte- and platelet-rich fibrin (L-PRF), and summarizes the level of evidence regarding the influence of L-PRF on anti-inflammatory reactions, analgesia, hemostasis, antimicrobial capacity, and its biological mechanisms on bone/soft tissue regeneration.

Comprehensive evaluation of advanced platelet-rich fibrin in common complications following sagittal split ramus osteotomy: a double-blind, split-mouth, randomized clinical trial

The sagittal split ramus osteotomy (SSRO) carries potential risks and complications. A double-blind, split-mouth, randomized clinical trial was performed, involving 30 patients undergoing mandibular setback. Advanced platelet-rich fibrin (A-PRF) was applied to one side, and the other side served as a control. The volume of postoperative drainage over 24 h was recorded. At 1, 2, and 5 days, and 3 months postsurgery, nerve recovery was assessed using the two-point discrimination test (TPD), while pain was evaluated using a visual analogue scale (VAS pain). Facial swelling was evaluated by taking linear measurements from facial reference points at the same time intervals. In the treatment group, the 24-hour drainage volume was lower (P = 0.011), pain was better on day 5 (P = 0.011), and TPD was better on day 2 (P = 0.011), day 5 (P = 0.007), and 3 months postoperatively (P = 0.020) than in the control group. There was also less facial swelling in the treatment group when compared to the baseline of 3 months postoperative (day 1, P = 0.012; day 2, P = 0.001; day 5, P = 0.011). The difference in bone mineral density (HU) at 3 months between the treatment group (469.7 ± 134.2) and the control group (348.3 ± 127.2) was statistically significant (P = 0.011), in favour of the treatment group. A-PRF may reduce postoperative complications such as neurosensory disturbance of the inferior alveolar nerve, pain, swelling, and drainage while enhancing bone healing in the osteotomy gap following SSRO. TRIAL REGISTRATION: The study was registered with the Chinese Clinical Trial Register (ChiCTR2200064534).

The Role of Leukocyte-Platelet-Rich Fibrin in Promoting Wound Healing in Diabetic Foot Ulcers

To explore the effect of leukocyte-platelet-rich fibrin (L-PRF) on promoting wound healing in diabetic foot ulcers. A total of 42 patients with diabetic foot ulcers at our hospital from January 2017 to July 2020 were retrospectively analyzed. A control group and a PRF group were established. The two groups of patients underwent debridement. In the platelet-rich fibrin (PRF) group, autologous L-PRF was used to cover ulcer wounds. One time each week, Vaseline gauze was used to cover the ulcer wounds. In contrast, the control group was treated with the external application of mupirocin ointment and recombinant human epidermal growth factor gel (yeast). Two times each week, the sterile Vaseline gauze was covered with a bandage. Both groups were treated for 5 weeks. The wound recovery of the two groups was observed. During the early stage of treatment (first and second weeks) for diabetic foot ulcers, the wound healing rate was significantly better with L-PRF treatment than traditional treatment. For later-stage treatment (third to fifth weeks), the overall cure rate was higher with L-PRF than the traditional treatment method. L-PRF can effectively promote wound healing in diabetic foot ulcers.

Human versus Rat PRF on Collagen Membranes: A Pilot Study of Mineralization in Rat Calvaria Defect Model

Platelet-rich fibrin, the coagulated plasma fraction of blood, is commonly used to support natural healing in clinical applications. The rat calvaria defect is a standardized model to study bone regeneration. It remains, however, unclear if the rat calvaria defect is appropriate to investigate the impact of human PRF (Platelet-Rich Fibrin) on bone regeneration. To this end, we soaked Bio-Gide® collagen membranes in human or rat liquid concentrated PRF before placing them onto 5 mm calvarial defects in Sprague Dawley rats. Three weeks later, histology and micro-computed tomography (μCT) were performed. We observed that the collagen membranes soaked with rat PRF show the characteristic features of new bone and areas of mineralized collagen matrix, indicated by a median mineralized volume of 1.5 mm3 (range: 0.9; 5.3 mm3). Histology revealed new bone growing underneath the membrane and hybrid bone where collagen fibers are embedded in the new bone. Moreover, areas of passive mineralization were observed. The collagen membranes soaked with human PRF, however, were devoid of histological features of new bone formation in the center of the defect; only occasionally, new bone formed at the defect margins. Human PRF (h-PRF) caused a median bone volume of 0.9 mm3 (range: 0.3-3.3 mm3), which was significantly lower than what was observed with rat PRF (r-PRF), with a BV median of 1.2 mm3 (range: 0.3-5.9 mm3). Our findings indicate that the rat calvaria defect model is suitable for assessing the effects of rat PRF on bone formation, but caution is warranted when extrapolating conclusions regarding the efficacy of human PRF.

L-PRF Secretome from Both Smokers/Nonsmokers Stimulates Angiogenesis and Osteoblast Differentiation In Vitro

Leukocyte and Platelet-Rich Fibrin (L-PRF) is part of the second generation of platelet-concentrates. L-PRF derived from nonsmokers has been used in surgical procedures, with its beneficial effects in wound healing being proven to stimulate biological activities such as cell proliferation, angiogenesis, and differentiation. Cigarette smoking exerts detrimental effects on tissue healing and is associated with post-surgical complications; however, evidence about the biological effects of L-PRF derived from smokers is limited. This study evaluated the impact of L-PRF secretome (LPRFS) derived from smokers and nonsmokers on angiogenesis and osteoblast differentiation. LPRFS was obtained by submerging L-PRF membranes derived from smokers or nonsmokers in culture media and was used to treat endothelial cells (HUVEC) or SaOs-2 cells. Angiogenesis was evaluated by tubule formation assay, while osteoblast differentiation was observed by alkaline phosphatase and osterix protein levels, as well as in vitro mineralization. LPRFS treatments increased angiogenesis, alkaline phosphatase, and osterix levels. Treatment with 50% of LPRFS derived from smokers and nonsmokers in the presence of osteogenic factors stimulates in vitro mineralization significantly. Nevertheless, differences between LPRFS derived from smokers and nonsmokers were not found. Both LPRFS stimulated angiogenesis and osteoblast differentiation in vitro; however, clinical studies are required to determine the beneficial effect of LPRFS in smokers.

How to explain the beneficial effects of platelet-rich plasma

Platelet-rich plasma (PRP) is the platelet and leukocyte-containing plasmatic fraction of anticoagulated autologous blood. While evidence supporting the clinical use of PRP in dentistry is low, PRP is widely used in sports medicine, orthopedics, and dermatology. Its beneficial activity is commonly attributed to the growth factors released from platelets accumulating in PRP; however, evidence is indirect and not comprehensive. There is thus a demand to revisit PRP with respect to basic and translational science. This review is to (i) recapitulate protocols and tools to prepare PRP; (ii) to discuss the cellular and molecular composition of PRP with a focus on platelets, leukocytes, and the fibrin-rich extracellular matrix of coagulated plasma; and finally (iii) to discuss potential beneficial effects of PRP on a cellular and molecular level with an outlook on its current use in dentistry and other medical fields.

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.

Does Liquid/Injectable Platelet-Rich Fibrin Help in the Arthrocentesis Treatment of Temporomandibular Joint Disorder Compared to Other Infusion Options? A Systematic Review of Randomized Clinical Trials

Temporomandibular joint disorders (TMDs) are prevalent musculoskeletal conditions involving pain and dysfunction of jaw mobility and function, which have proven difficult to treat satisfactorily. The present study aimed to assess the effectiveness of a liquid platelet-rich fibrin (i-PRF) infusion during arthrocentesis versus other options using coadjuvant materials to reduce TMD symptoms. A literature search was conducted using PubMed, EMBASE, Web of Science, Scopus, and ClinicalTrials.gov for RCTs published before January 2024, comparing i-PRF to any other TMD treatment. This systematic review was registered on PROSPERO (CRD42023495364). The searches generated several recent RCTs that compared i-PRF injection combined with arthrocentesis (AC) to AC-only or AC with platelet-rich plasma (PRP). The outcomes analyzed included measures of pain (visual analog scale, VAS), maximum mouth opening, joint sounds, and MRI-verified changes in joint structure. Across the RCTs, the addition of i-PRF injection to AC resulted in significant improvements in pain relief, joint function, mouth opening, and structural changes compared to AC-only or with PRP over follow-up periods ranging from 6 to 12 months. Current clinical evidence favors using i-PRF as an adjunct to AC rather than AC-only or AC with PRP for the treatment of TMDs. The improvements in subjective and objective outcome measures are clinically meaningful. Still, additional high-quality RCTs with larger sample sizes and longer follow-ups are required to strengthen the evidence base and better define the role of i-PRF in TMD management guidelines.

Platelet-rich fibrin stimulates the proliferation and expression of proteins related to survival, adhesion, and angiogenesis in gingival fibroblasts cultured on a titanium nano-hydroxyapatite-treated surface

OBJECTIVES

This in vitro study aimed to evaluate the cell viability and expression of proteins related to angiogenesis, adhesion, and cell survival (vascular endothelial growth factor, paxillin, vinculin, fibronectin, and protein kinase B) in gingival fibroblasts that were cultured on titanium discs treated with or without nanohydroxyapatite and exposed to platelet-rich fibrin (PRF)-conditioned medium.

METHODS

To obtain the conditioned medium, the PRF membranes were prepared and incubated for 48 h in a culture medium without fetal bovine serum. Analyses were performed at 24 and 48 h for the cells cultured on machined-titanium discs or surfaces treated with nanohydroxyapatite in a control medium or PRF-conditioned medium, resulting in four experimental groups (CT-TI, CT-NANO, PRF-TI, and PRF-NANO).

RESULTS

A decrease in the viability of the gingival fibroblasts was not observed in any of the experimental groups. The PRF-NANO group showed significantly higher immunoexpression of paxillin and AKT at 24 and 48 h (p < 0.01). The same result was observed for vinculin expression at 24 h (p < 0.001). The expression of fibronectin at 48 h and VEGF at 24 and 48 h was significantly higher when the cells were exposed to the PRF-conditioned medium, regardless of the disc surface (p < 0.05).

CONCLUSION

Gingival fibroblasts cultured on a nanohydroxyapatite-treated surface and in a PRF-conditioned medium showed a greater expression of proteins modulating adhesion, angiogenesis, and cell survival. Our results may contribute to the understanding of the mechanisms related to peri-implant soft tissue sealing.

The use of mesenchymal stromal cell secretome to enhance guided bone regeneration in comparison with leukocyte and platelet-rich fibrin

OBJECTIVES

Secretomes of mesenchymal stromal cells (MSC) represent a novel strategy for growth-factor delivery for tissue regeneration. The objective of this study was to compare the efficacy of adjunctive use of conditioned media of bone-marrow MSC (MSC-CM) with collagen barrier membranes vs. adjunctive use of conditioned media of leukocyte- and platelet-rich fibrin (PRF-CM), a current growth-factor therapy, for guided bone regeneration (GBR).

METHODS

MSC-CM and PRF-CM prepared from healthy human donors were subjected to proteomic analysis using mass spectrometry and multiplex immunoassay. Collagen membranes functionalized with MSC-CM or PRF-CM were applied on critical-size rat calvaria defects and new bone formation was assessed via three-dimensional (3D) micro-CT analysis of total defect volume (2 and 4 weeks) and 2D histomorphometric analysis of central defect regions (4 weeks).

RESULTS

While both MSC-CM and PRF-CM revealed several bone-related proteins, differentially expressed proteins, especially extracellular matrix components, were increased in MSC-CM. In rat calvaria defects, micro-CT revealed greater total bone coverage in the MSC-CM group after 2 and 4 weeks. Histologically, both groups showed a combination of regular new bone and 'hybrid' new bone, which was formed within the membrane compartment and characterized by incorporation of mineralized collagen fibers. Histomorphometry in central defect sections revealed greater hybrid bone area in the MSC-CM group, while the total new bone area was similar between groups.

CONCLUSION

Based on the in vitro and in vivo investigations herein, functionalization of membranes with MSC-CM represents a promising strategy to enhance GBR.

Ten years of injectable platelet-rich fibrin

The use of platelet-rich fibrin (PRF) has seen widespread advantages over platelet-rich plasma (PRP) in many fields of medicine. However, until 2014, PRF remained clinically available only in its solid clotted form. Modifications to centrifugation protocols and tube technology have led to the development of a liquid injectable version of PRF (i-PRF). This narrative review takes a look back at the technological developments made throughout the past decade and further elaborates on their future clinical applications. Topics covered include improvements in isolation techniques and protocols, ways to further concentrate i-PRF, and the clinical impact and relevance of cooling i-PRF. Next, various uses of i-PRF are discussed, including its use in regenerative periodontology, implantology, endodontics, temporomandibular joint injections, and orthodontic tooth movement. Furthermore, various indications in medicine are also covered, including its use in sports injuries and osteoarthritis of various joints, treatment of diabetic ulcers/wound care, and facial esthetics and hair regrowth. Finally, future applications are discussed, mainly its use as a drug delivery vehicle for small biomolecules, such as growth factors, antibiotics, exosomes, and other medications that may benefit from the controlled and gradual release of biomolecules over time.

Effects of Growth Factors on the Differentiation of Dental Stem Cells: A Systematic Review and Meta-analysis (Part I)

INTRODUCTION

To evaluate the biological interaction between dental stem cells (DSCs) and different growth factors in the field of regenerative endodontics.

METHODS

A systematic search was conducted in the electronic databases up to October 2021. This study followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Ex vivo studies evaluating the biological interactions of DSCs and growth factors were included. The meta-analysis was performed according to the type of growth factor. The outcomes were cell viability/ proliferation and mineralization. Standardized mean differences (SMDs) were estimated using the random-effect maximum-likelihood method (P < .05). Additional analysis was performed to find any potential source of heterogeneity.

RESULTS

Twenty articles were included in the systematic review; meta-analysis was performed for fibroblast growth factor-2 (FGF-2) and Transforming growth factor-ß1 (TGF-β1) (n = 5). Results showed that use of FGF-2 significantly increased cell proliferation on day 1-(SMD = 3.56, P = 0.00), 3-(SMD = 9.04, P = 0.00), 5-(SMD = 8.37, P = 0.01), and 7 (SMD=8.51, P=0.00) than the control group. TGF-ß1 increased alkaline phosphatase (ALP) activity more than control only on day 3 (SMD = 3.68, P = 0.02). TGF-β1 had no significant effect on cell proliferation on days 1 and 3 (P > 0.05) and on ALP activity on days 5 and 7 (P > 0.05). Meta-regression analysis showed that different covariates (i.e., cell type, passage number, and growth factors' concentration) could significantly influence the effect sizes at different follow- ups (P < 0.05).

CONCLUSION

Specific growth factors might enhance the proliferation and mineralization of DSCs; however, the obtained evidence was weak. Due to the high heterogeneity among the included studies, other growth factors' inhibitory/stimulatory effects on DSCs could not be evaluated.

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.

Comparison between platelet rich fibrin as space filling material versus xenograft and alloplastic bone grafting materials in immediate implant placement: a randomized clinical trial

BACKGROUND

This study aimed to compare the efficacy of different gap filling materials in immediate implant in anterior and premolar regions of maxilla.

MATERIALS AND METHODS

Thirty-six implants were inserted in patients seeking for replacement of non-restorable maxillary anterior and premolar teeth (esthetic zone) by immediate implant. Patients were randomly distributed into three equal groups, twelve implants in each group. Group 1 received Platelet Rich Fibrin (PRF) into the jumping distance, Group 2 received Xenograft into the jumping distance and Group 3 received Alloplastic bone grafting material into the jumping distance. Implant stability by measuring the changes in Resonance Frequency Analysis (RFA), peri-implant pocket depth, marginal bone loss and changes in buccal bone thickness were evaluated during follow up periods. All the clinical and radiographic data were subjected to statistical analysis by One Way ANOVA test and the Post Hoc Tukey test.

RESULTS

This study involved 19 female patients and 17 male patients who received 36 dental implants. There was no significant difference between the study groups regarding implant stability, peri-implant pocket depth and palatal bone loss, while there was a significant difference between PRF Group (Group 1) and the other Groups regarding buccal bone loss and changes in buccal bone thickness.

CONCLUSION

PRF can be used as a gap filling material in conjunction with immediate implant placement, but other bone grafting materials give superior result regarding buccal bone loss and changes in buccal bone thickness.

TRIAL REGISTRATION

The study was listed on www.

CLINICALTRIALS

gov with registration number (NCT05878392) on 26/05/2023. The Institutional Review Board (IRB) of the Faculty of Dentistry, Mansoura University, Mansoura, Egypt, approved the current study in compliance with the seventh revision of the Helsinki Declaration in 2013 (A0103023OS).

The role and mechanism of platelet-rich fibrin in alveolar bone regeneration

Platelet-rich fibrin (PRF), as an autologous blood preparation, has been receiving increasing attention in recent years and has been successfully applied in various clinical treatments for alveolar bone regeneration in the oral field. This review focuses on analyzing and summarizing the role and mechanism of PRF in alveolar bone regeneration. We first provide a brief introduction to PRF, then summarize the mechanisms by which PRF promotes alveolar bone regeneration from three aspects: osteogenesis mechanism, bone induction mechanism, and bone conduction mechanism, involving multiple signaling pathways such as Smad, ERK1/2, PI3K/Akt, and Wnt/β-catenin. We also explore the various roles of PRF as a scaffold, filler, and in combination with bone graft materials, detailing how PRF promotes alveolar bone regeneration and provides a wealth of experimental evidence. Finally, we summarize the current applications of PRF in various oral fields. The role of PRF in alveolar bone regeneration is becoming increasingly important, and its role and mechanism are receiving more and more research and understanding. This article will provide a reference of significant value for research in related fields. The exploration of the role and mechanism of PRF in alveolar bone regeneration may lead to the discovery of new therapeutic targets and the development of more effective and efficient treatment strategies.

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- β1), 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.

The Effects of Platelet-Rich Fibrin in the Behavior of Mineralizing Cells Related to Bone Tissue Regeneration-A Scoping Review of In Vitro Evidence

Platelet-rich fibrin (PRF) is a second-generation blood concentrate that serves as an autologous approach for both soft and hard tissue regeneration. It provides a scaffold for cell interaction and promotes the local release of growth factors. PRF has been investigated as an alternative to bone tissue therapy, with the potential to expedite wound healing and bone regeneration, though the mechanisms involved are not yet fully understood. This review aims to explore the in vitro evidence of PRF's effects on the behavior of mineralizing cells related to bone tissue regeneration. A systematic electronic search was conducted up to August 2023, utilizing three databases: PubMed, Web of Science, and Scopus. A total of 76 studies were selected, which presented in vitro evidence of PRF's usefulness, either alone or in conjunction with other biomaterials, for bone tissue treatment. PRF membranes' influence on the proliferation, differentiation, and mineralization of bone cells is linked to the constant release of growth factors, resulting in changes in crucial markers of bone cell metabolism and behavior. This further reinforces their therapeutic potential in wound healing and bone regeneration. While there are some notable differences among the studies, the overall results suggest a positive effect of PRF on cell proliferation, differentiation, mineralization, and a reduction in inflammation. This points to its therapeutic potential in the field of regenerative medicine. Collectively, these findings may help enhance our understanding of how PRF impacts basic physiological processes in bone and mineralized tissue.

Growth Factors Released from Advanced Platelet-Rich Fibrin in the Presence of Calcium-Based Silicate Materials and Their Impact on the Viability and Migration of Stem Cells of Apical Papilla

Advanced platelet-rich fibrin (A-PRF) provides the scaffold and growth factors necessary for stem cells to proliferate and differentiate in successful regenerative endodontic procedures. This study investigates the release of transforming growth factor-β1 (TGF-β1), platelet-derived growth factor (PDGF), and vascular endothelial growth factor (VEGF) from A-PRF in cell culture media in the presence and absence of mineral trioxide aggregate (MTA) or Biodentine. Additionally, this research assesses the viability and migration of stem cells of the apical papilla (SCAP) in previously conditioned media. A-PRF obtained from 14 participants were incubated for 7 days in cell culture media alone or via layering with MTA or Biodentine discs and the release of selected growth factors in the media was evaluated using ELISA. The viability of SCAP grown in conditioned media was measured using the CCK8 assay, while SCAP migration was assessed via a transwell assay by counting migrated cells. The release of TGF-β1, PDGF, and VEGF was significantly higher in media with A-PRF alone than in the presence of either calcium-based silicate material (p < 0.05), which showed no difference from the no-A-PRF control (p < 0.05). None of the tested growth factors released in the A-PRF-conditioned media correlated with clot weight. A-PRF-conditioned media, both with and without calcium-based silicate materials, did not impact SCAP viability and migration (p > 0.05). This study shows that SCAP behavior is not impacted by the decrease in growth factor released in the presence of calcium-based silicate materials and that their role in REPs warrants further investigation.

Proteomic Analysis of Mesenchymal Stromal Cells Secretome in Comparison to Leukocyte- and Platelet-Rich Fibrin

Secretomes of mesenchymal stromal cells (MSCs) are emerging as a novel growth factor (GF)-based strategy for periodontal and bone regeneration. The objective of this study was to compare the secretome of human bone marrow MSC (BMSC) to that of leukocyte- and platelet-rich fibrin (L-PRF), an established GF-based therapy, in the context of wound healing and regeneration. Conditioned media from human BMSCs (BMSC-CM) and L-PRF (LPRF-CM) were subjected to quantitative proteomic analysis using liquid chromatography with tandem mass spectrometry. Global profiles, gene ontology (GO) categories, differentially expressed proteins (DEPs), and gene set enrichment (GSEA) were identified using bioinformatic methods. Concentrations of selected proteins were determined using a multiplex immunoassay. Among the proteins identified in BMSC-CM (2157 proteins) and LPRF-CM (1420 proteins), 1283 proteins were common. GO analysis revealed similarities between the groups in terms of biological processes (cellular organization, protein metabolism) and molecular functions (cellular/protein-binding). Notably, more DEPs were identified in BMSC-CM (n = 550) compared to LPRF-CM (n = 118); these included several key GF, cytokines, and extracellular matrix (ECM) proteins involved in wound healing. GSEA revealed enrichment of ECM (especially bone ECM)-related processes in BMSC-CM and immune-related processes in LPRF-CM. Similar trends for intergroup differences in protein detection were observed in the multiplex analysis. Thus, the secretome of BMSC is enriched for proteins/processes relevant for periodontal and bone regeneration. The in vivo efficacy of this therapy should be evaluated in future studies.

Study of platelet-rich fibrin promoting endothelial cell differentiation and angiogenesis induced by transplantation of adipose-derived stem cells

Diabetic patients are characterized by long wound healing time, and adipose stem cells (ADSCs) can secrete growth factors to promote angiogenesis and improve diabetic wound healing. In this research, we attempted to interrogate the impact of platelet-rich fibrin (PRF) on ADSCs in diabetic wound healing. ADSCs were harvested from human adipose tissues and identified through flow cytometry. After pretreatment with cultured medium supplemented with different concentrations of PRF (2.5%, 5%, and 7.5%), proliferation and differentiation capacity of ADSCs were assessed by CCK-8 assay, qRT-PCR and immunofluorescence (IF), respectively. Tube formation assay measured angiogenesis. Western blot analysis analyzed expression of endothelial markers and the extracellular signal-regulated kinase (ERK) and serine/threonine kinase (Akt) pathways in PRF-induced ADSCs. The CCK-8 experiment indicated that PRF enhanced proliferation of ADSCs in dose-dependent manner, relative to normal control group. The expression of endothelial markers and the capacity of tube formation were significantly promoted by 7.5% PRF. The release of growth factors containing vascular endothelial grow factor (VEGF) and insulin-like growth factor-1 (IGF-1) from PRF was increased with the extension of detection time. When the receptors of VEGF or/and IGF-1 were neutralized, ADSCs differentiation into endothelial cells were obviously inhibited. Additionally, PRF stimulated ERK and Akt pathways, and the inhibitors of ERK and Akt attenuated PRF-induced differentiation of ADSCs into endothelial cells. In conclusion, PRF promoted endothelial cell differentiation and angiogenesis induced by ADSCs in diabetic wound healing, which appears to give guidance for treating patients.

Osteochondral Regeneration Ability of Uncultured Bone Marrow Mononuclear Cells and Platelet-Rich Fibrin Scaffold

OBJECTIVES

Platelet-rich fibrin (PRF) and bone marrow mononuclear cells are potential scaffolds and cell sources for osteochondral regeneration. The main aim of this paper is to examine the effects of PRF scaffolds and autologous uncultured bone marrow mononuclear cells on osteochondral regeneration in rabbit knees.

MATERIALS AND METHODS

Three different types of PRF scaffolds were generated from peripheral blood (Ch-PRF and L-PRF) and bone marrow combined with uncultured bone marrow mononuclear cells (BMM-PRF). The histological characteristics of these scaffolds were assessed via hematoxylin-eosin staining, PicroSirius red staining, and immunohistochemical staining. Osteochondral defects with a diameter of 3 mm and depth of 3 mm were created on the trochlear groove of the rabbit's femur. Different PRF scaffolds were then applied to treat the defects. A group of rabbits with induced osteochondral defects that were not treated with any scaffold was used as a control. Osteochondral tissue regeneration was assessed after 2, 4, and 6 weeks by macroscopy (using the Internal Cartilage Repair Society score, X-ray) and microscopy (hematoxylin-eosin stain, safranin O stain, toluidine stain, and Wakitani histological scale, immunohistochemistry), in addition to gene expression analysis of osteochondral markers.

RESULTS

Ch-PRF had a heterogeneous fibrin network structure and cellular population; L-PRF and BMM-PRF had a homogeneous structure with a uniform distribution of the fibrin network. Ch-PRF and L-PRF contained a population of CD45-positive leukocytes embedded in the fibrin network, while mononuclear cells in the BMM-PRF scaffold were positive for the pluripotent stem cell-specific antibody Oct-4. In comparison to the untreated group, the rabbits that were given the autologous graft displayed significantly improved healing of the articular cartilage tissue and of the subchondral bone. Regeneration was gradually observed after 2, 4, and 6 weeks of PRF scaffold treatment, which was particularly evident in the BMM-PRF group.

CONCLUSIONS

The combination of biomaterials with autologous platelet-rich fibrin and uncultured bone marrow mononuclear cells promoted osteochondral regeneration in a rabbit model more than platelet-rich fibrin material alone. Our results indicate that autologous platelet-rich fibrin scaffolds combined with uncultured bone marrow mononuclear cells applied in healing osteochondral lesions may represent a suitable treatment in addition to stem cell and biomaterial therapy.

Application of Platelet-Rich Fibrin and Bone Morphogenetic Protein for Full-Mouth Implant-Based Oral Rehabilitation in a Case of Mandibular Osteoradionecrosis

Osteoradionecrosis (ORN) is a debilitating complication following radiation therapy, which in the head and neck region, occurs most frequently in the mandible. Although ORN is rare, it is complex and multifactorial and requires appropriate management. Manipulation of bone in patients with head and neck cancers before radiotherapy can cause ORN. In this report, we aim to present successful insertion of four dental implants in the interforaminal segment combined with application of platelet-rich fibrin and bone morphogenetic protein in a 60-year-old male with stable ORN in the posterior regions of the mandible.

Lyophilized Platelet-Rich Fibrin Exudate-Loaded Carboxymethyl Chitosan/GelMA Hydrogel for Efficient Bone Defect Repair

Platelet-rich fibrin (PRF) is an autologous growth factor carrier that promotes bone tissue regeneration, but its effectiveness is restrained by poor storage capabilities, uncontrollable concentration of growth factors, unstable shape, etc. Herein, we developed a photocrosslinkable composite hydrogel by incorporating lyophilized PRF exudate (LPRFe) into the carboxymethyl chitosan methacryloyl (CMCSMA)/gelatin methacryloyl (GelMA) hydrogel to effectively solve the dilemma of PRF. The hydrogel possessed suitable physical properties and sustainable release ability of growth factors in LPRFe. The LPRFe-loaded hydrogel could improve the adhesion, proliferation, migration, and osteogenic differentiation of rat bone mesenchymal stem cells (BMSCs). Furthermore, the animal experiments demonstrated that the hydrogel possessed excellent biocompatibility and biodegradability, and the introduction of LPRFe in the hydrogel can effectively accelerate the bone healing process. Conclusively, the combination of LPRFe with CMCSMA/GelMA hydrogel may be a promising therapeutic approach for bone defects.

Cone-Beam Computed Tomography and Histological Findings for Socket Preservation Techniques Using Different Grafting Materials: A Systematic Review

OBJECTIVE

Socket preservation techniques have been used to maintain the ridge dimension following tooth extraction. The materials used influence the quality and quantity of newly formed bone. Therefore, the aim of this article was to systematically review the literature reporting both histological and radiographic outcomes of socket preservation techniques after tooth extraction in human subjects.

MATERIAL AND METHOD

A systematic electronic search was performed in the electronic databases. English language clinical studies that were published between 2017 and 2022 and included both histological and radiographic findings for the test and control groups. Our primary search produced 848 articles, and of these, 215 were duplicate studies. A total of 72 articles were then eligible for full-text reading.

RESULTS

The review included eight studies that met its inclusion criteria. Three outcomes were compared in the included studies. The percentage of newly formed bone ranged from 21.34 ± 9.14% to more than 50% of new bone formation. The materials that showed more than 50% of newly formed bone formation were demineralized dentin graft, platelet-rich fibrin, freeze-dried bone allograft, corticocancellous porcine, and autogenous bone. Four Studies did not report the percentage of the residual graft materials, while those who reported showed a variable range of a minimum 1.5% to more than 25%. One study did not report the changes in horizontal width at the follow-up period, while other studies ranged from 0.6 mm to 10 mm.

CONCLUSION

Socket preservation represents an efficient technique to preserve the ridge contour with satisfactory newly formed bone in the augmented site and maintaining the vertical and horizontal dimensions of the ridge.

PDGF and VEGF-releasing bi-layer wound dressing made of sodium tripolyphosphate crosslinked gelatin-sponge layer and a carrageenan nanofiber layer

The use of dressings is one of the most common methods for wound treatment. Since most single-layer dressings cannot mimic the hierarchical structure of the skin well, multi-layer dressings have been considered. In this study, a bilayer dressing was fabricated using a gelatin sponge layer cross-linked with sodium tripolyphosphate (Gel-STPP) and a layer of carrageenan nanofibers containing platelet-rich fibrin (Carr-PRF). Chemical interactions between the two layers were characterized by FTIR, and the microstructure was visualized by SEM. It was found that the presence of Carr-PRF nanofiber layer increased tensile strength by 12.96 % (from 0.216 ± 0.015 to 0.268 ± 0.036 MPa) and elastic modulus by 56.70 % (from 0.388 ± 0.072 to 0.608 ± 0.029 MPa) compared to Gel-STPP sponge. Gel-STPP/Carr-PRF wound dressing had a 45.76 ± 4.18 % degradability after 7 days of immersion in phosphate buffered saline (PBS). PRF-containing bilayer wound dressing was able to sustainably release growth factors over 7 days. The Carr-PRF nanofiber layer coated on Gel-STPP sponge was an ideal environment for adhesion and proliferation of L929 cells. Gel-STPP/Carr-PRF bilayer dressing outperformed the other tested samples in terms of angiogenic potential. Average wound closure was 94.21 ± 2.06 % in Gel-STPP/Carr-PRF dressing treated rats after 14 days, and based on the histopathological and immunohistochemical examinations, the Gel-STPP/Carr-PRF dressing group augmented full-thickness wound healing, keratin layer and skin appendages formation after 14 days.

Clinical application of platelet-rich fibrin to enhance dental implant stability: A systematic review and meta-analysis

Objective

To investigate the effect of platelet-rich fibrin application on implant stability.

Study design

Five databases, namely, PubMed, Embase, Web of Science, Wiley, and China National Knowledge Infrastructure, were searched for reports published up to November 20, 2022. Randomized controlled trials (RCT), including parallel RCTs and split-mouth RCTs, with at least 10 patients/sites were considered for inclusion.

Results

After screening based on the inclusion criteria, ten RCTs were included. Low heterogeneity was observed in study characteristics, outcome variables, and estimation scales (I² = 27.2%, P = 0.19). The qualitative and meta-analysis results showed that PRF increased the effect of implant stabilizers after implant surgery.

Conclusions

The results of the present systematic review and meta-analysis suggest that PRF can increase implant stability after implant surgery. PRF may also have a role in accelerating bone healing and tends to promote new bone formation at the implant site.

Evaluation of the Effect of Platelet-Rich Fibrin Matrix in the Correction of Periorbital Wrinkles: An Experimental Clinical Trial

INTRODUCTION

Skin rejuvenation techniques have gained substantial popularity due to increased life expectancy over recent years. Platelet-rich fibrin matrix (PRFM) is the new generation of platelet aggregate products that have surfaced in recent years to treat skin aging.

OBJECTIVES

We intend to use PRF to correct periorbital wrinkles in 15 volunteers and evaluate its effectiveness in this study.

METHODS

To evaluate the efficacy of PRFM intervention, eight men and women over the age of thirty entered our study. Blood samples were taken and were immediately centrifuged at 700rpm for 5 minutes. PRFM was extracted from the plasma and injected at the sub-dermis site in periorbital areas. The initial severity of periorbital wrinkles was determined by Visioface 1000D, and obtained data were delivered to the statistical unit for statistical analysis. Scoring and evaluation were based on tissue volume and depth and were measured before and twelve weeks after injection. Adverse effects were also taken into consideration.

RESULTS

The results demonstrated noticeable improvement in deep, fine, and small wrinkles, periocular hyperpigmentation, and overall skin freshness of the injection site. The subjects had swelling in the injection site for up to one day after the injection, which resolved without complications.

CONCLUSIONS

PRFM was observed to have potential in skin rejuvenation, demonstrating promising outcomes in terms of safety and long-term effects in improving skin condition.

Optimizing culturing conditions in patient derived 3D primary slice cultures of head and neck cancer

Background

Three-dimensional primary slice cultures (SC) of head and neck squamous cell carcinomas (HNC) are realistic preclinical models. Until now, preserving structure and viability ex vivo for several days has been difficult. The aim of this study was to optimize cultivation conditions for HNC SC and analyze the added effects of platelet rich fibrin (PRF) on these conditions.

Methods

SC were prepared from the tumor biopsies of 9 HNC patients. Cultures were incubated for 1 and 7 days in three different media- Keratinocyte serum-free medium (SFM), RPMI-1640i, and 1:1 mix of both, with and without addition of PRF. After culturing, SC were fixated, embedded, and stained with Hematoxylin-Eosin (HE) and cleaved caspase-3. In addition, triple immune fluorescence staining for cytokeratin, vimentin and CD45 was performed. Outcome parameters were cell count and cell density, viability and apoptosis, SC total area and proportions of keratinocytes, mesenchymal and immune cells. The effects of culture time, medium, and addition of PRF were calculated in an SPSS generalized linear model and using the Wald Chi-Squared test.

Results

Ninety-four slice cultures were analyzed. Viability remained stable for 7 days in culture. After addition of PRF, cell viability increased (p=0.05). SC total area decreased (0.44 ± 0.04 mm² on day 1 (95% CI: 0.35 to 0.56) to 0.29 ± 0.03 mm² on day 7 (95% CI: 0.22 to 0.36), but cell density and cell proportions remained stable. Differences in cultivation media had no significant impact on outcome parameters.

Conclusion

HNC SC can be preserved for up to 7 days using the tested cultivation media. Cell viability was best preserved with addition of PRF. HNC SC are a versatile experimental tool to study physiology and drug actions. Autologous PRF can help simulate realistic conditions in vitro.

Functionalization of a Volume-Stable Collagen Matrix Using Liquid Platelet-Rich Fibrin: A Case Report Presenting a New Approach for Root Coverage

This case report presents a novel approach for root coverage of multiple gingival recessions with a volume-stable collagen matrix functionalized with injectable platelet-rich fibrin (i-PRF). A patient with multiple gingival recessions in the anterior maxilla was submitted to root coverage by coronally advanced flap with split-full-split incisions. Blood collection was performed before surgery and i-PRF was obtained after centrifugation (relative centrifugal force (RCF) 400 g, 2700 rpm, 3 minutes). A volume-stable collagen matrix was soaked with i-PRF and applied as a substitute for autogenous connective tissue graft. A mean root coverage of 83% was observed after a 12-month follow-up period, and only slight modifications were detected in a 30-month follow-up consultation. The association of a volume-stable collagen matrix with i-PRF successfully treated multiple gingival recessions with reduced morbidity since a connective tissue collection was avoided.

Platelet-rich plasma injection in the treatment of patellar tendinopathy: a systematic review and meta-analysis

Purpose

The objective of the study was to assess the efficacy of autologous platelet-rich plasma (PRP) injections in the treatment of patellar tendinopathy.

Methods

The PubMed, MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials databases were searched for clinical trials which compared PRP injection with other ‘active treatment’ interventions (‘Non-PRP’ injection and ‘No-injection’ treatments) or ‘No-active treatment’ interventions. Randomized and non-randomized clinical trials that had been published up to 15 November 2021, were included in the meta-analysis. The primary outcome, pain relief, was measured on a ‘visual analog scale.’ Secondary outcomes were knee functional activities and quality of life (QoL). The PRISMA guidelines were followed throughout the study.

Results

Eight comparative studies were identified for inclusion in the meta-analysis. Assessment of these studies revealed that there were no significant differences in pain relief, functional outcomes, and QoL in the short, medium, and long term between PRP injection and Non-PRP injection interventions. Similarly, comparison of PRP injection to the No-active treatment intervention showed no differences in short- and medium-term pain relief. However, when PRP injection was compared to the No-injection treatment intervention extracorporeal shock wave therapy (ECWT), the former was found to be more effective in terms of pain relief in the medium term (mean difference [MD] − 1.50; 95% confidence interval [CI] − 2.72 to − 0.28) and long term (MD − 1.70; 95% CI, − 2.90 to − 0.50) and functional outcomes in the medium term (MD 13.0; 95% CI 3.01–22.99) and long term (MD 13.70; 95% CI 4.62–22.78).

Conclusions

In terms of pain relief and functional outcomes, the PRP injection did not provide significantly greater clinical benefit than Non-PRP injections in the treatment of patellar tendinopathy. However, in comparison with ESWT, there was a significant benefit in favor of PRP injection.

Plasma Rich in Growth Factors in the Treatment of Endodontic Periapical Lesions in Adult Patients: 3-Dimensional Analysis Using Cone-Beam Computed Tomography on the Outcomes of Non-Surgical Endodontic Treatment Using A-PRF+ and Calcium Hydroxide: A Retrospective Cohort Study

The study presents results of periapical lesion healing after one-visit root canal treatment (RCT) with Advanced Platelet Rich Fibrin plus (A-PRF+) application compared to a two-visit RCT with an inter-appointment calcium hydroxide filling. The comparison was made based on CBCT-Periapical Index (PAI) lesion volume changes and the occurrence of post endodontic pain. The results of 3D radiographic healing assessments based on volume reduction criteria were different from the CBCT-PAI. Based on volume changes, the healing assessment criteria-9 cases from the Study Group and six cases in the Control Group were defined as healed. Based on the CBCT-PAI healing assessment criteria, 8 cases from the Study Group and 9 cases from the Control Group were categorized as healed. The volumes of apical radiolucency were, on average, reduced by 85.93% in the Study Group and by 72.31% in the Control Group. Post-endodontic pain occurred more frequently in the Control than in the Study Group. The highest score of pain in the Study Group was five (moderate pain, n = 1), while in the Control Group, the highest score was eight (severe pain, n = 2). In the 6-month follow-up, CBCT scans showed a better healing tendency for patients in the Study Group.

Comparison of physical, mechanical and biological effects of leucocyte-PRF and advanced-PRF on polyacrylamide nanofiber wound dressings: In vitro and in vivo evaluations

Platelet-rich fibrin (PRF) is extracted from the blood without biochemical interference and, also, with the ability of a long-term release of growth factors that can stimulate tissue repair and regerenation. Here, leucocyte- and platelet-rich fibrin (L-PRF) and advanced platelet-rich fibrin (A-PRF) were extracted and utilized for the creation of nanofibers containing polyacrylamide (PAAm), PAAm / L-PRF and PAAm / A-PRP through electrospinning processing technique. The effect of the type of PRF on the physical, mechanical and biological properties of the resultant nanofiberous wound dressings are thoroughly evaluated. The results presented in the current study reveals that the fiber diameter is grealtly reduced through the utilization of L-PRF. In addition, mechanical property is also positively affected by L-PRF and the degradation rate is found to be higher compared to A-PRF group. The L929 cells proliferation and adhesion, angiogenesis potential and wound healing ability was significantly higher in PAAm/A-PRF nanofibers compared to pure PAAm and PAAm/L-PRF nanofibers owed to the release of vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF). Overall, the utilization of L-PRF or A-PRF can improve the physical, mechanical and biological behavior of nanofiber making them an ideal candidate for wound dressings, with the emphasis on the skin tissue repair and regeneration applications.

Coaxial electrospun angiogenic nanofiber wound dressing containing advanced platelet rich-fibrin

Advanced platelet-rich fibrin (A-PRF) provides long-term release of growth factors that potentially accelerate wound healing. In this study, core-shell nanofibrous structure of polyvinyl alcohol (PVA) core and gelatin (Gel) shell containing A-PRF is fabricated through coaxial electrospinning method. PVA/(Gel/A-PRF) core-shell nanofibers had the highest porosity, specific surface area and hydrophilicity among all the studied nanofibers. PVA/(Gel/A-PRF) core-shell nanofibers with a tensile stress of 7.43 ± 0.38 MPa and an elastic modulus of 102.05 ± 9.36 MPa had higher mechanical properties than PVA/Gel/A-PRF and PVA/Gel blend nanofibers. PVA/(Gel/A-PRF) nanofibers had a 47.41 ± 1.97 % degradability over 7 days of immersion in PBS. The release of VEGF and PDGF-AB growth factors from PVA/(Gel/A-PRF) core-shell nanofibers and PVA/Gel/A-PRF blend nanofibers were evaluated. It was shown that L929 cell proliferation and adhesion on PVA/(Gel/A-PRF) core-shell nanofibers were significantly higher than other samples. Also, chicken chorioallantoic membrane (CAM) assay revealed that the highest angiogenic potential among the studied samples related to PVA/(Gel/A-PRF) sample. In vivo studies on a rat model showed wound closure for PVA/(Gel/A-PRF) group was 97.83 ± 2.03 % after 11 days. Histopathological and immunohistochemical examinations approved the acceleration of wound healing by PVA/(Gel/A-PRF) core-shell nanofiber dressing. The results strongly recommend the use of PVA/(Gel/A-PRF) core-shell nanofiber dressing for the repair of full-thickness wounds.

Exploration of proper heating protocol for injectable horizontal platelet-rich fibrin gel

Purpose

Platelet-rich fibrin (PRF) has been proposed as promising biomaterials with the advantages of host accumulation of platelets and leukocytes with entrapment of growth factors and fibrin scaffold. However, limitations including fast resorption rate (~ 2 weeks) restricts its clinical application. Recent studies have demonstrated heating treatment can prolong PRF degradation. Current published articles used the method of 75 °C for 10 min to obtain longer degradation, while few studies investigated the most suitable temperature for heating horizontal PRF. Our present study was to discover and confirm the optimum temperature for heat treatment before obtaining H-PRF gels by investigating their structure, mechanical properties, and bioactivity of the H-PRF gels after heating treatment.

Methods

In the present study, 2-mL upper layer of horizontal PRF was collected and heated at 45 °C, 60 °C, 75 °C, and 90 °C to heat 2-mL upper layer of horizontal PRF for 10 min before mixing with the 2-mL lower layer horizontal PRF. The weight, solidification time and the degradation properties were subsequently recorded. Scanning electron microscopy (SEM) and rheologic tests were carried out to investigate the microstructure and rheologic properties of each H-PRF gel. The biological activity of each H-PRF gel was also evaluated using live/dead staining.

Results

H-PRF gel prepared at 75 °C for 10 min had the fast solidification period (over a tenfold increase than control) as well as the best resistance to degradation. The number of living cells in H-PRF gel is greater than 90%. SEM showed that H-PRF gel becomes denser as the heating temperature increases, and rheologic tests also revealed that the heat treatment improved the mechanical properties of H-PRF gels when compared to non-heated control group. Future clinical studies are needed to further support the clinical application of H-PRF gels in tissue regeneration procedures.

Conclusions

Our results demonstrated that the H-PRF gel obtained at 75 °C for 10 min could produce a uniform, moldable gel with a short time for solidification time, great rheologic behavior and, high percent of live cells in PRF gel. A promising use of the commonly utilized PRF gel was achieved facilitating tissue regeneration and preventing degradation.

The effect of platelet-rich concentrates on orthodontic tooth movement: A review of randomized controlled trials

Objectives

Platelet-rich concentrates, namely platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), have recently shown potential roles in accelerating orthodontic tooth movement (OTM) and reducing treatment duration. Our study aims to systematically evaluate the effect of platelet-rich concentrates on OTM.

Materials and methods

An electronic search of 11 databases, followed by a hand search of reference lists of eligible studies and related reviews, was conducted up to January 2022. Randomized controlled trials investigating OTM of patients with platelet-rich concentrates were included. Risk of bias was assessed by version 2 of Cochrane tool (RoB 2) for assessing risk of bias in randomized trials.

Results

Among 715 records initially identified, 9 studies were included, of which 3 used PRP and the other 6 applied PRF. 7 studies supported a positive relationship between platelet-rich concentrates and OTM, but the other 2 studies reported a null and a negative effect of PRF, respectively. The overall qualities of evidence were moderate to high.

Conclusions

Platelet-rich concentrates as PRP and PRF seem to be effective in accelerating OTM at early stages, while their long-term efficacy remains controversial. Repeated application of platelet concentrates may increase the accelerated stability of OTM.

"Platelet-Rich Fibrin Membrane-as a novel biomaterial for pressure injury healing in a person with spinal cord injury: A case report"

INTRODUCTION

Pressure injury (PI) impacts the quality of life, and socioeconomic and psychological well-being negatively in persons with Spinal Cord Injury (SCI). Autologous Platelet Rich Plasma (PRP) and Platelet Rich Fibrin (PRF) showed promising roles in wound healing. PRF is considered a second-generation PRP, contains more growth factors and is more biocompatible than PRP. It possesses an additional favourable impact on wound healing due to its three-dimensional fibrin architecture, and antimicrobial property. There are no studies on PRF membrane use for PI healing in SCI.

CASE PRESENTATION

A 25-year-old male with operated traumatic T10 American Spinal Injury Association Impairment Scale grade A paraplegia with neurogenic bowel, and bladder and a stage II PI over the left greater trochanter, was admitted for inpatient rehabilitation. The chronic non-healing PI which did not show any improvement following normal saline (0.9%) dressing for the past 3 months, was treated with autologous PRF membrane weekly for four weeks. The PI healed completely and no adverse events were noted. Weekly total scores of the Spinal Cord Impairment Pressure Ulcer Monitoring Tool and Pressure Ulcer Scale for Healing were 6, 6, 5, 2, 0 and 12, 10, 10, 3, and 0 respectively.

DISCUSSION

To the best of our knowledge, this is the first case report on the healing of PI in SCI with the use of PRF. This novel biomaterial is a safe and effective promising agent for PI management in SCI. But further randomized trials are needed to establish stronger evidence regarding feasibility and effectiveness.

Injectable Platelet-Rich Fibrin as a Drug Carrier Increases the Antibacterial Susceptibility of Antibiotic—Clindamycin Phosphate

The aim of this study was to investigate the change in clindamycin phosphate antibacterial properties against Gram-positive bacteria using the platelet-rich fibrin as a carrier matrix, and evaluate the changes in the antibiotic within the matrix. The antibacterial properties of CLP and its combination with PRF were tested in a microdilution test against reference cultures and clinical isolates of Staphylococcus aureus (S. aureus) or Staphylococcus epidermidis (S. epidermidis). Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analysis was done to evaluate the changes in the PRF_CLP matrix. Release kinetics of CLP was defined with ultra-performance liquid chromatography (UPLC). According to FTIR data, the use of PRF as a carrier for CLP ensured the structural changes in the CLP toward a more active form of clindamycin. A significant decrease in minimal bactericidal concentration values (from 1000 µg/mL to 62 µg/mL) against reference cultures and clinical isolates of S. aureus and S. epidermidis was observed for the CLP and PRF samples if compared to pure CLP solution. In vitro cell viability tests showed that PRF and PRF with CLP have higher cell viability than 70% after 24 h and 48 h time points. This article indicates that CLP in combination with PRF showed higher antibacterial activity against S. aureus and S. epidermidis compared to pure CLP solution. This modified PRF could be used as a novel method to increase drug delivery and efficacy, and to reduce the risk of postoperative infection.

The effect of resting and compression time post-centrifugation on the characteristics of platelet rich fibrin (PRF) membranes

OBJECTIVE

To evaluate the effect of resting and compression time after centrifugation on the physical properties of platelet rich fibrin (PRF) membranes, and to provide optimal guidance regarding the clinical preparation of PRF.

MATERIALS AND METHODS

A total of 12 volunteers enrolled in this study divided into 2 groups equally. For each volunteer, 6 tubes of 10 mL venous whole blood was drawn. To evaluate the influence of resting time after centrifugation, PRF clots were taken out 0, 1, 3, 5, 7, and 10 min from tubes following centrifugation, and then the weight, size, maximum stress, and maximum strain of each group were measured. To evaluate the influence of compression time on the preparation of PRF membranes, the weight ratio of PRF membranes to PRF clots was calculated by compression for 10 s, 30 s, 60 s, 90 s, 120 s, and 180 s, respectively. Scanning electron microscopy was performed to observe the cross-linking of the fibers within membranes, and the maximum stress and strain of PRF membranes were tested followed by stress-strain curve analysis.

RESULTS

The weight and volume of PRF clots and PRF membranes increased in size and weight reached the top at 3 min, followed by a decrease after 7-min resting. The maximum strain of the PRF membranes after 10 min decreased significantly compared to the 3-min and 5-min groups. The maximum stress was found at 3 min followed by a statistical decrease when resting time went on. Scanning electron microscopy demonstrated that the internal fibrous structure of the PRF membranes was looser when the compression time was less than 60 s when comparing the 90-s group. The maximum stress of PRF membranes was shown using a wait period of 3 min post-centrifugation followed by compression for 120 s.

CONCLUSION

The findings from the present study demonstrate that the time post-centrifugation of PRF membranes showed a maximum weight, volume, and mechanical properties after resting for 3-5 min in the tube post-centrifugation followed by a compression time of 120 s.

CLINICAL RELEVANCE

Although research to date has focused primarily on centrifugation protocols, this study revealed for the first time that the resting time post-centrifugation greatly affected the mechanical properties of PRF. This study demonstrated that the resting and compression time after centrifugation influences the mechanical strength of PRF membranes, which might explain differences in PRF characteristics prepared by different clinicians that may provide a standard guide for preparation of PRF membranes.

Changes in Migratory Speed Rate of Human Dental Pulp Stromal Cells Cultured in Advanced Platelet-Rich Fibrin

OBJECTIVE

 Migratory speed rate evaluation of human dental pulp stromal cells (hDP-SCs) is one of the important steps in dental pulp regeneration. Therefore, the aim of the study is to analyze various concentrations of advanced platelet-rich fibrin (A-PRF) culture media toward hDP-SCs' migratory speed rate evaluations.

MATERIALS AND METHODS

 The hDP-SCs were divided into four groups: control: hDP-SCs in Dulbecco's modified Eagle medium + 10% fetal bovine serum group; hDP-SCs in 1% A-PRF group; hDP-SCs in 5% A-PRF group; and hDP-SCs in 10% A-PRF group, which were planted in 24-well (5 × 10⁴ cell/well). The migratory speed rate of all groups was measured by using cell migration assay (scratch wound assay) after 24 hours. Cell characteristics were evaluated under microscope (Inverted microscope, Zeiss, Observer Z1, UK) that can be read through image-J interpretation. This image J represented the measurement of migratory speed rate (nm/h) data. Statistical analysis was conducted using one-way analysis of variance and post hoc Tamhane's test (p < 0.05) (IBM SPSS Statistics Software, version 22.0).

RESULTS

 There was a statistically significant difference in the migratory speed rates of hDP-SCs among various concentration groups of A-PRF (1, 5, and 10%) compared with the control group.

CONCLUSION

The increase in the migratory speed rate of hDP-SCs was highest in 10% A-PRF group.

Biofunctionalization of Xenogeneic Collagen Membranes with Autologous Platelet Concentrate-Influence on Rehydration Protocol and Angiogenesis

Background: The aim of this study was to analyze possible interactions of different xenogeneic collagen membranes (CM) and platelet-rich fibrin (PRF). PH values were evaluated in the CM rehydration process with PRF, and their influence on angiogenesis was analyzed in vivo. Materials and Methods: Porcine (Bio-Gide®, Geistlich)- and bovine-derived collagen membranes (Symbios®, Dentsply Sirona) were biofunctionalized with PRF by plotting process. PRF in comparison to blood, saline and a puffer pH7 solution was analysed for pH-value changes in CM rehydration process in vitro. The yolk sac membrane (YSM) model was used to investigate pro-angiogenic effects of the combination of PRF and the respective CM in comparison to native pendant by vessel in-growth and branching points after 24, 48 and 72 h evaluated light-microscopically and by immunohistochemical staining (CD105, αSMA) in vivo. Results: Significantly higher pH values were found at all points in time in PRF alone and its combined variants with Bio-Gide® and Symbios® compared with pure native saline solution and pH 7 solution, as well as saline with Symbios® and Bio-Gide® (each p < 0.01). In the YSM, vessel number and branching points showed no significant differences at 24 and 48 h between all groups (each p > 0.05). For PRF alone, a significantly increased vessel number and branching points between 24 and 48 h (each p < 0.05) and between 24 and 72 h (each p < 0.05) was shown. After 72 h, CM in combination with PRF induced a statistically significant addition to vessels and branching points in comparison with native YSM (p < 0.01) but not vs. its native pendants (p > 0.05). Summary: PRF represents a promising alternative for CM rehydration to enhance CM vascularization.

Effect of local application of platelet-rich fibrin scaffold loaded with simvastatin on peri-implant bone changes

Aim

The purpose of this study was to compare the effects of autologous platelet-rich fibrin (PRF) alone and PRF loaded with SIM on peri-implant bone changes and implant stability in patients undergoing implant rehabilitation.

Settings and Design

This was a nonrandomized controlled split-mouth study.

Materials and Methods

The study included 8 males between the ages of 45 and 60 years. Each patient received two implants, one on each side of the arch. One side was treated with PRF alone and the other side with PRF loaded with SIM at the time of osteotomy. A cone-beam computed tomography was used to evaluate bone changes around the insertion of implant sites at 3, 6, and 12 months postoperatively. The secondary outcome included measuring implant stability using Osstell device at baseline and 3 months postinsertion. To compare groups at different time periods, data were examined using a two-way analysis of variance.

Statistical Analysis Used

The results were compared between the groups using a two-way analysis of variance, followed by a post hoc Bonferroni test. To examine total bone changes and stability comparisons between the two groups at the end of the trial, an unpaired t-test was utilized.

Results

The mean crestal bone-level changes in the SIM/PRF group were significantly lower than the PRF group, with a mean shift of 0.9788 ± 0.04853 versus 1.356 ± 0.0434, respectively (P < 0.0001). There was no significant difference between the two groups in implant stability.

Conclusion

Peri-implant application of SIM/PRF resulted in less bone changes than PRF alone, which may prove to be beneficial for the long-term success of implants. SIM showed promising results in limiting peri-implant bone resorption providing new clinical application for SIM in dental implant rehabilitation.

Evaluation of mechanical properties of platelet-rich fibrin membrane for implant surgery: An analysis in vitro

The aim of this study was to evaluate and compare the mechanical resistance of platelet-rich fibrin (PRF) membrane when submitted to resistance traction on longitudinal axis. Blood collection of a healthy individual was collected with an amount of 300 mL and divided into 30 tubes containing 10 mL each one. The samples were divided into three groups, according to the g-force protocols: (1) F200 g: (2) F400 g; (3) F800 g. Membranes of each g-force group were divided into subgroups, according to waiting time after centrifugation: (T0) immediate use and (T30) use after 30 min. Considering these intervals of time, the concentrate was removed from tubes and inserted in a PRF metallic box to confection of the membrane. The PRF membranes were submitted to mechanical tension on a universal testing machine and obtained to a resistance force of each membrane. The centrifugation time showed no statistically significant difference for membrane resistance for any force applied (P > 0.05; Student's t-test). For T0 group results demonstrated no influence for membrane resistance (P = 0.357; Student's t-test), therefore T30 showed statistically significant difference (P = 0.040; Student's t-test) for membrane resistance for centrifugation forces applied, with highest value when applied greatest force. The findings suggest that the waiting time for centrifugation could be determined according to demand of application, and for immediate use of the membrane, the centrifugation did not influence the resistance, on the other hand, after 30 min, the application of higher force resulted in a membrane with considerable resistance.

Successful management of a large mucosal fenestration at 18-months follow-up

OBJECTIVES

Mucosal fenestrations are infrequent and often challenging to treat depending on the extent of soft and hard tissue destruction. This article presents the successful management of a relatively larger mucosal fenestration associated with complete absence of buccal bone plate in a mandibular incisor secondary to trauma-induced periapical pathosis.

CLINICAL CONSIDERATIONS

After non-surgical endodontic therapy, surgery was performed for debridement of the osseous defect, root resection/shaping, connective tissue graft (CTG) placement on the affected root surface and platelet rich fibrin (PRF) in periapical osseous defect rather than use of bone graft and/or barrier membrane. Healing was uneventful, however, a small mucosal defect remained at 2 weeks follow-up. After 3 months of primary surgery, a corrective surgery was performed utilizing an "incision-free" approach i.e. tunnel technique with CTG in contrast to the contemporary flap approach. At 18 months follow-up, complete closure of the mucosal defect with a thick gingival biotype, normal sulcus depth, and good esthetic outcome were achieved. No recurrence and any clinical signs of infection or inflammation were observed.

CONCLUSIONS

Based on the outcomes of present case, an early intervention utilizing the minimally invasive surgical therapy and autologous biomaterials may be considered a viable approach to treat such complex lesions.

CLINICAL SIGNIFICANCE

Endodontic therapy in combination with PRF and CTG appears to provide successful outcomes in treatment of a large mucosal fenestration with periapical osseous defect.

From Blood to Bone-The Osteogenic Activity of L-PRF Membranes on the Ex Vivo Embryonic Chick Femur Development Model

(1) Background: To evaluate the effects of the direct and indirect contact of leukocyte and platelet-rich fibrin (L-PRF) on bone development, in an ex vivo embryonic chick femur model. (2) Methods: Both sections of L-PRF membranes (red and yellow portions) were evaluated with scanning electron microscopy and histochemical staining. The in vivo angiogenic activity was evaluated using a chorioallantoic membrane model. The osteogenic activity was assessed with an organotypic culture of embryonic chick femora through direct and indirect contact, and assessment was conducted by microtomographic and histological analysis. Descriptive statistics, One-Way ANOVA and Tukey’s multiple comparisons tests were performed for datasets that presented a normal distribution, and Kruskal-Wallis tests were performed for non-parametric datasets. A significance level of 0.05 was considered. (3) Results: The L-PRF induced angiogenesis reflected by a higher number and a larger and more complex gauge in the vessels that invaded the membrane. The physical presence of the membrane over the bone (direct contact) unleashes the full potential of the L-PRF effects on bone growth enhancement. The greatest increase in mineral content was observed in the diaphysis region. (4) Conclusion: The L-PRF direct contact group presented higher values on mineral content for bone volume, bone surface and bone mineral density than the indirect contact and control groups.

Applying extrusion-based 3D printing technique accelerates fabricating complex biphasic calcium phosphate-based scaffolds for bone tissue regeneration

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Biphasic calcium phosphates offer a chemically similar biomaterial to the natural bone, which can significantly accelerate bone formation and reconstruction.

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Robocasting is a suitable technique to produce porous scaffolds supporting cell viability, proliferation, and differentiation.

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This review discusses materials and methods utilized for BCP robocasting, considering recent advancements and existing challenges in using additives for bioink preparation.

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Commercialization and marketing approach, in-vitro and in-vivo evaluations, biologic responses, and post-processing steps are also investigated.

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Possible strategies and opportunities for the use of BCP toward injured bone regeneration along with clinical applications are discussed.

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The study proposes that BCP possesses an acceptable level of bone substituting, considering its challenges and struggles.

Background

Aim of review

Key scientific concepts of review

Can platelet-rich plasma injections provide better pain relief and functional outcomes in persons with common shoulder diseases: a meta-analysis of randomized controlled trials

Background

To evaluate the efficacy of autologous platelet-rich plasma (PRP) injections in the treatment of common shoulder diseases.

Methods

The PubMed, Medline, and Central databases and trial registries were searched from their inception to October 2020 for randomized controlled trials of autologous PRP injections for shoulder diseases versus placebo or any control intervention. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed in the selection, analysis, and reporting of findings. The primary outcome was pain intensity (visual analog scale), and secondary outcomes were changes in function and quality of life (QoL).

Results

A total of 17 randomized controlled trials of PRP versus control were analyzed. From 8–12 weeks to ≥1 year, PRP injections were associated with better pain relief and functional outcomes than control interventions. PRP injections were also associated with greater QoL, with an effect size of 2.61 (95% confidence interval, 2.01–14.17) at medium-term follow-up. Compared with placebo and corticosteroid injections, PRP injections provided better pain relief and functional improvement. In subgroup analyses, trials in which PRP was prepared by the double centrifugation technique, the platelet concentration in the PRP was enriched ≥5 times, leucocyte-rich PRP was used, or an activating agent was used before application reported the most effective pain relief at 6–7 months.

Conclusions

PRP injections could provide better pain relief and functional outcomes than other treatments for persons presenting with common shoulder diseases. PRP injections have a greater capacity to improve shoulder-related QoL than other interventions.

Synergistic Effect of Biphasic Calcium Phosphate and Platelet-Rich Fibrin Attenuate Markers for Inflammation and Osteoclast Differentiation by Suppressing NF-κB/MAPK Signaling Pathway in Chronic Periodontitis

Background: Periodontitis is characterized by excessive osteoclastic activity, which is closely associated with inflammation. It is well established that MAPK/NF-kB axis is a key signaling pathway engaged in osteoclast differentiation. It is stated that that biphasic calcium phosphate (BCP) and platelet-rich fibrin (PRF) have significant antiostoeclastogenic effects in chronic periodontitis. Objective: We aimed to elucidate the synergetic effect of PRF/BCP involvement of the nuclear factor kappa–light–chain–enhancer of activated B cells (NF-kB) and the mitogen-activated protein kinase (MAPK) signaling pathway in osteoclast differentiation in chronic periodontitis. Methods: We induced osteoclast differentiation in vitro using peripheral blood mononuclear cells (PBMCs) derived from patients with chronic periodontitis. We assessed osteoclast generation by tartrate-resistant acid phosphatase (TRAP) activity, proinflammatory cytokines were investigated by ELISA and NF-κB, and IKB by immunoblot, respectively. MAPK proteins and osteoclast transcription factors were studied by Western blot analysis and osteoclast transcriptional genes were assessed by RT-PCR. Results: The results showed that the potent inhibitory effect of PRF/BCP on osteoclastogenesis was evidenced by decreased TRAP activity and the expression of transcription factors, NFATc1, c-Fos, and the osteoclast marker genes, TRAP, MMP-9, and cathepsin-K were found to be reduced. Further, the protective effect of PRF/BCP on inflammation-mediated osteoclastogenesis in chronic periodontitis was shown by decreased levels of proinflammatory cytokines, NF-kB, IKB, and MAPK proteins. Conclusions: PRF/BCP may promote a synergetic combination that could be used as a strong inhibitor of inflammation-induced osteoclastogenesis in chronic periodontitis.

Platelet-Rich Fibrin Decreases the Inflammatory Response of Mesenchymal Cells

Chronic inflammation is a pathological process where cells of the mesenchymal lineage become a major source of inflammatory mediators. Platelet-rich fibrin (PRF) has been shown to possess potent anti-inflammatory activity in macrophages, but its impact on mesenchymal cells has not been investigated. The aim of this study was, therefore, to expose mesenchymal cells to inflammatory cytokines together with lysates generated from liquid platelet-poor plasma (PPP), the cell-rich buffy coat layer (BC; concentrated-PRF or C-PRF), and the remaining red clot layer (RC), following centrifugation of blood. Heating PPP generates an albumin gel (Alb-gel) that when mixed back with C-PRF produces Alb-PRF. Membranes prepared from solid PRF were also subjected to lysis. We report here that lysates of PPP, BC, and PRF decreased the cytokine-induced expression of interleukin 6 (IL6) and nitric oxide synthase (iNOS) in the bone marrow-derived ST2 cells. Consistently, PPP, BC, and PRF greatly decreased the phosphorylation and nuclear translocation of p65 in ST2 cells. The inflammatory response caused by Pam3CSK4 was reduced accordingly. Moreover, PPP, BC, and PRF reduced the enhanced expression of inflammatory mediators IL6 and iNOS in 3T3-L1 pre-adipocyte mesenchymal cells, and iNOS and CCL5 in murine calvarial cells. Surprisingly, PRF lysates were not effective in reducing the inflammatory response of human gingival fibroblasts and HSC2 epithelial cells. The data from the present study suggest that both liquid PRF and solid PRF exert potent anti-inflammatory activity in murine mesenchymal cells.