Local delivery of platelet-derived factors mitigates ischemia and preserves ovarian function through angiogenic modulation: A personalized regenerative strategy for fertility preservation.

As the most prominent and ideal modality in female fertility preservation, ovarian tissue cryopreservation, and transplantation often confront the challenge of ischemic damage and follicular loss from avascular transplantation. To surmount this impediment, we engineered a novel platelet-derived factors-encapsulated fibrin hydrogel (PFH), a paradigmatic biomaterial. PFH encapsulates autologous platelet-derived factors, utilizing the physiological blood coagulation cascade for precise local delivery of bioactive molecules. In our study, PFH markedly bolstered the success of avascular ovarian tissue transplantation. Notably, the quantity and quality of follicles were preserved with improved neovascularization, accompanied by decreased DNA damage, increased ovulation, and superior embryonic development rates under a Low-concentration Platelet-rich plasma-derived factors encapsulated fibrin hydrogel (L-PFH) regimen. At a stabilized point of tissue engraftment, gene expression analysis mirrored normal ovarian tissue profiles, underscoring the effectiveness of L-PFH in mitigating the initial ischemic insult. This autologous blood-derived biomaterial, inspired by nature, capitalizes on the blood coagulation cascade, and combines biodegradability, biocompatibility, safety, and cost-effectiveness. The adjustable properties of this biomaterial, even in injectable form, extend its potential applications into the broader realm of personalized regenerative medicine. PFH emerges as a promising strategy to counter ischemic damage in tissue transplantation, signifying a broader therapeutic prospect. (197 words).

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.

Impaired fibrinolysis in JAK2V617F-related myeloproliferative neoplasms.

BACKGROUND: Myeloproliferative neoplasms (MPN) are characterized by a high rate of thrombotic complications that contribute to morbi-mortality. MPN-related thrombogenesis is assumed to be multifactorial involving both pro-coagulant and pro-inflammatory processes. Whether impaired fibrinolysis also participates in the pro-thrombotic phenotype of MPN has been poorly investigated. OBJECTIVES: We determined whether MPN, particularly JAK2V617F-positive MPN, are associated with fibrinolytic changes. PATIENTS: Tissue plasminogen activator (tPA)-mediated fibrinolysis was evaluated both in whole blood (WB) and plasma from mice with a hematopoietic-restricted Jak2V617F expression compared to wild type mice (Jak2WT) using: (1) halo clot lysis, (2) front lysis and (3) plasmin generation assays. tPA-clot lysis assay was performed in the plasma from 65 MPN patients (JAK2V617F mutation, n=50; CALR mutations, n=9) compared to 28 healthy controls. RESULTS: In WB from Jak2V617F mice, we observed a decreased fibrinolysis characterized by a significant lower halo clot lysis rate compared to Jak2WT (95±22 vs 147±39 UA/min, p<0.05). Similar results were observed in plasma (halo clot lysis rate: 130±27 vs 186±29 UA/min; front lysis rate: 2.8±1.6 vs 6.1±1.2 µm.min-1, p<0.05). Plasmin generation was significantly decreased both in plasma clots and standardized fibrin clots from Jak2V617F mice compared to Jak2WT mice. Among MPN patients, impaired tPA-related fibrinolysis with prolonged clot lysis time was observed in JAK2V617F and CALR patients. Plasminogen activator inhibitor-1 and alpha 2-antiplasmin were significantly increased in plasma from JAK2V617F patients compared to controls. CONCLUSIONS: Our results suggest that impaired tPA-mediated fibrinolysis represents an important pro-thrombotic mechanism in MPN patients that requires confirmation on larger studies.

L-PRF in extra-oral wound care.

Leukocyte- and platelet-rich fibrin (L-PRF), a by-product of centrifuged autologous whole blood, contains high concentrations of platelets, leukocytes, and fibrin (the latter spontaneously creating a strong 3-D network (a membrane)). L-PRF membranes possess several characteristics essential in wound healing, including a barrier function, an antibacterial and analgesic activity, and the release of growth factors enhancing tissue regeneration and neo-vasculogenesis. This review investigated the role of L-PRF in treating non-responding chronic wounds such as diabetic foot, venous leg ulcers, pressure ulcers, complex wounds, leprosy ulcers (Hansen's Disease), and other demanding wounds. Chronic wounds affect millions worldwide, negatively impacting their quality of life, productivity, and life expectancy while incurring high treatment costs for themselves and private and public health systems. L-PRF has demonstrated clear adjunctive advantages in treating chronic skin wounds, shortening the time to complete wound closure, and improving patient-reported outcome measures (including reducing pain and minimizing the need for analgesics). Also, in other demanding wounds, L-PRF facilitates healing. To help clinicians, this article also proposes recommendations for the use of L-PRF in the treatment of extra-oral wounds.

The adjunctive use of Leukocyte-Platelet Rich Fibrin (L-PRF) in the management of Medication Related Osteonecrosis of the Jaw (MRONJ): a retrospective observational study.

PURPOSE: Medication related osteonecrosis of the jaw (MRONJ) is a risk for patients taking anti-resorptive or anti-angiogenic medications. The American Association of Oral and Maxillofacial Surgeons (AAMOS) has classified MRONJ in stages to reflect the severity of the disease and allows implementation of suitable treatment pathways. MRONJ risk is < 5% in cancer patients and < 0.05% in osteoporosis patients. Management is subdivided into operative and non-operative, with advances in the literature investigating adjuvants. Leukocyte-Platelet Rich Fibrin (L-PRF) is an autologous biomaterial consisting of leukocytes and platelets embedded within a fibrin matrix with the ability to release growth factors enabling angiogenesis, bone regeneration and soft tissue healing. This paper's aim is to investigate the effects of L-PRF in conjuction with surgical debridement for management of MRONJ. METHODS: Twenty-two cases with established MRONJ were treated with either surgical intervention (Group A) or with surgical intervention and L-PRF (Group B), from 2016 to 2023 at Edinburgh Dental Institute (EDI). Treatments were deemed successful when the patients were asymptomatic, displayed complete soft tissue healing with the absence of infection/inflammation, fistula, or exposed bone. RESULTS: All cases in Group B had healed in contrast to 54.5% not healed in Group A; p value < 0.05 indicating statistical significance. CONCLUSION: The use of L-PRF as an adjuvant to surgical management of MRONJ is promising with its favourable functional capacity, simple application, and success of treatment outcomes.

Treatment of Corneal Dermoid with Fibrin Glue Boned Multi-Layer Lenticules from Small Incision Lenticules Extraction Surgery: A Preliminary Study of Five Patients.

PURPOSE: Dermoid excision combined with lamellar keratoplasty was one of the most common surgical techniques for corneal dermoid. Due to the huge shortage of corneal donors, small incision lenticule extraction (SMILE) derived lenticules might be the novel and feasible corneal grafts instead of traditional corneal donors. Therefore, we tried to use FG boned multi-layer lenticules as grafts in the treatment of corneal dermoid. METHODS: Five patients (the oldest patient was 54 years old and the youngest case was 5 years old) were diagnosed with corneal dermoid and complaining of blurred vision or unsatisfied cosmetic appearance. All patients underwent corneal dermoid excision combined with FG boned multi-layer corneal lenticules transplantation. Slit-lamp microscopy and anterior-segmental optical coherence tomography(AS-OCT)were used to observe ocular appearance, corneal grafts survival, epithelialization, transparency, interlamellar fluid accumulation and the degradation of FG. The preoperative and postoperative change of best-corrected visual acuity (BCVA) and astigmatism were respectively recorded. RESULTS: All patients were satisfied with the postoperative cosmetic results. BCVA had been increased and astigmatism had been decreased in all cases. We observed that the FG boned multi-layer corneal lenticules were covered with smooth corneal epithelium in one week after transplantation and successfully adhered to the corneal beds, without any dislocation or interlayer separation. FG was gradually degraded and absorbed within 1 month after surgery. The lenticule grafts grew well without rejection and kept transparency during the follow-up period. CONCLUSIONS: FG boned multi-layer lenticules would be the novel and feasible substitute for lamellar keratoplasty in the treatment of corneal dermoid. FG could not be only used as binder adhering multi-layer lenticules, closing the interlayer space of multi-layer lenticules, preventing the formation of interlayer fluid, but also increasing the thickness and toughness of lenticules, and therefore which is more facilitate to intraoperative suture.

Horizontal Platelet-Rich Fibrin in Vestibuloplasty: A Case Report.

Vestibuloplasty (VP) is a surgical technique that allows the deepening of the vestibule of the mouth. The gold standard, especially if an increase in keratinized tissue (KT) is required, is represented by the free gingival graft (FGG). The need for a donor site, however, is a source of discomfort and possible complications. To overcome these aspects, numerous techniques and materials have been used. Horizontal platelet-rich fibrin (H-PRF) has been very successful in recent years in various oral surgery procedures due to its ability to promote tissue healing and regeneration. The reported case presents a new technique of VP using H-PRF, which allows avoiding the second surgical site. A 25-year-old patient with post-surgical reduction of vestibule depth and poor KT was treated with VP. The patient refused an FGG procedure. Therefore, VP was performed using an H-PRF membrane as a graft material to lengthen the vestibule and promote KT regeneration. After nine weeks, an increase in vestibule depth and KT width was evident. The use of H-PRF in VP has allowed predictable surgery without significant complications. It therefore represents an alternative to the traditional FGG to be seriously taken into consideration.

Recent insights into bonding technologies in restructured meat production: A review.

Restructuring meat products is one way of improving material utilization and economic efficiency. In this process of combining meat pieces or granules to form larger pieces of meat, the additives and processing techniques employed in bonding the restructured meat play crucial roles in the formation of the structure and appearance of the meat while simultaneously reducing nutrient and water loss and enhancing flavor. This study reviews the adhesives commonly used in meat recombination technology, including transglutaminase, glucono-delta-lactone, fibrin, gelatin, and gel emulsifiers such as hydrophilic colloid, phosphate, starch, and cellulose. Additionally, processing technologies such as high-pressure, ultrasonic, vacuum-assisted, microwave, and three-dimensional printing are discussed, with emphasis on their principles, properties, functionalities, and safety. The study further summarizes the application and research progress of various bonding techniques in restructured meat. It analyzes the advantages, challenges, and development prospects of these techniques to provide support for further research in this field.

Clopidogrel protects against gentamicin-induced nephrotoxicity through targeting oxidative stress, apoptosis, and coagulation pathways.

Gentamicin (Genta)-induced nephrotoxicity poses a significant clinical challenge due to its detrimental effects on kidney function. Clopidogrel (Clop), an antiplatelet drug known for its ability to prevent blood clots by inhibiting platelet aggregation, also has potential effects on oxidative stress and cell death. This study investigates Clop's protective role against Genta-induced nephrotoxicity, emphasizing the importance of the coagulation cascade. The 32 adult male albino rats were randomly assigned to four groups of eight (n = 8). The first group received only the vehicle. Genta was injected intraperitoneally at 100 mg/kg/day for 8 days in the second group. Groups 3 and 4 received oral Clop at 10 and 20 mg/kg/day for 1 week before Genta delivery and throughout the experiment. Renal tissue showed renal function tests, oxidative stress, pro-inflammatory cytokines, apoptotic markers, coagulation profile, and fibrin expression. Clop improved Genta-induced kidney function and histopathology. Clop substantially reduced pro-inflammatory cytokines, oxidative stress indicators, pro-apoptotic proteins, and fibrin protein. Clop also significantly boosted renal tissue anti-inflammatory and anti-apoptotic protein expression. Genta-induced nephrotoxicity involves oxidative stress, apoptosis, and coagulation system activation, according to studies. This study underscores that Genta-induced nephrotoxicity is associated with oxidative stress, apoptosis, and activation of the coagulation system. Clop's protective effects on nephrons are attributed to its anticoagulant, antioxidant, anti-inflammatory, and anti-apoptotic properties, presenting it as a promising therapeutic strategy against Genta-induced kidney damage.

Modified minimally invasive surgical technique with clindamycin-augmented or non-augmented platelet-rich fibrin in periodontal regeneration: A randomized clinical trial.

AIM: Injectable platelet-rich fibrin (I-PRF), a second-generation platelet concentrate, is widely used to enhance soft and hard tissue healing alone or in combination with biomaterials, relying on its harboring of various pivotal growth/differentiation factors. This randomized trial assessed the effect of clindamycin (CLN) augmented injectable platelet-rich fibrin (I-PRF) with modified minimally invasive surgical technique (M-MIST) versus I-PRF alone with M-MIST on the clinical and radiographic parameters in the management of periodontal intra-bony defects in patients with stage-III grade B periodontitis. METHODS: This is a 9-month parallel-grouped, two arm, double-blinded, randomized controlled trial (RCT) that included 28 patients (n = 28) with stage-III grade B periodontitis, who were allocated randomly to test- (CLN/I-PRF + M-MIST, 50 µL of CLN per 1 mL of I-PRF; n = 14) or control-group (I-PRF + M-MIST; n = 14). Clinical attachment level (CAL; primary outcome), probing depth (PD), gingival margin level (GML), plaque index (PI), and gingival index (GI) were recorded at baseline, 3, 6, and 9 months, whereas radiographic parameters radiographic linear defect depth (RLDD), and radiographic defect area (RDA) were recorded at baseline, 6, and 9 months. The CLN release kinetics from the I-PRF were further characterized. RESULTS: Compared to baseline, both groups independently demonstrated significant improvements in CAL, PD, GML, GI, PI, RLDD and BDA at 3, 6 and 9 months (p < .05). A significant reduction in CAL measurements was noticeable in the CLN/I-PRF + M-MIST and I-PRF + M-MIST group independently over time (p < .05). CLN/I-PRF + M-MIST showed significantly lower CAL than PRF + M-MIST group at baseline, after three as well as 9 months (p < .05). Intergroup comparisons at 9 months demonstrated that CAL-gain was non-significant between groups (p > .05), GI significantly lower in CLN/I-PRF + M-MIST, whereas PD-reduction significantly higher I-PRF + M-MIST group (p < .05). CLN was steadily released for the I-PRF for up to 48 h, with a peak concentration at 24 h, which then gradually declined till the seventh day. CONCLUSIONS: I-PRF with M-MIST provided significant clinical and radiographic improvement up to 9 months postoperatively in stage-III grade B periodontitis. CLN, at the applied concentration and release duration, does not appear to further positively impact these observed I-PRF effects.

An Evaluation of the Effect of the Use of Platelet-Rich Fibrin on Tonsillectomy Results.

PURPOSE: The aim of this study was to investigate the effect of liquid platelet-rich fibrin (PRF) during tonsillectomy on postoperative results. PATIENTS AND METHODS: This study included 41 patients who underwent tonsillectomy between April 2022 and January 2023. Liquid-PRF at a dose of 1cc was injected to three different points of one of the tonsil fossae, selected at random intraoperatively. The same amount of physiological saline was injected to the symmetrical points on the opposite tonsil fossa using the same size injector. Pain, wound healing, and bleeding were evaluated on postoperative days 1, 7, and 14. The data of both sides were compared statistically as the study and control sides. RESULTS: The pain scores were the highest for both sides on postoperative day 1, and gradually decreased in the following days, with no significant difference determined between the sides (p>0.05). Wound healing rates in the 1st week and 2nd week were similar for both sides. Although there were more patients who have 100% epithelization in the PRF group on the postoperative day 14, the difference between the groups was not statistically significant (p>0.05). CONCLUSIONS: The injection of PRF following tonsillectomy had no significant effect on postoperative pain, wound healing, or bleeding.

Incorporating placental pathology into clinical care and research.

Despite recent standardization of placental evaluation and establishment of criteria for diagnosis of major patterns of placental injury, placental pathological examination remains undervalued and under-utilized. The placenta can harbor a significant amount of information relevant to both the pregnant person and offspring. Placental pathology can also provide a significant context for pathophysiological study of adverse pregnancy outcomes, helping to optimally subcategorize the 'great obstetric syndromes' of pre-eclampsia (PE), spontaneous preterm birth (sPTB), and fetal growth restriction (FGR), and to identify causes of stillbirth. We hereby propose that placental evaluation should be incorporated into routine delivery of obstetric and neonatal care, and further suggest that its integration into clinical, translational, and basic research could significantly advance our understanding of pregnancy complications and adverse neonatal outcomes.

Spontaneous bleeding in chronic kidney disease: global coagulation assays may predict bleeding risk.

Background: Chronic kidney disease (CKD) is associated with increased bleeding and thrombotic risks. Standard blood tests do not sufficiently quantify these risks. Global coagulation assays (GCAs) provide a more comprehensive assessment of coagulation. Objectives: We aimed to evaluate if GCAs are predictive of spontaneous major bleeding (sMB) in CKD. Methods: Adult patients with CKD (estimated glomerular filtration rate, <30 mL/min/1.73m2) were recruited to this pilot prospective observational study. Testing with GCAs (thromboelastography, overall hemostatic potential, calibrated automated thrombogram, and plasminogen activator inhibitor-1) was performed, and the results were correlated to sMB events. Results: Eighty-seven CKD patients (median age, 67 years; 67.8% male) were included, with median follow-up of 3.1 years. CKD patients demonstrated elevated fibrinogen, factor VIII, and von Willebrand factor antigen levels, while other conventional coagulation test results were within reference intervals. Ten episodes of sMB (11.5%) were captured (3.0/100 person-years), with no significant association demonstrated between sMB and antiplatelet use (P = .36), platelet count (P = .14), or renal function (urea, P = .27; estimated glomerular filtration rate, P = .09). CKD patients with sMB had more hypocoagulable GCA parameters compared with those without sMB. The lowest quartiles of endogenous thrombin potential (subhazard ratio [sHR], 7.11; 95% CI, 1.84-27.45), overall hemostatic potential (sHR, 6.81; 95% CI, 1.77-26.16), and plasminogen activator inhibitor-1 (sHR, 5.26; 95% CI, 1.55-17.91) were associated with sMB. Conclusion: This pilot study demonstrates that GCAs such as thrombin and fibrin generation may predict sMB risk in patients with CKD, which has potential to be practice-changing. Larger studies are required to validate these findings.

Enriched advanced platelet-rich fibrin plus gold nanoparticles against Enterococcus faecalis for its potential use in revascularization for necrotic immature permanent teeth.

Background: Regenerative endodontic procedures allow reinforcement of root canal wall and continuation of root development, opening new therapeutic possibilities. The root canal system of infected teeth is colonized by a variety of microorganisms, which hinder the regenerative process, leading to treatment failure if not adequately addressed, thereby requiring careful attention to microbial control. Aim and Objective: The aim of the study was to assess the antimicrobial activity of advanced platelet-rich fibrin (A-PRF) and gold nanoparticles (AuNps) against Enterococcus faecalis. Materials and Methods: Intravenous blood (5-6 ml) was drawn from four healthy individuals, and A-PRF was prepared through centrifugation at 1500 revolutions per minute (rpm) for 14 min. A-PRF was doped with 3 µl of AuNps and centrifuged at 1000 rpm for 1 min. Antimicrobial activity was assessed using disk diffusion; inhibition zones were measured. For minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), A-PRF + AuNps were added to the microbial broth at varying concentrations to determine growth inhibition and microbial death. Results: Disk diffusion assays revealed significant antibacterial effects against E. faecalis. Norfloxacin displayed the highest mean zone of inhibition (20.33 ± 1.53 mm), followed by the Test group (A-PRF + AuNPs) (19.33 ± 0.58 mm). Multiple comparisons indicated significant differences (P < 0.001). MIC of A-PRF + AuNPs against E. faecalis was 0.031 mg/ml, with MBC at 0.015 mg/ml. Conclusion: The addition of AuNPs to A-PRF offers the potential for sustained growth factor release while maintaining the sterility of the canal, leading to successful revitalization and regeneration. The combined use of A-PRF + AuNps shows promise for enhancing revascularization in necrotic immature permanent teeth.

Effectiveness of the Association of Fibrin Scaffolds, Nanohydroxyapatite, and Photobiomodulation with Simultaneous Low-Level Red and Infrared Lasers in Bone Repair.

Biomaterials and biopharmaceuticals for correcting large bone defects are a potential area of translational science. A new bioproduct, purified from snake venom and fibrinogen from buffalo blood, aroused interest in the repair of venous ulcers. Expanding potential uses, it has also been used to form biocomplexes in combination with bone grafts, associated with physical therapies or used alone. The aim of this preclinical study was to evaluate low-level laser photobiomodulation (PBM) in critical defects in the calvaria of rats filled with nanohydroxyapatite (NH) associated with the heterologous fibrin biopolymer (HFB). Sixty animals were used, divided into six groups (n = 10 each): G1 (NH); G2 (HFB); G3 (NH + HFB); G4 (NH + PBM); G5 (HFB + PBM); G6 (NH + HFB + PBM). PBM simultaneously used red (R) and infrared (IR) light emission, applied intraoperatively and twice a week, until the end of the experiment at 42 days. Microtomography, bone formation can be seen initially at the margins of the defect, more evident in G5. Microscopically, bone formation demonstrated immature and disorganized trabeculation at 14 days, with remnants of grafting materials. At 42 days, the percentage of new bone formed was higher in all groups, especially in G5 (HFB, 45.4 ± 3.82), with collagen fibers at a higher degree of maturation and yellowish-green color in the birefringence analysis with Picrosirius-red. Therefore, it is concluded that the HFB + PBM combination showed greater effectiveness in the repair process and presents potential for future clinical studies.

Role of Autologous Platelet-Rich Fibrin in Chronic Non-healing Ulcers With Various Etiologies in a Tertiary Care Rehabilitation Centre: A Case Series.

Introduction Chronic non-healing ulcers are defined as a discontinuity or break in the integrity of skin that is not healing in a reasonable period of time due to an underlying systemic etiology. Despite using conventional initial treatment and many other available dressing options, such wounds are difficult to completely heal, thus affecting the progress of rehabilitation measures and compromising functional improvement and quality of life. Materials and methods In this case series, platelet-rich fibrin (PRF) was applied to eight wounds from six patients. The patients included had various etiologies (including spinal cord injury, peripheral vascular disease, Guillain-Barré syndrome, and diabetic foot ulcer) with chronic non-healing wounds over different anatomical locations on the body. Pressure ulcer scale for healing (PUSH) score, surface area, and volume of the wounds were evaluated and monitored weekly after PRF dressing. We have applied PRF every week. On average, two PRF dressings were applied, the maximum being three applications. Results The maximum healing rate in terms of PUSH score was observed to be 3.84% per day, and the minimum was 1.19% per day. The maximum healing rate in terms of surface area was observed to be 5.89% per day, and the minimum was 1.78% per day. Three of the wounds showed complete closure. The maximum follow-up period was 10 weeks. The percentage mean Functional Independence Measure (FIM) improvement was calculated to be 15.87% ± 14.04 during the course of hospitalization after PRF application. Conclusion Based on the results, we can conclude that PRF showed accelerated improvement in the healing of chronic non-healing ulcers of various etiologies at different anatomical locations. It has proven to be a safe and effective method, thereby improving their quality of life and functional independence in performing activities of daily living. To our knowledge till date, no other study in a rehabilitation setting has been done on patients having non-healing ulcers due to various etiologies and at different anatomical locations.

Developing fibrin-based biomaterials/scaffolds in tissue engineering.

Tissue engineering technology has advanced rapidly in recent years, offering opportunities to construct biologically active tissues or organ substitutes to repair or even enhance the functions of diseased tissues and organs. Tissue-engineered scaffolds rebuild the extracellular microenvironment by mimicking the extracellular matrix. Fibrin-based scaffolds possess numerous advantages, including hemostasis, high biocompatibility, and good degradability. Fibrin scaffolds provide an initial matrix that facilitates cell migration, differentiation, proliferation, and adhesion, and also play a critical role in cell-matrix interactions. Fibrin scaffolds are now widely recognized as a key component in tissue engineering, where they can facilitate tissue and organ defect repair. This review introduces the properties of fibrin, including its composition, structure, and biology. In addition, the modification and cross-linking modes of fibrin are discussed, along with various forms commonly used in tissue engineering. We also describe the biofunctionalization of fibrin. This review provides a detailed overview of the use and applications of fibrin in skin, bone, and nervous tissues, and provides novel insights into future research directions for clinical treatment.

Effects of platelet-rich fibrin on human endometrial stromal cells behavior in comparison to platelet-rich plasma.

Introduction: Intrauterine transfusion of platelet-rich plasma (PRP) has become a new treatment for thin endometrium (TE) in recent years, but its low efficacy due to rapid release of growth factors limits its clinical use. Platelet-rich fibrin (PRF) starts the coagulation cascade reaction immediately after the blood comes into contact with the test tube. The natural coagulation process results in stable platelet activation and the slow release of growth factors. Methods: In our study, primary human endometrial stromal cells (hESCs) were extracted from endometrial tissue. PRP and PRF were prepared from the patient cubital vein blood. Stromal cells were cultured in conditioned medium supplemented with PRP and PRF. Differences in cell behavior were observed by cell proliferation test and cell migration test. The relative expression levels of apoptotic Bax and antiapoptotic Bcl-2 genes were measured by qRT-PCR. The release of growth factors from PRP and PRF was detected by ELISA. Results: We found that both PRP and PRF inhibited apoptosis of hESCs, which favored cell proliferation and migration. In addition, PRF releases growth factors for a longer period of time compared to PRP. Discussion: PRF offer a more sustained therapeutic effect compared to PRP, which provides a new idea for endometrial regeneration and repair.

Axonal Growth and Fasciculation of Spinal Neurons Promoted by Aldynoglia in Alkaline Fibrin Hydrogel: Influence of Tol-51 Sulfoglycolipid.

Traumatic spinal cord injury (tSCI) has complex pathophysiological events that begin after the initial trauma. One such event is fibroglial scar formation by fibroblasts and reactive astrocytes. A strong inhibition of axonal growth is caused by the activated astroglial cells as a component of fibroglial scarring through the production of inhibitory molecules, such as chondroitin sulfate proteoglycans or myelin-associated proteins. Here, we used neural precursor cells (aldynoglia) as promoters of axonal growth and a fibrin hydrogel gelled under alkaline conditions to support and guide neuronal cell growth, respectively. We added Tol-51 sulfoglycolipid as a synthetic inhibitor of astrocyte and microglia in order to test its effect on the axonal growth-promoting function of aldynoglia precursor cells. We obtained an increase in GFAP expression corresponding to the expected glial phenotype for aldynoglia cells cultured in alkaline fibrin. In co-cultures of dorsal root ganglia (DRG) and aldynoglia, the axonal growth promotion of DRG neurons by aldynoglia was not affected. We observed that the neural precursor cells first clustered together and then formed niches from which aldynoglia cells grew and connected to groups of adjacent cells. We conclude that the combination of alkaline fibrin with synthetic sulfoglycolipid Tol-51 increased cell adhesion, cell migration, fasciculation, and axonal growth capacity, promoted by aldynoglia cells. There was no negative effect on the behavior of aldynoglia cells after the addition of sulfoglycolipid Tol-51, suggesting that a combination of aldynoglia plus alkaline fibrin and Tol-51 compound could be useful as a therapeutic strategy for tSCI repair.

From Healing to Regeneration: A Comprehensive Review of the Efficacy of Platelet-Rich Fibrin in Periodontal Plastic Surgery Procedures.

This review examines platelet-rich fibrin (PRF) efficacy in periodontal plastic surgery, highlighting its crucial role in promoting periodontal regeneration and healing. Various forms of PRF are discussed, like leukocyte- and platelet-rich fibrin, advanced PRF, and injectable PRF, in addition to their application in different periodontal procedures such as root coverage and increasing the width of keratinized tissue surrounding the teeth. This review emphasizes the biological benefits of PRF, such as faster wound healing, reduced postsurgical pain, and better management of bleeding. The presence of growth factors, cytokines, and leukocytes in PRF significantly aids in promoting tissue regeneration, thereby improving the clinical outcomes of periodontal therapy. This review also provides recommendations for further research using standardized PRF protocols to optimize the benefits of PRF in clinical practice.