Leukocyte- And Platelet-rich Fibrin Research Articles

L-PRF in Osteoarthritis Treatment: Results of a Pilot study

Osteoarthritis (OA) is the most common chronic musculoskeletal disorder and is the most frequent single cause of disability in older adults [1]. OA is a chronic disease progressively involving the entire joint. Progression involves capsule-bursa inflammation, synovial fluid modifications, cartilage erosions, and osteochondral inflammatory deteriorations leading to bone erosion and distortion [1]. Early OA defines the initial cascade of events that trigger the disease and lead to the full-blown OA. The disease progression can sometimes last for years being quite often neglected or mistreated with palliative medications. Joint resident MSCs has always been a target for our research into and treatment of OA [1,2,3]. Recently L-PRF (leukocyte and platelet-rich fibrin), showed promising properties in connective tissue regeneration and, for this reason, is now widely applied in chronic wound healing and jawbone growth [4,5,6]. After centrifugation, L-PRF membranes hold vital platelets, leukocytes, and various peripheral blood cells [7,8]. As a result, we exposed these membranes to a thermic shock aimed to increase the pool of HSPs. The final product was named supercharged L-PRF. Supercharged L-PRF components -membranes and hyper-acute serum- were used in knee OA patients in a small preliminary comparative study. 20 consecutive patients were randomly divided into 2 groups: 10 patients treated with supercharged L-PRF and 10 with PRP+HA (PRP+ Hyaluronic acid). The primary outcome of this study was to induce persistent pain relief and recovery of motility. This article reports supercharged L-PRF preliminary experience in degenerative OA treatment.

Antibacterial effects of platelet-rich fibrin produced by horizontal centrifugation

Platelet-rich fibrin (PRF) has been widely used owing to its ability to stimulate tissue regeneration. To date, few studies have described the antibacterial properties of PRF. Previously, PRF prepared by horizontal centrifugation (H-PRF) was shown to contain more immune cells than leukocyte- and platelet-rich fibrin (L-PRF). This study aimed to compare the antimicrobial effects of PRFs against Staphylococcus aureus and Escherichia coli in vitro and to determine whether the antibacterial effects correlated with the number of immune cells. Blood samples were obtained from eight healthy donors to prepare L-PRF and H-PRF. The sizes and weights of L-PRF and H-PRF were first evaluated, and their antibacterial effects against S. aureus and E. coli were then tested in vitro using the inhibition ring and plate-counting test methods. Flow-cytometric analysis of the cell components of L-PRF and H-PRF was also performed. No significant differences in size or weight were observed between the L-PRF and H-PRF groups. The H-PRF group contained more leukocytes than the L-PRF group. While both PRFs had notable antimicrobial activity against S. aureus and E. coli, H-PRF demonstrated a significantly better antibacterial effect than L-PRF. Furthermore, the antimicrobial ability of the PRF solid was less efficient than that of wet PRF. In conclusion, H-PRF exhibited better antibacterial activity than L-PRF, which might have been attributed to having more immune cells.

Concentrated Growth Factors vs. Leukocyte-and-Platelet-Rich Fibrin for Enhancing Postextraction Socket Healing. A Longitudinal Comparative Study

Platelet concentrates (PCs) have been used for over 20 years in dentistry, as an adjunct to oral surgery procedures, to improve hard and soft tissue healing and control postoperative symptoms. Among various PCs, Leukocyte and Platelet-Rich Fibrin (L-PRF) has become very popular due to its excellent cost-effectiveness ratio, and to the simple preparation protocol, but comparative clinical studies with other PCs are lacking. The aim of this split-mouth cohort study was to evaluate the effect of Concentrated Growth Factors (CGF), a recently introduced PC, as compared to L-PRF for enhancing post-extraction socket healing. Methods: Patients in need of bilateral tooth extractions were included. Each side was treated with either CGF or L-PRF. Pain, socket closure and healing index were the main outcomes. Results: Forty-five patients (24 women), aged 60.52 ± 11.75 years (range 37–87 years) were treated. No significant difference in outcomes was found, except for Pain at day 1 (p < 0.001) and socket closure in the vestibulo-palatal/lingual dimension at day 7 post-extraction (p = 0.04), both in favor of CGF. Conclusions: based on the present results, CGF proved to be as effective and safe as L-PRF, representing a valid alternative option for improving alveolar socket healing and reducing postoperative discomfort.

Autologous Platelet-Rich Plasma for Diabetic Foot Ulcer

Application of autologous platelet-rich plasma (PRP), especially leukocyte- and platelet-rich fibrin (L-PRF), has emerged as a promising adjuvant therapy for the treatment of diabetic foot ulcers (DFUs). Conflicting results of PRP efficacy can be attributed to the lack of standardization in the PRP preparation process in addition to a paucity of well-designed randomized clinic trials (RCTs).

Micro- and nanoscale characterization of different natural biomaterials for ocular surface regeneration

Objectives: This study aims to characterize the widely used biological derived membranes in clinics in terms of micro-nano scale mechanical and morphological properties. Within this scope, advanced platelet-rich fibrin (A-PRF), leucocyte-and platelet-rich fibrin (L-PRF) and human amniotic membrane were studied in this research study. Methods: Nano-indentation, optical coherence tomography (OCT), scanning electron microscopy (SEM), and in vitro degradation test were performed for material characterization. Results: The nano-indentation test revealed significantly higher modulus of elasticity and hardness values in A-PRF group, while OCT presented significantly higher thickness measurements when compared L-PRF. A loose 3D architecture formation due to the large pores formed by means of large fiber diameter were observed in A-PRF group. Besides, platelets were observed among the large fibers in A-PRF membranes on the contrary of L-PRF membranes. Low fiber diameter and high cellular separation were recorded in L-PRF group due to the high centrifugal force application. Therefore, it was observed that the platelets were located mostly on the surface of the membranes in L-PRF. The loose 3D architecture of A-PRF membranes is thought to release growth factors for a longer period of time, ensuring cellular integrity. On the other hand, degradation test results indicated that amniotic membranes degrade to about 85% in one week, while L-PRF and A-PRF were lost their initial weights approximately 31% and 40%, respectively. Conclusions: This comparative characterization study of three different natural biomaterials used in a wide range of clinical applications, from dentistry to ophthalmology, was thought to guide surgeons on the selection of site-specific material.

Management of Medication-Related Osteonecrosis of the Jaw (MRONJ) Using Leukocyte- and Platelet-Rich Fibrin (L-PRF) and Photobiomodulation: A Retrospective Study.

Background. The aim of this study was to compare retrospectively the effect of three different treatment protocols on the healing outcome in patients with established medication-related osteonecrosis of the jaw (MRONJ). Methods. A total of 34 MRONJ patients were recruited from the Department database and were divided according to the treatment protocols in a study group (G1) and two control groups (G2 and G3). G1 was treated with antibiotic therapy, surgery, leukocyte- and platelet-rich fibrin (L-PRF), and photobiomodulation; G2 was treated with antibiotic therapy and surgery; G3 was treated with antibiotic therapy and photobiomodulation. Various clinical variables and treatment protocols were analyzed to determine their correlation with the healing outcome at three and six months of follow-up. Results. There was a significant association between the different treatment protocols and the outcomes at both three and six months follow-up (p = 0.001 and p = 0.002, respectively). No significant association was observed between the outcomes and MRONJ localization, MRONJ stage, duration of drug treatment, gender, diabetes, corticosteroid therapy, smoking habits, underlying disease, and history of chemotherapy at both three and six months follow-up. Conclusions. Our results show that the combination of antibiotic therapy, surgery, L-PRF, and photobiomodulation may effectively contribute to MRONJ management.

Development of a Multifunctional Bioerodible Nanocomposite Containing Metronidazole and Curcumin to Apply on L-PRF Clot to Promote Tissue Regeneration in Dentistry.

Teeth extractions are often followed by alveolar bone reabsorption, although an adequate level of bone is required for reliable rehabilitations by dental implants. Leukocyte and platelet-rich fibrin (L-PRF) has been widely applied in regenerative procedures and with antibiotic and antioxidant agents could play an essential role in hard and soft tissue healing. In this work, a nanocomposite (Sponge-C-MTR) consisting of a hyaluronate-based sponge loaded with metronidazole (MTR) and nanostructured lipid carriers containing curcumin (CUR-NLC) was designed to be wrapped in the L-PRF™ membrane in the post-extraction sockets and characterized. CUR-NLCs, obtained by homogenization followed by high-frequency sonication of the lipid mixture, showed loading capacity (5% w/w), drug recovery (95% w/w), spherical shape with an average particle size of 112.0 nm, and Zeta potential of −24 mV. Sponge-C-MTR was obtained by entrapping CUR-NLC in a hydrophilic matrix by a freeze-drying process, and physico-chemical and cytocompatibility properties were evaluated. Moreover, the aptitude of CUR and MTR to the penetrate and/or permeate both L-PRF™ and porcine buccal tissue was assessed, highlighting MTR penetration and CUR accumulation promoted by the system. The results positively support the action of nanocomposite in dental tissues regeneration when applied together with the L-PRF™.

Leukocyte and Platelet-Rich Fibrin Have Same Effect as Blood Clot in the 3-Dimensional Alveolar Ridge Preservation. A Split-Mouth Randomized Clinical Trial

Leukocyte- and platelet-rich fibrin (L-PRF) has been used for alveolar ridge preservation (ARP) in postextraction tooth sockets. However, current reports have measured its effectiveness in linear measurements of 3-dimensional ridge preservation. The purpose of this study was to determine the effectiveness of the use of L-PRF filling versus natural clot blood healing in ARP according to the clinical, radiographic, and volumetric measurements of postextraction tooth sockets. A split-mouth randomized clinical trial was designed. Healthy patients who needed bilateral extraction of upper third molars were selected. After the tooth extraction, the socket was filled and distributed randomly with L-PRF and the contralateral socket only with the blood clot. The dimensional change of soft tissue healing around the sockets, and the length, depth, and difference of bone formation were examined using standardized periapical radiographs. Volumetric measurement variation of the sockets was evaluated by 3-dimensional scanning of dental casts. Changes of all measures were analyzed at 7 days (initial) and 3 months (final) after the tooth extraction and compared between both groups (t test; P<.05). Sixteen patients (aged 24.75±3.53years; 56.25% women) participated. Measurements of wound healing and the length, depth, and difference of bone formation were similar for both study groups at initial and final times. The calculation of initial-final volumetric socket variation was 15.45±13.12μL using L-PRF and 14.12±11.23μL using blood clot (P=.78). L-PRF filling showed the same dimensional and volumetric behavior as normal blood clot healing in the ARP of postextraction tooth sockets. Future investigations will have to analyze the use of surgical models and digital instruments in ARP techniques.

Additive Effect of Platelet Rich Fibrin with Coronally Advanced Flap Procedure in Root Coverage of Miller's Class I and II Recession Defects-A PRISMA Compliant Systematic Review and Meta-Analysis.

Aim: This systematic review and meta-analysis aims to assess the additive effect of leukocyte and platelet-rich fibrin (L-PRF) on coronally advanced flap (CAF) procedures in root coverage of Miller’s class I and II gingival recession defects. Review methodology: A comprehensive search in MEDLINE (PubMed), Scopus and CENTRAL (the Cochrane Central Register of Controlled Trials), along with an additional hand search, provided eight randomized clinical trials to be included in this review. A total of 167 patients with 470 gingival recession defects were analyzed. A meta-analysis was carried out to assess the change in gingival thickness (GT), width of keratinized gingiva (WKG), root coverage percentage (%RC), clinical attachment level (CAL) and recession depth (RD) at all follow-ups between CAF alone and CAF + L-PRF groups for all included studies. A subgroup analysis was carried out based on recession type (single/multiple). Results: Overall, a significant improvement in GT, CAL and RD was found when treated with CAF + L-PRF. There was a trend for a positive effect in terms of an increase in WKG when using L-PRF, especially in the treatment of single recession, though significance was not achieved (p = 0.08 overall). The results of heterogeneity among the subgroups were varied and were found to be greater than 91.3% for GT and 32.8% for WKG. Conclusion: L-PRF when used in addition to CAF showed favorable results for the treatment of class I and II gingival recession defects.

Decontamination of rough implant surfaces colonized by multispecies oral biofilm by application of leukocyte- and platelet-rich fibrin.

Decontamination of biofilm-infected rough implant surfaces is challenging. Platelet rich blood products have been shown to have anti-microbial properties against periodontal pathogens. Our aim was to investigate the effect of a potential biological implant surface disinfectant, leukocyte- and platelet-rich fibrin (L-PRF), on a mature oral multispecies biofilm on a rough titanium surface. Sandblasted, large grit, acid-etched (SLA) titanium disks were inoculated with subgingival dental plaque and cultured anaerobically for 21 days. The L-PRF membranes were collected from 12 donors in three trials (four donors in each trial). The disks were rinsed with 0.9% NaCl and exposed to the cell-rich portion of the L-PRF membranes for 48hours followed by scanning electron microscope (SEM) analysis immediately or after rinsing with 0.9% NaCl prior to fixation. The presence of platelet factor-4 in the rinse samples was analyzed by Western blotting. Remaining bacteria were quantified from SEM images of the implant surfaces and their numbers statistically compared. The L-PRF-treated samples without rinsing displayed numerous cells with multiple pseudopodia in immediate contact with bacteria that appeared perforated and increased in size. The cells were identified as platelets based on morphological criteria and by positive reaction for platelet factor-4 by Western blotting. After post-treatment rinsing, the L-PRF-treated disks displayed a significant reduction in bacterial counts (in average 92% reduction). Application of L-PRF significantly reduced bacterial counts on contaminated SLA titanium surface, most likely through anti-microbial action by platelets.

Use of the Autologous Membrane in Structured Rhinoplasty: An Alternative to Camouflaging and Filling.

The membranes were obtained by centrifuging patients' peripheral blood before the rhinoplasty. At the time of use, the membrane was removed from the tube, separated from the clot, and used in the camouflage and filling process in patients operated on due to various indications: 19 associated with diced cartilage, and 4 sole. The authors present the clinical and photographic impressions of the immediate and late postoperative period, as well as the patients' opinions using a specific questionnaire. No patient had immediate or late postoperative complications. The use of leukocyte- and platelet-rich fibrin (L-PRF) was sufficient to carry out the camouflage and filling in all patients, and the patient declared satisfaction. This membrane was shown to be an excellent surgical alternative to the camouflage and filling in rhinoplasty. In addition, it is rich in factors that can improve and accelerate regeneration of tissues.

Histological comparison of DBBM and platelet rich fibrin for guided bone regeneration in a rabbit model

To histologically evaluate the use of bovine derived deproteinized xenograft (DBBM), leukocyte and platelet rich fibrin (L-PRF) and the combination of both in Guided Bone Regeneration (GBR) performed in non-critical size defects in rabbit. A prospective experimental study was performed. Four bone defects in the tibiae of 12 rabbits were made and each of them was filled with DBBM, L-PRF, a combination of DBBM+L-PRF or was left to heal as control site. All defects were covered with a collagen membrane. Rabbits were randomly distributed in three groups and euthanatized at 3, 6 or 9 weeks. Samples were obtained and histologically analyzed to determine vital bone, connective tissue and remaining graft particles percentage. Analysis of variance, Kruskal Wallis and non-paired t-test where used to evaluate the significance of the results. At 3 weeks of healing, DBBM showed significantly more vital bone percentage than L-PRF (p=0,05) and DBBM+L-PRF showed significantly less connective tissue than control (p<0,05). All other groups showed no statistical difference between them. At 6 weeks of healing, DBBM showed significantly more vital bone percentage than L-PRF (p<0,05), DBBM+L-PRF (p<0,05) and control (p<0,05) and there wasn't any other significant difference regarding to connective tissue or remaining particle percentage between groups. At t 9 weeks healing period, there weren't any significant differences between groups. DBBM seems to enhance vital bone formation at early healing stages. The use of L-PRF alone or combined with DBBM, didn't show any histological improvement regarding to vital bone formation. The use of DBBM, alone or in conjunction with L-PRF showed a trend to reduce connective tissue percentage. The use of L-PRF combined with DBBM didn't affect the remaining particle percentage.

Multi-modular bone healing assessment in a randomized controlled clinical trial of root-end surgery with the use of leukocyte- and platelet-rich fibrin and an occlusive membrane.

The aim of this study was to assess in a multi-modular manner the bone healing 1year post root-end surgery (RES) with leukocyte- and platelet-rich fibrin (LPRF) and Bio-Gide® (BG; Geistlich Pharma North America, Inc., Princeton, USA) as an occlusive membrane. A randomized controlled clinical trial (RCT) of RES +/- LPRF and +/- BG was performed. The follow-up until 1year post RES was performed by means of ultrasound imaging (UI), periapical radiographs (PR), and cone-beam computed tomography (CBCT). From the 50 included patients, 6 dropped-out during follow-up. For the 44 assessed patients (34 with UI and 42 with PR and CBCT), there was no evidence (p > 0.05) for an effect of LRPF, neither on UI measurements nor on CBCT assessments. On the contrary, there was an indication for a better outcome with BG. UI presented significant shorter healing time for the bony crypt surface (p = 0.014) and cortical opening (p = 0.006) for the groups with BG. The qualitative CBCT assessment for the combined scores of the apical area and cortical plane was significantly higher for BG (p = 0.01 and 0.02). The quantitative CBCT measurement for bone healing after 1year was lower with BG (p = 0.019), as well as the percentage of non-zero values (p = 0.026), irrespective of the preoperative lesion size and type. Furthermore, UI seemed to be safer for frequent follow-up during the early postoperative stage (0-3months), whereas CBCT gave more accurate results 1year post RES. Amongst the assessors, the qualitative PR analysis was inconsistent for a favorable outcome 1year post RES with LPRF (p = 0.11 and p = 0.023), but consistent for BG (p = 0.024 and p = 0.023). There was no evidence for improvement of bone healing when RES was applied with LPRF in comparison with RES without LPRF. However, RES with BG gave evidence for a better outcome than RES without BG. The addition of an occlusive membrane rather than an autologous platelet concentrate improved bone regeneration 1year post RES significantly, irrespective of the assessment device applied. The accuracy of PR assessment is questionable.

Mechanical and structural properties of leukocyte- and platelet-rich fibrin membranes: An in vitro study on the impact of anticoagulant therapy.

Little is known about structural and mechanical properties of leukocyte- and platelet-rich fibrin (L-PRF) membranes and even less about the influence of antithrombotic drugs on L-PRF. The aim of this in vitro study is therefore to investigate mechanical properties, fibrin structure and cell content of L-PRF membranes and the impact of anticoagulant therapy on L-PRF. Blood samples were obtained from 12 volunteers and supplemented with either no, 1.25IU, 2.5IU, 5IU, or 10IU enoxaparin. L-PRF membranes were characterized with tensile testing, scanning electron microscopy, and measurement of platelets and leukocytes. Control and enoxaparin-supplemented L-PRF membranes were compared. At 10IU enoxaparin, no L-PRF membranes could be generated, whereas the low doses of 1.25 and 2.5IU had no influence on L-PRF properties. The mechanical properties, fibrin networks, and number of platelets and leukocytes of 5IU supplemented membranes were unlike the control membranes, but were not found to be significantly different because of limited sampling and inter- and intra-variability. Low doses of the anticoagulant enoxaparin do not affect mechanical properties, fibrin network, nor cellular content of L-PRF, whereas high doses impair L-PRF generation.

Leucocyte- and platelet-rich fibrin regulates expression of genes related to early wound healing in human gingival fibroblasts.

Leucocyte- and platelet-rich fibrin (L-PRF) is a blood-derived biomaterial rich in leucocytes and platelets embedded in a high-density fibrin network that can be compressed into a membrane and used in surgical applications to stimulate tissue regeneration and wound healing, especially in oral cavity. This study aimed to determine the combined effects of the growth factors and cells present in L-PRF on fibroblasts that directly face the L-PRF membranes placed during surgical procedures. The effect of L-PRF from six donors on the expression of 84 key wound healing genes in normal human gingival fibroblasts was tested by RT-qPCR. L-PRF significantly regulated the expression of 33 fibroblast genes (39%), including interleukins, myofibroblast-, extracellular matrix- and angiogenesis-associated genes, and matrix metalloproteinase-1 and -3. L-PRF regulated fibroblast gene expression both time- and dose-dependently, and the effects were mediated by mitogen-activated protein kinases ERK1/2, JNK and p38. L-PRF also stimulated fibroblast wound closure and promoted the ability of fibroblasts to induce endothelial tube formation. L-PRF-induced gene expression changes in fibroblast were similar to those observed in early human and pig wounds. This study provides new insights into the biological mechanism by which L-PRF regulates key gingival fibroblast functions important in wound healing.

Leukocyte- and platelet-rich fibrin as an adjuvant to the surgical approach for osteoradionecrosis: a case report.

We present a case of osteoradionecrosis treated with leukocyte- and platelet-rich fibrin (LPRF) and surgery and followed up with clinical and tomographic investigations. A 65-year-old woman presented with pain in the posterior region of the right palate. Her medical history included cardiovascular disease and squamous cell carcinoma in the anterior region of the floor of the mouth that had been treated with intensity-modulated radiation therapy. Measurements of isodose curves showed a full dosage of 6,462.6 cGy in the anterior mandibular region, whereas that in the posterior region on the right side of the maxilla reached 5,708.1 cGy. Osteotomy was performed using rotary instruments, and debridement and placement of two LPRF membranes were also carried out. New gum tissue with no bone exposure was noted 14 days postoperatively. Tissue repair was complete, and the patient had no further complaints. During a 39-month follow-up period, the oral mucosa remained intact, and the patient was rehabilitated with a new upper denture. Since there is no consensus regarding the best protocol to treat osteoradionecrosis, LPRF might be an interesting adjuvant to a surgical approach. The use of LPRF is simple and reduces operational costs, time of handling, probability of technical failure, and associated morbidities for patients with osteoradionecrosis.

Histological comparison of Platelet rich fibrin clots prepared by fixed-angle versus horizontal centrifugation

Platelet-rich fibrin (PRF) is prepared from whole blood without any exogenous coagulation factors. Several preparation methods have now been introduced, particularly with differences in centrifugation parameters including g-force and time to improve their regenerative potential. Nevertheless, the centrifugation systems have not yet been clearly investigated for their influences on the PRF clot properties. The aim of the present study was to visually and histologically characterize the cell separation manner and blood cell localization on the whole PRF clots prepared by two different centrifugation system, fixed-angle and horizontal centrifugation. Leukocyte- and platelet-rich fibrin (L-PRF) was prepared on a fixed-angle centrifuge machine (IntraSpin, Intra-Lock, FL, USA) at 2700 rpm (~400 g at the RCF-clot; ~700 g at the RCF-max) for 12 min. The PRF prepared by horizontal centrifugation was prepared on a horizontal centrifugation (H-PRF) (Eppendorf 5702, Eppendorf, Germany) at 700 g at the RCF-max for 8 min. The cell morphology and localization were observed on the surface of PRF clots by scanning electron microscopy (SEM) and histologically by transaxial frozen sections by means of a film method. L-PRF clots demonstrated a sloped separation between the upper plasma and the bottom red blood cell (RBC) layers according to the angle of the rotor. Red dots were often observed on the distal walls of the tubes in the upper layers, consisting of aggregations of RBCs, leukocytes and platelets by SEM and histology. Clots produced on the horizontal centrifuge showed much smoother cell layer distribution/separation along the tube surfaces when compared to L-PRF. Horizontal centrifugation also demonstrated more evenly distributed platelets throughout the PRF clots when compared to L-PRF that gathered the majority of cells along the distal tube surface or within the buffy-coat region. In summary, it was found that horizontal centrifugation resulted in a more uniform blood cell separation of PRF clots when compared to the accumulation of cells gathered along the distal tube surfaces produced prepared by fixed-angle centrifugation. Future research is needed to evaluate the benefit of horizontal centrifugation in clinical practice.

Therapeutic Potential of Dental Pulp Stem Cells and Leukocyte- and Platelet-Rich Fibrin for Osteoarthritis.

Osteoarthritis (OA) is a degenerative and inflammatory joint disorder with cartilage loss. Dental pulp stem cells (DPSCs) can undergo chondrogenic differentiation and secrete growth factors associated with tissue repair and immunomodulation. Leukocyte- and platelet-rich fibrin (L-PRF) emerges in regenerative medicine because of its growth factor content and fibrin matrix. This study evaluates the therapeutic application of DPSCs and L-PRF in OA via immunomodulation and cartilage regeneration. Chondrogenic differentiation of DPSCs, with or without L-PRF exudate (ex) and conditioned medium (CM), and of bone marrow-mesenchymal stem cells was compared. These cells showed differential chondrogenesis. L-PRF was unable to increase cartilage-associated components. Immature murine articular chondrocytes (iMACs) were cultured with L-PRF ex, L-PRF CM, or DPSC CM. L-PRF CM had pro-survival and proliferative effects on unstimulated and cytokine-stimulated iMACs. L-PRF CM stimulated the release of IL-6 and PGE2, and increased MMP-13, TIMP-1 and IL-6 mRNA levels in cytokine-stimulated iMACs. DPSC CM increased the survival and proliferation of unstimulated iMACs. In cytokine-stimulated iMACs, DPSC CM increased TIMP-1 gene expression, whereas it inhibited nitrite release in 3D culture. We showed promising effects of DPSCs in an in vitro OA model, as they undergo chondrogenesis in vitro, stimulate the survival of chondrocytes and have immunomodulatory effects.

The use of leukocyte- and platelet-rich fibrin in the management of soft tissue healing and pain in post-extraction sockets: A randomized clinical trial

This study aimed to evaluate the clinical effect of leukocyte- and platelet-rich fibrin (L-PRF) to improve epithelialization and decrease postoperative pain in post-extraction sockets. Thirty two participants requiring extractions of posterior teeth were randomized into two groups: 1) extractions and socket filling with L-PRF membrane (test group) and 2) extraction with spontaneous healing (control group). One week after extraction, an assessment of soft tissue healing around the sockets was performed using the healing index. Also, postoperative pain by visual analog scale (VAS) and number of consumed analgesic tablets were recorded. In the first week, the sockets of the test group presented a significantly (mean of 3.81 ± 0.54; p = 0.0138) higher level of healing when compared to the sockets of the control group (mean of 3.18 ± 0.65). The participants of control group reported a significantly (mean of 5.12 ± 1.08; p = 0.0128) higher level of postoperative pain when compared to the test group (mean of 4 ± 1.15). Also, the control group consumed a greater number of analgesics (mean of 1.75 ± 0.85; p = 0.0136) when compared to the test group (mean of 1 ± 1.15). The results of the present study demonstrate that whenever improved healing of the extraction socket is needed, the use of L-PRF should be considered. In addition, the use of L-PRF decreases postoperative pain and discomfort.

Autologous platelet concentrates in maxillofacial regenerative therapy.

Platelet concentrates have emerged as innovative autologous blood products that enhance tissue healing and regeneration in regenerative therapy. A common feature of these products is their higher than baseline platelet concentration, which improves wound healing and tissue repair. Four main categories of products can be easily defined, based on their leukocyte content and fibrin architecture: pure platelet-rich plasma, such as Cell Separator PRP or Anitua' PRGF; leukocyte- and platelet-rich plasma (L-PRP), such as PCCS or Ace PRP; pure platelet-rich fibrin (P-PRF), such as Fibrinet PRFM; and leukocyte- and platelet-rich fibrin (L-PRF), such as Choukroun's PRF. Two families contain significant concentrations of leukocytes: L-PRP and L-PRF. These four families of products have different biological signatures and mechanisms and obviously different clinical applications. An L-PRF membrane releases growth factors and matrix proteins over a period longer than 7 days, whereas a PRP gel matrix releases and disperses its growth factors in a relatively quick download. In the near future, simple and inexpensive products such as L-PRF are expected to have applications in oral-maxillofacial surgery, periodontal surgery, plastic surgery, orthopedic surgery, and sports medicine. Leukocytes substantially affect the intrinsic biology and properties of platelet concentrates, not only because they enhance immune function and antibacterial potential, but also because they have essential roles in the wound healing process. Unfortunately, their impact has been almost completely neglected in the literature. Improved understanding of the effects of leukocytes in wound healing is essential for development of new clinical applications of platelet concentrates.