PRP And Platelet-poor Plasma Research Articles

(219) AUTOLOGOUS PLATELET-RICH PLASMA IMPROVES ENDOTHELIAL AND TADALAFIL-INDUCED RELAXATIONS IN CORPUS CAVERNOSUM FROM PATIENTS WITH ERECTILE DYSFUNCTION

Abstract Objectives Available clinical evidence suggests the potential therapeutic use of intracavernosal injections of platelet-rich plasma (PRP) to treat erectile dysfunction (ED). However, the effects of PRP on human cavernosal function have not been elucidated. Our aim was to evaluate the effects of acute exposure to autologous PRP on relaxant capacity of human corpus cavernosum (HCC) from patients with ED. Methods HCC strips were obtained from four ED patients undergoing penile prosthesis insertion and giving informed consent. Previous to intervention, PRP and platelet-poor plasma (PPP) were obtained from patients by apheresis and stored at -20°C until functional procedures. Endothelial relaxation to acetylcholine (ACh) was evaluated before and after 60 min exposure to PRP or PPP (1% v/v) in organ chamber. Relaxant response to the PDE5 inhibitor, tadalafil, was also evaluated in PRP or PPP (1%) treated HCC from the same patient. Results Average age of patients was 67-years-old (range 61-71) while hypertension and smoking history was present in 3/4, diabetes in 2/4, and obesity in 1/4. Mean platelet content in PRP was 1,096x10 9 /L (range 786 to 1,284 x109/L) while negligible platelet content was obtained in any PPP. Exposure to autologous PRP but not PPP significantly enhanced (p<0.0001 by two-factors ANOVA) ACh-induced endothelial relaxations (pEC50 5.75±0.65 vs. 7.16±0.50; Emax 57.3±14.8% vs. 88.5±2.0%; before and after 1%PRP, respectively). Additionally, HCC treated with autologous PRP displayed augmented relaxant responses to tadalafil (p=0.0018 by two-factors ANOVA) with respect to those treated with PPP (pEC50 6.08±0.5 vs. 6.82±0.51 for PPP and PRP, respectively). Conclusions Acute exposure to autologous PRP improves endothelial function and functional response to PDE5 inhibition. These results support the reported clinical improvement of erectile function in patients with ED and suggest that PRP injection might induce a functional effect on cavernosal tissue in addition to the claimed restorative/regenerative effect. Conflicts of Interest None

Evaluation of Platelet-Rich Plasma by means of PRGF®-Endoret® protocol in leukemia cats: PDGF-BB and TGF-ß1 valuation.

Feline leukemia virus (FeLV) is a chronic disease that leads to the weakening of a cat's immune system. Platelet-rich plasma (PRP) offers therapeutic effects for multiple diseases, the use of PRP and growth factors (GFs) determination could be an alternative treatment to improve the quality of life in these patients. The objectives of this study were to determine and compare the concentration of platelets (PLTs), red blood cells (RBCs) and white blood cells (WBCs) between samples of whole blood (WB), PRP and platelet-poor plasma (PPP) fractions, and to evaluate the concentration of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor β1 (TGF-β1) in both fractions in FeLV cats using a PRGF®-Endoret® protocol previously standardized in this species. WB was collected from 11 asymptomatic FeLV-positive cats. PRP and PPP was obtained following PRGF®-Endoret® technology according to centrifugation at 265 g for 10 min. Cellular components, RBCs, WBCs, PLTs, and the PDGF-BB and TGF-β1 concentrations in PRP and PPP fractions were determined. PLT in the PRP fraction was statistically higher than WB and PPP fraction, with no statistical differences between WB and PPP. PLT concentration increased 1.4 times in PRP fraction compared to WB. Mean platelet volume (MPV) did not differ significantly between the WB, PRP, and PPP fractions. Compared to WB, the absolute numbers of RBCs and WBCs were decreased by 99% and more than 95% in the PRP and PPP fractions, respectively. TGF-ß1 concentrations increased in PRP vs. PPP, with no changes in PDGF-BB. Based on the degree of PLT enrichment and the absence of RBCs and WBCs, this blood product could be classified as a Pure Platelet-Rich Plasma (P-PRP). The presence of GFs in PRP and PPP samples suggests that the PRGF®-Endoret® methodology is suitable for obtaining PRP in FeLV cats, despite future studies are necessary to optimize the technique, standardize the results and assess clinical efficacy.

The expression level of mir-21-3p in platelet-rich plasma: A potential effective factor and predictive biomarker in recurrent implantation failure.

Recurrent implantation failure (RIF) is the most important complication associated with in vitro fertilization (IVF). Despite the good quality of the transferred embryo, the success rate is rather disappointing. Therefore, predictive biomarkers for implantation are critical to making decisions about transferring high-quality embryos or cryopreserving them for cycles with a higher chance of implantation. Recently, intrauterine infusion of autologous platelet-rich plasma (PRP) has been proposed to increase the endometrial receptivity in RIF patients. PRP is rich in both growth factors and microRNAs (miRNAs). We investigated the possible association of mir-21-3p, mir-21-5p, mir-494-3p, mir-145-5p, and insulin-like growth factor-I (IGF-I) levels in PRP and platelet-poor plasma (PPP) samples with the pregnancy outcomes in RIF patients. The miRNA expression level and IGF-I concentration were assessed using real-time PCR and chemiluminescence methods respectively. Mir-21-3p was upregulated in PRP samples of the pregnant group in comparison to the nonpregnant group. There was no difference in the expression of mir-21-3p in PPP samples of these groups. The concentration of IGF-I was higher in PRP and PPP samples of the nonpregnant in comparison to the pregnant group. Receiver-operating characteristic curve analysis showed that mir-21-3p can be a valuable biomarker for the prediction of pregnancy chance in RIF patients treated with PRP.

Unraveling the Signaling Secretome of Platelet-Rich Plasma: Towards a Better Understanding of Its Therapeutic Potential in Knee Osteoarthritis.

Platelets and their secretory products play an important role in determining the balance between tissue repair and tissue damage. To obtain novel insights into the molecular composition of platelet-rich plasma (PRP) and contextualize them in knee osteoarthritis (OA), two different plasma formulations, namely PRP and platelet-poor plasma (PPP), were prepared from six healthy donors following a biobank-automated protocol. Inter-donor differences were analyzed, and pools were created before performing multiplexing protein arrays. In addition, PRP and PPP were prepared from six patients following our in-house protocols. Supernatants from PRP and PPP were harvested one hour after calcium chloride activation. Multiplexing protein arrays were performed in parallel for all plasma formulations. Results were normalized to fold change in relation to PPP and examined using Ingenuity Pathway Analysis Software. Bioinformatic predictions showed that PRPs constitute a signaling system with interrelated networks of inflammatory and angiogenic proteins, including but not limited to interleukin-6 and -8 (IL-6, IL-8), insulin like growth factor 1 (IGF-1), transforming growth factor beta, (TGF-b), and vascular endothelial growth factor (VEGF) signaling, underlying biological actions. Predictions of canonical systems activated with PRP molecules include various inflammatory pathways, including high-mobility group box protein (HMGB1) and interleukin 17 (IL-17) signaling, neuroinflammation, and nuclear factor-kappa b (NF-κB) pathways. Eventually, according to these predictions and OA evolving knowledge, selected PRP formulations should be tailored to modulate different inflammatory phenotypes, i.e., meta-inflammation, inflame-aging or posttraumatic inflammatory osteoarthritis. However, further research to discriminate the peculiarities of autologous versus allogeneic formulations and their effects on the various OA inflammatory phenotypes is needed to foster PRPs.

Cytokine Profiling and Intra-Articular Injection of Autologous Platelet-Rich Plasma in Knee Osteoarthritis.

Osteoarthritis (OA) is a degenerative joint disease leading to joint pain and stiffness. Due to lack of effective treatments, physical and psychological disabilities caused by OA have a detrimental impact on the patient’s quality of life. Emerging evidence suggests that intra-articular injection of platelet-rich plasma (PRP) may provide favorable results since PRP comprises not only a high level of platelets but also a huge amount of cytokines, chemokines, and growth factors. However, the precise mechanism and standardization method remain uncertain. This study aimed to examine cytokine profiling in both PRP and platelet-poor plasma (PPP) of knee OA patients and to determine the effects of PRP on OA chondrocytes and knee OA patients. PRP contained a wide variety of cytokines, chemokines, growth factors, and autologous intra-articular PRP injection resulted in favorable outcomes in knee OA patients. Significant increases in levels of IL-1, IL-2, IL-7, IL-8, IL-9, IL-12, TNF-α, IL-17, PDGF-BB, bFGF, and MIP-1β were detected in PRP compared to PPP (p < 0.001). An in vitro study showed a marked increase in proliferation in OA chondrocytes cultured with PRP, compared to PPP and fetal bovine serum (p < 0.001). In a clinical study, knee OA patients treated with PRP showed improvement of physical function and pain, assessed by physical performance, Western Ontario and McMaster Universities Arthritis Index and visual analog scale. Our findings from both in vitro and clinical studies suggest that intra-articular PRP injection in knee OA patients may be a potential therapeutic strategy for alleviating knee pain and delaying the need for surgery.

Platelet-rich plasma exhibits anti-inflammatory effect and attenuates cardiomyocyte damage by reducing NF-κB and enhancing VEGF expression in isoproterenol induced cardiotoxicity model.

The present study investigated the cardioprotective effects of activated platelet-rich plasma (PRP) on high dose isoproterenol (ISO) induced cardiotoxicity. ISO was injected at a dose of 85 mg/kg/day, s.c. for 2 days. Cardiac function parameters including dp/dt max/min, left ventricular end diastolic pressure (LVEDP), relaxation constant (tau) and electrocardiogram (ECG) changes, anti-oxidant and membrane bound enzymes assays, pro-inflammatory cytokine levels, collagen content, immunohistochemical staining/gene expression of vascular endothelial growth factor (VEGF), cTnI (cardiac troponin I), NF-κB (nuclear factor kappa B), Smad-2/3, TGF-β (transforming growth factor), collagen-1/3 proteins were evaluated. PRP and platelet-poor plasma (PPP) were injected intramyocardially (200 μl in each ventricle region) 3 h after first dose of ISO under anesthesia. ISO injection induced cardiac dysfunction, hypertrophy, fibrosis, necrosis due to decline in anti-oxidant capacity, enhanced NF-κB and reduced cTnI immunostaining. However, the PRP injection attenuated these cardiac pathological changes by exerting anti-inflammatory properties and promoting cardiomyocyte repair.

Platelet-rich plasma for the treatment of diabetic foot ulcer: a randomized, double-blind study

Background Diabetic foot ulcer is a major complication of diabetes mellitus. Over the recent years, great progress has made in the techniques of wound healing, among which autologous platelet-rich plasma (PRP) has attracted the most substantial attention. Platelets are known to start the wound healing process through the release of locally active growth factors. The evidence from studies of autologous PRP to support its use in wound healing is not robust, and further rigorously designed blinded trials are needed. The aim of the study was to evaluate the efficacy and safety of the autologous PRP for diabetic foot ulcer in a randomized control multicenter double-blind design. Patients and methods The study included 50 patients with diabetic foot ulcers, who were divided into two groups: PRP and platelet-poor plasma (PPP) groups. The PRP group was treated with autologous PRP in gel form as a dressing. The PPP group was treated with autologous poor plasma as a dressing. The frequency of dressing change for each group was twice weekly. Results The healing rate of the PRP group was found to be significantly higher than that of the PPP group. The healing rate per week of the PRP group was significantly higher than that of the PPP group. The rate of complete healing was significantly higher in the PRP group than that of the PPP group. Conclusion Autologous PRP is effective and safe for treatment of diabetic foot ulcer.

Erythrocyte sedimentation rate and fibrinogen concentration of whole blood influences the cellular composition of platelet-rich plasma obtained from centrifugation methods

Erythrocyte sedimentation rate (ESR), which reflects the sedimentation rate of platelets, leukocytes and erythrocytes in response to centrifugal force, may influence the cellular composition of platelet-rich plasma (PRP) obtained via centrifugation methods. However, no relevant studies have substantiated this. In the present study, blood was collected from 40 healthy volunteers and used to prepare PRP with two plasma-based preparation systems [YinPRP and Plasma Rich in Growth Factor (PRGF) systems] and two buffy coat-based systems (RegenPRP and WEGOPRP systems) in a single-donor model. Volumes of PRP and platelet-poor plasma (PPP) that were removed in the preparation process were recorded. Analyses of ESR, haematocrit, C-reaction protein, coagulation, serum glucose and serum lipid of the whole blood used for PRP preparation were performed to evaluate the levels of ESR and the factors known to influence it. Whole blood analysis was performed to evaluate the cellular composition of PRP. Results demonstrated that there were marked positive correlations between the ESR of the whole blood used for PRP preparation and PPP removal efficiencies, platelet concentrations, platelet capture efficiencies and platelet enrichment factors of PRP formulations obtained from plasma-based systems, and PRP yield efficiency of RegenPRP and PPP removal efficiency of WEGOPRP. Furthermore, there were marked negative correlations between ESR and concentrations and enrichment factors of platelets, leukocytes and erythrocytes of RegenPRP. Fibrinogen concentration of the whole blood, which had a marked positive correlation with ESR, also influenced the cellular composition of PRP. These findings may increase the understanding of PRP preparation and provide substantial evidence for the individualised optimisation of PRP preparation systems used in clinical practice.

Antimicrobial Effects of Platelet-rich Plasma against Selected Oral and Periodontal Pathogens.

Antimicrobial properties of platelet rich plasma (PRP) against various microorganisms have been recently pointed out. PRP could be an alternative to conventional antibiotics in preventing oral and periodontal infections. We examined whether PRP has in vitro antimicrobial properties against Aggregatibacter actinomycetemcomitans, Prophyromonas gingivalis, Staphylococcus aureus and Candida albicans. PRP and platelet-poor plasma (PPP) were obtained from whole blood of 10 healthy volunteers and 10 periodontitis patients. In vitro laboratory susceptibility was carried out using the modified agar diffusion method by measuring the diameters of inhibition zones on agar plates coated with selected microbial strains. Both calcium chloride (CaCl2) activated and non activated samples were tested. Both activated PRP and PPP, of both patients and controls, effectively inhibited the growth of A. actinomycetemcomitans, P. gingivalis and C. albicans. However, a statistically significant difference in favor of PRP was found indicating more susceptibility to PRP than PPP (p &lt; 0.05). Non activated PRP and PPP exhibited negative zones of inhibition against the studied microorganisms. There was no activity against S. aureus. No statistically significant difference was found between the antimicrobial effects of PRP and/or PPP obtained from patients and controls (p &gt; 0.05). We conclude that PRP is a potentially useful substance against oral and periodontal pathogens. Activated PRP was found to be more active than activated PPP and the activation of coagulation is a fundamental step. Additionally, the antimicrobial activity of PRP and/or PPP seems not to be affected by periodontitis.

Effect of PRP and PPP on proliferation and migration of human chondrocytes and synoviocytes in vitro

Abstract Cartilage tissue engineering can provide substantial relief to people suffering from degenerative cartilage disease, such as osteoarthritis. The autologous platelet-rich plasma (PRP) application appears to improve cartilage healing due to its ability to positively influence cellular mechanisms, mainly in cells from synovium and cartilage. Primary cultures of human synovial fluid stem cells (synoviocytes, SCs) and chondrocytes (CCs) were exposed to various concentrations of non-activated PRP and plateletpoor plasma (PPP) prepared by apheresis. Cell proliferation and migration were evaluated in real-time with the non-invasive xCELLigence System. It was found that PRP had a similar effect on the growth of cells as fetal bovine serum (FBS). Surprisingly, our proliferation assay results indicated that 50% PPP had the largest effect on both cell types, with a statistically significant increase in cell number (P&lt;0.001) compared to the (0% FBS) in vitro control. The migratory ability of SCs was significantly enhanced with 10% PRP and 0.8% hyaluronic acid (HA). HA also augmented migration of CCs. In summary, these results demonstrate that directed cell proliferation and migration are inducible in human articular CCs and SCs, and that both platelet-derived fractions may exert a positive effect and modulate several cell responses that are potentially involved in tissue integration during cartilage repair.

Platelet-Rich Plasma Can Replace Fetal Bovine Serum in Human Meniscus Cell Cultures

Concerns over fetal bovine serum (FBS) limit the clinical application of cultured tissue-engineered constructs. Therefore, we investigated if platelet-rich plasma (PRP) can fully replace FBS for meniscus tissue engineering purposes. Human PRP and platelet-poor plasma (PPP) were isolated from three healthy adult donors. Human meniscal fibrochondrocytes (MFCs) were isolated from resected tissue after a partial meniscectomy on a young patient. Passage-4 MFCs were cultured in monolayer for 24 h, and 3 and 7 days. Six different culture media were used containing different amounts of either PRP or PPP and compared to a medium containing 10% FBS. dsDNA was quantified, and gene expression levels of collagen types I and II and aggrecan were measured at different time points with quantitative polymerase chain reaction in the cultured MFCs. After 7 days, the dsDNA quantity was significantly higher in MFCs cultured in 10% and 20% PRP compared to the other PRP and PPP conditions, but equal to 10% FBS. Collagen type I expression was lower in MFCs cultured with medium containing 5% PRP, 10% and 20% PPP compared to FBS. When medium with 10% PRP or 20% PRP was used, expressions were not significantly different from medium containing 10% FBS. Collagen type II expression was absent in all medium conditions. Aggrecan expression did not show differences between the different media used. However, after 7 days a higher aggrecan expression was measured in most culture conditions, except for 5% PRP, which was similar compared to FBS. Statistical significance was found between donors at various time points in DNA quantification and gene expression, but the same donors were not statistically different in all conditions. At 7 days cell cultured with 10% PRP and 20% PRP showed a higher density, with large areas of clusters, compared to other conditions. In an MFC culture medium, FBS can be replaced by 10% PRP or 20% PRP without altering proliferation and gene expression of human MFCs.

Antiplatelet Agents Can Promote Two-Peaked Thrombin Generation in Platelet Rich Plasma: Mechanism and Possible Applications

BackgroundThrombin generation assay is a convenient and widely used method for analysis of the blood coagulation system status. Thrombin generation curve (TGC) is usually bell-shaped with a single peak, but there are exceptions. In particular, TGC in platelet-rich plasma (PRP) can sometimes have two peaks.ObjectiveWe sought to understand the mechanism underlying the occurrence of two peaks in the PRP thrombin generation curve.MethodsTissue factor-induced thrombin generation in PRP and platelet-poor plasma (PPP) was monitored using continuous measurement of the hydrolysis rate of the thrombin-specific fluorogenic substrate Z-Gly-Gly-Arg-AMC. Expression of phosphatidylserine (PS) and CD62P on the surface of activated platelets was measured by flow cytometry using corresponding fluorescently labeled markers.ResultsThe addition of the P2Y12 receptor antagonist MeS-AMP (160 µM), 83 nM prostaglandin E1 (PGE1), or 1.6% DMSO to PRP caused the appearance of two peaks in the TGC. The PS exposure after thrombin activation on washed platelets in a suspension supplemented with DMSO, PGE1 or MeS-AMP was delayed, which could indicate mechanism of the second peak formation. Supplementation of PRP with 1.6% DMSO plus 830 nM PGE1 mediated the disappearance of the second peak and decreased the amplitude of the first peak. Increasing the platelet concentration in the PRP promoted the consolidation of the two peaks into one.ConclusionsProcoagulant tenase and prothrombinase complexes in PRP assemble on phospholipid surfaces containing PS of two types - plasma lipoproteins and the surface of activated platelets. Thrombin generation in the PRP can be two-peaked. The second peak appears in the presence of platelet antagonists as a result of delayed PS expression on platelets, which leads to delayed assembly of the membrane-dependent procoagulant complexes and a second wave of thrombin generation.

Effect of autologous and allogenic platelet‐rich plasma on human gingival fibroblast function

Platelet-rich plasma (PRP) has been proposed as a method of delivering growth factors to enhance regeneration. The aim of this study was to investigate the use of autogenous and allogenic PRP and platelet-poor plasma (PPP) on migration and proliferation of human gingival fibroblasts in vitro. Various concentrations of PRP, as well as PPP, were prepared from autologous and allogenic sources and applied to primary gingival fibroblasts. Migration was determined by assessing the fibroblast response to a concentration gradient. (3)H-thymidine incorporation and crystal violet colorimetric assays were utilized to assess DNA synthesis and proliferation. Platelet-rich plasma provides a significant migratory stimulus to gingival fibroblasts. Furthermore, the various concentrations of PRP (50%, 20% and 10%) do not promote DNA synthesis in the short term (24 h), but over the longer term (5 days) they stimulate an increase in cell proliferation. Compared with PPP, PRP was superior in terms of encouraging migration, but was inferior in terms of promoting DNA synthesis and cell proliferation. No difference was noted between the autologous and allogenic PRP preparations on cell function. Both PPP and PRP promote gingival fibroblast migration and proliferation in vitro, without differences between preparations obtained from autologous and allogenic sources.

Adult and umbilical cord blood-derived platelet-rich plasma for mesenchymal stem cell proliferation, chemotaxis, and cryo-preservation

Platelet-rich plasma (PRP) was prepared from human adult peripheral blood and from human umbilical cord (uc) blood and the properties were compared in a series of in vitro bioassays. Quantification of growth factors in PRP and platelet-poor plasma (PPP) fractions revealed increased levels of mitogenic growth factors PDGF-AB, PDGF-BB, and FGF-2, the angiogenic agent VEGF and the chemokine RANTES in ucPRP compared to adult PRP (aPRP) and PPP. To compare the ability of the various PRP products to stimulate proliferation of human bone marrow (BM), rat BM and compact bone (CB)-derived mesenchymal stem cells (MSC), cells were cultured in serum-free media for 4 and 7 days with varying concentrations of PRP, PPP, or combinations of recombinant mitogens. It was found that while all forms of PRP and PPP were more mitogenic than fetal bovine serum, ucPRP resulted in significantly higher proliferation by 7 days than adult PRP and PPP. We observed that addition of as little as 0.1% ucPRP caused greater proliferation of MSC effects than the most potent combination of recombinant growth factors tested, namely PDGF-AB + PDGF-BB + FGF-2, each at 10 ng/mL. Similarly, in chemotaxis assays, ucPRP showed greater potency than adult PRP, PPP from either source, or indeed than combinations of either recombinant growth factors (PDGF, FGF, and TGF-β1) or chemokines previously shown to stimulate chemotactic migration of MSC. Lastly, we successfully demonstrated that PRP and PPP represented a viable alternative to FBS containing media for the cryo-preservation of MSC from human and rat BM.

Effects of platelet‐rich and ‐poor plasma on the reparative response of gingival fibroblasts

Although platelet-rich plasma (PRP) has been proposed as a therapeutic tool to enhance wound repair, the cellular and molecular mechanisms stimulated by this agent are still not completely understood. The present study was designed to characterize the effects of PRP and platelet-poor plasma (PPP) supernatants on cell responses involved in gingival tissue repair. We studied the response of human gingival fibroblasts (HGF) to PRP and PPP fractions on: matrix contraction, cell migration, myofibroblastic differentiation, production of matrix components and proteolytic enzymes. PRP and PPP were obtained from donors using a commercial kit. Matrix contraction was evaluated by means of collagen lattices in the presence of matrix metalloproteinase (MMP) and actin polymerization inhibitors. The production of matrix molecules and proteinases was assessed through Western-blot. RhoA activity was evaluated through a pull-down assay. Actin distribution and focal adhesions were assessed through immunofluorescence. Transforming growth factor-beta (TGF-β) was quantified through ELISA. Both PRP and PPP stimulated human gingival fibroblasts-populated collagen gel contraction and Ilomastat and cytochalasin D inhibited this response. PRP and PPP also stimulated MT1-MMP and TIMP-2 production, RhoA activation and actin cytoskeleton remodeling, cell migration/invasion and myofibroblastic differentiation. TGF-β1 was found at significantly higher concentrations in PRP than in PPP. Both PRP and PPP promote wound tissue remodeling and contraction through the stimulation of actin remodeling, the activity of MMPs, promotion of cell migration, and myofibroblastic differentiation. The similar biological responses induced by PRP and PPP suggest that both platelet-derived fractions may exert a positive effect on gingival repair.

Effect of Platelet-Rich Plasma and Fibrin Glue on Healing of Critical-Size Calvarial Bone Defects

Despite the insufficient number of experimental studies, platelet-rich plasma (PRP) including high amounts of growth factors is introduced to clinical use rapidly. The aim of this study was to compare the effects of PRP and platelet-poor plasma (PPP) on healing of critical-size bone defects.Bilateral full-thickness, critical-size bone defects were created in the parietal bones of 32 rabbits, which had been studied in 4 groups. Saline, thrombin solution, PPP, and PRP were applied to the created defects before closure. Radiologic defect area measurement results at 0, 4, and 16 weeks were compared between the groups. In addition, densities of the newly formed bones at 16th week were studied. Histologic parameters (primary and secondary bone trabecula, neovascularization, and bone marrow and connective tissue formation) were compared between 4- and 16-week groups.More rapid decrease in defect size was observed in groups 3 and 4 than in groups 1 and 2, both in the 4th and 16th weeks. Newly formed bone densities were also found to be higher in these 2 groups. New bone formation was detected to be more rapid considering histologic parameters, in groups 3 and 4 at 4th and 16th weeks.Study demonstrates that PRP and PPP might have favorable effects on bone healing. Although we cannot reveal any statistical difference between these 2 substances considering osteoinductive potential, PRP group has demonstrated superior results compared with fibrin glue group. Higher platelet concentrations may expose beneficial effects of PRP.

Quantitative and Qualitative Analysis of Platelet-Rich Plasma Collection Using the Haemonetics Cell Saver 5 in Open Heart Surgery

Many traditional autologous blood recovery systems (ABRSs) have undergone modifications to enable them to collect platelet-rich plasma (PRP). Because of the growing demand for autologous platelet gel (APG) in cardiac surgery, many open heart teams are faced with the choice of using their existing ABRS or purchasing a dedicated PRP device. This study was conducted to address the issues we had about our use of the Haemonetics Cell Saver 5 (CS5) to collect PRP during open heart surgery at our institution. PRP and platelet-poor plasma (PPP) were collected on 20 “first-time” elective open heart surgical patients. Baseline, PRP, and PPP platelet counts, as well as modified thrombelastograms (TEGs), were performed on all study patients. The mean baseline, PRP, and PPP platelet counts were 232,450, 1,348,850, and 18,100/mm3, respectively. We found a strong positive correlation (r= +0.7142) between the maximum amplitude (MA) of our modified PRP TEG and the platelet count of the PRP. Using the CS5, we achieved a mean platelet multiple of greater than six times baseline, which compares favorably with the multiple produced using dedicated PRP devices. These data support the conclusion that we achieved a high platelet multiple with the CS5, and our use of a modified TEG showed that platelet function of the collected PRP was preserved.

Platelet‐rich plasma/osteoblasts complex induces bone formation via osteoblastic differentiation following subcutaneous transplantation

Platelet-rich plasma (PRP) has been shown to enhance the maturation of bone grafts following local application and to have biological effects on osteoblasts in vitro. However, PRP is not applied by itself clinically as a result of its poor benefits in large bone defects. The present study was undertaken to develop a clinical alternative to autologous bone, by investigating the application of PRP in combination with osteoblastic cells and evaluating its effects after transplantation. PRP and platelet-poor plasma (PPP) were prepared from blood, obtained from ddY mice, by two centrifugation steps. MC3T3-E1 cells were labeled with fluorescent carbocyanine just before transplantation. The combination of labeled cells and PRP gel was subcutaneously transplanted into the back of severe combined immunodeficient (SCID) mice, and the transplants were evaluated radiographically and immunohistologically after 4 wk. The effects of PRP were assessed by alkaline phosphatase (ALP) staining and von Kossa staining, and the expression of bone-related markers was analyzed by reverse transcription-polymerase chain reaction before transplantation. Before transplantation, PRP enhanced the expression of Osterix and bone sialoprotein mRNAs compared with PPP. Furthermore, PRP elevated ALP activity and induced the formation of mineralized nodules. After transplantation, the combination of labeled cells and PRP gel formed mineralized tissue, and the transplanted cells visualized in the tissue using fluorescence microscopy expressed osteocalcin and type I collagen. These results suggest that the application of a PRP/osteoblasts complex has beneficial effects for transplanting engineered cells into bone defects through the promotion of osteoblastic differentiation.