Concentrations Of Platelet-rich Plasma Research Articles

Evaluation of an automated light transmission aggregometry

Light transmission aggregometry (LTA) is the “gold standard” for platelet function assessment, but it is time-consuming and labor intensive. Recently, an automated platelet aggregation method has been developed on a routine coagulation analyzer (Sysmex CS-2100i). In this study, the performances of CS-2100i including repeatability, correlation with a reference aggregometer (Chrono-log Model 700), and the threshold limitation of platelet counts in platelet-rich plasma (PRP) were evaluated for clinical use. The agonists were adenosine diphosphate (ADP), arachidonic acid, collagen, epinephrine, and ristocetin. The platelet concentration of PRP was adjusted with platelet-poor plasma (PPP) and physiological saline (PS). The CS-2100i showed an excellent repeatability and a strong correlation with the Chrono-log 700 in performing platelet aggregation, and its threshold limitation of platelet counts in PRP was 80 × 109/L. PPP had an inhibitory impact on platelet aggregation induced by ADP, arachidonic acid, collagen or epinephrine; while PS had an inhibitory impact on ristocetin-induced aggregation. PS should be used to adjust PRP for ADP-, arachidonic acid-, collagen-, or epinephrine-induced aggregation; while PPP was recommended for ristocetin-induced aggregation. The CS-2100i showed an excellent repeatability, a strong correlation with Chrono-log 700, a lower platelet count requirement, a shorter turnaround time for samples, the advantage of being a walk-away technology, and the ability to perform a highly standardized platelet function assessment.

The Bone Regeneration Using Bone Marrow Stromal Cells with Moderate Concentration Platelet-Rich Plasma in Femoral Segmental Defect of Rats.

Background:Platelet-rich plasma (PRP) can provide an assortment of growth factors, but how PRP effects bone regeneration is still unknown. The aim of the study was to explore an optimal method of using PRP and bone marrow stromal cells (BMSCs).Methods:An in vitro experiment was first conducted to determine an appropriate quantity of PRP. BMSCs were cultured with PRP of different concentrations to assess cell proliferation and osteogenic differentiation. Following the in vitro study, a rat femoral segmental defect model was used. Five collagen mixtures consisting of different concentrations of PRP and BMSCs were prepared as follows, i) BMSCs and PRP (platelet 20 x 104/µl), ii) BMSCs and PRP (platelet 100 x 104/µl), iii) BMSCs and PRP (platelet 500 x 104/µl), iv) BMSCs, and v) PRP group (platelet 100 x 104/µl), were used to fill defect. New bone formation was evaluated by soft X-ray and histologic analyses were performed at 2, 4, 6 and 8 weeks postoperatively.Results:The cell proliferation increased PRP concentration-dependently. Cellular alkaline phosphatase activity was higher in moderate concentration than high or low concentration group’s in vitro study. In vivo study, the bone fill percentage of newly formed bone in BMSCs and PRP (platelet 100 x 104/µl) was 46.9% at 8 weeks and increased significantly compared with other groups.Conclusion:BMSCs with moderate level of PRP significantly enhanced bone formation in comparison with BMSCs or PRP transplant in a rat femoral defect model.

Does leukocyte-poor or leukocyte-rich platelet-rich plasma applied with biopolymers have superiority to conventional platelet-rich plasma applications on chondrocyte proliferation?

This study aims to investigate the possible effects of leukocyte concentration in the content of platelet-rich plasma (PRP) and the administration of PRP using a drug delivery system on chondrocyte proliferation in vitro conditions. Blood from nine male patients (mean age 65 years; range 49 to 81 years) with advanced stage osteoarthritis who had not responded to medical or conservative treatments and underwent total knee arthroplasty was used to prepare two formulations: PRP with low concentration leukocytes (2000-4000 leukocytes/µL) was designated as pure PRP (P-PRP), whereas PRP with high concentration leukocytes (9000-11000 leukocytes/µL) as leukocyte-rich PRP (L-PRP). Samples were divided into five groups as control group (group 1), chondrocyte cultures with P-PRP applied directly (group 2), chondrocyte cultures with L-PRP applied directly (group 3), chondrocytes co-cultured with P-PRP applied hydrogel (group 4), and chondrocytes co-cultured with L-PRP applied hydrogel (group 5). In all groups; cell morphology, viability and proliferation were compared with the expression of stage-specific embryonic antigen-1 (SSEA-1), a precondrocyte marker. Maximum cell proliferation and SSEA-1 expression occurred in group 4, with a statistically significant correlation between SSEA-1 expression and cell proliferation. Our study showed the importance of leukocyte concentration of PRP and efficiency of delivery systems such as hydrogel and that L-PRP administered with a delivery system is more efficient than conventional applications of PRP in the treatment of cartilage damage.

Effects of local platelet-rich plasma injection on the rate of orthodontic tooth movement in a rat model: A histomorphometric study

The aims of this study were to determine the effects of different concentrations of platelet-rich plasma (PRP) on alveolar bone density and orthodontic tooth movement. Seventy-six rats were divided into 2 groups: a moderate concentration PRP injection group (n=38) and a high concentration PRP injection group (n=38). In each group, 5 time points were studied: 3, 7, 14, 21, and 60days. Before orthodontic mesialization of the maxillary first molars, moderate and high concentrations of PRP were injected on the right sides of the molar buccal sulcus, and the left sides served as the controls. Tooth movements were measured on 3-dimensional digital models. Alveolar bone volume density and osteoclastic activity in the first molar intraradicular areas were evaluated by histomorphometric analysis. Alveolar bone density was decreased in the experimental groups compared with the control groups (P=0.0001) at 3, 7, 14, and 21days. On day 3, osteoclastic activity of the experimental groups was higher than that of the controls (P=0.044, P=0.0001). On day 21, the amounts of tooth movement in the high-concentration experimental group were 1.7 times greater than in the high-concentration control group and 1.4 times greater than in the moderate-concentration experimental group (P=0.001). On day 60, alveolar bone density increased to the original levels in all groups. Injection of both moderate and high concentrations of PRP may accelerate orthodontic tooth movement by decreasing alveolar bone density on paradental tissues by enhancing osteoclastic activity in a transient way.

Comparison of Ufh and Enoxaparin Originated from Bovine, Ovine and Porcine Mucosa with Functional Coagulation Assays

Background Heparin is a widely used clinical anticoagulant. It is a linearglycosaminoglycan with an average mass between 10 and 20kDa and is primarily composed oftrisulfated disaccharides comprised of 1,4-linkediduronic acid and glucosamine residues containing someglucuronic acid residues.Heparin is biosynthesized in the Golgi of mast cells commonly found in the liver, intestines, and lungs. Pharmaceuticalheparin currently used in the United States is primarily extracted from porcine intestines. Other sources ofheparin including bovine or ovine intestine are being examined as potential substitutes for porcine intestinalheparin. These additional sources are intended to serve to diversify theheparin supply, making this lifesaving drug more available.Aim. The present in vitro study examines bovine, ovine and porcineunfractionated heparin (UFH) and respective low molecular weight heparinenoxaparin and compares these to thecommercialy available heparins.Methods. Independent samples of platelet poor (PPP) and platelet rich plasma (PRP) from 5 healthy volunteers were spiked with increasing concentrations (from 1 to 10 μg/ml) UFH or enoxaparin of bovine, ovine or porcine origin. Commercially available UFH (Calciparin¨) and enoxaparin (Lovenox¨/Clexan¨) were used as comparators. The studied agents were added in plasma at gravimetrically equal concentrations. The specific anti-Xa activity was measured in PPP (using the STA-Liquid anti-Xa assay) and thrombin generation was assessed in PPP and PRP with the Calibrated Automated Thrombogram (CAT¨) from Diagnostica Stago (France). Thrombin generation was triggered with PPP-reagent¨ or PRP-reagent¨ or by the presence of pancreatic cancer cells BXPC3 or breast cancer cells MCF7 as described elsewhere (Rousseau et al Thromb Res. 2015;136:1273-9). The activated partial thromboplastin clotting time (aPTT) was measured with the conventional assays on STA-R¨ instrument.Results. The anti-Xa activity per microgram of the studied preparations of UFH andenoxaparin as well as theconcentrations which induced a 2-fold prolongation of theaPTT are shown in Table 1. The studied compounds had different anti-Xa activity when compared at gravimetrically equivalent basis. When compared at anti-Xa equivalent basis the studied compounds had the similar potency to double theaPTT. The UFH from bovine, ovine or porcine origin as well asCalciparine¨ at the concentration of 0.6 anti-Xa IU/ml as well asenoxaparin of bovine, ovine or porcine origin andLovenox¨/Clexan¨ completely abrogated thrombin generation induced by physiologically relevant tissue factor andprocoagulantphospholipid concentration in PPP or PRP. At the same concentration (0.6 anti-Xa IU/ml) the studied preparation of UFH andenoxaparin inhibited thrombin generation triggered by pancreatic cancer cells or breast cancer cells.Conclusions. UFH orenoxaparin from different species demonstrate similar functional properties on the inhibition of blood coagulation independent of theprocoagulant trigger, when compared on the basis of equivalent anti-Xa activity. The establishment of functional criteria for the evaluation heparins originated from different species is warranted to demonstrate theirbiosimilarity. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

COMPARISON OF LABORATORY DATA AMONG THE SIX DIFFERENT PRP SEPARATION SYSTEMS USING 144 SAMPLES

Many systems for preparation of platelet-rich plasma (PRP) are commercially available, but comparative study among these systems is rare and only small sample size studies have been conducted. The purpose...

Kartogenin Enhances Tendon Graft And Bone Tunnel Healing In A Rat Model

Category: Basic Sciences/Biologics Introduction/Purpose: The normal tendon-bone junction (TBJ) is a strong structure protected by the fibrocartilage transition zone. This allows a gradual transition of mechanical forces between tendon and bone, thus decreasing stress-concentration effects. Healing of the TBJ interface after an injury is slow and even after healing the junction often lacks the transition zone. A study on human patients showed that even years after ACL reconstruction, patients had no fibrocartilage zone regeneration. This and other studies show that surgical repair alone does not restore the unique protective fibrocartilage transition zone. We have shown that KGN injection into injured rat Achilles tendon-bone junctions enhanced wound healing with restored fibrocartilage transition zone. Here, we examined the effects of KGN treatment, along with platelet-rich plasma (PRP), on tendon-bone tunnel healing in rats. Methods: KGN stock was prepared in DMSO and diluted to 100 μM with PRP. PRP was obtained from the blood of Sprague– Dawley rats and the platelet concentration in PRP was adjusted to 3 times over the baseline platelet concentration in whole blood. Thrombin (1 kU/mL), served as the PRP activator. 27 female rats (234˜268g) were used. A 1.5 mm tunnel was drilled at the distal end of tibia. Achilles tendon was resected and sutured in the tunnel. Rats were randomly divided into 1 of 3 treatment groups: Group A: 50µl KGN + PRP; Group B: 50µl PRP solution; Group C: control. Rats were sacrificed at 4, 8, and 12 weeks for histological analysis. Whole tibia with the tendon insertion were harvested, fixed in 10% formalin and decalcified in 10% EDTA. Tissue were sectioned and stained with Safranin O + Fast green, and immunostained for collagen types 1 and 2. Results: All animals were in good condition after surgery and complications were not present. Safranin O staining was higher in the KGN+PRP group than the other groups indicating more cartilage-like tissues regeneration in this group. Formation of the cartilage-like transitional zone was time dependent; i.e., it increased with increase in time (Fig. 1A-C). In contrast, both PRP and control groups had no cartilage-like tissues (Fig. 1D-I); in fact, some gaps in the control group were found in the tendon-bone interface after 4 and 8 weeks (Fig. 1G-I). Finally, the cartilage-like tissues in the KGN+PRP group also stained positive for both Col-1 and Col-2 indicating that these were fibrocartilage tissues (Fig. 2). Conclusion: Here we demonstrated that KGN promotes the formation of fibrocartilage-like interface between the tendon graft and bone tunnel. This result suggests that the delivery of KGN into the tendon-bone interface could be a promising, cell-free approach to augment the tendon-bone interface healing. PRP in this study, while not effective in promoting fibrocartilage formation of the interface in its own right, it functions as an effective carrier that supplies scaffolds and growth factors necessary for the enhancement of wound healing. Future research is required to determine the optimal KGN dosage regimens and the optimal delivery method (e.g. injection vs implantation).

Platelet-rich plasma stimulates human dermal fibroblast proliferation via a Ras-dependent extracellular signal-regulated kinase 1/2 pathway

Platelet-rich plasma (PRP) contains a high concentration of several growth factors and contributes to soft-tissue engineering and wound healing. However, the effect of PRP on human dermal fibroblast proliferation and responses is unknown. This was investigated in the present study using PRP prepared from the whole human blood using the double-spin method. Human dermal fibroblast cultures were established from skin samples collected during plastic surgery. Platelet concentration and growth factor levels in PRP were estimated, and a cell proliferation assay was carried out after PRP treatment. The role of Ras-dependent extracellular signal-regulated kinase (ERK)1/2 in the effects of PRP was investigated in human dermal fibroblasts by suppressing ERK1/2 expression with an inhibitor or by short interfering (si)RNA-mediated knockdown, and assessing ERK1/2 phosphorylation by western blotting as well as proliferation in PRP-treated cells. We found that PRP stimulated human dermal fibroblast proliferation, which was suppressed by ERK1/2 inhibitor treatment (P<0.01). ERK1/2 phosphorylation was increased in the presence of PRP, while siRNA-mediated knockdown of ERK1/2 blocked cell proliferation normally induced by PRP treatment (P<0.01). These results demonstrate that PRP induces human dermal fibroblast proliferation via activation of ERK1/2 signaling. Our findings provide a basis for the development of agents that can promote wound healing and can be applied to soft-tissue engineering.

Combination of Controlled Release Platelet-Rich Plasma Alginate Beads and Bone Morphogenetic Protein-2 Genetically Modified Mesenchymal Stem Cells for Bone Regeneration.

Platelet-rich plasma (PRP) consists of platelet-derived growth factor and transforming growth factor-β that increase proliferation of mesenchymal stem cells (MSCs), whereas bone morphogenetic protein-2 (BMP2) promotes osteogenic differentiation of MSCs. However, the high degradation rate of fibrin leads to the dissociation of cytokines even before the process of bone regeneration begins. To the best of the authors' knowledge, this is the first study to examine the combined effect of sustained release of PRP from alginate beads on BMP2-modified MSC osteogenic differentiation in vitro and sustained release of PRP alone on a fracture defect model ex vivo as well as its effect on calvarial suture closure. After optimizing the alginate concentration for microspheres, the combined osteogenic and mineralization effect of PRP and BMP2 on MSCs was studied. Self-setting alginate hydrogel carrying PRP was tested on a femur defect model ex vivo. The effect of PRP at day 15 on the closure of the embryonic mouse calvaria sutures ex vivo was also studied. Increase of PRP concentration promoted proliferation of MSCs, and 2.5% to 10% of PRP gradually increased alkaline phosphatase (ALP) activity in the cells in a dose-dependent manner. Sustained release of PRP and BMP2 demonstrated significantly higher ALP and mineralization activity (P <0.05). Radiographs of alginate hydrogel with PRP-treated bone demonstrated nearly complete healing of the fracture, and histologic sections of the embryonic calvaria revealed that PRP leads to suture fusion. Sustained release of PRP along with BMP2-modified MSCs can significantly promote bone regeneration.

Efficacy of autologous leukocyte-reduced platelet-rich plasma therapy for patellar tendinopathy in a rat treadmill model.

An autologous platelet-rich plasma (PRP) therapy has currently been applied for the tendinopathy; however, its efficacy and an optimal platelets concentration in PRP were uncertain. We analyzed them in an animal model prepared using a repetitive running exercise. We made the tendinopathy rat model of patellar tendon using a rodent treadmill machine. Rats with tendinopathy were injected with leukocyte-reduced PRP at the platelets concentration of 1.0×106/μL (P10 group), PRP at the platelets concentration of 5.0×105/μL (P5 group) or normal saline (control group) into the space between the patellar tendon and the fat pad bilaterally or were multiply dry-needled at the tibial insertion site (MN group) at once. To assess the pain-reliving effect, the spontaneous locomotor activities at night (12 h) were measured every day. Histological sections of the patellar tendon stained with hematoxylineosin or prepared by TdT-mediated dUTP nick end labeling were microscopically analyzed. The numbers of spontaneous locomotor activities in the P10 group were significantly larger than those in the P5, MN or control groups and they recovered up to a healthy level. On histologic examinations, the numbers of microtears, laminations, or apoptotic cells in the patellar tendons in the P10 or P5 groups were significantly lower than those in the MN or control groups, although no significant differences were observed between the P10 and P5 groups. The injections of an autologous leukocyte-reduced PRP were effective for pain relief and for partial restoration of the patellar tendon in the tendinopathy rat model. The injections of a PRP at the platelets concentration of 1.0×106/μL completely relieved the pain and were more effective than those at the platelets concentration of 5.0×105/μL whereas there was no difference for the effect of histological restoration or apoptosis inhibition between them.

The influence of environmental variables on platelet concentration in horse platelet-rich plasma.

Platelet-rich plasma (PRP) commonly refers to blood products which contain a higher platelet (PLT) concentration as compared to normal plasma. Autologous PRP has been shown to be safe and effective in promoting the natural processes of soft tissue healing or reconstruction in humans and horses. Variability in PLT concentration has been observed in practice between PRP preparations from different patients or from the same individual under different conditions. A change in PLT concentration could modify PRP efficacy in routine applications. The aim of this study was to test the influence of environmental, individual and agonistic variables on the PLT concentration of PRP in horses. Six healthy Standardbred mares were exposed to six different variables with a one-week washout period between variables, and PRP was subsequently obtained from each horse. The variables were time of withdrawal during the day (morning/evening), hydration status (overhydration/dehydration) treatment with anti-inflammatory drugs and training periods on a treadmill. The platelet concentration was significantly higher in horses treated with a non-steroidal anti-inflammatory drug (P = 0.03). The leukocyte concentration increased 2–9 fold with respect to whole blood in the PRP which was obtained after exposure to all the variable considered. Environmental variation in platelet concentration should be taken into consideration during PRP preparation.

Platelet - derived CD154 antigen in patients with chronic kidney disease

IntroductionCD154 is a surface glycoprotein present on activated platelets, lymphocytes and mast cells. It mediates the transmission of information between cells and initiates an inflammatory response. The interaction of CD154 with its receptor CD40 leads to increase in concentrations of soluble forms of both molecules (sCD154, sCD40), which has an important prognostic value in cardiovascular complications. The metabolic disorders in chronic kidney disease (CKD), chronic inflammation, increased oxidative stress and type of renal replacement therapy may influence on the balance of sCD154/sCD40 in plasma and blood platelets. The purpose of the reasearch was to analyse the concentrations of sCD154 antigen and sCD40 receptor in platelet pure plasma (PPP) and platelet rich plasma (PRP) of patients with CKD treated conservatively, haemodialysed and on petitoneal dialysis. MethodsThe group examined comprised 141 patients with chronic kidney disease: in pre-dialysis stage (n = 68), haemodialysed (n = 38) and on peritoneal dialysis (n = 35). The concentrations of sCD154 and sCD40 in PRP and PPP were determined with an ELISA method. The biochemical parameters were obtained using colorimetric method. ResultsThe concentrations of sCD154 and sCD40 in PPP and PRP in examined group were significantly different depending on the method of renal replacement therapy. The haemodialysis procedure caused a significant increase in sCD40 concentration in PRP. The concentrations of sCD40 and sCD154 were correlated with lipid parameters. ConclusionsThe type of renal replacement therapy influences on platelet activation which may be a factor contributing to increased cardiovascular complications in patients suffering from CKD.

Platelet-Rich Plasma Increases Growth and Motility of Adipose Tissue-Derived Mesenchymal Stem Cells and Controls Adipocyte Secretory Function.

ABSTRACTAdipose tissue‐derived mesenchymal stem cells (Ad‐MSC) and platelet derivatives have been used alone or in combination to achieve regeneration of injured tissues. We have tested the effect of platelet‐rich plasma (PRP) on Ad‐MSC and adipocyte function. PRP increased Ad‐MSC viability, proliferation rate and G1‐S cell cycle progression, by at least 7‐, 2‐, and 2.2‐fold, respectively, and reduced caspase 3 cleavage. Higher PRP concentrations or PRPs derived from individuals with higher platelet counts were more effective in increasing Ad‐MSC growth. PRP also accelerated cell migration by at least 1.5‐fold. However, PRP did not significantly affect mature adipocyte viability, differentiation and expression levels of PPAR‐γ and AP‐2 mRNAs, while it increased leptin production by 3.5‐fold. Interestingly, PRP treatment of mature adipocytes also enhanced the release of Interleukin (IL)‐6, IL‐8, IL‐10, Interferon‐γ, and Vascular Endothelial Growth Factor. Thus, data are consistent with a stimulatory effect of platelet derivatives on Ad‐MSC growth and motility. Moreover, PRP did not reduce mature adipocyte survival and increased the release of pro‐angiogenic factors, which may facilitate tissue regeneration processes. © 2015 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc. J. Cell. Biochem. 116: 2408–2418, 2015. © 2015 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc.

Differentiation Effects of Platelet-Rich Plasma Concentrations on Synovial Fluid Mesenchymal Stem Cells from Pigs Cultivated in Alginate Complex Hydrogel.

This article studied the effects of platelet-rich plasma (PRP) on the potential of synovial fluid mesenchymal stem cells (SF-MSCs) to differentiate. The PRP and SF-MSCs were obtained from the blood and knees of pigs, respectively. The identification of SF-MSCs and their ability to differentiate were studied by histological and surface epitopes, respectively. The SF-MSCs can undergo trilineage mesenchymal differentiation under osteogenic, chondrogenic, and adipocyte induction. The effects of various PRP concentrations (0%, 20% and 50% PRP) on differentiation were evaluated using the SF-MSCs-alginate system, such as gene expression and DNA proliferation. A 50% PRP concentration yielded better differentiation than the 20% PRP concentration. PRP favored the chondrogenesis of SF-MSCs over their osteogenesis in a manner that depended on the ratios of type II collagen/type I collagen and aggrecan/osteopontin. Eventually, PRP promoted the proliferation of SF-MSCs and induced chondrogenic differentiation of SF-MSCs in vitro. Both PRP and SF-MSCs could be feasibly used in regenerative medicine and orthopedic surgeries.

Do Platelets Inhibit the Effect of Aspirin on Cancer Cells?

Both platelets and cancer cells display an intimate reciprocal crosstalk resulting in alteration of each other's properties. Although many past studies have tried to demonstrate effect of platelets on tumour cells, exact role of platelets in carcinogenesis is still not clear. In the above study, we explored the effect of different concentrations of platelet rich plasma (PRP) on viability, proliferation and adhesion of HeLa cells in culture conditions. The above parameters were found to be slightly increased on incubation with lower two concentrations of PRP (4.4 × 10(5) & 1 × 10(6) platelets/μl) while a reverse effect was seen at high PRP concentration (2 × 10(6) lac platelets/μl) especially at 24h. To further validate that the above effects were due to platelets we repeated the experiments in the presence of antiplatelet drug aspirin (20mM). On treatment with aspirin alone, the cell viability, proliferation and adhesion were seen to be decreased indicating cytotoxicity of aspirin towards HeLa cells. However, all of the above parameters were found to increase on addition of all PRP concentrations at 24h. Overall, variations in the number of platelets produced different effects on the cancer cells. Use of aspirin reduced the viability of the cancer cells, but this effect was seen to be partially reversed by all the concentrations of PRP used.

The effects of platelet-rich plasma on the proliferation and release of growth factors from periodontal ligament cells

Periodontal ligament cells (PDLCs) play an important role in the regeneration of periodontium. The healing potential of PDLCs may be due to the high concentration of growth factors in platelet-rich plasma (PRP). In this study, the effects of PRP on the proliferation and activation of PDLCs and growth factor release from PDLCs were investigated. PDLCs were isolated from third molars or premolars of healthy patients. Whole blood was obtained from healthy volunteers for the preparation of activated PRP. The platelet concentration in PRP was measured and the amount of platelet-derived growth factor (PDGF)-AB, PDGF-BB, transforming growth factor-β1 (TGF-β1), and vascular endothelial growth factor (VEGF) were determined by enzyme-linked immunosorbent assay. The effects of activated PRP on PDLC proliferation, attachment, alkaline phosphatase (ALP) activity, and growth factor release were investigated. Platelet concentration was increased 5.41-fold in PRP compared to whole blood. PDGF-AB, PDGF-BB, TGF-β1, and VEGF were detected in PRP at concentrations of 273.38 ng/mL, 47.0 ng/mL, 168.42 ng/mL, and 510.56 pg/mL, respectively. PDLCs cultured with ≥10% PRP showed significantly increased cell proliferation and ALP activity compared to the control (p<0.05). PDLCs cultured with 10% PRP also presented higher cell attachment and increased release of TGF-β1 and VEGF compared to the control (p<0.05). PRP can deliver high concentrations of growth factors to a defect site to increase the proliferation, attachment, and ALP activity of PDLCs. These results suggest that PRP might effectively contribute to periodontal regeneration.

Platelet rich plasma enhances tissue incorporation of biologic mesh

BackgroundHigh recurrence rates because of poor tissue incorporation limit the use of acellular dermal matrices (ADMs) in ventral hernia repair (VHR). Platelet rich plasma (PRP) is a growth factor–rich autologous blood product known to enhance tissue repair through cellular proliferation and neovascularization. We sought to study the effect of PRP on a porcine noncross-linked ADM in an in vivo model of VHR. We hypothesized that PRP would enhance ADM-tissue incorporation in a rat model of VHR. MethodsWhole blood was extracted from Lewis rats followed by PRP isolation and characterization. Using a rat model of VHR, a noncross-linked ADM (Strattice) was implanted and activated PRP applied before closure. Rats were sacrificed at 2, 4, and 6 wk. Immunohistochemical staining of CD 31 on endothelial cells was used to quantify neovascularization. Hematoxylin eosin stained tissues were measured to quantify tissue deposition. ResultsPlatelet concentration of PRP was standardized to 1 × 106 platelets/μL. Grossly, vessels were more evident in PRP-treated rats. Immunohistochemical analysis demonstrated neovascularization was significantly greater in the PRP-treated ADMs at all time points. This increase in neovascularization correlated with an increased thickness of tissue deposition at 4 and 6 wk. ConclusionsPRP enhanced neovascularization and incorporation in a rat model of VHR. Enhanced neovascularization was associated with earlier and greater tissue deposition on the ADM. This suggests that PRP could be used as an adjunct to VHR in clinical scenarios where poor wound healing is anticipated and enhanced neovascularization and early tissue deposition are desired.

Can Platelet rich plasma stimulate human ACL growth in culture? A preliminary experience.

Platelet Rich Plasma (PRP) contains numerous growth factors; Platelet poor plasma (PPP) is plasma proteins without platelets, containing growth factors other than platelet derived. We planned to evaluate the effect of both autologous PRP & PPP on human ACL cell growth characteristics in culture conditions to see if one was better than the other. ACL remnants were collected from eleven patients during ACL reconstruction surgery; PPP and PRP were prepared from blood of these patients. Cells were isolated, identified and cultured and were then divided into six groups. Groups A-D had Fetal Bovine Serum (FBS) added to them along with different concentrations of PRP and PPP. Groups E and F had 5% and 10% PRP respectively but lacked FBS. Cell viability was assayed by MTT and Annexin V assay, and DNA content was evaluated by propidium iodide staining and flow cytometry. analysis of cultured cells showed that addition of PRP (5 or 10%) increased the viability of ACL cells in 4 out of 11 and promoted cell proliferation in 8 of 11 donor samples; 10% PRP was more effective than 5% PRP. However, the difference in effectiveness of 10% PRP was not significantly better than 5% PRP. 5% PPP had no significant effect on cell viability, but it led to an increase in DNA content in 5 of 11. There was no statistically significant effect of either PRP or PPP in preventing cell death (depicted by apoptosis rate). PRP may have an enhancing effect on ACL cell viability and promotion of cell proliferation but the ideal concentration of PRP for these positive effects needs to be determined before it could be used in clinical settings for enhancing primary repair of torn ACL. Also larger, more controlled and better studies are needed to confirm its clinical utility.

Synergistic anabolic actions of hyaluronic acid and platelet-rich plasma on cartilage regeneration in osteoarthritis therapy

Osteoarthritis (OA) is a common disease associated with tissue inflammation, physical disability and imbalanced homeostasis in cartilage. For advanced treatments, biological approaches are currently focused on tissue regeneration and anti-inflammation. This study was undertaken to evaluate the therapeutic efficacies of hyaluronic acid (HA) and platelet-rich plasma (PRP) (HA+PRP) on OA. Articular chondrocytes were obtained from five OA patients. The optimal HA and PRP concentrations were evaluated by MTT assay. The expressions of chondrogenic and inflammatory genes were analyzed by RT-PCR. Signaling pathway was examined by immunoblotting and the expressions of OA pathology-related chemokines and cytokines was demonstrated by real-time PCR-based SuperArray. The therapeutic efficacies of HA+PRP were then demonstrated in 3D arthritic neo-cartilage and ACLT-OA model. Here we showed that HA+PRP could greatly retrieve pro-inflammatory cytokines-reduced articular chondrocytes proliferation and chondrogenic phenotypes, the mechanism of which involve the sequential activation of specific receptors CD44 and TGF-βRII, downstream mediators Smad2/3 and Erk1/2, and the chondrogenic transcription factor SOX9. The real-time PCR-based SuperArray results also indicated that OA pathology-related chemokines and cytokines could be efficiently suppressed by HA+PRP. Moreover, the cartilaginous ECM could be retrieved from inflammation-induced degradation by HA+PRP in both 2D monolayer and 3D neo-cartilage model. Finally, the intra-articular injection of HA+PRP could strongly rescue the meniscus tear and cartilage breakdown and then decrease OA-related immune cells. The combination of HA+PRP can synergistically promote cartilage regeneration and inhibit OA inflammation. This study might offer an advanced and alternative OA treatment based on detailed regenerative mechanisms.

Autologous platelet-rich plasma: a biological supplement to enhance adipose-derived mesenchymal stem cell expansion.

Currently the use of non-autologous cell culture media (e.g., animal-derived or allogeneic serum) for clinical applications of mesenchymal stem cells (MSCs) is criticized by regulatory agencies. Autologous platelet-rich plasma (PRP) is proposed as a safer alternative medium supplement for adipose-derived mesenchymal stem cells (AT-MSC) culture. To study its efficiency on cell proliferation, AT-MSCs were cultured for 10 days in media supplemented with different concentrations of autologous non-activated PRP (nPRP) or thrombin-activated PRP (tPRP) (1-60%). AT-MSC proliferation, cell phenotype, multipotency capacity, and chromosome stability were assessed and compared to AT-MSCs expanded in a classical medium supplemented with 10% of fetal bovine serum (FBS). Culture media supplemented with nPRP showed dose-dependent higher AT-MSC proliferation than did FBS or tPRP. Twenty percent nPRP was the most effective concentration to promote cell proliferation. This condition increased 13.9 times greater AT-MSC number in comparison to culture with FBS, without changing the AT-MSC phenotype, differentiation capacity, and chromosome status. We concluded that 20% autologous nPRP is a safe, efficient, and cost-effective supplement for AT-MSC expansion. It should be considered as an alternative to FBS or other nonautologous blood derivatives. It could serve as a potent substitute for the validation of future clinical protocols as it respects good manufacturing practices and regulatory agencies' standards.