Activity Of Platelet-rich Plasma Research Articles

Activation of platelet-rich plasma by pulse electric fields: Voltage, pulse width and calcium concentration can be used to control and tune the release of growth factors, serotonin and hemoglobin.

Activated platelet-rich plasma (PRP) has been used in the clinical settings of wound healing and regenerative medicine, with activation typically induced by the addition of bovine thrombin. To eliminate issues with availability, cost and potential side effects associated with bovine thrombin, ex vivo PRP activation using pulse electric fields (PEF) has been proposed and demonstrated. The present study characterizes the effect of PEF voltage and pulse width, in combination with a range of calcium concentrations, on clot formation, growth factor release, and serotonin (5-HT) release from dense granules. The main findings are: 1) increasing calcium concentrations with most PEF conditions leads to increased levels of PDGF and 5-HT release; 2) whether EGF levels increase or decrease with increasing calcium concentration depends on the specific PEF parameters; 3) the pattern of PDGF and EGF levels in supernatants suggest that these molecules are localized differently within platelets; 4) significant levels of PDGF, EGF, and 5-HT can be released without inducing clot formation or hemoglobin release. In conclusion, voltage, pulse width and calcium concentration can be used to control and tune the release of growth factors, serotonin and hemoglobin from PEF-activated PRP. Because growth factor requirements vary for different types of wounds and for wounds at different stages of healing, the unique balance of factors in supernatants of PEF-activated PRP may provide more clinically advantageous than the current standard of bovine thrombin-activated PRP.

Three dimensional nanofibrous and compressible poly(L-lactic acid) bone grafts loaded with platelet-rich plasma

In this study, nanofibrous matrices of poly(L-lactic acid)-hydroxyapatite (PLLA-HAp) were successfully fabricated by three-dimensional (3D) electrospinning for use in the treatment of irregular bone damages. Compressibility analysis showed that 3D nanofibrous grafts occupied at least 2-fold more volume than their 2D form and they can easily take shape of the defect zone with irregular geometry. Moreover, the compression moduli of the PLLA and PLLA-HAp grafts were calculated as 8.0 ± 3.0 kPa and 11.8 ± 3.9 kPa, respectively, while the strain values of the same samples at the maximum load of 600 kPa were 164 ± 28% and 130 ± 20%, respectively. Treatment of the grafts with aqueous sodium hydroxide solution increased the surface roughness and thus the alloplastic graft materials (PLLA-HAp/M) protecting the fiber morphology were produced successfully. Then, platelet-rich plasma (PRP) was loaded into the surface modified grafts and activated with 10% calcium chloride. The efficiency of the activation was evaluated with flow cytometry and it was found that after activation the percentages of CD62 (P-selectin) and CD41/61 (glycoprotein IIb/IIIa) proteins increased approximately 4-fold. Surface hydrophilicity and biological activity of the PLLA-HAp grafts were enhanced by fibrin coating after PRP activation. The in vitro cell culture studies which were carried out by using mouse pre-osteoblasts (MC3T3-E1) showed that graft materials supported by PRP increased cellular proliferation and osteogenic differentiation significantly. The in vivo results demonstrated that compared with bare PLLA-HAp/M grafts, the PRP loaded grafts (PRP-PLLA-HAp/M) induced significantly greater bone formation based on computed tomography, histological and immunohistochemical analyses. Our findings suggest that 3D PLLA nanofibrous matrices can be used as a graft material for irregular bone defects especially when combined with PRP as an osteogenic induction agent.

Platlet-Rich Plasma - Review of Literature.

Wound healing is a dynamic and physiological process for restoring the normal architecture and functionality of damaged tissue. Platelet-rich plasma (PRP) is an autologous whole blood product that contains a large number of platelets in a small volume of plasma with complete set of coagulation factors, which are in physiological concentrations. PRP has haemostatic, adhesive properties and acts supraphysiologically in the process of wound healing and osteogenesis. Platelets play a very important role in the wound healing process by providing growth factors that enhance the rate and quality of wound healing by many different mechanisms. The aim of this review is to describe: the biology of platelets and their role in the wound healing process, the terminology of platelet rich products, PRP preparation, activation and concentration of PRP, as well as the use of PRP in plastic surgery.

Preparation of Platelet-Rich Plasma: National IADVL PRP Taskforce Recommendations.

The goal of these recommendations is to provide a framework to practitioners for implementing useful, evidence-based recommendations for the preparation of platelet-rich plasma (PRP) in various dermatological indications. The Indian Association of Dermatologists, Venereologists and Leprologists (IADVL) assigned the task of preparing these recommendations to its task force on PRP. A comprehensive literature search was done in the English language on the preparation of PRP across multiple databases. The grade of evidence and strength of recommendation was evaluated on the GRADE framework (Grading of Recommendation, Assessment, Development and Evaluation). A draft of clinical recommendations was developed on the best available evidence which was also scrutinized and critically evaluated by the IADVL Academy of Dermatology. Based on the inputs received, this final consensus statement was prepared. A total of 45 articles (meta-analyses, prospective and retrospective studies, reviews [including chapters in books], and case series) were critically evaluated and the evidence thus gathered was used in the preparation of these recommendations. This expert group recommends the use of double-spin manual method for the preparation of PRP. The recommended parameters for centrifuge are 100–300 g for 5–10 min for the first spin and 400–700 g for 10–17 min for the second spin. The recommended platelet concentration in PRP for the treatment of various dermatological conditions is 1–1.5 million platelets/μL. The activation of PRP is not required when it is injected into soft tissues.

Platelet-Rich Plasma in Androgenetic Alopecia.

The goal of these recommendations is to provide a framework to practitioners for implementing useful, evidence-based recommendations for the preparation of platelet-rich plasma (PRP) and its use in androgenetic alopecia (AGA). The Indian Association of Dermatologists, Venereologists and Leprologists (IADVL) assigned the task of preparing these recommendations to its taskforce on PRP. A comprehensive literature search was done in the English language on the PRP across multiple databases. The grade of evidence and strength of recommendation were evaluated on the GRADE (Grading of Recommendation, Assessment, Development, and Evaluation) framework. A draft of clinical recommendations was developed on the best available evidence, which was also scrutinized and critically evaluated by the IADVL Academy of Dermatology. Based on the inputs received, the final consensus statement was prepared. A total of 30 articles (meta-analyses, prospective and retrospective studies, reviews [including chapters in books], and case series) were critically evaluated, and the evidence thus gathered was used in the preparation of these recommendations. This expert group recommends use of manual double-spin method for the preparation of PRP for AGA. Minimum three to five sessions of PRP are recommended for AGA with a gap of 1 month between the two sessions. Patients with Grade II to V Norwood Hamilton classification of AGA are the ideal subset for PRP. A total of 5 to 7 mL of PRP and 0.05 to 0.1 mL/cm2 is the recommended dose of PRP for AGA. Activation of PRP is not required when it is used for AGA. About 1 to 1.5 million platelets/μL of platelets in PRP is the recommended platelet concentration in PRP for the treatment of AGA. I-PRF (injectable platelet-rich fibrin) has also been found to be useful in AGA, although further studies are required to establish its role. PRP can also have an adjunctive role in hair transplantation procedures.

A Multi-Donor Ex Vivo Platelet Activation and Growth Factor Release Study Using Electric Pulses With Durations Up to 100 Microseconds

In vitro platelet activation is established in various clinical settings for wound healing and tissue regeneration. After separating platelet rich plasma (PRP) from whole blood, a biochemical activator, typically bovine thrombin (BT), is applied to activate PRP, which clots the PRP and releases growth factors beneficial for wound healing. BT’s drawbacks, particularly cost, availability, workflow challenges, and potential immune responses, motivated the development of ex vivo electrical activation of PRP using pulsed electric fields (PEFs) with durations on the order of hundreds of nanoseconds and electric field strengths from $\sim 10$ -100 kV/cm. PEFs permeabilize platelets to facilitate Ca2+ transport into the cells to induce platelet activation; however, membrane permeabilization does not require PEFs of such short duration and high intensity. This study demonstrates that 5- $100~\mu \text{s}$ duration PEFs effectively activate platelets. Treating PRP with ten different single pulse waveforms with durations between 5 and $100~\mu \text{s}$ induces similar or higher levels of platelet derived, vascular endothelial, and epidermal growth factor release compared to BT. These results indicate the potential clinical relevance of microsecond PEFs for platelet stimulation, which may reduce the expense and device footprint for PEF mediated platelet stimulation compared to nanosecond pulse generators, facilitating technology transition for clinical and trauma applications.

ADP-Mediated Upregulation of Expression of CD62P on Human Platelets Is Critically Dependent on Co-Activation of P2Y1 and P2Y12 Receptors.

This study probed the differential utilization of P2Y1 and P2Y12 receptors in mobilizing CD62P (P-selectin) from intracellular granules following activation of human platelets with adenosine 5′-diphosphate (ADP, 100 µmol·L−1) Platelet-rich plasma (PRP) was prepared from the blood of adult humans. CD62P was measured by flow cytometry following activation of PRP with ADP in the absence and presence of the selective antagonists of P2Y1 and P2Y12 receptors, MRS2500 and PSB0739 (both 0.155–10 µmol·L−1), respectively. Effects of the test agents on ADP-activated, CD62P-dependent formation of neutrophil:platelet (NP) aggregates were also measured by flow cytometry, while phosphatidylinositol 3-kinase (PI3K) activity was measured according to Akt1 phosphorylation in platelet lysates. Treatment with MRS2500 or PSB0739 at 10 µmol·L−1 almost completely attenuated (94.6% and 86% inhibition, respectively) ADP-activated expression of CD62P and also inhibited NP aggregate formation. To probe the mechanisms involved in P2Y1/P2Y12 receptor-mediated expression of CD62P, PRP was pre-treated with U73122 (phospholipase C (PLC) inhibitor), 2-aminoethoxy-diphenyl borate (2-APB, inositol triphosphate receptor antagonist), calmidazolium chloride (calmodulin inhibitor), or wortmannin (PI3K inhibitor). U73122, 2-APB, and wortmannin caused almost complete inhibition of ADP-activated expression of CD62P, while calmidazolium chloride caused statistically significant, partial inhibition. PSB0739, but not MRS2500, caused potent inhibition of PI3K-mediated phosphorylation of Akt1. Optimal mobilization of CD62P by ADP-stimulated platelets is critically dependent on the co-activation of platelet P2Y1 and P2Y12 receptors. P2Y12 receptor activation is the key event in activation of PI3K, while activation of the P2Y1 receptor appears to create a high cytosolic Ca2+ environment conducive to optimum PI3K activity.

Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020.

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects, and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.

Electrical stimulation of whole blood for growth factor release and potential clinical implications

Clinicians have increasingly applied platelet-rich plasma (PRP) for wound healing treatments. Topical treatments commonly require biochemical agents such as bovine thrombin to activate PRP ex vivo for clotting and growth factor release to facilitate healing upon application to the wound of interest. Recent studies have explored electrical stimulation as an alternative to bovine thrombin for PRP activation due to the former’s cost, workflow complexity and potentially significant side effects; however, both approaches require separating the PRP from whole blood (WB) prior to activation. Eliminating the separation (typically centrifugation) step would reduce the cost and duration of the clinical procedure, which may be critical in trauma and surgical applications. We hypothesize that electric pulses (EPs) can release growth factors from WB, as they do from PRP, without requiring centrifugation of WB into PRP. A pilot study for two donors demonstrates the potential for EP stimulated growth factor release from WB. This motivates future experiments assessing EP parameter optimization for WB activation and in vivo studies to determine the clinical benefits for topical treatments and, especially, for injections in orthopedic applications that already utilize non-treated/non-activated WB.

Effects of Antiplatelet and Nonsteroidal Anti-inflammatory Medications on Platelet-Rich Plasma: A Systematic Review.

Background:Platelet-rich plasma (PRP) has wide applications in orthopaedic care. Its beneficial effects are attributed to the growth factor profile from the platelet secretome. In theory, these effects would be diminished by medications that inhibit platelet activation and/or the subsequent release of growth factors.Purpose:To determine whether commonly used antiplatelets, nonsteroidal anti-inflammatory drugs (NSAIDs), or anticoagulant medications affect platelet growth factor release in PRP.Study Design:Systematic review; Level of evidence, 2.Method:A systematic review of the literature related to antiplatelet, anti-inflammatory, and anticoagulant drugs was performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We used the Downs and Black objective quality scoring system. The literature search consisted of PubMed and Cochrane Library databases. Search terms consisted of 1 item selected from “platelet-rich plasma,” “platelet-derived growth factor,” and “platelet-rich plasma AND growth factor” combined with 1 item from “antiplatelet,” “aspirin,” “anticoagulant,” and “NSAID.” Only studies published within the past 25 years were included.Results:A total of 15 studies met the inclusion criteria: 7 studies detected no significant decrease in growth factors or mitogenesis, whereas 6 detected a decrease with antiplatelet agents, 1 detected mixed results with an antiplatelet agent, and 1 had mixed results with an antiplatelet agent/vasodilator. In terms of PRP activation, all 3 studies assessing collagen, the 2 studies analyzing adenosine diphosphate alone, and the 1 study investigating arachidonic acid found a decrease in growth factor concentration.Conclusion:Antiplatelet medications may decrease the growth factor release profile in a cyclooxygenase 1– and cyclooxygenase 2–dependent manner. Eight of 15 studies found a decrease in growth factors or mitogenesis. However, more studies are needed to comprehensively understand antiplatelet effects on the PRP secretome.

The Number of Platelets in Patient's Blood Influences the Mechanical and Morphological Properties of PRP-Clot and Lysophosphatidic Acid Quantity in PRP.

The objectives of this study were to compare platelet-rich plasma (PRP) from patients with different concentrations of platelets and to assess the influence of these PRP preparations on human osteoblast (hOB) activity. In the literature, growth factors released by activated platelets have been considered responsible for the active role of PRP on bone regeneration but no specific role has been attributed to lysophosphatidic acid (LPA) as a possible effector of biological responses. In this study, patients were grouped into either group A (poor in platelets) or group B (rich in platelets). Clots from PRP fraction 2 (F2-clots), obtained with CaCl2 activation of PRP from the two groups, were compared macroscopically and microscopically and for their mechanical properties before testing their activity on the proliferation and migration of hOB. LPA was quantified before and after PRP fractioning and activation. The fibrin network of F2-clots from patients with a lower platelet concentration had an organized structure with large and distinct fibers while F2-clots from patients in group B revealed a similar structure to those in group A but with a slight increase in density. ELISA results showed a significantly higher plasma level of LPA in patients with a higher platelet concentration (group B) in comparison to those in group A (p < 0.05). This different concentration was evidenced in PRP but not in the clots. Depending on the number of platelets in patient’s blood, a PRP-clot with higher or lower mechanical properties can be obtained. The higher level of LPA in PRP from patients richer in platelets should be considered as responsible for the higher hOB activity in bone regeneration.

EFFECT OF OZONE ACTIVATED PLATELET RICH PLASMA ON THE MANAGEMENT OF GRADE II FURCATION INVOLVEMENT (COMPARATIVEEXPERIMENTALSTUDY)

INTRODUCTION: Furcation defects are a frequent finding in periodontitis patients. Activated platelets release numerous proteins, among them adhesive glycoproteins and growth factors. Ozone (O3) is a triatomic molecule, consisting of three oxygen atoms, and its application in medicine and dentistry has been indicated for the treatment of different pathologies. AIM OF THE STUDY: The aim of this experimental study was to evaluate the effectiveness of combining Platelet Rich Plasma (PRP) and ozone therapy in the management of surgically created grade II furcation defects. MATERIALS AND METHODS: A split mouth design was carried out using six healthy mongrel dogs. A total of eighteen critical sized grade II furcation defects were surgically created in the third and fourth mandibular premolars, bilaterally. After reflecting a mucoperiosteal flap, the defects in the experimental side were treated with PRP activated by ozone, β-TCP and collagen membranes, whereas, the control side defects were treated with PRP, β-TCP and collagen membrane. The dogs were sacrificed after 4 and 8 weeks. Samples were dissected and prepared for histological evaluation. RESULTS: Histological results showed that PRP activated by ozone led to higher vascularization of the study samples at all time points; this was evident at four weeks in the form of numerous blood vessels entrapping RBCs and at eight weeks by the presence of red bone marrow and blood vessels entrapping RBCs within. Histomorphometry revealed that ozonated PRP accelerated bone regeneration at both time intervals, this acceleration was almost two –fold upon comparing test to controls. CONCLUSION: Activation of PRP by ozone is effective in enhancing angiogenesis and bone formation during periodontal regenerative therapy in grade II critical –sized furcation defectsin dogs

Effects of specific pathogen-free porcine platelet-rich plasma activated by the novel activator ectoine on cell proliferation and biological function

During the past two decades, cell culture has played an important role in many biochemical and biomedical fields. However, finding an alternative to animal serum is an important area in cell culture methods and related biotechnology industries. In a previous study, we demonstrated that the platelet-rich plasma (PRP) from specific pathogen-free pigs was a rich source of cytokines and growth factors and might serve as a replacement for animal serum. The selection of an activator is a crucial step in PRP activation and affects the availability of bioactive molecules. The present study is the first to demonstrate the ability of ectoine to activate PRP and to investigate the effects of ectoine-activated PRP on cell proliferation and biological function. The amounts of bioactive molecules, including TGF-β, PDGF-AB, EGF, VEGF, KGF and IGF, secreted from PRP activated by ectoine were measured. In addition, two types of primary cells and three types of cell lines were cultured with various concentrations of ectoine-activated PRP under animal serum-free conditions. Then, the effects of ectoine-activated PRP on cell growth kinetics, extracellular matrix secretion and melanin synthesis were also determined. Finally, our results demonstrated that ectoine is a novel and effective PRP activator and that ectoine-activated PRP can serve as an excellent replacement for animal serum in cell culture and related applications.

Optimizing the safety of intradiscal platelet-rich plasma: an in vitro study with Cutibacterium acnes.

Aim: The most common risk associated with intradiscal injection of platelet-rich plasma (PRP) is discitis with Cutibacterium acnes. It is hypothesized that antimicrobial activity of PRP can be enhanced through inclusion of leukocytes or antibiotics in the injectate. Materials & methods: Multiple PRP preparations of varying platelet and leukocyte counts were co-cultured with C. acnes with or without cefazolin, with viable bacterial colony counts being recovered at 0, 4, 24 and 48hours post-inoculation. Results: A direct correlation between C. acnes recovery and granulocyte counts were observed. Conclusion: We observed the greatest antimicrobial activity with the leukocyte-rich, high platelet PRP preparation combined with an antibiotic in the injectate. However, cefazolin did not completely clear the bacteria in this assay.

Antimicrobial action of autologous platelet-rich plasma on MRSA-infected skin wounds in dogs

Effective antimicrobial preparations, other than antibiotics, are important for the treatment of potentially fatal drug-resistant infections. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of hospital-acquired and post- operative infections. Fortunately, the antimicrobial properties of platelet-rich plasma (PRP) against various microorganisms enable its potential use as an alternative to conventional antibiotics. The present work was designed to evaluate the hypothesized antimicrobial activity of PRP against MRSA infected skin wounds. Six adult male dogs were divided equally into control and PRP groups. Unilateral circular full-thickness skin wounds were created then a MRSA suspension was injected locally. Treatment started at 1st week post infection with subcutaneous infiltration of autologous activated PRP every week in the PRP group and with topical application of clindamycin cream twice daily in the control group. PRP decreased wound size and significantly increased wound contractility and re-epithelization, as confirmed by histopathological and immunohistochemical findings. Also PRP treated group showed significant decrease in ROS and redox imbalance with over expression of the TNF-α and VEGFA genes that indicate angiogenesis and maximum antibacterial activity after three weeks. In conclusion, CaCl2-activated PRP exhibited antimicrobial activity against MRSA infection, which improved the infected wound healing re-epithelization and granulation tissue formation.

Optimization of leukocyte-poor platelet-rich plasma preparation: a validation study of leukocyte-poor platelet-rich plasma obtained using different preparer, storage, and activation methods

BackgroundAlternative methods of platelet-rich plasma (PRP) preparation, storage, and activation that can be stably reproduced are needed to improve PRP production. The purpose of this study was to investigate the effect of the preparer’s experience on the quality of prepared PRP, chronological changes occurring in PRP, and the effect of the activation procedures on the release of several growth factors from PRP, using PRP prepared with the PRGF-Endoret Kit.MethodsLeukocyte-poor PRP samples from seventeen healthy volunteers were prepared using the PRGF-Endoret Kit and the PRGF IV System Centrifuge. The platelet and leukocyte concentrations were compared based on the preparer’s experience. The concentrations of platelets, hepatocyte growth factor (HGF), platelet-derived growth factor-BB (PDGF-BB), and insulin-like growth factor-1 (IGF-1) were determined at 0 and 60 min after PRP preparation, and compared. Concentrations of the above growth factors from PRP activated by freeze–thaw cycling and by calcium chloride (CaCl2) were also compared.ResultsNo significant difference was observed in the platelet concentrations and leukocyte contamination rates, based on the preparer’s experience. At 60 min after PRP preparation, the platelet concentration decreased significantly, while the HGF, PDGF-BB, and IGF-1 concentrations remained unchanged. Activation with CaCl2 resulted in a significant increase in the PDGF-BB levels, although the HGF and IGF-1 concentrations remained unchanged.ConclusionsThe results of this study show that leukocyte-poor PRP prepared using the PRGF-Endoret Kit did not result in any qualitative difference that depended on the experience of the preparer. However, PRP preparation required standardization in terms of the time of blood count measurement. Growth factor concentrations in PRP differed according to the platelet-activation method used.

Using extracellular calcium concentration and electric pulse conditions to tune platelet-rich plasma growth factor release and clotting

Platelet-rich plasma (PRP) is an emerging autologous biologic method for wound healing. Clinicians apply PRP either topically (where it is activated ex-vivo before treatment by adding an external agent to trigger clotting and the release of growth factors that facilitate wound healing) or through injection (where it is activated in vivo at the injury site with no prior activation before injection). Because topical PRP activation typically utilizes bovine thrombin, which has significant potential side effects and high costs, recent studies have assessed the efficacy of combining extracellular calcium (EC) and electric pulses (EPs) to activate PRP. The potential to apply this novel technique to PRP both topically and internally via injection raises the question about the ability to tune the clotting time and growth factor release for a given application. While previous studies have assessed the impact of applying EPs of various durations either directly (conductive coupling) or indirectly (capacitive coupling) to PRP containing EC, no studies have assessed the tunability of this activation based on modifying EP parameters, EP delivery method (conductive or capacitive coupling), and the EC concentration. We hypothesize that tuning these parameters will modify intracellular calcium uptake to permit the control of growth factor release and clotting time, which are critical for optimizing PRP for either topical or internal clinical applications. A pilot study for a single donor demonstrates the potential for tunability as a function of the intensity of membrane manipulation and calcium concentration, which facilitate the increase of cytosolic calcium. This motivates future studies assessing EC and EP optimization and in vivo studies to determine the overall efficacy of this tunability for wound healing.

Selectively activated PRP exerts differential effects on tendon stem/progenitor cells and tendon healing

To understand the variable efficacy with platelet rich plasma (PRP) treatments for tendon injury, we determined the differential effects of proteinase-activated receptor (PAR)1- or PAR4-activated PRP (PAR1-PRP, PAR4-PRP) from humans on human patellar tendon stem/progenitor cells (TSCs) and tendon healing. We show that PAR1-PRP released VEGF, whereas PAR4-PRP released endostatin. Treatment of TSCs with PAR1-PRP increased collagen I expression and matrix metalloproteinase-1 (MMP-1), but cells treated with PAR4-PRP increased less collagen I and higher MMP-2 expression. The wound area treated with PAR4-PRP formed tendon-like tissues with well-organized collagen fibers and fewer blood vessels, while PAR1-PRP treatment resulted in the formation of blood vessels and unhealed tissues. These findings indicate that differential activation of PRP leads to different effects on TSCs and tendon healing. We suggest that based on acute or chronic type of tendon injury, selective activation of PRP should be applied in clinics in order to treat injured tendons successfully.

The effect of topical application of platelet-rich plasma in controlling bleeding and sternotomy wound infection after cardiac surgery

Background Bleeding and surgical wound infections after open heart surgery are associated with increased morbidity and mortality. These complications have devastating effects on patients’ recovery and a substantial economic effect on health care providers. There remains an incentive to reduce the risks further. Platelet-rich plasma (PRP) is a source of growth factors and cytokines, which can promote tissue healing and regeneration. Aim The aim of this study is to determine the effect of PRP on bleeding and surgical wound infection after cardiac surgery. Patients and methods A total of 34 patients were randomized into two groups: PRP group and control group. Overall, 30 ml of the patient’s autologous blood was centrifuged for 5 min to separate the red blood cells from the plasma. The plasma was then centrifuged for 10 min; the precipitate is the PRP. Activation of PRP was done by adding 1 ml of calcium gluconate to the syringe just before spraying the PRP in the operative field. After weaning the patient from cardiopulmonary bypass and before the insertion of sternal wires, the mediastinal cavity was irrigated with the PRP (30 ml of warm saline mixed with an equal amount of PRP) in group ‘A’ and saline only in group ‘B.’ Study end points were bleeding and blood transfusion. Results Wound discoloration occurred in 11.8% (two cases) in the control group; however, no wound discoloration was recorded in the PRP group, with P value of 0.145. Drainage (with mean drainage in control group was 473.53 ml and mean drainage in PRP group was 193.75 ml) and transfusion requirements (with mean transfusion requirements in control group was 1.5 pack and mean transfusion requirements in PRP group was 0.63 pack) showed a statistically significant difference between the two groups, in favor of the PRP group (P Conclusion Our results suggest that bleeding tendency, coagulation profile, and the incidence of blood transfusion are better with the application of PRP. Wound discoloration was better with the application of PRP.

The Effect of Collagen Activation on Platelet Rich Plasma for Proliferation of Periodontal Ligament Fibroblasts

BACKGROUND: Regenerative procedure in periodontal surgery aims to improve the structure and function of the periodontium to be strong enough to support the teeth. Growth factor is essential in the process of tissue regeneration; it can be generated from the activation of Platelet-Rich Plasma (PRP). In this study, collagen was used as PRP activator. PRP release growth factor from the granules when activated. The aim of this study was to evaluate the effect of collagen on PRP activation and the collagen-activated PRP storage to fibroblast proliferation of periodontal ligament (PDL).METHODS: Fibroblasts of PDL were obtained from extracted premolar. PRP were obtained from 100 mL of blood donors using double centrifugation methods. PRP were activated by collagen and subsequently incubated for 24, 48, 72 and 168 hours; after which the lysate was taken. Fibroblasts were divided into 7 groups, which consisted of one unstimulated group as negative control, one group stimulated by PRP lysate, and five groups stimulated with PRP-collagen lysates that had been incubated for 24, 48, 72 and 168 hours. MTT assay was then performed after 1 and 3 days.RESULTS: The proliferation rate of fibroblasts group stimulated by PRP-collagen lysate was higher than the group stimulated by PRP. The storage of collagen-activated PRP for 7 days at 4°C could increase the proliferation rate.CONCLUSION: The activation of collagen on PRP and the stored collaged-activated PRP could increase the fibroblasts proliferation rate of PDL.KEYWORDS: collagen, platelet-rich plasma, fibroblasts proliferation