scholarly journals Isolation, Activation, and Mechanism of Action of Platelet-Rich Plasma and Its Applications for Joint Repair

2020 ◽  
Author(s):  
Mikel Sánchez ◽  
Maider Beitia ◽  
Orlando Pompei ◽  
Cristina Jorquera ◽  
Pello Sánchez ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Platelet Rich Plasma ◽  
Joint Repair

Photobiomodulation with a 645 nm Diode Laser of Saos-2 Cells and Platelet-Rich Plasma: The Potential for a New Mechanism of Action

2021 ◽  
Vol 39 (2) ◽  
pp. 86-93
Author(s):  
Giulia Ghidini ◽  
Daniele Mori ◽  
Stefano Pulcini ◽  
Paolo Vescovi ◽  
Roberto Sala
Keyword(s):  
Diode Laser ◽  
Mechanism Of Action ◽  
Platelet Rich Plasma

Platelet Aggregation Induced by DAS in Vitro: Some Investigations on Its Mechanism of Action

1974 ◽  
Vol 31 (02) ◽  
pp. 354-362
Author(s):  
K. U Benner ◽  
K. A Schumacher ◽  
H. G Classen
Keyword(s):  
Platelet Aggregation ◽  
Mechanism Of Action ◽  
Active Substance ◽  
Platelet Rich Plasma ◽  
The Other ◽  
Second Phase ◽  
Induce Platelet Aggregation ◽  
Release Reaction

SummaryThe effect of the depressor active substance (DAS) on platelets of men, cats, pigs, dogs, rats, and rabbits has been studied by the method of Born (1962). DAS was found to induce platelet aggregation only in human and feline platelet rich plasma (PRP). Nevertheless, there are some striking similarities between platelet aggregation induced by DAS and ADP (i.e. inhibition by the same compounds, such as adenosine, tosylarginine methylester, or p-chloromercuribenzoic acid). The species specifity and a marked tachyphylactic action on platelets of both species makes DAS clearly discernible from all the other aggregation inducing substances which have been studied so far. From additional experiments there is evidence that DAS acts on human and cat platelets via a release reaction of cellular substances known to enhance platelet aggregation in a second phase. This process is strongly dependent on the presence of Ca++.

scholarly journals Platelet-rich plasma: a narrative review

2021 ◽  
Vol 6 (4) ◽  
pp. 225-235
Author(s):  
Thomas Collins ◽  
Dinesh Alexander ◽  
Bilal Barkatali
Keyword(s):  
Growth Factors ◽  
Clinical Application ◽  
Mechanism Of Action ◽  
Platelet Rich Plasma ◽  
Cruciate Ligament ◽  
Clinical Indication ◽  
Muscle Injuries ◽  
Cochrane Reviews ◽  
Anterior Cruciate ◽  
Key Terms

The aim of this article was to synopsize platelet-rich plasma (PRP) use in musculoskeletal pathologies through evidence-based assessment of the preparation, classification, mechanism of action and applications of PRP, thereby answering which PRP type is best for each clinical indication. The literature search was performed using Medline, EMBASE and Cochrane Reviews databases for papers containing the key terms “platelet-rich plasma” AND “orthopaedics” AND (“classification” OR “mechanism of action” OR “preparation” OR “clinical application”). Generated papers were evaluated for pertinence in following areas: preparation, classification, mechanism of action, clinical application within orthopaedics. Non-English papers were excluded. Included studies were evaluated for quality. Sixty studies were included in our review. There are many commercial PRP preparation kits with differing component concentrations. There is no consensus on optimal component concentrations. Multiple PRP classifications exist but none have been validated. Platelet-rich plasma acts via growth factors (GFs) released from α-granules within platelets. Growth factors have been shown to be beneficial in healing. Grossly elevated concentrations of GFs may have inhibitory effects on healing. Multiple systematic reviews show efficacy of PRP in tendinopathies, early osteoarthritis, acute muscle injuries and in combination with rotator cuff repair and anterior cruciate ligament reconstruction. The literature suggests leukocyte-rich PRP (L-PRP) is more beneficial in tendinopathies and pure PRP (P-PRP) is more beneficial in cartilage pathology. However, different PRP preparations have not been directly compared in any pathology. Classification of PRP type is frequently not stated in research. Standardization of PRP research parameters is needed to streamline findings and generate clear indications for PRP types to yield maximum clinical benefit. Cite this article: EFORT Open Rev 2021;6:225-235. DOI: 10.1302/2058-5241.6.200017

Inhibition of Rat Platelet Aggregation by Mycalolide-B, a Novel Inhibitor of Actin Polymerization with a Different Mechanism of Action from Cytochalasin-D

1998 ◽  
Vol 79 (03) ◽  
pp. 614-619 ◽  
Author(s):  
Fumitoshi Asai ◽  
Shinya Saito ◽  
Hiroshi Ozaki ◽  
Nobuhiro Fusetani ◽  
Hideaki Karaki ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Mechanism Of Action ◽  
Actin Polymerization ◽  
De Novo ◽  
Platelet Rich Plasma ◽  
Cytochalasin D ◽  
Dependent Manner ◽  
Clot Retraction ◽  
Concentration Dependent Manner ◽  
Induced Aggregation

SummaryIn vitro effects of mycalolide-B (MB), isolated from marine sponge, were investigated with regard to the activation of rat platelets. Collagen-induced platelet aggregation in platelet-rich plasma (PRP) was slightly but significantly potentiated by lower concentrations of MB (0.3 and 1 μM) but was inhibited by higher concentrations (3 and 10 μM). ADP-induced platelet aggregation in PRP was also significantly prevented by MB (1-10 μM). Potentiation of ADP-induced aggregation by MB (0.3 μM) was hardly observed. G-actin contents, determined by DNase I inhibition assay, were increased in resting washed platelets incubated with MB (3 μM). In contrast, cytochalasin-D (CD) at 3 μM slightly reduced G-actin contents in resting platelets. After platelet aggregation with collagen (3 μg/ml) or ADP (10 μM), G-actin contents in platelets were reduced, indicating de novo actin polymerization. MB (3 μM) and CD (3 μM) abolished both ADP (10 μM)- and collagen (3 μg/ml)-induced platelet aggregation and actin polymerization in washed platelets. MB (1-10 μM) had no effects on intracellular Ca2+ concentrations in ADP (10 μM)-stimulated platelets. [125I]-fibrinogen binding to activated platelets with ADP (10 μM) was inhibited by MB (0.3-3 μM) in a concentration-dependent manner. Thrombin-induced platelet-fibrin clot retraction was inhibited by MB (1 and 10 μM). These results suggest that MB inhibits platelet activation by interfering with actin polymerization through a different mechanism of action from CD. MB may be a useful tool for studying the role of actin polymerization in various cells.

Evaluation of Anticoagulant Drugs with TF-Induced Thrombin Generation: An In Vitro comparative Study In Platelet-Rich Plasma (PRP) Versus Platelet-Poor Plasma (PPP)

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3335-3335
Author(s):  
Severine Robert ◽  
François Mullier ◽  
Nicolas Lufin ◽  
Philippe Devel ◽  
Bernard Chatelain ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Thrombin Generation ◽  
Platelet Rich Plasma ◽  
Critical Role ◽  
Lag Time ◽  
Coagulation Cascade ◽  
Platelet Poor Plasma ◽  
Drug Mechanism ◽  
Healthy Donors ◽  
Anticoagulant Drugs

Abstract Abstract 3335 Introduction: We previously reported that thrombin generation (TG) conducted in human PPP supplemented with synthetic phospholipids (PL) and triggered by 5 pM tissue factor (TF) was a very rapid, suitable and reliable pharmacological tool for screening thrombin and/or FXa inhibitors whatever their inhibition mode. However, a drawback of this work was that platelets, which are known to play a critical role in blood coagulation cascade by providing the catalytic surfaces for coagulation factors activation, were lacking in these experiments. Aims: The aim of this study was thus to compare the effects of various anticoagulant agents on TF-induced TG in platelet rich plasma (PRP)and platelet poor plasma (PPP) in order to define the most relevant and reliable assay to evaluate the potency and the behavior of drugs targeting thrombin and/or FXa. Methods: TG experiments were conducted with Calibrated Automated Thrombogram® (Thrombinoscope) in fresh PRP (150 000 platelets/μL) of 3 individual healthy donors with 1 pM TF + 16.7 mM CaCl2 and in normal pool frozen-thawed PPP of 32 healthy donors with 5 or 1 pM TF + 4 μM PL + 16.7 mM CaCl2. Five anticoagulants with various mode of action (argatroban, lepirudin, enoxaparin, fondaparinux and rivaroxaban) were spiked in the plasmas at increasing concentrations ranging from 10 nM to 5 μM. Results: In the absence of the drugs, the peak of active thrombin concentration was delayed (lag time increase), prolonged (Tmax increase) and reduced (Cmax decrease) when using PRP instead of PPP with 1 pM TF. These effects were still higher when comparing to PPP with 5 pM TF. However, the total amount of active thrombin (ETP) was similar in the three experimental designs. For all the parameters, the experimental CVs were <5% for PPP with 5 pM TF and < 15% for both PPP and PRP with 1 pM TF. In presence of the anticoagulant drugs, the peak of active thrombin concentration was concentration-dependently delayed, prolonged and reduced within all the assays. In PRP with 1 pM TF, all the drugs displayed close behaviors, excepting lepirudin. In PPP, and especially with 5 pM TF, more different profiles were found according to the mechanism of action of drugs. Regarding to the potency of the drugs, the inhibition parameters (i.e. 2x lag time, 2x Tmax, Cmax EC50 and Vmax EC50) were in the same range for argatroban and lepirudin whatever the chosen assay. For enoxaparin, rivaroxaban and fondaparinux, the drug effects varied among the assays but also following to the studied parameters. In all the assays, lepirudin was the most active drug to increase the lag time and the Tmax. The Cmax was mostly decreased by fondaparinux in PRP with 1 pM TF, by rivaroxaban in PPP with 5 pM TF and by both drugs in PPP with 1 pM TF. The ETP was mostly diminished by fondaparinux in PRP with 1 pM TF while the stronger effects were found with fondaparinux and enoxaparin using the two others inducers. Conclusions: The present study did not demonstrate a superiority of TF-induced thrombin generation assay conducted in PRP compared to PPP supplemented with synthetic PL. Although the potency of the drugs varied according to the studied parameter and the experimental design of the assay, experiments conducted in PL-supplemented PPP with 5 pM TF seemed to be the best suited to study the effects of anticoagulant drugs targeting thrombin and/or FXa due to their high reproducibility and their relevancy on drug mechanism of action. Moreover, the use of frozen-thawed normal pool plasma within these assays was more convenient regarding to the sample collection, storage and handling. It also excluded the inter-donor variability to be more relevant on the normal population hemostatic system. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Platelet Rich Plasma- mechanism of action and clinical applications

2016 ◽  
Vol 1 (2) ◽  
pp. 41-46 ◽  
Author(s):  
Cristina N. Cozma ◽  
Laura Raducu ◽  
Cristian R. Jecan
Keyword(s):  
Mechanism Of Action ◽  
Platelet Rich Plasma ◽  
Clinical Applications

scholarly journals Platelet Rich Plasma- mechanism of action and clinical applications

2016 ◽  
Vol 1 (2) ◽  
pp. 41-46
Author(s):  
Cristina N. Cozma ◽  
Laura Raducu ◽  
Cristian R. Jecan
Keyword(s):  
Mechanism Of Action ◽  
Platelet Rich Plasma ◽  
Clinical Applications

Visualization of the Platelet-Plasma Interface

1977 ◽  
Vol 35 ◽  
pp. 494-495
Author(s):  
D. C. Brindley ◽  
M. McGill
Keyword(s):  
Platelet Rich Plasma ◽  
Coagulation Factors ◽  
Platelet Membrane ◽  
Rabbit Platelet ◽  
Surface Coat ◽  
Special Relationship ◽  
Routine Method ◽  
Embedding Technique ◽  
Biochemical Analyses ◽  
Adsorptive Properties

Morphological and cytochemical studies of platelets have reported a surface coat, or glycocalyx, external to the plasma membrane (1). Biochemical analyses have likewise confirmed the highly adsorptive properties of platelets as transporters of coagulation factors (2). However, visualization of the platelet membrane by conventional EM procedures does not reflect this special relationship between the platelet and its plasma environment. By the routine method of alcohol-propylene oxide dehydration for Epon embedding, the lipid bilayer nature of the platelet membrane appears similar to other blood cells (Fig. 1). A new rapid embedding technique using dimethoxypropane (DMP) as dehydrating agent (13) has permitted ultrastructural analyses of the surface features of the platelet-plasma interface.Aliquots of human or rabbit platelet-rich plasma (PRP) were added to equal volumes of 6% glutaraldehyde in Millonig's buffer at 37° for 45 minutes, rinsed in buffer and postfixed in 1% osmium in Millonig's buffer for 45 minutes.

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