A STUDY ON EFFICACY OF AUTOLOGOUS PLATELET RICH PLASMA IN MYRINGOPLASTY

Objective: To study the efficacy and advantage in using autologus platelet rich plasma during myringoplasty in closure of tympanic membrane perforation   preventing the graft displacement, promoting quicker healing & improving overall outcome.Methods : Platelet rich plasma(PRP) is an autologus platelet rich concentrate prepared from patients own blood  with growth factors up to 8 times that of normal serum and its efficacy when used during myringoplasty is studied.50 patients with chronic otitis media inactive mucosal disease were randomly chosen and 25 of them was the study group and other 25 were the control group. Both group patients underwent myringoplasty and PRP was used in the study group and the results were evaluated.Results: In our study among 25 cases that underwent myringoplasty with use of platelet rich fibrin, 24 had complete tympanic membrane closure and only one failure has been noticed. In controls 5 out of 25 cases had failure. The graft take up rate in our study is comparable with the reference studies. Use of PRP accelerates graft uptake.Conclusion: Platelet rich plasma is a cheap and cost effective platelet concentrate with enriched growth factors. It accelerates the tympanic membrane closure following myringoplasty.

Combined release of platelet-rich plasma and 3D-mesenchymal stem cell encapsulation in alginate hydrogels modified by the presence of silica

We report the modified release of platelet-rich plasma from alginate platelet-rich plasma hydrogels altered by the presence of silica. These PRP–alginate–silica compositions can be used as injectable carriers for viable mesenchymal stem cells

A manual method to obtain platelet rich plasma

OBJECTIVE:This study is to report a manual method to obtain platelet rich plasma (PRP).METHODS:For this study 61 ml of peripheral blood was obtained and submitted to centrifugation at 541g for 5 min. The centrifugation separates the blood into three components: red blood cells, buffy coat and platelet rich plasma. Blood and platelet rich plasma samples were sent to the Hospital's Laboratory and platelets and leukocytes were measured.RESULTS:A sample of 637 blood donors was evaluated. The platelet yield efficiency was 86.77% and the increase in platelet concentration factor was 2.89 times. The increase in leukocyte concentration factor was 1.97 times.CONCLUSION:The method described here produces leukocyte-rich and platelet-rich plasma with a high platelet and leukocyte increased factor.Level of Evidence IV, Controlled Laboratory Study.Hospital do Coração Knee InstituteUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Department of Orthopedics and TraumatologyUNIFESP, EPM, Department of Orthopedics and TraumatologySciEL

The effect of centrifugation speed and time on pre-analytical platelet activation

Abstract Background: The results of laboratory analyses are affected by pre-analytical variables, and in particular can platelets be activated by shear handling stress and secrete granular substances. We therefore evaluated the effect of centrifugation speed and time on pre-analytical platelet activation. Methods: Citrate- and EDTA-anticoagulated blood from healthy volunteers were centrifuged at 80–10,000 g for 5–15 min to prepare plasma and platelet-rich plasma. Pre-analytical platelet activation was assessed by flow cytometric measurement of platelet P-selectin (CD62p) expression. Blood cell counts, mean platelet volume (MPV), immature platelet fraction (IPF), and platelet distribution width (PDW) were measured. Platelet aggregation in platelet-rich plasma induced by arachidonic acid (AA), ADP or thrombin receptor activator peptide-6 (TRAP) was tested by 96-well aggregometry. Results: The median percentage of platelets expressing P-selectin in citrate- and EDTA-plasma centrifuged at 2000 g for 10 min were 43% [interquartile range (IQR), 38%–53%] and 56% (IQR, 31%–78%), respectively (p=0.82). Platelet-rich plasma prepared at 100–250 g for 10 min had significantly lower platelet P-selectin expression (11%–15%), p&lt;0.001. Platelet count in plasma samples decreased with increasing speed but platelets were only completely removed if plasma was re-centrifuged. In platelet-rich plasma, increasing centrifugation speed significantly increased platelet yield but decreased contamination from other blood cells, platelet composition was altered as platelet parameters (MPV, IPF, and PDW) was lowered. Platelet aggregation was not affected by the centrifugation speed platelet-rich plasma was prepared. Conclusions: Proportional to centrifugation speed, platelets in plasma and platelet-rich plasma were activated with centrifugation speed, cell content and composition changed while platelet aggregation was unaltered. </jats:sec

Myricetin, the main flavonoid in Syzygium cumini leaf, is a novel inhibitor of platelet thiol isomerases PDI and ERp5

Background: Flavonoids have been characterized as a prominent class of compounds to treat thrombotic diseases through the inhibition of thiol isomerases. Syzygium cumini is a flavonoid-rich medicinal plant that contains myricetin and gallic acid. Little is known about the potential anti-platelet properties of S. cumini and its constituent flavonoids. Objective To evaluate the anti-platelet effects and mechanism of action of a polyphenol-rich extract (PESc) from S. cumini leaf and its most prevalent polyphenols, myricetin and gallic acid. Methods PESc, myricetin and gallic acid were incubated with platelet-rich plasma and washed platelets to assess platelet aggregation and activation. In vitro platelet adhesion and thrombus formation as well as in vivo bleeding time were performed. Finally, myricetin was incubated with recombinant thiol isomerases to assess its potential to bind and inhibit these, whilst molecular docking studies predicted possible binding sites. Results: PESc decreased platelet activation and aggregation induced by different agonists. Myricetin exerted potent anti-platelet effects, whereas gallic acid did not. Myricetin reduced the ability of platelets to spread on collagen, form thrombi in vitro without affecting haemostasis in vivo. Fluorescence quenching studies suggested myricetin binds to different thiol isomerases with similar affinity, despite inhibiting only protein disulphide isomerase (PDI) and ERp5 reductase activities (IC50~3.5 μM). Finally, molecular docking studies suggested myricetin formed non-covalent bonds with PDI and ERp5. Conclusions: PESc and its most abundant flavonoid myricetin strongly inhibit platelet function. Additionally, myricetin is a novel inhibitor of ERp5 and PDI, unveiling a new therapeutic perspective for the treatment of thrombotic disorders

The Effect of Platelet Rich Plasma on Mesenchymal Stem Cells (Mscs) Differentiation Into Chondroblast

The addition of platelet rich plasma to mesenchymal stem cell culture on growth media and chondrogenic media had any effect on stem cell's proliferation and differentiation into chondroblast has not been determined. This research is to find out the effect of platelet rich plasma on mesenchymal stem cell's differentiation and proliferation into chondroblast on in vitro media. Randomized control group posttest only design. Blood was taken from the rabbit's vein to be processed into platelet rich plasma (PRP). Mesenchymal Stem Cell (MSC) was harvested from the bone marrow of the rabbit to be cultured. The MSC's culture were divided into three groups of modification. The first group was combination of MSC added with Complete Culture Medium (CCM) and Chondrogenic Diferentation Medium (CDM) without PRP as control group. The second group had the same combination as the first group with extra 5% PRP. The third group had the same combination as the first group with extra 10% PRP. The results were evaluated in the following 21 days. The group that received extra 5% PRP had significant increase of chondroblast count compared to the group without PRP addition (p=0,033). The same result also occured on the groups that received extra 10% PRP compared to the group without PRP addition (p=0,028). There were no significant diferences between both the second and the third groupchondroblast count (p=0,203). There was a significant effect of platelet rich plasma on mesenchymal stem cell's diferentiation and proliferation into chondroblast on invitro media

High Glucose, But Not Testosterone, Increases Platelet Aggregation Mediated by Endothelial Cells

Endothelial cells inhibit platelet aggregation by releasing thromboregulators, such as prostacyclin and nitric oxide. Male subject is a traditional risk factor for cardiovascular diseases. Platelet hyperreactivity has been frequently found in patient with diabetes mellitus. To examine whether testosterone and high glucose modify platelet aggregation through endothelial cells, we did an in vitro study using endothelial cells culture from human umbilical vein (HUVEC). Treatments were performed in HUVEC sub culture as either normoglucose (5.6 mM) or high glucose (22.4 mM) medium, with or without testosterone (0, 1, 10, 100 nM), for 24 hours. HUVEC were trypsinized, resuspended, and then incubated with platelet rich plasma from healthy male donors with ratio 1:104 for 3 minutes. Platelet aggregation measured by turbidimetry methode. This study showed that testosterone did not significantly influence platelet aggregation through endothelial cells in normoglucose (p = 0.144) or high glucose (p = 0.916) medium. There was no main effect of testosterone (p = 0.73) as well as no interaction between testosterone and glucose (p = 0.69), but there was a main effect of glucose (p = 0.004), to platelet aggregation through endothelial cells. In conclusion, high glucose, but not testosterone, inhibits platelet aggregation mediated by endothelial cells

Efficacy of platelet-rich plasma applied to post-extraction retained lower third molar alveoli. A systematic review

Dental retentions have a high prevalence among the general population and their removal can involve multiple complications. The use of platelet rich plasma has been proposed in an attempt to avoid these complications, as it contains high growth factors and stimulates diverse biological functions that facilitate the healing of soft and hard tissues. Objectives: To evaluate the available scientific evidence related to the application of platelet-rich plasma in the post-extraction alveoli of a retained lower third molars. Material and Methods: A systematic review of published literature registered in the Medline, EMBASE, Cochrane and NIH databases. The following categories were included: human randomized clinical studies. Key search words were: platelet rich plasma; platelet rich plasma and oral surgery; platelet rich in growth factors and third molar. Results: Of 101 potentially valid articles, seven were selected, of which four were rejected as they failed to meet quality criteria. Three studies fulfilled all selection and quality criteria: Ogundipe et al.; Rutkowski et al.; Haraji et al. The studies all measured osteoblast activity by means of sintigraphy, and also registered pain, bleeding, inflammation, temperature, numbness as perceived by the patients, radiological bone density and the incidence of alveolar osteitis. Conclusions: Scientific evidence for the use of PRP in retained third molar surgery is poor. For this reason rando - mized clinical trials are needed before recommendations for the clinical application of PRP can be made

An investigation of the antiplatelet effects of succinobucol (AGI-1067)

Succinobucol is a phenolic antioxidant with anti-inflammatory and antiplatelet effects. Given the importance of oxidant stress in modulating platelet–platelet and platelet–vessel wall interactions, the aim of this study was to establish if antioxidant activity was responsible for the antiplatelet activity of succinobucol. Platelet aggregation in response to collagen and adenosine diphosphate (ADP) was studied in rabbit whole blood and platelet-rich plasma using impedance aggregometry. The effect of oxidant stress on aggregation, platelet lipid peroxides, and vascular tone was studied by incubating platelets, washed platelets or preconstricted rabbit iliac artery rings respectively with a combination of xanthine and xanthine oxidase (X/XO). To study the effect of succinobucol in vivo, anaesthetized rats were injected with up to 150 mg/kg succinobucol and aggregation measured in blood removed 15 mins later. Succinobucol (10−5–10−4 M) significantly attenuated platelet aggregation to collagen and ADP in whole blood and platelet-rich plasma. X/XO significantly increased aggregation to collagen and platelet lipid peroxides and this was reversed by succinobucol. Addition of X/XO to denuded rabbit iliac arteries caused a dose-dependent relaxation which was significantly inhibited by succinobucol. In vivo administration up to 150 mg/kg had no effect on heart rate or mean arterial blood pressure but significantly inhibited platelet aggregation to collagen ex vivo. In conclusion, succinobucol displays anti-platelet activity in rabbit and rat blood and reverses the increase in platelet aggregation in response to oxidant stress