scholarly journals A Novel and Convenient Method for the Preparation and Activation of PRP without Any Additives: Temperature Controlled PRP

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Lijuan Du ◽  
Yong Miao ◽  
Xin Li ◽  
Panli Shi ◽  
Zhiqi Hu
Keyword(s):  
Convenient Method ◽  
Slow Release ◽  
Natural Fiber ◽  
Ph Value ◽  
Platelet Rich Plasma ◽  
Activation Process ◽  
Platelet Concentration ◽  
Novel Method ◽  
Human Blood Samples ◽  
Temperature Controlled

Platelet rich plasma (PRP) is a concentrate of autologous platelets which contain enrichment growth factors (GFs). However, the addition of exogenous anticoagulant and procoagulant may result in clinical side effects and raise the price of PRP. Herein, we report a novel method named temperature controlled PRP (t-PRP), in which exogenous additives are dispensable in the preparation and activation process. Human blood samples were processed by a two-step centrifugation process under hypothermic conditions (4°C) to obtain t-PRP and rewarming up to 37°C to activate t-PRP. Contemporary PRP (c-PRP) was processed as the control. t-PRP showed a physiological pH value between 7.46 and 7.48 and up to 6.58 ± 0.45-fold significantly higher platelet concentration than that of whole blood compared with c-PRP (4.06-fold) in the preparation process. Meanwhile, t-PRP also maintained a stable GF level between plasma and PRP. After activation, t-PRP demonstrated natural fiber scaffolding, which trapped more platelet and GFs, and exhibited a slow release and degradation rate of GFs. In addition, t-PRP exhibited the function of promoting wound healing. t-PRP is a novel and convenient method for the preparation and activation of PRP without any additives. Compared to c-PRP, t-PRP reflects more physiologic characteristics while maintaining high quality.

scholarly journals Platelet Rich Plasma - Platelet Counts and Application - A Literature Review

2020 ◽  
pp. 131-138
Author(s):  
P. Kalyani ◽  
G. Kaarthikeyan ◽  
M. P. Santhosh Kumar
Keyword(s):  
Tissue Regeneration ◽  
Platelet Rich Plasma ◽  
Interleukin 1 ◽  
Venous Blood ◽  
Differential Centrifugation ◽  
Number Of Factors ◽  
Fibrin Network ◽  
Platelet Concentration ◽  
Novel Method ◽  
Centrifugation Technique

Platelet rich plasma (PRP) is a novel method of using plasma concentrated with platelets for wound healing and tissue regeneration. Platelet rich plasma is prepared from the venous blood using a differential centrifugation technique. It involves a separation spin and a concentration spin, yielding platelet rich plasma. PRP products have been classified into 4 types depending upon major cell constituent and fibrin density upon activation. These are as follows: Pure PRP, Leukocyte and PRP, Pure PRF, Leukocyte and PRF. PRF differs from PRP in that it is rich in a high density fibrin network after activation. PRP is abundant in a variety of growth factors such as VEGF, PDGF, TGF, EGF, and Interleukin-1. Literature consists of reports by different authors about the platelet yield of PRP centrifuged by different systems. A number of factors have also been quoted to influence the platelet concentration in platelet rich plasma. Hence, the aim of this review is to discuss the platelet concentration in PRP centrifuged by different systems and to observe for variations if any.

Dipyridamole Inhibits Platelet Aggregation in Whole Blood

1983 ◽  
Vol 50 (04) ◽  
pp. 852-856 ◽  
Author(s):  
P Gresele ◽  
C Zoja ◽  
H Deckmyn ◽  
J Arnout ◽  
J Vermylen ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Whole Blood ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Significant Negative Correlation ◽  
Significant Inhibition ◽  
Oral Drug ◽  
Human Blood Samples ◽  
Induced Aggregation

SummaryDipyridamole possesses antithrombotic properties in the animal and in man but it does not inhibit platelet aggregation in plasma. We evaluated the effect of dipyridamole ex vivo and in vitro on platelet aggregation induced by collagen and adenosine- 5’-diphosphate (ADP) in human whole blood with an impedance aggregometer. Two hundred mg dipyridamole induced a significant inhibition of both ADP- and collagen-induced aggregation in human blood samples taken 2 hr after oral drug intake. Administration of the drug for four days, 400 mg/day, further increased the antiplatelet effect. A significant negative correlation was found between collagen-induced platelet aggregation in whole blood and dipyridamole levels in plasma (p <0.001). A statistically significant inhibition of both collagen (p <0.0025) and ADP-induced (p <0.005) platelet aggregation was also obtained by incubating whole blood in vitro for 2 min at 37° C with dipyridamole (3.9 μM). No such effects were seen in platelet-rich plasma, even after enrichment with leukocytes. Low-dose adenosine enhanced in vitro inhibition in whole blood.Our results demonstrate that dipyridamole impedes platelet aggregation in whole blood by an interaction with red blood cells, probably involving adenosine.

Failure Analysis Case Study of a 1.5 Meter Space Flex Harness

2017 ◽  
Author(s):  
Erick Kim ◽  
Kamjou Mansour ◽  
Gil Garteiz ◽  
Javeck Verdugo ◽  
Ryan Ross ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Failure Modes ◽  
Field Of View ◽  
Area Of Interest ◽  
Air Stream ◽  
Novel Method ◽  
Temperature Controlled ◽  
Non Destructive ◽  
Failure Site

Abstract This paper presents the failure analysis on a 1.5m flex harness for a space flight instrument that exhibited two failure modes: global isolation resistances between all adjacent traces measured tens of milliohm and lower resistance on the order of 1 kiloohm was observed on several pins. It shows a novel method using a temperature controlled air stream while monitoring isolation resistance to identify a general area of interest of a low isolation resistance failure. The paper explains how isolation resistance measurements were taken and details the steps taken in both destructive and non-destructive analyses. In theory, infrared hotspot could have been completed along the length of the flex harness to locate the failure site. However, with a field of view of approximately 5 x 5 cm, this technique would have been time prohibitive.

Anti-Inflammatory Effects of Novel Standardized Platelet Rich Plasma Releasates on Knee Osteoarthritic Chondrocytes and Cartilage in vitro

2019 ◽  
Vol 20 (11) ◽  
pp. 920-933 ◽  
Author(s):  
Lucía Gato-Calvo ◽  
Tamara Hermida-Gómez ◽  
Cristina R. Romero ◽  
Elena F. Burguera ◽  
Francisco J. Blanco
Keyword(s):  
Gene Expression ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Cartilage Explants ◽  
Ex Vivo Model ◽  
Chondrocyte Viability ◽  
Platelet Concentration ◽  
The Absolute ◽  
Anti Inflammatory

Background: Platelet Rich Plasma (PRP) has recently emerged as a potential treatment for osteoarthritis (OA), but composition heterogeneity hampers comparison among studies, with the result that definite conclusions on its efficacy have not been reached. Objective: 1) To develop a novel methodology to prepare a series of standardized PRP releasates (PRP-Rs) with known absolute platelet concentrations, and 2) To evaluate the influence of this standardization parameter on the anti-inflammatory properties of these PRP-Rs in an in vitro and an ex vivo model of OA. Methods: A series of PRPs was prepared using the absolute platelet concentration as the standardization parameter. Doses of platelets ranged from 0% (platelet poor plasma, PPP) to 1.5·105 platelets/µl. PRPs were then activated with CaCl2 to obtain releasates (PRP-R). Chondrocytes were stimulated with 10% of each PRP-R in serum-free culture medium for 72 h to assess proliferation and viability. Cells were co-stimulated with interleukin (IL)-1β (5 ng/ml) and 10% of each PRP-R for 48 h to determine the effects on gene expression, secretion and intra-cellular content of common markers associated with inflammation, catabolism and oxidative stress in OA. OA cartilage explants were co-stimulated with IL-1β (5 ng/ml) and 10% of either PRP-R with 0.75·105 platelets/µl or PRP-R with 1.5·105 platelets/µl for 21 days to assess matrix inflammatory degradation. Results: Chondrocyte viability was not affected, and proliferation was dose-dependently increased. The gene expression of all pro-inflammatory mediators was significantly and dose-independently reduced, except for that of IL-1β and IL-8. Immunoblotting corroborated this effect for inducible NO synthase (NOS2). Secreted matrix metalloproteinase-13 (MMP-13) was reduced to almost basal levels by the PRP-R from PPP. Increasing platelet dosage led to progressive loss to this anti-catabolic ability. Safranin O and toluidine blue stains supported the beneficial effect of low platelet dosage on cartilage matrix preservation. Conclusion: We have developed a methodology to prepare PRP releasates using the absolute platelet concentration as the standardization parameter. Using this approach, the composition of the resulting PRP derived product is independent of the donor initial basal platelet count, thereby allowing the evaluation of its effects objectively and reproducibly. In our OA models, PRP-Rs showed antiinflammatory, anti-oxidant and anti-catabolic properties. Platelet enrichment could favor chondrocyte proliferation but is not necessary for the above effects and could even be counter-productive.

scholarly journals Three Manual Noncommercial Methods to Prepare Equine Platelet-Rich Plasma

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1478
Author(s):  
Lorenzo G. T. M. Segabinazzi ◽  
Giorgia Podico ◽  
Michael F. Rosser ◽  
Som G. Nanjappa ◽  
Marco A. Alvarenga ◽  
...  
Keyword(s):  
Blood Transfusion ◽  
Platelet Rich Plasma ◽  
Upright Position ◽  
Platelet Counts ◽  
Cell Counts ◽  
Blood Cell Counts ◽  
Platelet Concentration ◽  
Manual Methods ◽  
White Blood Cell Counts ◽  
Over Time

In light of PRP’s increasing popularity in veterinary practice, this study aimed to compare three manual methods to prepare and cool equine PRP. The blood of 18 clinically healthy mares was collected via venipuncture in a blood transfusion bag (method 1), blood tubes (method 2), and a syringe (method 3). In method 1, samples were double centrifuged; method 2 involved one centrifugation, and in method 3 the syringe was kept in an upright position to sediment for 4 h. After processing with three methods, PRP and platelet-poor plasma (PPP) were extracted and assessed for red (RBC) and white blood cell counts (WBC), platelet counts, and viability. In a subset of mares (n = 6), samples were processed with the three methods, and PRP was evaluated at 6 and 24 h postcooling at 5 °C. Method 1 resulted in the highest and method 3 in the lowest platelet concentration (p < 0.05), and the latter also had greater contamination with WBC than the others (p < 0.001). Platelet viability was similar across treatments (p > 0.05). Cooling for 24 h did not affect platelet counts in all methods (p > 0.05); however, platelet viability was reduced after cooling PRP produced by method 3 (p = 0.04), and agglutination increased over time in all methods (p < 0.001). The three methods increased (1.8–5.6-fold) platelet concentration in PRP compared to whole blood without compromising platelet viability. In conclusion, all three methods concentrated platelets and while cooling affected their viability. It remains unknown whether the different methods and cooling would affect PRP’s clinical efficacy.

Separation and purification of horseradish peroxidase from horseradish roots using a novel integrated method

2021 ◽  
Author(s):  
Wei Ji ◽  
Wenmei Ao ◽  
Mengqiu Sun ◽  
Chunlai Feng ◽  
Yun Wang
Keyword(s):  
Horseradish Peroxidase ◽  
Phase Extraction ◽  
Separation And Purification ◽  
Two Phase ◽  
Affinity Precipitation ◽  
Integrated Method ◽  
Novel Method ◽  
Temperature Controlled ◽  
Aqueous Two Phase Extraction

The aim of the present work was to develop a novel method integrating two-step aqueous two-phase extraction and temperature-controlled affinity precipitation for the separation and purification horseradish peroxidase (HRP) from...

Selective Leaching Nickel from the Pre-Reduced Limonitic Laterite Ore at Atmospheric Pressure

2012 ◽  
Vol 560-561 ◽  
pp. 494-498
Author(s):  
Yong Feng Chang ◽  
Chuan Lin Fan ◽  
Bin Chuan Li ◽  
Xiu Jing Zhai ◽  
Ting An Zhang
Keyword(s):  
Atmospheric Pressure ◽  
Ph Value ◽  
Test Results ◽  
Selective Leaching ◽  
Nickel Extraction ◽  
Extraction Degree ◽  
Leaching Solution ◽  
Novel Method ◽  
Leaching Condition ◽  
Laterite Ore

In this paper a novel method for selective leaching nickel from pre-reduced laterite ore at atmospheric pressure was reported. The reduced calcine was leached in thin acid liquor to liberate the nickel and iron together firstly. By properly controlling the leaching condition, the leached iron ion could hydrolyze as goethite precipitate and regenerate the acid consumed in the leaching procedure. Finally, the nickel is selectively extracted into the leaching solution. The main factors in the leaching process, such as reduction degree of the laterite ore, acidity of the leaching solution were investigated as influence on the nickel extraction. The test results showed that selectively leaching of nickel could be achieved with an extraction degree up to 90% by reducing most of the iron in the lateritic ore to wuestite and controlling the pH value of the leaching solution below 2.5.

scholarly journals Use of platelet-rich plasma in regenerative medicine: technical tools for correct quality control

2018 ◽  
Vol 4 (1) ◽  
pp. e000442 ◽  
Author(s):  
Hajer Graiet ◽  
Anna Lokchine ◽  
Pauline Francois ◽  
Melanie Velier ◽  
Fanny Grimaud ◽  
...  
Keyword(s):  
Quality Control ◽  
Whole Blood ◽  
Sports Medicine ◽  
Platelet Rich Plasma ◽  
Systematic Sampling ◽  
Significant Difference ◽  
Platelet Concentration ◽  
Harvesting Method ◽  
Clinical Interest ◽  
The Subject

Background/aimsPlatelet-rich plasma (PRP) injections are used in sports medicine and have been the subject of increased clinical interest. However, there have been very few reports of the composition of initial whole blood and the final PRP product. The objective of this study was to provide technical tools to perform a correct characterisation of platelets, leucocytes and red blood cells (RBCs) from whole blood and PRP.MethodsBlood and PRP were obtained from 26 healthy volunteers and prepared according to the varying parameters encountered within PRP process preparation and quantification (harvesting method, anticoagulant used, sampling method, counting method). Concentrations were measured at t=0, t=1, t=6 and t=24 hours.ResultsSampling of blood in Eppendorf tubes significantly decreased platelet concentration over time, whereas sampling in Microvette EDTA-coated tube kept platelet concentration stable until 24 hours. A non-significant difference was observed in platelet counts in PRP with impedance (median (IQR): 521.8 G/L (505.3–524.7)) and fluorescence (591.5 G/L (581.5–595.8)) methods. Other studied parameters did not influence platelet concentrations in blood or PRP samples. Leucocytes and RBC counts were similar whatever the anticoagulant, sampling, harvesting and counting methods used for both blood and PRP samples.ConclusionsSystematic sampling of blood and PRP in EDTA-coated tubes for quality control is recommended. The use of a validated counter for PRP sample should also be taken into account.

scholarly journals Novel Method to Simultaneously Adjust the Size and pH Value of Individual Microdroplets in Silicone Oil

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 114183-114190
Author(s):  
Gengchao Chen ◽  
Xianmin Zhang ◽  
Ning Li
Keyword(s):  
Silicone Oil ◽  
Ph Value ◽  
Novel Method

scholarly journals Centrifugation Conditions in the L-PRP Preparation Affect Soluble Factors Release and Mesenchymal Stem Cell Proliferation in Fibrin Nanofibers

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2729 ◽  
Author(s):  
Melo ◽  
Luzo ◽  
Lana ◽  
Santana
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Platelet Rich Plasma ◽  
Clinical Practices ◽  
Soluble Factors ◽  
Tnf Α ◽  
Platelet Concentration ◽  
Tgf Β1

Leukocyte and platelet-rich plasma (L-PRP) is an autologous product that when activated forms fibrin nanofibers, which are useful in regenerative medicine. As an important part of the preparation of L-PRP, the centrifugation parameters may affect the release of soluble factors that modulate the behavior of the cells in the nanofibers. In this study, we evaluated the influences of four different centrifugation conditions on the concentration of platelets and leukocytes in L-PRP and on the anabolic/catabolic balance of the nanofiber microenvironment. Human adipose-derived mesenchymal stem cells (h-AdMSCs) were seeded in the nanofibers, and their viability and growth were evaluated. L-PRPs prepared at 100× g and 100 + 400× g released higher levels of transforming growth factor (TGF)-β1 and platelet-derived growth factor (PDGF)-BB due to the increased platelet concentration, while inflammatory cytokines interleukin (IL)-8 and tumor necrosis factor (TNF)-α were more significantly released from L-PRPs prepared via two centrifugation steps (100 + 400× g and 800 + 400× g) due to the increased concentration of leukocytes. Our results showed that with the exception of nanofibers formed from L-PRP prepared at 800 + 400× g, all other microenvironments were favorable for h-AdMSC proliferation. Here, we present a reproducible protocol for the standardization of L-PRP and fibrin nanofibers useful in clinical practices with known platelet/leukocyte ratios and in vitro evaluations that may predict in vivo results.

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