Concentrations Of Platelet-rich Plasma Research Articles

The effect of PRP and hyperosmolarity simultaneous use on expression profile alteration of miRNAs associated with cartilage differentiation in human adipose tissue-derived mesenchymal stem cells

BackgroundMesenchymal stem cells (MSC) are a type of multipotent stem cell whose differentiation into cartilage cells has been considered in recent years. Platelet-rich plasma (PRP) may impair cartilage differentiation due to its richness in growth factors and hyperosmolarity due to its proximity to the required cartilage environment. ObjectivesThe main purpose of this study was to treat human adipose tissue-derived MSCs concurrently with PRP and hyperosmolarity to investigate the expression profile of micro-RNA (miRNA) involved in the cartilage process differentiation. We examined the effect of PRP and the increase in osmolarity on the expression of miR-27, miR-101, miR-140, miR-145, miR-146, and miR-199. MethodsMesenchymal stem cells were extracted from human adipose tissue and differentiated into chondrocytes and the effect of baseline cultures (diff), PRP (prp), hyperosmolarity (os), base plus hyperosmolarity (diff + os), PRP plus hyperosmolarity (prp + os) next to the control group were studied in cartilage differentiation using specific stains such as Alcian blue, hematoxylin and eosin, and collagen type 2 and 10 immunohistochemistry. In addition, the expression of miR-27, miR-140, miR-199, miR-146, miR-101, and miR-145 was evaluated using real-time PCR. ConclusionHuman adipose tissue-derived MSCs with the ability to differentiate into adipocytes and osteocytes showed the properties of chondrocytes in all differentiation groups. Alkaline phosphatase (ALP) enzyme activity and calcium deposition were lower in the diff + os group than in other groups. Therefore, the diff + os group may be a more suitable environment for cartilage differentiation. Furthermore, 5% PRP concentration and hyperosmolarity showed a positive effect on miR-140, miR-199, miR-27, and, miR-146 and a negative effect on miR-101 and miR-145 on cartilage differentiation.

DETERMINATION OF THE OPTIMUM PLATELET-RICH PLASMA METHOD FOR THE ESSENTIAL AMOUNT OF PLATELETS

Objective: Platelet-rich plasma (PRP) is the cellular plasma component containing a higher platelet concentration obtained by centrifugation of autologous peripheral blood. PRP has an auxiliary role in regenerative medicine treatment. Current treatment protocols for tissue repair strategies may be globally insufficient. PRP treatment via Platelet-released growth factors (GF) supports inflammation, proliferation, and wound healing. PRP studies have progressed and have proposed different formulations in recent years. Although various methods and devices are used, there are few and different standardized protocols to obtain PRP with the highest platelet concentration. Although anticoagulants containing citrate are primarily preferred in PRP production To provide effective platelet concentration in PRP, we noticed differences in the literature regarding PRP tube volumes, anticoagulant-citrate, and blood amounts. We aimed to obtain the most appropriate platelet concentration in PRP treatment by using different concentration ratios of Acid Citrate dextrose (ACD) solution A and different blood amounts and introducing a new treatment method to the literature. Methods: The blood of 30 individuals aged between 30 and 75 was taken into 10cc laboratory tubes, and 15cc and 18cc hourglass-shaped PRP tubes containing 8% ACD-solution A. Blood fractions were separated by centrifugation, buffy coat area was collected, and count platelet amount by Hematology Analyzer. Results: The platelet amount per µl was statistically significantly higher in 18cc blood compared to 15cc and 10cc. Platelet amounts obtained from 15 and 18cc peripheral blood with 8% ACD-solution A were above the effective treatment amount recommended in the literature. Conclusion: It was observed that the amount of used blood volume was correlated with the amount of obtained platelets.

Integral and Local Methods for the Evaluation of the Hemostasiological Profile in Sheep at Various Stages of Implantation of a Biodegradable Vascular Graft.

The object of the study was the whole blood of sheep collected at the stage of premedication, during the intraoperative period, and in the early postoperative period. Thromboelastography was used to assess the kinetics of clot formation and changes in its viscoelastic properties in whole blood samples. The thrombin generation test was performed in platelet-rich plasma (PRP) and platelet-poor plasma (PPP) with the assessment of quantitative and temporal parameters. The platelet factor 4 concentration in PRP and PPP was measured by the enzyme immunoassay. The functional activity of platelets in PPP was assessed with inductors and without additional stimulation. Prothrombin complex activity, APTT values, thrombin time, fibrinogen concentration, antithrombin III and protein C activity, soluble fibrin monomer complexes, and fibrinolysis were determined in blood plasma. Multidirectional changes in the hemostasiological profile at various stages of vascular prosthesis implantation have been revealed. On the one hand, it is an increased prothrombogenic status, on the other hand, it is the development of hypocoagulation. Shortening of the R (blood coagulation time) and K (clot formation time) intervals and an increase in the angle parameter and maximum amplitude on the thromboelastogram in all the studied periods relative to the reference values, a significant increase in platelet factor 4 in PRP and increased platelet aggregation testified in favor of hypercoagulation. However, the quantitative parameters of the thrombin generation test and a number of coagulogram indicators pointed to hypocoagulation in the intraoperative and early postoperative periods. The comparative analysis of local tests characterizing the state of hemostasis and indicators of integral methods demonstrated the advantages of the latter in assessing thrombotic risks during implantation of vascular grafts. Local tests are not sufficient to assess the dynamics of the coagulation process in real time and are not always sensitive to hypercoagulation. The use of integral methods will help to fill these gaps, make a timely diagnosis of hypercoagulability and minimize the risks associated with the implantation of vascular grafts in future.

Effect of platelet-rich plasma scaffolding combined with osteochondral autograft transfer for full-thickness articular cartilage defects of the femoral condyle

We aimed to investigate the local application methods of platelet-rich plasma (PRP) and the effect and safety of PRP scaffolding combined with osteochondral autograft transfer (OAT) in the treatment of full-thickness articular cartilage defects of the femoral condyle. Patients with cartilage defects of the femoral condyle were treated with OAT combined with PRP scaffolding between July 2017 and December 2020. Preoperative magnetic resonance imaging (MRI) and computed tomography were utilized to assess the size, location, and severity of the osteochondral defects. X-ray and MRI images of the knee were obtained at the final follow-up to assess the osseointegration and integrity of the implanted articular cartilage. Osteoarthritic changes in the knee joint were evaluated using the Kellgren–Lawrence grading system. Clinical status was assessed using the visual analog scale (VAS), International Knee Documentation Committee (IKDC), and Lysholm scores before the treatment and at the final follow-up. Complications and patient satisfaction were recorded to assess the safety of this combination therapy. Twenty-one patients were recruited, with a mean follow-up duration of 18.23 ± 6.84 months. The mean lesion size was 2.3 ± 0.59 cm2. The mean platelet concentration in PRP at baseline was 6.27 ± 0.63 times greater than that in the peripheral blood. The VAS, IKDC, and Lysholm scores had improved significantly at the final follow-up (P < 0.001). No serious complications such as joint infection, deep venous thrombosis, or hematoma were observed. Eighteen patients (85.72%) were satisfied with their knee function and quality of life at the final follow-up. Three patients (14.28%) complained of mild anterior knee pain, which was relieved by oral administration of nonsteroidal anti-inflammatory drugs. MRI examinations of all patients showed bony consolidation and the defect surface was covered with cartilage-like tissue. X-ray evaluations indicated that osteoarthritis in two knees (9.5%) had progressed from grade 1 to grade 2 at the final follow-up. The preliminary results showed that OAT combined with PRP may be a safe and effective technique for the treatment of full-thickness articular cartilage defects in the knee.

Improvement of human sperm properties with platelet-rich plasma as a cryoprotectant supplement.

Platelet-rich plasma (PRP) is a remarkable substance, which involves the growth and proliferation of all cell types. As a source of growth factors, we evaluated whether sperm cryopreservation supplemented with PRP improves the rates of sperm motility, viability, and DNA integrity after vitrification compared with conventional cryo-medium. 20 normal semen specimens were collected from healthy men. After swim-up preparation, each sample was divided into four aliquots. One, as control, received no treatment, and the other three experimental samples were treated with three different concentrations of PRP as cryoprotectant. Sperm parameters were examined before and after freezing procedure. PRP had no significant effect on sperm count. Meanwhile, the percentage of sperm progressive motility and viability in the PRP treated samples with 1×105 /µL concentration was significantly higher than control group. Besides, the rate of immotile sperms in these samples was significantly lower than the control. Sperm viability was significantly higher in the PRP samples at 1×105/µL concentration. In the case of DNA integrity, CMA3 staining showed that the lower PRP concentration was correlated with the higher rate of abnormal spermatozoa. SCD showed that the rate of abnormal sperms in the PRP samples with 1×105 /µL concentration was significantly lower than control group. This study showed a protective effect of PRP on human sperm quality at an optimized concentration after vitrification. Besides, the effects of PRP supplementation of sperms on successful fertility following sperm preservation will be of interest.

316 Role of platelet and growth factor concentration in platelet rich plasma therapeutic response to alopecia

The use of platelet rich plasma (PRP) for the treatment of hair loss has increased significantly in recent years. PRP treatment involves obtaining autologous PRP from a patient’s blood sample and injecting it into the scalp. Although a promising treatment for alopecia, the role of platelet and growth factor (GF) concentration in PRP on hair growth is poorly understood. Herein, we present a case series of 3 patients (A, B and C) with androgenetic alopecia (AGA) who received PRP therapy containing platelet concentrations that were 15-55% of the baseline in the blood throughout the course of their treatment.

P-799 To evaluate the effect of Intra-ovarian platelet rich plasma instillation on the clinical outcome of women with diminished ovarian reserve: A prospective interventional study

Abstract Study question Does intra-ovarian instillation of platelet rich plasma (PRP) improves the clinical outcome of IVF cycles in women with Diminished Ovarian reserve (DOR)? Summary answer PRP instillation leads to consistent improvement in Antral follicle count (AFC), thus achieving clinical pregnancy rate of 33.3% per cycle in women with DOR. What is known already There is rising incidence of females with diminished ovarian reserve (DOR) especially among Asian ethnicity. With the emergence of regenerative medicine, multiple studies have evaluated the role of intra-ovarian PRP, demonstrating a beneficial role in improving ovarian reserve parameters (serum Follicular stimulating hormone (FSH), serum anti-Mullerian hormone (AMH), AFC). Despite its’ favorable effects on biochemical markers and AFC, data regarding improvement in clinical outcome remains elusive and led to inception of this study. Study design, size, duration A prospective interventional study was conducted at Division of Reproductive Medicine of a tertiary care institute. 41 infertile females aged 20-39 years with DOR (AMH &amp;lt;1.2 ng /ml; AFC&amp;lt;5) were enrolled in the study during a 6-month period beginning from August 2021. Participants/materials, setting, methods After informed consent, patients received fresh autologous PRP, prepared from 30 ml venous blood. 1.5ml of PRP instilled in each ovarian stroma between day 7-10 of menstrual cycle under sedation. Patients were followed up for three-consecutive months to assess ovarian reserve parameters including serum FSH, AMH and AFC. Patients showing significant improvement in parameters were recruited for fresh IVF cycles using Antagonist protocol with 1% transdermal testosterone. Outcomes were analysed using linear mix effect model. Main results and the role of chance The average platelet concentration in PRP was ∼10,00,000 platelets/µL. The mean age of enrolled patients was 31.22±4.16 years. Linear improvement in AFC (3.63 vs 6.98 vs 7.97 vs 6.90, p&amp;lt;0.001) was observed from baseline to three consecutive follow-up months with maximal response witnessed in second month in 57.1% of those undergoing IVF cycle. However, there was no significant difference in Serum FSH (p=0.11) and AMH (p=0.16) from the baseline post intervention. Of the 41 patients, 35 (85.3%) responded to the treatment and underwent IVF antagonist cycle. 5 out of 35 IVF cycles were cancelled mid-cycle due to poor ovarian response. The mean dose of gonadotropin requirement was 2667.5±281.1 IU (Follicular stimulating hormone) and 1400±337.3 IU (Human menopausal gonadotropin). The average number of oocytes retrieved was 5.7±2.2 whereas mean number of MII oocytes was 4.63±1.85. The fertilization rate and the cleavage rate were 92.4% and 74.1% respectively. Of the thirty patients, eight patients underwent day 2 transfer due to poor grade of embryos. Mean number of grade 1- day 3 embryos was 1.25±0.55 with surplus embryos available for cryopreservation in 14 patients. The overall clinical pregnancy rate per transfer was 33.33%. No adverse events were reported. Limitations, reasons for caution This was a prospective single arm study. A randomized controlled trial comprising a “no-treatment” arm would establish a Level-I evidence. However, “no-treatment” arm in a developing country like ours, imposes financial burden on the couple with no guaranteed clinical success and thus raising ethical concern and need for ovarian rejuvenation. Wider implications of the findings With the impetus to provide a biological child to these DOR women, intra-ovarian PRP instillation as a method of ovarian rejuvenation holds promising results. Evidently, PRP is not only effective in improving ovarian reserve but this translates into an improved reproductive outcome in a population, previously limited to oocyte donation. Trial registration number REF/2022/01/051033

Therapeutic Efficacy of Intravesical Platelet-Rich Plasma Injections for Interstitial Cystitis/Bladder Pain Syndrome-A Comparative Study of Different Injection Number, Additives and Concentrations.

Purpose: Intravesical platelet-rich plasma (PRP) injections have been demonstrated effective in relieving symptoms among patients with interstitial cystitis/bladder pain syndrome (IC/BPS). This study compared the clinical efficacy among different injection number, adding solution, and concentrations of PRP. Methods: A total of 63 patients with IC/BPS were enrolled and randomly allocated to four subgroups who received single high-dose PRP (from 100 ml whole blood) plus 10 ml of normal saline or plasma injected over 20 or 40 sites. Patients were followed up at 1, 3, and 6 months for changes in the IC symptom index (ICSI) and problem index (ICPI), visual analog scale (VAS), global response assessment (GRA), and urodynamic parameters. Furthermore, we compared the clinical outcome with our previous study in a group of 55 IC/BPS patients who underwent four monthly low-dose PRP (from 50 ml whole blood) injections. Results: The result of this study showed significant improvements in IC symptoms (ICSI 11.9 ± 4.4 vs. 10.2 ± 4.9, p = 0.009; ICPI 12.3 ± 3.4 vs. 10.6 ± 4.7, p = 0.003); VAS (5.46 ± 2.96 vs. 3.83 ± 3.1, p 0.000), and maximum flow rate (10.4 ± 4.9 vs. 17.1 ± 11.5 ml/s, p = 0.000) at 3 months after single high-dose PRP injection. However, no significant differences in therapeutic results were observed among subgroups, regardless of the added component or injecting site. The improvements of ICSI, ICPI, and GRA at 6 months were lower in comparison with the results of four low-dose PRP injections. All patients were free of dysuria, urinary retention, or urinary tract infection after PRP treatment. Conclusion: Intravesical PRP injection is effective for IC/BPS. The addition of normal saline or plasma and injection site had no influence on therapeutic efficacy. However, the symptom improvement and GRA after a single high-dose PRP injection was lower than that after four low-dose PRP injections 6 months after the first treatment. Limitation of the study is lack of sham control group.

Platelet-rich plasma pretreatment protects anterior cruciate ligament fibroblasts correlated with PI3K-Akt-mTOR pathway under hypoxia condition.

Background/Objective: Biological factors such as platelet-rich plasma (PRP) combined with anterior cruciate ligament (ACL) primary repair technology are used to treat ACL injury. However, the protective mechanism of PRP for ACL fibroblasts under hypoxia condition is still unknown. The aim of this study was to investigate the protective effect of PRP on ACL fibroblasts under hypoxia condition and illustrate the mechanism of PRP regulating the ACL fibroblasts under hypoxia condition.MethodsThe cells were divided into three groups: control group, hypoxia group and PRP pretreatment group. Lethal dose (LD) 50 for hypoxia induction time and the maximum efficacy of PRP concentration were confirmed by CCK-8 assay. The ability of cell apoptosis, cell proliferation, and cell migration were tested by flow cytometry, scratch assay and transwell assay, respectively. Extracellular matrix (ECM) synthesis and hypoxia-inducible factor 1α (HIF-1α) were identified by immunofluorescence staining, Masson's staining and transmission electron microscope analysis. Inflammatory cell infiltration was assessed by hematoxylin and eosin staining as well as immunofluorescence staining. Western blot analysis and real-time PCR were performed to assess the associated gene and protein expression, respectively. The ratio of phosphorylated/total PI3K, Akt and mTOR were also assessed by western blot analysis.Results① LD 50 of hypoxia was 48 ​h and the maximum efficacy of PRP concentration was 600 ​× ​109/L. ② ANNEXIN V-FITC/PI flow cytometry showed that the hypoxia condition significantly increased the apoptosis of cells (P ​< ​0.001) whereas PRP pretreatment significantly decreased the apoptosis of cells under hypoxia (P ​< ​0.001). The expressions of gene and protein of Bax, Bcl-2, cleaved-caspase 3 were consistent with the results of flow cytometric analysis. ③ Cell cycle analysis for flow cytometry showed the inhibitory effect of hypoxia and promotive effect of PRP pretreatment. ④ Immunofluorescence staining (HIF-1α, collagen I and III) showed the positive effect of hypoxia and negative effect of PRP on these parameters. Real-time PCR showed that type I and III collagen were 2.1 folds and 2.5 folds higher after 48 ​h hypoxia induction compared to the control group. PRP pretreatment significantly reduced the type I and III collagen mRNA expression of the hypoxia induced ACL fibroblasts to 78.5% and 77.7% at 48 ​h compared to hypoxia group (P ​< ​0.001), respectively.⑤ Cell migration assay showed that hypoxia condition significantly restrained cell migration compared with the control group. PRP could alleviate the inhibitory effect of hypoxia on fibroblasts. ⑥ Western blot analysis showed the ratio of phosphorylated/total PI3K, Akt and mTOR in hypoxia group increased to 31%, 20% and 44/% compared to control group, respectively. ⑦ The results of in vivo analysis was in accordance with the results of in vitro analysis.ConclusionPRP can protect ACL fibroblasts via decreasing apoptosis and increasing cell viability, cell migration and cell proliferation under hypoxia condition. And such PRP protective effect was correlated with PI3K/Akt/mTOR pathway.The translational potential of this articlePRP can be used to treat patients with ACL tear by injection under arthroscopy or ultrasound guiding.

Platelet-rich Plasma Extract promoting Migration of Mouse Bone Marrow Cells

Platelet-rich plasma (PRP) is a rich source of plateletderived growth factors such as PDGF, TGF and VEGF, making it a potential material in tissue regeneration, especially in regenerative medicine. Due to the limitation of ethical issues for direct research on humans, this study aimed to collect PRP from peripheral blood of the mouse and evaluate its features as platelet concentration, the structure of activated PRP gel, in vitro cytotoxicity and biological characteristics through migration with mouse bone marrow cells. The results showed that the platelet concentration of PRP was five times higher than that in whole blood and PRP has a dense fibrin network after activating by CaCl2 after 10 minutes. PRP is not only safe for cells but also supports bone marrow cells to migrate and close the gap. With these results, PRP can be seen as a material with a considerable potential for wound healing, especially regenerative medicine.

The Effect of Leukocyte Concentration on Platelet-Rich Plasma Injections for Knee Osteoarthritis: A Network Meta-Analysis.

It is hypothesized that leukocyte-poor (LP) platelet-rich plasma (PRP) is preferred over leukocyte-rich (LR) PRP for the treatment of knee osteoarthritis (OA). The MEDLINE, Embase, and Cochrane databases were reviewed for all English-language studies comparing LP-PRP or LR-PRP with relevant controls or each other. The follow-up periods were 6 months and 12 months. The primary outcome measure was the change in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between baseline and follow-up. The secondary outcome measures were changes in the WOMAC pain subscale, visual analog scale (VAS) for pain, and International Knee Documentation Committee (IKDC) subjective score between baseline and follow-up, and the incidence of local adverse reactions. Treatment outcomes were analyzed using the mean difference between treatments for continuous outcomes and the odds ratio for binary outcomes, with 95% credibility intervals. Treatment modalities were ranked using the surface under the cumulative ranking (SUCRA) probabilities. Risk of bias was assessed using the relevant Cochrane tools, RoB 2 (version 2 of the Cochrane risk-of-bias tools) for randomized controlled trials (RCTs) and ROBINS-I (Risk of Bias in Non-Randomized Studies - of Interventions) for prospective comparative studies (PCSs). This network meta-analysis included 23 studies: 20 RCTs and 3 PCSs, with a total of 2,260 patients and a mean follow-up period of 9.9 months. The overall risk-of-bias assessment of the RCTs revealed that 9 studies had low risk, 7 had some concerns, and 4 had high risk. The overall risk-of-bias assessment of the PCSs revealed that 1 study had low risk and 2 had moderate risk. We found no significant (p < 0.05) difference in all outcome measures and local adverse reactions between LP-PRP and LR-PRP. SUCRA rankings revealed that, for all outcome measures, LP-PRP is preferred to LR-PRP across follow-up periods. Leukocyte concentration of PRP does not play a significant role in patient-reported outcome measures for knee OA. LP-PRP is preferred to LR-PRP according to SUCRA rankings, but this preference may not be important in clinical practice. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Positive effect of autologous platelet rich plasma on Saanen buck semen cryopreservation in non-breeding season

The objective of the current study was to evaluate the effect of autologous platelet-rich plasma (PRP) addition into soybean lecithin based extender on buck semen at post-thaw. Semen samples were collected from eight Saanen buck, and each semen sample was split into four equal aliquots and diluted with different concentrations of PRP supplemented extenders [no PRP (control), 0.5 × 107/ml PRP, 1 × 107/ml PRP, or 2 × 107/ml PRP]. Motility, plasma membrane functional integrity, acrosome integrity, mitochondrial membrane potential, DNA integrity and malondialdehyde concentrations (MDA) were measured and analyzed at post-thaw. The results showed that 2 × 107/ml PRP group had a positive effect on motility (62.41 ± 4.24), membrane functional integrity (71.11 ± 2.90), mitochondrial membrane potential (69.70 ± 1.99), DNA integrity (7.22 ± 0.93) and MDA levels (2.56 ± 0.73) at post-thaw (P < 0.05). The results of the study demonstrated that autologous PRP has a protective effect on cryopreservation of buck spermatozoa and the fertility effects are worthy of further study.

Platelet rich plasma concentration improves biologic mesh incorporation and decreases multinucleated giant cells in a dose dependent fashion.

Platelet rich plasma (PRP) has been shown to improve incorporation and reduce inflammation in ventral hernia repair (VHR) with acellular dermal matrix (ADM). The concentration of platelets in PRP varies in clinical studies and an ideal concentration has yet to be defined. The effects of varied concentrations of PRP on ADM incorporation and inflammatory cell infiltration in a rat model of VHR. We hypothesized that increasing concentration of PRP would lead to improved incorporation, decreased CD8+ and multinucleated giant cell (MNGC) infiltrate. Lewis rats underwent ventral hernia creation and repair 30days later with porcine non-crosslinked ADM. PRP was applied to the mesh prior to skin closure at concentrations of 1×104 plt/μL (PRP-LOW), 1×106 plt/μL (PRP-MID), or 1×107 plt/μL (PRP-HIGH) and tissue harvested at 2 and 4weeks. Cellularization, tissue deposition, and mesh thickness using hematoxylin and eosin and Masson's trichrome, and neovascularization was assessed with VVG staining, to establish the relationship of PRP concentration to metrics of incorporation. MNGC and CD8+ T-cell infiltration were quantified to establish the relationship of inflammatory cell infiltration in response to PRP concentration. Lymphocyte infiltration was assessed using immunohistochemical staining for CD8. PRP-HIGH treated had significantly greater tissue deposition at 4weeks. PRP-MID showed increasing mesh thickness at 2weeks. Cell infiltration was significantly higher with PRP-HIGH at both 2 and 4weeks while PRP-LOW showed increased cell infiltration only at 4weeks. At both time points there was a trend towards a dose dependent response in cell infiltration to PRP concentration. Neovascularization was highest with MID-plt at 2weeks, yet no significant differences were noted compared to controls. CD8+ cell infiltrate was significantly decreased at 2 and 4weeks in PRP-LOW and PRP-MID treated groups. PRP at all concentrations significantly decreased MNGC infiltration at 2weeks while only PRP-HIGH and PRP-MID had significant reductions in MNGC at 4weeks. Both MNGC and CD8+ cell infiltration demonstrated dose dependent reduction in relation to PRP concentration. Increasing platelet concentrations of PRP correlated with improved incorporation, tissue deposition, and decreased scaffold degradation. These findings were associated with a blunted foreign body response. These findings suggest PRP reduces inflammation which may be beneficial for ADM incorporation in VHR.

Evaluation of Factors Affecting the Quantity and Quality of Platelet-Rich Plasma and Platelet-Derived Growth Factor-BB

Context: Platelet-rich plasma (PRP) releases growth factors (GFs) upon activation which accelerates the healing and regeneration in the target tissue. Wider applications of PRP warrant product standardization. PRP compositions may vary according to the patient's demographics and the constituents of PRP. Aims: Our study aimed to assess the correlations between age, gender, platelet counts, platelet indices, platelet yield, platelet dose, GF dose, and platelet-derived GF-BB (PDGF-BB) concentration. Settings and Design: This was an experimental study done in the Department of Pathology along with the Department of Dentistry at a tertiary care hospital in North India. Subjects and Methods: PRP was prepared from 40 ml of whole blood. Platelet counts, platelet indices (LH 750 coulter analyzer, Florida, USA), and PDGF-BB levels (enzyme-linked immunosorbent assay, Qayee Bio., Ltd, China) were measured. Platelet yield (%), platelet dose (×106), and GF dose (×1012) in PRP were also calculated. Statistical Analysis Used: All the parameters were analyzed using Pearson's correlation coefficient and linear regression. Paired t-test and Mann–Whitney test were used for two-group analysis. Results: Mean platelet count, PDGF-BB concentration, platelet yield, platelet dose, and GF dose in PRP were 1317 × 103/mm3, 30 ± 9.89 ng/ml, 71.62 ± 28.34%, 6.5 ± 3.5 × 109, and 159.62 ± 52.39 ng/ml, respectively. PRP platelet counts were positively correlated with PDGF-BB concentration, platelet yield, platelet dose, and GF dose. Conclusions: Of all the parameters, PDGF-BB concentration, platelet yield, platelet dose, and GF dose showed a positive correlation with PRP platelet count. Age, gender, and platelet indices had no significant influence.

OPTIMIZING A PLATELET-RICH PLASMA CONCENTRATION PROTOCOL FOR SOUTH AMERICAN SEA LIONS (OTARIA FLAVESCENS).

Accelerated healing in wild or captive South American sea lions (Otaria flavescens) is a key tool to help minimize infection and complications associated with open wounds, dental disease, and ocular pathology. Platelet-rich plasma (PRP) is an autogenous source for growth factors based on platelet concentration, which can be obtained by centrifuging whole blood collected in sodium citrate anticoagulant. Currently, there are well-defined PRP concentration protocols for humans and most domestic companion animal species. However, there is no clear centrifugation protocol for obtaining PRP in most marine mammal species. This study aimed to optimize the platelet concentration protocol based on whole blood centrifugation using speeds ranging from 500 to 5,000 rpm and times ranging from 3 to 6 min. Blood was drawn from seven adult South American sea lions, placed into 1-ml sodium citrate tubes, and centrifuged following 12 different centrifugation protocols. PRP was designated as the lower third fraction of the centrifuged plasma. Platelet counts were performed using flow cytometry and statistical analysis was carried out to establish a well-defined protocol for efficient PRP production. Transmission electron microscopy (TEM) analysis was performed to evaluate possible platelet degranulation during the different centrifugation protocols and measure platelet areas. Maximum concentration of platelets in PRP was 4.73-fold higher than the number of platelets in equal volume of whole blood, and significant differences in the concentrations obtained were found between the 12 centrifugation protocols evaluated using different speed and time combinations. The best one-step centrifugation protocol resulted from using 900-rpm speed for 3 min. The highest-fold increase was achieved using a two-step centrifugation protocol, which combined the most efficient one-step centrifugation protocol (900 rpm, 3 min) with a second centrifugation using 2,000-rpm speed for 6 min. TEM analysis confirmed that platelets were complete and maintained integrity after the proposed protocol.

Platelet-Rich Plasma Induces Autophagy and Promotes Regeneration in Human Dental Pulp Cells.

Regenerative endodontic procedures using autologous platelet-rich plasma (PRP) can improve the biologic outcome of treatment. However, its mechanism of action on improving pulp regeneration is not fully elucidated. Autophagy was recently shown to be related to tissue repair and osteogenesis. Therefore, the objective of this study was to investigate the effect of PRP in dental pulp regeneration and to elucidate the role of autophagy involved in this process. Human dental pulp cells (hDPCs) were isolated from healthy dental pulp and co-cultured with an increasing concentration of PRP. Cellular migration and proliferation were determined by scratch assay, transwell assay, and cell-counting kit 8 assay. Osteogenic differentiation was clarified by using alkaline phosphatase staining, alizarin red staining, and real-time polymerase chain reaction (RT-PCR) to measure the gene expression levels of alkaline phosphatase, collagen-1, osteocalcin, dentin matrix protein 1, and dentin sialophosphoprotein. Autophagic bodies were observed by transmission electron microscopy and the expression of autophagy marker light chain 3B (LC3B) was determined by immunofluorescence staining. The mRNA and protein expression level of LC3B and Beclin-1 were quantified by qRT-PCR and western blotting. The effect of PRP on cellular migration, proliferation, and osteogenic differentiation was further investigated in the milieu of autophagy activator, rapamycin, and inhibitor, 3-methyladenine. Results showed that PRP promoted cell migration, proliferation, and osteogenic differentiation. Autophagic bodies were strongly activated and the expression level of LC3B and Beclin-1 was significantly promoted by PRP. Autophagy inhibition suppressed PRP-induced hDPCs migration, proliferation, and osteogenic differentiation, whereas autophagy activator substantially augmented PRP-stimulated migration, proliferation, and differentiation. Taken together, these findings suggested that PRP could effectively promote regenerative potentials associated with autophagy.

Human platelet-rich plasma as a biological stimulant for proliferation and differentiation of mesenchymal stem cells

Platelet is one of the cells within the blood that have potential in regenerative therapy. Recently platelet-related products got special attention due to the abundance of growth factors and easy availability and processing. With the robust in cell-based therapy, platelet-rich plasma (PRP) has been intensively studied for its potential to substitute the fetal bovine serum (FBS) as the supplement in cell culture. Our study aimed to investigate the use of human PRP in mesenchymal stem cells (MSC) culture and its related effect on stem cell biology. We searched in vitro studies that used human PRP as a supplementing factor on human MSCs culture. From the initial 172 studies, 14 studies fulfilled the selection criteria and were analysed. The results showed that the sources of MSCs were varied, including adipose tissue, bone marrow, and dental tissue. The PRP concentration showing the best effects was ranged from 10 to 20%. In addition, most of the studies demonstrated the superiority of PRP to FBS in promoting the proliferation and differentiation of MSCs in vitro. Therefore, PRP could be an alternative to FBS in supporting a xeno-free culture system. Studies are needed to reveal the mechanism of PRP in maintaining the physiology of MSCs.

A 3D-printed PRP-GelMA hydrogel promotes osteochondral regeneration through M2 macrophage polarization in a rabbit model

Osteochondral regeneration is an orchestrated process of inflammatory immunity, host cell response, and implant degradation in tissue engineering. Here, the effects of a platelet-rich plasma (PRP)-gelatin methacryloyl (GelMA) hydrogel scaffold fabricated using the digital micro-mirror device (DMD) technique for osteochondral repair were investigated in a rabbit model. GelMA hydrogels with different PRP concentrations were fabricated, and their roles in bone marrow mesenchymal stem cells (BMSCs) and macrophage polarization in vitro were investigated. The incorporation of 20% PRP into the hydrogel showed optimal effects on the proliferation, migration, and osteogenic and chondrogenic differentiation of BMSCs. The 20% PRP-GelMA (v/v) hydrogel also promoted M2 polarization with high expression of Arg1 and CD206. Compared to the 20% PRP group, the 50% PRP group showed similar biological roles in BMSCs but less extent of osteogenesis. In the vivo study, the 20% PRP-GelMA composite was used for osteochondral reconstruction and showed more cartilage and subchondral bone regeneration than that observed using the pure GelMA hydrogel. The PRP-GelMA group exhibited more M2 macrophage infiltration and less M1 macrophage presentation at three time points as compared to the nontreatment group. The expression of Arg1 in the PRP-GelMA group increased significantly at 6 weeks but decreased to a lower level at 12 weeks, while CD163 showed sustained high expression until 18 weeks. Our findings demonstrated that the 3D-printed PRP-GelMA composite could promote osteochondral repair through immune regulation by M2 polarization and could be a potential candidate for osteochondral tissue engineering. Statement of significancePRP-GelMA hydrogels promoted the migration and osteogenic and chondrogenic differentiation of BMSCs. PRP-GelMA hydrogels participated in immune regulation and M1-to-M2 transition of macrophages. PRP-GelMA hydrogels coordinated and promoted several overlapping osteochondral repair events, including dynamic immune regulation, chemotaxis of MSCs, and osteochondral differentiation. PRP-GelMA hydrogels showed superior cartilage and subchondral bone repair properties.

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.

Commercial blood cell separation systems versus tube centrifugation methods for the preparation of platelet-rich plasma: a preliminary cross-sectional study.

Clinical studies claim that platelet-rich plasma (PRP) accelerates tissue healing due to its high concentration of growth factors and that the combination with leukocytes improves the antimicrobial effect of the concentrate. Most of these studies obtained PRP using different separation systems, and few analyzed the content of the PRP used for treatment. This study characterized the composition of PRP and white blood cells (WBC) from a single donor produced by three commercially available PRP separation systems and two anticoagulated general analytical tubes. Five patients donated 50 mL of blood, which was processed to produce PRP and WBC using three PRP concentration systems (i.e., Easy PRP Kit, GloPRP, and Wego) and two tubes for general analysis anticoagulated with ethylenediaminetetraacetic acid (EDTA) and citrate. Platelets and WBC in combination with their concentrates were analyzed by automated systems in a clinical laboratory. There were no significant differences in the average concentrations of PRP platelets and WBC between GloPRP and the tubes for general analysis with EDTA and citrate; however, the Easy PRP Kit gave results much superior to the rest of the methods, especially comparing it with the Wego Kit, whose concentrates were especially low, even nonexistent for WBC. The Easy PRP Kit concentrates WBC-rich PRP, resulting in increased WBC concentrations, compared with low WBC-low PRP of GloPRP and general tube methods for EDTA and citrate analysis and the even lower concentration of PRP from the Wego Kit, with the absence of leukocytes.