Publications by authors named "Peter A Everts"

20 Publications

  • Page 1 of 1

Proteomic analysis of platelet-rich and platelet-poor plasma.

Regen Ther 2020 Dec 1;15:226-235. Epub 2020 Nov 1.

Sports Medicine Center, 450 Broadway St., Pavilion C, Room C-433, MC 6120, Redwood City, CA, 94063, USA.

Background: Autologous blood products, such as platelet-rich plasma (PRP) are commercial products broadly used to accelerate healing of tissues after injuries. However, their content is not standardized and significantly varies in composition, which may lead to differences in clinical efficacy. Also, the underlying molecular mechanisms for therapeutic effects are not well understood.

Purpose: A proteomic study was performed to compare the composition of low leukocyte PRP, platelet poor plasma (PPP), and blood plasma. Pathway analysis of the proteomic data was performed to evaluate differences between plasma formulations at the molecular level. Low abundance regulatory proteins in plasma were identified and quantified as well as cellular pathways regulated by those proteins.

Methods: Quantitative proteomic analysis, using multiplexed isotopically labeled tags (TMT labeling) and label-free tandem mass spectrometry, was performed on plasma, low leukocyte PRP, and PPP. Plasma formulations were derived from two blood donors (one donor per experiment). Pathway analysis of the proteomic data identified the major differences between formulations.

Results: Nearly 600 proteins were detected in three types of blood plasma formulations in two experiments. Identified proteins showed more than 50% overlap between plasma formulations. Detected proteins represented more than 100 canonical pathways, as was identified by pathway analysis. The major pathways and regulatory molecules were linked to inflammation.

Conclusion: Three types of plasma formulations were compared in two proteomic experiments. The most represented pathways, such as Acute Phase Response, Coagulation, or System of the Complement, had many proteins in common in both experiments. In both experiments plasma sample sets had the same direction of biochemical pathway changes: up- or down-regulation. The most represented biochemical pathways are linked to inflammation.
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http://dx.doi.org/10.1016/j.reth.2020.09.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7770407PMC
December 2020

Platelet Rich Plasma in Orthopedic Surgical Medicine.

Platelets 2021 Feb 5;32(2):163-174. Epub 2021 Jan 5.

Gardner Orthopedics, Fort Myers, FL, USA.

There is a global interest in optimizing post-surgical tissue repair strategies, leading to better patient outcomes and fewer complications, most ideally with reduced overall cost. In this regard, in recent years, the interest in autologous biological treatments in orthopedic surgery and sports medicine has increased greatly, and the addition of platelet-rich plasma (PRP) to the surgical armamentarium is of particular note. Unfortunately, the number of PRP preparation devices has also grown immensely over the recent decades, raising meaningful concern for the considerable variation in the qualities of currently available PRP preparations. The lack of consensus on the standardization of PRP preparation and of agreement on condition specific PRP formulations is largely responsible for the sometimes contradictory outcomes in the literature. Furthermore, the full potential of PRP technology, the concept of individualized treatment protocols based on bioformulation options, and platelet dosing, angiogenesis, and antimicrobial and painkilling effects of PRP relevant to orthopedic surgery have rarely been addressed. In this review, we will discuss recent developments regarding PRP preparations and potential therapeutic effects. Additionally, we present a synopsis of several published data regarding PRP applications in orthopedic surgery for treating tendon injuries, inducing bone repair, strengthening spinal fusion outcomes, and supporting major joint replacements.
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http://dx.doi.org/10.1080/09537104.2020.1869717DOI Listing
February 2021

Role of Mechanical Loading for Platelet-Rich Plasma-Treated Achilles Tendinopathy.

Curr Sports Med Rep 2020 Jun;19(6):209-216

Department of Orthopedic Surgery at University of Pittsburgh School of Medicine, Pittsburgh, PA.

There is no consensus on the optimal rehabilitation protocol after platelet-rich plasma (PRP) treatment for tendinopathy despite basic science studies showing the critical role of mechanical loading in the restoration of tendon structure and function posttreatment. In this article, we will review tendon mechanobiology, platelet biology, and review levels I and II Achilles tendon clinical studies paying particular attention to the role of mechanical loading in rehabilitation of injured tendons. Animal studies emphasize the synergistic effect of mechanical tendon loading and PRP to treat tendon injury while clinical studies described minimal details on loading protocols.
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http://dx.doi.org/10.1249/JSR.0000000000000719DOI Listing
June 2020

Bone Marrow Aspirate Concentrate Is Equivalent to Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis at 1 Year: A Prospective, Randomized Trial.

Orthop J Sports Med 2020 Feb 18;8(2):2325967119900958. Epub 2020 Feb 18.

Andrews Research & Education Foundation, Gulf Breeze, Florida, USA.

Background: Approximately 47 million people in the United States have been diagnosed with arthritis. Autologous platelet-rich plasma (PRP) injections have been documented to alleviate symptoms related to knee osteoarthritis (OA) in randomized controlled trials, systematic reviews, and meta-analyses. Autologous bone marrow aspirate concentrate (BMC) injections have also emerged as a treatment option for knee OA, with a limited clinical evidence base.

Purpose: To compare the efficacy of BMC to PRP for the treatment of knee OA regarding pain and function at multiple time points up to 12 months after an injection. We hypothesized that BMC will be more effective in improving outcomes in patients with knee OA.

Study Design: Randomized controlled trial; Level of evidence, 2.

Methods: A total of 90 participants aged between 18 and 80 years with symptomatic knee OA (Kellgren-Lawrence grades 1-3) were randomized into 2 study groups: PRP and BMC. Both groups completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and subjective International Knee Documentation Committee (IKDC) questionnaires before and 1, 3, 6, 9, and 12 months after a single intra-articular injection of leukocyte-rich PRP or BMC.

Results: There were no statistically significant differences in baseline IKDC or WOMAC scores between the 2 groups. All IKDC and WOMAC scores for both the PRP and BMC groups significantly improved from baseline to 1 month after the injection ( < .001). These improvements were sustained for 12 months after the injection, with no difference between PRP and BMC at any time point.

Conclusion: Both PRP and BMC were effective in improving patient-reported outcomes in patients with mild to moderate knee OA for at least 12 months; neither treatment provided a superior clinical benefit. Autologous PRP and BMC showed promising clinical potential as therapeutic agents for the treatment of OA, and while PRP has strong clinical evidence to support its efficacy, BMC has limited support. This study did not prove BMC to be superior to PRP, providing guidance to clinicians treating OA. It is possible that the results were affected by patients knowing that there was no control group.

Registration: NCT03289416 (ClinicalTrials.gov identifier).
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http://dx.doi.org/10.1177/2325967119900958DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7029538PMC
February 2020

Optimizing the safety of intradiscal platelet-rich plasma: an study with .

Regen Med 2019 10 7;14(10):955-967. Epub 2019 Oct 7.

Regenerative SportsCare Institute, 62 East 88th Street, New York, NY 10128, USA.

The most common risk associated with intradiscal injection of platelet-rich plasma (PRP) is discitis with . It is hypothesized that antimicrobial activity of PRP can be enhanced through inclusion of leukocytes or antibiotics in the injectate. Multiple PRP preparations of varying platelet and leukocyte counts were co-cultured with with or without cefazolin, with viable bacterial colony counts being recovered at 0, 4, 24 and 48 hours post-inoculation. A direct correlation between recovery and granulocyte counts were observed. 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.
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http://dx.doi.org/10.2217/rme-2019-0098DOI Listing
October 2019

Assessing clinical implications and perspectives of the pathophysiological effects of erythrocytes and plasma free hemoglobin in autologous biologics for use in musculoskeletal regenerative medicine therapies. A review.

Regen Ther 2019 Dec 10;11:56-64. Epub 2019 May 10.

Emory University, Department of Physical Medicine & Rehabilitation, Atlanta GA, USA.

Autologous biologics, defined as platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMC), are cell-based therapy treatment options in regenerative medicine practices, and have been increasingly used in orthopedics, sports medicine, and spinal disorders. These biological products are produced at point-of-care; thereby, avoiding expensive and cumbersome culturing and expansion techniques. Numerous commercial PRP and BMC systems are available but reports and knowledge of bio-cellular formulations produced by these systems are limited. This limited information hinders evaluating clinical and research outcomes and thus making conclusions about their biological effectiveness. Some of their important cellular and protein properties have not been characterized, which is critical for understanding the mechanisms of actions involved in tissue regenerative processes. The presence and role of red blood cells (RBCs) in any biologic has not been addressed extensively. Furthermore, some of the pathophysiological effects and phenomena related to RBCs have not been studied. A lack of a complete understanding of all of the biological components and their functional consequences hampers the development of clinical standards for any biological preparation. This paper aims to review the clinical implications and pathophysiological effects of RBCs in PRP and BMC; emphasizes hemolysis, eryptosis, and the release of macrophage inhibitory factor; and explains several effects on the microenvironment, such as inflammation, oxidative stress, vasoconstriction, and impaired cell metabolism.
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http://dx.doi.org/10.1016/j.reth.2019.03.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6517793PMC
December 2019

Platelet-Rich Plasma as a Treatment for Androgenetic Alopecia.

Dermatol Surg 2019 10;45(10):1262-1273

International Society of Hair Restoration Surgery (ISHRS), Ad Hoc Committee on PRP.

Background: Platelet-rich plasma (PRP) treatment may encourage hair growth by promoting cellular maturation, differentiation, and proliferation.

Objective: The objective of this study was to evaluate the effectiveness of PRP as a treatment for androgenetic alopecia (AGA).

Materials And Methods: A literature search combined with meta-analysis was used to calculate the overall standardized mean difference (SMD) in hair density in patients treated with PRP injections in comparison with baseline and placebo treatment. Chi squared analysis and Fisher exact test were used to investigate variation in protocols.

Results: The overall SMD in hair density was 0.58 (95% confidence interval [CI]: 0.35-0.80) and 0.51 (95% CI: 0.23-0.80, p < .0004) in favor of PRP treatment when compared with baseline and placebo treatment, respectively.

Conclusion: Platelet-rich plasma is beneficial in the treatment of AGA. It is recommended that 3 monthly sessions of PRP (once monthly ×3 treatments) be used followed by a 3- to 6-month maintenance period.
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http://dx.doi.org/10.1097/DSS.0000000000001894DOI Listing
October 2019

Autologous pure platelet-rich plasma injections for facial skin rejuvenation: Biometric instrumental evaluations and patient-reported outcomes to support antiaging effects.

J Cosmet Dermatol 2019 Aug 23;18(4):985-995. Epub 2018 Oct 23.

Clinica Dermatologica do Areeiro, Lisboa, Portugal.

Background: During skin aging, a degeneration of connective tissue and decrease in hyaluronic acid polymers occur. Since platelet-rich plasma (PRP) contains growth factors and various cytokines, it was hypothesized that it could play a role in fibroblast activation and type I collagen expression in human fibroblasts.

Objectives: This study was performed to assess the efficacy of autologous PRP injections for facial skin rejuvenation, measured by biometric instrumental evaluations and patient-reported outcomes.

Patients And Methods: Patients signed an informed consent form. The EmCyte PurePRP system technology was used to produce neutrophil-poor PurePRP. The efficacy of the procedures was assessed by biometric parameters, and a patient outcome a self-assessment questionnaire on each visit and at 6-month follow-up.

Results: Eleven volunteers were included in the study, receiving 3 PurePRP treatments. A significant decrease in brown spot counts and area (P < 0.05) was seen after 3 months. Wrinkle count and volume were significantly reduced (P < 0.05 for total wrinkle appearance). Skin firmness parameters were significantly improved. Skin redness was significantly improved after 169 days post-therapy for both the nasolabial and malar areas. A decrease in SLEB thickness was already noted at 2 months after the first injection, with an increase in SLEB density (P < 0.05 for both parameters), without affecting subcutaneous fat thickness. Self-assessment at 6-month follow-up revealed an average satisfaction score of >90%.

Conclusions: A series of 3 PurePRP injections at 6-month follow-up resulted in significant skin rejuvenation as demonstrated by biometric parameters and confirmed by patient self-assessment score.
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http://dx.doi.org/10.1111/jocd.12802DOI Listing
August 2019

In search of a consensus terminology in the field of platelet concentrates for surgical use: platelet-rich plasma (PRP), platelet-rich fibrin (PRF), fibrin gel polymerization and leukocytes.

Curr Pharm Biotechnol 2012 06;13(7):1131-7

LoB5 Unit, Chonnam National University School of Dentistry, 77 Yongbong-Ro, Buk-Gu, Gwangju 500-757, South Korea.

In the field of platelet concentrates for surgical use, most products are termed Platelet-Rich Plasma (PRP). Unfortunately, this term is very general and incomplete, leading to many confusions in the scientific database. In this article, a panel of experts discusses this issue and proposes an accurate and simple terminology system for platelet concentrates for surgical use. Four main categories of products can be easily defined, depending on their leukocyte content and fibrin architecture: Pure Platelet-Rich Plasma (P-PRP), such as cell separator PRP, Vivostat PRF or Anitua's PRGF; Leukocyteand Platelet-Rich Plasma (L-PRP), such as Curasan, Regen, Plateltex, SmartPReP, PCCS, Magellan, Angel or GPS PRP; Pure Plaletet-Rich Fibrin (P-PRF), such as Fibrinet; and Leukocyte- and Platelet-Rich Fibrin (L-PRF), such as Choukroun's PRF. P-PRP and L-PRP refer to the unactivated liquid form of these products, their activated versions being respectively named P-PRP gels and L-PRP gels. The purpose of this search for a terminology consensus is to plead for a more serious characterization of these products. Researchers have to be aware of the complex nature of these living biomaterials, in order to avoid misunderstandings and erroneous conclusions. Understanding the biomaterials or believing in the magic of growth factors ? From this choice depends the future of the field.
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http://dx.doi.org/10.2174/138920112800624328DOI Listing
June 2012

The role of leukocytes from L-PRP/L-PRF in wound healing and immune defense: new perspectives.

Curr Pharm Biotechnol 2012 Jun;13(7):1153-62

LoB5 unit, Chonnam National University School of Dentistry, 77 Yongbong-Ro, Buk-Gu, Gwangju 500- 757, South Korea.

Platelet concentrates for topical use are innovative tools of regenerative medicine and their effects in various therapeutical situations are hotly debated. Unfortunately, this field of research mainly focused on the platelet growth factors, and the fibrin architecture and the leukocyte content of these products are too often neglected. In the four families of platelet concentrates, 2 families contain significant concentrations of leukocytes: L-PRP (Leukocyte- and Platelet-Rich Plasma) and L-PRF (Leukocyte- and Platelet-Rich Fibrin). The presence of leukocytes has a great impact on the biology of these products, not only because of their immune and antibacterial properties, but also because they are turntables of the wound healing process and the local factor regulation. In this article, the various kinds of leukocytes present in a platelet concentrate are described (particularly the various populations of granulocytes and lymphocytes), and we insist on the large diversity of factors and pathways that these cells can use to defend the wound site against infections and to regulate the healing process. Finally, the impact of these cells in the healing properties of the L-PRP and L-PRF is also discussed: if antimicrobial properties were already pointed out, effects in the regulation of cell proliferation and differentiation were also hypothesized. Leukocytes are key actors of many platelet concentrates, and a better understanding of their effects is an important issue for the development of these technologies.
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http://dx.doi.org/10.2174/138920112800624373DOI Listing
June 2012

Is the use of autologous platelet-rich plasma gels in gynecologic, cardiac, and general, reconstructive surgery beneficial?

Curr Pharm Biotechnol 2012 Jun;13(7):1163-72

Da Vinci Clinic, Center for Regenerative and Hyperbaric Medicine, Nieuwendijk 49, 5664 HB Geldrop, the Netherlands.

Tissue repair at wound sites begins with clot formation, and subsequently platelet degranulation with the release of platelet growth factors, which are necessary and well-regulated processes to achieve wound healing. Platelet-derived growth factors are biologically active substances that enhance tissue repair mechanisms, such as chemotaxis, cell proliferation, angiogenesis, extracellular matrix deposition, and remodeling. This review describes the biological background and results on the topical use of autologous platelet-rich plasma and platelet gel in gynecologic, cardiac, and general surgical procedures, including chronic wound management and soft-tissue injuries.
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http://dx.doi.org/10.2174/138920112800624346DOI Listing
June 2012

Autologous platelet gel in total knee arthroplasty: a prospective randomized study.

Knee Surg Sports Traumatol Arthrosc 2011 Jan 18;19(1):115-21. Epub 2010 Jul 18.

Department of Orthopedic Surgery, Kennemer Gasthuis, Location E.G., P.O. Box 417, 2000 AK Haarlem, The Netherlands.

Purpose: Total knee arthroplasty (TKA) is often associated with major postoperative blood loss, postoperative pain, and impaired wound healing. The application of autologous platelet gel (APG), prepared from the buffy coat of a unit of autologous blood, has been advocated to improve haemostasis after surgery, to decrease perioperative blood loss, diminish postoperative pain and to enhance the wound healing process. This randomized controlled pilot study was developed to assess the effects of APG after total knee arthroplasty on blood loss, wound healing, pain, range of motion, and hospital stay.

Method: A prospective, randomized observer blind controlled trial was performed. Forty patients with only osteoarthritis of the knee were scheduled to have a TKA, and they were randomized into two groups. Patients in the treatment group were all treated with the application of autologous platelet gel after the prosthesis was implanted. Patients in the control group were treated with the same protocol but no APG was used.

Results: Preoperative and postoperative Hb levels showed no significant difference and allogenic blood transfusions were not given in either group. Haematomas were significantly larger in the control group than in the platelet gel group (P = 0.03). The pain score at rest was higher in the control group on the 3rd day (P = 0.04). Wound healing disturbances were seen in four patients in the control group and in no patients in the APG group (n.s.). Range of motion of the knee was similar postoperatively. Hospital stay was 6.2 days in the APG and 7.5 days in the control group (n.s.).

Conclusion: In this prospective randomized pilot study on APG in total knee arthroplasty, differences in favour of the use of platelet gel were found, but these were subjective evaluations, marginal in effect, or did not reach statistical significance. The use of drains might have decreased the concentration of delivered platelets and may have diminished the effect. However, in this study, a statistically significant clinically important effect in favour of platelet gel application was not found. Further studies with larger numbers of patients, and without the use of drains, are warranted to investigate the possible benefits of autologous platelet gel in total knee arthroplasty.
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http://dx.doi.org/10.1007/s00167-010-1207-0DOI Listing
January 2011

Dutch perfusion incident survey.

Perfusion 2010 Sep 14;25(5):329-36. Epub 2010 Jul 14.

Department of Extracorporeal Circulation, Maastricht University Medical Centre, Maastricht, the Netherlands.

Background: Cardiopulmonary bypass procedures remain complex, involving many potential risks. Therefore, a nationwide retrospective study was conducted to gain insight into the number of incidents and accidents in Dutch adult perfusion practice.

Methods: An anonymous postal survey (85 questions about hardware, disposables, fluids and medication, air emboli, anticoagulation, practice, and safety measures) was sent to all Dutch perfusionists involved in adult cardiovascular perfusion during 2006 and 2007. To guarantee complete anonymity, respondents were asked to return the survey to a notary who discarded personal information.

Results: The net response rate was 72% and covered 23,500 perfusions. Individual respondents performed 240 ± 103 perfusions during the 2-year study period and had 13.8 ± 8.7 years of practical experience. The incident rate was 1 per 15.6 perfusions and the adverse event rate was 1 per 1,236 perfusions. The three most reported incidents were: (1) persistent inability to raise the activated coagulation time above 400s during perfusion (184 incidents); (2) an allergic or anaphylactic reaction to drugs, fluids, or blood products (114 incidents); and (3) clotting formation in the extracorporeal circuit (74 incidents). Furthermore, pre-bypass safety measures showed no statistically significant association with the reported incidents.

Conclusions: In comparison with data from the recent literature, the reported number of incidents is high. Nevertheless, the adverse outcome rate is well matched to other published surveys. The relatively high response rate conveys the impression that the Dutch perfusionist is vigilant and willing to report incidents. Hence, a web-based Dutch perfusion incident registration system is recommended.
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http://dx.doi.org/10.1177/0267659110377678DOI Listing
September 2010

Orthotopic location has limited benefit from allogeneic or autologous multipotent stromal cells seeded on ceramic scaffolds.

Tissue Eng Part A 2009 Nov;15(11):3231-9

Department of Orthopaedics, University Medical Center Utrecht, Utrecht, The Netherlands.

Improvement of tissue-engineered grafts is still a challenge in the field of regenerative medicine. Using multipotent stromal cells (MSCs), which have immunosuppressive qualities in an allogeneic situation, off-the-shelf implants can be created. This study compared allogeneic and autologous MSCs at an orthotopic (L1 transverse process model) and ectopic (intramuscular) implantation location in 2-year-old goats. Further, the possible additional effect of platelet-leukocyte gel (PLG) as a source of growth factors on bone formation was investigated. For the orthotopic implantation, cassettes were implanted in nine goats bilaterally on the lumbar transverse processes, either with PLG-seeded or with plasma-seeded constructs. To assess the onset of bone formation, fluorochromes were administered at weeks 3, 5, and 9. Their incorporation in newly formed bone indicated that seeded cells enhanced bone formation in the first weeks. Nevertheless, after 16 weeks no beneficial effects of cells were found in the cassettes in contrast to the ectopic location. No effect of PLG on bone formation was shown at either location. Finally, we show no significant difference in bone formation between autologous and allogeneic MSCs, an important finding when considering the use of allogeneic cells as an off-the-shelf component in tissue-engineered bone in goats.
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http://dx.doi.org/10.1089/ten.TEA.2009.0023DOI Listing
November 2009

Platelet leukocyte gel facilitates bone substitute growth and autologous bone growth in a goat model.

J Biomed Mater Res A 2010 Feb;92(2):746-53

Department of Peri-Operative Blood Management, Catharina Hospital, Eindhoven, The Netherlands.

The aim of this study is to evaluate multiple conditions on the formation of bone growth in a goat model. We prepared from a unit of whole blood, platelet-leukocyte gel (PLG) to stimulate bone formation, based on the release of platelet growth factors. Two 3-compartment cages containing autologous bone, calcium phosphate, and trabecular metal were implanted onto goat spinal transverse processes. One cage was treated with PLG, prepared according to a standardized protocol. An untreated cage served as a control. To monitor bone formation overtime, fluorochrome markers were administered at 2, 3, and 5 weeks. Animals were sacrificed at 9 weeks after implantation. Bone growth in these 3-compartments cages was examined by histology and histomorphometry of nondecalcified sections using traditional light and epifluorescent microscopy. Compared to the control samples, bone growth in the PLG-treated autologous bone and calcium phosphate samples was significantly more. Fairly little bone growth was seen in PLG treated or untreated trabecular metal scaffolds. The results obtained from this goat model suggest a potential role for the application of autologous PLG during surgeries in which autologous bone grafts or calcium phosphate scaffolds are used.
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http://dx.doi.org/10.1002/jbm.a.32372DOI Listing
February 2010

Antimicrobial activity of platelet-leukocyte gel against Staphylococcus aureus.

J Orthop Res 2008 Mar;26(3):404-10

Department of Orthopaedics, University Medical Center Utrecht, Room G05.228, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.

Platelet-leukocyte gel (PLG) contains high concentrations of platelets and leukocytes. As leukocytes play an important role in the innate host-defense, we hypothesized that PLG might have antimicrobial properties. This study investigated the antimicrobial activity of PLG against Staphylococcus aureus and the contribution of myeloperoxidase (MPO), present in leukocytes, in this process. Platelet-rich plasma (PRP) and platelet-poor plasma (PPP) were obtained from whole blood of six donors. PLG was prepared by mixing PRP with autologous (PLG-AT) or bovine thrombin (PLG-BT). Antimicrobial activity of PLG-AT, PLG-BT, PRP, and PPP was determined in a bacterial kill assay. MPO release was measured by ELISA and activity was measured using a MPO activity assay. Cultures showed a rapid decrease in the number of bacteria for both PLG-AT and PLG-BT, which was maximal between 4 and 8 h, to approximately 1% of the bacteria in controls. The effect of PLG-AT was largest and significantly different compared to PRP (p = 0.004) and PPP (p < 0.001), however not compared to PLG-BT (p = 0.093). PLG-AT, PLG-BT, and PRP showed a comparable, gradually increasing MPO release. MPO activity was comparable for all groups and remained stable. No correlation between MPO release, activity, and bacterial kill could be found. PLG appears to have potent antimicrobial capacity, but the role of MPO in this activity is questionable. PLG might represent a useful strategy against postoperative infections. However, additional research should elucidate its exact antimicrobial activity.
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http://dx.doi.org/10.1002/jor.20519DOI Listing
March 2008

Autologous platelet gel and fibrin sealant enhance the efficacy of total knee arthroplasty: improved range of motion, decreased length of stay and a reduced incidence of arthrofibrosis.

Knee Surg Sports Traumatol Arthrosc 2007 Jul 24;15(7):888-94. Epub 2007 Feb 24.

Department of Peri-Operative Blood Management, Catharina Hospital, Eindhoven, The Netherlands.

In this study we describe the potential role of autologous platelet gel and fibrin sealant in unilateral total knee arthroplasty to improve the postoperative range of motion and to reduce the incidence of arthrofibrosis. Total knee arthroplasty is often associated with a considerable amount of post-operative blood loss. Persistent limited motion directly after surgery may ultimately result in arthrofibrosis. To counteract these effects we investigated whether the use of autologous derived platelet gel and fibrin sealant would reduce postoperative blood loss, decrease the impaired range of motion and the incidence of arthrofibrosis. All patients were consecutively operated and assigned to the study or control groups. Study group patients (n = 85) were treated with the application of autologous platelet gel and fibrin sealant at the end of surgery. Eighty patients were operated without the use of platelet gel and fibrin sealant, and served as the control group. The postoperative hemoglobin decrease, range of motion and length of hospitalization were recorded. During a 5-month postoperative period patients were followed to observe the incidence of arthrofibrosis. In patients in the treatment group the hemoglobin concentration in blood decreased significantly less when compared to the control group. They also showed a superior postoperative range of motion when compared to those of the control group (P < 0.001). The incidence of arthrofibrosis and subsequent forced manipulation was significantly less (P < 0.001) in patients managed with platelet gel and fibrin sealant. We conclude that peri-operatively applied platelet gel and fibrin sealant may improve the range of motion after total knee arthroplasty, decreases the length of stay and may reduce the incidence of arthrofibrosis.
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http://dx.doi.org/10.1007/s00167-007-0296-xDOI Listing
July 2007

Platelet-rich plasma preparation using three devices: implications for platelet activation and platelet growth factor release.

Growth Factors 2006 Sep;24(3):165-71

Department of Extra Corporeal Blood Management, Catharina Hospital Eindhoven, Eindhoven, The Netherlands.

Background: In this study, three commercial systems for the preparation of platelet-rich plasma (PRP) were compared and platelet growth factors release was measured.

Methods: Ten healthy volunteers donated whole blood that was fractionated by a blood cell separator, and a table-top centrifuge to prepare PRP. Furthermore, an autologous growth factor filter was used to concentrate PRP fractionated by the blood cell separator. PRP was subsequently activated with autologously produced thrombin to degranulate the platelets to measure platelet-derived growth factor-AB (PDGF-AB), transforming growth factor-beta (TGF-beta), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF).

Results: PRP contained significantly higher platelet counts compared with baseline values (p < 0.001). PDGF-AB concentrations were increased more than 18-fold in the platelet gel supernatant when the cell-separator and GPS were used, whereas only a 3-fold increase was seen with the AGF.

Conclusion: The three PRP devices enable the preparation of PRP for the release of high concentrations of platelet growth factor, but showed different harvesting capacities for the collection of concentrated platelets. The administration of thrombin for PRP activation resulted in the release of high concentrations of PDGF-AB and TGF-beta but only when PRP had not been activated during the preparation process in vitro.
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http://dx.doi.org/10.1080/08977190600821327DOI Listing
September 2006

Platelet-rich plasma and platelet gel: a review.

J Extra Corpor Technol 2006 Jun;38(2):174-87

Department of Extra Corporeal Blood Management, Catharina Hospital, Eindhoven, The Netherlands.

Strategies to reduce blood loss and transfusion of allogeneic blood products during surgical procedures are important in modern times. The most important and well-known autologous techniques are preoperative autologous predonation, hemodilution, perioperative red cell salvage, postoperative wound blood autotransfusion, and pharmacologic modulation of the hemostatic process. At present, new developments in the preparation of preoperative autologous blood component therapy by whole blood platelet-rich plasma (PRP) and platelet-poor plasma (PPP) sequestration have evolved. This technique has been proven to reduce the number of allogeneic blood transfusions during open heart surgery and orthopedic operations. Moreover, platelet gel and fibrin sealant derived from PRP and PPP mixed with thrombin, respectively, can be exogenously applied to tissues to promote wound healing, bone growth, and tissue sealing. However, to our disappointment, not many well-designed scientific studies are available, and many anecdotic stories exist, whereas questions remain to be answered. We therefore decided to study perioperative blood management in more detail with emphasis on the application and production of autologous platelet gel and the use of fibrin sealant. This review addresses a large variety of aspects relevant to platelets, platelet-rich plasma, and the application of platelet gel. In addition, an overview of recent animal and human studies is presented.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4680757PMC
June 2006