The healing effects of autologous platelet gel on acute human skin wounds

Growth factor and proteinase profile of Vivostat® platelet-rich fibrin linked to tissue repair

BACKGROUND AND OBJECTIVES

Autologous platelet-rich fibrin (PRF(®)) is prepared by the automatic Vivostat(®) system. Conflicting results with Vivostat PRF in acute wound healing prompted us to examine its cellular and biomolecular composition. Specifically, platelets, selected growth factors and matrix metalloproteinase (MMP)-9 were quantified using novel analytical methods.

MATERIALS AND METHODS

Ten healthy non-thrombocytopenic volunteers donated blood for generation of intermediate fibrin-I and final PRF. Anticoagulated whole blood and serum procured in parallel served as baseline controls. Leucocyte, erythrocyte and platelet counts in whole blood and fibrin-I were determined by automated haematology analyser. Platelet concentration in PRF was quantified manually by stereologic analysis of Giemsa-stained tissue sections, and the total content of five growth factors and MMP-9 by enzyme-linked immunosorbent assays.

RESULTS

The number of leucocytes and erythrocytes was reduced (P < 0·001), whereas platelets increased (P < 0·001) in fibrin-I versus whole blood. PRF contained 982 ± 206 × 10(9) platelets/l representing 3·9-fold (P < 0·001) enrichment relative to whole blood. Growth factor abundance in Vivostat PRF and serum was in descending order: transforming growth factor-β1 [5·1-fold higher in PRF than serum, P < 0·001] > platelet-derived growth factor (PDGF)-AB [2·5-fold, P < 0·01] > PDGF-BB [1·6-fold, P < 0·05] > vascular endothelial growth factor > basic fibroblast growth factor [75-fold, P < 0·001]. MMP-9 was reduced 139-fold (P < 0·001) compared with serum, reflecting leucocyte depletion in PRF.

CONCLUSION

The gained knowledge on platelet enrichment and biomolecular constituents may guide clinicians in their optimal use of Vivostat PRF for tissue regenerative applications.

Rapidly in situ forming platelet-rich plasma gel enhances angiogenic responses and augments early wound healing after open abdomen

Objective. The purposes of our present study were to evaluate the potential of platelet-rich plasma gel to enhance granulation tissue formation after open abdomen and to examine whether the effect was attributable to stimulating rapid neovascularization. Methods. Twenty-four rats underwent colon ascendens stent peritonitis surgery to induce sepsis, followed by intraperitoneal injection of nitrogen to create intra-abdominal hypertension. Four hours later, laparotomies were performed. The rats were randomized into three groups (n = 8 for each group): control, platelet-poor plasma (PPP), and platelet-rich plasma (PRP) groups. One week after the treatment, granulation tissue formation and angiogenesis were evaluated by histological and laser Doppler analysis. Results. The resultant platelet count in platelet-rich plasma was higher than that of PPP. The concentrations of platelet-derived growth factor BB, transforming growth factor β-1, and vascular endothelial growth factor in PRP were significantly higher when compared with that of PPP. Myofibroblast count, granulation tissue thickness, vessel numbers, and blood perfusion were increased in PRP group, followed by PPP group, with control being the least. Conclusion. Rapidly in situ forming platelet-rich plasma gel promoted remarkable neovascularization and early wound healing after open abdomen and may lead to novel and effective treatments for open abdominal wounds.

The management of infantile extravasation injury using maternal platelet-rich plasma

Accidental leakage of infusions into surrounding tissue is an adverse event that commonly occurs in preterm infants in the intensive care unit. Although most of these extravasations do not cause severe damage, a small number progress to tissue necrosis, and extensive tissue loss can sometimes occur. Platelet-rich plasma (PRP) consists of a high concentration of platelets in a small volume of plasma and can be prepared easily from peripheral blood. Its wound healing effect is well known. We report the successful healing of extensive tissue necrosis with maternal PRP and suggest that the application of maternal PRP may be an easy and effective treatment option for infant wound management in selected cases that merits further investigation.

Prediction and modulation of platelet recovery by discontinuous centrifugation of whole blood for the preparation of pure platelet-rich plasma

The aim of this study was to describe the behavior of the separation of red blood cells (RBCs) by discontinuous centrifugation (DC) of whole blood to modulate and control the platelet recovery in the preparation of pure platelet-rich plasma (P-PRP). P-PRP is a platelet-rich plasma (PRP) in which the white blood cell layer is not included. To achieve this goal, an analytical model was derived that takes into account the packing of RBCs and predicts the behavior of platelet and plasma recovery efficiencies (PtPlRE) based on the volume of whole blood, the hematocrit, and the volume of supernatant, as a function of the operating variables, centrifugal acceleration, and time. The model was derived from the basic equation of DC, which originates from the equilibrium balance of forces on a particle, and included the addition of one factor that corrected the terminal velocity of RBCs and was also correlated to the PtPlRE in the supernatant. This factor was the ratio between the fractional volume concentrations of plasma and RBCs in the centrifugation pellet after centrifugation. The model was validated and the variability of the data was determined using experimental data from 10 healthy donors in the age range of 25-35 years. The predicted behavior for the packing of RBCs and the PtPlRE was consistent with the behavior seen in the experimental data. Thus, the PtPlRE could be modulated and controlled through centrifugal acceleration, time, and hematocrit. Use of this model based on a physical description of events is the first step of a reliable standardization of PRP preparations.

Use of Platelet-Rich Fibrin over Skin Wounds: Modified Secondary Intention Healing

The healing process after any surgical intervention has always posed a challenge for the surgeons. In spite of the advances in wound closure techniques and devices, there is a crucial need for newer methods of enhancing the healing process to achieve optimal outcomes. Fibrin adhesives and platelet concentrates have proven useful in various treatment modalities in the fields of microvascular and plastic surgery. This case report shows its unique use in the field of maxillofacial and cutaneous surgery. It shows an innovative technique of enhancement of skin wound healing by local application of platelet-rich fibrin.

Stem cells and molecular advances in the treatment of facial skin

Stem cell technology has been discussed chiefly in terms of organ replacement in end-stage diseases. However, improved understanding of adult stem cells and a more nuanced appreciation of aging skin as a disease state has focused greater attention on the potential for truly regenerative and rejuvenative skin therapy with autologous cells. Through enhanced understanding of the normal processes of wound healing, systems of treatment and avenues of therapy are emerging based on modulation and amplification of the natural processes of wound healing. This article presents skin-specific developments in stem cell and growth factor science and suggests further avenues of investigation.

The use of platelet-rich plasma in plastic surgery: a systematic review

OBJECTIVE

The study's aim was to evaluate the available evidence regarding the use of platelet-rich plasma in plastic and reconstructive surgery, through implementation of a systematic review of the literature.

DATA SOURCES

PubMed and The Cochrane Library were searched using MeSH terms: 'platelet rich plasma' and 'plastic surgery' for all publications up to July 2011. All English, German, French and Dutch papers were included. In addition, the reference lists of relevant articles were searched for potentially appropriate publications.

STUDY SELECTION

Included studies needed to report on topics related to plastic and reconstructive surgery, mentioning at least one clinical end point. Both in vivo and in vitro comparative studies, performed in humans or animals, were included. A total of 82 publications were found, of which 40 studies met the inclusion criteria and were relevant to be used in this systematic review.

DATA EXTRACTION

Data from retrieved studies were reviewed and tabulated according to year of publication, study design, human or animal studies, characteristics of the population, mode of application, outcomes and preparation method.

DATA SYNTHESIS

A total of 15 randomised controlled trials and 25 case-control studies were found. Thirty-six publications demonstrated favourable outcomes with the use of platelet-rich plasma. The included articles were divided into three topics related to plastic surgery: wound healing, fat grafting and bone grafting.

CONCLUSIONS

This systematic review describes a substantially beneficial effect of platelet-rich plasma for several indications, including a better wound healing rate, an increased survival rate of fat grafts and an enhancement of bone graft regeneration.

Platelet-rich plasma and blood components for non-transfusion use: technical and medicolegal aspects

There are a large number of publications describing the use of platelet-rich plasma (PRP) in multiple fields of application. These illustrate a large number of therapeutic elements with different and specific actions within 'platelet gel' (this term is used in the current regulations to define this product). This term, however, lacks specificity and, depending on the method used in its production is variable both in its blood composition and in platelet concentration, and several publications consider better and easier methods of platelet gel production, which may or may not lead to greater standardization in the product. The authors illustrate the general aspects of PRP and other blood components for non-transfusion use, briefly touching on the history and different fields of application and the rational of for its use. Given the increased use of such preparations, the authors describe critically the regulations in force in Europe and propose a new regulatory framework aimed to simplify and facilitate the use of such material as a therapeutic agent within medicine.

Wound healing after radiation therapy: review of the literature

Radiation therapy is an established modality in the treatment of head and neck cancer patients. Compromised wound healing in irradiated tissues is a common and challenging clinical problem. The pathophysiology and underlying cellular mechanisms including the complex interaction of cytokines and growth factors are still not understood completely. In this review, the current state of research regarding the pathomechanisms of compromised wound healing in irradiated tissues is presented. Current and possible future treatment strategies are critically reviewed.

[Use of platelet gel in breast reconstruction after breast-conserving cancer surgery]

INTRODUCTION

With the aim of decreasing breast defects after conservative cancer surgery, we present a new breast reconstruction technique using breast volume restitution with platelet gel.

PATIENTS AND METHOD

A pilot study was conducted on 20 breast cancer patients undergoing tumorectomy with placement a gel obtained by plateletpheresis of a healthy allogeneic donor in the surgical cavity. Patients had a clinical, photographic and histological follow-up, as well as an assessment of the aesthetic outcome.

RESULTS

The mean age was 50.5±8.6 years (range 42-70 years) and with a mean Charlson comorbidity index of 1.1±1.2 (range 0-5). The mean tumour volume was 63.1±31.1 ml (range 30-160 ml) and the mean restitution volume with platelet gel was 111.5±60.9 ml (range 40-250 ml). After a mean follow-up of 17 months, 80% of the patients maintained the breast volume and no further operations were needed due to surgical margin involvement. No recurrences were observed in any patient.

CONCLUSIONS

Platelet gel allows restitution of the breast volume adjusted to the tumorectomy volume, minimising the usual retractions and deformities after conservative surgery. It enables wide resections and safety margins.

Efficacy of platelet rich plasma and hydroxyapatite crystals in bone regeneration after surgical removal of mandibular third molars

PURPOSE

This study evaluates the efficacy of platelet rich plasma (PRP) & porous hydroxyapatite crystals in bone regeneration after surgical removal of mandibular third molar with the help of radiographs and its comparison with control side.

MATERIALS AND METHODS

A total of 40 patients; both male and female aged between 18 and 35 years, who had impacted mandibular third molars were randomly selected for this study. Twenty patients were taken for control group and 20 patients for study group. The extraction socket of the study group was packed with PRP and hydroxyapatite granules and that of control group was sutured without PRP and hydroxyapatite. The bone density of both extraction sockets were evaluated radiographically using gray level histogram and compared periodically on immediate postoperative day, 1st and 3rd month postoperatively and postoperative sequelae of both the control group and study group in terms of oedema & pain or any other adverse reactions were also assessed.

RESULTS

Data suggested evidence of early bone formation and maturation radiographically in study group as compared to control group. The percentage of facial swelling was numerically greater on the control side as compared to the study side, Pain was also assessed with VAS and it was found that the severity of pain was equal in both study and control groups and the results were not significant.

CONCLUSION

This study clearly indicated a definitive improvement in the wound healing, increase in bone density, which signifies and highlights the use of PRP and hydroxyapatite granules, certainly as a valid method in inducing and accelerating bone regeneration.

Proper care of early wounds to optimize healing and prevent complications

Proper wound care has broad applications for all clinicians. Much of the future direction for enhancing wound repair focuses on key cells and growth factors, which is why possessing a strong understanding of the basic physiology of wound healing is imperative. This article first provides a thorough review of the phases of wound healing followed by a discussion on the latest wound management strategies. Wound conditions and surgical techniques are important components for optimizing wound healing and preventing complications. Special consideration has been given to the unique settings of contaminated wounds, open wounds, or avulsed tissue.

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

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.

Novel use of platelet-rich plasma to augment curative diabetic foot surgery

Autologous platelet-rich plasma (PRP) may enhance wound healing through the formation of a platelet plug that provides both hemostasis and the secretion of biologically active proteins, including growth factors such as platelet-derived growth factor, transforming growth factor (TGF)-β, TGF-β2, and epidermal growth factor. The release of these growth factors into the wound may create an environment more conducive to tissue repair and could accelerate postoperative wound healing. To our knowledge, there are no reports of combining the use of PRP with curative diabetic foot surgery. This article provides a summary of the literature regarding PRP and wound healing and presents a case of a 49-year-old man with diabetes and a three-month history of a deep, nonhealing plantar hallux wound in which PRP was combined with a first metatarsophalangeal joint arthroplasty. Through the use of the PRP and bioengineered tissue to supplement curative diabetic foot surgery, the patient healed uneventfully at seven weeks.

Platelet-rich fibrin matrix for improvement of deep nasolabial folds

BACKGROUND

Dermal augmentation continues to grow as an aesthetic facial procedure. Many exogenous filler materials rely on an autologous fibrotic response for volume augmentation.

AIMS

To evaluate the efficacy of a single injection of autologous platelet-rich fibrin matrix (PRFM) for the correction of deep nasolabial folds (NLFs).

PATIENTS/METHODS

Whole blood was obtained from 15 adults, and an activated autologous PRFM produced using a proprietary system (Selphyl; Aesthetic Factors, Inc., Wayne, NJ, USA) was then injected into the dermis and immediate subdermis below the NLFs. Subjects were photographed before and after treatment; NLFs were rated by the treating physician before and after treatment using the Wrinkle Assessment Scale (WAS) and patients rated their appearance at each post-treatment visit using the Global Aesthetic Improvement Scale. Patients were evaluated at 1, 2, 6, and 12 weeks after treatment.

RESULTS

All patients were treated to maximal (no over-) correction, with a mean reduction in WAS score of 2.12 +/- 0.56. At 1 week after treatment, this difference was 0.65 +/- 0.68, but rose to 0.97 +/- 0.75, 1.08 +/- 0.59, and 1.13 +/- 0.72 at 2, 6, and 12 weeks after treatment, respectively (P < 0.001). No patient noted any fibrosis, irregularity, hardness, restricted movement, or lumpiness.

CONCLUSIONS

PRFM can provide significant long-term diminution of deep NLFs without the use of foreign materials. PRFM holds significant potential for stimulated dermal augmentation.

The use of autologous platelet gel in toenail surgery: a within-patient clinical trial

A number of studies have stressed the importance of platelets in acute and chronic wound healing, although their clinical utility remains controversial. To analyze the use of autologous platelet gel in the surgical treatment of ingrown toenails, a within-patient clinical trial was conducted. Thirty-five healthy volunteers (70 feet) underwent surgical treatment for bilateral ingrown hallux nails. Recovery time (days), postoperative pain (analog chromatic scale), and inflammation (digital circumference) at 48 hours postoperative were the outcomes of interest. Recovery time and postoperative pain were less in the experimental group, although the differences of means were not statistically significant. Based on these results, we suggest that local application of APG in surgical ingrown toenail wounds may produce a slight increase in acute inflammatory phase dermal wound healing, but it does not cause a statistically significant reduction in recovery times or postoperative pain.

Platelet-rich fibrin versus albumin in surgical wound repair: a randomized trial with paired design

OBJECTIVE

To study the effects of autologous platelet-rich fibrin (PRF) versus human albumin on incisional wound breaking strength and subcutaneous collagen deposition in patients undergoing laparoscopic cholecystectomy in a randomized trial.

SUMMARY BACKGROUND DATA

Platelet peptidic growth factors may stimulate collagen synthesis and tissue repair.

METHODS

One expanded polytetrafluoroethylene (ePTFE) tube was inserted subcutaneously from the edge of each of the two 10-mm trocar incisions in 51 patients. Treatment with PRF prepared from the patient's own blood or human albumin was randomized to respective wound site by concealed allocation. On postoperative day 10, breaking strength of the incisional wounds as well as the collagen concentration, type I procollagen mRNA, type III procollagen mRNA, matrix metalloproteinase-1 mRNA, and fibroblast density in the ePTFE tubes were determined. All analyses were assessor-blinded. The trial was registered in the Current Controlled Trials Registry (ISRCTN34481461).

RESULTS

Local PRF had no significant effect on incisional wound-breaking strength. In the ePTFE tubes, PRF treatment decreased collagen concentration by 24% (P=0.046) and type I procollagen mRNA level by 29% (P=0.003), but had no significant impact on type III procollagen mRNA, matrix metalloproteinase-1 mRNA or fibroblast infiltration. The profibrotic transforming growth factor-beta1 level increased (P<0.0001) 2-fold with PRF. Collagen concentration in albumin-treated ePTFE tubes correlated with breaking strength of the skin incisions (rs=0.48, P=0.03).

CONCLUSIONS

PRF did not improve wound strength significantly compared with albumin but suppressed subcutaneous collagen synthesis and deposition during early repair of surgical wounds in humans. Furthermore, deposition of reparative collagen in the subcutaneous ePTFE tube model partly predicted the breaking strength of an incisional skin wound.

Necrotizing fasciitis of the extremity caused by Haemophilus influenzae serotype b in a healthy adult

Haemophilus influenzae is a rare cause of necrotizing fasciitis with only a few previously reported cases. We describe the case of a 44-year-old man who had necrotizing fasciitis of the right lower extremity develop after intramuscular injections of paracetamol on his right buttock. The causative organism isolated was Haemophilus influenzae serotype b. This unusual infection was treated with repeated débridement and culture-guided antibiotics. There was no recurrence of infection at last followup 1 year after the initial surgery. Wound coverage was achieved with the use of a full-thickness skin graft after application of platelet-rich plasma and a dermal regeneration template. This resulted in a cosmetically acceptable appearance of the involved extremity for our patient.

Allogenic platelet gel in the treatment of pressure sores: a pilot study

Although platelet gel is considered one of the most popular tools in the treatment of chronic ulcers, current consensus on its use is not unanimous. A prospective randomised trial was carried out at the Plastic Surgery Unit of the 'Salvatore Maugeri' Foundation Hospital of Pavia (Italy). The study involved 13 patients affected by spinal cord injury with 16 pressure sores over a period of 20 months. The ulcer was considered the experimental unit of the study irrespective of the number of ulcers per patient. Each consecutive ulcer was randomised to be treated either with allogenic platelet gel or with current best practice approach to chronic wounds dressing protocol. At the end of the treatment 15 ulcers out of 16 improved clinically. No statistically significant difference was demonstrated in volume reduction between the two groups, although a statistically significant difference could be demonstrated in the onset time of granulation tissue proliferation as in the wounds treated with platelet gel the healing process was triggered earlier. Our study suggests that platelet gel is mostly effective within the first 2 weeks of treatment while a prolonged treatment does not provide any significant advantage versus the current best practice approach to chronic wounds protocols.

Buffered platelet-rich plasma enhances mesenchymal stem cell proliferation and chondrogenic differentiation

The success of tissue engineering applications can potentially be dramatically improved with the addition of adjuncts that increase the proliferation and differentiation of progenitor or stem cells. Platelet-rich plasma (PRP) has recently emerged as a potential biologic tool to treat acute and chronic tendon disorders. The regenerative potential of PRP is based on the release of growth factors that occurs with platelet rupture. Its autologous nature gives it a significant advantage in tissue engineering applications. To test whether PRP may be useful specifically for cartilage regeneration, a cell culture experiment was devised in which mesenchymal stem cells (MSCs) were grown in control media or media enhanced with inactivated, buffered PRP. Proliferation 7 days after PRP treatment was increased: 1.041 versus 0.199 for the control media cells ( p<0.001). The messenger RNA (mRNA) level of the osteogenic marker RUNX2 was 52.84 versus 26.88 for the control group ( p<0.005). Likewise the mRNA level of the chondrogenic markers Sox-9 and aggrecan was 29.74 versus 2.29 for the control group ( p<0.001) and 21.04 versus 1.93 ( p<0.001), respectively. These results confirm that PRP enhances MSC proliferation and suggest that PRP causes chondrogenic differentiation of MSC in vitro.

Bone and wound healing augmentation with platelet-rich plasma

Over the past two decades, autologous platelets that have been sequestered, concentrated, and mixed with thrombin to generate growth factor-concentrated platelet-rich plasma for application to bone and wounds to aide healing have been a subject of great interest. This article reviews the literature related to the use of autologous platelet-rich plasma in bone and wound healing, and reviews the processes necessary to secure a high concentration of viable platelets. Although not yet definitive, autologous platelet-rich plasma has been shown to be safe, reproducible, and effective in mimicking the natural process of bone and wound healing.

Effects of platelet-rich plasma on the repair of wounds on the distal aspect of the forelimb in horses

OBJECTIVE

To evaluate the effect of platelet-rich plasma on wounds on the distal aspect of the forelimb in horses.

ANIMALS

6 mixed-breed 10- to 15-year-old mares.

PROCEDURES

3 wounds were created on metacarpal regions in each of 6 horses (n = 36 wounds total). Eighteen wounds were treated with platelet-rich plasma and bandaged, whereas 18 control wounds were similarly bandaged with no prior topical treatment. Decrease in wound surface area and the required number of excisions of exuberant granulation tissue were recorded until complete healing. Tissue specimens were taken from wounds at 1 week for histologic examination and measurement of transforming growth factor-beta1 concentrations and at closure for histologic examination, biomechanical evaluation, and measurement of collagen type I and type III mRNA.

RESULTS

Platelet-rich plasma favored excessive development of granulation tissue and significantly slowed wound healing at 1, 2, and 3 weeks after surgery. Transforming growth factor-beta1 had a 1.6-fold higher concentration in treated wounds, compared with untreated wounds. Histologic, biomechanical, and gene expression data did not differ significantly between treated and control wounds.

CONCLUSIONS AND CLINICAL RELEVANCE

Topical application of autologous platelet-rich plasma did not accelerate or improve the quality of repair of small granulating wounds on limbs of horses. This treatment may better suit wounds with massive tissue loss or, alternatively, chronic wounds that would benefit from a fresh source of mediators to accelerate the healing process.

Platelet-rich plasma and platelet gel preparation using Plateltex

BACKGROUND

The platelet gel is made by embedding concentrate platelets within a semisolid (gel) network of polymerized fibrin. It is believed that this blood component will be used more and more in the treatment of several clinical conditions and as an adjunctive material in tissue engineering. Several systems are available to produce platelet-rich plasma (PRP) for topical therapy. Recently, a new system became commercially available, Plateltex. Here we report the technical performance of this system in comparison with the performance of other commercially available systems: PRGF, PRP-Landesber, Curasan, PCCS, Harvest, Vivostat, Regen and Fibrinet.

MATERIAL AND METHODS

Both the PRP and the gel were prepared according to the manufacturer's directions. The blood samples of 20 donors were used. The yield, the efficiency, and the amount of platelet-derived growth factor AB (PDGF-AB), transforming growth factor beta, vascular endothelial growth factor and fibroblast growth factor were measured in the resulting PRP. The feature of the batroxobin-induced gelation was evaluated.

RESULTS

The yield, the collection efficiency and the growth factor content of Plateltex were comparable to those of most of the other available systems. The gelation time was not dependent on the fibrinogen concentration; however, it was strongly influenced by the contact surface area of the container where the clotting reaction took place (P < 0.0001).

CONCLUSIONS

Plateltex provided platelet recovery, collection efficiency and PDGF-AB availability close to those provided by other systems marketed with the same intended use. Batroxobin, the enzyme provided to induce gelation, acts differently from thrombin, which is used by most other systems. Platelets treated with thrombin become activated; they release their growth factors quickly. Furthermore, thrombin-platelet interaction is a physiological mechanism that hastens the clot-retraction rate. On the contrary, platelets treated with batroxobin do not become activated; they are passively entrapped within the fibrin network, and their growth factor release occurs slowly. In these conditions, the clot retraction takes longer to occur. According to these differences between thrombin and batroxobin, it is expected that batroxobin-induced PRP activation will tailor slow release of the platelet content, thus, providing longer in loco availability of trophic factors. In selected clinical conditions, this durable anabolic factor availability might be preferable to quick thrombin-induced growth factor release.