Platelet-rich Fibrin Clot Research Articles

Clinical effects of platelet-rich fibrin (PRF) following surgical extraction of lower third molar

Abstract Objective The purpose of this study was to assess the effect of platelet-rich fibrin (PRF) on postoperative pain, analgesic consumption, soft tissue healing and socket complications following the extraction of mandibular third molars. Methods A total number of 50 impacted third molars were surgically removed from 47 patients (13 males and 34 females; with a mean age of 25.24 ± 7.04 years). PRF clots were placed in the extraction sockets of patients included in the study group, while the sockets remained empty in the control group. The variables assessed were pain, analgesic consumption, soft tissue healing and socket complications encountered during the first postoperative week. Results In the study group, a significantly less pain was recorded in the fifth, sixth and seventh postoperative days ( P = 0.041, 0.031 and 0.005 respectively). Patients included in the study group also significantly consumed less analgesics for the second, third, sixth and seventh postoperative days ( P = 0.019, 0.039, 0.045 and 0.020 respectively). PRF significantly reduced the incidence of alveolar osteitis ( P = 0.037) but not the infected or inflamed sockets ( P = 1.00 and 0.312 respectively). No significant difference was observed between PRF and control groups regarding soft tissue healing ( P = 0.187). Conclusion PRF could reduce alveolar osteitis, pain, and analgesic consumption following removal of impacted mandibular third molars.

Preliminary Evaluation of Platelet Rich Fibrin-Mediated Tissue Repair in Immature Canine Pulpless Teeth.

To evaluate the use of platelet-rich fibrin (PRF) in the regenerative therapy of immature canine permanent teeth. Eight immature premolars of beagle dogs were pulp extracted and cleaned with irrigation, then divided into two groups of empty root canals and those filled with a PRF clot. All of the eight premolars were sealed with mineral trioxide aggregate and glass ionomer cement. Two premolars were left naturally grown as a positive control. The root development was assessed radiographically and histologically after 12 weeks. The radiological findings showed greater increases in the thickness of lateral dentinal wall in the PRF group than in the vacant group. Histologically, dental-associated mineral tissue, connective tissue, and bone-like mineral tissue grew into the root canals independent of PRF clot use. The PRF was able to increase the thickness of dental-associated mineral tissue. However, the vital tissue differed from the pulp dentin complex. Our study demonstrated the feasibility of using PRF-mediated regenerative therapy in pulpless immature teeth for improving tissue repair.

Platelet-rich Fibrin Formation was delayed in Plastic Tubes

Introduction: Platelet-rich fibrin (PRF) is used in many regenerative treatments. Preparing PRF in glass tubes requires quick handling and generates biohazard concerns about silica contamination and glass breakage. Using plastic tubes may be an alternative to glass tubes. Objectives: This study investigated the formation of PRF prepared in polypropylene (PP) and polystyrene (PS) tubes compared with glass tubes. Methodology: PRF was prepared from human blood (n=20) in PP, PS, and glass tubes. The time required for PRF clot formation and retraction from the tube wall were observed. The PDGF-AB, TGF-β1 levels, and the gross/SEM appearance of the PRF clots were also evaluated. Results: The PRF clots in PP and PS tubes formed and retracted significantly slower compared with those in glass tubes. The PDGF-AB levels in the PRF from PP, PS, and glass tubes were not significantly different. Although the TGF-β1 levels in the PRF from PP and glass tubes were not different, that from the PRF from PS tubes was significantly higher. The gross structure and SEM appearance of PRF from the three tube types were similar.

Revascularization of immature necrotic teeth with platelet-rich fibrin and blood clot

Background: Endodontic treatment of immature permanent teeth with necrotic pulp, with or without apical pathosis, poses several clinical challenges. Regenerative endodontics is a promising alternative for the treatment of such immature necrotic permanent teeth. Aim: To assess the regenerative potential of young permanent teeth with necrotic pulps with platelet-rich fibrin (PRF) and blood clot using radiographic and clinical methods. Settings and Design: This was an experimental, in vivo study comparing the two groups. Materials and Methods: Immature necrotic permanent teeth (n = 14) in patients who belonged to the age group of 10-12 years were selected and divided into two groups. Group 1 was treated by conventional revascularization with blood clot and Group 2 with revascularization using PRF. Follow-up was done for 6 months. Standardized radiographs were analyzed for the periradicular healing and apical closure, and clinical analysis was performed using mobility index as compared to baseline values. Statistical Analysis Used: Results were analyzed using Friedman test, Wilcoxon test, and Mann-Whitney U-test. Results: There was increased periradicular healing and apical closure at 3 months and 6 months in Group 2 (PRF) when compared to Group 1 (conventional). Conclusions: Revascularization with PRF procedure leads to better and faster healing, reduced radiolucency, enhanced apical closure, and reduction in mobility of necrotic immature teeth.

Flap-free treatment of an oroantral communication with platelet-rich fibrin

a s t a t w ity was filled with platelet-rich fibrin (Fig. 2). Suturing the clots prevents them from migrating to the sinus, and stabilises them. After the cavity has been filled with clots, the gingival roantral communications can complicate dental surgery, articularly during extraction of a posterior maxillary root, ut they do heal spontaneously when the perforation is less han 5 mm in diameter. However, larger perforations need reatment, often with a mucoperiosteal buccal sliding flap r buccal fad pad.1 There are other options, but these have isadvantages such as postoperative swelling and pain, and oss of vestibular depth.2 A platelet-rich fibrin clot, first escribed by Chouckroun et al.,3 is formed by platelets, hite cells, cytokines, and circulating stem cells enmeshed n a fibrin matrix, and is a natural biomaterial that permits ptimal healing.4 It can be sutured to tissue because of its -dimensional fibrinous architecture. We have used plugs of latelet-rich fibrin clots for flap-free treatment of oroantral erforations after tooth extraction.

A comparative evaluation of the blood clot, platelet-rich plasma, and platelet-rich fibrin in regeneration of necrotic immature permanent teeth: A clinical study.

Introduction:This study was designed as a clinical trial to evaluate and compare the regenerative potential of platelet-rich fibrin (PRF), platelet-rich plasma (PRP), and blood clot in immature necrotic permanent teeth with or without associated apical periodontitis.Methods:Access preparation was done under rubber dam isolation. Copious irrigation was done with 2.5% NaOCl and triple antibiotic paste was placed as an intracanal medicament. After 4 weeks, the cases were divided into four groups with five patients in each group. The study design had three test arms and one control arm. Group I in which mineral trioxide aggregate apexification was carried out and it was kept as control group to evaluate the regenerative potential of blood clot and platelet concentrates, Group II in which blood clot was used as scaffold in the canal, Group III in PRF was used as scaffold, and Group IV in which PRP carried on collagen was used as a scaffold.Results:The clinical and radiographic evaluation after 6 and 18 months was done by two independent observers who were blinded from the groups. The scoring was done as: None score was denoted by, Fair by 1, Good by 2, and Excellent by 3. The data were then analyzed statistically by Fisher's exact test using Statistics and Data 11.1(PRP Using harvest Smart PReP2) which showed statistically significant values in Group III as compared to other Groups.Conclusion:PRF has huge potential to accelerate the growth characteristics in immature necrotic permanent teeth as compared to PRP and blood clot.

Can Autologous Platelet-Rich Fibrin Clot Enhance Healing after Surgical Extraction of Lower Third Molar?

Can Autologous Platelet-Rich Fibrin Clot Enhance Healing after Surgical Extraction of Lower Third Molar?

The bone integration effects of platelet-rich fibrin by removal torque of titanium screw in rabbit tibia

Platelet-rich fibrin (PRF) is nowadays often used in various fields, but no removal torque studies have yet been done to evaluate the effects of the platelet-rich fibrin on the bone integration at the initial healing period. An experimental study have been performed in rabbits to evaluate whether the complete PRF clots can accelerate the bone integration of implants at the initial healing period after creating bone defects in tibias. The effec t of the complete PRF clots on bone integration was studied in two rabbit groups, 4-week group (group A) and 6-week group (group B) after preparing bony defects. Artificial bony defects were prepared in the tibias of rabbits. The complete PRF clots was applied to the defects in the experimental group, whereas the defects were unfilled in the control group. Four weeks later, machined implants were installed into the rabbit tibias (group A). Six weeks after installation, the removal torque from nine rabbits was measured to examine the bone healing effect of PRF. In another rabbits (group B), 6 weeks after preparing bony defects, installation was performed, and another 6 weeks after installation, the removal torque from nine rabbits was measured. The authors found a positive significant effect of the complete PRF clots on bone integration (higher bone density) in group A installed at 4 weeks after preparing bony defects (p = 0.008; t-test), but not in group B installed at 6 weeks after preparing bony defects (p = 0.677).

Histopathological evaluation of the effect of platelet-rich fibrin on canine cutaneous incisional wound healing

Platelets are a natural source of growth factors and cytokines that promote wound healing, and platelet-rich fibrin contains concentrated growth factors. Growth factors in platelet-rich fibrin may promote wound repair. In this study the effect of platelet-rich fibrin was evaluated in a dog model of cutaneous incisional wounds using histology and semi-quantitative evaluation. A pair of ten-centimeter full-thickness parallel linear cutaneous wounds were created on the backs of 15 dogs on the both sides of vertebral column. On the left side the platelet-rich fibrin clot was applied to the edges of the wound (Treatment group) and the right side received nothing (Control group). All wounds were then closed with 3-0 non-absorbable Nylon suture. The dogs were divided into three groups of five dogs. The wound tissues were sampled by electrosurgery in group one after 3 days, group two after 7 days and group three after 14 days post surgery. For each specimen, histopathological examination and semi-quantitative evaluation was performed by light microscopy using Hematoxylin & Eosin and Masson’s trichrome staining. The results demonstrated that platelet-rich fibrin improved and accelerated cutaneous incisional wound healing.

The Dual Role Of Platelets In Thrombus Formation

The formation of a hemostatic thrombus during blood vessel injury is a highly regulated event which ensures that a blood clot is sufficiently stable but not overly robust to cause thrombus propagation and vessel occlusion. We have previously identified two anti-adhesive processes operating on the surface of fibrin clots that prevent excessive accumulation of blood cells such as platelets and leukocytes. In particular, binding of fibrinogen and plasminogen to fibrin creates a mechanically unstable surface through non-proteolytic and proteolytic mechanisms, respectively, which limits integrin-mediated cell adhesion. The proteolytic process depends on activation of plasminogen, which accumulates in a thin superficial layer of fibrin clots, by the plasminogen activation system assembled on transiently adherent blood cells. This is followed by plasmin generation and decomposition of the fibrin surface resulting in cell detachment under flow. We have further demonstrated that plasminogen activators tPA or uPA pre-bound to platelets can activate fibrin-bound plasminogen through the interfacial mechanism, i.e. when the components of the plasminogen activation system are assembled on different surfaces. Furthermore, plasminogen activators pre-bound to one population of platelets are able to activate plasminogen pre-bound to a separate pool of platelets. These data indicate that platelets activate both platelet- or fibrin-bound plasminogen and, potentially, could use their fibrinolytic potential during adhesion to fibrin clots. However, platelets are known also to contain high concentrations of PAI-1 which is secreted during clot formation. Therefore, it is uncertain whether the proteolytic anti-adhesive mechanism is functional when platelets encounter platelet-rich fibrin clots. To begin to address this question, we have compared fibrinolytic activity of tPA- or uPA-treated platelets placed on the surface of plasminogen-coated fibrin clots with that of platelets incorporated inside the gels prepared by mixing of fibrinogen with thrombin in the presence of uPA. The fibrinolytic activity was determined by detecting the release of 125Iodine-labeled fibrin degradation products or measuring plasmin amidolytic activity. While fibrinolysis by platelets inside the gel was completely inhibited, platelets adherent to the surface of fibrin clots retained their ability to activate plasminogen and degrade fibrin. Also, when both platelets and monocytic U937 cells, a cell line expressing endogenous uPA, were included in fibrin clots, platelets completely suppressed fibrinolytic activity of U937 cells. At the same time, proteolytic activity of U937 cells added on the top of platelet-rich gels was not affected. Confocal microscopy and Western blot analyses showed that by contrast with platelets incorporated in the gel which released substantial amounts of PAI-1, no PAI-1 was secreted from platelets adherent to the surface of the gel. These data may explain the well-known but hitherto unexplained capacity of platelets to either promote or inhibit fibrinolysis by introducing the idea that two different functions of platelets are relevant to different regions of the thrombus. Thus, platelets inside the clot, via the release of PAI-1, block fibrinolysis aiding in thrombus integrity. However, platelets transiently contacting fibrin are profibrinolytic enabling the anti-adhesive mechanism which prevents their excessive accumulation and, consequently, thrombus propagation. Disclosures:No relevant conflicts of interest to declare.

Influence of Platelet-Rich Fibrin on Alveolar Ridge Preservation

The aim of this study was to investigate the influence of platelet-rich fibrin (PRF) on early wound healing and preservation of the alveolar ridge shape following tooth extraction. In this clinical trial, 20 symmetrical, premolar extraction sockets using split-mouth design were randomly selected with PRF or blood clot. The evaluations of wound healing, alveolar ridge contour changes, and crestal bone resorption were performed in dental casts and periapical radiographs (T0, initial; T1, 1 week; T2, 2 weeks; T4, 4 weeks; T6, 6 weeks; T8, 8 weeks). Platelet-rich fibrin clinically showed early healing of soft tissue covering socket orifices in the first 4 weeks. At the first week, the horizontal resorption on buccal aspect of PRF (1.07 ± 0.31 mm) was significantly less than that of the control (1.81 ± 0.88 mm). Platelet-rich fibrin demonstrated the tendency to enter the steady stage after the fourth week following tooth extraction, whereas in the control group the progression of buccal contour contraction was still detected through the eighth week. Radiographically, the overall resorption of marginal bone levels at mesial and distal to the extraction site in PRF (0.70, 1.23 mm) was comparable to that of the control (1.33, 1.14 mm). Although the PRF group demonstrated faster bone healing compared with the control, no statistically significant difference was detected. This preliminary result demonstrated neither better alveolar ridge preservation nor enhanced bone formation of PRF in the extraction socket. The use of PRF revealed limited effectiveness by accelerated soft-tissue healing on the first 4 weeks.

Combination of Autologous Protein-Rich Fibrin and Bone Graft: An Invaluable Option for Reconstruction of Segmental Mandibular Defects

Combination of Autologous Protein-Rich Fibrin and Bone Graft: An Invaluable Option for Reconstruction of Segmental Mandibular Defects

Revascularization of an immature tooth with a necrotic pulp using platelet‐rich fibrin: a case report

To discuss the clinical and radiological outcome of a revascularization procedure in an immature tooth with a necrotic pulp using platelet-rich fibrin (PRF), a second-generation platelet concentrate. A 7-year-old male reported with pain in the maxillary anterior region as a result of the injury to his immature right maxillary central incisor tooth. After preparation of the access cavity, the necrotic pulp was removed and the canal irrigated using 5.25% sodium hypochlorite solution. The canal was then dried and packed with triantibiotic paste for 3weeks. After removal of the antibiotic paste, a 5mL sample of whole venous blood was drawn from the patient's forearm to prepare PRF. The freshly prepared PRF was condensed in the canal until the cementoenamel junction. Three millimetres of white MTA was placed directly over the PRF clot. Three days later, the tooth was restored using a permanent restoration. At 7-, 12- and 15-month recall, the tooth was asymptomatic with no sensitivity to percussion or palpation. At 12- and 15-month follow-up, the tooth responded positively to cold and an electric pulp test, and similarly to adjacent lateral incisor and canine teeth. Radiographic examination demonstrated continued thickening of root canal walls, root lengthening and apical closure. Platelet-rich fibrin might serve as a potentially ideal scaffold in revascularization of immature permanent teeth with necrotic pulps as it is rich in growth factors, enhances cellular proliferation and differentiation, and acts as a matrix for tissue ingrowth.

Socket preservation using platelet-rich fibrin in conjunction with epithelialized palatal free graft in minipigs

AimTo evaluate the potential of platelet-rich fibrin (PRF) and epithelialized palatal free graft (FGG) for preserving the alveolar ridge after tooth extraction in minipigs. Materials and methodsForty-eight alveoli from six minipigs were randomly sealed with PRF, FGG, PRF&FGG, and blood clot. After 2, 6 and 12 weeks of healing, alveolar ridge width and height, as well as, radiographic optical density were measured. The decalcified specimens were processed for histological and histomorphometric analysis. ResultsPRF clinically showed early healing of soft tissue covering socket orifices in the first 2 weeks. At the 6th week, the ridge width of PRF (5.2±1.2mm), FGG (4.4±0.9mm) and PRF&FGG (4.9±0.6mm) were better preserved than the control (3.7±1.1mm) (P>0.05). Radiographically, the mean bone height/overall height alteration at the 12th week of PRF (8.96/−1.11mm), FGG (7.99/−1.88mm), PRF&FGG (8.37/−1.79mm) and control (8.40/−1.57mm) were comparable. However, the PRF (158.57±30.74) showed a significant greater bone density than FGG (108.59±29.99) and control (91.31±37.33) (P<0.05). Histomorphometrically, the newly formed bone in PRF group was increased from 2nd to 12th weeks (42.31–52.00%), while the others showed unchanged percentage (FGG, 42.72–42.00%; PRF&FGG, 42.72–42.00%; control, 39.65–42.74) (P>0.05). ConclusionsThe use of PRF is an effective modality for short-term ridge preservation, while the use of FGG with or without PRF does not demonstrate any effect on early ridge preservation as evidence from clinical, radiographic and histomorphometric analysis.

Platelet-rich fibrin-mediated revitalization of immature necrotic tooth

Contemporary studies have shown that the regeneration of tissues and root elongation is possible in necrotic immature permanent teeth. The purpose of this case report is to add a new vista in regenerative endodontic therapy by using platelet rich fibrin for revitalization of immature non vital tooth. An 11year old boy with the history of trauma was diagnosed with the pulpal necrosis and symptomatic apical periodontitis in tooth #21. Intra oral periapical radiograph showed open apex and associated immature supernumerary tooth with respect to tooth #21. Access preparation and minimal instrumentation was done to remove necrotic debris under copious irrigation with 2.5% sodium hypochlorite. Triple antibiotic paste was packed in the canal for four weeks. During second visit, 5 mL of whole blood was drawn from the medial cubital vein of the patient and blood was then subjected to centrifugation at 2400 rpm for 12 minutes for the preparation of Platelet rich fibrin (PRF) utilizing Choukroun's method. Triple antibiotic paste was removed and canal was dried. PRF clot was pushed to the apical region of tooth #21 using hand pluggers. Three milimetres of Mineral trioxide (MTA) was placed in cervical part of the root canal and permanent restoration was done three days later. Clinical examination at 6 and 12 months revealed no sensitivity to percussion and palpation in tooth #21and it responded positively to both electric pulp and cold tests. Radiographic examination showed resolution of periapical rarefaction, further root development and apical closure of the tooth #21 and its associated supernumerary tooth. On the basis of successful outcome of the present case it can be stated that PRF clot may serve as a scaffold for regeneration of necrotic immature teeth.

A proposed protocol for the standardized preparation of PRF membranes for clinical use

Upon clinical application, thick platelet-rich fibrin (PRF) is usually compressed to fit the implantation site. However, it is speculated that the preservation of platelets and plasma content depends on the compression methods used. To accurately evaluate the clinical outcome of PRF, the preparation protocol should be standardized. Freshly prepared PRF clots were compressed into a thin membrane by our novel PRF compression device. The localization of platelets was examined by SEM and immunostaining. Growth factor levels were evaluated by bioassays and cytokine-antibody array techniques. The angiogenic activity was examined by the chick chorioallantoic membrane assay and the scratch assay using HUVEC cultures. Platelets were concentrated on the surface of the region adjacent to the red thrombus and this region was subjected to the experiments. Compared to the PRF membrane compressed by dry gauze (G-PRF), the preservation of the plasma content, 3D-fibrin meshwork, and platelets was more intact in the compressor-prepared PRF membrane (C-PRF). Among the growth factors tested, C-PRF contained PDGF isoforms at higher levels, and significantly stimulated cell proliferation and neovascularization. C-PRF may be useful for grafting while minimizing the loss of bioactive factors. This C-PRF preparation protocol is proposed as a standardized protocol for PRF membrane preparation.

치근단 병변이 있는 미성숙 영구치에서 Platelet-rich fibrin(PRF)를 이용한 보존적 근관치료

In case of an immature tooth with necrotic pulp, regeneration of pulp tissue into a canal would be the ideal outcome. It may be capable of promoting the continuation of normal root development. Platelet-rich fibrin has been suggested as a potentially ideal scaffold for regenerative endodontic treatment. Immature permanent teeth of young children were diagnosed with pulp necrosis and apical abscess as the result of clinical and radiographic examination. After removal of necrotic pulp, canal was irrigated with 5.25% NaOCl and dried with paper point. A triple antibiotic mixture was placed in canal space in 3 weeks. After removal of the antibiotic mixture, the platelet-rich fibrin was injected into the canal space with MTA placed directly over the platelet-rich fibrin clot. The coronal region was restored by composite resin. On the basis of short-term results of the present 3 cases, regeneration of vital tissues appears to be possible in a tooth with necrotic pulp and a periapical lesion. Also, platelet-rich fibrin proves to be potentially an ideal scaffold for this procedure. Therefore, long-term clinical observation and examination about this treatment using platelet-rich fibrin in immature permanent teeth of young children are considered to be necessary.

In Vitro Effects of Choukroun's Platelet-Rich Fibrin Conditioned Medium on 3 Different Cell Lines Implicated in Dental Implantology

The aim of this work was to determine the relevance of Choukroun's platelet-rich fibrin (PRF) in dental implantology by determining the in vitro effects of soluble factors released by PRF clot. We used 3 different cell lines implicated in dental implantology: osteoblast, keratinocyte, and fibroblast. Cellular viability, cell proliferation, and gene expression were analyzed using PRF conditioned medium. Three different cells lines were used: SaOS2 (osteoblast), MRC5 (fibroblast), and KB (epithelial cell). The sulforhodamine B assay showed a significant increase in cell number for the undiluted and 1:3 diluted conditioned medium after 24 and 48 hours. There was no effect for the 1:9 dilution. Cell cycle analysis by flow cytometry confirmed the viability test results. After 48 hours, PRF conditioned medium induced gene expression in osteoblasts. Expression of osteopontin and osteocalcin, late osteogenic markers, was observed using reverse transcriptase-polymerase chain reaction (RT-PCR). This study establishes a model to evaluate, in vitro, the effects of soluble growth factors released by PRF clot. Our work confirmed PRF is useful in stimulating tissue healing and bone regeneration. This work should recommend Choukroun's PRF in numerous implantology clinical applications.

Platelet Rich Fibrin in the revitalization of tooth with necrotic pulp and open apex

Regeneration of pulp-dentin complex in an infected necrotic tooth with an open apex is possible if the canal is effectively disinfected. The purpose of this case report is to add a regenerative endodontic case to the existing literature about using Platelet Rich Fibrin (PRF). A nine year old boy who accidently broke his immature maxillary central incisor tooth, developed pulpal necrosis with apical periodontitis. After the access cavity preparation, the canal was effectively irrigated with 20 ml of 5.25% sodium hypochlorite solution and 10ml of 0.2% chlorhexidine solution and dried with paper points. Triple antibiotic paste was placed inside the canal and left for 21 days. 12 ml of whole blood was drawn from the patient's right antecubital vein and centrifuged for 10 minutes to obtain the Choukroun's PRF. After the removal of the triple antibiotic paste, the PRF was placed into the canal till the level of cementoenamel junction and 3mm of grey MTA was placed directly over the PRF clot. The setting of MTA was confirmed 3 days later and the tooth was double sealed with GIC and Composite restoration. After 1 year the clinical examination revealed negative responses to percussion and palpation tests. The tooth responded positively to cold and electric pulp tests. Radiographic examination revealed continued thickening of the dentinal walls, root lengthening, regression of the periapical lesion and apical closure. On the basis of the results obtained in our case report we conclude that revitalization of necrotic infected immature tooth is possible under conditions of total canal disinfection and PRF is an ideal biomaterial for pulp-dentin complex regeneration.

Synergistic Effects of Bifunctional Antibodies Against beta3 Integrin on Dissolution of Platelet Thrombus,

Abstract 3350HIV-ITP patients have a unique Ab against platelet GPIIIa49-66 which induces oxidative platelet fragmentation in the absence of complement (Cell 106: 551, 2001; JCI 113: 973, 2004). Using a phage display single-chain antibody (scFv) library, we developed a novel human monoclonal scFv Ab against GPIIIa49-66 (named A11), which act similarly to the parental Ab (JBC 283: 3224, 2008). We then produced a bifunctional GPIIIa49-66 agent (named SLK), that targets newly deposited fibrin strands within and surrounding the platelet thrombus and has reduced effects on non-activated circulating platelets (Blood 116: 2336, 2010). In this study, we produced another bifunctional GPIIIa49-66 agent (named APAC), which homes to activated platelets. Like SLK, APAC destroys platelet aggregates ex vivo in an identical fashion with ∼85% destruction of platelet aggregates at 2 hrs. Platelet aggregate dissolution with a combination of SLK and APAC was ∼2 fold greater than either agent alone at 0.025 μM. Platelet-rich clot lysis experiments demonstrated the time required for 50% platelet-rich fibrin clot lysis (T50%) by APAC (95±6.1 min) was significantly longer than that by APAC+SLK (65±7.6 min) at a final concentration of 0.025 μM (APAC+SLK vs APAC, p<0.01). In comparison with APAC alone, the T50% of APAC+SLK was shortened by 1.56, 1.67 and 2.1 fold at the concentrations of 0.025, 0.5 and 0.1μM, respectively. Thus these low concentrations of a combination of both agents are likely to be more effective and less toxic when used therapeutically in vivo. Disclosures:No relevant conflicts of interest to declare.