Table 2.
Pre-clinical application of PRF for cartilage repair.
| End Use Destination | Hemocomponent/Experimental Groups | PRF Preparation Protocol | Characterization Parameters | Major Findings | Reference |
|---|---|---|---|---|---|
| Rabbits Chondral defect in the femoral condyle (diameter: 3 mm; depth: 0.5 mm) |
Rabbit PRF combined with cartilage granules derived from the created defect Control: - cartilage defect with no implantation |
Preparation according to Choukroun et al., 2001 [3]: - Blood collection without anticoagulant - Centrifugation (400 X g, 10 min) - Formation of a fibrin clot rich with platelets (PRF) in the middle of the tube, between the red blood cells and the acellular plasma |
- 3-month implantation - MRI - ICRS Visual Histological Assessment Scale (distribution of cells, mineralization of cartilage, tissue surface and matrix, cell population viability, subchondral bone abnormalities) |
- Less cartilage degradation in the PRF-treated group according to the MRI T2 values - Better histological scores in the PRF group, presenting normal cell distribution and cartilage mineralization, smooth and continuous tissue surface, hyaline cartilage-like formation and no subchondral abnormalities |
Kuo et al., 2011 [69] |
| Dogs Full thickness articular cartilage defect in the femoral condyle (diameter: 6 mm; depth: 5 mm) |
Dog PRF Control: - cartilage defect with no implantation |
Preparation according to Choukroun et al., 2001 [3] | - 4-, 16- and 24-week implantation - ICRS evaluation score for macroscopic assessment of the repaired tissue - O’Driscoll histological grading scale for microscopic investigation |
- Formation of cartilage-like reparative tissue in both experimental groups, with higher number of chondrocyte-like cells and better ECM deposition in the PRF groups - Macroscopic and histological grading scores were found to be higher in the PRF-treated groups, indicating a better quality of cartilage repair |
Kazemi et al., 2014 [70] |
| - Dog L-PRF - Dog L-PRP Control: - cartilage defect with no implantation |
Preparation according to Choukroun et al., 2001 [3] | - 4-, 16- and 24-week implantation - ICRS evaluation score for macroscopic assessment of the repaired tissue - O’Driscoll histological grading scale for microscopic investigation |
- No significant difference in macroscopic scores between L-PRP and L-PRF treated defects, but lower scores in the untreated control group - High quality repair tissue in both L-PRF and L-PRP treated groups according to histological evaluations |
Kazemi and Fakhrjou, 2015 [71] | |
| Rabbits Subcutaneous implant to test graft viability for rhinoplasty |
- Diced rabbit cartilage wrapped with rabbit PRFM - Diced rabbit cartilage wrapped with acellular dermal tissue - Diced rabbit cartilage wrapped with oxidized methylcellulose - Diced rabbit cartilage alone |
Preparation according to Choukroun et al., 2001 [3] | - 10-week implantation - Histological stainings - Graft evaluated for chondrocyte viability, collagen content, ECM fibrillar structure and changes in peripheral tissues |
- Better preservation of cartilage graft viability in the PRFM group - Less fibrosis, higher chondrocyte viability, better ECM deposition and less inflammation in the PRFM group |
Güler et al., 2015 [78] |
| Rabbits Subcutaneous implant to test graft viability for rhinoplasty |
- Diced rabbit cartilage wrapped with rabbit PRF - Diced rabbit cartilage wrapped with oxidized regeneratedcellulose - Diced rabbit cartilage wrapped with fascia - Diced rabbit cartilage alone |
Preparation according to Choukroun et al., 2001 [3] | - 2 month-implant - Macroscopic evaluation - Histological staining - Explants evaluated for graft viability, fibrosis, inflammation and vascularization |
- Superior viability of the cartilage graft wrapped with PRF in comparison with the cartilage graft wrapped with oxidized regenerated cellulose - No significant differences among the other groups - The 4 groups were not significantly different in terms of inflammation rate, fibrosis and vascularization |
Göral et al., 2016 [79] |
| Rabbits Full thickness articular cartilage defect in the patellar groove (diameter: 4 mm; depth: 3 mm) |
- Rabbit PRF - Rabbit PRP - Rabbit PRF + rhSDF1 - Rabbit PRP + rhSDF1 - Gelatin + rhSDF1 Control: - Untreated cartilage defect |
Preparation according to Choukroun et al., 2001 [3] | - 4-week implantation - ICRS scores for macroscopic evaluations - ICRS Visual Histological Assessment Scale - Immunofluorescence analysis of type-II collagen expression - Gene expression study of cartilage markers (Aggrecan, SOX9) |
- Higher ICRS macroscopic scores in the PRF + rhSDF1 group, with complete repair and good integration with the surrounding cartilage - ICRS histological scores of treated groups, except for the PRP group, were significantly higher than the untreated control - Neo-cartilages highly positive to type-II collagen in the PRF + rhSDF1, PRP + rhSDF1 and Gelatin + rhSDF1 groups - Higher expression of SOX9 in the regenerated tissue of all treated groups than the control group - Higher expression of Aggrecan in the treated groups, except for PRP group |
Bahmanpour et al., 2016 [62] |
| Horses Full thickness articular cartilage defect of the knee (diameter: 15 mm) |
Horse APEF (Autologous Platelet-enriched Fibrin) +/− horse BMDMSCs | - Blood collection into an acid citrate dextrose bag - Isolation of fibrinogen from plasma by use of an ethanol precipitation technique - Obtainment of a fibrinogen/platelet mixture (1:1) with the thrombin solution |
1-year implantation Repair tissues were evaluated by: - Arthroscopy (ICRS scores) - Histological examination - MRI - Micro-CT - Indentation tests |
- No significant differences between the two groups according to arthroscopic ICRS scores - Fair-to-good fill of chondral defects and integration with the surrounding cartilage in both groups according to histological scores - Less thick cartilaginous tissue in the repair site after the addition of BMDMSCs - No variations in the stiffness of the cartilaginous tissue between the two treatments |
Goodrich et al., 2016 [72] |
| Rabbits Chondral defect in the femoral condyle (diameter: 3 mm) |
- Rabbit PRF + cartilage granules (PRFCG) Controls: - Rabbit PRF - Untreated cartilage defect |
Preparation according to Choukroun et al., 2001 [3] | - 3-month implantation - Gross anatomy evaluation - ICRS histological scores |
- Repair tissue with an intact, smooth, and hyaline-like surface resembling normal cartilage in the PRFCG group - Integration of the PRFCG implant with adjacent normal tissue, with no signs of inflammation - Histologically, better repair of the cartilage defect in the PRFCG group versus the PRF and untreated groups |
Wong et al., 2017 [66] |
| Rabbits 2 mm wedge shape full-thickness defect in the medial meniscus |
- Rabbit PRF fragments + defect sutured with 5–0 prolene (PRF-augmented suture group) Controls: - Not sutured defects (non-suture group) - Defects sutured with 5–0 prolene (suture group) |
Preparation according to Choukroun et al., 2001 [3] | - 3-month implantation - Semi-quantitative histological scores |
- Better morphological integrity of the meniscus in the PRF-augmented suture group than the control groups - No signs of high-grade degeneration in the PRF-augmented suture group, but mucoid changes with clear signs of degeneration in the control groups - Better healing of the meniscal defect via PRF-augmentation according to histological scores - Better congruity of articular cartilage in the PRF treated group |
Wong et al., 2017 [67] |
| Rabbits osteochondral defect in the patellar groove (diameter: 5 mm; depth: 2 mm) |
- Rabbit PRF + osteochondral autograft - Rabbit PRP + osteochondral autograft Control: - Osteochondral autograft |
Preparation according to Choukroun et al., 2001 [3] | - 3- and 12-week implantation - ICRS macroscopic scoring system for repair evaluation - Histological examination - Immunohistochemical analysis of type-I and type-II collagen |
- Macroscopical healing of the defect in the PRF group versus PRP and control groups at 3 weeks - Macroscopical healing of the defect with normal or nearly normal cartilage in all the 3 groups at 12 weeks - In the nongrafted portion of the defect, formation of hyaline-like cartilage in the PRF group and fibrocartilage in the other 2 groups |
Maruyama et al., 2017 [73] |
| Rabbits Full thickness osteochondral defect in the knee joint (diameter: 5 mm; depth: 5 mm) |
- Rabbit i-PRF - Rabbit PRP Control: - Untreated defect |
- Blood collection without anticoagulant - Centrifugation (60 X g, 3 min) with Choukroun PRF Duo Centrifuge (Process for PRF, Nice, France) - Collection of the upper plasma layer designated as i-PRF |
- 4- and 12-week treatment - ICRS macroscopic scoring system - ICRS histological scoring - Safranin O/fast green staining of to assess GAG content |
- At 4 weeks, higher macroscopic IRCS scores in the i-PRF group in comparison with PRP and control groups, with formation of white opaque tissue well integrated with the surrounding healthy cartilage - At 12 weeks, no significant macroscopic differences among all groups - Higher ICRS histological scores in the i-PRF group, revealing complete regeneration of the cartilage and subchondral bone, with complete integration to normal tissues and identification of normal chondrocytes |
Abd El Raouf et al., 2017 [61] |
| Dogs Osteochondral defect in the femoral condyle (diameter: 6 mm; depth: 5 mm) |
- Dog PRF seeded with dog BM-MSCs Control: - Untreated defect |
Preparation according to Choukroun et al., 2001 [3] | - 4-, 16- and 24-week implantation - ICRS evaluation score for macroscopic analysis - O’Driscoll histological grading scale for microscopic studies |
- Consistently better integration of the repair tissue in the treated group versus the untreated control according to macroscopic scoring results - Formation of fibrous tissue in both experimental groups at 4 weeks - Histological detection of chondrocyte-like cells and cartilaginous ECM in the treated group at 16 and 24 weeks - Significantly higher histological scores in the treated group |
Kazemi et al., 2017 [74] |
| Pigs Osteochondral defect in the femoral condyle (diameter: 8 mm; depth: 5 mm) |
- Pig PRF +/- autologous cartilage fragments - Autologous cartilage fragments Control: - Untreated defect |
- Blood collection with clot activator and gel - Centrifugation (1,066 X g, 10 min) - Separation of the jelly-like PRF from the gel-clot without the red blood cells sinking to the bottom of the tube |
- 6-month implantation - Gross appearance of coverage, tissue color, defect margins, and surface - ICRS histological grading score |
- Significantly better healing and repair tissue integration in the PRF+cartilage group in comparison with other 3 groups - Significantly greater histological scores in the PRF+cartilage group, with smooth repaired hyaline-like cartilage containing columnar arrangements of chondrocytes and integration of the regenerated tissue with the normal hyaline cartilage as well as the underlying subchondral bone |
Sheu et al., 2017 [75] |
| Rabbits Osteochondral defect in the femoral condyle (diameter: 3 mm; length: 2 mm) |
- Rabbit PRF releasates (PRFr) +/− autologous bone marrow-derived MSCs - Autologous bone marrow-derived MSCs Control: - Untreated defect |
- Blood collection into a serum separation tube - Centrifugation (3,000 rpm, 10 min) - Obtainment of a fibrin clot (PRF) between a clear yellow serum layer and a coagulated red blood cell layer |
- 12-week treatment - Gross assessment of shape, color, contour, and uniformity of the cartilage - Histological scoring system |
- Decrease of the defect size and increase of the regenerated cartilage volume in the PRFr+MSCs group - Better histological indices (i.e., matrix deposition, cell distribution, and tissue surface) in the PRFr+MSCs group - Thicker hyaline-like cartilaginous tissue with normal GAG production in the PRFr+MSCs group in comparison with other 3 groups |
Wu et al., 2017 [53] |
| Rabbits Osteochondral defect in the femoral condyle (diameter: 3 mm; length: 2 mm) |
- Rabbit PRF releasates (PRFr) +/− autologous ADSCs - Rabbit PRFr + chondrocytes - Autologous ADSCs Control: - Untreated defect |
Preparation according to Wu et al., 2017 [53] | - 14-week treatment - Gross investigation of defect filling, integration to border zone and macroscopic appearance of the implant - ICRS histological grading score |
- Decrease of the defect size and increase of the repaired cartilage volume in the PRFr+ADMSCs group - Better matrix, cell distribution, and surface indices in the PRFr+ADSCs group than other groups according to histological grading scores - Thicker hyaline cartilage-specific ECM in the PRFr+ADMSCs group - Similar histological scores for ADSCs and PRFr groups |
Hsu et al., 2018 [76] |
| Rabbits Full thickness cartilage defect of the ear (5 × 5 × 1 mm) |
- Rabbit PRF +/- allogenic ADSCs - Allogenic ADSCs Control: - Untreated defect |
Preparation according to Choukroun et al., 2001 [3] | - 1-, 2-and 3-month implantation - Macroscopic evaluation - Histological analysis - Gene/protein expression study of type-II collagen - Immune response evaluation by determining blood levels of CD4/CD8, IL-2 and IL-4 |
- Best rate of repair at all observation points in the PRF+ADSCs group, with 90% greater repair rate than other groups at 3 months - More efficient repair of the cartilage defect in the PRF+ADSCs group, with the treated area almost completely filled by naïve chondrocytes. - Higher type-II collagen expression, both at the gene and protein levels, in the PRF and PRF+ADSCs groups - No significant immune response induced by allogenic ADSC transplantation |
Xu et al., 2018 [77] |
ADSCs, Adipose-derived Stem Cells; APEF, Autologous Platelet-enriched Fibrin; BMDMSCs, Bone Marrow-derived Mesenchymal Stem Cells; BM-MSCs, Bone Marrow-derived Mesenchymal Stem Cells; ECM, Extracellular Matrix; GAG, glycosaminoglycan; ICRS, International Cartilage Repair Society; IL, Interleukin; i-PRF, injectable Platelet-rich Fibrin; L-PRF, Leukocyte- and Platelet-rich Fibrin; L-PRP, Leukocyte- and Platelet-rich Plasma; micro-CT, micro-Computed Tomography; MRI, Magnetic Resonance Imaging; PRF, Platelet-rich Fibrin; PRFM, Platelet-rich Fibrin Matrix PRFr, Platelet-rich Fibrin releasates; PRP, Platelet-rich Plasma; rhSDF1, recombinant human Stromal cell-derived Factor 1; +/−, with or without.