Synergistic impact of platelet rich plasma-heparin sulfate with hydroxyapatite/zirconia on the osteoblast differentiation potential of adipose-derived mesenchymal stem cells.

3D porous hydroxyapatite (HA) has been reinforced by zirconia (ZrO2) coating and impregnation with a combination of platelet rich plasma (PRP) as a source of growth factors (GFs) and Heparin sulfate (HS) to sustain the release of GFs. Adipose mesenchymal stem cells (ADMSCs) were characterized by flow cytometry for CD (cluster of differentiation) 44, CD105, CD106, CD34 and CD144, along with checking the multipotency by differentiation into the adipocytes and osteoblasts. Then, they were cultured on the scaffold treated with and without osteogenic media on days 7, 14 and 21. Electron micrograph and PKH staining show that the ADMSCs have a fusiform phenotype in the absence of osteogenic induction. Cell viability assay shows a higher number of the viable cells on the PRP-containing scaffolds than PRP-free scaffolds on day 7. Colorimetric evaluation, quantitative RT-PCR and immunocytochemistry demonstrate that PRP and HS significantly elevate the alkaline phosphatase enzyme activity and also accelerate the production of both early and mid-osteogenic markers, including collagen I and osteopontin expression with and without osteogenic conditions. The PRP-HS also accelerates the expression of the late osteogenic marker, osteocalcin, in both mRNA and protein level expression with a peak on day 21. In conclusion, supplementation of HA/ZrO2 with PRP/HS has a synergistic impact on the ADMSCs, even in the absence of chemical induction. It seems that HA/ZrO2/PRP/HS scaffold provides a higher osteoconductive microenvironment for stem cell differentiation to osteoblasts.

Impact of platelet-rich plasma versus selenium in ameliorating induced toxicity in rat testis: histological, immunohistochemical, and molecular study.

This study was conducted on forty adult rats divided into four groups: Group I (control) that is divided into subgroups A, B, and C and Group II (methotrexate (MTX)-treated); the rats were injected intraperitoneally with MTX at a dose of 1 mg/kg/week, for 8 weeks. Group III (MTX-Se co-treated) was injected with MTX like Group II plus an oral administration of selenium at a dose of 10 µg/kg b.w/day, for 8 weeks. Group IV (MTX-PRP co-treated), rats were injected intraperitoneally with MTX like Group II plus platelet-rich plasma (PRP) injection under the scrotum, three times with 2-week intervals (volume-0.1 ml per injection) and euthanized after 8 weeks. Histological, immunohistochemical, and genetic expression using qPCR and western blotting technique were conducted. There was improvement in histological structure of testes in most specimens of Group IV. The latter group revealed a significant decrease in Bax and an increase in Bcl-2. The regeneration of testicular tissue was more observed in Group IV as measured by an increase in mean number of PCNA. Moreover, Group IV revealed an increased genetic level of FSCN3, GCNF, UBQLN3, and DAZL. Both MTX-Se and MTX-PRP have an anti-inflammatory effect as measured by a reduction in NF-κb. The anti-oxidative effect of selenium and PRP was noticed by a decrease in the level of the iNos and an increase in eNos protein and the autophagy marker LC3. PRP has ameliorative effects on induced rat testicular toxicity as evaluated by morphological changes and confirmed by immunohistochemical reactions, genetic expression, and western blotting analyses including oxidative and anti- oxidative markers.

Low-fluence laser-facilitated platelet-rich plasma permeation for treating MRSA-infected wound and photoaging of the skin.

Platelet-rich plasma (PRP) is rich in cytokines and growth factors and is a novel approach for tissue regeneration. It can be used for skin rejuvenation but the large molecular size of the actives limits its topical application. In this study, low-fluence laser-facilitated PRP was delivered to evaluate its effect on absorption through the skin, infection-induced wound, and photoaging. The PRP permeation enhancement was compared for two ablative lasers: fractional (CO2) laser and fully-ablative (Er:YAG) laser. In the Franz cell experiment, pig skin was treated with lasers with superficial ablation followed by the application of recombinant cytokines, growth factors, or PRP. The transport of interferon (IFN)-γ and tumor necrosis factor (TNF)-α was negligible in intact skin and stratum corneum (SC)-stripped skin. Both lasers significantly elevated skin deposition of IFN-γ and TNF-α from PRP, and fully-ablative laser showed a higher penetration enhancement. A similar tendency was found for vascular endothelial growth factor and epidermal growth factor. Er:YAG laser-exposed skin displayed 1.8- and 3.9-fold higher skin deposition of platelet-derived growth factor (PDGF)-BB and transforming growth factor (TGF)-ß1 from PRP, respectively. According to the confocal images, both laser interventions led to an extensive and deep distribution of IFN-γ and PDGF-BB in the skin. In the in vivo methicillin-resistant Staphylococcus aureus (MRSA) infection model, CO2 laser- and Er:YAG laser-assisted PRP delivery reduced bacterial load from 1.8 × 106 to 5.9 × 105 and 1.4 × 104 colony-forming units, respectively. The open wound induced by MRSA was closed by the laser-assisted PRP penetration. In the mouse photoaging model, elastin and collagen deposition were fully restored by combined PRP and full-ablative laser but not by PRP alone and PRP combined with fractional laser. Laser-facilitated PRP delivery even with a low fluence setting can be considered a promising strategy for treating some dermatological disorders.

A comparative study of low-level laser efficacy on autologous activity of PRP injected in knee arthritis, in vivo study.

There were many studies that attempt to measure the effect of growth factors of platelets through platelet-rich plasma (PRP) techniques on repairing of different human tissues and their efficiency either by platelets account or measuring the concentrations of growth factors secreted from platelets at various experimental conditions, to get the optimal parameters for platelets functions in healing processes. There were little trails dealing with laser and PRP for accelerating healing process that generally takes two methods, either by studding the stimulation effect of LLLT (low-level laser therapy), by subjecting laser irradiation on injured part and left for a period of time that is necessary for photobiostimulation of cell proliferations, then PRP treatment followed, or by studding the direct effects of laser on PRP factors activity. The objectives of this study are to investigate the indirect and prolonged influence of laser irradiation (650 nm with 100 mW output power) on healing processes of knee joints with induced osteoarthritis (OA), by comparison of radiated and non-radiated PRP on repairing of joint cartilage. In material and methods, we used 9 rats divided in to four groups: C1, control without any treatment, for positive comparisons of healing; C2 and C3, controls with induced OA, left for 14 days, then sacrificed for histological analysis of negative comparisons; and P and L groups that had induced with OA for 14 days and then treated with non-irradiated and radiated PRP, respectively. Preparation of PRP (condensed platelets account with high concentration of growth factors) in order to accelerate repairing processes on induced- osteoarthritis cartilage in rats groups. To estimate the efficacy of photobiostimulation or photobioinhibition on platelets' granules, we determine the absorbance of PRP by spectrophotometer. The technique was based on PRP, as a feature of platelets quantity, that compares the quality of PRP on healing of induced osteoarthritis with and without irradiation of laser, using Wistar rats as a model. The quality of platelets was measured by time required for healing according to histopathological observations and grades of OA. Finally, the results were analyzed statistically using ANOVA test (P = 0.05). Our conclusion was emphasizing the idea of inhibiting the effect of LLLT on growth factors of PRP that is responsible of speed up healing of OA.

The potential protective and therapeutic effects of platelet-rich plasma on ischemia/reperfusion injury following experimental torsion/detorsion of testis in the Albino rat model.

AIMS: This study was designed to evaluate the protective and therapeutic efficacy of platelet-rich plasma (PRP) against testicular degeneration and germ cell apoptosis after induced spermatic cord torsion/detorsion (TD) in rats. MATERIALS: Forty rats were allocated into 5 groups: 1) control, 2) short torsion/detorsion (STD), 3) long torsion detorsion (LTD), 4) protective (PRP/P) and 5) treatment (PRP/T). Testicular ischemia was induced by twisting the right testis 1080° clockwise for 2.5 h. PRP (10 µl) was injected intra-testicular 5 min before (PRP/P) and 3 h after (PRP/T) detorsion. At the end of the experiment, rats were euthanized at 2, 30, 2, and 30 days for groups 2-5 respectively. Nitric oxide, malondialdehyde, catalase, total antioxidant capacity, reduced glutathione, glutathione-S-transferase, interleukin1 beta, tumor necrosis factor, caspase-3, and B-cell lymphoma 2 expressions were assessed in the testes. Moreover, histological examination was performed. KEY FINDINGS: PRP treatment significantly mitigated the torsion-detorsion induced testicular degeneration. Particularly, by improving the state of oxidative stress (NO, P = 0.0001) and antioxidant markers (TAC, GSH, GST, P = 0.0001-0.01) and decreasing the expression of IL-1ß, TNF-α and cas 3 and increase the BCL2 fold changes (P = 0.0001). The protective use of PRP is superior to the therapeutic use of PRP in the restoration of the testicular histoarchitecture following TD. SIGNIFICANCE: This study illustrates the cyto-protective role of PRP against TD induced testicular cell injury that highlight possible application of PRP as a complementary therapy in different testicular degenerative diseases which might attribute to its ability to ameliorate the oxidative stress and inhibit induced apoptosis.

Regenerative effects of hyperbaric oxygen therapy and platelet-rich plasma on the osteochondral defects of rats.

OBJECTIVES: This study aims to investigate the effects of hyperbaric oxygen (HBO) therapy and platelet-rich plasma (PRP) on the regeneration of osteochondral defects of the rats, and the synergistic effect of this combined treatment. MATERIALS AND METHODS: This randomized, controlled, and interventional animal study was conducted between May 2014 and August 2014 Osteochondral regeneration was evaluated in four treatment groups (control, PRP, HBO, and HBO+PRP groups) at the 30th day after iatrogenic injury. Thirty-two female Wistar albino rats (weighing 248-305 g) underwent arthrotomy and osteochondral surgery on left knees. The regenerations of defects were then examined histologically by the modified version of O'Driscoll score. RESULTS: Groups that were treated with either HBO or PRP alone regenerated significantly better than the control group (p=0.01), while no significant difference was found between the HBO- and PRP-treated groups (p>0.05). The defects in group 4 (treated with both HBO and PRP) regenerated significantly better than the control group, the HBO-treated group alone, and the PRP-treated group alone (p=0.01). CONCLUSION: The results of this study showed a synergistic effect of HBO and PRP on knee cartilage regeneration. However, the possible underlying mechanisms should be the subject of future researches. The aggregation and activation of growth factors released from platelets whose activation is increased in the hyperbaric environment may explain this effect. This may result in a better regeneration than the effect of PRP or HBO alone.

Low-level laser therapy and narrative review of other treatment modalities in androgenetic alopecia.

Androgenetic alopecia (AGA), also termed as androgenic alopecia or common baldness, is a condition where there is androgen mediated conversion of susceptible terminal hair into vellus hair. Although it is reported more commonly in males, it also affects females but the incidence is relatively unknown. AGA tremendously affects the psychology of the patient due to its chronicity of treatment and cosmetic implications. There are numerous treatment options available for AGA but the choice of treatment has to often be tailored according to the patient's needs, affordability, and compliance. This review focusses on the various treatment options available, with special emphasis on the role of low-level laser therapy (LLLT) in the management of AGA. The literature research considered published journal articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) and reference lists of respective articles. Only articles available in English were considered for this review.

In vitro study of cartilage tissue engineering using human adipose-derived stem cells induced by platelet-rich plasma and cultured on silk fibroin scaffold.

BACKGROUND: Cartilage tissue engineering is a promising technique for repairing cartilage defect. Due to the limitation of cell number and proliferation, mesenchymal stem cells (MSCs) have been developed as a substitute to chondrocytes as a cartilage cell-source. This study aimed to develop cartilage tissue from human adipose-derived stem cells (ADSCs) cultured on a Bombyx mori silk fibroin scaffold and supplemented with 10% platelet-rich plasma (PRP). METHODS: Human ADSCs and PRP were characterized. A silk fibroin scaffold with 500 µm pore size was fabricated through salt leaching. ADSCs were then cultured on the scaffold (ADSC-SS) and supplemented with 10% PRP for 21 days to examine cell proliferation, chondrogenesis, osteogenesis, and surface marker expression. The messenger ribonucleic acid (mRNA) expression of type 2 collagen, aggrecan, and type 1 collagen was analysed. The presence of type 2 collagen confirming chondrogenesis was validated using immunocytochemistry. The negative and positive controls were ADSC-SS supplemented with 10% foetal bovine serum (FBS) and ADSC-SS supplemented with commercial chondrogenesis medium, respectively. RESULTS: Cells isolated from adipose tissue were characterized as ADSCs. Proliferation of the ADSC-SS PRP was significantly increased (p < 0.05) compared to that of controls. Chondrogenesis was observed in ADSC-SS PRP and was confirmed through the increase in glycosaminoglycans (GAG) and transforming growth factor-ß1 (TGF-ß1) secretion, the absence of mineral deposition, and increased surface marker proteins on chondrogenic progenitors. The mRNA expression of type 2 collagen in ADSC-SS PRP was significantly increased (p < 0.05) compared to that in the negative control on days 7 and 21; however, aggrecan was significantly increased on day 14 compared to the controls. ADSC-SS PRP showed stable mRNA expression of type 1 collagen up to 14 days and it was significantly decreased on day 21. Confocal analysis showed the presence of type 2 collagen in the ADSC-SS PRP and positive control groups, with high distribution outside the cells forming the extracellular matrix (ECM) on day 21. CONCLUSION: Our study showed that ADSC-SS with supplemented 10% PRP medium can effectively support chondrogenesis of ADSCs in vitro and promising for further development as an alternative for cartilage tissue engineering in vivo.

Comparison of Platelet Rich Plasma and Prolotherapy in the Management of Osteochondral Lesions of the Talus: A Retrospective Cohort Study.

BACKGROUND Osteochondral lesions of talus (OLT) are among the most common ankle problems. Platelet-rich plasma (PRP) and prolotherapy (PrT) are 2 successful injection-based techniques for treatment of chronic musculoskeletal problems. The aim of the present study was to compare PRP and PrT injections for the management of OLT. MATERIAL AND METHODS This was a retrospective cohort study of 49 patients with OLT symptoms of more than 6 months who had been refractory to 3 months of treatment using conservative methods. The patients were divided into 2 groups: PrT injections (PrT group, n=27) or PRP injections (PRP group, n=22). The patients were given 3 injections of 4 mL solution into periarticular and intra-articular ankle joint spaces. After treatment, patients were evaluated via Visual Analogue Scale (VAS), American Orthopedic Foot and Ankle Society Score (AOFAS), and Ankle Osteoarthritis Scale (AOS) at baseline and 21-, 90-, 180-, and 360-day follow-up periods. RESULTS Both PRP and PrT treatments resulted in greater improvement in pain and ankle functions at follow-up periods extending to 1 year (P<0.001) and there was no difference between the groups for the outcomes at follow-up periods (P>0.05). Excellent or good outcomes were reported by 88.8% of the patients in PrT group and 90.9% of the patients in PRP group. CONCLUSIONS Both PRP and PrT are efficient and safe methods in treatment of OLT. PrT offers advantages of less cost and minimal invasiveness.

The mechanism of activated platelet-rich plasma supernatant promotion of hair growth by cultured dermal papilla cells.

BACKGROUND: Platelet-rich plasma (PRP) is an innovative treatment of androgenic alopecia in the early stages of development, and its mechanism of action is not well investigated. OBJECTIVE: The objective was to investigate the promotion of hair growth by activated PRP supernatant in cultured dermal papilla cells (DPCs). METHODS AND MATERIALS: Human DPCs were isolated and grown in culture with or without activated PRP supernatant. The expression of phosphorylated growth factor receptors (GFRs) in cultured DPCs was assayed by immunofluorescence and Western blotting. Signal pathways mediated by GFRs were identified by a human phosphokinase array. RESULTS: Activated PRP supernatant enhanced the expression of phosphorylated fibroblast growth factor receptor (FGFR)-1, platelet-derived growth factor receptor (PDGFR)α, and PDGFRß in cultured DPCs. Activated PRP supernatant activated mitogen-activated protein kinase (MAPK) and protein kinase B (Akt) signaling pathways that promoted proliferation of DPCs. Downregulation of glycogen synthase kinase-3 was consistent with the involvement of Wnt signaling. Activated PRP supernatant increased the hair growth promoting ability of DPCs by activating the Wnt signaling pathway. CONCLUSION: Autologous activated PRP supernatant promoted signaling in cultured human DPCs via pathways known to be involved in hair growth. The results warrant further study of PRP for the clinical treatment of androgenic alopecia.

Allogeneic platelet rich plasma serves as a scaffold for articular cartilage derived chondroprogenitors.

Limited self-restorative ability of the cartilage has necessitated the use of cell and tissue engineering based therapies. Recent advances in the isolation, expansion and characterization of articular cartilage derived chondroprogenitors(CPs) has gained popularity in its role for cartilage repair. Platelet rich plasma (PRP) is a reliable biological scaffold for in-vitro and in-vivo studies with reported therapeutic applications in cartilage and bone pathologies. The aim of this study was to evaluate whether human allogeneic PRP could serve as a biological scaffold for chondroprogenitors (CPs) in cartilage repair. CPs were isolated from the superficial layer of three osteoarthritic knee joints by fibronectin adhesion assay and characterized using flow cytometric analysis. Allogeneic citrated blood was harvested from three subjects to obtain PRP. CPs at a concentration of one million cells per ml were gelled with PRP using calcium chloride. The PRP-CP scaffolds were subjected for adipogeneic, osteogenic, chondrogeneic differentiation and processed for post differentiation-staining studies (Oil Red O, Von Kossa, Alcian blue staining), immunofluorescence (collagen II) and live dead assays (Calcein AM-Ethidium Homodimer). We show that PRP was able to sustain CP cell viability and differentiate towards adipogenic, osteogenic and chondrogenic lineage under appropriate culture conditions. We also noted positive extracellular matrix production in PRP-CP scaffolds cultured without chondrogenic supplementation. Our results suggest that PRP could be a promising bio-active scaffold due to its synergistic effect in supporting cell proliferation, maintaining cell viability and favoring extracellular matrix production. PRP can be used as biological scaffold for the delivery of CPs in cartilage healing.

Comparative study of different anticoagulants and coagulants in the evaluation of clinical application of platelet-rich plasma (PRP) standardization.

To investigate the impact of different anticoagulants and coagulants with autologous platelet-rich plasma (PRP) in order to evaluate the clinical application of PRP standardization. Bone marrow stem cells (BMSCs) were seeded into autologous PRP gel scaffolds with different anticoagulants (EDTA, heparin sodium HS, and sodium citrate SC) as well as control group (the whole blood group). Quality of PRP was evaluated and flow cytometric assay was used to detect the activity of the platelet (CD62p, PAC-1). BMSCs were also seeded into PRP with different coagulants (Thrombin, Collagen-I, ADP) as well as PRP un-activated (negative group) and L-DMEM complete culture without PRP (control group). The effects of different coagulants with PRP on proliferation, osteogenic differentiation of BMSCs were analyzed by methyl thiazolyl tetrazolium assay (MTT), ALP staining, Von Kossa staining, Confocal microscopic observation, RT-PCR and Western Blot at the morphological, cellular and molecular levels. Different anticoagulants (EDTA, HS, and SC) could affect the quality of PRP. EDTA group revealed the best quality and activity (CD62p, PAC-1). With different coagulants (Thrombin, Collagen-I and ADP) in the proliferation of BMSCs, the MTT assay showed that the proliferation of BMSCs was increased in all groups with time. On the sixth day of culture, the cell number of each PRP group was significantly higher than that in the control group (P < 0.05), while the most rapidly increasing was found in Collagen-I group. The cumulative release of growth factor (TGF-ß1, PDGF) at each time point in the PRP gel of the four groups was higher than that in the control group (P < 0.05). Collagen-I was considered as the best PRP coagulant. When thrombin was used as a platelet coagulant, the release of growth factor in PRP was rapid and direct, while the release of growth factor in Collagen-I-activated PRP was sustained and slow, and the total release of ADP-activated PRP growth factors was the lowest. The study demonstrated the similar outcome in osteogenic differentiation. In terms of gene expression and western bolt, the PCR results showed that the expression levels of OCN gene and RUNX2 protein in each PRP group were higher than that in the control group (P < 0.05). Different anticoagulants caused different degrees of lysis and spontaneous activation of platelets, which lead to different quality of PRP. Compared with HS and SC, EDTA could maintain the structural integrity of platelets, reduce their spontaneous activation, and increase the release of PRP growth factors for a longer period of time, thus ensuring the biomass of PRP. In addition, different coagulants also showed different results in the proliferation as well as osteogenic differentiation of BMSCs. Compared with Thrombin and ADP, Collagen-I may be a better choice.

In Vitro Antithrombotic Properties of Salmon (Salmo salar) Phospholipids in a Novel Food-Grade Extract.

Marine and salmon polar lipids (PLs) extracted by conventional extractions with non-food-grade solvents (CE-salmon-PLs) possess antithrombotic bioactivities against platelet-activating factor (PAF) and thrombin. Similar effects of food-grade-extracted (FGE) marine PLs have not yet been reported. In this study, food-grade solvents were used to extract PLs from Irish organic farmed salmon (Salmo salar) fillets (FGE-salmon-PLs), while their antithrombotic bioactivities were assessed in human platelets induced by platelet aggregation agonists (PAF/thrombin). FGE-salmon-PLs were further separated by thin layer chromatography (TLC) into lipid subclasses, and the antithrombotic bioactivities of each subclass were also assessed. LC-MS was utilized to elucidate the structure-activity relationships. FGE-salmon-PLs strongly inhibited PAF-induced platelet aggregation, while their relevant anti-thrombin effects were at least three times more potent than the previously reported activities of CE-salmon-PLs. TLC-derived lipid fractions corresponding to phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were the most bioactive lipid subclasses obtained, especially against thrombin. Their LC-MS analysis elucidated that they are diacyl- or alkyl-acyl- PC and PE moieties baring ω3 polyunsaturated fatty acids (PUFA) at their sn-2 position, such as eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA). Our results concerning the potent antithrombotic effects of FGE-salmon-PLs against both PAF and thrombin pathways strongly suggest that such food-grade extracts are putative candidates for the development of novel cardioprotective supplements and nutraceuticals.

Platelet-rich plasma ameliorates gamma radiation-induced nephrotoxicity via modulating oxidative stress and apoptosis.

AIMS: As a source of growth factors and with its cytoprotective properties, platelet-rich plasma (PRP) received considerable attention in regenerative medicine. Thus, this study was designed to evaluate the protective efficacy of PRP against γ-radiation-induced nephrotoxicity. MAIN METHODS: Forty male rats were distributed in four groups: 1) control, 2) PRP, 3) Radiation, and 4) PRP + radiation. Nephrotoxicity was examined in rats after a whole body γ-irradiation at a single dose of 8 Gy. Activated PRP (0.5 ml/kg BW) was injected subcutaneously twice weekly for three successive weeks prior to γ-irradiation. At the end of the experiment, creatinine, urea, albumin, and neutrophil gelatinase-associated lipocalin (NGAL) serum levels, as well as renal relative gene expression level of kidney injury molecule-1 (KIM-1) were estimated. Further, malondialdehyde level, nitric oxide content and reduced glutathione content in addition to superoxide dismutase and catalase activities were measured. Moreover, the expression levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), and caspase-3 proteins were assayed. KEY FINDINGS: PRP pre-treatment significantly reduced the radiation-induced abnormalities in kidney histology and attenuated the induced cell injury. Furthermore, PRP notably ameliorated the state of oxidative stress and appeared to inhibit the induced apoptosis. SIGNIFICANCE: This study lends a probable protective role of PRP against γ-radiation-induced nephrotoxicity which can highlight the possibilities of its application as a complementary procedure during radiotherapy.

Effect of light-emitting diodes, platelet-rich plasma, and their combination on the activity of sheep tenocytes.

Healthy tendons play an important role in joint movements and subjected to a group of pathologies called tendinopathy due to multiple factors. Tendons have a slowly repairing process due to the low vascularity and cellularity. Treatment options aimed at potentiating the healing response and relieving symptoms. Phototherapy and platelet-rich plasma were novel treatment modalities in tendons based on photobiomodulation and growth factors during healing, and the results were encouraging suggesting calibrating treatment parameters. This study utilizes cell culture to explore the potential effect of light-emitting diode and/or growth factors in the form of platelet-rich plasma (PRP) on the activity of tenocytes isolated from sheep Achilles tendons by measuring the cell metabolism and cell mobility using cell viability and migration assays to proof safety and confirm activity. Results showed that sheep tenocyte-cultured groups treated with 5% platelet-rich plasma alone or combined with 4 J/cm2 light-emitting diode have increased viability significantly when compared to control group after a 48 h, while light-emitting diode treatment has not decreased cell migration significantly when compared with control. Result suggests that using platelet-rich plasma alone or combined with light-emitting diode might have potential to enhance healing response at the conditions applied. PRP could enhance proliferation while LED could enhance migration and proliferation. Further research is needed at longer durations.

Osteogenic capacity of diluted platelet-rich plasma in ectopic bone-forming model: Benefits for bone regeneration.

Platelet-rich plasma (PRP) with normal and below-normal physiological concentrations of platelets is designated as diluted PRP (dPRP). The aims of this study are to evaluate whether bone mineral matrix in combination with dPRP possesses osteogenic capacity; and whether the differences in dynamics and osteogenic process pattern depend on different platelet concentrations, to what extent, and also what could be benefits for bone regeneration in clinical practice. Three types of implants were made: BMM-bone mineral matrix alone; dPRP/10-bone mineral matrix mixed with dPRP (concentration of platelets 10 times lower than physiological level) and dPRP/3-bone mineral matrix mixed with dPRP (concentration of platelets 3 times lower than physiological level). A subcutaneous implantation model in Balb/c mice was used. The implants were analyzed using expression analysis of bone-related genes, histochemical, immunohistochemical and histomorphometrical analysis. All types of implants induced creation of necessary preconditions for supporting osteogenic processes, but did not induce visible young bone growth. Implant types dPRP/10 and dPRP/3 showed very similar and significantly better stimulatory effects on osteogenic processes than bone matrix alone. In this study, significant ectopic osteogenic potential of concentration of platelets in PRP that are lower than physiological level in blood plasma in combination with bone mineral matrix was demonstrated. Diluted platelet-rich plasma could be a promising and useful adjuvant therapeutic agent in bone regeneration.

Wound healing effects of a Curcuma zedoaria polysaccharide with platelet-rich plasma exosomes assembled on chitosan/silk hydrogel sponge in a diabetic rat model.

One homogeneous polysaccharide (ZWP) was successfully isolated and purified from the rhizomes of Curcuma zedoaria and the aim of present study was to determine the potential of chitosan/silk hydrogel sponge loaded with platelet-rich plasma exosomes (PRP-Exos), ZWP or PRP-Exos/ZWP on wound-healing in diabetic rats. An in vivo diabetic wound healing study showed that separate or combined treatments all resulted in a wound contraction in diabetic rats, as evidenced by a decrease of ulcer and an increase of epidermal thickness, but PRP-Exos/ZWP combination therapy was more successful in wound closing than either PRP-Exos or ZWP single administration. This could be due to the upregulation of collagen synthesis and deposition, as well as angiogenesis at the wound site. In addition to this, no side effects was observed in all treated groups during healing process. These findings provide a mechanistic basis for PRP-Exos/ZWP as a potential therapeutic strategy to accelerate skin repair in diabetes.

Platelet-Rich Plasma, Adipose Tissue, and Scar Modulation.

Level of Evidence: 4.

Activated platelet-rich plasma improves cartilage regeneration using adipose stem cells encapsulated in a 3D alginate scaffold.

In the current study, the effect of superimposing platelet-rich plasma (PRP) on different culture mediums in a three-dimensional alginate scaffold encapsulated with adipose-derived mesenchymal stem cells for cartilage tissue repair is reported. The three-dimensional alginate scaffolds with co-administration of PRP and/or chondrogenic supplements had a significant effect on the differentiation of adipose mesenchymal stem cells into mature cartilage, as assessed by an evaluation of the expression of cartilage-related markers of Sox9, collagen II, aggrecan and collagen, and glycosaminoglycan assays. For in vivo studies, following induction of osteochondral lesion in a rabbit model, a high degree of tissue regeneration in the alginate plus cell group (treated with PRP plus chondrogenic medium) compared with other groups of cell-free alginate and untreated groups (control) were observed. After 8 weeks, in the alginate plus cell group, functional chondrocytes were observed, which produced immature matrix, and by 16 weeks, the matrix and hyaline-like cartilage became completely homogeneous and integrated with the natural surrounding cartilage in the defect site. Similar effect was also observed in the subchondral bone. The cell-free scaffolds formed fibrocartilage tissue, and the untreated group did not form a continuous cartilage over the defect by 16 weeks.

Effects of pulsed electromagnetic fields and platelet rich plasma in preventing osteoclastogenesis in an in vitro model of osteolysis.

Osteolysis is the main limiting cause for the survival of an orthopedic prosthesis and is accompanied by an enhancement in osteoclastogenesis and inflammation, due by wear debris formation. Unfortunately therapeutic treatments, besides revision surgery, are not available. The aim of the present study was to evaluate the effects of Pulsed Electro Magnetic Fields (PEMFs) and platelet rich plasma (PRP), alone or in combination, in an in vitro model of osteolysis. Rats peripheral blood mononuclear cells were cultured on Ultra High Molecular Weight Polyethylene particles and divided into four groups of treatments: (1) PEMF stimulation (12 hr/day, 2.5 mT, 75 Hz, 1.3 ms pulse duration); (2) 10% PRP; (3) combination of PEMFs, and PRP; (4) no treatment. Treatments were performed for 3 days and cell viability, osteoclast number, expression of genes related to osteoclastogenesis and inflammation and production of pro-inflammatory cytokines were assessed up to 14 days. PEMF stimulation exerted best results because it increased cell viability at early time points and counteracted osteoclastogenesis at 14 days. On the contrary, PRP increased osteoclastogenesis and reduced cell viability in comparison to PEMFs alone. The combination of PEMFs and PRP increased cell viability over time and reduced osteoclastogenesis in comparison to PRP alone. However, these positive results did not exceed the level achieved by PEMF alone. At longer time points PEMF could not counteract osteoclastogenesis increased by PRP. Regarding inflammation, all treatments maintained the production of pro-inflammatory cytokines at low level, although PRP increased the level of interleukin 1 beta.