Role of platelet-released growth factors in detoxification of reactive oxygen species in osteoblasts

Effect of autologous platelet-rich plasma on the fertility and quality of cryopreserved buffalo bull semen: a comparative study using OptiXcell® and tris egg yolk extenders

BACKGROUND

Buffalo spermatozoa have a distinct membrane structure that makes them more vulnerable to cryopreservation, resulting in lower-quality post-thawed sperm. This decreases the success rate of artificial insemination in buffaloes. Understanding and addressing these specific vulnerabilities are essential for improving reproductive techniques in buffalo populations. The properties of cryopreserved buffalo bull semen were examined in this study regarding the impact of adding autologous platelet-rich plasma (PRP) to OptiXcell® or Tris egg yolk-based extenders. Ten buffalo bulls were used to collect semen. Each bull's ejaculate was separated into two main equal amounts, each of which was then diluted with either OptiXcell® or Tris egg yolk-based extender, supplemented with various PRP concentrations (5%, 10%, and 15%), and the control (0%), before being cryopreserved according to established protocols. Following equilibration and thawing, the quality and functionality of the sperm were evaluated, along with the antioxidant enzyme activities (GSH and TAC), malondialdehyde (MDA) content, and in vivo fertilization rate of the thawed semen.

RESULTS

All PRP concentrations in both extenders, particularly 10% PRP, improved the quality and functionality of the sperm in both equilibrated and frozen-thawed semen. Additionally, the antioxidant enzyme activities in both extenders were higher in the PRP-supplemented groups compared to the control group in thawed semen (P < 0.05). All post-thaw sperm quality, antioxidant enzyme activities, and functionality aside from DNA integrity were higher (P < 0.05) in the PRP-supplemented OptiXcell® than in the PRP-supplemented Tris egg yolk-based extender. The fertility of cryopreserved semen in the extenders supplemented with 10% and 15% PRP increased (P < 0.05) significantly more than that of the control extenders, with 10% PRP being the optimum concentration in OptiXcell® (80%) compared to that of Tris egg yolk-based extender (66.67%) and control of two extenders (53.33% and 46.67%, respectively).

CONCLUSIONS

Even though autologous PRP-supplemented extenders have a protective impact on equilibrated and cryopreserved semen, 10% PRP-supplemented OptiXcell® extenders are more effective at preserving post-thaw semen quality, functionality, and antioxidant capacity, which increases the in vivo fertility of buffalo bulls.

Platelet-Rich Plasma (PRP) in Dermatology: Cellular and Molecular Mechanisms of Action

Platelet-rich plasma (PRP) therapy has gained attention in the scientific field due to its potential regenerative effects and great benefit-risk ratio. This review extensively explores the most studied mechanisms of this therapy according to the etiopathogenesis of skin diseases: cellular proliferation, matrix formation, regulation of inflammation, angiogenesis, collagen synthesis, and the remodeling of new tissue. Moreover, it draws on newly reported and lesser-known effects of PRP: its anti-apoptotic effects, immunological suppression, decrease in melanin synthesis, anti-microbial effects, overexpression of miR-155, antioxidant effects, and their involved pathways. This work aims to provide a complete update for understanding PRP's benefits and clinical relevance in wound healing, alopecia, pigmentary disorders, scars, rejuvenation, lichen sclerosus, and other inflammatory dermatoses, based on the current evidence. Furthermore, recent reports with novel indications for PRP therapy are highlighted, and new potential pathways correlated with the pathogenesis of skin diseases are explored.

The Contribution of the Nrf2/ARE System to Mechanotransduction in Musculoskeletal and Periodontal Tissues

Mechanosensing plays an essential role in maintaining tissue functions. Across the human body, several tissues (i.e., striated muscles, bones, tendons, ligaments, as well as cartilage) require mechanical loading to exert their physiological functions. Contrary, mechanical unloading triggers pathological remodeling of these tissues and, consequently, human body dysfunctions. At the cellular level, both mechanical loading and unloading regulate a wide spectrum of cellular pathways. Among those, pathways regulated by oxidants such as reactive oxygen species (ROS) represent an essential node critically controlling tissue organization and function. Hence, a sensitive balance between the generation and elimination of oxidants keeps them within a physiological range. Here, the Nuclear Factor-E2-related factor 2/Antioxidant response element (Nrf2/ARE) system plays an essential role as it constitutes the major cellular regulation against exogenous and endogenous oxidative stresses. Dysregulations of this system advance, i.a., liver, neurodegenerative, and cancer diseases. Herein, we extend our comprehension of the Nrf2 system to the aforementioned mechanically sensitive tissues to explore its role in their physiology and pathology. We demonstrate the relevance of it for the tissues' functionality and highlight the imperative to further explore the Nrf2 system to understand the physiology and pathology of mechanically sensitive tissues in the context of redox biology.

Efficacy of Platelet-Rich Plasma Therapy in Oral Lichen Planus: A Systematic Review

Background and Objectives: Oral lichen planus (OLP) is an autoimmune, mucocutaneous, oral potentially malignant disorder (OPMD), which characteristically manifests with chronic, recalcitrant lesions, with frequent flare-ups and remissions. The precise etiopathogenesis of OLP is still debatable, although it is believed to be a T-cell-mediated disorder of an unidentified antigen. Despite the availability of various treatments, no cure for OLP exists due to its recalcitrant nature and idiopathic etiology. Platelet-rich plasma (PRP) has antioxidant, anti-inflammatory, and immunomodulatory properties, in addition to its regulatory action on keratinocyte differentiation and proliferation. These salient properties substantiate the possible role of PRP in the treatment of OLP. Our systematic review focuses on assessing the therapeutic potential of PRP as a treatment modality in OLP. Materials and Methods: We conducted a detailed literature search for studies assessing PRP as a therapeutic regimen in OLP, using the Google Scholar and PubMed/MEDLINE search engines. The search was limited to studies published from January 2000 to January 2023 and included a combination of Medical Subject Heading (MeSH) terms. ROBVIS analysis was carried out for the assessment of publication bias. Descriptive statistics were performed using Microsoft Excel. Results: This systematic review included five articles that met the inclusion criteria. Most of the included studies demonstrated that PRP treatment considerably ameliorated both objective and subjective symptoms in OLP subjects, with comparable efficacy to the standard corticosteroid treatment. Further, PRP therapy offers the added benefit of minimal adverse effects and recurrences. Conclusion: This systematic review suggests that PRP has significant therapeutic potential for treating OLP. However, further research with larger sample sizes is imperative to corroborate these findings.

Analysis of Single- and Double-Stranded DNA Damage in Osteoblastic Cells after Hyperbaric Oxygen Exposure

(1) Background: Hyperbaric oxygen (HBO) exposure induces oxidative stress that may lead to DNA damage, which has been observed in human peripheral blood lymphocytes or non-human cells. Here, we investigated the impact of hyperbaric conditions on two human osteoblastic cell lines: primary human osteoblasts, HOBs, and the osteogenic tumor cell line SAOS-2. (2) Methods: Cells were exposed to HBO in an experimental hyperbaric chamber (4 ATA, 100% oxygen, 37 °C, and 4 h) or sham-exposed (1 ATA, air, 37 °C, and 4 h). DNA damage was examined before, directly after, and 24 h after exposure with an alkaline comet assay and detection of γH2AX+53BP1 colocalizing double-strand break (DSB) foci and apoptosis. The gene expression of TGFß-1, HO-1, and NQO1, involved in antioxidative functions, was measured with qRT-PCR. (3) Results: The alkaline comet assay showed significantly elevated levels of DNA damage in both cell lines after 4 h of HBO, while the DSB foci were similar to sham. γH2AX analysis indicated a slight increase in apoptosis in both cell lines. The increased expression of HO-1 in HOB and SAOS-2 directly after exposure suggested the induction of an antioxidative response in these cells. Additionally, the expression of TGF-ß1 was negatively affected in HOB cells 4 h after exposure. (4) Conclusions: in summary, this study indicates that osteoblastic cells are sensitive to the DNA-damaging effects of hyperbaric hyperoxia, with the HBO-induced DNA damage consisting largely of single-strand DNA breaks that are rapidly repaired.

In vitro effects of plasma rich in growth factors on human teratozoospermic semen samples

There is a correlation between teratozoospermia and production of reactive oxygen species leading to poor assisted reproductive techniques outcomes. This study aimed to examine the effect of plasma-rich in growth factors (PRGF) on teratozoospermic samples. Twenty-five teratozoospermic samples were included in this study. After sperm preparation, it was divided into four groups, including 0 (control), 1, 5, and 10% PRGF. Sperm motility, viability (eosin-nigrosin staining), morphology (Papanicolaou staining), DNA fragmentation (sperm chromatin dispersion test), mitochondrial membrane potential (JC-1 staining by flow cytometry), and lipid peroxidation (measurement of malondialdehyde, MDA) were evaluated before and after 1 h of incubation with or without PRGF. Our results showed that after 1 h of incubation, the addition of 1% PRGF improved sperm progressive motility (47.72 ± 13.76%) compared to the control group (17.36 ± 8.50%) (p < 0.001). Also, 1% PRGF preserved the sperm's total motility (77.50 ± 13.28% vs. 65.63 ± 19.03%, for 1% PRGF and control, respectively) and viability after incubation. The rate of normal sperm morphology was the same between different groups. Higher mitochondrial membrane potential and lower DNA fragmentation were also observed in sperm treated with different concentrations of PRGF compared to the control group, but the differences were non-significant. The MDA levels were significantly decreased in PRGF-treated groups compared to the control group (0.99 ± 0.62, 0.95 ± 0.33, 0.95 ± 0.79, and 1.49 ± 0.27 for 1% PRGF, 5% PRGF, 10% PRGF and control, respectively). Based on our results, it seems that PRGF incubation can improve sperm parameters and especially decrease the level of malondialdehyde as an indicator of oxidative stress, which is one of the main problems of teratozoospermic samples.

The effect of platelet lysate on mouse ovarian structure, function and epigenetic modifications after autotransplantation

RESEARCH QUESTION

What are the effects of platelet lysate on structure, function and epigenetic modifications of heterotopically transplanted mouse ovarian tissues?

DESIGN

Mice were divided into three groups (n = 17 per group): control (mice with no ovariectomy, grafting or treatment), autograft and autograft plus platelet lysate (3 ml/kg at the graft sites). Inflammatory markers, serum malondialdehyde (MDA) concentration and total antioxidant capacity were assessed on day 7 after transplantation. Twenty-eight days after transplantation, stereological and hormonal analyses were conducted. Chromatin immunoprecipitation and quantitative real-time polymerase chain reaction were also used to quantify the epigenetic modifications of maturation genes, parallel to their expression.

RESULTS

The total volume of the ovary, cortex and medulla, and the number of different types of follicles, the concentration of interleukin (IL)-10, progesterone and oestradiol and total antioxidant capacity significantly decreased in the autograft group compared with the control group (P < 0.001); these parameters significantly increased in the autograft plus platelet lysate group compared with the autograft group (P < 0.001). The concentrations of tumour necrosis factor alpha, IL-6 and MDA increased significantly in the autograft group compared with the control group (P < 0.001); in the autograft plus platelet lysate group, these parameters significantly decreased compared with the autograft group (P < 0.001). In the autograft plus platelet lysate group, the expression levels of Gdf-9 (P < 0.0021), Igf-1 (P < 0.0048) and Igf-2 (P < 0.0063) genes also increased along with a lower incorporation of MeCP2 in the promoter regions (P < 0.001) compared with the autograft group.

CONCLUSIONS

Platelet lysate can contribute to follicular survival by improving folliculogenesis and increasing the expression of oocyte maturation genes.

Potential Mechanism of Platelet-rich Plasma Treatment on Testicular Problems Related to Diabetes Mellitus

Diabetes mellitus is a condition of continuously increased blood glucose levels that causes hyperglycemia. This condition can result in disorders of various organs including testicular problems. The use of platelet-rich plasma (PRP) which is contained in several growth factors shows its potential in overcoming testicular problems. This literature review study was conducted to identify the potential of PRP in overcoming various testicular problems due to diabetic conditions.

Platelet-Rich Plasma: A Promising Regenerative Therapy in Gynecological Disorders

Platelet-rich plasma (PRP) could be understood as a special preparation of plasma in which the concentration of platelet is immensely high. This rationale for plasma use has been in the medical science for many years with plenty of success in various fields where it was inculcated, bringing dramatically favorable and better outcomes in terms of disease management and prognosis. PRP has been widely used in orthopedics from the very beginning, but in the past few years its use has been extended to other fields too, such as obstetrics and gynecology. From the very onset of the introduction of platelet-rich plasma in gynecology, there had been constant research being carried out all around the globe in order to scientifically prove and confirm its exact role in the management of gynecological problems. Regenerative medicine in gynecology was among the first areas where the platelet-rich plasma was implemented and has substantially given great results, which encouraged further extensive research to be carried out in other spectrums of gynecology. The implications of such great struggles ultimately gave way to evidence suggesting the importance of platelet-rich plasma in managing gynecological disorders like Asherman’s syndrome, urinary incontinence, genital fistulas, thin endometrium, etc. This review article collectively summarizes the various use of platelet-rich plasma in gynecology.

Improvement of human sperm properties with platelet-rich plasma as a cryoprotectant supplement

PURPOSE

Platelet-rich plasma (PRP) is a remarkable substance, which involves the growth and proliferation of all cell types. As a source of growth factors, we evaluated whether sperm cryopreservation supplemented with PRP improves the rates of sperm motility, viability, and DNA integrity after vitrification compared with conventional cryo-medium.

MATERIALS AND METHODS

20 normal semen specimens were collected from healthy men. After swim-up preparation, each sample was divided into four aliquots. One, as control, received no treatment, and the other three experimental samples were treated with three different concentrations of PRP as cryoprotectant. Sperm parameters were examined before and after freezing procedure.

RESULTS

PRP had no significant effect on sperm count. Meanwhile, the percentage of sperm progressive motility and viability in the PRP treated samples with 1×10⁵ /µL concentration was significantly higher than control group. Besides, the rate of immotile sperms in these samples was significantly lower than the control. Sperm viability was significantly higher in the PRP samples at 1×10⁵/µL concentration. In the case of DNA integrity, CMA3 staining showed that the lower PRP concentration was correlated with the higher rate of abnormal spermatozoa. SCD showed that the rate of abnormal sperms in the PRP samples with 1×10⁵ /µL concentration was significantly lower than control group.

CONCLUSIONS

This study showed a protective effect of PRP on human sperm quality at an optimized concentration after vitrification. Besides, the effects of PRP supplementation of sperms on successful fertility following sperm preservation will be of interest.

The Clinical Efficacy of Platelet-Rich Plasma versus Conventional Drug Injection in the Treatment of Knee Osteoarthritis: A Study Protocol for a Randomized Controlled Trial

Knee osteoarthritis is a common chronic degenerative joint disease in middle-aged and elderly people. Intra-articular injection for the treatment of knee osteoarthritis is a regularly utilized nonsurgical treatment in modern medicine. Hyaluronic acid (HA) and platelet-rich plasma (PRP) are two frequently employed intra-articular devices. Hyaluronic acid (HA) is an accepted nonsurgical treatment for symptomatic KOA, and platelet-rich plasma is a popular option in the treatment of KOA in recent years. The purpose of this research is to compare the efficacy and safety of intra-articular injection of platelet-rich plasma (PRP) versus hyaluronic acid (HA) on the pain score scale, knee function, and related inflammatory biomarkers in KOA patients using a clinical randomized controlled trial. Participants are being randomized into either the hyaluronic acid (HA) or into the platelet-rich plasma (PRP) group. All patients receive 4 weeks of treatment (once a week), and well-being support and quadriceps training (3 times a week). The primary outcomes are measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the visual analog scale (VAS). The secondary outcomes include the activities of daily living score, erythrocyte sedimentation rate, C-reactive protein testing, interleukin-6 levels, and X-ray examination. In order to monitor the occurrence of irregularities and abnormalities, patients are assessed at each visit, and restorative treatment is given if necessary. The results of this clinical trial will verify the efficacy of PRP and HA in the treatment of KOA and provide important evidence for the clinical treatment of KOA. The trial was enlisted at the Chinese Clinical Trial Registry on 26 September 2020 (ChiCTR2000038635).

The effect of protection of platelet-rich plasma against experimental ischemia/reperfusion injury in the rat ovary on in vitro fertilization outcomes

OBJECTIVE

Ovarian torsion is a common cause of local ischemic damage, reduced follicular activity and infertility. This study aimed to investigate how well platelet-rich plasma (PRP) protects against experimental ischemic (I) and ischemia-reperfusion (I/R) injury in rat ovaries and its effect on in vitro fertilization (IVF) outcomes.

METHOD

Fifty-six adult female Sprague-Dawley albino rats were randomly assigned to six groups of eight animals each: Sham, Ischemia, I/R, Sham + PRP, I + PRP, and I/R + PRP. The remaining eight animals were used to prepare the PRP. The ischemia groups were subjected to bilateral adnexal torsion for 3 h, while the I/R and I/R + PRP groups received subsequent detorsion for 3 h. Intraperitoneal (i.p.) PRP was administered 30 min prior to ischemia (I + PRP) or reperfusion (I/R + PRP). The ovaries were stimulated through an intraperitoneal injection of 150-300 internal units of IU/kg PMSG. After ovulation induction, oocytes were taken from the ovaries, and IVF was performed.

RESULTS

The number of MII oocytes reached the highest number with 4.63 ± 0.74 in the S group and had the lowest number with 0.50 ± 0.53 in the I/R group. There were statistically significant differences for the number of embryos obtained on the second day between the I and I + PRP groups and the I/R and I/R + PRP groups (p = 0.000). In comparing anti-Müllerian hormone 1 (AMH1) and AMH2 values within the group, the highest decrease was observed in the I and I/R groups.

CONCLUSION

PRP is effective in minimizing ovarian damage and preserving ovarian reserves following ovarian torsion.

The osteoprotective role of USP26 in coordinating bone formation and resorption

Bone homeostasis is maintained through a balance of bone formation by osteoblasts and bone resorption by osteoclasts. Ubiquitin-specific proteases (USPs) are involved in regulating bone metabolism by preserving bone formation or antagonizing bone resorption. However, the specific USPs that maintain bone homeostasis by orchestrating bone formation and bone resorption simultaneously are poorly understood. Here, we identified USP26 as a previously unknown regulator of bone homeostasis that coordinates bone formation and resorption. Mechanistically, USP26 stabilizes β-catenin to promote the osteogenic activity of mesenchymal cells (MSCs) and impairs the osteoclastic differentiation of bone myelomonocytes (BMMs) by stabilizing inhibitors of NF-κBα (IκBα). Gain-of-function experiments revealed that Usp26 supplementation significantly increased bone regeneration in bone defects in aged mice and decreased bone loss resulting from ovariectomy. Taken together, these data show the osteoprotective effect of USP26 via the coordination of bone formation and resorption, suggesting that USP26 represents a potential therapeutic target for osteoporosis.

Platelet-released growth factors protect articular chondrocytes from inflammatory condition

BACKGROUND

Although platelet-released growth factors (PRGF) can protect cells from inflammation or oxidative stress condition, their therapeutic efficacy for articular cartilage degeneration has been little discussed. The purpose of this study was to investigate the effect of PRGF on human articular chondrocytes under inflammatory conditions.

METHODS

Human C-28/I2 chondrocytes were treated with PRGF, the production from liquid-preserved platelet concentrates obtained by platelet apheresis from human volunteers. Cell proliferation/viability, and collagen type (COL) II and SOX9 gene expressions for chondrogenesis were evaluated with different PRGF concentrations. Additionally, in vitro inflammatory condition was mimicked by stimulating the cells with tumor necrosis factor (TNF)-α. Under inflammation, cell viability, TNF-α gene expression, and the protein levels of cytokines including TNF-α, interleukin (IL)-1β and -6, and vascular endothelial growth factor (VEGF) angiogenesis marker, were compared with and without PRGF treatment.

RESULTS

Cell proliferation/viability, and SOX9 and COL II expressions in chondrocytes stimulated with 10% PRGF were significantly higher than without treatment. Cell viability with 10% PRGF was also statistically higher than without treatment under inflammation. The TNF-α gene expression with 10% PRGF was significantly lower than without treatment under inflammation. The protein levels of endogenous TNF-α with 5% PRGF, IL-1β with 10% PRGF, and IL-6 with 5 and 10% PRGF in chondrocytes were significantly lower than untreated ones under inflammation. The VEGF-protein level in chondrocytes stimulated with 20% PRGF was significantly higher than without treatment under inflammation, while there was no significant difference between with 10% PRGF and without treatment.

CONCLUSIONS

Our results reveal that optimal PRGF treatment leads to the increase of chondrocyte proliferation/viability and chondrogenic markers, while it increased cell viability but reduced IL-1β and IL-6 expressions under inflammatory condition, suggesting the therapeutic role of PRGF for protection from articular cartilage degeneration through anti-inflammatory effects.

An update on platelet-rich plasma (PRP) therapy in endometrium and ovary related infertilities: clinical and molecular aspects

Administration of platelet-rich plasma (PRP) is one of the well-recommended strategies for the treatment of endometrium- and ovary-associated infertility. Due to the autologous source of PRP, minimal risks for disease transmission and immunogenic and allergic responses are expected in this method. Despite the extensive use of PRP in medicine, its precise mechanism of action in endometrial and ovarian tissues is still unknown. Nevertheless, the induction of cell proliferation, chemotaxis, regeneration, extracellular matrix synthesis, remodeling, angiogenesis, and epithelialization are the main pathways for PRP to affect female reproductive organs. Given the promising results of previous studies, it is necessary to standardize PRP preparation protocols for different therapeutic purposes and also clearly determine appropriate inclusion and exclusion criteria for recruiting patients. In the current review, we presented a summary of studies on PRP therapy for endometrium- and ovary-associated infertility with a focus on the possible mechanisms by which PRP enhances endometrial receptivity and regenerates ovarian function.Abbreviations: PRP: platelet-rich plasma; ART: assisted reproductive technology; POF: premature ovarian failure; TGF: transforming growth factors; PDGF: platelet-derived growth factors; IGF-I: insulin-like growth factor-1; HGF: hepatocyte growth factor; EGF: epidermal growth factor; FGF: fibroblast growth factor; VEGF: vascular endothelial growth factor; ADP: adenosine diphosphate, ATP: adenosine triphosphate; PDGF: platelet-derived growth factor; COX2: cyclooxygenase-2; TP53: tumor protein 53; ER-α: estrogen receptors alpha; ER-β: estrogen receptors beta; PR: progesterone receptor; RIF: recurrent implantation failure; G-CSF: granulocyte colony-stimulating factor; iNOS: inducible nitric oxide synthase; NF-kβ: nuclear factor kappa beta; MMPs: matrix metalloproteinases; Col1a1: collagen type I alpha 1; IL: interleukin; FSH: follicle-stimulating hormone; AMH: anti-Mullerian hormone; GDF-9: growth differentiation factor 9.

Platelet Lysate Nebulization Protocol for the Treatment of COVID-19 and Its Sequels: Proof of Concept and Scientific Rationale

One of the most severe effects of coronavirus disease 2019 (COVID-19) is lung disorders such as acute respiratory distress syndrome. In the absence of effective treatments, it is necessary to search for new therapies and therapeutic targets. Platelets play a fundamental role in respiratory disorders resulting from viral infections, being the first line of defense against viruses and essential in maintaining lung function. The direct application of platelet lysate (PL) obtained from the platelet-rich plasma of healthy donors could help in the improvement of the patient due its anti-inflammatory, immunomodulatory, antifibrotic, and repairing effects. This work evaluates PL nebulization by analyzing its levels of growth factors and its biological activity on lung fibroblast cell cultures, besides describing a scientific basis for its use in this kind of pathology. The data of the work suggest that the molecular levels and biological activity of the PL are maintained after nebulization. Airway administration would allow acting directly on the lung tissue modulating inflammation and stimulating reparative processes on key structures such as the alveolocapillary barrier, improving the disease and sequels. The protocol developed in this work is a first step for the study of nebulized PL both in animal experimentation and in clinical trials.

The Management of Postsurgical Wound Complications with Plasma Rich in Growth Factors: A Preliminary Series

BACKGROUND

Postsurgical wound complications constitute a relevant public health issue because of their frequency. There is growing evidence regarding platelet-based autologous therapies that support their use in promoting cutaneous regeneration.

OBJECTIVE

To provide preliminary data regarding the potential benefit of plasma rich in growth factors (PRGF) in the management of postsurgical wound complications.

DESIGN

Three patients suffering from poorly healing severe full-thickness wounds were treated with either one or a combination of different formulations derived from their own blood: autologous clot, fibrin membrane, injectable plasma, or topical ointment. Different treatment protocols are described, and follow-up results are reported.

RESULTS

Within 4 to 12 months, the treated wounds healed completely with no signs of infection, tissue necrosis, or functional impairment. No adverse events were reported.

CONCLUSION

Additional clinical trials with long-term follow-up periods and larger patient populations are needed to establish the efficacy of PRGF technology. However, these preliminary findings suggest that PRGF merits further randomized controlled studies exploring its capacity to accelerate re-epithelialization and restore functional integrity to cutaneous ulcers resulting from surgical complications.

Platelet-Rich Plasma Ameliorates Monosodium Iodoacetate-Induced Ankle Osteoarthritis in the Rat Model via Suppression of Inflammation and Oxidative Stress

Until now, there is no treatment that cause complete cure of the chronic inflammatory and degenerative disease, osteoarthritis (OA). Moreover, the underlying mechanisms of OA development and progress are not fully elucidated, and the present pharmacological treatment alternatives are restricted and associated with adverse side effects. Thus, the present study was conducted to evaluate the role of platelet-rich plasma (PRP) in the remedy of OA in the rat model in terms of inflammation, ankle histopathological alterations, and oxidative stress. OA was induced in male Wistar rats by injection of MIA (2 mg)/50 µL isotonic saline in the right ankle joint for two successive days in each rat. After the 2nd MIA injection, the osteoarthritic rats were allocated into two groups such as the MIA group (group 2) and MIA + PRP group (group 3). The MIA + PRP group was treated with PRP (50 µL) by injection into the ankle joint of the right hind limb of each rat at days 14, 21, and 28 after the 2nd injection of MIA. The same equivalent volume of saline, as a substitute of PRP, was injected into the ankle joint of each rat of the normal control group (group 1) and MIA group (group 2) at the same tested periods. Swelling of joint, bodyweight, total leucocytes count (TLC), and morphological as well as histological changes of ankle joints were evaluated. Serum lipid peroxides (LPO), glutathione (GSH), and glutathione S-transferase (GST) levels were examined as biomarkers of oxidative stress. Serum tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), and interleukin-4 (IL-4) were investigated by ELISA as biomarkers of inflammation. In addition, magnetic resonance imaging (MRI) was carried out to investigate the soft tissues in joints. The obtained results revealed that PRP reduced LPO and increased GSH and GST levels in osteoarthritic rats. Also, PRP significantly diminished serum TNF-α and IL-17 levels, while it increased IL-4 serum levels in rats with MIA-induced OA. Morphological observations, histological analysis, and MRI revealed a gradual diminishing in joint inflammation and destruction of cartilage in PRP-injected osteoarthritic rats. Based on these results, it can be suggested that PRP has antiarthritic potential in MIA-induced OA, which may be mediated via suppression of inflammation and oxidative stress.

Combined platelet-rich plasma and cold water immersion treatment minimize the damage following a skeletal muscle stretch injury in rats

The skeletal muscle stretch injuries are commonly observed in sports. In order to stimulate tissue healing, the platelet-rich plasma (PRP) and cold water immersion (CWI) are widely used in clinical practice. This study investigated the effects of isolated or combined PRP and/or CWI on the oxidative damage determined by a stretch injury induced in gastrocnemius muscle of rats. PRP and CWI are applied immediately after the injury, and the biochemical analysis was performed after 1, 3, 5, or 7 days. The levels of o thiobarbituric acid reactive substances and oxidized dichlorofluorescein were significantly increased, both in skeletal muscle tissue and erythrocytes preparations, and the combined PRP and CWI minimized these parameters. Moreover, combined PRP and CWI were more effective than the isolated treatments to increase catalase activity, also the ratio of reduced/oxidized glutathione, and the non-protein thiols (-SH) group levels. In conclusion, we could infer that the combination of these regular treatments used in an isolated form shows a great potential for treatments of muscular injuries.

Methodological variations affect the release of VEGF in vitro and fibrinolysis' time from platelet concentrates

Blood Concentrates (BCs) are autologous non-transfusional therapeutical preparations with biological properties applied in tissue regeneration. These BCs differ in the preparation method, in fibrin network architecture, growth factors release as well as in platelet/cell content. Methodological changes result in distinct matrices that can compromise their clinical effectiveness. The present study evaluated the influence of different g-forces and types of tubes in the release of vascular endothelial growth factor (VEGF) from platelet-rich fibrin (PRF) as a function of time. The PRF-like samples were obtained with three g-forces (200, 400, and 800 x g) for 10 minutes in pure glass tubes or in polystyrene-clot activator tubes. Scanning and Transmission electron microscopy was used to morphometric analyzes of PRF’s specimens and flow cytometry was used to quantify VEGF slow release until 7 days. Our results showed that platelets were intact and adhered to the fibrin network, emitting pseudopods and in degranulation. The fibrin network was rough and twisted with exosomic granulations impregnated on its surface. An increase in the concentration of VEGF in the PRF supernatant was observed until 7 days for all g forces (200, 400 or 800 xg), with the highest concentrations observed with 200 x g, in both tubes, glass or plastic. Morphological analyzes showed a reduction in the diameter of the PRF fibers after 7 days. Our results showed that g-force interferes with the shape of the fibrin network in the PRF, as well as affect the release of VEGF stored into platelets. This finding may be useful in applying PRF to skin lesions, in which the rapid release of growth factors can favor the tissue repair process. Our observations point to a greater clarification on the methodological variations related to obtaining PRF matrices, as they can generate products with different characteristics and degrees of effectiveness in specific applications.

Extracellular fraction of adipose tissue as an innovative regenerative approach for vitiligo treatment

Vitiligo is a common, disfiguring autoimmune disease that negatively affects patients' self-esteem and quality of life. Current treatments are moderately effective in reversing disease and promoting melanocyte regeneration. Thus, therapeutic advanced strategies are emerging from regenerative medicine. It has recently emerged that adipose tissue secretome may be used as a cell-free therapy in skin regeneration since paracrine functions of adipose-derived stem cells alone are responsible for most of the therapeutic effect of stem cells in several animal disease models. In this study, we tested the effect of adipose tissue extracellular fraction (AT-Ex) isolated from lipoaspirates on dermal and epidermal vitiligo cells in vitro. Using this experimental model, we demonstrated that molecules secreted by adipose tissue ameliorate the capability to counteract oxidative stress by a physiological stimulation of intracellular antioxidant enzymes and positively impact on cell proliferation. Due to the presence of Wnt-secreted factors, AT-Ex treatment promotes glycogen synthase kinase 3β inactivation and consequently Wnt/β-catenin pathway activation. Collectively, our findings show that AT-Ex could be useful as a natural approach to improve treatment of vitiligo.

Intraosseous injections of platelet rich plasma for knee bone marrow lesions treatment: one year follow-up

PURPOSE

Cartilage lesions are usually accompanied by subchondral bone alterations or bone marrow lesions (BMLs). BML associated with joint degeneration and cartilage lesions are considered to be predictors of rapidly progressing OA. Currently no existing treatment can fully halt OA progression. One of the approaches is an autologous, biological treatment based on the use of platelet rich plasma (PRP) injections. The purpose of this study is to assess the short-term effectiveness of intraosseous PRP injections, within the BML of individuals affected by OA, in ameliorating pain and improving knee functionality.

MATERIALS AND METHODS

The study involved 17 patients with an average age of 41.7 ± 14.3 years old. OA stage was determined using the Kellgren-Lawrence grading system by performing radiographic scanning of the knee joint before surgical intervention. Patients with K-L grade 3 knee joint OA prevailed. Patient OA history varied between one and nine years (average 5.2 ± 4.5 years). Clinical and functional state of the knee were assessed by pain visual analogue scale (VAS) score, the Western Ontario and McMaster Universities Score (WOMAC), and the Knee Injury and Osteoarthritis Outcome Score (KOOS) which were filled out by patients previous to the surgical procedure at one, three, six and 12 months post-operatively. Before surgery, in addition to standard blood tests, serum cartilage oligomeric matrix protein (COMP) levels were tested for all patients.

RESULTS

Evaluation of preliminary results revealed a statistically significant reduction of pain based on the VAS score. A significant improvement was also observed in the patients' WOMAC score and in the overall KOOS score. Serum marker levels were initially elevated in our experimental patient group compared to the same marker in healthy control respondents, and continued to rise one month and three months following surgery, at six and 12 month the level was similar as at three months.

CONCLUSIONS

In our opinion, first COMP increasing can be caused by injection of platelet rich plasma. It is not adequate to interpret this growth in COMP levels as increased osteochondral degeneration. One year follow-up period showed good quality of life improvement, significant pain reduction, and essential MRI changes. The long-term observation of these cohort of patients combined with an analysis of MRI images is still ongoing.

Platelet-derived bio-products: Classification update, applications, concerns and new perspectives

Platelet derived bio-products in the form of platelet rich plasma, plasma rich in growth factors, or plasma-free platelet releasates, are being studied worldwide with the aim of proving their efficacy in tissue regeneration within many different clinical areas, such as traumatology, maxillofacial surgery, ophthalmology, dermatology and otorhinolaryngology, amongst others. The current lack of consensus in the preparation method and application form, or in the quality assessment of each bio-product, precludes adequate interpretation of the relevance of reported clinical outcomes, and, while many in clinicians are very positive about them, many are sceptic. Relevant aspects of these products are considered to propose a classification nomenclature which would aid a comprehensive comparison of clinical outcomes of bio-products of the same characteristics. Finally, the uses of platelet-derived bio-products in in vitro culture (for cell therapy purposes) as a substitute of animal-origin sera, and other future perspectives of applications of platelet-derived bio-products are discussed.

The effects of epidermal growth factor on early burn-wound progression in rats

After burns, protecting tissues by medicines in the zone of stasis reduces the width and depth of injury. This study's goal was to reduce burned tissue damage in the zone of stasis using epidermal growth factor (EGF). Forty-eight Wistar rats were separated into three groups. In all groups, the burn procedure was applied following the comb burn model. In Group 1, no postburn treatment was administered. In Group 2, physiological saline solution (0.3 cc) was injected intradermally and in Group 3, EGF (0.3 cc) was injected intradermally into stasis zone tissues after the burn procedure. Surviving tissue rates were 24.0% in Group 1, 25.3% in Group 2, and 70.2% in Group 3. The average numbers of cells stained with Nrf2, HO-1, and the number of apoptotic cells were 230, 150, and 17.5 in Group 1, 230, 145, and 15.0 in Group 2, and 370, 230, and 0 in Group 3, respectively. Values in Group 3 were found to be statistically significantly different than those of Groups 1 and 2; there was no difference between Groups 1 and 2. This study shows that EGF protects zone of stasis tissue from burn damage.

Treatment of hepatotoxicity induced by γ-radiation using platelet-rich plasma and/or low molecular weight chitosan in experimental rats

Background and aim: Platelet-rich plasma (PRP) is rich in growth factors and plays an important role in tissue healing and cytoprotection. Also, it has been proved that low molecular weight chitosan (LMC) possesses many outstanding health benefits. The aim of this study was to assess the possibility of using PRP and/or fungal LMC to treat hepatotoxicity induced by γ-radiation in albino rats.Materials and methods: Forty-eight adult male albino rats were randomly divided into eight groups. Group I (control), Group II (PRP alone), Group III (LMC alone), Group IV (PRP + LMC), Group V (γ-irradiated alone), Group VI (γ-irradiated + PRP), Group VII (γ-irradiated + LMC), and Group VIII (γ-irradiated + PRP + LMC). The irradiated rats were whole body exposed to γ-radiation (8 Gy) as fractionated doses (2 Gy) twice a week for 2 consecutive weeks. The treated groups received PRP (0.5 mL/kg body weight, s.c.) and/or LMC (10 mg/kg body weight, s.c.) 2 days a week 1 h after every dose of γ-radiation and continued for another week after the last dose of radiation. Serum alanine transaminase (ALT) and aspartate transaminase (AST) activities, as well as reduced glutathione (GSH) content, malondialdehyde (MDA), total antioxidant capacity (TAC), and nuclear factor erythroid 2-related factor 2 (Nrf2) levels in the liver tissue and relative expression of microRNA-21 (miR-21) in serum were measured, in addition to histopathological examination.Results: Exposure of rats to γ-radiation resulted in a significant increase in serum ALT and AST activities, hepatic MDA levels, and serum miR-21 relative expression, along with a significant decrease in hepatic GSH content, TAC, and Nrf2 levels. Treatment with PRP and/or fungal LMC after exposure to γ-radiation ameliorated these parameters and improved the histopathological changes induced by γ-radiation.Conclusions: The results demonstrated that PRP and/or LMC inhibited γ-radiation-induced hepatotoxicity and using both of them together seems more effective. They can be a candidate to be studied toward the development of a therapeutic strategy for liver diseases.

Regenerative effects of glycyrrhizin and/or platelet rich plasma on type-II collagen induced arthritis: Targeting autophay machinery markers, inflammation and oxidative stress

Rheumatoid arthritis (RA) is a systemic chronic autoimmune disease manifested by joint destruction and deformity, hence decreasing patient's life quality. The aim of the present work is to explore the mechanistic effects of glycyrrhizin (GL)and/or platelet rich plasma (PRP) treatment on collagen induced arthritis. 75 female Wistar rats were allocated into five equal groups. Group I: control group. Group II: arthritis group (A group); arthritis was induced by type-II collagen Group III: Glycyrrhizin treated group(A + GL group), Group IV: platelet rich plasma treated group(A + PRP group)and Group V: combined treatment group(A + GL + PRP group). Hind paw joint tissue levels of high-mobility group box 1 protein (HMGB-1), beclin-1 and nuclear factor (erythroid-2)-related factor 2 (Nrf2) DNA binding activity were detected by ELISA. Activities of myeloperoxidase (MPO) and catalase enzymes were determined spectrophotometrically. mRNA expression levels of microtubule associated protein light chain 3 (LC3) was detected by quantitative real time PCR. After 8 weeks treatment, there was improvement of inflammation and autophagy biomarkers by the significant reduction of HMGB-1 and beclin-1 levels, down regulation ofLC3mRNA expression. On the other hand, we monitored restoration of the anti-oxidant status through the inhibited MPO activity besides induction of both catalase and Nrf2-DNA binding activities. It could be concluded that, the mutual use of both PRP and GL had a greater effect than each alone against arthritis which is considered a novel finding that can highlight the regenerative and ameliorative effects of this combined treatmentthus launching promising avenues for RA treatment.

Treating Severe Knee Osteoarthritis with Combination of Intra-Osseous and Intra-Articular Infiltrations of Platelet-Rich Plasma: An Observational Study

OBJECTIVE

Assessing the therapeutic effects of a combination of intra-articular and intra-osseous infiltrations of platelet-rich plasma (PRP) to treat severe knee osteoarthritis (KOA) using intra-articular injections of PRP as the control group.

DESIGN

In this observational study, 60 patients suffering from severe KOA were treated with intra-articular infiltrations of PRP (IA group) or with a combination of intra-osseous and intra-articular infiltrations of PRP (IO group). Both groups were matched for sex, age, body mass index, and radiographic severity (III and IV degree according to Ahlbäck scale). Clinical outcome was evaluated at 2, 6, and 12 months, using the Knee injury and Osteoarthritis Outcome Score (KOOS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaires.

RESULTS

At 2, 6 and 12 months after treatment, IO group had a significant improvement in all KOOS and WOMAC subscales ( P < 0.05). On the contrary, patients of the IA group did not improve in any of the scores. Sixteen out of 30 IO group patients showed minimal clinically important improvement (MCII) whereas 8 out of 30 IA group patients showed this response at 6 months (26.7%; 95% CI -0.4 to 49.9; P = 0.037). At 12 months, 14 patients of IO group and 5 patients of the IA group showed MCII (30%; 95% CI 4.3 to 51.9; P = 0.013). No differences between groups were observed at 2 months.

CONCLUSIONS

PRP intra-articular injections in severe KOA were not effective and did not provide any benefit. Combination of intra-articular and intra-osseous infiltrations of PRP was not clinically superior at 2 months, but it showed superior clinical outcomes at 6 and 12 months when compared with intra-articular injections of PRP.

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.

Current concepts in intraosseous Platelet-Rich Plasma injections for knee osteoarthritis

Knee osteoarthritis (OA) is a degenerative process that slowly destroys the joints producing pain and loss of function, and diminishes the quality of life. Current treatments alleviate this symptomatology but do not stop the disease, being total knee arthroplasty the only definitive solution. Among the emerging treatments, Platelet-Rich Plasma (PRP) has shown promising results in the treatment of OA. However, to improve its effectiveness, it is necessary to approach this pathology targeting the whole joint, not only the cartilage, but including other tissues such as subchondral bone. The pathological processes that occur in the subchondral bone have influence of the cartilage loss, aggravating the disease. The combination of intraarticular infiltrations with intraosseous infiltrations regulates the biological processes of the tissues, reducing the inflammatory environment and modulating the overexpression of biomolecules that generate an aberrant cellular behavior. Although the first clinical results using this technique are promising, further research and developing adequate protocols are necessary to achieve good clinical results.

Platelet-rich plasma as a potential therapeutic approach against lead nitrate- and/or gamma radiation-induced hepatotoxicity

Because of the potential regenerative and cytoprotective effects of its content of numerous bioactive growth factors and cytokines, platelet-rich plasma (PRP) became an attractive biomaterial for therapeutic purposes. Therefore, the current study was designed to investigate the potential therapeutic effect of PRP against lead nitrate- and/or γ-radiation-induced hepatotoxicity. To do so, hepatotoxicity was induced in rats by intraperitoneal administration of lead nitrate (7.5 mg/kg) thrice weekly for two consecutive weeks and/or a whole-body γ-irradiation at a single dose of 6 Gy. Activated PRP (0.5 ml/kg) was injected subcutaneously 24 h after the last dose of lead nitrate and/or γ-irradiation and continued twice weekly for three successive weeks. Lead nitrate intoxication and/or γ-irradiation resulted in a significant elevation of serum alanine transaminase and aspartate transaminase activities accompanied with a significant decrease in serum levels of total protein and albumin. Further, a significant increase in malondialdehyde level and nitric oxide content accompanied with a significant decrease in the reduced glutathione content and the enzyme activities of glutathione-S-transferase, superoxide dismutase, and catalase were observed. Additionally, hepatic extracellular signal-regulated kinase (ERK) and Akt signaling pathways were stimulated. PRP treatment notably ameliorated the induced cell injury, reduced the intracellular oxidative and interestingly increased the upregulation of phosphorylated ERK1/2 and Akt. Moreover, PRP treatment relieved lead nitrate and/or γ-radiation-induced hepatic histological damages. In conclusion, this study sheds the light on a probable therapeutic role of PRP against lead nitrate- and/or γ-radiation-induced hepatotoxicity which might attribute to its ability to activate ERK and Akt signaling pathways.

Irbesartan attenuates advanced glycation end products-mediated damage in diabetes-associated osteoporosis through the AGEs/RAGE pathway

AIMS

Diabetes-associated osteoporosis is mainly caused by the formation and accumulation of advanced glycation end products (AGEs). Angiotensin II type 1 receptor blocker (ARB) has anabolic bone effects on the physicochemical properties of the bone in diabetes. We hypothesized that ARB could inhibit AGEs-induced deleterious effects.

MAIN METHODS

In this study, we chose seven-week-old Leprdb/Lepr+ (db/+) and Leprdb/Leprdb (db/db) mice. After 12 week intervention by irbesartan, the microarchitecture and mechanical strength of the bone of seven-week-old db/db mice were investigated systematically. Meanwhile, the molecular mechanisms of the osteoblasts were analyzed, after AGEs or irbesartan were added to the culture. Also, intracellular formation of reactive oxygen species (ROS) was measured with DCF fluorescence.

KEY FOUNDINGS

Results showed that 12-week irbesartan treatment could dramatically improve trabecular bone microarchitecture through increasing BV/TV (p = 0.003, +46.7%), Tb.N (p = 0.020, +52.0%), and decreasing that of Tb.Sp (p = 0.005, -21.2%) and SMI (p = 0.007, -26.4%), comparing with the db/db group. Irbesartan could also substantially raise biomechanical parameters including max load (p = 0.013, +20.7%), fracture load (p = 0.014, +70.5%), energy absorption (p = 0.019, +99.4%). Besides, it could inhibit AGEs-induced damage of cell proliferation and osteogenic differentiation of osteoblasts, as well as suppressing the activation of apoptosis caused by AGEs. Moreover, co-incubation with irbesartan could prevent the AGEs-induced increase of intracellular oxidative stress and RAGE expression in osteoblasts.

SIGNIFICANCE

In conclusion, this study suggested that irbesartan might play a protective role in diabetes-related bone damages by blocking the deleterious effects of AGEs/RAGE-mediated oxidative stress. This may provide a revolutionary benefits to therapy with irbesartan on diabetic osteoporosis.

Biologic therapies to enhance intervertebral disc repair

Degenerative disc disease is a progressive, chronic disorder with strong association to pain, where the dysregulated tissue environment signals disc cells, thereby leading to a low inflammatory process and slow extracellular matrix degradation and fibrosis in a perpetual vicious cycle, generating a structural and functional failure of intervertebral disc joint (IVDJ). Among current biologic therapies, there is an emerging minimally invasive strategy that consists of infiltrating plasma rich in growth factors, a safe and efficacious therapeutic approach for other musculoskeletal degenerative conditions. This review summarizes the homeostasis and degeneration of IVDJ, discusses some results on basic science and therapeutic use of platelet-rich plasma products and advances an alternative minimally invasive biologic therapy in IVDJ degeneration and chronic back pain.

A novel personalized 3D injectable protein scaffold for regenerative medicine

Biomaterials should be designed to closely resemble the characteristics and functions of the native extracellular matrix to provide mechanical support and signals to direct biological events. Here we have developed a novel injectable plasma rich in growth factors (PRGF-Endoret)-based formulation that combines a thermal-denaturation step of plasma with an autologous fibrin crosslinking. Rheological and mechanical properties were evaluated. Additionally, the microstructure and biological capacity of the biomaterial was also characterized. This novel formulation exhibited ideal mechanical properties and a gel-like behavior with the ability to progressively release its growth factor load over time. The results also suggested that the novel injectable formulation is non-cytotoxic, biocompatible and suitable for cell ingrowth as it is deduced from the fibroblast proliferation within the scaffold. Finally, stimulation of both cell proliferation and matrix proteins synthesis demonstrated the regenerative potential of this autologous protein based injectable scaffold.

Platelet-Released Growth Factors Modulate the Secretion of Cytokines in Synoviocytes under Inflammatory Joint Disease

The etiology and pathogenesis of rheumatoid arthritis (RA) are marked by a complex interplay of various cell populations and is mediated by different signaling pathways. Traditionally, therapies have primarily focused on pain relief, reducing inflammation and the recovery of joint function. More recently, however, researchers have discussed the therapeutic efficacy of autologous platelet-rich plasma (PRP). The main objective of this work is to examine the influences of platelet-released growth factor (PRGF) on human synoviocytes under inflammatory conditions. Additionally, it is checked to which extend treatment with platelet concentrate influences the release of cytokines form synoviocytes. For this purpose, an in vitro RA model was created by stimulating the cells with the TNF-α. The release of cytokines was measured by ELISA. The cytokine gene expression was analyzed by real-time PCR. It has been observed that the stimulation concentration of 10 ng/ml TNF-α resulted in a significantly increased endogenous secretion and gene expression of IL-6 and TNF-α. The anti-inflammatory effect of PRGF could be confirmed through significant reduction of TNF-α and IL-1β. An induced inflammatory condition seems to cause PRGF to inhibit the release of proinflammatory cytokines. Further study is required to understand the exact effect mechanism of PRGF on synoviocytes.

In-vitro release pharmacokinetics of amikacin, teicoplanin and polyhexanide in a platelet rich fibrin-layer (PRF)-a laboratory evaluation of a modern, autologous wound treatment

Objectives

Platelet rich fibrin (PRF) is an autologous fibrin glue, produced from patients' blood, which, besides intraoperative use, has applications in the treatment of infected wounds. The combination with antimicrobial agents results in a prolonged antibacterial effect allowing for wound dressing change intervals of seven days even in infected wounds. The aim of this study was to evaluate release kinetics of amikacin, teicoplanin or polyhexanide from a PRF-layer.

Methods

PRF mixed with teicoplanin, amikacin or polyhexanide was sprayed on a silicon gauze patch and put on a colombia agar with bacteria with known minimal inhibitory concentration (MIC) and incubated for 24 hours and afterwards transferred to another agar with the same bacterial strain. Inhibition zones were measured every 24 hours. This was repeated on 7 consecutive days. Antibiotic concentrations were calculated by interpolation.

Results

More than 1000 mg/L teicoplanin were released within the first 24 hours and 28.22 mg/L after 168 hours. Amikacin release was above 10,000 mg/L within the first 24 hours and still 120.8 mg/L after 120 hours. A release of polyhexanide could be verified for the first 24 hours only. Consequently teicoplanin and amikacin released from PRF showed antimicrobial in-vitro effects for almost a week, whereas an antimicrobial effect of polyhexanide could only be verified for the first 24 hours.

Conclusions

Our Results show that a weekly dressing regimen may be justified in wounds treated with PRF plus amikacin or teicoplanin, since bacteria will be eradicated over a considerable period of time after a single application of PRF.

Chronic Oxidative Stress, Mitochondrial Dysfunction, Nrf2 Activation and Inflammation in the Hippocampus Accompany Heightened Systemic Inflammation and Oxidative Stress in an Animal Model of Gulf War Illness

Memory and mood dysfunction are the key symptoms of Gulf war illness (GWI), a lingering multi-symptom ailment afflicting >200,000 veterans who served in the Persian Gulf War-1. Research probing the source of the disease has demonstrated that concomitant exposures to anti-nerve gas agent pyridostigmine bromide (PB), pesticides, and war-related stress are among the chief causes of GWI. Indeed, exposures to GWI-related chemicals (GWIR-Cs) and mild stress in animal models cause memory and mood impairments alongside reduced neurogenesis and chronic low-level inflammation in the hippocampus. In the current study, we examined whether exposure to GWIR-Cs and stress causes chronic changes in the expression of genes related to increased oxidative stress, mitochondrial dysfunction, and inflammation in the hippocampus. We also investigated whether GWI is linked with chronically increased activation of Nrf2 (a master regulator of antioxidant response) in the hippocampus, and inflammation and enhanced oxidative stress at the systemic level. Adult male rats were exposed daily to low-doses of PB and pesticides (DEET and permethrin), in combination with 5 min of restraint stress for 4 weeks. Analysis of the hippocampus performed 6 months after the exposure revealed increased expression of many genes related to oxidative stress response and/or antioxidant activity (Hmox1, Sepp1, and Srxn1), reactive oxygen species metabolism (Fmo2, Sod2, and Ucp2) and oxygen transport (Ift172 and Slc38a1). Furthermore, multiple genes relevant to mitochondrial respiration (Atp6a1, Cox6a1, Cox7a2L, Ndufs7, Ndufv1, Lhpp, Slc25a10, and Ucp1) and neuroinflammation (Nfkb1, Bcl6, Csf2, IL6, Mapk1, Mapk3, Ngf, N-pac, and Prkaca) were up-regulated, alongside 73–88% reduction in the expression of anti-inflammatory genes IL4 and IL10, and nuclear translocation and increased expression of Nrf2 protein. These hippocampal changes were associated with elevated levels of pro-inflammatory cytokines and chemokines (Tnfa, IL1b, IL1a, Tgfb, and Fgf2) and lipid peroxidation byproduct malondialdehyde in the serum, suggesting the presence of an incessant systemic inflammation and elevated oxidative stress. These results imply that chronic oxidative stress, inflammation, and mitochondrial dysfunction in the hippocampus, and heightened systemic inflammation and oxidative stress likely underlie the persistent memory and mood dysfunction observed in GWI.

Effect of platelet mediator concentrate (PMC) on Achilles tenocytes: an in vitro study

Background

Although there are many studies discussing the etiological and pathological factors leading to both, acute and chronic tendon injuries, the pathophysiology of tendon injuries is still not clearly understood. Although most lesions are uncomplicated, treatment is long and unsatisfactory due to the poor vascularity of tendon tissue. Platelet mediator concentrate (PMC) contains many growth factors derived from platelets, which can promote wound healing. In this study we investigate the effects of PMC on tenocyte proliferation and differentiation in order to provide an experimental basis for tissue regeneration strategies and to develop new treatment concepts.

Methods

Using enzyme linked immunosorbent assay (ELISA) we were able to quantify the several growth factors and cytokines found in PMC. Tenocytes were isolated both from human and from mouse Achilles tendons and stimulated with PMC. CyQuant® and Cell Titer Blue® assays were carried out to analyze tendon growth and viability at different concentrations of PMC. Real time RT-PCR was used to analyze tenocyte gene expression with or without PMC treatment. Immunohistochemistry was carried out to detect the tenocyte-specific antibody tenomodulin (TNMD) and scleraxis (SCX).

Results

We were able to detect numerous mediators such as platelet derived growth factor BB (PDGF-BB), interleukin 6 (IL-6), vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF-α), transforming growth factor beta 1 (TGF-ß1), and bone morphogenetic proteins 2, 4 and 7 (BMP-4, BMP-2, BMP-7) in PMC. It was possible to show a positive effect of PMC on human tendon cell growth and viability in a dose-dependent manner. Furthermore, PMC treatment led to induction of gene expression of scleraxis (SCX), type I collagen A 1 (Col1A1) and TNMD by tenocytes.

Conclusions

We suggest that the use of autologous PMC may be a suitable addition to conventional tendon therapy that is capable of increasing and optimizing tendon healing and reducing the risk of recurrence.