Platelet-rich plasma: growth factors and pro- and anti-inflammatory properties

The effect of platelet-rich plasma and sodium alginate hydrogel on corneal wound healing after corneal alkali burns in rats with computer-assisted anterior segment optical coherence tomography image analysis

Our objective was to determine the effect of a semi-synthetic sodium alginate hydrogel and its combination with platelet-rich plasma (PRP) on histopathological, biochemical, clinical, and anterior segment optical coherence tomography (AS-OCT) data. Alkali chemical burn of the cornea was induced. Injured rats were randomly divided into five equal groups and topically treated with phosphate-buffered saline (sham), platelet-rich plasma (PRP), 0.5% sodium citrate, a semi-synthetic sodium alginate hydrogel, or a combination of PRP and hydrogel (combined group) three times daily. The degree of corneal opacity (CO), corneal epithelial staining (CES), percentage of corneal epithelial defects (CEDP), degree of ciliary hyperemia (CH), neovascularization size (NVS), and extent of neovascularization (NVE) were evaluated. AS-OCT was performed at nine days, and then rats were sacrificed. Histological examination and enzyme-linked immunosorbent assays were performed to detect the concentrations of IL-1β and MMP-9 in the cornea. There were no significant differences between the groups regarding CEDP, CO, CES, CH, NVS, or NVE on the first day after corneal alkali burn injury (p > 0,05). At the last examination, CO was significantly lower in the PRP group than in the sham group (p = 0,044), while the CO concentrations were similar in terms of NVS (p > 0,05). Similarly, in terms of tissue MMP-9 levels, there were no significant differences between groups (p > 0,05). However, there was a significant difference in tissue IL-1β levels between the groups (p < 0,001). In the PRP and combined groups, the level of IL-1β was significantly lower than that in the sham group (p = 0,043 and p = 0,036, respectively). There was a significant difference in epithelial necrosis between the PRP, and it was the lowest in the combined group (p = 0,003). Epithelial thickness was highest in the combined group (p = 0,002). CEDP was significantly different at the last visit between the groups (p = 0.042). The fastest epithelial closing rate was observed for the combined group (p = 0,026). There was a significant negative correlation between tissue MMP-9 levels and corneal solidity and between tissue MMP-9 levels and the corneal area according to the AS-OCT measurements (p = 0,012 and p = 0,027, respectively). When used alone, topical hydrogel application did not significantly enhance the healing of corneal wounds. However, when combined with PRP, it leads to an increased rate of epithelial closure and neovascularization. This combination did not exacerbate inflammation or corneal opacity compared to PRP alone. The anticoagulant citrate solution in the PRP tube did not prove effective. The synergistic use of PRP and hydrogel could enhance epithelial thickness and reduce epithelial necrosis. The use of new parameters for corneal wound healing assessment was facilitated through AS-OCT image processing.

Use of regenerative medicine in the treatment of endometritis in mares: A systematic review and meta-analysis

Defining the optimal therapy for endometritis remains a significant challenge for clinicians. Given the public health threat posed by antibiotic resistance and the inconclusiveness of traditional therapies, regenerative medicine has been proposed as an alternative. The objective of this study was to conduct a comprehensive systematic review and meta-analysis, to investigate the efficacy of regenerative medicine products in the treatment of both post-breeding persistent and chronic degenerative endometritis (PBIE/CDE) in mares, following the PRISMA guidelines. This research could be a comprehensive scientific reference for determining appropriate treatments and clinical strategies. All studies exploring the use of regenerative medicine therapies (i.e., plasma products, autologous conditioned serum, mesenchymal stem cells MSCs, and MSC derivatives) in the treatment of PBIE/CDE were included, regardless of the specific protocol used, the evaluated outcomes, or the diagnostic method employed. Two authors independently gathered data and evaluated the risk of bias for each study. Treatment effects were assessed using risk ratios for dichotomous data, accompanied by 95 % confidence intervals. Data were aggregated utilizing the fixed-effects model. The quality of evidence for each outcome was evaluated using GRADE criteria. Eighteen studies were included in the systematic review, while fifteen trials were included in the meta-analysis. A sub-meta-analysis was conducted separately on platelet-derived products, as well as on MSCs and their derivatives. The results demonstrated an overall positive effect of regenerative therapies in treating PBIE/CDE, particularly those involving MSCs and their derivatives. The positive outcomes include an anti-inflammatory effect, characterized by reduced intrauterine fluid accumulation, neutrophils, and cytokine concentrations. Additionally, improvements in pregnancy, foaling, and embryo recovery rates have been observed in some cases. Despite the limited number of randomized controlled studies and the high variability among protocols, including the timing of treatment, type, and volume of products used, the use of regenerative products, especially MSCs and their derivatives, has promising results in terms of both efficacy and safety for treating PBIE/CDE in mares.

Local delivery of platelet-derived factors mitigates ischemia and preserves ovarian function through angiogenic modulation: A personalized regenerative strategy for fertility preservation

As the most prominent and ideal modality in female fertility preservation, ovarian tissue cryopreservation, and transplantation often confront the challenge of ischemic damage and follicular loss from avascular transplantation. To surmount this impediment, we engineered a novel platelet-derived factors-encapsulated fibrin hydrogel (PFH), a paradigmatic biomaterial. PFH encapsulates autologous platelet-derived factors, utilizing the physiological blood coagulation cascade for precise local delivery of bioactive molecules. In our study, PFH markedly bolstered the success of avascular ovarian tissue transplantation. Notably, the quantity and quality of follicles were preserved with improved neovascularization, accompanied by decreased DNA damage, increased ovulation, and superior embryonic development rates under a Low-concentration Platelet-rich plasma-derived factors encapsulated fibrin hydrogel (L-PFH) regimen. At a stabilized point of tissue engraftment, gene expression analysis mirrored normal ovarian tissue profiles, underscoring the effectiveness of L-PFH in mitigating the initial ischemic insult. This autologous blood-derived biomaterial, inspired by nature, capitalizes on the blood coagulation cascade, and combines biodegradability, biocompatibility, safety, and cost-effectiveness. The adjustable properties of this biomaterial, even in injectable form, extend its potential applications into the broader realm of personalized regenerative medicine. PFH emerges as a promising strategy to counter ischemic damage in tissue transplantation, signifying a broader therapeutic prospect. (197 words).

Injectable GelMA Hydrogel Microspheres with Sustained Release of Platelet-Rich Plasma for the Treatment of Thin Endometrium

Platelet-rich plasma (PRP) intrauterine infusion has been demonstrated to be effective in treating thin endometrium and achieving pregnancy. However, the rapid release of growth factors limits its effectiveness in clinical applications, and thus, multiple intrauterine infusions are often required to achieve therapeutic efficacy. In this study, a GelMA hydrogel microsphere biomaterial is developed using droplet microfluidics to modify the delivery mode of PRP and thus prolong its duration of action. Its biocompatibility is confirmed through both in vivo and in vitro studies. Cell experiments show that PRP-loaded microspheres significantly enhance cell proliferation, migration, and angiogenesis. In vivo experiments show that the effects of PRP-loaded microspheres on repairing the endometrium and restoring fertility in mice could achieve the impact of triple PRP intrauterine infusions. Further mechanistic investigations reveal that PRP could facilitate endometrial repair by regulating the expression of E2Fs, a group of transcription factors. This study demonstrates that hydrogel microspheres could modify the delivery of PRP and prolong its duration of action, enabling endometrial repair and functional reconstruction. This design avoids repeated intrauterine injections of PRP in the clinic, reduces the number of patient visits, and provides a new avenue for clinical treatment of thin endometrium.

Current Challenges in the Development of Platelet-Rich Plasma-Based Therapies

Nowadays, biological therapies are booming and more of these formulations are coming to the market. Platelet-rich plasma, or PRP, is one of the most widely used biological therapies due to its ease of obtention and autologous character. Most of the techniques to obtain PRP are focusing on new processes and methods of optimization. However, not enough consideration is being given to modify the molecular components of PRP to generate more effective formulations with the aim of improving PRP treatments. Therefore, this review covers different novel PRP-obtaining methods that attempt to modify the molecular composition of the plasma.

Revitalizing female fertility: platelet-rich plasma - hype or hope?

Platelet-rich plasma (PRP) has gained popularity as an experimental tool in regenerative medicine, with potential applications in reproductive medicine. This review will assess the existing literature on the role of PRP in female fertility enhancement, focusing on ovarian rejuvenation and increased endometrial thickness. PRP is being explored as a treatment for recurrent implantation failure, primary ovarian insufficiency and poor ovarian response. While the influence of PRP on endometrial thickness and implantation success is postulated, its effectiveness remains the subject of debate due to protocol variability and unclear patient selection criteria. This narrative review includes 36 articles published before December 2022, and highlights the lack of comprehensive molecular studies examining the impact of PRP on reproductive capacity. This review underscores the importance of standardizing PRP preparation protocols in reproductive medicine. However, challenges persist, and there is a need for well-planned randomized controlled trials and a deeper understanding of the patient population that would gain the greatest benefit from PRP treatment. Clarifying these aspects is crucial to improve outcomes for low-prognosis patients undergoing assisted reproductive technology.

Activated platelet-rich plasma accelerate endometrial regeneration and improve pregnancy outcomes in murine model of disturbed endometrium

Platelet Rich Plasma (PRP) contains high concentrations of growth factors, therefore, PRP activation results in their release, stimulating the process of healing and regeneration. The study was conducted to check whether activated platelet-rich plasma (aPRP) treatment can improve regeneration of the endometrium in an experimental model of ethanol-induced disturbed endometrium. Seventy-two female Wistar rats were randomly assigned into the control group, disturbed endometrium (DE) group and aPRP treated group. Activation of PRP was performed by adding thrombin. All the animals were sacrificed on day 1, day 3, day 6 and day 9 and samples were taken from the miduterine horn. Quantification of Cytokine and chemokine profiles of activated and non-activated PRP for CCL2, TNF- α, IL-1β, CXCL8, CXCL10, IL2, IL4, IL-6 IL-10, IL-12, IL-17A, TGF- β, IFN-γ was carried out. Functional and structural recovery of the endometrium was analyzed by hematoxylin-eosin (HE) and immunohistochemical (IHC) analyses. HE confirmed proliferated epithelial lining and stromal reconstruction with decreased fibrosis in PRP treated group compared to the DE group. Epithelial thickness in aPRP treated on day 1, day 3, day 6 and day 9 revealed an significant increase (p ≤ 0.05). Significantly stronger IHC expression of alpha smooth muscle actin, Cytokeratin 18, Cytokeratin 19, Connexin-40, E-Cadherin, Claudin-1, Zona Occludin-1was found in the aPRP treated group compared to the DE group. Furthermore, aPRP treatment was associated with birth of live pups. Our results suggest that intrauterine administration of aPRP stimulated and accelerated the regeneration of endometrium in the murine model of disturbed endometrium.

Percutaneous bone marrow concentrate and platelet products versus exercise therapy for the treatment of rotator cuff tears: a randomized controlled, crossover trial with 2-year follow-up

BACKGROUND

Surgical repair is recommended for the treatment of high-grade partial and full thickness rotator cuff tears, although evidence shows surgery is not necessarily superior to non-surgical therapy. The purpose of this study was to compare percutaneous orthobiologic treatment to a home exercise therapy program for supraspinatus tears.

METHODS

In this randomized-controlled, crossover design, participants with a torn supraspinatus tendon received either 'BMC treatment', consisting of a combination of autologous bone marrow concentrate (BMC) and platelet products, or underwent a home exercise therapy program. After three months, patients randomized to exercise therapy could crossover to receive BMC treatment if not satisfied with shoulder progression. Patient-reported outcomes of Numeric Pain Scale (NPS), Disabilities of the Arm, Shoulder, and Hand, (DASH), and a modified Single Assessment Numeric Evaluation (SANE) were collected at 1, 3, 6, 12, and 24 months. Pre- and post-treatment MRI were assessed using the Snyder Classification system.

RESULTS

Fifty-one patients were enrolled and randomized to the BMC treatment group (n = 34) or the exercise therapy group (n = 17). Significantly greater improvement in median ΔDASH, ΔNPS, and SANE scores were reported by the BMC treatment group compared to the exercise therapy group (-11.7 vs -3.8, P = 0.01; -2.0 vs 0.5, P = 0.004; and 50.0 vs 0.0, P < 0.001; respectively) after three months. Patient-reported outcomes continued to progress through the study's two-year follow-up period without a serious adverse event. Of patients with both pre- and post-treatment MRIs, a majority (73%) showed evidence of healing post-BMC treatment.

CONCLUSIONS

Patients reported significantly greater changes in function, pain, and overall improvement following BMC treatment compared to exercise therapy for high grade partial and full thickness supraspinatus tears.

TRIAL REGISTRATION

This protocol was registered with www.

CLINICALTRIALS

gov (NCT01788683; 11/02/2013).

Leukocytes within Autologous Blood Concentrates Have No Impact on the Growth and Proliferation of Human Primary Osteoblasts: An In Vitro Study

Platelet-rich fibrin (PRF) is a widely used autologous blood concentrate in regenerative medicine. This study aimed to characterize the cellular composition and distribution of different PRF matrices generated by high (710 g) and low (44 g) relative centrifugal forces (RCFs) and to analyze their bioactivity on human primary osteoblasts (pOBs). PRF was separated into upper layer (UL) and buffy coat (BC) fractions, and their cellular contents were assessed using histological and immunohistochemical staining. The release of platelet-derived growth factor (PDGF) and transforming growth factor (TGF-β) was quantified using an ELISA. Indirect PRF treatment on pOBs was performed to evaluate cell viability and morphology. A histological analysis revealed higher quantities of leukocytes and platelets in the low-RCF PRF. TGF-β release was significantly higher in the low-RCF PRF compared to the high-RCF PRF. All PRF fractions promoted pOB proliferation regardless of the centrifugation protocol used. The low-RCF PRF showed higher TGF-β levels than the high-RCF PRF. These findings contribute to understanding the cellular mechanisms of PRF and provide insights into optimizing PRF protocols for bone regeneration, advancing regenerative medicine, and improving patient outcomes.

Review of Dohan Eherenfest et al. (2009) on "Classification of platelet concentrates: From pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF)"

This classic discusses the original publication of Dohan Eherenfest et al. on "Classification of platelet concentrates: from pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF)", in which the authors propose four categories of platelet concentrates depending on their leucocyte and fibrin content (P-PRP, leucocyte- and platelet-rich plasma (L-PRP), pure platelet-rich fibrin (P-PRF), and L-PRF) to group a "jungle" of products in which the term platelet-rich plasma (PRP) was used indistinctly. They were able to identify common factors such as: (1) the use of anticoagulants and immediate centrifugation of the blood after its collection; (2) most preparation techniques allowed platelet concentrate preparation within an hour; (3) the centrifugation aimed to separate the blood in layers that would allow the extraction of specific fractions; and (4) the product was activated with thrombin or calcium chloride. The reviewed manuscript has been listed among the most cited PRP articles in regenerative medicine, with more than 800 citations, driving current scientific research and clinical practise by categorising L-PRP and P-PRP (now, leucocyte-poor PRP). The classification has also opened the door to understanding intrinsic biological mechanisms between platelets, leukocytes, fibrin, and growth factors, which will later be considered for studying the proliferation and differentiation of cells in different tissues affected by PRP. Since the initial classification of platelet concentrates, several other classification systems have been proposed and published in the current literature such as platelet, activation, white blood cell (PAW), Mishra, platelet, leucocyte, red blood cells, and activation (PLRA), dose of platelet, efficiency, purity, and activation (DEPA), method, activation, red blood cells, spin, platelets, image guidance, leukocytes, and light activation (MARSPILL), etc. These classifications have identified important aspects of PRP that affect the biological composition and, ultimately, the indications and outcomes. To date, there is still a lack of standardisation in sample preparation, cohort heterogeneity, and incomplete reporting of sample preparation utilised, leading to a lack of clarity and challenging researchers and clinicians.

Methacrylated gelatin and platelet-rich plasma based hydrogels promote regeneration of critical-sized bone defects

Physiological repair of large-sized bone defects requires instructive scaffolds with appropriate mechanical properties, biocompatibility, biodegradability, vasculogenic ability and osteo-inductivity. The objective of this study was to fabricate in situ injectable hydrogels using platelet-rich plasma (PRP)-loaded gelatin methacrylate (GM) and employ them for the regeneration of large-sized bone defects. We performed various biological assays as well as assessed the mechanical properties of GM@PRP hydrogels alongside evaluating the release kinetics of growth factors (GFs) from hydrogels. The GM@PRP hydrogels manifested sufficient mechanical properties to support the filling of the tissue defects. For biofunction assay, the GM@PRP hydrogels significantly improved cell migration and angiogenesis. Especially, transcriptome RNA sequencing of human umbilical vein endothelial cells and bone marrow-derived stem cells were performed to delineate vascularization and biomineralization abilities of GM@PRP hydrogels. The GM@PRP hydrogels were subcutaneously implanted in rats for up to 4 weeks for preliminary biocompatibility followed by their transplantation into a tibial defect model for up to 8 weeks in rats. Tibial defects treated with GM@PRP hydrogels manifested significant bone regeneration as well as angiogenesis, biomineralization, and collagen deposition. Based on the biocompatibility and biological function of GM@PRP hydrogels, a new strategy is provided for the regenerative repair of large-size bone defects.

Regenerative potential of platelet concentrates in chronic oral mucosal lesions

Chronic oral mucosal diseases (COMDs) represent a significant challenge for clinicians and patients. They are commonly associated with chronic pain and negative effects on healing and patient's quality of life. Regenerative medicine including the use of biological autologous blood-derived substances (e.g., platelet concentrates [PCs]), has been reported to improve healing and reduce pain in orthopedic and maxillofacial surgeries as well as chronic oral mucosal diseases. In this review, we aim to describe the different types of PCs and their applications in the management of COMDs such as lichen planus, mucositis, pemphigus vulgaris, mucous membrane pemphigoid, and plasma cell mucositis, in terms of healing potential, pain control, and quality of life. Overall, PC applications seem to enhance healing and reduce pain in patients with COMDs. However, due to the small sample size and the lack of standardized clinical trials, further research is required to support these findings.

Intravesical instillation of platelet-rich plasma for treatment of interstitial cystitis/bladder pain syndrome: A pilot study

Objective

The aim of this study was to evaluate the feasibility of intravesical instillation of platelet-rich plasma (PRP) to treat interstitial cystitis/bladder pain syndrome (IC/BPS).

Materials and methods

Twenty PRP samples were tested in vitro for stability after exposure to urine samples with different pH. A pilot study involving 21 female patients with IC/BPS was conducted, and 6 weekly doses of autologous PRP (50 mL) were administered. Patients were followed up at the 2nd, 4th, 8th, and 12th weeks after terminating instillation. The primary endpoint was the visual analog scale (VAS) for pain, and the secondary endpoints included the IC symptom index, IC problem index of the O'Leary-Sant questionnaire and global response assessment, urine culture, and uroflowmetry. Success was defined as a reduction in VAS by 30% or more compared with basal level, and adverse events were recorded.

Results

The mean ± SD of VAS was significantly reduced compared with basal level (4.4 ± 2.6 vs. 8.8 ± 1.1, respectively, p = 0.001). Meanwhile, 80% of cases were considered successful, with a 50.1% reduction in the mean score compared with the basal level. The mean ± SD of IC symptom index and IC problem index significantly improved compared with the basal level. Global response assessment was markedly, moderately, and slightly improved in 2 (10%), 10 (50%), and 5 (25%) patients, respectively, and showed no change in 3 (15%). Three patients had positive urine cultures at follow-up, but 1 withdrew after 2 sessions because of a lack of efficacy.

Conclusions

Repeated intravesical instillation of PRP could be considered an effective and safe approach for treating IC/BPS.

Optimization of Platelet-Rich Plasma Preparation for Regenerative Medicine: Comparison of Different Anticoagulants and Resuspension Media

Platelet-rich plasma (PRP) has emerged as a promising therapy in regenerative medicine. However, the lack of standardization in PRP preparation protocols presents a challenge in achieving reproducible and accurate results. This study aimed to optimize the PRP preparation protocol by investigating the impact of two different anticoagulants, sodium citrate (SC) and ethylenediaminetetraacetic acid (EDTA), and resuspension media, plasma versus sodium chloride (NaCl). Platelet recovery rates were calculated and compared between groups, in addition to platelet activity and vascular endothelial growth factor (VEGF) released into plasma after PRP activation. The platelet recovery rate was higher with EDTA in comparison to SC (51.04% vs. 29.85%, p = 0.005). Platelet activity was also higher, with a higher expression of two platelet antibodies, platelet surface P-Selectin (CD62p) and PAC-1, in the EDTA group. The concentration of VEGF was higher with SC in comparison to EDTA (628.73 vs. 265.44 pg/mL, p = 0.013). Platelet recovery rates and VEGF levels were higher in PRP resuspended in plasma when compared to NaCl (61.60% vs. 48.61%, p = 0.011 and 363.32 vs. 159.83 pg/mL, p = 0.005, respectively). Our study reinforces the superiority of EDTA (as anticoagulant) and plasma (for resuspension) in obtaining a higher platelet recovery and preserving platelet functionality during PRP preparation.

Efficacy and safety of platelet-rich plasma in the treatment of venous ulcers: A systematic review and meta-analysis of randomized controlled trials

Considering the substantial impact of venous ulcers on quality of life and healthcare systems, this study evaluated the efficacy and safety of platelet-rich plasma (PRP) in comparison to conventional therapy. A systematic review of four databases identified 16 randomized clinical trials, including 20 study groups. PRP significantly enhanced complete ulcer healing, exhibiting an odds ratio (OR) of 5.06 (95% confidence interval [CI]: 2.35-10.89), and increased the percentage of healed ulcer area by a mean difference of 47% (95% CI: 32%-62%). Additionally, PRP shortened the time required for complete healing by an average of 3.25 months (95% CI: -4.06 to -2.43). Although pain reduction was similar in both groups, PRP considerably decreased ulcer recurrence rates (OR = 0.16, 95% CI: 0.05-0.50) without increasing the risks of infection or irritative dermatitis. These results suggest PRP as a viable, safe alternative for venous ulcer treatment, providing significant improvements in healing outcomes.

Enhanced Diabetic Rat Wound Healing by Platelet-Rich Plasma Adhesion Zwitterionic Hydrogel

BACKGROUND

The skin is the largest organ in the human body and serves as a barrier for protective, immune, and sensory functions. Continuous and permanent exposure to the external environment results in different levels of skin and extracellular matrix damage. During skin wound healing, the use of good dressings and addition of growth factors to the wound site can effectively modulate the rate of wound healing. A dressing containing bioactive substances can absorb wound exudates and reduce adhesion between the wound and dressing, whereas growth factors, cytokines, and signaling factors can promote cell motility and proliferation.

AIM AND OBJECTIVES

We prepared a functional wound dressing by combining platelet-rich plasma (PRP) and zwitterionic hydrogels. Functional wound dressings are rich in various naturally occurring growth factors that can effectively promote the healing process in various types of tissues and absorb wound exudates to reduce adhesion between wounds and dressings. Furthermore, PRP-incorporated zwitterionic hydrogels have been used to repair full-thickness wounds in Sprague-Dawley rats with diabetes (DM SD).

MATERIALS AND METHODS

Fibroblasts and keratinocytes were cultured with PRP, zwitterionic hydrogels, and PRP-incorporated zwitterionic hydrogels to assess cell proliferation and specific gene expression. Furthermore, PRP-incorporated zwitterionic hydrogels were used to repair full-thickness skin defects in DM SD rats.

RESULTS

The swelling ratio of hydrogel, hydrogel + PRP1000 (108 platelets/mL), and hydrogel + PRP1000 (109 platelets/mL) groups were similar (~07.71% ± 1.396%, 700.17% ± 1.901%, 687.48% ± 4.661%, respectively) at 144 hours. The tensile strength and Young modulus of the hydrogel and hydrogel + PRP10000 groups were not significantly different. High concentrations of PRP (approximately 108 and 109 platelets/mL) effectively promoted the proliferation of fibroblasts and keratinocytes. The zwitterionic hydrogels were not cytotoxic to any cell type. High PRP concentration-incorporated zwitterionic hydrogels increased the rate of cell proliferation and significantly increased the expression of characteristic genes such as collagen, fibronectin, involucrin, and keratin. Subsequently, zwitterionic hydrogels with high PRP concentrations were used to repair full-thickness skin defects in DM SD rats, and a wound healing rate of more than 90% was recorded on day 12.

CONCLUSIONS

PRP contains high concentrations of growth factors that promote cell viability, enhance specific gene expression, and have a high medical value in cell therapy. Zwitterionic hydrogels have a 3-dimensional interconnected microporous structure and can resist cell adhesion without causing cytotoxicity. Platelet-rich plasma-incorporated zwitterionic hydrogels further enhance the cellular properties and provide an effective therapeutic option for wound healing.

An Update on Orthobiologics: Cautious Optimism

Orthobiologics are rapidly growing in use given their potential to augment healing for multiple musculoskeletal conditions. Orthobiologics consist of a variety of treatments including platelet-rich plasma and stem cells that provide conceptual appeal in providing local delivery of growth factors and inflammation modulation. The lack of standardization in nomenclature and applications within the literature has led to a paucity of high-quality evidence to support their frequent use. The purpose of this review was to describe the current landscape of orthobiologics and the most recent evidence regarding their use.

Therapeutic applications of canine platelets and their derivatives: a narrative review

Platelets contain a multitude of growth factors and play a crucial role in physiological processes such as thrombogenesis, tissue repair, and angiogenesis. As a result, platelet-derived products have significant potential for efficient utilization in the realm of regenerative medicine due to their therapeutic and biological attributes. Numerous studies have already substantiated the therapeutic viability of platelets in various canine ailments. The existing literature indicates a substantial surge in the clinical application of canine platelets, positioning platelet-derived products as a viable alternative to conventional therapeutic agents. Platelet concentrates, including platelet-rich plasma and platelet-rich fibrin are commonly used as a therapeutic modality in clinical cases. These therapeutic derivatives exhibit effectiveness in tissue regeneration and can serve as complementary therapies. Notably, they offer a cost-effective and easily accessible therapeutic option, which has demonstrated its benefits in chronic inflammatory disorders such as osteoarthritis and tendinitis, ophthalmic conditions, wound healing, and mandibular injuries in canine patients. The broad spectrum of therapeutic effects displayed by platelets is providing researchers with novel perspectives for crafting therapeutic models in future investigations. This review centers on exploring the therapeutic potential of canine platelets across diverse disorders. Further exploration into platelet products, encompassing their preparation and applicability in canine medicine, is imperative. These inquiries hold the promise of unveiling fresh horizons for the domain of regenerative medicine.

Autologous concentrated growth factor mediated accelerated bone healing in root-end microsurgery: A multicenter randomized clinical trial

Introduction

Concentrated growth factor (CGF) is a new-generation autologous platelet concentrate that promotes tissue regeneration and has anti-inflammatory properties. This randomized multicenter trial aimed to evaluate the effects of CGF on bone healing in combination with root-end microsurgery.

Methods

Healthy adult patients indicated for root-end microsurgery were randomly assigned to either the CGF or control (no CGF implantation) groups. CGF was implanted into the bone cavity after root-end filling with mineral trioxide aggregate. Clinical and periapical radiographic evaluations were conducted at 1, 3, 6, and 12 months postoperatively, with follow-up cone-beam computed tomography (CBCT) at 6 months. The lesion volume reduction rate was calculated based on data from the preoperative and follow-up CBCT images.

Results

A total of 24 patients were enrolled. The treatment success rate was 91.7% and 83.3% on 12-month periapical radiography and 6-month CBCT, respectively, without a significant difference between the two groups. The lesion volume reduction rate in the CGF group (75.6%) was significantly higher than that in the control (61.0%) group.

Conclusions

Autologous CGF in conjunction with root-end microsurgery accelerated lesion reduction as observed on CBCT. Administering autologous blood products to stimulate healing in addition to removing the source of infection appears to be a promising treatment option for root-end microsurgery.

Comparison of Antimicrobial Activity of Injectable Platelet-Rich Fibrin (i-PRF) and Leukocyte and Platelet-Rich Fibrin (l-PRF) Against Oral Microbes: An In Vitro Study

Aim Injectable platelet-rich fibrin (i-PRF) and leukocyte and platelet-rich fibrin (l-PRF) are both blood-derived products used in regenerative medicine and dentistry. They contain platelets, growth factors, and leukocytes, which can have antimicrobial properties to some extent, but their primary purpose is tissue regeneration and wound healing. i-PRF and l-PRF may have some indirect antimicrobial properties due to their composition and ability to enhance tissue healing and immune responses, and they are primarily used in dentistry for their regenerative and wound healing capabilities rather than as standalone antimicrobial agents. This study aims to compare the anti-microbial activity of i-PRF and l-PRF against oral microbes. Methodology This study included 30 patients who were selected using G*Power software version 3.1 (Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany) calculation with the population size. The plaque samples were collected from the subjects using area-specific Gracey curettes used for scaling and root planing to remove plaque and calculus from the teeth and root surfaces. The collected plaque samples were transferred to a tube containing 5 ml of saline (sterile saltwater). The purpose of using saline is to preserve the microbial content of the plaque sample without altering the microbial composition. To obtain a uniform solution, the samples in the saline-containing tube were vortexed for 5 minutes. After vertexing, a small amount of the suspension (0.1 ml) was taken for further analysis. The 0.1 ml suspension was used to plate blood agar using the streak method. A loop or needle is used to streak the sample back and forth across the surface of the agar, leading to the dilution and separation of the bacteria. Results Results state that i-PRF has a maximum zone of inhibition (2.19±0.47 mm) when compared with metronidazole (0.14±0.09 mm). It can be stated that platelet concentrates demonstrate better antimicrobial activity due to their higher oxygen metabolites which help in the aggregation and internalization of microorganisms, which enhances the clearance of pathogens from the bloodstream. Paired t-test has been used for the comparison between the two groups, and the p-value is >0.05 stating that the difference is statistically significant. Conclusion The present study states that i-PRF demonstrated better antimicrobial efficacy as compared to l-PRF. Hence, i-PRF helps in reducing microbial load at the periodontally infected sites when compared with l-PRF.

Systematic Review of Platelet-Rich Plasma for Low Back Pain

BACKGROUND

Low back pain (LBP) has a high economic burden and is strongly related to the degenerative process of the spine, especially in the intervertebral disc and of the facet joints. Numerous treatment modalities have been proposed for the management of LBP, and the use of platelet-rich plasma (PRP) has emerged as an innovative therapeutic option for degenerative disease of the spine. The present study aims to evaluate the efficacy of PRP injections in managing low back pain.

METHODS

We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, a registered at PROSPERO Systematic Reviews Platform, under number CRD42021268491. The PubMed, Web of Science, and Scopus databases were searched to identify relevant articles, along with hand searching to identify gray literature articles, with no language restrictions. Randomized clinical trials (RCTs), nonrandomized trials (NRTs), and case series (CSs) with more than 10 patients were considered eligible. The quality assessment and the risk of bias of the randomized clinical trials were evaluated using the RoB II tool. An evaluation of the description of the preparation methods was performed using an adapted version of the MIBO checklist.

RESULTS

An electronic database search resulted in 2324 articles, and after the exclusion of noneligible articles, 13 RCTs and 27 NRTs or CSs were analyzed. Of the 13 RCTs, 11 found favorable results in comparison to the control group in pain and disability, one showed no superiority to the control group, and one was discontinued because of the lack of therapeutic effect at eight-week evaluation. Description of the PRP preparation techniques were found in almost all papers. The overall risk of bias was considered high in 2 papers and low in 11. An adapted MIBO checklist showed a 72.7% compliance rate in the selected areas.

CONCLUSIONS

In this systematic review, we analyzed articles from English, Spanish and Russian language, from large databases and grey literature. PRP was in general an effective and safe treatment for degenerative LPB. Positive results were found in almost studies, a small number of adverse events were related, the risk of bias of the RCTs was low. Based on the evaluation of the included studies, we graded as level II the quality of the evidence supporting the use of PRP in LBP. Large-scale, multicenter RCTs are still needed to confirm these findings.

Platelet-rich plasma in the pathologic processes of tendinopathy: a review of basic science studies

Tendinopathy is a medical condition that includes a spectrum of inflammatory and degenerative tendon changes caused by traumatic or overuse injuries. The pathological mechanism of tendinopathy has not been well defined, and no ideal treatment is currently available. Platelet-rich plasma (PRP) is an autologous whole blood derivative containing a variety of cytokines and other protein components. Various basic studies have found that PRP has the therapeutic potential to promote cell proliferation and differentiation, regulate angiogenesis, increase extracellular matrix synthesis, and modulate inflammation in degenerative tendons. Therefore, PRP has been widely used as a promising therapeutic agent for tendinopathy. However, controversies exist over the optimal treatment regimen and efficacy of PRP for tendinopathy. This review focuses on the specific molecular and cellular mechanisms by which PRP manipulates tendon healing to better understand how PRP affects tendinopathy and explore the reason for the differences in clinical trial outcomes. This article has also pointed out the future direction of basic research and clinical application of PRP in the treatment of tendinopathy, which will play a guiding role in the design of PRP treatment protocols for tendinopathy.

Maxillary Sinus Augmentation Using Autologous Platelet Concentrates (Platelet-Rich Plasma, Platelet-Rich Fibrin, and Concentrated Growth Factor) Combined with Bone Graft: A Systematic Review

BACKGROUND

The current review aims to provide an overview of the most recent research on the potentials of concentrated growth factors used in the maxillary sinus lift technique.

MATERIALS AND METHODS

"PRP", "PRF", "L-PRF", "CGF", "oral surgery", "sticky bone", "sinus lift" were the search terms utilized in the databases Scopus, Web of Science, and Pubmed, with the Boolean operator "AND" and "OR".

RESULTS

Of these 1534 studies, 22 publications were included for this review.

DISCUSSION

The autologous growth factors released from platelet concentrates can help to promote bone remodeling and cell proliferation, and the application of platelet concentrates appears to reduce the amount of autologous bone required during regenerative surgery. Many authors agree that growth factors considerably enhance early vascularization in bone grafts and have a significantly positive pro-angiogenic influence in vivo when combined with alloplastic and xenogeneic materials, reducing inflammation and postoperative pain and stimulating the regeneration of injured tissues and accelerating their healing.

CONCLUSIONS

Even if further studies are still needed, the use of autologous platelet concentrates can improve clinical results where a large elevation of the sinus is needed by improving bone height, thickness and vascularization of surgical sites, and post-operative healing.

Hypoxia Preconditioned Serum (HPS) Promotes Proliferation and Chondrogenic Phenotype of Chondrocytes In Vitro

Autologous chondrocyte implantation (ACI) for the treatment of articular cartilage defects remains challenging in terms of maintaining chondrogenic phenotype during in vitro chondrocyte expansion. Growth factor supplementation has been found supportive in improving ACI outcomes by promoting chondrocyte redifferentiation. Here, we analysed the chondrogenic growth factor concentrations in the human blood-derived secretome of Hypoxia Preconditioned Serum (HPS) and assessed the effect of HPS-10% and HPS-40% on human articular chondrocytes from osteoarthritic cartilage at different time points compared to normal fresh serum (NS-10% and NS-40%) and FCS-10% culture conditions. In HPS, the concentrations of TGF-beta1, IGF-1, bFGF, PDGF-BB and G-CSF were found to be higher than in NS. Chondrocyte proliferation was promoted with higher doses of HPS (HPS-40% vs. HPS-10%) and longer stimulation (4 vs. 2 days) compared to FCS-10%. On day 4, immunostaining of the HPS-10%-treated chondrocytes showed increased levels of collagen type II compared to the other conditions. The promotion of the chondrogenic phenotype was validated with quantitative real-time PCR for the expression of collagen type II (COL2A1), collagen type I (COL1A1), SOX9 and matrix metalloproteinase 13 (MMP13). We demonstrated the highest differentiation index (COL2A1/COL1A1) in HPS-10%-treated chondrocytes on day 4. In parallel, the expression of differentiation marker SOX9 was elevated on day 4, with HPS-10% higher than NS-10/40% and FCS-10%. The expression of the cartilage remodelling marker MMP13 was comparable across all culture conditions. These findings implicate the potential of HPS-10% to improve conventional FCS-based ACI culture protocols by promoting the proliferation and chondrogenic phenotype of chondrocytes during in vitro expansion.

Platelet-rich plasma in the treatment of alopecia areata after COVID-19 vaccination

Key Clinical Message

Alopecia areata may develop in patients after COVID-19 vaccination. Platelet-rich plasma (PRP) has an outstanding anti-inflammatory effect and could be an alternative treatment for alopecia patients who are refractory or intolerant to corticosteroids.

Abstract

A 34-year-old female with no systemic illness presented with non-scarring hair loss after the second COVID-19 vaccination shot 4 weeks ago. The hair loss worsened and progressed to severe alopecia areata. We started double-spin PRP therapy. Her hair recovered completely after six courses of PRP treatment.

Platelet Rich Plasma and Adipose-Derived Mesenchymal Stem Cells Mitigate Methotrexate-Induced Nephrotoxicity in Rat via Nrf2/Pparγ/HO-1 and NF-Κb/Keap1/Caspase-3 Signaling Pathways: Oxidative Stress and Apoptosis Interplay

BACKGROUND

the nephrotoxicity of methotrexate (MTX) is observed in high-dose therapy. Moreover, low-dose MTX therapy for rheumatic diseases is debatable and claimed to cause renal impairment. This study aimed at studying the effect of methotrexate in repeated low doses on rat kidneys and assessing the efficacy of adipose-derived mesenchymal stem cells (AD-MSCs) and platelet rich plasma (PRP) for attenuating this effect.

METHODS

Forty-two male Wistar rats were used, 10 rats were donors of AD-MSCs and PRP, 8 rats served as control, and the remaining rats were subjected to induction of nephrotoxicity by MTX intraperitoneal injection once weekly for successive 8 weeks and then assigned into 3 groups of 8 animals each: Group II: received MTX only. Group III: received MTX + PRP. Group IV: received MTX + AD-MSCs. After one month, rats were anaesthetized, serum-sampled, and renal tissue removed for biochemical, histological, and ultrastructural evaluation.

RESULTS

there was significant tubular degeneration, glomerulosclerosis, fibrosis, decreased renal index, along with increased levels of urea and creatinine in the MTX group compared to the control group. Immunohistochemical expression of caspase-3 and iNOS in the renal tissue was significantly increased in group II compared to groups III and IV. Biochemical results revealed higher tissue malondialdehyde (MDA) concentration in the MTX-injected group which decreased significantly in co-treatment with either AD-MSC or PRP + MTX. MSC promoted the activation of the Nrf2/PPARγ/HO-1 and NF-κB/Keap1/caspase-3 pathways, increased antioxidant enzyme activities, reduced lipid peroxidation levels, and alleviated oxidative damage and apoptosis. PRP showed therapeutic effects and molecular mechanisms similar to MSC. Furthermore, MSC and PRP treatment significantly reduced MTX-induced upregulation of the pro-inflammatory (NF-κB, interleukin-1ß, and TNF-α), oxidative stress (Nrf-2, hemoxygenase-1, glutathione, and malondialdehyde), and nitrosative stress (iNOS) markers in the kidney.

CONCLUSION

repeated administration of low-dose MTX resulted in massive renal tissue toxicity and deterioration of renal function in rats which proved to be attenuated by PRP and AD-MSCs through their anti-inflammatory, anti-apoptotic and anti-fibrotic properties.

Ovarian rescue in women with premature ovarian insufficiency: facts and fiction

The ovary has a comparatively short functional lifespan compared with other organs, and genetic and pathological injuries can further shorten its functional life. Thus, preserving ovarian function should be considered in the context of women with threats to ovarian reserve, such as ageing, premature ovarian insufficiency (POI) and diminished ovarian reserve (DOR). Indeed, one-third of women with POI retain resting follicles that can be reactivated to produce competent oocytes, as proved by the in-vitro activation of dormant follicles. This paper discusses mechanisms and clinical data relating to new therapeutic strategies using ovarian fragmentation, stem cells or platelet-rich plasma to regain ovarian function in women of older age (>38 years) or with POI or DOR. Follicle reactivation techniques show promising experimental outcomes and have been successful in some cases, when POI is established or DOR diagnosed; however, there is scarce clinical evidence to warrant their widespread clinical use. Beyond these contexts, also discussed is how new insights into the biological mechanisms governing follicular dynamics and oocyte competence may play a role in reversing ovarian damage, as no technique modifies oocyte quality. Additional studies should focus on increasing follicle number and quality. Finally, there is a small but important subgroup of women lacking residual follicles and requiring oocyte generation from stem cells.

Evaluation of the effect of local administration of PRP vs vitamin D3 on the rate of orthodontic tooth movement and the associated external apical root resorption

Background

Increased orthodontic treatment duration is associated with iatrogenic risks such as root resorption, white spot lesions etc. Recent research using pharmacological agents to accelerate tooth movement has mostly been conducted on animals and there is no reported research conducted on humans comparing the effects of Vitamin D3 and Platelet Rich Plasma (PRP) in the same subjects using a split mouth technique.

Objectives

To determine and compare effects of local injection of PRP and Vitamin D3 on the rate of tooth movement. Also, to assess association of external apical root resorption with the use of PRP, Vitamin D3 and compare it to a control group.

Materials & methods

11 subjects who diagnosed with Class I bi-maxillary malocclusion and who gave informed consent were recruited in the study. The patients were randomly divided using split mouth design and each quadrant served as either experimental or control group one. At the beginning of retraction phase, Vitamin D3 and PRP were injected to the randomly assigned quadrants while the contralateral side served as a control. The amount of space closure in 4 months was measured from distal surface of canine to mesial surface of 2nd premolar. Root resorption was assessed using CBCT taken at the beginning and at the closure of retraction phase.

Results

Mean rate of tooth movement was higher in PRP and Vitamin D3 groups compared to their controls. In the PRP group, the increased rate of tooth movement was observed throughout the study interval, but in the Vitamin D3 group it was only seen in first two months. Also, the PRP group demonstrated a higher rate of tooth movement compared to Vitamin D3 group. Root resorption was lesser in both experimental groups. Among the teeth assessed, lateral incisor showed maximum root resorption and canine the least.

Conclusions

PRP is a more efficient pharmacological agent compared to Vitamin D3 for accelerating tooth movement.

The levels of TGFβ1, VEGF, PDGF-BB, and PF4 in platelet-rich plasma of professional soccer players: a cross-sectional pilot study

Background

Regenerative therapy using platelet-rich plasma (PRP), a rich source of growth factors, has become popular in orthopedic sports medicine. Elite athletes prefer PRP therapy for their injured muscles and tendons primarily to avoid the possible risks of surgical treatment. However, the clinical effectiveness of PRP therapy in elite athletes compared to that in non-athletes remains unknown. Therefore, to investigate the effectiveness of PRP therapy in professional athletes (pro-athletes), we focused on the quality of PRP preparations and compared the levels of bioactive molecules between pro-athletes and non-athletes.

Methods

PRP was prepared from healthy, non-smoking male professional soccer players (pro-athletes) (n = 22) and non-athletes (VEGF: n = 34, others: n = 38). The levels of TGFβ1, PDGF-BB, VEGF, and PF4 were determined using ELISA kits. Polyphosphate was probed with 4’,6-diamidino-2-phenylindole and monitored using a fluorometer. The body composition of the donors was determined using a bathroom weighing scale.

Results

The levels of TGFβ1 and VEGF were significantly lower in pro-athletes than in non-athletes, whereas PF4 levels were significantly higher in pro-athletes. No significant difference was found in PDGF-BB levels between these groups. Biomolecule levels were not correlated with polyphosphate levels.

Conclusion

TGFβ1, VEGF, and PDGF-BB levels in pro-athletes were not higher than those in non-athletes. These findings suggest that growth factor levels in PRP may not be a predominant determinant of the clinical effectiveness of PRP therapy in pro-athletes. Increased PF4 levels in pro-athletes suggest an immunological function of PRP that may positively influence tissue regeneration.

Tolerance and efficacy of platelet-rich plasma injections in Peyronie's disease: Pilot study

INTRODUCTION

Platelet-rich plasma (PRP) injections are increasingly proposed for the treatment of Peyronie's disease since the discontinuation of Xiapex® despite poorly understood results.

OBJECTIVES

Evaluation of the tolerance and efficacy of intra-plate PRP injections in patients with Peyronie's disease.

METHODS

Three intra-plate injections of PRP were performed 15 days apart in 17 patients with Peyronie's disease. The Peyronie's Disease Questionnaire (PDQ) and the measurement of the angle of curvature of the erect penis were assessed before treatment and then 1, 3 and 6 months after treatment. Erectile function was assessed by different questionnaires (IIEF-EF, EHS, SEP, sexual discomfort score).

RESULTS

No side effects were noted during the study period. Three months after treatment, all three PDQ domains were significantly improved (P=0.002; P=0.015; P=0.017 respectively). The angle of curvature of the penis was significantly decreased by 11.8° with a mean angle of 40.4° before treatment and 28.6° after (P=0.007). The IIEF-EF score was significantly improved after treatment (mean preoperative value: 10.67) with a gain of 5 points at months 1 and 6 (P=0.01 and P=0.036 respectively) and 7 points at month 3 (P=0.04).

CONCLUSION

Our initial experience suggests that PRP injections for Peyronie's disease are safe. Although the limited data is suggestive of efficacy, a placebo control will be required for confirmation.

Potential therapeutic effect of platelet-rich plasma and albendazole on the muscular phase of experimental Trichinella spiralis infection

Trichinellosis is a food-borne parasitic infection causing muscle damage. This study aimed to detect the potential therapeutic effect of platelet-rich plasma (PRP) alone or in combination with albendazole (ALB) on the muscular phase of experimental Trichinella infection in rats. The study was conducted on 70 rats divided into four main groups: healthy non-infected non-treated rats, non-infected rats treated with PRP, infected untreated rats (seven rats in each group), and an infected group of 49 rats. The infected group was further subdivided based on the drug therapy received. The effects of drug therapy were evaluated using parasitological and histopathological analyses. The percent reduction in the number of Trichinella spiralis larvae per gram of muscle in the PRP-treated groups (one, two, and three doses) was 43.1%, 78.8%, and 86.1%, respectively. Groups treated with combined therapy of ALB & PRP (one, two, and three doses) showed overall reduction percentages of 87.7%, 90.9% and 95.2%, respectively. In contrast, the ALB-treated group showed a 69.4% reduction. All results of the abovementioned groups were statistically significant compared to the control-infected non-treated group. The findings of the histopathological analysis were consistent with the parasitological results. Groups receiving combined therapy showed the most significant improvement in terms of the degree of inflammation and fibrosis. It can be concluded that PRP has a modulatory effect on the pathology caused by T. spiralis larvae in the muscular phase of trichinellosis. To our knowledge, this is the first study to investigate the effect of PRP on the muscular phase of T. spiralis infection.

Autologous Platelet-Rich Growth Factor Reduces M1 Macrophages and Modulates Inflammatory Microenvironments to Promote Sciatic Nerve Regeneration

The failure of peripheral nerve regeneration is often associated with the inability to generate a permissive molecular and cellular microenvironment for nerve repair. Autologous therapies, such as platelet-rich plasma (PRP) or its derivative platelet-rich growth factors (PRGF), may improve peripheral nerve regeneration via unknown mechanistic roles and actions in macrophage polarization. In the current study, we hypothesize that excessive and prolonged inflammation might result in the failure of pro-inflammatory M1 macrophage transit to anti-inflammatory M2 macrophages in large nerve defects. PRGF was used in vitro at the time the unpolarized macrophages (M0) macrophages were induced to M1 macrophages to observe if PRGF altered the secretion of cytokines and resulted in a phenotypic change. PRGF was also employed in the nerve conduit of a rat sciatic nerve transection model to identify alterations in macrophages that might influence excessive inflammation and nerve regeneration. PRGF administration reduced the mRNA expression of tumor necrosis factor-α (TNFα), interleukin-1β (IL-1β), and IL-6 in M0 macrophages. Increased CD206 substantiated the shift of pro-inflammatory cytokines to the M2 regenerative macrophage. Administration of PRGF in the nerve conduit after rat sciatic nerve transection promoted nerve regeneration by improving nerve gross morphology and its targeted gastrocnemius muscle mass. The regenerative markers were increased for regrown axons (protein gene product, PGP9.5), Schwann cells (S100β), and myelin basic protein (MBP) after 6 weeks of injury. The decreased expression of TNFα, IL-1β, IL-6, and CD68⁺ M1 macrophages indicated that the inflammatory microenvironments were reduced in the PRGF-treated nerve tissue. The increase in RECA-positive cells suggested the PRGF also promoted angiogenesis during nerve regeneration. Taken together, these results indicate the potential role and clinical implication of autologous PRGF in regulating inflammatory microenvironments via macrophage polarization after nerve transection.

Do platelet concentrates accelerate orthodontic tooth movement?: a systematic review

PURPOSE

Surgical techniques in orthodontics have received widespread attention in recent years. Meanwhile, biomaterials with high molecular content have been introduced, such as platelet concentrates (PCs), which may accelerate orthodontic tooth movement (OTM) and reduce periodontal damage. The present systematic review aimed to answer the following PICO question: "In patients in whom orthodontic surgical techniques are performed (P), what is the effectiveness of using PCs over the surgical site (I) when compared to not placing PCs (C) to achieve faster tooth movement (O)?"

METHODS

A search was performed in 6 databases. The criteria employed were those described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses declaration. The present review included studies with a control group that provided information about the influence of PCs on the rate of OTM.

RESULTS

The electronic search identified 10 studies that met the established criteria.

CONCLUSIONS

The included studies were very diverse, making it difficult to draw convincing conclusions. However, a tendency was observed for OTM to be accelerated when PCs were used as an adjuvant for canine distalization after premolar extraction when distalization was started in the same session. Likewise, studies seem to indicate an association between PC injection and the amount of canine retraction. However, it is not possible to affirm that the use of PCs in corticotomy shortens the overall treatment time, as this question has not been studied adequately.

TRIAL REGISTRATION

PROSPERO Identifier: CRD42021278542.

The use of platelet-rich plasma in management of musculoskeletal pain: a narrative review

Musculoskeletal pain is the most common pain reported by patients. Platelet-rich plasma (PRP) is widely used to treat musculoskeletal pain. However, the efficacy of PRP to treat this pain remains controversial. This review highlights the application of PRP in the treatment of musculoskeletal pain. PRP treatment appears to reduce pain and improve function in patients with musculoskeletal pain. However, there are limitations to the currently published studies. These limitations include the PRP preparation methods, type of activators, types of pathology to be treated, methods and times of administration, and association of PRP with other treatments.

Current Advances in the Development of Hydrogel-Based Wound Dressings for Diabetic Foot Ulcer Treatment

Diabetic foot ulcers (DFUs) are one of the most prevalent complications associated with diabetes mellitus. DFUs are chronic injuries that often lead to non-traumatic lower extremity amputations, due to persistent infection and other ulcer-related side effects. Moreover, these complications represent a significant economic burden for the healthcare system, as expensive medical interventions are required. In addition to this, the clinical treatments that are currently available have only proven moderately effective, evidencing a great need to develop novel strategies for the improved treatment of DFUs. Hydrogels are three-dimensional systems that can be fabricated from natural and/or synthetic polymers. Due to their unique versatility, tunability, and hydrophilic properties, these materials have been extensively studied for different types of biomedical applications, including drug delivery and tissue engineering applications. Therefore, this review paper addresses the most recent advances in hydrogel wound dressings for effective DFU treatment, providing an overview of current perspectives and challenges in this research field.

Pilot study of intra-cavernous injections of platelet-rich plasma (P-shot®) in the treatment of vascular erectile dysfunction

INTRODUCTION

Intracavernosal injections of platelet-rich plasma (PRP) or P-shot® are increasingly proposed as a curative treatment for organic sexual dysfunction despite the lack of evidence of effectiveness.

OBJECTIVES

We conducted a pilot study to evaluate the safety and efficacy of intracavernous PRP injections in patients with vascular erectile dysfunction (ED).

METHODS

Three intracavernosal injections of PRP were performed 15days apart in 15 patients with vascular ED unresponsive to medical treatment with 5-phosphodiesterase inhibitors and/or prostaglandin E instillations or injections. Questionnaires assessing erectile function (IIEF-EF, EHS, SEP, Sexual discomfort score) were completed prior to treatment and 1, 3 and 6 months after the last injection.

RESULTS

No side effects were noted during the study period. The IIEF-EF score was significantly improved after treatment (P<0.001) with a gain of 5 points at 1month, 4 points at 3months and 3 points at 6months (respectively P=0.001, P=0.003 and P=0.022). The other questionnaires did not change significantly. In total, 20% of patients considered that the erection lasted long enough to have a sexual intercourse (SEP score) before P-shot® versus 26.7% after the treatment (P=1).

CONCLUSION

This study suggests that the effect of P-Shot® remains moderate in cases of ED with vascular origin. Larger clinical studies are needed to determine the real effectiveness of this therapeutic strategy.

LEVEL OF PROOF

2.

Pulsed Electric Fields for Valorization of Platelets with No Therapeutic Value towards a High Biomedical Potential Product—A Proof of Concept

Nowadays, the standard media used in clinical-scale mesenchymal stem cell (MSC) production to supply hundreds of clinical trials uses animal-derived components as supplements, which raises several health concerns. Consequently, the development of xeno-free media supplements has emerged. In the current study, the effect of pulse electric field (PEF) application to platelet concentrates (PC) with no therapeutic value for producing platelet releasates (PR) able to sustain the ability of bone marrow-MSCs (BM-MSCs) to self-renew and differentiate was tested. It was demonstrated that PEF application to PC induces platelet activation and growth factor (GF) release, namely PDGF, FGF, IGF, and TGF-β. The highest GF release was observed for TGF-β, achieving similar levels to those attained in platelet lysates (PL). BM-MSCs expanded in the presence of PR obtained by the application of PEF (7 pulses of 10 and 12.5 kV/cm) to PC (PR PEF) retained the characteristic MSC cell-surface markers, and the ability to proliferate and differentiate into osteogenic, adipogenic, and chondrogenic lineages. In this study, evidence is provided that PR PEF represents a suitable alternative to fetal bovine serum (FBS) for use in MSC production.

The Optimal Timing of Platelet-Rich Plasma (PRP) Injection for Nerve Lesion Recovery: A Preliminary Study

Introduction

Without appropriate treatment, nerve injuries may result in permanent loss of function. Platelet-rich plasma (PRP) injection is found to help in nerve regeneration. PRP is a concentrated platelet derived from autologous blood with the potential to release various growth factors (GF) to promote nerve regeneration. This study aims to know the best time for PRP injection to promote nerve regeneration.

Methods

This is an experimental in vivo research using male New Zealand white rabbits in the randomized control group posttest only design. Samples were divided into 5 groups (1 control group and 4 treatment groups). The control group without PRP injection and treated groups injected immediately after nerve injury, 3 days, 7 days, and 14 days afterward. Nerve regeneration was evaluated by the histology specimen sacrificed on day 21. Inflammation cells and endoneurium vacuoles were counted as mean percentage of five nerve fragments in each injured nerve sample specimen.

Result

Inflammation cells and vacuole cells increased significantly when PRP was administered 3 days after injury (group 2) (respectively, 14 ± 6.7 and 56.6 ± 11.6) compared to all treatment groups (p < 0.005) (control group, respectively, 6 ± 2.6 and 15.7 ± 9.5). On the other hand, significantly lower endoneurium vacuoles and inflammation cells were found on "the day 14" sample group (respectively, 5 ± 1.3 and 5.2 ± 1.6) compared to all other groups (p < 0.005).

Conclusion

This study found that the best time for injecting PRP for nerve regeneration is 14 days after injury.

Human Platelet-Rich Plasma Facilitates Angiogenesis to Restore Impaired Uterine Environments with Asherman’s Syndrome for Embryo Implantation and Following Pregnancy in Mice

Asherman’s syndrome (AS) is caused by intrauterine adhesions and inactive endometrium from repeated curettage of the uterine endometrium. AS is a major cause of recurrent implantation failure and miscarriage and is very difficult to treat because of the poor recovery of endometrial basal cells. Platelet-rich plasma (PRP) has abundant growth factors that may induce angiogenesis and cell proliferation. Here, we demonstrate that human PRP (hPRP) significantly enhances angiogenesis to restore embryo implantation, leading to successful pregnancy in mice with AS. In mice with AS, hPRP treatment considerably reduced the expression of fibrosis markers and alleviated oligo/amenorrhea phenotypes. Mice with AS did not produce any pups, but the hPRP therapy restored their infertility. AS-induced abnormalities, such as aberrantly delayed embryo implantation and intrauterine growth retardation, were considerably eliminated by hPRP. Furthermore, hPRP significantly promoted not only the elevation of various angiogenic factors, but also the migration of endometrial stromal cells. It also increased the phosphorylation of STAT3, a critical mediator of wound healing, and the expression of tissue remodeling genes in a fibrotic uterus. PRP could be a promising therapeutic strategy to promote angiogenesis and reduce fibrosis in impaired uterine environments, leading to successful embryo implantation for better clinical outcomes in patients with AS.

Platelet-rich plasma exhibits anti-inflammatory effect and attenuates cardiomyocyte damage by reducing NF-κB and enhancing VEGF expression in isoproterenol induced cardiotoxicity model

The present study investigated the cardioprotective effects of activated platelet-rich plasma (PRP) on high dose isoproterenol (ISO) induced cardiotoxicity. ISO was injected at a dose of 85 mg/kg/day, s.c. for 2 days. Cardiac function parameters including dp/dt max/min, left ventricular end diastolic pressure (LVEDP), relaxation constant (tau) and electrocardiogram (ECG) changes, anti-oxidant and membrane bound enzymes assays, pro-inflammatory cytokine levels, collagen content, immunohistochemical staining/gene expression of vascular endothelial growth factor (VEGF), cTnI (cardiac troponin I), NF-κB (nuclear factor kappa B), Smad-2/3, TGF-β (transforming growth factor), collagen-1/3 proteins were evaluated. PRP and platelet-poor plasma (PPP) were injected intramyocardially (200 μl in each ventricle region) 3 h after first dose of ISO under anesthesia. ISO injection induced cardiac dysfunction, hypertrophy, fibrosis, necrosis due to decline in anti-oxidant capacity, enhanced NF-κB and reduced cTnI immunostaining. However, the PRP injection attenuated these cardiac pathological changes by exerting anti-inflammatory properties and promoting cardiomyocyte repair.

Repair of experimentally induced femoral chondral defect in a rabbit model using Lyophilized growth promoting factor extracted from horse blood platelets (L-GFequina)

Lyophilized equine platelet derived growth factors (LGF) is a novel advanced platelet rich protein growth factor. It has been successfully applied in various fields of regenerative medicine to treat a variety of inflammatory and degenerative musculoskeletal conditions. Our study aimed to evaluate the efficacy of intraarticularly injected LGF for the remedy of articular cartilage injury, commonly characterized by progressive pain and loss of joint function in osteoarthritic rabbits. Full-thickness cylindrical cartilage defects were generated in both femoral condylar articular surfaces in twenty rabbits. The left joint of all animals was injected with the adjuvant as a self-control negative, while the right joint was injected by LGF. Four- and eight-weeks post-surgery, the femoral condyles were harvested, and assessed grossly, microscopically and immunohistochemically. Cytokines (TNF-α, IL-1β, PDGF and TGF-β1) contents of the chondral defects were quantified by ELISA as well as the gene expression of Col I and Col II via RT-qPCR. The LGF treated defects showed significant higher ICRS (International cartilage repair society) healing scores of cartilaginous regeneration with a significant higher histological healing score on using O'Driscoll histological scoring system. Additionally, LGF significantly lowered the levels of the pro-inflammatory cytokines TNF-α and IL-1β. It also significantly increased the anabolic and angiogenic growth factors (PDGF and TGF-β1), and significantly elevated the expression of chondrogenic-related marker genes; Col I and Col II. The current study reveals that LGF improves chondral healing and thus it can be a superior nominee as an adjunctive therapy to positively influence regeneration of chondral defects in osteoarthritic patients.

Platelet-Activating Biominerals Enhanced Injectable Hydrogels With Superior Bioactivity for Bone Regeneration

Refractory bone fracture, which is difficult to be treated, is a common clinical disease. Taking inspiration from the natural process of bone regeneration, we provide a biomimetic strategy to develop a new injectable biomaterial for repairing bone defects, which is mainly composed of platelets, fibrins, and biominerals. Biomineral nanoparticles (EACPNs) with an amorphous phase are prepared by an enzyme-catalyzed route and display a platelet-activating property. The composite hydrogel (EPH) of EACPNs, fibrins, and platelets is injectable, and has similar chemical properties to natural materials in bone regeneration. The dried EPH samples display a highly porous structure, which would be favorable for cell attachment and growth. The results from in vitro studies indicate that EPH has high biocompatibility and superior bioactivity in promoting the osteogenic differentiation of rat bone marrow stem cells (rBMSCs). Furthermore, the results from in vivo studies clearly indicate that EPH can induce the formation of new collagen and vessels in the defect area, thus leading to faster regeneration of bone defects at 2 weeks. Our study provides a strategy for designing new biomimetic materials, which may be favorable in the treatment of refractory bone fracture.

Platelet Rich Plasma and Its Use in Hair Regrowth: A Review

Platelet rich plasma (PRP) was described as a small volume of plasma containing higher concentrations of platelets than those found in peripheral blood and initially used as a transfusion product for treatment of thrombocytopenia. To date, it was discovered that there are several growth factors and cytokines that can accelerate wound healing and tissue regeneration, leading to a wider range of applications in the medical field, such as in sport medicine, regenerative medicine, and aesthetic medicine. Several studies have shown that PRP can be used effectively for treatment of hair loss. Although it has been widely used, the exact mechanism of action of PRP is still not fully elucidated. In this article, we aim to review and update current information on the definition, classification, mechanism of action, clinical efficacy in hair regrowth, and adverse events of PRP.

The Assessment of the Usefulness of Platelet-Rich Fibrin in the Healing Process Bone Resorption

The main subject of this research was the use of PRF in dental surgery aimed at preventing changes in alveolar height and width after tooth extraction. Due to the large growth factor content, it seems to be particularly useful in bone loss management starting from the simplest loss occurring after tooth extraction through loss resulting from tooth resection ending with loss caused by large bone cysts. The study was performed on 50 patients. The extraction of two maxillary or mandibular homonymous teeth was carried out in each patient, where PRF was placed in one alveolus while the other alveolus was left empty. Then, the alveoli were surgically managed with a split flap technique. On the extraction day, after 10 days, and after 6 months, the alveolar process was measured, soft tissues healing was assessed, and imaging examinations were analyzed. It was proved that the healing of soft tissues in the PRF group was better. In the PRF group after 6 months from surgery, the newly formed bone had higher grayscale values in volumetric tomography (CBCT). Moreover, the reduced atrophy of the alveolar process at the site of the extracted tooth was proved in this study.

Cytokine Profiling and Intra-Articular Injection of Autologous Platelet-Rich Plasma in Knee Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease leading to joint pain and stiffness. Due to lack of effective treatments, physical and psychological disabilities caused by OA have a detrimental impact on the patient’s quality of life. Emerging evidence suggests that intra-articular injection of platelet-rich plasma (PRP) may provide favorable results since PRP comprises not only a high level of platelets but also a huge amount of cytokines, chemokines, and growth factors. However, the precise mechanism and standardization method remain uncertain. This study aimed to examine cytokine profiling in both PRP and platelet-poor plasma (PPP) of knee OA patients and to determine the effects of PRP on OA chondrocytes and knee OA patients. PRP contained a wide variety of cytokines, chemokines, growth factors, and autologous intra-articular PRP injection resulted in favorable outcomes in knee OA patients. Significant increases in levels of IL-1, IL-2, IL-7, IL-8, IL-9, IL-12, TNF-α, IL-17, PDGF-BB, bFGF, and MIP-1β were detected in PRP compared to PPP (p < 0.001). An in vitro study showed a marked increase in proliferation in OA chondrocytes cultured with PRP, compared to PPP and fetal bovine serum (p < 0.001). In a clinical study, knee OA patients treated with PRP showed improvement of physical function and pain, assessed by physical performance, Western Ontario and McMaster Universities Arthritis Index and visual analog scale. Our findings from both in vitro and clinical studies suggest that intra-articular PRP injection in knee OA patients may be a potential therapeutic strategy for alleviating knee pain and delaying the need for surgery.

Randomized controlled study on effect of concentrated growth factors on crestal bone levels and peri-implant bone density in dental implants

Introduction:

Modern dentistry aims to restore the comfort and health of the stomatognathic system. Dental implants have emerged as a promising option for this purpose. Concentrated growth factors (CGFs) have been suggested to enhance the healing of bone grafts and enhance the integration of implants into the bone. Growth factors are proteins which regulate the complex process of wound healing. They play an important role in cell migration, cell proliferation, and angiogenesis in the tissue regeneration phase. CGF was first developed by Sacco in 2006. It can be used as a barrier membrane to accelerate soft-tissue healing. CGF does not require any chemical or anticoagulants, and hence, it is free from viral transmission diseases. Crestal bone levels, peri-implant bone density, bleeding, probing depth, mobility, occlusion factors, restoration adequacy, radiographic images, oral hygiene, and patient health status are some of the important parameters for determining longevity of success rates in implant dentistry. This study will assess the peri-implant bone density and crestal bone levels with and without the use of CGF.

Aim:

To evaluate the effect of CGFs on peri-implant bone density and in the preservation of crestal bone levels around dental implants.

Materials and Methods:

Sampling procedure: Random selection of population (Sealed envelope method)

Number of groups: Two-Control group (Group 1) and Experimental group (Group 2)

Sample size: 20

For Group 2, implants were placed with CGF. For Group 1, implants were placed without CGF. The peri-implant bone density and bone levels were measured by Digora and signora software.

Results:

The mean crestal bone loss on the mesial aspect of implants placed in Group 2 is 0.294 mm and Group 1 is 0.345 mm, and the mean crestal bone loss on the distal aspect of implants placed in Group 2 is 0.320 mm and in Group 1 is 0.331 mm. There are no many significant differences on mesial and distal aspects around implants between the two groups Intragroup comparison of bone density values in Group 1 shows the mean difference from baseline to 1 month is 0.6, and after three and 6 months periods are 1.1 and 1.1, respectively, which indicates not much significant improvement in bone density values in Group 1. Intergroup comparison shows a significant difference between both the groups starting from as early as the 1^st month.

Conclusion:

The results of this study indicate that CGF is significantly better in the regeneration of bone around the implants when comparing with nonCGF groups. Although CGF showed improvement in bone formation, there are no many differences in crestal bone level changes on mesial and distal sides of the implants between the two groups.

Effects of submucosally administered platelet-rich plasma on the rate of tooth movement

OBJECTIVES

To evaluate the effects of submucosally administered platelet-rich plasma (PRP) on the rate of maxillary canine retraction. Levels of soluble receptor activator of nuclear factor-κb ligand (sRANKL) and osteoprotegerin (OPG) in the gingival crevicular fluid (GCF) were also measured over 2 months.

MATERIALS AND METHODS

This split-mouth trial involved 20 sites in 10 subjects randomly assigned to PRP (experimental) side and control side. After alignment, the freshly prepared PRP was injected submucosally distal to the experimental side maxillary canine, and retraction was performed using NiTi closed-coil springs (150 g) on 0.019 × 0.025-inch stainless steel wire. The rate of canine movement was assessed using digital model superimposition at 0, 30, and 60 days. The OPG and sRANKL were assayed using enzyme-linked immunosorbent assay from GCF collected at 0, 1, 7, 21, 30, and 60 days.

RESULTS

Twenty sites were analyzed using paired t test. The rate of tooth movement increased significantly by 35% on the PRP side compared with the control side in the first month (P = .0001) and by 14% at the end of the second month (P = .015). Using the Mann-Whitney U test, OPG levels were found to be significantly decreased on the 7th (P = .003) and 30th day on the PRP side (P = .01), while sRANKL became detectable by the third week postinjection on the PRP side (P = .069).

CONCLUSIONS

Submucosal injection of platelet-rich plasma significantly increased tooth movement during the 60-day observation period. Local injection of PRP significantly altered the levels of OPG and sRANKL in GCF.