The Use of Platelet-Rich Plasma in Aesthetic and Regenerative Medicine: A Comprehensive Review

Fat Grafting and Regenerative Medicine in Burn Care

Regenerative therapies such as fat grafting and Platelet Rich Plasma (PRP) have emerged as new options to tackle burn-related injuries and their long-term sequelae. Fat grafting is able to promote wound healing by regulating the inflammatory response, stimulating angiogenesis, favoring the remodeling of the extracellular matrix, and enhancing scar appearance. PRP can enhance wound healing by accelerating stages including hemostasis and re-epithelization. It can improve scar quality and complement fat grafting procedures. Their cost-effectiveness, minimal invasiveness, and promising results observed in the literature have made these tools as therapeutic candidates. The current evidence on fat grafting and PRP in acute and reconstructive burns is described and discussed in this study.

Effects of submucoperichondrial application of platelet-rich plasma on nasal mucosal healing after septoplasty

OBJECTIVE(S)

Our aim is to investigate the effects of the submucoperichondrial application of Platelet Rich Plasma (PRP) on nasal mucosal healing after septoplasty surgery.

METHOD(S)

This prospective randomized observational study was conducted between July 2019 and February 2021, with 40 patients aged 18-60 years who underwent closed the only septoplasty operation for similar septal deviations. Patient divided into two group; 21 patients were placed in PRP group to which PRP was applied on all mucosal surface and submucoperichondrial area of septum and 19 patients were placed in control group to which saline solution was applied on same regions. Nasal obstruction score, mucociliary clearance time, presence of nasal crusting, and bleeding time were evaluated on 5th, 10th, 15th day after surgery and compared between groups.

RESULTS

Intranasal crusting on day 10 was found to be lower in the PRP group (n:13 68.4 %) than control group (n:7 33.3 %) with a statistically significant difference (p = 0.028). The nasal obstruction score on day 10 and 15 were found to be lower in the PRP group (3,33 ± 2,75, 2,07 ± 2,20) (than the control group (5,44 ± 2,26, 3,37 ± 1,92) with a statistically significant difference (p = 0,003,p = 0,009). The mucociliary clearance rate was found to be higher and the bleeding time was found to be lower in the PRP group, but a statistically significant difference was not observed.

CONCLUSIONS

Application of submucoperichondrial PRP could have beneficial effects on nasal mucosal repair, nasal crusting, and congestion after septoplasty surgery.

Platelet-rich plasma alleviates knee arthritis in rats by inhibiting p65

Knee osteoarthritis (KOA) is a chronic joint disease characterized by the degeneration of articular cartilage. In this study, we explored the potential therapeutic effects of platelet-rich plasma (PRP) and identified molecular targets for treating KOA. A rat model of KOA was established via the Hulth method and primary knee joint chondrocytes were isolated to evaluate the effects of PRP and shRNA targeting p65 (sh-p65). ELISA was used to detect inflammatory factors, including IL-6, IL-1β, and TNF-α. HE staining, Safranin O/Fast Green staining and Masson staining were performed to evaluate the morphology of articular cartilage, followed by detection of p65, COL2A1, ACAN, MMP13, and ADAMTS5 expression. The proliferation and apoptosis of primary knee chondrocytes were detected by the CCK-8 assay and TUNEL staining, respectively. Treatment with either PRP or sh-p65 decreased IL-6, IL-1β, and TNF-α levels in the peripheral blood of KOA rats and chondrocyte culture supernatants, increased COL2A1 and ACAN levels, and decreased MMP13 and ADAMTS5 expression. Furthermore, administration of PRP or sh-p65 exerted protective effects on articular cartilage, enhanced the vitality of knee joint chondrocytes, and inhibited apoptosis. Collectively, PRP inhibited inflammation, promoted chondrocyte proliferation and cartilage matrix secretion, and induced cartilage regeneration by suppressing p65 expression; these effects allow PRP to alleviate KOA progression. P65-based targeted therapy administered in combination with PRP might be a promising strategy for treating KOA.

Platelet-Rich Plasma in Young and Elderly Humans Exhibits a Different Proteomic Profile

As people age, their ability to resist injury and repair damage decreases significantly. Platelet-rich plasma (PRP) has demonstrated diverse therapeutic effects on tissue repair. However, the inconsistency of patient outcomes poses a challenge to the practical application of PRP in clinical practice. Furthermore, a comprehensive understanding of the specific impact of aging on PRP requires a systematic investigation. We derived PRP from 6 young volunteers and 6 elderly volunteers, respectively. Subsequently, 95% of high-abundance proteins were removed, followed by mass spectrometry analysis. Data are available via ProteomeXchange with the identifier PXD050061. We detected a total of 739 proteins and selected 311 proteins that showed significant differences, including 76 upregulated proteins in the young group and 235 upregulated proteins in the elderly group. Functional annotation and enrichment analysis unveiled upregulation of proteins associated with cell apoptosis, angiogenesis, and complement and coagulation cascades in the elderly. Conversely, IGF1 was found to be upregulated in the young group, potentially serving as the central source of enhanced cell proliferation ability. Our investigation not only provides insights into standardizing PRP preparation but also offers novel strategies for augmenting the functionality of aging cells or tissues.

The Use of Platelet-Rich Plasma and Stem Cell Injections in Musculoskeletal Injuries

Injuries to the musculoskeletal (MSK) system can have a significant impact on an individual's activities of daily living, as this multifunctional unit is associated with physical movement. Treatment of MSK injuries often involves corticosteroid injections, supplements, pharmaceutical agents, and/or surgery. While these approaches have been shown to be effective for some patients over both the short and long term, they can be associated with limited relief, adverse effects, and/or decreases in activities of daily living. An unmet need exists to develop and/or implement more effective treatment approaches for MSK injuries. Treatment options being explored include platelet-rich plasma (PRP) and stem cell injections. This review outlines the current state of research evaluating PRP and stem cell injections in the treatment of various MSK injuries. A literature search was conducted using the PubMed database to identify the relevant published articles related to the use of PRP and/or stem cell injections for the treatment of MSK and cartilage injuries. PRP and stem cell injections have been shown to improve an individual's quality of life (QOL) and are associated with fewer side effects as compared to invasive standards of care in multiple MSK injuries such as plantar fasciitis, Achilles tendinopathy, acute muscle and tendon tears, ligament injuries, chondral and medial collateral ligament (MCL) knee injuries and arthritis, rotator cuff lesions, and avascular femoral necrosis. Specifically, these studies on PRP and stem cell injections suggest that both approaches are associated with a quicker return to activities of daily living while providing longer lasting relief without significant adverse events. The studies reviewed demonstrated PRP and stem cell approaches to be effective and safe for the treatment of certain MSK injuries, but as standardized protocols were not utilized across studies in the discussion of similar injuries, it was therefore difficult to compare their efficacy and safety. As such, further research is warranted to establish standardized research protocols across MSK injury studies to gain further insight into the efficacy, safety, and durability of PRP and stem cell injections.

Therapeutic roles of platelet-rich plasma to restore female reproductive and endocrine dysfunction

Millions of women worldwide are infertile due to gynecological disorders, including premature ovarian insufficiency, polycystic ovary syndrome, Asherman syndrome, endometrial atrophy, and fallopian tube obstruction. These conditions frequently lead to infertility and have a substantial impact on the quality of life of the affected couples, primarily because of their psychological implications and high financial costs. Recently, using platelets to stimulate cell proliferation and tissue differentiation has emerged as a promising approach in regenerative medicine. Platelet-rich plasma (PRP) shows considerable potential for promoting endometrial hypertrophy and follicle development, making it a promising therapeutic option for tissue repair or replacement. This review provides an overview of the recent advancements and underlying mechanisms of PRP therapy for various female reproductive diseases and presents new therapeutic options for addressing female infertility.

Therapeutic approaches of cell therapy based on stem cells and terminally differentiated cells: Potential and effectiveness

Cell-based therapy, as a promising regenerative medicine approach, has been a promising and effective strategy to treat or even cure various kinds of diseases and conditions. Generally, two types of cells are used in cell therapy, the first is the stem cell, and the other is a fully differentiated cell. Initially, all cells in the body are derived from stem cells. Based on the capacity, potency and differentiation potential of stem cells, there are four types: totipotent (produces all somatic cells plus perinatal tissues), pluripotent (produces all somatic cells), multipotent (produces many types of cells), and unipotent (produces a particular type of cells). All non-totipotent stem cells can be used for cell therapy, depending on their potency and/or disease state/conditions. Adult fully differentiated cell is another cell type for cell therapy that is isolated from adult tissues or obtained following the differentiation of stem cells. The cells can then be transplanted back into the patient to replace damaged or malfunctioning cells, promote tissue repair, or enhance the targeted organ's overall function. With increasing science and knowledge in biology and medicine, different types of techniques have been developed to obtain efficient cells to use for therapeutic approaches. In this study, the potential and opportunity of use of all cell types, both stem cells and fully differentiated cells, are reviewed.

The role of platelet rich plasma enriched fat graft for correction of deformities after conservative breast surgery

BACKGROUND

Fat transfer has been widely used after breast conservative surgery (BCS) where it aims to recover shapes as a simple, inexpensive, biocompatible method but the technique is not without complications. Platelet Rich Plasma (PRP) is a promising approach to enhance fat graft survival and subsequently improve the outcome. The aim of this study was to evaluate the effect of enriching fat graft with PRP for delayed correction of deformities after conservative surgery for breast cancer regarding esthetic outcome and incidence of complications.

METHODS

The current study included 50 female patients who were scheduled for delayed lipofilling for correction of deformities after conservative surgery for breast cancer. The studied patients were randomly allocated into 2 groups: Group I (G I) included 25 patients scheduled for PRP enriched lipoinjection and Group II (G II) included 25 patients scheduled for lipoinjection without PRP as a control group.

RESULTS

Number of sessions of lipoinjection was significantly less in G I in comparison to G II (P = 0.024). During the 2nd session; the amounts of fat injected and harvested were significantly less in G I in comparison to G II (P = 0.049 and 0.001 respectively). Recipient site complications were significantly more evident in G II in comparison to G I (P = 0.01). Surgeon and patient satisfactions were significantly more evident in GI in comparison to G II (P = 0.005 and 0.029 respectively).

CONCLUSION

The addition of PRP to fat grafts is a simple, cost-effective and safe method to improve esthetic outcome and decrease complications.

Effect of intrauterine infusion of platelet-rich plasma for women with recurrent implantation failure: a systematic review and meta-analysis

This study evaluated the effect of intrauterine perfusion of autologous platelet-rich plasma (PRP) on pregnancy outcomes in women with recurrent implantation failure (RIF). Key biomedical databases were searched to identify relevant clinical trials and observational studies. Outcomes included clinical pregnancy rate, chemical pregnancy rate, implantation rate, live birth rate, and abortion rate. Data was extracted from ten studies (six randomised controlled trials, four cohort studies) involving 1555 patients. Pregnancy outcomes were improved in women treated with PRP compared to controls: clinical pregnancy rate (RR = 1.96, 95% CI [1.67, 2.31], p < 0.00001, I² = 46%), chemical pregnancy rate (RR = 1.79, 95% CI [1.54, 2.08], p < 0.00001, I² = 29%), implantation rate (RR = 1.90, CI [1.50, 2.41], p < 0.00001, I² = 0%), live birth rate (RR = 2.83, CI [1.45, 5.52], p = 0.0007, I² = 83%), abortion rate (RR = 0.40, 95% CI [0.18, 0.90], p = 0.03, I² = 59%). These data imply PRP has potential to improve pregnancy outcomes in women with RIF, suggesting a promising role in assisted reproductive technology.IMPACT STATEMENTWhat is already known on this subject? Platelet-rich plasma (PRP) is an autologous blood product that contains platelets, various growth factors, and cytokines at concentrations above the normal baseline level. Recent studies have shown that intrauterine infusion of autologous PRP can improve pregnancy outcomes in infertile women.What do the results of this study add? This systematic review and meta-analysis of data from ten studies (n = 1555; 775 cases and 780 controls) investigated the effect of intrauterine perfusion of autologous PRP on pregnancy outcomes in women with recurrent implantation failure (RIF). Findings suggest that pregnancy outcomes, including clinical pregnancy rate, chemical pregnancy rate, implantation rate, live birth rate and abortion rate were improved in women treated with PRP compared to controls.What are the implications of these findings for clinical practice and/or further research? RIF remains a challenge for researchers, clinicians, and patients. Our study identified PRP as a potential intervention in assisted reproduction. As an autologous blood preparation, PRP eliminates the risk of an immune response and transmission of disease. PRP is low cost and effective and may represent a new approach to the treatment of patients with RIF.

Beneficial effects of intraovarian injection of platelet-rich plasma in women with poor ovarian response

OBJECTIVE

Infertility can result from a diminished ovarian reserve, but a potential remedy exists in the form of platelet-rich plasma (PRP) administration. This treatment involves both biological factors and tissue trauma mechanisms, which stimulate folliculogenesis, making it a promising and effective strategy. We assessed the impact of direct PRP injections into the ovaries on the fertility outcomes of women classified as poor responders.

METHODS

A quasi-experimental study was conducted from April 2021 to December 2022, focusing on patients classified as POSEIDON grade 3 or 4. PRP injections were administered into both ovaries. After 3 months, data were collected on anti-Müllerian hormone (AMH) level, follicle-stimulating hormone (FSH) level, and the numbers of oocytes, mature oocytes, and good-quality embryos following ovarian stimulation. We then compared the data from before and after PRP injection.

RESULTS

This study included 50 women, with a mean of 39 years (interquartile range [IQR], 35 to 43) and 4 years (IQR, 2 to 6) for age and infertility duration, respectively. FSH levels decreased after treatment, while AMH levels and the numbers of oocytes, metaphase II oocytes, and high-quality embryos increased. However, only the increase in high-quality embryos was significant. The pregnancy and spontaneous pregnancy rates were 20% and 14%, respectively. Notably, women with secondary infertility exhibited a significantly higher pregnancy rate than those with primary infertility.

CONCLUSION

Ample evidence suggests that PRP can enhance ovarian function. However, further studies are needed to identify the appropriate candidates for this procedure, establish the optimal PRP preparation method, and standardize the procedure for its adjuvant use in assisted reproductive technology cycles.

Anti-Aging Potential of Platelet Rich Plasma (PRP): Evidence from Osteoarthritis (OA) and Applications in Senescence and Inflammaging

Aging and age-related changes impact the quality of life (QOL) in elderly with a decline in movement, cognitive abilities and increased vulnerability towards age-related diseases (ARDs). One of the key contributing factors is cellular senescence, which is triggered majorly by DNA damage response (DDR). Accumulated senescent cells (SCs) release senescence-associated secretory phenotype (SASP), which includes pro-inflammatory cytokines, matrix metalloproteinases (MMPs), lipids and chemokines that are detrimental to the surrounding tissues. Chronic low-grade inflammation in the elderly or inflammaging is also associated with cellular senescence and contributes to ARDs. The literature from the last decade has recorded the use of platelet rich plasma (PRP) to combat senescence and inflammation, alleviate pain as an analgesic, promote tissue regeneration and repair via angiogenesis-all of which are essential in anti-aging and tissue regeneration strategies. In the last few decades, platelet-rich plasma (PRP) has been used as an anti-aging treatment option for dermatological applications and with great interest in tissue regeneration for orthopaedic applications, especially in osteoarthritis (OA). In this exploration, we connect the intricate relationship between aging, ARDs, senescence and inflammation and delve into PRP's properties and potential benefits. We conduct a comparative review of the current literature on PRP treatment strategies, paying particular attention to the instances strongly linked to ARDs. Finally, upon careful consideration of this interconnected information in the context of aging, we suggest a prospective role for PRP in developing anti-aging therapeutic strategies.

Developing Consensus-Based Guidelines for Case Reporting in Aesthetic Medicine: Enhancing Transparency and Standardization

Clinical case reporting plays a vital role in sharing detailed patient narratives, providing insights into rare conditions, innovative treatments, and unexpected outcomes. However, existing reporting guidelines in aesthetic medicine fail to capture the specific nuances of procedures and outcomes in this field. The authors' objectives were to develop comprehensive guidelines for Case REporting in Aesthetic Medicine (CREAM). The study employed a 3-phase consensus process, including a literature review, expert interviews, and a consensus meeting. A diverse group of 10 expert participants (plastic surgeons, dermatologists, noncore specialists, evidence-based medicine expert, and research scientist) in Phase I and 30 experienced aesthetic practitioners in Phase II contributed to the research. Statistical analysis was conducted to assess agreement levels among participants and explore associations and variations within the data. The participants represented various specialties, genders, LGBTQ+ identities, and ethnic backgrounds. The research resulted in the development of the CREAM guidelines, consisting of a 16-item checklist. The guidelines covered essential aspects of case reporting, such as patient and practice information, procedure details, clinical assessment and outcomes, adverse events, and ethical considerations. Statistical analysis indicated a high level of consensus among participants, as well as significant associations between checklist items. CREAM guidelines represent a step toward enhancing transparency and standardization in case reporting in aesthetic medicine. Adhering to these guidelines will allow authors to contribute to a robust evidence base, prioritize patient safety, and drive advancements aesthetic medicine.

Platelet-derived extracellular vesicles formulated with hyaluronic acid gels for application at the bone-implant interface: An animal study

Background/Objective

Platelet derived extracellular vesicles (pEV) are promising therapeutical tools for bone healing applications. In fact, several in vitro studies have already demonstrated the efficacy of Extracellular Vesicles (EV) in promoting bone regeneration and repair in various orthopedic models. Therefore, to evaluate the translational potential in this field, an in vivo study was performed.

Methods

Here, we used hyaluronic acid (HA) gels formulated with pEVs, as a way to directly apply pEVs and retain them at the bone defect. In this study, pEVs were isolated from Platelet Lysate (PL) through size exclusion chromatography and used to formulate 2% HA gels. Then, the gels were locally applied on the tibia cortical bone defect of New Zeland White rabbits before the surgical implantation of coin-shaped titanium implants. After eight weeks, the bone healing process was analyzed through biomechanical, micro-CT, histological and biochemical analysis.

Results

Although no biomechanical differences were observed between pEV formulated gels and non-formulated gels, biochemical markers of the wound fluid at the interface presented a decrease in Lactate dehydrogenase (LDH) activity and alkaline phosphatase (ALP) activity for pEV HA treated implants. Moreover, histological analyses showed that none of the treatments induced an irritative effect and, a decrease in the fibrotic response surrounding the implant for pEV HA treated implants was described.

Conclusion

In conclusion, pEVs improve titanium implants biocompatibility at the bone-implant interface, decreasing the necrotic effects of the surgery and diminishing the fibrotic layer associated to the implant encapsulation that can lead to implant failure.

Intrauterine Infusion of Leukocyte-Poor Platelet-Rich Plasma Is an Effective Therapeutic Protocol for Patients with Recurrent Implantation Failure: A Retrospective Cohort Study

BACKGROUND

The clinical application of autologous leukocyte-poor platelet-rich plasma (LP-PRP) in patients with recurrent implantation failure (RIF) is rare. This retrospective observational cohort study aimed to evaluate the efficacy of LP-PRP intrauterine infusion in patients with RIF.

METHODS

Patients with RIF undergoing frozen embryo transfer (FET) from January 2019 to December 2021 (n = 118) were enrolled, with those undergoing LP-PRP intrauterine infusion as the PRP group (n = 64), and those receiving no LP-PRP treatment as the control group (n = 54). The beta-human chorionic gonadotropin (β-hCG)-positive rate, clinical pregnancy rate (CPR), live birth rate (LBR), and miscarriage rate (MR) per ET cycle were compared.

RESULTS

The β-hCG-positive rate (57.8% vs. 38.9%, p = 0.041), CPR (45.3% vs. 24.5%, p = 0.022), and LBR per ET cycle (42.2% vs. 18.5%, p = 0.009) were higher in the PRP group than in the control group, and the three variables (62.5% vs. 41.2%, p = 0.040, 47.5% vs. 23.5%, p = 0.033, and 47.5% vs. 20.6%, p = 0.027) in the PRP group transferred with the blastocyst-stage embryos were also higher than those in the control group. The MR was similar in all groups.

CONCLUSIONS

The LP-PRP treatment could improve the β-hCG-positive rate, CPR, and LBR in RIF patients undergoing FET cycles.

Process Optimization and Efficacy Assessment of Standardized PRP for Tendinopathies in Sports Medicine: Retrospective Study of Clinical Files and GMP Manufacturing Records in a Swiss University Hospital

Platelet-rich plasma (PRP) preparations have recently become widely available in sports medicine, facilitating their use in regenerative therapy for ligament and tendon affections. Quality-oriented regulatory constraints for PRP manufacturing and available clinical experiences have underlined the critical importance of process-based standardization, a pre-requisite for sound and homogeneous clinical efficacy evaluation. This retrospective study (2013–2020) considered the standardized GMP manufacturing and sports medicine-related clinical use of autologous PRP for tendinopathies at the Lausanne University Hospital (Lausanne, Switzerland). This study included 48 patients (18–86 years of age, with a mean age of 43.4 years, and various physical activity levels), and the related PRP manufacturing records indicated a platelet concentration factor most frequently in the range of 2.0–2.5. The clinical follow-up showed that 61% of the patients reported favorable efficacy outcomes (full return to activity, with pain disappearance) following a single ultrasound-guided autologous PRP injection, whereas 36% of the patients required two PRP injections. No significant relationship was found between platelet concentration factor values in PRP preparations and clinical efficacy endpoints of the intervention. The results were in line with published reports on tendinopathy management in sports medicine, wherein the efficacy of low-concentration orthobiologic interventions appears to be unrelated to sport activity levels or to patient age and gender. Overall, this study confirmed the effectiveness of standardized autologous PRP preparations for tendinopathies in sports medicine. The results were discussed in light of the critical importance of protocol standardization for both PRP manufacturing and clinical administration to reduce biological material variability (platelet concentrations) and to enhance the robustness of clinical interventions (comparability of efficacy/patient improvement).

Reparative potential of mesenchymal stem cells and platelet-rich plasma on irradiated submandibular glands of male albino rats

OBJECTIVE

To appraise and compare the reparative role of bone marrow-mesenchymal stem cells (BM-MSCs) and platelet-rich plasma (PRP) against irradiation damage on albino rats' submandibular gland.

DESIGN

Seventy four male albino rats were used, one for BM-MSCs harvesting, 10 for PRP preparation, seven as control group (Group 1). The remaining 56 rats were subjected to single dose (6 Gy) gamma irradiation and were divided into equal four groups; (Group 2): received no treatment, (Group 3): each rat was injected with 1 × 10⁵ BM-MSCs, (Group 4): each rat was injected with 0.5 ml/kg PRP, and (Group 5): each rat was injected with 1 × 10⁵ BM-MSCs and 0.5 ml/kg PRP. Each group was further subdivided into two subgroups in which rats sacrificed after one and two weeks from irradiation. Any structural changes were examined histopathologically, immunohistochemically using proliferating cell nuclear antigen (PCNA) and CD31 primary antibodies and histochemically using picrosirius red (PSR) stain, then analyzed statistically.

RESULTS

Histopathological examination of Group 2 showed atrophied acini, with nuclear changes and signs of degeneration in duct systems. Treated groups revealed signs of regeneration in form of uniform acini and regenerated duct systems especially in Group 5 and in a time depended manner. Immunohistochemical examination revealed increased immunoexpression of PCNA and CD31, while histochemical examination showed decreased PSR in all treated groups in relation to the irradiated group and this was proved statistically.

CONCLUSIONS

BM-MSCs and PRP are effective as treatment for irradiation-induced submandibular gland damage. However, the combined therapy is recommended over each one separately.

Efficacy of Platelet-Rich Plasma Versus Autologous Fat Transfer With Nanofat in the Treatment of Infraorbital Dark Circles: A Single-Blinded Randomized Comparative Clinical Trial

BACKGROUND

Treating infraorbital dark circles is one of the commonest aesthetic demands worldwide. Autologous fat transfer is commonly used to treat dark circles by filling the grooves, without effect on skin quality. Platelet-rich plasma has been reported to improve skin quality. Autologous fat can be emulsified and filtered to produce nanofat, which is then injected superficially in the dark circles to improve skin quality and discoloration.

OBJECTIVE

To compare the efficacy of platelet-rich plasma versus combined fat transfer and nanofat in treating infraorbital dark circles.

MATERIALS AND METHODS

30 patients with infraorbital dark circles of combined etiological factors were randomized into 2 equal groups: Group A treated with platelet-rich plasma and Group B treated with autologous fat transfer with emulsified fat injection.

RESULTS

Excellent and moderate responses were observed in 3 (20%) and 2 (13%) patients in group A versus 7 (46.7%) and 4 (27%) in group B, respectively. Nonresponders were 8 (53.3%) in group A and only 1 patient (6.7%) in group B. The difference was statistically significant regarding improvement ( p = .048) and patient satisfaction ( p = .032).

CONCLUSION

Autologous fat transfer with nanofat is significantly superior to platelet-rich plasma in improvement and satisfaction.

PRPCalc2: An App for Platelet-Rich Plasma Preparation

Platelet-rich plasma (PRP), an inexpensive yet powerful treatment modality, is widely used but poorly understood. Three areas of unmet need are the ability to compare results using differing centrifuges and methods; translating a study result into a specific practice; and estimating yield and dosage without the benefit of an in-office hematology analyzer. PRPCalc2 is a set of software tools that facilitates these goals. The app consists of software tools that (1) calculate the appropriate radius for centrifugation, (2) calculate the correct revolutions per minute (RPM) for the centrifuge, (3) calculate the mean yield for the method and its confidence interval, and (4) calculate platelet dosage. Using these tools, a practitioner with any centrifuge can create and validate their own PRP preparation method and then use it to create a standardized PRP.

Current Status of PRP Manufacturing Requirements & European Regulatory Frameworks: Practical Tools for the Appropriate Implementation of PRP Therapies in Musculoskeletal Regenerative Medicine

Providing accurate and up-to-date practical tools enabling oversight of platelet-rich plasma (PRP) legislation and of the appropriate standards to be implemented for its manufacture and use in Europe is a demanding task. This is due to rapid medico-technological advancements, slowness and disparity in legislation updates and enforcement between member states, and many reported gray-zone practices, notably for autologous PRP use. The levels of risk associated with blood manipulation processes generally dictate the manufacturing requirements for PRP preparations, which have gradually shifted toward good manufacturing practices (GMP) for standardization and overall quality enhancement. This work firstly outlines Western European and Swiss legislation for PRP products/preparations, providing key simplified information and recommendations for medical doctors seeking to implement this biological-based therapy for safe use in hospital settings, clinics, or private offices. This work secondly shows the importance of PRP-based product manufacturing standardization, which subsequently enables sound clinical evaluation of therapeutic interventions. Although the applicable legal bases provide guidelines for GMP manufacturing infrastructure and basic process design, paramount importance is set on the definition of workflows, technical specifications, and key parameters for PRP preparation and delivery. Overall, the development of simple and robust technologies and processes for PRP preparation is critical for guaranteeing the high therapeutic quality of the intervention, in collaboration with qualified GMP manufacturing platforms. Importantly, this work aims to serve as a practical tool for clinicians based in Western Europe who are willing to appropriately (i.e., administratively and technically) implement autologous PRP treatments in musculoskeletal regenerative medicine workflows, to ensure they make informed and optimal regulatory or process-based decisions.

Combination of PDGF-BB and adipose-derived stem cells accelerated wound healing through modulating PTEN/AKT pathway

Adipose-derived stem cells (ADSCs) have been widely proven to facilitate wound healing. Our study aimed to estimate the influence of combined ADSCs and platelet-derived growth factor-BB (PDGF-BB) on wound healing. We utilized 4 healthy SD rats to isolate ADSCs. Platelet-rich plasma (PRP) was acquired utilizing a two-step centrifugation technology. The role of PRP, PDGF-BB, and PDGF-BB combined with a PI3k inhibitor LY294002 on the viability, migration, and PTEN/AKT pathway in ADSCs were examined utilizing CCK-8, Transwell, and western blot assays. Then, we constructed an open trauma model in SD rats. Effects of ADSCs treated with PDGF-BB on pathological changes, CD31, and PTEN/AKT pathway of wound closure were assessed by hematoxylin & eosin (H&E) staining, Masson staining, immunohistochemical, and western blot assays, respectively. PRP and PDGF-BB intensified the viability and migration of ADSCs by modulating the PTEN/AKT pathway. Interestingly, LY294002 reversed the role of PDGF-BB on ADSCs. In vivo experiments, combined intervention with ADSCs plus PDGF-BB/PRP facilitated wound closure and ameliorated histological injury. Moreover, combined intervention with ADSCs and PDGF-BB attenuated the PTEN level and elevated the CD31 level as well as the ratio of p-AKT/AKT in the skin tissues. A combination of ADSCs and PDGF-BB facilitated wound healing might associate with the regulation of the PTEN/AKT pathway.

Autologous adipose-derived stromal vascular fraction and platelet concentrates for the treatment of complex perianal fistulas

BACKGROUND

Complex perianal fistulas are a major challenge for modern surgery since 10-35% of patients have functional problems after treatment. Sphincter-saving techniques have a wide range of efficacy (10-80%). We hypothesised that autologous adipose-derived stromal vascular fraction in combination with platelet rich plasma is a new therapeutic strategy with enhanced cure and function preservation rates.

METHODS

Adult patients with complex cryptoglandular perianal fistulas were treated with injection of autologous adipose-derived stromal vascular fraction in combination with platelet rich plasma around and inside the fistulous tract between May 2018 and April 2019 at the General and Emergency Surgery Operative Unit of the University Hospital "P. Giaccone" of Palermo. Fistulas were confirmed by magnetic resonance imaging. Patients completed the Short Form-36 score on quality of life and the Wexner and Vaizey scores on faecal incontinence, and they were functionally studied using a three-dimensional anorectal manometry. The clinical and functional follow-up was performed at 1 year and 2 years after surgery.

RESULTS

Nine patients (4 males, 5 females; median age 42 years [19-63 years]) with high trans-sphincteric or horseshoe fistulas were treated. The average number of previous surgeries per patient was 4.8. At 1 year follow-up, 77.7% of patients were cured, while at 2 years there was 1case of relapse. The variation in Short Form-36 score in cured patients was not significant (p = 0.0936). No statistically significant differences were found in continence scores.

CONCLUSIONS

The proposed treatment is a treatment option that preserves sphincter integrity and function, potentially avoiding postoperative incontinence and the need of repeated treatments.

Biomimetic Approaches in Clinical Endodontics

In the last few decades, biomimetic concepts have been widely adopted in various biomedical fields, including clinical dentistry. Endodontics is an important sub-branch of dentistry which deals with the different conditions of pulp to prevent tooth loss. Traditionally, common procedures, namely pulp capping, root canal treatment, apexification, and apexigonesis, have been considered for the treatment of different pulp conditions using selected materials. However, clinically to regenerate dental pulp, tissue engineering has been advocated as a feasible approach. Currently, new trends are emerging in terms of regenerative endodontics which have led to the replacement of diseased and non-vital teeth into the functional and healthy dentine-pulp complex. Root- canal therapy is the standard management option when dental pulp is damaged irreversibly. This treatment modality involves soft-tissue removal and then filling that gap through the obturation technique with a synthetic material. The formation of tubular dentine and pulp-like tissue formation occurs when stem cells are transplanted into the root canal with an appropriate scaffold material. To sum up tissue engineering approach includes three components: (1) scaffold, (2) differentiation, growth, and factors, and (3) the recruitment of stem cells within the pulp or from the periapical region. The aim of this paper is to thoroughly review and discuss various pulp-regenerative approaches and materials used in regenerative endodontics which may highlight the current trends and future research prospects in this particular area.

Modifying Orthobiological PRP Therapies Are Imperative for the Advancement of Treatment Outcomes in Musculoskeletal Pathologies

Autologous biological cellular preparations have materialized as a growing area of medical advancement in interventional (orthopedic) practices and surgical interventions to provide an optimal tissue healing environment, particularly in tissues where standard healing is disrupted and repair and ultimately restoration of function is at risk. These cellular therapies are often referred to as orthobiologics and are derived from patient's own tissues to prepare point of care platelet-rich plasma (PRP), bone marrow concentrate (BMC), and adipose tissue concentrate (ATC). Orthobiological preparations are biological materials comprised of a wide variety of cell populations, cytokines, growth factors, molecules, and signaling cells. They can modulate and influence many other resident cells after they have been administered in specific diseased microenvironments. Jointly, the various orthobiological cell preparations are proficient to counteract persistent inflammation, respond to catabolic reactions, and reinstate tissue homeostasis. Ultimately, precisely delivered orthobiologics with a proper dose and bioformulation will contribute to tissue repair. Progress has been made in understanding orthobiological technologies where the safety and relatively easy manipulation of orthobiological treatment tools has been demonstrated in clinical applications. Although more positive than negative patient outcome results have been registered in the literature, definitive and accepted standards to prepare specific cellular orthobiologics are still lacking. To promote significant and consistent clinical outcomes, we will present a review of methods for implementing dosing strategies, using bioformulations tailored to the pathoanatomic process of the tissue, and adopting variable preparation and injection volume policies. By optimizing the dose and specificity of orthobiologics, local cellular synergistic behavior will increase, potentially leading to better pain killing effects, effective immunomodulation, control of inflammation, and (neo) angiogenesis, ultimately contributing to functionally restored body movement patterns.

Platelet-rich plasma application in diabetic ulcers: A review

There are 422 million diabetic people in the world. 25% of these individuals are diagnosed with diabetic foot ulcer (DFU). 20% of patients with DFU will suffer amputation of the lower limbs. Following amputation procedures, the mortality rate of patients is over 70% in 5 years. Diabetes has no cure and, therefore, treatment aims to prevent and treat its complications. Autologous platelet-rich plasma (PRP) has been shown to be a therapeutic tool for many types of disorders, including the treatment of DFU. This manuscript aims to carry out a review to provide more knowledge about the efficacy and safety of autologous PRP for wound closure in patients with DFU. The majority of studies included in this review state that PRP promotes improvement of DFU lesions by accelerating tissue healing processes. However, many studies have a small sample size and thus require larger sample range in order to improve robustness of data in the literature.

Exokine and the Youth-Boosting Treatment Based on One's Own Serum: Wheat and Chaff

Within the field of skin rejuvenation, clinicians have broadened the application of proven therapies toward antiaging medicine. Specifically, both platelet-rich plasma (PRP) and autologous-conditioned serum (ACS) have received great consideration among experts for novel indications. While the medical research focused on ACS is strengthened in their evidence and supported by promising outcomes, much more debates exist regarding the efficacy of PRP. Despite limited supporting literature to date, physicians and surgeons should be encouraged to explore the use of these approaches and in shedding further light on their potential benefits by contributing new evidence from basic and clinical scientific investigation.

Platelet-Rich Fibrin in Fat Grafts for Facial Lipofilling: A Randomized, Controlled Split-Face Clinical Trial

Objective

Previous studies have reported that platelet-rich fibrin (PRF) may enhance the efficacy of fat grafts in facial lipofilling. However, these studies either lacked objective data or were not randomized, controlled trials. Thus, we aimed to objectively evaluate the efficacy of PRF in facial lipofilling.

Methods

A controlled, split-face, randomized trial (January 2018 to May 2019) based on 18 patients who underwent fat grafts for bilateral temple lipofilling was performed. Each patient received a combination of an autologous fat graft and PRF on one side and a fat graft combined with an equal volume of saline on the other side. The effects of PRF were evaluated by comparing the remaining bilateral fat graft volumes through a digital three-dimensional reconstruction technique. Improvements in the appearance and recovery time of each temple were assessed by both a surgeon and patients who were blinded to the treatment assignment. Complications were also recorded.

Results

Bilateral temple lipofilling showed no evidence of fat embolism, vascular/nerve injury, infection, massive edema, or prolonged bruising. Three-dimensional reconstruction data and the assessments from both the surgeon and patients revealed no significant differences in fat graft retention volume between the PRF-positive and PRF-negative lipofilling groups. However, recovery time in the PRF-positive lipofilling sites was significantly shortened compared with that of the PRF-negative lipofilling sites.

Conclusion

Facial filling with autologous fat grafts is effective and safe. Our results show that PRF does not markedly improve fat graft volume retention in the temple but significantly reduces postoperative recovery time.

Trial Registration Number

ChiCTR2100053663.

Mesenchymal Stem Cells and PRP Therapy Favorize Leak Closure After Sleeve Gastrectomy in Zucker Rats

INTRODUCTION

Sleeve gastrectomy (SG) is the most performed bariatric surgery but gastric leaks following SG occur in up to 2% of cases. Regenerative medicine is emerging as a promising field offering multiple possibilities in wound healing. We studied the efficiency of locally administered mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) on leak closure following SG in rats.

METHODS

The amount of PRP and MSCs extracted from one rat was analyzed and a model of gastric leak was developed in 10-week-old male Zucker rats. Twenty-four rats underwent SG fashioned with a leak. After 24 h, a second surgery was performed. The control group was treated by peritoneal lavage and drainage only while the experimental group received an additional treatment of locally administered MSCs and PRP at the leak orifice. Analysis of the leak healing process was done by an anatomopathological examination of the stomach 1, 2, 3, and 4 weeks after SG.

RESULTS

The extraction of MSCs and PRP from one rat was necessary for three recipients. Anatomopathological examination suggests that the closure of the leak orifice was faster in the experimental group. Statistical analysis revealed a significantly increased mucosae renewal and fibrosis score at the leak orifice after treatment with MSCs and PRP (p < 0.001).

CONCLUSION

These results suggest that PRP and MSCs may accelerate the closure of leaks following SG in rats and may become a new tool in the treatment of human gastric leaks but more research on this topic is needed to confirm these findings.

Polysaccharide hydrogels: Functionalization, construction and served as scaffold for tissue engineering

Polysaccharide hydrogels have been widely utilized in tissue engineering. They interact with the organismal environments, modulating the cargos release and realizing of long-term survival and activations of living cells. In this review, the potential strategies for modification of polysaccharides were introduced firstly. It is not only used to functionalize the polysaccharides for the consequent formation of hydrogels, but also used to introduce versatile side groups for the regulation of cell behavior. Then, techniques and underlying mechanisms in inducing the formation of hydrogels by polysaccharides or their derivatives are briefly summarized. Finally, the applications of polysaccharide hydrogels in vivo, mainly focus on the performance for alleviation of foreign-body response (FBR) and as cell scaffolds for tissue regeneration, are exemplified. In addition, the perspectives and challenges for further research are addressed. It aims to provide a comprehensive framework about the potentials and challenges that the polysaccharide hydrogels confronting in tissue engineering.

Combined Effect of Microneedling and Platelet-Rich Plasma for the Treatment of Acne Scars: A Meta-Analysis

Background

Microneedling is a promising method for the treatment of acne scars, while the effect of microneedling combined with platelet-rich plasma (PRP) remains unknown. We performed a meta-analysis of controlled studies to compare the efficacy and safety of microneedling treatment with and without additional PRP in patients with acne scars.

Methods

Randomized and non-randomized controlled studies were identified by search of Medline, Embase, and Cochrane's Library databases. Results were pooled with a random-effects model, incorporating the possible heterogeneity.

Results

Four randomized and 10 split-face non-randomized controlled studies with 472 patients were included. Compared to microneedling therapy without PRP, combined treatment with microneedling and PRP was associated with increased odds of clinical improvement of >50% in Goodman's qualitative scale [GQS: odds ratio (OR): 2.97, 95% confidence interval (CI): 1.96–4.51, p < 0.001; I² = 0%], and a significantly improved mean GQS score (mean difference: −0.32, 95% CI: −0.44 to −0.20, p < 0.001; I² = 0%). Combined treatment was associated with a higher patient satisfying rate (OR: 4.15, 95% CI: 2.13 to 8.09, p < 0.001; I² = 53%), while the incidence of severe adverse events such as severe erythema (OR: 1.59, 95% CI:.73 to 3.46, P = 0.24; I² = 0%) and severe edema (OR: 1.14, 95% CI: 0.47 to 2.76, P = 0.77; I² = 0%) were not significantly different.

Conclusions

Combined treatment with microneedling with PRP is more effective than microneedling without PRP for patients with acne scars.

Efficiency of platelet-rich plasma therapy for healing sports injuries in young athletes

In recent years, platelet-rich plasma (PRP) therapy has been a subject of controversy in orthopedics field. Our objective was to assess the efficiency of PRP therapy for patients who have suffered grade 2 meniscal lesions and grade 2 anterior cruciate ligament (ACL) lesions, graded by magnetic resonance imaging (MRI). A retrospective observational study was conducted, which included 72 young recreational athletes who had been diagnosed with grade 2 meniscal injury, graded using MRI, that benefited from PRP therapy as an enhancement of the primary treatment, after cast immobilization. The Lysholm score, the pain intensity and the resuming of the physical activity before the PRP treatment and one month after were analyzed. Our study revealed that patients had an improved subjective perception of pain after PRP therapy and an improvement of the Lysholm score. Concurrently, 83.3% of patients could return to sports and daily physical activity. It can be concluded that PRP therapy is a safe, easy to manage treatment, efficient for pain relief and in resuming of sports activities for young recreational athletes who have sustained partial meniscal or ACL tears. In terms of pain relief, it appears that the PRP therapy could be more efficient for young patients with ACL injuries.

Why might ovarian rejuvenation fail? Decision analysis of variables impacting reproductive response after autologous platelet-rich plasma

Experience with platelet-rich plasma (PRP) has accumulated from use in dental restoration, post-infarct myocardial repair, tendon surgery, pain management, and aesthetic enhancements. Reproductive medicine joined this arena in 2016, beginning with reports of menopause reversal and fertility recovery after autologous PRP for senescent ovaries. Although recent publications have highlighted benefits of 'ovarian rejuvenation', the absence of randomized placebo-controlled clinical trial data has limited its acceptance. Because selection bias tends to underreport negative outcomes, reliable estimates cannot be calculated for how often intraovarian PRP is unsuccessful. Ample information is available, however, to permit an operational root-cause analysis when failures are considered. This assessment uses a PRP treatment care path with a decision theory model to critique pre-intake screening, baseline audit, sample processing, ovarian tissue placement method, equipment selection, and follow-up monitoring. These branched choice points enable interventions likely to determine outcome. Specimen handling for intraovarian PRP merits particular scrutiny, since enormous variation in platelet protocols already exists across unrelated clinical areas. As a new addition to fertility practice, intraovarian PRP requires validation of safety and efficacy to gain wider support. Borrowing PRP knowledge from other domains can facilitate this goal, ideally with appreciation of aspects unique to intraovarian use.

Effect of Intraarticular Injection of Platelet-Rich Plasma on Knee Osteoarthritis: A Multicenter Retrospective Clinical Study

This study aimed to evaluate the effect of intraarticular injection with platelet-rich plasma on knee osteoarthritis. A total of 250 patients with stages I-III osteoarthritis from December 2018 to June 2020 were included in this study. All the patients had received autologous PRP injection (3 ml) into the affected knee joint every week for totally 3 injections. The VAS score and WOMAC index were used to evaluate knee function before and at 3 days, 1 month, and 3 months after injection. A total of 250 patients were enrolled in this study, including 130 patients in the PRP group and 120 patients in the control group. The content of platelets in PRP of patients in the PRP group was 958.0 ± 283.1 × 109/L. The VAS score and WOMAC index of patients in the PRP group before treatment were not significantly different from those in the control group. At 3 days, 1 month, and 3 months after PRP treatment, the VAS score and WOMAC index of the PRP group were significantly lower than those of the control group. PRP is effective in treatment of knee osteoarthritis. The pain symptoms can be alleviated at 3 days after injection.

Platelet rich plasma effectiveness in bowel anastomoses: A systematic review

BACKGROUND

Anastomotic leak constitutes a major problem in abdominal surgery. Technical insufficiency, topical or systemic factors contribute to disrupted healing of the performed bowel anastomosis and result in anastomosis leakage, with detrimental effects on patient postoperative outcomes. Despite the investigation of several factors and the invention of protective materials, the ideal agent to prevent anastomotic leaks is yet to be determined.

AIM

To study the effect of platelet rich plasma (PRP) on the healing of bowel anastomoses.

METHODS

A systematic literature search was performed in PubMed, EMBASE, and Scopus databases to identify studies investigating the effect of PRP application on bowel anastomosis.

RESULTS

Eighteen studies were eligible with a total population of 712 animals including rats (14 studies), rabbits (2 studies) and pigs (2 studies). No postoperative complications were reported following PRP application. Fourteen out of 18 studies reported a statistically significant higher anastomosis bursting pressure in PRP groups compared to control either in healthy animals or animal models with underlying condition or intervention, such as intraperitoneal chemotherapy or peritonitis. Similar results were reported by ten studies in terms of tissue hydroxyproline levels. One study reported significant increase in collagen deposition in PRP groups. PRP application resulted in significantly decreased inflammatory cell infiltration in the presence of peritonitis or intraperitoneal chemotherapy (6 studies).

CONCLUSION

The application of PRP is associated with improved bowel anastomosis outcomes, especially in animal models having an underlying condition affecting the normal healing process. PRP application seems to augment the normal healing process under these circumstances. However, further studies are needed to investigate the potential role of PRP on bowel anastomosis healing, especially in clinical settings.

Platelet-Rich Plasma Facial Rejuvenation: Myth or Reality?

Platelet-rich plasma (PRP) rejuvenation's efficacy has been reported by numerous uncontrolled clinical case studies of inconsistent quality rather than large randomized and placebo-controlled trials. It was suggested that PRP could be considered as a valid anti-aging and rejuvenation treatment modality. The current literature review summarizes available evidence so far described in the literature with special critical attention to higher quality comparative studies published over the last 10 years. The few studies that could be retrieved and included in this review documented less favorable results. So far, there is no international consensus on clinical PRP use for esthetic rejuvenation. Whether a mix of growth factors does in fact generate a clinically significant more youthful look and whether PRP injections result in comparable or better rejuvenation than what can be expected from other simpler non-surgical modalities. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effect of Cryo-Processing on Platelet-Rich Autoplasma Preparations

Platelet-derived growth factor (PDGF) plays an important role in angiogenesis, affects activation of migration and proliferation of mesenchymal stem cells, fibroblasts, smooth muscle cells, osteoblasts; activation of migration of monocytes, macrophages, and neutrophils.

The aim of the investigation was to study the effect of cryo-processing on the qualitative properties of platelet-rich autoplasma (PRP) at different time intervals.

Treatments for the amelioration of persistent factors in complex anal fistula

Anal fistulae are abnormal hollow connections between the wall of the anal canal and the perianal skin around the anus that have remained a burden on the medical sector for centuries. The complexity of this disease is attributed to a number of factors such as the degree of associated sphincter muscle, concomitant illnesses, existence of multiple fistulous tracts and the number of previous interventions. Persistence of a complex anal fistula can cause a decline in patient's physical quality of life as well as impact on the psychological status of patients who often suffer from anxiety and depression. Surgical intervention remains the gold standard for treatment, however; the risk of incontinence and high recurrence potential has led to interest into developing alternative treatment approaches such as the use of biologics, bioactives and biomaterials. One potential reason for these varied outcomes could be the multifactorial interplay between genetic, immune-related, environmental, and microbial persistence factors on tissue regeneration. Recent observations have proposed that adverse inflammatory mediators may contribute more than microbial factors. The moderate to high success rates of biotechnological advances (mesenchymal stem cells and biomaterial scaffolds) show promise as therapies for the amelioration of adverse persistent factors while facilitating a means to closing the fistula tract. The purpose of this review is to outline recent advances in biologics and combination therapies to treat persistent factors associated with complex anal fistula.

Biologic Augmentation during Meniscal Repair

We reviewed the literature regarding utility of biologic augmentation in meniscal repair. We hypothesized that the addition of biologic augmentation during meniscal repair improves postoperative knee function and reduces risk of repair failure. PubMed and Embase databases were systematically searched. Included studies were clinical studies in humans, published in English, and reported use of biologic augmentation techniques in addition to meniscal repair (including platelet-rich plasma [PRP], fibrin clot, bone marrow stimulation, meniscal wrapping, and bioscaffolds) for treatment of knee meniscal tears. Outcome measures included repair failure, repeat knee arthroscopic surgery, and magnetic resonance imaging), visual analog scale for pain, the International Knee Documentation Committee questionnaire, the Western Ontario and McMaster Universities Osteoarthritis Index Lysholm's Knee Scoring Scale, and the Knee Injury and Osteoarthritis Outcome Score. Study quality was assessed using the modified Coleman methodology score. Nineteen studies reported repair of 1,092 menisci including six studies that investigated fibrin clot augmentation, five studies that investigated PRP augmentation, three studies that investigated bone marrow stimulation augmentation, two studies that used meniscal wrapping augmentation, and three studies that used other techniques. The level of evidence ranged from I to IV and mean modified Coleman methodology score was 43 (range: 17-69), with higher scores noted in studies completed in recent years. PRP and bone marrow stimulation augmentation appear to decrease risk of failure in patients undergoing isolated meniscal repair but do not improve knee symptom scores. Fibrin clot and trephination augmentation techniques do not have sufficient evidence to support decreased failure risk at this time. Meniscal wrapping augmentation and scaffold implantation augmentation appear to be an attractive option to meniscectomy in complicated tears that are not candidates for repair alone, but further confirmatory studies are needed to support initial data. Evidence supporting augmentation of meniscal repair is limited at this time but suggests that the highest likelihood for effectiveness of augmentation is in the settings of isolated meniscal repair or meniscal repairs that would normally not be amenable to repair.

Positive effect of autologous platelet rich plasma on Saanen buck semen cryopreservation in non-breeding season

The objective of the current study was to evaluate the effect of autologous platelet-rich plasma (PRP) addition into soybean lecithin based extender on buck semen at post-thaw. Semen samples were collected from eight Saanen buck, and each semen sample was split into four equal aliquots and diluted with different concentrations of PRP supplemented extenders [no PRP (control), 0.5 × 10⁷/ml PRP, 1 × 10⁷/ml PRP, or 2 × 10⁷/ml PRP]. Motility, plasma membrane functional integrity, acrosome integrity, mitochondrial membrane potential, DNA integrity and malondialdehyde concentrations (MDA) were measured and analyzed at post-thaw. The results showed that 2 × 10⁷/ml PRP group had a positive effect on motility (62.41 ± 4.24), membrane functional integrity (71.11 ± 2.90), mitochondrial membrane potential (69.70 ± 1.99), DNA integrity (7.22 ± 0.93) and MDA levels (2.56 ± 0.73) at post-thaw (P < 0.05). The results of the study demonstrated that autologous PRP has a protective effect on cryopreservation of buck spermatozoa and the fertility effects are worthy of further study.

Platelet-Derived Extracellular Vesicles for Regenerative Medicine

Extracellular vesicles (EVs) present a great potential for the development of new treatments in the biomedical field. To be used as therapeutics, many different sources have been used for EVs obtention, while only a few studies have addressed the use of platelet-derived EVs (pEVs). In fact, pEVs have been shown to intervene in different healing responses, thus some studies have evaluated their regenerative capability in wound healing or hemorrhagic shock. Even more, pEVs have proven to induce cellular differentiation, enhancing musculoskeletal or neural regeneration. However, the obtention and characterization of pEVs is widely heterogeneous and differs from the recommendations of the International Society for Extracellular Vesicles. Therefore, in this review, we aim to present the main advances in the therapeutical use of pEVs in the regenerative medicine field while highlighting the isolation and characterization steps followed. The main goal of this review is to portray the studies performed in order to enhance the translation of the pEVs research into feasible therapeutical applications.

Platelet-Therapeutics to Improve Tissue Regeneration and Wound Healing-Physiological Background and Methods of Preparation

Besides their function in primary hemostasis, platelets are critically involved in the physiological steps leading to wound healing and tissue repair. For this purpose, platelets have a complex set of receptors allowing the recognition, binding, and manipulation of extracellular structures and the detection of pathogens and tissue damage. Intracellular vesicles contain a huge set of mediators that can be released to the extracellular space to coordinate the action of platelets as other cell types for tissue repair. Therapeutically, the most frequent use of platelets is the intravenous application of platelet concentrates in case of thrombocytopenia or thrombocytopathy. However, there is increasing evidence that the local application of platelet-rich concentrates and platelet-rich fibrin can improve wound healing and tissue repair in various settings in medicine and dentistry. For the therapeutic use of platelets in wound healing, several preparations are available in clinical practice. In the present study we discuss the physiology and the cellular mechanisms of platelets in hemostasis and wound repair, the methods used for the preparation of platelet-rich concentrates and platelet-rich fibrin, and highlight some examples of the therapeutic use in medicine and dentistry.

Human Platelets Take up Anti-VEGF Agents

Purpose

Growing evidence suggests different systemic exposure of anti-vascular endothelial growth factor (anti-VEGF) agents with repeated intravitreal application. Since the penetration of anti-VEGF agents through vascular barrier was reported, the interaction of anti-VEGF with nonresident platelets has become a topic of interest. The purpose of this study was to evaluate, with the help of visualization techniques, whether platelets take up the anti-VEGF agents ranibizumab, aflibercept, and bevacizumab.

Methods

The uptake of anti-VEGF agents with or without VEGF treatment was investigated using immunofluorescence and immunogold staining in human platelets. The role of actin filaments and clathrin-coated vesicles in the transport of ranibizumab, aflibercept, and bevacizumab was evaluated by two pharmacologic inhibitors: staurosporine (protein kinase C inhibitor) and cytochalasin D.

Results

All three anti-VEGF agents were taken up by platelets and colocalized with VEGF. Ranibizumab and aflibercept were mainly detected in alpha-granules; however, bevacizumab was equally localized in alpha-granules and in platelet vesicles. Both staurosporine and cytochalasin D completely inhibited the uptake of aflibercept into platelets. Both pharmacological inhibitors also decreased the transport of ranibizumab and bevacizumab into platelets. Bevacizumab was significantly more frequently colocalized within clathrin-coated vesicles than ranibizumab and aflibercept.

Conclusion

All three anti-VEGF agents are taken up by platelets and internalized in alpha-granules, which may result in a higher local exposure of anti-VEGF after the activation of platelets, potentially contributing to arterial thromboembolic events. Clathrin-coated vesicles seem to be more prominent in the transport of bevacizumab than ranibizumab and aflibercept. Nevertheless, whether the different localization and transport of bevacizumab are truly related to specific differences of receptor-mediated endocytosis has to be revealed by further research.

Autologous platelet-rich plasma in the treatment of refractory wounds in cutaneous leukocytoclastic vasculitis complicated with hypertension (grade 2 moderate risk): A case report

INTRODUCTION

Cutaneous leukocytoclastic vasculitis is an inflammatory variant of vasculitis with a variety of causes that only affects the skin. Its pathological manifestations include neutrophil infiltration and nuclear fragmentation. Clinically, it is characterised by a pleomorphic rash, including erythema, purpuric skin lesions, reticulocytosis, necrosis and ulceration. Once formed, local ulcerations are very difficult to heal.

CASE PRESENTATION

A 46-year-old female was diagnosed with cutaneous leukocytoclastic vasculitis. The patient's legs exhibited ulcers with a black eschar on the surface. The largest wound was 4.5 × 4.0 cm and the deepest wound was 1.7 × 1.8 × 1.0 cm. The ulcers had been present for 6 months and did not exhibit signs of healing. Treatment was commenced with platelet-rich plasma, and the wounds healed within 1 month.

CONCLUSION

Topical application of autologous platelet-rich plasma gel exerts beneficial effects in cutaneous leukocytoclastic vasculitis with regard to wound size reduction, and it induces granulation tissue formation. Platelet-rich plasma may represent a safe and cost-effective treatment for managing cutaneous wound healing to reduce the length of the recovery period.