Search Results (62)

Background: Arthroscopic rotator cuff repair faces high retear risks in multi-tendon injuries due to insufficient biological healing; leukocyte-rich PRP may enhance tendon–bone integration through inflammatory modulation and growth factor release. Methods: Four databases including PubMed, Embase, Cochrane Library, and Web of Science were searched until March 2025. Literature screening, quality evaluation, and data extraction were performed according to inclusion and exclusion criteria. GRADE was used to grade the strength of the evidence and the results. Results: The main finding of this study was that leukocyte-rich platelet-rich plasma combined with arthroscopic surgery for rotator cuff injuries can improve the Constant Score (MD = 1.13, 95% CI: 0.19, 2.07, p = 0.02, I² = 47%), American Shoulder and Elbow Surgeons score (MD = 6.02, 95% CI: 4.67, 7.36, p < 0.01, I² = 0%), and University of California, Los Angeles score (MD = 1.20, 95% CI: 0.34, 2.06, p < 0.01, I² = 0%) of patients with rotator cuff tear after treatment, and reduce the postoperative Visual Analog Scale score (MD = −0.62, 95% CI: −1.16, −0.08, p = 0.02, I² = 83%) of patients. However, there were no statistical differences regarding the Simple Shoulder Test (MD = 0.08, 95% CI: −0.23, 0.39, p = 0.61, I² = 5%). Conclusions: Based on current evidence, the use of LR-PRP in arthroscopic rotator cuff repair could lessen postoperative pain and improve postoperative functional scores in individuals with rotator cuff injuries. Full article

Background: Platelet-rich plasma (PRP) is increasingly utilized for managing knee osteoarthritis (KOA), yet its clinical value remains debated due to the variability in preparation protocols and outcome measures. Methods: This narrative review synthesizes current evidence from 40 high-quality studies published between 2013 and March 2025, including randomized controlled trials, systematic reviews, and meta-analyses. The biological mechanisms, clinical effectiveness, safety, and implementation challenges of PRP therapy in KOA are examined. Results: PRP injections—particularly leukocyte-poor PRP—demonstrate superior pain relief and functional improvement compared to hyaluronic acid and corticosteroids, especially in patients with mild to moderate KOA (Kellgren–Lawrence grades I–III). However, heterogeneity in PRP formulations (platelet/leukocyte content and activation protocols), injection regimens, and follow-up durations limits direct comparability across studies. Evidence from high-quality placebo-controlled trials shows inconsistent long-term benefits, with some failing to demonstrate superiority over saline beyond 6–12 months. The GRADE assessment rates the overall certainty of evidence as moderate. PRP appears safe, with few adverse events reported, but remains costly and variably reimbursed. Guidelines from major societies remain cautious or inconclusive. Conclusions: PRP is a promising, safe, and well-tolerated option for early to moderate KOA. However, the standardization of preparation protocols, patient selection criteria, and outcome reporting is essential to improve comparability and guide clinical practice. Full article

Background/Objectives: The inconsistent clinical outcomes of platelet-rich plasma (PRP) therapy for knee osteoarthritis (KOA) highlight the need to elucidate PRP’s therapeutic potential and influencing factors. Real-world evidence can provide valuable insights in a broad patient population. This study aims to analyze real-world data from KOA patients treated with PRP. Methods: Real-world data from 86 KOA patients treated with intraosseous combined with intra-articular (IO + IA) PRP injections were utilized to retrospectively evaluate the long-term effectiveness of this procedure and the impact of PRP characteristics and patient variables on treatment response. Results: The WOMAC score was reduced 2 months after completing the treatment procedure. Such a reduction was sustained throughout the follow-up time points, up to 18 months. The percentage of responders was between 55 and 67%. The PRP erythrocyte and leukocyte counts negatively correlated with the change in WOMAC score (ΔWOMAC). The PRP platelet count did not correlate with the WOMAC or the ΔWOMAC scores. The KL severity degree did not affect the responsiveness to treatment. Women reported a higher WOMAC score than men, both before and 2 and 3 months after PRP treatment. However, the ΔWOMAC score was not different between sexes within this period. A negative correlation trend was detected between the patient’s age and the ΔWOMAC score. Conclusions: IO + IA PRP administration alleviated severe KOA symptoms with sustained relief for up to 18 months in most patients, potentially delaying the need for knee prostheses. The clinical efficacy was not influenced by narrow platelet dose variations but was negatively impacted by the leukocyte content in the long term, while sex and KOA severity had no influence. Full article

Effective local hemostasis is essential in oral surgery to prevent complications such as delayed healing, infection, and the need for re-intervention. Postoperative bleeding occurs in 4–6% of cases, increasing to 9–12% in patients receiving anticoagulant or antiplatelet therapy. This review evaluates the efficacy, safety, and clinical utility of local hemostatic agents based on 51 studies published between 1990 and 2023. Traditional agents, such as oxidized cellulose and gelatin sponges, control bleeding in over 85% of standard cases but offer limited regenerative benefits. Autologous platelet concentrates (APCs), including platelet-rich plasma (PRP) and leukocyte- and platelet-rich fibrin (L-PRF), reduce bleeding time by 30–50% and enhance soft tissue healing. Studies show the PRP may reduce postoperative bleeding in dental surgery by 30–50%, and in orthopedic and cardiac surgery by 10–30%, particularly in patients on anticoagulants. Tranexamic Acid mouthwash can reduce postoperative bleeding by up to 50–60%. Fibrin sealants achieve a 70–90% reduction in bleeding among high-risk patients, while topical tranexamic acid decreases hemorrhagic events by up to 80% in anticoagulated individuals without increasing thromboembolic risk. However, comparative studies remain limited, particularly in medically compromised populations. Additional gaps persist regarding long-term outcomes, cost-effectiveness, and the standardized use of emerging agents such as nanomaterials. Future research should prioritize high-quality trials across diverse patient groups and develop clinical guidelines that integrate both safety and regenerative outcomes. Full article

Background: This study aimed to investigate the effects of prostate tissue on platelet activation markers, primarily assessed through P-selectin expression, and to assess the formation of platelet–leukocyte aggregations in response to prostate tissue exposure. Furthermore, we compared platelet activation induced by prostate tissue homogenates with that induced by thrombin stimulation. These processes may play a role in the development of disseminated intravascular coagulation (DIC) following transurethral resection of the prostate (TURP). Methods: We collected prostate tissue samples from 12 patients undergoing TURP. The samples were homogenized and used to stimulate platelet-rich plasma in vitro. Flow cytometry was used to measure platelet P-selectin expression and platelet–leukocyte aggregation. Additionally, four experimental groups were established: (A) saline control, (B) thrombin stimulation, (C) phosphate-buffered saline (PBS) control, and (D) prostate tissue homogenate. Data were analyzed to assess the impact of prostate tissue and thrombin on platelet activation and platelet–leukocyte interactions. Results: Prostate tissue homogenates significantly increased platelet P-selectin expression and platelet–neutrophil aggregation compared with the control groups (p < 0.05). Overall, platelet–leukocyte aggregation was not significantly different between the thrombin and prostate tissue groups. However, prostate tissue exposure did not significantly affect platelet–monocyte and platelet–lymphocyte aggregations. Conclusions: Prostate tissue exposure during TURP induces platelet activation, particularly platelet P-selectin expression and platelet–neutrophil aggregation, suggesting a potential mechanism for DIC development. These findings highlight the importance of monitoring platelet activity in patients undergoing TURP and indicate that interventions targeting platelet P-selectin expression and platelet–neutrophil interactions may help mitigate DIC risk. Full article

(1) Background: Tendon and ligament injuries are a leading cause of lameness in horses, with significant economic implications. Platelet-rich plasma (PRP) has gained attention for its regenerative potential, but its efficacy remains uncertain due to inconsistent study designs and reporting. (2) Methods: This systematic review, following the PRISMA guidelines, evaluated 22 studies (clinical and experimental) to assess the safety and efficacy of PRP in treating equine tendon and ligament injuries. The risk of bias was analyzed using the ROBINS-I and RoB 2.0 tools. (3) Results: PRP demonstrated a favorable safety profile, with no severe adverse effects reported. Clinical outcomes included improved lameness scores, ultrasonographic tissue organization, and return-to-work rates. However, variability in PRP formulations (e.g., leukocyte-rich vs. leukocyte-reduced) and activation methods (e.g., calcium chloride, thrombin) contributed to inconsistent results. Experimental studies supported PRP’s role in collagen synthesis and neovascularization, but comparative trials with stem cells or other therapies (e.g., extracorporeal shockwave) showed mixed results. The methodological quality of studies varied, with only 27% achieving “good” scores for PRP reporting. (4) Conclusions: PRP is a safe and potentially effective treatment, but its clinical application is hindered by a lack of standardization. Future research should focus on large, randomized controlled trials with uniform PRP protocols, long-term (≥2 years) efficacy assessments, comparative studies with MSC combinations, and cost-effectiveness analyses. Full article

Platelet-rich plasma (PRP) therapy is increasingly recognized as a promising treatment for musculoskeletal disorders, including osteoarthritis (OA), tendinopathy, and muscle injuries. This narrative review synthesizes the current literature to evaluate the efficacy of PRP, with a focus on platelet dosing strategies, leukocyte composition, and preparation protocols. Evidence suggests that optimal therapeutic outcomes are achieved when platelet doses exceed 3.5 billion per injection, with cumulative doses of 10–12 billion across multiple treatments. In intra-articular applications, leukocyte-poor PRP (LP-PRP), characterized by reduced neutrophil content, demonstrates superior efficacy compared to leukocyte-rich PRP (LR-PRP). However, its effectiveness in tendon and muscle regeneration remains a subject of debate. Preliminary data suggest that the inclusion of peripheral blood mononuclear cells (PBMNCs) may enhance PRP efficacy, though robust clinical trials are required to confirm these findings. Furthermore, red blood cell contamination and pre-activation have been identified as detrimental to PRP effectiveness, highlighting the need for standardized preparation protocols. This review emphasizes the importance of tailoring PRP formulations to patient-specific factors and musculoskeletal conditions. Future research should focus on refining PRP preparation techniques, identifying optimal leukocyte compositions, and establishing standardized guidelines to enhance clinical outcomes. Full article

Injectable Platelet-Rich Fibrin (i-PRF) has emerged as a promising tool in regenerative medicine, particularly in orthopedics, due to its unique biological properties and ease of preparation. i-PRF is an autologous platelet concentrate derived through a simple, anticoagulant-free centrifugation process, resulting in a liquid matrix enriched with fibrin, leukocytes, and growth factors. These components promote tissue regeneration, angiogenesis, and anti-inflammatory responses, making i-PRF suitable for bone and cartilage repair as well as drug delivery systems. This review discusses the history, biological mechanisms, and clinical applications of i-PRF in orthopedics, highlighting its potential advantages over traditional platelet-rich plasma (PRP). Furthermore, we address the challenges and limitations of i-PRF, including drug stability, release control, and bioactive interactions, underscoring the need for further research to optimize its therapeutic efficacy. Full article

This study aimed to evaluate the effect of leukocyte and platelet-rich plasma (L-PRP) on the pulpal healing process following immediate and intentionally delayed tooth replantation in mice. After the maxillary first molars of 3-week-old mice were extracted, the teeth were immersed for 1 min [immediate reimplantation (IR)] or 30 min [intentionally delayed reimplantation (IDR)] in phosphate-buffered saline (PBS) solution. The alveolar socket was filled with or without 1.5 μL of L-PRP [experimental or control groups (EG or CG)] followed by tooth replantation. Samples were collected from day 1 to week 4 after the operation, processed for histology, and evaluated by immunohistochemistry for Nestin and Ki-67 expression. Quantitative analysis revealed positive Nestin staining during pulpal healing in the EG at week 1 following IR and week 2 following IDR. Hard tissue deposition was significantly increased in the EG after IR at week 2. Cell proliferation was higher in the EG compared with that in the CG at week 1 and significantly decreased in the coronal pulp of the EG after the IDR at week 2. Our data suggest that treatment with L-PRP may have a positive effect on pulpal healing, even in teeth replanted after an extended extra-oral period. Full article

Background: Aldehyde dehydrogenase class 1 (ALDH1) is an enzyme that is ubiquitously distributed in adult tissues and may serve as a prognostic marker in various cancer types. In blood, 99% of ALDH1 is found in erythrocytes; although, it was also demonstrated that leukocytes and platelets exhibit ALDH activity. No ALDH activity was detected in plasma, even when employing the highly sensitive fluorometric method with 7-methoxy-1-naphthaldehyde as a substrate. However, some reports have been released describing stable and measurable ALDH1 activity in the serum of healthy subjects using 6-methoxy-2-naphthaldehyde as a substrate and a Shimadzu RF—5301 spectrofluorometer. Methods: Our study aimed to verify whether ALDH1 activity can be measured in plasma or serum (n = 80) using 6-methoxy-2-naphthaldehyde as a substrate and a highly sensitive Hitachi F7000 spectrofluorometer, which offers a higher signal-to-noise ratio compared to the Shimadzu RF-5301. Additionally, HPLC with fluorometric detection was used to validate the results (n = 25) and analyze the influence of hemolysis (n = 5) and liver cell damage (n = 15) on ALDH1 activity in serum. Results: Measurable ALDH activity in serum/plasma was very rarely detected using a spectrofluorometer (2 cases out of 80). However, background drift in assays without coenzyme addition was observed, and it may be easily mistaken for ALDH or oxidase activity. Therefore, the spectrofluorometer drift observed in blank assays and modified by a matrix, e.g., enhanced in protein-rich samples, should be considered in ALDH1 activity assays. Conclusions: The spectrofluorometric method has limited applicability for determining ALDH activity in plasma and serum. HPLC can measure ALDH1 activity in plasma or serum; however, factors like hemolysis and elevated liver enzymes significantly affect activity and must be considered in diagnostic interpretations. To enhance research quality on ALDH1 as a biomarker for diseases, including cancers, we recommend using control samples, reference materials, and purifying commercially available aldehyde substrates to improve method sensitivity. Full article

Differences in cell count and growth factor expression between first- and second-generation autologous platelet concentrates (APCs) have been well described. The debate over which formula best supports wound healing in various surgical procedures is still ongoing. This study aims to assess the whole proteome assembly, cell content, immunological potential and pro-angiogenic potential of second-generation APC, Platelet-Rich Fibrin (PRF) vs. first-generation APC, Platelet-Rich Plasma (PRP). The global proteome of the APCs was analyzed using nano-liquid chromatography mass spectrometry. Blood cell concentrations were determined by an automated cell counter. The effect of APCs on macrophage polarization was analyzed by flow cytometry. A yolk sac membrane (YSM) assay was used to monitor the neo-vessel formation and capillary branching in vivo. Cell count analysis revealed a higher number/concentration of leukocytes in PRF vs. PRP. Incubation of macrophages with PRP or platelet-free plasma (PFP) did not induce a significant pro-inflammatory state but led to a shift to the M0/M2 phenotype as seen in wound healing for all tested formulas. Label-free proteomics analysis identified a total of 387 proteins from three biological replicates of the respective designated groups. PRF induced increased formation of neo-vessels and branching points in vivo in comparison to PRP and PFP (each p < 0.001), indicating the enhanced pro-angiogenic potential of PRF. Overall, PRF seems superior to PRP, an important representative of first-generation formulas. Inclusion of leucocytes in PRF compared to PRP suggested rather an anti-inflammatory effect on macrophages. These results are important to support the versatile clinical applications in regenerative medicine for second-generation autologous platelet concentrates to optimize wound healing. Full article

The buffy-coat, a layer of leukocytes and platelets obtained from peripheral blood centrifugation, plays a crucial role in tissue regeneration and the modulation of inflammatory responses. This article explores the mechanisms of regenerative inflammation, highlighting the critical role of the buffy-coat in influencing macrophage polarization and its therapeutic potential. Macrophage polarization into M1 and M2 subtypes is pivotal in balancing inflammation and tissue repair, with M1 macrophages driving pro-inflammatory responses and M2 macrophages promoting tissue healing and regeneration. The buffy-coat’s rich composition of progenitor cells, cytokines, and growth factors—such as interleukin-10, transforming growth factor-β, and monocyte colony-stimulating factor—supports the transition from M1 to M2 macrophages, enhancing tissue repair and the resolution of inflammation. This dynamic interaction between buffy-coat components and macrophages opens new avenues for therapeutic strategies aimed at improving tissue regeneration and managing inflammatory conditions, particularly in musculoskeletal diseases such as osteoarthritis. Furthermore, the use of buffy-coat-derived therapies in conjunction with other regenerative modalities, such as platelet-rich plasma, holds promise for more effective clinical outcomes. Full article

Radiotherapy is one of the risk factors for radiation-induced premature ovarian failure and infertility in cancer patients. The development of methods for ovarian radioprotection remains relevant. Moreover, electrons are a little-studied and promising method of radiation with the least toxic effect on normal tissues. The assessment of intracellular mechanisms regulating the protective effects of leukocyte-poor platelet-rich plasma in a model of radiation-induced premature ovarian failure caused by electron irradiation. Wistar rats were divided into four groups, namely a control group, irradiation group (electron exposure), irradiation + leukocyte-poor platelet-rich plasma group, and only leukocyte-poor platelet-rich plasma group. Fragments of ovaries were removed and hormonal, oxidant, histological, and morphometric studies were carried out. The cell cycle of ovarian follicles and the inflammatory and vascular response were assessed using immunohistochemistry. The activity of MAPK, ERK, and PI3K pathways was also assessed using the RT-qPCR. We found that electron irradiation causes a decrease in the functional activity of the ovaries and the death of follicular cells through apoptosis. The administration of LP-PRP led to a partial restoration of the cytokine balance. In addition, minor ovarian damage and mild inflammation were observed in this group. Leukocyte-poor platelet-rich plasma components have anti-inflammatory, angiogenetic, and radioprotective effects, reducing the activation of the NOX4, caspase and cytokine cascades, and inflammatory response severity through the MAPK/p38/JNK signaling pathway. This leads to the induction of endogenous antioxidant protection, the repair of post-radiation follicular damage, and slowing down the development of radiation-induced premature ovarian failure after electron irradiation. Full article

Osteoarthritis of the knee (OAK), a progressive degenerative disease affecting quality of life, is characterized by cartilage degeneration, synovial inflammation, and osteophyte formation causing pain and disability. Platelet-rich plasma (PRP) is an autologous blood product effective in reducing OAK-associated pain. PRP compositions depend on their purification. In clinical practice, PRP is typically administered immediately after purification, while cryopreserved PRP is used in research. Platelets are activated by freezing followed by release of their humoral factors. Therefore, PRP without any manipulation after purification (utPRP) and freeze–thawed PRP (fPRP) may differ in their properties. We purified leukocyte-poor PRP (LPPRP) and autologous protein solution (APS) to compare the properties of utPRPs and fPRPs and their effects on OAK target cells. We found significant differences in platelet activation and humoral factor content between utPRPs and fPRPs in both LPPRP and APS. Freeze–thawing affected the anti-inflammatory properties of LPPRP and APS in chondrocytes and synovial cells differed. Both utPRPs and fPRPs inhibited polarization toward M1 macrophages while promoting polarization toward M2 macrophages. Freeze–thawing specifically affected humoral factor production in macrophages, suggesting that evaluating the efficacy of PRPs requires considering PRP purification methods, properties, and conditions. Understanding these variations may enhance therapeutic application of PRPs in OAK. Full article

This observational study reports the process for the manufacture of RAPID^TM Biodynamic Haematogel and explores the properties of the platelet and leukocyte-rich plasma gels formed. Gels were manufactured from 60 mL of human blood using the protocol of Biotherapy Services. Platelet and leukocyte content, time-to-gel, gel weight and the temporal profile of liquid exudation from the gels were measured, along with the content of growth factors VEGF and PDGF in the releasate. The effect of the releasate on human keratinocyte (HaCat) cell proliferation was also determined. The platelet and leukocyte concentrations in donor blood were 1.60–8.10 × 10⁸ and 1.00 × 10⁶–2.00 × 10⁷ cells/mL, which were concentrated 2.67- and 1.12-fold, respectively, during processing. Structurally weak gels were formed which exuded a clear liquid releasate (77.4% w/w of gel weight over 60 min) that contained 278 pg/mL VEGF and 1319 pg/mL PDGF. The releasate produced concentration-dependent proliferation of HaCat cells: 5–15% releasate produced a 2.7–8.9-fold increase in growth over 48 h. In conclusion, we have described the point-of-care manufacturing protocol and characterised the gel properties of RAPID^TM Biodynamic Haematogel. This is an essential first step towards identifying, understanding and controlling critical processing parameters that impact on this medicinal product’s quality. Full article