Autologous platelet lysate local injections for the treatment of refractory lateral epicondylitis

Platelet lysate and tendon healing: comparative analysis of autologous frozen-thawed PRP and ketorolac tromethamine in the treatment of patients with rotator cuff tendinopathy

Platelet-rich blood derivatives are being nowadays increasingly used in the treatment of tendon-related pathologies as a rich source of growth factors. We sought to ascertain if local application of platelet lysate (PL) to augment rotator cuff repair ameliorates patient outcomes compared to ketorolac tromethamine treated group. A total of forty patients, with clinical diagnosis of Rotator Cuff Tendinopathy were randomized to receive sub acromial injections of PL every week for a total of 3 injections and two injection of ketorolac tromethamine once every two weeks. Subjective assessments included VAS, SPADI and shoulder range of motion were assessed at baseline and at 1 and 6 months after injection. Taking both control and PL groups, it was vividly seen that the outcomes were identical at the initial state, as well as the short-term one; whereas, when considering the 6-month period, there is a seemingly remarkable superiority in PL group in all parameters.

Effectiveness of Platelet-Rich Plasma for Lateral Epicondylitis: A Systematic Review and Meta-analysis Based on Achievement of Minimal Clinically Important Difference

Background:

The effectiveness of platelet-rich plasma (PRP) injection in the treatment of lateral epicondylitis remains debatable.

Purpose:

To evaluate the effectiveness of PRP in lateral epicondylitis treatment using minimal clinically important difference (MCID) values as a reference and to investigate if leukocyte content can influence the effectiveness of the therapy.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, the authors searched the Medline and Scopus databases for studies on lateral epicondylitis and PRP therapy that used the following patient-reported outcome measures (PROMs): visual analog scale (VAS) for pain; Disabilities of the Arm, Shoulder and Hand (DASH); Patient-Rated Tennis Elbow Evaluation (PRTEE); and Mayo Clinic Performance Index (MAYO). The weighted arithmetic means for the PROMs were calculated at baseline (week 0) and follow-up weeks 4, 8, 12, 24, 52, and 104. The mean differences in outcomes (ΔVAS, ΔDASH, ΔPRTEE, and ΔMAYO) were compared with the MCID values at each follow-up point. In addition, the effectiveness of leukocyte-rich PRP (LR-PRP) versus leukocyte-poor PRP (LP-PRP) was also compared. The Student t test was used in all analyses.

Results:

A total of 26 studies were included in the analysis. After PRP injection, all PROM scores improved with time. The scores improved significantly from baseline to each follow-up time ( P < .0001), with the exception of the PRTEE (no significant difference at follow-up weeks 12 and 52). The mean difference in scores from baseline exceeded the respective MCIDs from weeks 4 to 104 for the VAS and DASH, from weeks 4 to 52 for the MAYO, and from weeks 8 to 52 for the PRTEE. The MCID for each of the PROMs was exceeded at almost every observation period in both the LR-PRP and the LP-PRP systems.

Conclusion:

Based on comparisons with the MCID values of commonly used outcome scores, PRP seems to be an effective form of treatment for lateral epicondylitis. Both the LR- PRP and the LP- PRP systems were effective in the context of meeting the MCID.

Persistent Abnormal Immunocytes Induced Systemic Bone Loss in Locally Irradiated Rats

Chronic and systemic bone complications frequently occur in patients who undergo radiotherapy; however, the pathological mechanisms underlying these complications remain unclear. This study aimed to observe persistent and systemic changes in locally irradiated rats and to determine the systemic pathological changes that persistently affect bone metabolism. We examined the inflammatory and oxidative stress responses that occurred after local irradiation using enzyme immunoassays and biochemical analyses. Lymphocytes obtained from the blood, spleen, thymus, and bone marrow were evaluated using flow cytometry. The proliferation and apoptosis characteristics of co-cultured bone marrow-derived mesenchymal stem cells (BMSCs) were detected by MTT assay and PI/Annexin V-FITC staining, respectively, and the differentiation of BMSCs was measured according to alkaline phosphatase (ALP) staining, alizarin red staining, and Oil Red O staining and by evaluating the mRNA expression of ALP, osteocalcin (OCN), osteopontin (OPN), collagen I, Runx2, and PPARγ. Our results revealed that no significant or continuous differences were present in the inflammatory response or the oxidative stress response throughout the body after local irradiation. B lymphocyte levels increased continuously in the blood, spleen, and bone marrow after local irradiation. T lymphocyte levels were decreased at 2 weeks after local irradiation, and CD8⁺T lymphocyte levels were increased in the blood, thymus, and bone marrow at 12 weeks after local irradiation. The ratio of CD4⁺/CD8⁺T lymphocytes began to decrease during the early phase after local irradiation and became significantly decreased at 12 weeks after local irradiation. Normal BMSCs co-cultured with lymphocytes derived from irradiated rats exhibited decreased proliferation and increased apoptosis, and the ALP staining intensity, alizarin red staining intensity, and mRNA expression of related genes were all also decreased. Oil Red O staining intensity and mRNA expression of PPARγ were both increased. Lymphocyte levels contribute to chronic and systemic bone complications after radiotherapy by inhibiting the proliferation and osteoblastogenesis of BMSCs.

Human platelet lysate - A potent (and overlooked) orthobiologic

The knowledge of the essential role of platelets in tissue healing is gradually increasing and as regenerative medicine prompts new solutions, platelet-derived bioproducts have been proposed as a potential tool in this field. In orthopaedics and sports medicine, the use of PRP has been rapidly increasing in popularity as patients seek novel non-surgical approaches to acute and chronic musculoskeletal conditions. The concept of having platelets as a secretory organ other than a mere sponge-like coagulation component opens up new frontiers for the use of the platelet secretome. Platelet lysate is a solution saturated by growth factors, proteins, cytokines, and chemokines involved in crucial healing processes and is administered to treat different diseases such as alopecia, oral mucositis, radicular pain, osteoarthritis, and cartilage and tendon disorders. For this purpose, the abundant presence of growth factors and chemokines stored in platelet granules can be naturally released by different strategies, mostly through lyophilization, thrombin activation or ultrasound baths (ultrasonication). As a result, human platelet lysate can be produced and applied as a pure orthobiologic. This review outlines the current knowledge about human platelet lysate as a powerful adjuvant in the orthobiological use for the treatment of musculoskeletal injuries, without however failing to raise some of its most applicable basic science.

Super Activated Platelet Lysate, a Novel Autologous Platelet Lysate, Regulates the Expression of Inflammasome and Cytokine in the Experimental Periodontitis in Rats

Purpose

The aim of the present study was to evaluate the expression of inflammasome and cytokine on experimental periodontitis with super activated platelet lysate (SPL) in rats.

Methods

Periodontitis was induced by submerging cotton ligatures on the right side of the maxillary second molar in 36 Wistar rats. The rats were divided into 3 groups randomly: the rats received no treatment (control group); local injection with sterile saline (ligature+saline group) and local injection with SPL (ligature+SPL group). After treatments, the alveolar bone level and inflammation of periodontal tissue were evaluated by micro-computed tomography (micro-CT) scanning and histological examination, respectively. The expression of inflammasome and cytokine was evaluated by real-time quantitative polymerase chain reaction (RT-qPCR) assay.

Results

Compared with the control group, the bone loss significantly increased by 0.9 mm in the ligature+saline group and 0.4 mm in the ligature+SPL group (P < 0.001). 0.5 mm reduction in the bone loss was founded in the ligature+SPL group compared with the ligature+saline group (P < 0.001). The gene expression of CCL2, CXCL2, IL-6, IL-18, IL-1α, IL-1β, CXCL10, CXCL16, CCL5 was significantly reduced in the ligature+SPL group compared with the ligature+saline group (P < 0.05). Compared with the ligature+saline group, the expression for inflammasome NLRP3, AIM2, CASP1 was both downregulated in the ligature+SPL group (P < 0.05).

Conclusion

Our present study demonstrated local injection of SPL regulated the expression of inflammasome and cytokine and had a visible effect of relieving inflammation in the experimental periodontitis in rats.

Washed Equine Platelet Extract as an Anti-Inflammatory Biologic Pharmaceutical

Mammalian platelets participate in the immediate tissue injury response by initiating coagulation and further promoting tissue injury mitigation and repair. The latter properties are deployed following platelet release of presynthetized morphogens, cytokines, and growth and chemotactic factors, which launch a tissue regenerative, angiogenic, and anti-inflammatory program. Several blood-derived biologic products, like platelet-rich plasma (PRP) and platelet lysate (PL), are currently on the market to allow proper healing and tissue regeneration. However, not all growth factors are released from the platelets and the final products contain plasma proteins such as albumin, fibrinogen, complement, and immunoglobulins, increasing the risks of serum sickness or allergic reaction. To address this problem, we developed a new platelet extract where equine blood platelets are concentrated, washed, and thereafter lysed by detergent Triton X-114. Distinct from PRP, this extract is devoid of albumin, fibrinogen, and immunoglobulins and is 266-fold enriched in platelet-derived growth factor content relative to PRP. Washed equine platelet extract (WEPLEX) is amenable to lyophilization without loss of biological activity. In vitro, WEPLEX significantly inhibits human and equine T cell proliferative response to phytohemagglutinin and also polarizes murine CD45⁺/CD11b⁺ peritoneal macrophages to an IL-10⁺ M2-like phenotype. In vivo, WEPLEX substantially improves clinical outcome of murine experimental dextran sulfate sodium colitis. We propose that equine-sourced, zoonosis-free WEPLEX may serve as an anti-inflammatory biological therapy across mammalian species.

Novel therapeutic approaches in utilizing platelet lysate in regenerative medicine: Are we ready for clinical use?

Hemoderivative materials are used to treat different diseases. These derivatives include platelet-rich plasma, serum, platelet gel, and platelet lysate (PL). Among them, PL contains more growth factors than the others and its production is inexpensive and easy. PL is one of the proper sources of platelet release factors. It is used in cells growth and proliferation and is a good alternative to fetal bovine serum. In recent years, the clinical use of PL has gained more appeal by scientists. PL is a solution saturated by growth factors, proteins, cytokines, and chemokines and is administered to treat different diseases such as wound healing, bone regeneration, alopecia, oral mucositis, radicular pain, osteoarthritis, and ocular diseases. In addition, it can be used in cell culture for cell therapy and tissue transplantation purposes. Platelet-derived growth factor, fibroblast growth factor, insulin-like growth factor, transforming growth factor β, and vascular endothelial growth factor are key PL growth factors playing a major role in cell proliferation, wound healing, and angiogenesis. In this paper, we scrutinized recent advances in using PL and PL-derived growth factors to treat diseases and in regenerative medicine, and the ability to replace PL with other hemoderivative materials.

Injectable and tunable hyaluronic acid hydrogels releasing chemotactic and angiogenic growth factors for endodontic regeneration

Bioengineered soft tissues on any meaningful scale or complexity must incorporate aspects of the functional tissue, namely a vasculature, providing cells oxygen and nutrients critical for their survival. However, the ability of tissue engineering strategies to promote a fast revascularization is critically limited. Particularly in endodontic regenerative therapies, the complicated anatomy of the root canal system, and the narrow apical access limit the supply of new blood vessels and pulp tissue ingrowth. Here we characterize the viscoelastic and microstructural properties of a class of injectable hyaluronic acid (HA) hydrogels formed in situ, reinforced with cellulose nanocrystals (CNCs) and enriched with platelet lysate (PL), and test its ability to promote cells recruitment and proangiogenic activity in vitro. The incorporation of CNCs enhanced the stability of the materials against hydrolytic and enzymatic degradation. Moreover, the release of the chemotactic and pro-angiogenic growth factors (GFs) (PDGF and VEGF) from the PL-laden hydrogels showed an improved sustained profile proportional to the amount of incorporated CNCs. The PL-laden hydrogels exhibited preferential supportive properties of encapsulated human dental pulp cells (hDPCs) in in vitro culture conditions. Finally, PL-laden hydrogels stimulated chemotactic and pro-angiogenic activity by promoting hDPCs recruitment and cell sprouting in hDPCs/human umbilical vein endothelial cell co-cultures in vitro, and in an ex vivo model. These results support the use of the combined system as a scaffold for GFs delivery and cells recruitment, thereby exhibiting great clinical potential in treating injuries in vascularized tissues.

STATEMENT OF SIGNIFICANCE

Innovative strategies for improved chemotactic and pro-angiogenic features of TE constructs are needed. In this study, we developed an injectable HA/CNC/PL hydrogel with improved structural and biologic properties, that not only provide a sustained release of chemotactic and proangiogenic GFs from PL but also enhance the cells' viability and angiogenic activity. As a result of their unique traits, the developed hydrogels are ideally suited to simultaneously act as a GFs controlled delivery system and as a supportive matrix for cell culture, recruitment, and revascularization induction, holding great potential for the regeneration of vascularized soft tissues, such as the dentin-pulp complex.

Platelet-rich plasma in tendon-related disorders: results and indications

PURPOSE

Platelet-rich plasma (PRP) is currently the most exploited strategy in the clinical practice to provide a regenerative stimulus for tendon healing. The aim of the present study was to systematically review the available evidence on the treatment of the main tendon disorders where PRP is currently applied.

METHODS

A systematic review of the literature was performed on the use of PRP as a treatment for tendinopathies focusing on the following sites: Achilles tendon, patellar tendon, rotator cuff tendons, and lateral elbow tendons. The following inclusion criteria for relevant articles were used: clinical trials written in English language up to 21 June 2016 on the use of PRP in the conservative or surgical treatment of the aforementioned tendinopathies.

RESULTS

The research identified the following clinical trials dealing with the application of PRP in the selected tendons: 19 papers on patellar tendon (6 being RCTs: 4 dealing with PRP conservative application and 2 surgical), 24 papers on Achilles tendon (4 RCTs: 3 conservative and 1 surgical), 29 on lateral elbow tendons (17 RCTs, all conservative), and 32 on rotator cuff (22 RCTs: 18 surgical and 3 conservative).

CONCLUSION

Patellar tendons seem to benefit from PRP injections, whereas in the Achilles tendon, PRP application is not indicated neither as a conservative approach nor as a surgical augmentation. Lateral elbow tendinopathy showed an improvement in most of the high-level studies, but the lack of proven superiority with respect to the more simple whole-blood injections still questions its use in the clinical practice. With regard to rotator cuff pathology, the vast majority of surgical RCTs documented a lack of beneficial effects, whereas there is still inconclusive evidence concerning its conservative application in rotator cuff disorders.

LEVEL OF EVIDENCE

Systematic review of level I-IV trials, Level IV.

Platelet-Rich Plasma Injection With Percutaneous Needling for Recalcitrant Lateral Epicondylitis: Comparison of Tenotomy and Fenestration Techniques

Background

Recalcitrant lateral epicondylitis (LE) is a common debilitating condition, with numerous treatment options of varying success. An injection of platelet-rich plasma (PRP) has been shown to improve LE, although it is unclear whether the method of needling used in conjunction with a PRP injection is of clinical importance.

Purpose

To determine whether percutaneous needle tenotomy is superior to percutaneous needle fenestration when each is combined with a PRP injection for the treatment of recalcitrant LE.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 93 patients with recalcitrant LE were treated with a PRP injection and percutaneous needle fenestration (n = 45) or percutaneous needle tenotomy (n = 48) over a 5-year study interval. Preoperative patient data, including visual analog scale for pain (VAS-P), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), and Patient-Rated Tennis Elbow Evaluation (PRTEE) scores and grip strength, were obtained from a chart review and compared with postoperative values obtained prospectively. Secondary outcomes included the incidence of complications, need for additional interventions, return to work, and patient satisfaction.

Results

At a mean follow-up of 40 months, significant improvements in VAS-P (mean, -6.1; 95% CI, -6.8 to -5.5; P < .0001), QuickDASH (mean, -46; 95% CI, -52 to -40; P < .0001), and PRTEE (mean, -57; 95% CI, -64 to -50; P < .0001) scores and grip strength (mean, +6.1 kg; 95% CI, 4.9 to 7.3; P < .0001) were observed across the entire study cohort, with no significant differences noted between the fenestration and tenotomy groups. Nine of 45 patients (22%) underwent additional procedures to treat recurrent symptoms in the fenestration group compared with 5 of 48 patients (10%) in the tenotomy group (P = .05). No complications occurred in any patients, and no patients expressed dissatisfaction with their treatment course.

Conclusion

A PRP injection with concomitant percutaneous needling is an effective treatment for recalcitrant LE, with sustained improvements in pain, strength, and function demonstrated at a mean follow-up of longer than 3 years. Although the method of concomitant needling does not appear to have a significant effect on treatment outcomes, more aggressive needle tenotomy is less likely to require conversion to open tenotomy than needle fenestration in the short term to midterm.

Optimisation of platelet concentrates therapy: Composition, localisation, and duration of action

Platelet concentrates (PC) generally refers to a group of products that are prepared from autologous blood intended to enhance healing activities. PC therapy is now very popular in treating musculoskeletal injuries; however, inconsistent clinical results urge the need to understand the working mechanism of PC. It is generally believed that the platelet-derived bioactive factors are the active constituents, and their bioavailability in the vicinity of the lesion sites determines the treatment efficacies. Therefore, the composition, localisation, and duration of the action of PC would be key determinants. In this review, we discuss how different preparations and delivery methods of PC would affect the treatment outcomes with respect to clinical evidence about PC therapy for osteoarthritis, tendinopathies, rotator cuff tears, anterior cruciate ligament injuries, and bone fractures. This review can be used as a quick guide for the use of PC therapy and provide insights for the further optimisation of the therapy in the near future.