Platelet-released growth factors enhance the secretion of hyaluronic acid and induce hepatocyte growth factor production by synovial fibroblasts from arthritic patients

Clinical Outcome of Multiple Platelet-Rich Plasma Injection and Correlation with PDGF-BB in the Treatment of Knee Osteoarthritis

(1) Background: Current treatments for knee osteoarthritis (KOA), such as intra-articular corticosteroids or hyaluronic acid (HA) injections, are controversial due to their ineffectiveness in preventing disease progression. Platelet-rich plasma (PRP) has become a promising and possible treatment for KOA. It is thought to enhance articular cartilage regeneration and reduce OA-related impairment. PRP contains growth factors such as PDGF-BB, which stimulates growth and inhibits joint damage. Based on numerous studies, after a certain amount of time, it was found that multiple PRP treatments reduced pain more than a single injection. This study evaluates the efficacy of multiple PRP (m-PRP) injections compared to multiple HA (m-HA) injections for KOA treatment, focusing on their correlation with PDGF-BB levels. (2) Methods: In this single-center, open-label, randomized, comparative clinical trial, 30 KOA patients received m-PRP and m-HA injections. VAS and WOMAC were used to evaluate clinical outcomes and PDGF-BB concentrations. (3) Results: The study analysis revealed a statistically significant reduction in pain indices. In both the m-PRP and m-HA groups after 12 weeks, m-PRP showed superior results. PDGF-BB concentrations also increased, with a strong negative correlation and statistical significance using Spearman's rho. (4) Conclusions: Multiple PRP injections are safe and associated with elevated PDGF-BB, reduced VAS and WOMAC scores, providing the potential for articular cartilage regeneration and inhibiting knee osteoarthritis progression.

Efficacy and Safety of Platelet-Rich Plasma Injection for Chronic Plantar Fasciitis: A Prospective Study on Functional Restoration and Pain Relief

Background Heel discomfort and functional impairment are frequently caused by plantar fasciitis, and treating it can be extremely difficult for clinicians and occasionally have unfavorable clinical consequences. Recently, platelet-rich plasma (PRP) has been used as an alternative therapy for plantar fasciitis (PF) to reduce heel pain and improve functional restoration. We evaluated the current evidence concerning the efficacy and safety of PRP as a treatment for PF. Methodology This was a hospital-based prospective study on patients with plantar fasciitis with a symptom duration of six months or more with failed conservative therapy. All patients included in the study were assessed clinically and by a visual analog score (VAS) for heel pain, the Ankle-Hindfoot Scale (AHS) component of the American Orthopedic Foot and Ankle Society (AOFAS) and Foot and Ankle Ability Measure (FAAM) scores before injection, and at three weeks, three and six-months post-PRP treatment follow-up. Ultrasonography (USG) measurement of plantar fascia thickness was done pre-injection and at the six-month follow-up for clinical outcomes and any complications. Results The study included 25 patients with plantar fasciitis, with the majority (48%) in the age group of 21-30 years. Females accounted for 64% of the patients while males accounted for 36%. Most patients (56%) had a moderately active daily activity level. The study found that 16 patients had bilateral plantar fasciitis while nine had unilateral plantar fasciitis. Among the patients with bilateral plantar fasciitis, a total of 32 heels were affected while the 9 patients with unilateral plantar fasciitis had 9 affected heels. Most female patients (75%) had bilateral plantar fasciitis while most male patients (56%) had unilateral plantar fasciitis. Before PRP therapy, both male and female patients reported high pain scores on the VAS for both heels. However, after PRP infiltration, the VAS scores significantly decreased at three weeks, three months, and six months post-injection, indicating pain relief. The AOFAS hindfoot and ankle scores and FAAM scores showed improvement over the follow-up period. Both male and female patients experienced significant improvements in functional outcomes, with increases in AOFAS (p-value 0.45) and FAAM scores (p-value 0.31) at three weeks, three months, and six months post-injection compared to baseline. Statistical analysis revealed a significant decrease in pain scores (73% pain relief), as well as significant improvements in AOFAS scores with an average of 22.33 from baseline (mean = 67.75±9.7) to final follow-up (mean = 90.08±7.9) and FAAM scores with an average of 23.72 from baseline (mean = 49.38±5.2) to final follow-up (mean = 73.10±5.2) after PRP infiltration. Conclusion The outcomes of a single dosage of PRP injections demonstrate clinically and statistically substantial improvements in functional outcome scores, plantar fascia thickness evaluated by USG, and VAS scores for heel pain. According to the results of this study, local PRP injection is an effective treatment for chronic plantar fasciitis.

Does Platelet-Rich Plasma Promote Facial Rejuvenation? Revising the Latest Evidence in a Narrative Review

Facial aging is characterized by progressive macroscopic, histological, and molecular changes. Due to its regenerative and rejuvenating properties, the use of platelet-rich plasma (PRP) as a facial antiaging agent has gained popularity over the last decade. In order to gather and evaluate the latest evidence focusing on the effect of PRP on facial skin rejuvenating, a search through MEDLINE (PubMed) using relevant keywords, inclusion, and exclusion criteria was performed. A total of 539 articles were initially retrieved, and from those, 16 were included in the review. Treatment protocols comprised the use of PRP both in monotherapy and in combination with other substances and by means of direct injection or topical application following skin permeation. The selected studies presented high variability regarding PRP preparation methods, administration protocols, and results assessment. In most studies, PRP seemed to improve to some degree the signs of facial aging, such has wrinkles, skin quality, and pigmentation, accompanied by significant histological and molecular responses. Optimizing treatment protocols should be the next step in assessing the full potential of PRP.

Intraarticular management of chronic haemophilic arthropathy (Review)

Hemophilia is an inherited X-linked bleeding condition with predominant joint involvement due to intra-articular bleeding, hemosiderin deposition and the synovial hypertrophy that is responsible for cartilage destruction, joint deformity and malalignment, pain and functional restriction. Management of chronic arthropathy includes conservative and surgical approaches. Conservative therapies consist of pain modulation, oral drugs, physiotherapy and intra-articular agents. For the present review, the literature was searched for intra-articular agents and 20 papers on the use of corticosteroids (CS), hyaluronic acid (HA) and platelet-rich plasma (PRP), with different regimes of administration, were included. CS had a longer record of injection, with statistically significant pain reduction and functional improvement in the short-term and moderate persistence in the long-term. HA was able to improve the clinical and functional status of joints with moderate or severe hemophilia. PRP was relatively recently introduced to joint management and the results remain controversial. Different associations between the above-mentioned agents were proposed by studies including a small number of patients, producing comparable results. It was concluded that there is a need for extensive research on intra-articular agents, with stratification according to the severity of joint involvement. The lack of a blinded or placebo-controlled arm due to ethical aspects makes the task challenging.

The Effects of the Combination of Rhein and Platelet-Rich Plasma on Human Articular Chondrocytes

BACKGROUND

The presence of side effects and low bioavailability of rhein has limited its use in the treatment of osteoarthritis. We aimed to evaluate the in vitro response of human articular chondrocytes to the presence of the combination of platelet-rich plasma (PRP) and rhein.

METHODS

Solutions of rhein were prepared to assess solubility and select a working concentration. A stimulus with interleukin-1β (IL-β, 10 ng/mL) was induced for 24 h on human chondrocytes. Five treatment groups were established: control, IL-β control, PRP, rhein, and PRP + rhein. Cell viability, cell migration, nitric oxide (NO) production, tumor necrosis factor-α (TNF-α), and gene expression analyses were carried out.

RESULTS

A concentration of 50 mg/L was selected after a dose-response curve assay. Both NO and tumor TNF-α production significantly decreased after PRP and PRP + rhein treatments at 24 and 48 h. The wound healing assay revealed a significant stimulation of migration after 72 h with the PRP and PRP + rhein treatments. Expression of IL-1β, IL-6, MMP-13, and ADAMTS-5 was significantly downregulated, particularly after treatment with the combination of PRP + rhein.

CONCLUSIONS

Much of the determinations denoted a better performance of the combination of PRP and rhein in decreasing the levels of the different targets evaluated; however, this was not great enough to detect a significant difference in comparison with the PRP treatment alone.

Safety and efficacy of intra-articular injection of platelet-rich plasma for the treatment of ankle osteoarthritis: a systematic review and meta-analysis

PURPOSE

To evaluate the safety and efficacy of platelet-rich plasma (PRP) intra-articular injective treatments for ankle osteoarthritis (OA).

METHODS

A systematic literature search was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in PubMed, Scopus, Embase, Google Scholar, and the Cochrane library until May 2022. Both randomized and non-randomized studies were included with the assessment of the risk of bias. We recorded the participant's age, gender, type of PRP, injection volume, the kit used, and activating agent. We subsequently assessed the short-term and long-term efficacy of PRP using the functional scores and visual analog scale (VAS).

RESULTS

We included four studies with a total of 127 patients, with a mean age of 56.1 years. 47.2% were male (60/127), according to eligibility criteria. There were three cohort studies and one randomized controlled trial (RCT) study, and no study reported severe adverse events. All included studies used the Leukocyte-poor PRP. Short-term follow-up results suggested significant improvement of the American Orthopaedic Foot and Ankle Society (AOFAS) score in the PRP injection group compared to the control group (n = 87 patients; MD: 6.94 [95% CI: 3.59, 10.29]; P < 0.01). Consistently, there was a statistical difference in AOFAS score between PRP injection and control groups in the final follow-up (≥ 6 months) (n = 87 patients; MD: 9.63 [95% CI: 6.31, 12.94]; P < 0.01). Furthermore, we found a significant reduction in VAS scores in the PRP groups at both the short-term follow-up (n = 59 patients; MD, - 1.90 [95% CI, - 2.54, - 1.26]; P < 0.01) and the ≥ six months follow-up (n = 79 patients; MD, - 3.07 [95% CI, - 5.08, - 1.05]; P < 0.01). The improvement of AOFAS and VAS scores at ≥ six months follow-up reached the minimal clinically important difference (MCID). Nevertheless, the treatment effect of AOFAS and VAS scores offered by PRP at short-term follow-up did not exceed the MCID. Substantial heterogeneity was reported at the ≥ six months follow-up in VAS scores (I2: 93%, P < 0.01).

CONCLUSION

This meta-analysis supports the safety of PRP intra-articular injection for ankle OA. The improvements of AOFAS and VAS scores in the PRP group at short-term follow-up do not exceed the MCID to be clinically significant. PRP injection provides significant improvement of AOFAS score and reduced pain at ≥ six months follow-up. The efficacy of PRP should be interpreted with caution regarding the high heterogeneity and the scarcity of available literature, which urges large-scale RCTs with longer follow-up to confirm the potential efficacy of PRP injection for ankle OA.

Efficacy of the combination therapy of platelet-rich plasma and hyaluronic acid on improving knee pain and dysfunction in patients with moderate-to-severe KOA: a protocol for a randomised controlled trial

INTRODUCTION

54% of patients with moderate-to-severe knee osteoarthritis (KOA) still reported persistent pain and functional loss after conservative treatment according to guidelines. As an emerging treatment, platelet-rich plasma (PRP) has been proven to significantly relieve pain and improve activity function in patients with mild-to-moderate KOA, either used alone or in combination with hyaluronic acid (HA). However, it is still unclear of its efficacy in moderate-to-severe KOA. This study aims to evaluate the clinical efficacy of PRP and the combination therapy of PRP and HA in patients with moderate-to-severe KOA and to explore the potential synergistic effect of PRP and HA.

METHODS AND ANALYSIS

This triple-blind randomised controlled trial will involve a total of 162 participants with moderate-to-severe KOA from two study centres. Participants will be allocated randomly into three groups: the HA group, the PRP group and the combination (PRP+HA) group and, respectively, receive HA (2.5 mL)+saline (3 mL)/PRP (3 mL)+saline (2.5 mL)/PRP (3 mL)+HA (2.5 mL) intra-articular injection each week for 4 consecutive weeks. All of the injections will be performed under the guidance of ultrasound. The primary outcome is the change of Western Ontario and McMaster Universities Osteoarthritis Index from baseline to 6 months, and secondary outcomes include the change of ultrasound images (suprapatellar bursa effusion and synovitis), Timed Up and Go test and 12-Item Short-Form Health Survey. All outcomes will be evaluated at baseline and 1-month, 3-month and 6-month follow-ups. Data will be analysed on intention-to-treat principles and a per-protocol basis.

ETHICS AND DISSEMINATION

This protocol was approved by the Medical Ethics Committee of the Third Affiliated Hospital of Sun Yat-sen University (reference number (2021)-02-231-02). The study results will be submitted to a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ChiCTR2100050974.

Regenerative methods in osteoarthritis

Osteoarthritis (OA) is the most common type of arthritis that can affect all joint structures. The primary goals of osteoarthritis treatment are to alleviate pain, reduce functional limitations, and improve quality of life. Despite its high prevalence, treatment options for osteoarthritis are limited, with most therapeutic approaches focusing on symptom management. Tissue engineering and regenerative strategies based on biomaterials, cells, and other bioactive molecules have emerged as viable options for osteoarthritis cartilage repair. Platelet-rich plasma (PRP) and mesenchymal stem cells (MSCs) are the most commonly used regenerative therapies today to protect, restore, or increase the function of damaged tissues. Despite promising results, there is conflicting evidence regarding the efficacy of regenerative therapies, and their efficacy remains unknown. The data suggest that more research and standardization are required for the use of these therapies in osteoarthritis. This article provides an overview of the application of MSCs and PRP applications.

Autologous Fat and Platelet-Rich Plasma Injections in Trapeziometacarpal Osteoarthritis: A Systematic Review and Meta-Analysis

BACKGROUND

For the treatment of carpometacarpal arthritis of the thumb, various therapies are used. Infiltration therapy with autologous substances such as platelet-rich plasma and autologous fat have recently gained increasing attention because of beneficial pain-reducing effects in arthritis and the associated regenerative potential. However, the extent of clinical evidence in this area and how well autologous substances work in terms of pain reduction and improvements in hand function remain unclear.

METHODS

A systematic review and meta-analysis were conducted to evaluate the current evidence and to provide more insight into pain reduction and improvement in hand function after infiltration of autologous substances. The authors identified 11 clinical trials, of which we included eight in the meta-analysis.

RESULTS

Autologous substances achieved a good and long-lasting pain reduction, which may also be accompanied by corresponding improvement in hand function. Autologous substances appear to be more effective than corticoid infiltrations. The infiltration of autologous fat seems to be particularly promising in more advanced stages of carpometacarpal arthritis of the thumb. Our meta-analysis showed a mean pain reduction of 2.4 to 3 in visual analogue scale score and a reduction of 18 to 19 points in the Disabilities of the Arm, Shoulder, and Hand questionnaire after infiltration with autologous substances.

CONCLUSION

Both platelet-rich plasma and autologous fat infiltration offer an efficient and long-lasting, minimally invasive therapy option in the treatment of carpometacarpal arthritis of the thumb.

Autologous platelet concentrates for facial rejuvenation

Autologous platelet concentrates (APCs) are promising therapeutic agents in facial rejuvenation since they are a great source of cytokines, growth factors and other biologically active substances. Obtained from the patient’s blood, they have the advantages of reducing immunological reactions, making the procedure safer, well tolerated, with minimal adverse effects and lower cost. Currently, they are used for facial rejuvenation both in combination with microneedling and in mesotherapy techniques, as well as to treat facial acne scars, melasma and wounds after laser ablative treatments. This review summarizes current knowledge on the use of APCs, ranging from basic concepts related to their composition and mechanisms of action to up-to-date information on their clinical efficacy.

Swiss Medical Devices for Autologous Regenerative Medicine: From Innovation to Clinical Validation

Regenerative medicine, based on the use of autologous tissues and embryonic, stem or differentiated cells, is gaining growing interest. However, their preparation, in a manner compliant with good practices and health regulations, is a technical challenge. The aim of this manuscript is to present the design of reliable CE marked medical devices for the preparation of standardized platelet-rich plasma (PRP) and other autologous biologics intended for therapeutic uses. There are numerous PRP isolation processes. Depending on the methodology used, PRP composition varies greatly in terms of platelet concentration, platelet quality, and level of contamination with red and white blood cells. This variability in PRP composition might affect the clinical outcomes. The devices presented here are based on a specific technology, patented all over the world, that allows the precise separation of blood components as a function of their density using thixotropic separator gels in closed systems. This allows the preparation, in an automated manner, of leukocyte poor PRP with a standardized composition. Production of different forms of PRP is a clinical asset to suit various therapeutic needs. Therefore, we are offering solutions to prepare PRP either in liquid or gel form, and PRP combined with hyaluronic acid. These biologics have been successfully used in many different therapeutic domains, resulting in more than 150 published clinical studies. We also developed the CuteCell technology platform for cell culture expansion for further autologous cell therapies. This technology enables the safe and rapid in vitro expansion of cells intended for therapeutic use in good manufacturing practices (GMP) and autologous conditions, using blood-derived products as culture media supplementation. We summarize in this article our 20 years’ experience of research and development for the design of PRP devices and, more recently, for PRP combined with hyaluronic acid.

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

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

Efficacy of a Novel Intra-Articular Administration of Platelet-Rich Plasma One-Week Prior to Hyaluronic Acid versus Platelet-Rich Plasma Alone in Knee Osteoarthritis: A Prospective, Randomized, Double-Blind, Controlled Trial

Recent studies have suggested that the combined injection of platelet-rich plasma (PRP) and hyaluronic acid (HA) may have additive benefits for knee osteoarthritis over PRP alone, but there is insufficient evidence to support this combined injection. Moreover, the simultaneous injection of PRP and HA may offset the combined effect. Hence, the aim of this prospective, randomized, double-blind study was to assess their combined efficacy with a novel injection protocol. Forty-six study subjects with unilateral knee osteoarthritis were randomized to receive either a single-dose injection of HA (intervention group) or normal saline (control group) 1 week after a single-dose injection of leukocyte-poor PRP. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and static balance and the risk of falls measured by Biodex Balance System were, respectively, the primary and secondary outcome measures. Evaluations were performed at baseline, 1 month, 3 months, 6 months, and 12 months post-injection. The intervention group exhibited significant declines in WOMAC pain, stiffness, and total scores, as well as static balance, compared to the control group (p < 0.05). These randomized double-blind control trials, with novel protocol of intra-articular injection of PRP 1-week prior to HA, provide greater symptom relief and improve static balance compared to PRP alone in patients with knee osteoarthritis.

Regenerative Effect of Low-Intensity Pulsed Ultrasound and Platelet-Rich Plasma on the Joint Friction and Biomechanical Properties of Cartilage: A Non-traumatic Osteoarthritis Model in the Guinea Pig

This study was aimed at investigating the effects of platelet-rich plasma (PRP) and low-intensity pulsed ultrasound (LIPUS) on the joint friction parameters and biomechanical properties of articular cartilage in a non-traumatic knee osteoarthritis (OA) model. Fifty adult male Dunkin Hartley guinea pigs were randomly divided into five groups: control, OA60, OA + US, OA + PRP and OA + US + PRP). Non-traumatic knee OA was induced with a single dose of 3 mg of mono-iodoacetate (MIA) by intra-articular injection. Intra-articular PRP was injected twice in the OA + PRP and OA + US + PRP groups. LIPUS was delivered in 10 sessions in the OA + US and OA + US + PRP groups. By use of the pendulum free oscillation test, joint friction (coefficient of friction) was measured. In addition, the instantaneous elastic modulus and aggregate modulus were measured using the stress-relaxation test. MIA injection decreased cartilage thickness, instantaneous elastic modulus and aggregate modulus, and increased joint friction. The friction coefficients in the OA + US and OA + US + PRP groups reached near-normal values, and there was no significant difference compared with the control group (p = 0.232 and p = 0.459, respectively). The instantaneous elastic modulus and aggregate modulus in the OA + US group increased significantly compared with the OA + PRP group (p < 0.05). It seems that both LIPUS and PRP injection effectively improved joint lubrication, but LIPUS was superior to PRP in improving the mechanical properties of the articular cartilage.

Autologous platelet-rich plasma 'fluid' versus 'gel' form in combination with fractional CO2 laser in the treatment of atrophic acne scars: a split-face randomized clinical trial

BACKGROUND

The treatment of atrophic acne scars represents a therapeutic challenge. Recently, plasma gel has been introduced among treatment modalities.

OBJECTIVE

To compare the efficacy of platelet-rich-plasma 'fluid' versus 'gel' form combined with fractional CO₂ laser in the treatment of atrophic acne scars.

METHODS

Twenty-seven patients with atrophic acne scars were included. Treatment with fractional CO₂ laser plus plasma fluid/gel was randomly assigned to the right/left sides of the face. Clinical and Optical Coherence Tomography (OCT) assessments were scheduled at baseline, one month, and three months after the last session.

RESULTS

There was a significant improvement in clinical assessment scores at third-month follow-up on the plasma gel- and plasma fluid-treated sides compared to those at the first-month follow-up (p < .001). Scar depth decreased significantly at third-month follow-up when compared to baseline on both plasma gel- and plasma fluid-treated sides (p < .001). The numerical pain score was significantly lower on the plasma fluid-treated side compared to the plasma gel-treated side (p = .004).

CONCLUSION

The use of platelet-rich plasma in combination with fractional CO₂ laser, both in fluid and gel form, produced significant results in the treatment of atrophic acne scars. Patients reported an immediate more noticeable effect with plasma gel. However, the fluid injection was less painful.

A safety evaluation of allogeneic freeze-dried platelet-rich plasma or conditioned serum compared to autologous frozen products equivalents in equine healthy joints

Background

Hemoderivatives such as autologous conditioned serum (ACS) and platelet-rich plasma (PRP) have been used as potential disease-modifying therapies in musculoskeletal disorders such as osteoarthritis (OA). These therapies are based on the delivery of multiple growth factors and anti-inflammatory cytokines that are known to participate in inflammatory processes. The variability of cytokine content due to the autologous nature of the product, the non-availability for immediate use and need for storage at low temperatures are limitations for its use in the field. An allogeneic freeze-dried conditioned serum (CS) and PRP would provide field clinicians with a more practical approach to use such products in daily practice. Based on in vitro preliminary data, this experimental study aimed to test the in vivo safety of allogeneic freeze-dried CS and PRP in healthy joints, using the horse as a model.

Results

Eight horses were randomly assigned and treated with PRP or CS. Horses had three joints injected with ALLO-FD PRP or CS, and three contralateral joints injected with the AUTO version of the same product, by a blinded clinician. Horses were evaluated clinically, and had synovial fluid collected at different time points and evaluated for cell content, PGE₂ and protein. Both CS and PRP products triggered a self-limiting and mild inflammatory response in equine healthy joints. This was indicated by the transient increase in nucleated cell count, PGE₂ and total protein in synovial fluid. This mild inflammatory response did not result in significant lameness and was not different among the groups.

Conclusions

The allogeneic freeze-dried PRP and CS showed to be overall safe and not dissimilar compared to their autologous frozen version in equine healthy joints. Further studies are necessary to evaluate the modulatory effects of these therapies in a clinical setting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03225-4.

Intra-articular injection with platelet-rich plasma compared to triamcinolone hexacetonide or saline solution in knee osteoarthritis: A double blinded randomized controlled trial with one year follow-up

OBJECTIVES

To compare the effectiveness of intra-articular injection (IAI) of Platelet-Rich Plasma (PRP) with Triamcinolone Hexacetonide (TH) and Saline Solution (SS), in patients with knee osteoarthritis (OA).

DESIGN

A randomized controlled trial, with blinded patients and assessor.

SETTING

Outpatient rheumatology service.

SUBJECTS

Patients with knee osteoarthritis grades II and III.

INTERVENTIONS

Patients received IAI with PRP, 40 mg TH, or SS.

METHODS

Patients were assessed at baseline and after 4, 8, 12 e 52 weeks with: visual analogue scale (VAS) for pain at rest and movement, WOMAC questionnaire, Timed to Up and Go test, 6-min walk test, percentage of improvement, goniometry, quality of life SF-36 questionnaire, Likert scale and Kelgreen & Lawrence (KL) radiographic scale (only at baseline and 52 weeks).

RESULTS

100 patients were studied, with a mean age of 67.13(6.56) years. The TH group was superior for: percentage of improvement (versus SS group from 4 to 52 weeks); WOMAC total and pain (versus PRP group at 4 weeks); and WOMAC stiffness (versus SS group at 12 weeks). The SS group was inferior for WOMAC function (from 8 to 52 weeks). The PRP group showed lowest radiographic progression [TH 17 (51.51%) to 24 (72.72%); SS 17 (51.51%) to 30 (90.90%); PRP 20 (58.82%) to 21 (61.76%)].

CONCLUSION

The Triamcinolone Hexacetonide group was superior for percentage of improvement and WOMAC, pain and stiffness. For the WOMAC function, the Platelet-Rich Plasma group and Triamcinolone Hexacetonide group were superior to the Saline group. The Platelet-Rich Plasma group showed the lowest radiographic progression at 52 weeks of follow-up.

Comparison of the Effect of MFAT and MFAT + PRP on Treatment of Hip Osteoarthritis: An Observational, Intention-to-Treat Study at One Year

Hip osteoarthritis (OA) is a major contributor to reduced quality of life and concomitant disability associated with lost working life months. Intra-articular injection of various biological materials has shown promise in alleviating symptoms and potentially slowing down the degenerative process. Here, we compared the effects of treatment of a cohort of 147 patients suffering from grade 1–4 hip OA; with either micro-fragmented adipose tissue (MFAT), or a combination of MFAT with platelet-rich plasma (PRP). We found significant improvements in both the visual analogue score for pain (VAS) and Oxford hip score (OHS) that were similar for both treatments with over 60% having an improvement in the VAS score of 20 points or more. These results suggest a positive role for intra-articular injection of MFAT + PRP as a treatment for hip osteoarthritis which may be important particularly in low body mass index (BMI) patients where the difficulty in obtaining sufficient MFAT for treatment could be offset by using this combination of biologicals.

Device-Based Enrichment of Knee Joint Synovial Cells to Drive MSC Chondrogenesis Without Prior Culture Expansion In Vitro: A Step Closer to 1-Stage Orthopaedic Procedures

BACKGROUND

Synovial fluid (SF) mesenchymal stem cells (MSCs) are derived from the synovial membrane and have cartilage repair potential. Their current use in clinical practice is largely exploratory. As their numbers tend to be small, therapeutic procedures using MSCs typically require culture expansion. Previous reports indicate that the stem cell-mobilizing device (STEM device) intraoperatively increases SF-MSCs.

PURPOSE

This study evaluated the chondrogenic potential of non-culture expanded synovium-mobilized MSCs and SF-microfragments obtained after enrichment using the STEM device and ascertained if device-mediated synovial membrane manipulation facilitated ongoing MSC release.

STUDY DESIGN

Controlled laboratory study.

METHODS

Two samples of aspiration fluid were collected intraoperatively before and after STEM device utilization from patients (n = 16) undergoing diagnostic or therapeutic knee arthroscopy. Human knee synovium (n = 5) was collected during total knee replacement, and a suspended culture was performed to assess the effect of the STEM device on ongoing MSC release. Colony forming unit-fibroblastic assays were used to determine the number of MSCs. Additionally, cytometric characterization of stromal and immune cells and chondrogenesis differentiation assay were performed without culture expansion. Filtered platelet concentrates were prepared using the HemaTrate system.

RESULTS

After STEM device use, a significant increase was evident in SF-MSCs (P = .03) and synovial fluid-resident synovial tissue microfragments (P = .03). In vitro-suspended synovium released significantly more MSCs following STEM device use than nonstimulated synovium (P = .01). The STEM device-released total cellular fraction produced greater in vitro chondrogenesis with significantly more glycosaminoglycans (GAGs; P < .0001) when compared with non-STEM device synovial fluid material. Nonexpanded SF-MSCs and SF-microfragments combined with autologous filtered platelet concentrate produced significantly more GAGs than the complete chondrogenic media (P < .0001). The STEM device-mobilized cells contained more M2 macrophage cells and fewer M1 cells.

CONCLUSION

Non-culture expanded SF-MSCs and SF-microfragments had the potential to undergo chondrogenesis without culture expansion, which can be augmented using the STEM device with increased MSC release from manipulated synovium for several days. Although preliminary, these findings offer proof of concept toward manipulation of the knee joint environment to facilitate endogenous repair responses.

CLINICAL RELEVANCE

Although numbers were small, this study highlights 3 factors relevant to 1-stage joint repair using the STEM device: increased SF-MSCs and SF-microfragments and prolonged synovial release of MSCs. Joint repair strategies involving endogenous MSCs for cartilage repair without the need for culture expansion in a 1-stage procedure may be possible.

Platelet-Rich Plasma in Facial Rejuvenation: A Systematic Appraisal of the Available Clinical Evidence

Purpose

Platelet-rich plasma (PRP) is a promising noninvasive technique for facial rejuvenation. This systematic literature review aims to appraise the nature and quality of published evidence evaluating the effectiveness and safety of PRP in facial rejuvenation.

Patients and Methods

A systematic literature review was conducted with the search string “Platelet-rich plasma AND Facial rejuvenation” in PubMed and Embase. Clinical studies evaluating the outcomes after PRP-based facial rejuvenation either as monotherapy or in combination with other treatment modalities were included. Studies evaluating wound-healing properties of PRP were excluded. The outcomes included both patient-reported and physician-assessed outcomes. Nonstatistical synthesis of evidence was performed by qualitative assessment. The results are reported by the Synthesis Without Meta-analysis (SWiM) reporting standard.

Results

A total of 36 studies that included a total of 3172 patients were considered for the evidence synthesis. The number of patients in the included studies ranging from 11 to 2005 with a median of 27.5 patients that reflects the challenges in clinically assessing the aesthetic outcomes after PRP-based facial rejuvenation. Among the 36 studies, 17 were observational studies and 18 were interventional studies with 1 being case report PRP was evaluated either alone or in combination with hyaluronic acid, lipofilling, micro-needling technique, and laser-based interventions. Among the studies, 1 study reported the enhanced platelet concentrate in a fibrin matrix to be relatively safe and effective with a maximum benefit observed at 12 weeks suggesting the platelet-rich fibrin matrix may provide desired aesthetic outcomes and it requires further studies to substantiate.

Conclusion

The results suggest very limited clinical evidence, and further clinical studies are warranted to establish the effectiveness of PRP in facial rejuvenation. Furthermore, a consensus for end points used for establishing clinical utility in patients requiring facial rejuvenation is warranted.

Short- and Midterm Comparison of Platelet-Rich Plasma with Hyaluronic Acid versus Leucocyte and Platelet-Rich Plasma on Pain and Function to Treat Hip Osteoarthritis. A Retrospective Study

Hip osteoarthritis (HOA) leads to pain and reduced function. The use of intra-articular injections based on corticosteroids, platelet-rich plasma (PRP), or hyaluronic acid (HA) is becoming a common symptomatic therapy for HOA. For the first time, we compare the effectiveness of plasma with a high concentration of platelets and leukocytes (L-PRP) with PRP+HA in patients with mild to moderate HOA. A total of 26 patients in each group were administered with either L-PRP or PRP+HA. Outcomes were evaluated at baseline, 3 months, and 1 year after the injection. The mean visual analog scale (VAS) and Harris hip score (HHS) within and between groups among different time points were compared using repeated measures ANCOVA (age set as a covariate). Both treatments were effective in reducing VAS, but not in significantly increasing HHS. In the group treated with L-PRP, VAS showed interaction between time and treatment (in favor of L-PRP). Pairwise comparison for treatment and time point evidenced a significant difference at 1-year follow-up between L-PRP and PRP-HA. Outcomes support the idea that both treatments may be effective in reducing pain, with maximal pain reduction achieved after 3 months. L-PRP showed better results in reducing VAS over time. Both treatments are effective at reducing pain in the short to medium term. L-PRP could be the treatment of choice due to a more marked effect over time. Nevertheless, further research is needed to better describe the clinical outcome of these formulations.

"Platelet-rich plasma holds promise in management of rheumatoid arthritis"-systematic review

The treatment of rheumatoid arthritis (RA) has been closely evolving with an understanding of disease pathogenesis with disease modifying anti-rheumatoid drugs (DMARDS) and Biologic DMARDS being the main stay. platelet rich plasma (PRP) has been the center of research in many specialties in the past decade. Its ability to stop and reverse inflammation have attracted researchers to try PRP in RA. A systematic review of studies on PRP in RA is lacking. The study protocol was prospectively registered in PROSPERO. Detailed search of Cochrane, Scopus, Medline, Embase, and Web of science databases were made to identify the relevant articles till Sep 2020 following Cochrane and PRISMA guidelines. Number of subjects, Animal model used, cell lines used for the study, method of induction of arthritis, PRP dose, concentration used, frequency of administration and clinical, histologic, and molecular changes from baseline following PRP use were extracted and analysed. Eight studies were included for the review. Four of these were in-vitro studies. Two were exclusive animal studies. One study analysed the effects of PRP in RA in both animal models (mice) and Hela cell lines. One study was a report of a series of patients of resistant RA treated with PRP. In the in vitro studies while platelets increase the migration and invasion of RA-FLS, they suppressed the inflammation on the whole. Available animal studies and the Human study have shown encouraging results. There has been no evidence of exacerbation of inflammation in these studies. The quantity and quality of literature on the effects of PRP in treating joint pathologies in RA is limited. Preclinical studies show decrease in disease activity with good safety profile. Invitro studies show suppression of inflammation. Thus, the available literature is encouraging towards the use of PRP in RA. Larger trials and molecular studies to understand the exact role of platelets in disease pathogenesis and treatment mechanisms are needed to decide the future course of PRP in RA.

Photobiomodulation (λ=808nm) and Platelet-Rich Plasma (PRP) for the Treatment of Acute Rheumatoid Arthritis in Wistar Rats

Introduction: Rheumatoid arthritis (RA) causes inflammation, pain, edema, and articular degradation and its treatment can be based on anti-inflammatory drugs, photobiomodulation (PBM) and/or platelet-rich plasma (PRP) that can decrease cell flow and promote local healing. In the present study, we evaluate the effects of PBM and PRP on acute arthritis in Wistar rats through inflammatory and oxidative stress parameters. Methods: Thirty female Wistar rats were assigned to five groups (n=6, each group): Control, Sham, PRP, Laser, and PRP+Laser. For arthritis induction, all animals of groups Sham, PRP, Laser and PRP+Laser received an intraarticular injection of Zymosan® (200µg) in the right knee. Twenty-four hours post-arthritis induction, PRP was prepared and injected (8 × 105 of platelets) in animals of PRP and PRP+Laser groups. PBM was performed in Laser and PRP+Laser groups by single-dose therapy with the GaAlAs laser (λ=808 nm, P=25 mW, fluence=30 J/cm2, beam area=0.02 mm2, t=33 seconds, E=0.825 J, punctual application). After seven days of induction, serum samples were collected and thiobarbituric acid reactive substances (TBARS), nitric oxide (NO) and catalase activity were analysed. Morphological parameters were measured for inflammation areas, cartilage thickness, and C3 protein expression in knee samples. Statistical analysis was performed with an ANOVA test and Tukey's post-hoc test with a significance level of 5% (P<0.05). Results: NO was lower in the treated groups compared to the Sham group, and TBARS did not show any differences, while catalase showed greater activity between PRP+Laser versus PRP (P<0.05). Inflammatory areas and cartilage thickness were lower in the treated groups compared to Sham (P<0.05), while no differences in C3 protein expression was observed. Conclusion: PBM associated with PRP is better for anti-inflammatory and joint preservation by morphological aspects and NO levels that concern a potential clinical application.

Synergistic Effects of Autologous Platelet-Rich Plasma and Hyaluronic Acid Injections on Facial Skin Rejuvenation

BACKGROUND

Many therapeutic options are currently available for facial skin rejuvenation, but little evidence exists about the efficacy of combining such procedures.

OBJECTIVES

The aim of this study was to assess and investigate the synergistic effect of hyaluronic acid (HA) and autologous platelet-rich plasma (a-PRP) injections on facial skin rejuvenation.

METHODS

For this randomized controlled prospective study, 93 eligible patients were enrolled and randomized into 3 intervention groups to undergo a series of 3 treatment sessions with either a-PRP, HA, or a mixture of a-PRP and HA (Cellular Matrix; Regen Lab) injected into facial cheeks.

RESULTS

A total of 93 patients were included. Treatment with Cellular Matrix led to a very significant improvement in the overall facial appearance compared with treatment with a-PRP or HA alone (P < 0.0001). Participants treated with Cellular Matrix showed a 20%, 24%, and 17% increase in FACE-Q score at 1, 3, and 6 months posttreatment, respectively. For the HA group, the improvement in FACE-Q score was 12%, 11%, and 6% at 1, 3, and 6 months posttreatment, respectively, whereas for the a-PRP group the improvement was 9%, 11%, and 8% at 1, 3, and 6 months posttreatment, respectively. Biophysical measurements showed significantly improved skin elasticity for the Cellular Matrix group compared with the groups receiving a-PRP or HA alone. No serious adverse events were reported.

CONCLUSIONS

Combining a-PRP and HA seems to be a promising treatment for facial rejuvenation with a highly significant improvement in facial appearance and skin elasticity compared with a-PRP or HA alone.

LEVEL OF EVIDENCE: 3

Platelet-rich plasma administering in osteoarthrosis treatment

Background — According to the data from the published sources worldwide, about 10% of the world population suffers from osteoarthrosis. While searching for novel methods of osteoarthrosis treatment, we proposed administering intra-articular injections of autologous platelet-rich plasma. The goal of this clinical study was to evaluate the effectiveness of autologous platelet-rich plasma injections in osteoarthrosis patient treatment. Methods — This open-label parallel-group study was a pilot randomized controlled trial. An analysis of the treatment outcomes for 128 patients with knee joint arthrosis was performed. All patients were split among three groups, and subjects in two of those were receiving conventional treatment. Clinical efficacy was calculated from pain intensity, determined using Visual Analog Scale, Lequesne index and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Inflammatory response intensity was assessed by superoxide dismutase content and erythrocyte catalase activity. Results — It was demonstrated that administering platelet-rich plasma allowed achieving tangible clinical and laboratory results without any side effects and with very few contraindications. The latter included, for instance, blocking inflammatory process in the joints, thereby inhibiting the oxidative stress, which is the most pathogenetically substantiated treatment of osteoarthrosis. Conclusion — Thus, we have discovered that platelet-rich plasma injections had apparent anti-inflammatory and pain-relieving effects, along with inhibiting action of destructive processes in the cartilaginous tissue, hence improving life quality of the patients with osteoarthrosis.

Moving toward targeting the right phenotype with the right platelet-rich plasma (PRP) formulation for knee osteoarthritis

Intra-articular injections of platelet-rich plasma (PRP) and other novel blood-derived products developed specifically for osteoarthritis (OA) can provide pain relief and potential benefits in disease progression. Meta-analyses show the clinical superiority of PRP compared with other intra-articular injections, but results are modest and the effect sizes are small. PRP injections in knee OA are performed indiscriminately, but the clinical response varies enormously between patients because of an array of mixed OA phenotypes. Subgroup analyses are scarce; some studies stratify patients according to radiographic severity and found better results in early OA, without consensus for more advanced stages of the condition. Parallel identification of soluble and imaging biomarkers is essential to personalise and leverage PRP therapies. The inflammatory phenotype is most interesting from the PRP perspective because PRPs modulate inflammation by releasing a large pool of chemokines and cytokines, which interact with synovial fibroblasts and macrophages; in addition, they can modulate the innate immune response. No soluble biomarkers have been discovered that have implications for OA research and PRP interventions. Clinical examination of patients based on their inflammatory phenotype and imaging identification of pain sources and structural alterations could help discern who will respond to PRP. Synovial inflammation and bone marrow lesions are sources of pain, and intra-articular injections of PRP combined with subchondral bone injection can enhance clinical outcomes. Further refining ultrasound phenotypes may aid in personalising PRP therapies. Intra-articular delivery combined with injections in altered ligamentous structures, medial and coronal ligaments or premeniscal pes anserinus showed positive clinical outcomes. Although the evidence supporting these approaches are weak, they merit further consideration to refine PRP protocols and target the right OA phenotypes.

Platelet-rich plasma as an effective biological therapy in early-stage knee osteoarthritis: One year follow up

Objective: PRP is produced by centrifugation of whole blood containing highly concentrated platelets, associated growth factors, and other bioactive agents which has been shown to provide some symptomatic relief in early knee osteoarthritis (OA). The principal objective of our study was to evaluate the effectiveness and safety of standardized intra-articular injection of autologous PRP in early osteoarthritis knee. Methods: A total of 98 eligible symptomatic patients received two injections of standardized PRP 3 weeks apart. Clinical outcomes were evaluated using the VAS and Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire before treatment and at 6 weeks, 3 months, 6 months, and 1 year after treatment. Secondary objectives were safety (side effects), and the effect of PRP on the different grades of knee degeneration. Results: There was a statistically significant improvement in mean VAS and WOMAC scores at 6 weeks, 3 months, 6 months, and slight loss of improvement at 1 year follow-up. There was also a correlation between the degree of degeneration and improvement in the mean scores. The decrease in mean pain score is more in grades 1 and 2 (early OA) than in grade 3. The intraarticular injection is safe, with no major complications. Conclusion: PRP is a safe and effective biological regenerative therapy for early OA Knees. It provides a significant clinical improvement in patients with some loss of improvement with time. More studies will be needed to confirm our findings.

Comparing Intra-articular Injections of Leukocyte-Poor Platelet-Rich Plasma Versus Low-Molecular Weight Hyaluronic Acid for the Treatment of Symptomatic Osteoarthritis of the Hip: A Double-Blind, Randomized Pilot Study

Background:

Hyaluronic acid (HA) and leukocyte-poor platelet-rich plasma (LP-PRP) are 2 nonoperative treatment options that have been studied in patients with hip osteoarthritis (OA).

Purpose:

To compare the efficacy of intra-articular injections of low–molecular weight (LMW) HA and LP-PRP in patients with hip OA.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A total of 34 patients (36 hips) presenting with signs of hip OA were randomized to receive 3 blinded, weekly intra-articular injections of either LP-PRP or LMW-HA. Patients were prospectively evaluated before injections and at 6 weeks and then at 3, 6, 12, and 24 months. The primary outcome, conversion to total hip arthroplasty (THA) or a hip resurfacing procedure, was analyzed along with secondary outcomes including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and hip range of motion.

Results:

The final analysis included 33 hips (mean Kellgren-Lawrence grade, 2.73) (LMW-HA: n = 14; LP-PRP: n = 19) in 31 patients (18 male; mean age, 53.8 years). Significantly more patients converted to THA or a hip resurfacing procedure in the LMW-HA group (7/14; 50.0%) (mean, 1.3 years after first injection) than the LP-PRP group (3/19; 15.8%) (mean, 0.73 years after first injection) (P = .035). There was no significant improvement or decline in any outcome scores within the LMW-HA group from before injections to 6 weeks or 3, 6, and 12 months. For the LP-PRP group, WOMAC overall (P = .032), joint (P = .030), and function scores (P = .025) significantly improved from before injections to 6 weeks, and WOMAC joint scores significantly improved from before injections to 6 months (P = .036). When comparing the difference between groups in internal rotation at 90° of hip flexion from before injections to 6 months, the LP-PRP group demonstrated a mean 5.0° improvement, while the LMW-HA group showed a mean 1.5° decrease (P = .028).

Conclusion:

Intra-articular hip injections of LP-PRP in patients with hip OA resulted in an improvement in WOMAC scores and hip internal rotation at 6 months and delayed the need for THA or a hip resurfacing procedure compared with treatment with LMW-HA. A longer follow-up is necessary to further compare the effects of LP-PRP and LMW-HA injections in patients with hip OA.

Registration:

NCT01920152 (ClinicalTrials.gov identifier).

Rejuvenating the periorbital area using platelet-rich plasma: a systematic review and meta-analysis

Intradermal injection of autologous platelet-rich plasma (PRP) is a non-surgical cosmetic therapy to rejuvenate the periorbital area pathologies of wrinkles, periorbital hyperpigmentation (POH), and photoaging. The past decade has seen the adoption of this novel therapy around the world. This is the first systematic review and meta-analysis evaluating PRP treatment of periorbital pathologies. This is a PRISMA compliant review that includes a comprehensive search of the databases Cochrane Library, Ovid Medline, Ovid Embase, and clinicaltrials.gov. The search was performed in June 2019 to obtain all peer-reviewed articles published in English that describe the application of PRP to periorbital pathologies. A meta-analysis of patient satisfaction was performed for randomized controlled trials. Nineteen studies treating 455 patients (95% female, age range 28-60) were included. Studies were categorized based on reported outcomes: wrinkles (11 studies), POH (7 studies), and photoaging (6 studies). Patients were treated a mean of 3 times (range 1-8) in mean intervals of 23 days (range 14-56 days). Follow-up averaged 3 months (range 1-6 months). Meta-analysis of 3 randomized controlled clinical trials (RCTs) shows that patients treated with PRP have increased satisfaction above controls of saline, platelet-poor plasma, mesotherapy, and as an adjunct to laser therapy (overall effect p = 0.001, heterogeneity I² = 64%). PRP treatment of periorbital area pathologies results in histologic improvements of photoaging, subjective satisfaction score increases, and blind evaluator assessments of rejuvenated skin appearance. Future studies are needed to address limitations of the current literature and should include long-term follow-up, delineation of the POH etiology that is treated, RCTs with low risk of bias, and be absent conflicts of interest or industry sponsors.Trial registration: Prospero Systematic Review Registration ID: CRD42019135968.

Comparing efficacy of intraarticular single crosslinked Hyaluronan (HYAJOINT Plus) and platelet-rich plasma (PRP) versus PRP alone for treating knee osteoarthritis

Intraarticular hyaluronan or platelet-rich plasma (PRP) is widely used in the treatment of knee osteoarthritis (OA). The efficacy of combined hyaluronan with PRP remained inconclusive. This study aimed to investigate the efficacy of combined a single crosslinked hyaluronan (HYAJOINT Plus) and a single PRP versus a single PRP in patients with knee OA. In a prospective randomized-controlled trial, 85 patients with knee OA (Kellgren-Lawrence 2) were randomized to receive a single intraarticular injection of HYAJOINT Plus (3 ml, 20 mg/ml) followed by 3 ml PRP (the combined-injection group, N = 43) or a single injection of 3 ml PRP (the one-injection group, N = 42). The primary outcome was the change from baseline in the visual analog scale (VAS) pain (0–00 mm) at 6 months. Secondary outcomes included The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC, Likert Scale), Lequesne index, single leg stance test (SLS), use of rescue analgesics and patient satisfaction at 1, 3 and 6 months. Seventy-eight patients were available for the intention-to-treat analysis at 6 months. Both groups improved significantly in VAS pain, WOMAC, Lequesne index and SLS at each follow-up visit (p < 0.001). Patients receiving a single PRP experienced significantly greater improvements in VAS pain than patients receiving combined injections at 1-month follow-up (adjusted mean difference: − 5.6; p = 0.017). There were no significant between-group differences in several of the second outcomes at each follow-up visit, except the WOMAC-pain and WOMAC-stiffness scores favoring the one-injection group at 1 month (p = 0.025 and p = 0.011). However, at 6-month follow-up, the combined-injection group achieved significantly better VAS pain reduction (p = 0.020). No serious adverse events occurred following injections. In conclusion, either combined injections of HYAJOINT Plus and PRP or a single PRP alone was safe and effective for 6 months in patients with Kellgren-Lawrence 2 knee OA. Combined injections of HYAJOINT Plus and PRP achieved better VAS pain reduction than a single PRP at 6 months. The results indicating a long term benefit effect of a combination of HYAJOINT Plus and PRP in a particular subset of patients with moderate knee OA need to be replicated in larger trials.

ClinicalTrials.gov number NCT04315103.

Comparison of Autologous Platelet-Rich Plasma and Chitosan in the Treatment of Temporomandibular Joint Osteoarthritis: A Retrospective Cohort Study

PURPOSE

The purpose of this article is to study the effect of autologous platelet-rich plasma (PRP) injected into the upper cavity of the temporomandibular joint (TMJ) on the treatment of TMJ osteoarthritis.

PATIENTS AND METHODS

We retrospectively analyzed the data of 27 patients with TMJ osteoarthritis treated at the China Medical University Hospital of Stomatology from September 2018 to September 2019. Maximal interincisal opening, pain intensity, and TMJ sounds were recorded and compared before treatment and at the 3rd and 6th months after the treatment. SPSS 24.0 software was used to analyze the data of each group, and the imaging changes in the condylar bone were compared before and 6 months after the treatment. The P-value was set at .05.

RESULTS

Better results were observed in the group treated with PRP on maximal interincisal opening and pain intensity than in the group receiving chitosan treatment. Regarding TMJ sounds, relief was observed in both groups, with no significant difference.

CONCLUSIONS

The effect of PRP on the improvement of the maximal interincisal opening and pain intensity of patients with TMJ osteoarthritis is better than that of chitosan. However, it should be noted that the incidence of complications associated with the injection of PRP may be higher than that with injection of chitosan.

Pancreatic extracellular matrix and platelet-rich plasma constructing injectable hydrogel for pancreas tissue engineering

The development of pancreatic extracellular matrices enriched with insulin-secreting β-cells is a promising tissue engineering approach to treat type 1 diabetes. However, its long-term therapeutic efficacy is restricted by the defensive mechanism of host immune response and the lack of developed vascularization as appropriate after transplantation. Platelet-rich plasma (PRP), as an autologous platelet concentrate, contains a large number of active factors that are essential for the cell viability, vascularization, and immune regulation. In this study, we have incorporated pancreatic extracellular matrix (PEM) with PRP to develop a three-dimensional (3D) injectable PEM-PRP hydrogel to coculture and transplant rat insulinoma cells (INS-1) and human umbilical vein endothelial cells (HUVECs). Results from this study demonstrated that PEM-PRP hydrogel mimicked the biochemical compositions of native extracellular matrices, and possessed the enhanced elastic modulus and resistance to enzymatic degradation that enabled biomaterials to maintain its volume and slowly degrade. Additionally, PEM-PRP hydrogel could release growth factors in a sustained manner. In vitro, PEM-PRP hydrogel significantly promoted the viability, insulin-secreting function, and insulin gene expression of gel encapsulated INS-1 cells. Moreover, HUVECs encapsulated in PEM-PRP hydrogel were found to constitute many lumen-like structures and exhibited high expression of proangiogenic genes. In vivo transplantation of PEM-PRP hydrogel encapsulated with INS-1 cells and HUVECs improved the viability of INS-1 cells, promoted vascularization, inhibited the host inflammatory response, and reversed hyperglycemia of diabetic rats. Our study suggests that the PEM-PRP hydrogel offers excellent biocompatibility and proangiogenic property, and may serve as an effective biomaterial platform to maintain the long-term survival and function of insulin-secreting β cells.

Intra-articular platelet-rich plasma vs corticosteroids in the treatment of moderate knee osteoarthritis: a single-center prospective randomized controlled study with a 1-year follow up

BACKGROUND

Osteoarthritis is the most prevalent type of arthritis, which significantly impacts the patient's mobility and quality of life. Pharmacological treatments for osteoarthritis, such as corticosteroids, produce an immediate reduction of the patient's pain as well as an improvement in the patient's mobility and quality of life, but with a limited long-term efficacy. In this context, platelet-rich plasma (PRP) infiltrations represent a therapeutic tool due to its trophic properties and its ability to control inflammatory processes, especially in musculoskeletal applications. The aim of this study is to evaluate and compare the clinical benefits of PRP when injected intra-articularly vs a commonly used corticosteroid (CS, triamcinolone acetonide, Kenalog®) in patients affected by mild to moderate symptomatic knee osteoarthritis.

METHODS

Forty patients affected by symptomatic radiologically confirmed knee osteoarthritis (Kellgren-Lawrence grades II-III) were enrolled in this randomized study. Patients randomized in the PRP group (n = 20) received an intra-articular injection of PRP (8 mL) while patients randomized in the CS group (n = 20) received an intra-articular injection of triamcinolone acetonide (1 mL of 40 mg/mL) plus lidocaine (5 mL of 2%). The pain and function of the target knee were evaluated by the VAS, IKDC, and KSS scales at the baseline (V1), 1 week (V2), 5 weeks (V3), 15 weeks (V4), 30 weeks (V5), and 1 year (V6) after treatment.

RESULTS

No serious adverse effects were observed during the follow-up period. A mild synovitis was registered in 15 patients (75%) in the PRP group within the first week after treatment which resolved spontaneously. Both treatments were effective in relieving pain and improving the knee function in the very short-term follow-up visit (1 week). A high improvement of the subjective scores was observed for both groups up to 5 weeks, with no significative differences between the groups for the VAS, IKDC, or KSS. After 15 weeks of follow-up, the PRP group showed significative improvements in all scores when compared to the CS group. Overall, the patients who received PRP treatment had better outcomes in a longer follow-up visit (up to 1 year) than those who received CS.

CONCLUSIONS

A single PRP or CS intra-articular injection is safe and improves the short-term scores of pain and the knee function in patients affected by mild to moderate symptomatic knee OA (with no significant differences between the groups). PRP demonstrated a statistically significant improvement over CS in a 1-year follow-up. This study was registered at ISRCTN with the ID ISRCTN46024618.

The Physician's Guide to Platelet-Rich Plasma in Dermatologic Surgery Part I: Definitions, Mechanisms of Action, and Technical Specifications

BACKGROUND

Platelet-rich plasma (PRP) is an increasingly popular treatment modality for various dermatologic conditions, but there are limitations in both the published literature and clinician knowledge.

OBJECTIVE

To create a high-yield, in-depth analysis of PRP in procedural dermatology by reviewing available data on its role in hair restoration, soft-tissue remodeling, resurfacing, and rejuvenation; identifying practice gaps and controversies; and making suggestions for future research that will establish dermatologists as pioneers of regenerative medicine.

MATERIALS AND METHODS

A 2-part systematic review and expert analysis of publications before October 2018.

RESULTS AND CONCLUSION

Most studies on PRP report favorable outcomes with the strongest level of evidence existing for androgenetic alopecia followed by postprocedure wound healing, scar revision, striae, rejuvenation, and dermal filling. There is a dearth of large randomized controlled trials, considerable heterogeneity in the variables studied, and lack of specificity in the preparatory protocols, which may influence clinical outcomes. Future investigations should use consistent nomenclature, find ideal solution parameters for each cutaneous indication, determine significant outcome metrics, and follow double-blinded, randomized, controlled methodologies. Addressing these deficiencies will take sound scientific inquiry but ultimately has the potential to benefit the authors' specialty greatly.

Platelet-Rich Plasma-Derived Growth Factor vs Hyaluronic Acid Injection in the Individuals with Knee Osteoarthritis: A One Year Randomized Clinical Trial

OBJECTIVE

In this study, we aimed at performing a comparison between intra-articular injections of PRP-derived growth factor (PGRF) and hyaluronic acid regarding their effect on pain and patient's function in knee osteoarthritis, as well as their safety profiles.

METHODS

During our single-masked randomized clinical trial, the candidates with symptomatic knee osteoarthritis received two intra-articular injections of PRGF with 3 weeks apart or received three weekly injections of HA. The mean improvements from before treatment until the second, sixth, and twelfth months post-intervention in scores obtained by visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Lequesne index were our primary outcomes.

RESULTS

A total of 102 candidates were finally included in the study. Patients' mean age was 57.08±7.3 years old in the PRGF group compared to the mean age of 58.63±7.09 years old in HA patients. In the PRGF group, total WOMAC index decreased from 41.96±11.71 to 27.10±12.3 (P = 0.02), and from 39.71±10.4 to 32.41±11.8 in the HA group after 12 months (P > 0.05). Regarding the Lequesne index, pain, ADL, and global scores significantly decreased after 12 months in the PRGF group compared to the HA group (P<0.001). There was also a meaningful higher rate of satisfaction in the PRGF group compared to the HA group after 12 months of treatment (P<0.001).

CONCLUSION

Besides significantly higher satisfaction belonging to the PRGF group, there was a statistically significant improvement in VAS score and global, pain, and ADL score of Lequesne by passing 12 months from injection in PRGF compared to HA.

Enhanced vascularization and biocompatibility of rat pancreatic decellularized scaffolds loaded with platelet-rich plasma

The ultimate goal of pancreatic tissue engineering is to create a long-lived substitute organ to treat diabetes. However, the lack of neovascularization and the occurrence of immune response limit the efficacy of tissue-engineered pancreas after in vivo transplantation. Platelet-rich plasma (PRP) is an autologous platelet concentrate containing a large number of growth factors and immunoregulatory factors. The aim of this study was to evaluate rat pancreatic decellularized scaffold (PDS) loaded with PRP for vascularization, host inflammatory response and macrophage polarization in an animal model. The study results indicated that compared to PDS, PRP-loading PDS exhibited the enhanced mechanical properties and released growth factors in a slow and sustained manner to supplement the loss of growth factors during decellularization. In vitro, human umbilical vein endothelial cells (HUVECs) were seeded in PDS and PRP-loading PDS, and cultured in the circular perfusion system. When compared with PDS, PRP-loading PDS significantly promoted the colonization, proliferation and pro-angiogenic genes expression of cells on scaffolds. In vivo, PDS loaded with PRP then re-endothelialized with HUVECs were implanted subcutaneously in rats, which enhanced the angiogenesis of scaffolds, inhibited the host inflammatory response, and induced the polarization dominated by pro-regenerative M2 macrophages that also facilitated tissue vascular regeneration. Thus, the re-endothelialized PRP-loading PDS may represent a promising bioengineered pancreas with sustained vascularization and excellent biocompatibility.

Autologous adipose tissue injection versus platelet-rich plasma (PRP) injection in the treatment of knee osteoarthritis: a randomized, controlled study - study protocol

Background

Knee osteoarthritis (OA) is a common, chronic, progressive and degenerative disease which affects patients’ quality of life and may cause disability and social isolation. OA is a huge economic burden for the patient and a large strain for the whole healthcare system. Articular cartilage has a small potential to repair, with progressively more clinicians emphasizing cellular therapy. Subcutaneous fat tissue in human body is a large reservoir of mesenchymal stem cells (MSCs) and is been harvested in minimally invasive, simple procedure. Up to date there is no prospective randomized controlled studies demonstrating effectiveness and role of adipose tissue injections in OA treatment. The purpose of this study is to assess functional and clinical changes among patients with symptomatic knee OA treated with intra-articular injections of autologous adipose tissue or platelet rich plasma (PRP) and to compare efficacy of both therapeutic methods.

Methods

This is a prospective, randomized, controlled study. Patients who meet inclusion criteria will be allocated to Fat Tissue group or PRP group randomly. Subjects will receive an intra articular injection with autologous adipose tissue and PRP respectively. Patients will be assessed five times: before treatment and 1, 3, 6 and 12 months after the treatment. The assessment consists of patient reported outcome measures (The Knee injury and Osteoarthritis Outcome Score, International Knee Documentation Committee 2000, the Western Ontario and McMaster Universities Osteoarthritis Index, the Health Questionnaire EQ- 5D- 5 L), three functional tests (The Timed Up and Go Test, The 5 Times Sit to Stand Test, The 10 m Walk Test) and Maximal Isometric Voluntary Contraction.

Discussion

This study protocol has several strengths and weaknesses. One of strongest point of this study is the wide, multidimensional functional assessment which will give a large amount of objective data. On the other hand, lack of blinding has to be considered as a risk of both subject and investigator bias.

Trial registration

name of registry: ClinicalTrials.gov, trial registration number: NCT04321629, retrospectively registered on date of registration.

Comparison of the short-term results of single-dose intra-articular peptide with hyaluronic acid and platelet-rich plasma injections in knee osteoarthritis: a randomized study

Introduction/objectives

Intra-articular injections may be useful in terms of pain and functional status, in knee osteoarthritis (OA). Besides hyaluronic acid (HA) and platelet-rich plasma (PRP), peptide molecules recently begin to be used. The aim of this study was to compare the efficacy of intra-articular peptide Prostrolane® (CAREGEN Co. Ltd.) injection with that of the HA and PRP in the persons with OA.

Method

Fifty-four patients with OA were included in this prospective, randomized study. Patients were randomized into three groups as intra-articular HA, peptide, and PRP groups. Paracetamol was permitted three times a day to all groups. All the patients were evaluated by the Western Ontario and McMaster Universities Arthritis Index (WOMAC), Health Assessment Questionnaire (HAQ), and visual analogue scale (VAS) at rest and during movements. Measurements performed at the baseline, after the first week of injection, and at the first and third months of follow-up.

Results

Mean age was 55.8 ± 8.9 years. Forty-four (81.6%) were women. A week after the injections, rest and movement pain severity was measured by VAS decreased significantly in all the study groups (p < 0.05). There were no statistically significant differences between the groups in terms of first week pain relief (p > 0.05). WOMAC pain, stiffness, function, and total scores were improved significantly in all the groups a week after the injections (p < 0.05). Improvement continued at the third month control; however, the improvement in the WOMAC pain score was significantly better in the peptide group at the third month control (p < 0.05). The decrease in the rest and movement pain was continued for 3 months except the HA group’s rest pain. There were no differences among the groups for all measurements, except for the WOMAC pain score at 3 months after treatment, which was significantly lower in the peptide group.

Conclusion

As a result, pain relief and functional improvement were obtained after the intra-articular HA, peptide, and PRP injections in OA, and decrease in pain was better in the peptide group.

Key Points • The short-term effects of intra-articular HA, peptide, and PRP injections were compared in knee osteoarthritis. • HA, peptide, and PRP injections may be useful in pain relief and functional improvement in knee osteoarthritis.

Neuroimmune modulation of pain and regenerative pain medicine

Regenerative pain medicine, which seeks to harness the body's own reparative capacity, is rapidly emerging as a field within pain medicine and orthopedics. It is increasingly appreciated that common analgesic mechanisms for these treatments depend on neuroimmune modulation. In this Review, we discuss recent progress in mechanistic understanding of nociceptive sensitization in chronic pain with a focus on neuroimmune modulation. We also examine the spectrum of regenerative outcomes, including preclinical and clinical outcomes. We further distinguish the analgesic mechanisms of regenerative therapies from those of cellular replacement, creating a conceptual and mechanistic framework to evaluate future research on regenerative medicine.

Release kinetic of pro- and anti-inflammatory biomolecules from platelet-rich plasma and functional study on osteoarthritis synovial fibroblasts

BACKGROUND AIMS

This study evaluated the release kinetics of numerous representative and less studied platelet-rich plasma (PRP) cytokines/chemokines with regard to the effects of various cellular compositions and incubation times. In addition, the biological effects of different PRPs on osteoarthritis synovial fibroblasts in vitro were tested.

METHODS

Peripheral whole blood was collected from healthy donors, and pure platelet-rich plasma (P-PRP), leukocyte-rich platelet-rich plasma (L-PRP) and platelet-poor plasma (PPP) were prepared for the analysis of the following biomolecules: IL-1β, IL-4, IL-6, IL-10, IL-17a, IL-22, MIP-1α/CCL-3, RANTES/CCL-5, MCP-3/CCL-7, Gro-α/CXCL-1, PF-4/CXCL-4, ENA-78/CXCL-5, NAP-2/CXCL-7, IL-8/CXCL-8, Fractalkine/CX3CL-1, s-CD40L P-PRP, L-PRP and PPP. Their effect on osteoarthritis synovial fibroblasts in vitro was tested by analyzing changes induced in both gene expression on a panel of representative molecules involved in physiopathology of joint environment and synthesis of IL-1β, IL-8 and hyaluronic acid.

RESULTS

This study demonstrated that among the 16 analyzed biomolecules, four were undetectable, whereas most of the detected biomolecules were more concentrated in L-PRP even when concentrations were normalized to platelet number. Despite the pro-inflammatory boost, the various PRP preparations did not alter synovial fibroblast gene expression of specific factors that play a pivotal role in joint tissue homeostasis and are able to induce anti-inflammatory (TIMP-1) biomolecules.

DISCUSSION

This study provides a set of reference data on the concentration and release kinetics of some less explored biomolecules that could represent potential specific effectors in the modulation of inflammatory processes and in tissue repair after treatment with PRP.

Treatment With Platelet Lysate Inhibits Proteases of Synovial Fluid in Equines With Osteoarthritis

Osteoarthritis (OA) is the most prevalent arthropathy in sport horses. The administration of a platelet lysate (PL) is an alternative method for the treatment of musculoskeletal conditions. The mechanisms by which PL exerts its beneficial effects have not been determined, and less is known about its effect on the activity of the proteolytic enzymes of the synovial fluid of equines with OA. In this work, the effect of the administration of PL to horses with OA was analyzed both clinically and molecularly by determining the levels of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), glycosaminoglycans (GAGs), and tissue inhibitor of metalloproteinase 1 (TIMP-1) in synovial fluid. One mL of PL was administered intra-articularly followed by the extraction of synovial fluid on days 0, 10, 30, and 60. Results were evaluated by an analysis of variance for repeated measures. The levels of MMP-9 decreased significantly (P < .05) on day 10 after treatment with PL. A disintegrin and metalloproteinase with thrombospondin motifs 5 decreased significantly on days 10 (P < .05), 30 (P < .05), and 60 (P < .01) after treatment. The levels of synovial TIMP-1 increased significantly on day 30 (P < .001) after treatment. Glycosaminoglycans showed a significant increase on days 10 (P < .05) and 30 (P < .01). A significant decrease was found for MMP-2 on day 10 (P < .01), 30 (P < .01), and 60 (P < .001). In conclusion, the beneficial effects of PL in OA could be attributed to the decreased activity of MMP-2, MMP-9, and ADAMTS-5 and the increased concentration of GAGs and TIMP-1 after the administration of platelet-rich plasma.

Autologous platelet-rich plasma therapy for refractory pain after low-grade medial collateral ligament injury

Objective

This study was performed to explore the effect of intra-articular injection of autologous platelet-rich plasma (PRP) on refractory pain after low-grade medial collateral ligament (MCL) injury.

Methods

In total, 52 patients with refractory pain after low-grade knee MCL injury were treated by intra-articular injection of autologous PRP. Every patient received a 5-mL intra-articular injection of autologous PRP once weekly for 3 weeks. All patients were evaluated by the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form score before treatment and 1, 3, and 6 months after treatment. Magnetic resonance imaging of the knee was performed to observe the healing of the MCL injury 6 months after treatment.

Results

After one injection, the patients’ pain was greatly decreased and they stopped taking nonsteroidal anti-inflammatory drugs. The IKDC Subjective Knee Evaluation Form scores were significantly better after than before treatment; however, there were no significant differences among the various post-treatment time points. Magnetic resonance imaging showed that the low-grade MCL injury had completely healed, and no edema was present around the MCL.

Conclusions

Intra-articular injection of autologous PRP is an effective treatment for refractory pain after low-grade MCL injury.

Treating hand and foot osteoarthritis using a patient's own blood: A systematic review and meta-analysis of platelet-rich plasma

Background

This study summarizes all literature investigating platelet-rich plasma (PRP) in the treatment of osteoarthritis of the hands and feet.

Materials & methods

This is a PRISMA compliant systematic review of 7 databases and includes a meta-analysis of randomized controlled trial (RCT) data on pain and function.

Results

Nine articles were included in the review. Meta-analysis of 4 RCTs shows PRP significantly improves pain and function versus control. More results are significant at longer duration follow-up.

Conclusions

PRP improves pain and function of osteoarthritis. Heterogeneity and risk-of-bias limit current data, requiring more RCTs to determine any regenerative potential of PRP.

Prospero Systematic Review Registration Number

136582.

A Meta-analysis of the Evidence for Assisted Therapy with Platelet-Rich Plasma for Atrophic Acne Scars

BACKGROUND

A number of studies have investigated the role of platelet-rich plasma (PRP) as an assisted therapy for atrophic acne scars. However, the results are diverse, and no up-to-date meta-analysis was found that exclusively examined atrophic acne scar treatment.

OBJECTIVES

To perform a meta-analysis to assess improvements in the side effects of PRP and the effect of assisted therapy for atrophic acne scars.

METHODS

This study followed PRISMA guidelines. A comprehensive search of the literature was carried out in September 2018 using the electronic databases of PubMed, EMBASE, MEDLINE, and the Cochrane Library.

RESULTS

Seven articles were included in this review. All of the studies published utilized PRP as additive therapy. The major therapies included fractional carbon laser therapy and microneedling. Five studies (249 participants) reported four degrees of improvement on an improvement scale (degrees 3 and 4 were considered improvement in this analysis). Four studies (200 participants) reported mean improvement scores. A significantly higher degree of improvement was shown in the PRP group compared to the control group (OR = 8.19; 95% CI 4.32-15.52; p < 0.00001), as well as better mean improvement score (WMD = 23.73; 95% CI 18.60-28.87; p < 0.00001). Substantial heterogeneity was seen in the degree of improvement (I² = 54% p = 0.07) and the mean improvement score (I² = 75%; p = 0.008). There were overall fewer monitored side effects, including erythema and edema (in days), in the PRP groups; however, no significance was found.

CONCLUSIONS

This review shows that PRP is a useful assisted therapy for atrophic acne scars, which can achieve better improvement.

LEVEL OF EVIDENCE III

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.

Evaluation of allogeneic freeze-dried platelet lysate in cartilage exposed to interleukin 1-β in vitro

Background

Platelet-rich plasma (PRP) as well as other platelet-derived products have been used as a potential disease-modifying treatment for musculoskeletal diseases, such as osteoarthritis (OA). The restorative properties of such products rely mainly on the high concentrations of growth factors, demonstrating encouraging results experimentally and clinically. Yet, the autologous blood-derived nature of the PRP product lead to limitations that precludes it’s widespread use. The main limitations for PRP use are; product variability, the need for minimum laboratory settings in most cases, and the need for storage at low temperatures to preserve its properties. Based on these limitations, the objective of this study was to investigate an allogeneic off-the-shelf platelet lysate (PL) in cartilage exposed to interleukin 1β (IL-1β). For this purpose, blood and cartilage were harvested from eight skeletally mature and healthy horses. Blood was processed into PL aliquots and divided into three groups (Frozen, Freeze-dried and Filtered freeze-dried), used in autologous and allogeneic conditions and in three different concentrations (1.5, 3 and 6-fold). Different PL preparations were then applied in cartilage culture with interleukin-1 beta and cultured for 10 days. Cartilage and media samples were collected and analyzed for total GAG and ³⁵SO₄-labeled GAG content.

Results

No significant differences between the controls and PL groups in cartilage and media were demonstrated. The effects of PL on cartilage matrix were concentration dependent and intermediate concentrations (3-fold) in PL showed increased ³⁵SO₄-labelled GAG in cartilage.

Conclusion

In conclusion, the allogeneic freeze-dried PL presented equivalent effects compared to frozen autologous PL. Intermediate platelet concentration on average demonstrated improved results, demonstrating less GAG loss compared to other concentrations.

Multiple Platelet-Rich Plasma Injections Versus Single Platelet-Rich Plasma Injection in Early Osteoarthritis of the Knee: An Experimental Study in a Guinea Pig Model of Early Knee Osteoarthritis

BACKGROUND

Platelet-rich plasma (PRP) has emerged as the forerunner among disease-modifying treatment options for early osteoarthritis (OA) of the knee. However, no consensus is available regarding optimum dosing schedules.

PURPOSE

To determine whether multiple injections of PRP (3 injections) provide better short-term and long-term results than a single injection of PRP in a guinea pig model of knee OA.

STUDY DESIGN

Controlled laboratory study.

METHODS

36 Dunkin-Hartley guinea pigs (weighing ~600-800 g) were chosen for this study. The animals were assigned to group DC (disease control group), group G1 (single-PRP group), and group G2 (multiple-PRP group) containing 10, 10, and 12 animals, respectively. Another 4 animals were used for preparation of allogenic PRP. Groups G1 and G2 received 1 and 3 injections of PRP, respectively, at weekly intervals in the intervention knee while the contralateral knee was injected with normal saline. Group DC received no intervention in either knee. Half of the animals from each group (subgroups DC.3, G1.3, and G2.3) were sacrificed at 3 months, and the remaining half (subgroups DC.6, G1.6, and G2.6) were sacrificed at 6 months after intervention. Both knee joints were harvested for histological assessment of articular cartilage and synovium.

RESULTS

The mean synovial scores for groups G1 and G2 were significantly better than those for group DC at 3 months. No difference was found between groups G1 and G2 at 3 months. At 6 months, group G2 had significantly better mean synovial scores than group G1 and group DC. The mean articular cartilage scores in group G2 were significantly better than those in group DC at 3 months. However, at 6 months, no significant difference was found among any of the groups in terms of mean articular scores.

CONCLUSION

Both single and multiple injections of PRP exert similar anti-inflammatory effects on the synovium in the short term. However, this effect is sustained in the long term only for multiple injections. Multiple injections of PRP exert a chondroprotective effect, but only in the short term. This effect is not seen with a single injection of PRP.

CLINICAL RELEVANCE

This study provides insight into the histological basis for the superiority of multiple injections of PRP.

Centrifugation Conditions in the L-PRP Preparation Affect Soluble Factors Release and Mesenchymal Stem Cell Proliferation in Fibrin Nanofibers

Leukocyte and platelet-rich plasma (L-PRP) is an autologous product that when activated forms fibrin nanofibers, which are useful in regenerative medicine. As an important part of the preparation of L-PRP, the centrifugation parameters may affect the release of soluble factors that modulate the behavior of the cells in the nanofibers. In this study, we evaluated the influences of four different centrifugation conditions on the concentration of platelets and leukocytes in L-PRP and on the anabolic/catabolic balance of the nanofiber microenvironment. Human adipose-derived mesenchymal stem cells (h-AdMSCs) were seeded in the nanofibers, and their viability and growth were evaluated. L-PRPs prepared at 100× g and 100 + 400× g released higher levels of transforming growth factor (TGF)-β1 and platelet-derived growth factor (PDGF)-BB due to the increased platelet concentration, while inflammatory cytokines interleukin (IL)-8 and tumor necrosis factor (TNF)-α were more significantly released from L-PRPs prepared via two centrifugation steps (100 + 400× g and 800 + 400× g) due to the increased concentration of leukocytes. Our results showed that with the exception of nanofibers formed from L-PRP prepared at 800 + 400× g, all other microenvironments were favorable for h-AdMSC proliferation. Here, we present a reproducible protocol for the standardization of L-PRP and fibrin nanofibers useful in clinical practices with known platelet/leukocyte ratios and in vitro evaluations that may predict in vivo results.