Biochemical investigation of the effects of human platelet releasates on human articular chondrocytes

SOX9 functionalized scaffolds as a barrier to against cartilage fibrosis

Hyaline cartilage regeneration will bring evangel to millions of people suffered from cartilage diseases. However, uncontrollable cartilage fibrosis and matrix mineralization are the primary causes of cartilage regeneration failure in many tissue engineering scaffolds. This study presents a new attempt to avoid endochondral ossification or fibrosis in cartilage regeneration therapy by establishing biochemical regulatory area. Here, SOX9 expression plasmids are assembled in cellulose gels by chitosan gene vectors to fabricate SOX9+ functionalized scaffolds. RT-qPCR, western blot and biochemical analysis all show that the SOX9 reinforcement strategy can enhance chondrogenic specific proteins expression and promote GAG production. Notably, the interference from SOX9 has resisted osteogenic inducing significantly, showing an inhibition of COL1, OPN and OC production, and the inhibition efficiency was about 58.4 %, 22.8 % and 76.9 % respectively. In vivo study, implantation of these scaffolds with BMSCs can induce chondrogenic differentiation and resist endochondral ossification effectively. Moreover, specific SOX9+ functionalized area of the gel exhibited the resistance to matrix mineralization, indicating the special biochemical functional area for cartilage regeneration. These results indicate that this strategy is effective for promoting the hyaline cartilage regeneration and avoiding cartilage fibrosis, which provides a new insight to the future development of cartilage regeneration scaffolds.

Athlete-Specific Considerations of Cartilage Injuries

Cartilage injuries can present in a diverse setting of anatomic locations, with varying severity, and can impact athletes of all ages and competition levels. Moreover, the timing of when an injury presents introduces an additional dimension to treatment decision-making. Frequently, the level of competition, in conjunction with career trajectory and short-term and long-term athlete goals, will dictate whether a temporary or definitive treatment strategy is ideal. Although indicating the correct therapeutic regimen may prove challenging, understanding the athlete-specific considerations can be essential to meeting the goals of the athlete and other stakeholders involved in the athlete's career. The purpose of this review is to comprehensively present the deliberations a treating physician must consider in managing cartilage injuries within a spectrum of athletic levels ranging from youth to professional levels, with a secondary focus on the presentation of temporizing treatment strategies and associated outcomes.

Using Macrophage Polarization in Human Platelet Lysate to Test the Immunomodulatory Potential of Cells for Clinical Use

Macrophage-based co-cultures are used to test the immunomodulatory function of candidate cells for clinical use. This study aimed to characterize a macrophage polarization model using human platelet lysate (hPL) as a GMP-compliant alternative to Fetal Bovine Serum (FBS). Primary human monocytes were differentiated into unpolarized (M0) or polarized (M1, M2a, and M2c) macrophages in an hPL- or FBS-based medium. The protein secretion profiles and expression of phenotypic markers (CD80 for M1, CD206 for M2a, and CD163 for M2c) were analyzed. Subsequently, chondrocytes were tested in an hPL-based co-culture model to assess their immunomodulatory function in view of their possible use in patients with osteoarthritis. The results showed similar marker regulation between hPL and FBS cultures, but lower basal levels of CD206 and CD163 in hPL-cultured macrophages. Functional co-culture experiments with chondrocytes revealed increased CD206 expression both in hPL and in FBS, indicating an interaction between macrophages and chondrocytes. While markers in FBS-cultured macrophages were confirmed in hPL-cultured cells, the interpretation of marker modulation in immunomodulatory assays with hPL-based cultures should be carried out cautiously due to the observed differences in the basal marker levels for CD206 and CD163. This research underscores the utility of hPL as a GMP-compliant alternative to FBS for macrophage-based co-cultures and highlights the importance of understanding marker expressions in different culture conditions.

Utility of Platelet-Rich Plasma Therapy in the Management of Meniscus Injuries: A narrative review

Menisci are crucial for knee joint functions and meniscal tears are common injuries, especially in sports activities. Platelet-rich plasma (PRP), which enhances healing, has emerged as a promising additive treatment for meniscus injuries, utilizing the regenerative properties of platelets and growth factors for improved clinical outcomes. In studies with a follow-up period of less than one year, the use of platelet-rich plasma (PRP) therapy for meniscus injuries showed significant improvements in knee symptoms and daily activity. Patients experienced enhanced outcomes in terms of pain reduction and increased sports activity, with MRI scans indicating stable meniscus conditions after six months. Studies with a follow-up of more than one year, however, did not find significant differences between groups treated with PRP and groups not treated with PRP in terms of various outcome measures, including pain and knee function. The vascularization of the menisci is vital for their proper function, and insufficient blood supply can affect healing of meniscal injuries. PRP therapy is used to enhance meniscal healing by introducing growth factors and anti-inflammatory agents. PRP therapy may enable athletes with meniscal tears to return to sports more quickly and has less rehabilitation duration. While PRP seems promising as an alternative to failed treatment or as an adjunct to treatment in the short term, its long-term effectiveness remains inconclusive. Patient preferences, commitment to therapy rehabilitation, and cost should all be considered on an individual basis.

Effect of autologous platelet-rich plasma on new bone formation and viability of a Marburg bone graft

This study aimed to compare the new bone formation, the process of remodeling, and the viability of bone grafts, using a combination of platelet-rich plasma (PRP) and Marburg bone graft versus bone grafts without any additional elements. For this study, 48 rabbits (with 24 rabbits in each group) were used. Bone defects were made in the femur, and the bone graft used was the human femoral head prepared according to the Marburg Bone Bank. Rabbits were divided into the following groups: heat-treated bone graft (HTBG group) and HTBG with PRP (HTBG + PRP group). After 14, 30, and 60 days post-surgery, the assessment of the results involved X-ray, histopathological, and histomorphometric analyses. The greater new bone formation was detected in the HTBG + PRP group on the 14 and 30 day (p < 0.001). Furthermore, the group using bone grafts with PRP demonstrated notably enhanced remodeling, characterized by stronger bone integration, more significant graft remineralization, and a circular pattern of newly formed bone. The PRP-bone graft complex improves bone tissue repair in the bone defect in the initial stages of bone regeneration. PRP has been identified to enhance the remodeling process and amplify the osteoconductive and osteoinductive capabilities of HTBGs.

Comparative effectiveness of hyaluronic acid, platelet-rich plasma, and platelet-rich fibrin in treating temporomandibular disorders: a systematic review and network meta-analysis

OBJECTIVE

This study aims to compare the efficacy of intra-articular injections of hyaluronic acid (HA), platelet-rich plasma (PRP), and platelet-rich fibrin (PRF) for treating temporomandibular disorders (TMDs) and summarize their mechanisms of action.

METHODS

Randomized controlled trials (RCTs) published until November 13, 2021, were identified using electronic and manual searches. Each study was evaluated for the risk of bias using the Cochrane risk of bias tool. The studies found via searches were categorized by follow-up time (1, 3, or 6 months). Evidence quality was graded according to the GRADE system.

RESULTS

Twelve RCTs were included that involved 421 patients with TMD. The network meta-analysis showed that all treatment groups improved compared to the placebo groups in terms of pain and maximal mouth opening (MMO). For pain evaluated via the visual analog scale, PRF exhibited better analgesic effects than PRP or HA after 1 and 3 months. PRP appeared to be more effective than PRF was after 6 months but there were no statistically significant differences between the two. For MMO, the effect of PRP was superior to those of PRF and HA after 1 month. However, after 3 and 6 months, PRF provided more encouraging results in improving MMO.

CONCLUSION

PRP and PRF exhibited similar short-term efficacy in treating TMD, while PRF was more advantageous in terms of long-term efficacy. Therefore, PRF was recommended for treating TMD.

Current Progress of Platelet-Rich Derivatives in Cartilage and Joint Repairs

In recent years, several types of platelet concentrates have been investigated and applied in many fields, particularly in the musculoskeletal system. Platelet-rich fibrin (PRF) is an autologous biomaterial, a second-generation platelet concentrate containing platelets and growth factors in the form of fibrin membranes prepared from the blood of patients without additives. During tissue regeneration, platelet concentrates contain a higher percentage of leukocytes and a flexible fibrin net as a scaffold to improve cell migration in angiogenic, osteogenic, and antibacterial capacities during tissue regeneration. PRF enables the release of molecules over a longer period, which promotes tissue healing and regeneration. The potential of PRF to simulate the physiology and immunology of wound healing is also due to the high concentrations of released growth factors and anti-inflammatory cytokines that stimulate vessel formation, cell proliferation, and differentiation. These products have been used safely in clinical applications because of their autologous origin and minimally invasive nature. We focused on a narrative review of PRF therapy and its effects on musculoskeletal, oral, and maxillofacial surgeries and dermatology. We explored the components leading to the biological activity and the published preclinical and clinical research that supports its application in musculoskeletal therapy. The research generally supports the use of PRF as an adjuvant for various chronic muscle, cartilage, and tendon injuries. Further clinical trials are needed to prove the benefits of utilizing the potential of PRF.

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

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

Comparison of Functional Outcome of Single Versus Multiple Intra-articular Platelet-Rich Plasma Injection for Early Osteoarthritis Knee

Background Osteoarthritis (OA) is a leading cause of pain and disability and has a negative impact on patients' quality of life. Platelet-rich plasma (PRP) has emerged as a promising treatment for various orthopaedic conditions, such as tendinopathies, nonunion, and arthritis of the knee. We sought to determine whether a single intra-articular platelet-rich plasma injection has better functional and pain outcomes when compared with multiple (two) articular platelet-rich plasma injections given in the early stages of OA of the knee, measured using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the visual analogue scale for pain (VAS) at the sixth week, third month, and sixth month. Materials and methods The prospective observational study was conducted among patients diagnosed with early OA who presented to the Department of Orthopaedics, R. L. Jalappa Hospital and Research Centre, Kolar, Karnataka, India, between January 2020 and June 2021. A total of 64 patients were divided into: (i) S-PRP group (34 patients), which received a single PRP injection, and (ii) M-PRP group (30 patients), which received multiple (two) PRP injections, one on presentation and the second in the thirdmonth. VAS and WOMAC scores to assess functional outcomes were used at the first visit before the intervention and at the sixth week, third month, and sixth month. Results The average age of the patients was 55.26 years in the S-PRP group and 51.13 years in the M-PRP group. Both genders were equal among study participants in the M-PRP group, but 79.4% were females in the S-PRP group. In the S-PRP group, 74% had grade II OA and 26% had grade I OA. In the M-PRP group, 60% had grade II OA and the remaining 40% had grade I OA. The decreasing trend of pain and functional limitation, which was measured by VAS and WOMAC, respectively, was observed in both groups at pre-injection, sixth week, third month, and sixth month. These differences were statistically significant. The mean difference in VAS score between the pre-injection period and at six months was 4 in the S-PRP group, whereas it was 5.77 in the M-PRP group, and this was statistically significant (p-value = 0.001). Thus, multiple PRP injections have a greater response to pain reduction when compared to single PRP injections, according to the VAS score. According to the WOMAC score, there is no statistically significant difference in the treatment response with PRP injection between the S-PRP and M-PRP groups at any follow-up period. Conclusion According to the VAS score, single PRP injections have a lower pain score than multiple PRP injections until three months of follow-up, while at six months, single PRP injections have no better effect than multiple PRP injections. But multiple PRP injections have a higher reduction in the intensity of pain when compared to single PRP injections during the follow-up period. According to the WOMAC score, there is no statistically significant difference in the treatment response with PRP injection between S-PRP and M-PRP groups.

Inflammaging and Osteoarthritis

Osteoarthritis is a highly prevalent disease particularly in subjects over 65 years of age worldwide. While in the past it was considered a mere consequence of cartilage degradation leading to anatomical and functional joint impairment, in recent decades, there has been a more dynamic view with the synovium, the cartilage, and the subchondral bone producing inflammatory mediators which ultimately lead to cartilage damage. Inflammaging is defined as a chronic, sterile, low-grade inflammation state driven by endogenous signals in the absence of infections, occurring with aging. This chronic status is linked to the production of reactive oxygen species and molecules involved in the development of age-related disease such as cancer, diabetes, and cardiovascular and neurodegenerative diseases. Inflammaging contributes to osteoarthritis development where both the innate and the adaptive immune response are involved. Elevated systemic and local inflammatory cytokines and senescent molecules promote cartilage degradation, and antigens derived from damaged joints further trigger inflammation through inflammasome activation. B and T lymphocyte populations also change with inflammaging and OA, with reduced regulatory functions, thus implicating self-reactivity as an additional mechanism of joint damage. The discovery of the underlying pathogenic pathways may help to identify potential therapeutic targets for the management or the prevention of osteoarthritis. We will provide a comprehensive evaluation of the current literature on the role of inflammaging in osteoarthritis and discuss the emerging therapeutic strategies.

Efficacy of Platelet-Rich Plasma Versus Placebo in the Treatment of Tendinopathy: A Meta-analysis of Randomized Controlled Trials

OBJECTIVE

To evaluate the efficacy of platelet-rich plasma (PRP) injections versus placebo in the treatment of tendinopathy.

DATA SOURCES

We performed a systematic literature search in MEDLINE, Embase, Scopus, CINAHL, Cochrane Library, and ClinicalTrials.gov through November 2020 to identify randomized controlled trials (RCTs) that evaluated the clinical efficacy of PRP versus placebo for the treatment of tendinopathy. Outcomes were analyzed on an intention-to-treat basis with random-effects models.

MAIN RESULTS

A total of 13 RCTs were included in this meta-analysis. The pooled analysis showed no significant difference in pain relief at 4 to 6 weeks (standard mean difference [SMD]: -0.18, 95% confidence intervals [CI]: -0.62 to 0.26), 12 weeks (SMD: -0.14, 95% CI: -0.55 to 0.26), and ≥24 weeks (SMD: -0.56, 95% CI: -1.16 to 0.05) or function improvement at 4 to 6 weeks (SMD: 0.11, 95% CI: -0.13 to 0.35), 12 weeks (SMD: 0.18, 95% CI: -0.13 to 0.49), and ≥24 weeks (SMD: 0.26, 95% CI: -0.14 to 0.66) for PRP compared with placebo in the treatment of tendinopathy. The sensitivity analysis indicated no significant difference in pain relief or function improvement at 12 weeks between PRP and placebo for different types of tendinopathies, treatment regimens, leukocyte concentrations, or cointerventions.

CONCLUSIONS

Platelet-rich plasma injection was not found to be superior to placebo in the treatment of tendinopathy, as measured by pain relief and functional improvement at 4 to 6, 12, and ≥24 weeks.

Intra-Articular Leukocyte-Rich Platelet-Rich Plasma versus Intra-Articular Hyaluronic Acid in the Treatment of Knee Osteoarthritis: A Meta-Analysis of 14 Randomized Controlled Trials

(1) Background: To evaluate the clinical effects of leukocyte-rich platelet-rich plasma (LR-PRP) and hyaluronic acid (HA) injections in treating patients suffering from knee osteoarthritis (OA); (2) Methods: Randomized controlled trials (RCTs) were searched from PubMed, Web of Science, and Cochrane Library. Keywords were: platelet-rich plasma, LR-PRP, leukocyte-rich, hyaluronic acid, and knee osteoarthritis. The included RCTs were published between the 1st of November 2011 and the 3rd of February 2021. Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores, visual analog scale (VAS) scores, International Knee Documentation Committee (IKDC) scores, and adverse events were used as outcomes for evaluation; (3) Results: A total of 14 RCTs were enrolled. At 6 months, revealed that the LR-PRP group was better than the HA group in WOMAC total, pain, and physical function scores. At 12 months, the LR-PRP group was better than the HA group in WOMAC stiffness and physical function scores. There was no significant difference in adverse events; (4) Conclusion: LR-PRP injection showed no significant pain relief effect as compared with HA injection. However, LR-PRP demonstrated better overall outcomes as compared to HA in knee OA patients at the follow-up periods of 3, 6, and 12 months. LR-PRP injection may be recommended as a feasible option in treating patients with knee OA.

Repeated Intra-Articular Administration of Platelet-Rich Plasma (PRP) in Temporomandibular Disorders: A Clinical Case Series

Background: Temporomandibular joint disorders (TMDs) are manifested, inter alia, by pain and limited scope of the mandibular abduction. Among the treatment strategies for these ailments, intra-articular injections of autologous blood preparations, including platelet-rich plasma (PRP), are administered. This prospective case series was aimed at assessing the effectiveness of repeated platelet-rich plasma (PRP) administration to the TMJ cavities in terms of reducing articular pain and increasing the mobility of the mandible. Material and methods: 40 consecutive patients diagnosed with TMJ pain qualified for the case series. The entire treatment program consisted of five PRP administrations and a summary appointment. Regression was analyzed for (1) intensity of spontaneous pain; (2) effectiveness of spontaneous pain relief; (3) mastication efficiency values; (4) painless mandibular abduction; (5) maximum mouth opening. The correlations between the abovementioned variable series were analyzed. Results: The mean spontaneous pain decreased consistently with successive PRP administrations in line with the regression model: −0.4x + 4.2 (R2 = 0.98). Articular pain improvement was reported in 71% of joints treated. Improvement in chewing quality at the end of the entire injection cycle was found in 63% of patients. The equations for the linear regression models for painless mandibular abduction (five applications of PRP) and maximum mouth opening (the first four applications of PRP) were x + 34 (R2 = 0.89) and 0.6x + 43.6 (R2 = 0.96), respectively. Improvement in these domains was found in 78% and 53% of patients, respectively. The strongest correlations were found between pain and chewing efficiency (−0.95), pain and painless mandible abduction (−0.96), and painless mandibular abduction and mastication efficiency (0.94). Conclusion: PRP injections into TMJ cavities should be considered as a low invasive, highly accessible form of treatment for various TMDs causing pain and mandible movement limitation.

The Clinical Efficacy of Platelet-Rich Plasma versus Conventional Drug Injection in the Treatment of Knee Osteoarthritis: A Study Protocol for a Randomized Controlled Trial

Knee osteoarthritis is a common chronic degenerative joint disease in middle-aged and elderly people. Intra-articular injection for the treatment of knee osteoarthritis is a regularly utilized nonsurgical treatment in modern medicine. Hyaluronic acid (HA) and platelet-rich plasma (PRP) are two frequently employed intra-articular devices. Hyaluronic acid (HA) is an accepted nonsurgical treatment for symptomatic KOA, and platelet-rich plasma is a popular option in the treatment of KOA in recent years. The purpose of this research is to compare the efficacy and safety of intra-articular injection of platelet-rich plasma (PRP) versus hyaluronic acid (HA) on the pain score scale, knee function, and related inflammatory biomarkers in KOA patients using a clinical randomized controlled trial. Participants are being randomized into either the hyaluronic acid (HA) or into the platelet-rich plasma (PRP) group. All patients receive 4 weeks of treatment (once a week), and well-being support and quadriceps training (3 times a week). The primary outcomes are measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the visual analog scale (VAS). The secondary outcomes include the activities of daily living score, erythrocyte sedimentation rate, C-reactive protein testing, interleukin-6 levels, and X-ray examination. In order to monitor the occurrence of irregularities and abnormalities, patients are assessed at each visit, and restorative treatment is given if necessary. The results of this clinical trial will verify the efficacy of PRP and HA in the treatment of KOA and provide important evidence for the clinical treatment of KOA. The trial was enlisted at the Chinese Clinical Trial Registry on 26 September 2020 (ChiCTR2000038635).

Dynamics of Connexin 43 Down Modulation in Human Articular Chondrocytes Stimulated by Tumor Necrosis Factor Alpha

Connexin 43 (Cx43) exerts pivotal functions in articular chondrocytes (CH). It is involved in the communication among cells and between cells and the extracellular environment, and it contributes to the maintenance of the correct cell phenotype. The pro-inflammatory cytokine TNFα induces a reduction in Cx43 expression in CH. Here, we studied the dynamics of this decrease in expression. We evaluated Cx43 protein and gene expression and the involvement of C-terminal domain (CTD) cleavage and proteasomal degradation. Treatments able to counteract TNFα action were also examined, together with Gap Junction (GJ) functionality and Cx43 localization. TNFα induced a significant reduction in Cx43 expression already at day 1, and the down modulation reached a peak at day 3 (−46%). The decrease was linked to neither gene expression modulation nor CTD cleavage. Differently, the proteasome inhibitor MG132 reverted TNFα effect, indicating the involvement of proteasomal degradation in Cx43 reduction. In addition, the co-treatment with the anabolic factor TGF-β1 restored Cx43 levels. Cx43 decrease occurred both at the membrane level, where it partially influenced GJ communication, and in the nucleus. In conclusion, TNFα induced a rapid and lasting reduction in Cx43 expression mostly via the proteasome. The down modulation could be reverted by cartilage-protective factors such as MG132 and TGF-β1. These findings suggest a possible involvement of Cx43 perturbation during joint inflammation.

Clinical Effect of Bushen Huoxue Method Combined with Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis and Its Effect on IL-1, IL-6, VEGF, and PGE-2

Objective

To observe the clinical efficacy of the Bushen Huoxue method combined with platelet-rich plasma (PRP) in the treatment of knee osteoarthritis (KOA) and its effect on serum and joint fluid interleukin-1 (IL-1), interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), and prostaglandin E2 (PGE-2).

Methods

A total of 64 cases of KOA diagnosed and treated from January 2020 to January 2021 were randomly divided into research group and control group, with 32 cases in each group. The control group was treated with PRP, and the research group took the prescription of the Bushen Huoxue method on the basis of the control group. The clinical efficacy was assessed according to the criteria in "the diagnosis and Treatment of osteoarthritis," osteoarthritis index score and pain visual analogue score (VAS). Serum and articular fluid VAS, IL-1, IL-6, VEGF, and PGE-2 levels were detected by the enzyme-linked immunosorbent assay (ELISA).

Results

The clinical effective rate of the research group was 93.8%, which was significantly higher than that of the control group (90.6%). There was no significant difference in the scores of osteoarthritis index between the two groups before treatment, but the scores of both groups decreased after treatment and was lower in the research group than those in the control group. VAS was significantly decreased in two groups after treatment and it was lower in the research group than that in the control group. After treatment, the levels of IL-1, IL-6, and PGE-2 in serum and articular fluid all indexes were decreased, and the levels in the research group were lower than those in the control group.

Conclusions

PRP joint cavity injection combined with oral administration of Bushen Huoxue prescription, and PRP joint cavity injection alone can improve the efficacy of KOA, relieve knee pain, and promote the recovery of knee function. The mechanism may be related to the reduction of IL-1, IL-6, VEGF levels, and PGE-2 levels in the serum and joint fluid. However, the efficacy of combination therapy was superior to PRP alone.

Retrospective Analysis of Autologous Chondrocyte-Based Cytotherapy Production for Clinical Use: GMP Process-Based Manufacturing Optimization in a Swiss University Hospital

Cultured autologous human articular chondrocyte (HAC) implantation has been extensively investigated for safe and effective promotion of structural and functional restoration of knee cartilage lesions. HAC-based cytotherapeutic products for clinical use must be manufactured under an appropriate quality assurance system and follow good manufacturing practices (GMP). A prospective clinical trial is ongoing in the Lausanne University Hospital, where the HAC manufacturing processes have been implemented internally. Following laboratory development and in-house GMP transposition of HAC cell therapy manufacturing, a total of 47 patients have been treated to date. The main aim of the present study was to retrospectively analyze the available manufacturing records of the produced HAC-based cytotherapeutic products, outlining the inter-individual variability existing among the 47 patients regarding standardized transplant product preparation. These data were used to ameliorate and to ensure the continued high quality of cytotherapeutic care in view of further clinical investigations, based on the synthetic analyses of existing GMP records. Therefore, a renewed risk analysis-based process definition was performed, with specific focus set on process parameters, controls, targets, and acceptance criteria. Overall, high importance of the interdisciplinary collaboration and of the manufacturing process robustness was underlined, considering the high variability (i.e., quantitative, functional) existing between the treated patients and between the derived primary HAC cell types.

A single intraarticular platelet-rich plasma improves pain and function for patients with early knee osteoarthritis: Analyses by radiographic severity and age

BACKGROUND

Most studies use platelet-rich plasma (PRP) requiring multiple intraarticular injections for knee osteoarthritis (OA).

OBJECTIVE

To investigate the efficacy of a single intraarticular PRP injection for patients with early knee OA and consider subgroup analyses of radiographic severity and age, respectively.

METHODS

Forty-one patients with knee OA (Kellgren-Lawrence grade 1-2) received a single PRP injection into the target knee and were assessed at baseline and 1, 3, and 6 months postinjection. The primary outcome was the mean change from baseline in the visual analog scale (VAS) pain (0-100 mm) at 6 months postinjection. Secondary outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lequesne index, single leg stance test (SLS), use of rescue analgesics and patients' satisfaction.

RESULTS

Thirty-eight patients completed the study. The mean pain VAS decreased significantly from 45.6 ± 13.0 mm at baseline to 16.9 ± 13.4 mm, 14.0 ± 13.1 mm and 15.5 ± 14.0 mm at 1, 3 and 6-month follow-ups (p< 0.001 for all). Significant improvements in WOMAC, Lequesne index, SLS and consumption of analgesics from baseline (p< 0.001 for all) were noted at each follow-up. Patients' satisfaction was high. No serious adverse events occurred. Subgroup analyses revealed that patients with grade 1 OA showed significantly greater VAS pain reduction at 3 months (p= 0.006) and 6 months (p= 0.005) than patients with grade 2 OA. The older-age group (age > 60) showed significantly greater improvements in VAS pain, WOMAC function subscale scores and total scores at 6-month postinjection, compared with the younger age-group (age ≤ 60). The younger-age group reported better satisfaction at 1 and 3-month postinjection.

CONCLUSIONS

One injection of PRP improved pain and function for 6 months for patients with early knee OA. This study supports putting the one-injection regimen into clinical practice. Further research is needed for more definite conclusions.

Chondroprotective effects of multiple PRP injections in osteoarthritis by apoptosis regulation and increased aggrecan synthesis- Immunohistochemistry based Guinea pig study

OBJECTIVE

Use of Immunohistochemistry as a tool to assess anti-apoptotic effects and cartilage regeneration effects of PRP in guinea pig model of spontaneous OA.

STUDY DESIGN

Controlled Laboratory Study involving Dunkin-Hartley guinea pigs.

METHODS

12 Dunkin-Hartley guinea pigs (weighing ∼600-800 g) were chosen for this study. One knee of each animal received 3 injections of allogenic PRP at weekly intervals (Group A = 12 Knees). The other knee received normal saline and acted as the control group (Group B = 12 Knees). Half of the animals from each group (subgroups A3 & B3 = 6 Knees each) were sacrificed at 3 months, and the remaining half (subgroups A6 & B6 = 6 Knees each) were sacrificed at 6 months after intervention. Immunohistochemistry (IHC) staining and evaluation were done for Collagen-II, Caspase-3 and Aggrecan.

RESULTS

The mean IHC score for Caspase-3 were significantly low in PRP knees compared to placebo Knees at 3 months (P = 0.031) and 6 months (P = 0.012) suggesting its down-regulation and inhibition of apoptosis. The mean IHC score for content of collagen- II and aggrecan at 3 months were higher in PRP Knees (A3) compared to placebo (B3) (Not significant). At 6 months, the Mean IHC Score decreased in both PRP (A6) and Control Knees (B6) for Collagen, but increased for aggrecan compared to its value at 3 months; and this was better in PRP group than in the control (P = 0.024).

CONCLUSION

Multiple injections of PRP has a chondroprotective role by its anti-apoptotic effect and by increasing the aggrecan content in ECM.

Effect of Combined Leukocyte-Poor Platelet-Rich Plasma and Hyaluronic Acid on Bone Marrow-Derived Mesenchymal Stem Cell and Chondrocyte Metabolism

OBJECTIVE

Given the potential applications of combined biologics, the authors sought to evaluate the in vitro effect of combined platelet-rich plasma (PRP) and hyaluronic acid (HA) on cellular metabolism.

DESIGN

Bone marrow-derived mesenchymal stem cells (BMSCs) and chondrocytes were obtained from the femurs of Sprague-Dawley rats. An inflammatory model was created by adding 10 ng/mL interleukin-1-beta to culture media. Non-crosslinked high-molecular-weight HA, activated-PRP (aPRP), and unactivated-PRP (uPRP) were tested. Cellular proliferation and gene expression were measured at 1 week. Genes of interest included aggrecan, matrix metalloproteinase (MMP)-9, and MMP-13.

RESULTS

Combined uPRP-HA was associated with a significant increase in chondrocyte and BMSC proliferation at numerous preparations. There was a trend of increased chondrocyte aggrecan expression with combined PRP-HA. The greatest and only significant decrease in BMSC MMP-9 expression was observed with combined PRP-HA. While a significant reduction of BMSC MMP-13 expression was seen with PRP and HA-alone, a greater reduction was observed with PRP-HA. MMP-9 chondrocyte expression was significantly reduced in cells treated with PRP-HA. PRP-alone and HA-alone at identical concentrations did not result in a significant reduction. The greatest reduction of MMP-13 chondrocyte expression was observed in chondrocytes plus combined PRP-HA.

CONCLUSIONS

We demonstrated a statistically significant increase in BMSC and chondrocyte proliferation and decreased expression of catabolic enzymes with combined PRP-HA. These results demonstrate the additive in vitro effect of combined PRP-HA to stimulate cellular growth, restore components of the articular extracellular matrix, and reduce inflammation.

Human Platelet Lysate as an Alternative to Autologous Serum for Human Chondrocyte Clinical Use

OBJECTIVE

A pivotal aspect of cartilage tissue engineering resides in cell culture medium supplementation, in view of maximizing in vitro cell proliferation and preserving cellular functionality. Autologous human serum (aHS) is commonly used as an inducive supplement for safe human articular chondrocyte (HAC) proliferation prior to clinical implantation. However, practical clinical use of aHS is hindered by constraining manufacturing requirements and quality assurance-driven downstream processing. The present study investigated potential alternative use of commercial human platelet lysate (hPL) supplements in HAC manufacturing workflows related to clinical therapeutic pathways.

DESIGN

Differential effects of hPL, aHS, and fetal bovine serum were assessed on primary cultured HAC parameters (viability, proliferative rates, and morphology) in 2-dimensional in vitro systems. A 3-dimensional HAC pellet model served for postexpansion assessment of cellular functionality, by visualizing proteoglycan production (Alcian blue staining), and by using qRT-PCR relative quantification of chondrogenic marker (SOX9, COL2-A1, and ACAN) genetic expression.

RESULTS

We found that monolayer HAC culture with hPL or aHS supplements presented similar characteristics (elongated cell morphology and nearly identical growth kinetics). Chondrogenic activity appeared as conserved in HACs expanded with human or bovine supplements, wherein histologic analysis indicated a progressive sGAG accumulation and SOX9, COL2-A1, ACAN gene expression was upregulated in 3-dimensional HAC pellet models.

CONCLUSION

This study therefore supports the use of hPL as a functional equivalent and alternative to aHS for cultured HAC batch preparation, with the potential to effectively alleviate pressure on clinical and manufacturing bottlenecks in cell therapy approaches for cartilage regeneration.

Evaluation of the influence of platelet-rich plasma (PRP), platelet lysate (PL) and mechanical loading on chondrogenesis in vitro

The aim of this work is to investigate the capability of PRP as an adjuvant therapy to autologous chondrocyte implantation (ACI) in combination with multi-axial load with respect to cartilage regeneration. Articular cartilage shows poor repair capacity and therapies for cartilage defects are still lacking. Well-established operative treatments include ACI, and growing evidence shows the beneficial effects of PRP. Platelets contain numerous growth factors, among them transforming growth factor beta (TGF-β). Dynamic mechanical loading is known to be essential for tissue formation, improving extracellular matrix (ECM) production. For our ACI model monolayer expanded human chondrocytes were seeded into polyurethane scaffolds and embedded in fibrin (hChondro), in PRP-Gel (PRP), or in fibrin with platelet lysate (PL), which was added to the media once a week with a concentration of 50 vol%. The groups were either exposed to static conditions or multi-axial forces in a ball-joint bioreactor for 1 h per day over 2 weeks, mimicking ACI under physiological load. The culture medium was collected and analyzed for glycosaminoglycan (GAG), nitrite and transforming growth factor beta 1 (TGF-β1) content. The cell-scaffold constructs were collected for DNA and GAG quantification; the expression of chondrogenic genes, TGF-β and related receptors, as well as inflammatory genes, were analyzed using qPCR. Loading conditions showed superior chondrogenic differentiation (upregulation of COL2A1, ACAN, COMP and PRG4 expression) than static conditions. PRP and PL groups combined with mechanical loading showed upregulation of COL2A1, ACAN and COMP. The highest amount of total TGF-β1 was quantified in the PL group. Latent TGF-β1 was activated in all loaded groups, while the highest amount was found in the PL group. Load increased TGFBR1/TGFBR2 mRNA ratio, with further increases in response to supplements. In general, loading increased nitrite release into the media. However, over time, the media nitrite content was lower in the PL group compared to the control group. Based on these experiments, we conclude that chondrogenic differentiation is strongest when simulated ACI is performed in combination with dynamic mechanical loading and PRP-gel or PL supplementation. An inflammatory reaction was reduced by PRP and PL, which could be one of the major therapeutic effects. Loading presumably can enhance the action of TGF-β1, which was predominantly activated in loaded PL groups. The combination of load and PRP represents an effective and promising synergy concerning chondrocyte-based cartilage repair.

Optimization of Lyophilized Hyperacute Serum (HAS) as a Regenerative Therapeutic in Osteoarthritis

Hyperacute serum (HAS) is a blood derivative product that promotes the proliferation of various cell types and controls inflammation in vitro. The aim of this study is to investigate the regenerative potential of different formulations of HAS, including lyophilized and hyaluronic acid combined versions, to obtain a stable and standardized therapeutic in osteoarthritis (OA), which may be able to overcome the variability limitations of platelet-rich plasma (PRP). Primary human osteoarthritic chondrocytes were used for testing cellular viability and gene expression of OA-related genes. Moreover, a co-culture of human explants of cartilage, bone and synovium under inflammatory conditions was used for investigating the inflammatory control capacities of the different therapeutics. In this study, one formulation of lyophilized HAS achieved the high cell viability rates of liquid HAS and PRP. Gene expression analysis showed that HAS induced higher Col1a1 expression than PRP. Cytokine quantification from supernatant fluids revealed that HAS treatment of inflamed co-cultures significantly reduced levels of IL-5, IL-15, IL-2, TNFα, IL-7 and IL-12. To conclude, lyophilized HAS is a stable and standardized therapeutic with high potential in joint regeneration.

Applications of Biocompatible Scaffold Materials in Stem Cell-Based Cartilage Tissue Engineering

Cartilage, especially articular cartilage, is a unique connective tissue consisting of chondrocytes and cartilage matrix that covers the surface of joints. It plays a critical role in maintaining joint durability and mobility by providing nearly frictionless articulation for mechanical load transmission between joints. Damage to the articular cartilage frequently results from sport-related injuries, systemic diseases, degeneration, trauma, or tumors. Failure to treat impaired cartilage may lead to osteoarthritis, affecting more than 25% of the adult population globally. Articular cartilage has a very low intrinsic self-repair capacity due to the limited proliferative ability of adult chondrocytes, lack of vascularization and innervation, slow matrix turnover, and low supply of progenitor cells. Furthermore, articular chondrocytes are encapsulated in low-nutrient, low-oxygen environment. While cartilage restoration techniques such as osteochondral transplantation, autologous chondrocyte implantation (ACI), and microfracture have been used to repair certain cartilage defects, the clinical outcomes are often mixed and undesirable. Cartilage tissue engineering (CTE) may hold promise to facilitate cartilage repair. Ideally, the prerequisites for successful CTE should include the use of effective chondrogenic factors, an ample supply of chondrogenic progenitors, and the employment of cell-friendly, biocompatible scaffold materials. Significant progress has been made on the above three fronts in past decade, which has been further facilitated by the advent of 3D bio-printing. In this review, we briefly discuss potential sources of chondrogenic progenitors. We then primarily focus on currently available chondrocyte-friendly scaffold materials, along with 3D bioprinting techniques, for their potential roles in effective CTE. It is hoped that this review will serve as a primer to bring cartilage biologists, synthetic chemists, biomechanical engineers, and 3D-bioprinting technologists together to expedite CTE process for eventual clinical applications.

Efficacy of platelet-rich plasma injections in patients with adhesive capsulitis of the shoulder

PURPOSE

The goal of this study is to investigate whether platelet-rich plasma (PRP) injections are effective in the management of adhesive capsulitis of the shoulder (AC). A triple-blind, randomized controlled trial was designed and conducted in a medical school hospital.

METHODS

32 adult patients with adhesive capsulitis (21 female, 11 male with a mean age of 57, ranging from 23 to 70) were included in this study. Patients had to have shoulder pain and restrictions in movements (at least 25% when compared to the other side, and at least in two directions) for three months minimum and nine months maximum. Patients were randomized to two groups, and one group took PRP injections for three times every two weeks, while the other group took saline injections in same frequency and volume. A standardized exercise program was also applied to all patients. Patients were evaluated with Shoulder Pain and Disability Index (SPADI), Visual Analogue Scales for pain and disability, ranges of movements, and use of analgesics in before, after, and third month after the initiation of the therapy.

RESULTS

Baseline comparisons between groups showed no differences. SPADI and ranges of motion in all directions showed significant improvements with therapy, and the group which took PRP injections showed better improvements when compared to the control group (p < 0.05). Visual Analogue Scale was found to be better for the PRP group after therapy and third month, and not for the control group (0.4 ± 1.06 and 0.17 ± 0.72 vs. 2.5 ± 2.6 and 2 ± 2.2, respectively, p < 0.05). Use of analgesics was not found to be significant for both groups (p > 0.05).

CONCLUSION

PRP injections were found to be effective in both pain and disability, and showed improvements in a restricted shoulder due to adhesive capsulitis. These findings might point out PRP as a therapeutic option in the management of adhesive capsulitis.

Efficacy of platelet-rich plasma in the treatment of hemiplegic shoulder pain

OBJECTIVE

The aim of this study was to examine the effects of platelet-rich plasma (PRP) on pain and functional outcomes in patients with hemiplegic shoulder pain. We compared the effects of PRP against saline solution by designing a double blind, randomized, prospective study.

DESIGN

Forty-four patients with hemiplegia were included in this study. All patients received a total of 3 injections, 1 week apart. The first group received PRP injections while the second group received placebo injections. After 3 months of follow-up, 40 patients completed the trial. Primary outcome measure was movement-induced pain score (VAS), and secondary outcome measures were spontaneous pain score, shoulder passive range of motion (ROM), functional independence measure score, and the amount of paracetamol used. All subjects were evaluated at baseline, 1 week, 1 month, and 3 months after the completion of the last injection.

RESULTS

Both groups showed an improvement in spontaneous and movement-related pain scores and shoulder passive ROM values on 1st and 3rd month visits (p < 0.05). No significance difference was detected between groups (p > 0.05). Similarly, FIM scores improved significantly in both groups (p < 0.05) but no difference was found between groups. Paracetamol use did not differ significantly between groups.

CONCLUSION

The PRP injections were found not to be superior to placebo. Improvements in both groups can be attributed to the use of rehabilitation techniques and exercises in all patients. There is still need for further research to show whether PRP is a treatment option in the course of hemiplegic shoulder pain.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03931824.

Platelet lysate reduces the chondrocyte dedifferentiation during in vitro expansion: Implications for cartilage tissue engineering

In vitro studies have demonstrated that platelet lysate (PL) can serve as an alternative to platelet-rich plasma (PRP) to sustain chondrocyte proliferation and production of extracellular matrix components in chondrocytes. The present study aimed to evaluate the direct effects of PL on equine articular chondrocytes in vitro in order to provide a rationale for in vivo use of PL. An in vitro cell proliferation and de-differentiation model was used: primary articular chondrocytes isolated from horse articular cartilage were cultured at low density under adherent conditions to promote cell proliferation. Chondrocytes were cultured in serum-free medium, 10% foetal bovine serum (FBS) supplemented medium, or in the presence of alginate beads containing 5%, 10% and 20% PL. Cell proliferation and gene expression of relevant chondrocyte differentiation markers were investigated. The proliferative capacity of cultured chondrocytes, was sustained more effectively at certain concentrations of PL as compared to that with FBS. In addition, as opposed to FBS, PL, particularly at percentages of 5% and 10%, could maintain the gene expression pattern of relevant chondrocyte differentiation markers. In particular, 5% PL supplementation showed the best compromise between chondrocyte proliferation capacity and maintenance of differentiation. The results of the present study provide a rationale for using PL as an alternative to FBS for in vitro expansion of chondrocytes for matrix-assisted chondrocyte implantation, construction of 3D scaffolds for tissue engineering, and treatment of damaged articular cartilage.

Regenerative effects of hyperbaric oxygen therapy and platelet-rich plasma on the osteochondral defects of rats

Objectives

This study aims to investigate the effects of hyperbaric oxygen (HBO) therapy and platelet-rich plasma (PRP) on the regeneration of osteochondral defects of the rats, and the synergistic effect of this combined treatment.

Materials and methods

This randomized, controlled, and interventional animal study was conducted between May 2014 and August 2014 Osteochondral regeneration was evaluated in four treatment groups (control, PRP, HBO, and HBO+PRP groups) at the 30th day after iatrogenic injury. Thirty-two female Wistar albino rats (weighing 248-305 g) underwent arthrotomy and osteochondral surgery on left knees. The regenerations of defects were then examined histologically by the modified version of O’Driscoll score.

Results

Groups that were treated with either HBO or PRP alone regenerated significantly better than the control group (p=0.01), while no significant difference was found between the HBO- and PRP-treated groups (p>0.05). The defects in group 4 (treated with both HBO and PRP) regenerated significantly better than the control group, the HBO-treated group alone, and the PRP-treated group alone (p=0.01).

Conclusion

The results of this study showed a synergistic effect of HBO and PRP on knee cartilage regeneration. However, the possible underlying mechanisms should be the subject of future researches. The aggregation and activation of growth factors released from platelets whose activation is increased in the hyperbaric environment may explain this effect. This may result in a better regeneration than the effect of PRP or HBO alone.

Dose-Dependent Effects of Platelet-Rich Plasma Powder on Chondrocytes In Vitro

BACKGROUND

Platelet-rich plasma (PRP) is widely used in sports medicine. However, neither preparation nor parameters for clinical application, such as concentration, timing, and number of applications, are standardized, making research and clinical utilization challenging.

PURPOSE

To investigate the effect of varying doses of PRP powder in terms of different concentrations, timing, and number of applications on human chondrocytes in a reproducible cell culture model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A standardized lyophilized platelet growth factor preparation (PRP powder) was used to stimulate human chondrocytes. Chondrocytes were cultivated for 2 weeks with different stimulation frequencies (2×, 3×, 6×) and different concentrations of PRP powders (0.5%, 1%, 5%). Cell proliferation and metabolic cell activity were analyzed on days 7 and 14. Phenotypic changes were visualized through live-dead staining. Chondrogenic differentiation was quantified with enzyme-linked immunosorbent assay to assess the synthesis of procollagen types 1 and 2. Furthermore, sulfated proteoglycans and glycosaminoglycans were analyzed.

RESULTS

Human chondrocytes exhibited a significant dose- and time-dependent increase after 14 days in cell number (1% and 5% PRP powder vs unstimulated control: 7.95- and 15.45-fold increase, respectively; 2× vs 6× stimulation with 5% PRP powder: 4.00-fold increase) and metabolic cell activity (1% and 5% PRP powder vs unstimulated control: 3.27-fold and 3.58-fold change, respectively). Furthermore, cells revealed a significant increase in the amount of bone-specific procollagen type 1 (14 days, 1.94-fold) and sulfated glycosaminoglycans (14 days, 2.69-fold); however, no significant change was observed in the amount of cartilage-specific collagen type 2.

CONCLUSION

We showed that chondrocytes exhibit a significant dose- and time-dependent increase in cell number and metabolic cell activity. The standardized use of growth factor concentrates in cell culture models can contribute to clinical knowledge in terms of dosage and timing of PRP applications.

CLINICAL RELEVANCE

Problems with PRP, such as the absence of standardization, lack of consistency among studies, and unknown dosage, could be solved by using characterized PRP powder made by pooling and lyophilizing multiple platelet concentrates. The innovative PRP powder generates new possibilities for PRP research, as well as for the treatment of patients.

Platelet-Rich Plasma Augmentation to Microfracture Provides a Limited Benefit for the Treatment of Cartilage Lesions: A Meta-analysis

Background:

Microfracture is the most common first-line option for the treatment of small chondral lesions, although increasing evidence shows that the clinical benefit of microfracture decreases over time. Platelet-rich plasma (PRP) has been suggested as an effective biological augmentation to improve clinical outcomes after microfracture.

Purpose:

To evaluate the clinical evidence regarding the application of PRP, documenting safety and efficacy of this augmentation technique to improve microfracture for the treatment of cartilage lesions.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A systematic review was performed in PubMed, EBSCOhost database, and the Cochrane Library to identify comparative studies evaluating the clinical efficacy of PRP augmentation to microfracture. A meta-analysis was performed on articles that reported results for visual analog scale (VAS) for pain, International Knee Documentation Committee (IKDC), and American Orthopaedic Foot and Ankle Society (AOFAS) scores. Risk of bias was documented through use of the Cochrane Collaboration Risk of Bias 2.0 and Risk of Bias in Non-randomized Studies of Interventions assessment tools. The quality assessment was performed according to the Grading of Recommendations Assessment, Development and Evaluation guidelines.

Results:

A total of 7 studies met the inclusion criteria and were included in the meta-analysis: 4 randomized controlled trials, 2 prospective comparative studies, and 1 retrospective comparative study, for a total of 234 patients. Of the 7 studies included, 4 studies evaluated the effects of PRP treatment in the knee, and 3 studies evaluated effects in the ankle. The analysis of all scores showed a difference favoring PRP treatment in knees (VAS, P = .002 and P < .001 at 12 and 24 months, respectively; IKDC, P < .001 at both follow-up points) and ankles (both VAS and AOFAS, P < .001 at 12 months). The improvement offered by PRP did not reach the minimal clinically important difference (MCID).

Conclusion:

PRP provided an improvement to microfracture in knees and ankles at short-term follow-up. However, this improvement did not reach the MCID, and thus it was not clinically perceivable by the patients. Moreover, the overall low evidence and the paucity of high-level studies indicate further research is needed to confirm the potential of PRP augmentation to microfracture for the treatment of cartilage lesions.

Platelet-rich plasma versus hyaluronic acid in the treatment of knee osteoarthritis: A meta-analysis

BACKGROUND

This meta-analysis focuses on the controversial efficacy and safety of platelet-rich plasma (PRP) as compared with hyaluronic acid (HA) in the clinical treatment of knee osteoarthritis. We have attempted to provide an evidence-based medicine protocol for the conservative treatment of knee osteoarthritis. In addition, we included the latest relevant literature in this meta-analysis, and a staging study was conducted to compare the therapeutic effects of PRP and HA for knee osteoarthritis over different time periods.

METHODS

An online computer search with "platelet-rich plasma" and "knee osteoarthritis" as search terms was conducted in the PubMed, EMBASE, and Cochrane Library databases. We conducted a quality assessment of the retrieved literature and extracted the following indicators: visual analog scale (VAS) score, subjective International Knee Documentation Committee (IKDC) score, Western Ontario and McMaster Universities (WOMAC) score, Knee Injury and Osteoarthritis Outcome Score (KOOS), and adverse events. RevMan5.3 software was used to determine the effect sizes, and indicators were compared across studies at three different time points from the administration of treatment.

RESULTS

A total of 14 randomized controlled trials (RCTs) involving 1350 patients were included. Long-term VAS, IKDC, WOMAC-Pain, WOMAC-Stiffness, WOMAC-Physical Function, and WOMAC-Total scores at each time point were higher in the PRP group than in the HA group. There were no significant differences in the remaining indicators between the two groups.

CONCLUSION

Compared with HA, PRP offers obvious advantages in the conservative treatment of knee osteoarthritis. Treatment with PRP can reduce long-term pain and improve knee joint function with no additional risks. Therefore, PRP can be widely used for the conservative treatment of knee osteoarthritis.

Platelet-Rich Fibrin Facilitates One-Stage Cartilage Repair by Promoting Chondrocytes Viability, Migration, and Matrix Synthesis

The main aim of this study is to develop a one-stage method to combine platelet-rich fibrin (PRF) and autologous cartilage autografts for porcine articular cartilage repair. The porcine chondrocytes were treated with different concentrations of PRF-conditioned media and were evaluated for their cell viability and extracellular glycosaminoglycan (GAG) synthesis during six day cultivation. The chemotactic effects of PRF on chondrocytes on undigested cartilage autografts were revealed in explant cultures. For the in vivo part, porcine chondral defects were created at the medial femoral condyles of which were (1) left untreated, (2) implanted with PRF combined with hand-diced cartilage grafts, or (3) implanted with PRF combined with device-diced cartilage grafts. After six months, gross grades, histological, and immunohistochemical analyses were compared. The results showed that PRF promotes the viability and GAG expression of the cultured chondrocytes. Additionally, the PRF-conditioned media induce significant cellular migration and outgrowth of chondrocytes from undigested cartilage grafts. In the in vivo study, gross grading and histological scores showed significantly better outcomes in the treatment groups as compared with controls. Moreover, both treatment groups showed significantly more type II collagen staining and minimal type I collagen staining as compared with controls, indicating more hyaline-like cartilage and less fibrous tissue. In conclusion, PRF enhances the viability, differentiation, and migration of chondrocytes, thus, showing an appealing capacity for cartilage repair. The data altogether provide evidences to confirm the feasibility of a one-stage, culture-free method of combining PRF and cartilage autografts for repairing articular cartilage defects. From translational standpoints, these advantages benefit clinical applications by simplifying and potentiating the efficacy of cartilage autograft transplants.

Platelet-rich plasma combined with allograft to treat osteochondritis dissecans of the knee: a case report

BACKGROUND

Osteochondritis dissecans of the knee is a prevalent pathology in young, active people that is brought about by either traumatic, developmental, or iatrogenic etiologies.

CASE PRESENTATION

A 40-year-old Caucasian man reporting pain, swelling, and functional reduction was evaluated and diagnosed with internal condyle osteochondritis dissecans of the knee. Harnessing the trophic, chondroprotective, anti-inflammatory, and immunomodulatory properties of platelet-rich plasma, we carried out a knee open-sky surgical technique in which we combined autologous therapy with osteochondral allograft to treat the focal, large, and deep traumatic-iatrogenic osteochondritis dissecans of the knee. The axial computed tomographic scan taken 1 year after surgery revealed an area of abnormal signal intensity that was reduced on a computed tomographic scan 2 years later. The computed tomographic scan obtained 2 years later and the magnetic resonance imaging scan 3 years later also showed a clear reattachment and incorporation of the graft. Seven years after the surgery, the patient resumed his daily routine without any recurrent symptoms.

CONCLUSION

Platelet-rich plasma application in osteochondral allograft implantation open surgery could enhance the healing process of medial condyle osteochondritis dissecans of the knee.

The Role of Platelet-Rich Plasma in Cartilage Pathology: An Updated Systematic Review of the Basic Science Evidence

PURPOSE

To review the basic science studies on platelet-rich plasma (PRP) for cartilage and determine whether there has been an improvement in methodology and outcome reporting that would allow for a more meaningful analysis regarding the mechanism of action and efficacy of PRP for cartilage pathology.

METHODS

The PubMed/MEDLINE and EMBASE databases were screened in May 2017 with publication dates of January 2011 through May 2017 using the following key words: "platelet-rich plasma OR PRP OR autologous conditioned plasma (ACP) OR ACP AND cartilage OR chondrocytes OR chondrogenesis OR osteoarthritis OR arthritis." Two authors independently performed the search, determined study inclusion, and extracted data. Data extracted included cytology/description of PRP, study design, and results.

RESULTS

Twenty-seven studies (11 in vitro, 13 in vivo, 3 in vitro and in vivo) met the inclusion criteria and were included in the study. All of the studies (100%) reported the method by which PRP was prepared. Two studies reported basic cytologic analysis of PRP, including platelet, white blood cell, and red blood cell counts (6.7%). Nine studies reported both platelet count and white blood cell count (30.0%). Twelve studies reported platelet count alone (40.0%). Nine studies (30.0%) made no mention at all as to the composition of the PRP used. PRP was shown to increase cell viability, cell proliferation, cell migration, and differentiation. Several studies demonstrated increased proteoglycan and type II collagen content. PRP decreased inflammation in 75.0% of the in vitro studies reporting data and resulted in improved histologic quality of the cartilage tissue in 75.0% of the in vivo studies reporting data.

CONCLUSIONS

Although the number of investigations on PRP for cartilage pathology has more than doubled since 2012, the quality of the literature remains limited by poor methodology and outcome reporting. A majority of basic science studies suggest that PRP has beneficial effects on cartilage pathology; however, the inability to compare across studies owing to a lack of standardization of study methodology, including characterizing the contents of PRP, remains a significant limitation. Future basic science and clinical studies must at a minimum report the contents of PRP to better understand the clinical role of PRP for cartilage pathology.

CLINICAL RELEVANCE

Establishing proof of concept for PRP to treat cartilage pathology is important so that high-quality clinical studies with appropriate indications can be performed.

Redifferentiation of Articular Chondrocytes by Hyperacute Serum and Platelet Rich Plasma in Collagen Type I Hydrogels

Matrix-assisted autologous chondrocyte transplantation (MACT) for focal articular cartilage defects often fails to produce adequate cartilage-specific extracellular matrix in vitro and upon transplantation results in fibrocartilage due to dedifferentiation during cell expansion. This study aimed to redifferentiate the chondrocytes through supplementation of blood-products, such as hyperacute serum (HAS) and platelet-rich plasma (PRP) in vitro. Dedifferentiated monolayer chondrocytes embedded onto collagen type I hydrogels were redifferentiated through supplementation of 10% HAS or 10% PRP for 14 days in vitro under normoxia (20% O₂) and hypoxia (4% O₂). Cell proliferation was increased by supplementing HAS for 14 days (p < 0.05) or by interchanging from HAS to PRP during Days 7–14 (p < 0.05). Sulfated glycosaminoglycan (sGAG) content was deposited under both HAS, and PRP for 14 days and an interchange during Days 7–14 depleted the sGAG content to a certain extent. PRP enhanced the gene expression of anabolic markers COL2A1 and SOX9 (p < 0.05), whereas HAS enhanced COL1A1 production. An interchange led to reduction of COL1A1 and COL2A1 expression marked by increased MMP13 expression (p < 0.05). Chondrocytes secreted less IL-6 and more PDGF-BB under PRP for 14 days (p < 0.0.5). Hypoxia enhanced TGF-β1 and BMP-2 release in both HAS and PRP. Our study demonstrates a new approach for chondrocyte redifferentiation.

Platelet-Rich Plasma

Platelet-rich plasma (PRP) is a promising treatment for musculoskeletal maladies and clinical data to date have shown that PRP is safe. However, evidence of its efficacy has been mixed and highly variable depending on the specific indication. Additional future high-quality large clinical trials will be critical in shaping our perspective of this treatment option. The heterogeneity of PRP preparations, both presently and historically, leads sweeping recommendations about its utility impossible to make. This heterogeneity has also made interpreting existing literature more complicated.

Intra-articular platelet-rich plasma (PRP) injections for treating knee pain associated with osteoarthritis of the knee in the Japanese population: a phase I and IIa clinical trial

Intra-articular platelet-rich plasma (PRP) injection has been found to be effective for treating osteoarthritis in patients from Western countries; however, the safety and efficacy of PRP have not been sufficiently investigated in Japanese patients. The present study aimed to evaluate the safety and feasibility of intra-articular PRP injection in Japanese patients with knee osteoarthritis. PRP without white blood cells was prepared using a single-spin centrifuge (PRGF-Endoret; BTI Biotechnology Institute, Vitoria, Spain). A 6-mL PRP volume was injected in the knee joint three times at 1 week intervals. All patients were prospectively evaluated before intervention and at 1, 3, and 6 months after the treatment. Adverse events, the Visual Analog Scale (VAS) pain score, Japanese Knee Osteoarthritis Measure (JKOM) score and Japanese Orthopedic Association score were evaluated. Ten patients (all women; average age, 60.6 years) were treated. Only minor adverse events after injection were noted, and symptoms resolved within 48 hours after the injection. The average VAS pain scores were 71.6 mm and 18.4 mm at baseline and the 6-month follow-up, respectively (P < 0.05). At the 6-month follow-up, 80% of patients had a decrease in the VAS pain score of 50% or more. The average JKOM scores were 35.2 and 14.3 at baseline and at the 1-month follow-up, respectively (P < 0.05). Intra-articular PRP injection likely represents a safe treatment option for Japanese patients with mild-to-moderate knee osteoarthritis, and has the potential to relieve pain for up to 6 months, but further study is needed to verify the efficacy.

Clinical Update: Why PRP Should Be Your First Choice for Injection Therapy in Treating Osteoarthritis of the Knee

PURPOSE OF REVIEW

The purpose of this review is to update the reader on the current applications of platelet-rich plasma (PRP) in the treatment of knee osteoarthritis (KOA). This review will focus on PRP's effect on the osteoarthritic joint, how PRP compares to traditional treatments of KOA, and provide clinical feedback on the use of PRP in an orthopedic and sports medicine practice.

RECENT FINDINGS

Recent research into the applications of PRP for KOA has further indicated both the efficacy and safety of PRP treatment. Although research has shown a tendency toward better efficacy at earlier stages of osteoarthritis (OA), evidence exists to indicate positive effects at all stages of OA. In summary, since KOA is an extremely prevalent condition that can be a challenge to treat, it is imperative that safe and effective nonoperative treatment methods be available to individuals that are suffering from this condition.

Optimization of the Platelet-Rich Plasma Concentration for Mesenchymal Stem Cell Applications

IMPACT STATEMENT

In the current study, we screened the effects of different concentrations of platelet-rich plasma (PRP) on the mesenchymal stem cell (MSC) proliferation and differentiation. Our data demonstrated that concentrated PRP exerted different effects on cell proliferation and on the osteogenic, adipogenic, and chondrogenic differentiation of human bone marrow-derived MSCs. Meanwhile, we optimized PRP concentrations for each of these lineage differentiation and MSC expansion and, thus, suggested several promising clinical strategies for different kinds of diseases. These findings may help explain the controversial effects of PRP on MSCs and improve the progress in precise applications of PRP-based regenerative strategies.

Chondrogenic differentiation of adipose-derived mesenchymal stem cells induced by L-ascorbic acid and platelet rich plasma on silk fibroin scaffold

Articular cartilage is an avascular tissue with limited regenerative property. Therefore, a defect or trauma in articular cartilage due to disease or accident can lead to progressive tissue deterioration. Cartilage tissue engineering, by replacing defective cartilage tissue, is a method for repairing such a problem. In this research, three main aspects-cell, biomaterial scaffold, and bioactive factors-that support tissue engineering study were optimized. Adipose-derived mesenchymal stem cells (ADSC) that become cartilage were grown in an optimized growth medium supplemented with either platelet rich plasma (PRP) or L-ascorbic acid (LAA). As the characterization result, the ADSC used in this experiment could be classified as Mesenchymal Stem Cell (MSC) based on multipotency analysis and cell surface marker analysis. The biomaterial scaffold was fabricated from the Bombyx morii cocoon using silk fibroin by salt leaching method and was engineered to form different sizes of pores to provide optimized support for cell adhesion and growth. Biocompatibility and cytotoxicity evaluation was done using MTT assay to optimize silk fibroin concentration and pore size. Characterized ADSC were grown on the optimized scaffold. LAA and PRP were chosen as bioactive factors to induce ADSC differentiation to become chondrocytes. The concentration optimization of LAA and PRP was analyzed by cell proliferation using MTT assay and chondrogenic differentiation by measuring glycosaminoglycan (GAG) using Alcian Blue at 605 nm wavelength. The optimum silk fibroin concentration, pore size, LAA concentration, and PRP concentration were used to grow and differentiate characterized ADSC for 7, 14, and 21 days. The cell morphology on the scaffold was analyzed using a scanning electron microscope (SEM). The result showed that the ADSC could adhere on plastic, express specific cell surface markers (CD73, CD90, and CD105), and could be differentiated into three types of mature cells. The silk fibroin scaffold made from 12% w/v concentration formed a 500 µm pore diameter (SEM analysis), and was shown by MTT assay to be biocompatible and to facilitate cell growth. The optimum concentrations of the bioactive factors LAA and PRP were 50 µg/mL and 10%, respectively. GAG analysis with Alcian Blue staining suggested that PRP induction medium and LAA induction medium on 12% w/v scaffold could effectively promote not only cell adhesion and cell proliferation but also chondrogenic differentiation of ADSC within 21 days of culture. Therefore, this study provides a new approach to articular tissue engineering with a combination of ADSC as cell source, LAA and PRP as bioactive factors, and silk fibroin as a biocompatible and biodegradable scaffold.

Role of Intra-articular Platelet Rich Plasma in the Management of Osteoarthritis: A Review

Intra-articular injections are a minimally invasive option developed for the management of patients with joint degenerative conditions. These injections can involve the use of steroid preparations, hyaluronic acid, and blood products. Platelet-rich plasma (PRP) is a cost-effective management modality developed for patients with joint degenerative conditions and has provided promising outcomes. It provides nourishment to the chondrocytes through a rich supply of growth factors and cytokines. This article demonstrates the beneficial effects of PRP therapy in patients with osteoarthritis.

Platelet-Rich Plasma and Cartilage Repair

PURPOSE OF REVIEW

To assess the utilization and efficacy of platelet-rich plasma (PRP), for the treatment of articular cartilage injury, most commonly characterized by progressive pain and loss of joint function in the setting of osteoarthritis (OA).

RECENT FINDINGS

PRP modulates the inflammatory and catabolic environment through a locally applied concentrate of platelets, leukocytes, and growth factors. Clinically, PRP has been shown to be possibly a viable treatment adjuvant for a variety of inflammatory and degenerative conditions. Recent efforts have focused on optimizing delivery methods that enable platelets to slowly degranulate their biological constituents, which may promote healing and improve OA symptoms for a longer duration. There are various factors that affect the progression of OA within joints, including inhibition of inflammatory cytokines and altering the level of enzymatic expression. PRP therapy aims to mediate inflammatory and catabolic factors in a degenerative environment through the secretion of anti-inflammatory factors and chemotaxic effects. There are a growing number of studies that have demonstrated the clinical benefit of PRP for non-operative management of OA. Additional randomized controlled trials with long-term follow-up are needed in order to validate PRP's therapeutic efficacy in this setting. Additionally, continued basic research along with well-designed pre-clinical studies and reporting standards are necessary in order to clarify the effectiveness of PRP for cartilage repair and regeneration for future clinical applications.

Co-treatment of TGF-β3 and BMP7 is superior in stimulating chondrocyte redifferentiation in both hypoxia and normoxia compared to single treatments

Signaling by members of the transforming growth factor-β (TGF-β) superfamily, such as TGF-β3 and BMP7, and oxygen tension play a pivotal role in chondrocyte biology. The objective of this research was to investigate the endogenous BMP7 expression in human osteoarthritis (OA) cartilage and the effect of oxygen tension on the single or combined treatment with TGF-β3 and BMP7 on OA chondrocyte redifferentiation in three dimensional (3D) pellet cultures. The results showed the expression of BMP7 and its intracellular signaling target SMAD1/5/8 was decreased in early OA, while it was increased in later stages of OA. The combined treatment with TGF-β3 and BMP7, both in normoxia and hypoxia, was more effective than TGF-β3 or BMP7 alone in redifferentiating chondrocytes. This was reflected by Alcian blue/Safranin O staining and collagen type II protein expression, as well as by gene expression. Hypoxia elevated TGF-β3 and BMP7-induced matrix formation of OA chondrocytes and alleviated the catabolic gene expression. Interestingly, cells cultured under normoxia displayed mild signs of an inflammatory stress response, which was effectively counteracted by culturing the cells under low oxygen tension. Our data underscores the important modulatory role of oxygen tension on the chondrocyte's responsiveness to TGF-β3 and/or BMP7.

Platelet-Rich Plasma and Hyaluronic Acid Are Not Synergistic When Used as Biological Adjuncts with Autologous Osteochondral Transplantation

Introduction Autologous osteochondral transplantation (AOT) is a treatment for osteochondral lesions with known concerns, including histological degradation of the graft and poor cartilage integration. Platelet-rich plasma (PRP) and hyaluronic acid (HA) have been described has having the potential to improve results. The aim of this study was to evaluate the effect of PRP and HA on AOT in a rabbit model. Methods Thirty-six rabbits underwent bilateral knee AOT treated with either the biological adjunct (PRP, n = 12; HA, n = 12; PRP + HA, n = 12) or saline (control). PRP and HA were administered as an intra-articular injection. The rabbits were euthanized at 3, 6, or 12 weeks postoperatively. The graft sections were assessed using the modified International Cartilage Repair Society (ICRS) scoring system. The results from the PRP alone group is from previously published data. Results The mean modified ICRS histological score for the PRP-treated group was higher than its control ( P = 0.002). The mean modified ICRS histological score for the HA-treated group showed no difference compared with its control ( P = 0.142). The mean modified ICRS histological score for the PRP + HA-treated group was higher than its control ( P = 0.006). There was no difference between the mean modified ICRS scores of the PRP- and the PRP + HA-treated grafts ( P = 0.445). Conclusion PRP may decrease graft degradation and improve chondral integration in an animal model. In this model, the addition of HA was not synergistic for the parameters assessed.

LEVEL OF EVIDENCE

Basic science, Level V.

CLINICAL RELEVANCE

PRP can be used as an adjunct to AOT, which may decrease graft degeneration and improve clinical outcomes. HA may not influence AOT.