Inhibitory effects of platelet-rich plasma on intervertebral disc degeneration: a preclinical study in a rabbit model

Comparison of the efficacy of autologous Lp-PRP and Lr-PRP for treating intervertebral disc degeneration: in vitro and in vivo study

BACKGROUND

Intervertebral disc degeneration (IDD) was the most common cause of low back pain. Platelet rich plasma (PRP) has the potential to repair IDD, however, there is still no conclusion on whether Leukocyte-poor platelet rich plasma (Lp-PRP) or Leukocyte-rich platelet rich plasma (Lr-PRP) is better for the treatment of IDD.

METHODS

First, we conducted an in vitro study to compare the effects of autologous Lp-PRP and Lr-PRP on human degenerated nucleus pulposus (NP) cells. Then we verified the in vivo effects of autologous Lp-PRP and Lr-PRP in treating disc degeneration through a rabbit IDD model.

RESULTS

The in vitro study showed both autologous Lp-PRP and Lr-PRP can promote the cell proliferation, the synthesis of COL II and Aggrecan of human degenerated NP cells, while Lp-PRP are better than Lr-PRP (P<0.05). In addition, only Lp-PRP can inhibit the apoptosis of human degenerated NP cells (P<0.05), whereas Lr-PRP activates the catabolism on the contrary (P<0.05). Further, the in vivo study through the rabbit IDD model verified that autologous Lp-PRP has better effects than autologous Lr-PRP in repairing IDD according to X-ray, MRI, histological, and immunohistochemical assessment (P<0.05, respectively). And the caspase-3 IHC results also showed that only autologous Lp-PRP treatment could inhibit apoptosis of NP cells in the rabbit IDD model (P<0.05).

CONCLUSION

Combining in vivo and in vitro studies, the present study confirmed that autologous Lp-PRP has a better effect than autologous Lr-PRP in repairing IDD, which may be due to the inflammatory factors (TNFα, IL-1β, etc.) in Lr-PRP antagonizing part of the repair effects and promoting the catabolism additionally. Therefore, our findings suggest that Lp-PRP may provide better results than Lr-PRP for treating IDD. Further randomized clinical trials will provide evidence to guide practice.

Percutaneous endoscopic lumbar discectomy combined with platelet-rich plasma injection for lumbar disc herniation: analysis of clinical and imaging outcomes

OBJECTIVE

To evaluate the clinical efficacy and imaging outcomes of percutaneous endoscopic lumbar discectomy (PELD) combined with platelet-rich plasma (PRP) for the treatment of lumbar disc herniation (LDH).

METHODS

A total of 155 patients with LDH between January 2020 and June 2022 were retrospective analyzed, of which 75 underwent PELD with PRP and 80 underwent PELD only. Clinical functional scores and imaging data were compared. Clinical functional scores included visual analog scale of leg pain (VAS-LP) and back pain (VAS-BP), Japanese Orthopedic Association score (JOA), Oswestry Disability Index (ODI) and modified MacNab criteria. Imaging data included disc height index (DHI), spinal cross-sectional area (SCSA), disc protrusion size (DPZ), and ratio value of disc grey scales (RVG).

RESULTS

Both groups showed clinical improvement, and VAS-LP, VAS-BP, JOA and ODI were significantly improved in the PRP group compared with the control group at 3, 6 and 12 months postoperatively (P < 0.05). At the last follow-up, the differences in SCSA, DPZ and RVG between the two groups were statistically significant (P < 0.05), with the PRP group being superior to the control group. The excellent and good rates of the modified Macnab criteria in the PRP group and control group were 93.3% and 90%, respectively, with no statistically significant difference (P > 0.05). No serious complications occurred during the follow-up period.

CONCLUSION

PELD combined with PRP is a safe and effective method for treating patients with LDH. PRP injection was beneficial for delaying disc degeneration and promoting disc remodeling.

Intravesical instillation of platelet-rich plasma for treatment of interstitial cystitis/bladder pain syndrome: A pilot study

Objective

The aim of this study was to evaluate the feasibility of intravesical instillation of platelet-rich plasma (PRP) to treat interstitial cystitis/bladder pain syndrome (IC/BPS).

Materials and methods

Twenty PRP samples were tested in vitro for stability after exposure to urine samples with different pH. A pilot study involving 21 female patients with IC/BPS was conducted, and 6 weekly doses of autologous PRP (50 mL) were administered. Patients were followed up at the 2nd, 4th, 8th, and 12th weeks after terminating instillation. The primary endpoint was the visual analog scale (VAS) for pain, and the secondary endpoints included the IC symptom index, IC problem index of the O'Leary-Sant questionnaire and global response assessment, urine culture, and uroflowmetry. Success was defined as a reduction in VAS by 30% or more compared with basal level, and adverse events were recorded.

Results

The mean ± SD of VAS was significantly reduced compared with basal level (4.4 ± 2.6 vs. 8.8 ± 1.1, respectively, p = 0.001). Meanwhile, 80% of cases were considered successful, with a 50.1% reduction in the mean score compared with the basal level. The mean ± SD of IC symptom index and IC problem index significantly improved compared with the basal level. Global response assessment was markedly, moderately, and slightly improved in 2 (10%), 10 (50%), and 5 (25%) patients, respectively, and showed no change in 3 (15%). Three patients had positive urine cultures at follow-up, but 1 withdrew after 2 sessions because of a lack of efficacy.

Conclusions

Repeated intravesical instillation of PRP could be considered an effective and safe approach for treating IC/BPS.

Transforaminal Endoscopic Lumbar Discectomy with versus without Platelet-Rich Plasma Injection for Lumbar Disc Herniation: A Prospective Cohort Study

Objective

Transforaminal endoscopic lumbar discectomy (TELD) is an effective treatment for patients with lumbar disc herniation (LDH) with failure of conservative treatment. However, defects in the annulus fibrosus after TELD usually lead to a recurrence of LDH. Platelet-rich plasma (PRP) injection has shown promising potential for the repair of injured tissues. The combination of TELD and PRP injection has rarely been reported. Hence, this study aimed to evaluate the effectiveness, disc remodeling, and recurrence rate of LDH in TELD with or without PRP in LDH treatment.

Methods

A total of 108 consecutive patients who underwent TELD were prospectively registered between July 2018 and December 2019 (https://clinicaltrials.gov/ct2/show/ChiCTR1800017228). Fifty-one and fifty-seven patients underwent TELD with PRP injections and TELD only, respectively. The visual analog scale (VAS) score for back and leg pain, Oswestry Disability Index (ODI), and MacNab criteria were evaluated, and perioperative complications were documented. The disc protrusion, spinal cross-sectional area (SCSA), and disc height were measured on MRI and evaluated preoperatively, postoperatively, and at regular follow-up.

Results

All patients were followed up. Clinical improvement was noted in both groups. There were statistical differences in the VAS scores of back and leg pain and ODI between the two groups at 3 months, 6 months, and 1 year follow-up (P < 0.05); the improvement in the PRP group was significant. The disc protrusion and SCSA on MRI in the PRP group showed better improvement, with lower recurrence rate, than that in the control group at the final follow-up (P < 0.05). No adverse events were reported in our study following PRP injection.

Conclusion

Our study showed that TELD with PRP injection was a safe and effective treatment for patients with LDH in the medium and long-term follow-up. PRP injection was beneficial for disc remodeling after endoscopic discectomy and decreased the recurrence of LDH.

Effect of Platelet-Rich Plasma on Intervertebral Disc Degeneration In Vivo and In Vitro: A Critical Review

Intervertebral disc degeneration (IDD) is a globally occurring disease that represents a significant cause of socioeconomic problems. Currently, the main method for treating IDD is surgery, including discectomy and vertebral fusion. Several in vitro experiments demonstrated that platelet-rich plasma (PRP) could stimulate cell proliferation and extracellular matrix regeneration. Additionally, in vivo experiments have proven that PRP injection could restore intervertebral disc height. Clinical studies demonstrated that PRP injection could significantly relieve patient pain. However, further studies are still required to clarify the roles of PRP in IDD prevention and treatment. This review is aimed at summarizing and critically analyzing the current evidence regarding IDD treatment with PRP.

Use of Platelet-Rich Plasma in Treating Low Back Pain: A Review of the Current Literature

Low back pain (LBP) is a common problem encountered by physicians. It is a considerable cause of morbidity and socioeconomic loss and is one of the most expensive musculoskeletal disorders. Conventional treatments include bed rest, analgesics, therapeutic exercises, lumbar or caudal epidural corticosteroids, and surgery. Several new biological therapies are being investigated for use in LBP and one of these is platelet-rich plasma (PRP). In this article, we summarize the current literature published on PRP concerning its composition, classification, and application in LBP. We believe our review will prove useful to clinicians and academics alike, interested in new developing therapies for LBP.

A percutaneous, minimally invasive annulus fibrosus needle puncture model of intervertebral disc degeneration in rabbits

PURPOSE

Various animal models have been proposed to mimic the pathophysiologic process of intervertebral disc degeneration, a leading cause of back pain. The purpose of this study is to describe a minimally invasive technique via percutaneous needle puncture of the annulus fibrosus in New Zealand white rabbits.

METHODS

Under fluoroscopic guidance, an 18-gauge spinal needle was inserted 2 cm lateral to the midline spinous process. The needle was slowly advanced at approximately 45° angle until it was adjacent to the L5/L6 disc space. Lateral and anteroposterior views were used to verify correct needle position before advancing into the nucleus pulposus. The rabbits underwent weekly X-rays for 4 weeks to assess disc height index. MRI T2 relaxation was evaluated at week four to assess morphological changes. Discs were histologically graded on a 12-point scale to assess degeneration and compared to discs obtained from uninjured rabbits.

RESULTS

There were no complications associated with the percutaneous needle puncture procedure. All animals survived the duration of the experiment. Four weeks after injury, the disc height had progressively narrowed to approximately 50% of baseline. MRI assessment at the 4-week time point demonstrated a mean T2 relaxation time at the L5/L6 level that was 20.9% of the T2 relaxation time at the uninjured L4/L5 disc level ( p < 0.001). Histological analysis demonstrated lamellar disorganization of the annulus and decreased cellularity and proteoglycan content within the injured nucleus compared to uninjured control discs.

CONCLUSION

The present study demonstrated a reliable technique of inducing an annular tear via a percutaneous needle puncture. Compared to open surgical approaches, the percutaneous model produces similar progressive disc degeneration while minimizing harm to the animal subjects.

CLINICAL RELEVANCE

The present study establishes a technique for the introduction of novel therapeutic agents to treat disc degeneration that may translate to future clinical trials.

Platelet-rich plasma in the management of chronic low back pain: a critical review

Low back pain (LBP) is now regarded as the first cause of disability worldwide and should be a priority for future research on prevention and therapy. Intervertebral disc (IVD) degeneration is an important pathogenesis of LBP. Platelet-rich plasma (PRP) is an autologous blood concentrate that contains a natural concentration of autologous growth factors and cytokines and is currently widely used in the clinical setting for tissue regeneration and repair. PRP has great potential to stimulate cell proliferation and metabolic activity of IVD cells in vitro. Several animal studies have shown that the injection of PRP into degenerated IVDs is effective in restoring structural changes (IVD height) and improving the matrix integrity of degenerated IVDs as evaluated by magnetic resonance imaging (MRI) and histology. The results of this basic research have shown the great possibility that PRP has significant biological effects for tissue repair to counteract IVD degeneration. Clinical studies for evaluating the effects of the injection of PRP into degenerated IVDs for patients with discogenic LBP have been reviewed. Although there was only one double-blind randomized controlled trial, all the studies reported that PRP was safe and effective in reducing back pain. While the clinical evidence of tissue repair of IVDs by PRP treatment is currently lacking, there is a great possibility that the application of PRP has the potential to lead to a feasible intradiscal therapy for the treatment of degenerative disc diseases. Further large-scale studies may be required to confirm the clinical evidence of PRP for the treatment of discogenic LBP.

Minimally Invasive and Regenerative Therapeutics

Advances in biomaterial synthesis and fabrication, stem cell biology, bioimaging, microsurgery procedures, and microscale technologies have made minimally invasive therapeutics a viable tool in regenerative medicine. Therapeutics, herein defined as cells, biomaterials, biomolecules, and their combinations, can be delivered in a minimally invasive way to regenerate different tissues in the body, such as bone, cartilage, pancreas, cardiac, skeletal muscle, liver, skin, and neural tissues. Sophisticated methods of tracking, sensing, and stimulation of therapeutics in vivo using nano-biomaterials and soft bioelectronic devices provide great opportunities to further develop minimally invasive and regenerative therapeutics (MIRET). In general, minimally invasive delivery methods offer high yield with low risk of complications and reduced costs compared to conventional delivery methods. Here, minimally invasive approaches for delivering regenerative therapeutics into the body are reviewed. The use of MIRET to treat different tissues and organs is described. Although some clinical trials have been performed using MIRET, it is hoped that such therapeutics find wider applications to treat patients. Finally, some future perspective and challenges for this emerging field are highlighted.

Platelet-rich plasma injections: an emerging therapy for chronic discogenic low back pain

Autologous platelet-rich plasma (PRP) injections have been investigated in recent years as an emerging therapy for various musculoskeletal conditions, including lumbar degenerative disc disease. Although PRP has received increasing attention from medical science experts, comprehensive clinical reports of its efficacy are limited to those treating knee osteoarthritis and epicondylitis. Use of PRP is gaining popularity in the area of degenerative disc disease, but there is a clear need for reliable clinical evidence of its applications and effectiveness. In this article, we review the current literature on PRP therapy and its potential use in the treatment of chronic discogenic low back pain, with a focus on evidence from clinical trials.

Biologic therapies to enhance intervertebral disc repair

Degenerative disc disease is a progressive, chronic disorder with strong association to pain, where the dysregulated tissue environment signals disc cells, thereby leading to a low inflammatory process and slow extracellular matrix degradation and fibrosis in a perpetual vicious cycle, generating a structural and functional failure of intervertebral disc joint (IVDJ). Among current biologic therapies, there is an emerging minimally invasive strategy that consists of infiltrating plasma rich in growth factors, a safe and efficacious therapeutic approach for other musculoskeletal degenerative conditions. This review summarizes the homeostasis and degeneration of IVDJ, discusses some results on basic science and therapeutic use of platelet-rich plasma products and advances an alternative minimally invasive biologic therapy in IVDJ degeneration and chronic back pain.

Efficacy of Platelet-Rich Plasma in Retarding Intervertebral Disc Degeneration: A Meta-Analysis of Animal Studies

Objectives

Several animal studies have demonstrated the positive effects of platelet-rich plasma (PRP) on disc degeneration retardation. The present meta-analysis was to verify the efficacy of PRP in retarding disc degeneration in animal.

Methods

Relevant studies were identified and evaluated according to our inclusion and exclusion criteria. The standardized mean difference (SMD) and related 95% confidence interval (95% CI) were estimated to assess PRP efficiency.

Results

In total, eleven studies were included in this meta-analysis. Significant differences were found in the PRP treatment group, which showed increased disc height (SMD = 2.66, 95% CI: 1.86, 3.47, p = 0.000), increased MRI T2 signal intensity (SMD = −3.29, 95% CI: −4.44, −2.13, p = 0.000), and decreased histological degeneration grade (SMD = −4.28, 95% CI: −5.26, −3.30, p = 0.000). However, no significant increase in collagen II expression was found (SMD = 25389.74, 95% CI: −27585.72, 78365.21, p = 0.348). Apart from the subgroup analysis of the disc height based on animal species (pig) and disc degeneration model (chymopapain induction), other subgroup analysis based on animal species (rabbit and rat), study design, disc degeneration model, and follow-up period demonstrated that PRP treatment can significantly restore disc height and increase MRI T2 signal intensity.

Conclusions

PRP treatment is potentially effective in restoring disc height of rodent rabbit and rat, reducing histological degeneration grade, and increasing MRI T2 image signal. PRP injection may be promising therapy for retarding disc degeneration.

Potential Role of lncRNAs in Contributing to Pathogenesis of Intervertebral Disc Degeneration Based on Microarray Data

Background

Our study intended to identify potential long non-coding RNAs (lncRNAs) and genes, and to elucidate the underlying mechanisms of intervertebral disc degeneration (IDD).

Material/Methods

The microarray of GSE56081 was downloaded from the Gene Expression Omnibus database, including 5 human control nucleus pulposus tissues and 5 degenerative nucleus pulposus tissues, which was on the basis of GPL15314 platform. Identification of differentially expressed lncRNAs and mRNAs were performed between the 2 groups. Then, gene ontology (GO) and pathway enrichment analyses were performed to analyze the biological functions and pathways for the differentially expressed mRNAs. Simultaneously, lncRNA-mRNA weighted coexpression network was constructed using the WGCNA package, followed by GO and KEGG pathway enrichment analyses for the genes in the modules. Finally, the protein-protein interaction (PPI) network was visualized.

Results

A total of 135 significantly up- and 170 down-regulated lncRNAs and 2133 significantly up- and 1098 down-regulated mRNAs were identified. Additionally, UBA52 (ubiquitin A-52 residue ribosomal protein fusion product 1), with the highest connectivity degree in PPI network, was remarkably enriched in the pathway of metabolism of proteins. Eight lncRNAs – LINC00917, CTD-2246P4.1, CTC-523E23.5, RP4-639J15.1, RP11-363G2.4, AC005082.12, MIR132, and RP11-38F22.1 – were observed in the modules of lncRNA-mRNA weighted coexpression network. Moreover, SPHK1 in the green-yellow module was significantly enriched in positive regulation of cell migration.

Conclusions

LncRNAs LINC00917, CTD-2246P4.1, CTC-523E23.5, RP4-639J15.1, RP11-363G2.4, AC005082.12, MIR132, and RP11-38F22.1 were differentially expressed and might play important roles in the development of IDD. Key genes, such as UBA52 and SPHK1, may be pivotal biomarkers for IDD.