Platelet-rich plasma can release nutrient factors to promote facial nerve crush injury recovery in rats

Ultrasound-Guided Thoracic Paravertebral Injection of Platelet-Rich Plasma for the Treatment of Thoracic Herpes Zoster-Related Pain: A Study Protocol

BACKGROUND

Herpes zoster (HZ), triggered by the reactivation of the varicella-zoster virus, manifests as a painful rash known as zoster-associated pain (ZAP), which can progress to postherpetic neuralgia (PHN). This study evaluates the efficacy and safety of ultrasound-guided thoracic paravertebral injections of platelet-rich plasma (PRP) in managing acute ZAP and preventing PHN.

METHODS

This is a prospective, randomized, controlled, open-label, endpoint-blinded, single-center trial involving 128 participants suffering from zoster-associated pain. Participants will be randomly assigned to the PRP treatment in combination with antiviral therapy group or the antiviral therapy group at a 1:1 ratio. Pain intensity (NRS-11), quality of life (SF-12), sleep quality (PSQI), pain characteristics, skin lesion recovery, average weekly consumption of rescue analgesics, and adverse events will be assessed. Follow-up assessments will be conducted at 1, 3, 6, and 12 months post-intervention to evaluate the incidence rate of PHN, pain intensity, quality of life, sleep quality, and safety.

ETHICS AND DISSEMINATION

Adhering to the 2013 SPIRIT statement and the Declaration of Helsinki, this study has received ethical approval from the relevant committee. Results will be disseminated through scientific journals and conferences, contributing to global data on managing ZAP.

CONCLUSIONS

By comparing PRP with antiviral therapy, this trial seeks to establish a more effective treatment paradigm for reducing acute zoster-associated pain and the incidence of PHN, potentially setting a new standard in therapeutic strategies for HZ.

TRIAL REGISTRATION

This clinical trial is registered with the Chinese Clinical Trial Registry (ChiCTR) at https://www.chictr.org.cn/index.html (Registration Number: ChiCTR2400087248, Registration Date: 2024-07-23).

Platelet-rich plasma (PRP) in nerve repair

Platelet-rich plasma (PRP) has the capability of assisting in the recovery of damaged tissues by releasing a variety of biologically active factors to initiate a hemostatic cascade reaction and promote the synthesis of new connective tissue and revascularization. It is now widely used for tissue engineering repair. In addition, PRP has demonstrated nerve repair and pain relief, and has been studied and applied to the facial nerve, median nerve, sciatic nerve, and central nerve. These suggest that PRP injection therapy has a positive effect on nerve repair. This indicates that PRP has high clinical value and potential application in nerve repair. It is worthwhile for scientists and medical workers to further explore and study PRP to expand its application in nerve repair, and to provide a more reliable scientific basis for the opening of a new approach to nerve repair.

The Effectiveness of Ebselen in Facial Nerve Crush Injury: An Experimental Study

Background

Ebselen is a neuroprotective drug that protects cellular components from oxidative damage by modulating enzymatic cofactors, metalloproteins, gene expression, antioxidant-anti-inflammatory effects, and immunological systems. Our goal was to compare the efficacy of Ebselen and methylprednisolone on rat facial nerve crush injury.

Methods

Thirty healthy male Wistar rats (mean weight of 245 g) were used in this study. The rats were randomly divided into four groups: Group 1 (ebselen group), Group 2 (methylprednisolone group), Group 3 (control group), and Group 4 (sham group (the right side of the control group)). Except for the sham group, all groups had their left facial nerve crushed. Three weeks after surgery, prospective functional, histologic, and electrophysiologic recovery was reported.

Results

The ebselen group and methylprednisolone group had similar and more significant recovery at Nerve Excitability Thresholds (NET) at the end of three weeks. These groups also showed similar features in terms of histopathological parameters such as axonal degeneration, vascular congestion, axon diameter, and myelin thickness. Except for the macrovacuolization parameter, both showed statistically better results than the control group. Although there was an earlier improvement in the whiskers and blink tests in the ebselen group compared to the methylprednisolone and control groups, complete recovery was observed in all groups on the 21st day.

Conclusion

Ebselen was found to be similarly effective to methylprednisolone in nerve regeneration in a rat model of experimental facial nerve crush. Considering that methylprednisolone has serious systemic side effects, ebselen may be a good alternative.

Establishment of a facial nerve trunk crush injury model and evaluation of facial nerve self-healing in rats

INTRODUCTION/AIMS

To facilitate further investigation into the mechanisms of facial nerve regeneration, a simple and reliable model of facial nerve crush injury is essential. Nevertheless, the establishment of such models lacks standardization and repeatability, while the healing capacity of the nerve is often overlooked, potentially affecting future studies.

METHODS

We made facial nerve trunk crush injury models with different pressing times and detected the changes from the distal nerves to the motoneurons via behavior analysis, electrophysiological test, and histomorphometry analysis.

RESULTS

It revealed a particular capacity for self-healing following facial nerve crush damage because there was almost no facial motoneuron apoptosis in the MC group during the observation period, and rats in MC group had total facial paralysis in behavioral tests following surgery and varying degrees of recovery 28 days postoperatively with no treatments. As the pressing time increased, the latency, wave amplitude, nerve fiber damage degree, nerve axon ratio, myelin thickness, electroneurograph (ENoG) value, ultrastructural damage, abnormal morphological changes, and the buccal muscle atrophy of each MC group gradually increased or got worse during the observation period. However, after 28 postoperative days, only the ENoG values of the M10min and M12min groups were beyond 90%, indicating no self-healing.

DISCUSSION

It suggests that a stable model of peripheral facial palsy may be created by applying a 12.5 cm mosquito clamped to the facial nerve trunk for at least 10 min, which laid the foundation for the subsequent research to objectively evaluate facial nerve regeneration.

Effects of platelet-rich fibrin and dexamethasone on nerve regeneration after acute facial-nerve injury

BACKGROUND

Acute facial-nerve injury.

OBJECTIVE

To investigate the effects of platelet-rich fibrin (PRF) and dexamethasone on nerve regeneration.

MATERIALS AND METHODS

Thirty-six rats were randomly divided into six groups. Facial-nerve injury was created using a full-thickness incision in all groups except Group E. Next, primary anastomosis, PRF application, topical dexamethasone application, primary anastomosis with topical PRF and dexamethasone application, and no facial-nerve repair were performed in Groups A, B, C, D, and F, respectively. Clinical, functional, and structural improvements were evaluated at eight weeks.

RESULTS

The mean eye-closure movement score in Group B was significantly higher than that in Group F (p < .001). The mean whisker-movement score in Group B was significantly higher than that in Group F (p = .001). The mean amplitude of whisker movement in Group F was significantly lower than those in Groups A, B, C, and E, and the mean amplitude in Group D was significantly lower than that in Group E (p < .001). Furthermore, an improvement in nerve ultrastructure was observed in Group B.

CONCLUSION

PRF application has a positive effect on nerve recovery after anastomosis.

SIGNIFICANCE

Contribute to the literature to improve nerve regeneration.

Possible Neoplastic or Proliferative Effects of Intra-Tympanic Platelet-Rich Plasma on the MiddleEarMucosa: A Myth or a Fact to Consider?

BACKGROUND

Platelet-rich plasma is a frequently used plasma-derived material; however, a possible neoplastic or proliferative effect is one of the limiting issues in its use. The aim of our experimental study was to investigate the long-term histological effects of platelet-rich plasma on the middle ear mucosa.

METHODS

The rats were divided into 2 groups randomly (groups 1 and 2). Group 1 represented the control group and 8 rats were included in this group. To the left ear, 0.3 mL of normal saline solution was administered intra-tympanically. No injections were done to the right ears. Group 2 represented the platelet-rich plasma group and 11 rats were included. To the left ears, 0.3 mL of platelet-rich plasma and to the right ears 0.3 mL of normal saline solution was administered intra-tympanically. The intra-tympanic platelet-rich plasma injections were done twice with an interval of 1 week. All animals were sacrificed in the third month. The degree of mucosal thickness, the presence of metaplasia, atypical cells, myofibroblastic infiltration, angiogenesis, and acute or chronic inflammation were evaluated histopathologically.

RESULTS

Histopathological findings in the right and left ears in each group were compared in itself. The degree of inflammation and mucosal thickness were significantly higher in the perforated and saline administered side, in group 1 (P < .001). In group 2, the degree of angiogenesis was significantly higher in the platelet-rich plasma administered side (P < .001). The degree of mucosal thickness was significantly higher in the saline administered side (P < .001).

CONCLUSION

Considering the anti-inflammatory and regenerative features and its safety, intra-tympanic-PRP may, in the future, be an alterna- tive to current intra-tympanic treatment modalities.

Dental Pulp Cell Sheets Enhance Facial Nerve Regeneration via Local Neurotrophic Factor Delivery

An effective strategy for sustained neurotrophic factor (NTF) delivery to sites of peripheral nerve injury (PNI) would accelerate healing and enhance functional recovery, addressing the major clinical challenges associated with the current standard of care. In this study, scaffold-free cell sheets were generated using human dental pulp stem/progenitor cells, that endogenously express high levels of NTFs, for use as bioactive NTF delivery systems. Additionally, the effect of fibroblast growth factor 2 (FGF2) on NTF expression by dental pulp cell (DPC) sheets was evaluated. In vitro analysis confirmed that DPC sheets express high levels of NTF messenger RNA (mRNA) and proteins, and the addition of FGF2 to DPC sheet culture increased total NTF production by significantly increasing the cellularity of sheets. Furthermore, the DPC sheet secretome stimulated neurite formation and extension in cultured neuronal cells, and these functional effects were further enhanced when DPC sheets were cultured with FGF2. These neuritogenic results were reversed by NTF inhibition substantiating that DPC sheets have a positive effect on neuronal cell activity through the production of NTFs. Further evaluation of DPC sheets in a rat facial nerve crush injury model in vivo established that in comparison with untreated controls, nerves treated with DPC sheets had greater axon regeneration through the injury site and superior functional recovery as quantitatively assessed by compound muscle action potential measurements. This study demonstrates the use of DPC sheets as vehicles for NTF delivery that could augment the current methods for treating PNIs to accelerate regeneration and enhance the functional outcome. Impact statement The major challenges associated with current treatments of peripheral nerve injuries (PNIs) are prolonged repair times and insufficient functional recovery. Dental pulp stem/progenitor cells (DPCs) are known to endogenously express high levels of neurotrophic factors (NTFs), growth factors that enhance axon regeneration. In this study, we demonstrate that scaffold-free DPC sheets can act as effective carrier systems to facilitate the delivery and retention of NTF-producing DPCs to sites of PNIs and improve functional nerve regeneration. DPC sheets have high translational feasibility and could augment the current standard of care to enhance the quality of life for patients dealing with PNIs.

Effects and mechanism of platelet-rich plasma on military drill injury: a review

Military drill injury is a significant part of military medical research. The increase of training intensity and changes in training methods lead to differences in injury types. The ideal therapeutic modality should allow rapid healing at a reasonable cost and minimize impact on patients' life. Platelet -rich plasma (PRP), a platelet concentrate, is rich in a variety of growth factors and widely used clinically as a minimally invasive treatment. It plays an important role in injury repair and rehabilitation. In this article, we review the therapeutic role of PRP in military drill injury and its possible underlying mechanisms, with a focus on plantar fasciitis, stress fractures and other common injuries, in order to provide basic support for military reserve.