The gelling effect of platelet-rich fibrin matrix when exposed to human tenocytes from the rotator cuff in small-diameter culture wells and the design of a co-culture device to overcome this phenomenon

Advances in the application of hydrogel-based scaffolds for tendon repair

Tendon injuries often lead to joint dysfunction due to the limited self-regeneration capacity of tendons. Repairing tendons is a major challenge for surgeons and imposes a significant financial burden on society. Therefore, there is an urgent need to develop effective strategies for repairing injured tendons. Tendon tissue engineering using hydrogels has emerged as a promising approach that has attracted considerable interest. Hydrogels possess excellent biocompatibility and biodegradability, enabling them to create an extracellular matrix-like growth environment for cells. They can also serve as a carrier for cells or other substances to accelerate tendon repair. In the past decade, numerous studies have made significant progress in the preparation of hydrogel scaffolds for tendon healing. This review aims to provide an overview of recent research on the materials of hydrogel-based scaffolds used for tendon tissue engineering and discusses the delivery systems based on them.

Leukocyte-Rich Platelet-Rich Plasma Has Better Stimulating Effects on Tenocyte Proliferation Compared With Leukocyte-Poor Platelet-Rich Plasma

BACKGROUND

Rotator cuff (RC) tendinopathy is one of the most common causes of shoulder pain. Platelet-rich plasma (PRP) has been frequently used in clinical scenarios, but its efficacy remains inconsistent.

PURPOSE

To investigate the different responses of human tenocytes from torn RCs to leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP) in a 2-chamber coculture device.

STUDY DESIGN

Controlled laboratory study.

METHODS

PRP was prepared using different platelet and leukocyte concentrations according to 5 groups: (1) LR-PRP with 5000 platelets/µL, (2) LR-PRP with 10,000 platelets/µL, (3) LP-PRP with 5000 platelets/µL, (4) LP-PRP with 10,000 platelets/µL, and (5) control with only culture medium supplementation and without PRP stimulation. Platelet-derived growth factor-AB (PDGF-AB) and transforming growth factor-β1 (TGF-β1) were measured in LR-PRP and LP-PRP via enzyme-linked immunosorbent assay. Microscopy, water-soluble tetrazolium salt assay, and quantitative real-time polymerase chain reaction were used to investigate the morphology, proliferation, and gene expression of RC tenocytes exposed to different PRP formulations. Data were collected from at least 3 independent measurements. The results were analyzed via 1-way analysis of variance, followed by the post hoc Bonferroni test.

RESULTS

The ratio of leukocytes to 5000 platelets/µL was 29.5 times higher in LR-PRP than in LP-PRP (P < .05). In the 5000 platelets/µL groups, the levels of TGF-β1 and PDGF-AB were both significantly higher in LR-PRP versus LP-PRP (TGF-β1: 367.0 ± 16.5 vs 308.6 ± 30.3 pg/mL, respectively [P = .043]; PDGF-AB: 172.1 ± 1.8 vs 94.1 ± 4.2 pg/mL, respectively [P < .001]). Compared with the control group, RC tenocyte proliferation was 1.42 ± 0.01 and 1.41 ± 0.03 times higher in the LR-PRP groups with 5000 platelets/µL and 10,000 platelets/µL, respectively (P < .05). The expression of tenocyte-related genes was higher in tenocytes cultured in LR-PRP.

CONCLUSION

Both the LR-PRP groups with 5000 platelets/µL and 10,000 platelets/µL induced more growth factor release and increased RC tenocyte proliferation than did the LP-PRP groups.

CLINICAL RELEVANCE

In RC repair, LR-PRP may be better than LP-PRP for increasing the proliferation of tenocytes.

Time-Dependent Cytokine-Release of Platelet-Rich Plasma in 3-Chamber Co-Culture Device and Conventional Culture Well

Platelet-rich plasma (PRP) contains bioactive cytokines to enhance tissue healing. The best PRP preparation protocol and timing of the treatment have not been determined yet. To screen the best-fit PRP, a 3-chamber co-culture device was developed. We hypothesized the concentrations of the cytokines from different PRPs in the co-culture plates had a high correlation with those in conventional 24-well culture plates at different time points. The concentrations of the cytokine from PRPs would be correlated with platelet concentrations. The correlation of transforming growth factor beta-1 (TGF-β1) and platelet-derived growth factor AB (PDGF-AB) in both devices were compared at 0, 24, 48, 72, and 96 h from two PRPs as well as that of platelet and cytokines concentrations. The results revealed that there was a moderate to high correlation in TGF-β1 concentrations between the 3-chamber co-culture and conventional culture device until 96 h. The correlation of PDGF-AB concentrations in both devices had moderate to high correlation in the first 24 h, and then it became modestly correlated from 48 to 96 h. A high correlation was found between platelet and TGF-β1 concentration at 96 h. However, they were modestly correlated in other time points. A negative or modest correlation was found between platelet and PDGF-AB concentration in all time points. In conclusion, TGF-β1 and PDGF-AB revealed a time-dependent manner of release at five time points. There is a moderate to high correlation of the TGF-β1 and PDGF-AB concentration in both devices at different time points. However, TGF-β1 and PDGF-AB concentrations are not always proportional to the platelet concentration of the PRPs.

Application of Platelet-Rich Plasma in Arthroscopic Rotator Cuff Repair: A Systematic Review and Meta-analysis

Background:

It is unclear how and which factors affect the clinical efficacy of platelet-rich plasma (PRP) applied during arthroscopic rotator cuff repair.

Purpose:

To evaluate the clinical efficacy of PRP for arthroscopic repair of full-thickness rotator cuff tear and investigate the factors that affect its clinical efficacy.

Study Design:

Systematic review; Level of evidence, 1.

Methods:

We searched Cochrane Library, EMBASE, MEDLINE, and OVID to identify randomized controlled trials (RCTs) of patients who received PRP treatment and arthroscopic rotator cuff repair (PRP group) versus controls (no-PRP group). The primary outcomes included retear rate, Constant-Murley score, University of California Los Angeles (UCLA) score, short-term American Shoulder and Elbow Surgeons (ASES) score, visual analog scale (VAS) score for pain, and adverse events.

Results:

A total of 14 RCTs were included in this systematic review. Significant improvement in Constant-Murley, UCLA, and VAS pain scores were found in the PRP group during short-term, midterm, and long-term follow-up. The PRP group had a significantly decreased retear rate (risk ratio [RR], 0.57 [95% CI, 0.42 to 0.78]; P = .0003), especially for long-term follow-up (RR, 0.38 [95% CI, 0.17 to 0.83]; P = .02), large to massive tears (RR, 0.58 [95% CI, 0.42 to 0.80]; P = .0008), use of leukocyte-poor PRP (RR, 0.50 [95% CI, 0.33 to 0.76]; P = .001), and intraoperative application of PRP (RR, 0.57 [95% CI, 0.42 to 0.79]; P = .0007). No significant difference between the 2 groups was found in the incidence of adverse events (RR, 1.34 [95% CI, 0.83 to 2.15]; P = .23) or in ASES scores at short-term follow-up (weighted mean difference, 1.04 [95% CI, –3.10 to 5.19]; P = .62).

Conclusion:

The results of this review indicated that arthroscopic rotator cuff repair with PRP significantly reduced the long-term retear rate and shoulder pain and provided improved long-term shoulder function in patients. Intraoperative application of PRP, use of leukocyte-poor plasma, and large to massive tear size contributed to a significantly decreased retear rate for rotator cuff repair combined with PRP.

Personalized, Predictive, Participatory, Precision, and Preventive (P5) Medicine in Rotator Cuff Tears

Rotator cuff (RC) disease is a common musculoskeletal disorder of the shoulder entailing pain, with reduced functionality and quality of life. The main objective of this study was to present a perspective of the current scientific evidence about personalized, predictive, participatory, precision, and preventive approaches in the management of RC diseases. The personalized, predictive, participatory, precision and preventive (P5) medicine model is an interdisciplinary and multidisciplinary approach that will provide researchers and clinicians with a comprehensive patrimony of knowledge in the management of RC diseases. The ability to define genetic predispositions in conjunction with the evaluation of lifestyle and environmental factors may boost the tailoring of diagnosis and therapy in patients suffering from RC diseases.