Exosomes derived from bone marrow mesenchymal stem cell preconditioned by low-intensity pulsed ultrasound stimulation promote bone-tendon interface fibrocartilage regeneration and ameliorate rotator cuff fatty infiltration

[Effectiveness analysis of channel-assisted minimally invasive repair technique combined with flexor hallucis longus tendon transfer for Achilles tendon sleeve avulsion]

Objective

To evaluate the effectiveness of the channel-assisted minimally invasive repair (CAMIR) technique combined with flexor hallucis longus (FHL) tendon transfer in the treatment of Achilles tendon sleeve avulsion.

Methods

A retrospective analysis was conducted on 17 patients with Achilles tendon sleeve avulsion who underwent CAMIR technique combined with FHL transfer between January 2019 and January 2023. The cohort comprised 13 males and 4 females, aged 32 to 65 years (mean, 49.7 years). Etiologies included sports-related injuries in 15 cases and blunt trauma in 2 cases. The interval from injury to surgery ranged from 4 to 368 days (median, 15 days). All patients exhibited calcification at the Achilles tendon insertion site, with 7 cases complicated by Haglund deformity. Postoperative complications were meticulously monitored, and tendon healing was assessed via MRI. Clinical outcome were evaluated using the visual analogue scale (VAS) score for pain, Tegner activity level rating scale, ankle activity score (AAS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, Victorian Institute of Sport Assessment-Achilles (VISA-A) score, and subjective clinical scoring systems preoperatively and at last follow-up.

Results

The operation time was 50-62 minutes (mean, 56 minutes), and the intraoperative blood loss was 5-50 mL (mean, 19.7 mL). All patients were followed up 12-67 months (mean, 38 months). No postoperative complication, such as Achilles tendon re-rupture, incision infection, deep vein thrombosis, heel raise insufficiency, or sural nerve injury, was observed. At last follow-up, MRI examination confirmed satisfactory tendon healing in all cases. Significant improvements were noted in VAS scores, Tegner activity level rating scale, AAS scores, AOFAS ankle-hindfoot scores, and VISA-A scores compared to preoperative ones ( P<0.05). At last follow-up, the subjective clinical score ranged from 6 to 10 (median, 9).

Conclusion

The CAMIR technique combined with FHL tendon transfer is a good treatment for repair of Achilles tendon sleeve avulsion, with good recovery of ankle function and few complications.

Targeting Caveolin-1 for enhanced rotator cuff repair: findings from single-cell RNA sequencing

Rotator cuff injury (RCI), a prevalent cause of shoulder pain and disability, often leads to significant functional impairments due to adipocyte infiltration into the damaged tissue. Caveolin-1 (Cav-1), a critical membrane protein, plays a significant role in adipocyte differentiation and lipid metabolism. This study utilized single-cell RNA sequencing (scRNA-seq) to investigate the heterogeneity of cell subpopulations in RCI tissues and assess the regulatory effects of Cav-1. The findings revealed that Cav-1 expression negatively correlates with adipogenic activity, and its modulation through exercise or targeted therapies can significantly reduce adipocyte infiltration and enhance tissue repair. Further, Cav-1 knockout and overexpression models demonstrated the protein's impact on key genes involved in adipocyte differentiation and lipid metabolism, such as Scd1, fatty acid synthase (FASN), and peroxisome proliferator-activated receptor gamma (Pparg). Animal studies corroborated these results, showing that exercise intervention increased Cav-1 expression, decreased adipocyte infiltration, and promoted structural repair. These insights suggest that targeting Cav-1 could offer a novel therapeutic strategy for improving RCI outcomes.

Regenerative properties of bone marrow mesenchymal stem cell derived exosomes in rotator cuff tears

ABSTRCT

Rotator cuff injury (RCI), characterized by shoulder pain and restricted mobility, represents a subset of tendon-bone insertion injuries (TBI). In the majority of cases, surgical reconstruction of the affected tendons or ligaments is required to address the damage. However, numerous clinical failures have underscored the suboptimal outcomes associated with such procedures. Further investigations have revealed that these failures are largely attributable to delayed healing at the tendon-bone interface, excessive formation of vascularized scar tissue, and inadequate integration of tendon grafts within bone tunnels. As a result, the healing process of rotator cuff injuries faces significant challenges.Bone marrow-derived mesenchymal stem cell exosomes (BMSC-exos) have emerged as a prominent focus of research within the field of bioengineering, owing to their remarkable potential to regulate cellular proliferation and differentiation, modulate immune responses, and facilitate tissue repair and regeneration following cellular damage. In this review, we explore the anti-inflammatory, angiogenic, anti-scarring, and bone metabolism-modulating effects of BMSC-exos in the context of rotator cuff injury. Additionally, we address the limitations and ongoing challenges within current research, offering insights that could guide the clinical application of BMSC-exos in the treatment of rotator cuff injuries in the future.