In-situ gelation of fibrin gel encapsulating platelet-rich plasma-derived exosomes promotes rotator cuff healing.

Although platelet-rich plasma-derived exosomes (PRP-Exos) hold significant repair potential, their efficacy in treating rotator cuff tear (RCT) remains unknown. In light of the potential for clinical translation of fibrin gel and PRP-Exos, we evaluated their combined impact on RCT healing and explored suitable gel implantation techniques. In vitro experiments demonstrated that PRP-Exos effectively enhanced key phenotypes changes in tendon stem/progenitor cells. Multi-modality imaging, including conventional ultrasound, shear wave elastography ultrasound, and micro-computed tomography, and histopathological assessments were performed to collectively evaluate the regenerative effects on RCT. The regenerated tendons exhibited a well-ordered structure, while bone and cartilage regeneration were significantly improved. PRP-Exos participated in the healing process of RCT. In-situ gelation of fibrin gel-encapsulated PRP-Exos at the bone-tendon interface during surgery proved to be a feasible gel implantation method that benefits the healing outcome. Comprehensive multi-modality postoperative evaluations were necessary, providing a reliable foundation for post-injury repair.

Value of Multimodality Ultrasound in Quantitative Evaluation of the Intra-compartmental Pressure and Perfusion Pressure in Acute Compartment Syndrome in a Rabbit Model.

OBJECTIVE: The aim of the work described here was to investigate the feasibility of using multimodality ultrasound in quantitative evaluation of the intra-compartmental pressure (ICP) and perfusion pressure (PP) changes in acute compartment syndrome (ACS). METHODS: Infusion technique was used to increase the ICP of the anterior compartment of 10 rabbits from baseline to 20, 30, 40, 50, 60, 70 and 80 mmHg. The anterior compartment was evaluated with conventional ultrasound, shear wave elastography (SWE) and contrast-enhanced ultrasound (CEUS). The shape of the anterior compartment, shear wave velocity (SWV) of the tibialis anterior (TA) muscle and CEUS parameters of the TA muscle were measured. RESULTS: When the ICP exceeded 30 mmHg, the shape of the anterior compartment did not expand significantly with increasing ICP. There was a strong correlation between the SWV of TA muscle and measured ICP (ρ = 0.927). Arrival time (AT), time to peak (TTP), peak intensity (PI) and area under the curve (AUC) were significantly correlated with PP (AT, ρ = -0.763; TTP, ρ = -0.900; PI, ρ = 0.665; AUC, ρ = 0.706), whereas mean transit time (MTT) was not. CONCLUSION: Multimodality ultrasound can be used to quantitatively evaluate ICP and PP and, thus, could provide more information for the rapid diagnosis and monitoring of ACS.

Ultrasound-Targeted Microbubble Destruction Assisted Delivery of Platelet-Rich Plasma-Derived Exosomes Promoting Peripheral Nerve Regeneration.

Peripheral nerve injury is prevalent and has a high disability rate in clinical settings. Current therapeutic methods have not achieved satisfactory efficacy, underscoring the need for novel approaches to nerve restoration that remains an active area of research in neuroscience and regenerative medicine. In this study, we isolated platelet-rich plasma-derived exosomes (PRP-exos) and found that they can significantly enhance the proliferation, migration, and secretion of trophic factors by Schwann cells (SCs). In addition, there were marked changes in transcriptional and expression profiles of SCs, particularly via the upregulation of genes related to biological functions involved in nerve regeneration and repair. In the rat model of sciatic nerve crush injury, ultrasound-targeted microbubble destruction (UTMD) enhanced the efficiency of PRP-exos delivery to the injury site. This approach ensured a high concentration of PRP-exos in the injured nerve and improved the therapeutic outcomes. In conclusion, PRP-exos may promote nerve regeneration and repair, and UTMD may increase the effectiveness of targeted PRP-exos delivery to the injured nerve and enhance the therapeutic effect.