LIPUS Promotes Chitosan and Prussian Blue Nanoparticle Absorption for Tissue Elasticity Recovery in Rats with Acute Tendon Injury

Low Intensity Pulsed Ultrasound (LIPUS) has been gradually used in the treatment of tendon diseases, and nanoparticle materials have received considerable attention in the biomedical research field because of their flexible molecular structures, controllable physicochemical properties, and porosity. This paper aims to investigate the efficacy of Chitosan (CS) and Prussian blue (PB) nanoparticles with LIPUS on tendon injuries through animal experiments. Healthy adult male rats were randomly assigned into blank control group (Contorl, n=3) and model group (n=18). The acute tendon injury model for rats was constructed by transverse incisions and clamp injuries in the middle of the longitudinal axis of the bilateral Achilles tendon in the model group. Then rats in the model group were randomly divided into PBS, CS, PB, CSPB, LIPUS, and CSPB+LIPUS group (n=3/group). After intervention of 14 days, the elasticity of tendon was evaluated by Shear Wave Elastography (SWE). Results showed significant differences between the PBS group and the CSPB, LIPUS, CSPB+LIPUS groups; the CSPB+LIPUS group and the Control group showed no statistical differences. The findings indicated that the combination of CS and PB (CSPB), LIPUS, and the combination of CSPB and LIPUS are potential therapeutic strategies for tendon injuries.