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Purpose: Hypoxia is considered to be obstructive to tumor treatment, but the reduced oxygen surroundings provide a suitable habitat for Bifidobacterium bifidum (BF) to colonize. The anaerobe BF selectively colonizes into tumors following systemic injection due to its preference for the hypoxia in the tumor cores. Therefore, BF may be a potential targeting agent which could be used effectively in tumor treatment. We aimed to determine whether a novel BF-mediated strategy, that was designed to deliver AP-PFH/PLGA NPs (aptamers CCFM641-5-functionalized Perfluorohexane (PFH) loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles) by aptamer-directed approach into solid tumor based on the tumortargeting ability of BF, could improve efficiency of high intensity focused ultrasound (HIFU) treatment of breast cancer. Methods: We synthesized AP-PFH/PLGA NPs using double emulsion method and carbodiimide method. Then, we evaluated targeting ability of AP-PFH/PLGA NPs to BF in vivo. Finally, we studied the efficacy of HIFU ablation based on BF plus AP-PFH/PLGA NPs (BFmediated HIFU ablation) in tumor. Results: The elaborately designed AP-PFH/PLGA NPs can target BF colonized in tumor to achieve high tumor accumulation, which can significantly enhance HIFU therapeutic efficiency. We also found that, compared with traditional chemotherapy, this therapy not only inhibits tumor growth, but also significantly prolongs the survival time of mice. More importantly, this treatment strategy has no obvious side effects. Conclusion:We successfully established a novel therapy method, BF-mediated HIFU ablation, which provides an excellent platform for highly efficient and non-invasive therapy of tumor.

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Breast cancer is detrimental to the health of women due to the difficulty of early diagnosis and unsatisfactory therapeutic efficacy of available breast cancer therapies. High intensity focused ultrasound (HIFU) ablation is a new method for the treatment of breast tumors, but there is a problem of low ablation efficiency. Therefore, the improvement of HIFU efficiency to combat breast cancer is immediately needed. This study aimed to describe a novel anaerobic bacteria-mediated nanoplatform, comprising synergistic HIFU therapy for breast cancer under guidance of ultrasound (US) and magnetic resonance (MR) bimodal imaging. Methods: The PFH@CL/Fe 3 O 4 nanoparticles (NPs) (Perfluorohexane (PFH) and superparamagnetic iron oxides (SPIO, Fe 3 O 4 ) with cationic lipid (CL) NPs) were synthesized using the thin membrane hydration method. The novel nanoplatform Bifidobacterium bifidum-mediated PFH@CL/Fe 3 O 4 NPs were constructed by electrostatic adsorption. Thereafter, US and MR bimodal imaging ability of B. bifidum-mediated PFH@CL/Fe 3 O 4 NPs was evaluated in vitro and in vivo. Finally, the efficacy of HIFU ablation based on B. bifidum-PFH@CL/Fe 3 O 4 NPs was studied. Results: B. bifidum combined with PFH@CL/Fe 3 O 4 NPs by electrostatic adsorption and enhanced the tumor targeting ability of PFH@CL/Fe 3 O 4 NPs. US and MR bimodal imaging clearly displayed the distribution of the bio-targeting nanoplatform in vivo. It was conducive for accurate and effective guidance of HIFU synergistic treatment of tumors. Furthermore, PFH@CL/Fe 3 O 4 NPs could form microbubbles by acoustic droplet evaporation and promote efficiency of HIFU ablation under guidance of bimodal imaging. Conclusion:A bio-targeting nanoplatform with high stability and good physicochemical properties was constructed. The HIFU synergistic agent achieved early precision imaging of tumors and promoted therapeutic effect, monitored by US and MR bimodal imaging during the treatment process.

Objectives To evaluate the efficacy of low‐intensity focused ultrasound (LIFU) treatment on rapid relief of delayed‐onset muscle soreness (DOMS) triggered by high‐intensity exercise. Methods A total of 16 healthy male college students were randomly divided into two groups: the LIFU group (n = 8) and the Sham group (n = 8). After the exercise protocol, the LIFU group received treatment, which parameters included that the power output was 2.5 W/cm2, the frequency was 1 MHz, and the treating time was 20 minutes. The Sham group was treated with LIFU without energy output. Visual analog scale was used to evaluate the level of DOMS in every participant. The activities of plasma creatine kinase, lactate dehydrogenase, and the plasma concentration were measured by spectrophotometry. Tumor necrosis factor‐α and interleukin‐6 of serum were analyzed by enzyme‐linked immunosorbent assay. Results The visual analog scale of quadriceps femoris and/or calf muscles in the LIFU group decreased significantly at 24 hours (P < 0.01) and 48 hours (P < .01) after the exercise protocol. Both the accumulation of lactic acid (P < .01) in muscle and the activity of lactate dehydrogenase (P < .01) reduced immediately after LIFU treatment. The activities of tumor necrosis factor‐α and interleukin‐6 24 hours lowered in the LIFU group (P < .01). Conclusions LIFU treatment could relieve muscle soreness rapidly and effectively in the early stages of DOMS. The application of LIFU may provide a potential strategy for clinical treatment for DOMS.