Treatment of hepatic tumors by thermal versus mechanical effects of pulsed high intensity focused ultrasound in vivo

Engineering Versatile Nanomedicines for Ultrasonic Tumor Immunotherapy

Due to the specific advantages of ultrasound (US) in therapeutic disease treatments, the unique therapeutic US technology has emerged. In addition to featuring a low-invasive targeted cancer-cell killing effect, the therapeutic US technology has been demonstrated to modulate the tumor immune landscape, amplify the therapeutic effect of other antitumor therapies, and induce immunosensitization of tumors to immunotherapy, shedding new light on the cancer treatment. Tremendous advances in nanotechnology are also expected to bring unprecedented benefits to enhancing the antitumor efficiency and immunological effects of therapeutic US, as well as therapeutic US-derived bimodal and multimodal synergistic therapies. This comprehensive review summarizes the immunological effects induced by different therapeutic US technologies, including ultrasound-mediated micro-/nanobubble destruction (UTMD/UTND), sonodynamic therapy (SDT), and focused ultrasound (FUS), as well as the main underlying mechanisms involved. It is also discussed that the recent research progress of engineering intelligent nanoplatform in improving the antitumor efficiency of therapeutic US technologies. Finally, focusing on clinical translation, the key issues and challenges currently faced are summarized, and the prospects for promoting the clinical translation of these emerging nanomaterials and ultrasonic immunotherapy in the future are proposed.

Tumor-homing bacterium-adsorbed liposomes encapsulating perfluorohexane/doxorubicin enhance pulsed-focused ultrasound for tumor therapy

Objective: To make up for the insufficient ultrasound ablation of tumors, the energy output or synergist is increased but faces the big challenge of normal tissue damage. In this study, we report a tumor-homing bacterium, Bifidobacterium bifidum (B. bifidum), adsorbing liposomes that encapsulate perfluorohexane (PFH) and doxorubicin (DOX) to enhance the pulsed-focused ultrasound (PFUS) for tumor therapy, so as to improve the efficacy, safety and controllability of ultrasound treatment. Methods: The PFH and DOX co-loaded cationic liposomal nanoparticles (CL-PFH-DOX-NPs) were prepared for ultrasound (US) imaging, cell-killing, and B. bifidum adsorption for the reactive oxygen species (ROS) testing. The aggregation of B. bifidum and CL-PFH-DOX-NPs is called tumor-homing aggregation (B. bifidum@CL-PFH-DOX-NPs) in this study, and the synergistic effects of B. bifidum@CL-PFH-DOX-NPs were analyzed in vivo. Results: Comprehensive studies validated that CL-PFH-DOX-NPs can enhance US imaging and cell-killing and B. bifidum can promote ROS, and B. bifidum@CL-PFH-DOX-NPs achieve PFUS synergism in vivo. Importantly, active homing of B. bifidum facilitated the delivery and retention of CL-PFH-DOX-NPs in tumors, reducing dispersion in normal tissues, achieving the targeting ability of B. bifidum@CL-PFH-DOX-NPs. The best sonication time was chosen according to the distribution of CL-PFH-DOX-NPs in vivo to achieve efficient therapy. Especially, B. bifidum@CL-PFH-DOX-NPs amplified cavitation and the immune-boosting effects. Conclusion: Multifunctional B. bifidum@CL-PFH-DOX-NPs were successfully constructed with well targeting, which not only realized US imaging monitoring, strong cavitation and complementary killing during PFUS, but also achieved immunity enhancement after PFUS. The combination of PFUS, B. bifidum and CL-PFH-DOX-NPs provides a new idea for the potential application of ultrasound therapy in solid tumors.

A new method for preparing a rat intracerebral hemorrhage model by combining focused ultrasound and microbubbles

BACKGROUND

We aimed to prepare a non-invasive, reproducible, and controllable rat model of intracerebral hemorrhage with focused ultrasound (FUS).

METHODS

A rat intracerebral hemorrhage (ICH) model was established by combining FUS and microbubbles (μBs), and edaravone was used to verify whether the free radical scavenger had a protective effect on the model. The brain tissue of each group was sectioned to observe the gross histology, blood-brain barrier (BBB) permeability, cerebral infarction volume, and histopathological changes.

RESULTS

Compared with the FUS group, the BBB permeability was significantly increased in the FUS + μBs (F&B) group (p = 0.0021). The second coronal slice in the F&B group had an obvious hemorrhage lesion, and the FUS + μBs + edaravone (F&B&E) group had smaller hemorrhage areas; however, ICH did not occur in the FUS group. The cerebral infarction volume in the F&B group was significantly larger than that in the FUS group (p = 0.0030) and F&B&E group (p = 0.0208). HE staining results showed that nerve fibrinolysis, neuronal necrosis, microglia production, and erythrocytes were found in both the F&B group and the F&B&E group, but the areas of the nerve fibrinolysis and neuronal necrosis in the F&B group were larger than the F&B&E group.

CONCLUSIONS

A rat ICH model was successfully prepared using the μBs assisted FUS treatment, and edaravone had a therapeutic effect on this model. This model can be used to study the pathophysiological mechanism of ICH-related diseases and in preclinical research on related new drugs.

Does mpMRI guidance improve HIFU partial gland ablation compared to conventional ultrasound guidance? Early functional outcomes and complications from a single center

Background

Focal therapy (FT) for localized prostate cancer (PCa) treatment is raising interest. New technological mpMRI-US guided FT devices have never been compared with the previous generation of ultrasound-only guided devices.

Materials and Methods

We retrospectively analyzed prospectively recorded data of men undergoing FT for localized low- or intermediate-risk PCa with US- (Ablatherm®-2009 to 2014) or mpMRI-US (Focal One®-from 2014) guided HIFU. Follow-up visits and data were collected using internationally validated questionnaires at 1, 2, 3, 6 and 12 months.

Results

We included n=88 US-guided FT HIFU and n=52 mpMRI-US guided FT HIFU respectively. No major baseline differences were present except higher rates of Gleason 3+4 for the mpMRI-US group. No major differences were present in hospital stay (p=0.1), catheterization time (p=0.5) and complications (p=0.2) although these tended to be lower in the mpMRI-US group (6.8% versus 13.2% US FT group). At 3 months mpMRI-US guided HIFU had significantly lower urine leak (5.1% vs. 15.9%, p=0.04) and a lower drop in IIEF scores (2 vs. 4.2, p=0.07). Of those undergoing 12-months control biopsy in the mpMRI-US-guided HIFU group, 26% had residual cancer in the treated lobe.

Conclusion

HIFU FT guided by MRI-US fusion may allow improved functional outcomes and fewer complications compared to US- guided HIFU FT alone. Further analysis is needed to confirm benefits of mpMRI implementation at a longer follow-up and on a larger cohort of patients.