Ultrasound contrast agents from microbubbles to biogenic gas vesicles

Diagnostic performance of contrast-enhanced ultrasound (CEUS) combined with Ovarian-Adnexal Reporting and Data System (O-RADS) ultrasound risk stratification for adnexal masses: a systematic review and meta-analysis

AIM

A number of studies have reported that contrast-enhanced ultrasound (CEUS) imaging might be used for the early diagnosis of adnexal masses. A meta-analysis was performed to evaluate the diagnostic accuracy of CEUS combined with Ovarian-Adnexal Reporting and Data System (O-RADS) ultrasound risk stratification for adnexal masses.

MATERIALS AND METHODS

Related articles were retrieved from PubMed, Web of Science, Embase, and the Cochrane Library in strict accordance with established standards, and data (including true positive, false positive, false negative, and true negative values) was extracted from the original articles. The Quality Assessment of Diagnostic Accuracy Studies 2 was used to evaluate the quality of articles and the possibility of bias. STATA 12.0 software was used to perform statistical analysis.

RESULTS

Five articles that included 598 patients were analyzed in this meta-analysis. The pooled sensitivity and specificity of CEUS combined with O-RADS for the diagnosis of adnexal masses were 0.95 (95% confidence interval [CI]: 0.91-0.98) and 0.86 (95% CI: 0.79-0.91). Moreover, the positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR), and area under the curve (AUC) were 6.81 (95% CI: 4.61-10.08), 0.05 (95% CI: 0.03-0.11), 111.30 (95% CI: 65.32-189.65), and 0.97 (95% CI: 0.95-0.98), respectively. The pooled AUC and DOR for the detection of CEUS combined with O-RADS were superior to O-RADS US.

CONCLUSION

Our findings revealed that O-RADS combined with CEUS can improve the diagnostic accuracy of ovarian adnexal masses.

Nanoscale contrast agents: A promising tool for ultrasound imaging and therapy

Nanoscale contrast agents have emerged as a versatile platform in the field of biomedical research, offering great potential for ultrasound imaging and therapy. Various kinds of nanoscale contrast agents have been extensively investigated in preclinical experiments to satisfy diverse biomedical applications. This paper provides a comprehensive review of the structure and composition of various nanoscale contrast agents, as well as their preparation and functionalization, encompassing both chemosynthetic and biosynthetic strategies. Subsequently, we delve into recent advances in the utilization of nanoscale contrast agents in various biomedical applications, including ultrasound molecular imaging, ultrasound-mediated drug delivery, and cell acoustic manipulation. Finally, the challenges and prospects of nanoscale contrast agents are also discussed to promote the development of this innovative nanoplatform in the field of biomedicine.

Nanomedicine as a multimodal therapeutic paradigm against cancer: on the way forward in advancing precision therapy

Recent years have witnessed dramatic improvements in nanotechnology-based cancer therapeutics, and it continues to evolve from the use of conventional therapies (chemotherapy, surgery, and radiotherapy) to increasingly multi-complex approaches incorporating thermal energy-based tumor ablation (e.g. magnetic hyperthermia and photothermal therapy), dynamic therapy (e.g. photodynamic therapy), gene therapy, sonodynamic therapy (e.g. ultrasound), immunotherapy, and more recently real-time treatment efficacy monitoring (e.g. theranostic MRI-sensitive nanoparticles). Unlike monotherapy, these multimodal therapies (bimodal, i.e., a combination of two therapies, and trimodal, i.e., a combination of more than two therapies) incorporating nanoplatforms have tremendous potential to improve the tumor tissue penetration and retention of therapeutic agents through selective active/passive targeting effects. These combinatorial therapies can correspondingly alleviate drug response against hypoxic/acidic and immunosuppressive tumor microenvironments and promote/induce tumor cell death through various multi-mechanisms such as apoptosis, autophagy, and reactive oxygen-based cytotoxicity, e.g., ferroptosis, etc. These multi-faced approaches such as targeting the tumor vasculature, neoangiogenic vessels, drug-resistant cancer stem cells (CSCs), preventing intra/extravasation to reduce metastatic growth, and modulation of antitumor immune responses work complementary to each other, enhancing treatment efficacy. In this review, we discuss recent advances in different nanotechnology-mediated synergistic/additive combination therapies, emphasizing their underlying mechanisms for improving cancer prognosis and survival outcomes. Additionally, significant challenges such as CSCs, hypoxia, immunosuppression, and distant/local metastasis associated with therapy resistance and tumor recurrences are reviewed. Furthermore, to improve the clinical precision of these multimodal nanoplatforms in cancer treatment, their successful bench-to-clinic translation with controlled and localized drug-release kinetics, maximizing the therapeutic window while addressing safety and regulatory concerns are discussed. As we advance further, exploiting these strategies in clinically more relevant models such as patient-derived xenografts and 3D organoids will pave the way for the application of precision therapy.