Gene and oligonucleotide delivery via micro- and nanobubbles by ultrasound exposure

Delivery of sPD1 gene by anti-CD133 antibody conjugated microbubbles combined with ultrasound for the treatment of cervical cancer in mice

To explore new therapeutic options for cervical cancer, the inhibitory effect on cervical cancer of targeted CD133-loaded sPD1 gene microbubbles (MBs) combined with low-frequency ultrasound was studied and its mechanism was explored. We prepared microbubbles conjugated with anti-CD133 antibody to deliver the sPD1 gene and determined concentration, particle size, and potentials of MBs. In addition, we verified that CD133 targeted-MBs could specifically bind to U14 cervical cancer cells in vitro. A mouse model of subcutaneous xenograft cervical cancer was established and mice were divided into a control group, an non-targeted microbubble group, a CD133-MBs group, an sPD1-MBs group and a CD133/sPD1-MBs group. Compared with the control group, tumor growth was inhibited in each group, with the CD133/sPD1 group showing the strongest inhibitory effect after treatment. The tumor volume and weight inhibition rates in the CD133/sPD1-MBs group were 78.01% and 72.25% respectively, which were statistically different from the other groups (P < 0.05), and HE staining and TUNEL immunofluorescence showed necrosis and apoptosis in tumor tissue. Flow cytometry, lactate dehydrogenase, and indirect immunofluorescence experiments showed that T lymphocytes were activated and a large number of CD8-positive T cells infiltrated the tumor tissue after treatment, with the CD133/sPD1-MBs group showing the most prominent effects (P < 0.05). The combination of ultrasound with anti- CD133 antibody-conjugated microbubbles loaded with the sPD1 gene can inhibit the growth of cervical cancer, suggesting that the immunosuppressive microenvironment of the tumor is improved after treatment.

Bubble-Based Drug Delivery Systems: Next-Generation Diagnosis to Therapy

Current radiologic and medication administration is systematic and has widespread side effects; however, the administration of microbubbles and nanobubbles (MNBs) has the possibility to provide therapeutic and diagnostic information without the same ramifications. Microbubbles (MBs), for instance, have been used for ultrasound (US) imaging due to their ability to remain in vessels when exposed to ultrasonic waves. On the other hand, nanobubbles (NBs) can be used for further therapeutic benefits, including chronic treatments for osteoporosis and cancer, gene delivery, and treatment for acute conditions, such as brain infections and urinary tract infections (UTIs). Clinical trials are also being conducted for different administrations and utilizations of MNBs. Overall, there are large horizons for the benefits of MNBs in radiology, general medicine, surgery, and many more medical applications. As such, this review aims to evaluate the most recent publications from 2016 to 2022 to report the current uses and innovations for MNBs.

Ultrasound nanotheranostics: Toward precision medicine

Ultrasound (US) is a mechanical wave that can penetrate biological tissues and trigger complex bioeffects. The mechanisms of US in different diagnosis and treatment are different, and the functional application of commercial US is also expanding. In particular, recent developments in nanotechnology have led to a wider use of US in precision medicine. In this review, we focus on US in combination with versatile micro and nanoparticles (NPs)/nanovesicles for tumor theranostics. We first introduce US-assisted drug delivery as a stimulus-responsive approach that spatiotemporally regulates the deposit of nanomedicines in target tissues. Multiple functionalized NPs and their US-regulated drug-release curves are analyzed in detail. Moreover, as a typical representative of US therapy, sonodynamic antitumor strategy is attracting researchers' attention. The collaborative efficiency and mechanisms of US and various nano-sensitizers such as nano-porphyrins and organic/inorganic nanosized sensitizers are outlined in this paper. A series of physicochemical processes during ultrasonic cavitation and NPs activation are also discussed. Finally, the new applications of US and diagnostic NPs in tumor-monitoring and image-guided combined therapy are summarized. Diagnostic NPs contain substances with imaging properties that enhance US contrast and photoacoustic imaging. The development of such high-resolution, low-background US-based imaging methods has contributed to modern precision medicine. It is expected that the integration of non-invasive US and nanotechnology will lead to significant breakthroughs in future clinical applications.

Exploring chitosan-shelled nanobubbles to improve HER2 + immunotherapy via dendritic cell targeting

Immunotherapy is a valuable approach to cancer treatment as it is able to activate the immune system. However, the curative methods currently in clinical practice, including immune checkpoint inhibitors, present some limitations. Dendritic cell vaccination has been investigated as an immunotherapeutic strategy, and nanotechnology-based delivery systems have emerged as powerful tools for improving immunotherapy and vaccine development. A number of nanodelivery systems have therefore been proposed to promote cancer immunotherapy. This work aims to design a novel immunotherapy nanoplatform for the treatment of HER2 + breast cancer, and specially tailored chitosan-shelled nanobubbles (NBs) have been developed for the delivery of a DNA vaccine. The NBs have been functionalized with anti-CD1a antibodies to target dendritic cells (DCs). The NB formulations possess dimensions of approximately 300 nm and positive surface charge, and also show good physical stability up to 6 months under storage at 4 °C. In vitro characterization has confirmed that these NBs are capable of loading DNA with good encapsulation efficiency (82%). The antiCD1a-functionalized NBs are designed to target DCs, and demonstrated the ability to induce DC activation in both human and mouse cell models, and also elicited a specific immune response that was capable of slowing tumor growth in mice in vivo. These findings are the proof of concept that loading a tumor vaccine into DC-targeted chitosan nanobubbles may become an attractive nanotechnology approach for the future immunotherapeutic treatment of cancer.