Functional micro/nanobubbles for ultrasound medicine and visualizable guidance

Bioinspired Approaches for Central Nervous System Targeted Gene Delivery

Disorders of the central nervous system (CNS) which include a wide range of neurodegenerative and neurological conditions have become a serious global issue. The presence of CNS barriers poses a significant challenge to the progress of designing effective therapeutic delivery systems, limiting the effectiveness of drugs, genes, and other therapeutic agents. Natural nanocarriers present in biological systems have inspired researchers to design unique delivery systems through biomimicry. As natural resource derived delivery systems are more biocompatible, current research has been focused on the development of delivery systems inspired by bacteria, viruses, fungi, and mammalian cells. Despite their structural potential and extensive physiological function, making them an excellent choice for biomaterial engineering, the delivery of nucleic acids remains challenging due to their instability in biological systems. Similarly, the efficient delivery of genetic material within the tissues of interest remains a hurdle due to a lack of selectivity and targeting ability. Considering that gene therapies are the holy grail for intervention in diseases, including neurodegenerative disorders such as Alzheimer's disease, Parkinson's Disease, and Huntington's disease, this review centers around recent advances in bioinspired approaches to gene delivery for the prevention of CNS disorders.

Sono-Immunotherapy Mediated Controllable Composite Nano Fluorescent Probes Reprogram the Immune Microenvironment of Hepatocellular Carcinoma

Background

Despite the clinical efficacy of immunotherapy in treating malignant tumors, its effectiveness is often hampered by the immunosuppressive nature of the tumor microenvironment (TME). In this study, we propose the design of a nanoscale ultrasound contrast agent capable of triggering macrophage polarization and immunogenic cell death (ICD) for the treatment of hepatocellular carcinoma (HCC) through sonodynamic treatment (SDT) and immunotherapy.

Methods

The re-educator (designated as ICG@C3F8-R848 NBs) is composed of the Toll-like receptor agonist resiquimod (R848) and the sonosensitizer Indocyanine green (ICG), utilizing nanobubbles (NBs) as carriers. The technique known as ultrasound-targeted nanobubble destruction (UTND) employs nanosized microbubbles and low-frequency ultrasound (LFUS) to ensure accurate drug delivery and enhance safety.

Results

Following intravenous delivery, ICG@C3F8-R848 NBs have the potential to selectively target and treat primary tumors using SDT in conjunction with ultrasonography. Importantly, R848 can enhance antitumor immunity by inducing the polarization of macrophages from an M2 to an M1 phenotype.

Conclusion

The SDT-initiated immunotherapy utilizing ICG@C3F8-R848 NBs demonstrates significant tumor suppression effects with minimal risk of systemic toxicity. The utilization of this self-delivery re-education technique would contribute to advancing the development of nanomedicine for the treatment of hepatocellular carcinoma.

Ultrasound mediated gold nanoclusters-capped gas vesicles for enhanced fluorescence imaging

The intercellular tight junction inhibits tumor imaging efficiency of nanomaterials, and enhanced cellular drug delivery with efficient detection is an important tool for tumor diagnosis. Herein, we fabricate fluorescence gold nanoclusters (Au NCs) decorated gas vesicles (GV-Au) for ultrasound (US)-mediated enhanced cellular delivery and imaging, in which GVs are living cell derived protein bubbles. GV-Au is rod-shaped sack-like structure around 230 nm, and displays improved stability and fluorescence ability compared with free Au NCs. Flow cytometry assay confirms the intracellular localization of Au NCs and GV-Au with a respective 2.20-fold enhanced cellular uptake post US treatment. Confocal images reveal the efficient cellular uptake of GV-Au under US impact, indicating that GV-Au is suitable for cellular and in vivo fluorescence imaging. Our strategy provides a new idea for efficient fluorescence imaging by penetrating cell membranes at the presence of US treatment.

Preparation of targeted theranostic red blood cell membranes-based nanobubbles for treatment of colon adenocarcinoma

OBJECTIVES

Designing and fabrication of theranostic systems based on nanoscale gaseous vesicular systems, named nanobubbles (NBs), attracted enormous interest in recent years. Biomimetic vesicular platform (V-RBC-M) can improve the pharmacokinetics of the prepared platform due to augmented circulation half-life, desirable biodegradability and biocompatibility and reduced immunogenicity.

METHODS

V-RBC-M were used for the encapsulation of lipophilic camptothecin (CPT) in the bilayer of vesicles through top-down method, followed by filling the core of V-RBC-M with inert SF6 gas to fabricate NBs with ultrasonic contrast enhancement capability (SF6-NB-CPT). In the next step, targeted NBs were formed via decoration of MUC1 aptamer on the surface of NBs (Apt-SF6-NB-CPT).

RESULTS

The designed bio-NBs indicated high encapsulation efficiency and the sustained release of CPT at pH 7.4. In vitro study demonstrated higher cellular uptake and cytotoxicity of Apt-SF6-NB-CPT compared to SF6-NB-CPT in MUC1-overexpressing cells (C26). In vivo antitumor efficacy of the prepared NBs on C26 bearing BALB/c mice showed greater therapeutic efficacy and survival rate for Apt-SF6-NB-CPT. In this regard, SF6-NB-CPT showed 58% tumor growth suppression while Apt-SF6-NB-CPT system provided 95% tumor growth suppression. Furthermore, echogenic capability of SF6-NB-CPT was demonstrated through in vitro and in vivo ultrasonic imaging.

CONCLUSIONS

Our finding demonstrated that the prepared targeted NBs are a promising theranostic platform with effective therapeutic and diagnotic potentials.

Interactions between O2 Nanobubbles and the Pulmonary Surfactant in the Presence of Inhalation Medicines

A dispersion of oxygen nanobubbles (O₂-NBs) is an extraordinary gas-liquid colloidal system where spherical gas elements can be considered oxygen transport agents. Its conversion into inhalation aerosol by atomization with the use of nebulizers, while maintaining the properties of the dispersion, gives new opportunities for its applications and may be attractive as a new concept in treating lung diseases. The screening of O₂-NBs interactions with lung fluids is particularly needed in view of an O₂-NBs application as a promising aerosol drug carrier with the additional function of oxygen supplementation. The aim of the presented studies was to investigate the influence of O₂-NBs dispersion combined with the selected inhalation drugs on the surface properties of two types of pulmonary surfactant models (lipid and lipid-protein model). The characteristics of the air-liquid interface were carried out under breathing-like conditions using two selected tensiometer systems: Langmuir-Wilhelmy trough and the oscillating droplet tensiometer. The results indicate that the presence of NBs has a minor effect on the dynamic characteristics of the air-liquid interface, which is the desired effect in the context of a potential use in inhalation therapies.

Biomedical polymers: synthesis, properties, and applications

Biomedical polymers have been extensively developed for promising applications in a lot of biomedical fields, such as therapeutic medicine delivery, disease detection and diagnosis, biosensing, regenerative medicine, and disease treatment. In this review, we summarize the most recent advances in the synthesis and application of biomedical polymers, and discuss the comprehensive understanding of their property-function relationship for corresponding biomedical applications. In particular, a few burgeoning bioactive polymers, such as peptide/biomembrane/microorganism/cell-based biomedical polymers, are also introduced and highlighted as the emerging biomaterials for cancer precision therapy. Furthermore, the foreseeable challenges and outlook of the development of more efficient, healthier and safer biomedical polymers are discussed. We wish this systemic and comprehensive review on highlighting frontier progress of biomedical polymers could inspire and promote new breakthrough in fundamental research and clinical translation.

Circularly polarized luminescence from helical N,O-boron-chelated dipyrromethene (BODIPY) derivatives

We report N,O-boron-chelated dipyrromethene derivatives exhibiting circularly polarized luminescence (CPL) in the red/near-infrared region, both in solution and the aggregated state. The CPL is originated from the helical chirality through intramolecular substitution of fluorine by an alkenolic substituent. The self-assembly of the fluorophores significantly enhances the |g_lum| values from 10^-4 to 10^-2.

How Could Nanomedicine Improve the Safety of Contrast Agents for MRI during Pregnancy?

Pregnancy is a delicate state, during which timely investigation of possible physiological anomalies is essential to reduce the risk of maternal and fetal complications. Medical imaging encompasses different technologies to image the human body for the diagnosis, course of treatment management, and follow-up of diseases. Ultrasound (US) is currently the imaging system of choice for pregnant patients. However, sonographic evaluations can be non-effective or give ambiguous results. Therefore, magnetic resonance imaging (MRI), due to its excellent tissue penetration, the possibility of acquisition of three-dimensional anatomical information, and its high spatial resolution, is considered a valid diagnostical alternative. Nevertheless, currently employed contrast agents to improve the MRI image quality are harmful to the fetus. Because of their ability to cross the placenta, their use on pregnant patients is avoided. This review will firstly recapitulate the most common non-obstetrical, obstetrical, and fetal indications for magnetic resonance imaging on pregnant women. Fetal safety risks, due to the use of strong magnetic fields and exogenous contrast agents, will be presented. Then, possible advantages of nanostructured contrast agents compared to current molecular ones are explored. Nanosystems’ characteristics affecting contrast efficiency, and their potential for improving contrast-enhanced MRI’s safety in pregnant women, are discussed. Lastly, promising examples of nanoparticles as safer alternatives to current MRI contrast agents in pregnancy are discussed.

Ferroptosis promotes sonodynamic therapy: a platinum(ii)–indocyanine sonosensitizer

Sonodynamic therapy (SDT) has unique advantages in deep tumour ablation due to its deep penetration depth, showing great preclinical and clinical potential. Herein, a platinum(ii)–cyanine complex has been designed to investigate its potential as a SDT anticancer agent. It generates singlet oxygen (¹O₂) under ultrasound (US) irradiation or light irradiation, and exhibits US-cytotoxicity in breast cancer 4T1 cells but with negligible dark-cytotoxicity. Mechanistic investigations reveal that Pt-Cy reduces the cellular GSH and GPX4, and triggers cancer cell ferroptosis under US irradiation. The metabolomics analysis illustrates that Pt-Cy upon US treatment significantly dysregulates glutathione metabolism, and finally induces ferroptosis. In vivo studies further demonstrate that Pt-Cy inhibits tumor growth under US irradiation and its efficiency for SDT is better than that for PDT in vivo. This is the first example of platinum(ii) complexes for sonodynamic therapy. This work extends the biological applications of metal complexes from PDT to SDT.

A novel platinum(ii)–cyanine complex showed a greater excellent sonodynamic therapeutic effect than photodynamic therapy in vivo. This work expands the biological applications of metal complexes from traditional photodynamic therapy to sonodynamic therapy.