Microbubbles For Ultrasound Imaging Research Articles

Redox Responsive Metal Organic Framework Nanoparticles Induces Ferroptosis for Cancer Therapy.

Ferroptosis is attracting significant attention due to its effectiveness in tumor treatment. The efficiency to produce toxic lipid peroxides (LPOs) at the tumor site plays a key role in ferroptosis. A hybrid PFP@Fe/Cu-SS metal organic framework (MOF) is synthesized and shown to increase intratumoral LPO content through redox reactions generating ·OH. In addition, glutathione (GSH) depletion through disulfide-thiol exchange leads to the inactivation of glutathione peroxide 4 (GPX4), which results in a further increase in LPO content. This MOF exhibits high inhibitory effect on the growth of xenografted Huh-7 tumors in mice. The coadministration of a ferroptosis inhibitor reduces the antitumor effect of the MOF, leading to a restoration of GPX4 activity and an increase in tumor growth. Moreover, the construction of Cu into mesoporous PFP@Fe/Cu-SS not only allows the MOF to be used as a contrast agent for T1 -weighted magnetic resonance imaging, but also renders its photothermal conversion capacity. Thus, near-infrared irradiation is able to induce photothermal therapy and transform the encapsulated liquid perfluoropentane into microbubbles for ultrasound imaging.

Polymeric theranostics: using polymer-based systems for simultaneous imaging and therapy.

Polymer-based nanomedicine is a large and fast growing field. Polymer-based systems have been extensively used as therapeutic carriers as well as bioimaging agents for example in tumour diagnosis. However, fewer polymeric systems have been able to combine both therapy and imaging in a new field that is called theranostics (theragnostics). This review aims to summarise the recent developments and trends on polymeric theranostics. Four different types of therapies/treatments are examined namely drug delivery, gene delivery, photodynamic therapy and hyperthermia treatment combined with different imaging moieties like magnetic resonance imaging agents, fluorescent agents and microbubbles for ultrasound imaging.

Molecular Imaging of Cardiovascular Disease

Molecular imaging aims at sensing specific molecular targets, fundamental biological processes, and certain cell types in living subjects. An integrative discipline rooted in the biological, chemical, and imaging sciences, molecular imaging has broad applications in biology and drug discovery1–5 and increasingly within cardiovascular disease.6–12 Before discussing key factors spurring the growth of this field, we first briefly review 2 essential components of this technology: imaging agents and imaging hardware. Molecular imaging requires highly sensitive and specific imaging agents. Such agents incorporate 2 key factors: (1) a signal detection compound and the corresponding imaging hardware platform and (2) an affinity ligand that recognizes the intended molecular or cellular target. Favorable targets include those with established biological and clinical importance in a disease of interest, as well as targets with inherent signal amplification potential such as internalizing receptors or enzymes. Inaccessible and low-abundance targets (DNA, RNA, sparsely expressed proteins) present greater challenges, particularly in a noninvasive, clinical setting. Signal detection compounds include radioisotopes for positron emission tomography (PET) and single-photon-emission computed tomography (SPECT) imaging, paramagnetic (gadolinium)/superparamagnetic (iron oxide) agents for magnetic resonance imaging (MRI), fluorochromes for near-infrared fluorescence imaging, and microbubbles for ultrasound imaging. Certain agents can exhibit unique physical changes favorable for signal amplification when spaced close together (eg, quenching of fluorochromes13–18 or augmented relaxivity of magnetic substrates19–21). These tags can form the basis of imaging agents with inherent chemical amplification capabilities. Amplification strategies generally enable higher target-to-background ratios, a key strategy for developing sufficiently sensitive agents for clinical use. Affinity ligands confer molecular or cellular specificity for the target of interest. The application of novel ligand screening methods, emerging new chemistries for conjugation and signal amplification, and nanotechnology have fostered substantial growth in ligand development. From a clinical perspective, qualities of an ideal ligand include (1) …