An Optical/Photoacoustic Dual-Modality Probe: Ratiometric in/ex Vivo Imaging for Stimulated H2S Upregulation in Mice.

Tracking signaling H2S in live mice demands responsive imaging with fine tissue imaging depth and low interferences from tissue scattering/autofluorescence and probe concentration. With complementary advantages of fluorescence and photoacoustic (PA) imaging, optical/PA dual-modality imaging was suggested for in/ex vivo H2S imaging. Therefore, a meso-benzoyloxyltricarboheptamethine cyanine, HS-CyBz, was prepared as the first ratiometric optical/PA dual-modality probe for H2S, profiting from a keto-enol transition sensing mechanism. Tail intravenous injection of this probe leads to probe accumulation in the liver of mice, and the endogenous H2S upregulation triggered by S-adenosyl-l-methionine has been verified by ratiometric optical/PA imaging, suggesting the promising potential of this ratiometric dual-modality imaging.

Paclitaxel-Induced Ultrasmall Gallic Acid-Fe@BSA Self-Assembly with Enhanced MRI Performance and Tumor Accumulation for Cancer Theranostics.

Ultrasmall nanoparticles have attracted great attention because of their efficient renal clearance. However, their bioapplication is still severely hampered by the poor performance derived from low tumor accumulation. Here, a large, self-assembled nanoparticle was designed for cancer theranostics and used with paclitaxel (PTX) to assemble bovine serum albumin-coated ultrasmall gallic acid-Fe(III) (GA-Fe@BSA-PTX) nanoparticles by the hydrophobic effect. The GA-Fe@BSA-PTX self-assembled nanoparticles featured appropriate size (∼115 nm), high water dispersity and stability, and low cell toxicity. Importantly, the magnetic resonance imaging performance and tumor accumulation of GA-Fe@BSA-PTX self-assembled nanoparticles were much better than those of the ultrasmall GA-Fe@BSA nanoparticles. Furthermore, the GA-Fe@BSA-PTX self-assembled nanoparticles exhibited an excellent therapeutic effect on tumors, owing to the combined chemo- and photothermal effects. This work highlights the great potential of the as-synthesized GA-Fe@BSA-PTX self-assembled nanoparticles as a multifunctional theranostic nanoplatform, offering compelling opportunities for theranostic applications in the clinic.

BSA-assisted synthesis of ultrasmall gallic acid-Fe(III) coordination polymer nanoparticles for cancer theranostics.

Protein-related nanotheranostic agents hold great promise as tools to serve many clinical applications. Proteins such as BSA are used to regulate the synthesis of nondegradable inorganic nanoparticles (NPs). To fully employ the potential of such proteins, a new type of biosafe nanotheranostic agent must be designed to optimize BSA as a biomineralization agent. Here, a straightforward BSA-assisted biomineralization method was developed to prepare gallic acid (GA)-Fe(III) coordination polymer NPs. BSA-coated GA-Fe (GA-Fe@BSA) NPs were ultrasmall (3.5 nm) and showed good biocompatibility, a lower r2:r1 ratio (1.06), and strong absorption in the visible near-infrared region. T1-weighted magnetic resonance imaging of tumor-bearing mice before and after intratumoral injection with GA-Fe@BSA NPs definitively demonstrated positive change. In a subsequent in vivo study, antitumor activity was precipitated by intratumoral injection of GA-Fe@BSA NPs combined with laser treatment, suggesting excellent outcomes with this treatment method. These results describe a successful protocol in which BSA regulated the synthesis of benign organic polymer NPs. GA-Fe@BSA NPs have the potential to be ideal agents to be used in clinical theranostic nanoplatforms.