Biomineralization of Aggregation-Induced Emission-Active Photosensitizers for pH-Mediated Tumor Imaging and Photodynamic Therapy

Abstract

As an efficient, noninvasive, and high spatiotemporal resolved approach, photodynamic therapy (PDT) has high therapeutic potential for cancer treatment, whereas its development still faces a number of challenges, such as the lack of efficient and stable photosensitizers (PSs) and the inadequate ability of PSs to accumulate at tumor sites and target responses. Herein, a pH-responsive calcium carbonate (CaCO 3 )-mineralized AIEgen nanoprobe was prepared by using bovine serum albumin as the skeleton and loaded with a mitochondria-specific aggregation-induced emission (AIE)-active PS of 1-methyl-4-(4-(1,2,2triphenylvinyl)styryl)quinolinium iodide (TPE-Qu + ), which exhibits superior singlet oxygen ( 1 O 2 )-generation ability and meanwhile possesses a bright near-infrared fluorescence emission. The biomineralized nanoparticles have small sizes (100 ± 10 nm) with good water dispersion and stability. With an increase in acidity (pH = 7.4−5.0), the internal TPE-Qu + molecules are released gradually and accumulated in the mitochondria due to their hydrophobicity and electropositivity and then generate fluorescence emission and PDT under an external light source. Tumor inhibition and low acute toxicity were further successfully confirmed by the intracellular uptake test and 4T1-tumorbearing mouse model.

Microemulsion-Confined Biomineralization of PEGylated Ultrasmall Fe3O4 Nanocrystals for T2-T1 Switchable MRI of Tumors

“…One can conclude from Figure A that the CaCO 3 -coated nanoprobe can enter the lysosome of the cell smoothly within 1 h, and with the increase of incubation time (3 h), the escaped MB and USPIONs from the lysosome will be released into the cytoplasm, and MB will eventually accumulate in the mitochondria because of its positive charge. This above phenomenon is consistent with our previous report . Next, the ability of this T2-T1 switchable MRI nanoprobe in application to tumor MRI was demonstrated using a mouse model bearing a subcutaneous 4T1 xenograft.…”

“…This above phenomenon is consistent with our previous report. 31 Next, the ability of this T2-T1 switchable MRI nanoprobe in application to tumor MRI was demonstrated using a mouse model bearing a subcutaneous 4T1 xenograft. The mice were injected in the tail vein with the PEG-USPIONs@CaCO 3 nanoprobes (25 mg/kg of mice), and the sagittal T1-MRI images at different times after the injection were collected using an MRI instrument (Figure 5B,C).…”

Aggregation-Induced Emission Luminogens for Enhanced Photodynamic Therapy: From Organelle Targeting to Tumor Targeting

“…(3) Using a carrier such as PEG-encapsulating drugs to form nanoparticles. There are several AIE-PSs with an association with albumin that have been reported [ 155 , 156 , 157 , 158 ].…”

New insight into the application of fluorescence platforms in tumor diagnosis: From chemical basis to clinical application

“…Similar to CDT, PDT kills tumor cells by generating endogenous ROS from photosensitizers under light conditions. 170 The difference is that PTT kills tumor cells by light-activating photosensitizers that generate localized temperature increases. 171 Generally, photosensitizers/photothermal agents for PDT and PTT are essentially fluorophores with ROS generation or high photothermal conversion efficiency, and they can play dual roles of diagnosis and treatment in an integrated platform for tumor diagnosis and treatment.…”