Near-infrared light activatable niosomes loaded with indocyanine green and plasmonic gold nanorods for theranostic applications.

Light-mediated theranostic platforms involve the use of agents (small molecules/nanomaterials), which can absorb light to produce either heat or reactive chemical species (RCS) and emit fluorescence. Such platforms are advantageous in the field of personalized medicine, as they provide enhanced diagnostic capabilities, improved therapeutic efficiencies, and can also simultaneously monitor the treatment outcomes using imaging modalities. Specifically, agents absorbing near-infrared (NIR) light can provide minimal scattering, low autofluorescence, superior spatio-temporal resolution, and deeper tissue penetration depths. Gold nanorods (GNR) and indocyanine green (ICG) are two agents known to absorb light in the NIR region. GNR can provide tunable plasmonic properties, while ICG is an FDA-approved NIR fluorophore. However, the use of ICG and GNR suffers from various limitations, such as photobleaching, non-specificity, toxicity, and aggregation in solution. To overcome these limitations, herein, we report on NIR light-activatable niosomes loaded with GNR and ICG for cancer theranostic applications. Both agents were encapsulated into non-ionic surfactant-based biocompatible niosomes to form ICG-GNR@Nio with superior loading efficiencies and enhanced properties. ICG-GNR@Nio offers excellent storage stability, photostability, elevated temperature rise and generation of reactive oxygen species (ROS) upon 1064 nm laser irradiation. Subsequently, the enhanced phototherapeutic capabilities mediated by ICG-GNR@Nio were validated in the in vitro cellular experiments. Overall, ICG-GNR@Nio-based theranostic platforms can provide a significant benchmark in the improved diagnosis and therapeutic capabilities for biomedical clinicians to tackle various diseases.

Cellular metabolic activity and electrochemical stability assay of embedded oxidoreductase enzyme confined in the nanospace of a framework exoskeleton.

In the present study, we sought to reveal how embedding oxidoreductase enzymes in a metal-organic framework influences restoring the biofunctionality when encapsulated within zeolitic imidazolate framework (ZIF-8 and ZIF-90), wherein these biocomposites were explored for their cellular metabolic activity using the (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) (MTT) assay on A549 lung cancer cells and NIH3T3 (mouse fibroblasts) cells. We chose two biocomposites, namely catalase-encapsulated ZIF-8 and ZIF-90, wherein the enzyme was encapsulated at varied loadings through a rapid self-triggered nucleation around the protein surfaces of the enzyme. Interestingly, this embedding pattern of catalase in both ZIF-8 and ZIF-90 depended on the surface chemistry of the enzyme. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy analysis revealed the stability of the encapsulated enzyme in the nanospace of the ZIF-8 and ZIF-90 frameworks. Investigation of the cellular metabolic activity by the MTT assay of Cat@ZIF-8 and Cat@ZIF-90 on the lung cancer cell A549 showed cell viability enhancement in the case of Cat@ZIF-8 at a higher percentage compared to that of Cat@ZIF-90. A similar metabolic activity assay was performed with the internalization of Cat@ZIF-90 for NIH3T3 (mouse fibroblasts) cells. The revealed difference between the MOF compounds was due to the nano-confinement effect in ZIF-8 compared to ZIF-90, which can accelerate the utilization in cellar metabolic activity.