Optical-Property-Enhancing Novel Near-Infrared Active Niosome Nanoformulation for Deep-Tissue Bioimaging

Abstract

Indocyanine green (ICG) is a clinically approved near-infrared (NIR) contrast agent used in medical diagnosis. However, ICG has not been used to its fullest for biomedical imaging applications due to its low fluorescence quantum yield, aqueous instability, concentration-dependent aggregation, and photo and thermal degradations, leading to quenching of its fluorescence emission. In the present study, a nanosized niosomal formulation, ICGNiosomes (ICGNios), is fabricated to encapsulate and protect ICG from degradation. Interestingly, compared to free ICG, the ICGNios exhibited higher fluorescence quantum yield and fluorescence emission with a bathochromic shift. Also, ICGNios nanoparticles are biocompatible, biodegradable, and readily uptaken by the cells. Furthermore, ICGNios show more enhanced fluorescence intensity through ∼1 cm thick chicken breast tissue compared to free ICG, which showed minimal emission through the same thickness of tissue. Our results suggest that ICGNios could offer a promising platform for deep-tissue NIR in vivo imaging to visualize inaccessible tissue microstructures for disease diagnosis and therapeutics.

TLR-7/8 Agonist-Loaded Polypyrrole-Based Theranostic Nanovaccine for Second Near-Infrared Photothermal Immunotherapy of Cancer

“…In contrast to the considerable decrease in optical absorption of ICG under 808 nm laser irradiation, the absorption spectra of NC remained unchanged before and after 5 min of exposure under 808 and 1064 nm lasers under the same conditions for 5 cycles, demonstrating that NC exhibited high photothermal conversion stability (Figure e). Moreover, the photostability of NC was superior to that of the clinical NIR dye ICG after 1 W/cm 2 of NIR laser irradiation for 25 min (Figure f) …”

Spontaneous Transfer of Indocyanine Green from Liposomes to Albumin Is Inhibited by the Antioxidant α-Tocopherol

“…Our results suggest that fluorescence imaging performance with fluid-phase ICG liposomes can be enhanced by including clinically approved α-tocopherol as a liposome additive that will reduce ICG transfer and inhibit ICG photobleaching. Further studies are needed to determine if spontaneous ICG transfer to albumin occurs when the ICG is embedded in gel-phase liposomes with high transition temperatures ,, or non-phospholipid vesicles. − …”

Synthesis of 2,5-bis(9H-fluoren-9-ylidene)-2,5-dihydrothiophene derivatives and a systematic study of the substituent effect

“…On the other hand, most of these compounds did not show fluorescence when measured as a solid, except B1 and B5, which might be caused by the serious aggregation leading to fluorescence quenching. 20 Fig. 1 Representative TG curves for ThBF derivatives.…”