Assembly of Macrocycle Dye Derivatives into Particles for Fluorescence and Photoacoustic Applications

Abstract

Optical imaging is a rapidly progressing medical technique that can benefit from the development of new and improved optical imaging agents suitable for use in vivo. However, the molecular rules detailing what optical agents can be processed and encapsulated into in vivo presentable forms are not known. We here present the screening of series of highly hydrophobic porphyrin, phthalocyanine, and naphthalocyanine dye macrocycles through a self-assembling Flash NanoPrecipitation process to form a series of water dispersible dye nanoparticles (NPs). Ten out of 19 tested dyes could be formed into poly(ethylene glycol) coated nanoparticles 60-150 nm in size, and these results shed insight on dye structural criteria that are required to permit dye assembly into NPs. Dye NPs display a diverse range of absorbance profiles with absorbance maxima within the NIR region, and have absorbance that can be tuned by varying dye choice or by doping bulking materials in the NP core. Particle properties such as dye core load and the compositions of co-core dopants were varied, and subsequent effects on photoacoustic and fluorescence signal intensities were measured. These results provide guidelines for designing NPs optimized for photoacoustic imaging and NPs optimized for fluorescence imaging. This work provides important details for dye NP engineering, and expands the optical imaging tools available for use.

Performances of a Pristine Graphene–Microbubble Hybrid Construct as Dual Imaging Contrast Agent and Assessment of Its Biodistribution by Photoacoustic Imaging

“…The hybrid graphene PVA microbubbles with different diamine length spacers were studied in vitro (phantom) at various concentrations. The in vitro results show a strong PA signal almost independent from the wavelength in a wide spectral window extending from 680 to 900 nm, which could be considered as an advantage with respect to other highly promising NIR absorber candidates which often show a narrower PA spectral window . It is worth noting that the length of the diamine spacer influences dramatically the PA response (see Figure a).…”

“…Several dye molecules and nanoparticles have been tested, all of them enabling the light absorption in the NIR where water and tissues absorb in a lesser extent. NIR absorbers such as methylene blue, indocyanine green, porphyrin, Au nanoparticles, copper sulfide, semiconducting polymer nanoparticles, etc., have been proposed as potential injectable PAI enhancers . These exogenous absorbers can be coupled with microbbubles, droplets, or liposomes to the make advanced ad hoc platform for imaging .…”

A Magnetic Adsorbent for the Removal of Cationic Dyes from Wastewater

“…It is estimated that more than 100,000 commercially available dyes are produced at a rate of over 7 × 10 8 kg every year [ 4 ]. The discharge of dyes into the environment causes both toxicological and esthetic problems [ 5 ]. There are diverse toxic substances and organic compounds in this wastewater, such as methylene blue (MB), rhodamine B (RhB), safranine T (T), gentian violet (GV), fuchsin basic (FB), and methyl orange (MO), which are harmful to fish and other aquatic organisms [ 4 , 5 , 6 ].…”

“…The discharge of dyes into the environment causes both toxicological and esthetic problems [ 5 ]. There are diverse toxic substances and organic compounds in this wastewater, such as methylene blue (MB), rhodamine B (RhB), safranine T (T), gentian violet (GV), fuchsin basic (FB), and methyl orange (MO), which are harmful to fish and other aquatic organisms [ 4 , 5 , 6 ]. Until now, more than 15% of dye loss is due to incomplete depletion of dye washing operations and the dyeing process [ 7 ].…”

Nanoparticle Regrowth Enhances Photoacoustic Signals of Semiconducting Macromolecular Probe for In Vivo Imaging

“…The amphiphilic semiconducting macromolecules (PCBP and PCP) were synthesized by using zinc‐tetranitrophthalocyanine (TNPc) as the starting material (Figure b). Zinc rather than other metal ions was chosen here, (i) because zinc‐phthalocyanine shows almost no fluorescence and thus benefits photoacoustic signals; (ii) zinc is more biocompatible as compared with Cu, Co, and Cr; (iii) zinc‐phthalocyanine has a longer absorption wavelength than iron‐phthalocyanine . The nitro groups of TNPc were first reduced by sodium sulfide nonahydrate to give zinc‐tetraaminophthalocyanine (TAPc) with four amino groups.…”