The
design of organic photothermal agents (PTAs) for in
vivo applications face a demanding set of performance requirements,
especially intense NIR-absorptivity and sufficient photobleaching
resistance. J-aggregation offers a facile way to tune the optical
properties of dyes, thus providing a general design platform for organic
PTAs with the desired performance. Herein, we present a supramolecular
strategy to build a water-stable, nonphotobleaching, and NIR-absorbing
nano-PTA (J-NP) from J-aggregation of halogenated BODIPY dyes (BDP)
for efficient in vivo photothermal therapy. Multiple
intermolecular halogen-bonding and π–π stacking
interactions triggered the formation of BDP J-aggregate, which adsorbed
amphiphilic polymer chains on the surface to provide PEGylated sheetlike
nano-J-aggregate (J-NS). We serendipitously discovered that the architecture
of J-NS was remodeled during a long-time ultrafiltration process,
generating a discrete spherical nano-J-aggregate (J-NP) with controlled
size. Compared with J-NS, the remodeled J-NP significantly improved
cellular uptake efficiency. J-aggregation brought J-NP striking photothermal
performance, such as strong NIR-absorptivity, high photothermal conversion
efficiency up to 72.0%, and favorable nonphotobleaching ability. PEGylation
and shape-remodeling imparted by the polymer coating enabled J-NP
to hold biocompatibility and stability in vivo, thereby
exhibiting efficient antitumor photothermal activities. This work
not only presents a facile J-aggregation strategy for preparing PTAs
with high photothermal performance but also establishes a supramolecular
platform that enables the appealing optical functions derived from
J-aggregation to be applied in vivo.
Scheme 2. Conventional fractional PDT (fPDT) with intermittent light irradiation allowing oxygen replenishment between two PDT cycles; the designed enhanced-fPDT with sustained 1 O 2 generation and additional PTT between two PDT cycles.
Scutellarein-7-O-β-D-glucuronide (SG) and apigenin-7-O-β-D-glucuronide (AG) are two major bioactive constituents with known pharmacological effects in Erigeron multiradiatus. In this study, a simple method for preparative separation of the two flavone glucuronides was established with macroporous resins. The performance and adsorption characteristics of eight macroporous resins including AB-8, HPD100, HPD450, HPD600, D100, D101, D141, and D160 have been evaluated. The results confirmed that D141 resin offered the best adsorption and desorption capacities and the highest desorption ratio for the two glucuronides among the tested resins. Sorption isotherms were constructed for D141 resin under optimal ethanol conditions and fitted well to the Freundlich and Langmuir models (R2 > 0.95). Dynamic adsorption and desorption tests was performed on column packed with D141 resin. After one-run treatment with D141 resin, the two-constituent content in the final product was increased from 2.14% and 1.34% in the crude extract of Erigeron multiradiatus to 24.63% and 18.42% in the final products with the recoveries of 82.5% and 85.4%, respectively. The preparative separation of SG and AG can be easily and effectively achieved via adsorption and desorption on D141 resin, and the method developed can be referenced for large-scale separation and purification of flavone glucuronides from herbal raw materials.
A stereoselective high performance liquid chromatography method has been developed for the chiral separation of the enantiomers of six antihistamines, doxylamine, carbinoxamine, dioxopromethazine, oxomemazine, cetirizine and hydroxyzine. The effects of mobile phase additive, column temperature and flow rate on the retention time and resolution were studied. Enantiomeric separation of cetirizine, doxylamine and hydroxyzine were achieved on cellulose tris-(3,5-dichlorophenylcarbamate) immobilized on silica gel chiral stationary phase known as Chiralpak IC (RS = 3.74, RS = 1.85 and RS = 1.74, respectively).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.