Quinoid Conjugated Polymer Nanoparticles with NIR-II Absorption Peak Toward Efficient Photothermal Therapy.

Recently, extensive efforts have been devoted to the development of the second near-infrared bio-window (NIR-II, 1000-1700 nm) theranostic agents owing to the excellent tissue-penetration capability of NIR-II light. The exploration of organic NIR-II photothermal therapy materials, especially those with absorption peak over 1000 nm, is an appealing yet significantly challenging task. Herein, we have designed conjugated polymer nanoparticles (PIS NPs) with NIR-II absorption peak at 1026 nm through a combined strategy of introducing quinoid donor-acceptor (D-A) structures, constructing intramolecular "conformational locks" and extending the conjugation area to narrow the band gap. Irradiated at 1064 nm, PIS NPs showed remarkable photothermal conversion performance for efficient photothermal ablation of tumor cells in vitro and in vivo. This study provides useful insights into the rational design of organic NIR-II photothermal agents based on multiple strategies.

[Enriching of total flavonoids from Herba Leonuri with polyamide and macroporous resin].

OBJECTIVE: To study the enriching method of total flavonoid from Herba Leonuri with polyamide and macroporous resin. METHOD: Seven enriching and purifying methods were compared with the yield and purity as indexes. The method of enriching with polyamide and macroporous resin was confirmed and the process of purifying was determined by orthogonal design. RESULT: D101 resin is packed by wet method, the ratio of diameter to height is 1:7. After mixed with the extract liquids, the weight of wet resin increased to 3 times of the dry resin. Evaporated the wet resin to dryness, mixed well with a little of 95% ethanol and dry polyamide powder, evaporated them to dryness again. Elute with deionized water until the effluent being colourless, then loaded it on the macroporous adsorptive resin, elute with 50% ethanol, the volume of effluents was collected to 7 times of the column volume. The purity of total flavonoids reached to 23%, while the diversion rate from raw Herba Leonuri was to 69%. CONCLUSION: The process is simple and convenient, and the regeneration of resin is easy, which has a good application foreground.

The Structure-Dependent Electric Release and Enhanced Oxidation of Drug in Graphene Oxide-Based Nanocarrier Loaded with Anticancer Herbal Drug Berberine.

The aim of the current investigation is to explore graphene oxide (GO) special electric and electrochemical properties in modulating and tuning drug delivery in tumor special environment of electrophysiology. The electric-sensitive drug release and redox behavior of GO-bearing berberine (Ber) was studied. Drug release in cell potential was applied in a designed electrode system: tumor environment was simulated at pH 6.2 with 0.1 V pulse voltage, whereas the normal was at pH 7.4 with 0.2 V. Quite different from the pH-depended profile, the electricity-triggered behavior indicated a high correlation with the carriers' structure: GO-based nanocomposite showed a burst release on its special "skin effect," whereas the PEGylated ones released slowly owing to the electroviscous effect of polymer. Cyclic voltammetry was used to investigate the redox behaviors of colloid PEGylated GO toward absorbed Ber in pH 5.8 and 7.2 solutions. After drug loading, the oxidation of Ber was enhanced in a neutral environment, whereas the enhancement of PEG-GO was in an acidic one, which means a possible increased susceptibility of their biotransformation in vivo. The studies designed in this work may help to establish a kind of carrier system for the sensitive delivery and metabolic regulation of drugs according to the different electrophysiological environment in tumor therapy.

Improved oral bioavailability of breviscapine via a Pluronic P85-modified liposomal delivery system.

OBJECTIVES: Breviscapine, a hydrophobic drug used for treating cardiovascular disease, was encapsulated in liposomes to improve its pharmaceutical characteristics. This study describes a novel liposome composition approach to specifically inhibit the P-glycoprotein efflux system. METHODS: Breviscapine-loaded Pluronic P85-coated liposomes were prepared by the thin film hydration technique. The particle size, zeta potential and encapsulation efficiency of the formulations were characterized. In-vitro drug release and permeability of Caco-2 cells were investigated. In-vitro characteristics and pharmacokinetics of the liposomes were evaluated in rat studies. KEY FINDINGS: The Pluronic P85-modified liposomes dispersed individually and had an approximate diameter of 118.8 ± 4.9 nm and a zeta potential of -35.4 ± 1.5 mV. Encapsulation efficiency was more than 90%. The use of the P85-coated liposomes resulted in significantly (P<0.05) increased absorption of breviscapine in Caco-2 cells and in 5.6-fold enhancement in its oral bioavailability in rats. CONCLUSION: The P85-modified liposomes for the oral delivery of breviscapine were prepared using l-α-phosphatidylcholine (soy-hydrogenated) and cholesterol with a narrow size distribution. This method seems to effectively enhance the bioavailability of breviscapine in rats.