Anti-inflammatory, antipyretic efficacy and safety of inhaled Houttuynia cordata thunb. essential oil formulation.

ETHNOPHARMACOLOGICAL RELEVANCE: Houttuynia cordata Thunb. (H. cordata) is a well-known folk traditional Chinese medicine that is renowned for its use in the management of inflammatory respiratory diseases and pneumonia. Its essential oils have demonstrated their anti-inflammatory efficacy in vitro, however, their in vivo biological effects via inhalation have not been elucidated. AIM OF THE STUDY: This study aims to evaluate the anti-inflammation and toxicology of H. cordata essential oil-containing formulation, H16 aerosol in vivo. MATERIALS AND METHODS: A laser diffraction particle size analyser and a Next Generation Impactor were used to measure the mass median aerodynamic diameter (MMAD) of the H16 aerosol. The anti-inflammatory and antipyretic effects of the H16 aerosol were evaluated in the xylene-evoked ear oedema and Brewer's yeast-induced fever models, respectively. The biological safety of the H16 aerosol was evaluated by acute toxicity and local toxicity tests in animal models. RESULTS: Our data showed that the MMAD of the bioactive aerosol was 3-5 µm, which implied tracheal and pharyngeal deposits. Significant anti-inflammatory and antipyretic effects were also observed in the animal models treated with H16 aerosol. The maximum tolerable dose of H16 in rats was >2.5 mL/kg. Irritation was not found on respiratory tract mucosa in the local toxicity test. CONCLUSIONS: Taken together, the present study suggested that H16 could be delivered in the form of aerosol and possessed its antipyretic and anti-inflammatory effects. This study provides a new perspective for the development of a new herbal aerosol therapy and herbal modernization.

Fluorescent Labeling and Biodistribution of Latex Nanoparticles Formed by Surfactant-Free RAFT Emulsion Polymerization.

The authors report the preparation of a novel range of functional polyacrylamide stabilized polystyrene nanoparticles, obtained by surfactant-free reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization, their fluorescent tagging, cellular uptake, and biodistribution. The authors show the versatility of the RAFT emulsion process for the design of functional nanoparticles of well-defined size that can be used as drug delivery vectors. Functionalization with a fluorescent tag offers a useful visualization tool for tracing, localization, and clearance studies of these carriers in biological models. The studies are carried out by labeling the sterically stabilized latex particles chemically with rhodamine B. The fluorescent particles are incubated in a healthy human renal proximal tubular cell line model, and intravenously injected into a mouse model. Cellular localization and biodistribution of these particles on the biological models are explored.

Preparation of Inert Polystyrene Latex Particles as MicroRNA Delivery Vectors by Surfactant-Free RAFT Emulsion Polymerization.

We present the preparation of 11 nm polyacrylamide-stabilized polystyrene latex particles for conjugation to a microRNA model by surfactant-free RAFT emulsion polymerization. Our synthetic strategy involved the preparation of amphiphilic polyacrylamide-block-polystyrene copolymers, which were able to self-assemble into polymeric micelles and "grow" into polystyrene latex particles. The surface of these sterically stabilized particles was postmodified with a disulfide-bearing linker for the attachment of the microRNA model, which can be released from the latex particles under reducing conditions. These nanoparticles offer the advantage of ease of preparation via a scaleable process, and the versatility of their synthesis makes them adaptable to a range of applications.

Hyperbranched alternating block copolymers using thiol-yne chemistry: materials with tuneable properties.

Alternating-block hyperbranched polymers were synthesized using the highly versatile thiol-yne reaction. Dimethyl acrylamide-styrene and tert-butyl acrylate-styrene polymers were prepared, with subsequent hydrolysis of the tert-butyl ester to acrylic acid. The dimethyl acrylamide-styrene hyperbranched polymers self-assembled into large aggregates, as did the acrylic acid-styrene system at low pH. However, high pH triggers the formation of very well defined small particles in the latter system.