Droplet Motion on a Shape Gradient Surface.

We demonstrate a facile method to induce water droplet motion on an wedge-shaped superhydrophobic copper surface combining with a poly(dimethylsiloxane) (PDMS) oil layer on it. The unbalanced interfacial tension from the shape gradient offers the actuating force. The superhydrophobicity critically eliminates the droplet contact line pinning and the slippery PDMS oil layer lubricates the droplet motion, which makes the droplet move easily. The maximum velocity and furthest position of droplet motion were recorded and found to be influenced by the gradient angle. The mechanism of droplet motion on the shape gradient surface is systematically discussed, and the theoretical model analysis is well matched with the experimental results.

Nanoencapsulation of the sasanquasaponin from Camellia oleifera, its photo responsiveness and neuroprotective effects.

Sasanquasaponin, a bioactive compound isolated from seeds of Camellia oleifera, shows central effects in our previous research. In order to investigate its neuroprotective effects, a new kind of nanocapsule with photo responsiveness was designed to deliver sasanquasaponin into the brain and adjusted by red light. The nanocapsule was prepared using sasanquasaponin emulsified with soybean lecithin and cholesterol solution. The natural phaeophorbide from silkworm excrement as a photosensitizer was added in the lipid phase to make the nanocapsules photo responsive. The physicochemical properties of encapsulation efficiency, size distribution, morphology and stability were measured using high-performance liquid chromatography, particle size analyzer, transmission electron microscope, differential scanning calorimetry and thermogravimetry. Photo responsiveness was determined by the sasanquasaponin release in pH 7.5 phosphate buffer under the laser at 670 nm. The neuroprotective effects were evaluated by the expression of tyrosine hydroxylase (TH), decrease of inflammatory cytokines TNF-α and IL-1ß in the brain, and amelioration of kainic acid-induced behavioral disorder in mice. The nanocapsules had higher encapsulation efficiency and stability when the phaeophorbide content was 2% of lecithin weight. The average size was 172.2 nm, distributed in the range of 142-220 nm. The phaeophorbide was scattered sufficiently in the outer lecithin layer of the nanocapsules and increased the drug release after irradiation. TH expression in brain tissues and locomotive activities in mice were reduced by kainic acid, but could be improved by the sasanquasaponin nanocapsules after tail vein injection with 15 minutes of irradiation at the nasal cavity. The sasanquasaponin took effect through inflammatory alleviation in central tissues. The sasanquasaponin nanocapsules with phaeophorbide have photo responsiveness and neuroprotective effects under the irradiation of red light. This preparation presents a new approach to brain neuroprotection, and has potential for clinical application.

[Effect of panax notoginseng powder on pathological features and expressions of VEGF and its receptors of chronic subdural hematoma rabbits: an experimental study].

OBJECTIVE: To observe the effect of Panax notoginseng (PN) on pathological features in chronic subdural hematoma (CSDH) rabbits and its mechanisms. METHODS: A stable pathological animal model similar to CSDH in humans could be established using subdural injections of small number of blood through a subdural pre-catheter in rabbits. After successful modeling, 18 rabbits were randomly divided into the model group, the low dose PN group (0.125 g/kg), and the high dose PN group (0.250 g/kg), 6 in each group. Normal saline was given to rabbits in the model group, while PN power was given to those in the PN groups by gastrogavage for 6 successive days. Pathologic features of the hematoma outer membrane were observed by HE staining. The activity of SOD and the content of MDA in the hematoma outer membrane were examined by the colorimetric method. Expressions of CD31, CD34, and VEGF in the hematoma outer membrane were observed by immunohistochemical assay. Expressions of VEGF in the peripheral blood and the subdural hematoma were detected by enzyme-linked immunosorbent assay (ELISA). Expressions of VEGFR-1 and VEGFR-2 in the hematoma outer membrane were detected by Western blot. RESULTS: Compared with the model group, the inflammatory reaction was comparatively lessen and the proliferation of the fibrous tissue was relatively mature in the low and high dose PN groups. The activity of SOD increased (P < 0.05); expressions of CD31 and CD34 were reduced (P < 0.01); VEGF expression in the residual hematoma fluid decreased (P < 0.05) in the high dose PN group. Expressions of VEGF and VEGFR-2 were all reduced in the high and low dose PN groups (P < 0. 05, P < 0.01). Compared with the low dose PN group, expressions of CD31 and CD34 were reduced (P < 0.01), and the VEGFR-2 expression was also reduced (P < 0.05) in the high dose PN group. CONCLUSIONS: PN could promote the fibrous repairing of subdural hematoma in CSDH rabbits. It also lessened inflammation and oxidative injury of the hematoma outer membrane and reduced expressions of VEGF. The pathological angiogenesis could be reduced through influencing VEGFR-2 receptor pathways, which might be an important mechanism.

Anti-inflammatory and analgesic activities of the hydrolyzed sasanquasaponins from the defatted seeds of Camellia oleifera.

The defatted seeds of Camellia oleifera (Abel.) are used for stopping itching and pain in old days, the effective compounds need to be investigated. Sasanquasaponin as a rich fraction was extracted with 70% ethanol, purified by AB-8 macro-reticular resin, crystallized in 80% ethanol, and further hydrolyzed by 4% hydroxyl potassium or 2 M hydrochloride. Anti-inflammatory activities of the extracts were measured by carrageenan-induced paw edema in rats and croton oil induced ear inflammation in mice; the analgesic activities were analyzed by hot plate test, acetic acid induced writhing in mice; the levels of pain mediators of IL-1ß, TNF-α and PGE2 were determined; the antioxidative activities in vivo were evaluated by MDA, SOD and GSH-Px in serum of rats. The extracts showed significant (p < 0.01) anti-inflammatory and analgesic activities, remarkably (p < 0.01) inhibited production of pro-inflammatory cytokines and PGE2, decreased MDA and increased SOD and GSH-Px in serum. Inhibition of IL-1ß, TNF-α and PGE2 may contribute to their anti-inflammatory and analgesic effects; elimination of free radicals is also involved. The sapogenin and acid hydrolyzed product have better anti-inflammatory, analgesic effects, and stronger antioxidative activity than sasanquasaponin and alkaline hydrolyzed product, and they are better candidate medicines for inflammation and pain.