The permeability of puerarin loaded poly(butylcyanoacrylate) nanoparticles coated with polysorbate 80 on the blood-brain barrier and its protective effect against cerebral ischemia/reperfusion injury.

Puerarin (PUE) is a good candidate for treating stroke, but its low concentration in brain after administration limits its curative efficacy. The aim of the present work was to design and characterize PUE loaded poly(butylcyanoacrylate) nanoparticles (PBCN) coated with polysorbate 80 (Ps 80), and to evaluate the effect of PBCN on the permeability of PUE across the blood-brain barrier (BBB) and the effect of PUE loaded PBCN on the cerebral ischemia/reperfusion injury. PUE loaded PBCN were successfully prepared by anionic polymerization method with the mean particle size of 201.2 nm and the zeta potential of -7.72 mV. The in vitro release behavior of PUE from the nanoparticles showed a biphasic profile manner with an initial burst release followed by a sustained release. The results of pharmacokinetic and biodistribution to brain performed in mice after intravenous administration showed that the drug concentrations in blood and brain for PUE loaded PBCN were both greater than these for the free drug. Moreover, compared with free drug, the vein injection of PUE loaded PBCN exerted the better neuroprotective effect in rats with focal cerebral ischemic injury via significantly decreasing neurological deficit scores, increasing body weight, lowing brain water content, and reducing the infarct volume. The results indicated that this preparation may reduce the total dose required for the stroke therapy with concurrent reduction in dose related toxicity. All these findings suggest that PBCN could enhance the transport of PUE to brain and have a potential as a neuroprotective agent in the focal cerebral ischemic injury.

[Clinical application of self-made drainage tube with balloon for iatrogenic colonic perforation].

OBJECTIVE: To investigate the clinical efficacy of colonic bypass drainage by self-made drainage tube with balloon for iatrogenic colonic perforation. METHODS: A retrospective analysis of 8 patients with iatrogenic colonic perforations from January 2009 to March 2011 was performed. Self-made drainage tubes with balloon were placed in the bowel lumen endoscopically after perforations were closed with endoclips or endoloops under endoscope. The inflatable balloon at the front-end of the tube was fixed at the mouth side of colonic perforation to achieve continuous drainage of stool and intestinal juice. RESULTS: Endoscopic bypass continuous drainage by using self-made drainage tube with balloon was successfully carried out in all the 8 patients. All the perforations healed and no surgical intervention required. Bypass drainage continued for 3-10 days(mean 7.6 days). One patient received colonoscopy 3 days after the procedure, and displacement of the drainage tube was noticed requiring endoscopic adjustment. All the drainage tubes were removed uneventfully, and no ulceration or perforation occurred at balloon fixed site after removal. After follow up ranging from 12 to 36 months, no chronic fistula, adhesive obstruction, or abdominal infection occurred. CONCLUSION: Colonic bypass drainage by self-made drainage tube with balloon for iatrogenic colonic perforation is simple, feasible, safe and reliable.

Molecularly imprinted solid-phase extraction combined with high performance liquid chromatography for analysis of phenolic compounds from environmental water samples.

The molecularly imprinted bulk polymer with 2,4,6-trichlorophenol (2,4,6-TCP) as the template molecule and methylacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA) as functional monomer and the crosslinker, respectively, has been prepared and applied to the molecularly imprinted solid-phase extraction (MISPE) procedure for selective preconcentration of phenolic compounds from environmental water samples. Various parameters affecting the extraction efficiency of the polymer have been evaluated to optimize the selective preconcentration of the phenolic compounds from aqueous samples. The characteristics of the MISPE method were validated by HPLC. The recoveries ranged between 90% and 98% (RSD: 0.9-2.3%, n=3) for tap water, between 85% and 105% (RSD: 2.6-4.9%, n=3) for river water, between 78% and 98% (RSD: 2.6-5.4%, n=3) for sewage water fortified with 0.4 mg L(-1) of phenol, 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), pentachlorophenol (PCP). It was demonstrated that this MISPE-HPLC method could be applied to direct preconcentration and determination of phenolic compounds in environmental water samples.