ABSTRACT
<p><b>OBJECTIVE</b>To investigate the preparation method of polystyrene core-poly (acrylamide-acrylic acid) shell fluorescent microspheres.</p><p><b>METHODS</b>The polystyrene core-poly (acrylamide-acrylic acid) shell (P-(St-co-AAM)) fluorescent microspheres were prepared using fluorescent microspheres as the core and acrylamide/acrylic as polymerization monomer. Reaction conditions affecting the morphology of core-shell structure including feeding mode, initiator, cross linker, pH, concentration and swelling were studied.</p><p><b>RESULT</b>Fluorescent microscopy showed that the relatively uniform particle sizes were distributed in a range of 7-8 μm. Fourier transform infra-red spectroscopy (FT-IR) proved the existence of poly (acrylamide-acrylic acid) shell and amide group on the surface. The optimal conditions for seeding polymerization: azobisisobutyronitrile was used as the initiator in the absence of cross linker, after a 40 h swelling treatment by using alcohol with the appropriate reaction temperature (70 degree), reaction time (3 h) and pH(6-7). The average dispersion and stability were 25.14 % and 90.21%, respectively. The fluorescein release percentage was kept stable at approximately 30% after 40 h.</p><p><b>CONCLUSION</b>The fluorescent microspheres prepared by this method have core-shell structure and satisfactory fluorescence properties with good dispersion and stability.</p>
Subject(s)
Acrylates , Chemistry , Acrylic Resins , Chemistry , Fluorescein , Chemistry , Microspheres , Polymerization , Polystyrenes , ChemistryABSTRACT
Objective To investigate the analgesic effect of oxysophoridine(OSR)and the influence of verapamil(Ver)on the antinociception of OSR when two drugs were co-administrated in mice.Methods The number of writhing within 15 min after ip different doses of OSR was observed in painful mouse mo- dels caused by acetic acid.The hot plate method was used to assess nociceptive sensitivity of CaCl_2 and Ver before ip OSR.Nitric oxide(NO)in serum was measured by spectrophotometry.Results The number of writhing was decreased and the latency of licking the hind paws was prolonged in a dose-dependent manner after ip OSR.The antinociception of OSR could be antagonized by CaCl_2 and enhanced by Ver.No inter- ference was detected in serum volume of NO.Conclusion These results suggest that OSR can antagonize the acute pain caused by acetic acid and hot plate in a dose-dependent manner in mice.Calcium channel blocker could enhance the effect of OSR.