RESUMO
OBJECTIVE:To prepare Puerarin polymeric micelles and establish a method to determine its entrapment efficiency. METHODS:Puerarin polymeric micelles were prepared by film dispersion method. The polymeric micelles and free drug were sepa-rated by centrifugal-millipore filter filtration method. The entrapment efficiency of puerarin polymeric micelles was determined by HPLC. Diamonsil C18(2)column was used with 1% citric acid solution-methanol(65∶35)at the flow rate of 1 ml/min. The detec-tion wavelength was set at 250 nm,and column temperature was room temperature. RESULTS:The prepared polymeric micelles were spherical and spherical-like in shape with a mean particle size of 54.12 nm,polydispersity index of 0.122,Zeta potential of -13.60 mV;the linear range of puerarin was 2-10μg/ml(R2=0.999 4)with average recovery rate of 99.2%(RSD=0.9%,n=3). The re-covery rate of free drug was 95.3%(RSD=1.7%,n=3). The mean entrapment efficiency and drug-loading amount of puerarin were(35.5±2.12)% and(0.3±0.07)%,respectively(n=3). CONCLUSIONS:Film dispersion method is suitable for the prepara-tion of Puerarin polymeric micelles. Established method is convenient,accurate and reliable for the content and entrapment efficien-cy determination of Puerarin polymeric micelles.
RESUMO
An experimental study was done to evaluate factors influencing guided regeneration of bone in standardized calvarial bony defect. An 8 mm circular transosseous calvarial bony defect was made. Various material such as demineralized freeze-dried bone (DFDB), BioMesh , Millipore filter and its combination was placed in the bony defect. A sequential histopathologic, histochemical, immunohistochemical, and histomorphometric studies were done on the guided bone regeneration in the calvarial bony defect. Bone formation was sigificantly enhanced when the DFDB was retained within the bony defect with a protective bioabsorbable membrane. Inframembranous DFDB-filling was required to prevent collapse of the membrane and preserve spaces for bone regeneration. The bioabsorbable membrane should presumably remain intact for longer than at least 5 weeks to facilitate bone regeneration. The new bone formation was dependent on the barrier-effect (preserving secluded spaces) and inflammation-inducing property of membrane, and guiding bone regeneration of the grafts. Macrophages recruited by grafts were partly involved in decrease of bone regeneration via the sequential events of release of fibronectin, chemotactic effect of the fibronectin to fibroblasts, and collagen lay-down.