The purpose of this study is to synthesize nanometer calcium carbonate/poly(L-lactide) composites and evaluate its biocompatibility, and mechanical properties. The nanometer calcium carbonate/poly(L-lactide) composites was prepared by the method of solution mixing and cell culture. Its properties were analyzed using, mechanical tests, MTT assay, transmission electron microscope and scanning electron microscope. It was found that the new kind copolymer had good biocompatibility, nanometer calcium carbonate could enhance the strength of the pure poly (L-lactide) matrix. The nanometer calcium carbonate/poly (L-lactide) composites is a promising bioabsorbable material. It is worth further medical research.
Animals ; Biocompatible Materials ; Calcium Carbonate ; Cell Line ; Materials Testing ; Mice ; Nanostructures ; Polyesters ; Tensile Strength

A novel HPLC method with the quantitative analysis of multi-components by single marker( QAMS) combined with the dual-wavelength method was developed for simultaneous determination of six flavonoids in Dendrobium officinale stems from different producing areas,cultivation and processing methods to clarify the main factors contributing to the different composition of flavonoids.The separation of six flavonoids was performed on a Shiseido Capcell PAK MGⅡ C18 column( 4. 6 mm×250 mm,5 μm) using a linear gradient elution system of acetonitrile-0. 1% formic acid aqueous solution. Schaftoside,isoschaftoside,vicenin-2,and glucosylvitexin were simultaneously analyzed using rutin as a reference standard at detection wavelength of 340 nm,and naringenin was determined at290 nm. The credibility and feasibility of QAMS method were validated and the results demonstrated that no significant differences were observed as compared with the external standard method. Finally,a total of 82 batches of D. officinale samples were analyzed and principal component analysis( PCA) and discriminant analysis were applied to distinguish and compare D. officinale samples from different producing areas,cultivation and processing methods. The results showed that the total flavonoid content of D. officinale stems cultivated in the simulated wild( attached tree cultivation or attached stone cultivation) was significantly higher than that in greenhouse bed cultivation. The content of flavonoids in simulated-wild D. officinale stems was higher in Jiangxi,Guizhou,Zhejiang,and Fujian provinces,while that in greenhouse bed cultivation was higher in Fujian and Zhejiang provinces. The content of naringenin was positively correlated with processing temperature,and that of the other five flavonoids was negatively correlated with processing temperature. PCA showed that wild-simulated D. officinale and greenhouse bed-cultivated D. officinale could be roughly divided into two clusters. The samples cultivated in the greenhouse bed were divided into four categories according to the geographical habitats. Wild-simulated D. officinale samples from Guizhou gathered together,and there was no obvious rule in samples from other producing areas. The established method simplified the determination method of flavonoids in D. officinale,and could provide the basis for effective quality control,cultivation and processing of D. officinale.
Chromatography, High Pressure Liquid ; Dendrobium ; Drugs, Chinese Herbal ; Flavonoids ; Quality Control