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Objective After hydrogen bonding between collagen ( COL) and silk fibroin ( SF ) at different concentrations, a composite scaffold with adjustable stiffness was prepared by combining with gel system, and its physical and chemical properties were characterized. Methods SF with different qualities was dissolved in sodium alginate (SA) solution, then COL solution at different concentration and calcium carbonate ( CaCO3 ) powder were added. The hydrogels of SC1, SC2, and SC3 groups were obtained by taking out the mixed solution and adding some gluconic acid lactone ( GDL) powder, and different SF scaffolds were obtained after freeze drying. Results The SF scaffolds with adjustable stiffness were successfully prepared. The compression moduli of SC1, SC2, and SC3 groups were (17. 31±2. 73), (24. 12±1. 81), (32. 54±1. 81) kPa, respectively. The innerstructure of the scaffolds was observed. From SC1 group to SC3 group, pores of the scaffolds were smaller and fewer, and hydrophilicity of the materials become better and better. Conclusions Three-dimensional ( 3D) porous scaffolds with different matrix stiffness can be prepared by changing the concentration of SF and COL solution. The concentration of SF and COL is proportional to the compression modulus, water absorption, water retention and swelling rate of SF scaffolds, while inversely proportional to porosity. The findings of this study are expected to provide theoretical guidance for construction of scaffolds with appropriate matrix stiffness for inducing osteogenic differentiation of mesenchymal stem cells
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OBJECTIVE:To establish a method for the simultaneous determination of(R,S)-goitrin,chlorogenic acid,luteolo-side and isochlorogenic acid A in Xiaoer ganmao granule. METHODS:HPLC was performed on the column of Hedera C18 with mo-bile phase of acetonitrile-0.1% formic acid aqueous at a flow rate of 1.0 ml/min,the detection wavelength was 254 nm,330 nm and 370 nm,column temperature was 40 ℃,and the injection volume was 5 μl,RESULTS:The linear range was 6.6-105 μg/ml for (R,S)-goitrin (r=0.999 9),9-140 μg/ml for chlorogenic acid (r=0.999 9),9-144 μg/ml for luteoloside (r=0.999 8) and 9-138 μg/ml for isochlorogenic acid A(r=0.999 6);the limits of quantitation were 330 ng,450 ng,450 ng and 450 ng,limits of detection were 66 ng,90 ng,90 ng and 90 ng,respectively;RSDs of precision,stability and reproducibility tests were lower than 3%;recoveries were 95.01%-98.77%(RSD=1.48%,n=6),95.14%-98.91%(RSD=1.52%,n=6),95.11%-97.54%(RSD=0.93%,n=6) and 95.58%-99.63%(RSD=1.73%,n=6). CONCLUSIONS:The method is simple and accurate,and suitable for the simultaneous determination of(R,S)-goitrin,chlorogenic acid,luteoloside and isochlorogenic acid A in Xiaoer ganmao granule.