BACKGROUND:Some scholars have prepared zein/chitosan composite membrane based on blending methods, and preliminary evaluation ofitsphysical and chemical properties showsthat chitosan partly improvesthe mechanical properties and hydrophilic properties of zein. Therefore, zein/chitosan composite membrane presumably has good cytocompati bility, which is beneficial to osteogenic differentiation of bone marrow mesenchymal stem cels.
OBJECTIVE:To explore the effect of zein/chitosan composite membrane on the differentiation of bone marrow mesenchymal stem cels into osteoblasts and its feasibility asabone tissue-engineered material.
METHODS:With 60% acetic acid as solvent, zein/chitosan composite membrane was prepared by blending and casting method. The structure and physicochemical properties of the composite membrane were investigated by Fourier transform infrared spectroscopy, tensile testing, water absorption testing and scanning electron microscopy. And the cytocompatibility of the membrane was evaluated byin vitrocel cufture. Besides,bone marrow mesenchymal stem celsfrom Sprague-Dawley ratwere isolatedvia adherence screening method, andthe effects of thecompositemembrane on theosteogenic differentiation ofthese celswere observedby scanning electron microscopy, fluorescent labeling and alkaline phosphatase assay.
RESULTS AND CONCLUSION:The tensile strength, water absorption and hydrophilicity of the films were improved with the chitosan increased; chitosan could promote cel proliferation indicating the good cytocompatibility of the composite films. Moreover, osteogenic induction occurredin bone marrow mesenchymal stem cels cultured on the compositem embrane, and with an increase of chitosan, the induction was promoted. In conclusion, zein/chitosan composite membrane can be applied widely in the field of bone tissue engineering.

Seventy-five preschool children with hemoglobin content below 11 g/dl in kindergartens and nurseries were divided into five groups. The first, second and third groups were given 10 mg, 20 mg and 30 mg of iron in the form of ferrous sulfate syrup respectively every day for two months, while the fourth and fifth groups were given 100 mg ascorbic acid and 100 mg ascorbic acid plus 10 mg iron respectively every day for one month. The average hemoglobin content in the order of the five groups were 9.6?1.16, 10.6?1.34, 9.7?0.91, 9.7?0.85 and 11.0?1.86 g/dl respectively before treatment. After 1-2 months of iron or ascorbic acid therapy, the average hemoglobin contents raised to 12.0?.31, 12.0?1.06, 12.0?0.79, 11.0?1.86 and 12.7?1.37 g/dl respectively. There were highly significant differences (P