Behavior of MC3T3-E1 Osteoblast Cultured on Chitosan Modified with Polyvinylpyrrolidone

The physical and chemical properties of four kinds of modified chitosan materials made by blending chitosan with polyvinylpyrrolidone （PVP） were investigated. All four of these modified chitosan materials were hydrophilic with water contact angles ranging from 59°to 69°. Fourier transform-infrared spectra of the modified materials showed a new band at 1288 cm^-1, implying formation of a surface physical interpenetrating network structure. Enzyme linked immunosorbent assay results indicated that much less fibronectin was adsorbed on the modified materials than on only chitosan. The viability of MC3T3-E1 osteoblasts cultured on the materials was assessed by 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl- 2H-tetrazolium bromide assay. The results show that adding PVP10000 into the chitosan promotes adhesion of MC3T3-E1 osteoblasts on the modified materials, but has no effect on cell growth and proliferation; while adding PVP40000 reduces cell adhesion, growth, and proliferation. The results suggest that the increased hydrophilicity of the material surface does not always improve its biocompatibility, which will influence the selection and design of biomaterials.     

Effects of Quenching Temperature and Time on Pore Diameter of Poly（3-hydroxybutyrate-co-3-hydroxyhexanoate） Porous Scaffolds and MC3T3-E1 Osteoblast Response to the Scaffolds

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) scaffolds were prepared by thermally inducing phase separation (TIPS) for bone reconstruction. Scanning electron microscopy and porosity measurements were used to analyze the structure and properties of the scaffolds. The pore diameter of the scaffolds could be easily controlled by changing the quenching temperature and time. The biocompatibility was assessed by examining the proliferation and morphology of MC 3T3-E1 osteoprogenitor cells seeded on the scaffolds. Cultures grown in the presence of a source of phosphate ions showed the formation of a mineralized extracellular matrix. The results indicate that PHBHHx scaffolds prepared using TIPS are a promising candidate for bone reconstruction.