Biocompatibility of poly-3-hydroxybutyrate-co-3-hydroxyvalerate and canine bone marrow stem cells in vitro / 中国组织工程研究

ABSTRACT

BACKGROUND: Poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) is a novel scaffold made by solvent casting/particulate leaching procedure, composed of polyhydroxybutyrate and polyhyclroxyvalerate at certain ratio, which has good biocompatibility as well as high intensity and modulus. It has three-dimensional porous net structure and good biodegradation. OBJECTIVE: To evaluate the biocompatibility between copolymers of PHBV and canine bone marrow mesenchymal stem cells(BMSCs).DESIGN, TIME AND SETTING: In vitro comparative observation. The study was performed at the Laboratory of Histology and Embryology, Sun Yat-sen University between June 2003 and March 2004.MATERIALS PHBV scaffold, film porosity > 85% and 100-350 μ m aperture size.METHODS: Canine BMSCs were isolated and cultured. The 3-4 passage cells were seeded onto the PHBV films and three-dimensional foam scaffold. Cells cultured alone served as control.MAIN OUTCOME MEASURES: The seeded cells were observed under inverted microscope; at 1, 2, 3 weeks after seeding, the BMSCs were treated with 4% paraformaldehyde and stained with hematoxylin-eosin (HE); The protein content in seeded cells was determined by bicinchoninic acid assay (BCA), and the content of DNA was quantified using Hoechst33258 assay at 5, 10, 14 days after culture.RESULTS: Inverted microscopic observation showed that the PHBV fibers were fairly thick with weak lucency, and the fibers were hardly detectable under contrast phase microscope. Majority of cells attached onto the PHBV films 2 hours after seeding, and extended well in a spindle shape at 3 days. One week after culture, 2 PHBV were fixed, and BMSCs proliferation was observed after HE staining. At two weeks, cells continued to proliferate and densely covered the PHBV film. The cells grew in the three-dimensional pores, connected at 1 week, extended at 3 weeks, secreting a large amount of material around cells. Cell proliferation did not change much at 3 weeks compared with 2 weeks, and there was no significant difference in DNA and protein contents between control and PHBV groups (P > 0.05).CONCLUSION: As a kind of tissue-engineered scaffold material for BMSCs, PHBV displays good biocompatibility.