ABSTRACT
BACKGROUND: Aromatic polyester can not be used alone as degradable material due to its poor biodegradation. In the School of Materials Science and Engineering, Nanchang University, aromatic/aliphatic copolyesters, a new kind of degradable biomaterial is synthesized by melt co-polycondensation and transesterification of terephthalyl chloride, bisphenol A, hexanediol as well as low lacticacid polymer, which has been patented. OBJECTIVE: To study the biocompatibility between aromatic/aliphatic copolyesters and bone marrow mesenchymal stem cells (BM-MSCs) in rats. DESIGN, TIME AND SETTING: An in vitro cellular-materials experiment. The experiment was performed at the Institute of Urology, the First Affiliated Hospital of Nanchang University between April 2006 and April 2007. MATERIALS: Five healthy, adult, male, Sprague Dawley rats were provided by the experimental animal center of Jiangxi University of Traditional Chinese Medicine. The bio-degradable polyester was aromatic/aliphatic copolyesters prepared by our group. METHODS: A new degradable biomaterial poly (4,4'-isopropylidenediphenyl terephthalate)-co-poly(hexylene terephthalate)-co-polylactide (PBHTL) was prepared into biomembrane by casting method. Simultaneously, polyvinyl chloride biomembrane was prepared with the same method. The leaching liquor of biomembrane was collected when the biomembranes were sterilized and immersed in culture medium. The BM-MSCs of rats with the 3~(rd) or 4(th) passage were incubated at the 96-well plates with density of 2×10~7/L and at 24-well plate with 1.3×10~5 per well. The experiment divided into 3 groups. In the negative control group, cells were cultured with DMEM. In the experimental group, 12.5%, 25%, 50%. 100% material leaching liquor were additional added based on DMEM. In the positive group, polyvinyl chloride leaching liquor was added except DMEM. MAIN OUTCOME MEASURES: The cytotoxicity of material was evaluated by neutral red uptake assay, basic fuchsin staining and MTT method. Growth of BM-MSCs on aromatic/aliphatic copolyesters membrane was estimated by electron microscope. RESULTS: The cell viability and metabolic capability were decreased 11%-16% in the positive control group at days 1, 3, 5, and 7 after culture. The absorbance value of the experimental group was significantly different from the positive control group (P < 0.001), which increased cell viability and metabolic capability with time prolonged (1%-4%). However, there was not obviouslydifference between the experimental group and negative group in absorbance value (P> 0.05). Acridine orange/ethylene dibromide staining showed that the BM-MSCs attached and grew in spindle-like manner on the surface of aromatic/aliphatic copolyesters biomembrane, which increased cell number with decreased apoptosis rate with time prolonged. CONCLUSION: The results demonstrated that aromatic/aliphatic copolyesters membrane has no eligible cytotoxicity to cell growth with good cell compatibility, which meets the requirements for applied biomaterials.