The comparison and biological evaluation of PCL/BP scaffold for tissue engineered artificial sternum / 中华胸心血管外科杂志

ABSTRACT

Objective To prepare the composite of Polycaprolactone(PCL) and Bone powder(BP) for bone repairing,and evaluate the biocompatibility of the material.Methods The materials were prepared in college of chemical engineering and materials science,Shanghai Jiaotong University,and the animal tests were fulfilled in Animal Experimental Center of the Second Military Medical University of PLA from June 2010 to March 2011.The PCL and BP were blended together to get the copolymer by haake ( Rheocord 900 ) torque rheometer.Then the extracts of the material in DMEM for 24 hours were obtained.Firstly biological safety detection of the materials was performed①cytotoxicity testthe extracts were mixed with DMEM to seed rabbit osteoblasts for 24 hours.The cell proliferation was detected by MTT method.The cell proliferation rate and toxicity grate were also calculated ( cytotoxicity of grade 0 or 1 was qualified).②hemolysis testthe extracts were mixed with fresh rabbit blood,hemolysis rate were calculated ( hemolysis mte less than 5％ was qualified).③pyrogenic testthe extracts were injected into the rabbit ear vein with the dose of 10 ml/kg.The anus temperature was measured per hour for three times.The elevator degree was calculated by subtracting the natural temperature from the highest one.Secondly,cellular adhesion test of the material composite was performed.The composite was casted on the cover glasses.The samples were put in 6-well tissue culture plates,totally 6 × 104 osteoblasts were seeded each well and cultured for 3 days.The cells were observed at 24 and 72 hours of culture,and photography was performed using inverted phase contrast microscope.④general toxioity testthe extracts were injected into mouse vein with the dose of 50 ml/kg.The toxic symptoms were observed within 72 hours.Results The novel copolymer of PCL/BP was prepared.①Biological safetythe cell viability of the composite was 87.8％ and cytotoxicity was grade 1.The hemolysis rate was 2.4％,less than 5％.The maximal variety of body temperature in rabbits were 0.4℃,which accorded with the national standard ( ＜0.6℃ ).The general toxicity test showed that there were no adverse effects in the animals,such as death,convulsion,paralysis,respiratory depression,diarrhea and decreasing weight.②Cell adhesionadhesive cells manifold obviously and assembled 24 hours later,inosculated gradually 3 days later,and the cells were in good fettle.Conclusion The composite of PCL/BP accords with cytotoxicity demand of the biological materials,presenting no toxicity,pyrogenicity or hemolysis.It possesses good biocompatibility and cellular adhesion.