It is still problems that how to preserve tissue-engineered cartilage with bioactivity, maintain the bioactivity for a long period, and built a bank of tissue-engineered cartilage.OBJECTIVE:
To study the effect of cryopreservation on the bioactivity of tissue-engineered cartilage.DESIGN, TIME AND SETTING:
A randomized controlled animal study was performed at the Experimental Center of Tangdu Hospital, the Fourth Military Medical University of Chinese PLA from February 2006 to December 2008.MATERIALS:
Polyglycolic acid (PGA) was provided by Albany Company, USA; 5 New Zealand white rabbit aging 2 weeks and 20 adult rabbits were provided by the Experimental Animal Center of the Fourth Military Medical University of Chinese PLA.METHODS:
Cartilage was collected from 2-week-old rabbits. The cartilage cells in the second logarithmic phase were obtained to make cell suspension which was adjusted to the density of 5×1010/L and then inoculated on the three-dimensional PGA scaffold. The composite was cultured in vitro for 1 week, cooled for 4, 8, and 12 weeks, and then thawed. One week later, the composite was subcutaneously inoculated in the adult rabbits for 12 weeks.MAIN OUTCOME MEASURES:
The growth of thawed tissue-engineered cartilage was observed under optic microscope and scanning electron microscope; the survival rate was measured using MTT colorimetry; cartilage morphology, collagen secreted from cartilage, and acid mucopolysaccharide secreted from matrix were detected in vivo.RESULTS:
The tissue-engineered cartilage grew well following cryopreservation, and there was no significant difference in survival rate at 4, 8, and 12 weeks after cryopreservation. Histological examination demonstrated that cartilage formed, and collagen and acid mucopolysaccharide were rich in implanted region of thawed tissue-engineered cartilage.CONCLUSION:
Cryopreservation does not have any effect on bioactivity of tissue-engineered cartilage, so it can be used to preserve tissue-engineered cartilage.