Objective To investigate the way and process of degradation behavior of acellular porcine aortic valve in vitro. Methods Acellular porcine aortic valve（n=90）were randomly divided into 3 groups （collagenase group, elastase group, control group）, 30 piece in each group . Behavior of acellular porcine aortic valve was degradated with 0.05mg/ml collagenase Ⅰ, 0. 05mg/ml elastase, phosphate buffered solution in collagenase group, elastase group and control group. The histomorphology, weight loss, value of protein and hydroxyproline were observed at 3,6,9, 12, 15 and 30d after degradation. Results The behavior of acellular porcine aortic valve of collagenase group and elastase group became poorer, looser and broken gradually in degradation. The weight loss of valve, the value of protein and hydroxyproline in vehiculum became greater gradually in collagenase group and elastase group（P〈0. 01）. Furthermore the effect of collagenase Ⅰ was b than elastase in degradation. Conclusion The effect of collagenase Ⅰ and elastase can degradate the acellular porcine aortic valve in vitro. Collagenase Ⅰ is b than elastase in degradation.
Objective To study degradation of the antigen-extracted meniscus in PBS solution with no enzyme or with different enzymes. Methods Four types of enzymes (collagenase, hyaluronidase, trypsin, papain) were used to enzymolyze the antigen-extracted meniscus and the fresh meniscus for 3, 7, 15 and 30 days (37℃). The antigenextracted meniscus and the fresh meniscus were immersed in PBS solution (37℃) for 30 days. Weight loss measurement, UV spectrophotometry, and scanning electron microscopy (SEM) were used to characterize the degraded materials. Results The two types of the materials were remarkably digested under the enzymes, especially under trypsin. The degradation curves showed that the antigen-extracted meniscus was enzymolyzed less than the fresh meniscus. The degradation products were grouped as amino, peptide, and polyose by the analysis. Both of the materials could hardly behydrolyzed in PBS solution without the enzymes. The four different enzymes had different surface morphologies under the examination of SEM. Conclusion The antigen-extracted meniscus is enzymolyzed more slowly than the fresh meniscus in vitro, and the result can be used as a guideline to the further research.
Objective To study the degradable properties of 3D-SC artificial skin in vitro. Methods The 3D-SC artificial skin materials wererespectively immersed into the solutions of 0.9% normal saline (control group), pancreatic tissue liquid (experimental group 1), physiological buffer (Hanks balanced salt solution，experimental group 2) and 0.2 mol/L phosphate buffer (pH 7.4，experimentalgroup 3), and the degradation was carried out at 37℃. The quality lost ratioswere determined on the 3rd day, the 5th day, the 7th day, the 9th day, 11th dayand 14th day in the experimental group 1, while on the 3rd day, 7th day, 14th day, 15th day, 21st day and 30th day in the other groups. Results The 3D-SC artificial skin was degraded completely in pancreatic tissue liquid about within 14 days in the experimental group 1; in the control group, and in the experimental groups 2 and 3, the degradation ratios were 868%±2.30%,28.51%±10.68% and 7.35%±0.61% on the 14th day; 71.83%±2.58%, 91.32%±1.87% and 75.64%±6.13% on the 15th day, being significant difference between the control group and the experimental group 2(Plt;0.01); and 91.87%±8.15%, 95.62%±1.36% and 92.10%±2.26% on the 30th day, being no significant differences between these 3 groups(Pgt;0.05), respectivelies. Conclusion The 3D-SC artificial skin materials have good degradable properties. The trend of degradation speed is from slow to quick and then to slow without enzyme.