Construction Of Large Volume Cartilage In Tissue Engineering Chamber

Objective This experiment was designed to creat a large volume of tissue engineered cartilage by adding auricular cartilage fragment mixed with PRP scaffold and introducing axial blood vessels.Methods 48 New Zealand white rabbits were randomly divided,there were 6 rabbits in each group.Perforated Silicone tissue engineering chamber(TEC)was made,New Zealand rabbit auricular cartilage was harvest and cut into fragments of about 2mm size.group A: the auricular cartilage fragments were placed into TEC and the tissue were harvest after 8 weeks culture.Group B: the femoral artery or inferior epigastric artery was transferred into TEC combined with autologous auricular cartilage fragments.Group C: the autogenous auricular cartilage fragments evenly mixed with plateletrich plasma(PRP)and added to TEC.Group D: the femoral artery or inferior epigastric artery were placed into silicone chamber and then autogenous auricular cartilage fragments mixed with platelet-rich plasma(PRP)were added into it.The specimens were harvested at 8 weeks after operation,the growth of the structure in the chamber was observed,the volume of the structure was measured,and the tissue of the structure was retained for paraffin embedded sections.HE staining,Masson staining,safranin-O staining,Verhoeff Van-Gieson staining and immunohistochemistry were used to evaluate vascularization and composition of the structure,and the cell proliferation area.The elastic modulus of the structure was measured by compression method.Results After 8 weeks culture in vivo,constructs of group B? C and D developed a white,cartilage-like appearance while the construct of group A The original cartilage fragment is clearly visible.The volume of engineered cartilage tissue in group A increased from 0.3ml to(0.9±0.2366)ml;the volume of cartilage in group B increased from 0.3ml to(1.25±0.1517)ml;the volume of cartilage in group C increased from 0.3ml(1.207±0.2066)ml.The volume of cartilage in group D increased from 0.3 ml to(1.8 ± 0.1789)ml.the cartilage tissue between the four groups were statistically significant(P<0.05).up to 4 months culture in vivo,the structures of group D were well preserved without obvious necrosis or atrophy.HE staining and Masson staining showed that cartilage fragments we previously placed was wrapped in collagen fibers.KI-67 immunohistochemistry showed the proliferation area was located at the cutting edge and the surface of cartilage fragments.Safran O staining,Verhoeff Van-Giesonstaining showed the secretion of elastic cartilage specific extracellular matrix in the group D which was richer than those in the control group.The result of Young's modulus showed no significant difference between group B and D and normal rabbit auricular cartilage,but not group A and C.(P<0.05).The gross view of fibrous tissue obtained after 8 weeks showed richer blood supply of all experimental groups than that of the control group.in group B and D,the previously introduced axial vascular could be seen,which formed branches and nourished the whole structure.The Vessel density were measured in multiplel field under the same microscope which showed higher vascular density in group D.the vascular density between all four groups had statistical differences(P<0.05).Conclusion NPWT By using tissue engineer chamber technic,adding auricular cartilage fragments which mixed with platelet-rich plasma(PRP)and introducing axial blood vessels can promote the growth of cartilage tissue,so as to obtain clinically available tissue cartilage in a short time(8W).