Prefabricated, ear-shaped cartilage tissue engineering by scaffold-free porcine chondrocyte membrane.

BACKGROUND

Ear defects caused by traumatic injury, tumor ablation, and congenital deficiency are still challenging problems for the plastic and reconstructive surgeon. The authors developed a scaffold-free, ear-shaped cartilage by tailoring a multilayered chondrocyte membrane on an ear-shaped titanium alloy model and investigated the possibility of long-term ear-shaped maintenance in nude mice.

METHODS

High-density chondrocytes (approximately 30 × 10 cells) were seeded to produce chondrocyte membranes after cultivation under chondrogenic medium for 2 weeks. Then, three-layer chondrocyte membranes were tailored on the ear-shaped titanium mold and fixed by 6-0 nylon. The constructs were implanted onto the dorsal pockets of nude mice for 8 and 24 weeks. The chondrocyte membrane, 8- and 24-week implants were analyzed by safranin O, toluidine blue, elastica van Gieson, and collagen type II immunohistochemistry stains and quantitative measurement of glycosaminoglycan and total collagen compared with native cartilage. Mechanical strength was compared by compressive Young's modulus.

RESULTS

Results showed that the chondrocyte membrane was durable and nonfragile and easily manipulated by forceps. The composite of chondrocyte membrane and titanium alloy maintained the stable ear-like shape after 8 and 24 weeks of subcutaneous implantation. Histologic examination verified that the newly formed tissue at the implant construct was elastic cartilage at both 8 and 24 weeks by safranin O, toluidine blue, elastica van Gieson, and collagen type II immunohistochemistry stains. The Young's modulus was only half of and similar to normal cartilage in 8- and 24-week implants, respectively.

CONCLUSION

This study demonstrated that an ear-shaped elastic cartilage could be regenerated by a scaffold-free chondrocyte membrane shaped by a prefabricated, three-dimensional, ear-shaped titanium mold.