Temporomandibular joint disc replacement made by tissue-engineered growth of cartilage.
OBJECTIVE
To test the effectiveness of the new technique of tissue-engineered growth of cartilage, temporomandibular joint (TMJ) disc replacements were created by seeding dissociated chondrocytes on synthetic, three-dimensional, bioresorbable polymer constructs of a predetermined anatomic shape, incubating the cell-polymer constructs in vitro, and transplanting them into test animals.


METHODS
Twelve highly porous and bioresorbable cell-transplantation devices in the shape of TMJ discs were created using biodegradable polylactid and polyglycolic acid fibers. Bovine articular cartilage was dissociated into chondrocytes and the cells were allowed to attach to the three-dimensional polymer scaffolds and multiply in vitro. After 1 week, the cell-polymer constructs were implanted subcutaneously into nude mice. The neocartilage was assessed by magnetic resonance imaging (MRI) techniques, gross inspection, histology, and biomechanical and biochemical analysis after 12 weeks.


RESULTS
All implants seeded with chondrocytes showed gross evidence of histologically organized hyaline cartilage. The scaffolds maintained their specific shape. They not only showed appropriate intrinsic stability during neomorphogenesis of cartilage in vitro and in vivo, but also seemed to guide the growth of cartilage. The presence of sulfated glycosaminoglycans was shown by aldehyde fuchsin alcian blue staining of the specimens. Type II collagen, considered to be indicative of cartilage formation, was found in the specimens tested. MRI showed signal characteristics similar to those of hyaline cartilage. Analysis of neocartilage force/displacement curves and aqueous phase compliance using a closed compression chamber suggested that the ability of the constructs to resist deformation was similar to that of native donor cartilage.


CONCLUSIONS
The technology of tissue-engineered growth of cartilage on individually designed scaffolds may have many applications not only in reconstructive surgery of the TMJ, but also in craniomaxillofacial, plastic, and orthopedic surgery.
Laboratory for Transplantation and Tissue Engineering, University Clinic of Dental Medicine, Leopold Franzens University, Innsbruck, Austria.
W C
WC
Puelacher
J
J
Wisser
C A
CA
Vacanti
N F
NF
Ferraro
D
D
Jaramillo
J P
JP
Vacanti
D000818:Animals; D001673:Biodegradation, Environmental; D001696:Biomechanical Phenomena; D001705:Bioprosthesis; D002358:Cartilage, Articular / Q000166:cytology / Q000254:growth & development / Q000637:transplantation*; D002417:Cattle; D017690:Cell Transplantation / Q000379:methods*; D003094:Collagen / Q000032:analysis; D006025:Glycosaminoglycans / Q000032:analysis; D007773:Lactates; D019344:Lactic Acid; D008279:Magnetic Resonance Imaging; D008297:Male; D051379:Mice; D008819:Mice, Nude; D011091:Polyesters; D011108:Polymers; D013704:Temporomandibular Joint / Q000601:surgery*; D014183:Transplantation, Heterologous
D006025:Glycosaminoglycans; D007773:Lactates; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D003094:Collagen