Maturation of tissue engineered cartilage implanted in injured and osteoarthritic human knees.
The regeneration of damaged organs requires that engineered tissues mature when implanted at sites of injury or disease. We have used new analytic techniques to determine the extent of tissue regeneration after treatment of knee injury patients with a novel cartilage tissue engineering therapy and the effect of pre-existing osteoarthritis on the regeneration process. We treated 23 patients, with a mean age of 35.6 years, presenting with knee articular cartilage defects 1.5 cm2 to 11.25 cm2 (mean, 5.0 cm2) in area. Nine of the patients had X-ray evidence of osteoarthritis. Chondrocytes were isolated from healthy cartilage removed at arthroscopy. The cells were cultured for 14 days, seeded onto esterified hyaluronic acid scaffolds (Hyalograft C), and grown for a further 14 days before implantation. A second-look biopsy was taken from each patient after 6 to 30 months (mean, 16 months). After standard histological analysis, uncut tissue was further analyzed using a newly developed biochemical protocol involving digestion with trypsin and specific, quantitative assays for type II collagen, type I collagen, and proteoglycan, as well as mature and immature collagen crosslinks. Cartilage regeneration was observed as early as 11 months after implantation and in 10 out of 23 patients. Tissue regeneration was found even when implants were placed in joints that had already progressed to osteoarthrosis. Cartilage injuries can be effectively repaired using tissue engineering, and osteoarthritis does not inhibit the regeneration process.
Hollander
Anthony P
AP
University of Bristol Academic Rheumatology, Department of Clinical Science at North Bristol, Avon Orthopaedic Centre, Southmead Hospital, Bristol, United Kingdom.
Dickinson
Sally C
SC
Sims
Trevor J
TJ
Brun
Paola
P
Cortivo
Roberta
R
Kon
Elisaveta
E
Marcacci
Maurilio
M
Zanasi
Stefano
S
Borrione
Anna
A
De Luca
Claudio
C
Pavesio
Alessandra
A
Soranzo
Carlo
C
Abatangelo
Giovanni
G
D000293:Adolescent; D000328:Adult; D001705:Bioprosthesis; D002356:Cartilage / Q000378:metabolism / Q000637:transplantation*; D019902:Chondrocytes / Q000378:metabolism / Q000637:transplantation*; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis; D005260:Female; D006801:Humans; D006820:Hyaluronic Acid; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000628:therapy*; D012038:Regeneration; D013997:Time Factors; D023822:Tissue Engineering
D016326:Extracellular Matrix Proteins; D006820:Hyaluronic Acid